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Sample records for cleanable steel hepa

  1. Requirements for a cleanable steel HEPA filter derived from a systems analysis

    International Nuclear Information System (INIS)

    A systems analysis was conducted to determine customer requirements for a cleanable high efficiency particulate air (HEPA) filter in DOE Environmental Management (EM) facilities. The three principal drivers for cleanable steel HEPA are large cost savings, improved filter reliability, and new regulations; they produce a strong incentive to DOE customers to use cleanable steel HEPA filters. Input for customer requirements were obtained from field trips to EM sites and from discussions. Most existing applications require that cleanable steel HEPA filters meet size/performance requirements of standard glass HEPA filters; applications in new facilities can relax size/weight/pressure drop requirements on a case-by-case basis. We then obtained input from commercial firms on availability of cleanable steel HEPA filters. Systems analysis then showed that currently available technology was only able to meet customer needs in a limited number of cases. Further development is needed to meet requirements of EM customers. For cleanable steel HEPA to be retrofitted into existing systems, pressure drop and weight must be reduced. Pressure drop can be reduced by developing steel fiber media from 0.5 μm dia steel fibers. Weight can be reduced by packaging the steel fiber media in one of the standard HEPA configurations. Although most applications will be able to use standard 304 or 316L alloys, an acid resistant alloy such as Hastelloy or Inconel will be needed for incinerator and other thermal processes

  2. Further development of the cleanable steel HEPA filter, cost/benefit analysis, and comparison with competing technologies

    International Nuclear Information System (INIS)

    We have made further progress in developing a cleanable steel fiber HEPA filter. We fabricated a pleated cylindrical cartridge using commercially available steel fiber media that is made with 1 μm stainless steel fibers and sintered into a sheet form. Test results at the Department of Energy (DOE) Filter Test Station at Oak Ridge show the prototype filter cartridge has 99.99% efficiency for 0.3 μm dioctyl phthalate (DOP) aerosols and a pressure drop of 1.5 inches. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned using reverse air pulses. Our analysis of commercially optimized filters suggest that cleanable steel HEPA filters need to be made from steel fibers less than 1μm, and preferably 0.5 μm, to meet the standard HEPA filter requirements in production units. We have demonstrated that 0.5 μm steel fibers can be produced using the fiber bundling and drawing process. The 0.5 μm steel fibers are then sintered into small filter samples and tested for efficiency and pressure drop. Test results on the sample showed a penetration of 0.0015 % at 0.3 μm and a pressure drop of 1.15 inches at 6.9 ft/min (3.5 cm/s) velocity. Based on these results, steel fiber media can easily meet the requirements of 0.03 % penetration and 1.0 inch of pressure drop by using less fibers in the media. A cost analysis of the cleanable steel HEPA filter shows that, although the steel HEPA filter costs much more than the standard glass fiber HEPA filter, it has the potential to be very cost effective because of the high disposal costs of contaminated HEPA filters. We estimate that the steel HEPA filter will save an average of $16,000 over its 30 year life. The additional savings from the clean-up costs resulting from ruptured glass HEPA filters during accidents was not included but makes the steel HEPA filter even more cost effective. 33 refs., 28 figs., 1 tab

  3. Further development of the cleanable steel HEPA filter, cost/benefit analysis, and comparison with competing technologies

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Lopez, R.; Wilson, K. [Lawrence Livermore National Lab., CA (United States)] [and others

    1997-08-01

    We have made further progress in developing a cleanable steel fiber HEPA filter. We fabricated a pleated cylindrical cartridge using commercially available steel fiber media that is made with 1 {mu}m stainless steel fibers and sintered into a sheet form. Test results at the Department of Energy (DOE) Filter Test Station at Oak Ridge show the prototype filter cartridge has 99.99% efficiency for 0.3 {mu}m dioctyl phthalate (DOP) aerosols and a pressure drop of 1.5 inches. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned using reverse air pulses. Our analysis of commercially optimized filters suggest that cleanable steel HEPA filters need to be made from steel fibers less than 1{mu}m, and preferably 0.5 {mu}m, to meet the standard HEPA filter requirements in production units. We have demonstrated that 0.5 {mu}m steel fibers can be produced using the fiber bundling and drawing process. The 0.5 {mu}m steel fibers are then sintered into small filter samples and tested for efficiency and pressure drop. Test results on the sample showed a penetration of 0.0015 % at 0.3 {mu}m and a pressure drop of 1.15 inches at 6.9 ft/min (3.5 cm/s) velocity. Based on these results, steel fiber media can easily meet the requirements of 0.03 % penetration and 1.0 inch of pressure drop by using less fibers in the media. A cost analysis of the cleanable steel HEPA filter shows that, although the steel HEPA filter costs much more than the standard glass fiber HEPA filter, it has the potential to be very cost effective because of the high disposal costs of contaminated HEPA filters. We estimate that the steel HEPA filter will save an average of $16,000 over its 30 year life. The additional savings from the clean-up costs resulting from ruptured glass HEPA filters during accidents was not included but makes the steel HEPA filter even more cost effective. 33 refs., 28 figs., 1 tab.

  4. Further development of the cleanable steel HEPA filter, cost/benefit analysis, and comparison with competing technologies

    International Nuclear Information System (INIS)

    We have made further progress in developing a cleanable steel fiber HEPA filter. We fabricated a pleated cylindrical cartridge using commercially available steel fiber media that is made with 1 μm stainless steel fibers and sintered into a sheet form. Test results at the Department of Energy (DOE) Filter Test Station at Oak Ridge show the prototype filter cartridge has 99.99% efficiency for 0.3 μm dioctyl phthalate (DOP) aerosols and a pressure drop of 1.5 inches. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned using reverse air pulses. Our analysis of commercially optimized filters suggest that cleanable steel HEPA filters need to be made from steel fibers less than 1 μm, and preferably 0.5 μm, to meet the standard HEPA filter requirements in production units. We have demonstrated that 0.5 μm steel fibers can be produced using the fiber bundling and drawing process. The 0.5 μm steel fibers are then sintered into small filter samples and tested for efficiency and pressure drop. Test results on the sample showed a penetration of 0.0015% at 0.3 μm and a pressure drop of 1.15 inches at 6.9 ft/min (3.5 cm/s) velocity. Based on these results, steel fiber media can easily meet the requirements of 0.03% penetration and 1.0 inch of pressure drop by using less fibers in the media. A cost analysis of the cleanable steel HEPA filter shows that, although the steel HEPA filter costs much more than the standard glass fiber HEPA filter, it has the potential to be very cost effective because of the high disposal costs of contaminated HEPA filters. We estimate that the steel HEPA filter will save an average of $16,000 over its 30 year life. The additional savings from the clean-up costs resulting from ruptured glass HEPA filters during accidents was not included but makes the steel HEPA filter even more cost effective. We also present the results of our evaluation of competing technologies with metallic and ceramic powder

  5. In Situ Cleanable HEPA Filter

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, T.D.

    1999-11-18

    This paper describes a welded steel HEPA filter which uses liquid spray cleaning and vacuum drying. Development of the filter was initiated in order to eliminate personnel exposure, disposal cost, and short lifetime associated with systems commonly employed throughout the Department of Energy complex. In addition the design promises to resolve the issues of fire, elevated temperatures, wetting, filter strength, air leaks and aging documented in the May, 1999 DNFSB-TECH-23 report.

  6. Insitu Cleanable Alternative HEPA Filter Media

    International Nuclear Information System (INIS)

    Two types of filter media, sintered nickel metal and ceramic monolith membrane, are being investigated as in situ regenerable/cleanable high efficiency particulate air (HEPA) filters. Particle retention testing was conducted on the filters at the Oak Ridge Filter Test Facility to ensure HEPA efficiency, greater than 99.97 percent. During simulant testing, The filters were challenged using non-radioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. After plugging the filters they were cleaned in situ using an aqueous solution. This innovative approach of the in situ regenerative filtration system may be a significant improvement upon the shortfalls of conventional disposable HEPA filters

  7. Insitu Cleanable Alternative HEPA Filter Media

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D.J.

    2002-05-14

    Two types of filter media, sintered nickel metal and ceramic monolith membrane, are being investigated as in situ regenerable/cleanable high efficiency particulate air (HEPA) filters. Particle retention testing was conducted on the filters at the Oak Ridge Filter Test Facility to ensure HEPA efficiency, greater than 99.97 percent. During simulant testing, The filters were challenged using non-radioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. After plugging the filters they were cleaned in situ using an aqueous solution. This innovative approach of the in situ regenerative filtration system may be a significant improvement upon the shortfalls of conventional disposable HEPA filters.

  8. In Situ Cleanable Alternative HEPA Filter Media

    International Nuclear Information System (INIS)

    The Westinghouse Savannah River Company, located at the Savannah River Site in Aiken, South Carolina, is currently testing two types of filter media for possible deployment as in situ regenerable/cleanable High Efficiency Particulate Air (HEPA) filters. The filters are being investigated to replace conventional, disposable, glass-fiber, HEPA filters that require frequent removal, replacement, and disposal. This is not only costly and subjects site personnel to radiation exposure, but adds to the ever-growing waste disposal problem. The types of filter media being tested, as part of a National Energy Technology Laboratory procurement, are sintered nickel metal and ceramic monolith membrane. These media were subjected to a hostile environment to simulate conditions that challenge the high-level waste tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using nonradioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. The filters are cleaned in situ using an aqueous solution. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and in situ cleaning cycles. Air Techniques International is conducting particle retention testing on the filter media at the Oak Ridge Filter Test Facility. The filters are challenged using 0.3-mm di-octyl phthalate particles. Both the ceramic and sintered media have a particle retention efficiency > 99.97%. The sintered metal and ceramic filters not only can be cleaned in situ, but also hold great potential as a long life alternative to conventional HEPA filters. The Defense Nuclear Facility Safety Board Technical Report, ''HEPA Filters Used in the Department of

  9. In Situ Cleanable Alternative HEPA Filter Media

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D. J.; Terry, M. T.

    2002-02-28

    The Westinghouse Savannah River Company, located at the Savannah River Site in Aiken, South Carolina, is currently testing two types of filter media for possible deployment as in situ regenerable/cleanable High Efficiency Particulate Air (HEPA) filters. The filters are being investigated to replace conventional, disposable, glass-fiber, HEPA filters that require frequent removal, replacement, and disposal. This is not only costly and subjects site personnel to radiation exposure, but adds to the ever-growing waste disposal problem. The types of filter media being tested, as part of a National Energy Technology Laboratory procurement, are sintered nickel metal and ceramic monolith membrane. These media were subjected to a hostile environment to simulate conditions that challenge the high-level waste tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using nonradioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. The filters are cleaned in situ using an aqueous solution. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and in situ cleaning cycles. Air Techniques International is conducting particle retention testing on the filter media at the Oak Ridge Filter Test Facility. The filters are challenged using 0.3-mm di-octyl phthalate particles. Both the ceramic and sintered media have a particle retention efficiency > 99.97%. The sintered metal and ceramic filters not only can be cleaned in situ, but also hold great potential as a long life alternative to conventional HEPA filters. The Defense Nuclear Facility Safety Board Technical Report, ''HEPA Filters Used in the

  10. Experimental Investigation of In Situ Cleanable HEPA Filters

    Energy Technology Data Exchange (ETDEWEB)

    Hatcher, S.A.

    2001-04-11

    Savannah River Technology Center (SRTC) located at Westinghouse Savannah River Site (WSRS) is currently conducting research and development experimentation to develop a replacement of the conventional high efficiency particulate air (HEPA) filter system currently used by commercial industry and DOE facilities. It has been determined that a cleanable or regenerable HEPA filter system may be the most cost effective and efficient HEPA filter system to be considered for use in a more safe and reliable work environment.

  11. Experimental investigation of in situ cleanable HEPA filter

    International Nuclear Information System (INIS)

    The Westinghouse Savannah River Company located at the Savannah River Site (SRS) in Aiken, South Carolina is currently testing the feasibility of developing an in situ cleanable high efficiency particulate air (HEPA) filter system. Sintered metal filters are being tested for regenerability or cleanability in simulated conditions found in a high level waste (HLW) tank ventilation system. The filters are being challenged using materials found in HLW tanks. HLW simulated salt, HLW simulated sludge and South Carolina road dust. Various cleaning solutions have been used to clean the filters in situ. The tanks are equipped with a ventilation system to maintain the tank contents at negative pressure to prevent the release of radioactive material to the environment. This system is equipped with conventional disposable glass-fiber HEPA filter cartridges. Removal and disposal of these filters is not only costly, but subjects site personnel to radiation exposure and possible contamination. A test apparatus was designed to simulate the ventilation system of a HLW tank with an in situ cleaning system. Test results indicate that the Mott sintered metal HEPA filter is suitable as an in situ cleanable or regenerable HEPA filter. Data indicates that high humidity or water did not effect the filter performance and the sintered metal HEPA filter was easily cleaned numerous times back to new filter performance by an in situ spray system. The test apparatus allows the cleaning of the soiled HEPA filters to be accomplished without removing the filters from process. This innovative system would eliminate personnel radiation exposure associated with removal of contaminated filters and the high costs of filter replacement and disposal. The results of these investigations indicate that an in situ cleanable HEPA filter system for radioactive and commercial use could be developed and manufactured

  12. Experimental investigation of in situ cleanable HEPA filter

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D.J.

    1999-07-01

    The Westinghouse Savannah River Company located at the Savannah River Site (SRS) in Aiken, South Carolina is currently testing the feasibility of developing an in situ cleanable high efficiency particulate air (HEPA) filter system. Sintered metal filters are being tested for regenerability or cleanability in simulated conditions found in a high level waste (HLW) tank ventilation system. The filters are being challenged using materials found in HLW tanks. HLW simulated salt, HLW simulated sludge and South Carolina road dust. Various cleaning solutions have been used to clean the filters in situ. The tanks are equipped with a ventilation system to maintain the tank contents at negative pressure to prevent the release of radioactive material to the environment. This system is equipped with conventional disposable glass-fiber HEPA filter cartridges. Removal and disposal of these filters is not only costly, but subjects site personnel to radiation exposure and possible contamination. A test apparatus was designed to simulate the ventilation system of a HLW tank with an in situ cleaning system. Test results indicate that the Mott sintered metal HEPA filter is suitable as an in situ cleanable or regenerable HEPA filter. Data indicates that high humidity or water did not effect the filter performance and the sintered metal HEPA filter was easily cleaned numerous times back to new filter performance by an in situ spray system. The test apparatus allows the cleaning of the soiled HEPA filters to be accomplished without removing the filters from process. This innovative system would eliminate personnel radiation exposure associated with removal of contaminated filters and the high costs of filter replacement and disposal. The results of these investigations indicate that an in situ cleanable HEPA filter system for radioactive and commercial use could be developed and manufactured.

  13. Development of cleanable HEPA filters - recleaning of deep pleated HEPA filters by flow

    International Nuclear Information System (INIS)

    Fine particle dusts with diameters less than about 2 μm, often emitted from high temperature industrial processes, cannot be sufficiently well removed from gas streams using current methods. Frequently concentrated in this small size range are heavy metals, the emission of which poses a growing environmental threat in the form of soil contamination. Current HEPA filter technology, via removal efficiencies for submicron particles some of three orders of magnitude above those of bag filters or electrostatic precipitators, offers the potential for practically eliminating fine particle emissions. A cost effective means of high efficiency gas cleaning, with total operating expenses comparable to those of conventional methods for larger particles, is offered by the development of cleanable HEPA filter units. In case of recleaning HEPA filter media by reverse flow at 1 m/s the stable filtration of fine particle dusts with diameters > 0.3 μm may be possible. Experimental investigations had been performed concerning the dependance of static pressure inside a filter pleat from several pleat configurations and the recleaning device during the recleaning process. The results are compared with a model predicting pressure and velocity profiles inside a filter pleat during the recleaning by reverse flow. Results from field tests with an improved filter configuration are also presented. (orig.)

  14. Experimental Investigation of In Situ Cleanable HEPA Filters

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D.J.

    1999-03-23

    The Westinghouse Savannah River Company located at the Savannah River Site in Aiken, South Carolina is currently testing the feasibility of developing an in situ cleanable high efficiency particulate air filter system. Sintered metal filters are being tested for regenerability or cleanability in simulated conditions found in a high level waste (HLW) tank ventilation system. The filters are being challenged using materials found in HLW tanks. HLW simulated salt, HLW simulated sludge and South Carolina road dust. Various cleaning solutions have been used to clean the filters in situ.

  15. Development and evaluation of a cleanable high efficiency steel filter

    International Nuclear Information System (INIS)

    We have developed a high efficiency steel filter that can be cleaned in-situ by reverse air pulses. The filter consists of 64 pleated cylindrical filter elements packaged into a 6l0 x 6l0 x 292 mm aluminum frame and has 13.5 m2 of filter area. The filter media consists of a sintered steel fiber mat using 2 μm diameter fibers. We conducted an optimization study for filter efficiency and pressure drop to determine the filter design parameters of pleat width, pleat depth, outside diameter of the cylinder, and the total number of cylinders. Several prototype cylinders were then built and evaluated in terms of filter cleaning by reverse air pulses. The results of these studies were used to build the high efficiency steel filter. We evaluated the prototype filter for efficiency and cleanability. The DOP filter certification test showed the filter has a passing efficiency of 99.99% but a failing pressure drop of 0.80 kPa at 1,700 m3/hr. Since we were not able to achieve a pressure drop less than 0.25 kPa, the steel filter does not meet all the criteria for a HEPA filter. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned by reverse air pulses. The next phase of the prototype evaluation consisted of installing the unit and support housing in the exhaust duct work of a uranium grit blaster for a field evaluation at the Y-12 Plant in Oak Ridge, TN. The grit blaster is used to clean the surface of uranium parts and generates a cloud of UO2 aerosols. We used a 1,700 m3/hr slip stream from the 10,200 m3/hr exhaust system

  16. Testing cleanable/reuseable HEPA prefilters for mixed waste incinerator air pollution control systems

    Energy Technology Data Exchange (ETDEWEB)

    Burns, D.B.; Wong, A.; Walker, B.W.; Paul, J.D. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1997-08-01

    The Consolidated Incineration Facility (CIF) at the US DOE Savannah River Site is undergoing preoperational testing. The CIF is designed to treat solid and liquid RCRA hazardous and mixed wastes from site operations and clean-up activities. The technologies selected for use in the air pollution control system (APCS) were based on reviews of existing incinerators, air pollution control experience, and recommendations from consultants. This approach resulted in a facility design using experience from other operating hazardous/radioactive incinerators. In order to study the CIF APCS prior to operation, a 1/10 scale pilot facility, the Offgas Components Test Facility (OCTF), was constructed and has been in operation since late 1994. Its mission is to demonstrate the design integrity of the CIF APCS and optimize equipment/instrument performance of the full scale production facility. Operation of the pilot facility has provided long-term performance data of integrated systems and critical facility components. This has reduced facility startup problems and helped ensure compliance with facility performance requirements. Technical support programs assist in assuring all stakeholders the CIF can properly treat combustible hazardous, mixed, and low-level radioactive wastes. High Efficiency Particulate Air (HEPA) filters are used to remove hazardous and radioactive particulates from the exhaust gas strewn before being released into the atmosphere. The HEPA filter change-out frequency has been a potential issue and was the first technical issue to be studied at the OCTF. Tests were conducted to evaluate the performance of HEPA filters under different operating conditions. These tests included evaluating the impact on HEPA life of scrubber operating parameters and the type of HEPA prefilter used. This pilot-scale testing demonstrated satisfactory HEPA filter life when using cleanable metal prefilters and high flows of steam and water in the offgas scrubber. 8 figs., 2 tabs.

  17. Testing cleanable/reuseable HEPA prefilters for mixed waste incinerator air pollution control systems

    International Nuclear Information System (INIS)

    The Consolidated Incineration Facility (CIF) at the US DOE Savannah River Site is undergoing preoperational testing. The CIF is designed to treat solid and liquid RCRA hazardous and mixed wastes from site operations and clean-up activities. The technologies selected for use in the air pollution control system (APCS) were based on reviews of existing incinerators, air pollution control experience, and recommendations from consultants. This approach resulted in a facility design using experience from other operating hazardous/radioactive incinerators. In order to study the CIF APCS prior to operation, a 1/10 scale pilot facility, the Offgas Components Test Facility (OCTF), was constructed and has been in operation since late 1994. Its mission is to demonstrate the design integrity of the CIF APCS and optimize equipment/instrument performance of the full scale production facility. Operation of the pilot facility has provided long-term performance data of integrated systems and critical facility components. This has reduced facility startup problems and helped ensure compliance with facility performance requirements. Technical support programs assist in assuring all stakeholders the CIF can properly treat combustible hazardous, mixed, and low-level radioactive wastes. High Efficiency Particulate Air (HEPA) filters are used to remove hazardous and radioactive particulates from the exhaust gas strewn before being released into the atmosphere. The HEPA filter change-out frequency has been a potential issue and was the first technical issue to be studied at the OCTF. Tests were conducted to evaluate the performance of HEPA filters under different operating conditions. These tests included evaluating the impact on HEPA life of scrubber operating parameters and the type of HEPA prefilter used. This pilot-scale testing demonstrated satisfactory HEPA filter life when using cleanable metal prefilters and high flows of steam and water in the offgas scrubber. 8 figs., 2 tabs

  18. Development and evaluation of a cleanable high efficiency steel filter

    International Nuclear Information System (INIS)

    In this work the authors describe the development and evaluation of a high efficiency steel filter that can be cleaned in-situ by reverse air pulses. The filter consists of 64 pleated cylindrical filter elements packaged into a 610x610x292 mm (24x24x11.5 in.) aluminum frame and has 13.5 m2 (145 square feet) of filter area. The filter media consists of a sintered steel fiber mat using 2 μm diameter fibers. An optimization study was conducted for filter efficiency and pressure drop to determine the filter design parameters of pleat width, pleat depth, outside diameter of the cylinder, and the total number of cylinders. Several prototype cylinders were then built and evaluated in terms of filter cleaning by reverse air pulses. The results of these studies were used to build the high efficiency steel filter. The prototype filter was evaluated for efficiency and cleanability. The DOP filter certification test showed the filter had a passing efficiency of 99.99% but a failing pressure drop of 0.80 kPa (3.2 in w.g.) at 1,700 m3/hr (1,000 cfm). Since a pressure drop less than 0.25 kPa (1 inch w.g.) could not be achieved, the steel filter did not meet all the criteria for a HEPA filter. Filter loading and cleaning tests using AC Fine dust showed the filter could be repeatedly cleaned by reverse air pulses. The next phase of the prototype evaluation consisted of installing the unit and support housing in the exhaust duct work of a uranium grit blaster for a field evaluation at the Y-12 Plant in Oak Ridge, TN. The grit blaster was used to clean the surface of uranium parts and generated a cloud of UO2 aerosols. A 1,700 m3/hr (1,000 cfm) slip stream from the 10,200 m3/hr (6,000 cfm) exhaust system was used. 12 refs., 24 figs

  19. Water washable stainless steel HEPA filter

    Science.gov (United States)

    Phillips, Terrance D.

    2001-01-01

    The invention is a high efficiency particulate (HEPA) filter apparatus and system, and method for assaying particulates. The HEPA filter provides for capture of 99.99% or greater of particulates from a gas stream, with collection of particulates on the surface of the filter media. The invention provides a filter system that can be cleaned and regenerated in situ.

  20. Self Cleaning HEPA Filtration without Interrupting Process Flow

    International Nuclear Information System (INIS)

    The strategy of protecting the traditional glass fibre HEPA filtration train from it's blinding contamination and the recovery of dust by the means of self cleaning, pre-filtration is a proven means in the reduction of ultimate disposal volumes and has been used within the Fuel Production Industry. However, there is an increasing demand in nuclear applications requiring elevated operating temperatures, fire resistance, moisture resistance and chemical composition that the existing glass fibre HEPA filtration cannot accommodate, which can be remedied by the use of a metallic HEPA filter media. Previous research (Bergman et al 1997, Moore et al 1992) suggests that the then costs to the DOE, based on a five year life cycle, was $29.5 million for the installation, testing, removal and disposal of glass fibre HEPA filtration trains. Within these costs, $300 was the value given to the filter and $4,450 was given to the peripheral activity. Development of a low cost, cleanable, metallic, direct replacement of the traditional filter train will the clear solution. The Bergman et al work has suggested that a 1000 ft3/min, cleanable, stainless HEPA could be commercially available for $5,000 each, whereas the industry has determined that the truer cost of such an item in isolation would be closer to $15,000. This results in a conflict within the requirement between 'low cost' and 'stainless HEPA'. By proposing a system that combines metallic HEPA filtration with the ability to self clean without interrupting the process flow, the need for a tradition HEPA filtration train will be eliminated and this dramatically reduces the resources required for cleaning or disposal, thus presenting a route to reducing ultimate costs. The paper will examine the performance characteristics, filtration efficiency, flow verses differential pressure and cleanability of a self cleaning HEPA grade sintered metal filter element, together with data to prove the contention. (authors)

  1. Geometric Algorithms for Cleanability in Manufacturing

    OpenAIRE

    Yasui, Yusuke

    2011-01-01

    This thesis describes geometric algorithms to check the cleanability of a design during the manufacturing process. The automotive industry needs a computational tool to determine how to clean their products due to the trend of miniaturization and increased geometric complexity of mechanical parts. A newly emerging concept in a product design, Design-for-Cleanability, necessitates algorithms to help designers to design parts that are easy to clean during the manufacturing process. In this thes...

  2. Self Cleaning High Efficiency Particulate Air (HEPA) Filtration without Interrupting Process Flow - 59347

    International Nuclear Information System (INIS)

    The strategy of protecting the traditional glass fibre HEPA filtration train from it's blinding contamination and the recovery of dust by the means of self cleaning, pre-filtration is a proven means in the reduction of ultimate disposal volumes and has been used within the Fuel Production Industry. However, there is an increasing demand in nuclear applications requiring elevated operating temperatures, fire resistance, moisture resistance and chemical composition that the existing glass fibre HEPA filtration cannot accommodate, which can be remedied by the use of a metallic HEPA filter media. Previous research suggests that the then costs to the Department of Energy (DOE), based on a five year life cycle, was $29.5 million for the installation, testing, removal and disposal of glass fibre HEPA filtration trains. Within these costs, $300 was the value given to the filter and $4, 450 was given to the peripheral activity. Development of a low cost, cleanable, metallic, direct replacement of the traditional filter train will the clear solution. The Bergman et al work has suggested that a 1000 ft3/min, cleanable, stainless HEPA could be commercially available for $5, 000 each, whereas the industry has determined that the truer cost of such an item in isolation would be closer to $15, 000. This results in a conflict within the requirement between 'low cost' and 'stainless HEPA'. By proposing a system that combines metallic HEPA filtration with the ability to self clean without interrupting the process flow, the need for a tradition HEPA filtration train will be eliminated and this dramatically reduces the resources required for cleaning or disposal, thus presenting a route to reducing ultimate costs. The paper will examine the performance characteristics, filtration efficiency, flow verses differential pressure and cleanability of a self cleaning HEPA grade sintered metal filter element, together with data to prove the contention. (authors)

  3. HEPA Help

    Science.gov (United States)

    Rathey, Allen

    2006-01-01

    Poor indoor air quality in school facilities can detract from the health and productivity of students, teachers and other employees. Asthma--often triggered or aggravated by dust--is the No. 1 cause of chronic absenteeism in schools. Using vacuum cleaners equipped with high-efficiency particulate air (HEPA) filters to clean education institutions…

  4. Experimental Investigation of In Situ Cleanable or Regenerative Filters for High Level Radioactive Waste Tanks

    International Nuclear Information System (INIS)

    The Westinghouse Savannah River Company, located at the Savannah River Site (SRS) in Aiken, South Carolina, is currently testing two types of filter media for application as in situ regenerable/cleanable filters on high-level radioactive liquid waste tanks. Each of the 1.3 million-gallon tanks is equipped with an exhaust ventilation system to provide tank ventilation and to maintain the tank contents at approximately 1-in. water gauge vacuum to prevent the release of radioactive material to the environment. These systems are equipped with conventional, disposable, glass-fiber, High Efficiency Particulate Air (HEPA) filters that require frequent removal, replacement, and disposal. The need for routine replacements is often caused by accelerated filter loading due to the moist operating environment, which structurally weakens the filter media. This is not only costly, but subjects site personnel to radiation exposure and possible contamination. The types of filter media tested, as part of a National Energy Technology Laboratory procurement, were sintered metal and monolith ceramic. The media were subjected to a hostile environment to simulate conditions that challenge the tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using non-radioactive, simulated high level waste materials and atmospheric dust, as these materials are most responsible for filter pluggage in the field. The filters were cleaned/regenerated in situ using an aqueous solution of dilute (10% volume) nitric acid. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and cleaning cycles. The filters were leak tested using poly alpha olefin aerosol at the beginning, middle, and end of the

  5. The impact of metallic filter media on HEPA filtration

    International Nuclear Information System (INIS)

    Traditional HEPA filter systems have limitations that often prevent them from solving many of the filtration problems in the nuclear industry; particularly in applications where long service or storage life, high levels of radioactivity, dangerous decomposition products, chemical aggression, organic solvents, elevated operating temperatures, fire resistance and resistance to moisture are issues. This paper addresses several of these matters of concern by considering the use of metallic filter media to solve HEPA filtration problems ranging from the long term storage of transuranic waste at the WIPP site, spent and damaged fuel assemblies, in glove box ventilation and tank venting to the venting of fumes at elevated temperatures from incinerators, vitrification processes and conversion and sintering furnaces as well as downstream of iodine absorbers in gas cooled reactors in the UK. The paper reviews the basic technology, development, performance characteristics and filtration efficiency, flow versus differential pressure, cleanability and costs of sintered metal fiber in comparison with traditional resin bonded glass fiber filter media and sintered metal powder filter media. Examples of typical filter element and system configurations and applications will be presented The paper will also address the economic case for installing self cleaning pre-filtration, using metallic media, to recover the small volumes of dust that would otherwise blind large volumes of final disposable HEPA filters, thus presenting a route to reduce ultimate disposal volumes and secondary waste streams. (authors)

  6. The impact of metallic filter media on HEPA filtration

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, Chris; Kaufman, Seth [Microfiltrex, Porvair Filtration Group Ltd Fareham Industrial Park, Fareham, Hampshire, PO16 8XG (United Kingdom)

    2006-07-01

    Traditional HEPA filter systems have limitations that often prevent them from solving many of the filtration problems in the nuclear industry; particularly in applications where long service or storage life, high levels of radioactivity, dangerous decomposition products, chemical aggression, organic solvents, elevated operating temperatures, fire resistance and resistance to moisture are issues. This paper addresses several of these matters of concern by considering the use of metallic filter media to solve HEPA filtration problems ranging from the long term storage of transuranic waste at the WIPP site, spent and damaged fuel assemblies, in glove box ventilation and tank venting to the venting of fumes at elevated temperatures from incinerators, vitrification processes and conversion and sintering furnaces as well as downstream of iodine absorbers in gas cooled reactors in the UK. The paper reviews the basic technology, development, performance characteristics and filtration efficiency, flow versus differential pressure, cleanability and costs of sintered metal fiber in comparison with traditional resin bonded glass fiber filter media and sintered metal powder filter media. Examples of typical filter element and system configurations and applications will be presented The paper will also address the economic case for installing self cleaning pre-filtration, using metallic media, to recover the small volumes of dust that would otherwise blind large volumes of final disposable HEPA filters, thus presenting a route to reduce ultimate disposal volumes and secondary waste streams. (authors)

  7. HEPA filter jointer

    Energy Technology Data Exchange (ETDEWEB)

    Hill, D.; Martinez, H.E.

    1998-02-01

    A HEPA filter jointer system was created to remove nitrate contaminated wood from the wooden frames of HEPA filters that are stored at the Rocky Flats Plant. A commercial jointer was chosen to remove the nitrated wood. The chips from the wood removal process are in the right form for caustic washing. The jointer was automated for safety and ease of operation. The HEPA filters are prepared for jointing by countersinking the nails with a modified air hammer. The equipment, computer program, and tests are described in this report.

  8. HEPA air filter (image)

    Science.gov (United States)

    ... pet dander and other irritating allergens from the air. Along with other methods to reduce allergens, such ... controlling the amount of allergens circulating in the air. HEPA filters can be found in most air ...

  9. Cost and waste volume reduction in HEPA filter trains by effective pre-filtration

    International Nuclear Information System (INIS)

    Data published elsewhere (Moore, et el 1992; Bergman et al 1997) suggests that the then costs of disposable type Glass Fibre HEPA filtration trains to the DOE was USD 55 million per year (based on an average usage of HEPA panels of 11,748 pieces per year between 1987 and 1990), USD 50 million of which was attributable to installation, testing, removal and disposal - although the life cycle costs are themselves based on estimates dating from 1987-1990. The same authors suggest that by 1995 the number of HEPA panels being used had dropped to an estimated 4000 pieces per year due to the ending of the Cold War. The yearly cost to the DOE of 4000 units per year was estimated to be USD 29.5 million using the same parameters that suggested the previously stated USD 55 million for the larger quantity. Within that cost estimate, USD 300 was the value given to the filter and USD 4,450 was given to peripheral activity per filter. Clearly, if the USD 4,450 component could be reduced, tremendous saving could result, in addition to a significant reduction in the legacy burden of waste volumes. This same cost is applied to both the 11,748 and 4000 usage figures. The work up to now has focussed on the development of a low cost, long life (cleanable) direct replacement of the traditional filter train, but this paper will review an alternative strategy, that of preventing the contaminating dust from reaching and blinding the HEPA filters, and thereby removing the need to replace them. What has become clear is that 'low cost' and 'stainless HEPA' are not compatible terms. The original Bergman et al work suggested that 1000 ft3/min stainless HEPAs could be commercially available for USD 5000 each after development (although the USD 70,000 development unit may be somewhat exaggerated - the authors have estimated that development units able to be retro-fitted into strengthened standard housings would be available for perhaps USD 30,000). The likely true cost of such an item produced

  10. Cost and waste volume reduction in HEPA filter trains by effective pre-filtration

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, Chris; Kaufman, Seth [Microfiltrex, Porvair Filtration Group Ltd, Fareham Industrial Park, Fareham, Hampshire, PO16 8XG (United Kingdom)

    2006-07-01

    Data published elsewhere (Moore, et el 1992; Bergman et al 1997) suggests that the then costs of disposable type Glass Fibre HEPA filtration trains to the DOE was USD 55 million per year (based on an average usage of HEPA panels of 11,748 pieces per year between 1987 and 1990), USD 50 million of which was attributable to installation, testing, removal and disposal - although the life cycle costs are themselves based on estimates dating from 1987-1990. The same authors suggest that by 1995 the number of HEPA panels being used had dropped to an estimated 4000 pieces per year due to the ending of the Cold War. The yearly cost to the DOE of 4000 units per year was estimated to be USD 29.5 million using the same parameters that suggested the previously stated USD 55 million for the larger quantity. Within that cost estimate, USD 300 was the value given to the filter and USD 4,450 was given to peripheral activity per filter. Clearly, if the USD 4,450 component could be reduced, tremendous saving could result, in addition to a significant reduction in the legacy burden of waste volumes. This same cost is applied to both the 11,748 and 4000 usage figures. The work up to now has focussed on the development of a low cost, long life (cleanable) direct replacement of the traditional filter train, but this paper will review an alternative strategy, that of preventing the contaminating dust from reaching and blinding the HEPA filters, and thereby removing the need to replace them. What has become clear is that 'low cost' and 'stainless HEPA' are not compatible terms. The original Bergman et al work suggested that 1000 ft{sup 3}/min stainless HEPAs could be commercially available for USD 5000 each after development (although the USD 70,000 development unit may be somewhat exaggerated - the authors have estimated that development units able to be retro-fitted into strengthened standard housings would be available for perhaps USD 30,000). The likely true cost of

  11. HEPA Filter Vulnerability Assessment

    Energy Technology Data Exchange (ETDEWEB)

    GUSTAVSON, R.D.

    2000-05-11

    This assessment of High Efficiency Particulate Air (HEPA) filter vulnerability was requested by the USDOE Office of River Protection (ORP) to satisfy a DOE-HQ directive to evaluate the effect of filter degradation on the facility authorization basis assumptions. Within the scope of this assessment are ventilation system HEPA filters that are classified as Safety-Class (SC) or Safety-Significant (SS) components that perform an accident mitigation function. The objective of the assessment is to verify whether HEPA filters that perform a safety function during an accident are likely to perform as intended to limit release of hazardous or radioactive materials, considering factors that could degrade the filters. Filter degradation factors considered include aging, wetting of filters, exposure to high temperature, exposure to corrosive or reactive chemicals, and exposure to radiation. Screening and evaluation criteria were developed by a site-wide group of HVAC engineers and HEPA filter experts from published empirical data. For River Protection Project (RPP) filters, the only degradation factor that exceeded the screening threshold was for filter aging. Subsequent evaluation of the effect of filter aging on the filter strength was conducted, and the results were compared with required performance to meet the conditions assumed in the RPP Authorization Basis (AB). It was found that the reduction in filter strength due to aging does not affect the filter performance requirements as specified in the AB. A portion of the HEPA filter vulnerability assessment is being conducted by the ORP and is not part of the scope of this study. The ORP is conducting an assessment of the existing policies and programs relating to maintenance, testing, and change-out of HEPA filters used for SC/SS service. This document presents the results of a HEPA filter vulnerability assessment conducted for the River protection project as requested by the DOE Office of River Protection.

  12. HEPA Filter Vulnerability Assessment

    International Nuclear Information System (INIS)

    This assessment of High Efficiency Particulate Air (HEPA) filter vulnerability was requested by the USDOE Office of River Protection (ORP) to satisfy a DOE-HQ directive to evaluate the effect of filter degradation on the facility authorization basis assumptions. Within the scope of this assessment are ventilation system HEPA filters that are classified as Safety-Class (SC) or Safety-Significant (SS) components that perform an accident mitigation function. The objective of the assessment is to verify whether HEPA filters that perform a safety function during an accident are likely to perform as intended to limit release of hazardous or radioactive materials, considering factors that could degrade the filters. Filter degradation factors considered include aging, wetting of filters, exposure to high temperature, exposure to corrosive or reactive chemicals, and exposure to radiation. Screening and evaluation criteria were developed by a site-wide group of HVAC engineers and HEPA filter experts from published empirical data. For River Protection Project (RPP) filters, the only degradation factor that exceeded the screening threshold was for filter aging. Subsequent evaluation of the effect of filter aging on the filter strength was conducted, and the results were compared with required performance to meet the conditions assumed in the RPP Authorization Basis (AB). It was found that the reduction in filter strength due to aging does not affect the filter performance requirements as specified in the AB. A portion of the HEPA filter vulnerability assessment is being conducted by the ORP and is not part of the scope of this study. The ORP is conducting an assessment of the existing policies and programs relating to maintenance, testing, and change-out of HEPA filters used for SC/SS service. This document presents the results of a HEPA filter vulnerability assessment conducted for the River protection project as requested by the DOE Office of River Protection

  13. DOE HEPA filter test program

    International Nuclear Information System (INIS)

    This standard establishes essential elements of a Department of Energy (DOE) program for testing HEPA filters to be installed in DOE nuclear facilities or used in DOE-contracted activities. A key element is the testing of HEPA filters for performance at a DOE Filter Test Facility (FTF) prior to installation. Other key elements are (1) providing for a DOE HEPA filter procurement program, and (2) verifying that HEPA filters to be installed in nuclear facilities appear on a Qualified Products List (QPL)

  14. DOE HEPA filter test program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    This standard establishes essential elements of a Department of Energy (DOE) program for testing HEPA filters to be installed in DOE nuclear facilities or used in DOE-contracted activities. A key element is the testing of HEPA filters for performance at a DOE Filter Test Facility (FTF) prior to installation. Other key elements are (1) providing for a DOE HEPA filter procurement program, and (2) verifying that HEPA filters to be installed in nuclear facilities appear on a Qualified Products List (QPL).

  15. HEPA filter encapsulation

    Science.gov (United States)

    Gates-Anderson, Dianne D.; Kidd, Scott D.; Bowers, John S.; Attebery, Ronald W.

    2003-01-01

    A low viscosity resin is delivered into a spent HEPA filter or other waste. The resin is introduced into the filter or other waste using a vacuum to assist in the mass transfer of the resin through the filter media or other waste.

  16. HEPA and PARSE

    Science.gov (United States)

    Xu, Qing-Wen; Zhang, Yu; Wang, Xiao-Song

    2013-01-01

    The effective discovery of tumor-specific antigens (TSAs) holds the key for the development of new diagnostic assays and immunotherapeutic approaches against cancer. Here, we discuss our recently developed technologies, HEPA and PARSE, which allow for the systematic identification of TSAs, generating a reservoir of immunologically and clinically relevant targets. PMID:23802073

  17. Hydrofluoric acid dissolution of spent radioactive and hazardous HEPA filters

    International Nuclear Information System (INIS)

    This document discusses a process that treats High Efficiency Particulate Air (HEPA) filters contaminated with radioactive particles containing transuranic and hazardous elements which has been studied at the Idaho Chemical Processing Plant (ICPP). This process uses three to four steps to spent HEPA filter so that they meet regulatory requirements for disposal. The first step of the process is to bake the spent HEPA filters at 550 degrees C for 3 hours to volatilize organic binder which is used to provide strength in the filter's silicon glass media. In the second step, the filters are first leached in nitric acid, then are dissolved in hydrofluoric acid. The dissolution is conducted using an optimum fluoride to silicone molar ratio of 7/1 to prevent: (1) excess unreacted HF (free HF), (2) the formation of insoluble fluoride salts, and (3) the need of excessive aluminum nitrate to complex the free HF. Finally, the free HF is complexed with aluminum nitrate to an [HF] between 0.020 and 0.04 molar. The resulting solution from this process is minimally corrosive to stainless steel and is a stable high-level liquid waste that can be converted to a high-level solid waste in a fluidized bed operated at 500 degrees C. The stainless steel HEPA filter housing, which is not dissolved during the dissolution step, is compacted and disposed of as a nonhazardous, low-level radioactive waste

  18. Real world industrial solutions to cost and waste volume reduction using metallic HEPA/THE filtration together with an examination of effective HEPA Pre-Filtration Preventing the Blinding Solids from reaching the HEPA/THE filters and recovering the blinding solids for disposal, reducing both waste volume and cost

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, Ch. [Microfiltrex Ltd, Fareham, Hampshire (United Kingdom)

    2008-07-01

    The disposal costs of contaminated HEPA and THE filter elements have been proved to be disproportionately high compared with the cost of the elements themselves. If HEPA filters could be cleaned to a condition where they could either be re-used or decontaminated to the extent that they could be stored as a lower cost wasteform or if HEPA/THE filter elements were available without any organic content likely to give rise to flammable or explosive decomposition gases during long term storage this would also reduce the costs and monitoring necessary in storage. Using current state-of-the-art metallic filter media, it is possible to provide robust, completely inorganic, cleanable HEPA/THE filter elements to meet any duty already met by traditional glass-fibre HEPA/THE elements, within the same space limitations and with equivalent pressure loss. Additionally, traditional HEPA filter systems have limitations that often prevent them from solving many of the filtration problems in the nuclear industry. The paper will address several of these matters of concern by considering the use of metallic filter media to solve HEPA filtration problems ranging from the long term storage of transuranic waste at the WIPP site, spent and damaged fuel assemblies, in glove box ventilation and tank venting to the venting of fumes at elevated temperatures from incinerators, vitrification processes, conversion and sintering furnaces as well as downstream of iodine absorbers in gas cooled reactors in the UK. The paper reviews the technology, development, performance characteristics, filtration efficiency, flow/differential pressure character, cleanability and cost of sintered metal fiber in comparison with traditional resin bonded glass fiber filter media and sintered metal powder filter media. Examples of typical filter element and system configurations and applications will be presented. In addition, the paper will also address the economic case for installing self cleaning pre

  19. Real world industrial solutions to cost and waste volume reduction using metallic HEPA/THE filtration together with an examination of effective HEPA Pre-Filtration Preventing the Blinding Solids from reaching the HEPA/THE filters and recovering the blinding solids for disposal, reducing both waste volume and cost

    International Nuclear Information System (INIS)

    The disposal costs of contaminated HEPA and THE filter elements have been proved to be disproportionately high compared with the cost of the elements themselves. If HEPA filters could be cleaned to a condition where they could either be re-used or decontaminated to the extent that they could be stored as a lower cost wasteform or if HEPA/THE filter elements were available without any organic content likely to give rise to flammable or explosive decomposition gases during long term storage this would also reduce the costs and monitoring necessary in storage. Using current state-of-the-art metallic filter media, it is possible to provide robust, completely inorganic, cleanable HEPA/THE filter elements to meet any duty already met by traditional glass-fibre HEPA/THE elements, within the same space limitations and with equivalent pressure loss. Additionally, traditional HEPA filter systems have limitations that often prevent them from solving many of the filtration problems in the nuclear industry. The paper will address several of these matters of concern by considering the use of metallic filter media to solve HEPA filtration problems ranging from the long term storage of transuranic waste at the WIPP site, spent and damaged fuel assemblies, in glove box ventilation and tank venting to the venting of fumes at elevated temperatures from incinerators, vitrification processes, conversion and sintering furnaces as well as downstream of iodine absorbers in gas cooled reactors in the UK. The paper reviews the technology, development, performance characteristics, filtration efficiency, flow/differential pressure character, cleanability and cost of sintered metal fiber in comparison with traditional resin bonded glass fiber filter media and sintered metal powder filter media. Examples of typical filter element and system configurations and applications will be presented. In addition, the paper will also address the economic case for installing self cleaning pre

  20. HEPA filter monitoring program

    Science.gov (United States)

    Kirchner, K. N.; Johnson, C. M.; Aiken, W. F.; Lucerna, J. J.; Barnett, R. L.; Jensen, R. T.

    1986-07-01

    The testing and replacement of HEPA filters, widely used in the nuclear industry to purify process air, are costly and labor-intensive. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow determination of overall filter performance but preclude detection of incipient filter failure such as small holes in the filters. Using current technology, a continual in-situ monitoring system was designed which provides three major improvements over current methods of filter testing and replacement. The improvements include: cost savings by reducing the number of intact filters which are currently being replaced unnecessarily; more accurate and quantitative measurement of filter performance; and reduced personnel exposure to a radioactive environment by automatically performing most testing operations.

  1. Decontamination of HEPA filters

    International Nuclear Information System (INIS)

    Mound Facility, during many years of plutonium-238 experience, has recovered over 150 kg of plutonium-238. Much of this material was recovered from HEPA filters or from solid wastes such as sludge and slag. The objective of this task was to modify and improve the existing nitric acid leaching process used at Mound so that filters from the nuclear fuel cycle could be decontaminated effectively. Various leaching agents were tested to determine their capability for dissolving PuO2, UO2, U3O8, AmO2, NpO2, CmO2, and ThO2 in mixtures of the following: HNO3-HF; HNO3-HF-H2SO4; and HNO3-(NH4)2Ce(NO3)6. Adsorption isotherms were obtained for two leaching systems. In some tests simulated contaminated HEPA filter material was used, while in others actual spent glovebox filters were used. The maximum decontamination factor of 833 was achieved in the recovery of plutonium-238 from actual filters. The dissolution was accomplished by using a six-stage process with 4N HNO3-0.23M (NH4)2Ce(NO3)6 as the leaching agent. Thorium oxide was also effectively dissolved from filter media using a mixture of nitric acid and ceric ammonium nitrate. Sodium carbonate and Na2CO3-KNO3 fusion tests were performed using simulated PuO2-contaminated filter media at various temperatures. Approximately 70 wt% of the PuO2 was soluble in a mixture composed of 70 wt% Na2CO3-30 wt% KNO3 (heated for 1 h at 9500C). 23 figs., 14 tables

  2. FULL SCALE REGENERABLE HEPA FILTER DESIGN USING SINTERED METAL FILTER ELEMENTS

    International Nuclear Information System (INIS)

    A Department of Energy funded contract involved the development of porous metal as a HEPA filter, and the subsequent design of a full-scale regenerable HEPA filtration system (RHFS). This RHFS could replace the glass fiber HEPA filters currently being used on the high level waste (HLW) tank ventilation system with a system that would be moisture tolerant, durable, and cleanable in place. The origins of the contract are a 1996 investigation at the Savannah River Technology Center (SRTC) regarding the use of porous metal as a HEPA filter material. This contract was divided into Phases I, IIA and IIB. Phase I of the contract evaluated simple filter cylinders in a simulated High Level Waste (HLW) environment and the ability to clean and regenerate the filter media after fouling. Upon the successful completion of Phase I, Phase IIA was conducted, which included lab scale prototype testing and design of a full-scale system. The work completed under Phase IIA included development of a full-scale system design, development of a filter media meeting the HEPA filtration efficiency that would also be regenerable using prescribed cleaning procedures, and the testing of a single element system prototype at Savannah River. All contract objectives were met. The filter media selected was a nickel material already under development at Mott, which met the HEPA filtration efficiency standard. The Mott nickel media met and exceeded the HEPA requirement, providing 99.99% removal against a requirement of 99.97%. Double open-ended elements of this media were provided to the Savannah River Test Center for HLW simulation testing in the single element prototype filter. These elements performed well and further demonstrated the practicality of a metallic media regenerable HEPA filter system. An evaluation of the manufacturing method on many elements demonstrated the reproducibility to meet the HEPA filtration requirement. The full-scale design of the Mott RHFS incorporated several important

  3. FULL SCALE REGENERABLE HEPA FILTER DESIGN USING SINTERED METAL FILTER ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Gil Ramos; Kenneth Rubow; Ronald Sekellick

    2002-11-27

    A Department of Energy funded contract involved the development of porous metal as a HEPA filter, and the subsequent design of a full-scale regenerable HEPA filtration system (RHFS). This RHFS could replace the glass fiber HEPA filters currently being used on the high level waste (HLW) tank ventilation system with a system that would be moisture tolerant, durable, and cleanable in place. The origins of the contract are a 1996 investigation at the Savannah River Technology Center (SRTC) regarding the use of porous metal as a HEPA filter material. This contract was divided into Phases I, IIA and IIB. Phase I of the contract evaluated simple filter cylinders in a simulated High Level Waste (HLW) environment and the ability to clean and regenerate the filter media after fouling. Upon the successful completion of Phase I, Phase IIA was conducted, which included lab scale prototype testing and design of a full-scale system. The work completed under Phase IIA included development of a full-scale system design, development of a filter media meeting the HEPA filtration efficiency that would also be regenerable using prescribed cleaning procedures, and the testing of a single element system prototype at Savannah River. All contract objectives were met. The filter media selected was a nickel material already under development at Mott, which met the HEPA filtration efficiency standard. The Mott nickel media met and exceeded the HEPA requirement, providing 99.99% removal against a requirement of 99.97%. Double open-ended elements of this media were provided to the Savannah River Test Center for HLW simulation testing in the single element prototype filter. These elements performed well and further demonstrated the practicality of a metallic media regenerable HEPA filter system. An evaluation of the manufacturing method on many elements demonstrated the reproducibility to meet the HEPA filtration requirement. The full-scale design of the Mott RHFS incorporated several important

  4. Decontamination of HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    Koenst, J.W. Jr.; Lewis, E.L.; Luthy, D.F.

    1978-01-01

    Mound Facility, during many years of plutonium-238 experience, has recovered over 150 kg of plutonium-238. Much of this material was recovered from HEPA filters or from solid wastes such as sludge and slag. The objective of this task was to modify and improve the existing nitric acid leaching process used at Mound so that filters from the nuclear fuel cycle could be decontaminated effectively. Various leaching agents were tested to determine their capability for dissolving PuO/sub 2/, UO/sub 2/, U/sub 3/O/sub 8/, AmO/sub 2/, NpO/sub 2/, CmO/sub 2/, and ThO/sub 2/ in mixtures of the following: HNO/sub 3/-HF; HNO/sub 3/-HF-H/sub 2/SO/sub 4/; and HNO/sub 3/-(NH/sub 4/)/sub 2/Ce(NO/sub 3/)/sub 6/. Adsorption isotherms were obtained for two leaching systems. In some tests simulated contaminated HEPA filter material was used, while in others actual spent glovebox filters were used. The maximum decontamination factor of 833 was achieved in the recovery of plutonium-238 from actual filters. The dissolution was accomplished by using a six-stage process with 4N HNO/sub 3/-0.23M (NH/sub 4/)/sub 2/Ce(NO/sub 3/)/sub 6/ as the leaching agent. Thorium oxide was also effectively dissolved from filter media using a mixture of nitric acid and ceric ammonium nitrate. Sodium carbonate and Na/sub 2/CO/sub 3/-KNO/sub 3/ fusion tests were performed using simulated PuO/sub 2/-contaminated filter media at various temperatures. Approximately 70 wt% of the PuO/sub 2/ was soluble in a mixture composed of 70 wt% Na/sub 2/CO/sub 3/-30 wt% KNO/sub 3/ (heated for 1 h at 950/sup 0/C). 23 figs., 14 tables.

  5. Ceramic HEPA Filter Program

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, M A; Bergman, W; Haslam, J; Brown, E P; Sawyer, S; Beaulieu, R; Althouse, P; Meike, A

    2012-04-30

    Potential benefits of ceramic filters in nuclear facilities: (1) Short term benefit for DOE, NRC, and industry - (a) CalPoly HTTU provides unique testing capability to answer questions for DOE - High temperature testing of materials, components, filter, (b) Several DNFSB correspondences and presentations by DNFSB members have highlighted the need for HEPA filter R and D - DNFSB Recommendation 2009-2 highlighted a nuclear facility response to an evaluation basis earthquake followed by a fire (aka shake-n-bake) and CalPoly has capability for a shake-n-bake test; (2) Intermediate term benefit for DOE and industry - (a) Filtration for specialty applications, e.g., explosive applications at Nevada, (b) Spin-off technologies applicable to other commercial industries; and (3) Long term benefit for DOE, NRC, and industry - (a) Across industry, strong desire for better performance filter, (b) Engineering solution to safety problem will improve facility safety and decrease dependence on associated support systems, (c) Large potential life-cycle cost savings, and (d) Facilitates development and deployment of LLNL process innovations to allow continuous ventilation system operation during a fire.

  6. Ceramic HEPA Filter Program

    International Nuclear Information System (INIS)

    Potential benefits of ceramic filters in nuclear facilities: (1) Short term benefit for DOE, NRC, and industry - (a) CalPoly HTTU provides unique testing capability to answer questions for DOE - High temperature testing of materials, components, filter, (b) Several DNFSB correspondences and presentations by DNFSB members have highlighted the need for HEPA filter R and D - DNFSB Recommendation 2009-2 highlighted a nuclear facility response to an evaluation basis earthquake followed by a fire (aka shake-n-bake) and CalPoly has capability for a shake-n-bake test; (2) Intermediate term benefit for DOE and industry - (a) Filtration for specialty applications, e.g., explosive applications at Nevada, (b) Spin-off technologies applicable to other commercial industries; and (3) Long term benefit for DOE, NRC, and industry - (a) Across industry, strong desire for better performance filter, (b) Engineering solution to safety problem will improve facility safety and decrease dependence on associated support systems, (c) Large potential life-cycle cost savings, and (d) Facilitates development and deployment of LLNL process innovations to allow continuous ventilation system operation during a fire.

  7. Effect of plasticizer and surface topography on the cleanability of plasticized PVC materials

    International Nuclear Information System (INIS)

    A quantitative radiochemical measuring procedure was used to investigate soil adhesion on laboratory-made polyvinyl chloride (PVC) surfaces. The materials contained different plasticizers and microstructures. Both the quality and amount of plasticizers and the microstructure affected the cleanability of the PVC samples. The surface topography and structures were examined with a contact angle meter, atomic force microscopy (AFM) and a contact profilometer

  8. Preliminary field evaluation of high efficiency steel filters

    International Nuclear Information System (INIS)

    The authors have conducted an evaluation of two high efficiency steel filters in the exhaust of an uranium oxide grit blaster at the Y-12 Plant in Oak Ridge Tennessee. The filters were installed in a specially designed filter housing with a reverse air-pulse cleaning system for automatically cleaning the filters in-place. Previous tests conducted on the same filters and housing at LLNL under controlled conditions using Arizona road dust showed good cleanability with reverse air pulses. Two high efficiency steel filters, containing 64 pleated cartridge elements housed in the standard 2' x 2' x l' HEPA frame, were evaluated in the filter test housing using a 1,000 cfm slip stream containing a high concentration of depleted uranium oxide dust. One filter had the pleated cartridges manufactured to the authors specifications by the Pall Corporation and the other by Memtec Corporation. Test results showed both filters had a rapid increase in pressure drop with time, and reverse air pulses could not decrease the pressure drop. The authors suspected moisture accumulation in the filters was the problem since there were heavy rains during the evaluations, and the pressure drop of the Memtec filter decreased dramatically after passing clean, dry air through the filter and after the filter sat idle for one week. Subsequent laboratory tests on a single filter cartridge confirmed that water accumulation in the filter was responsible for the increase in filter pressure drop and the inability to lower the pressure drop by reverse air pulses. No effort was made to identify the source of the water accumulation and correct the problem because the available funds were exhausted

  9. Preliminary field evaluation of high efficiency steel filters

    International Nuclear Information System (INIS)

    We have conducted an evaluation of two high efficiency steel filters in the exhaust of an uranium oxide grit blaster at the Y-12 Plant in Oak Ridge Tennessee. The filters were installed in a specially designed filter housing with a reverse air-pulse cleaning system for automatically cleaning the filters in-place. Previous tests conducted on the same filters and housing at LLNL under controlled conditions using Arizona road dust showed good cleanability with reverse air pulses. Two high efficiency steel filters, containing 64 pleated cartridge elements housed in the standard 2' x 2' x 1' HEPA frame, were evaluated in the filter test housing using a 1,000 cfm slip stream containing a high concentration of depleted uranium oxide dust. One filter had the pleated cartridges manufactured to our specifications by the Pall Corporation and the other by Memtec Corporation. Test results showed both filters had a rapid increase in pressure drop with time, and reverse air pulses could not decrease the pressure drop. We suspected moisture accumulation in the filters was the problem since there were heavy rains during the evaluations, and the pressure drop of the Memtec filter decreased dramatically after passing clean, dry air through the filter and after the filter sat idle for one week. Subsequent laboratory tests on a single filter cartridge confirmed that water accumulation in the filter was responsible for the increase in filter pressure drop and the inability to lower the pressure drop by reverse air pulses. No effort was made to identify the source of the water accumulation and correct the problem because the available funds were exhausted

  10. Preliminary field evaluation of high efficiency steel filters

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Larsen, G.; Lopez, R. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    We have conducted an evaluation of two high efficiency steel filters in the exhaust of an uranium oxide grit blaster at the Y-12 Plant in Oak Ridge Tennessee. The filters were installed in a specially designed filter housing with a reverse air-pulse cleaning system for automatically cleaning the filters in-place. Previous tests conducted on the same filters and housing at LLNL under controlled conditions using Arizona road dust showed good cleanability with reverse air pulses. Two high efficiency steel filters, containing 64 pleated cartridge elements housed in the standard 2` x 2` x 1` HEPA frame, were evaluated in the filter test housing using a 1,000 cfm slip stream containing a high concentration of depleted uranium oxide dust. One filter had the pleated cartridges manufactured to our specifications by the Pall Corporation and the other by Memtec Corporation. Test results showed both filters had a rapid increase in pressure drop with time, and reverse air pulses could not decrease the pressure drop. We suspected moisture accumulation in the filters was the problem since there were heavy rains during the evaluations, and the pressure drop of the Memtec filter decreased dramatically after passing clean, dry air through the filter and after the filter sat idle for one week. Subsequent laboratory tests on a single filter cartridge confirmed that water accumulation in the filter was responsible for the increase in filter pressure drop and the inability to lower the pressure drop by reverse air pulses. No effort was made to identify the source of the water accumulation and correct the problem because the available funds were exhausted.

  11. Utilization of profilometry, SEM, AFM and contact angle measurements in describing surfaces of plastic floor coverings and explaining their cleanability

    Science.gov (United States)

    Kuisma, R.; Pesonen-Leinonen, E.; Redsven, I.; Kymäläinen, H.-R.; Saarikoski, I.; Sjöberg, A.-M.; Hautala, M.

    2005-06-01

    The tendency to soil and cleanability of ten commercial plastic floor coverings: eight vinyl (PVC) floor coverings, one vinyl composite tile and one plastic composite tile, were examined. Floor coverings were soiled with inorganic, organic and biological soil. The cleanability was measured both by bioluminescence of ATP (adenosine triphosphate) and colorimetrically. The surface topography was studied by AFM, SEM and with a profilometer. From the 2D- and 3D-profilometric measurements several characteristic parameters of the surface profiles were extracted. The tendency to soil and cleanability were compared with the characteristics of the surface. A weak correlation was found between roughness and soilability but no correlation between roughness and cleanability. Roughness had no correlation with contact angle.

  12. HEPA Filter Use at the Hanford Site

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air (HEPA) filters are relied upon at the Hanford site to support several different activities. Each facility relies upon the filters to provide the same function, remove radioactive particulate However, HEPA filters are operated in differing environmental conditions from one facility to another and the constituents in the air streams also differ. In addition, some HEPA filters at the Hanford site have been in service for several years. As a result, an assessment was performed which evaluated the service life and conditions of the HEPA filters at the Hanford site

  13. Characteristics of airflow turbulence behind HEPA filter

    International Nuclear Information System (INIS)

    The characteristics of airflow turbulence in unidirectional cleanroom are described in this paper. First, the airflow turbulence distribution is measured in a cleanbooth with a hot-wire anemometer. Through the analysis of turbulence intensity, the shape of pleated HEPA filter is found out to be an important factor of eddy generation in airflow, Secondly, turbulence distribution behind HEPA filter is measured in detail. It concludes that the shear stress, caused by the airflow difference between pleated concave and convex part of HEPA filter, makes eddy generation in airflow behind HEPA filter

  14. HEPA Filter Use at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Kriskovich, J. R.

    2002-02-28

    High Efficiency Particulate Air (HEPA) filters are relied upon at the Hanford site to support several different activities. Each facility relies upon the filters to provide the same function; remove radioactive particulate from various air streams. However, HEPA filters are operated in differing environmental conditions from one facility to another and the constituents in the air streams also differ. In addition, some HEPA filters at the Hanford site have been in service for several years. As a result, an assessment was performed which evaluated the service life and conditions of the HEPA filters at the Hanford site.

  15. HEPA Filter Use at the Hanford Site

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air (HEPA) filters are relied upon at the Hanford site to support several different activities. Each facility relies upon the filters to provide the same function; remove radioactive particulate from various air streams. However, HEPA filters are operated in differing environmental conditions from one facility to another and the constituents in the air streams also differ. In addition, some HEPA filters at the Hanford site have been in service for several years. As a result, an assessment was performed which evaluated the service life and conditions of the HEPA filters at the Hanford site

  16. HEPA Filter Use at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    KRISKOVICH, J.R.

    2002-02-20

    High Efficiency Particulate Air (HEPA) filters are relied upon at the Hanford site to support several different activities. Each facility relies upon the filters to provide the same function, remove radioactive particulate However, HEPA filters are operated in differing environmental conditions from one facility to another and the constituents in the air streams also differ. In addition, some HEPA filters at the Hanford site have been in service for several years. As a result, an assessment was performed which evaluated the service life and conditions of the HEPA filters at the Hanford site.

  17. Survey of HEPA filter experience

    International Nuclear Information System (INIS)

    A survey of high efficiency particulate air (HEPA) filter applications and experience at Department of Energy (DOE) sites was conducted to provide an overview of the reasons and magnitude of HEPA filter changeouts and failures. Results indicated that approximately 58% of the filters surveyed were changed out in the three year study period, and some 18% of all filters were changed out more than once. Most changeouts (63%) were due to the existence of a high pressure drop across the filter, indicative of filter plugging. Other reasons for changeout included leak-test failure (15%), preventive maintenance service life limit (13%), suspected damage (5%) and radiation buildup (4%). Filter failures occurred with approximately 12% of all installed filters. Of these failures, most (64%) occurred for unknown or unreported reasons. Handling or installation damage accounted for an additional 19% of reported failures. Media ruptures, filter-frame failures and seal failures each accounted for approximately 5 to 6% of the reported failures

  18. HEPA filter concerns - an overview

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) recently initiated a complete review of the DOE High Efficiency Particulate Air (HEPA) Filter Program to identify areas for improvement. Although this process is currently ongoing, various issues and problems have already been identified for action that not only impacts the DOE HEPA filter program, but potentially the national and international air cleaning community as well. This paper briefly reviews a few of those concerns that may be of interest, and discusses actions initiated by the DOE to address the associated issues and problems. Issues discussed include: guidance standards, in-place testing, specifications, Test Facilities, portable units, vacuum cleaners, substitute aerosols, filter efficiencies, aging/shelf life/service life, fire suppression, handbook, Quality Products List (QPL), QA testing, and evaluations

  19. Factors Influencing HEPA Filter Performance

    International Nuclear Information System (INIS)

    Properly functioning HEPA air filtration systems depend on a variety of factors that start with the use of fully characterized challenge conditions for system design and then process control during operation. This paper addresses factors that should be considered during the design phase as well as operating parameters that can be monitored to ensure filter function and lifetime. HEPA filters used in nuclear applications are expected to meet design, fabrication, and performance requirements set forth in the ASME AG-1 standard. The DOE publication Nuclear Air Cleaning Handbook (NACH) is an additional guidance document for design and operation HEPA filter systems in DOE facilities. These two guidelines establish basic maximum operating parameters for temperature, maximum aerosol particle size, maximum particulate matter mass concentration, acceptable differential pressure range, and filter media velocity. Each of these parameters is discussed along with data linking variability of each parameter with filter function and lifetime. Temporal uncertainty associated with gas composition, temperature, and absolute pressure of the air flow can have a direct impact on the volumetric flow rate of the system with a corresponding impact on filter media velocity. Correlations between standard units of flow rate (standard meters per minute or cubic feet per minute) versus actual units of volumetric flow rate are shown for variations in relative humidity for a 70 deg. C to 200 deg. C temperature range as an example of gas composition that, uncorrected, will influence media velocity. The AG-1 standard establishes a 2.5 cm/s (5 feet per minute) ceiling for media velocities of nuclear grade HEPA filters. Data are presented that show the impact of media velocities from 2.0 to 4.0 cm/s media velocities (4 to 8 fpm) on differential pressure, filter efficiency, and filter lifetime. Data will also be presented correlating media velocity effects with two different particle size

  20. Strategies for Burr Minimization and Cleanability in Aerospace and Automotive Manufacturing

    OpenAIRE

    Avila, Miguel C.; Gardner, Joel D.; Reich-Weiser, Corinne; Vijayaraghavan, Athulan; Dornfeld, David

    2006-01-01

    The quality of machined components in the aerospace and automotive industries has become increasingly critical in the past years because of greater complexity of the workpieces, miniaturization, usage of new composite materials, and tighter tolerances. This trend has put continual pressure not only on improvements in machining operations, but also on the optimization of the cleanability of parts. The paper reviews recent work done in these areas at the University of California-Berkele...

  1. Particulate soils adherence and surface cleanability: influence of biomacromolecules at interfaces and of substrate hydrophobicity

    OpenAIRE

    Toure, Yetioman

    2014-01-01

    Cleaning of particulate soils is an important issue in food and pharmaceutical production. Understanding the adherence of these soils is a fundamental requirement for improving surfaces cleanability. The combination of particles and macromolecules substances appears in many processes. Adsorbed compounds from these mixtures may influence interactions at interfaces and thus fouling and cleaning. This thesis deals with a deeper understanding of the physico-chemical mechanisms affecting soili...

  2. Penetration of aerosol particles through two-stage HEPA filter system

    International Nuclear Information System (INIS)

    One of the measures for the removal of airborne radioactivity in the exhaust air from nuclear facilities is to filtrate the air with multi-stage HEPA (high efficiency particulate air) filters. The efficiency of a two-stage HEPA filter system has been investigated for polydispersed DOP (di-octyle phthalate) and NaCl aerosols, in a stainless steel test duct; the size of HEPA filters was 200 mm x 200 mm x 150 mm. The penetration increased with the face velocity, and this trend was nearly the same in both the first and the second stage filters. The particles larger than 0.5 μm were not detected behind the second stage filter at any face velocity. The penetration of DOP particles increased with the loaded mass on the filter. The penetration of NaCl particles decreased exponentially with the increase of the loaded mass, while the pressure drop increased. (Mori, K.)

  3. Evaluation of pressure drop and service life for HEPA filter

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H. K.; Hong, K. P.; Min, D. K. and others [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    Pressure drop and service life of High Efficiency Particulate Air (HEPA) filters were evaluated for economical utilization and radioactive waste reduction of filters used in PIEF. As a result of the evaluation, V- pleat type HEPA filter was lower than separator type in the initial pressure, and the time reaching to the replacement pressure of V- pleat type HEPA filter took 28 months. Consequently, service life of V- pleat type HEPA filter appeared longer two times than that of separator type HEPA filter.

  4. Evaluation of pressure drop and service life for HEPA filter

    International Nuclear Information System (INIS)

    Pressure drop and service life of High Efficiency Particulate Air (HEPA) filters were evaluated for economical utilization and radioactive waste reduction of filters used in PIEF. As a result of the evaluation, V- pleat type HEPA filter was lower than separator type in the initial pressure, and the time reaching to the replacement pressure of V- pleat type HEPA filter took 28 months. Consequently, service life of V- pleat type HEPA filter appeared longer two times than that of separator type HEPA filter

  5. Factors affecting the wettability of different surface materials with vegetable oil at high temperatures and its relation to cleanability

    DEFF Research Database (Denmark)

    Ashokkumar, Saranya; Adler-Nissen, Jens; Møller, Per

    2012-01-01

    different levels of roughness. The cosine of the contact angle of olive oil on different surface materials rises linearly with increasing temperature. Among the materials analyzed, polymers (PTFE, silicone) gave the lowest cosθ values. Studies of the effect of roughness and surface flaws on wettability......The main aim of the work was to investigate the wettability of different surface materials with vegetable oil (olive oil) over the temperature range of 25–200°C to understand the differences in cleanability of different surfaces exposed to high temperatures in food processes. The different surface...... contact angle and cleanability. In addition to surface wettability with oil many other factors such as roughness and surface defects play an essential role in determining their cleanability....

  6. A Novel HEPA Filter Encapsulation Process

    International Nuclear Information System (INIS)

    Waste management engineers at Lawrence Livermore National Laboratory have developed an innovative process for the treatment of contaminated HEPA filters. The In Situ Stabilization and Filter Encapsulation (IS SAFE) Process provides several advantages over existing HEPA filter treatment processes. Treatment is accomplished by filling a spent HEPA filter with a low viscosity resin that cures to form a solid monolith. Once a solid monolith has been formed, the HEPA filter has been transformed in two ways: (1) worker hazards/risks associated with handling the filter are eliminated and (2) the in situ encapsulated filter meets LDR requirements and can be disposed of in a permitted landfill. A patent has been filed for this process. The IS SAFE process will be applicable to hazardous, mixed, and low level radioactively contaminated spent filters. Spent HEPA filters are prepared for processing by attaching vacuum fittings to the top and bottom openings of the filter. These fittings are used to attach the filter to a vacuum system comprised of a vacuum pump, vacuum gauge, resin reservoir and associated tubing and fittings. Resin is delivered to the filter in a controlled fashion. The total processing time for a 50-cubic feet per minute (cfm) filter is approximately 25 minutes. The resin filled HEPA filter is allowed to cure at ambient temperature and pressure for at least 24 hours. The final product is a solid monolith with less that 0.1 percent by volume of void space and 100 percent of the filter media coated with resin. Proof of concept studies have been completed using 50, 135, and 1000 cfm closed face HEPA filters. During these studies, we were able to develop and demonstrate a resin delivery process that yielded a final product that was suitable for in ground disposal. Additional adaptations of the process may be required for specific application, but the process equipment, supplies, and methodology have been fully established for contact handled, closed face

  7. A Novel HEPA Filter Encapsulation Process

    Energy Technology Data Exchange (ETDEWEB)

    Gates-Anderson, D.; Kidd, S.; Attebery, R.; Belue, T.; Bowers, J.; Rogers, H.

    2002-02-28

    Waste management engineers at Lawrence Livermore National Laboratory have developed an innovative process for the treatment of contaminated HEPA filters. The In Situ Stabilization and Filter Encapsulation (IS SAFE) Process provides several advantages over existing HEPA filter treatment processes. Treatment is accomplished by filling a spent HEPA filter with a low viscosity resin that cures to form a solid monolith. Once a solid monolith has been formed, the HEPA filter has been transformed in two ways: (1) worker hazards/risks associated with handling the filter are eliminated and (2) the in situ encapsulated filter meets LDR requirements and can be disposed of in a permitted landfill. A patent has been filed for this process. The IS SAFE process will be applicable to hazardous, mixed, and low level radioactively contaminated spent filters. Spent HEPA filters are prepared for processing by attaching vacuum fittings to the top and bottom openings of the filter. These fittings are used to attach the filter to a vacuum system comprised of a vacuum pump, vacuum gauge, resin reservoir and associated tubing and fittings. Resin is delivered to the filter in a controlled fashion. The total processing time for a 50-cubic feet per minute (cfm) filter is approximately 25 minutes. The resin filled HEPA filter is allowed to cure at ambient temperature and pressure for at least 24 hours. The final product is a solid monolith with less that 0.1 percent by volume of void space and 100 percent of the filter media coated with resin. Proof of concept studies have been completed using 50, 135, and 1000 cfm closed face HEPA filters. During these studies, we were able to develop and demonstrate a resin delivery process that yielded a final product that was suitable for in ground disposal. Additional adaptations of the process may be required for specific application, but the process equipment, supplies, and methodology have been fully established for contact handled, closed face

  8. Environmental Properties and Installation Requirements of HEPA Filters

    International Nuclear Information System (INIS)

    The ability of HEPA (i.e. 'absolute') filters to withstand severe environmental conditions is often critical to reliable operation of a contaminated exhaust system. This paper discusses findings related to the installation, mechanical strength, and the heat, moisture, and corrosion resistance of HEPA filters determined during the course of the filter development program of the USAEC Division of Operational Safety. As a result of these findings, wood- cased filter units are recommended in preference to steel-cased filter units wherever possible, wood-cased filter units should have rabbeted casing joints, not butt joints. The limiting temperature for continuous exposure of HEPA filters to hot air is 400°F, above this temperature the tensile strength of the media drops sharply, to as little as 50% of the room-temperature tensile strength at 500°F. Fibre fracture and fibre loss occur at temperatures in excess of about 550°F. The limiting temperature of the assembled filter element is actually determined by the sealant used between the casing and the frame and, for wood- cased units, the casing material. Plywood is good for continuous exposure at temperatures up to 300°F for periods up to 48 hours, and up to 200°F for indefinite exposure (i.e. weeks or months). Steel is good for any temperature within the useful operating range of the media, although damage may be caused by differential expansion between the casing and the filter pack. Volatilization and reduction in shear strength of adhesives limits continuous operating temperatures to 250-350°F for periods up to 48 hours, and 200-275°F for indefinite exposure (according to adhesive used in manufacture). Steel-cased units with special sealants may withstand substantially higher continuous operating temperatures but in most cases are unable to meet the requirements of Underwriter’s Laboratories Standard UL-586 for fire and hot (750°F) air. Resistance of the filter element to flexure, vibration damage

  9. Evaluation of HEPA filter service life

    International Nuclear Information System (INIS)

    Rocky Flats Environmental Technology Site (RFETS), has approximately 10,000 High Efficiency Particulate Air (HEPA) Filters installed in a variety of filter plenums. These ventilation/filtration plenum systems are used to control the release of airborne particulate contaminates to the environment during normal operations and potential accidents. This report summarizes the results of destructive and non-destructive tests on HEPA filters obtained from a wide variety of ages and service conditions. These tests were performed to determine an acceptable service life criteria for HEPA filters used at Rocky Flats Environmental Technology Site (RFETS). A total of 140 filters of various ages (1972 to 1996) and service history (new, aged unused, used) were tested. For the purpose of this report, filter age from manufacture date/initial test date to the current sample date was used, as opposed to the actual time a filter was installed in an operating system

  10. HEPA filters in nuclear power plants

    International Nuclear Information System (INIS)

    HEPA filters have been in use in the nuclear power industry as long as the industry has existed. This paper traces a short history of their development and use as it relates to the engineering of systems that contain HEPA filters. The all too common misuses of HEPA filters could be, in part, due to this historical development. Examples of common problems of basic design and operation are provided. All examples are from operating U.S. Light Water Reactors. Suggestions for possible solutions to some of the basic reasons for poor design are offered. While no single answer exists, understanding of the reasons the problems do exist can greatly aid in developing effective solutions

  11. Evaluation of HEPA filter service life

    Energy Technology Data Exchange (ETDEWEB)

    Fretthold, J.K.; Stithem, A.R.

    1997-07-14

    Rocky Flats Environmental Technology Site (RFETS), has approximately 10,000 High Efficiency Particulate Air (HEPA) Filters installed in a variety of filter plenums. These ventilation/filtration plenum systems are used to control the release of airborne particulate contaminates to the environment during normal operations and potential accidents. This report summarizes the results of destructive and non-destructive tests on HEPA filters obtained from a wide variety of ages and service conditions. These tests were performed to determine an acceptable service life criteria for HEPA filters used at Rocky Flats Environmental Technology Site (RFETS). A total of 140 filters of various ages (1972 to 1996) and service history (new, aged unused, used) were tested. For the purpose of this report, filter age from manufacture date/initial test date to the current sample date was used, as opposed to the actual time a filter was installed in an operating system.

  12. In-place HEPA filter penetration test

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Wilson, K.; Elliott, J. [Lawrence Livermore National Lab., CA (United States)] [and others

    1997-08-01

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in-place penetration test is practical. 14 refs., 14 figs., 3 tabs.

  13. HEPA filter fire (and subsequent unfiltered release)

    Energy Technology Data Exchange (ETDEWEB)

    Powers, T.B.

    1996-09-27

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: HEPA Filter Failure - Exposure to High Temperature or Pressure. The calculations needed to quantify the risk associated with this accident scenario are included within.

  14. Realization of commercial high strength HEPA filters

    International Nuclear Information System (INIS)

    HEPA-filter media though having excellent particle removal efficiencies, remain characterized as rather brittle, fragile and weak materials. As a result, undesired structural damage followed by significant losses in filtration efficiency can easily occur in handling, transport, and even normal operation of filter units. In recent years extensive investigations into the structural limits of HEPA filters in dry air and under extended exposure to high humidity airflow have been carried out. In the course of this work the failure modes and the underlying failure mechanisms were thoroughly studied. On the basis of the information obtained, considerable improvements in the structural strength of HEPA filters could be achieved. As verified by removal efficiency tests, differential pressures up to 56kPa in dry air and 15kPa after extended operation under fog conditions were proven to be sustainable without mechanical damage to the filter medium. In cooperation with three major European filter manufacturers the know-how gained has been transferred into practical application through development of commercially available high-strength filter units. Three new KWU (Siemens-Kraftwerksunion) nuclear power plants in Germany have already been fully equipped with HEPA filters of this improved design. The German licensing authorities are now considering modifications of their requirement specifications to reflect the increased strength of the new filter units

  15. HEPA filter fire (and subsequent unfiltered release)

    International Nuclear Information System (INIS)

    This document supports the development and presentation of the following accident scenario in the TWRS Final Safety Analysis Report: HEPA Filter Failure - Exposure to High Temperature or Pressure. The calculations needed to quantify the risk associated with this accident scenario are included within

  16. In-place HEPA filter penetration test

    International Nuclear Information System (INIS)

    We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in- place penetration test is practical

  17. Validation of the integrity of a HEPA filter system.

    Science.gov (United States)

    Wang, Wei-Hsung

    2003-11-01

    The objective of this study was to establish a delayed air sampling method to verify the integrity of an existing HEPA filter system in a ventilated fume hood. (238U,232Th)O2 microspheres were generated to fabricate cement nuclear fuel pellets in a HEPA-filtered hood. To comply with the air effluent concentration limits by NRC, the capture efficiency of the HEPA filter was examined. An in-line isokinetic air sampling system was installed downstream of the HEPA filter. Utilizing a gas flow proportional counter, 212Pb was used as a surrogate to indicate any possible penetration of the (238U,232Th)O2 particles through the HEPA filter. Based on the experimental results, this delayed sampling method proved to be an easy and effective way to validate the integrity of the HEPA filter. PMID:14570263

  18. DOE standard: Quality assurance inspection and testing of HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    This standard establishes essential elements for the quality assurance inspection and testing of HEPA filters by US Department of Energy (DOE)-accepted Filter Test Facilities (FTF). The standard specifies HEPA filter quality assurance inspection and testing practices established in DOE-STD-3022-98, DOE HEPA Filter Test Program, and provides a basis for the preparation of written operating procedures for primary FTF functions.

  19. Steel

    International Nuclear Information System (INIS)

    Composition of age hardening steel, % : Fe - (12.0-12.4) Cr - (2-2.7) Ni (0.5-0.6) Ti - (1.0-1.2) Mn - (0.03 - 0.04) C having high values of magnetoelastic internal friction and mechanical properties as well as an ability to operate under the conditions of alternating loadings are proposed. Damping properties of the steel permit to improve labour conditions. Data for the above steel on internal friction, impact strength and tensile properties are given

  20. HEPA/Vaccine Plan for Indoor Anthrax Remediation

    OpenAIRE

    Lawrence M Wein; Liu, Yifan; Leighton, Terrance J.

    2005-01-01

    We developed a mathematical model to compare 2 indoor remediation strategies in the aftermath of an outdoor release of 1.5 kg of anthrax spores in lower Manhattan. The 2 strategies are the fumigation approach used after the 2001 postal anthrax attack and a HEPA/vaccine plan, which relies on HEPA vacuuming, HEPA air cleaners, and vaccination of reoccupants. The HEPA/vaccine approach leads to few anthrax cases among reoccupants if applied to all but the most heavily contaminated buildings, and ...

  1. INEEL HEPA Filter Leach System: A Mixed Waste Solution

    Energy Technology Data Exchange (ETDEWEB)

    Argyle, Mark Don; Demmer, Ricky Lynn; Archibald, Kip Ernest; Brewer, Ken Neal; Pierson, Kenneth Alan; Shackelford, Kimberlee Rene; Kline, Kelli Suzanne

    1999-03-01

    Calciner operations and the fuel dissolution process at the Idaho National Engineering and Environmental Laboratory have generated many mixed waste high-efficiency particulate air (HEPA) filters. The HEPA Filter Leach System located at the Idaho Nuclear Technology and Engineering Center lowers radiation contamination levels and reduces cadmium, chromium, and mercury concentrations on spent HEPA filter media to below disposal limits set by the Resource Conservation and Recovery Act (RCRA). The treated HEPA filters are disposed as low-level radioactive waste. The technical basis for the existing system was established and optimized in initial studies using simulants in 1992. The treatment concept was validated for EPA approval in 1994 by leaching six New Waste Calcining Facility spent HEPA filters. Post-leach filter media sampling results for all six filters showed that both hazardous and radiological constituent levels were reduced so the filters could be disposed of as low-level radioactive waste. Since the validation tests the HEPA Filter Leach System has processed 78 filters in 1997 and 1998. The Idaho National Engineering and Environmental Laboratory HEPA Filter Leach System is the only mixed waste HEPA treatment system in the DOE complex. This process is of interest to many of the other DOE facilities and commercial companies that have generated mixed waste HEPA filters but currently do not have a treatment option available.

  2. INEEL HEPA Filter Leach System: A Mixed Waste Solution

    International Nuclear Information System (INIS)

    Calciner operations and the fuel dissolution process at the Idaho National Engineering and Environmental Laboratory have generated many mixed waste high-efficiency particulate air (HEPA) filters. The HEPA Filter Leach System located at the Idaho Nuclear Technology and Engineering Center lowers radiation contamination levels and reduces cadmium, chromium, and mercury concentrations on spent HEPA filter media to below disposal limits set by the Resource Conservation and Recovery Act (RCRA). The treated HEPA filters are disposed as low-level radioactive waste. The technical basis for the existing system was established and optimized in initial studies using simulants in 1992. The treatment concept was validated for EPA approval in 1994 by leaching six New Waste Calcining Facility spent HEPA filters. Post-leach filter media sampling results for all six filters showed that both hazardous and radiological constituent levels were reduced so the filters could be disposed of as low-level radioactive waste. Since the validation tests the HEPA Filter Leach System has processed 78 filters in 1997 and 1998. The Idaho National Engineering and Environmental Laboratory HEPA Filter Leach System is the only mixed waste HEPA treatment system in the DOE complex. This process is of interest to many of the other DOE facilities and commercial companies that have generated mixed waste HEPA filters but currently do not have a treatment option available

  3. INEEL HEPA Filter Leach System: A Mixed Waste Solution

    Energy Technology Data Exchange (ETDEWEB)

    K. Archibald; K. Brewer; K. Kline; K. Pierson; K. Shackelford; M. Argyle; R. Demmer

    1999-02-01

    Calciner operations and the fuel dissolution process at the Idaho National Engineering and Environmental Laboratory have generated many mixed waste high-efficiency particulate air (HEPA)filters. The HEPA Filter Leach System located at the Idaho Nuclear Technology and Engineering Center lowers radiation contamination levels and reduces cadmium, chromium, and mercury concentrations on spent HEPA filter media to below disposal limits set by the Resource Conservation and Recovery Act (RCRA). The treated HEPA filters are disposed as low-level radioactive waste. The technical basis for the existing system was established and optimized in initial studies using simulants in 1992. The treatment concept was validated for EPA approval in 1994 by leaching six New Waste Calcining Facility spent HEPA filters. Post-leach filter media sampling results for all six filters showed that both hazardous and radiological constituent levels were reduced so the filters could be disposed of as low-level radioactive waste. Since the validation tests the HEPA Filter Leach System has processed 78 filters in 1997 and 1998. The Idaho National Engineering and Environmental Laboratory HEPA Filter Leach System is the only mixed waste HEPA treatment system in the DOE complex. This process is of interest to many of the other DOE facilities and commercial companies that have generated mixed waste HEPA filters but currently do not have a treatment option available.

  4. Multi-Canister overpack internal HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    SMITH, K.E.

    1998-11-03

    The rationale for locating a filter assembly inside each Multi-Canister Overpack (MCO) rather than include the filter in the Cold Vacuum Drying (CVD) process piping system was to eliminate the potential for contamination to the operators, processing equipment, and the MCO. The internal HEPA filters provide essential protection to facility workers from alpha contamination, both external skin contamination and potential internal depositions. Filters installed in the CVD process piping cannot mitigate potential contamination when breaking the process piping connections. Experience with K-Basin material has shown that even an extremely small release can result in personnel contamination and costly schedule disruptions to perform equipment and facility decontamination. Incorporating the filter function internal to the MCO rather than external is consistent with ALARA requirements of 10 CFR 835. Based on the above, the SNF Project position is to retain the internal HEPA filters in the MCO design.

  5. Degradation of HEPA filters exposed to DMSO

    International Nuclear Information System (INIS)

    Dimethyl sulfoxide (DMSO) sprays are being used to remove the high explosive (HE) from nuclear weapons in the process of their dismantlement. A boxed 50 cfm HEPA filter with an integral prefilter was exposed to DMSO vapor and aerosols that were generated by a spray nozzle to simulate conditions expected in the HE dissolution operation. After 198 hours of operation, the pressure drop of the filter had increased from 1.15 inches to 2.85 inches, and the efficiency for 0.3 μm dioctyl sebacate (DOS) aerosols decreased from 99.992% to 98.6%. Most of the DMSO aerosols had collected as a liquid pool inside the boxed HEPA. The liquid was blown out of the filter exit with 100 cfm air flow at the end of the test. Since the filter still met the minimum allowed efficiency of 99.97% after 166 hours of exposure, we recommend replacing the filter every 160 hours of operation or sooner if the pressure drop increases by 50%. Examination of the filter showed that visible cracks appeared at the joints of the wooden frame and a portion of the sealant had pulled away from the frame. Since all of the DMSO will be trapped in the first HEPA filter, the second HEPA filter should not suffer from DMSO degradation. Thus the combined efficiency for the first filter (98.6%) and the second filter (99.97%) is 99.99996% for 0.3μm particles. If the first filter is replaced prior to its degradation, each of the filters will have 99.97% efficiency, and the combined efficiency will be 99.999991%. The collection efficiency for DMSO/HE aerosols will be much higher because the particle size is much greater

  6. Degradation of HEPA filters exposed to DMSO

    International Nuclear Information System (INIS)

    Dimethyl sulfoxide (DMSO) sprays are being used to remove the high explosive (HE) from nuclear weapons in the process of their dismantlement. A boxed 50 cmf HEPA filter with an integral prefilter was exposed to DMSO vapor and aerosols that were generated by a spray nozzle to simulate conditions expected in the HE dissolution operation. After 198 hours of operation, the pressure drop of the filter had increased form 1.15 inches to 2,85 inches, and the efficiency for 0.3 μm dioctyl sebacate (DOS) aerosols decreased form 99.992% to 98.6%. Most of the DMSO aerosols had collected as a liquid pool inside the boxed HEPA. The liquid was blown out of the filter exit with 100 cmf air flow at the end of the test. Since the filter still met the minimum allowed efficiency of 99.97% after 166 hours of exposure, we recommend replacing the filter every 160 hours of operation or sooner if the pressure drop increases by 50%. Examination of the filter showed that visible cracks appeared at the joints of the wooden frame and a portion of the sealant had pulled away from the frame. Since all of the DMSO will be trapped in the first HEPA filter, the second HEPA filter should not suffer from DMSO degradation. Thus the combined efficiency for the first filter (98.6%) and the second filter (99.97%) is 99.99996% for 0.3 μm particles. If the first filter is replaced prior to its degradation, each of the filters will have 99.97% efficiency, and the combined efficiency will be 99.999991%. The collection efficiency for DMSO/HE aerosols will be much higher because the particle size is much greater

  7. Degradation of HEPA filters exposed to DMSO

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; Wilson, K.; Larsen, G. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    Dimethyl sulfoxide (DMSO) sprays are being used to remove the high explosive (HE) from nuclear weapons in the process of their dismantlement. A boxed 50 cmf HEPA filter with an integral prefilter was exposed to DMSO vapor and aerosols that were generated by a spray nozzle to simulate conditions expected in the HE dissolution operation. After 198 hours of operation, the pressure drop of the filter had increased form 1.15 inches to 2,85 inches, and the efficiency for 0.3 {mu}m dioctyl sebacate (DOS) aerosols decreased form 99.992% to 98.6%. Most of the DMSO aerosols had collected as a liquid pool inside the boxed HEPA. The liquid was blown out of the filter exit with 100 cmf air flow at the end of the test. Since the filter still met the minimum allowed efficiency of 99.97% after 166 hours of exposure, we recommend replacing the filter every 160 hours of operation or sooner if the pressure drop increases by 50%. Examination of the filter showed that visible cracks appeared at the joints of the wooden frame and a portion of the sealant had pulled away from the frame. Since all of the DMSO will be trapped in the first HEPA filter, the second HEPA filter should not suffer from DMSO degradation. Thus the combined efficiency for the first filter (98.6%) and the second filter (99.97%) is 99.99996% for 0.3 {mu}m particles. If the first filter is replaced prior to its degradation, each of the filters will have 99.97% efficiency, and the combined efficiency will be 99.999991%. The collection efficiency for DMSO/HE aerosols will be much higher because the particle size is much greater.

  8. Performance of HEPA filters under severe conditions, (6)

    International Nuclear Information System (INIS)

    In order to demonstrate the safety of high efficiency particulate air (HEPA) filter units from seismic phenomena, HEPA filters and HEPA filter units were shaked with sine waves and seismic waves. Acceleration responses, decontamination factor and air tightness were measured. The fundamental natural frequency of an HEPA filter was higher than 40 Hz and that of the filter unit higher than 20 Hz. The degree of amplification for filter units under seismic shaking was, therefore, nearly unity. Filter units, subjected to seismic excitations with 400 gal maximum horizontal acceleration and together with 200 gal maximum vertical acceleration, kept their performance during and after shaking tests. To estimate the seismic margin, filter units were subjected to acceleration higher than design base one, and it was found that filter units withstood to the earthquake with 4,000 gal horizontal floor acceleration. From the results mentioned above, it was shown experimentally that the HEPA filter unit was sufficiently strong against earthquakes. (author)

  9. Performance of HEPA filters under severe conditions, 3

    International Nuclear Information System (INIS)

    Performance of high efficiency particulate air (HEPA) filters at temperatures from ambient to 240 deg C was measured to prove that HEPA filters kept up their regulated decontamination factor (DF) at elevated temperatures. The DF for NaCl aerosol was measured by using a laser particle spectrometer. Pressure drop of HEPA filters at elevated temperatures was also measured. The DF increased at elevated temperatures. The DF at 200 deg C was an order of magnitude higher than that at ambient. The change of DF at elevated temperatures of various HEPA filters was effectively evaluated by using the ratio of single fiber collection efficiencies at ambient to those at elevated temperatures. Pressure drop of HEPA filters also increased at elevated temperatures. The pressure drop at 200 deg C was 1.3 times larger than that at ambient. The change of DF and pressure drop at elevated temperatures was explained by applying Kirsh's theory to elevated temperatures. (author)

  10. Qualification of box HEPA filters for nuclear applications

    International Nuclear Information System (INIS)

    We have successfully completed qualification tests on high efficiency particulate air (HEPA) filters that are encapsulated within a box and manufactured by American Air Filters. The qualification tests are required by the American Society of Mechanical Engineers Standard ASME N509 and the U.S. Military Standard MIL-F-51068 for HEPA filters to be used in nuclear applications. The qualification tests specify minimum filter efficiencies following exposure to heated air, overpressure, and rough handling. Prior to this study, no box HEPA filters from any manufacturer had been qualified despite their wide-spread use in Department of Energy (DOE) facilities. Box HEPA filters are not addressed in any of the existing HEPA standards and only briefly discussed in the Nuclear Air Cleaning Handbook

  11. Technology development: HEPA filter service life test plan

    Energy Technology Data Exchange (ETDEWEB)

    Kirchner, K.N.; Cummings, K.G.; Leck, W.C.; Fretthold, J.K.

    1995-05-31

    Rocky Flats Environmental Technology Site (the Site) has approximately 10,000 High Efficiency Particulate Air (HEPA) Filters installed in a variety of filter plenums. These ventilation/filtration plenum systems are used to control the release of airborne particulate contaminates to the environment during normal operations and also during potential design-based accidents. The operational integrity of the HEPA filter plenums is essential to maintaining the margins of safety as required by building specific Final Safety Analysis Reports (FSARS) for protection of the public and environment. An Unreviewed Safety Question Determination (USQD), USDQ-RFP94.0615-ARS, was conducted in 1994 addressing the potential inadequacy of the safety envelope for Protected Area building HEPA plenums. While conducting this USQD, questions were raised concerning the maximum service life criteria for HEPA filters. Accident scenarios in existing FSARs identify conditions that could potentially cause plugging or damage of down stream HEPA filters as a result of impaction from failed filters. Additionally, available data indicates that HEPA filters experience structural degradation due to the effects of age. The Unresolved Safety Question (USQ) compensatory measures thus require testing and analysis of used HEPA filters in order to determine and implement service life criteria.

  12. Airborne Microorganism Disinfection by Photocatalytic HEPA Filter

    Directory of Open Access Journals (Sweden)

    Rotruedee Chotigawin

    2010-07-01

    Full Text Available This study determined the efficacy of photocatalytic HEPA filters on microorganism disinfection in a closed-loop chamber and later applied it in an air purifier and tested its efficacy in an 8-m3 chamber and in a hospital. The photocatalytic filters were made by dip-coating a HEPA filter in a TiO2 slurry. In order to disinfect the microorganisms retained on the filter, UV-A light was irradiated onto the filter to create strong oxidative radicals which can destroy microorganisms. The findings showed that disinfection efficiency of the photocatalytic filters with high TiO2 loading was insignificantly higher than with lower loading. S. epidermidis was completely eliminated within 2 hours, while 86.8% of B. subtilis, 77.1% of A. niger, and 82.7% of P. citrinum were destroyed within 10 hours. When applying the photocatalytic filters into an air purifier in a 8-m3 chamber, it was found that as soon as the air purifier was turned on, 83.4% of S. epidermidis, 81.4% of B. subtilis, 88.5% of A. niger, and 75.8% of P. citrinum were removed from the air. In a hospital environment, the PCO air purifier efficacy was lower than that in the chamber. Besides, relative humidity, distances from the air purifier and room size were suspected to affect the efficacy of the photocatalytic filters.

  13. The characteristics of HEPA filter and its handling technology

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Young Gerl; Kim, Ki Hong; Kil, Kwac Koung

    2001-12-01

    When cleaning air of radioactive or toxic contaminants, even small particles have to be removed with high efficiency as low concentrations in the air can be harmful. HEPA filter is very high efficient filter as much as its removal efficiency is more than 99.97 % for 0.3 {mu}m particles. But, because of their structural weakness, their careless handling reduce their performance easily, and there are actually many cases like that HEPA filter systems do not ensure their performance because of inadequate installations. Thus, workers that are concerned with the air cleaning system and designers of HEPA filter system must understand the characteristics of HEPA filter and their installation techniques.

  14. Experience in the quality assurance testing of HEPA filters

    International Nuclear Information System (INIS)

    The DOE HEPA (high efficiency particulate air) filter quality-assurance test program was initiated in 1960 to ensure the supply of adequate filters for environmental control applications in DOE operations. The program has played a significant role in the development and improvement of HEPA filters, and has more than paid for itself. However, the receipt of large numbers of filters which require repair or waiver of specification requirements, even as recent as 1980 and 1981, indicates that there are problems in the HEPA filter manufacturing industry. It is clear that DOE users are receiving the 'cream of the crop' of HEPA filters, but that other users who do not avail themselves of the DOE testing service are receiving filters of lesser quality. (author)

  15. Alternative HEPA Filter Full-Scale Single Element Testing

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D.J.

    2003-01-15

    Conventional disposable glass-fiber high efficiency particulate air (HEPA) filters are used throughout the Department of Energy complex in various process systems. Alternative filter media is being addressed that would have a long life on the HLW tanks.

  16. Performance of HEPA filters under severe conditions, 1

    International Nuclear Information System (INIS)

    Collection efficiencies of high efficiency particulate air (HEPA) filters for dioctyl phthalate (DOP) aerosol were measured by using a laser particle spectrometer and a diffusion battery (DB)/condensation nucleus counter (CNC) submicron sizing system to obtain the basic information to prove the performance of HEPA filters under severe conditions. Test parameters were such as DOP aerosol diameter, air flow rate, temperature and humidity of air flow and the number of filtering stages. It was found that the most penetrating particle size through HEPA filters ranged 0.10 -- 0.15 μm in diameter, and the collection efficiency at 0.3 μm which is generally applied for the efficiency of HEPA filters was about an order of magnitude higher than that for the most penetrating particles. Among the parameters governing the conditions of air flow tests, the flow rate was most effective on the collection efficiency, whereas the influences of temperature and humidity were insignificant. The collection efficiencies of multi-stage HEPA filters were almost consistent between the first and the second filters for the same sized particles. Besides these, indispensable data for estimating collection efficiencies of HEPA filters such as, charge of DOP aerosol, the effect of pinhole in the filters etc. were obtained. (author)

  17. Experience with HEPA filters at United States nuclear installations

    International Nuclear Information System (INIS)

    Part 50 of Title 10 of the United States Code of Federal Regulations requires that a number of atmosphere cleanup systems be included in the design of commercial nuclear power plants to be licensed in the United States. These filtering systems are to contain high efficiency particulate air (HEPA) filters for removal of radioactive particulate matter generated during normal and accident conditions. Recommendations for the design, testing and maintenance of the filtering systems and HEPA filter components are contained in a number of United States Nuclear Regulatory Commission documents and industry standards. This paper will discuss this published guidance available to designers of filtering systems and the plant operators of U.S. commercial nuclear power plants. The paper will also present a survey of published reports of experience with HEPA filters, failures and possible causes for the failures, and other abnormal occurrences pertaining to HEPA filters installed in U.S. nuclear power installations. A discussion will be included of U.S. practices for qualification of HEPA filters before installation, and verification of continued performance capability at scheduled intervals during operation

  18. Performance of HEPA filters under severe conditions, (5)

    International Nuclear Information System (INIS)

    The structural limits of 305 x 305 mm size HEPA filters subjected to shock transients were measured. The purpose of this test is obtaining the basic data to evaluate the safety of HEPA filters subjected to shock transients. Shock transients were generated by a shock tube driven by pressurized air. Filters were subjected to shock transients uniformly and unequally in the filter unit. Structural limits of HEPA filters uniformly subjected to shock transients of 50 ms in duration were at about 20 kPa overpressure. A reflection coefficient of 1.4 was obtained. Structural limits of the tandem HEPA filters were higher than that of a single filter because of the increase in pressure between the 1st and 2nd filters caused by reflection of shock transients from the 2nd filter. The pressure difference of HEPA filters in the filter unit at structural limits was lower than that of filters uniformly subjected to shock transients because of the partial flow in the filter unit. (author)

  19. Aerosol penetration inside HEPA filtration media

    International Nuclear Information System (INIS)

    Attempts made to modelize changes in high-efficiency particulate air (HEPA) filter pressure drop as a function of such parameters as the amount of aerosol collected, which also take account of filtering medium characteristics, those of the filtered aerosol and the filtration velocity, have always been limited by a lack of knowledge of the distribution of particles within the medium. For the last few years, a method, developed over 25 years ago to study the distribution of Radon daughters within filter media made of cellulose fibers, has been reused and applied to radioactive and fluorescent aerosols penetration studies. This method enables determination of aerosol distribution on the surface and inside the filter medium by peeling away successive layers using an adhesive tape and measuring the specific amounts removed each time. Knowledge of aerosol penetration within the filter has revealed that, for a give aerosol, particle distribution inside the filter rapidly decreased exponentially and that fixation on the filter's front surface rapidly superseded penetration inside the medium. The deposit profiles thus measured have made it possible to propose a model for determining the rate of filter pressure drop increase that closely agrees with experimental results

  20. HEPA Filter Performance under Adverse Conditions

    International Nuclear Information System (INIS)

    This study involved challenging nuclear grade high-efficiency particulate air (HEPA) filters under a variety of conditions that can arise in Department of Energy (DOE) applications such as: low or high RH, controlled and uncontrolled challenge, and filters with physically damaged media or seals (i.e., leaks). Reported findings correlate filter function as measured by traditional differential pressure techniques in comparison with simultaneous instrumental determination of up and down stream PM concentrations. Additionally, emission rates and failure signatures will be discussed for filters that have either failed or exceeded their usable lifetime. Significant findings from this effort include the use of thermocouples up and down stream of the filter housing to detect the presence of moisture. Also demonstrated in the moisture challenge series of tests is the effect of repeated wetting of the filter. This produces a phenomenon referred to as transient failure before the tensile strength of the media weakens to the point of physical failure. An evaluation of the effect of particle size distribution of the challenge aerosol on loading capacity of filters is also included. Results for soot and two size distributions of KCl are reported. Loading capacities for filters ranged from approximately 70 g of soot to nearly 900 g for the larger particle size distribution of KCl. (authors)

  1. Effect of DOP heterodispersion on HEPA-filter-penetration measurements

    International Nuclear Information System (INIS)

    The accuracy of the standard US test method for certifying High-Efficiency Particulate Air (HEPA) filters has been in question since the finding by Hinds, et al. that the dioctyl phthalate (DOP) aerosol used in the test is not monodisperse as had been assumed and that particle-size analyzers, or owls, could not distinguish between different particle-size distributions with the same owl reading. We have studied theoretically and experimentally the filter efficiency for different DOP size distributions with the same owl reading. Our studies show that the effect of varying DOP size distributions on the measured HEPA-filter penetration depends on the light-scattering-photometer response and on the HEPA-filter penetration curve, both measured as a function of particle size. HEPA-filter penetration for a heterodisperse DOP aerosol may be increased, decreased, or remain the same when compared to the filter penetration for monodisperse aerosols. Using experimental HEPA-filter penetration and photometer response curves, we show that heterodisperse DOP aerosols (D/sub cmd/ 0.19 and sigma g = 1.4) yield 24% lower penetrations than that for monodisperse DOP aerosols (D/sub cmd/ = 0.3 and sigma g = 1.0). This surprisingly small effect of the DOP heterodispersion on HEPA-filter penetration is due to the response function of the owl that is similar to the response of the photometer. Changes in the particle-size distribution are therefore seen in a similar fashion by both the photometer and the owl. We also show that replacing the owl with modern particle-size spectrometers may lead to large errors in filter penetration because the particle-size spectrometers do not provide measurements that correspond to the photometer measurements. 15 references, 16 figures

  2. Effect of DOP heterodispersion on HEPA-filter-penetration measurements

    International Nuclear Information System (INIS)

    The accuracy of the standard US test method for certifying High-Efficiency Particulate Air (HEPA) filters has been in question since the finding by Hinds, et al. that the dioctyl phthalate (DOP) aerosol used in the test is not monodisperse as had been assumed and that particle-size analyzers, or owls, could not distinguish between different particle-size distributions with the same owl reading. The filter efficiency for different DOP size distributions with the same owl reading were studied. The studies show that the effect of varying DOP size distributions on the measured HEPA-filter penetration depends on the light-scattering-photometer response and on the HEPA-filter penetration curve, both measured as a function of particle size. HEPA-filter penetration for a heterodisperse DOP aerosol may be increased, decreased, or remain the same when compared to the filter penetration for monodisperse aerosols. Using experimental HEPA-filter penetration and photometer response curves, we show that heterodisperse DOP aerosols (D/sub cmd/ 0.19 and sigmag = 1.4) yield 24% lower penetrations than that for monodisperse DOP aerosols (D/sub cmd/ = 0.3 and sigmag = 1.0). This surprisingly small effect of the DOP heterodispersion on HEPA-filter penetration is due to the response function of the owl that is similar to the response of the photometer. Changes in the particle-size distribution are, therefore, seen in a similar fashion by both the photometer and the owl. It is also shown that replacing the owl with modern particle-size spectrometers may lead to large error in filter penetration because the particle-size spectrometers do not provide measurements that correspond to the photometer measurements

  3. Determination of HEPA Filter Efficiency With Diocthyl Pthalate Aerosol

    International Nuclear Information System (INIS)

    Ultrafine aerosol filtration by HEPA (High Efficiency Particulate Air) filter has been determinated experimentally, based on the measurement of monodisperse Diocthyl Pthalate (DOP) aerosol concentration before and after passing the test filter. Using this technique, filter efficiency can be determined as a function of aerosol diameter with range from 0.017 to 0.747 um. The average efficiencies for Whatman -41 ; Whatman -42 and Whatman GF/A filters were 56.14 %; 95,74 %; and 99.65 % respectively. Gelman A Fiber Glass and Whatman membrane filter have fulfilled criterion as HEPA filter according to standard of IAEA, because of their minimum effiency of 99.90 %

  4. Chemical analysis and volume reduction of radioactive HEPA filter waste

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, In Ho; Choi, Wang Kyu; Lee, Suk Chol; Min, Byung Youn; Yang, Hee Chul; Lee, Kun Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    According to the active operation of nuclide facilities at KAERI, many spent filters used in a ventilation system of the nuclear facilities have been generated as a spent filter wastes. These spent filter wastes have generally consisted of a HEPA filter after filtering of all the contaminants in the air stream generated during the operation of nuclide facilities. Therefore, this study is conducted to investigate the radionuclide and heavy metals in HEPA filters, and the characteristics of the melting as a decontamination and volume reduction

  5. ALTERNATE HIGH EFFICIENCY PARTICULATE AIR (HEPA) FILTRATION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Bruce Bishop; Robert Goldsmith; Karsten Nielsen; Phillip Paquette

    2002-08-16

    In Phase IIA of this project, CeraMem has further developed and scaled up ceramic HEPA filters that are appropriate for use on filtration of vent gas from HLW tanks at DOE sites around the country. This work included procuring recrystallized SiC monoliths, developing membrane and cement materials, and defining a manufacturing process for the production of prototype full sizes HEPA filters. CeraMem has demonstrated that prototype full size filters can be manufactured by producing 9 full size filters that passed DOP aerosol testing at the Oak Ridge Filter Test Facility. One of these filters was supplied to the Savannah River Technical Center (SRTC) for process tests using simulated HLW tank waste. SRTC has reported that the filter was regenerable (with some increase in pressure drop) and that the filter retained its HEPA retention capability. CeraMem has also developed a Regenerable HEPA Filter System (RHFS) design and acceptance test plan that was reviewed by DOE personnel. The design and acceptance test plan form the basis of the system proposal for follow-on work in Phase IIB of this project.

  6. ALTERNATE HIGH EFFICIENCY PARTICULATE AIR (HEPA) FILTRATION SYSTEM

    International Nuclear Information System (INIS)

    In Phase IIA of this project, CeraMem has further developed and scaled up ceramic HEPA filters that are appropriate for use on filtration of vent gas from HLW tanks at DOE sites around the country. This work included procuring recrystallized SiC monoliths, developing membrane and cement materials, and defining a manufacturing process for the production of prototype full sizes HEPA filters. CeraMem has demonstrated that prototype full size filters can be manufactured by producing 9 full size filters that passed DOP aerosol testing at the Oak Ridge Filter Test Facility. One of these filters was supplied to the Savannah River Technical Center (SRTC) for process tests using simulated HLW tank waste. SRTC has reported that the filter was regenerable (with some increase in pressure drop) and that the filter retained its HEPA retention capability. CeraMem has also developed a Regenerable HEPA Filter System (RHFS) design and acceptance test plan that was reviewed by DOE personnel. The design and acceptance test plan form the basis of the system proposal for follow-on work in Phase IIB of this project

  7. Scanning electron microscopy of ULPA and HEPA filtering papers

    International Nuclear Information System (INIS)

    The behavior of newly developed ULPA and HEPA filtering papers has been examined in an abnormal condition due to overheating up to 400 degree C. A noteworth failure in mechanical resistance has been observed, whereas efficiency was scarcely affected. Scanning electron microscopy showed that observed anticipated failures were accompanied with ruptures of the glass microfibers of the papers

  8. Evaluation of data from HEPA filter quality assurance testing stations

    International Nuclear Information System (INIS)

    In Revision 1 to Regulatory Guide 1.52, issued in July 1976, the NRC recommended that high efficiency particulate air (HEPA) filters for use in engineered safety features (ESF) atmosphere cleanup systems be visually inspected and dioctylphtalate (DOP) tested at either of two Department of Energy (DOE) operated QA Filter Testing Stations prior to their installation and use in commercial nuclear power plants. This practice was initiated because filter vendors were unable to consistently provide a HEPA filter that would meet the stringent requirements established by DOE and NRC and its predecessor the AEC. In 1977, the NRC staff undertook a program to revise Regulatory Guide 1.52 to reflect recently issued industry standards (e.g., ANSI N509 and N510) and current industry practices. Revision 2 to Regulatory Guide 1.52 was formally issued in March 1978. In conducting this review, the recommendation that HEPA filters, intended for use in ESF systems in commercial nuclear power plants, be routinely tested at the DOE-QA Filter Testing Stations was revaluated. As part of this evluation a detailed analysis of the filter test results recorded by the two QA Testing Stations during the period 1971 to 1977 was conducted. This paper summarizes the results of the analysis and explains the rationale for deleting the requirement that all HEPA filters intended for use in ESF systems be tested at the AQ Testing Station

  9. Some experience in HEPA filtration at DERE and AWRE

    International Nuclear Information System (INIS)

    The Dounreay experimental reactor establishment has now been in operation for 20 years, mainly concerned with operation of an experimental fast reactor and the supporting fuel cycles. In this period highly enriched uranium metal fuel elements have been fabricated, irradiated, examined at very short cooling times and reprocessed. In this period, tens of millions of curies of fission products have been handled, together with tens of tonnes of highly enriched uranium in a variety of physical forms, gaseous, liquid, powder and solid metal. These operations have necessitated HEPA filtration protection of the active gaseous effluents emanating from a wide variety of wet and dry chemical and metallurgical processes. This has resulted in some very difficult demands on HEPA filter efficiency. The site is at present changing over to a plutonium fast reactor fuel cycle, which will greatly increase the throughput of fission products. The alpha activity associated with the fuel will rise by 3 orders magnitude. Thus the HEPA filter requirements will be more stringent and at the same time used HEPA filter disposal become a much greater problem. A complete re-appraisal has been made and major changes are necessary on filter housings, changing techniques, disposal methods and ventilation philosophy and design. These changes are being implemented at the moment

  10. Effect of age on the structural integrity of HEPA filters

    International Nuclear Information System (INIS)

    All of the controls on high-efficiency particulate air (HEPA) filters are based on rigid manufacturing standards with regard to filtration efficiency, temperature performance, pressure integrity, and strength. Third-party inspection and testing by the US Department of Energy increases the reliability of new HEPA filters, but only routine in-place testing is used to assure that an aging filter performs adequately. In 1980 the Lawrence Livermore National Laboratory initiated a small evaluation to determine if age has a significant effect on the structural integrity of HEPA filters. A series of used uncontaminated filters dating back to 1965 was obtained for these tests. Tensile strength tests on the old media indicated a decrease in strength. To provide additional measurement of the filters' overall strength, several of these aged filters were subjected to pressure pulses equivalent to the NRC Region I tornado pulses and shock wave over pressures. Data from these tests indicate a decrease in breaking pressure of from 25-50%. A large increase in complete filter pack blow-out during the simulated NRC Region I tornado tests was also observed. The preliminary results indicate the need for an administrative lifetime for HEPA filters used in critical nuclear facilities. Due to the unique conditions in each facility, different administrative lifetimes may be necessary

  11. HEPA/vaccine plan for indoor anthrax remediation.

    Science.gov (United States)

    Wein, Lawrence M; Liu, Yifan; Leighton, Terrance J

    2005-01-01

    We developed a mathematical model to compare 2 indoor remediation strategies in the aftermath of an outdoor release of 1.5 kg of anthrax spores in lower Manhattan. The 2 strategies are the fumigation approach used after the 2001 postal anthrax attack and a HEPA/vaccine plan, which relies on HEPA vacuuming, HEPA air cleaners, and vaccination of reoccupants. The HEPA/vaccine approach leads to few anthrax cases among reoccupants if applied to all but the most heavily contaminated buildings, and recovery is much faster than under the decades-long fumigation plan. Only modest environmental sampling is needed. A surge capacity of 10,000 to 20,000 Hazmat workers is required to perform remediation within 6 to 12 months and to avoid permanent mass relocation. Because of the possibility of a campaign of terrorist attacks, serious consideration should be given to allowing or encouraging voluntary self-service cleaning of lightly contaminated rooms by age-appropriate, vaccinated, partially protected (through masks or hoods) reoccupants or owners. PMID:15705325

  12. QUANTITATIVE EVALUATION OF HEPA FILTRATION UNITS AT ASBESTOS ABATEMENT SITES

    Science.gov (United States)

    A study was conducted to determine-the filtering efficiencies of 31 high efficiency particulate air (HEPA) filtration units in use at asbestos-abatement projects. article-removal efficiencies for these units ranged from 90.53 to > 99.99 percent. ineteen (61%) of the units tested ...

  13. A review of DOE HEPA filter component test activities

    Energy Technology Data Exchange (ETDEWEB)

    Slawski, J.W.; Bresson, J.F. [Informatics Corp., Inc., Albuquerque, NM (United States); Scripsick, R.C. [Los Alamos National Lab., NM (United States)

    1997-08-01

    All HEPA filters purchased for installation in DOE nuclear facilities are required to be tested at a Filter Test Facility (FTF) prior to installation. The number of HEPA filters purchased by DOE has been reduced so much that the Hanford FTF was closed. From Fiscal Year (FY) 1992 to 1994, funding was not provided to the FTF Technical Support Group (TSG) at the Los Alamos National Laboratory. As a consequence, Round Robin Tests (RRTs), performed twice each year by the FTFs to assess constituency of test results among the FTFs, were not performed in FY 1992 and FY 1993. The Annual Reports of FTF test activities were not prepared for FY 1992 - 1995. Technical support provided to the FTFs was minimal. There is talk of closing a second FTF, and ongoing discussions as to whether DOE will continue to fund operation of the FTFs. In FY 1994, DOE Defense Programs commenced funding the TSG. RRT data for FY 1994 and 1995 have been entered into the database; the FY 1994 RRT report has been issued; and the FY 1995 RRT report is in progress. Data from semiannual reports have been retrieved and entered into the database. Standards related to HEPA filter test and procurement activities are now scheduled for issuance by FY 1996. Continuation of these activities depends on whether DOE will continue to support the HEPA filter test program. The history and activities of the FTFs and the TSG at Los Alamos have been reported at previous Air Cleaning Conferences. Data from the FY 1991 Annual Report of FTF activities was presented at the 1992 Air Cleaning Conference. Preparation of the Annual Reports was temporarily suspended in 1992. However, all of the FTF Semiannual report data have been retrieved and entered into the data base. This paper focuses primarily on the results of HEPA filter tests conducted by FTFs during FY 1992 - FY 1995, and the possible effects of the DOE program uncertainties on the quality of HEPA filters for installation at the DOE sites. 15 refs., 13 tabs.

  14. A review of DOE HEPA filter component test activities

    International Nuclear Information System (INIS)

    All HEPA filters purchased for installation in DOE nuclear facilities are required to be tested at a Filter Test Facility (FTF) prior to installation. The number of HEPA filters purchased by DOE has been reduced so much that the Hanford FTF was closed. From Fiscal Year (FY) 1992 to 1994, funding was not provided to the FTF Technical Support Group (TSG) at the Los Alamos National Laboratory. As a consequence, Round Robin Tests (RRTs), performed twice each year by the FTFs to assess constituency of test results among the FTFs, were not performed in FY 1992 and FY 1993. The Annual Reports of FTF test activities were not prepared for FY 1992 - 1995. Technical support provided to the FTFs was minimal. There is talk of closing a second FTF, and ongoing discussions as to whether DOE will continue to fund operation of the FTFs. In FY 1994, DOE Defense Programs commenced funding the TSG. RRT data for FY 1994 and 1995 have been entered into the database; the FY 1994 RRT report has been issued; and the FY 1995 RRT report is in progress. Data from semiannual reports have been retrieved and entered into the database. Standards related to HEPA filter test and procurement activities are now scheduled for issuance by FY 1996. Continuation of these activities depends on whether DOE will continue to support the HEPA filter test program. The history and activities of the FTFs and the TSG at Los Alamos have been reported at previous Air Cleaning Conferences. Data from the FY 1991 Annual Report of FTF activities was presented at the 1992 Air Cleaning Conference. Preparation of the Annual Reports was temporarily suspended in 1992. However, all of the FTF Semiannual report data have been retrieved and entered into the data base. This paper focuses primarily on the results of HEPA filter tests conducted by FTFs during FY 1992 - FY 1995, and the possible effects of the DOE program uncertainties on the quality of HEPA filters for installation at the DOE sites. 15 refs., 13 tabs

  15. Development of a Pulp Process Treating Contaminated HEPA Filters (III)

    International Nuclear Information System (INIS)

    The Pulp Process (PP) Treatment option was conceived as a replacement for the current Filter Leaching System (FLS). The FLS has operated at the Idaho Nuclear Technology and Engineering Center of the Idaho National Engineering and Environmental Laboratory since 1995 to treat radioactive, mixed waste HEPA filters. In recent years, the FLS has exhibited difficulty in removing mercury from the HEPA filters as the concentration of mercury in the spent HEPA filters has increased. The FLS leaches and washes the whole filter without any preparation or modification. The filter media and the trapped calcine particles are confined in a heavy filter housing that contributes to poor mixing zones around the edges of the filter, low media permeability, channeling of the liquid through cracks and tears in the filter media, and liquid retention between leach and rinse cycles. In the PP, the filter media and the trapped calcine particles are separated from the filter housing and treated as a pulp, taking advantage of improved contact with the leach solution that cannot be achieved when the media is still in the HEPA filter housing. In addition to removing the mercury more effectively, the PP generates less volume of liquid waste, requires a shorter leach cycle time, and possesses the versatility for treating filters of different sizes. A series of tests have been performed in the laboratory to demonstrate the advantages of the PP concept. These tests compare the PP with the FLS under controlled conditions that simulate the current operating parameters. A prior study using blended feed, a mixture of shredded clean HEPA filter media and non-radioactive calcine particles, indicated that the PP would significantly increases the calcine dissolution percentages. In this study, hazardous-metal contaminated HEPA filter media was studied. The results of side-by-side tests indicated that the PP increased the mercury removal percentage by 80% and might be a solution to the mercury removal

  16. Development of a Pulp Process Treating Contaminated HEPA Filters (III)

    Energy Technology Data Exchange (ETDEWEB)

    Hu, J. S.; Ramer, J.; Argyle, M. D.; Demmer, R. L.

    2002-02-28

    The Pulp Process (PP) Treatment option was conceived as a replacement for the current Filter Leaching System (FLS). The FLS has operated at the Idaho Nuclear Technology and Engineering Center of the Idaho National Engineering and Environmental Laboratory since 1995 to treat radioactive, mixed waste HEPA filters. In recent years, the FLS has exhibited difficulty in removing mercury from the HEPA filters as the concentration of mercury in the spent HEPA filters has increased. The FLS leaches and washes the whole filter without any preparation or modification. The filter media and the trapped calcine particles are confined in a heavy filter housing that contributes to poor mixing zones around the edges of the filter, low media permeability, channeling of the liquid through cracks and tears in the filter media, and liquid retention between leach and rinse cycles. In the PP, the filter media and the trapped calcine particles are separated from the filter housing and treated as a pulp, taking advantage of improved contact with the leach solution that cannot be achieved when the media is still in the HEPA filter housing. In addition to removing the mercury more effectively, the PP generates less volume of liquid waste, requires a shorter leach cycle time, and possesses the versatility for treating filters of different sizes. A series of tests have been performed in the laboratory to demonstrate the advantages of the PP concept. These tests compare the PP with the FLS under controlled conditions that simulate the current operating parameters. A prior study using blended feed, a mixture of shredded clean HEPA filter media and non-radioactive calcine particles, indicated that the PP would significantly increases the calcine dissolution percentages. In this study, hazardous-metal contaminated HEPA filter media was studied. The results of side-by-side tests indicated that the PP increased the mercury removal percentage by 80% and might be a solution to the mercury removal

  17. Closure of 324 Facility potential HEPA filter failure unreviewed safety questions

    International Nuclear Information System (INIS)

    This document summarizes the activities which occurred to resolve an Unreviewed Safety Question (USQ) for the 324 Facility [Waste Technology Engineering Laboratory] involving Potential HEPA Filter Breach. The facility ventilation system had the capacity to fail the HEPA filters during accident conditions which would totally plug the filters. The ventilation system fans were modified which lowered fan operating parameters and prevented HEPA filter failures which might occur during accident conditions

  18. Closure of 324 Facility potential HEPA filter failure unreviewed safety questions

    Energy Technology Data Exchange (ETDEWEB)

    Enghusen, M.B.

    1997-11-07

    This document summarizes the activities which occurred to resolve an Unreviewed Safety Question (USQ) for the 324 Facility [Waste Technology Engineering Laboratory] involving Potential HEPA Filter Breach. The facility ventilation system had the capacity to fail the HEPA filters during accident conditions which would totally plug the filters. The ventilation system fans were modified which lowered fan operating parameters and prevented HEPA filter failures which might occur during accident conditions.

  19. Development and evaluation of a HEPA filter for increased strength and resistance to elevated temperature

    International Nuclear Information System (INIS)

    We have completed a preliminary study of an improved HEPA filter for increased strength and resistance to elevated temperature to improve the reliability of the standard deep pleated HEPA filter under accident conditions. The improvements to the HEPA filter consist of a silicone rubber sealant and a new HEPA medium reinforced with a glass cloth. Three prototype filters were built and evaluated for temperature and pressure resistance and resistance to rough handling. The temperature resistance test consisted of exposing the HEPA filter to 1,000 scan (1,700 m3/hr) at 700 degrees F (371 degrees C) for five minutes.The pressure resistance test consisted of exposing the HEPA filter to a differential pressure of 10 in. w.g. (2.5 kPa) using a water saturated air flow at 95 degrees F (35 degrees C). For the rough handling test, we used a vibrating machine designated the Q110. DOP filter efficiency tests were performed before and after each of the environmental tests. In addition to following the standard practice of using a separate new filter for each environmental test, we also subjected the same filter to the elevated temperature test followed by the pressure resistance test. The efficiency test results show that the improved HEPA filter is significantly better than the standard HEPA filter. Further studies are recommended to evaluate the improved HEPA filter and to assess its performance under more severe accident conditions

  20. Development and evaluation of a HEPA filter for increased strength and resistance to elevated temperature

    International Nuclear Information System (INIS)

    The authors have competed a preliminary study of an improved HEPA filter for increased strength and resistance to elevated temperature to improve the reliability of the standard deep pleated HEPA filter under accident conditions. The improvements to the HEPA filter consist of a silicone rubber sealant and a new HEPA medium reinforced with a glass cloth. Three prototype filters were built and evaluated for temperature and pressure resistance and resistance to rough handling. The temperature resistance test consisted of exposing the HEPA filter to 1,000 scfm (1,700 m3/hr) at 700 degrees F (371 degrees C) for five minutes. The pressure resistance test consisted of exposing the HEPA filter to a differential pressure of 10 in. w.g. (2.5 kPa) using a water saturated air flow at 95 degrees F (35 degrees C). A vibrating machine designated the Q110 was used for the rough handling test. DOP filter efficiency tests were performed before and after each of the environmental tests. In addition to following the standard practice of using a separate new filter for each environmental test, the same filter was also subjected to the elevated temperature test followed by the pressure resistance test. The efficiency test results show that the improved HEPA filter is significantly better than the standard HEPA filter. Further studies are recommended to evaluate the improved HEPA filter and to assess its performance under more severe accident conditions. 15 refs., 12 figs., 3 tabs

  1. Overhead robot system for remote HEPA filter replacement

    International Nuclear Information System (INIS)

    A high-efficiency particulate air (HEPA) filter system for facility exhaust air filtraction of radioactive particles has been designed that utilizes a modified industrial gantry robot to remotely replace filter elements. The system filtration design capacity can be readily changed by increasing or decreasing the number of plenums, which only affects the cell length and robot bridge travel. The parallel flow plenum design incorporates remote HEPA filter housings, which are commercially available. Filter removal and replacement is accomplished with the robot under sequenced program control. A custom-designed robot control console, which interfaces with the standard gantry robot power center controller, minimizes operator training. Critical sequence steps are operator verified, using closed-circuit television (CCTV), before proceeding to the next programmed stop point. The robot can be operated in a teleoperator mode to perform unstructured maintenance tasks, such as replacing filter housing components and cell lights

  2. The effects of temperature on HEPA filter media

    International Nuclear Information System (INIS)

    This paper presents the results from a series of experiments to study the changes in the physical properties of HEPA filter media after exposure to elevated temperatures. Data are presented for papers heated in the range 120-500 degrees C. The observed changes in strength and paper stiffness are explained in terms of alterations to the binder due to thermal degradation. The information generated has clarified a particular failure mode associated with a small number of filter inserts at elevated temperatures

  3. Response of HEPA filters to simulated-accident conditions

    International Nuclear Information System (INIS)

    High-efficiency particulate air (HEPA) filters have been subjected to simulated accident conditions to determine their response to abnormal operating events. Both domestic and European standard and high-capacity filters have been evaluated to determine their response to simulated fire, explosion, and tornado conditions. The HEPA filter structural limitations for tornado and explosive loadings are discussed. In addition, filtration efficiencies during these accident conditions are reported for the first time. Our data indicate efficiencies between 80% and 90% for shock loadings below the structural limit level. We describe two types of testing for ineffective filtration - clean filters exposed to pulse-entrained aerosol and dirty filters exposed to tornado and shock pulses. Efficiency and material loss data are described. Also, the resonse of standard HEPA filters to simulated fire conditions is presented. We describe a unique method of measuring accumulated combustion products on the filter. Additionally, data relating to pressure drop vs accumulated mass during plugging are reported for simulated combustion aerosols. The effects of concentration and moisture levels on filter plugging were evaluated. We are obtaining all of the above data so that mathematical models can be developed for fire, explosion, and tornado accident analysis computer codes. These computer codes can be used to assess the response of nuclear air cleaning systems to accident conditions

  4. Performance of HEPA filters under hot dynamic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Frankum, D.P.; Costigan, G. [AEA Technology, Oxfordshire (United Kingdom)

    1995-02-01

    Accidents in nuclear facilities involving fires may have implications upon the ventilation systems where high efficiency particulate air (HEPA) filters are used to minimise the airborne release of radioactive or toxic particles. The Filter Development Section at Harwell Laboratory has been investigating the effect of temperature on the performance of HEPA filters under hot dynamic conditions[{sub 1}] for a number of years. The test rig is capable of delivering air flows of 10001/s (at ambient conditions) at temperatures up to 500{degrees}C, where measurements of the penetration and pressure drop across the filter are obtained. This paper reports the experiments on different constructions of HEPA filters; rectangular and circular. The filters were tested at an air temperature of 200{degrees}C for up to 48 hours at the rated airflow to assess their performance. The penetration measurements for rectangular filters were observed to be below 0.021% after prolonged operation. In a number of cases, holes appeared along the pleat creases of circular filters although the penetration remained below 1%. The sealing gasket for these filters was noted to deform with temperature, permitting a leakage path. A prototype high strength circular filter was evaluated at temperatures of up to 400{degrees}C with a penetration less than 0.65%.

  5. Collection efficiency and decontamination factor of HEPA filter

    International Nuclear Information System (INIS)

    It is very important in a nuclear air cleaning system that HEPA (High Efficiency Particulate Air) filter is for reduction of releasing amounts of airborne radioactive particles. HEPA filter, by definition, has a minimum collection efficiency of 99.97 % for 0.3 μm particles. However, DF (Decontamination Factor), which is necessary for safety management, can not be directly derived from the efficiency. And the current standard defined for 0.3 μm particles has no scientific justification, because it has been found that the most penetrating particle size through HEPA filter is not always 0.3 μm. In the present paper, a numerical experiment was made in order to estimate a relationship between DF and the efficiency. And new standard, in which the minimum DF is able to be easily obtained, was proposed. In the multistage filtration system, it was found that lower values of DF was possible to be experimentally indicated in the second and the third stages, even if the collection performance of the each filter is the same. (author)

  6. Structural testing of salt loaded HEPA filters for WIPP

    International Nuclear Information System (INIS)

    The ventilation studies of the Waste Isolation Pilot Plant described in this paper were performed by personnel from New Mexico State Univ. in collaboration with Sandia National Laboratories, Los Alamos National Laboratory and Westinghouse Corporation. High efficiency particulate air filters (0.61m by 0.61m by 0.3m) of the type in use at the Waste Isolation Pilot Plant were loaded with salt aerosol provided from that site. The structural strength of salt-loaded, high-efficiency filters was investigated at two humidity levels, high (75%RH) and low (13-14% RH), by subjecting the filters to pressure transients of the types expected from tornadoes. Filters loaded under the high humidity condition proved to have a greater structural strength than did the filters loaded under the low humidity conditions, when both types were subjected to tornado-like pressure pulses. This unexpected results was apparently due to the crystallization of salt upon the wire face guard of the HEPA filter loaded under the high humidity condition which kept salt from penetrating the filter medium while still providing a substantial pressure drop at the standard flow rate. Results are also presented for HEPA filters pre-conditioned at 100% RH before structural testing and for HEPA filters in series with pre-filters

  7. Performance of HEPA filters under severe conditions, 2

    International Nuclear Information System (INIS)

    Performance of high efficiency particulate air (HEPA) filters loaded high concentration of dusts was examined to experimentally show the effectiveness of the filters under these conditions. Decontamination factors (DF) for dioctyl phthalate (DOP) aerosol before and after the dust loading, and for the loaded dusts; the JIS No.11 dust (mass median diameter 1.2 μm) and NaCl aerosol (MMD 0.2 μm) were measured by a laser particle spectrometer. Dust holding capacity of HEPA filters was proportional to the MMD of the loaded dusts. Decontamination factor for the dusts increased with the pressure drop which also increased by the dust loading and two or three orders of magnitude higher values were obtained at the pressure drop in 1.5 times of the initial one. This trend continued until the limit pressure of the filters, 250 mmAq. After the dust loading stopped, DF decreased gradually due to the change of structure of loaded dusts. The DF of pinholed filters loaded dusts decreased with increasing pressure drop but still the higher enough values were obtained compared with the regulated DF. From the results mentioned above, it was shown experimentally that the effectiveness of HEPA filters loaded high concentration of dusts was enough for the regulated one. (author)

  8. Performance of HEPA filters under hot dynamic conditions

    International Nuclear Information System (INIS)

    Accidents in nuclear facilities involving fires may have implications upon the ventilation systems where high efficiency particulate air (HEPA) filters are used to minimise the airborne release of radioactive or toxic particles. The Filter Development Section at Harwell Laboratory has been investigating the effect of temperature on the performance of HEPA filters under hot dynamic conditions[1] for a number of years. The test rig is capable of delivering air flows of 10001/s (at ambient conditions) at temperatures up to 500 degrees C, where measurements of the penetration and pressure drop across the filter are obtained. This paper reports the experiments on different constructions of HEPA filters; rectangular and circular. The filters were tested at an air temperature of 200 degrees C for up to 48 hours at the rated airflow to assess their performance. The penetration measurements for rectangular filters were observed to be below 0.021% after prolonged operation. In a number of cases, holes appeared along the pleat creases of circular filters although the penetration remained below 1%. The sealing gasket for these filters was noted to deform with temperature, permitting a leakage path. A prototype high strength circular filter was evaluated at temperatures of up to 400 degrees C with a penetration less than 0.65%

  9. The high efficiency steel filters for nuclear air cleaning

    International Nuclear Information System (INIS)

    We have, in cooperation with industry, developed high-efficiency filters made from sintered stainless-steel fibers for use in several air-cleaning applications in the nuclear industry. These filters were developed to overcome the failure modes in present high-efficiency particulate air (HEPA) filters. HEPA filters are made from glass paper and glue, and they may fail when they get hot or wet and when they are overpressured. In developing our steel filters, we first evaluated the commercially available stainless-steel filter media made from sintered powder and sintered fiber. The sintered-fiber media performed much better than sintered-powder media, and the best media had the smallest fiber diameter. Using the best media, we then built prototype filters for venting compressed gases and evaluated them in our automated filter tester. 12 refs., 20 figs

  10. High efficiency steel filters for nuclear air cleaning

    International Nuclear Information System (INIS)

    The authors have, in cooperation with industry, developed high-efficiency filters made from sintered stainless-steel fibers for use in several air-cleaning applications in the nuclear industry. These filters were developed to overcome the failure modes in present high-efficiently particulate air (HEPA) filters. HEPA filters are made from glass paper and glue, and they may fail when they get hot or wet and when they are overpressured. In developing steel filters, they first evaluated the commercially available stainless-steel filter media made from sintered powder and sintered fiber. The sintered-fiber media performed much better than sintered-powder media, and the best media had the smallest fiber diameter. Using the best media, prototype filters were then built for venting compressed gases and evaluated in their automated filter tester

  11. Advances on HEPA filtration technology for nuclear applications (Paper No. 8.6)

    International Nuclear Information System (INIS)

    High efficiency particulate air (HEPA) filters have been extensively used worldwide over the years for various nuclear applications. This paper describes design concept of various HEPA filter configurations developed world over including India in recent years for increasing of collection efficiency, arrestance of finer pariculates, extension of service life, suitability of remote handling and compactness for easier waste disposal. (author). 4 refs., 6 figs

  12. Effect of dust loading on the pressure drop and efficiency of HEPA filters

    International Nuclear Information System (INIS)

    The challenge for High Particulate Air (HEPA) filters is to predict pressure drop evolution according to the filtration conditions. A preliminary test programme has been carried out to determine dust loading and efficiency versus pressure drop in order to predict service life of HEPA filters. The results have been compared with Bergman's dust loading model and show good agreement with the theory. (author)

  13. Development and evaluation of a HEPA filter for increased strength and resistance to elevated temperature

    International Nuclear Information System (INIS)

    We have developed an improved HEPA filter for increased strength and resistance to elevated temperature to improve the reliability of HEPA filters under accident conditions. The improvements to the HEPA filter consist of a silicone rubber sealant and a new HEPA medium reinforced with a glass cloth. Several prototype filters were built and evaluated for temperature and pressure resistance and resistance to rough handling. The temperature resistance test consisted of exposing the HEPA filter to 1,000 scan at 700 degrees F for five minutes. The pressure resistance test consisted of exposing the HEPA filter to a differential pressure of 10 in. w.g. using a water saturated air flow at 95 degrees F. For the rough handling test, we used a vibrating machine designated the Q110. DOP filter efficiency tests were performed before and after each of the environmental tests. In addition to following the standard practice of using a separate new filter for each environmental test, we also subjected the same filter to the elevated temperature test followed by the pressure resistance test. The efficiency test results show that the improved HEPA filter is significantly better than the standard HEPA filter

  14. Testing HEPA filter response to high flow velocity and overpressure

    International Nuclear Information System (INIS)

    In cooperation with the Los Alamos National Laboratory (LANL) HEPA filters presently on the market and modified versions were tested using the LANL blowdown facility. The filter response during the test was documented on high speed films which indicated, among other information, the load when first failure occurred and the failure mode. Differential pressure through the filter and velocity were measured with variable reluctance pressure transducers and an oscilloscope recorder. New HEPA filters show first failures already at differential pressures between some 4 kPa and 17 kPa. The better results are obtained with conventionally pleated filter paper packs sealed in a wooden frame with a polyurethane material. However, these filters cannot be used under accident conditions. Metal frame filters considered as potential filters for accident situations showed only poor resistance against overpressures. The weakest point in such filters proved to be the attachment of the filter pack in the metal frame, which limited the loadability to about 10 kPa. As soon as proper attachment is assured, the integrity of the filter pack limits the admissible differential pressure. Through some modifications of wood frame filters, physical integrity was improved to a failure pressure of 24 kPa. During operation, the filter elements are loaded with dust. Dust loading up to 1000 Pa pressure drop at rated flow, which was simulated with polystyrene latex aerosols, was found to reduce the mechanical stability by up to 40%. Pressure drop characteristics of HEPA filters influence the occurrence of high differential pressures and high mechanical loads. Pressure drops (δp) of unloaded and preloaded filters were investigated up to high flow velocities (v). Measured data can be presented in the form of δp=av+bv2, where a and b are constants. Theory, in contrast, predicts a linear relationship. The deviation is due to deformations of the pleated filter paper pack with increasing flow velocity and

  15. Development of acid-resistant HEPA filter components

    International Nuclear Information System (INIS)

    Laboratory and in-service tests of various HEPA filter media and separators were conducted to establish their relative resistances to HNO3-HF vapors. Filter medium of glass fiber with Nomex additive and aluminum separators with an epoxy-vinyl coating have performed quite well in the acid environment in the laboratory, and in prototype-filters placed in service in a plenum at Rocky Flats. Proprietary filters with new design and/or components were also tested in service with generally good results

  16. Behavior of HEPA filters under high humidity airflows

    International Nuclear Information System (INIS)

    To help determine and improve the safety margins of High Efficiency Particulate Air (HEPA) filter units in nuclear facilities under possible accident conditions, the structural limits and failure mechanisms of filter in high-humidity airflows were established and the fundamental physical phenomena underlying filter failure or malfunction in humid air were identified. Empirical models for increases in filter pressure drop with time in terms of the relevant airstream parameters were also developed. The weaknesses of currently employed humidity countermeasures used in filter protection are discussed and fundamental explanations for reported filter failures in normal service are given. (orig./DG)

  17. Method of treating contaminated HEPA filter media in pulp process

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian S.; Argyle, Mark D.; Demmer, Ricky L.; Mondok, Emilio P.

    2003-07-29

    A method for reducing contamination of HEPA filters with radioactive and/or hazardous materials is described. The method includes pre-processing of the filter for removing loose particles. Next, the filter medium is removed from the housing, and the housing is decontaminated. Finally, the filter medium is processed as pulp for removing contaminated particles by physical and/or chemical methods, including gravity, flotation, and dissolution of the particles. The decontaminated filter medium is then disposed of as non-RCRA waste; the particles are collected, stabilized, and disposed of according to well known methods of handling such materials; and the liquid medium in which the pulp was processed is recycled.

  18. In-place leak testing of multiple HEPA filter

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H. K.; Hong, K. P.; Jun, Y. B.; Min, D. K.; Park, K. J.; Yang, S. Y.; Lee, E. P.; Hwang, Y. H.; Su, H. S.; Kim, K. S.; Kwon, H. M. [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    In-place leak test for the filter banks with multiple high efficiency particulate air(HEPA) filters was carried in KAERI. As a result of the test, in the air flow capacity of 31,500 CMH and 22,800 CMH, penetration rate appeared to be 0.015 {approx} 0.036 %. These values satisfy the Regulatory Guide 1.14 reference, 0.05%. Although test has a complicated procedure, the testing technique was established by KAERI, and will be contributed to the safety inspection of ventilation system in nuclear facilities in the future.

  19. Comparison of HEPA filter test methods in corrosive environments

    International Nuclear Information System (INIS)

    An evaluation of the three HEPA filter test methods in corrosive environments was conducted: the dioctyl phthalate (DOP) method (US Standard Method ANSI N-101.1-1972), the sodium chloride method (British Standard 3928:1969), and the soda-fluorescein or uranine method (French Standard AFNOR STD NFX 44-011). The effects of humidity, temperature and oxides of nitrogen (NO/sub x/) on each method was examined. The experimental design used in the evaluation measured and separated both the effect of each variable and any interaction between variables on the test method. Recommendations for changes in the standard methods to reduce erratic online results are presented

  20. Thermal treatment for radioactive HEPA filter media generated from nuclear facilities

    International Nuclear Information System (INIS)

    Many radioactive HEPA filter wastes are generated from the high radioactive facilities in operation, improvement and repair, and under decommissioning. Spent filter wastes of about 1,500 drums have been stored in the waste storage facility of the Korea Atomic Energy Research Institute (KAERI) since its operation. In the future, a lot of HEPA filters in high radioactivity will be occurred from pyroprocessing which is treatment facility for used nuclear fuel. Therefore, the technology development for the radioactive HEPA filter treatment is necessary for effective management and safe disposal for HEPA filter wastes. The thermal treatment has been known as one of the most effective technologies for volume reduction and recycling of metallic radioactive wastes. In this study, the thermal treatment for radioactive HEPA filter media was conducted for the volume reduction. The volatility and leachability for heavy metals and radionuclides in radioactive HEPA filter media were analyzed to investigate the volatilization during thermal treatment and stability after thermal treatment for safe disposal, respectively. The knowledge gained from this study will aid in the development of thermal treatment for HEPA filter media

  1. Potential for Hepa filter damage from water spray systems in filter plenums

    International Nuclear Information System (INIS)

    The water spray systems in high efficiency particulate air (HEPA) filter plenums that are used in nearly all Department of Energy (DOE) facilities for protection against fire was designed under the assumption that the HEPA filters would not be damaged by the water sprays. The most likely scenario for filter damage involves filter plugging by the water spray, followed by the fan blowing out the filter medium. A number of controlled laboratory tests that were previously conducted in the late 1980s are reviewed in this paper to provide a technical basis for the potential HEPA filter damage by the water spray system in HEPA filter plenums. In addition to the laboratory tests, the scenario for HEPA filter damage during fires has also occurred in the field. Afire in a four-stage, HEPA filter plenum at Rocky Flats in 1980 caused the first three stages of HEPA filters to blow out of their housing and the fourth stage to severely bow. Details of this recently declassified fire are presented in this paper. Although these previous findings suggest serious potential problems exist with the current water spray system in filter plenum , additional studies are required to confirm unequivocally that DOE's critical facilities are at risk

  2. Thermal treatment for radioactive HEPA filter media generated from nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, In Ho; Choi, Wang Kyu; Lee, Suk Chol; Min, Byung Youn; Yang, Hee Chul; Lee, Kun Woo; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    Many radioactive HEPA filter wastes are generated from the high radioactive facilities in operation, improvement and repair, and under decommissioning. Spent filter wastes of about 1,500 drums have been stored in the waste storage facility of the Korea Atomic Energy Research Institute (KAERI) since its operation. In the future, a lot of HEPA filters in high radioactivity will be occurred from pyroprocessing which is treatment facility for used nuclear fuel. Therefore, the technology development for the radioactive HEPA filter treatment is necessary for effective management and safe disposal for HEPA filter wastes. The thermal treatment has been known as one of the most effective technologies for volume reduction and recycling of metallic radioactive wastes. In this study, the thermal treatment for radioactive HEPA filter media was conducted for the volume reduction. The volatility and leachability for heavy metals and radionuclides in radioactive HEPA filter media were analyzed to investigate the volatilization during thermal treatment and stability after thermal treatment for safe disposal, respectively. The knowledge gained from this study will aid in the development of thermal treatment for HEPA filter media

  3. Preliminary studies to determine the shelf life of HEPA filters

    International Nuclear Information System (INIS)

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blow-out. We recommend that DOE initiate a filter qualification program to prevent this occurrence

  4. Improved HEPA Filter Technology for Flexible and Rigid Containment Barriers

    Energy Technology Data Exchange (ETDEWEB)

    P. A. Pinson

    1998-07-01

    Safety and reliability in glovebox operations can be significantly improved and waste packaging efficiencies can be increased by inserting flexible, lightweight, high capacity HEPA filters into the walls of plastic sheet barriers. This HEPA filter/barrier technology can be adapted to a wide variety of applications: disposable waste bags, protective environmental barriers for electronic equipment, single or multiple use glovebag assemblies, flexible glovebox wall elements, and room partitions. These reliable and inexpensive filtered barriers have many uses in fields such as radioactive waste processing, HVAC filter changeout, vapor or grit blasting, asbestos cleanup, pharmaceutical, medical, biological, and electronic equipment containment. The applications can result in significant cost savings, improved operational reliability and safety, and total waste volume reduction. This technology was developed at the Argonne National Laboratory-West (ANL-W) in 1993 and has been used at ANL-W since then at the TRU Waste Characterization Chamber Gloveboxes. Another 1998 AGS Conference paper titled "TRU Waste Characterization Gloveboxes", presented by Mr. David Duncan of ANL-W, describes these boxes.

  5. Multiple HEPA filter test methods, January--December 1976

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, B.; Kyle, T.; Osetek, D.

    1977-06-01

    The testing of tandem high-efficiency particulate air (HEPA) filter systems is of prime importance for the measurement of accurate overall system protection factors. A procedure, based on the use of an intra-cavity laser particle spectrometer, has been developed for measuring protection factors in the 10/sup 8/ range. A laboratory scale model of a filter system was constructed and initially tested to determine individual HEPA filter characteristics with regard to size and state (liquid or solid) of several test aerosols. Based on these laboratory measurements, in-situ testing has been successfully conducted on a number of single and tandem filter installations within the Los Alamos Scientific Laboratory as well as on extraordinary large single systems at Rocky Flats. For the purpose of recovery and for simplified solid waste disposal, or prefiltering purposes, two versions of an inhomogeneous electric field air cleaner have been devised and are undergoing testing. Initial experience with one of the systems, which relies on an electrostatic spraying phenomenon, indicates performance efficiency of greater than 99.9% for flow velocities commonly used in air cleaning systems. Among the effluents associated with nuclear fuel reprocessing is /sup 129/I. An intra-cavity laser detection system is under development which shows promise of being able to detect mixing ratios of one part in 10/sup 7/, I/sub 2/ in air.

  6. Comparison of HEPA filter test methods in corrosive environments

    International Nuclear Information System (INIS)

    The in-plant testing of process off-gas high efficiency particular air (HEPA) filters is an important quality control activity of the ALARA (As Low As Reasonably Achievable) policy at nuclear facilities. Imprecise and irreproducible data were recorded during DOP testing at the Atmospheric Protection System (APS) of the Idaho Chemical Processing Plant (ICPP). The tests at the APS are performed in an environment that has high humidity, high temperatures and has NO/sub x/ present. An evaluation of three HEPA filter test methods in corrosive environments was conducted: the dioctyl phthalate (DOP) method (US Standard Method ANSI N-101.1-1979) the sodium chloride method (British Standard 3928:1969), and the soda-fluorescein or uranine method (French Standard AFNOR STD NFX 44-011). The effects of high humidity, temperature, and oxides of nitrogen (NO/sub x/) on each method was examined. The effects of each variable and any interaction between variables on the test methods were examined. Recommendations for changes in the standard methods to reduce erratic on-line results are presented

  7. Preliminary studies to determine the shelf life of HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, H.; Fretthold, J.K.; Rainer, F. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blow-out. We recommend that DOE initiate a filter qualification program to prevent this occurrence.

  8. Survey of life-cycle costs of glass-paper HEPA filters

    International Nuclear Information System (INIS)

    We have conducted a survey of the major users of glass-paper HEPA filters in the DOE complex to ascertain the life cycle costs of these filters. Purchase price of the filters is only a minor portion of the costs; the major expenditures are incurred during the removal and disposal of contaminated filters. Through personal interviews, site visits and completion of questionnaires, we have determined the costs associated with the use of HEPA filters in the DOE complex. The total approximate life-cycle cost for a standard (2 in. x 2 in. x 1 in.) glass-paper HEPA filter is $3,000 for one considered low-level waste (LLW), $11,780 for transuranic (TRU) and $15,000 for high-level waste (HLW). The weighted-average cost for a standard HEPA filter in the complex is $4,753

  9. Criteria for calculating the efficiency of HEPA filters during and after design basis accidents

    International Nuclear Information System (INIS)

    We have reviewed the literature on the performance of high efficiency particulate air (HEPA) filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be structurally damaged and have a residual efficiency of 0%. Despite the many studies on HEPA filter performance under adverse conditions, there are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen when there was insufficient data

  10. Scoping decision document for HEPA filter differential pressure interlock control installation and tank farm exhauster operation

    Energy Technology Data Exchange (ETDEWEB)

    GUSTAVSON, R.D.

    2001-06-27

    This document is a decision document regarding the scope of HEPA filter differential pressure interlock system installations at Tank Farm emission units. It is intended to provide supporting information for administration of Baseline Change Request.

  11. Particle Removal Efficiency of the Portable HEPA Air Cleaner in a Simulated Hospital Ward

    DEFF Research Database (Denmark)

    Qian, Hua; Li, Yuguo; Sun, Hequan; Nielsen, Peter V.; Huang, Xinghua; Zheng, Xiaohong

    2010-01-01

    Use of a HEPA (high efficiency particulate air) filter in a room is believed to assist in reducing the risk of transmission of infectious diseases through removing the particles or large droplets to which pathogens may be attached. Use of a portable HEPA filter(s) in hospital wards is hypothesized...... to increase the effective ventilation rate (for particles only). Use of a portable HEPA filter is also hypothesized to increase the effective airflow rate of the general ward to the standard of an isolation ward for emerging infection diseases. This may be a good solution for housing patients when...... the number of beds in an isolation ward is insufficient. An experiment was conducted in a full scale experimental ward with a dimension of 6.7 m × 6 m × 2.7 m and 6 beds to test these hypotheses for a portable HEPA filter. The removal efficiency for different size particles was measured at different...

  12. 235U Holdup Measurements in the 321-M Cooling Hut HEPA Bank

    Energy Technology Data Exchange (ETDEWEB)

    Dewberry, R.A.

    2002-03-22

    This report covers holdup measurements of uranium residue in the cooling hut HEPA bank of the 321-M facility. This report discusses the methodology, non-destructive assay measurements, assumptions, and results of the uranium holdup in this item.

  13. Scoping decision document for HEPA filter differential pressure interlock control installation and tank farm exhauster operation

    International Nuclear Information System (INIS)

    This document is a decision document regarding the scope of HEPA filter differential pressure interlock system installations at Tank Farm emission units. It is intended to provide supporting information for administration of Baseline Change Request

  14. Evaluation of the Hepa Wash® treatment in pigs with acute liver failure

    OpenAIRE

    Al-Chalabi, Ahmed; Matevossian, Edouard; v. Thaden, Anne-K.; Luppa, Peter; Neiss, Albrecht; Schuster, Tibor; Yang, Zejian; Schreiber, Catherine; Schimmel, Patrick; Nairz, Ewald; Perren, Aurel; Radermacher, Peter; Huber, Wolfgang; Schmid, Roland M.; Kreymann, Bernhard

    2013-01-01

    Background Mortality of patients with acute liver failure (ALF) is still unacceptably high. Available liver support systems are still of limited success at improving survival. A new type of albumin dialysis, the Hepa Wash® system, was newly introduced. We evaluated the new liver support system as well as the Molecular Adsorbent Recycling System (MARS) in an ischemic porcine model of ALF. Methods In the first study animals were randomly allocated to control (n=5) and Hepa Wash (n=6) groups. In...

  15. Evaluation of the Hepa Wash® treatment in pigs with acute liver failure

    OpenAIRE

    Al-Chalabi, Ahmed; Matevossian, Edouard; v. Thaden, Anne-K.; Luppa, Peter; Neiss, Albrecht; Schuster, Tibor; Yang, Zejian; Schreiber, Catherine; Schimmel, Patrick; Nairz, Ewald; Radermacher, Peter; Huber, Wolfgang; Schmid, Roland M.; Kreymann, Bernhard; Perren, Aurel

    2013-01-01

    BACKGROUND Mortality of patients with acute liver failure (ALF) is still unacceptably high. Available liver support systems are still of limited success at improving survival. A new type of albumin dialysis, the Hepa Wash® system, was newly introduced. We evaluated the new liver support system as well as the Molecular Adsorbent Recycling System (MARS) in an ischemic porcine model of ALF. METHODS In the first study animals were randomly allocated to control (n=5) and Hepa Wash (n=6...

  16. Sampling Procedure for a Radionuclide Assessment of a Spent HEPA Filter Waste

    International Nuclear Information System (INIS)

    According to the operation of nuclear facilities and a continuous construction of them, a great amount of used high efficiency particulate air (HEPA) filters which are widely used in a ventilation system in the nuclear industry has been generated as spent filter waste. All these HEPA filter wastes generated at KAERI have been stored in accordance with the original form without any treatment of them. However, to secure space in a waste storage facility approaching saturation, it is desirable to treat them by a compaction in view of a radioactive waste treatment and storage, and finally, to repack the compacted spent filters into a 200 liter drum for sending them to a disposal site. In order to dispose of the HEPA filters, it is first necessary to conduct a radionuclide assessment of them before compacting them. However, it is difficult to directly measure a radioactive concentration level of the nuclides captured in a HEPA filter because of its great bulk and specific shape. Therefore, after taking a representative sample from a HEPA filter, the analysis results for it are regarded as a representative value for the corresponding HEPA filter. To use this method, it is essential to confirm the validity of the sampling procedure and representative value. In this study, the depth distribution of the captured nuclides in a HEPA filter waste was first investigated. From the results, it was possible to obtain a representative sample from the intake part and the outlet part of a HEPA filter without a dismantlement. And then, a punch device with a diameter of 2 inch was developed for taking a representative sample which has a regular size

  17. Results from nondestructive assay measurement of the 296-P-34 Rotary mode core sampler HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    HOMAN, N.A.

    1999-06-04

    The objective of this data acquisition was to measure and identify the gamma emissions from the 296-P-34 exhauster high-efficiency particulate air (HEPA) filters. Data acquisition was accomplished by nondestructive assay (NDA), using a portable gamma spectrometer calibrated to the exhauster HEPA filter geometry. The NDA technique that was used is referenced in 40 CFR 61 Appendix B Method 114 and also addressed in HNF-EP-0528.

  18. Safety evaluation for packaging (onsite) for the Pacific Northwest National Laboratory HEPA filter box

    Energy Technology Data Exchange (ETDEWEB)

    McCoy, J.C.

    1998-07-15

    This safety evaluation for packaging (SEP) evaluates and documents the safe onsite transport of eight high-efficiency particulate air (HEPA) filters in the Pacific Northwest National Laboratory HEPA Filter Box from the 300 Area of the Hanford Site to the Central Waste Complex and on to burial in the 200 West Area. Use of this SEP is authorized for 1 year from the date of release.

  19. Sampling Procedure for a Radionuclide Assessment of a Spent HEPA Filter Waste

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Young-Yong; Hong, Dae-Seok; Kang, Il-Sik; Kim, Tae-Kuk; Lee, Young-Hee; Shon, Jong-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2007-10-15

    According to the operation of nuclear facilities and a continuous construction of them, a great amount of used high efficiency particulate air (HEPA) filters which are widely used in a ventilation system in the nuclear industry has been generated as spent filter waste. All these HEPA filter wastes generated at KAERI have been stored in accordance with the original form without any treatment of them. However, to secure space in a waste storage facility approaching saturation, it is desirable to treat them by a compaction in view of a radioactive waste treatment and storage, and finally, to repack the compacted spent filters into a 200 liter drum for sending them to a disposal site. In order to dispose of the HEPA filters, it is first necessary to conduct a radionuclide assessment of them before compacting them. However, it is difficult to directly measure a radioactive concentration level of the nuclides captured in a HEPA filter because of its great bulk and specific shape. Therefore, after taking a representative sample from a HEPA filter, the analysis results for it are regarded as a representative value for the corresponding HEPA filter. To use this method, it is essential to confirm the validity of the sampling procedure and representative value. In this study, the depth distribution of the captured nuclides in a HEPA filter waste was first investigated. From the results, it was possible to obtain a representative sample from the intake part and the outlet part of a HEPA filter without a dismantlement. And then, a punch device with a diameter of 2 inch was developed for taking a representative sample which has a regular size.

  20. Safety evaluation for packaging (onsite) for the Pacific Northwest National Laboratory HEPA filter box

    International Nuclear Information System (INIS)

    This safety evaluation for packaging (SEP) evaluates and documents the safe onsite transport of eight high-efficiency particulate air (HEPA) filters in the Pacific Northwest National Laboratory HEPA Filter Box from the 300 Area of the Hanford Site to the Central Waste Complex and on to burial in the 200 West Area. Use of this SEP is authorized for 1 year from the date of release

  1. In-place HEPA filter testing summary (1993)

    International Nuclear Information System (INIS)

    This report is the latest in a series of annual reports regarding the in-place testing program for highly efficient filtration systems at Los Alamos National Laboratory. This testing is conducted to maintain regulatory permits and verify the performance levels of these filtration systems have not deteriorated over the last operating cycle. In-place testing is also conducted on systems when maintenance and/or repair to the filtration system have been performed to verify that the system components have been installed correctly and there has been no damage to the filter media. Performance testing of negative air pressure machines and HEPA filtered vacuums has been included as part of the decontamination and decommissioning activities and the asbestos management program at Los Alamos National Laboratory. This report provides a brief overview of the testing procedures used to conduct in-place tests, a summary of individual system performance, and trends observed since the previous year

  2. Method for HEPA filter leak scanning with differentiating aerosol detector

    Energy Technology Data Exchange (ETDEWEB)

    Kovach, B.J.; Banks, E.M.; Wikoff, W.O. [NUCON International, Inc., Columbus, OH (United States)

    1997-08-01

    While scanning HEPA filters for leaks with {open_quotes}Off the Shelf{close_quote} aerosol detection equipment, the operator`s scanning speed is limited by the time constant and threshold sensitivity of the detector. This is based on detection of the aerosol density, where the maximum signal is achieved when the scanning probe resides over the pinhole longer than several detector time-constants. Since the differential value of the changing signal can be determined by observing only the first small fraction of the rising signal, using a differentiating amplifier will speed up the locating process. The other advantage of differentiation is that slow signal drift or zero offset will not interfere with the process of locating the leak, since they are not detected. A scanning hand-probe attachable to any NUCON{reg_sign} Aerosol Detector displaying the combination of both aerosol density and differentiated signal was designed. 3 refs., 1 fig.

  3. Investigation and deactivation of B Plant HEPA filters

    International Nuclear Information System (INIS)

    This paper describes the integrated approach used to manage environmental, safety, and health considerations related to the B Plant canyon exhaust air filters at the US Department of Energy (DOE) Hanford Site. The narrative illustrates the development and implementation of integrated safety management as applied to a facility and its systems undergoing deactivation. During their lifetime, the high efficiency particulate air (HEPA) filters prevented the release of significant quantities of radioactive materials into the air. As the material in B Plant AVESF accumulated on the filters, it created an unusual situation. Over long periods of time, the radiation dose from the filter loading, combined with aging and chemical exposure actually degrade those filters which were intended to protect against any release to the environment

  4. Behavior of HEPA filter systems under accident conditions

    International Nuclear Information System (INIS)

    With respect to the behavior of HEPA filters under high humidity conditions, emphasis was placed on the study of the differential pressure increase. Under fog conditions, the differential pressure of dust loaded filters increased within minutes, up to values sufficient to damage normal commercial filters units. The investigation into the failure mechanisms was completed with the development of an equation to calculate filter medium tensile stresses for two of the three most important modes of failure. Initial work was begun toward the development of a computer code to model transient fluiddynamic and thermodynamic conditions in complex air cleaning systems. Further investigation into the transmission of weak shock waves in air-cleaning system ductwork were carried out in branches of ducts with square cross-sections and with variable cross-sections. (orig./DG)

  5. In-service ageing effects on HEPA filters

    International Nuclear Information System (INIS)

    HEPA filters with in-plant lives of up to ten years have been obtained from both nuclear and non-nuclear facilities within the United Kingdom and have been examined in detail to identify whether in-service deterioration has taken place. Filters with radioactive contamination levels of up to 100 μCi α and 1 mCi βγ have been care-fully disassembled and the casing, spacers, gaskets, and seals examined. Paper samples from each disassembled filter have been subjected to an extensive range of tests including tensile strength, flexibility, particle penetration, burst strength and water repellency measurements. The results of this work indicate reductions in paper strength properties and serious corrosion of aluminium spacers leading to their adhesion to the filter paper. (author)

  6. Method for HEPA filter leak scanning with differentiating aerosol detector

    International Nuclear Information System (INIS)

    While scanning HEPA filters for leaks with open-quotes Off the Shelf close-quote aerosol detection equipment, the operator's scanning speed is limited by the time constant and threshold sensitivity of the detector. This is based on detection of the aerosol density, where the maximum signal is achieved when the scanning probe resides over the pinhole longer than several detector time-constants. Since the differential value of the changing signal can be determined by observing only the first small fraction of the rising signal, using a differentiating amplifier will speed up the locating process. The other advantage of differentiation is that slow signal drift or zero offset will not interfere with the process of locating the leak, since they are not detected. A scanning hand-probe attachable to any NUCON reg-sign Aerosol Detector displaying the combination of both aerosol density and differentiated signal was designed. 3 refs., 1 fig

  7. Flow resistance of HEPA filters in supersaturated airstreams

    International Nuclear Information System (INIS)

    A loss of coolant accident or fire suppression with water sprays would release free moisture into the air within the containment building of a nuclear reactor. The resulting high air humidity could be expected to unfavorably affect the behavior of the HEPA filters in the facility air cleaning systems. Still to be found in the literature are instances of moisture related deterioration in filter performance during less serious incidents, and even during normal operations. One phenomenon which contributes to filter failure, and which also causes air-cleaning system malfunction characterized by drastically reduced flow rates, is the increase in filter differential pressure resulting from supersaturated airflow. In order to better evaluate the performance and the reliability of filters exposed to fog, a study of the factors which influence filter pressure drop was carried out in tests of clean and dust loaded full scale HEPA-filter units. Investigated were the effects of several airstream parameters and such filter characteristics as manufacturer, design, pack geometry, extent and type of dust loading, as well as pleat orientation to the airflow. A discontinuous gravimetric method employing full-size filter units as sampling filters was successfully implemented to determine the average liquid moisture content of the airstream with an uncertainty of ≤10%. The dust loading in filters removed from service and the liquid moisture content of the air proved to most adversely affect the rate and extent of the pressure drop increase. Reductions in the susceptibility of clean filters to pressure drop increases can be obtained by changes in filter geometry, design or orientation to the airflow that enhance the drainage of water from the filter medium. However, the predominance of the adverse influence of dust loading appears to be able to counteract the effectiveness of the improvements studied

  8. Radioactive analysis of a spent HEPA filter using the distribution characteristics of the captured radionuclide

    International Nuclear Information System (INIS)

    To investigate the species and the distribution of the captured nuclides in a HEPA filter, it was dismantled into a metal part and a filter medium part to obtain a filter medium. From the nuclide analysis results for a filter medium part through pre-treatment of it, it was possible to obtain three kinds of typical distributions in view of the distribution of the captured nuclides in the filter medium. When considering these distribution characteristics of the captured radionuclide, the region showing the high concentration of the captured nuclides was the intake or the outlet part of the HEPA filter. On the other side, the middle part generally represented a uniform distribution below the average concentration of the captured nuclides. Therefore, in the event of taking a representative sample of a HEPA filter at the intake and the outlet part, the results of a nuclide analysis for that sample could be estimated as existing in the range from 1.0 to 1.5 times the real concentration of the nuclides captured by a filter medium. As a result, to conduct a radionuclide assessment of a spent HEPA filter without a dismantlement of it, the analysis results for a representative sample taken from both the intake and the outlet part of a spent HEPA filter could be regarded as an average value for the corresponding HEPA filter. (author)

  9. Evaluation of glass fiber Hepa filters as a function of media velocity

    International Nuclear Information System (INIS)

    Section FC of the ASME AG-1 Code addresses glass fiber HEPA filters and restricts the media velocity to a maximum of 5 ft./min. Advances in filter media technology allow glass fiber HEPA filters to function at significantly higher velocities and still achieve HEPA performance. Ultrafine particles (< 100 nm) are removed by a diffusive capture mechanism. The removal efficiency of these particles is reduced at higher media velocities due to shorter residence times within the media matrix. Therefore, it is unlikely that higher media velocities for HEPA filters will be allowed without data to demonstrate the effect of media velocity on removal of particles in the smaller size classes. Additional questions remain regarding particle loading and filter lifetimes at higher media velocities. In order to address these issues, nuclear grade AG-1 HEPA filters obtained from two manufacturers have been evaluated at media velocities ranging from 4 to 8.8 ft./min. KCl was utilized as aerosol challenge material and data regarding filter lifetimes, loading characteristics, changes in filtering efficiency and the most penetrating particle size are presented. Results of this testing will be provided to the ASME AG-1 FC Committee for consideration in future versions of the HEPA standard and will be useful for the development of air filtration systems in a nuclear environment. (authors)

  10. Induction of cytochrome P-450 1A2 by oxidized tryptophan in Hepa lclc7 cells.

    Science.gov (United States)

    Sindhu, R K; Mitsuhashi, M; Kikkawa, Y

    2000-03-01

    Recent studies from this laboratory have demonstrated that L-tryptophan, after oxidation either by UV-irradiation or ozone, induces aryl hydrocarbon receptor (AhR) activation and binding of the liganded AhR complex to its specific DNA recognition site, thereby initiating transcription of the cytochrome P-450 1a1 (Cyp1a1) gene with concomitant increase of CYP1A1 protein and 7-ethoxyresorufin O-deethylase activity in wild-type mouse hepatoma cells, Hepa lclc7 (Hepa-1), in culture. Temporary inhibition of protein synthesis by cycloheximide resulted in superinduction of oxidized tryptophan-inducible CYP1A1 mRNA, protein, and 7-ethoxyresorufin O-deethylase activity in Hepa-1 cells. In the present communication, the results obtained by immunoblot analyses with monoclonal CYP1A1/1A2 antibody (NIH 1-7-1) demonstrate that both UV- or ozone-oxidized tryptophan also induce CYP1A2 protein in Hepa-1 cells. CYP1A2 mRNA, detected by reverse transcription-polymerase chain reaction, was markedly induced in the UV- or ozone-oxidized tryptophan-treated cells. Temporary inhibition of protein synthesis by cycloheximide further induced oxidized tryptophan-inducible CYP1A2 mRNA as well as the protein in Hepa-1 cells. This is the first report demonstrating the induction of CYP1A2 mRNA and protein in Hepa-1 cells. PMID:10688617

  11. Extension of the maintenance cycle of HEPA filters by optimization of the technical characteristics of filters and their construction

    International Nuclear Information System (INIS)

    The knowledge of the parameters of HEPA filters used at present in nuclear plants allows optimization of such filters with respect to flow rate, pressure drop and service life. The application of optimizing new types of HEPA filters of improved performance is reported. The calculated results were checked experimentally. The use of HEPA filters optimized with respect to dust capacity and service life, and the effects of this new type of filter on the reduction of operating and maintenance costs are discussed

  12. The Treatment Procedure for a Volume Reduction of the Spent HEPA Filters in KAERI

    International Nuclear Information System (INIS)

    Spent filter wastes of about 2,200 units have been stored in the radioactive waste storage facility of the Korea Atomic Energy Research Institute since its operation. Among these spent filter wastes, a HEPA filter account for about 95 %. All these HEPA filter wastes generated at KAERI have been stored inside a poly bag in accordance with the original form without any treatment of them. Therefore, in order to secure a space in a radioactive waste storage facility approaching its saturation, it is necessary to treat them by a compaction in view of a radioactive waste treatment and storage, and finally to repack the compacted spent filters into a regular drum for sending them to a final disposal site. To do that, the spent HEPA filter wastes were classified according to their generation facility, their generation date and their surface dose rate by investigating the inventory of them. And also, a nuclide assessment of them was conducted by taking a representative sample at the spot of a high dose rate at the intake surface and the outlet surface of a spent HEPA filter without a dismantlement, before compacting them. At present, for the spent HEPA filter wastes after a radionuclide assessment, a compaction treatment of them is now being conducted by using the shaping and compacting equipment developed at KAERI. Thus, to put a HEPA filter with a hexahedral form of a 610(W) x 610(H) x 305(T) mm into a regular drum (DOT-17H) with an inner diameter of about 572 mm, a columnar shaping with a capacity of 15 tons was conducted. From this shaping, a shaped HEPA filter waste with a diameter of about 500 mm was directly put into a regular drum. And then, the compaction treatment of a shaped HEPA filter with a capacity of about 60 tons was conducted by vertically compacting it. As a result, a volume reduction rate of a spent HEPA filter waste by a shaping and compacting of it accounted for about 1/8 when compared to its original form. (authors)

  13. Filter Paper: Solution to High Self-Attenuation Corrections in HEPA Filter Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Oberer, R.B.; Harold, N.B.; Gunn, C.A.; Brummett, M.; Chaing, L.G.

    2005-10-01

    An 8 by 8 by 6 inch High Efficiency Particulate Air (HEPA) filter was measured as part of a uranium holdup survey in June of 2005 as it has been routinely measured every two months since 1998. Although the survey relies on gross gamma count measurements, this was one of a few measurements that had been converted to a quantitative measurement in 1998. The measurement was analyzed using the traditional Generalized Geometry Holdup (GGH) approach, using HMS3 software, with an area calibration and self-attenuation corrected with an empirical correction factor of 1.06. A result of 172 grams of {sup 235}U was reported. The actual quantity of {sup 235}U in the filter was approximately 1700g. Because of this unusually large discrepancy, the measurement of HEPA filters will be discussed. Various techniques for measuring HEPA filters will be described using the measurement of a 24 by 24 by 12 inch HEPA filter as an example. A new method to correct for self attenuation will be proposed for this measurement Following the discussion of the 24 by 24 by 12 inch HEPA filter, the measurement of the 8 by 8 by 6 inch will be discussed in detail.

  14. Survey of life-cycle costs of glass-paper HEPA filters

    International Nuclear Information System (INIS)

    The authors have conducted a survey of the major users of glass-paper HEPA filters in the DOE complex to ascertain the life cycle costs of these filters. Purchase price of the filters is only a minor portion of the costs; the major expenditures are incurred during the removal and disposal of contaminated filters. Through a combination of personal interviews, site visits and completion of questionnaires, the costs associated with the use of HEPA filters in the DOE complex have been determined. The total approximate life-cycle cost of glass-paper HEPA filter is $3,000 for one considered low-level waste (LLW), $11,780 for transuranic (TRU) and $15,000 for high-level waste (HLW). The weighted-average cost for a standard HEPA filter in the complex is $4,753. Although the cost estimate represents an average for all sizes and types of HEPA filters used in DOE facilities, the majority of the filters are 2x2x1 filters with wooden frames, deep pleated glass-fiber media, and an adhesive sealant. 6 refs., 5 tabs

  15. Filter Paper: Solution to High Self-Attenuation Corrections in HEPA Filter Measurements

    International Nuclear Information System (INIS)

    An 8 by 8 by 6 inch High Efficiency Particulate Air (HEPA) filter was measured as part of a uranium holdup survey in June of 2005 as it has been routinely measured every two months since 1998. Although the survey relies on gross gamma count measurements, this was one of a few measurements that had been converted to a quantitative measurement in 1998. The measurement was analyzed using the traditional Generalized Geometry Holdup (GGH) approach, using HMS3 software, with an area calibration and self-attenuation corrected with an empirical correction factor of 1.06. A result of 172 grams of 235U was reported. The actual quantity of 235U in the filter was approximately 1700g. Because of this unusually large discrepancy, the measurement of HEPA filters will be discussed. Various techniques for measuring HEPA filters will be described using the measurement of a 24 by 24 by 12 inch HEPA filter as an example. A new method to correct for self attenuation will be proposed for this measurement Following the discussion of the 24 by 24 by 12 inch HEPA filter, the measurement of the 8 by 8 by 6 inch will be discussed in detail

  16. Performance limitations of HEPA filters at high temperatures

    International Nuclear Information System (INIS)

    Over the last few years a number of studies have investigated the performance of High Efficiency Particulate Air (HEPA) filters under simulated accident conditions modelling a fire or high temperature airflow. Earlier studies have concentrated on evaluating the insert performance when subjected to hot airflows at 500 degree C through the clean filter. This temperature was selected on the basis of a static oven test for flammability required by the purchasing specification. At these temperatures, the work showed that the filters could fail catastrophically. Calculations have shown that the temperature seen by main filter banks, distant from the source of a fire, would be of the order of 250 degree C. The work has now extended to an investigation of the performance of loaded, as opposed to clean filters at temperatures up to 275 degree C thereby attempting to produce a more representative model of the real fire/accident condition. The work reported here has considered three filter designs and records their performance at temperatures of up to 275 degree C for periods of up to 24 hours. The filters all have an initial pressure differential of 750 Pa produced by loading with a test dust

  17. Characterizing radionuclides in the B Plant HEPA filters

    International Nuclear Information System (INIS)

    B Plant was built during World War II to separate plutonium for nuclear weapons from reactor fuel. Later, the plant was re-equipped and used to separate radioactive fission products from the Hanford Site's nuclear processing waste tanks. The facility is now being deactivated: eliminating, stabilizing, and documenting existing hazards to allow safe surveillance and maintenance pending a final disposition which is yet to be determined. The processing areas of the plant, including process cells and exhaust air system, are heavily contaminated with radioactive cesium and strontium from the tank waste separation process. However, detailed characterization is difficult because many of these areas are inaccessible because of physical barriers and high radiological dose rates. The five existing canyon high efficiency particulate air (HEPA) filters were thought to contain a significant fraction of the inventory, but estimates were highly uncertain. This paper describes the process used to inspect and characterize the radionuclide content in one of these filters. The investigation required a collaborative effort among field and technical personnel. Sophisticated computer modeling and detector technologies were employed in conjunction with sound radiological control and field work practices. The outcome of the effort was a considerable reduction in the filter inventory estimate, accompanied by a greatly improved level of confidence in the data. The information derived from this project will provide a sound basis for future decisions regarding filter disposition

  18. Effects of high relative humidities on HEPA filter media

    International Nuclear Information System (INIS)

    The effects of high relative humidities and water on HEPA glass fiber filter media used in off-gas and emergency systems in Swedish nuclear power stations have been investigated. The experiments also comprised exposure to pure steam for some hours at elevated temperature. After exposure samples of filter media were dried and tested with respect to particle penetration and tensile strength. The penetration measurements were carried out with DOP aerosols. The results showed a tendency to increased penetration when exposed to high humidities at elevated temperature. The tensile strength of the filter material decreased to about 40% of its original value after being exposed to flowing steam for 4-5 hours. As expected the media lost their tensile strength in flowing steam (1000C) the strength decreased almost to zero. Exposure for a few hours to approximately 100% humidified airstream at ambient temperatures did not cause any significant changes in the particle retention ability. The strength was also uneffected by high humidities at ambient temperatures. No damage to the fibers could be seen on examination in a scanning electronic microscope

  19. The Application of Plastic Fibre HEPA Filters to the Treatment of Airborne Radioactive Wastes

    International Nuclear Information System (INIS)

    HEPA filters used to separate airborne radioactive wastes must not be inflammable. This particular safety requirement is met with almost ideally by HEPA filters made of glassfibre. Plastic-fibre filters are inflammable, and therefore they appear to be unsuitable for the purpose from a safety standpoint. While glass-fibre filters are rather bulky when disposed of, plastic-fibre filters can be reduced to tiny lumps by the use of suitable solvents. Filter frame and filter layer are moulded together using identical plastic material. The use of solvents and the application of subsequent evaporation techniques will reduce the bulk of the radioactive waste to a minimum. The plastic-fibre filter layer also offers a method of recovering valuable radioactive components. Safety requirements, however, make it compulsory to combine plastic-fibre filters with glass-fibre filters of the HEPA type. Several applications will be demonstrated and the results discussed. (author)

  20. HEPA Filter Differential Pressure Fan Interlock System Functional Requirements and Technical Design Criteria

    International Nuclear Information System (INIS)

    Double-shell tanks (DSTs) and Double Contained Receiver Tanks (DCRTs) are actively ventilated, along with certain single-shell tanks (SSTs) and other RPP facilities. The exhaust air stream on a typical primary ventilation system is drawn through two stages of high-efficiency particulate air (HEPA) filtration to ensure confinement of airborne radioactive materials. Active ventilation exhaust stacks require a stack CAM interlock to detect releases from postulated accidents, and to shut down the exhaust fan when high radiation levels are detected in the stack airstream. The stack CAM interlock is credited as a mitigating control to stop continued unfiltered radiological and toxicological discharges from the stack, which may result from an accident involving failure of a HEPA filter. This document defines the initial technical design baseline for a HEPA filter AP fan interlock system

  1. HEPA filters of high structural strength for nuclear air cleaning systems

    International Nuclear Information System (INIS)

    HEPA-filter media, though having excellent particle-removal efficiencies, remain characterized as rather brittle, fragile, and weak materials. As a result, undesired structural damage, followed by significant losses in filtration efficiency, can easily occur in handling, transport, and even normal operation of filter units. In recent years, extensive investigations into the structural limits of HEPA filters in dry air and under extended exposure to high-humidity airflow have been carried out. In the course of this work, the failure modes and the underlying failure mechanisms were thoroughly studied. On the basis of the information obtained, considerable improvements in the structural strength of HEPA filters could be achieved. As verified by removal efficiency tests, differential pressures up to 56 kPA in dry air and 15 kPA after extended operation under fog conditions were proved to be sustainable without mechanical damage to the filter medium

  2. HEPA Filter Differential Pressure Fan Interlock System Functional Requirements and Technical Design Criteria

    Energy Technology Data Exchange (ETDEWEB)

    TUCK, J.A.

    2000-05-11

    Double-shell tanks (DSTs) and Double Contained Receiver Tanks (DCRTs) are actively ventilated, along with certain single-shell tanks (SSTs) and other RPP facilities. The exhaust air stream on a typical primary ventilation system is drawn through two stages of high-efficiency particulate air (HEPA) filtration to ensure confinement of airborne radioactive materials. Active ventilation exhaust stacks require a stack CAM interlock to detect releases from postulated accidents, and to shut down the exhaust fan when high radiation levels are detected in the stack airstream. The stack CAM interlock is credited as a mitigating control to stop continued unfiltered radiological and toxicological discharges from the stack, which may result from an accident involving failure of a HEPA filter. This document defines the initial technical design baseline for a HEPA filter AP fan interlock system.

  3. Summary of meeting on disposal of LET ampersand D HEPA filters

    International Nuclear Information System (INIS)

    This report is a compilation of correspondence between Westinghouse Idaho Nuclear Company and the US EPA over a period of time from 1988 to 1992 (most from 1991-92) regarding waste management compliance with EPA regulations. Typical subjects include: compliance with satellite accumulation requirements; usage of ''Sure Shot'' containers in place of aerosol cans; notice of upcoming recyclable battery shipments; disposition of batteries; HEPA filter leach sampling and permit impacts; functional and operation requirements for the spent filter handling system; summary of meeting on disposal of LET and D HEPA filters; solvent substitution database report; and mercury vapor light analytical testing

  4. Summary of meeting on disposal of LET&D HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    1991-11-21

    This report is a compilation of correspondence between Westinghouse Idaho Nuclear Company and the US EPA over a period of time from 1988 to 1992 (most from 1991-92) regarding waste management compliance with EPA regulations. Typical subjects include: compliance with satellite accumulation requirements; usage of ``Sure Shot`` containers in place of aerosol cans; notice of upcoming recyclable battery shipments; disposition of batteries; HEPA filter leach sampling and permit impacts; functional and operation requirements for the spent filter handling system; summary of meeting on disposal of LET and D HEPA filters; solvent substitution database report; and mercury vapor light analytical testing.

  5. Exposure Assessment of Four Pharmaceutical Powders Based on Dustiness and Evaluation of Damaged HEPA Filters

    DEFF Research Database (Denmark)

    Levin, Marcus; Koponen, Ismo K.; Jensen, Keld A.

    2014-01-01

    , if the active ingredients were associated with high hazard or unique product purity is required. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: An example...... of a typical particle number time-series of a complete dustiness test. It provides information on the HEPA-filter used including a scanning electron microscopy image of it. It also provides APS-measurements of particles penetrating the damaged HEPA-filter.]...

  6. The development of non-separation HEPA filter in nuclear field

    International Nuclear Information System (INIS)

    At present, to lower the operation cost of cleaning equipment and to reduce the solid waste amount are urgent tasks for the air cleaning system in nuclear facilities. In order to meet this demand a new type air cleaning equipment, non-separation HEPA filter (high efficiency particulate air filter), has been developed. The peculiarity of this non-separation HEPA filter, the developed status in China and abroad as well as some key issues are systematically summarized in the article. (1 ref., 5 figs., 7 tabs.)

  7. Development of the two cylinder operated radioactive HEPA filter waste compactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K. M.; Lee, Y. H.; Kim, T. K.; Ahn, S. J.; Hong, K. P. [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    The shape and size of HEPA filter waste (Hexahedron, 610 mm x 610 mm x 292 mm) is unsuitable to pack in the cylindrical package, DOT17H({phi}606 mm x 884 mm) which is used as the standard package for the radioactive wastes in the country and abroad commonly. We developed the two cylinder operated compactor for changing the shape and size of the HEPA filter waste into the cylindrical shape of {phi}500 mm x 300 mm in oder to pack in the standard package of DOT17H Drum.

  8. Development of the two cylinder operated radioactive HEPA filter waste compactor

    International Nuclear Information System (INIS)

    The shape and size of HEPA filter waste (Hexahedron, 610 mm x 610 mm x 292 mm) is unsuitable to pack in the cylindrical package, DOT17H(φ606 mm x 884 mm) which is used as the standard package for the radioactive wastes in the country and abroad commonly. We developed the two cylinder operated compactor for changing the shape and size of the HEPA filter waste into the cylindrical shape of φ500 mm x 300 mm in oder to pack in the standard package of DOT17H Drum

  9. Alpha activity estimation in used HEPA filters of glove box ventilation system

    International Nuclear Information System (INIS)

    At Radiochemistry facility, various radio-chemical operations are carried out on isotopes of Plutonium and trans-plutonics under containment and safe operational conditions. The ventilation system is designed with separate headers for laboratory and glove box exhausts. The ventilation provided to the labs act as dynamic containment is a Once - through system with the ventilation inlet as processed air and exhausted through stack after filtration through HEPA filter banks. These activity saturated/used HEPA filters are changed periodically. This paper describes the assessment of buildup α activity in the used filter. (author)

  10. CAF-30H1 air cleaner with inverter motor and HEPA filter; `Inverter and HEPA` kuki seijoki CAF-30H1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    An air cleaner series CAF-30H1, equipped with an inverter motor and HEPA filter, has been developed. It has the following major feature: long-life HEPA filter, a special, highly functional filter having a dust-collection efficiency of 99.97% or more for particles of 0.3 {mu}m or more in size; noise of 15.5 dB in the breeze mode, which is the lowest level in the industry; power consumption of 3.5 W in the breeze mode, which is the lowest level in the industry; automatic operational function with a W sensor system incorporating a `dust sensor` and `odor sensor;` and powerful deodorizing filter to adsorb odor of tobacco smoke, to begin with, and that caused by nitrogen oxides and formaldehyde. (translated by NEDO)

  11. CAF-30H1 air cleaner with inverter motor and HEPA filter. 'Inverter and HEPA' kuki seijoki CAF-30H1

    Energy Technology Data Exchange (ETDEWEB)

    1999-03-01

    An air cleaner series CAF-30H1, equipped with an inverter motor and HEPA filter, has been developed. It has the following major feature: long-life HEPA filter, a special, highly functional filter having a dust-collection efficiency of 99.97% or more for particles of 0.3 [mu]m or more in size; noise of 15.5 dB in the breeze mode, which is the lowest level in the industry; power consumption of 3.5 W in the breeze mode, which is the lowest level in the industry; automatic operational function with a W sensor system incorporating a 'dust sensor' and 'odor sensor;' and powerful deodorizing filter to adsorb odor of tobacco smoke, to begin with, and that caused by nitrogen oxides and formaldehyde. (translated by NEDO)

  12. Alternative strategies to reduce cost and waste volume in HEPA filtration using metallic filter media - 59348

    International Nuclear Information System (INIS)

    Document available in abstract form only. Full text of publication follows: The disposal costs of contaminated HEPA and THE filter elements have been proved to be disproportionately high compared with the cost of the elements themselves. Work published elsewhere (Moore, et el 1992; Bergman et al 1997) suggests that the cost of use of traditional, panel type, glass fibre HEPA filtration trains to the DOE was, during that period, $29.5 million, based on a five year life cycle, and including installation, testing, removal and disposal life cycle costs being based on estimates dating from 1987-1990. Within that cost estimate, $300 was the value given to the filter and $4, 450 was given to the peripheral activity. Clearly, if the $4, 450 component could be reduced, tremendous saving could ensue, in addition to the reduction of the legacy burden of waste volume. This issue exists for operators in both the US and in Europe. If HEPA filters could be cleaned to a condition where they could either be re-used or decontaminated to the extent that they could be stored as a lower cost wasteform or if HEPA/THE filter elements were available without any organic content likely to give rise to flammable or explosive decomposition gases during long term storage this would also reduce the costs and monitoring necessary in storage. (author)

  13. The HepaRG cell line is suitable for bioartificial liver application

    NARCIS (Netherlands)

    R. Hoekstra; G.A.A. Nibourg; T.V. van der Hoeven; M.T. Ackermans; T.B.M. Hakvoort; T.M. van Gulik; W.H. Lamers; R.P. Oude Elferink; R.A.F.M. Chamuleau

    2011-01-01

    For bioartificial liver application, cells should meet the following minimal requirements: ammonia elimination, drug metabolism and blood protein synthesis. Here we explore the suitability of HepaRG cells, a human cell line reported to differentiate into hepatocyte clusters and surrounding biliary e

  14. Measurement of gamma activity from the PUREX stack, Number 296-A-10, HEPA filters

    International Nuclear Information System (INIS)

    In response to the Environmental Protection Agency's requirements for evaluating radioactive emissions from stacks, this test plan was developed. The test plan employs the use of low resolution (NaI) portable gamma spectrometry to identify and measure gamma emitting radionuclides from HEPA filters. The test description, expected results, and test set-up and steps are discussed

  15. New procedure for testing HEPA filters: a method omitting testing at 20% rated flow

    International Nuclear Information System (INIS)

    A theoretical analysis of HEPA penetration vs. pinholes in filter media is presented. A calculation formula which shows the tendency of such changes was derived and has been demonstrated experimentally. By this formula equivalent penetration was calculated. Nomograms were used to facilitate the work. As a result, testing needs to be performed only at rated flow

  16. Time dependency of HEPA filter performance during loading with liquid particles

    Energy Technology Data Exchange (ETDEWEB)

    Tsunoda, Masahiko; Kitano, Kyoshiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ikezawa, Yoshio

    1997-06-01

    The time dependency of filter performance across a high-efficiency particulate air (HEPA) filter was experimentally studied. The experimental study was carried out using a HEPA filter (203 x 203 x 150 mm) clogged with liquid particles (mosquito stick aerosol). The aerosol concentration for filter loading was 0.84 mg/m{sup 3} and the size distribution was similar to lognormal distribution (CMD=0.21 {mu}m, {sigma}=1.65). The mass loading was about 60 g/m{sup 2} when the pressure drop across the HEPA filter reached twice the initial pressure drop. The DOP particle penetrations through the HEPA filter were evaluated when relative pressure drops ({Delta}P/{Delta}P{sub 0}) were nearly 1.0, 1.3, 1.4, 1.6, 1.8 and 2.1. The most penetrating particle size (MPPS) was almost independent of the mass loading if the face velocity was constant. However, the DOP particle penetration increased remarkably with mass loading, and the tendency of increase was not affected by particle size or face velocity. (author)

  17. A Method for Cobalt and Cesium Leaching from Glass Fiber in HEPA Filter

    International Nuclear Information System (INIS)

    A great amount of radioactive waste has been generated during the operation of nuclear facilities. Recently, the storage space of a radioactive waste storage facility in the Korea Atomic Energy Research Institute (KAERI) was almost saturated with many radioactive wastes. So, the present is a point of time that a volume reduction of the wastes in a radioactive waste storage facility needs. There are spent HEPA filter wastes of about 2,226 sets in the radioactive waste storage facility in KAERI. All these spent filter wastes have been stored in accordance with their original form without any treatment. Up to now a compression treatment of these spent HEPA filters has been carried out to repack the compressed spent HEPA filters into a 200 liter drum for their volume reduction. Frame and separator are contaminated with a low concentration of nuclide, while the glass fiber is contaminated with a high concentration of nuclide. So, for the disposal of the glass filter to the environment, the glass fiber should be leached to lower its radioactive concentration first and then must be stabilized by solidification and so on. Therefore, it is necessary to develop a leaching process of glass fiber in a HEPA filter. Leaching is a separation technology, which is often used to remove a metal or a nuclide from a solid mixture with the help of a liquid solvent

  18. Potential for HEPA filter damage from water spray systems in filter plenums

    International Nuclear Information System (INIS)

    The water spray systems in high efficiency particulate air (HEPA) filter plenums that are used in nearly all Department of Energy (DOE) facilities for protection against fire was designed under the assumption that the HEPA filters would not be damaged by the water sprays. The most likely scenario for filter damage involves filter plugging by the water spray, followed by the fan blowing out the filter medium. A number of controlled laboratory tests that were previously conducted in the late 1980s are reviewed in this paper to provide a technical basis for the potential HEPA filter damage by the water spray system in HEPA filter plenums. In addition to the laboratory tests, the scenario for BEPA filter damage during fires has also occurred in the field. A fire in a four-stage, BEPA filter plenum at Rocky Flats in 1980 caused the first three stages of BEPA filters to blow out of their housing and the fourth stage to severely bow. Details of this recently declassified fire are presented in this paper. Although these previous findings suggest serious potential problems exist with the current water spray system in filter plenums, additional studies are required to confirm unequivocally that DOE's critical facilities are at risk. 22 refs., 15 figs

  19. ASBESTOS FIBER RELEASE DURING CHANGE-OUT OF FILTER BAGS FROM HEPA-FILTERED VACUUM CLEANERS

    Science.gov (United States)

    High efficiency particulate air (HEPA) filtered vacuum cleaners are the primary tool used to clean up asbestos containing material during operations and maintenance (O&M) activities. he change-out of vacuum bags is a potential source of airborne asbestos contamination. n 1989 and...

  20. HEPA and PARSE: Systematic discovery of clinically relevant tumor-specific antigens.

    Science.gov (United States)

    Xu, Qing-Wen; Zhang, Yu; Wang, Xiao-Song

    2013-03-01

    The effective discovery of tumor-specific antigens (TSAs) holds the key for the development of new diagnostic assays and immunotherapeutic approaches against cancer. Here, we discuss our recently developed technologies, HEPA and PARSE, which allow for the systematic identification of TSAs, generating a reservoir of immunologically and clinically relevant targets. PMID:23802073

  1. A Survey of Mixed-Waste HEPA Filters in the DOE Complex

    Energy Technology Data Exchange (ETDEWEB)

    Felicione, F. S.; Barber, D. B.; Carney, K. P.

    2002-02-28

    A brief investigation was made to determine the quantities of spent, mixed-waste HEPA filters within the DOE Complex. The quantities of both the mixed-waste filters that are currently being generated, as well as the legacy mixed-waste filters being stored and awaiting disposition were evaluated. Seven DOE sites representing over 89% of the recent HEPA filter usage were identified. These sites were then contacted to determine the number of these filters that were likely destined to become mixed waste and to survey the legacy-filter quantities. Inquiries into the disposition plans for the filters were also made. It was determined that the seven sites surveyed possess approximately 500 m3 of legacy mixed-waste HEPA filters that will require processing, with an annual generation rate of approximately 25 m3. No attempt was made to extrapolate the results of this survey to the entire DOE Complex. These results were simply considered to be the lower bound of the totality of mixed-waste HEPA filters throughout the Complex. The quantities determined encourage the development of new treatment technologies for these filters, and provide initial data on which an appropriate capacity for a treatment process may be based.

  2. Time dependency of HEPA filter performance during loading with liquid particles

    International Nuclear Information System (INIS)

    The time dependency of filter performance across a high-efficiency particulate air (HEPA) filter was experimentally studied. The experimental study was carried out using a HEPA filter (203 x 203 x 150 mm) clogged with liquid particles (mosquito stick aerosol). The aerosol concentration for filter loading was 0.84 mg/m3 and the size distribution was similar to lognormal distribution (CMD=0.21 μm, σ=1.65). The mass loading was about 60 g/m2 when the pressure drop across the HEPA filter reached twice the initial pressure drop. The DOP particle penetrations through the HEPA filter were evaluated when relative pressure drops (ΔP/ΔP0) were nearly 1.0, 1.3, 1.4, 1.6, 1.8 and 2.1. The most penetrating particle size (MPPS) was almost independent of the mass loading if the face velocity was constant. However, the DOP particle penetration increased remarkably with mass loading, and the tendency of increase was not affected by particle size or face velocity. (author)

  3. A Survey of Mixed-Waste HEPA Filters in the DOE Complex

    International Nuclear Information System (INIS)

    A brief investigation was made to determine the quantities of spent, mixed-waste HEPA filters within the DOE Complex. The quantities of both the mixed-waste filters that are currently being generated, as well as the legacy mixed-waste filters being stored and awaiting disposition were evaluated. Seven DOE sites representing over 89% of the recent HEPA filter usage were identified. These sites were then contacted to determine the number of these filters that were likely destined to become mixed waste and to survey the legacy-filter quantities. Inquiries into the disposition plans for the filters were also made. It was determined that the seven sites surveyed possess approximately 500 m3 of legacy mixed-waste HEPA filters that will require processing, with an annual generation rate of approximately 25 m3. No attempt was made to extrapolate the results of this survey to the entire DOE Complex. These results were simply considered to be the lower bound of the totality of mixed-waste HEPA filters throughout the Complex. The quantities determined encourage the development of new treatment technologies for these filters, and provide initial data on which an appropriate capacity for a treatment process may be based

  4. Applied patent RFID systems for building reacting HEPA air ventilation system in hospital operation rooms.

    Science.gov (United States)

    Lin, Jesun; Pai, Jar-Yuan; Chen, Chih-Cheng

    2012-12-01

    RFID technology, an automatic identification and data capture technology to provide identification, tracing, security and so on, was widely applied to healthcare industry in these years. Employing HEPA ventilation system in hospital is a way to ensure healthful indoor air quality to protect patients and healthcare workers against hospital-acquired infections. However, the system consumes lots of electricity which cost a lot. This study aims to apply the RFID technology to offer a unique medical staff and patient identification, and reacting HEPA air ventilation system in order to reduce the cost, save energy and prevent the prevalence of hospital-acquired infection. The system, reacting HEPA air ventilation system, contains RFID tags (for medical staffs and patients), sensor, and reacting system which receives the information regarding the number of medical staff and the status of the surgery, and controls the air volume of the HEPA air ventilation system accordingly. A pilot program was carried out in a unit of operation rooms of a medical center with 1,500 beds located in central Taiwan from Jan to Aug 2010. The results found the air ventilation system was able to function much more efficiently with less energy consumed. Furthermore, the indoor air quality could still keep qualified and hospital-acquired infection or other occupational diseases could be prevented. PMID:22081235

  5. IN-PLACE PERFORMANCE EVALUATION OF HEPA-FILTRATION SYSTEMS AT ASBESTOS-ABATEMENT SITES

    Science.gov (United States)

    This study was conducted to assess the in-place performance of high efficiency particulate air (HEPA) filtration systems at asbestos-abatement siteS in New Jersey to determine each systems particle-removal efficiency. n air-generated dioctyl phthalate aerosol was used to challeng...

  6. A Method for Cobalt and Cesium Leaching from Glass Fiber in HEPA Filter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gye Nam; Lee, Suk Chol; Yang, Hee Chul; Yoon, In Ho; Choi, Wang Kyu; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    A great amount of radioactive waste has been generated during the operation of nuclear facilities. Recently, the storage space of a radioactive waste storage facility in the Korea Atomic Energy Research Institute (KAERI) was almost saturated with many radioactive wastes. So, the present is a point of time that a volume reduction of the wastes in a radioactive waste storage facility needs. There are spent HEPA filter wastes of about 2,226 sets in the radioactive waste storage facility in KAERI. All these spent filter wastes have been stored in accordance with their original form without any treatment. Up to now a compression treatment of these spent HEPA filters has been carried out to repack the compressed spent HEPA filters into a 200 liter drum for their volume reduction. Frame and separator are contaminated with a low concentration of nuclide, while the glass fiber is contaminated with a high concentration of nuclide. So, for the disposal of the glass filter to the environment, the glass fiber should be leached to lower its radioactive concentration first and then must be stabilized by solidification and so on. Therefore, it is necessary to develop a leaching process of glass fiber in a HEPA filter. Leaching is a separation technology, which is often used to remove a metal or a nuclide from a solid mixture with the help of a liquid solvent

  7. Effect of high temperature on the removal efficiency of HEPA filters

    International Nuclear Information System (INIS)

    As part of a study aimed at the evaluation and improvement of the performance of HEPA filters under elevated temperatures, the effect of elevated temperatures up to 400 degree C on the removal efficiency of HEPA filter medium (which is the limiting factor in terms of the filter performance) was studied. The Variation in HEPA filter efficiency under high temperatures up to 250 degree C were also studied. Removal efficiency tests following thermal challenge show that the filtration efficiency of filter medium was scarcely effected even after 6 h exposure to 400 degree c. the experimental results with HEPA filter unit show a decrease in removal efficiency with increase in temperature. This may be explained by structural changes observed in the filter components of the filter units tested. All filter units tested at design air flow and elevated temperatures showed loosening of the filter pack. In some cases kinks in the filter pleats close to the frame were observed. Local damages resulting from such structural changes may have caused reduction in filtration efficiency. This was confirmed by efficiency measurements carried out at room temperature on filter units after repeated exposure to 250 degree C in a laboratory oven. 6 fig., 2 tab

  8. Performances of pleated HEPA filters as a function of relative humidity of air

    International Nuclear Information System (INIS)

    Pleated High Efficiency Particulate Air (HEPA) filters are used for maintaining the containment of radioactive substances in nuclear plants; thus, they are sensitive elements of nuclear safety. Some accidental situations, such as the emergence of a hole on a pipe with release of steam, can lead to a high increase of the air humidity. This work can overcome the lack of analytical data in the literature regarding the behaviour of pleated HEPA filters, in terms of changes in pressure drop and efficiency, in presence of humidity (unsaturated air). Experimental clogging tests have been performed on a test bench with two aerosols: non hygroscopic micron-size alumina particles and hygroscopic sub-micron sodium chloride particles. The results showed that the influence of humidity during the clogging of a HEPA filter depends on several parameters: the geometry of the filter (plane or pleated), the size distribution and hygroscopicity of the aerosol clogging and finally the interaction time between the aerosol and humid air. Measurements of efficiency of clean and clogged filters (at different degrees of clogging), performed with the normalized soda fluorescein aerosol, are also sensitive to the presence of more or less relative humidity in the air. Finally, all results helped to develop an empirical model for estimating the evolution of the pressure drop of HEPA filters; this model is applicable during the formation of the particulate cake in presence of humidity without reducing of the surface area filtration. (author)

  9. Potential for HEPA filter damage from water spray systems in filter plenums

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W. [Lawrence Livermore National Lab., CA (United States); Fretthold, J.K. [Rocky Flats Safe Sites of Colorado, Golden, CO (United States); Slawski, J.W. [Department of Energy, Germantown, MD (United States)

    1997-08-01

    The water spray systems in high efficiency particulate air (HEPA) filter plenums that are used in nearly all Department of Energy (DOE) facilities for protection against fire was designed under the assumption that the HEPA filters would not be damaged by the water sprays. The most likely scenario for filter damage involves filter plugging by the water spray, followed by the fan blowing out the filter medium. A number of controlled laboratory tests that were previously conducted in the late 1980s are reviewed in this paper to provide a technical basis for the potential HEPA filter damage by the water spray system in HEPA filter plenums. In addition to the laboratory tests, the scenario for BEPA filter damage during fires has also occurred in the field. A fire in a four-stage, BEPA filter plenum at Rocky Flats in 1980 caused the first three stages of BEPA filters to blow out of their housing and the fourth stage to severely bow. Details of this recently declassified fire are presented in this paper. Although these previous findings suggest serious potential problems exist with the current water spray system in filter plenums, additional studies are required to confirm unequivocally that DOE`s critical facilities are at risk. 22 refs., 15 figs.

  10. Software Verification and Validation Test Report for the HEPA filter Differential Pressure Fan Interlock System

    Energy Technology Data Exchange (ETDEWEB)

    ERMI, A.M.

    2000-09-05

    The HEPA Filter Differential Pressure Fan Interlock System PLC ladder logic software was tested using a Software Verification and Validation (V&V) Test Plan as required by the ''Computer Software Quality Assurance Requirements''. The purpose of his document is to report on the results of the software qualification.

  11. Characteristics of HEPA filter waste compactor developed by KAERI and comparison with Japan's and U. S. A's compactors

    International Nuclear Information System (INIS)

    The HEPA filter waste (Hexahedron, 610 x 610 x 292 mm, 20 Kg), which is used for the ventilation system in the nuclear industries, has relatively large volume to compare with it's weight. Due to the large volume of HEPA filter waste, it needs the large storage and/or disposal space and managing cost during the long period of storage and management. Many countries use the compactor to reduce the volume of HEPA filter waste. On this paper we introduce the new type compactor developed by KAERI with the characteristic comparison to the Japan's and U. S. A's compactors

  12. Test plan for N2 HEPA filters assembly shop stock used on PFP E4 exhaust system

    Energy Technology Data Exchange (ETDEWEB)

    DICK, J.D.

    1999-09-01

    At Plutonium Finishing Plant (PFP) and Plutonium Reclamation Facility (PRF) Self-contained HEPA filters, encased in wooden frames and boxes, are installed in the E4 Exhaust Ventilation System to provide confinement of radioactive releases to the environment and confinement of radioactive contamination within designated zones inside the facility. Recently during the routine testing in-leakage was discovered downstream of the Self-contained HEPA filters boxes. This Test Plan describes the approach to conduct investigation of the root causes for the in-leakage of HEPA filters.

  13. Synergistic anticancer effects of curcumin and resveratrol in Hepa1-6 hepatocellular carcinoma cells.

    Science.gov (United States)

    Du, Qin; Hu, Bing; An, Hong-Mei; Shen, Ke-Ping; Xu, Ling; Deng, Shan; Wei, Meng-Meng

    2013-05-01

    Hepatocellular carcinoma remains one of the most prevalent malignancies worldwide. Curcuma aromatica and Polygonum cuspidatum are one of the commonly used paired-herbs for liver cancer treatment. Curcumin and resveratrol are the major anticancer constituents of Curcuma aromatica and Polygonum cuspidatum, respectively. Curcumin and resveratrol have been found to exhibit a synergistic anticancer effect in colon cancer. However, the combined effect of curcumin and resveratrol against hepatocellular carcinoma remains unknown. In the present study, we evaluated the combined effects of curcumin and resveratrol in hepatocellular carcinoma Hepa1-6 cells. The results showed that curcumin and resveratrol significantly inhibited the proliferation of Hepa1-6 cells in a dose- and time-dependent manner. The combination treatment of curcumin and resveratrol elicited a synergistic antiproliferative effect in Hepa1-6 cells. The apoptosis of Hepa1-6 cells induced by the combination treatment with curcumin and resveratrol was accompanied by caspase-3, -8 and -9 activation, which was completely abrogated by a pan caspase inhibitor, Z-VAD-FMK. Combination of curcumin and resveratrol upregulated intracellular reactive oxygen species (ROS) levels in Hepa1-6 cells. The ROS scavenger, NAC, partially attenuated the apoptosis and caspase activation induced by the combination treatment of curcumin and resveratrol. In addition, the combination of curcumin and resveratrol downregulated XIAP and survivin expression. These data suggest that the combination treatment of curcumin and resveratrol is a promising novel anticancer strategy for liver cancer. The present study also provides new insights into the effective mechanism of paired-herbs in traditional Chinese medicine. PMID:23446753

  14. Innovative HEPA filter designs to reduce waste generation and simplify waste treatment

    International Nuclear Information System (INIS)

    The treatment and disposal of spent high-efficiency particulate air (HEPA) filters has presented a problem at some defense production plants and could be a problem at potential future spent-fuel consolidation or fuel-reprocessing facilities. During studies of transuranic (TRU) waste treatment options conducted by Pacific Northwest Laboratory, it was concluded that treatment of spent HEPA filters would become easier and less costly if some modifications were made to the present materials of construction and design. This study was undertaken to develop and evaluate alternative materials and innovative designs for HEPA filters, making them more compatible with volume reduction technology. The following treatment options were selected for this study: 1) no treatment; 2) compaction; 3) supercompaction; 4) incinerate and melt; and 5) separate the frame from the media and dispose of the frame as low-level waste, and incinerate and melt the filter media and sealant. Forty HEPA design concepts were identified and evaluated by means of a figure-of-merit methodology for technical performance and an economic evaluation that considered filter fabrication and disposal costs. Results of the study indicate that if improved HEPA designs are combined with volume reduction treatments, the costs of filter disposal can be reduced substantially over the use of standard-flow filter designs with no volume reduction treatment. It is estimated that by combining the new design concepts with waste volume reduction treatments, manufacturing and disposal costs can be reduced by $290 or more per filter if classified as low-level waste (LLW) and up to $23,000 per filter if it is high-activity waste (containing activity greater than class-C LLW) and requires repository disposal

  15. Investigation of water accumulation in an offgas test facility HEPA housing

    International Nuclear Information System (INIS)

    The Consolidated Incineration Facility, at the Department of Energy's Savannah River Site, is designed to treat solid and liquid RCRA hazardous and mixed wastes generated by site operations and clean-up activities. During CIF's pretrial burn campaigns in 1995, an appreciable amount of water was recovered from the HEPA housings. Questions were immediately raised as to the source of the water, and the degree of wetness of the filters during operation. There are two primary issues involved: Water could reduce the life expectancy and performance of the HEPA filters, housing, and associated ducting, and wet HEPAs also present radiological concerns for personnel during filter change-out. A similar phenomenon was noted at the Offgas Components Test Facility (OCTF), a 1/10 scale pilot of CIF's air pollution control system. Tests at OCTF indicated the water's most likely origin to be vapor condensing out from the flue gas stream due to excessive air in-leakage at housing door seals, ducting flanges, and actual holes in the ducting. The rate of accumulation bears no statistical correlation to such process parameters as steam flow, reheater outlet temperature and offgas velocity in the duct. Test results also indicated that the HEPA filter media is moistened by the initial process flow while the facility is being brought on line. However, even when the HEPA filters were manually drenched prior to startup, they became completely dry within four hours of the time steam was introduced to the reheater. Finally, no demonstrable relationship was found between the degree of filter media wetness and filter dP

  16. Define and Quantify the Physics of Air Flow, Pressure Drop and Aerosol Collection in Nuclear Grade HEPA Filters

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Murray E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-23

    Objective: Develop a set of peer-review and verified analytical methods to adjust HEPA filter performance to different flow rates, temperatures and altitudes. Experimental testing will measure HEPA filter flow rate, pressure drop and efficiency to verify the analytical approach. Nuclear facilities utilize HEPA (High Efficiency Particulate Air) filters to purify air flow for workspace ventilation. However, the ASME AG-1 technical standard (Code on Nuclear Air and Gas Treatment) does not adequately describe air flow measurement units for HEPA filter systems. Specifically, the AG-1 standard does not differentiate between volumetric air flow in ACFM (actual cubic feet per minute)compared to mass flow measured in SCFM (standard cubic feet per minute). More importantly, the AG-1 standard has an overall deficiency for using HEPA filter devices at different air flow rates, temperatures, and altitudes. Technical Approach: The collection efficiency and pressure drops of 18 different HEPA filters will be measured over a range of flow rates, temperatures and altitudes. The experimental results will be compared to analytical scoping calculations. Three manufacturers have allocated six HEPA filters each for this effort. The 18 filters will be tested at two different flow rates, two different temperatures and two different altitudes. The 36 total tests will be conducted at two different facilities: the ATI Test facilities (Baltimore MD) and the Los Alamos National Laboratory (Los Alamos NM). The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally designed to evaluate small air samplers. In 2010, modifications were started to convert the wind tunnel for HEPA filter testing. (Extensive changes were necessary for the required aerosol generators, HEPA test fixtures, temperature control devices and measurement capabilities.) To this date, none of these modification activities have been funded through a specific DOE or NNSA program. This is

  17. A Study on Replacement of HEPA Filter In-place Leak Test Challenge Agent from DOP to PAO in NPP

    International Nuclear Information System (INIS)

    Atmosphere cleanup system of nuclear power plants is a gas waste treatment system to minimize the leakage of radioactive materials produced during normal operation and accidents. The HEPA(High Efficiency Particulate Air) filter in this system has the major role to filter the particulate radioactive materials. The leak test method of HEPA filter conforms to the Reg. Guide 1.140 and Reg. Guide 1.52 of USNRC, which were both revised in 2001. The revisions include the permission of alternative challenging aerosol agents besides DOP (dioctyl phthalate) for HEPA filter in-place leak test. US DOE is demanding to stop using DOP since DOP was suspected as a carcinogen. Currently, industries other than nuclear power plants mostly use PAO (polyalpha olefin) as HEPA filter leak test challenge aerosol agent. Due to Reg. Guide 1.140(Rev.2) and 1.52(Rev.2), only DOP has been allowed to be used in nuclear power plants. As a result, nuclear power plant workers have been exposed to mental and physical risks whenever there is HEPA filter in-place leak test. In this paper, the leak test results using DOP and PAO are compared to verify that DOP can be replaced with non-carcinogenic PAO for HEPA filter leak test in nuclear power plants

  18. Volatility and leachability of heavy metals and radionuclides in thermally treated HEPA filter media generated from nuclear facilities.

    Science.gov (United States)

    Yoon, In-Ho; Choi, Wang-Kyu; Lee, Suk-Chol; Min, Byung-Youn; Yang, Hee-Chul; Lee, Kune-Woo

    2012-06-15

    The purpose of the present study was to apply thermal treatments to reduce the volume of HEPA filter media and to investigate the volatility and leachability of heavy metals and radionuclides during thermal treatment. HEPA filter media were transformed to glassy bulk material by thermal treatment at 900°C for 2h. The most abundant heavy metal in the HEPA filter media was Zn, followed by Sr, Pb and Cr, and the main radionuclide was Cs-137. The volatility tests showed that the heavy metals and radionuclides in radioactive HEPA filter media were not volatilized during the thermal treatment. PCT tests indicated that the leachability of heavy metals and radionuclides was relatively low compared to those of other glasses. XRD results showed that Zn and Cs reacted with HEPA filter media and were transformed into crystalline willemite (ZnO·SiO(2)) and pollucite (Cs(2)OAl(2)O(3)4SiO(2)), which are not volatile or leachable. The proposed technique for the volume reduction and transformation of radioactive HEPA filter media into glassy bulk material is a simple and energy efficient procedure without additives that can be performed at relatively low temperature compared with conventional vitrification process. PMID:22525481

  19. A State of the Art on the Technology for Downgrading and Volume Reduction of Radioactive HEPA Filter Waste

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Wang Kyu; Min, Byung Youn; Kim, Gyu Nam; Lee, Kune Woo [KAERI, Daejeon (Korea, Republic of)

    2010-05-15

    The technology development for volume reduction and self-disposal of radioactive wastes is emerging as an important issue in the world due to the increasing waste generated from a decommissioning, operation and maintenance in nuclear plants and facilities. Lots of radioactive HEPA filter waste, of which volume is bulky and packing density is relatively low, are generated from the high radioactive facilities in operation, improvement and repair, and under decommissioning. From the fact that the management of radioactive HEPA filter waste has been known to be very difficult, it is necessary to the technology development for volume reduction and stabilization of radioactive HEPA filter wastes. Therefore, this report was reviewed to the state of art of the related technologies for a volume reduction and a downgrading of radioactive HEPA filter wastes from nuclear facilities. It is expected that the volume reduction and downgrading of radioactive HEPA filter waste through an appropriate treatment will be greatly contributed to increase in economical feasibility and safety by cutting down the disposal cost and improving disposal safety due to the reduction of the amount of disposal wastes. This report will be furnished basic data to develop the downgrading and volume reduction technologies for the treatment of radioactive HEPA filter wastes generated during the operation and maintenance and repair of not only high radioactive nuclear facilities but also relatively low radioactive nuclear facilities

  20. A Study on Replacement of HEPA Filter In-place Leak Test Challenge Agent from DOP to PAO in NPP

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. K.; Kim, K.; Sohn, S. H. [KEPRI, Daejeon (Korea, Republic of); Bae, J. C.; Park, J. S.; Cho, B. H. [KHNP, Yonggwang (Korea, Republic of); Yu, B. J. [KPS, Yonggwang (Korea, Republic of); Hong, S. J. [FNC Tech. Co. Ltd., Seoul (Korea, Republic of); Kang, S. H. [KFTL, Gwangju (Korea, Republic of)

    2008-10-15

    Atmosphere cleanup system of nuclear power plants is a gas waste treatment system to minimize the leakage of radioactive materials produced during normal operation and accidents. The HEPA(High Efficiency Particulate Air) filter in this system has the major role to filter the particulate radioactive materials. The leak test method of HEPA filter conforms to the Reg. Guide 1.140 and Reg. Guide 1.52 of USNRC, which were both revised in 2001. The revisions include the permission of alternative challenging aerosol agents besides DOP (dioctyl phthalate) for HEPA filter in-place leak test. US DOE is demanding to stop using DOP since DOP was suspected as a carcinogen. Currently, industries other than nuclear power plants mostly use PAO (polyalpha olefin) as HEPA filter leak test challenge aerosol agent. Due to Reg. Guide 1.140(Rev.2) and 1.52(Rev.2), only DOP has been allowed to be used in nuclear power plants. As a result, nuclear power plant workers have been exposed to mental and physical risks whenever there is HEPA filter in-place leak test. In this paper, the leak test results using DOP and PAO are compared to verify that DOP can be replaced with non-carcinogenic PAO for HEPA filter leak test in nuclear power plants.

  1. Evaluation of the effect of media velocity on HEPA filter performance

    International Nuclear Information System (INIS)

    Section FC of the ASME AG-1 Code addresses glass fiber HEPA filters and restricts the media velocity to a maximum of 2.54 cm/s (5 ft/min). Advances in filter media technology allow glass fiber HEPA filters to function at significantly higher velocities and still achieve HEPA performance. However, diffusional capture of particles < 100 nm is reduced at higher media velocities due to shorter residence times within the media matrix. Therefore, it is unlikely that higher media velocities for HEPA filters will be allowed without data to demonstrate the effect of media velocity on removal of particles in the smaller size classes. In order to address this issue, static testing has been conducted to generate performance related data and a range of dynamic testing has provided data regarding filter lifetimes, loading characteristics, changes in filter efficiency and the most penetrating particle size over time. Testing was conducted using 31 cm x 31 cm x 29 cm deep pleat HEPA filters supplied from two manufacturers. Testing was conducted at media velocities ranging from 2.0-4.5 cm/s with a solid aerosol challenge composed of potassium chloride. Two set of media velocity data were obtained for each filter type. In one set of evaluations, the maximum aerosol challenge particle size was limited to 3 μm, while particles above 3 μm were not constrained in the second set. This provided for considerable variability in the challenge mass mean diameter and overall mass loading rate. Results of this testing will be provided to the ASME AG-1 FC Committee for consideration in future versions of the HEPA standard. In general, the initial filter efficiency decreased with increasing media velocity. However, initial filter efficiencies were generally good in all cases. Filter efficiency values averaged over the first ten minute of the loading cycle ranged from 99.970 to 99.996 %. Additionally, the most penetrating particle size was observed to decrease with increasing media velocity

  2. Regulation of hepA of Anabaena sp. Strain PCC 7120 by Elements 5′ from the Gene and by hepK

    Science.gov (United States)

    Zhu, Jinsong; Kong, Renqiu; Wolk, C. Peter

    1998-01-01

    In Anabaena spp., synthesis of the heterocyst envelope polysaccharide, required if the cell is to fix dinitrogen under aerobic conditions, is dependent on the gene hepA. A transcriptional start site of hepA was localized 104 bp 5′ from its translational initiation codon. A 765-bp open reading frame, denoted hepC, was found farther upstream. Inactivation of hepC led to constitutive expression of hepA and prevented the synthesis of heterocyst envelope polysaccharide. However, the glycolipid layer of the heterocyst envelope was synthesized. A hepK mutation blocked both the synthesis of the heterocyst envelope polysaccharide and induction of hepA. The predicted product of hepK resembles a sensory protein-histidine kinase of a two-component regulatory system. Analysis of the region between hepC and hepA indicated that DNA sequences required for the induction of hepA upon nitrogen deprivation are present between bp −574 and −440 and between bp −340 and −169 relative to the transcriptional start site of hepA. Gel mobility shift assays provided evidence that one or more proteins bind specifically to the latter sequence. The Fox box sequence downstream from hepA appeared inessential for the induction of hepA. PMID:9696774

  3. Life prolongation and cost reduction of steel ladles with improving refractories and their structure; Taikabutsu zaishitsu to kozo kaizen ni yoru shuka taikabutsu no chojumyoka to kosuto teigen

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, Masato; Kasahara, Hajime; Fukutani, Fujio; Imai, Hiroyuki [Nippon Steel Corp., Tokyo (Japan)

    1999-06-01

    Steel Making Plant, Hirohata Iron Works, Nippon Steel Corp. succeeded to reduce the cost of furnace materials by measures described below down to 49% compared to that in 1992. (1) For tuyre bricks, cleanability against oxygen was improved by compacting by vacuum cast forming. (2) For SL bricks, the cost was reduced by applying imported bricks and optimization of the range of use. (3) For alumina-magnesia amorphous refractories for side walls, low expansion and breaking resistance were improved by optimization of magnesia quantity and silica ultra fine powder quantity. (4) For side wall structure, improvement of tie-in between the ground part and the side wall and lining with efficient thickness were carried out. (NEDO)

  4. Characteristics of borosilicate glass media fabricated by melting HEPA filter media with inorganic additives

    International Nuclear Information System (INIS)

    HEPA filters are widely used in the nuclear fields as a final off-gas cleaning unit. To assess the applicability of vitrification technology either to treat used filter media or to produce borosilicate glass medium for the solidification of alpha-contaminated wastes, various waste glasses of different compositions were fabricated by melting mixture of HEPA filter media and inorganic additives. Physicochemical properties such as microhardness, density, thermal expansion, and short-term leaching behavior were characterized. XRD analysis showed that amorphous glasses were formed for a wide range of mixing ratio. Leach resistances, measured by PCT-B leach tests, were superior to that of EA (Environmental Assessment) glass. Other properties were similar to those of glass media used for the vitrification of high-level radioactive wastes in foreign countries

  5. First Study Of HEPA Filter Prototype Performance To Control The Airborne Pollution

    International Nuclear Information System (INIS)

    This paper will report the efficiency test result of the filtration tool prototype of High Efficiency Particulate Air (HEPA filter) for low temperature, to control the airborne pollution of aerosol particle of solid and liquid. The prototype design of HEPA filter was based on the characteristic data of filter material (fibrous diameter, density, filter thickness), flow rate of air and first pressure drop. From the result of laboratory scale test, using DOP/PSL aerosol with 0,3 mum diameter and the flow rate of 3,78 m exp.3/min, was obtained filtration efficiency revolve between 89,90 and 99,94 % for the filter prototype of A, B, C, and D. the efficiency estimation of theory with filtration programme and the experiment was different amount 1 %. The value of the prototype efficiency of D filter was not far different with AAF-USA filter and its price is cheaper 30 % than the price of AAF-USA filter

  6. Efficiency of standard and high capacity HEPA filters during simulated tornado and explosive pulses

    International Nuclear Information System (INIS)

    Standard HEPA (high efficiency particulate air) filters were subjected to simulated tornado transients and high capacity HEPA filters to simulated explosive shock waves to determine their filtering efficiency and particulate release characteristics during these events. Efficiencies, measured by introducing a monodispersed aerosol upstream of the test filters and collecting it on nucleopore filters downstream of the test filters proved to be as low as 98.17% during tornado transients and as low as 71% during explosive transients. Particulate released from loaded filters during tornado transients amounted to about 10 μg of polystyrene latex. For explosive transients the mass of released polystyrene particulate was on the order of 1.0 mg. (author)

  7. Particle size for greatest penetration of HEPA filters - and their true efficiency

    International Nuclear Information System (INIS)

    The particle size that most greatly penetrates a filter is a function of filter media construction, aerosol density, and air velocity. In this paper the published results of several experiments are compared with a modern filtration theory that predicts single-fiber efficiency and the particle size of maximum penetration. For high-efficiency particulate air (HEPA) filters used under design conditions this size is calculated to be 0.21 μm diam. This is in good agreement with the experimental data. The penetration at 0.21 μm is calculated to be seven times greater than at the 0.3 μm used for testing HEPA filters. Several mechanisms by which filters may have a lower efficiency in use than when tested are discussed

  8. Investigation into the behaviour of HEPA filters at high temperature, air humidity, and elevated differential pressure

    International Nuclear Information System (INIS)

    Investigations into the response of full-size HEPA filters to extended operation under high humidity airflows were continued with tests of 47 commercial and 13 prototypical filter units. The parameters studied were relative air humidity or liquid moisture content, temperatures between 20 and 800C, filter loading with dust, exposure time, and filter orientation to airflow. In view of complementary investigations with samples of HEPA-filter media, a laboratory test facility was built and put into operation. Based on the establishment of the main failure mechanisms, new prototype filters, incorporating a filter medium reinforced by glass-fiber cloth and a new separator design with modified corrugations, were built and tested. (orig./DG)

  9. Feasibility study for an additional HEPA filter leaching system in NWCF

    International Nuclear Information System (INIS)

    This report documents the feasibility of installing a second high-efficiency particulate air (HEPA) filter leaching system in the New Waste Calcining Facility at the Idaho Chemical Processing Plant (ICPP). A large spent filter backlog already exists at the ICPP, and it has been uncertain whether the existing HEPA filter leaching system will have a throughput rate sufficient to work off the existing backlog in a timely manner. Three areas within the New Waste Calcining Facility (NWCF) have been identified as possible locations for a second filter leaching system. This report examines the suitability of each location, identifies modifications that would be necessary-to install a filter leaching system at each location, examines the impact of modifying each location, and discusses recent efforts to estimate filter throughput using the existing filter leaching system. Based on all available information, installation of a second filter leaching system is not recommended at the present time

  10. Prediction of HEPA filter pressure drop and removal efficiency during dust loading

    International Nuclear Information System (INIS)

    The challenge of the HEPA filter is to predict the evolution of the pressure drop as a function of the conditions of filtration. The crucial factor in analyzing the service life of HEPA filters resides in determining the pressure drop and the efficiency as a function of the mass deposited on the filter. An experimental program has been developed to estimate the service life of a filter as a function of its clogging. The study was carried out on plane filters clogged with a fluorescein soda aerosol at different rates of filtration. A method of peeling was developed to determine the profile of particle deposit within the filter and to demonstrate its feasibility. Comparison between the experimental results and the clogging model developed by Bergman reveals a satisfactory correlation

  11. In-place leak test for HEPA filter using emery 3004 aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H. K.; Jeon, Y. B.; Park, K. J.; Yang, S. W.; Lee, E. P.; Hwang, Y. H. [KAERI, Taejon (Korea, Republic of)

    2002-10-01

    New air filter leak testing aerosol, Emery 3004, was used to carry out the in-place leak test for High Efficiency Particulate Air(HEPA) filters at PIEF in KAERI. As a result of leak test, penetration rate appeared to be 0.003 {approx} 0.006 %. These values satisfy that of Regulatory Guide 1.14 reference, 0.05%. Therefore, Emery 3004 aerosol which has not any elements causing the cancers, was confirmed to be able to employ as the HEPA filter leak test aerosol in place of DOP(Dioctyl Phthlate). And also it can reduce some additional works such as wearing mask and cloths for protecting the personnel from poisonous gas.

  12. Verification of HEPA Filter Analysis for the Canberra Q2 Waste Assay System

    Energy Technology Data Exchange (ETDEWEB)

    Casella, V.R.

    2002-12-06

    Data from measurements of a standard 20 inches x 20 inches source positioned on the end and in the middle of a HEPA filter verified that assaying HEPA filters with the Canberra Q2 and using the standard drum calibration with a percent full parameter of 70 percent gives acceptable results for gamma rays above 122 keV. For the gamma-ray energy range of 122 keV to 1400 keV, nuclide concentrations would be somewhat overestimated by from about 35 percent (122 keV) to about 10 percent (1400 keV). Also, Am-241 (60 keV) is conservatively overestimated by about a factor of 2.6 using this configuration.

  13. Characteristics of borosilicate glass media fabricated by melting HEPA filter media with inorganic additives

    Energy Technology Data Exchange (ETDEWEB)

    Kim, I. T.; Kim, H. Y.; Park, K. I.; Park, H. S.; Kim, J. H. [KAERI, Taejon (Korea, Republic of)

    1999-05-01

    HEPA filters are widely used in the nuclear fields as a final off-gas cleaning unit. To assess the applicability of vitrification technology either to treat used filter media or to produce borosilicate glass medium for the solidification of alpha-contaminated wastes, various waste glasses of different compositions were fabricated by melting mixture of HEPA filter media and inorganic additives. Physicochemical properties such as microhardness, density, thermal expansion, and short-term leaching behavior were characterized. XRD analysis showed that amorphous glasses were formed for a wide range of mixing ratio. Leach resistances, measured by PCT-B leach tests, were superior to that of EA (Environmental Assessment) glass. Other properties were similar to those of glass media used for the vitrification of high-level radioactive wastes in foreign countries.

  14. A new electrostatic precipitator for HEPA prefilter use in the nuclear industries

    International Nuclear Information System (INIS)

    Fibrous prefilters extend the service life of HEPA filters by removing most of the larger airborne particles. Such prefilters, however, are less effective in removing submicron particles until they are well loaded and a substantial pressure drop exists. We propose for HEPA prefilter service a radically new design of two-stage electrostatic precipitator (ESP) which is under development in our laboratory. It has the advantages of washability, efficiency largely independent of aerosol particle size, and very low pressure drop, all of which are common to conventional ESP's. In addition, however, the efficiency of the new design is improved by an order of magnitude or more over conventional ESP's. Moreover, the new design appears to be largely or entirely sparkproof, an important consideration in the filtration of combustible aerosols

  15. Performance of HEPA Filter Medium under Accidental Conditions in Nuclear Installations

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air filters (HEPA Filters) are the main components in ventilation or confinement system for the retention of radioactive particles in nuclear installations. During abnormal conditions or accidents (e.g. fire accident, criticality in a nuclear fuel cycle facility and LOCA in power reactors) the resulting heat, smoke and humidity affect to a large extent the performance of HEPA filters. As a part of a research programme aims at the evaluation and improvement of the performance of HEPA filter media during abnormal conditions, the effect of elevated temperatures up to 400 degree C on the resistance of medium to penetration of water under pressure has been investigated. The test results showed that the resistance of the medium to penetration of water decreases with increase in temperature and thermal exposure time. This could be attributed to burnout of the organic binder used to improve the resistance of the medium to the penetration of water. The results also showed that at 400 degree C the resistance of the medium to the penetration of water disappeared. This was confirmed by inspection of the filter medium samples after exposure to high temperature using a scanning electron microscope. The inspection of the medium samples showed that the organic binder in the medium was deformed and finally collapsed at 400 degree C. Also, a best estimate model for the relation of filter medium resistance to water penetration under elevated temperature has been implemented. The results of this study can help in establishing a regulatory operating limit conditions (OLCs) for HEPA filter operation at high temperatures conditions in nuclear installations

  16. The application of HEPA filter units in gas streams of high dust concentrations

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air Filter (HEPA) units are currently employed for cleaning air and gas streams of very low dust concentrations where their high removal efficiencies reliably protect the environment. The high dust concentrations encountered during the modification and decommissioning of nuclear facilities, in the processing of contaminated scrap, or in the incineration of radioactive waste have limited the use of HEPA filters to the role of final stage clean-up filters. Recleaning HEPA filter units in their service locations offers economic advantages compared with conventional combinations of multiple dust removal devices. Fluid dynamic techniques come into consideration for the nondetrimental recleaning of inherently fragile, glass fiber filter media. This is explained by the relatively low mechanical stress induced during the required high-intensity recleaning processes, in comparison to beating or shaking methods. In this work, recleaning via low pressure reverse flow is addressed in detail. The influence of reverse flow intensity and particle size on recleanability is studied in laboratory tests on specimens of HEPA filter media. The minimum required reverse flow intensity is determined on the basis of the residual pressure drop after recleaning. Measurements of local pressures in a single pleat and theoretically calculated flow patterns showed that airflows in conventional deep-pleat pack geometries during reverse flow recleaning are not uniformly distributed. The difference between the air velocities at the pleat inlet and the downstream end can vary by up to a factor of five at typical reverse flow intensities, decreasing the overall effectiveness of particle dislodgement from the filter medium and shortening filter unit service life. Results are presented of field investigations into the recleanability of deep-pleat filter units during actual service conditions for three different dust types. 7 refs., 12 figs., 1 tab

  17. Performance of HEPA Filter Medium under Accidental Conditions in Nuclear Installations

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air filters (HEPA Filters) are the main components in ventilation or confinement system for the retention of radioactive particles in nuclear installations. During abnormal conditions or accidents (e.g. fire accident, criticality in a nuclear fuel cycle facility and LOCA in power reactors) the resulting heat, smoke and humidity affect to a large extent the performance of HEPA filters. As a part of a research programme aims at the evaluation and improvement of the performance of HEPA filter media during abnormal conditions, the effect of elevated temperatures up to 400 degree C on the resistance of medium to penetration of water under pressure has been investigated. The test results showed that the resistance of the medium to penetration of water decreases with increase in temperature and thermal exposure time. This could be attributed to burnout of the organic binder used to improve the resistance of the medium to the penetration of water. The results also showed that at 400 degree C the resistance of the medium to the penetration of water disappeared. This was confirmed by inspection of the filter medium samples after exposure to high temperature using a scanning electron microscope. The inspection of the medium samples showed that the organic binder in the medium was deformed and finally collapsed at 400 degree C. Also, a best estimate model for the relation of filter medium resistance to water penetration under elevated temperature has been implemented. The results of this study can help in establishing a regulatory operating limit conditions (OLCs) for HEPA filter operation at high temperatures conditions in nuclear installations.

  18. ASME AG-1 Section FC Qualified HEPA Filters; a Particle Loading Comparison - 13435

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air (HEPA) Filters used to protect personnel, the public and the environment from airborne radioactive materials are designed, manufactured and qualified in accordance with ASME AG-1 Code section FC (HEPA Filters) [1]. The qualification process requires that filters manufactured in accordance with this ASME AG-1 code section must meet several performance requirements. These requirements include performance specifications for resistance to airflow, aerosol penetration, resistance to rough handling, resistance to pressure (includes high humidity and water droplet exposure), resistance to heated air, spot flame resistance and a visual/dimensional inspection. None of these requirements evaluate the particle loading capacity of a HEPA filter design. Concerns, over the particle loading capacity, of the different designs included within the ASME AG-1 section FC code[1], have been voiced in the recent past. Additionally, the ability of a filter to maintain its integrity, if subjected to severe operating conditions such as elevated relative humidity, fog conditions or elevated temperature, after loading in use over long service intervals is also a major concern. Although currently qualified HEPA filter media are likely to have similar loading characteristics when evaluated independently, filter pleat geometry can have a significant impact on the in-situ particle loading capacity of filter packs. Aerosol particle characteristics, such as size and composition, may also have a significant impact on filter loading capacity. Test results comparing filter loading capacities for three different aerosol particles and three different filter pack configurations are reviewed. The information presented represents an empirical performance comparison among the filter designs tested. The results may serve as a basis for further discussion toward the possible development of a particle loading test to be included in the qualification requirements of ASME AG-1

  19. Radioactive air emissions notice of construction HEPA filtered vacuum radioactive air emission units

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSON, R.E.

    1999-09-01

    This notice of construction (NOC) requests a categorical approval for construction and operation of certain portable high-efficiency particulate air (HEPA) filtered vacuum radionuclide airborne emission units (HVUs). Approval of this NOC application is intended to allow operation of the HVUs without prior project-specific approval. This NOC does not request replacement or supersedence of any previous agreements/approvals by the Washington State Department of Health for the use of vacuums on the Hanford Site. These previous agreement/approvals include the approved NOCs for the use of EuroClean HEPA vacuums at the T Plant Complex (routine technical meeting 12/10/96) and the Kelly Decontamination System at the Plutonium-Uranium Extraction (PUREX) Plant (routine technical meeting 06/25/96). Also, this NOC does not replace or supersede the agreement reached regarding the use of HEPA hand-held/shop-vacuum cleaners for routine cleanup activities conducted by the Environmental Restoration Project. Routine cleanup activities are conducted during the surveillance and maintenance of inactive waste sites (Radioactive Area Remedial Action Project) and inactive facilities. HEPA hand-held/shop-vacuum cleaners are used to clean up spot surface contamination areas found during outdoor radiological field surveys, and to clean up localized radiologically contaminated material (e.g., dust, dirt, bird droppings, animal feces, liquids, insects, spider webs, etc.). This agreement, documented in the October 12, 1994 Routine Meeting Minutes, is based on routine cleanup consisting of spot cleanup of low-level contamination provided that, in each case, the source term potential would be below 0.1 millirem per year.

  20. ASME AG-1 Section FC Qualified HEPA Filters; a Particle Loading Comparison - 13435

    Energy Technology Data Exchange (ETDEWEB)

    Stillo, Andrew [Camfil Farr, 1 North Corporate Drive, Riverdale, NJ 07457 (United States); Ricketts, Craig I. [New Mexico State University, Department of Engineering Technology and Surveying Engineering, P.O. Box 30001 MSC 3566, Las Cruces, NM 88003-8001 (United States)

    2013-07-01

    High Efficiency Particulate Air (HEPA) Filters used to protect personnel, the public and the environment from airborne radioactive materials are designed, manufactured and qualified in accordance with ASME AG-1 Code section FC (HEPA Filters) [1]. The qualification process requires that filters manufactured in accordance with this ASME AG-1 code section must meet several performance requirements. These requirements include performance specifications for resistance to airflow, aerosol penetration, resistance to rough handling, resistance to pressure (includes high humidity and water droplet exposure), resistance to heated air, spot flame resistance and a visual/dimensional inspection. None of these requirements evaluate the particle loading capacity of a HEPA filter design. Concerns, over the particle loading capacity, of the different designs included within the ASME AG-1 section FC code[1], have been voiced in the recent past. Additionally, the ability of a filter to maintain its integrity, if subjected to severe operating conditions such as elevated relative humidity, fog conditions or elevated temperature, after loading in use over long service intervals is also a major concern. Although currently qualified HEPA filter media are likely to have similar loading characteristics when evaluated independently, filter pleat geometry can have a significant impact on the in-situ particle loading capacity of filter packs. Aerosol particle characteristics, such as size and composition, may also have a significant impact on filter loading capacity. Test results comparing filter loading capacities for three different aerosol particles and three different filter pack configurations are reviewed. The information presented represents an empirical performance comparison among the filter designs tested. The results may serve as a basis for further discussion toward the possible development of a particle loading test to be included in the qualification requirements of ASME AG-1

  1. Methods for in-place testing of HEPA and iodine filters used in nuclear power plants

    International Nuclear Information System (INIS)

    The purpose of this work was a general investigation of existing in-place test methods and to build an equipment for in-place testing of HEPA and iodine sorption filters. In this work the discussion is limited to methods used in in-place testing of HEPA and iodine sorption filters used in light-water-cooled reactor plants. Dealy systems, built for the separation of noble gases, and testing of them is not discussed in the work. Contaminants present in the air of a reactor containment can roughly be diveded into three groups: aerosols, reactive gases, and noble gases. The aerosols are filtered with HEPA (High Efficiency Particulate Air) filters. The most important reactive gases are molecular iodine and its two compounds: hydrogen iodide and methyl iodide. Of gases to be removed by the filters methyl iodide is the gas most difficult to remove especially at high relative humidities. Impregnated activated charcoal is generally used as sorption material in the iodine filters. Experience gained from the use of nuclear power plants proves that the function of high efficiency air filter systems can not be considered safe until this is proved by in-place tests. In-place tests in use are basically equal. A known test agent is injected upstream of the filter to be tested. The efficiency is calculated from air samples taken from both sides of the filter. (author)

  2. The effect of media area on the dust holding capacity of deep pleat HEPA filters

    International Nuclear Information System (INIS)

    The high potential cost of storage, treatment and disposal of radioactive wastes places a premium on the longevity of installed HEPA filters in situations in radioactive processing facilities where dust capacity is a life determining factor. Previous work investigated the dust holding capacity v pressure drop characteristics of different designs of HEPA filter and also the effect of using graded density papers. This paper records an investigation of the effect of media area variation on the dust holding capacity of the open-quotes deep-pleatclose quotes design of HEPA filter. As in the previously reported work two test dusts (carbon black and sub micron sodium chloride) in the range (0.15 - 0.4μm) were used. Media area adjustment was effected by varying the number of separators within the range 60 - 90. Results with the coarser dust allowed an optimum media area to be identified. Media areas greater or smaller than this optimum retained less dust than the optimum for the same terminal pressure drop. Conversely with the finer sodium chloride aerosol the dust holding capacity continued to increase up to the maximum area investigated. 7 refs., 4 figs

  3. Efficiency and mass loading characteristics of a typical HEPA filter media material

    International Nuclear Information System (INIS)

    The particle removal efficiency of the high-efficiency particulate air (HEPA) filter material used at the Savannah River Site was measured as a function of monodisperse particle diameter and two gas filtration velocities. the results indicate that the material meets or exceeds the minimum specified efficiency of 99.97% for all particle diameters at both normal and minimum operating flow conditions encountered at the Savannah River site. The pressure drop across the HEPA filter material used at the Savannah River site was measured as a function of particle mass loading for various aerosol size distributions. The pressure drop was found to increase linearly with the particle mass loaded onto the filters, as long as the particles were completely dry. The slope of the curve was found to be dependent on the particle diameter and velocity of the aerosol. The linear behavior between the initial pressure drop (clean filter) and the final pressure drop (loaded filter) implies that the filtration mechanism is dominated by the particle cake that rapidly forms on the front surface of the HEPA filter. This behavior is consistent with the high filtration efficiency of the material

  4. The effect of media area on the dust holding capacity of deep pleat HEPA filters

    Energy Technology Data Exchange (ETDEWEB)

    Dyment, J. [AWE, Aldermaston (United Kingdom); Loughborough, D. [AEAT Harwell, Oxford (United Kingdom)

    1997-08-01

    The high potential cost of storage, treatment and disposal of radioactive wastes places a premium on the longevity of installed HEPA filters in situations in radioactive processing facilities where dust capacity is a life determining factor. Previous work investigated the dust holding capacity v pressure drop characteristics of different designs of HEPA filter and also the effect of using graded density papers. This paper records an investigation of the effect of media area variation on the dust holding capacity of the {open_quotes}deep-pleat{close_quotes} design of HEPA filter. As in the previously reported work two test dusts (carbon black and sub micron sodium chloride) in the range (0.15 - 0.4{mu}m) were used. Media area adjustment was effected by varying the number of separators within the range 60 - 90. Results with the coarser dust allowed an optimum media area to be identified. Media areas greater or smaller than this optimum retained less dust than the optimum for the same terminal pressure drop. Conversely with the finer sodium chloride aerosol the dust holding capacity continued to increase up to the maximum area investigated. 7 refs., 4 figs.

  5. Multiple HEPA filter test methods, July 1, 1974--March 31, 1975

    International Nuclear Information System (INIS)

    A laboratory apparatus has been constructed for testing two HEPA filters in a series configuration. The apparatus consists of an instrumented wind tunnel in which the HEPA filters are mounted, and an auxiliary wind tunnel for obtaining diluted samples of the challenge aerosol upstream of the first filter. Measurements performed with a single particle aerosol spectrometer demonstrate the capability for measuring overall protection factors of greater than 2.5 x 108. The decay of penetration as a function of time in individual HEPA filters indicates no preferential size discrimination in the range of 0.1 μm to 1.0 μm; nor is there a preferential size discrimination of penetration in this same range. A theoretical feasibility study has been performed on the use of an inhomogeneous electric field/induced aerosol electric dipole interaction for potential use as an air cleaning mechanism. Numerical evaluation of a coaxial cylinder geometry indicates that the method is feasible for collection of particles down to 0.1 μm under typical airflow velocity conditions. Small modifications in the geometry may be incorporated to create an instrument capable of measuring particle size. Geometries other than coaxial cylinders are also under investigation

  6. Behavior of the polygonal HEPA filter exposed to water droplets carried by the offgas flow

    International Nuclear Information System (INIS)

    A polygonal high-efficiency particulate air (HEPA) filter element has been developed and tested with a view to cleaning the dissolver offgas from reprocessing plants. It is likewise suited to filter process offgases generated in other plants. Due to its high dew point (about 30 degree C) the dissolver offgas, before being directed into the HEPA filter, is heated with a gas heater to approx. 100 degree C so that condensation in the pipework upstream of the filter and in the filter proper is avoided. In case of failure of the heater the offgas may undergo condensation upstream of the HEPA filter until it is bypassed to a standby heater or a standby filter system. Consequently, the filter may be loaded with water droplets. therefore, experiments have been performed with a view to estimating the behavior of the polygonal filter element when exposed to condensate droplets in a real plant. According to the experiments performed so far it can be anticipated that in case of failure of the heater the amount of condensate produced until bypassing to a standby system will not damage a new or little loaded polygonal filter element. The experiments will be carried on with the goal of investigating the behavior of a heavily loaded polygonal filter element exposed to water droplets

  7. Effect of elevated temperature on the mechanical strength of HEPA filters

    International Nuclear Information System (INIS)

    The effect of elevated temperature on the mechanical strength of HEPA filters was studied in order to evaluate and improve their performance under high temperature conditions. As part of this study the mechanical strength of HEPA filter medium which is the limiting factor in terms of the filter strength was experimentally studied at elevated temperature up to 400 degree C, and thermal exposure times ranged from 2 min to 4 h. The failure pressures of HEPA filter units after long exposure to 250 degree C were also investigated. The test results show that the medium strength decreases with increase in temperature challenge and thermal exposure time due to burnout of the organic binder used to improve the strength and flexibility of the medium. The test results also show that the tensile strength of the conventional filter medium drops to about 40 % of the value at room temperature after exposure to 250 degree C for 6 h; therefore, the continuous exposure of the conventional filter medium to this temperature is critical. The average failure differential pressures of all commercial tested filters were found to lie between 9 and 18 kPa at ambient temperature and between 6 and 11 kPa after thermal challenge at 250 degree C for 100 h. It was found that swelling and capture of the ends of individual pleats has led to filter failure.3 fig., 2 tab

  8. Recleaning of HEPA filters by reverse flow - evaluation of the underlying processes and the cleaning technique

    International Nuclear Information System (INIS)

    HEPA filter operation at high concentrations of fine dusts requires the periodic recleaning of the filter units in their service locations. Due to the low mechanical stress induced during the recleaning process the regenration via low pressure reverse flow is a very suitable technique. Recleanability of HEPA filter had been attained for particle diameter >0,4 μm at air velocities up to 1 m/s, but filter clogging occurred in case of smaller particles. The recleaning forces are too weak for particles <0,4 μm. With respect to the low tensile strength of HEPA filter media higher flow velocities are excluded. The analysis of reverse flow recleaning in a single pleat device showed extremly non uniform flow pattern in conventional deep-pleat pack geometries. More uniform flow conditions are attained by changing the pleat geometry. The realisation of high flow velocities at the glas fiber medium inside the filter pack requires shortening of the pleates to some 150 mm and the adaptation of the distance between filter pack and the recleaning device with respect to the nozzle diameter and the width of the filter pleats. (orig.). 44 figs., 36 refs

  9. Seismic qualification of HEPA filters by test in an actual operating condition

    International Nuclear Information System (INIS)

    Flander's Filters, Inc., has completed an analysis and test program which has resulted in a seismically prequalified high efficiency particulate air (HEPA) filter housing with the HEPA filters installed and operating during the qualification testing. The nuclear seismic qualification program was performed by Corporate Consulting and Development Company, Ltd. During the seismic qualification testing a dioctylphthalate (DOP) test was performed for the duration of the shake table test and the system performed successfully. The details of the seismic qualification test procedure, housing and filter design, and the structural performance results are presented. Comparisons are made between theoretically predicted results and test results. The preliminary test program pointed out some potential vibration problems with separator type filters due to media puncture during shaking. HEPA filters have typically been given less emphasis from a seismic qualification standpoint than the primary structure and equipment (such as fans, cooling coils, heaters, etc.) in filter trains and/or air handling units. This nuclear seismic qualification program has shown that this design for filters and housing will withstand the seismic occurrence and perform its required safety related function during and after the seismic occurrence. Conclusions resulting from this test program are presented and some recommendations and precautions are given

  10. Clogging of industrial pleated high efficiency particulate air (HEPA) filters in the event of fire

    International Nuclear Information System (INIS)

    Research highlights: → Study of the clogging of pleated HEPA filters in case of fire in a nuclear installation. → Influence of fuels, filtration velocity and burnings conditions on aerosol characteristics and filter clogging. → Development of an empirical way to predict the clogging behaviour of HEPA filters in the event of fire. - Abstract: The IRSN and AREVA NC are currently conducting a common interest fire research programme with the aim, among other things, of improving knowledge of clogging of high efficiency particulate air (HEPA) filters and developing an empirical model for clogging of such filters by combustion aerosols. This model must - insofar as possible - be independent of the nature of the fuel and be able to be integrated in a calculation code covering the interaction between the ventilation and the fire. This paper discusses the influence of various 'direct' factors such as the filtration velocity, the mass of deposited aerosol per filter area, the diameter and morphology of the combustion particles, the condensate content of the aerosols, and 'indirect' factors such as the air flow feeding the fire and its oxygen content, which influence the evolution of the aeraulic resistance of a clogged filter.

  11. Behavior of the loaded polygonal HEPA filter exposed to water droplets carried by the offgas flow

    International Nuclear Information System (INIS)

    For cleaning of the dissolver offgas from reprocessing plants a HEPA polygonal filter was developed and tested which can be used to filter also exhausts from processes in other facilities. The following tests were carried out in order to obtain information about the behavior of the loaded filter element exposed to water droplets in the offgas stream: The filter elements were loaded up to 1300 Pa differential pressure with (a) alumina powder particulates < 3 μm in size, (b) a sorted fine dust fraction taken from dust bags of household vacuum cleaners, and (c) salt aerosols and then exposed to water aerosols supplied to the offgas flow upstream of the filter. Throughout the tests with filter element loading according to (a) and (b) the filter elements were not damaged. Whereas in the test series with type (a) loading the differential pressure remained almost unchanged, it increased at different degrees in the tests with loading according to (b), depending on the amount of water aerosols supplied. In the test involving type (c) loading the differential pressure steeply rose at the filter and the filter element was damaged after about 25 minutes at a final differential pressure of approx. 14.5 kPa. With the results from the last test campaign on hand, mechanical testing of the HEPA polygonal filter element was terminated. A special device was developed, built and put into operation for manufacturing the HEPA polygonal filter element. This device is briefly described here. 2 refs., 3 figs

  12. Clogging of industrial pleated high efficiency particulate air (HEPA) filters in the event of fire

    Energy Technology Data Exchange (ETDEWEB)

    Mocho, V.M. [Institut de Radioprotection et de Surete Nucleaire (IRSN), Saclay, BP 68, 91192 Gif-sur-Yvette cedex (France); Ouf, F.-X., E-mail: francois-xavier.ouf@irsn.f [Institut de Radioprotection et de Surete Nucleaire (IRSN), Saclay, BP 68, 91192 Gif-sur-Yvette cedex (France)

    2011-05-15

    Research highlights: Study of the clogging of pleated HEPA filters in case of fire in a nuclear installation. Influence of fuels, filtration velocity and burnings conditions on aerosol characteristics and filter clogging. Development of an empirical way to predict the clogging behaviour of HEPA filters in the event of fire. - Abstract: The IRSN and AREVA NC are currently conducting a common interest fire research programme with the aim, among other things, of improving knowledge of clogging of high efficiency particulate air (HEPA) filters and developing an empirical model for clogging of such filters by combustion aerosols. This model must - insofar as possible - be independent of the nature of the fuel and be able to be integrated in a calculation code covering the interaction between the ventilation and the fire. This paper discusses the influence of various 'direct' factors such as the filtration velocity, the mass of deposited aerosol per filter area, the diameter and morphology of the combustion particles, the condensate content of the aerosols, and 'indirect' factors such as the air flow feeding the fire and its oxygen content, which influence the evolution of the aeraulic resistance of a clogged filter.

  13. Performance and environmental characteristics of a compact, high-capacity HEPA filter design

    International Nuclear Information System (INIS)

    An improved version of the HEPA filter has been developed and evaluated for conformity with MIL-51068. In this design, the filter paper (conforming to MIL-F-51079) is pleated to a depth of only 18 mm. Ribbons essentially the same material as the filter paper form inter-pleat spacers, providing a crest-to-crest spacing of 3 mm. The resultant filter has the same DOP penetration level as the standard MIL-F-51068 HEPA filter, but about half its pressure drop at the same airflow. Materials of construction, adhesives, gaskets and faceguards match MIL-f-51068. Both flat-panel and zig-zag configurations of the filter meet the rough handling test of MIL-F-51068. Preliminary indications are that both filters will meet the overpressure tests of MIL-F-51068D and the flammability requirements of UL 586; these tests are in progress. Filters can be supplied to interchange with existing HEPA filter sizes. The improved pressure drop characteristic of these filters can be used to provide longer intervals between filter changes, or equal life at greater capacity

  14. Introduction of a new generation of high-capacity HEPA filters and a comparison of their performance to HEPA filters available on the market

    International Nuclear Information System (INIS)

    A recently developed manufacturing process has resulted in a high capacity hepa filter that meets the United States Department of Energy requirements. The DIMPLE-PLEAT trademark process, using newly developed low resistance media formulation, has been successfully employed to produce a true separatorless glass microfiber filter element, SUPER-FLOW reg sign, II* in any practical depth from 1 to 12 inches. A good number of 24'' x 24'' x 11 1/2'' filters, after passing tests at the filter retest facility, have already been employed by a facility operated for the DOE. These filters are installed in a system designed for 2000 CFM per unit - a high capacity operation. In addition, these new filters are also routinely being supplied to other DOE operations. This specially formulated all glass microfiber non-woven media is unique because it offers the lowest resistance and the highest dust holding capacity of any hepa filters meeting DOE requirements for strength and thickness as per MIL-F-51079D. Application of this media to an appropriate design for circular filters similar to those employed at Harwell (U.K.) is in progress

  15. Volatility and leachability of heavy metals and radionuclides in thermally treated HEPA filter media generated from nuclear facilities

    International Nuclear Information System (INIS)

    Highlights: ► Thermally treated HEPA filter media was transformed into glassy bulk materials. ► Main radionuclide and heavy metal were Cs-137 and Zn. ► Cs and Zn were transformed into stable form without volatilization and leaching. ► The proposed technique is simple and energy efficient procedure. - Abstract: The purpose of the present study was to apply thermal treatments to reduce the volume of HEPA filter media and to investigate the volatility and leachability of heavy metals and radionuclides during thermal treatment. HEPA filter media were transformed to glassy bulk material by thermal treatment at 900 °C for 2 h. The most abundant heavy metal in the HEPA filter media was Zn, followed by Sr, Pb and Cr, and the main radionuclide was Cs-137. The volatility tests showed that the heavy metals and radionuclides in radioactive HEPA filter media were not volatilized during the thermal treatment. PCT tests indicated that the leachability of heavy metals and radionuclides was relatively low compared to those of other glasses. XRD results showed that Zn and Cs reacted with HEPA filter media and were transformed into crystalline willemite (ZnO·SiO2) and pollucite (Cs2OAl2O34SiO2), which are not volatile or leachable. The proposed technique for the volume reduction and transformation of radioactive HEPA filter media into glassy bulk material is a simple and energy efficient procedure without additives that can be performed at relatively low temperature compared with conventional vitrification process.

  16. Volatility and leachability of heavy metals and radionuclides in thermally treated HEPA filter media generated from nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, In-Ho [Korea Atomic Energy Research Institute (KAERI), 1045 Daedeokdaero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Choi, Wang-Kyu, E-mail: nwkchoi@kaeri.re.kr [Korea Atomic Energy Research Institute (KAERI), 1045 Daedeokdaero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Lee, Suk-Chol; Min, Byung-Youn; Yang, Hee-Chul; Lee, Kune-Woo [Korea Atomic Energy Research Institute (KAERI), 1045 Daedeokdaero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Thermally treated HEPA filter media was transformed into glassy bulk materials. Black-Right-Pointing-Pointer Main radionuclide and heavy metal were Cs-137 and Zn. Black-Right-Pointing-Pointer Cs and Zn were transformed into stable form without volatilization and leaching. Black-Right-Pointing-Pointer The proposed technique is simple and energy efficient procedure. - Abstract: The purpose of the present study was to apply thermal treatments to reduce the volume of HEPA filter media and to investigate the volatility and leachability of heavy metals and radionuclides during thermal treatment. HEPA filter media were transformed to glassy bulk material by thermal treatment at 900 Degree-Sign C for 2 h. The most abundant heavy metal in the HEPA filter media was Zn, followed by Sr, Pb and Cr, and the main radionuclide was Cs-137. The volatility tests showed that the heavy metals and radionuclides in radioactive HEPA filter media were not volatilized during the thermal treatment. PCT tests indicated that the leachability of heavy metals and radionuclides was relatively low compared to those of other glasses. XRD results showed that Zn and Cs reacted with HEPA filter media and were transformed into crystalline willemite (ZnO{center_dot}SiO{sub 2}) and pollucite (Cs{sub 2}OAl{sub 2}O{sub 3}4SiO{sub 2}), which are not volatile or leachable. The proposed technique for the volume reduction and transformation of radioactive HEPA filter media into glassy bulk material is a simple and energy efficient procedure without additives that can be performed at relatively low temperature compared with conventional vitrification process.

  17. Adhesion and removal kinetics of Bacillus cereus biofilms on Ni-PTFE modified stainless steel.

    Science.gov (United States)

    Huang, Kang; McLandsborough, Lynne A; Goddard, Julie M

    2016-01-01

    Biofilm control remains a challenge to food safety. A well-studied non-fouling coating involves codeposition of polytetrafluoroethylene (PTFE) during electroless plating. This coating has been reported to reduce foulant build-up during pasteurization, but opportunities remain in demonstrating its efficacy in inhibiting biofilm formation. Herein, the initial adhesion, biofilm formation, and removal kinetics of Bacillus cereus on Ni-PTFE-modified stainless steel (SS) are characterized. Coatings lowered the surface energy of SS and reduced biofilm formation by > 2 log CFU cm(-2). Characterization of the kinetics of biofilm removal during cleaning demonstrated improved cleanability on the Ni-PTFE coated steel. There was no evidence of biofilm after cleaning by either solution on the Ni-PTFE coated steel, whereas more than 3 log and 1 log CFU cm(-2) of bacteria remained on the native steel after cleaning with water and an alkaline cleaner, respectively. This work demonstrates the potential application of Ni-PTFE non-fouling coatings on SS to improve food safety by reducing biofilm formation and improving the cleaning efficiency of food processing equipment. PMID:27020838

  18. Radioactive air emissions notice of construction for HEPA filtered vacuum radioactive air emission units

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.E.

    1997-10-27

    This notice of construction (NOC) requests a categorical approval for construction and operation of certain portable high-efficiency particulate air (HEPA) filtered vacuum radionuclide airborne emission units (HVUs). Approval of this NOC application is intended to allow operation of the HVUs without prior project-specific approval. This NOC does not request replacement or supersedence of any previous agreements/approvals by the Washington State Department of Health (WDOH) for the use of vacuums on the Hanford Site. These previous agreements/approvals include the approved NOCs for the use of EuroClean HEPA vacuums at the T Plant Complex and the Kelly Decontamination System at the Plutonium-Uranium Extraction (PUREX) Plant. Also, this NOC does not replace or supersede the agreement reached regarding the use of HEPA hand-held/shop-vacuum cleaners for routine cleanup activities conducted by the Environmental Restoration Project. Routine cleanup activities are conducted during the surveillance and maintenance of inactive waste sites (Radioactive Area Remedial Action Project) and inactive facilities. HEPA hand-held/shop-vacuum cleaners are used to clean up spot surface contamination areas found during outdoor radiological field surveys, and to clean up localized radiologically contaminated material (e.g., dust, dirt, bird droppings, animal feces, liquids, insects, spider webs, etc.). This agreement, documented in the October 12, 1994 Routine Meeting Minutes, is based on routine cleanup consisting of spot cleanup of low-level contamination provided that, in each case, the source term potential would be below 0.1 millirem per year. This application is intended to request sitewide approval for the new activities, and provide an option for any facility on the site to use this approval, within the terms of this NOC. The HVUs used in accordance with this NOC will support reduction of radiological contamination at various locations on the Hanford Site. Radiation Protection Air

  19. Radioactive air emissions notice of construction for HEPA filtered vacuum radioactive air emissions units

    International Nuclear Information System (INIS)

    This notice of construction (NOC) requests a categorical approval for construction and operation of certain portable high-efficiency particulate air (HEPA) filtered vacuum radionuclide airborne emission units (HVUs). Approval of this NOC application is intended to allow operation of the HVUs without prior project-specific approval. This NOC does not request replacement or supersedence of any previous agreements/approvals by the Washington State Department of Health (WDOH) for the use of vacuums on the Hanford Site. These previous agreements/approvals include the approved NOCs for the use of EuroClean HEPA vacuums at the T Plant Complex and the Kelly Decontamination System at the Plutonium-Uranium Extraction (PUREX) Plant. Also, this NOC does not replace or supersede the agreement reached regarding the use of HEPA hand-held/shop-vacuum cleaners for routine cleanup activities conducted by the Environmental Restoration Project. Routine cleanup activities are conducted during the surveillance and maintenance of inactive waste sites (Radioactive Area Remedial Action Project) and inactive facilities. HEPA hand-held/shop-vacuum cleaners are used to clean up spot surface contamination areas found during outdoor radiological field surveys, and to clean up localized radiologically contaminated material (e.g., dust, dirt, bird droppings, animal feces, liquids, insects, spider webs, etc.). This agreement, documented in the October 12, 1994 Routine Meeting Minutes, is based on routine cleanup consisting of spot cleanup of low-level contamination provided that, in each case, the source term potential would be below 0.1 millirem per year. This application is intended to request sitewide approval for the new activities, and provide an option for any facility on the site to use this approval, within the terms of this NOC. The HVUs used in accordance with this NOC will support reduction of radiological contamination at various locations on the Hanford Site. Radiation Protection Air

  20. Highly efficient gene transfer into hepatocyte-like HepaRG cells: new means for drug metabolism and toxicity studies.

    Science.gov (United States)

    Laurent, Veronique; Fraix, Aurore; Montier, Tristan; Cammas-Marion, Sandrine; Ribault, Catherine; Benvegnu, Thierry; Jaffres, Paul-Alain; Loyer, Pascal

    2010-03-01

    HepaRG progenitor cells are capable of differentiating into hepatocyte-like cells that express a large set of liver-specific functions. These cells, however, only express small amounts of an important cytochrome P450, the CYP2E1, which limits their use for toxicological studies of drugs metabolized by this pathway. Our aim was to establish an efficient transfection protocol to increase CYP2E1 expression in HepaRG cells. Transfection protocols of the green fluorescent protein (GFP) reporter gene were evaluated using electroporation and cationic lipids belonging to the lipophosphonates, lipophosphoramidates and lipids derived from glycine betaine. Following optimization of the charge ratios, plasmid DNA and formulations with neutral co-lipids, the lipophosphoramidate compounds KLN47 and BSV10, allowed expression of the GFP in approximately 50% of adherent progenitor HepaRG cells, while electroporation targeted GFP expression in approximately 85% of both progenitor and differentiated cells in suspension. Transient enforced expression of active CYP2E1 was also achieved in progenitors and/or differentiated HepaRG cells using the electroporation and the lipophosphoramidate compound BSV10. Importantly, in electroporated cells, CYP2E1 expression level was correlated with a significant increase in CYP2E1-specific enzymatic activity, which opens new perspectives for this CYP-dependent drug metabolism and toxicity studies using HepaRG cells. PMID:20213646

  1. Criteria for calculating the efficiency of deep-pleated HEPA filters with aluminum separators during and after design basis accidents

    International Nuclear Information System (INIS)

    The authors have reviewed the literature on the performance of high efficiency particulate air (HEPA) filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). This study is only applicable to the standard deep-pleated HEPA filter with aluminum separators as specified in ASME N509. The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be structurally damaged and have a residual efficiency of 0%. Despite the many studies on HEPA filter performance under adverse conditions, there are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen when there was insufficient data

  2. Design and construction of a type testing and production test facility for HEPA filters to be installed in ventilation systems of German nuclear power plants

    International Nuclear Information System (INIS)

    High-efficiency particulate air filters (HEPA filters) in nuclear plants frequently constitute part of the last barrier separating potentially contaminated areas from the environment. Their failure may cause radioactive substances to be released. The sensitivity of the filter media employed, and the problems associated with manufacturing the HEPA filters normally used in nuclear plants, result in considerable differences in the quality of commercial HEPA filters. Aging of filter components during operation may greatly reduce the loading capacity of the entire filter. A relatively large number of HEPA filters were found to be defective at the end of service life. In order to be able to guarantee the removal efficiency of HEPA filters over a sufficient length of service life and under accident conditions, quality control measures must be introduced. Type tests of the HEPA filters to be used in nuclear plants must include a number of criteria beyond the loads imposed by the rated volumetric flow rate under the usual room air conditions. These criteria have been combined in a special type test (DIN 25 414), and passing this test should be made a prerequisite for the use of HEPA filters in nuclear plants. In addition, random inspections of production HEPA filters should be carried out to allow an adequate standard of quality to be guaranteed for a long time. (orig./GL)

  3. Health hazards associated with the use of di-(2-ethylhexyl) phthalate (commonly referred to as DOP) in HEPA filter test

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    Di-(2-ethylhexyl) phthalate (DEHP), commonly referred to as di-octyl phthalate, is an important production chemical in the US. In addition to its major use as an additive in plastics, DEHP is widely used to evaluate the effectiveness of high efficiency particulate air (HEPA) filters. Historically, DEHP was also used in quantitative fit testing for respirators. Evaluations of this compound a decade ago showed that it can induce hepatocellular carcinomas in laboratory animals. Although most Department of Energy (DOE) facilities have since discontinued using DEHP in respirator fit testing, DEHP continues to be used for evaluating HEPA filters. This report summarizes available information on the toxicity, mutagenicity, carcinogenicity, and other hazards and problems posed by DEHP, specifically with reference to HEPA filter testing. Information on work practice improvements as well as the availability and suitability of DEHP substitutes are also presented. This material should assist the DOE in the safe use of this material.

  4. A Custom Robotic System for Inspecting HEPA Filters in the Payload Changeout Room at the NASA Kennedy Space Center

    Science.gov (United States)

    Spencer, James E., Jr.; Looney, Joe

    1994-01-01

    In this paper, the prime objective is to describe a custom 4-dof (degree-of-freedom) robotic arm capable of autonomously or telerobotically performing systematic HEPA filter inspection and certification in the Shuttle Launch Pad Payload Changeout Rooms (PCR's) on pads A and B at the Kennedy Space Center, Florida. This HEPA filter inspection robot (HFIR) has been designed to be easily deployable and is equipped with the necessary sensory devices, control hardware, software and man-machine interfaces needed to implement HEPA filter inspection reliably and efficiently without damaging the filters or colliding with existing PCR structures or filters. The main purpose of the HFIR is to implement an automated positioning system to move special inspection sensors in pre-defined or manual patterns for the purpose of verifying filter integrity and efficiency. This will ultimately relieve NASA Payload Operations from significant problems associated with time, cost and personnel safety, impacts realized during non-automated PCR HFIR filter certification.

  5. Criteria for calculating the efficiency of deep-pleated HEPA filters with aluminum separators during and after design basis accidents

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, W.; First, M.W.; Anderson, W.L. [Lawrence Livermore National Laboratory, CA (United States)] [and others

    1995-02-01

    We have reviewed the literature on the performance of HEPA filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). This study is only applicable to the standard deep-pleated HEPA filter with aluminum separators as specified in ASME N509[1]. Other HEPA filter designs such as the mini-pleat and separatorless filters are not included in this study. The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be damaged and have a residual efficiency of 0%. There are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen. The estimation of the efficiency of the HEPA filters under DBA conditions involves three steps: (1) The filter pressure drop and environmental parameters are determined during and after the DBA, (2) Comparing the filter pressure drop to a set of threshold values above which the filter is damaged. There is a different threshold value for each combination of environmental parameters, and (3) Determining the filter efficiency. If the filter pressure drop is greater than the threshold value, the filter is damaged and is assigned 0% efficiency. If the pressure drop is less, then the filter is not damaged and the efficiency is determined from literature values of the efficiency at the environmental conditions.

  6. Criteria for calculating the efficiency of deep-pleated HEPA filters with aluminum separators during and after design basis accidents

    International Nuclear Information System (INIS)

    We have reviewed the literature on the performance of HEPA filters under normal and abnormal conditions to establish criteria for calculating the efficiency of HEPA filters in a DOE nonreactor nuclear facility during and after a Design Basis Accident (DBA). This study is only applicable to the standard deep-pleated HEPA filter with aluminum separators as specified in ASME N509[1]. Other HEPA filter designs such as the mini-pleat and separatorless filters are not included in this study. The literature review included the performance of new filters and parameters that may cause deterioration in the filter performance such as filter age, radiation, corrosive chemicals, seismic and rough handling, high temperature, moisture, particle clogging, high air flow and pressure pulses. The deterioration of the filter efficiency depends on the exposure parameters; in severe exposure conditions the filter will be damaged and have a residual efficiency of 0%. There are large gaps and limitations in the data that introduce significant error in the estimates of HEPA filter efficiencies under DBA conditions. Because of this limitation, conservative values of filter efficiency were chosen. The estimation of the efficiency of the HEPA filters under DBA conditions involves three steps: (1) The filter pressure drop and environmental parameters are determined during and after the DBA, (2) Comparing the filter pressure drop to a set of threshold values above which the filter is damaged. There is a different threshold value for each combination of environmental parameters, and (3) Determining the filter efficiency. If the filter pressure drop is greater than the threshold value, the filter is damaged and is assigned 0% efficiency. If the pressure drop is less, then the filter is not damaged and the efficiency is determined from literature values of the efficiency at the environmental conditions

  7. Development of a method for nuclide leaching from glass fiber in HEPA filter

    International Nuclear Information System (INIS)

    For the disposal of the high efficiency particulate air (HEPA) glass filter to environment, the glass fiber should be leached to lower its radioactive concentration. To derive the optimum method for removal of Co and Cs from HEPA glass fiber, four methods were applied in this study. Results of electrochemical leaching of glass fiber by 4.0 M HNO3-0.1 M Ce(IV) solution showed that the removal efficiency of 134Cs, 137Cs, and 60Cs from glass fiber after 5 h was 96.4, 93.6, and 93.8%, respectively. Results by 5 wt% NaOH solution showed that the removal efficiency of 134Cs, 137Cs, and 60Cs after 30 h was 81.7, 82.1, and 10.0%, respectively. Results by repeat 2.0 M HNO3 solution showed that the removal efficiencies of 134Cs, 137Cs, and 60Cs after 2 h of three repetitions were 96.2, 99.4, and 99.1%, respectively. Finally, results by repeat 4.0 M HNO3 solution showed that the removal efficiencies of 134Cs, 137Cs, and 60Cs after 4 h of three repetitions were 100, 99.9, and 99.9%, respectively, and their radioactivities were below 0.1 Bq/g. Therefore, the chemical leaching method by 4.0 M HNO3 solution was considered as an optimum one for removal of cesium and cobalt from HEPA glass fiber for self disposal. Also the removal efficiencies of 60Co, 134Cs, and 137Cs from the waste-solution after its precipitation-filtration treatment for reuse of 4.0 M HNO3 waste-solution were 88.0, 95.0, and 99.8%. (author)

  8. Limits of HEPA-filter application under high-humidity conditions

    International Nuclear Information System (INIS)

    As a result of a loss-of-coolant accident in a water-cooled nuclear reactor, the HEPA filters inside the air-cleaning systems can be exposed to high relative humidity, to condensing water vapor, and even to aerosols of liquid water. The data documented in the literature on the response of HEPA filters to such challenges was judged to be inconclusive and incomplete particularly with respect to filters preloaded with dust during service operation. Therefore, an experimental program was initiated using the test facility TAIFUN, equipped with instrumentation to accurately measure relative humidity. An optical system permitted observation and documentation of the response of the downstream side of the test filter during the tests, which lasted between 6 and 250 hours. The 21 filters tested at 500C, constant volumetric air flow rate, and ambient pressure demonstrated that the differential pressure of new clean filters increased significantly only above 95% r.h., rose up to 0.5 to 2 kPa at 100% r.h. and reached values between 6 and 9 kPa during filtration of liquid-water aerosols. Extended challenge with liquid-water aerosols caused all new filters to fail structurally. The HEPA filters that were preloaded during prior service exhibited a considerably higher rate and extent of increase in differential pressure. Such filters had already failed under test at 100% r.h. The installation of a highly efficient mist eliminator did not prevent failure of the dust loaded filters. The modes and mechanisms of filter failure are discussed

  9. Development of a Sampling Method for a Radionuclide Assessment of a Spent HEPA Filter Waste

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Young-Yong; Hong, Dae-Seok; Kang, Il-Sig; Kim, Tae-Kuk; Lee, Young-Hee; Shon, Jong-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2007-07-01

    Spent filter wastes of about 2,160 units have been stored in the waste storage facility of the Korea Atomic Energy Research Institute since its operation. These spent filters have generally consisted of a HEPA filter after its filtering of all the contaminants in the gas stream generated during the operation of the HANARO research reactor and the nuclear fuel cycle facilities. At the moment, to secure a storage space, it is necessary to make a volume reduction of the stored radioactive wastes through a compression treatment or a regulatory clearance. These methods are considered in view of a reduction of a management cost and disposal cost and the security of a free space for a waste storage facility approaching saturation. In order to dispose of the spent filters, it is first necessary to conduct a radionuclide assessment of them. To do that, a sampling procedure should be prepared for obtaining the representative sample in the spent filter. As for conducting a nuclide analysis for this representative sample, a corresponding spent filter can be sorted as either a regulatory clearance waste or a radioactive waste. In this study, the spent filter wastes were classified according to their generating facilities, their generation date and their surface dose rate. After selecting several HEPA filters, they were dismantled into a frame part and a filter medium part. And then, a quantitative analysis of the nuclide existing in the filter medium was conducted. From the analysis results, it was possible to divide the filter medium into three specific regions in respect of the nuclide distribution. As a result, these three regions could be a sampling guide to take a representative sample of a spent HEPA filter waste for treating it.

  10. Development of a Sampling Method for a Radionuclide Assessment of a Spent HEPA Filter Waste

    International Nuclear Information System (INIS)

    Spent filter wastes of about 2,160 units have been stored in the waste storage facility of the Korea Atomic Energy Research Institute since its operation. These spent filters have generally consisted of a HEPA filter after its filtering of all the contaminants in the gas stream generated during the operation of the HANARO research reactor and the nuclear fuel cycle facilities. At the moment, to secure a storage space, it is necessary to make a volume reduction of the stored radioactive wastes through a compression treatment or a regulatory clearance. These methods are considered in view of a reduction of a management cost and disposal cost and the security of a free space for a waste storage facility approaching saturation. In order to dispose of the spent filters, it is first necessary to conduct a radionuclide assessment of them. To do that, a sampling procedure should be prepared for obtaining the representative sample in the spent filter. As for conducting a nuclide analysis for this representative sample, a corresponding spent filter can be sorted as either a regulatory clearance waste or a radioactive waste. In this study, the spent filter wastes were classified according to their generating facilities, their generation date and their surface dose rate. After selecting several HEPA filters, they were dismantled into a frame part and a filter medium part. And then, a quantitative analysis of the nuclide existing in the filter medium was conducted. From the analysis results, it was possible to divide the filter medium into three specific regions in respect of the nuclide distribution. As a result, these three regions could be a sampling guide to take a representative sample of a spent HEPA filter waste for treating it

  11. Proposed retrofit of HEPA filter plenums with injection and sampling manifolds for in-place filter testing

    International Nuclear Information System (INIS)

    The importance of testing HEPA filter exhaust plenums with consideration for As Low as Reasonably Achievable (ALARA) will require that new technology be applied to existing plenum designs. HEPA filter testing at Rocky Flats has evolved slowly due to a number of reasons. The first plenums were built in the 1950's, preceding many standards. The plenums were large, which caused air dispersal problems. The systems were variable air flow. Access to the filters was difficult. The test methods became extremely conservative. Changes in methods were difficult to make. The acceptance of new test methods has been made in recent years with the change in plant mission and the emphasis on worker safety

  12. HEPA filter leaching concept validation trials at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    The enclosed report documents six New Waste Calcining Facility (NWCF) HEPA filter leaching trials conducted at the Idaho Chemical Processing Plant using a filter leaching system to validate the filter leaching treatment concept. The test results show that a modified filter leaching system will be able to successfully remove both hazardous and radiological constituents to RCRA disposal levels. Based on the success of the filter leach trials, the existing leaching system will be modified to provide a safe, simple, effective, and operationally flexible filter leaching system

  13. Intervention study of airborne fungal spora in homes with portable HEPA filtration units.

    Science.gov (United States)

    Cheong, C D; Neumeister-Kemp, H G; Dingle, P W; Hardy, G St J

    2004-11-01

    The concentrations and composition of airborne fungal spores in homes fitted with portable HEPA filtration units were examined to provide information to evaluate the importance of varying levels of fungal spores in residential environments in Perth, Australia. A novel method for simulating activity/impaction on carpeted environments was also investigated. Reductions in fungal (35%) and particulate (38%) levels were achieved in the air filter homes. Penicillium, Cladosporium and yeasts were the most common and widespread fungi recovered indoors and outdoors. Fungal range decreased over the study period but this could be due to an overall reduced dissemination of spores (less spores in the air). PMID:15536499

  14. Assessment of the Nuclide Inventory for Uranium-Contaminated HEPA Filter Wastes

    International Nuclear Information System (INIS)

    Around 3,000 units of spent HEPA filter waste at KAERI have been dismantled into a filter frame and filter media part, where most radioisotopes are captured, for efficient management. The filter media generated from the same facility were then compacted into a 200- L drum, after taking the representative samples for the assessment of the nuclide inventory of them according to the sampling procedure. In general, uranium existing in the waste could be analyzed using radiochemical methods such as alpha spectrometry, a liquid scintillation counting (LSC) system, and mass spectrometry. Although these methods can be processed with low detection limits by using the chemical pre-treatment of samples and the specific detector, time and cost constrains compared with their accuracy dictates the use of a simpler method of application. High resolution gamma spectrometry can simply and easily provide a reasonable estimate of the uranium activity as a less time and cost consuming technique. In this study, a high purity germanium (HPGe) detector was employed to determine the activity of uranium-contaminated HEPA filter waste. The activity of U-235 and U-238 was identified by the analyses of a gamma ray peak of 143.76 keV belong to U-235 and of the daughters of U-238 such as Th-234 and Pa-234m with a secular equilibrium. To confirm their feasibility using gamma ray spectroscopy, the analysis results were compared with the gross alpha activity in the same sample

  15. Iron-mediated effect of alcohol on hepatocyte differentiation in HepaRG cells.

    Science.gov (United States)

    Do, Thi Hong Tuoi; Gaboriau, François; Cannie, Isabelle; Batusanski, Florence; Ropert, Martine; Moirand, Romain; Brissot, Pierre; Loreal, Olivier; Lescoat, Gérard

    2013-11-25

    The development of alcoholic liver diseases depends on the ability of hepatocyte to proliferate and differentiate in the case of alcohol-induced injury. Our previous work showed an inhibitory effect of alcohol on hepatocyte proliferation. However, the effect of alcohol on hepatocyte differentiation has not yet been precisely characterized. In the present study, we evaluated the effect of alcohol on hepatocyte differentiation in relationship with changes of iron metabolism in HepaRG cells. This unique bipotent human cell line can differentiate into hepatocytes and biliary epithelial cells, paralleling liver development. Results showed that alcohol reduced cell viability, total protein level and enhanced hepatic enzymes leakage in differentiated HepaRG cells. Moreover, it caused cell enlargement, decreased number of hepatocyte and expression of C/EBPα as well as bile canaliculi F-actin. Alcohol increased expression of hepatic cell-specific markers and alcohol-metabolizing enzymes (ADH2, CYP2E1). This was associated with a lipid peroxidation and an iron excess expressed by an increase in total iron content, ferritin level, iron uptake as well as an overexpression of genes involved in iron transport and storage. Alcohol-induced hepatoxicity was amplified by exogenous iron via exceeding iron overload. Taken together, our data demonstrate that in differentiated hepatocytes, alcohol reduces proliferation while increasing expression of hepatic cell-specific markers. Moreover, iron overload could be one of the underlying mechanisms of effect of alcohol on the whole differentiation process of hepatocytes. PMID:24025710

  16. Performance of HEPA filters at LLNL following the 1980 and 1989 earthquakes

    International Nuclear Information System (INIS)

    The Lawrence Livermore National Laboratory has experienced two significant earthquakes for which data is available to assess the ability of HEPA filters to withstand seismic conditions. A 5.9 magnitude earthquake with an epicenter 10 miles from LLNL struck on January 24, l980. Estimates of the peak ground accelerations ranged from 0.2 to 0.3 g. A 7.0 magnitude earthquake with an epicenter about 50 miles from LLNL struck on October 17, 1989. Measurements of the ground accelerations at LLNL averaged 0.1 g. The results from the in-place filter tests obtained after each of the earthquakes were compiled and studied to determine if the earthquakes had caused filter leakage. Our study showed that only the 1980 earthquake resulted in a small increase in the number of HEPA filters developing leaks. In the 12 months following the 1980 and 1989 earthquakes, the in-place filter tests showed 8.0% and 4.1% of all filters respectively developed leaks. The average percentage of filters developing leaks from 1980 to 1993 was 3.3%+/-1.7%. The increase in the filter leaks is significant for the 1980 earthquake, but not for the 1989 earthquake. No contamination was detected following the earthquakes that would suggest transient releases from the filtration system

  17. High-efficiency particulate air (HEPA) filter performance following service and radiation exposure

    International Nuclear Information System (INIS)

    Small HEPA filters were exposed to a 60Co source with a radiation strength of 3 x 107 rads per hour and then exposed to steam--air mixtures at several times filter design flow, followed by extended exposure to steam and air at reduced flow. Additional filters were exposed to air flow in a reactor confinement system and then similarly tested with steam--air mixture flows. The test data and calculated effects of filter pluggage with moisture on confinement system performance following potential reactor accidents are described. Gamma radiation exposure impaired the performance of new filters only slightly and temporarily improved performance of service aged filters. Normal confinement system service significantly impaired filter performance although not sufficiently to prevent adequate performance of the SRP confinement system following an unlikely reactor accident. Calculations based on measured filter pluggage indicate that during an accident air flow could be reduced approximately 50 percent with service-degraded HEPA filters present, or approximately 10 percent with new filters damaged by the radiation exposure. (U.S.)

  18. Preliminary studies to determine the shelf life of HEPA filters. Revision 1

    International Nuclear Information System (INIS)

    We have completed a preliminary study using filter media tests and filter qualification tests to investigate the effect of shelf-life on HEPA filter performance. Our media studies showed that the tensile strength decreased with age, but the data were not sufficient to establish a shelf-life. Thermogravimetric analyses demonstrated that one manufacturer had media with low tensile strength due to insufficient binder. The filter qualification tests (heated air and overpressure) conducted on different aged filters showed that filter age is not the primary factor affecting filter performance; materials and the construction design have a greater effect. An unexpected finding of our study was that sub-standard HEPA filters have been installed in DOE facilities despite existing regulations and filter qualification tests. We found that the filter with low tensile strength failed the overpressure test. The same filter had passed the heated air test, but left the filter so structurally weak, it was prone to blow-out. We recommend that DOE initiate a filter qualification program to prevent this occurrence

  19. In-situ continuous scanning high efficiency particulate air (HEPA) filter monitoring system

    International Nuclear Information System (INIS)

    The testing and replacement of HEPA filters, which are widely used in the nuclear industry to purify process air before it is ventilated to the atmosphere, is a costly and labor-intensive undertaking. Current methods of testing filter performance, such as differential pressure measurement and scanning air monitoring, allow for determination of overall filter performance but preclude detection of symptoms of incipient filter failure, such as small holes in the filters themselves. Using current technology, a continual in-situ monitoring system has been designed which provides three major improvements over current methods of filter testing and replacement. This system (1) realizes a cost savings by reducing the number of intact filters which are currently being replaced unnecessarily, (2) provides a more accurate and quantitative measurement of filter performance than is currently achieved with existing testing methods, and (3) reduces personnel exposure to a radioactive environment by automatically performing most testing operations. The operation and performance of the HEPA filter monitoring system are discussed

  20. Replacement of HEPA Filters at the LANL CMR Facility: Risks Reduced by Comprehensive Waste Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Corpion, J.; Barr, A.; Martinez, P.; Bader, M.

    2002-02-28

    In March 2001, the Los Alamos National Laboratory (LANL) completed the replacement of 720 radioactively contaminated HEPA filters for $5.7M. This project was completed five months ahead of schedule and $6.0M under budget with no worker injuries or contaminations. Numerous health and safety, environmental, and waste disposal problems were overcome, including having to perform work in a radioactively contaminated work environment, that was also contaminated with perchlorates (potential explosive). High waste disposal costs were also an issue. A project risk analysis and government cost estimate determined that the cost of performing the work would be $11.8M. To reduce risk, a $1.2M comprehensive condition assessment was performed to determine the degree of toxic and radioactive contamination trapped on the HEPA filters; and to determine whether explosive concentrations of perchlorates were present. Workers from LANL and personnel from Waldheim International of Knoxville, TN collected hundreds of samples wearing personnel protective gear against radioactive, toxic, and explosive hazards. LANL also funded research at the New Mexico Institute of Mining and Technology to determine the explosivity of perchlorates. The data acquired from the condition assessment showed that toxic metals, toxic organic compounds, and explosive concentrations of perchlorates were absent. The data also showed that the extent of actinide metal contamination was less than expected, reducing the potential of transuranic waste generation by 50%. Consequently, $4.2M in cost savings and $1.8M in risk reduction were realized by increased worker productivity and waste segregation.

  1. Replacement of HEPA Filters at the LANL CMR Facility : risk reduced by comprehensive waste characterization

    Energy Technology Data Exchange (ETDEWEB)

    Corpion, J. C. (Juan C.)

    2002-01-01

    In March 2001, the Los Alamos National Laboratory (LANL) completed the replacement of 720 radioactively contaminated HEPA filters for $5.7M. This project was completed five months ahead of schedule and $6.0M under budget with no worker injuries or contaminations. Numerous health and safety, environmental, and waste disposal problems were overcome, including having to perform work in a radioactively contaminated work environment, that was also contaminated with perchlorates (potential explosive). High waste disposal costs were also an issue. A project risk analysis and government cost estimate determined that the cost of performing the work would be $11.8M. To reduce risk, a $1.2M comprehensive condition assessment was performed to determine the degree of toxic and radioactive contamination trapped on the HEPA filters; and to determine whether explosive concentrations of perchlorates were present. Workers from LANL and personnel from Waldheim International of Knoxville, TN collected hundreds of samples wearing personnel protective gear against radioactive, toxic, and explosive hazards. LANL also funded research at the New Mexico Institute of Mining and Technology to determine the explosivity of perchlorates. The data acquired from the condition assessment showed that toxic metals, toxic organic compounds, and explosive concentrations of perchlorates were absent. The data also showed that the extent of actinide metal contamination was less than expected, reducing the potential of transuranic waste generation by 50%. Consequently, $4.2M in cost savings and $1.8M in risk reduction were realized by increased worker productivity and waste segregation.

  2. Performance Evaluation of Axial Flow AG-1 FC and Prototype FM (High Strength) HEPA Filters - 13123

    Energy Technology Data Exchange (ETDEWEB)

    Giffin, Paxton K.; Parsons, Michael S.; Wilson, John A.; Waggoner, Charles A. [Institute for Clean Energy Technology, Mississippi State University, 205 Research Blvd Starkville, MS 39759 (United States)

    2013-07-01

    High efficiency particulate air (HEPA) filters are routinely used in DOE nuclear containment activities. The Nuclear Air Cleaning Handbook (NACH) stipulates that air cleaning devices and equipment used in DOE nuclear applications must meet the American Society of Mechanical Engineers (ASME) Code on Nuclear Air and Gas Treatment (AG-1) standard. This testing activity evaluates two different axial flow HEPA filters, those from AG-1 Sections FC and FM. Section FM is under development and has not yet been added to AG-1 due to a lack of qualification data available for these filters. Section FC filters are axial flow units that utilize a fibrous glass filtering medium. The section FM filters utilize a similar fibrous glass medium, but also have scrim backing. The scrim-backed filters have demonstrated the ability to endure pressure impulses capable of completely destroying FC filters. The testing activities presented herein will examine the total lifetime loading for both FC and FM filters under ambient conditions and at elevated conditions of temperature and relative humidity. Results will include loading curves, penetration curves, and testing condition parameters. These testing activities have been developed through collaborations with representatives from the National Nuclear Security Administration (NNSA), DOE Office of Environmental Management (DOE-EM), New Mexico State University, and Mississippi State University. (authors)

  3. Assessment of the Nuclide Inventory for Uranium-Contaminated HEPA Filter Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Young Yong; Hong, Dae Seok; Kang, Il Sik; Kim, Tae Kuk; Ryu, Woo Seog [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-10-15

    Around 3,000 units of spent HEPA filter waste at KAERI have been dismantled into a filter frame and filter media part, where most radioisotopes are captured, for efficient management. The filter media generated from the same facility were then compacted into a 200- L drum, after taking the representative samples for the assessment of the nuclide inventory of them according to the sampling procedure. In general, uranium existing in the waste could be analyzed using radiochemical methods such as alpha spectrometry, a liquid scintillation counting (LSC) system, and mass spectrometry. Although these methods can be processed with low detection limits by using the chemical pre-treatment of samples and the specific detector, time and cost constrains compared with their accuracy dictates the use of a simpler method of application. High resolution gamma spectrometry can simply and easily provide a reasonable estimate of the uranium activity as a less time and cost consuming technique. In this study, a high purity germanium (HPGe) detector was employed to determine the activity of uranium-contaminated HEPA filter waste. The activity of U-235 and U-238 was identified by the analyses of a gamma ray peak of 143.76 keV belong to U-235 and of the daughters of U-238 such as Th-234 and Pa-234m with a secular equilibrium. To confirm their feasibility using gamma ray spectroscopy, the analysis results were compared with the gross alpha activity in the same sample

  4. Factors influencing the performance and lifetime of fibrous glass and metal media HEPA filters - 16285

    International Nuclear Information System (INIS)

    High efficiency particulate air (HEPA) filters are used in a variety of nuclear applications as final air treatment units. The design of air filtration systems in nuclear facilities that will function well requires a significant amount of knowledge about the challenge conditions that these filters will be exposed to. Additionally, risk assessments conducted as a review of these systems need also to be based on knowledge of filter challenge parameters during upset conditions that may be used as design basis conditions. This paper presents a summary of findings of factors that influence the performance lifetime of conventional fibrous glass media filters. These factors include aerosol challenge (particle size distributions and mass concentrations), media velocities, wetting conditions, and changes in gas density. These data are correlated to design considerations for new systems and to process upset conditions used in risk assessments, particularly those involving fires. Data from filter testing activities are also compared to filter loading models and to literature information regarding aerosol emission rates from combustion of various materials. Additional data are provided relating the performance of metal media HEPA filters under conditions that exceed maximum ranges for fibrous glass filters. These discussions focus on selection factors between these two categories of filter units. (authors)

  5. Efficiency of HEPA filters at elevated temperatures: investigations with the TiO2 test method

    International Nuclear Information System (INIS)

    Knowledge of the variations in HEPA filter efficiency at elevated temperatures is an important prerequisite for estimating the release of particulate radioactivity in the case of an accident in a nuclear power plant. The experimental data available up to now cannot be considered sufficient for reliable estimates. Efficiency measurements were carried out with the TiO2-test method, specially suited for use under extreme conditions. Standard size deep-pleat HEPA filters from four different manufacturers were tested at temperatures up to 250 degree C under static and at rated airflow of 1700 m3/h. The experimental results in partial contradiction to filtration theory showed both increases and decreases in efficiency with rising temperature. This may be explained by structural changes observed in the filter medium of the filter units tested. All units tested under airflow showed a loosening of the filter pack. In some cases kinks in the filter pleats near the bottom close to the frame were observed. Local damages resulting from such structural changes may have caused reductions in filtration efficiency, apparently supported by partial decomposition of the organic binder. This was confirmed by additional efficiency measurements carried out at room temperature on filter units after repeated exposure to 250 degree C in an oven. The findings show that the efficiency of filter units at elevated temperatures is governed not only by the effects of temperature on the filtration mechanisms but can also be influenced by filter mechanical alterations resulting from thermal stress

  6. Disruption of BSEP Function in HepaRG Cells Alters Bile Acid Disposition and Is a Susceptive Factor to Drug-Induced Cholestatic Injury.

    Science.gov (United States)

    Qiu, Xi; Zhang, Yueping; Liu, Tongtong; Shen, Hong; Xiao, Yongling; Bourner, Maureen J; Pratt, Jennifer R; Thompson, David C; Marathe, Punit; Humphreys, W Griffith; Lai, Yurong

    2016-04-01

    In the present study, we characterized in vitro biosynthesis and disposition of bile acids (BAs) as well as hepatic transporter expression followed by ABCB11 (BSEP) gene knockout in HepaRG cells (HepaRG-KO cells). BSEP KO in HepaRG cells led to time-dependent BA accumulation, resulting in reduced biosynthesis of BAs and altered BA disposition. In HepaRG-KO cells, the expression of NTCP, OATP1B1, OATP2B1, BCRP, P-gp, and MRP2 were reduced, whereas MRP3 and OCT1 were up-regulated. As a result, BSEP KO altered the disposition of BAs and subsequently underwent adaptive regulations of BA synthesis and homeostasis to enable healthy growth of the cells. Although BSEP inhibitors caused no or slight increase of BAs in HepaRG wild type cells (HepaRG-WT cells), excessive intracellular accumulation of BAs was observed in HepaRG-KO cells exposed to bosentan and troglitazone, but not dipyridamole. LDH release in the medium was remarkably increased in HepaRG-KO cultures exposed to troglitazone (50 μM), suggesting drug-induced cellular injury. The results revealed that functional impairment of BSEP predisposes the cells to altered BA disposition and is a susceptive factor to drug-induced cholestatic injury. In total, BSEP inhibition might trigger the processes but is not a sole determinant of cholestatic cellular injury. As intracellular BA accumulation is determined by BSEP function and the subsequent adaptive gene regulation, assessment of intracellular BA accumulation in HepaRG-KO cells could be a useful approach to evaluate drug-induced liver injury (DILI) potentials of drugs that could disrupt other BA homeostasis pathways beyond BSEP inhibition. PMID:26910619

  7. Investigations into the penetration and pressure drop of HEPA filter media during loading with submicron particle aerosols at high concentrations

    International Nuclear Information System (INIS)

    High Efficiency Particulate Air (HEPA) filters are typically employed in particle removal and retention within the air cleaning systems of clean rooms in the pharmaceutical, nuclear and semiconductor industries for dust concentrations of some μg/m3. Their extremely high removal efficiencies for submicron particles make them attractive candidates in complying with increasingly lower emission limits for industrial processes that involve dust concentrations of up to several g/m3. Cost-effective operation under such conditions requires the filter units to be recleanable. The recleanability of HEPA filter media depends not only on the operating conditions during the cleaning process but also on the filtration conditions during particle loading. The structure and location of the particles captured by the glass fiber matrix greatly affect the degree to which they can be subsequently dislodged and removed from the filter medium. Changes in filtration efficiency with service time for various particle diameters in the critical submicron size range, as well as the effects of filtration velocity on the increase in pressure drop, are important criteria with regard to recleaning HEPA filter units. Of special significance for the recleanability of HEPA filter media is knowledge of how operating conditions affect dust cake formation. (author)

  8. Advantageous use of HepaRG cells for the screening and mechanistic study of drug-induced steatosis.

    Science.gov (United States)

    Tolosa, Laia; Gómez-Lechón, M José; Jiménez, Nuria; Hervás, David; Jover, Ramiro; Donato, M Teresa

    2016-07-01

    Only a few in vitro assays have been proposed to evaluate the steatotic potential of new drugs. The present study examines the utility of HepaRG cells as a cell-based assay system for screening drug-induced liver steatosis. A high-content screening assay was run to evaluate multiple toxicity-related cell parameters in HepaRG cells exposed to 28 compounds, including drugs reported to cause steatosis through different mechanisms and non-steatotic compounds. Lipid content was the most sensitive parameter for all the steatotic drugs, whereas no effects on lipid levels were produced by non-steatotic compounds. Apart from fat accumulation, increased ROS production and altered mitochondrial membrane potential were also found in the cells exposed to steatotic drugs, which indicates that all these cellular events contributed to drug-induced hepatotoxicity. These findings are of clinical relevance as most effects were observed at drug concentrations under 100-fold of the therapeutic peak plasmatic concentration. HepaRG cells showed increased lipid overaccumulation vs. HepG2 cells, which suggests greater sensitivity to drug-induced steatosis. An altered expression profile of transcription factors and the genes that code key proteins in lipid metabolism was also found in the cells exposed to drugs capable of inducing liver steatosis. Our results generally indicate the value of HepaRG cells for assessing the risk of liver damage associated with steatogenic compounds and for investigating the molecular mechanisms involved in drug-induced steatosis. PMID:27089845

  9. Evaluation of Alternative Control for Prevention and or Mitigation of HEPA Filter Failure Accidents at Tank Farm Facilities

    International Nuclear Information System (INIS)

    This study evaluates the adequacy and benefit of use of HEPA filter differential pressure limiting setpoints to initiate exhauster shut down as an alternative safety control for postulated accidents that might result in filtration failure and subsequent unfiltered release from Tank Farm primary tank ventilators

  10. Acetaminophen inhibits NF-kappaB activation by interfering with the oxidant signal in murine Hepa 1-6 cells.

    Science.gov (United States)

    Boulares, A H; Giardina, C; Inan, M S; Khairallah, E A; Cohen, S D

    2000-06-01

    A toxic dose of acetaminophen (APAP) reduces the activity of NF-kappaB in mouse liver. NF-kappaB inactivation may be important for APAP toxicity, as this transcription factor can play a central role in maintaining hepatic viability. We recently reported that APAP likewise inhibits serum growth factor activation of NF-kappaB in a mouse hepatoma cell line (Hepa 1-6 cells). Here we present evidence that APAP's antioxidant activity may be involved in this NF-kappaB inhibition in Hepa 1-6 cells. Like the antioxidants N-acetylcysteine (NAC) and pyrrolidinedithiocarbamate (PDTC), APAP was found to suppress the H(2)O(2)-induced oxidation of an intracellular reactive oxygen species probe (dihydrodichlorofluorescein) in Hepa 1-6 cells. Treatment of Hepa 1-6 cells with H(2)O(2) was sufficient for NF-kappaB activation and IkappaBalpha degradation, and APAP was able to block both of these events. The APAP inhibition of NF-kappaB activation by serum growth factors may also be due to APAP's antioxidant activity, as the antioxidants NAC and PDTC likewise inhibit this activation. The potential role of NF-kappaB and oxidant-based growth factor signal transduction in APAP toxicity is discussed. PMID:10828269

  11. Effect of dust loading due to fire accident on pressure drop across HEPA filters in a nuclear installation

    International Nuclear Information System (INIS)

    HEPA filters are the principal air cleaning components in ventilation systems of nuclear facilities. They must be capable of continued operation under severe conditions created during emergency situations. Of considerable interest to the Regulatory Body is the filter performance during fire accidental conditions in nuclear installations. This study aims at the investigation of combustion products effect, resulting from a postulated fire accident in a nuclear fuel processing facility, on the performance of HEPA filter as a part of the evaluation of air cleaning system components physical performance. A theoretical study has been performed to investigate how a simulated combustion aerosol affects the pressure drop across a HEPA filter. Several theoretical models have been verified with previous experimental work. The comparisons showed that, the agreement is not quantitative, and these theoretical models are not capable for use to determine the pressure drop caused by particle loading. Therefore , new assumptions as well as new parameters have been implemented, and a new correlation has been derived for the resistance ratio with the filter mass gain for polystyrene aerosols. A best estimate computer model calculations based on this formula have been developed for the prediction of the filter resistance,aerosol particles concentration and accumulated mass on the HEPA filter performance

  12. Evaluation of Alternative Control for Prevention and or Mitigation of HEPA Filter Failure Accidents at Tank Farm Facilities

    Energy Technology Data Exchange (ETDEWEB)

    GUSTAVSON, R.D.

    2000-01-28

    This study evaluates the adequacy and benefit of use of HEPA filter differential pressure limiting setpoints to initiate exhauster shut down as an alternative safety control for postulated accidents that might result in filtration failure and subsequent unfiltered release from Tank Farm primary tank ventilators.

  13. Characteristics of HEPA filter waste compactor developed by KAERI and comparison with Japan's and U. S. A's compactors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, G. M.; Ann, S. J.; Bae, S. M.; Son, J. S.; Hong, K. P. [KAERI, Taejon (Korea, Republic of); Kim, H. T. [KINS, Taejon (Korea, Republic of)

    2003-07-01

    The HEPA filter waste (Hexahedron, 610 x 610 x 292 mm, 20 Kg), which is used for the ventilation system in the nuclear industries, has relatively large volume to compare with it's weight. Due to the large volume of HEPA filter waste, it needs the large storage and/or disposal space and managing cost during the long period of storage and management. Many countries use the compactor to reduce the volume of HEPA filter waste. On this paper we introduce the new type compactor developed by KAERI with the characteristic comparison to the Japan's and U. S. A's compactors.

  14. Application of Emery 3004 as a substitute for DOP in the HANARO HEPA filter In-place leakage test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M. J.; Kim, Y. G.; Choi, Y. S.; Lee, Y. S.; Wu, J. S. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2005-07-01

    HEPA (High Efficiency Particulate Air) filter system is installed on the outlet duct of the Reactor hall HVAC system of HANARO and it filters the particulate from the exhaust air. Although most HEPA filter manufacturers guarantee a minimum 99.97% efficiency when challenged with an aerosol of 0.3 {+-} 0.03 {mu}m an in-place leakage test of a HEPA filter is still required after a filter replacement, after any maintenance activity in the filter housing, or every 18 months to verify that the filters have been installed properly, that there are no leaks in the mounting frame, and that the system contains no bypassing. DOP (dioctylphtalate) had been widely used as a tracer gas for a HEPA filter in-place leak test. In April, 1986, U.S. Army's Office of the Surgeon General (OTSG) announced that the DOP posed potentially serious health risks to workers, and placed severe restrictions upon a testing with it. For this reason, they commenced study for finding a substitute material for DOP and finally found a synthetic lubricant named Emery 3004 from the class of compound called poly-alpha olefin. We could find from the DOE conference proceeding that it was approved by the OTSG after a successful completion of a mutagenicity testing in Jan. 8, 1992. And we could find that Emery 3004 has already been used for the Brookhaven National Laboratory's HEPA Filter In-place Leakage Test procedure and HEPA Filter and In-place Leak Testing Standard of Lawrence Livermore National Laboratory. In HANARO, we performed the HEPA Filter In-place Leakage Test using both tracer agents in order to compare the performance of Emery 3004 with that of DOP. As a result, we found that the characteristics of Emery 3004 is very much similar to that of DOP and it was easy to handle the chemical compound since it has no toxicity. We finally came to the conclusion that Emery 3004 will be a good substitute for DOP through the test result and we are trying to revise the relevant documents and test

  15. Application of Emery 3004 as a substitute for DOP in the HANARO HEPA filter In-place leakage test

    International Nuclear Information System (INIS)

    HEPA (High Efficiency Particulate Air) filter system is installed on the outlet duct of the Reactor hall HVAC system of HANARO and it filters the particulate from the exhaust air. Although most HEPA filter manufacturers guarantee a minimum 99.97% efficiency when challenged with an aerosol of 0.3 ± 0.03 μm an in-place leakage test of a HEPA filter is still required after a filter replacement, after any maintenance activity in the filter housing, or every 18 months to verify that the filters have been installed properly, that there are no leaks in the mounting frame, and that the system contains no bypassing. DOP (dioctylphtalate) had been widely used as a tracer gas for a HEPA filter in-place leak test. In April, 1986, U.S. Army's Office of the Surgeon General (OTSG) announced that the DOP posed potentially serious health risks to workers, and placed severe restrictions upon a testing with it. For this reason, they commenced study for finding a substitute material for DOP and finally found a synthetic lubricant named Emery 3004 from the class of compound called poly-alpha olefin. We could find from the DOE conference proceeding that it was approved by the OTSG after a successful completion of a mutagenicity testing in Jan. 8, 1992. And we could find that Emery 3004 has already been used for the Brookhaven National Laboratory's HEPA Filter In-place Leakage Test procedure and HEPA Filter and In-place Leak Testing Standard of Lawrence Livermore National Laboratory. In HANARO, we performed the HEPA Filter In-place Leakage Test using both tracer agents in order to compare the performance of Emery 3004 with that of DOP. As a result, we found that the characteristics of Emery 3004 is very much similar to that of DOP and it was easy to handle the chemical compound since it has no toxicity. We finally came to the conclusion that Emery 3004 will be a good substitute for DOP through the test result and we are trying to revise the relevant documents and test procedures

  16. Innovative HEPA [high-efficiency particulate air] filter designs to reduce waste generation and simplify waste treatment

    International Nuclear Information System (INIS)

    The treatment and disposal of spent high-efficiency particulate air (HEPA) filters has presented a problem at some defense production plants and could be a problem at potential future spent-fuel consolidation or fuel reprocessing facilities. During studies of transuranic (TRU) waste treatment options conducted by Pacific Northwest Laboratory, it was concluded that treatment of spent HEPA filters would become easier and less costly if some modifications were made to the present materials of construction and design. This study was undertaken to develop and evaluate alternative materials and innovative designs for HEPA filters, making them more compatible with volume reduction technology. The following treatment options were selected for this study: (1) no treatment; (2) compaction; (3) supercompaction; (4) incinerate and melt; and (5) separate the frame from the media and dispose of the frame as low-level waste, and incinerate and melt the filter media and sealant. Forty HEPA design concepts were identified and evaluated by means of a figure-of-merit methodology for technical performance and an economic evaluation that considered filter fabrication and disposal costs. Results of the study indicate that if improved HEPA designs are combined with volume reduction treatments, the costs of filter disposal can be reduced substantially over the use of standard-flow filter designs with no volume reduction treatment. It is estimated that by combining the new design concepts with waste volume reduction treatments, manufacturing and disposal costs can be reduced by $290 or more per filter if classified as low-level waste (LLW) and up to $23,000 per filter if it is high-activity waste (containing activity greater than class-C LLW) and requires repository disposal

  17. PPAR agonists reduce steatosis in oleic acid-overloaded HepaRG cells

    International Nuclear Information System (INIS)

    Although non-alcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease there is no pharmacological agent approved for its treatment. Since peroxisome proliferator-activated receptors (PPARs) are closely associated with hepatic lipid metabolism, they seem to play important roles in NAFLD. However, the effects of PPAR agonists on steatosis that is a common pathology associated with NAFLD, remain largely controversial. In this study, the effects of various PPAR agonists, i.e. fenofibrate, bezafibrate, troglitazone, rosiglitazone, muraglitazar and tesaglitazar on oleic acid-induced steatotic HepaRG cells were investigated after a single 24-hour or 2-week repeat treatment. Lipid vesicles stained by Oil-Red O and triglycerides accumulation caused by oleic acid overload, were decreased, by up to 50%, while fatty acid oxidation was induced after 2-week co-treatment with PPAR agonists. The greatest effects on reduction of steatosis were obtained with the dual PPARα/γ agonist muraglitazar. Such improvement of steatosis was associated with up-regulation of genes related to fatty acid oxidation activity and down-regulation of many genes involved in lipogenesis. Moreover, modulation of expression of some nuclear receptor genes, such as FXR, LXRα and CAR, which are potent actors in the control of lipogenesis, was observed and might explain repression of de novo lipogenesis. Conclusion: Altogether, our in vitro data on steatotic HepaRG cells treated with PPAR agonists correlated well with clinical investigations, bringing a proof of concept that drug-induced reversal of steatosis in human can be evaluated in in vitro before conducting long-term and costly in vivo studies in animals and patients. - Highlights: • There is no pharmacological agent approved for the treatment of NAFLD. • This study demonstrates that PPAR agonists can reduce fatty acid-induced steatosis. • Some nuclear receptors appear to be potent actors in the control

  18. Exposure assessment of four pharmaceutical powders based on dustiness and evaluation of damaged HEPA filters.

    Science.gov (United States)

    Levin, Marcus; Koponen, Ismo K; Jensen, Keld A

    2014-01-01

    In this study, we show the different dustiness characteristics of four molecular pharmaceutical powder candidates and evaluate the performance of HEPA filters damaged with three different pinhole sizes and exposed to dust using real industrial powders in a miniaturized EN15051 rotating drum dustiness tester. We then demonstrate the potential use of such data using first-order exposure modeling to assess the potential worker exposure and transmission of active powder ingredients into ventilation systems. The four powders had highly variable inhalable dustiness indices (1,036 - 14,501 mg/kg). Dust particle size-distributions were characterized by three peaks; the first occurred around 60-80 nm, the second around 250 nm, and the third at 2-3 μm. The second and third peaks are often observed in dustiness test studies, but peaks in the 60-80 nm range have not been previously reported. Exposure modeling in a 5 times 20 kg powder pouring scenario, suggests that excessive dust concentrations may be reached during use of powders with the highest dustiness levels. By number, filter-damage by three pinhole sizes resulted in damage-dependent penetration of 70-80 nm-size particles, but by volume and mass the penetration is still dominated by particles larger than 100 nm. Whereas the exposure potential was evident, the potential dust concentrations in air ducts following the pouring scenario above were at pg/m(3) levels. Hence, filter penetration at these damage levels was assumed to be only critical, if the active ingredients were associated with high hazard or unique product purity is required. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: An example of a typical particle number time-series of a complete dustiness test. It provides information on the HEPA-filter used including a scanning electron microscopy image of it. It also

  19. PPAR agonists reduce steatosis in oleic acid-overloaded HepaRG cells

    Energy Technology Data Exchange (ETDEWEB)

    Rogue, Alexandra [Inserm UMR 991, 35043 Rennes Cedex (France); Université de Rennes 1, Faculté des Sciences Pharmaceutiques et Biologiques, 35043 Rennes Cedex (France); Biologie Servier, Gidy (France); Anthérieu, Sébastien; Vluggens, Aurore [Inserm UMR 991, 35043 Rennes Cedex (France); Université de Rennes 1, Faculté des Sciences Pharmaceutiques et Biologiques, 35043 Rennes Cedex (France); Umbdenstock, Thierry [Technologie Servier, Orléans (France); Claude, Nancy [Institut de Recherches Servier, Courbevoie (France); Moureyre-Spire, Catherine de la; Weaver, Richard J. [Biologie Servier, Gidy (France); Guillouzo, André, E-mail: Andre.Guillouzo@univ-rennes1.fr [Inserm UMR 991, 35043 Rennes Cedex (France); Université de Rennes 1, Faculté des Sciences Pharmaceutiques et Biologiques, 35043 Rennes Cedex (France)

    2014-04-01

    Although non-alcoholic fatty liver disease (NAFLD) is currently the most common form of chronic liver disease there is no pharmacological agent approved for its treatment. Since peroxisome proliferator-activated receptors (PPARs) are closely associated with hepatic lipid metabolism, they seem to play important roles in NAFLD. However, the effects of PPAR agonists on steatosis that is a common pathology associated with NAFLD, remain largely controversial. In this study, the effects of various PPAR agonists, i.e. fenofibrate, bezafibrate, troglitazone, rosiglitazone, muraglitazar and tesaglitazar on oleic acid-induced steatotic HepaRG cells were investigated after a single 24-hour or 2-week repeat treatment. Lipid vesicles stained by Oil-Red O and triglycerides accumulation caused by oleic acid overload, were decreased, by up to 50%, while fatty acid oxidation was induced after 2-week co-treatment with PPAR agonists. The greatest effects on reduction of steatosis were obtained with the dual PPARα/γ agonist muraglitazar. Such improvement of steatosis was associated with up-regulation of genes related to fatty acid oxidation activity and down-regulation of many genes involved in lipogenesis. Moreover, modulation of expression of some nuclear receptor genes, such as FXR, LXRα and CAR, which are potent actors in the control of lipogenesis, was observed and might explain repression of de novo lipogenesis. Conclusion: Altogether, our in vitro data on steatotic HepaRG cells treated with PPAR agonists correlated well with clinical investigations, bringing a proof of concept that drug-induced reversal of steatosis in human can be evaluated in in vitro before conducting long-term and costly in vivo studies in animals and patients. - Highlights: • There is no pharmacological agent approved for the treatment of NAFLD. • This study demonstrates that PPAR agonists can reduce fatty acid-induced steatosis. • Some nuclear receptors appear to be potent actors in the control

  20. Decontamination of Stainless Steel SS 304 Type with Pressurized CO2 Solid

    International Nuclear Information System (INIS)

    The abrasive decontamination of the stainless steel valve using 12 bar pressurized CO2 solid has been done. Experiment activities was performed in the HOT CELL facility with variation of blasting time 15, 30, 45 and 60 seconds. The result of experiment shown that the operation of abrasive decontamination during 45 seconds gives the decreasing of the equipment radiation dose rate from 460 to 200 mRem/h and decontamination factor 1.35. The secondary waste from decontamination activities was treated by filtration method using HEPA filter and activated carbon filter. (author)

  1. Steel Planning

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China releases a new plan for the iron and steel industry centered on industrial upgrades The new 12th Five-Year Plan (2011-15) for China’s iron and steel industry, recently released on the website of the Ministry of Industry and Information

  2. Use of evidence in 3 local level HEPA policies in Denmark

    DEFF Research Database (Denmark)

    Jakobsen, Mette Winge; Juel Lau, Cathrine; Skovgaard, Thomas;

    2013-01-01

    Purpose: The University of Southern Denmark and the Research Centre for Prevention and Health in the Capital Region of Denmark are involved in the first work package of the REPOPA project dealing with mapping and further analyses of use of research evidence in selected health enhancing physical......, followed by interviews with key stakeholders involved in the policy making process, were carried out. The data were analyzed with the focus on the characteristics of the research knowledge used for policy making and factors influencing the use of research and other kinds of information. Findings...... local context was reported. Policy makers focus on both using and generating knowledge. However, research evidence is only used in HEPA policy making if applicable to the local setting. Many factors influence the use of research into policy making such as involvement of stakeholders, availability of...

  3. Effect of various polymeric binders on the radiation resistance of glass fiber HEPA filter media

    International Nuclear Information System (INIS)

    Glass fiber HEPA filter media bonded with various polymeric materials were exposed to several levels of radiation dosage from an electron beam source. The effects on water repellency, tensile strength, DOP filtration efficiency and organic content were noted. All media suffered degradation at the highest levels of radiation dosage (7 x 108 rads). However, at intermediate levels, radiation resistance was affected by the type of binder. Greatest resistance to radiation was exhibited by media bonded with a phenylated polysiloxane resin. Cross-linking polymers such as polystyrene and SBR displayed improvement in some properties, such as in water repellency and tensile strength, at low levels of radiation exposure (less than 2 x 108 rads), however degraded at higher levels of exposure. Filtration properties such as DOP efficiency and resistance to air flow did not appear to be greatly affected by radiolysis. (U.S.)

  4. U-235 Holdup Measurements in the 321-M Lathe HEPA Banks

    Energy Technology Data Exchange (ETDEWEB)

    Salaymeh, S.R.

    2002-07-08

    The Analytical Development Section of Savannah River Technology Center (SRTC) was requested by the Facilities Decommissioning Division (FDD) to determine the holdup of enriched uranium in the 321-M facility as part of an overall deactivation project of the facility. The results of the holdup assays are essential for determining compliance with the Waste Acceptance Criteria, Material Control and Accountability, and to meet criticality safety controls. This report covers holdup measurements of uranium residue in six high efficiency particulate air (HEPA) filter banks of the A-lathe and B-lathe exhaust systems of the 321-M facility. This report discusses the non-destructive assay measurements, assumptions, calculations, and results of the uranium holdup in these six items.

  5. Performance testing of HEPA filters: Progress towards a European standard procedure

    International Nuclear Information System (INIS)

    Proposals for a future European testing procedure for 'High Efficiency Particulate Air Filters (HEPA and ULPA)' are being developed by CEN (Comite Europeen de Normalisation). The new standard will be given the status of national standard in participating countries, conflicting national standards being withdrawn. The standard will comprise 5 parts covering the grouping and classification of HEPA and ULPA filters according to their efficiency, fundamental principles of testing, marking etc (in part 1). Part 2 will cover aerosol production, measurement principles, counting equipment and statistics. Parts 3-5 will cover testing flat sheet media, leak testing of filter elements and the efficiency testing of filter elements respectively. The efficiency test methods allow the use of either homogeneous monodisperse or polydisperse aerosols for the determination of particulate filtration efficiencies as a function of particle size. The particle size at which maximum penetration occurs is first determined in flat sheet media tests; tests on filter elements (constructed using the same filter medium) may be carried out using either a homogeneous monodisperse aerosol of the size at which maximum penetration occurs (MPPS) or a polydisperse aerosol whose median size is close to the MPPS. Tests with monodisperse aerosols may be conducted using condensation nucleus counting equipment; tests using polydisperse test aerosols require the use of optical sizing particle counters. When determining the efficiency of filter elements the downstream aerosol concentrations may be determined from air samples obtained using either an overall method (single point sampling after mixing) or a scan method. The scan method also allows 'local' efficiency values to be determined. 1 ref., 1 fig., 1 tab

  6. In-place testing of tandem HEPA filter stages using fluorescent aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Elder, J.C.; Kyle, T.G.; Tillery, M.I.; Ettinger, H.J.

    1980-01-01

    Fluorescent test aerosols were used in field testing of large multiple-stage HEPA filter systems. The technique excluded interference from non-fluorescent background particles known to leak into the plenum or ducting between the filters and the downstream sampling probe. This technique solved the problem of measuring extremely low concentrations of the test aerosol in the presence of background aerosol. The upstream fluorescent test aerosol was diluted with clean air and drawn into a single particle aerosol spectrometer capable of counting, sizing, and detecting fluorescence of each particle. The particle sizing function was performed on light scattered by the particle passing through the beam of a helium-cadmium laser. Concurrently the fluorescence excited by the laser illumination was detected at a longer wavelength. Since spectrometer response in the fluorescent mode was <2% of naturally occurring aerosols, background aerosols were insignificant as an interference to the downstream concentration measurement. Decontamination factors (DF) on the order of 10/sup 8/ were measured in the field studies on >9.4 m/sup 3//s (20,000 cfm) systems. Additional generator capacity and acceptably lower test aerosol to background aerosol concentraion ratios could be used to extend this capability to measure DF greater than 10/sup 8/. Dye-tagged DOP aerosols were generated either by gas-thermal or sonic nozzle generators. Experiments with the gas-thermal generator showed only 20% of fluorescence from the dye was degraded by the vaporization process. A single sonic nozzle was shown to aerosolize 0.7 to 1.0 L/h of dye-tagged DOP aerosol in the proper size range for HEPA filter testing. A multiple sonic nozzle generator is a practical consideration to provide greater capacity.

  7. Performance testing of HEPA filters: Progress towards a European standard procedure

    Energy Technology Data Exchange (ETDEWEB)

    Dyment, J.

    1997-08-01

    Proposals for a future European testing procedure for {open_quotes}High Efficiency Particulate Air Filters (HEPA and ULPA){close_quotes} are being developed by CEN (Comite Europeen de Normalisation). The new standard will be given the status of national standard in participating countries, conflicting national standards being withdrawn. The standard will comprise 5 parts covering the grouping and classification of HEPA and ULPA filters according to their efficiency, fundamental principles of testing, marking etc (in part 1). Part 2 will cover aerosol production, measurement principles, counting equipment and statistics. Parts 3-5 will cover testing flat sheet media, leak testing of filter elements and the efficiency testing of filter elements respectively. The efficiency test methods allow the use of either homogeneous monodisperse or polydisperse aerosols for the determination of particulate filtration efficiencies as a function of particle size. The particle size at which maximum penetration occurs is first determined in flat sheet media tests; tests on filter elements (constructed using the same filter medium) may be carried out using either a homogeneous monodisperse aerosol of the size at which maximum penetration occurs (MPPS) or a polydisperse aerosol whose median size is close to the MPPS. Tests with monodisperse aerosols may be conducted using condensation nucleus counting equipment; tests using polydisperse test aerosols require the use of optical sizing particle counters. When determining the efficiency of filter elements the downstream aerosol concentrations may be determined from air samples obtained using either an overall method (single point sampling after mixing) or a scan method. The scan method also allows {open_quotes}local{close_quotes} efficiency values to be determined. 1 ref., 1 fig., 1 tab.

  8. Reduction in MRSA environmental contamination with a portable HEPA-filtration unit.

    Science.gov (United States)

    Boswell, T C; Fox, P C

    2006-05-01

    There is renewed interest in the hospital environment as a potentially important factor for cross-infection with methicillin-resistant Staphylococcus aureus (MRSA) and other nosocomial pathogens. The aim of this study was to evaluate the effectiveness of a portable high-efficiency particulate air (HEPA)-filtration unit (IQAir Cleanroom H13, Incen AG, Goldach, Switzerland) at reducing MRSA environmental surface contamination within a clinical setting. The MRSA contamination rate on horizontal surfaces was assessed with agar settle plates in ward side-rooms of three patients who were heavy MRSA dispersers. Contamination rates were measured at different air filtration rates (60-235 m(3)/h) and compared with no air filtration using Poisson regression. Without air filtration, between 80% and 100% of settle plates were positive for MRSA, with the mean number of MRSA colony-forming units (cfu)/10-h exposure/plate ranging from 4.1 to 27.7. Air filtration at a rate of 140 m(3)/h (one patient) and 235 m(3)/h (two patients), resulted in a highly significant decrease in contamination rates compared with no air filtration (adjusted rate ratios 0.037, 0.099 and 0.248, respectively; P < 0.001 for each). A strong association was demonstrated between the rate of air filtration and the mean number of MRSA cfu/10-h exposure/plate (P for trend < 0.001). In conclusion, this portable HEPA-filtration unit can significantly reduce MRSA environmental contamination within patient isolation rooms, and this may prove to be a useful addition to existing MRSA infection control measures. PMID:16517004

  9. Impact of isomalathion on malathion cytotoxicity and genotoxicity in human HepaRG cells.

    Science.gov (United States)

    Josse, Rozenn; Sharanek, Ahmad; Savary, Camille C; Guillouzo, Andre

    2014-02-25

    Isomalathion is a major impurity of technical grade malathion, one of the most abundantly applied insecticides; however little is known about its hepatotoxicity. In the present study, cytotoxicity and genotoxicity of malathion and isomalathion either individually or in combination, were assessed using the metabolically competent human liver HepaRG cell line. Isomalathion reduced cell viability starting at a 100 μM concentration after a 24h exposure. It also significantly induced caspase-3 activity in a dose-dependent manner starting at 5 μM. On the contrary, even at concentrations as high as 500 μM malathion affected neither cell viability nor caspase-3 activity. Moreover, co-exposure of both compounds resulted in decreased toxicity of isomalathion. By contrast, malathion and isomalathion either separately or in combination, slightly induced micronuclei formation at low concentrations and had additive genotoxic effects when combined at 25 μM. Individually or combined isomalathion directly inhibited activity of carboxyesterases which are involved in detoxication of malathion. In addition, transcripts of CYP2B6 and CYP3A4, two CYPs responsible for malathion phase I metabolism, were strongly induced by the mixture while isomalathion alone only moderately decreased CYP1A2 and increased CYP2B6 transcripts. However, these CYPs were not altered at the protein or activity levels. Taken altogether, our results showed that isomalathion was much more cytotoxic than malathion while both compounds had comparable genotoxic effects in HepaRG hepatocytes at low concentrations and brought further support to the importance of considering impurities and interactions during evaluation of health risks of pesticides. PMID:24333466

  10. Analysis of fire and smoke threat to off-gas HEPA filters in a transuranium processing plant

    International Nuclear Information System (INIS)

    The author performed an analysis of fire risk to the high-efficiency particulate air (HEPA) filters that provide ventilation containment for a transuranium processing plant at the Oak Ridge National Laboratory. A fire-safety survey by an independent fire-protection consulting company had identified the HEPA filters in the facility's off-gas containment ventilation system as being at risk from fire effects. Independently studied were the ventilation networks and flow dynamics, and typical fuel loads were analyzed. It was found that virtually no condition for fire initiation exists and that, even if a fire started, its consequences would be minimal as a result of standard shut-down procedures. Moreover, the installed fire-protection system would limit any fire and thus would further reduce smoke or heat exposure to the ventilation components. 4 references, 4 figures, 5 tables

  11. Prenylated chalcones and flavanones as inducers of quinone reductase in mouse Hepa 1c1c7 cells.

    Science.gov (United States)

    Miranda, C L; Aponso, G L; Stevens, J F; Deinzer, M L; Buhler, D R

    2000-02-28

    The objective of this study was to determine if prenylchalcones (open C-ring flavonoids) and prenylflavanones from hops and beer are inducers of quinone reductase (QR) in the mouse hepatoma Hepa 1c1c7 cell line. All the prenylchalcones and prenylflavanones tested were found to induce QR but not CYP1A1 in this cell line. In contrast, the synthetic chalcone, chalconaringenin, and the flavanone, naringenin, with no prenyl or geranyl groups, were ineffective in inducing QR. The hop chalcones, xanthohumol and dehydrocycloxanthohumol hydrate, also induced QR in the Ah-receptor-defective mutant cell line, Hepa 1c1c7 bp(r)c1. Thus, the prenylflavonoids represent a new class of monofunctional inducers of QR. PMID:10737704

  12. Performance of 1000- and 1800- cfm HEPA filters on long exposure to low atmospheric dust loadings, II

    International Nuclear Information System (INIS)

    Comparative tests were made to evaluate the performance characteristics of American- and European-design HEPA filters when exposed, for a number of years, to aerosols characteristic of nuclear and biohazard service. Although some of the European-design filters were operated at their rated airflow capacity of 1800 cfm, some were downrated to 1000 cfm to determine if their service life could be more than tripled compared to conventional 1000-cfm Americal-design HEPA filters, as filter theory predicts. Initial results indicate, however, that for the ambient aerosol used in this study, a European-design filter has a service life of only 1.6 times greater than an American-design filter when both operate at 1000 cfm. Further tests are in progress to verify this result

  13. 5-azacytidine inhibits the proliferation of bladder cancer cells via reversal of the aberrant hypermethylation of the hepaCAM gene.

    Science.gov (United States)

    Wang, Xiaorong; Chen, E; Yang, Xue; Wang, Yin; Quan, Zhen; Wu, Xiaohou; Luo, Chunli

    2016-03-01

    Hepatocyte cell adhesion molecule (hepaCAM), a tumor-suppressor gene, is rarely expressed in bladder carcinoma. However, little is known concerning the mechanisms of low hepaCAM expression in bladder cancer. Abnormal hypermethylation in the promoter plays a crucial role in cancer by silencing tumor-suppressor genes, which is catalyzed by DNA methyltransferases (DNMTs). In the present study, a total of 31 bladder cancer and 22 adjacent tissues were assessed by immunohistochemistry to detect DNMT3A/3B and hepaCAM expression. Methylation of hepaCAM was determined by methylation‑specific polymerase chain reaction (MSP). The mRNA and protein levels of DNMT3A/3B and hepaCAM were determined by RT-PCR and western blot analysis after treatment with 5-azacytidine (AZAC). Following AZAC treatment, the proliferation of bladder cancer cells was detected by CCK-8 and colony formation assays. Cell cycle distribution was examined by flow cytometry. To further evaluate the tumor‑suppressive roles of AZAC and the involved mechanisms, the anti-tumorigenicity of AZAC was tested in vivo. The expression of DNMT3A/3B protein was markedly increased in the bladder carcinoma tissues (P<0.05), and had a negative linear correlation with hepaCAM expression in the same patients according to Pearson's analysis (r=-0.7176/-0.7127, P<0.05). The MSP results indicated that the hepaCAM gene was hypermethylated in three bladder cancer cell lines. Furthermore, we found that downregulation of DNMT3A/3B expression, after treatment with AZAC, reversed the hypermethylation and expression of hepaCAM in bladder cancer cells. In addition, AZAC inhibited the proliferation of bladder cancer cells and arrested cells at the G0/G1 phase. The in vivo results showed that expression of DNMT3A/3B and hepaCAM as well as tumor growth of nude mice were markedly altered which corresponded with the in vitro results. Due to the ability to reactivate expression of hepaCAM and inhibit growth of bladder cancer cells

  14. Tool steels

    DEFF Research Database (Denmark)

    Højerslev, C.

    2001-01-01

    On designing a tool steel, its composition and heat treatment parameters are chosen to provide a hardened and tempered martensitic matrix in which carbides are evenly distributed. In this condition the matrix has an optimum combination of hardness andtoughness, the primary carbides provide...... resistance against abrasive wear and secondary carbides (if any) increase the resistance against plastic deformation. Tool steels are alloyed with carbide forming elements (Typically: vanadium, tungsten, molybdenumand chromium) furthermore some steel types contains cobalt. Addition of alloying elements...... serves primarily two purpose (i) to improve the hardenabillity and (ii) to provide harder and thermally more stable carbides than cementite. Assuming proper heattreatment, the properties of a tool steel depends on the which alloying elements are added and their respective concentrations....

  15. Alloyed steel

    International Nuclear Information System (INIS)

    The composition and properties are listed of alloyed steel for use in the manufacture of steam generators, collectors, spacers, emergency tanks, and other components of nuclear power plants. The steel consists of 0.08 to 0.11% w.w. C, 0.6 to 1.4% w.w. Mn, 0.35 to 0.6% w.w. Mo, 0.02 to 0.07% w.w. Al, 0.17 to 0.37% w.w. Si, 1.7 to 2.7% w.w. Ni, 0.03 to 0.07% w.w. V, 0.005 to 0.012% w.w. N, and the rest is Fe. The said steel showed a sufficiently low transition temperature between brittle and tough structures, a greater depth of hardenability, and better weldability than similar steels. (B.S.)

  16. Steel welding.

    OpenAIRE

    Kučera, Marek

    2011-01-01

    Topic of the thesis concerns the problem of steel welding. The aim was to give acomprehensive overview on the topic, describe the known methods, advantages and disadvantages of welding technology. The introductory part is focused on introducing the basics of the process required to produce high-quality connections. Chapter three offers an overview of known and used welding methods with thein brief description of the method. The next chapter describes steel as material suitable for welding....

  17. Study on DOP substitutes for leaking rate testing of HEPA filter used in nuclear air cleaning systems

    International Nuclear Information System (INIS)

    Based on an extensive investigation over available literatures concerning HEPA filter testing, PEG400, SHELL on dina oil 15 and P.a. were chosen as candidates for Dop substitutes, and on which a series of tests were conducted about their aerosol conversion rate, particle size distribution, Dop detector response and leaking rate in H EPA filter. With consideration of technical properties, safety performance and economy, homemade P.a. is finally selected as the best substitute for Dop among the three. (authors)

  18. Comparative Localization and Functional Activity of the Main Hepatobiliary Transporters in HepaRG Cells and Primary Human Hepatocytes.

    Science.gov (United States)

    Bachour-El Azzi, Pamela; Sharanek, Ahmad; Burban, Audrey; Li, Ruoya; Guével, Rémy Le; Abdel-Razzak, Ziad; Stieger, Bruno; Guguen-Guillouzo, Christiane; Guillouzo, André

    2015-05-01

    The role of hepatobiliary transporters in drug-induced liver injury remains poorly understood. Various in vivo and in vitro biological approaches are currently used for studying hepatic transporters; however, appropriate localization and functional activity of these transporters are essential for normal biliary flow and drug transport. Human hepatocytes (HHs) are considered as the most suitable in vitro cell model but erratic availability and inter-donor functional variations limit their use. In this work, we aimed to compare localization of influx and efflux transporters and their functional activity in differentiated human HepaRG hepatocytes with fresh HHs in conventional (CCHH) and sandwich (SCHH) cultures. All tested influx and efflux transporters were correctly localized to canalicular [bile salt export pump (BSEP), multidrug resistance-associated protein 2 (MRP2), multidrug resistance protein 1 (MDR1), and MDR3] or basolateral [Na(+)-taurocholate co-transporting polypeptide (NTCP) and MRP3] membrane domains and were functional in all models. Contrary to other transporters, NTCP and BSEP were less abundant and active in HepaRG cells, cellular uptake of taurocholate was 2.2- and 1.4-fold and bile excretion index 2.8- and 2.6-fold lower, than in SCHHs and CCHHs, respectively. However, when taurocholate canalicular efflux was evaluated in standard and divalent cation-free conditions in buffers or cell lysates, the difference between the three models did not exceed 9.3%. Interestingly, cell imaging showed higher bile canaliculi contraction/relaxation activity in HepaRG hepatocytes and larger bile canaliculi networks in SCHHs. Altogether, our results bring new insights in mechanisms involved in bile acids accumulation and excretion in HHs and suggest that HepaRG cells represent a suitable model for studying hepatobiliary transporters and drug-induced cholestasis. PMID:25690737

  19. Modulation of CYP3A4 activity alters the cytotoxicity of lipophilic phycotoxins in human hepatic HepaRG cells.

    Science.gov (United States)

    Ferron, P J; Hogeveen, K; De Sousa, G; Rahmani, R; Dubreil, E; Fessard, V; Le Hegarat, L

    2016-06-01

    The aim of this study was to investigate (i) the cytotoxic effects of lipophilic phycotoxins, including okadaic acid (OA) and dinophysistoxin-1 and -2 (DTX-1 and DTX-2), pectenotoxin-2 (PTX-2), yessotoxin (YTX), spirolide (SPX), and azaspiracids-1, -2 and -3 (AZA-1, AZA-2 and AZA-3), in human HepaRG cells using a multiparametric high content analysis approach, (ii) the ability of nine lipophilic phycotoxins to act as PXR agonists in a HepG2-PXR cell line, (iii) their potential to induce CYP450 activity, and (iv) the role of CYP3A4 in cytotoxicity induced by lipophilic phycotoxins. Our results indicate that while OA, DTX-1 and DTX-2 activated PXR-dependent transcriptional activity in HepG2 cells, no increase of CYP450 (1A2, 3A4, 2C9, 2C19) activities were observed in HepaRG cell following a 72h treatment with these toxins. Multiparametric analysis showed that OA, DTX-1, DTX-2, and PTX-2 were highly cytotoxic in HepaRG cells; inducing cell loss, activation of caspase-3 and γ-H2AX formation. However, no toxicity was observed for YTX, SPX, and AZAs. Moreover, we found that inhibition of CYP3A4 activity by ketoconazole enhances the toxic effects of OA, DTX-1, DTX-2, and PTX-2 in HepaRG cells. Taken together, these results suggest that CYP3A4-mediated metabolism of some lipophilic phycotoxins decreases their in vitro toxicity. PMID:26956883

  20. Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide

    International Nuclear Information System (INIS)

    Supercritical fluid extraction (SFE) using unmodified carbon dioxide has been explored as an alternative method for the extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters. HEPA filters provide the final stage of containment on many exhaust systems in US Department of Energy (DOE) facilities by preventing the escape of chemical and radioactive materials entrained in the exhausted air. The efficiency of the filters is tested by the manufacturer and DOE using dioctylphthalate (DOP), a substance regulated by the US Environmental Protection Agency under the Resource Conservation and Recovery Act. Therefore, the filters must be analyzed for semivolatile organics before disposal. Ninety-eight acid, base, and neutral semivolatile organics were spiked onto blank HEPA material and extracted using SFE, Soxhlet, automated Soxhlet, and sonication techniques. The SFE conditions were optimized using a Dionex SFE-703 instrument. Average recoveries for the 98 semivolatile compounds are 82.7% for Soxhlet, 74.0% for sonication, 70.2% for SFE, and 62.9% for Soxtec. Supercritical fluid extraction reduces the extraction solvent volume to 10--15 mL, a factor of 20--30 less than Soxhlet and more than 5 times less than Soxtec and sonication. Extraction times of 30--45 min are used compared to 16--18 h for Soxhlet extraction

  1. Evaluation of Regulatory and Standard Performance Testing Techniques for HEPA Filters Used in Radiological and Nuclear Installations

    International Nuclear Information System (INIS)

    With the recent remarkable growth in peaceful applications of radiation technology and nuclear energy in various human activation, the protection of personnel and environmental against radiation hazards is an important safety related issue. In this context High Efficiency Particulate Air filters units (HEPA) are the main components in VACS system used in radiological and nuclear installations to guarantee air quality and environmental control for safety of personnel and protection of safety related and control instruments. Several investigations have been carried out for the evaluation of different HEPA filter technical standard test methods. In this paper, a set of new ten HEPA filter units from different manufactures were tested by different four testing techniques. More important safety related parameters like for the decontamination factors (DF) and removal efficiency have been determined, compared and evaluated for the four methods. The results indicated that; the (Ur) method is more suited only for the laboratory investigations of filter media because of its longer duration of testing and of its high sensitivity. The sodium chloride test is fast and reproducible adapt for large scale evaluation of filters and as an accurate laboratory test. The method is difficult to adapt as an in-situ test method because of the limitation of using flame photometry at the site. Correlations resulting from this study enable the user and the manufacturer to select and adapt the proper testing technique for the evaluation of their VACS systems

  2. Asbestos-fiber release during change-out of filter bags from HEPA-filtered vacuum cleaners

    Energy Technology Data Exchange (ETDEWEB)

    Kominsky, J.R.; Freyberg, R.W.; Hollett, B.A.; Clark, P.J.; Brackett, K.A.

    1991-01-01

    High-efficiency particulate air (HEPA) filtered vacuum cleaners are the primary tool used to clean up asbestos containing material during operations and maintenance (O M) activities. The change-out of vacuum bags is a potential source of airborne asbestos contamination. In 1989 and 1990 the Risk Reduction Engineering Laboratory (RREL) of the U.S. Environmental Protection Agency conducted a series of controlled tests to determine airborne asbestos fiber levels during change-out of filters bags used in HEPA-filtered vacuum cleaners. Five different HEPA-filtered vacuums of varying brands and capacities were tested. The study was conducted at EPA's controlled asbestos test (CAT) facility. The data from two studies indicates that airborne asbestos levels can increase significantly during normal bag change-out operations and that these increases vary with the configuration of the vacuum cleaner. The primary potential point of fiber release during each bag change-out occurred when the paper bag was separated from the intake tube. The use of a glove-box enclosure significantly reduced the increase in airborne asbestos concentrations during bag change-out.

  3. Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, J.B.

    1997-09-01

    Supercritical fluid extraction (SFE) using unmodified carbon dioxide has been explored as an alternative method for the extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters. HEPA filters provide the final stage of containment on many exhaust systems in US Department of Energy (DOE) facilities by preventing the escape of chemical and radioactive materials entrained in the exhausted air. The efficiency of the filters is tested by the manufacturer and DOE using dioctylphthalate (DOP), a substance regulated by the US Environmental Protection Agency under the Resource Conservation and Recovery Act. Therefore, the filters must be analyzed for semivolatile organics before disposal. Ninety-eight acid, base, and neutral semivolatile organics were spiked onto blank HEPA material and extracted using SFE, Soxhlet, automated Soxhlet, and sonication techniques. The SFE conditions were optimized using a Dionex SFE-703 instrument. Average recoveries for the 98 semivolatile compounds are 82.7% for Soxhlet, 74.0% for sonication, 70.2% for SFE, and 62.9% for Soxtec. Supercritical fluid extraction reduces the extraction solvent volume to 10--15 mL, a factor of 20--30 less than Soxhlet and more than 5 times less than Soxtec and sonication. Extraction times of 30--45 min are used compared to 16--18 h for Soxhlet extraction.

  4. A device for uranium series leaching from glass fiber in HEPA filter

    International Nuclear Information System (INIS)

    For the disposal of a high efficiency particulate air (HEPA) glass filter into the environment, the glass fiber should be leached to lower its radioactive concentration to the clearance level. To derive an optimum method for the removal of uranium series from a HEPA glass fiber, five methods were applied in this study. That is, chemical leaching by a 4.0 M HNO3-0.1 M Ce(IV) solution, chemical leaching by a 5 wt% NaOH solution, chemical leaching by a 0.5 M H2O2-1.0 M Na2CO3 solution, chemical consecutive chemical leaching by a 4.0 M HNO3 solution, and repeated chemical leaching by a 4.0 M HNO3 solution were used to remove the uranium series. The residual radioactivity concentrations of 238U, 235U, 226Ra, and 234Th in glass after leaching for 5 h by the 4.0 M HNO3-0.1 M Ce(IV) solution were 2.1, 0.3, 1.1, and 1.2 Bq/g. The residual radioactivity concentrations of 238U, 235U, 226Ra, and 234Th in glass after leaching for 36 h by 4.0 M HNO3-0.1 M Ce(IV) solution were 76.9, 3.4, 63.7, and 71.9 Bq/g. The residual radioactivity concentrations of 238U, 235U, 226Ra, and 234Th in glass after leaching for 8 h by a 0.5 M H2O2-1.0 M Na2CO3 solution were 8.9, 0.0, 1.91, and 6.4 Bq/g. The residual radioactivity concentrations of 238U, 235U, 226Ra, and 234Th in glass after consecutive leaching for 8 h by the 4.0 M HNO3 solution were 2.08, 0.12, 1.55, and 2.0 Bq/g. The residual radioactivity concentrations of 238U, 235U, 226Ra, and 234Th in glass after three repetitions of leaching for 3 h by the 4.0 M HNO3 solution were 0.02, 0.02, 0.29, and 0.26 Bq/g. Meanwhile, the removal efficiencies of 238U, 235U, 226Ra, and 234Th from the waste solution after its precipitation-filtration treatment with NaOH and alum for reuse of the 4.0 M HNO3 waste solution were 100, 100, 93.3, and 100%. (author)

  5. Evaluation of HEPA vacuum cleaning and dry steam cleaning in reducing levels of polycyclic aromatic hydrocarbons and house dust mite allergens in carpets.

    Science.gov (United States)

    Yu, Chang Ho; Yiin, Lih-Ming; Tina Fan, Zhi-Hua; Rhoads, George G

    2009-01-01

    Dry steam cleaning, which has gained recent attention as an effective method to reduce house dust mite (HDM) allergen concentration and loading in carpets, was evaluated in this study for its efficacy in lowering levels of polycyclic aromatic hydrocarbons (PAHs) as well as HDM allergens. Fifty urban homes with wall-to-wall carpets, mostly low-income and with known lead contamination, were studied in 2003 and 2004. Two carpet-cleaning interventions were compared: Repeated HEPA (High Efficiency Particulate Air filtered) vacuuming alone and repeated HEPA vacuuming supplemented with dry steam cleaning. Vacuum samples were collected to measure carpet loading of dust and contaminants immediately before and after cleaning. Paired comparisons were conducted to evaluate the effectiveness of the cleaning protocols in reducing the levels of PAHs and HDM allergens in carpets. The results indicated that both cleaning methods substantially reduced the loading of PAHs and HDM allergens as well as dust in carpets (p < 0.0001). The reductions in loading of dust (64.4%), PAHs (69.1%), and HDM allergens (85.5%), by dry steam cleaning plus repetitive HEPA vacuuming were larger than the reductions by regular HEPA vacuuming alone: dust (55.5%), PAHs (58.6%), and HDM allergens (80.8%), although the difference was statistically significant only for dust and PAHs. We conclude that intensive HEPA vacuum cleaning substantially reduced the loading of PAHs and HDM allergens in carpets in these urban homes and that dry steam cleaning added modestly to cleaning effectiveness. PMID:19137159

  6. The development of a HEPA filter with improved dust holding characteristics

    International Nuclear Information System (INIS)

    A limitation of the HEPA filters used in the extract of nuclear facilities is their relatively low capacity for captured dust. The costs associated with the disposal of a typical filter means that there are clear incentives to extend filter life. The work described in this report are the initial stages in the development of a filter which incorporates a medium which enhances its dust holding capacity. Experimental equipment was installed to enable the dust loading characteristics of candidate media to be compared with those of the glass fibre based papers currently used in filter construction. These tests involved challenging representative samples of the media with an air stream containing a controlled concentration of thermally generated sodium chloride particles. The dust loading characteristics of the media were then compared in terms of the rate of increasing in pressure differential. A number of open-quotes graded densityclose quotes papers were subsequently identified which appeared to offer significant improvements in dust holding. In the second phase of the programme deep-pleat filters (1,700 M3h-1) incorporating graded density papers were manufactured and tested. Improvements of up to 50% were observed in their capacity for the sub-micron sodium chloride test dust. Smaller differences (15%) were measured when a coarser, carbon black, challenge was used. This is attributed to the differences in the particles sizes of the two dusts

  7. The development of a HEPA filter with improved dust holding characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Dyment, J.; Hamblin, C.

    1995-02-01

    A limitation of the HEPA filters used in the extract of nuclear facilities is their relatively low capacity for captured dust. The costs associated with the disposal of a typical filter means that there are clear incentives to extend filter life. The work described in this report are the initial stages in the development of a filter which incorporates a medium which enhances its dust holding capacity. Experimental equipment was installed to enable the dust loading characteristics of candidate media to be compared with those of the glass fibre based papers currently used in filter construction. These tests involved challenging representative samples of the media with an air stream containing a controlled concentration of thermally generated sodium chloride particles. The dust loading characteristics of the media were then compared in terms of the rate of increasing in pressure differential. A number of {open_quotes}graded density{close_quotes} papers were subsequently identified which appeared to offer significant improvements in dust holding. In the second phase of the programme deep-pleat filters (1,700 M{sup 3}h{sup {minus}1}) incorporating graded density papers were manufactured and tested. Improvements of up to 50% were observed in their capacity for the sub-micron sodium chloride test dust. Smaller differences (15%) were measured when a coarser, carbon black, challenge was used. This is attributed to the differences in the particles sizes of the two dusts.

  8. The histone deacetylase inhibiting drug Entinostat induces lipid accumulation in differentiated HepaRG cells

    Science.gov (United States)

    Nunn, Abigail D. G.; Scopigno, Tullio; Pediconi, Natalia; Levrero, Massimo; Hagman, Henning; Kiskis, Juris; Enejder, Annika

    2016-06-01

    Dietary overload of toxic, free metabolic intermediates leads to disrupted insulin signalling and fatty liver disease. However, it was recently reported that this pathway might not be universal: depletion of histone deacetylase (HDAC) enhances insulin sensitivity alongside hepatic lipid accumulation in mice, but the mechanistic role of microscopic lipid structure in this effect remains unclear. Here we study the effect of Entinostat, a synthetic HDAC inhibitor undergoing clinical trials, on hepatic lipid metabolism in the paradigmatic HepaRG liver cell line. Specifically, we statistically quantify lipid droplet morphology at single cell level utilizing label-free microscopy, coherent anti-Stokes Raman scattering, supported by gene expression. We observe Entinostat efficiently rerouting carbohydrates and free-fatty acids into lipid droplets, upregulating lipid coat protein gene Plin4, and relocating droplets nearer to the nucleus. Our results demonstrate the power of Entinostat to promote lipid synthesis and storage, allowing reduced systemic sugar levels and sequestration of toxic metabolites within protected protein-coated droplets, suggesting a potential therapeutic strategy for diseases such as diabetes and metabolic syndrome.

  9. Aging assessment of nuclear air-treatment system HEPA filters and adsorbers

    International Nuclear Information System (INIS)

    A Phase I aging assessment of high-efficiency particulate air (HEPA) filters and activated carbon gas adsorption units (adsorbers) was performed by the Pacific Northwest Laboratory (PNL) as part of the US Nuclear Regulatory Commission's (NRC) Nuclear Plant Aging Research (NPAR) Program. Information concerning design features; failure experience; aging mechanisms, effects, and stressors; and surveillance and monitoring methods for these key air-treatment system components was compiled. Over 1100 failures, or 12 percent of the filter installations, were reported as part of a Department of Energy (DOE) survey. Investigators from other national laboratories have suggested that aging effects could have contributed to over 80 percent of these failures. Tensile strength tests on aged filter media specimens indicated a decrease in strength. Filter aging mechanisms range from those associated with particle loading to reactions that alter properties of sealants and gaskets. Low radioiodine decontamination factors associated with the Three Mile Island (TMI) accident were attributed to the premature aging of the carbon in the adsorbers. Mechanisms that can lead to impaired adsorber performance include oxidation as well as the loss of potentially available active sites as a result of the adsorption of pollutants. Stressors include heat, moisture, radiation, and airborne particles and contaminants

  10. Survey of HEPA filter applications and experience at Department of Energy sites

    International Nuclear Information System (INIS)

    Results indicated that approximately 58% of the filters surveyed were changed out in the 1977 to 1979 study period and some 18% of all filters were changed out more than once. Most changeouts (60%) were due to the existence of a high pressure drop across the filter, indicative of filter plugging. The next most recurrent reasons for changeout and their percentage changeouts were leak test failure (15%) and preventive maintenance service life limit (12%). An average filter service life was calculated to be 3.0 years with a 2.0-year standard deviation. The labor required for filter changeout was calculated as 1.5 manhours per filter changed. Filter failures occurred with approximately 12% of all installed filters. Most failures (60%) occurred for unknown reasons and handling or installation damage accounted for an additional 20% of all failures. Media ruptures, filter frame failures and seal failures occurred with approximately equal frequency at 5 to 6% each. Subjective responses to the questionnaire indicate problems are: need for improved acid and moisture resistant filters; filters more readily disposable as radioactive waste; improved personnel training in filter handling and installation; and need for pretreatment of air prior to HEPA filtration

  11. Plutonium and uranium emission experience in U.S. nuclear facilities using HEPA filtration

    International Nuclear Information System (INIS)

    The weekly, monthly and yearly emission experience of eleven U.S. nuclear facilities is presented, and reviewed. Each of these facilities uses HEPA filtration to control emissions, the various vent streams using from one to three such filtration systems in series. Available emission records cover from one to five vents at each facility, and cover periods ranging from two to eleven years. The majority of the facilities process plutonium, either exclusively or as mixed oxide, but a few process highly enriched uranium-235, natural uranium and/or thorium. Facilities include fuel fabrication plants, fuel reprocessing plants, and experimental facilities. The emission curves show clearly not only the normal operation of the filter systems, but also the effects of minor leaks, and of major failures, as well as the effects of retention of material in ducts and other passive parts of the filtration systems. An analysis is presented of the operation of such systems in real environments, and the non-Stokes Law behavior of very dense particles is exemplified by experiments done with a non-radoactive tracer, whose crystal is isomorphous with those of plutonium and uranium dioxides, tungsten dioxide

  12. A Device for Uranium series Leaching from Glass Fiber in HEPA Filter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gye Nam; Lee, Suk Chol; Yang, Hee Chul; Yoon, In Ho; Choi, Wang Kyu; Lee, Kune Woo; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    A great amount of radioactive waste has been generated during the operation of nuclear facilities. Recently, the storage space of a radioactive waste storage facility in the Korea Atomic Energy Research Institute (KAERI) was almost saturated with many radioactive wastes. To derive an optimum method for the removal of uranium series from HEPA glass fiber, five methods were applied in this study. That is, chemical leaching by 4.0 M HNO{sub 3}-0.1M Ce(IV) solution, chemical leaching by 5 wt% NaOH solution, chemical leaching by 0.5M H{sub 2}O{sub 2}-1.0M Na{sub 2}CO{sub 3} solution, chemical consecutive leaching by 4.0 M HNO{sub 3} solution, and chemical repeated leaching by 4.0 M HNO{sub 3} solution were used to remove uranium series. Also, in order to reuse the leaching waste-solution contaminated with {sup 238}U, {sup 235}U, {sup 226}Ra, and {sup 234}Th, the precipitation-filtration experiment was carried out with NaOH and alum as precipitants

  13. Preliminary assessment of the dust loading versus pressure drop characteristic of high capacity HEPA filters

    International Nuclear Information System (INIS)

    A design of High Efficiency Particulate Air (HEPA) filter offering enhanced flow capacity on conventional deep-pleat designs has been developed in Europe and is now available from several manufacturers. These filters offer significant reductions in the physical size of filtration installations and are also claimed to have an extended service life. Dust loading versus pressure drop tests have been carried out on filters from two manufacturers using both ASHRAE and BS 2831 No. 2 test dusts at a flow rate of 3400 m3/h and also downrated to 1700 m3/h. Similar tests have been carried out on conventional deep-pleat design filters rated at 1700 m3/h as a datum base for a comparison of performance for the two designs. These initial results suggest that the high capacity filter might be used to advantage by plant designers in one of two ways. A significantly greater dust loading and hence filter life can be obtained by operating the filters at half their rated capacity. Alternatively the high flow rates can be used to reduce the size of a given installation but with a resulting reduction in the life of the filter. Unexpectedly large differences were found between the filters from the two sources. This suggests that further work is required to compare products from all sources in order to optimize the potential savings from adoption of the new design

  14. Hegelian Steel

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2015-01-01

    Even in our globalized world the notion of national economies remain incredibly strong, just as a considerable part of the literature on transnational governance and globalization continue to rely on a zero-sum perspective concerning the relationship between the national and the transnational. De...... of the European steel industry....

  15. Interactions between hepatitis B virus and aflatoxin B(1): effects on p53 induction in HepaRG cells.

    Science.gov (United States)

    Lereau, Myriam; Gouas, Doriane; Villar, Stéphanie; Besaratinia, Ahmad; Hautefeuille, Agnès; Berthillon, Pascale; Martel-Planche, Ghislaine; Nogueira da Costa, André; Ortiz-Cuaran, Sandra; Hantz, Olivier; Pfeifer, Gerd P; Hainaut, Pierre; Chemin, Isabelle

    2012-03-01

    Infection by hepatitis B virus (HBV) and dietary exposure to aflatoxin B(1) (AFB(1)) are the main risk factors for the development of chronic liver disease and hepatocellular carcinoma (HCC). How these factors cooperate is still largely unknown. AFB(1) activation leads to DNA adduction and mutagenesis, with a specific mutation at codon 249 in TP53 (p.R249S). So far, only limited studies have addressed the effects of AFB(1) on HBV replication. We have analysed the effects of both risk factors on p53 induction during HBV infection in HepaRG, a cell line with hepatocyte-like morphology that metabolizes AFB(1) and supports HBV infection. Exposure to AFB(1) up to 5 µM induced a downregulation of HBV replication after 48 h, as measured by a decrease in viral antigens in the culture medium (HBsAg, HBeAg and large envelope protein) and in intracellular levels of HBV transcripts, DNA and HBsAg. Conversely, HBV infection did not significantly modify AFB(1)-DNA adduct formation or repair as assessed by immunodot-blot assay, and the induction of p53 in response to AFB(1) was similar in infected and non-infected HepaRG cells. Overall, our results suggest that AFB(1) exposure decreases HBV replication, whereas DNA damage by AFB(1) and subsequent p53 induction is not affected by the presence of the virus. Thus, in HepaRG cell line, AFB(1) and HBV do not cooperate to increase DNA damage by AFB(1). Further studies on the effects of both factors in a context of chronicity are needed to better understand synergistic effects. PMID:22113009

  16. In Vivo Evaluation of a New Embolic Spherical Particle (HepaSphere) in a Kidney Animal Model

    International Nuclear Information System (INIS)

    HepaSphere is a new spherical embolic material developed in a dry state that absorbs fluids and adapts to the vessel wall, leaving no space between the particle and the arterial wall. The aim of this study was to elucidate the final in vivo size, deformation, final location, and main properties of the particles when reconstituted with two different contrast media (Iodixanol and Ioxaglate) in an animal model. Two sizes of 'dry-state' particles (50-100 and 150-200 μm) were reconstituted using both ionic and nonionic contrast media. The mixture was used to partly embolize both kidneys in an animal model (14 pigs). The animals were sacrificed 4 weeks after the procedure and the samples processed. The final size of the particles was 230.2 ± 62.5 μm for the 50- to 100-μm dry-state particles and 314.4 ± 71 μm for the 150- to 200-μm dry-state particles. When the contrast medium (ionic versus nonionic) used for the reconstitution was studied to compare (Student's t-test) the final size of the particles, no differences were found (p > 0.05). The mean in vivo deformation for HepaSphere was 17.1% ± 12.3%. No differences (p > 0.05) were found in the deformation of the particle regarding the dry-state size or the contrast medium (Mann-Whitney test). We conclude that HepaSphere is stable, occludes perfectly, and morphologically adapts to the vessel lumen of the arteries embolized. There is no recanalization of the arteries 4 weeks after embolization. Its final in vivo size is predictable and the particle has the same properties in terms of size and deformation with the two different contrast media (Iodixanol and Ioxaglate)

  17. Results from Evaluation of Representative ASME AG-1 Section FK Radial Flow Dimple Pleated HEPA Filters Under Elevated Conditions - 12002

    Energy Technology Data Exchange (ETDEWEB)

    Giffin, Paxton K.; Parsons, Michael S.; Rickert, Jaime G.; Waggoner, Charles A. [Institute for Clean Energy Technology, Mississippi State University, 205 Research Blvd Starkville, MS 39759 (United States)

    2012-07-01

    The American Society of Mechanical Engineers (ASME) has recently added Section FK establishing requirements for radial flow HEPA filters to the Code on Nuclear Air and Gas Treatment (AG-1). Section FK filters are expected to be a major element in the HEPA filtration systems across the US Department of Energy (DOE) complex. Radial flow filters have been used in Europe for some time, however a limited amount of performance evaluation data exists with respect to these new AG-1 Section FK units. In consultation with a technical working group, the Institute for Clean Energy Technology (ICET) at Mississippi State University (MSU)has evaluated a series of representative AG-1 Section FK dimple pleated radial flow HEPA filters. The effects of elevated relative humidity and temperature conditions on these filters are particularly concerning. Results from the evaluation of Section FK filters under ambient conditions have been presented at the 2011 waste management conference. Additions to the previous test stand to enable high temperature and high humidity testing, a review of the equipment used, the steps taken to characterize the new additions, and the filter test results are presented in this study. Test filters were evaluated at a volumetric flow rate of 56.6 m{sup 3}/min (2000 cfm) and were challenged under ambient conditions with Alumina, Al(OH){sub 3}, until reaching a differential pressure of 1 kPa (4 in. w.c.), at which time the filters were tested, unchallenged with aerosol, at 54 deg. C (130 deg. F) for approximately 1 hour. At the end of that hour water was sprayed near the heat source to maximize vaporization exposing the filter to an elevated relative humidity up to 95%. Collected data include differential pressure, temperature, relative humidity, and volumetric flow rate versus time. (authors)

  18. Protective effect of Porphyra yezoensis glycoprotein on D-galactosamine‑induced cytotoxicity in Hepa 1c1c7 cells.

    Science.gov (United States)

    Choi, Jeong-Wook; Kim, Young-Min; Park, Su-Jin; Kim, In-Hye; Nam, Taek-Jeong

    2015-05-01

    The present study aimed to examine the signaling pathways and enzyme activity associated with the protective effect of Porphyra yezoensis glycoprotein (PYGP) on D‑galactosamine (D‑GaIN)‑induced cytotoxicity in Hepa 1c1c7 cells. D‑GaIN is commonly used to induce hepatic injury models in vivo as well as in vitro. PYGP was extracted from Porphyra yezoensis, a red algae distributed along the coasts of Republic of Korea, China and Japan. In the present study, Hepa 1c1c7 cells were pre‑treated with PYGP (20 and 40 µg/ml) for 24 h and then the media was replaced with D‑GaIN (20 mM) and PYGP (20 and 40 µg/ml). The results demonstrated that D‑GaIN induced Hepa 1c1c7 cell death and pretreatment with PYGP was found to attenuate D‑GaIN toxicity. In addition, D‑GaIN decreased the antioxidant activity and increased lipid peroxidation processes; however, pre‑treatment with PYGP reduced the generation of lipid peroxidation products, such as thiobarbituric acid reactive substances, as well as increased the activity of antioxidant enzymes, including superoxide dismutase, catalase and glutathione‑s‑transferase (GST). PYGP was shown to suppress the overexpression of extracellular signal‑regulated kinase, c‑jun N‑terminal kinase and p38 mitogen‑activated protein kinase (MAPK) phosphorylation induced by D‑GaIN. Furthermore, PYGP increased the protein expression of nuclear factor erythroid 2‑related factor 2 (Nrf2), quinine oxidoreductase 1, GST and heme oxygenase 1 protein expression. These results suggested that PYGP had cytoprotective effects against D‑GaIN‑induced cell damage, which may be associated with MAPKs and the Nrf2 signaling pathway. PMID:25626067

  19. Results from Evaluation of Representative ASME AG-1 Section FK Radial Flow Dimple Pleated HEPA Filters Under Elevated Conditions - 12002

    International Nuclear Information System (INIS)

    The American Society of Mechanical Engineers (ASME) has recently added Section FK establishing requirements for radial flow HEPA filters to the Code on Nuclear Air and Gas Treatment (AG-1). Section FK filters are expected to be a major element in the HEPA filtration systems across the US Department of Energy (DOE) complex. Radial flow filters have been used in Europe for some time, however a limited amount of performance evaluation data exists with respect to these new AG-1 Section FK units. In consultation with a technical working group, the Institute for Clean Energy Technology (ICET) at Mississippi State University (MSU)has evaluated a series of representative AG-1 Section FK dimple pleated radial flow HEPA filters. The effects of elevated relative humidity and temperature conditions on these filters are particularly concerning. Results from the evaluation of Section FK filters under ambient conditions have been presented at the 2011 waste management conference. Additions to the previous test stand to enable high temperature and high humidity testing, a review of the equipment used, the steps taken to characterize the new additions, and the filter test results are presented in this study. Test filters were evaluated at a volumetric flow rate of 56.6 m3/min (2000 cfm) and were challenged under ambient conditions with Alumina, Al(OH)3, until reaching a differential pressure of 1 kPa (4 in. w.c.), at which time the filters were tested, unchallenged with aerosol, at 54 deg. C (130 deg. F) for approximately 1 hour. At the end of that hour water was sprayed near the heat source to maximize vaporization exposing the filter to an elevated relative humidity up to 95%. Collected data include differential pressure, temperature, relative humidity, and volumetric flow rate versus time. (authors)

  20. Dose- and time-dependent effects of phenobarbital on gene expression profiling in human hepatoma HepaRG cells

    International Nuclear Information System (INIS)

    Phenobarbital (PB) induces or represses a wide spectrum of genes in rodent liver. Much less is known about its effects in human liver. We used pangenomic cDNA microarrays to analyze concentration- and time-dependent gene expression profile changes induced by PB in the well-differentiated human HepaRG cell line. Changes in gene expression profiles clustered at specific concentration ranges and treatment times. The number of correctly annotated genes significantly modulated by at least three different PB concentration ranges (spanning 0.5 to 3.2 mM) at 20 h exposure amounted to 77 and 128 genes (p ≤ 0.01) at 2- and 1.8-fold filter changes, respectively. At low concentrations (0.5 and 1 mM), PB-responsive genes included the well-recognized CAR- and PXR-dependent responsive cytochromes P450 (CYP2B6, CYP3A4), sulfotransferase 2A1 and plasma transporters (ABCB1, ABCC2), as well as a number of genes critically involved in various metabolic pathways, including lipid (CYP4A11, CYP4F3), vitamin D (CYP24A1) and bile (CYP7A1 and CYP8B1) metabolism. At concentrations of 3.2 mM or higher after 20 h, and especially 48 h, increased cytotoxic effects were associated with disregulation of numerous genes related to oxidative stress, DNA repair and apoptosis. Primary human hepatocyte cultures were also exposed to 1 and 3.2 mM PB for 20 h and the changes were comparable to those found in HepaRG cells treated under the same conditions. Taken altogether, our data provide further evidence that HepaRG cells closely resemble primary human hepatocytes and provide new information on the effects of PB in human liver. These data also emphasize the importance of investigating dose- and time-dependent effects of chemicals when using toxicogenomic approaches

  1. Effects of Rutaecarpine on Hydrogen Peroxide-Induced Apoptosis in Murine Hepa-1c1c7 Cells

    OpenAIRE

    Lee, Sung-Jin; Ahn, Hyunjin; Nam, Kung-Woo; Kim, Kyeong Ho; Mar, Woongchon

    2012-01-01

    The aim of this study was to investigate the inhibitory effects of rutaecarpine on DNA strand breaks and apoptosis induced by hydrogen peroxide (H2O2) in murine Hepa-1c1c7 cells. Oxidative DNA damage was estimated by nuclear condensation assessment, fluorescence-activated cell sorting analysis, and Comet assay. Rutaecarpine inhibited cell death induced by 500 μM H2O2, as assessed by 4',6-diamidino-2-phenylindole (DAPI) staining. Treatment with rutaecarpine reduced the number of DNA strand bre...

  2. The case for improved HEPA-filter mechanical performance standards revisited

    Energy Technology Data Exchange (ETDEWEB)

    Ricketts, C.I.; Smith, P.R. [New Mexico State Univ., Las Cruces, NM (United States)

    1997-08-01

    Under benign operating conditions, High Efficiency Particulate Air (HEPA) filter units serve as reliable and relatively economical components in the air cleaning systems of nuclear facilities worldwide. Despite more than four decades of filter-unit evaluation and improvements, however, the material strength characteristics of the glass fiber filter medium continue to ultimately limit filter functional reliability. In worst-case scenarios involving fire suppression, loss-of-coolant accidents (LOCA`s), or exposure to shock waves or tornado induced flows, rupture of the filter medium of units meeting current qualification standards cannot be entirely ruled out. Even under so-called normal conditions of operation, instances of filter failure reported in the literature leave open questions of filter-unit reliability. Though developments of filter units with improved burst strengths have been pursued outside the United States, support for efforts in this country has been comparatively minimal. This despite user requests for filters with greater moisture resistance, for example. Or the fact that conventional filter designs result in not only the least robust component to be found in a nuclear air cleaning system, but also the one most sensitive to the adverse effects of conditions deviating from those of normal operation. Filter qualification-test specifications of current codes, standards, and regulatory guidelines in the United States are based primarily upon research performed in a 30-year period beginning in the 1950`s. They do not seem to reflect the benefits of the more significant developments and understanding of filter failure modes and mechanisms achieved since that time. One overseas design, based on such knowledge, has proven reliability under adverse operating conditions involving combined and serial challenges. Its widespread use, however, has faltered on a lack of consensus in upgrading filter performance standards. 34 refs., 2 figs., 3 tabs.

  3. Differential toxicity of heterocyclic aromatic amines and their mixture in metabolically competent HepaRG cells

    International Nuclear Information System (INIS)

    Human exposure to heterocyclic aromatic amines (HAA) usually occurs through mixtures rather than individual compounds. However, the toxic effects and related mechanisms of co-exposure to HAA in humans remain unknown. We compared the effects of two of the most common HAA, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), individually or in combination, in the metabolically competent human hepatoma HepaRG cells. Various endpoints were measured including cytotoxicity, apoptosis, oxidative stress and DNA damage by the comet assay. Moreover, the effects of PhIP and/or MeIQx on mRNA expression and activities of enzymes involved in their activation and detoxification pathways were evaluated. After a 24 h treatment, PhIP and MeIQx, individually and in combination, exerted differential effects on apoptosis, oxidative stress, DNA damage and cytochrome P450 (CYP) activities. Only PhIP induced DNA damage. It was also a stronger inducer of CYP1A1 and CYP1B1 expression and activity than MeIQx. In contrast, only MeIQx exposure resulted in a significant induction of CYP1A2 activity. The combination of PhIP with MeIQx induced an oxidative stress and showed synergistic effects on apoptosis. However, PhIP-induced genotoxicity was abolished by a co-exposure with MeIQx. Such an inhibitory effect could be explained by a significant decrease in CYP1A2 activity which is responsible for PhIP genotoxicity. Our findings highlight the need to investigate interactions between HAA when assessing risks for human health and provide new insights in the mechanisms of interaction between PhIP and MeIQx.

  4. ANALYSIS OF VAPORS FROM METHYLENE CHLORIDE EXTRACTS OF NUCLEAR GRADE HEPA FILTER FIBERGLASS SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    FRYE JM; ANASTOS HL; GUTIERREZ FC

    2012-06-07

    While several organic compounds were detected in the vapor samples used in the reenactment of the preparation of mounts from the extracts of nuclear grade high-efficiency particulate air filter fiberglass samples, the most significant species present in the samples were methylene chloride, phenol, phenol-d6, and 2-fluorophenol. These species were all known to be present in the extracts, but were expected to have evaporated during the preparation of the mounts, as the mounts appeared to be dry before any vapor was collected. These species were present at the following percentages of their respective occupational exposure limits: methylene chloride, 2%; phenol, 0.4%; and phenol-d6, 0.6%. However, there is no established limit for 2-fluorophenol. Several other compounds were detected at low levels for which, as in the case of 2-fluorophenol, there are no established permissible exposure limits. These compounds include 2-chlorophenol; N-nitroso-1-propanamine; 2-fluoro-1,1{prime}-biphenyl; 1,2-dihydroacenaphthylene; 2,5-cyclohexadiene-1,4-dione,2,6-bis(1,1-dimethylethyl); trimethyl oxirane; n-propylpropanamine; 2-(Propylamino)ethanol; 4-methoxy-1-butene; 6-methyl-5-hepten-2-one; and 3,4-dimethylpyridine. Some of these were among those added as surrogates or spike standards as part ofthe Advanced Technologies and Laboratories International, Inc. preparation ofthe extract of the HEPA filter media and are indicated as such in the data tables in Section 2, Results; other compounds found were not previously known to be present. The main inorganic species detected (sulfate, sodium, and sulfur) are also consistent with species added in the preparation of the methylene chloride extract of the high-efficiency particulate air sample.

  5. Investigation of HEPA filters subjected to tornado pressure pulses. Initial structural testing

    International Nuclear Information System (INIS)

    Initial results from a program to determine response of 610- x 610-mm (24- x 24-in.) HEPA filters to tornado-induced pressure transients are described. Filters were structurally tested by subjecting them to 20.7-kPa (3-psi) pressure differentials at pressurization rates from 6.9 kPa/s (1 psi/s) to 34.5 kPa/s (5 psi/s). Two sizes of filters were used in the tests: 149 mm (57/8 in.) thick and 292 mm (111/2 in.) thick. The 149-mm (57/8 in.-) thick filters failed catastrophically at 20.7-kPa (3-psi) pressure differentials. Pressure drop across the filters, not pressurization rate, appears to be the primary cause of failure. The 292-mm- (111/2-in.) thick filters were also tested with the above pressurization rates. These units failed by breakage of the folded downstream ends of the fiber mat. Of four 292-mm- (111/2-in.-) thick filters tested, a 20.7-kPa (3-psi) pressure differential produced failure at the lowest and highest pressurization rates, but not at two intermediate rates. Additional tests will be required to determine a possible relationship between structural failure and pressurization rate. Flow-resistance data were also obtained for the 610- x 610-mm (24- x 24-in.) filters. Other activities described concern construction of small-scale particulate-loading and pressure-testing devices. These devices will be used to test 203- x 203-mm (8- x 8-in.) filters so that methods of testing and instrumentation requirements can be established for the full-scale tests. Progress is also reported on the data acquisition systems, the laser instrumentation system, and the construction of a building over the facility test section

  6. Mathematical models for changes in HEPA filter pressure drop caused by high air humidity

    International Nuclear Information System (INIS)

    Possible high air humidities resulting from an accident in a nuclear installation threaten the integrity of high-efficiency particulate air (HEPA) filter units in the facility air cleaning systems. Field surveys indicate that filter units continue to be exposed to adverse humidities in routine service despite the development of moisture countermeasures. One of the detrimental consequences of exposure to high air humidity is an increase in filter pressure drop (Δp). Reported failures due to a tearing of the filter medium partly result from elevated structural loadings imposed by Δp increases. The extent to which filter Δp varies with airstream conditions can be used to help calculate safety margins for filter units during normal and upset operations as well as during postulated accidents involving high air humidity. Studies of humidity-related changes in pressure drop were carried out to help explain structural failures in routine service and to obtain the empirical data needed to numerically model flow dynamics in air cleaning systems under accident conditions. Tests were performed on full-scale filter units under fog conditions and on samples of filter media at humidities up to 99% RH. Test results show that typical changes in Δp can be mathematically modeled by a number of time functions having coefficients that can only be determined empirically. Regression analysis is used to establish the coefficients for specific filter units and dust loadings tested under the operating conditions of interest. Comparison of measured and calculated increases in pressure drop for clean filter units under fog conditions show that good agreement can be obtained with coefficients determined as relatively simple functions of the airstream velocity and liquid water content

  7. The case for improved HEPA-filter mechanical performance standards revisited

    International Nuclear Information System (INIS)

    Under benign operating conditions, High Efficiency Particulate Air (HEPA) filter units serve as reliable and relatively economical components in the air cleaning systems of nuclear facilities worldwide. Despite more than four decades of filter-unit evaluation and improvements, however, the material strength characteristics of the glass fiber filter medium continue to ultimately limit filter functional reliability. In worst-case scenarios involving fire suppression, loss-of-coolant accidents (LOCA's), or exposure to shock waves or tornado induced flows, rupture of the filter medium of units meeting current qualification standards cannot be entirely ruled out. Even under so-called normal conditions of operation, instances of filter failure reported in the literature leave open questions of filter-unit reliability. Though developments of filter units with improved burst strengths have been pursued outside the United States, support for efforts in this country has been comparatively minimal. This despite user requests for filters with greater moisture resistance, for example. Or the fact that conventional filter designs result in not only the least robust component to be found in a nuclear air cleaning system, but also the one most sensitive to the adverse effects of conditions deviating from those of normal operation. Filter qualification-test specifications of current codes, standards, and regulatory guidelines in the United States are based primarily upon research performed in a 30-year period beginning in the 1950's. They do not seem to reflect the benefits of the more significant developments and understanding of filter failure modes and mechanisms achieved since that time. One overseas design, based on such knowledge, has proven reliability under adverse operating conditions involving combined and serial challenges. Its widespread use, however, has faltered on a lack of consensus in upgrading filter performance standards. 34 refs., 2 figs., 3 tabs

  8. 235U Holdup Measurements in Three 321-M Exhaust HEPA Banks

    Energy Technology Data Exchange (ETDEWEB)

    Dewberry, R

    2005-02-24

    The Analytical Development Section of Savannah River National Laboratory (SRNL) was requested by the Facilities Disposition Division to determine the holdup of enriched uranium in the 321-M facility as part of an overall deactivation project of the facility. The 321-M facility was used to fabricate enriched uranium fuel assemblies, lithium-aluminum target tubes, neptunium assemblies, and miscellaneous components for the production reactors. The results of the holdup assays are essential for determining compliance with the Waste Acceptance Criteria, Material Control & Accountability, and to meet criticality safety controls. This report covers holdup measurements of uranium residue in three HEPA filter exhaust banks of the 321-M facility. Each of the exhaust banks has dimensions near 7' x 14' x 4' and represents a complex holdup problem. A portable HPGe detector and EG&G Dart system that contains the high voltage power supply and signal processing electronics were used to determine highly enriched uranium (HEU) holdup. A personal computer with Gamma-Vision software was used to control the Dart MCA and to provide space to store and manipulate multiple 4096-channel {gamma}-ray spectra. Some acquisitions were performed with the portable detector configured to a Canberra Inspector using NDA2000 acquisition and analysis software. Our results for each component uses a mixture of redundant point source and area source acquisitions that yielded HEU contents in the range of 2-10 grams. This report discusses the methodology, non-destructive assay (NDA) measurements, assumptions, and results of the uranium holdup in these items. This report includes use of transmission-corrected assay as well as correction for contributions from secondary area sources.

  9. Trends and developments for in-situ testing of HEPA filters

    International Nuclear Information System (INIS)

    Many on-site tests are mainly tests of holes or sealing leaks as they employ heterodisperse clouds of particles, significant fractions of which are too large for penetration of intact HEPA filters. If it can be assumed that the filter material, when intact, is of high efficiency towards submicrometre particles, it is at least arguable that these types of test are adequate and that laboratory or factory rig tests are unnecessary. For detection of holes in systems the aerosol size is relatively unimportant and it is found in practice that different size distributions give similar results. There is, however, likely to be a need for on-site tests which give a true value - that is, of filter penetration plus leakage - when the system is challenged with submicrometre aerosols. An example appears to be in processing plutonium. We may therefore address ourselves to two types of on-site assessment. Firstly to search for holes (leakages) and secondly to measure the passage of submicrometre particles. Improvements in the first type are likely to be concerned with mixing and sampling of aerosols while the second, additionally, requires investigation into generation and detection methods. In all tests it is important that results are reliable. This involves thorough mixing of aerosol both upstream and downstream of the filter. Unfortunately few systems have been designed for ease of on-site tests and operators have to employ makeshift devices, often in cramped and uncomfortable situations. This paper gives examples of the need for mixing and sampling and of the penetration of intact filters by aerosols of different size distributions. Tests in common use are outlined, together with problems and likely developments. (author)

  10. Resistance of HEPA filter separator materials to humid air--hydrogen fluoride--fluorine environments

    International Nuclear Information System (INIS)

    The U. S. Energy Research and Development Administration (ERDA) is interested in the development of a high-efficiency particulate air (HEPA) filter that is resistant to such corrosive reagents as hydrogen fluoride (HF) and fluorine (F2) in air environments of normal relative humidity (about 50% RH). Several types of separator materials are used in the fabrication of commercial filters. The basic types of separator materials are asbestos, Kraft paper, plastic, and aluminum. At the request of the ERDA Division of Operational Safety, the different types of separator materials have been evaluated for their resistance to corrosive attack by HF and F2. The separator materials were dynamically tested in the 4-stage multiunit tester located in the Oak Ridge Gaseous Diffusion Plant laboratories. This is the system previously used in the evaluation of the Herty Foundation filter paper samples. Concurrent with the testing of filter media for its resistance to HF and F2, another component of the completed filter, the separator, was tested. All samples were exposed to a constant air flow (50% RH) of 32 liters/min, at 1000F, containing 900 ppM HF and 300 ppM F2. Exposure periods varied from 2 to 1000 h; however, the longer exposures were made only on the stronger candidates. Test results show the plastic and aluminum separator materials to be superior to the other types in resistance to HF and F2. The asbestos separators disintegrated after a relatively short exposure time; the Kraft paper types were the next weakest. The Clear Plastic S was the best performer of the plastics tested

  11. Study of the effect of humidity, particle hygroscopicity and size on the mass loading capacity of HEPA filters

    International Nuclear Information System (INIS)

    The effect of humidity, particle hygroscopicity and size on the mass loading capacity of glass fiber HEPA filters has been studied. At humidifies above the deliquescent point, the pressure drop across the HEPA filter increased non-linearly with the areal loading density (mass collected/filtration area) of NaCl aerosol, thus significantly reducing the mass loading capacity of the filter compared to dry hygroscopic or non-hygroscopic particle mass loadings. The specific cake resistance, K2, has been computed for different test conditions and used as a measure of the mass loading capacity. K. was found to decrease with increasing humidity for the non-hygroscopic aluminum oxide particles and the hygroscopic NaCl particles (at humidities below the deliquescent point). It is postulated that an increase in humidity leads to the formation of a more open particulate cake which lowers the pressure drop for a given mass loading. A formula for predicting K2 for lognormally distributed aerosols (parameters obtained from impactor data) is derived. The resistance factor, R, calculated using this formula was compared to the theoretical R calculated using the Rudnick-Happel expression. For the non-hygroscopic aluminum oxide the agreement was good but for the hygroscopic sodium chloride, due to large variation in the cake porosity estimates, the agreement was poor

  12. Solutions for Dioctyl Phthalate (DOP) tested high efficiency particulate air (HEPA) filters destined for disposal at Hanford, Washington

    International Nuclear Information System (INIS)

    In January 1992, Argonne National Laboratory East, Environmental and Waste Management Program, learned that a chemical material used for testing of all HEPA filters at the primary source, Flanders Filter, Inc. in Washington, NC, was considered a hazardous chemical by Washington State Dangerous Waste Regulations. These regulations are under the jurisdiction of the Washington Administration Code, Chapter 173-303, and therefore directly under impact the Hanford Site Solid Waste Acceptance Criteria. Dioctyl Phthalate, ''DOP'' as it is referred to in chemical abbreviation form, is added in small test quantities at the factory, at three Department of Energy (DOE) operated HEPA filter test facilities, and in the installed duct work at various operating laboratories or production facilities. When small amounts of radioactivity are added to the filter media in operation, the result is a mixed waste. This definition would normally only develop in the state of Washington since their acceptance criteria is ten times more stringent then the US Environmental Protection Agencys' (US EPA). Methods of Processing will be discussed, which will include detoxification, physical separation, heat and vacuum separation, and compaction. The economic impact of a mixed waste definition in the State of Washington, and an Low Level Waste (LLW) definition in other locations, may lend this product to be a prime candidate for commercial disposal in the future, or a possible de-listing by the State of Washington

  13. Correlation of dysfunction of nonmuscle myosin IIA with increased induction of Cyp1a1 in Hepa-1 cells.

    Science.gov (United States)

    Ebina, Masayuki; Shibazaki, Masahiko; Kudo, Kyoko; Kasai, Shuya; Kikuchi, Hideaki

    2011-03-01

    The aryl hydrocarbon receptor (AhR) is one of the best known ligand-activated transcription factors and it induces Cyp1a1 transcription by binding with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Recent focus has been on the relationship of AhR with signaling pathways that modulate cell shape and migration. In nonmuscle cells, nonmuscle myosin II is one of the key determinants of cell morphology, but it has not been investigated whether its function is related to Cyp1a1 induction. In this study, we observed that (-)-blebbistatin, which is a specific inhibitor of nonmuscle myosin II, increased the level of CYP1A1-mRNA in Hepa-1 cells. Comparison of (-)-blebbistatin with (+)-blebbistatin, which is an inactive enantiomer, indicated that the increase of CYP1A1-mRNA was due to nonmuscle myosin II inhibition. Subsequent knockdown experiments observed that reduction of nonmuscle myosin IIA, which is only an isoform of nonmuscle myosin II expressed in Hepa-1 cells, was related to the enhancement of TCDD-dependent Cyp1a1 induction. Moreover, chromatin immunoprecipitation assay indicated that the increase of Cyp1a1 induction was the result of transcriptional activation due to increased binding of AhR and RNA polymerase II to the enhancer and proximal promoter regions of Cyp1a1, respectively. These findings provide a new insight into the correlation between the function of nonmuscle myosin II and gene induction. PMID:21216307

  14. γ-Tocotrienol attenuates triglyceride through effect on lipogenic gene expressions in mouse hepatocellular carcinoma Hepa 1-6.

    Science.gov (United States)

    Burdeos, Gregor Carpentero; Nakagawa, Kiyotaka; Watanabe, Akio; Kimura, Fumiko; Miyazawa, Teruo

    2013-01-01

    Vitamin E is the generic name for tocopherol (Toc) and tocotrienol (T3), which have saturated and unsaturated side chains, respectively. Such differences allow T3 to be different from Toc in terms of their functions. T3 has been known to attenuate cholesterol (Cho) level by inhibiting 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoAR). Recent reports also showed the efficacy of T3 in improving triglyceride (TG) profiles in both in vivo and in vitro studies. However the mechanism involved in this biological activity is still unclear and needs to be further investigated. In the present study, we elucidated the effect of γ-T3 on lipid levels and lipogenic gene expressions in mouse hepatocellular carcinoma Hepa 1-6. γ-T3 showed attenuation of TG through effect on fatty acid synthase, sterol regulatory element-binding transcription factor 1, stearoyl CoA desaturase 1, and carnitine palmitoyl transferase 1A gene expression in Hepa 1-6. In contrast, the Cho level remained unchanged. These results expanded our previous finding of lipid-lowering effects of T3, especially for TG. Therefore, T3 is a potential lipid-lowering compound candidate with realistic prospects for its use as a therapy for lipid-related diseases in humans. PMID:23727646

  15. Walking in the high-rise city: a Health Enhancement and Pedometer-determined Ambulatory (HEPA) program in Hong Kong.

    Science.gov (United States)

    Leung, Angela Y M; Cheung, Mike K T; Tse, Michael A; Shum, Wai Chuen; Lancaster, B J; Lam, Cindy L K

    2014-01-01

    Due to the lack of good infrastructure in the public estates, many older adults in urban areas are sedentary. The Health Enhancement and Pedometer-Determined Ambulatory (HEPA) program was developed to assist older adults with diabetes and/or hypertension to acquire walking exercise habits and to build social support, while engaged in regular physical activity. This study aimed to describe the HEPA program and to report changes in participants' walking capacity and body strength after 10-week walking sessions. A pre- and postintervention design was used. Pedometers were used to measure the number of steps taken per day before and after the 10-week intervention. Upper and lower body strength, lower body flexibility, and quality of life were assessed. A total of 205 older adults completed the program and all health assessments. After the 10-week intervention, the average number of steps per day increased by 36%, from 6,591 to 8,934. Lower body strength, upper body strength, and aerobic fitness increased significantly after 10 weeks, along with improvement in the 12-item Short Form Health Survey (SF™-12) physical and mental health component summary scores. A social support network was built in the neighborhood, and the local environment was utilized to make walking possible and enjoyable. PMID:25170259

  16. Suppression of CYP1A1 expression by naringenin in murine Hepa-1c1c7 cells.

    Science.gov (United States)

    Kim, Ji Young; Han, Eun Hee; Shin, Dong Weon; Jeong, Tae Cheon; Lee, Eung Seok; Woo, Eun-Rhan; Jeong, Hye Gwang

    2004-08-01

    Naringenin, dietary flavonoid, is antioxidant constituents of many citrus fruits. In the present study, we investigated the effect of naringenin on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible CYP1A1 gene expression in mouse hepatoma Hepa-1c1c7 cells. Naringenin alone did not affect CYP1A1-specific 7-ethoxyresorufin O-deethylase (EROD) activity. In contrast, the TCDD-inducible EROD activities were markedly reduced upon concomitant treatment with TCDD and naringenin in a dose dependent manner. TCDD-induced CYP1A1 mRNA level was also markedly suppressed by naringenin. A transient transfection assay using dioxin-response element (DRE)-linked luciferase and electrophoretic mobility shift assay revealed that naringenin reduced transformation of the aryl hydrocarbons receptor(AhR) to a form capable of specifically binding to the DRE sequence in the promoter of the CYP1A1 gene. These results suggest the down regulation of the CYP1A1 gene expression by either naringenin in Hepa-1c1c7 cells might be antagonism of the DRE binding potential of nuclear AhR. PMID:15460448

  17. Changes in the protein expression profiles of the Hepa-T1 cell line when exposed to Cu2+.

    Science.gov (United States)

    Chen, Dong-Shi; Chan, King Ming

    2009-09-14

    Copper is an essential element in a variety of biological processes, but it can be toxic when present in excessive amounts. The central regulators of cellular copper metabolism include copper-binding proteins, copper transporters, metal membrane active transporters and copper-dependent enzymes. However, the way in which cupric ions (Cu(2+)) cause cellular changes in proteins and lead to toxic effects is less well-known. The aim of this study is to identify the proteins related to Cu(2+) toxicity or detoxification mechanisms in tilapia (Oreochromis niloticus) using a proteomic approach. A cell line derived from the liver of tilapia, Hepa-T1, was used as a model and exposed to two sub-lethal concentrations of waterborne copper for 96 h. The proteins expressed in Hepa-T1 were investigated by differential protein profiling using two-dimensional gel electrophoresis (2DE). It was found that Cu(2+) (120 and 300 microM) caused the differential expression of 93 different proteins, 18 of which were further verified by real-time quantitative polymerase chain reaction (PCR) analysis. Following analysis with ingenuity pathway software, several proteins were found to be involved in lipid metabolism, tissue connective development and cell cycle control, thus indicating that copper toxicity affects these cellular functions. PMID:19616320

  18. Suppression of CYP1A1 expression by 4-nonylphenol in murine Hepa-1c1c7 cells.

    Science.gov (United States)

    Jeong, H G; Kim, J Y; Choi, C Y; You, H J; Hahm, K

    2001-04-10

    This study investigated the effects that 4-nonylphenol (NP) has on CYP1A1 expression in Hepa-1c1c7 cell cultures. NP alone did not affect CYP1A1-specific 7-ethoxyresorufin-O-deethylase (EROD) activity. In contrast, the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible EROD activities were markedly reduced upon concomitant treatment with TCDD and NP in a dose-dependent manner. Treatment with tamoxifen, an anti-estrogen that acts through the estrogen receptor, did not affect the suppressive effects that NP has on TCDD-inducible EROD activity. The TCDD-inducible CYP1A1 mRNA levels were markedly suppressed upon concomitant treatment with TCDD and NP that is consistent with their effects on EROD activity. A transient transfection assay using dioxin-response element (DRE)-linked luciferase and an electrophoretic mobility shift assay revealed that NP reduced the transformation of the aryl hydrocarbon (Ah) receptor to a form capable of binding specifically to the DRE sequence of the CYP1A1 gene promoter. These results suggest that the down-regulation of CYP1A1 gene expression by NP in Hepa-1c1c7 cells might be an antagonism of the DRE-binding potential of the nuclear Ah receptor, but is not mediated through the estradiol receptor. PMID:11248424

  19. Allogeneic hematopoietic SCT performed in non-HEPA filter rooms: initial experience from a single center in India.

    Science.gov (United States)

    Kumar, R; Naithani, R; Mishra, P; Mahapatra, M; Seth, T; Dolai, T K; Bhargava, R; Saxena, R

    2009-01-01

    In developing countries, it is important to ascertain the safety of performing allogeneic hematopoietic SCT (HSCT) in single rooms without high-efficiency particulate air (HEPA) filters. We present our experience of performing 40 such transplants from July 2004 to November 2007. Source of stem cells was peripheral blood in 33, bone marrow in six and combined in one. G-CSF started from day +1. The indications were SAA-18, CML-7, AML-7, ALL-2, myelodysplastic syndrome-2 and thalassemia major-4. The median age was 19 years (range 2.2-46) with 29 male and 11 female participants. Antibacterial and antifungal prophylaxis was administered along with conditioning, and at the onset of fever, systemic antibiotics were started. Antifungal agents were added if fever persisted for 3 days. Median time for neutrophil engraftment was 10 days (range 8-17). Fever occurred in 38 (95%) for a median of 5 days (range 1-38), and blood cultures were positive in seven (17.5%). Systemic antibiotics were used in 95% and antifungals in 57.5% cases. The 30-day mortality was nil, and 100-day mortality was 1 (2.5%). After day 100, there were eight fatalities (20%) due to chronic GVHD-3, relapse-2, graft rejection-2, disseminated tuberculosis and aspergillosis-1. Our experience suggests that allogeneic HSCT can be safely performed in non-HEPA filter rooms in India. PMID:18794872

  20. MicroRNA Responses to the Genotoxic Carcinogens Aflatoxin B1 and Benzo[a]pyrene in Human HepaRG Cells.

    Science.gov (United States)

    Marrone, April K; Tryndyak, Volodymyr; Beland, Frederick A; Pogribny, Igor P

    2016-02-01

    Recent advances in toxicogenomics present an opportunity to develop new in vitro testing methodologies to identify human carcinogens. We have investigated microRNA expression responses to the treatment of human liver HepaRG cells with the human genotoxic carcinogens aflatoxin B1 (AFB1) and benzo[a]pyrene (B[a]P), and the structurally similar compounds aflatoxin B2 (AFB2) and benzo[e]pyrene (B[e]P) that exhibit minimal carcinogenic potential. We demonstrate that treatment of HepaRG cells with AFB1 or B[a]P resulted in specific changes in the expression of miRNAs as compared with their non-carcinogenic analogues, particularly in a marked over-expression of miR-410. An additional novel finding is the dose- and time-dependent inhibition of miR-122 in AFB1-treated HepaRG cells. Mechanistically, the AFB1-induced down-regulation of miR-122 was attributed to inhibition of the HNF4A/miR-122 regulatory pathway. These results demonstrate that HepaRG cells can be used to investigate miRNA responses to xenobiotic exposure, and illustrate the existence of early non-genotoxic events, in addition to a well-established genotoxic mode of action changes, in the mechanism of AFB1 and B[a]P carcinogenicity. PMID:26609139

  1. Reliability and Validity of the SE-HEPA: Examining Physical Activity- and Healthy Eating-Specific Self-Efficacy among a Sample of Preadolescents

    Science.gov (United States)

    Steele, Michael M.; Burns, Leonard G.; Whitaker, Brandi N.

    2013-01-01

    Objective. The purpose of this study was to examine the psychometric properties of the self-efficacy for healthy eating and physical activity measure (SE-HEPA) for preadolescents. Method. The reliability of the measure was examined to determine if the internal consistency of the measure was adequate (i.e., [alpha]s greater than 0.70). Next, in an…

  2. Automated detection of hepatotoxic compounds in human hepatocytes using HepaRG cells and image-based analysis of mitochondrial dysfunction with JC-1 dye

    International Nuclear Information System (INIS)

    In this study, our goal was to develop an efficient in situ test adapted to screen hepatotoxicity of various chemicals, a process which remains challenging during the early phase of drug development. The test was based on functional human hepatocytes using the HepaRG cell line, and automation of quantitative fluorescence microscopy coupled with automated imaging analysis. Differentiated HepaRG cells express most of the specific liver functions at levels close to those found in primary human hepatocytes, including detoxifying enzymes and drug transporters. A triparametric analysis was first used to evaluate hepatocyte purity and differentiation status, mainly detoxication capacity of cells before toxicity testing. We demonstrated that culturing HepaRG cells at high density maintained high hepatocyte purity and differentiation level. Moreover, evidence was found that isolating hepatocytes from 2-week-old confluent cultures limited variations associated with an ageing process occurring over time in confluent cells. Then, we designed a toxicity test based on detection of early mitochondrial depolarisation associated with permeability transition (MPT) pore opening, using JC-1 as a metachromatic fluorescent dye. Maximal dye dimerization that would have been strongly hampered by efficient efflux due to the active, multidrug-resistant (MDR) pump was overcome by coupling JC-1 with the MDR inhibitor verapamil. Specificity of this test was demonstrated and its usefulness appeared directly dependent on conditions supporting hepatic cell competence. This new hepatotoxicity test adapted to automated, image-based detection should be useful to evaluate the early MPT event common to cell apoptosis and necrosis and simultaneously to detect involvement of the multidrug resistant pump with target drugs in a human hepatocyte environment. - Highlights: → We define conditions to preserve differentiation of selective pure HepaRG hepatocyte cultures. → In these conditions, CYPs

  3. Experimental study of plane and pleated HEPA filters clogged by particles simulating a combustion aerosol

    International Nuclear Information System (INIS)

    In nuclear facilities, airborne particles are the vector of most of the radiological contamination. For this reason, pleated HEPA filters are one of the containment devices which are actively studied by the IRSN (Institut de Radioprotection et de Surete Nucleaire) to ensure the safety of nuclear exploitation. To avoid contamination of the environment, the understanding of the behavior of the filters especially in accidental situation has to be as exhaustive as possible. The most probable accident and the most penalizing for the containment devices is fire which leads to a massive soot particle production. In this case, the clogging of the filters is a problematic which has to be taken into account. Up to now, an empirical correlation has been developed to predict the pressure drop increase. The empirical nature of this correlation doesn't allow its use in ail situations. A phenomenological understanding and model of the clogging is then necessary. The following PhD work aims to reduce the pressure drop evolution to physical observations for each step of the clogging in order to model it on the most physical basis as possible. To do so, the study has been divided in two parts. The first one focusing on the behavior of flat filter by measuring the penetration of particles inside the medium and the porosity of the deposit formed on its surface. In the second part a small scale experiment based on a single pleat has been developed. Accumulation of the particles inside the pleat has been directly observed, deformation of the pleat as well as airflow in the pleat (using a PIV method) has been measured. During these experiments, pressure drop has been monitored and the measured parameters have been linked to the pressure drop evolution. Finality is to build a simple analytical model to predict the pressure drop evolution of the filters as a function of the deposited mass, the aerosol characteristics and the ventilation conditions. The main perspective opened by these

  4. Cellular impact of combinations of endosulfan, atrazine, and chlorpyrifos on human primary hepatocytes and HepaRG cells after short and chronic exposures.

    Science.gov (United States)

    Nawaz, Ahmad; Razpotnik, Andrej; Rouimi, Patrick; de Sousa, Georges; Cravedi, Jean Pierre; Rahmani, Roger

    2014-02-01

    Chronic exposure to low doses of pesticides present in the environment is increasingly suspected to cause major health issues to humans. Toxicological evaluations become more complex when the exposure concerns chemical combinations. Atrazine, chlorpyrifos, and endosulfan are pesticides used worldwide in agriculture and are therefore currently found at residual levels in food and the environment, even in countries in which they are now banned. Our study aimed to use Real-Time Cell Impedance Analyzer to investigate changes in phenotypical status of primary human hepatocytes and differentiated HepaRG cells induced by short and chronic exposures to these three chemicals. In contrast to the traditionally used endpoint cytotoxicity test, this technology allows kinetic measurements in real-time throughout the entire experiment. Our data show significantly higher cytotoxic effects of mixtures as compared to individual pesticides and a greater susceptibility of human hepatocytes as compared to HepaRG to short-term exposure (24 h). Repeated exposure over 2 weeks to endosulfan and endosulfan-containing mixture induced HepaRG cell death in a time- and dose-dependent manner. Of the typical genes involved in metabolism and cell-response to xenobiotics, we found an exposure time- and condition-dependent deregulation of the expression of CYP3A4 and UGT1A in HepaRG cells exposed to low doses of pesticides and mixtures. Our data demonstrate the usefulness of real-time cell monitoring in long-term toxicological evaluations of co-exposure to xenobiotics. In addition, they support but at the same time highlight certain limitations in the use of HepaRG cells as the gold standard liver cell model in toxicity studies. PMID:24343343

  5. Effect of particle-size variation on filtration efficiency measured by the HEPA-filter quality-assurance test

    International Nuclear Information System (INIS)

    A theoretical model has been used to calculate the filtration efficiency that would be indicated by the photometer for challenge aerosols of different size distributions and HEPA filters with different efficiencies as functions of particle size. The model compares the calculated overall efficiency indicated by the photometer with efficiencies calculated with respect to particle number and mass. This calculation assumes three aerosol distributions previously measured at the Filter Test Facilities and four different filtration efficiency versus size curves. The differences in efficiency measured by the QA test procedure and the efficiencies with respect to aerosol mass and number have been calculated for a range of different size particles. The results of these calculations are discussed

  6. Induction of quinone reductase activity by psoralidin isolated from Psoralea corylifolia in mouse hepa 1c1c7 cells.

    Science.gov (United States)

    Lee, Sung-Jin; Nam, Kung-Woo; Mar, Woongchon

    2009-07-01

    Quinone reductase (QR) is a protective phase II enzyme against mutagens and carcinogens which is inducible by a number of chemical compounds in plants. This study was carried out to investigate effects of the fractions from the seeds of Psoralea corylifolia on the induction of QR with Hepa 1c1c7 murine hepatoma cell line. The ethyl acetate-soluble fraction of the methanolic extract from the seeds was found to induce QR and the concentration of 1.5 fold QR induction (1.5 FIC) was 1.2 mug/mL. We obtained as an active compound, psoralidin, isolated from the ethyl acetate-soluble fraction after further sequential fractionation with column chromatography and 1.5 FIC of psoralidin was 0.5 mug/mL. The seeds of Psoralea corylifolia and psoralidin might be a candidate for developing QR inducers. PMID:19641888

  7. Induction of quinone reductase activity by stilbene analogs in mouse Hepa 1c1c7 cells.

    Science.gov (United States)

    Heo, Y H; Kim, S; Park, J E; Jeong, L S; Lee, S K

    2001-12-01

    Based on the potential cancer chemopreventive activity of resveratrol, a trihydroxystilbene with the induction of quinone reductase activity, this study was designed to determine if stilbene-related compounds were inducers of phase II detoxifying metabolic enzyme quinone reductase (QR) in the mouse hepatoma Hepa 1c1c7 cells. Among the thirteen compounds tested, several compounds including 3,4,5,3',5'-pentamethoxy-trans-stilbene were found to potentially induce QR activity in this cell line. In addition, substitution with 3-thiofurane ring instead of phenyl ring in the stilbene skeleton also exhibited potential induction of QR activity. This result will give primary information to design the potential inducers of QR activity in the stilbene analogs. PMID:11794542

  8. Differential regulation of polysome mRNA levels in mouse Hepa-1C1C7 cells exposed to dioxin.

    Science.gov (United States)

    Thornley, Jessica A; Trask, Heidi W; Ridley, Christian J A; Korc, Murray; Gui, Jiang; Ringelberg, Carol S; Wang, Sinny; Tomlinson, Craig R

    2011-10-01

    The environmental agent 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin) causes a multitude of human illnesses. In order to more fully understand the underlying biology of TCDD toxicity, we tested the hypothesis that new candidate genes could be identified using polysome RNA from TCDD-treated mouse Hepa-1c1c7 cells. We found that (i) differentially expressed whole cell and cytoplasm RNA levels are both poor predictors of polysome RNA levels; (ii) for a majority of RNAs, differential RNA levels are regulated independently in the nucleus, cytoplasm, and polysomes; (iii) for the remaining polysome RNAs, levels are regulated via several different mechanisms, including a "tagging" of mRNAs in the nucleus for immediate polysome entry; and (iv) most importantly, a gene list derived from differentially expressed polysome RNA generated new genes and cell pathways potentially related to TCDD biology. PMID:21570461

  9. Effects of rutaecarpine on hydrogen peroxide-induced apoptosis in murine hepa-1c1c7 cells.

    Science.gov (United States)

    Lee, Sung-Jin; Ahn, Hyunjin; Nam, Kung-Woo; Kim, Kyeong Ho; Mar, Woongchon

    2012-09-01

    The aim of this study was to investigate the inhibitory effects of rutaecarpine on DNA strand breaks and apoptosis induced by hydrogen peroxide (H2O2) in murine Hepa-1c1c7 cells. Oxidative DNA damage was estimated by nuclear condensation assessment, fluorescence-activated cell sorting analysis, and Comet assay. Rutaecarpine inhibited cell death induced by 500 μM H2O2, as assessed by 4',6-diamidino-2-phenylindole (DAPI) staining. Treatment with rutaecarpine reduced the number of DNA strand breaks induced by H2O2, as assessed by DAPI staining and Comet assay, and increased quinone reductase, phosphatidylinositol 3-kinase, and pAkt protein levels, as assessed by western blotting. PMID:24009839

  10. Performance of 1,000 and 1800 CFM HEPA filters on long exposure to low atmospheric dust loadings

    International Nuclear Information System (INIS)

    Comparative tests are in progress to determine the performance characteristics of European-design HEPA filters compared to US-design units made with the same filter paper. European filters are being operated at their rated capacity of 1,800 cfm and at 1,000 cfm. The US-design unit is operated at 1,000 cfm. Filters, installed on the roof of a 15-story building, are continuously exposed to an atmospheric dust aerosol of low concentration and small particle size. Plans are to continue these tests over a period of two or more years. Early results confirm that 1,800 cfm rated filters will have a very slow rate of pressure increase when operated at 1,000 cfm and an extended service life

  11. Trichostatin A, a histone deacetylase inhibitor stimulate CYP3A4 proximal promoter activity in Hepa-I cells.

    Science.gov (United States)

    Ahn, Mee Ryung; Kim, Dae-Kee; Sheen, Yhun Yhong

    2004-04-01

    Cytochrome P450 3A4 (CYP3A4) is the most abundant CYPs in human liver, comprising approximately 30% of the total liver CYPs contents and is involved in the metabolism of more than 60% of currently used therapeutic drugs. However, the molecular mechanisms underlying regulation of CYP3A4 gene expression have not been understood. Thus, this study has been carried out to gain the insight of the molecular mechanism of CYP3A4 gene expression, investigating if the histone deacetylation is involved in the regulation of CYP3A4 gene expression by proximal promoter. Also SXR was investigated to see if they were involved in the regulation of CYP3A4 proximal promoter activity. Hepa-I cells were transfected with a plasmid containing approximately 1 kb of the human CYP3A4 proximal promoter region (863 to +64 bp) cloned in front of a reporter gene, luciferase, in the presence or absence of SXR. Transfected cells were treated with CYP3A4 inducers such as rifampicin, PCN and RU 486, in order to examine the regulation of CYP3A4 gene expression in the presence or absence of trichostatin A (TSA). In Hepa-I cells, CYP3A4 inducers increased modestly the luciferase activity when TSA was co-treated, but this increment was not enhanced by SXR cotransfection. Taken together, these results indicated that the inhibition of histone deacetylation was required to SXR-mediated increase in CYP3A4 proximal promoter region when rifampicin, or PCN was treated. Further a trans-activation by SXR may demand other species-specific transcription factors. PMID:15180307

  12. Invasive pulmonary aspergillosis in neutropenic patients during hospital construction: before and after chemoprophylaxis and institution of HEPA filters.

    Science.gov (United States)

    Oren, I; Haddad, N; Finkelstein, R; Rowe, J M

    2001-04-01

    Between September 1993 and December 1993, during extensive hospital construction and indoor renovation, a nosocomial outbreak of invasive pulmonary aspergillosis occurred in acute leukemia patients treated in a regular ward that has only natural ventilation. The observed infection rate was 50%. Chemoprophylaxis with intravenous continuous low-dose amphotericin B was then instituted as a preventive measure. During the next 18 months invasive pulmonary aspergillosis developed in 43% of acute leukemia patients. After that period a new hematology ward was opened with an air filtration system through high-efficiency particulate air filtration (HEPA) filters, and a bone marrow transplantation program was started on the hematology service. During the following three years, none of the acute leukemia or bone marrow transplantation patients who were hospitalized exclusively in the hematology ward developed invasive pulmonary aspergillosis, although 29% of acute leukemia patients who were housed in a regular ward, because of shortage of space in the new facility, still contracted invasive pulmonary aspergillosis. Overall, 31 patients were diagnosed with invasive pulmonary aspergillosis during almost five years: 74% of patients recovered from invasive pulmonary aspergillosis, and 42% are long-term survivors; 26% of patients died of resistant leukemia with aspergillosis, but no one died of invasive pulmonary aspergillosis alone. In conclusion, during an on-going construction period, an extremely high incidence rate of invasive pulmonary aspergillosis in acute leukemia patients undergoing intensive chemotherapy was observed. Institution of low-dose intravenous amphotericin B prophylaxis marginally reduced the incidence rate of invasive pulmonary aspergillosis. Keeping patients in a special ward with air filtration through a HEPA system eliminated invasive pulmonary aspergillosis completely. Among patients who developed invasive pulmonary aspergillosis, early diagnosis and

  13. Ultrahigh carbon steels, Damascus steels, and superplasticity

    Energy Technology Data Exchange (ETDEWEB)

    Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering; Wadsworth, J. [Lawrence Livermore National Lab., CA (United States)

    1997-04-01

    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  14. Reactor construction steels

    International Nuclear Information System (INIS)

    The basic functions of light water reactor components are shown on the example of a pressurized water reactor and the requirements resulting therefrom for steel, the basic structural material, are derived. A detailed analysis of three main groups of reactor steels is presented and the applications are indicated of low-alloyed steels, high-alloyed austenitic steels, and steels with a high content of Ni and of alloying additions for steam generator pipes. An outline is given of prospective fast breeder reactor steels. (J.K.)

  15. Recovery of plutonium from HEPA filters by Ce(IV)-promoted dissolution of PuO2 and recycle of the cerium promoter

    International Nuclear Information System (INIS)

    The experimental studies carried out included (1) the electrolytic production of Ce(IV) from Ce(III), (2) the leaching of refractory PuO2 from HEPA filter materials with maintenance of Ce(IV) concentrations by anodic oxidation during leaching, and (3) evaluation of methods for contacting the HEPA solids with the leaching solution and for separating the solid residue from the leaching liquor. Anodic oxidation of Ce(III) was accomplished with an electric current efficiency of about 85% at current densities of 0.04 to 0.4 A/dm2 at a platinum anode. Refractory PuO2 was dissolved by a 4.0 M HNO3 - 0.1 M Ce(IV) solution in 1.5 h at 1000C using stirred-contact leaching of the solids or by recirculating the leachant through a packed column of the solids. Cerium (IV) concentrations were maintained continuously by anodic oxidation throughout leaching. Dissolution times up to 10 h were required unless the HEPA media were oxidized initially in air at 3000C to destroy carbonaceous species which consumed Ce(IV) more rapidly than it could be regenerated by anodic oxidation. Leaching solids in packed columns avoided the relatively difficult liquid-solids separation by centrifugation which was required after stirred-contact leaching; however, the solids handling difficulties associated with charging and discharging of the packed columns in a remote environment remain a significant design obstacle. A chemical flowsheet is proposed for the recovery of actinides from HEPA filters. A 4 M HNO3 - 0.1 M Ce(IV) nitrate solution is used as the leachant and the Ce(III) is recycled to the leaching operation using bidentate solvent extraction

  16. Evaluation of HEPA vacuum cleaning and dry steam cleaning in reducing levels of polycyclic aromatic hydrocarbons and house dust mite allergens in carpets

    OpenAIRE

    Yu, Chang Ho; Yiin, Lih-Ming; Fan, Zhi-hua (Tina); Rhoads, George G.

    2008-01-01

    Dry steam cleaning, which has gained recent attention as an effective method to reduce house dust mite (HDM) allergen concentration and loading in carpets, was evaluated in this study for its efficacy in lowering levels of polycyclic aromatic hydrocarbons (PAHs) as well as HDM allergens. Fifty urban homes with wail-to-wall carpets, mostly low-income and with known lead contamination, were studied in 2003 and 2004. Two carpet-cleaning interventions were compared: Repeated HEPA (High Efficiency...

  17. Recovery of plutonium from HEPA filters by Ce(IV): promoted dissolution of PuO2 and recycle of the cerium promoter

    International Nuclear Information System (INIS)

    Studies carried out in this investigation included (1) electrolytic production of Ce(IV) from Ce(III), (2) leaching of refractory PuO2 from HEPA filters with maintenance of Ce(IV) by anodic oxidation during leaching, and (3) evaluation of methods for contacting the HEPA solids with the leaching solution and for separating the solid residue from the leaching liquor. Anodic oxidation of Ce(III) was accomplished with an electric current efficiency of about 85% at current densities of 0.04 to 0.4 A/dm2 at Pt anode. Refractory PuO2 was dissolved by a 4.0 M HNO3 - 0.1 M Ce(IV) solution in 1.5 h at 1000C using stirred-contact leaching of the solids or by recirculating the leachant through a packed column of the solids. Cerium(IV) concentrations were maintained continuously by anodic oxidation throughout leaching. Dissolution times up to 10 h were required unless the HEPA media were oxidized initially in air at 3000C to destroy carbonaceous species which consumed Ce(IV) more rapidly than it could be regenerated be anodic oxidation. Leaching solids in packed columns avoided the relatively difficult liquid-solids separation by centrifugation which was required after stirred-contact leaching; however, the solids handling difficulties remain. A flowsheet is proposed for the recovery of actinides from HEPA filters. A 4 M HNO3 - 0.1 M Ce(IV) nitrate solution is used as the leachant and the Ce(III) is recycled to the leaching operation using bidentate solvent extraction

  18. The synthetic retinoid AGN 193109 but not retinoic acid elevates CYP1A1 levels in mouse embryos and Hepa-1c1c7 cells.

    Science.gov (United States)

    Soprano, D R; Gambone, C J; Sheikh, S N; Gabriel, J L; Chandraratna, R A; Soprano, K J; Kochhar, D M

    2001-07-15

    The synthetic retinoid AGN 193109 is a potent pan retinoic acid receptor (RAR) antagonist. Treatment of pregnant mice with a single oral 1 mg/kg dose of this antagonist on day 8 postcoitum results in severe craniofacial (median cleft face or frontonasal deficiency) and eye malformations in virtually all exposed fetuses. Using differential display analysis, we have determined that CYP1A1 mRNA levels are elevated in mouse embryos 6 h following treatment with AGN 193109. Similarly, an elevation in CYP1A1 mRNA levels, protein levels, and aryl hydrocarbon hydoxylase activity occurs in Hepa-1c1c7 cells, with the maximal elevation observed when the cells were treated with 10(-5) M AGN 193109 for 4 to 8 h. Elevation in CYP1A1 mRNA levels in mouse embryos and Hepa-1c1c7 cells does not occur upon treatment with the natural retinoid, all-trans-retinoic acid. Finally, elevation in CYP1A1 mRNA levels was not observed when mutant Hepa-1c1c7 cells, which are defective in either the aryl hydrocarbon receptor (AhR) or aryl hydrocarbon receptor nuclear translocator (ARNT), were treated with AGN 193109. This suggests that the AhR/ARNT pathway and not the RAR/RXR pathway is mediating the elevation of CYP1A1 mRNA levels by AGN 193109, at least in the Hepa-1c1c7 cells. This is the first example of a retinoid that displays the abililty to regulate both the RAR/RXR and AhR/ARNT transcriptional regulatory pathways. PMID:11446831

  19. Fire tests to evaluate the potential fire threat and its effects on HEPA filter integrity in cell ventilation at the Oak Ridge National Laboratory, Building 7920

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, H.K.; Staggs, K.J.; Doughty, S.M. [Oak Ridge National Lab., TN (United States)

    1992-12-01

    As a result of a DOE (Tiger Team) Technical Safety Appraisal (November 1990) of the Radiochemical Engineering Development Center (REDC), ORNL Building 7920, a number of fire protection concerns were identified. The primary concern was the perceived loss of ventilation system containment due to the thermal destruction and/or breaching of the prefilters and/or high-efficiency particulate air filters (HEPA `s) and the resultant radioactive release to the external environment. The following report describes the results of an extensive fire test program performed by the Fire Research Discipline (FRD) of the Special Projects Division of Lawrence Livermore National Lab (LLNL) and funded by ORNL to address these concerns. Full scale mock-ups of a REDC hot cell tank pit, adjacent cubicle pit, and associated ventilation system were constructed at LLNL and 13 fire experiments were conducted to specifically answer the questions raised by the Tiger Team. Our primary test plan was to characterize the burning of a catastrophic solvent spill (kerosene) of 40 liters and its effect on the containment ventilation system prefilters and HEPA filters. In conjunction with ORNL and Lockwood Greene we developed a test matrix that assessed the fire performance of the prefilters and HEPA filters; evaluated the fire response of the fiber reinforced plastic (FRP) epoxy ventilation duct work; the response and effectiveness of the fire protection system, the effect of fire in a cubicle on the vessel off-gas (VOG) elbow, and other fire safety questions.

  20. Prediction of HEPA filter collection efficiency with a bimodal fiber size distribution; Koseino air filter no nihosei sen`ikei bunpu wo koryoshita hoshu koritsu no suitei

    Energy Technology Data Exchange (ETDEWEB)

    Bao, L.; Otani, Y.; Namiki, N.; Emi, H. [Kanazawa University, Ishikawa (Japan); Mori, J. [Toyama National College of Technology, Toyama (Japan)

    1998-09-05

    Estimation of particle penetration through HEPA (High Efficiency Particulate Air) filters with the conventional filtration theory requires accurate measurements of average fiber size and variance of fiber diameters. However, it is not an easy task to obtain these properties because fiber size distribution varies to a large extent from point to point in a HEPA filter. In the present work, measurements of representative fiber size distribution from scanning electron micrographs of HEPA filter cross-section are performed and the particle penetrations are predicted with the measured fiber size distribution. They are compared with those from the conventional method (measurement from filter surfaces) and experimental data. As a result, even for filters with inhomogeneity factor {delta}p < 1 by the conventional method, the present method gave {delta}p > 1, suggesting that {delta}p < 1 is caused by the failure in measurement for representative fiber size distribution. However, the improvement in prediction with more reliable filter properties is not satisfactory because the conventional filtration theory cannot account for the contribution of fine fibers properly. Introduction of bimodal fiber size distribution together with the measurement of fiber size distribution in a cross-section of a filter is found to give comparable prediction results with the conventional method without resorting the inhomogeneity factor of filter packing. 3 refs., 6 figs., 1 tab.

  1. Walking in the high-rise city: a Health Enhancement and Pedometer-determined Ambulatory (HEPA program in Hong Kong

    Directory of Open Access Journals (Sweden)

    Leung AYM

    2014-08-01

    Full Text Available Angela YM Leung,1,2 Mike KT Cheung,3 Michael A Tse,4 Wai Chuen Shum,5 BJ Lancaster,1,6 Cindy LK Lam7 1School of Nursing, 2Research Centre on Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, University of Hong Kong, 3Centre on Research and Advocacy, Hong Kong Society for Rehabilitation, 4Institute of Human Performance, University of Hong Kong, 5Sheng Kung Hui Holy Carpenter Church Social Services, Hong Kong Special Administrative Region, People’s Republic of China; 6School of Nursing, Vanderbilt University, Nashville, TN, USA; 7Department of Family Medicine and Primary Care, University of Hong Kong, Hong Kong Special Administrative Region, People’s Republic of China Abstract: Due to the lack of good infrastructure in the public estates, many older adults in urban areas are sedentary. The Health Enhancement and Pedometer-Determined Ambulatory (HEPA program was developed to assist older adults with diabetes and/or hypertension to acquire walking exercise habits and to build social support, while engaged in regular physical activity. This study aimed to describe the HEPA program and to report changes in participants’ walking capacity and body strength after 10-week walking sessions. A pre- and postintervention design was used. Pedometers were used to measure the number of steps taken per day before and after the 10-week intervention. Upper and lower body strength, lower body flexibility, and quality of life were assessed. A total of 205 older adults completed the program and all health assessments. After the 10-week intervention, the average number of steps per day increased by 36%, from 6,591 to 8,934. Lower body strength, upper body strength, and aerobic fitness increased significantly after 10 weeks, along with improvement in the 12-item Short Form Health Survey (SF™-12 physical and mental health component summary scores. A social support network was built in the neighborhood, and the local environment was

  2. Weldability of Stainless Steels

    International Nuclear Information System (INIS)

    It gives an outline of metallographic properties of welding zone of stainless steels, generation and mechanisms of welding crack and decreasing of corrosion resistance of welding zone. It consists of seven chapters such as introduction, some kinds of stainless steels and properties, metallographic properties of welding zone, weld crack, toughness of welding zone, corrosion resistance and summary. The solidification modes of stainless steels, each solidification mode on the cross section of Fe-Cr-Ni alloy phase diagram, each solidification mode of weld stainless steels metal by electron beam welding, segregation state of alloy elements at each solidification mode, Schaeffler diagram, Delong diagram, effects of (P + S) mass content in % and Cr/Ni equivalent on solidification cracking of weld stainless steels metal, solidification crack susceptibility of weld high purity stainless steels metal, effects of trace impurity elements on solidification crack susceptibility of weld high purity stainless steels metal, ductile fracture susceptibility of weld austenitic stainless steels metal, effects of H2 and ferrite content on generation of crack of weld 25Cr-5N duplex stainless steels, effects of O and N content on toughness of weld SUS 447J1 metals, effect of ferrite content on aging toughness of weld austenitic stainless steel metal, corrosion morphology of welding zone of stainless steels, generation mechanism of knife line attack phenomenon, and corrosion potential of some kinds of metals in seawater at room temperature are illustrated. (S.Y.)

  3. CYP3A4 activity reduces the cytotoxic effects of okadaic acid in HepaRG cells.

    Science.gov (United States)

    Kittler, Katrin; Fessard, Valérie; Maul, Ronald; Hurtaud-Pessel, Dominique

    2014-08-01

    The biotoxin okadaic acid (OA), produced by dinoflagellates in marine environment, can accumulate in sponges and shellfish. Consumption of contaminated shellfish induces acute toxic effects such as diarrhea, nausea, vomiting, and abdominal pain. CYP3A4, one of the most important human xenobiotic metabolizing enzymes, is supposed to be involved in the metabolism of OA. Aim of our study was to evaluate the role of CYP3A4 in OA in vitro metabolism as well as in cell cytotoxicity in parallel. Therefore, a metabolic competent HepaRG cell line was exposed to OA with and without addition of the CYP3A4 inhibitor ketoconazole. Without the inhibitor, two mono-hydroxylated metabolites could be identified, whereas in its presence, no metabolites could be detected. Confirmation of the formed metabolites was accomplished by measuring the exact masses and investigating the fragmentation pattern. Data obtained from cytotoxicity assays showed that OA cytotoxicity is reduced when CYP3A4 is active. Thus, hydroxylation appears to be a crucial step for metabolic OA detoxification. PMID:24504163

  4. Zinc ionophore activity of quercetin and epigallocatechin-gallate: from Hepa 1-6 cells to a liposome model.

    Science.gov (United States)

    Dabbagh-Bazarbachi, Husam; Clergeaud, Gael; Quesada, Isabel M; Ortiz, Mayreli; O'Sullivan, Ciara K; Fernández-Larrea, Juan B

    2014-08-13

    Labile zinc, a tiny fraction of total intracellular zinc that is loosely bound to proteins and easily interchangeable, modulates the activity of numerous signaling and metabolic pathways. Dietary plant polyphenols such as the flavonoids quercetin (QCT) and epigallocatechin-gallate act as antioxidants and as signaling molecules. Remarkably, the activities of numerous enzymes that are targeted by polyphenols are dependent on zinc. We have previously shown that these polyphenols chelate zinc cations and hypothesized that these flavonoids might be also acting as zinc ionophores, transporting zinc cations through the plasma membrane. To prove this hypothesis, herein, we have demonstrated the capacity of QCT and epigallocatechin-gallate to rapidly increase labile zinc in mouse hepatocarcinoma Hepa 1-6 cells as well as, for the first time, in liposomes. In order to confirm that the polyphenols transport zinc cations across the plasma membrane independently of plasma membrane zinc transporters, QCT, epigallocatechin-gallate, or clioquinol (CQ), alone and combined with zinc, were added to unilamellar dipalmitoylphosphocholine/cholesterol liposomes loaded with membrane-impermeant FluoZin-3. Only the combinations of the chelators with zinc triggered a rapid increase of FluoZin-3 fluorescence within the liposomes, thus demonstrating the ionophore action of QCT, epigallocatechin-gallate, and CQ on lipid membrane systems. The ionophore activity of dietary polyphenols may underlay the raising of labile zinc levels triggered in cells by polyphenols and thus many of their biological actions. PMID:25050823

  5. Re-entrainment of {sup 239}PuO{sub 2} Particles Captured on HEPA Filter Fibres

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Y.; Koizumi, A.; Miyamoto, K

    1999-07-01

    Filter performance is very important not only before use but also in use. In addition to particle collection, particle retention or dispersion rate should be evaluated. Re-entrainment of {sup 239}PuO{sub 2} particles collected on HEPA filter fibres was investigated under various conditions of air flow direction, air flow rate, air flow pattern and dust loading. Plutonium aerosols with an activity median aerodynamic diameter of 0.45 {mu}m and a geometric standard deviation of 2.0 were used. Dispersion rate per hour, which is defined as activity ratio on the sampling filter downstream to that on the source filter, under forward flow, was measured as less than 2.3 x 10{sup -7} h{sup -1}. Under reverse flow, higher dispersion rates were observed, but the dispersion decreased with repeated sample runs. A high air flow rate increased the dispersion rate. There was no significant differences among air flow patterns. Dispersion rate depended strongly on the dust loading level. For example, at 2.9 times the loading of atmospheric aerosols compared with the initial pressure drop the dispersion rate was increased by approximately 100 times to 10{sup -2} h{sup -1}. (author)

  6. Effects of ceiling-mounted HEPA-UV air filters on airborne bacteria concentrations in an indoor therapy pool building.

    Science.gov (United States)

    Kujundzic, Elmira; Zander, David A; Hernandez, Mark; Angenent, Largus T; Henderson, David E; Miller, Shelly L

    2005-02-01

    The purpose of this study was to assess the effectiveness of a new generation of high-volume, ceiling-mounted high-efficiency particulate air (HEPA)-ultraviolet (UV) air filters (HUVAFs) for their ability to remove or inactivate bacterial aerosol. In an environmentally controlled full-scale laboratory chamber (87 m3), and an indoor therapy pool building, the mitigation ability of air filters was assessed by comparing concentrations of total bacteria, culturable bacteria, and airborne endotoxin with and without the air filters operating under otherwise similar conditions. Controlled chamber tests with pure cultures of aerosolized Mycobacterium parafortuitum cells showed that the HUVAF unit tested provided an equivalent air-exchange rate of 11 hr(-1). Using this equivalent air-exchange rate as a design basis, three HUVAFs were installed in an indoor therapy pool building for bioaerosol mitigation, and their effectiveness was studied over a 2-year period. The HUVAFs reduced concentrations of culturable bacteria by 69 and 80% during monitoring periods executed in respective years. The HUVAFs reduced concentrations of total bacteria by 12 and 76% during the same monitoring period, respectively. Airborne endotoxin concentrations were not affected by the HUVAF operation. PMID:15796111

  7. In-place testing of HEPA filter using monodisperse DOP aerosols in the most penetrating particle size range

    International Nuclear Information System (INIS)

    Recent filtration studies have revealed that the most penetrating particle size MPPS, through HEPA filter is smaller than 0.3 μm, which is the test aerosol size in the current filter testing. Furthermore, in the radiation protection field the filter performance is required to be linked to a DF (Decontamination Factor). To meet this evaluation criterion, a new in-place filter test system was developed. Our system consists of a newly designed aerosol generator and a computer-aided aerosol measuring system. The aerosol generator, which is a vaporization-condensation type, generates DOP (Dioctyl Phthalate) aerosols in the most penetrating particle size range from 0.1 to 0.2 μm with a geometric standard deviation (σg) less than 1.2. This high monodispersity makes possible to use a CNC (Condensation Nucleus Counter) for determination of aerosol penetration. Test aerosols are simultaneously measured by using a laser aerosol spectrometer in the upstream and the CNC in the downstream. It was shown that the collection efficiency of seven-nine percentage class for the MPPS range can be measured at air flow of 7800 m3/hr in in-place test. (4 figs., 2 tabs.)

  8. Welding irradiated stainless steel

    International Nuclear Information System (INIS)

    Conventional welding processes produced severe underbead cracking in irradiated stainless steel containing 1 to 33 appm helium from n,a reactions. A shallow penetration overlay technique was successfully demonstrated for welding irradiated stainless steel. The technique was applied to irradiated 304 stainless steel that contained 10 appm helium. Surface cracking, present in conventional welds made on the same steel at the same and lower helium concentrations, was eliminated. Underbead cracking was minimal compared to conventional welding methods. However, cracking in the irradiated material was greater than in tritium charged and aged material at the same helium concentrations. The overlay technique provides a potential method for repair or modification of irradiated reactor materials

  9. Nitrogen-alloyed martensitic steels

    International Nuclear Information System (INIS)

    A report is presented on initial results with pressure-nitrided martensitic steels. In heat-resistant steels, thermal stability and toughness are raised by nitrogen. In cold work steel, there is a more favourable corrosion behaviour. (orig./MM)

  10. Evaluation of cytochrome P450 inductions by anti-epileptic drug oxcarbazepine, 10-hydroxyoxcarbazepine, and carbamazepine using human hepatocytes and HepaRG cells.

    Science.gov (United States)

    Sugiyama, Ikuo; Murayama, Norie; Kuroki, Ayaka; Kota, Jagannath; Iwano, Shunsuke; Yamazaki, Hiroshi; Hirota, Takashi

    2016-09-01

    Anti-epileptic drug oxcarbazepine is structurally related to carbamazepine, but has reportedly different metabolic pathway. Auto-induction potentials of oxcarbazepine, its pharmacologically active metabolite 10-hydroxyoxcarbazepine and carbamazepine were evaluated by cytochrome P450 (CYP) 1A2, CYP2B6 and CYP3A4 mRNA levels and primary metabolic rates using human hepatocytes and HepaRG cells. For the CYP1A2 the induction potential determined as the fold change in mRNA levels was 7.2 (range: 2.3-11.5) and 10.0 (6.2-13.7) for oxcarbazepine and carbamazepine, respectively, while 10-hydroxyoxcarbazepine did not induce. The fold change in mRNA levels for CYP2B6 was 11.5 (3.2-19.3), 7.0 (2.5-10.8) and 14.8 (3.1-29.1) for oxcarbazepine, 10-hydroxyoxcarbazepine and carbamazepine, respectively. The fold change for CYP3A4 induction level by oxcarbazepine, 10-hydroxyoxcarbazepine and carbamazepine was 3.5 (1.2-7.4), 2.7 (0.8-5.7) and 8.3 (3.5-14.5), respectively. The data suggest lower induction potential of oxcarbazepine and 10-hydroxyoxcarbazepine relative to carbamazepine. The results in HepaRG cells showed similar trend as the human hepatocytes. After incubation for 72 h in hepatocytes and HepaRG cells, auto-induction was evident for only carbamazepine metabolism. The 10-keto group instead of double bond at C10 position is evidently a determinant factor for limited auto-induction of P450 enzymes by oxcarbazepine. PMID:26711482

  11. Experience with a standardized method and application of the recent trends for in-situ testing of HEPA-filtration systems

    International Nuclear Information System (INIS)

    The standardized DOP-method is used in Belgium for in-situ testing of HEPA-filtration systems of nuclear power plants and other nuclear applications. Since 1968, about 2.184 air-cleaning systems were tested in this manner, in different nuclear facilities. The results of these leak-testings were that 13% of the tested systems had a penetration greater than 0.05%. The main two leaking-faults were damaged gaskets (29%) or insufficient clamping (35%). Nevertheless 16% were owing to a defective filtermedium and the remaining 20% from different causes. For the nuclear power plants the main leaking-fault came through by-passing (29%) and defective filtermedium (22%), leaking through gaskets was less important (13%). The size distributions are also important in the case that we try not only to test the leakage but also the efficiency of the air-cleaning system. Indeed measurement of the particle size efficiency can be of importance to regulatory agencies. This trend to transform the in-situ testing into an efficiency test was the reason to obtain experience with the intercavity laser single particle spectrometer. This method developed through B.G. Schuster and D.J. Oselek was applicated to our installations and our testing. ''In-situ''-testing was performed with the laser intercavity spectrometer on the air cleaning systems in comparison with the standardized DOP-method. The results of these in-situ tests are summarized. The laser spectrometer is also an important method for testing in-situ HEPA-filters in serie. This method was further investigated on a testrig with two HEPA-filters in serie. On this testrig penetration less than 2.3.10-7 and 4.10-8 could be measured. (author)

  12. The effect of SAMe and betaine on Hepa 1-6, C34 and E47 liver cell survival in vitro.

    Science.gov (United States)

    Oliva, Joan; Zhong, Jin; Buslon, Virgil S; French, Samuel W

    2012-02-01

    In recent years, methyl one-carbon metabolism has received a great deal of attention because the disruption of methyl balance in a variety of genetically modified mice is associated with the development of various forms of liver injury, namely fatty liver disease and hepatocellular carcinoma (HCC). In addition, patients with liver disease often have an abnormal expression of key genes involved in methionine metabolism as well as elevated serum levels of methionine and homocysteine (Hcy). S-adenosylmethionine (SAMe) has rapidly moved from being a methyl donor to a key metabolite that regulates hepatocyte proliferation, necrosis and differentiation. Biosynthesis of SAMe occurs in all mammalian cells as the first step in methionine catabolism in a reaction catalyzed by methionine adenosyltransferase (MAT). Decreased hepatic SAMe biosynthesis is a consequence of numerous forms of chronic liver injury. In an animal model of chronic liver SAMe deficiency, the liver is predisposed to further injury and develops spontaneous steatohepatitis and HCC. SAMe treatment in experimental animal models of liver injury shows hepatoprotective properties. Meta-analyses also showed that it is effective in the treatment of patients with cholestatic liver diseases. We studied the survival of liver cells treated with SAMe and betaine using Hepa 1-6 and E47/C34 cell lines. We showed that exogenous SAMe decreased the number of Hepa 1-6 and E47/C34 cells, and increased the number of dead cells in vitro. Betaine had no significant effect on the number of surviving cells and the number of dead cells. The combination of both methyl donors significantly increased the survival of liver cells and reduced necrosis, compared to SAMe alone. This study showed the inhibition of the proliferation and increased necrosis in response to SAMe on liver cancer cell lines Hepa 1-6 and C34. PMID:22032937

  13. Apoptosis in murine hepatoma hepa 1c1c7 wild-type, C12, and C4 cells mediated by bilirubin.

    Science.gov (United States)

    Seubert, John M; Darmon, Alison J; El-Kadi, Ayman O S; D'Souza, Sudhir J A; Bend, John R

    2002-08-01

    Elevated serum and tissue bilirubin concentrations that occur in pathological conditions such as cholestasis, jaundice, and other liver diseases are known to stimulate cytotoxic responses. In preliminary studies, we noted that bilirubin seemed to cause apoptosis in murine hepatoma Hepa 1c1c7 wild-type (WT) cells. Consequently, we investigated apoptosis caused by bilirubin in WT, mutant C12 [aryl hydrocarbon receptor (AHR)-deficient], and C4 (AHR nuclear translocator-deficient) Hepa 1c1c7 cells. Three independent measures of apoptosis were used to quantify the effects of exogenous bilirubin (0, 1, 10, 25, 50, or 100 microM). Caspase-3 activity and cytochrome c release from mitochondria increased at 3 h post-treatment, before increased caspase-8 activity at 6 h, and nuclear condensation by 24 h after treatment with bilirubin. No differences in whole-cell lipid peroxidation were observed between the cell types; however, intracellular reactive oxygen species (ROS) production was greater in WT cells than C12 or C4 cells 3 h after bilirubin exposure. Pretreatment of cells for 1 h with 1 or 10 microM alpha-naphthoflavone, an AHR antagonist, before bilirubin exposure resulted in decreased caspase-3 activity at 6 h and nuclear condensation at 24 h in WT cells. These results indicate that bilirubin, a potential AHR ligand, causes apoptosis in murine Hepa 1c1c7 WT cells by a mechanism(s) partially involving the AHR, disruption of membrane integrity, and increased intracellular ROS production. PMID:12130676

  14. Preferential induction of the AhR gene battery in HepaRG cells after a single or repeated exposure to heterocyclic aromatic amines

    International Nuclear Information System (INIS)

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) are two of the most common heterocyclic aromatic amines (HAA) produced during cooking of meat, fish and poultry. Both HAA produce different tumor profiles in rodents and are suspected to be carcinogenic in humans. In order to better understand the molecular basis of HAA toxicity, we have analyzed gene expression profiles in the metabolically competent human HepaRG cells using pangenomic oligonucleotide microarrays, after either a single (24-h) or a repeated (28-day) exposure to 10 μM PhIP or MeIQx. The most responsive genes to both HAA were downstream targets of the arylhydrocarbon receptor (AhR): CYP1A1 and CYP1A2 after both time points and CYP1B1 and ALDH3A1 after 28 days. Accordingly, CYP1A1/1A2 induction in HAA-treated HepaRG cells was prevented by chemical inhibition or small interference RNA-mediated down-regulation of the AhR. Consistently, HAA induced activity of the CYP1A1 promoter, which contains a consensus AhR-related xenobiotic-responsive element (XRE). In addition, several other genes exhibited both time-dependent and compound-specific expression changes with, however, a smaller magnitude than previously reported for the prototypical AhR target genes. These changes concerned genes mainly related to cell growth and proliferation, apoptosis, and cancer. In conclusion, these results identify the AhR gene battery as the preferential target of PhIP and MeIQx in HepaRG cells and further support the hypothesis that intake of HAA in diet might increase human cancer risk.

  15. Tumor Necrosis Factor-alpha Potentiates the Cytotoxicity of Amiodarone in Hepa1c1c7 Cells: Roles of Caspase Activation and Oxidative Stress

    OpenAIRE

    Lu, Jingtao; Miyakawa, Kazuhisa; Roth, Robert A.; Ganey, Patricia E.

    2012-01-01

    Amiodarone (AMD), a class III antiarrhythmic drug, causes idiosyncratic hepatotoxicity in human patients. We demonstrated previously that tumor necrosis factor-alpha (TNF-α) plays an important role in a rat model of AMD-induced hepatotoxicity under inflammatory stress. In this study, we developed a model in vitro to study the roles of caspase activation and oxidative stress in TNF potentiation of AMD cytotoxicity. AMD caused cell death in Hepa1c1c7 cells, and TNF cotreatment potentiated its t...

  16. 3-Nitrobenzanthrone and 3-aminobenzanthrone induce DNA damage and cell signalling in Hepa1c1c7 cells

    Energy Technology Data Exchange (ETDEWEB)

    Landvik, N.E. [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway); Arlt, V.M.; Nagy, E. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Solhaug, A. [Section for Toxicology, Department of Feed and Food Safety, National Veterinary Institute Pb 750 Sentrum, N-0106 Oslo (Norway); Tekpli, X. [EA SeRAIC, Equipe labellisee Ligue contre le Cancer, IFR 140, Universite de Rennes 1, Rennes (France); Schmeiser, H.H. [Research Group Genetic Alteration in Carcinogenesis, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Refsnes, M. [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway); Phillips, D.H. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Lagadic-Gossmann, D. [EA SeRAIC, Equipe labellisee Ligue contre le Cancer, IFR 140, Universite de Rennes 1, Rennes (France); Holme, J.A., E-mail: jorn.holme@fhi.no [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway)

    2010-02-03

    3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts ({sup 32}P-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of I{kappa}B-{alpha} (suggesting activation of NF-{kappa}B) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-{kappa}B play a role in this process. In conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system.

  17. 3-Nitrobenzanthrone and 3-aminobenzanthrone induce DNA damage and cell signalling in Hepa1c1c7 cells

    International Nuclear Information System (INIS)

    3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts (32P-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of IκB-α (suggesting activation of NF-κB) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-κB play a role in this process. In conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system.

  18. Reduced cardiolipin content decreases respiratory chain capacities and increases ATP synthesis yield in the human HepaRG cells.

    Science.gov (United States)

    Peyta, Laure; Jarnouen, Kathleen; Pinault, Michelle; Guimaraes, Cyrille; Pais de Barros, Jean-Paul; Chevalier, Stephan; Dumas, Jean-François; Maillot, François; Hatch, Grant M; Loyer, Pascal; Servais, Stephane

    2016-04-01

    Cardiolipin (CL) is a unique mitochondrial phospholipid potentially affecting many aspects of mitochondrial function/processes, i.e. energy production through oxidative phosphorylation. Most data focusing on implication of CL content and mitochondrial bioenergetics were performed in yeast or in cellular models of Barth syndrome. Previous work reported that increase in CL content leads to decrease in liver mitochondrial ATP synthesis yield. Therefore the aim of this study was to determine the effects of moderate decrease in CL content on mitochondrial bioenergetics in human hepatocytes. For this purpose, we generated a cardiolipin synthase knockdown (shCLS) in HepaRG hepatoma cells showing bioenergetics features similar to primary human hepatocytes. shCLS cells exhibited a 55% reduction in CLS gene and a 40% decrease in protein expression resulting in a 45% lower content in CL compared to control (shCTL) cells. Oxygen consumption was significantly reduced in shCLS cells compared to shCTL regardless of substrate used and energy state analyzed. Mitochondrial low molecular weight supercomplex content was higher in shCLS cells (+60%) compared to shCTL. Significant fragmentation of the mitochondrial network was observed in shCLS cells compared to shCTL cells. Surprisingly, mitochondrial ATP synthesis was unchanged in shCLS compared to shCTL cells but exhibited a higher ATP:O ratio (+46%) in shCLS cells. Our results suggest that lowered respiratory chain activity induced by moderate reduction in CL content may be due to both destabilization of supercomplexes and mitochondrial network fragmentation. In addition, CL content may regulate mitochondrial ATP synthesis yield. PMID:26768115

  19. Isolation and characterization of revertants from four different classes of aryl hydrocarbon hydroxylase-deficient hepa-1 mutants.

    Science.gov (United States)

    Van Gurp, J R; Hankinson, O

    1984-01-01

    Revertants were selected from aryl hydrocarbon hydroxylase (AHH)-deficient recessive mutants belonging to three complementation groups and from a dominant mutant of the Hepa-1 cell line. The recessive mutants had low spontaneous reversion frequencies (less than 4 X 10(-7] that were increased by mutagenesis. The majority of these revertants also had reacquired only partial AHH activity. Revertants of group A mutants were identical to the wild type with respect to both in vivo and in vitro enzyme stability and the Km for the substrate, benzo [alpha]pyrene, and therefore failed to provide evidence that gene A is the AHH structural gene. Group B and group C mutants are defective in the functioning of the Ah receptor required for AHH induction. Revertants of these groups were normal with respect to in vivo temperature sensitivity for AHH induction and for the 50% effective dose for the inducer, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and thus provided no evidence that the B and C genes code for components of the receptor. Two rare group C revertants possessed AHH activity in the absence of induction. The phenotype of one of these was shown to be recessive to the wild type. Spontaneous revertants of the dominant mutant occurred at a frequency 300-fold greater than those of the recessive mutants, and this frequency was not increased by mutagenesis. These revertants all displayed complete restoration of AHH activity to wild type levels. These observations and the results from cell hybridization studies suggest that the dominant revertants arose by a high frequency event leading to functional elimination of the dominant mutation. PMID:6493230

  20. Stability of the aryl hydrocarbon receptor and its regulated genes in the low activity variant of Hepa-1 cell line.

    Science.gov (United States)

    Humphrey-Johnson, Andria; Abukalam, Rawia; Eltom, Sakina E

    2015-03-01

    We examined the expression kinetics of some of the aryl hydrocarbon receptor (AhR)-regulated genes in LA1 variant cells compared to wild type (WT) Hepa-1 mouse hepatoma cell lines, and we investigated the stability of AhR protein as a key step in the function of this receptor. Treatment of both cell types with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) resulted in increased CYP1A1 and CYP1B1 mRNA with a subsequent down regulation of AhR. We show here that co-treatment with transcription inhibitor actinomycin D (ActD) has reversed the TCDD-induced depletion of AhR protein in WT. However, the proteolytic degradation of AhR in absence of TCDD was significantly higher in LA1 cells than in WT, and ActD treatment reduced this loss. Induction of CYP1A1 and CYP1B1 mRNA by TCDD in WT cells each exhibited bursts of activity in the initial hour which were about 3-fold greater than in LAI cells. The induced mRNA levels in LA1 exhibited a slow and sustained increase approximating the WT levels by 20h. The induction of two other AhR-regulated genes also showed comparable turnover differences between the two types of cell. Thus, altered regulation of the AhR responsive genes in LA1 may result from a difference in AhR stability. PMID:25637755

  1. Manganese in sintered steels

    International Nuclear Information System (INIS)

    Based on the review of papers the results of the investigations of sintered manganese steels are presented. The effect of additional alloying elements such as copper, molybdenum and silicon on dimensional changes, density, tensile strength, hardness and elongation of such steels are also reported. (author)

  2. Clean Production of Steel and Refractories in China's Steel Industry

    Institute of Scientific and Technical Information of China (English)

    SU Tiansen

    2002-01-01

    The paper describes the importance of clean production of steel and the relationships amongst sustaining development of steel industry, environment protection and the role of refractories in the clean production of steel. The main achievements and main shortcomings in the clean production of China' s steel industry have been reviewed together with the introduction of the policy supporting system and the future development of clean production in China' s steel industry.

  3. Differences in TCDD-elicited gene expression profiles in human HepG2, mouse Hepa1c1c7 and rat H4IIE hepatoma cells

    Directory of Open Access Journals (Sweden)

    Burgoon Lyle D

    2011-04-01

    Full Text Available Abstract Background 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD is an environmental contaminant that elicits a broad spectrum of toxic effects in a species-specific manner. Current risk assessment practices routinely extrapolate results from in vivo and in vitro rodent models to assess human risk. In order to further investigate the species-specific responses elicited by TCDD, temporal gene expression responses in human HepG2, mouse Hepa1c1c7 and rat H4IIE cells were compared. Results Microarray analysis identified a core set of conserved gene expression responses across species consistent with the role of AhR in mediating adaptive metabolic responses. However, significant species-specific as well as species-divergent responses were identified. Computational analysis of the regulatory regions of species-specific and -divergent responses suggests that dioxin response elements (DREs are involved. These results are consistent with in vivo rat vs. mouse species-specific differential gene expression, and more comprehensive comparative DRE searches. Conclusions Comparative analysis of human HepG2, mouse Hepa1c1c7 and rat H4IIE TCDD-elicited gene expression responses is consistent with in vivo rat-mouse comparative gene expression studies, and more comprehensive comparative DRE searches, suggesting that AhR-mediated gene expression is species-specific.

  4. Experimental relationship between the specific resistance of a HEPA [High Efficiency Particulate Air] filter and particle diameters of different aerosol materials

    International Nuclear Information System (INIS)

    The increase in pressure drop across a HEPA filter has been measured as a function of the particle mass loading using two materials with different particle morphologies. The HEPA filter media chosen, is identical to the filter media used in the Airborne Activity Confinement System (AACS) on the Savannah River Reactors. The velocity through the test filter media was the same as the velocity through the AACS media, under normal operating flow conditions. Sodium Chloride challenge particles were generated using an atomizer, resulting in regularly shaped crystalline forms. Ammonium chloride aerosols were formed from the gas phase reaction of HCl and NH4OH vapors resulting in irregular agglomerates. In both cases, the generation conditions were adjusted to provide several different particle size distributions. For each particle size distribution, the mass of material loaded per unit area of filter per unit pressure drop for a given filtration velocity (1/Specific resistance) was measured. Theoretical considerations in the most widely accepted filter cake model predict that the mass per unit area and per unit pressure drop should increase with the particle density times the particle diameter squared. However, these test results indicate that the increase in the mass loaded per unit area per unit pressure drop, for both materials, can be better described by plotting the specific resistance divided by the particle density as an inverse function of the particle density times the particle diameter squared. 9 refs., 7 figs

  5. Activation of the black seabream (Acanthopagrus schlegeli) somatolactin-alpha gene promoter by Pit-1c in the Hepa-T1 cell-line.

    Science.gov (United States)

    Tian, Jing; Chan, King Ming

    2010-03-01

    Somatolactin (SL) is a pituitary hormone of the growth hormone (GH) gene family found only in fish. To understand the regulation of this hormone at the level of gene transcription, we obtained a SLalpha gene from black seabream (bsb), with its 5' flanking promoter region carrying several putative transcription factors including seven binding sites for pituitary-specific transcription factor 1 (Pit-1). To study the actions of Pit-1 on this gene promoter, we cloned three variants of bsbPit-1 (Pit-1a, Pit-1b and Pit-1c) derived from alternative splicing of mRNA or differential transcription start sites from black seabream pituitary. The deduced amino acid sequences of these Pit-1s contained 371 amino acids (aa), 333 and 311aa for the three Pit-1 variants, Pit-1a, Pit-1b and Pit-1c, respectively, with diverse regions of Pit-1 located at the transactivation domain. The actions of bsbPit-1 variants on the bsbSL gene promoter were investigated using a co-transfection assay, with a reporter gene using a transient expression assay in Hepa-T1 cells. The N-terminus truncated isoform bsbPit-1c showed the highest level of activity on SLalpha gene promoter activation in Hepa-T1 cells; however, neither Pit-1a nor Pit-1b activated the bsbSL gene promoter in the same study. PMID:19766121

  6. The utility of intensified environmental surveillance for pathogenic moulds in a stem cell transplantation ward during construction work to monitor the efficacy of HEPA filtration.

    Science.gov (United States)

    Nihtinen, A; Anttila, V-J; Richardson, M; Meri, T; Volin, L; Ruutu, T

    2007-09-01

    A 12-week environmental study was performed to ensure that the patient rooms of an SCT ward with high-efficiency particulate air (HEPA) filtration remained uncontaminated by moulds during close-by construction work. The sampling included measuring the ventilation channel pressure, particle count measurements, air sampling, settled dust analysis and fungal cultures from the oral and nasal cavities of the patients. No changes in the air pressure occurred. Median particle counts in patient rooms were 63-420 particles/l. The mean particle count of the outside air was 173,659 particles/l. Patient room air samples were negative for aspergilli in 32 of 33 cases. All samples of the outside air were positive for moulds. Aspergillus fumigatus was isolated at the beginning of excavation works at the construction area and in two of 33 dust samples from patient rooms. All 70 nasal samples were negative. Of 35 mouth samples, one sample was positive for A. niger in a patient with a previously diagnosed aspergillus infection. During a median follow-up of 214 days, no invasive aspergillus infections were diagnosed in the 55 patients treated during the construction period. In conclusion, the HEPA filters seemed to have performed well in preventing an aspergillosis outbreak. PMID:17589532

  7. Nuclear transmutation in steels

    Science.gov (United States)

    Belozerova, A. R.; Shimanskii, G. A.; Belozerov, S. V.

    2009-05-01

    The investigations of the effects of nuclear transmutation in steels that are widely used in nuclear power and research reactors and in steels that are planned for the application in thermonuclear fusion plants, which are employed under the conditions of a prolonged action of neutron irradiation with different spectra, made it possible to study the effects of changes in the isotopic and chemical composition on the tendency of changes in the structural stability of these steels. For the computations of nuclear transmutation in steels, we used a program complex we have previously developed on the basis of algorithms for constructing branched block-type diagrams of nuclide transformations and for locally and globally optimizing these diagrams with the purpose of minimizing systematic errors in the calculation of nuclear transmutation. The dependences obtained were applied onto a Schaeffler diagram for steels used for structural elements of reactors. For the irradiation in fission reactors, we observed only a weak influence of the effects of nuclear transmutation in steels on their structural stability. On the contrary, in the case of irradiation with fusion neutrons, a strong influence of the effects of nuclear transmutation in steels on their structural stability has been noted.

  8. In vivo – in vitro toxicogenomic comparison of TCDD-elicited gene expression in Hepa1c1c7 mouse hepatoma cells and C57BL/6 hepatic tissue

    Directory of Open Access Journals (Sweden)

    Boverhof Darrell R

    2006-04-01

    Full Text Available Abstract Background In vitro systems have inherent limitations in their ability to model whole organism gene responses, which must be identified and appropriately considered when developing predictive biomarkers of in vivo toxicity. Systematic comparison of in vitro and in vivo temporal gene expression profiles were conducted to assess the ability of Hepa1c1c7 mouse hepatoma cells to model hepatic responses in C57BL/6 mice following treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD. Results Gene expression analysis and functional gene annotation indicate that Hepa1c1c7 cells appropriately modeled the induction of xenobiotic metabolism genes in vivo. However, responses associated with cell cycle progression and proliferation were unique to Hepa1c1c7 cells, consistent with the cell cycle arrest effects of TCDD on rapidly dividing cells. In contrast, lipid metabolism and immune responses, representative of whole organism effects in vivo, were not replicated in Hepa1c1c7 cells. Conclusion These results identified inherent differences in TCDD-mediated gene expression responses between these models and highlighted the limitations of in vitro systems in modeling whole organism responses, and additionally identified potential predictive biomarkers of toxicity.

  9. Performances of pleated HEPA filters as a function of relative humidity of air; Performances des filtres plisses a Tres Haute Efficacite en fonction de l'humidite relative de l'air

    Energy Technology Data Exchange (ETDEWEB)

    Joubert, A.

    2009-11-15

    Pleated High Efficiency Particulate Air (HEPA) filters are used for maintaining the containment of radioactive substances in nuclear plants; thus, they are sensitive elements of nuclear safety. Some accidental situations, such as the emergence of a hole on a pipe with release of steam, can lead to a high increase of the air humidity. This work can overcome the lack of analytical data in the literature regarding the behaviour of pleated HEPA filters, in terms of changes in pressure drop and efficiency, in presence of humidity (unsaturated air). Experimental clogging tests have been performed on a test bench with two aerosols: non hygroscopic micron-size alumina particles and hygroscopic sub-micron sodium chloride particles. The results showed that the influence of humidity during the clogging of a HEPA filter depends on several parameters: the geometry of the filter (plane or pleated), the size distribution and hygroscopicity of the aerosol clogging and finally the interaction time between the aerosol and humid air. Measurements of efficiency of clean and clogged filters (at different degrees of clogging), performed with the normalized soda fluorescein aerosol, are also sensitive to the presence of more or less relative humidity in the air. Finally, all results helped to develop an empirical model for estimating the evolution of the pressure drop of HEPA filters; this model is applicable during the formation of the particulate cake in presence of humidity without reducing of the surface area filtration. (author)

  10. BORONIZING OF STEEL

    Directory of Open Access Journals (Sweden)

    Arzum ULUKÖY

    2006-02-01

    Full Text Available Boride layer has many advantages in comparison with traditional hardening methods. The boride layer has high hardening value and keeps it's hardeness at high temperatures, and it also shows favorible properties, such as the resistance to wear, oxidation and corrosion. The process can be applied at variety of materials, for instance steel, cast iron, cast steel, nickel and cobalt alloys and cermets. In this rewiew, boronizing process properties, boride layer on steel surfaces and specifications and the factors that effect boride layer are examined

  11. Glass Stronger than Steel

    Science.gov (United States)

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  12. Life after Steel

    Science.gov (United States)

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  13. Articles comprising ferritic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Rakowski, James M.

    2016-06-28

    An article of manufacture comprises a ferritic stainless steel that includes a near-surface region depleted of silicon relative to a remainder of the ferritic stainless steel. The article has a reduced tendency to form an electrically resistive silica layer including silicon derived from the steel when the article is subjected to high temperature oxidizing conditions. The ferritic stainless steel is selected from the group comprising AISI Type 430 stainless steel, AISI Type 439 stainless steel, AISI Type 441 stainless steel, AISI Type 444 stainless steel, and E-BRITE.RTM. alloy, also known as UNS 44627 stainless steel. In certain embodiments, the article of manufacture is a fuel cell interconnect for a solid oxide fuel cell.

  14. Activation of the sonic hedgehog signaling pathway occurs in the CD133 positive cells of mouse liver cancer Hepa 1–6 cells

    Directory of Open Access Journals (Sweden)

    Jeng KS

    2013-08-01

    Full Text Available Kuo-Shyang Jeng,1 I-Shyan Sheen,2 Wen-Juei Jeng,2 Ming-Che Yu,3 Hsin-I Hsiau,3 Fang-Yu Chang,3 Hsin-Hua Tsai31Department of Surgery, Far Eastern Memorial Hospital, Taipei, 2Department of Hepato-Gastroenterology, Chang Gung Memorial Hospital, Linkou Medical Center, Chang Gung University, 3Department of Medical Research, Far Eastern Memorial Hospital, Taipei, Taiwan, Republic of ChinaBackground: The important role of cancer stem cells in carcinogenesis has been emphasized in research. CD133+ cells have been mentioned as liver cancer stem cells in hepatocellular carcinoma (HCC. Some researchers have proposed that the sonic hedgehog (Shh pathway contributes to hepatocarcinogenesis and that the pathway activation occurs mainly in cancer stem cells. We investigated whether the activation of the Shh pathway occurs in CD133+ cells from liver cancer.Materials and methods: We used magnetic sorting to isolate CD133+ cells from mouse cancer Hepa 1–6 cells. To examine the clonogenicity, cell culture and soft agar colony formation assay were performed between CD133+ and CD133- cells. To study the activation of the Shh pathway, we examined the mRNA expressions of Shh, patched homolog 1 (Ptch-1, glioma-associated oncogene homolog 1 (Gli-1, and smoothened homolog (Smoh by real-time polymerase chain reaction of both CD133+ and CD133- cells.Results: The number (mean ± standard deviation of colonies of CD133+ cells and CD133- cells was 1,031.0 ± 104.7 and 119.7 ± 17.6 respectively. This difference was statistically significant (P < 0.001. Their clonogenicity was 13.7% ± 1.4% and 1.6% ± 0.2% respectively with a statistically significant difference found (P < 0.001. CD133+ cells and CD133– cells were found to have statistically significant differences in Shh mRNA and Smoh mRNA (P = 0.005 and P = 0.043 respectively.Conclusion: CD133+ Hepa 1–6 cells have a significantly higher colony proliferation and clonogenicity. The Shh pathway is activated in these

  15. Baicalin induces NAD(P)H:quinone reductase through the transactivation of AP-1 and NF-kappaB in Hepa 1c1c7 cells.

    Science.gov (United States)

    Park, H J; Lee, Y W; Lee, S K

    2004-12-01

    Baicalin (5,6,7-trihydroxyflavone-7-O-D-glucuronic acid, BA) is a flavone isolated from Scutellariae radix. In our previous report BA was a major active principle of NAD(P)H:quinone reductase (QR) induction mediated by Scutellariae radix extract and the induction was related to the transcriptional activation of the QR gene in Hepa 1c1c7 cells. The primary aim of the present study was to determine the molecular mechanism of QR gene expression by baicalin. The antioxidant or electrophile response element (ARE/EpRE) found at the 5'-flanking region of phase II genes may play an important role in mediating their induction by xenobiotics, including chemopreventive agents. In accordance, to study the molecular mechanisms of QR gene expression by BA, electrophoretic mobility shift assay (EMSA), using nuclear extracts of treated and untreated cells against ARE, activator protein-1 (AP-1) or nuclear factor-kappaB (NF-kappaB) binding sites, showed that BA increased the binding levels of the parameters in a dose-dependent manner. Further, Hepa 1c1c7 cells were transiently transfected with a plasmid containing three copies of the AP-1- or NF-kappaB-binding site linked to a chloramphenicol acetyltransferase (CAT) reporter gene. Using the CAT reporter gene assay, a dose-dependent transactivation of AP-1- or NF-kappaB-mediated CAT expression was observed with the treatment of BA. These results clearly indicate that BA induces the QR gene expression and activity by transactivation of AP-1 and NF-kappaB, and thus BA may be considered as a potential cancer chemopreventive agent with the induction of phase II detoxification enzyme. PMID:15548947

  16. Activation of the sonic hedgehog signaling pathway occurs in the CD133 positive cells of mouse liver cancer Hepa 1–6 cells

    Science.gov (United States)

    Jeng, Kuo-Shyang; Sheen, I-Shyan; Jeng, Wen-Juei; Yu, Ming-Che; Hsiau, Hsin-I; Chang, Fang-Yu; Tsai, Hsin-Hua

    2013-01-01

    Background The important role of cancer stem cells in carcinogenesis has been emphasized in research. CD133+ cells have been mentioned as liver cancer stem cells in hepatocellular carcinoma (HCC). Some researchers have proposed that the sonic hedgehog (Shh) pathway contributes to hepatocarcinogenesis and that the pathway activation occurs mainly in cancer stem cells. We investigated whether the activation of the Shh pathway occurs in CD133+ cells from liver cancer. Materials and methods We used magnetic sorting to isolate CD133+ cells from mouse cancer Hepa 1–6 cells. To examine the clonogenicity, cell culture and soft agar colony formation assay were performed between CD133+ and CD133− cells. To study the activation of the Shh pathway, we examined the mRNA expressions of Shh, patched homolog 1 (Ptch-1), glioma-associated oncogene homolog 1 (Gli-1), and smoothened homolog (Smoh) by real-time polymerase chain reaction of both CD133+ and CD133− cells. Results The number (mean ± standard deviation) of colonies of CD133+ cells and CD133− cells was 1,031.0 ± 104.7 and 119.7 ± 17.6 respectively. This difference was statistically significant (P < 0.001). Their clonogenicity was 13.7% ± 1.4% and 1.6% ± 0.2% respectively with a statistically significant difference found (P < 0.001). CD133+ cells and CD133− cells were found to have statistically significant differences in Shh mRNA and Smoh mRNA (P = 0.005 and P = 0.043 respectively). Conclusion CD133+ Hepa 1–6 cells have a significantly higher colony proliferation and clonogenicity. The Shh pathway is activated in these cells that harbor stem cell features, with an underexpression of Shh mRNA and an overexpression of Smoh mRNA. Blockade of the Shh signaling pathway may be a potential therapeutic strategy for hepatocarcinogenesis. PMID:23950652

  17. Continuous steel production and apparatus

    Science.gov (United States)

    Peaslee, Kent D.; Peter, Jorg J.; Robertson, David G. C.; Thomas, Brian G.; Zhang, Lifeng

    2009-11-17

    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  18. Thermochemical surface engineering of steels

    OpenAIRE

    2015-01-01

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels

  19. Thermochemical surface engineering of steels

    DEFF Research Database (Denmark)

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels...

  20. Fatigue damage of steel components

    DEFF Research Database (Denmark)

    Fæster, Søren; Zhang, Xiaodan; Huang, Xiaoxu;

    2014-01-01

    Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials......Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials...

  1. A-3 steel work completed

    Science.gov (United States)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  2. Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

    Science.gov (United States)

    Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam

    2015-07-01

    The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

  3. High-purity steel making

    International Nuclear Information System (INIS)

    The conference heard a total of 32 papers of which 8 were inputted in INIS. These papers are centred on certain topical problems related to the manufacture of high purity steels, on impurities in steels, the effect of the radiation environment on steels made by different melting methods, argon protection against reoxidation during casting, the effects of secondary metallurgy on the properties of stainless austenitic steel, the properties of electroslag remelted steel, the metallurgic quality of the central part of ingots weighing 135 tons, and the chemical heterogeneity of ingots and castings. (J.C.)

  4. On choice of tempered steels

    International Nuclear Information System (INIS)

    For the purpose of developing a graphical method for choosing structural steels, a change in the propagation work of a crack and in the critical temperature of brittleness of 40, 40Kh, 40KhN, and 40KhNM steels, was examined depending on the hardness after hardening and tempering. A diagram enabling to choose the grade of steel for making an article of known dimensions according to the preset values of its mechanical properties has been plotted. The developed selection scheme takes into account the hardenability of steels and the influence of the hardness after thermal treatment on the cold-shortness of steel

  5. Thermomechanical treatment of steel

    International Nuclear Information System (INIS)

    Thermomechanical treatment is defined as a process in which a forming operation is carried out in the course of a treatment in order to improve the mechanical properties of a material. Several thermomechanical processes for the treatment of steel are described. (WBU)

  6. Japan steel mill perspective

    Energy Technology Data Exchange (ETDEWEB)

    Murase, K. [Kobe Steel Ltd., Tokyo (Japan)

    2004-07-01

    The international and Japan's steel industry, the coking coal market, and Japan's expectations from Canada's coal industry are discussed. Japan's steel mills are operating at full capacity. Crude steel production for the first half of 2004 was 55.8 million tons. The steel mills are profitable, but costs are high, and there are difficulties with procuring raw materials. Japan is trying to enhance the quality of coke, in order to achieve higher productivity in the production of pig iron. Economic growth is rising disproportionately in the BRICs (Brazil, Russia, India, and China), with a large increase in coking coal demand from China. On the supply side, there are several projects underway in Australia and Canada to increase production. These include new developments by Elk Valley Coal Corporation, Grande Cache Coal, Western Canadian Coal, and Northern Energy and Mining in Canada. The Elga Mine in the far eastern part of Russia is under development. But the market is expected to remain tight for some time. Japan envisions Canadian coal producers will provide a stable coal supply, expansion of production and infrastructure capabilities, and stabilization of price. 16 slides/overheads are included.

  7. Early steps in bilirubin-mediated apoptosis in murine hepatoma (Hepa 1c1c7) cells are characterized by aryl hydrocarbon receptor-independent oxidative stress and activation of the mitochondrial pathway.

    Science.gov (United States)

    Oakes, Garth H; Bend, John R

    2005-01-01

    Unconjugated bilirubin (UCB), the end product of heme catabolism, causes apoptosis in cells of the central nervous system, endothelial cells, and hepatotoma cells. However, the molecular mechanisms that contribute to UCB cytotoxicity remain unclear. The purpose of this study was to characterize the sequence of early events leading to UCB-mediated cytotoxicity in murine hepatoma Hepa 1c1c7 cells. In the present study, UCB (5-50 microM) was found to markedly increase the intracellular generation of reactive oxygen species (ROS) in a concentration-dependent manner, which is significantly elevated by 30 min post-treatment. This generation of ROS by UCB is not dependent on aryl hydrocarbon receptor (Ahr) signaling, as cells deficient in the Ahr (C12 cells) or the Ahr nuclear translocator protein (Arnt; C4 cells) were as efficient at generating ROS as wild type (WT) Hepa 1c1c7 cells. Mitochondrial membrane depolarization, evaluated with the lipophilic cationic dye, JC-1, occurred at least by 2 h after treatment with 50 muM UCB. Analysis of the caspase cascade demonstrated that activation of caspase-9 preceded activation of caspase-3. No conversion of procaspase-2 to active caspase-2 was detected in this study. These results demonstrate that UCB-mediated apoptosis in Hepa 1c1c7 cells is associated with increased oxidative stress and that caspase-9, and definitely not caspase-2, is the initiator caspase for apoptosis in UCB-treated Hepa 1c1c7 cells. PMID:16173058

  8. History of ultrahigh carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Wadsworth, J.; Sherby, O.D.

    1997-06-20

    The history and development of ultrahigh carbon steels (i.e., steels containing between 1 and 2.l percent C and now known as UHCS) are described. The early use of steel compositions containing carbon contents above the eutectoid level is found in ancient weapons from around the world. For example, both Damascus and Japanese sword steels are hypereutectoid steels. Their manufacture and processing is of interest in understanding the role of carbon content in the development of modern steels. Although sporadic examples of UHCS compositions are found in steels examined in the early part of this century, it was not until the mid-1970s that the modern study began. This study had its origin in the development of superplastic behavior in steels and the recognition that increasing the carbon content was of importance in developing that property. The compositions that were optimal for superplasticity involved the development of steels that contained higher carbon contents than conventional modern steels. It was discovered, however, that the room temperature properties of these compositions were of interest in their own right. Following this discovery, a period of intense work began on understanding their manufacture, processing, and properties for both superplastic forming and room temperature applications. The development of superplastic cast irons and iron carbides, as well as those of laminated composites containing UHCS, was an important part of this history.

  9. Steel containment buckling

    International Nuclear Information System (INIS)

    The Steel Containment Buckling program is in its fourth phase of work directed at the evaluation of the effects of the structural failure mode of steel containments when the membrane stresses are compressive. The structural failure mode for this state of stress is instability or buckling. The program to date has investigated: (1) the effect on overall buckling capacity of the ASME area replacement method for reinforcing around circular penetrations; (2) a set of benchmark experiments on ring-stiffened shells having reinforced and framed penetrations; (3) large and small scale experiments on knuckle region buckling from internal pressure and post-buckling behavior to failure for vessel heads having torispherical geometries; and (4) buckling under time-dependent loadings (dynamic buckling). The first two investigations are complete, the knuckle buckling experimental efforts are complete with data analysis and reporting in progress, and the dynamic buckling experimental and analytical work is in progress

  10. Cleanable sintered metal filters in hot off-gas systems

    International Nuclear Information System (INIS)

    Filters with sintered metal elements, arranged as tube bundles with backflush air cleaning, are the equivalent of bag filters for high-temperature, harsh environments. They are virtually the only alternative for high-temperature off-gas systems where a renewable, highly efficient particle trap is required. Tests were conducted which show that the sintered metal elements installed in a filter system provide effective powder collection in high-temperature atmospheres over thousands of cleaning cycles. Such a sintered metal filter system is now installed on the experimental defense waste calciner at the Savannah River Laboratory. The experimental results included in this paper were used as the basis for its design

  11. Reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Research and development activities related to reactor pressure vessel steels during 1997 are reported. The objectives of activities of the Belgian Nuclear Research Centre SCK/CEN in this domain are: (1) to develop enhanced surveillance concepts by applying micromechanics and fracture-toughness tests to small specimens, and by performing damage modelling and microstructure characterization; (2) to demonstrate a methodology on a broad database; (3) to achieve regulatory acceptance and industrial use

  12. Steels and welding nuclear

    International Nuclear Information System (INIS)

    This ENEA Data-Base regards mechanical properties, chemical composition and heat treatments of nuclear pressure vessel materials: type A533-B, A302-B, A508 steel plates and forgings, submerged arc welds and HAZ before and after nuclear irradiation. Irradiation experiments were generally performed in high flux material test reactors. Data were collected from international available literature about water nuclear reactors pressure vessel materials embrittlement

  13. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  14. Contaminated Mexican steel incident

    International Nuclear Information System (INIS)

    This report documents the circumstances contributing to the inadvertent melting of cobalt 60 (Co-60) contaminated scrap metal in two Mexican steel foundries and the subsequent distribution of contaminated steel products into the United States. The report addresses mainly those actions taken by US Federal and state agencies to protect the US population from radiation risks associated with the incident. Mexico had much more serious radiation exposure and contamination problems to manage. The United States Government maintained a standing offer to provide technical and medical assistance to the Mexican Government. The report covers the tracing of the source to its origin, response actions to recover radioactive steel in the United States, and return of the contaminated materials to Mexico. The incident resulted in significant radiation exposures within Mexico, but no known significant exposure within the United States. Response to the incident required the combined efforts of the Nuclear Regulatory Commission (NRC), Department of Energy, Department of Transportation, Department of State, and US Customs Service (Department of Treasury) personnel at the Federal level and representatives of all 50 State Radiation Control Programs and, in some instances, local and county government personnel. The response also required a diplomatic interface with the Mexican Government and cooperation of numerous commercial establishments and members of the general public. The report describes the factual information associated with the event and may serve as information for subsequent recommendations and actions by the NRC. 8 figures

  15. Stainless Steel Permeability

    Energy Technology Data Exchange (ETDEWEB)

    Buchenauer, Dean A. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Karnesky, Richard A. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States)

    2015-09-01

    An understanding of the behavior of hydrogen isotopes in materials is critical to predicting tritium transport in structural metals (at high pressure), estimating tritium losses during production (fission environment), and predicting in-vessel inventory for future fusion devices (plasma driven permeation). Current models often assume equilibrium diffusivity and solubility for a class of materials (e.g. stainless steels or aluminum alloys), neglecting trapping effects or, at best, considering a single population of trapping sites. Permeation and trapping studies of the particular castings and forgings enable greater confidence and reduced margins in the models. For FY15, we have continued our investigation of the role of ferrite in permeation for steels of interest to GTS, through measurements of the duplex steel 2507. We also initiated an investigation of the permeability in work hardened materials, to follow up on earlier observations of unusual permeability in a particular region of 304L forgings. Samples were prepared and characterized for ferrite content and coated with palladium to prevent oxidation. Issues with the poor reproducibility of measurements at low permeability were overcome, although the techniques in use are tedious. Funding through TPBAR and GTS were secured for a research grade quadrupole mass spectrometer (QMS) and replacement turbo pumps, which should improve the fidelity and throughput of measurements in FY16.

  16. Cloning and characterization of a tilapia (Oreochromis aureus) metallothionein gene promoter in Hepa-T1 cells following the administration of various heavy metal ions.

    Science.gov (United States)

    Chan, William Wai Lun; Chan, King Ming

    2008-01-20

    Metallothioneins (MTs) are highly conserved intracellular metal-binding proteins that contribute to the homeostasis of essential metals and the detoxification of non-essential heavy metals. MT gene expression is induced by various heavy metal ions, and Zn(2+) is able to bind and activate a transcription factor associated with the MT gene that is known as the metal responsive element (MRE) binding transcription factor-1 (MTF-1). Heavy metals other than Zn(2+), such as Cd(2+) and Cu(2+), fail to activate the binding of MTF-1 to MREs despite their ability to induce the transcription of the MT gene. To study how different metal ions regulate MT gene expression, a tilapia (ti)-MT gene promoter was cloned and its responses to activation by various metal ions measured using a Hepa T1 cell culture model. The tiMT gene promoter contains six functional MREs within 2118bp 5' of the translational start site. A transient gene expression study showed the tiMT gene promoter fragment to be responsive to Cd(2+), Cu(2+), Hg(2+), Pb(2+), and Zn(2+). Deletions from the 5' end and the site-directed mutagenesis of individual MREs in the tiMT gene promoter confirmed that both proximal and distal clusters of MREs were required for the maximal metal induction of the tiMT gene. The distal cluster of MREs greatly enhanced the induction of tiMT gene expression by several of the heavy metal ions, and especially the non-Zn(2+) ions. Individual MREs showed a different responsiveness to metal ions, with MREe being the most potent, MREb being responsive to Zn(2+) but not to other metal ions, and MREa being mainly for the basal expression of the tiMT gene. Electrophoretic mobility shift assay (EMSA) identified a transcription factor that was able to bind most of the MREs, with the exception of MREd, but the binding was only activated by the in vivo administration of Zn(2+), not the administration of Cd(2+) or Cu(2+). In conclusion, the results of this study on a Hepa T1 cell model suggest that the

  17. PHOSPHORUS REMOVAL USING STEEL SLAG

    Institute of Scientific and Technical Information of China (English)

    Y.Z. Lan; S. Zhang; J.K. Wang; R. W. Smith

    2006-01-01

    Steel slag is a byproduct produced in large amounts in the steel-making process. It is an important resource that can be effectively utilized. An experiment was described in which steel slag was tested as an adsorbent for the removal of phosphorus from waste water. Phosphorus removal depended on the amount of steel slag added, the pH value, the contact time, and the initial concentration. Under laboratory conditions when the added slag was 7.5g/L, the contact time 2h, and the pH value was equivalent to 6.5, over 99% of the phosphorus was removed; the experimental data on steel slag adsorption of phosphorus in the water fitted the Freundlich isotherm model. Steel slag was found to be very effective in adsorbing phosphorus.

  18. Fracture Mechanisms in Steel Castings

    Directory of Open Access Journals (Sweden)

    Z. Stradomski

    2013-07-01

    Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

  19. Fatique behaviour of electrical steel

    OpenAIRE

    Bode B.; Zeismann F.; Brückner-Foit A.

    2014-01-01

    Electrical steel comes into focus with the development of electrically powered cars. In contrast to electrical motors used stationarily (e.g. conveyer belt drives in industrial applications), electrical steel in a car engine is subjected to cyclic loading due to vibrations caused by the imbalance of the rotor and start and stop driving events. For a safe and reliable design of an electrical motor the fatigue behaviour of electrical steel needs to be analysed. To minimize eddy current losses, ...

  20. Mechanics in Steels through Microscopy

    OpenAIRE

    Tirumalasetty, G.K.

    2013-01-01

    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP steels, highlighting the importance of microstructure - mechanical properties - applications relationships. In Chapter 2 the material properties and material processing are described into more detai...

  1. Synthesis of thermit noncorrodible steels

    OpenAIRE

    Жигуц, Юрій Юрійович

    2013-01-01

    The present paper the basic solutions to the problem of obtaining cavitation-resistant steels examined the use of thermite steels, the benefits of combining thermite steels with metallotermic methods of getting is showed. The advantages of metallotermic synthesis methods include: autonomy of processes, independence of energy sources, simplicity of equipment, high-performance process and easy transition from experimental research to industrial production. The need to developed the technology o...

  2. Strip casting of stainless steels

    OpenAIRE

    Raabe, D.

    1997-01-01

    FLAT PRODUCTS OF STAINLESS STEELS ARE CONVENTIONALLY MANUFACTURED BY CONTINUOUS CASTING, HOT ROLLING, HOT BAND ANNEALING, PICKLING, COLD ROLLING AND RECRYSTALLISATION. IN THE LAST YEARS STRIP CASTING HAS INCREASINGLY ATTRACTED ATTENTION. IT OFFERS THREE IMPROVEMENTS IN COMPARISON TO THE CONVENTIONAL METHOD.1.) IT ALLOWS TO CAST STEEL SHEETS WITH THE SAME THICKNESS AND WIDTH AS THOSE PRODUCED BY HOT ROLLING. THIS MEANS THAT THE HOT ROLLING PROCESSIS BYPASSED. 2.) THE STRIP CAST STEEL REVEALS A...

  3. Output Model of Steel Plant

    Institute of Scientific and Technical Information of China (English)

    ZHANG Long-qiang; TIAN Nai-yuan; ZHANG Jin; XU An-jun

    2008-01-01

    Based on the requirement of compactivity, continuity, and high efficiency, and taking full advantage of cushion capability of flexible parts such as external refining in new generation steel plant, an output model of steel plant was established in terms of matching between BOF and caster. Using this model, the BOF nominal capacity is selected, the caster output and equipment amount are computed, and then the steel plant output is computed.

  4. Milled Die Steel Surface Roughness Correlation with Steel Sheet Friction

    DEFF Research Database (Denmark)

    Berglund, J.; Brown, C.A.; Rosén, B.-G.;

    2010-01-01

    This work investigates correlations between the surface topography ofmilled steel dies and friction with steel sheet. Several die surfaces were prepared by milling. Friction was measured in bending under tension testing. Linear regression coefficients (R2) between the friction and texture...

  5. The Effect of Aromatic Hydrocarbon Receptor on the Phenotype of the Hepa 1c1c7 Murine Hepatoma Cells in the Absence of Dioxin

    Directory of Open Access Journals (Sweden)

    Feng Wang

    2007-01-01

    Full Text Available The aromatic hydrocarbon receptor (AhR mediates biological responses to certain exogenous ligands, such as the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, and has also been demonstrated to modulate the cell cycle and differentiated state of several cell lines independently of exogenous ligands. In this study, we used DNA micorarray analysis to elucidate the profile of genes responsive to the expression of unliganded AhR by re-introducing AhR into an AhR-deficient mouse derivative (c19 of the mouse hepatoma cell line Hepa1c1c7. 22 gene products were up-regulated and 8 were down-regulated two-fold or more in c19 cells infected with a retroviral vector expressing mouse AhR. Surprisingly, expression of genes involved in cell proliferation or differentiation were not affected by introduction of AhR. AhR also did not restore expression of the albumin gene in c19 cells. Introduction of AhR into c12, a similar AhRdefective mouse hepatoma cell line, also did not restore albumin expression, and furthermore, did not lead to changes in cellular morphology or cell cycle parameters. These observations fail to support the notion that unliganded AhR regulates proliferation and differentiation of liver-derived cells.

  6. 3-Nitrofluoranthene (3-NF) but not 3-aminofluoranthene (3-AF) elicits apoptosis as well as programmed necrosis in Hepa1c1c7 cells

    International Nuclear Information System (INIS)

    In this study, we show that the environmental pollutant, 3-nitrofluoranthene (3-NF) but not its amine form, 3-aminofluoranthene (3-AF), induces apoptosis as well as regulated necrosis with necroptotic features in Hepa1c1c7 cells. Upon exposure to 3-NF, both typical apoptotic and necrotic cells were observed. A large number of the cells exhibited a characteristic partial nuclear chromatin condensation. Cycloheximide completely attenuated 3-NF-induced cell death. Activation of caspase-8, -9, and -3 were observed. Moreover, Z-VAD-FMK decreased the apoptotic cells, whereas the number of propidium iodide (PI)-positive cells with partial chromatin condensation was reduced by Nec-1, an inhibitor of receptor interacting protein (RIP-1). Cyp1a1, but not nitric oxide synthase (NOS), appears to be involved in activation of 3-NF to reactive metabolites. Increase in the number as well as size of lysosomes, myelinosomes, and activation of autophagy were also observed. 3-NF induced phosphorylation of ERK1/2, JNK and p38 MAPKs. Interestingly, while inhibitors of ERK1/2 and JNK reduced apoptotic as well as necrotic cell death, the p38 inhibitor, SB202190 reduced only the necrotic cell death. Taken together, 3-NF elicits both apoptosis and a caspase-independent programmed cell death (PCD) with autophagic characteristics. Conversely, with 3-AF, no apparent cytotoxic effects besides a reduction in cell proliferation was observed

  7. The effect of aromatic hydrocarbon receptor on the phenotype of the Hepa 1c1c7 murine hepatoma cells in the absence of dioxin.

    Science.gov (United States)

    Wang, Feng; Zhang, Ruixue; Shi, Shengli; Hankinson, Oliver

    2007-01-01

    The aromatic hydrocarbon receptor (AhR) mediates biological responses to certain exogenous ligands, such as the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and has also been demonstrated to modulate the cell cycle and differentiated state of several cell lines independently of exogenous ligands. In this study, we used DNA microarray analysis to elucidate the profile of genes responsive to the expression of unliganded AhR by re-introducing AhR into an AhR-deficient mouse derivative (c19) of the mouse hepatoma cell line Hepa 1c1c7. 22 gene products were up-regulated and 8 were down-regulated two-fold or more in c19 cells infected with a retroviral vector expressing mouse AhR. Surprisingly, expression of genes involved in cell proliferation or differentiation were not affected by introduction of AhR. AhR also did not restore expression of the albumin gene in c19 cells. Introduction of AhR into c12, a similar AhR-defective mouse hepatoma cell line, also did not restore albumin expression, and furthermore, did not lead to changes in cellular morphology or cell cycle parameters. These observations fail to support the notion that unliganded AhR regulates proliferation and differentiation of liver-derived cells. PMID:19936078

  8. Steels for nuclear power. I

    International Nuclear Information System (INIS)

    The principles are listed of nuclear reactor operation and the reactors are classified by neutron energy, fuel and moderator designs, purpose and type of moderator. The trend and the development of light-water reactor applications are described. The fundamental operating parameters of the WWER type reactors are indicated. The effect is discussed of neutron radiation on reactor structural materials. The characteristics are described of steel corrosion due to the contact of the steel with steam or sodium in the primary coolant circuit. The reasons for stress corrosion are given and the effects of radiation on corrosion are listed. The requirements and criteria are given for the choice of low-alloy steel for the manufacture of pressure vessels, volume compensators, steam generators, cooling conduits and containment. A survey is given of most frequently used steels for pressure vessels and of the mechanical and structural properties thereof. The basic requirements for the properties of steel used in the primary coolant circuit are as follows: sufficient strength in operating temperature, toughness, good weldability, resistance to corrosion and low brittleness following neutron irradiation. The materials are listed used for the components of light-water and breeder reactors. The production of corrosion-resistant steels is discussed with a view to raw materials, technology, steel-making processes, melting processes, induction furnace steel-making, and to selected special problems of the chemical composition of steels. The effects are mainly discussed of lead, bismuth and tin as well as of some other elements on hot working of high-alloy steels and on their structure. The problems of corrosion-resistant steel welding and of pressure vessel cladding are summed up. Also discussed is the question of the concept and safeguards of the safety of nuclear installation operation and a list is presented of most commonly used nondestructive materials testing methods. The current

  9. Niobium in rail steels

    International Nuclear Information System (INIS)

    The strengthening capacity of niobium in high carbon steels is governed by the carbon content, soaking conditions prior to rolling and the finish rolling temperature. Yield and tensile strengths may be increased by up to 70-100 MPa (10-15 k.s.i.) in C-Mn-Cr rails with niobium additions of about 0.03 percent. The strengthening mechanism appears to be precipitation hardening of niobium carbonitride in the pro-eutectoid ferrite and ferrite lamellae in pearlite. In addition, ductility improvements may be effected through the austenite grain refining action of niobium in hot rolling leading to a reduction in pearlite colony size

  10. Steel designers' handbook

    CERN Document Server

    Gorenc, Branko; Tinyou, Ron

    2012-01-01

    The Revised 7th Edition of Steel Designers' Handbook is an invaluable tool for all practising structural, civil and mechanical engineers as well as engineering students at university and TAFE in Australia and New Zealand. It has been prepared in response to changes in the design Standard AS 4100, the structural Design Actions Standards, AS /ANZ 1170, other processing Standards such as welding and coatings, updated research as well as feedback from users. This edition is based on Australian Standard (AS) 4100: 1998 and subsequent amendments. The worked numerical examples in the book have been e

  11. The industrial ecology of steel

    Energy Technology Data Exchange (ETDEWEB)

    Considine, Timothy J.; Jablonowski, Christopher; Considine, Donita M.M.; Rao, Prasad G.

    2001-03-26

    This study performs an integrated assessment of new technology adoption in the steel industry. New coke, iron, and steel production technologies are discussed, and their economic and environmental characteristics are compared. Based upon detailed plant level data on cost and physical input-output relations by process, this study develops a simple mathematical optimization model of steel process choice. This model is then expanded to a life cycle context, accounting for environmental emissions generated during the production and transportation of energy and material inputs into steelmaking. This life-cycle optimization model provides a basis for evaluating the environmental impacts of existing and new iron and steel technologies. Five different plant configurations are examined, from conventional integrated steel production to completely scrap-based operations. Two cost criteria are used to evaluate technology choice: private and social cost, with the latter including the environmental damages associated with emissions. While scrap-based technologies clearly generate lower emissions in mass terms, their emissions of sulfur dioxide and nitrogen oxides are significantly higher. Using conventional damage cost estimates reported in the literature suggests that the social costs associated with scrap-based steel production are slightly higher than with integrated steel production. This suggests that adopting a life-cycle viewpoint can substantially affect environmental assessment of new technologies. Finally, this study also examines the impacts of carbon taxes on steel production costs and technology choice.

  12. Stainless steels low temperature nitriding

    International Nuclear Information System (INIS)

    Nitrogen ions implantation of 316L stainless steel leads to monophasic diffusion layers, which are constituted of a solid solution (γN) fcc, metastable, nitrogen sur-saturated, and without order. This article shows that for 316L stainless steels,these layers improve the tribological properties without degradation of the corrosion resistance. (A.B.). 13 refs. 6 figs

  13. Mechanics in Steels through Microscopy

    NARCIS (Netherlands)

    Tirumalasetty, G.K.

    2013-01-01

    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP s

  14. Steel structures for nuclear facilities

    International Nuclear Information System (INIS)

    The guide presents requirements on the design and manufacturing of steel structures for nuclear facilities as well as on documents to be submitted to Finnish Radiation and Nuclear Safety Authority (STUK). Inspection of steel structures during plant construction and operation is also described

  15. Steels from materials science to structural engineering

    CERN Document Server

    Sha, Wei

    2013-01-01

    Steels and computer-based modelling are fast growing fields in materials science as well as structural engineering, demonstrated by the large amount of recent literature. Steels: From Materials Science to Structural Engineering combines steels research and model development, including the application of modelling techniques in steels.  The latest research includes structural engineering modelling, and novel, prototype alloy steels such as heat-resistant steel, nitride-strengthened ferritic/martensitic steel and low nickel maraging steel.  Researchers studying steels will find the topics vital to their work.  Materials experts will be able to learn about steels used in structural engineering as well as modelling and apply this increasingly important technique in their steel materials research and development. 

  16. Dual phase bainitic linepipe steels

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, D.; Yakubtsov, I.; Zhang, R. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mechanical and Materials Engineering; Poruks, P. [Atomic Energy of Canada Ltd., Chalk River, ON (Canada); Turi, T. [Stelco Lake Erie, Nanticoke, ON (Canada); Emadi, D.; Essadiqi, E. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Lab

    2005-07-01

    Over the past 50 years, the strength of commercial linepipe steel has increased at a steady rate of about 70 MPa per decade due to advances in steelmaking, plate processing and microstructural design. API X100 grade steel, which has a yield strength of 690 MPa, is currently available, and X120 steels are under development. The microstructure of linepipe steels has evolved from predominantly polygonal ferrite to fine bainite. For the X120 steels, lower bainite-, tempered lath martensite- and dual phase microstructures are being examined. This study obtained the microstructures of ultrafine bainite with dispersed particles of the carbon-rich martensite-austenite (M-A) phase. The objective was to obtain a matrix of mostly intragranularly-nucleated bainitic ferrite containing a high volume fraction of dispersed M-A particles. The mechanical properties of bainitic linepipe steels were also examined. Basic studies of phase transformations and mechanical properties in these steels established significant relationships between processing schedule and the evolution of microstructure, and between final microstructure and mechanical properties. The optimal combination of strength and toughness properties was obtained with a microstructure consisting of a matrix of intragranularly-nucleated bainite and small dispersed particles of martensite. This microstructure was described as being a dual phase acicular ferrite (AF) with M-A. The window of steel composition and processing parameters which give the dual phase AF-M-A microstructure was determined in an experimental study on 15 mm thick plate. The minimum strength and toughness properties for Grade 621 (X90) linepipe steel can be achieved by either a lean steel composition with extreme processing parameters, or by a higher alloy composition with a more industrially realistic processing schedule. This study also proposed how this approach can be extended to obtain high strength linepipe grades. 15 refs., 9 tabs., 10 figs.

  17. 2169 Steel Waveform Experiments

    Science.gov (United States)

    Furnish, M.; Alexander, C.; Reinhart, W.; Brown, J.

    2013-06-01

    In support of efforts to develop multiscale models of materials, we performed eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn). These experiments provided shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were used, with samples 1 to 5 mm thick. The study focused on dynamic strength determination via the release/reshock paths. Reshock tests with explosively welded impactors produced clean results. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allowed release information to be determined from these free surface samples as well. The sample strength appears to increase with stress from ~1 GPa to ~3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  18. Effects of KLF14 gene overexpression on insulin resistance in hepa1-6 hepatoma carcinoma cell%KLF14基因过表达对改善Hepa1-6小鼠肝癌细胞胰岛素抵抗的作用

    Institute of Scientific and Technical Information of China (English)

    代继桓; 李伶; 杨刚毅; 任艳; 贾彦军; 罗小河; 冉文侠; 曾梦

    2015-01-01

    Objective To investigate the role of KLF14 overexpression on insulin resistance in Hepa1-6 cell.Methods The tissue distribution of KLF14 in healthy C57/6J mice was detected by real-time quantitative PCR(RT-PCR).Expression vector for pIRES2-EGFP-KLF14 gene was constructed and transfected into Hepa1-6 cell.The mRNA level of KLF14 was determined by RT-QPCR;KLF14 and p-AKT protein levels were measured by Western blot.Results The recombinant plasmid pIRES2-EGFP-KLF14 was constructed successfully.In transfected hepa1-6 cell,KLF14 mRNA and protein were significantly higher than those of control and blank cells after 48 h(P<0.01).The KLF14 gene was ubiquitously in mice.The relative mRNA expression level of KLF14 from high to low in order was heart,muscle,liver,fat, intestine,kidney,brain,lung,stomach,speech and epididymis.After treated with serum intervention,there was no significant difference be-tween normal and patient groups without transfection;whereas the p-AKT expression in the patient group with transfection was significantly in-creased compared with that in normal group.In insulin-stimulated conditions,the p-AKT expression was inhibited after treated with PI3K in-hibitor LY294002 regardless of transfection or not.Conclusions There is an extensive expression of KLF14 in various tissues of C57BL/6J mice,indicating that KLF14 might play a role in maintaining normal physiological function;KLF14 gene overexpression could promote the ac-tivation of AKT,and its effects in increasing insulin sensitivity in diabetics is more distinct than normal people.%目的:探讨KLF14基因过表达对小鼠肝癌细胞Hepa1-6胰岛素抵抗的影响。方法实时荧光定量PCR(RT-QPCR)检测KLF14基因mRNA在健康C57BL/6J小鼠各组织的表达分布情况;构建小鼠KLF14基因重组真核表达质粒pIRES2-EGFP-KLF14并转染Hepa1-6细胞,RT-PCR法检测KLF14基因mRNA的表达;Western印迹检测KLF14及p-AKT蛋白水平的

  19. KLF14基因过表达对改善Hepa1-6小鼠肝癌细胞胰岛素抵抗的作用%Effects of KLF14 gene overexpression on insulin resistance in hepa1-6 hepatoma carcinoma cell

    Institute of Scientific and Technical Information of China (English)

    代继桓; 李伶; 杨刚毅; 任艳; 贾彦军; 罗小河; 冉文侠; 曾梦

    2015-01-01

    Objective To investigate the role of KLF14 overexpression on insulin resistance in Hepa1-6 cell.Methods The tissue distribution of KLF14 in healthy C57/6J mice was detected by real-time quantitative PCR(RT-PCR).Expression vector for pIRES2-EGFP-KLF14 gene was constructed and transfected into Hepa1-6 cell.The mRNA level of KLF14 was determined by RT-QPCR;KLF14 and p-AKT protein levels were measured by Western blot.Results The recombinant plasmid pIRES2-EGFP-KLF14 was constructed successfully.In transfected hepa1-6 cell,KLF14 mRNA and protein were significantly higher than those of control and blank cells after 48 h(P<0.01).The KLF14 gene was ubiquitously in mice.The relative mRNA expression level of KLF14 from high to low in order was heart,muscle,liver,fat, intestine,kidney,brain,lung,stomach,speech and epididymis.After treated with serum intervention,there was no significant difference be-tween normal and patient groups without transfection;whereas the p-AKT expression in the patient group with transfection was significantly in-creased compared with that in normal group.In insulin-stimulated conditions,the p-AKT expression was inhibited after treated with PI3K in-hibitor LY294002 regardless of transfection or not.Conclusions There is an extensive expression of KLF14 in various tissues of C57BL/6J mice,indicating that KLF14 might play a role in maintaining normal physiological function;KLF14 gene overexpression could promote the ac-tivation of AKT,and its effects in increasing insulin sensitivity in diabetics is more distinct than normal people.%目的:探讨KLF14基因过表达对小鼠肝癌细胞Hepa1-6胰岛素抵抗的影响。方法实时荧光定量PCR(RT-QPCR)检测KLF14基因mRNA在健康C57BL/6J小鼠各组织的表达分布情况;构建小鼠KLF14基因重组真核表达质粒pIRES2-EGFP-KLF14并转染Hepa1-6细胞,RT-PCR法检测KLF14基因mRNA的表达;Western印迹检测KLF14及p-AKT蛋白水平的

  20. Determination of Human Hepatocyte Intrinsic Clearance for Slowly Metabolized Compounds: Comparison of a Primary Hepatocyte/Stromal Cell Co-culture with Plated Primary Hepatocytes and HepaRG.

    Science.gov (United States)

    Bonn, Britta; Svanberg, Petter; Janefeldt, Annika; Hultman, Ia; Grime, Ken

    2016-04-01

    A key requirement in drug discovery is to accurately define intrinsic clearance (CLint) values of less than 1 µl/min/10(6) hepatocytes, which requires assays that allow for longer incubation time as a complement to suspended hepatocytes. This study assessed the effectiveness of plated HepaRG cells, plated primary human hepatocytes (PHHs), and the HµREL human hepatocyte/stromal cell co-cultures for determination of low CLint values. The investigation demonstrated that the systems were capable of providing statistically significant CLint estimations down to 0.2 µl/min/10(6) cells. The HµREL assay provided a higher level of reproducibility, with repeat significant CLint values being defined in a minimum of triplicate consecutive assays for six of seven of the low CLint compounds compared with four of seven for PHHs and two of seven for HepaRG. The assays were also compared with a suspension assay using drugs with higher CLint values and diverse enzymology. The CLint values from the PHH and HµREL assays were similar to those defined by a hepatocyte suspension assay, indicating that they can be used interchangeably alongside a standard assay. Finally, data from these two assays could also predict in vivo hepatic metabolic CLint to within 3-fold for greater than 70% of the compounds tested, with average fold errors (AFE) of 1.6 and 2.3, respectively, whereas the HepaRG data were predictive to within 3-fold for only 50% of compounds (AFE 2.9). In summary, all systems have utility for low CLint determination, but the HµREL co-culture appears slightly superior regarding overall assay performance. PMID:26851239

  1. Methoxychlor suppresses the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible CYP1A1 expression in murine Hepa-1c1c7 cells.

    Science.gov (United States)

    Han, Eun Hee; Jeong, Tae Cheon; Jeong, Hye Gwang

    2007-08-01

    Methoxychlor (MXC) is a pesticide that was developed as a replacement for dichlorodiphenyltrichloroethane (DDT). The influence of MXC on CYP1A1 expression or the functions of mouse hepatoma Hepa-1clc7 remain unclear. Cultured Hepa-1c1c7 cells were treated with MXC with or without 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to assess the role of MXC on CYP1A1 expression. MXC alone did not affect CYP1A1-specific 7-ethoxyresorufin O-deethylase (EROD) activity. In contrast, TCDD-inducible EROD activities were markedly reduced upon concomitant treatment with TCDD and MXC in a concentration-dependent manner. Treatment with ICI 182.780, an estrogen-receptor antagonist, did not affect the suppressive effects of MXC on TCDD-inducible EROD activity. TCDD-inducible CYP1A1 mRNA levels were markedly suppressed upon treatment with TCDD and MXC, and this is consistent with their effects on EROD activity. A transient transfection assay using dioxin-response element (DRE)-linked luciferase and an electrophoretic mobility shift assay revealed that MXC reduced the transformation of the aryl hydrocarbons (Ah) receptor to a form capable of specifically binding to the DRE sequence in the promoter region of the CYP1A1 gene. These results suggest that the downregulation of CYP1A1 gene expression by MXC in Hepa-1c1c7 cells might be an antagonism of the DRE binding potential of the nuclear Ah receptor but is not mediated through the estradiol receptor. PMID:17654248

  2. Suppression of cytochrome P450 1A1 expression induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in mouse hepatoma hepa-1c1c7 cells treated with serum of (-)-epigallocatechin-3-gallate- and green tea extract-administered rats.

    Science.gov (United States)

    Fukuda, Itsuko; Tsutsui, Miki; Sakane, Iwao; Ashida, Hitoshi

    2009-05-01

    The suppression of cytochrome P450 1A1 (CYP1A1) expression was examined in mouse hepatoma Hepa-1c1c7 cells treated with serum prepared from (-)-epigallocatechin-3-gallate- and green tea extract-administered rats. Catechins were found in the rat plasma after the administration. In Hepa-1c1c7 cells, 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced CYP1A1 expression was suppressed by treatment with the rat serum. It is concluded that catechins can possibly modulate CYP1A1 expression. PMID:19420696

  3. 49 CFR 192.55 - Steel pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  4. New structural high strength rationally alloyed steels

    International Nuclear Information System (INIS)

    New developments in high strength structural steels are reported. Properties and perspective fields of application are described for the following materials: austenitic chromium steels with ultra equilibrium nitrogen content, steels with nitrogen martensite structure, microalloyed ferritic-pearlitic steels with decreased concentrations of Mn and Ni, high ductility heat resisting steels, nonmagnetic chromium free Mn-Ni-Cu-V-C steels and iron powder alloys with superhard carbon phases. Steel 02Kh12G14N4YuM is recommended to be used for parts and assemblies of nuclear power plants

  5. Camel Milk Modulates the Expression of Aryl Hydrocarbon Receptor-Regulated Genes, Cyp1a1, Nqo1, and Gsta1, in Murine hepatoma Hepa 1c1c7 Cells

    OpenAIRE

    Korashy, Hesham M.; El Gendy, Mohamed A. M.; Alhaider, Abdulqader A.; El-Kadi, Ayman O.

    2012-01-01

    There is a traditional belief in the Middle East that camel milk may aid in prevention and treatment of numerous cases of cancer yet, the exact mechanism was not investigated. Therefore, we examined the ability of camel milk to modulate the expression of a well-known cancer-activating gene, Cytochrome P450 1a1 (Cyp1a1), and cancer-protective genes, NAD(P)H:quinone oxidoreductase 1 (Nqo1) and glutathione S-transferase a1 (Gsta1), in murine hepatoma Hepa 1c1c7 cell line. Our results showed that...

  6. High-strength, low-alloy steels.

    Science.gov (United States)

    Rashid, M S

    1980-05-23

    High-strength, low-alloy (HSLA) steels have nearly the same composition as plain carbon steels. However, they are up to twice as strong and their greater load-bearing capacity allows engineering use in lighter sections. Their high strength is derived from a combination of grain refinement; precipitation strengthening due to minor additions of vanadium, niobium, or titanium; and modifications of manufacturing processes, such as controlled rolling and controlled cooling of otherwise essentially plain carbon steel. HSLA steels are less formable than lower strength steels, but dualphase steels, which evolved from HSLA steels, have ferrite-martensite microstructures and better formability than HSLA steels of similar strength. This improved formability has substantially increased the utilization potential of high-strength steels in the manufacture of complex components. This article reviews the development of HSLA and dual-phase steels and discusses the effects of variations in microstructure and chemistry on their mechanical properties. PMID:17772810

  7. Modelling fracture in ferritic steel

    CERN Document Server

    Smith, G

    2002-01-01

    Results from mathematical models and computer simulations of fracture in polycrystalline steels are presented for a range of temperatures. The proportions of intergranular and intragranular failure predicted are compared with experimental results for brittle fracture, ductile fracture and in the transition region. Interactive software to create two-dimensional polycrystalline models, which allow a range of physical to be varied independently, is described. The results include those for model materials chosen to match steels used by the power generation industry. The models simulate segregation and cavitation effects in steel and fracture of weldments and their associated heat-affected zones.

  8. Stainless steel denitriding with slag

    International Nuclear Information System (INIS)

    Calculation and experimental methods were used to investigate the process of titanium nitride formation when alloying chromium nickel stainless steels with titanium. At common concentrations of titanium and nitrogen, titanium nitrides were observed to be precipitated from the melt into slag in amounts of 0.1% and more. The laboratory study of the slag influence of the process of steel refining from titanium nitrides showed that the slag containing calcium, aluminium and magnesium oxides is favourable to the denitriding of steel. In addition, the possibility of direct transition of dissolved nitrogen from the metal into the slag is revealed. 7 refs., 1 fig., 2 tabs

  9. Stainless steel display evaluation

    Science.gov (United States)

    Hopper, Darrel G.; Meyer, Frederick M.; Longo, Sam J.; Trissell, Terry L.

    2007-04-01

    Active matrix organic light emitting diode (AMOLED) technology is one candidate to become a low power alternative in some applications to the currently dominant, active matrix liquid crystal display (AMLCD), technology. Furthermore, fabrication of the AMOLED on stainless steel (SS) foil rather than the traditional glass substrate, while presenting a set of severe technical challenges, opens up the potential for displays that are both lighter and less breakable. Also, transition to an SS foil substrate may enable rollable displays - large when used but small for stowage within gear already worn or carried or installed. Research has been initiated on AMOLED/SS technology and the first 320 x 240 color pixel 4-in. demonstration device has been evaluated in the AFRL Display Test and Evaluation Laboratory. Results of this evaluation are reported along with a research roadmap.

  10. JPDR vessel steel examination

    International Nuclear Information System (INIS)

    There is a need to validate the results of irradiation effects research by the examination of material taken directly from the wall of a pressure vessel which has been irradiated during normal service. This task has been included with the HSSI Program to provide just such an evaluation of material from the wall of the pressure vessel from the JPDR. The JPDR was a small BWR that began operation in 1963. It operated until 1976, accumulating ∼17,000 h of operation, of which a little over 14,000 h were with the original 45-MWTh core, and the remaining fraction, late in life, with an upgraded 90-MWTh core. The pressure vessel of the JPDR, fabricated from A 302, grade B, modified steel with an internal weld overlay cladding of 304 stainless steel, is approximately 2 m ID and 73 mm thick. It was fabricated from two shell halves joined by longitudinal seam welds located 180 degrees from each other. The rolling direction of the shell plates is parallel to the axis of the vessel. It operated at 273 degrees C and reached a maximum fluence of about 2.3 x 1018 n/cm2 (> 1 MeV). The impurity contents in the base metal are 0.10 to 0.11% Cu and 0.010 to 0.017% P with a nickel content of 0.63 to 0.65%. Impurity contents of the weld metal are 0.11 to 0.14% Cu and 0.025 to 0.039% P with a nickel content of 0.59%

  11. 2169 steel waveform experiments.

    Energy Technology Data Exchange (ETDEWEB)

    Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd; Brown, Justin L.

    2012-11-01

    In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included the elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe - phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mm-thick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allows release information to be determined from these free surface samples. The sample strength appears to increase with stress from ~1 GPa to ~ 3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model.

  12. 1-Nitropyrene (1-NP) induces apoptosis and apparently a non-apoptotic programmed cell death (paraptosis) in Hepa1c1c7 cells

    International Nuclear Information System (INIS)

    Mechanistic studies of nitro-PAHs (polycyclic aromatic hydrocarbons) of interest might help elucidate which chemical characteristics are most important in eliciting toxic effects. 1-Nitropyrene (1-NP) is the predominant nitrated PAH emitted in diesel exhaust. 1-NP-exposed Hepa1c1c7 cells exhibited marked changes in cellular morphology, decreased proliferation and different forms of cell death. A dramatic increase in cytoplasmic vacuolization was observed already after 6 h of exposure and the cells started to round up at 12 h. The rate of cell proliferation was markedly reduced at 24 h and apoptotic as well as propidium iodide (PI)-positive cells appeared. Electron microscopic examination revealed that the vacuolization was partly due to mitochondria swelling. The caspase inhibitor Z-VAD-FMK inhibited only the apoptotic cell death and Nec-1 (an inhibitor of necroptosis) exhibited no inhibitory effects on either cell death or vacuolization. In contrast, cycloheximide markedly reduced both the number of apoptotic and PI-positive cells as well as the cytoplasmic vacuolization, suggesting that 1-NP induced paraptotic cell death. All the MAPKs; ERK1/2, p38 and JNK, appear to be involved in the death process since marked activation was observed upon 1-NP exposure, and their inhibitors partly reduced the induced cell death. The ERK1/2 inhibitor PD 98057 completely blocked the induced vacuolization, whereas the other MAPKs inhibitors only had minor effects on this process. These findings suggest that 1-NP may cause apoptosis and paraptosis. In contrast, the corresponding amine (1-aminopyrene) elicited only minor apoptotic and necrotic cell death, and cells with characteristics typical of paraptosis were absent

  13. Down-regulation of the detoxifying enzyme NAD(P)H:quinone oxidoreductase 1 by vanadium in Hepa 1c1c7 cells.

    Science.gov (United States)

    Anwar-Mohamed, Anwar; El-Kadi, Ayman O S

    2009-05-01

    Recent data suggest that vanadium (V5+) compounds exert protective effects against chemical-induced carcinogenesis, mainly through modifying various xenobiotic metabolizing enzymes. In fact, we have shown that V5+ down-regulates the expression of Cyp1a1 at the transcriptional level through an ATP-dependent mechanism. However, incongruously, there is increasing evidence that V5+ is found in higher amounts in cancer cells and tissues than in normal cells or tissues. Therefore, the current study aims to address the possible effect of this metal on the regulation of expression of an enzyme that helps maintain endogenous antioxidants used to protect tissues/cells from mutagens, carcinogens, and oxidative stress damage, NAD(P) H:quinone oxidoreductase 1 (Nqo1). In an attempt to examine these effects, Hepa 1c1c7 cells and its AhRdeficient version, c12, were treated with increasing concentrations of V5+ in the presence of two distinct Nqo1 inducers, the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and isothiocyanate sulforaphane (SUL). Our results showed that V5+ inhibits the TCDD- and SUL-mediated induction of Nqo1 at mRNA, protein, and catalytic activity levels. At transcriptional level, V5+ was able to decrease the TCDD- and SUL-induced nuclear accumulation of Nrf2 and the subsequent binding to antioxidant responsive element (ARE) without affecting Nrf2 protein levels. Looking at post-transcriptional level; we found that V5+ did not affect Nqo1 mRNA transcripts turn-over rates. However, at the post-translational level V5+ increased Nqo1 protein half-life. In conclusion, the present study demonstrates that V5+ down-regulates Nqo1 at the transcriptional level, possibly through inhibiting the ATP-dependent activation of Nrf2. PMID:19367690

  14. Induction of cytochrome P450 1A1 gene expression by a vitamin K3 analog in mouse hepatoma Hepa-1c1c7 cells.

    Science.gov (United States)

    Chun, Y J; Lee, B Y; Yang, S A; Ryu, C K; Kim, M Y

    2001-10-31

    Nine vitamin K3 analogs were compared with respect to the induction of the cytochrome P450 1A1 (CYP1A1) expression in mouse hepatoma Hepa-1c1c7 cells. 6-(4-Diethylamino)phenyl-7-chloro-5,8-quinolinedione (EA4) caused a significant induction of the CYP1A1-mediated ethoxyresorufin O-deethylase activity in a time- and concentration-dependent manner. The induction was accompanied by an increase of the Cyp1a1 mRNA transcription. The transient expression of the mouse Cyp1a1-CAT gene into cells showed that EA4 induced CAT activity. However, the aryl hydrocarbon receptor and its nuclear partner, aryl hydrocarbon receptor nuclear translocator mRNA transcription, were unaffected by the EA4 treatment. When the cells were incubated with EA4 in the presence of 1 nM TCDD, the ethoxyresorufin O-deethylase activity that was induced by TCDD was significantly suppressed by EA4. Inhibition of protein synthesis by cycloheximide strongly enhanced the EA4-dependent Cyp1a1 mRNA expression. Up-regulation of protein kinase C by a 2 h preincubation with phorbol 12-myristate 13-acetate increased the EA4-dependent expression of the Cyp1a1 gene. In human cells, such as HepG2 (human hepatocarcinoma), MCF-7 (human breast adenocarcinoma cell line), and HL-60 (human promyelocytic cell line), the expression of CYP1A1 mRNA was also induced by EA4 treatment. Moreover, CYP1B1 mRNA was increased by EA4 in MCF-7 cells. These results indicate that EA4 modulates CYP1A1 and CYP1B1 expressions by transcriptional activation. Also, protein kinase C may be involved in the induction mechanism of CYP1A1 by EA4. PMID:11710520

  15. Down-regulation of aryl hydrocarbon receptor-regulated genes by tumor necrosis factor-alpha and lipopolysaccharide in murine hepatoma Hepa 1c1c7 cells.

    Science.gov (United States)

    Gharavi, Negar; El-Kadi, Ayman O S

    2005-03-01

    Although much is known concerning the effects of inflammation and oxidative stress on the cytochrome P450 1A1 (CYP1A1), little is known about the modulation of other aryl hydrocarbon receptor (AHR)-regulated genes such as glutathione-S-transferase Ya (GST Ya) and NAD(P)H:quinone oxidoreductase (QOR) by inflammation. In the present study, the effect of tumor necrosis factor (TNF)-alpha and lipopolysaccharides (LPS) on the constitutive and inducible expression of the AHR-regulated genes cyp1a1, GST Ya, and QOR was determined in murine hepatoma Hepa 1c1c7 (WT), AHR-deficient (C12), and AHR nuclear translocator protein (ARNT)-deficient (C4) cells. We found that both TNF-alpha and LPS strongly repressed the constitutive expression and the beta-naphthoflavone-mediated induction of cyp1a1, GST Ya, and QOR in WT but not in C12 and C4 cells. The induction of GST Ya and QOR activities and mRNA levels by phenolic antioxidant, tert-butylhydroquinone, through the antioxidant response element was not significantly affected by TNF-alpha or LPS. In addition, a significant increase in reactive oxygen species was observed in WT, C12, and C4 cells treated with TNF-alpha or LPS which was completely prevented by tert-butylhydroquinone. These results show that the down-regulation of AHR-regulated genes by TNF-alpha and LPS is dependent on the presence of both heterodimeric transcription factors, AHR and ARNT. Furthermore, reactive oxygen species may be involved in the down-regulation of AHR-regulated genes. PMID:15627257

  16. Interactions of endosulfan and methoxychlor involving CYP3A4 and CYP2B6 in human HepaRG cells.

    Science.gov (United States)

    Savary, Camille C; Jossé, Rozenn; Bruyère, Arnaud; Guillet, Fabrice; Robin, Marie-Anne; Guillouzo, André

    2014-08-01

    Humans are usually exposed to several pesticides simultaneously; consequently, combined actions between pesticides themselves or between pesticides and other chemicals need to be addressed in the risk assessment. Many pesticides are efficient activators of pregnane X receptor (PXR) and/or constitutive androstane receptor (CAR), two major nuclear receptors that are also activated by other substrates. In the present work, we searched for interactions between endosulfan and methoxychlor, two organochlorine pesticides whose major routes of metabolism involve CAR- and PXR-regulated CYP3A4 and CYP2B6, and whose mechanisms of action in humans remain poorly understood. For this purpose, HepaRG cells were treated with both pesticides separately or in mixture for 24 hours or 2 weeks at concentrations relevant to human exposure levels. In combination they exerted synergistic cytotoxic effects. Whatever the duration of treatment, both compounds increased CYP3A4 and CYP2B6 mRNA levels while differently affecting their corresponding activities. Endosulfan exerted a direct reversible inhibition of CYP3A4 activity that was confirmed in human liver microsomes. By contrast, methoxychlor induced this activity. The effects of the mixture on CYP3A4 activity were equal to the sum of those of each individual compound, suggesting an additive effect of each pesticide. Despite CYP2B6 activity being unchanged and increased with endosulfan and methoxychlor, respectively, no change was observed with their mixture, supporting an antagonistic effect. Altogether, our data suggest that CAR and PXR activators endosulfan and methoxychlor can interact together and with other exogenous substrates in human hepatocytes. Their effects on CYP3A4 and CYP2B6 activities could have important consequences if extrapolated to the in vivo situation. PMID:24832206

  17. Some peculiarities of corrosion of wheel steel

    OpenAIRE

    Alexander SHRAMKO; Alfred KOZLOWSKY; Elena BELAJA; Yuriy PROIDAK; Pinchuk, Sofia; Gubenko, Svetlana

    2009-01-01

    Corrosion mechanism and rate of different chemical composition and structural condition of wheel steel were investigated. It was shown that “white layers”, variation in grain size and banding of wheel steel structure results in corrosion rate. Microstructure of steel from different elements of railway wheels after operation with corrosion was investigated. Wheel steel with addition of vanadium corroded more quickly than steel without vanadium. Non-metallic inclusions are the centre of corrosi...

  18. Effects of changes in steel industry concentration

    OpenAIRE

    Bobenič, T.; A. Bobenič Hintošová; Hliboká, L.; I. Vasková

    2015-01-01

    The paper on a basis of completed mergers and acquisitions within global steel industry presents changes in steel industry concentration and analyzes its effects on world trade with steel products and on prices of input materials as well as of output products. The analyses performed for the 1990 - 2012 period revealed that increased concentration in global steel industry did not lead to more intensive world trade with steel products; however it is connected with increase of finished products ...

  19. Review on Cold-Formed Steel Connections

    OpenAIRE

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connection...

  20. CHANGES IN DISTRIBUTION OF STEEL PRODUCTS

    OpenAIRE

    Beata Œlusarczyk

    2009-01-01

    Steel industry is one of the most globalized branch, globalization has had the influence on iron ore supply, steel production and distribution as well. In last years, steel products distribution process has changed significantly, because of rising competitiveness due to common world market influence and main global players actions. The paper presents changes in steel products distribution in Poland focusing on main steel producers activity in distribution as well as distributors response on n...

  1. Corrosion of Steels in Steel Reinforced Concrete in Cassava Juice

    Science.gov (United States)

    Oluwadare, G. O.; Agbaje, O.

    The corrosion of two types of construction steels, ST60Mn and RST37-2♦, in a low cyanide concentration environment (cassava juice) and embedded in concrete had been studied. The ST60 Mn was found to be more corrosion resistant in both ordinary water and the cassava juice environment. The cyanide in cassava juice does not attack the steel but it provides an environment of lower pH around the steel in the concrete which leads to breakdown of the passivating film provided by hydroxyl ions from cement. Other factors such as the curing time of the concrete also affect the corrosion rates of the steel in the concrete. The corrosion rate of the steel directly exposed to cassava juice i.e., steel not embedded in concrete is about twice that in concrete. Long exposure of concrete structure to cassava processing effluent might result in deterioration of such structures. Careful attention should therefore be paid to disposal of cassava processing effluents, especially in a country like Nigeria where such processing is now on the increase.

  2. High manganese non magnetic steel

    International Nuclear Information System (INIS)

    A high-manganese, non-magnetic steel is specified, having excellent weldability and machinability and suitable for use in the structural parts of electrical equipment or nuclear fusion equipment. (author)

  3. Overlay welding irradiated stainless steel

    International Nuclear Information System (INIS)

    An overlay technique developed for welding irradiated stainless steel may be important for repair or modification of fusion reactor materials. Helium, present due to n,α reactions, is known to cause cracking using conventional welding methods. Stainless steel impregnated with 3 to 220 appm helium by decay of tritium was used to develop a welding process that could be used for repair. The result was a gas metal arc weld overlay technique with low-heat input and low-penetration into the helium-containing material. Extensive metallurgical and mechanical testing of this technique demonstrated substantial reduction of helium embrittlement damage. The overlay technique was applied to irradiated 304 stainless steel containing 10 appm helium. Surface cracking, present in conventional welds made on the same steel at lower helium concentrations, was eliminated. Underbead cracking, although greater than for tritium charged and aged material, was minimal compared to conventional welding methods

  4. Mechanical Behaviour and Microstructural Characterization of Carbon Steel Samples from Three Selected Steel Rolling Plants

    OpenAIRE

    P. O. Atanda; Abioye, A. A.; A. O. Iyiola

    2015-01-01

    The research investigated the mechanical behavior of samples of steel rods obtained from three selected Steel Rolling Companies in South Western part of Nigeria. This was done by carrying out some mechanical tests such as tensile, impact and hardness as well as microstructural examination.Four sets of 16 mm steel rod samples were collected from Tiger steel industries, Phoenix steel and Oxil steel Industies, all located in South West Nigeria, The chemical composition was carried out using a...

  5. MICROALLOYED STEELS FOR THE AUTOMOTIVE INDUSTRY

    Directory of Open Access Journals (Sweden)

    Debanshu Bhattacharya

    2014-12-01

    Full Text Available Two major drivers for the use of newer steels in the automotive industry are fuel efficiency and increased safety performance. Fuel efficiency is mainly a function of weight of steel parts, which in turn, is controlled by gauge and design. Safety is determined by the energy absorbing capacity of the steel used to make the part. All of these factors are incentives for the U.S. automakers to use both Highly Formable and Advanced High Strength Steels (AHSS to replace the conventional steels used to manufacture automotive parts in the past. AHSS is a general term used to describe various families of steels. The most common AHSS is the dual-phase steel that consists of a ferrite-martensite microstructure. These steels are characterized by high strength, good ductility, low tensile to yield strength ratio and high bake hardenability. Another class of AHSS is the complex-phase or multi-phase steel which has a complex microstructure consisting of various phase constituents and a high yield to tensile strength ratio. Transformation Induced Plasticity (TRIP steels is another class of AHSS steels finding interest among the U.S. automakers. These steels consist of a ferrite-bainite microstructure with significant amount of retained austenite phase and show the highest combination of strength and elongation, so far, among the AHSS in use. High level of energy absorbing capacity combined with a sustained level of high n value up to the limit of uniform elongation as well as high bake hardenability make these steels particularly attractive for safety critical parts and parts needing complex forming. A relatively new class of AHSS is the Quenching and Partitioning (Q&P steels. These steels seem to offer higher ductility than the dual-phase steels of similar strengths or similar ductility as the TRIP steels at higher strengths. Finally, martensitic steels with very high strengths are also in use for certain parts. The most recent initiative in the area of AHSS

  6. MMFX Microcomposite Steel (MMFX2)

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    One of the major problems facing the construction industry today is the effect of corrosion on steel, and the inherent structural weaknesses it causes in highways, bridges and buildings. MMFX 2 rebar was developed through the use of nanotechnology by Dr. Gareth Thomas, graduate school professor of materials science at Univ. of California, Berkeley. It is highly corrosion resistant and equal, or in many cases, far superior to existing conventional carbon steel in its properties of strength, en...

  7. Hydrogen embrittlement of ferritic steels

    International Nuclear Information System (INIS)

    Hydrogen embrittlement (HE) of ferritic and duplex stainless steels (SS) has been studied by charging annealed or quenched specimens with hydrogen through cathodic polarization. Cathodic charge has been found to reduce severely the ductility of these materials. Using microscopic observations (TEM and SEM and optical) attempts have been made to clarify the initial stage of microstructural changes which are induced by hydrogen charging in these steels. (author)

  8. Atmospheric corrosion of mild steel

    OpenAIRE

    Morcillo, M.; de la Fuente, D.; I. Díaz; Cano, H.

    2011-01-01

    The atmospheric corrosion of mild steel is an extensive topic that has been studied by many authors in different regions throughout the world. This compilation paper incorporates relevant publications on the subject, in particular about the nature of atmospheric corrosion products, mechanisms of atmospheric corrosion and kinetics of the atmospheric corrosion process, paying special attention to two matters upon which relatively less information has been published: a) the morphology of steel c...

  9. Fatigue Strength of Weathering Steel

    OpenAIRE

    Kunz, Ludvík; Lukáš, Petr; Klusák, Jan

    2012-01-01

    Fatigue behaviour of Atmofix 52 steel (comparable to COR-TENâ steel) exposed to atmospheric corrosion for 20 years was investigated. S-N curves for load symmetrical cycling and cycling with stress ratio R = 0 were determined on specimens detracted from a failed transmission tower. The data were compared with those on material without a rust layer. The fracture surfaces and, in particular, the sites of fatigue crack initiation were analyzed. Substantial decrease of fatigue life and fatigue lim...

  10. Fatigue properties of weathering steel

    OpenAIRE

    Zavadilová, Petra

    2012-01-01

    This work deals with the influence of atmospheric corrosion on high-cycle fatigue properties of a weathering steel ATMOFIX B. New experimental data on fatigue strength of a steel exposed for 20 years to an atmospheric corrosion were compared to those characterizing the base material. Reduction of the fatigue lifetime of the exposed material compared with the base material was predicted on the basic of fractographic examination of fracture surfaces and the influence of surface notches on fatig...

  11. Streamlining Iron and Steel Production

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Eliminating unproductive iron and steel facilities is vital to environmental protection and sustainable development of this industry The Chinese Government is once again shutting down unproductive plants in tune with its green policy and the march toward sustainable development.This time it’s the iron and steel industry to feel the brunt of the Chinese Government’s stringent measures. The deafening buzz of factory floors have

  12. Chinese steel: limits to growth

    Energy Technology Data Exchange (ETDEWEB)

    Hites, B. [World Steel Dynamics, Englewood Cliffs, NJ (US)

    2004-07-01

    Twenty one slides/overheads outline the opinion of World Steel Dynamics (WSD) on the future of China's steel industry. Until recently WSD likened this to a Greyhound bus, experiencing massive expansion and gaining momentum. Now constraints have emerged and a new analogy is being used, of a freight train - with slower growth, from 2005-2010 of 5-7% per annum. Ten reasons are identified for this slower growth.

  13. Fatique behaviour of electrical steel

    Directory of Open Access Journals (Sweden)

    Bode B.

    2014-06-01

    Full Text Available Electrical steel comes into focus with the development of electrically powered cars. In contrast to electrical motors used stationarily (e.g. conveyer belt drives in industrial applications, electrical steel in a car engine is subjected to cyclic loading due to vibrations caused by the imbalance of the rotor and start and stop driving events. For a safe and reliable design of an electrical motor the fatigue behaviour of electrical steel needs to be analysed. To minimize eddy current losses, a rotor consists of several hundred electrical steel sheets with a typical thickness of less than 1 mm. Due to optimal electrical and magnetic properties a very coarse microstructure of electrical steel is required. Only one to three grains are distributed along sheet thickness. Regarding the grain size and sheet thickness the material behaviour is governed by the reaction of single grains and grain-grain-interaction to external cyclic loading. Fatigue experiments with a load ratio of R = 0.005 and R = 0.1 were carried out. They give a very flat S-N-curve where the fatigue limit is close to the yield strength of this electrical steel. Crack initiation is observed at surface roughness and areas of stress concentration resulting from manufacturing processes.

  14. Properties of hot rolled steels for enamelling

    International Nuclear Information System (INIS)

    The results of an investigation of the structure and properties of experimental produced hot rolled steels suitable for enamelling are presented in the paper. Hot rolled steels for enamelling represent a special group of the steels for conventional enamelling. Their quality has to be adapted to the method and conditions of enamelling. Therefore, these steels should meet some specific requirements. In addition to usual investigation of the chemical composition and mechanical properties, microstructure and quality of the steel surface also were investigated. The basic aim was to examine steels capability for enamelling, i. e. steels resistance to the fish scales phenomena, by trial enamelling, as well as quality of the steel - enamel contact surface, to evaluate the binding. Also, the changes of the mechanical properties, especially the yield point, during thermal treatment, as a very specific requirement, were investigated, by simplified method. Good results were obtained confirming the steels capability for enamelling. (Original)

  15. Carbon Segregation of Bearing Steel Concasting Billet

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The formation mechanism of “white band” and central carbon segregation of high-carbon Cr bearing steel concasting billets are discussed in this paper. The maximum oxygen content in the steel produced by concasting process was 13x10-6 with an average oxygen content of 9.3x 10-6.Comparison of metallurgical quality and fatigue property between the concasting steel (CC) andingot casting steel (IC) showed that the carbon segregation (C/C0) in former steel was 0.92~1.10and its fatigue life was equal to that of the latter steel.

  16. Review on Cold-Formed Steel Connections

    Science.gov (United States)

    Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  17. Microbial corrosion of stainless steel.

    Science.gov (United States)

    Ibars, J R; Moreno, D A; Ranninger, C

    1992-11-01

    Stainless steel, developed because of their greater resistance to corrosion in different aggressive environments, have proved to be affected, however, by various processes and types of corrosion. Some of these types of corrosion, mainly pitting, is activated and developed in the presence of microorganisms, which acting in an isolated or symbiotic way, according to their adaptation to the environment, create a favorable situation for the corrosion of these steel. The microorganisms that are involved, mainly bacteria of both the aerobic and anaerobic type, modify the environment where the stainless steel is found, creating crevices, differential aeration zones or a more aggressive environment with the presence of metabolites. In these circumstances, a local break of the passive and passivating layer is produced, which is proper to these types of steel and impedes the repassivation that is more favorable to corrosion. In the study and research of these types of microbiologically influenced corrosion are found electrochemical techniques, since corrosion is fundamentally an electrochemical process, and microbiological techniques for the identification, culture, and evaluation of the microorganisms involved in the process, as well as in the laboratory or field study of microorganism-metal pairs. Microstructural characterization studies of stainless steel have also been considered important, since it is known that the microstructure of steel can substantially modify their behavior when faced with corrosion. As for surface analysis studies, it is known that corrosion is a process that is generated on and progresses from the surface. The ways of dealing with microbiologically influenced corrosion must necessarily include biocides, which are not always usable or successful, the design of industrial equipment or components that do not favor the adherence of microorganisms, using microstructures in steel less sensitive to corrosion, or protecting the materials. PMID:1492953

  18. Kinetics of borided gear steels

    Indian Academy of Sciences (India)

    Ibrahim Gunes

    2013-06-01

    In this study, the case properties and diffusion kinetics of GS18NiMoCr36 (GS18), GS22NiMoCr56 (GS22) and GS32NiCrMo6.4 (GS32) gear steels borided in Ekabor-II powder were investigated by conducting a series of experiments at temperatures of 1123, 1173 and 1223 K for 2, 4 and 6 h. The boride layer was characterized by optical microscopy, X-ray diffraction technique and microVickers hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FeB, Fe2B, CrB and Cr2B compounds. The thickness of the boride layer increases by increasing boriding time and temperature for all steels. The hardness of the boride compounds formed on the surface of the steels GS18, GS22 and GS32 ranged from 1624 to 1905 HV0,05, 1702 to 1948 HV0,05, and 1745 to 2034 HV0,05 respectively, whereas Vickers hardness values of the untreated steels GS18, GS22 and GS32 were 335 HV0,05, 358 HV0,05 and 411 HV0,05, respectively. The activation energies (Q) of borided steels were 228.644 kJ/mol for GS18, 280.609 kJ/mol for GS22 and 294.359 kJ/mol for GS32. The growth kinetics of the boride layers forming on the GS18, GS22 and GS32 steels and the thickness of boride layers were also investigated.

  19. Irradiation embrittlement of ferritic stainless steels

    International Nuclear Information System (INIS)

    The characteristics of the irradiation embrittlement of some ferritic stainless steels were examined by tensile tests. Steels selected in this investigation were classified into three groups: chi phase, precipitation hardened Fe-13Cr steels; tempered martensitic Fe-12Cr steels; and low alloy steels. The latter steels were chosen in order to compare the irradiation embrittlement characteristics with those of stainless steels. The stainless steels were superior to the low alloy steels with regard to the irradiation embrittlement (the changes in both ductile-brittle transition temperature (DBTT) and unstable plastic flow transition temperature (UPFTT)), irrespective of whether these stainless steels had chi phase precipitated structures or tempered martensitic structures. The suppression of the DBTT increase owing to irradiation results from low yield stress increase Δσsub(y) and high |[dσsub(y)(u)/dT]|, where u denotes unirradiated, in the stainless steels. The suppression of the UPFTT results from the high work hardening rate or the high work exponent and the low Lueders strain in the stainless steels. These characteristics of irradiation embrittlement in the ferritic stainless steels are thought to be caused by the defect structure, which is modified by Cr atoms. (author)

  20. Anodized Steel Electrodes for Supercapacitors.

    Science.gov (United States)

    Sagu, Jagdeep S; Wijayantha, K G Upul; Bohm, Mallika; Bohm, Siva; Kumar Rout, Tapan

    2016-03-01

    Steel was anodized in 10 M NaOH to enhance its surface texture and internal surface area for application as an electrode in supercapacitors. A mechanism was proposed for the anodization process. Field-emission gun scanning electron microscopy (FEGSEM) studies of anodized steel revealed that it contains a highly porous sponge like structure ideal for supercapacitor electrodes. X-ray photoelectron spectroscopy (XPS) measurements showed that the surface of the anodized steel was Fe2O3, whereas X-ray diffraction (XRD) measurements indicated that the bulk remained as metallic Fe. The supercapacitor performance of the anodized steel was tested in 1 M NaOH and a capacitance of 18 mF cm(-2) was obtained. Cyclic voltammetry measurements showed that there was a large psueudocapacitive contribution which was due to oxidation of Fe to Fe(OH)2 and then further oxidation to FeOOH, and the respective reduction of these species back to metallic Fe. These redox processes were found to be remarkably reversible as the electrode showed no loss in capacitance after 10000 cycles. The results demonstrate that anodization of steel is a suitable method to produce high-surface-area electrodes for supercapacitors with excellent cycling lifetime. PMID:26891093