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Sample records for concrete decontamination results

  1. Phase 2 microwave concrete decontamination results

    International Nuclear Information System (INIS)

    White, T.L.; Foster, D. Jr.; Wilson, C.T.; Schaich, C.R.

    1995-01-01

    The authors report on the results of the second phase of a four-phase program at Oak Ridge National Laboratory to develop a system to decontaminate concrete using microwave energy. The microwave energy is directed at the concrete surface through the use of an optimized wave guide antenna, or applicator, and this energy rapidly heats the free water present in the interstitial spaces of the concrete matrix. The resulting steam pressure causes the surface to burst in much the same way popcorn pops in a home microwave oven. Each steam explosion removes several square centimeters of concrete surface that are collected by a highly integrated wave guide and vacuum system. The authors call this process the microwave concrete decontamination, or MCD, process. In the first phase of the program the principle of microwaves concrete removal concrete surfaces was demonstrated. In these experiments, concrete slabs were placed on a translator and moved beneath a stationary microwave system. The second phase demonstrated the ability to mobilize the technology to remove the surfaces from concrete floors. Area and volume concrete removal rates of 10.4 cm 2 /s and 4.9 cm 3 /S, respectively, at 18 GHz were demonstrated. These rates are more than double those obtained in Phase 1 of the program. Deeper contamination can be removed by using a longer residence time under the applicator to create multiple explosions in the same area or by taking multiple passes over previously removed areas. Both techniques have been successfully demonstrated. Small test sections of painted and oil-soaked concrete have also been removed in a single pass. Concrete with embedded metal anchors on the surface has also been removed, although with some increased variability of removal depth. Microwave leakage should not pose any operational hazard to personnel, since the observed leakage was much less than the regulatory standard

  2. Concrete decontamination scoping tests

    International Nuclear Information System (INIS)

    Archibald, K.E.

    1995-01-01

    This report details the research efforts and scoping tests performed at the Idaho Chemical Process Plant using scabbling, chemical, and electro-osmotic decontamination techniques on radiologically contaminated concrete

  3. Electrokinetic decontamination of concrete

    Energy Technology Data Exchange (ETDEWEB)

    Lomasney, H. [ISOTRON Corp., New Orleans, LA (United States)

    1995-10-01

    The U.S. Department of Energy has assigned a priority to the advancement of technology for decontaminating concrete surfaces which have become contaminated with radionuclides, heavy metals, and toxic organics. This agency is responsible for decontamination and decommissioning of thousands of buildings. Electrokinetic extraction is one of the several innovative technologies which emerged in response to this initiative. This technique utilizes an electropotential gradient and the subsequent electrical transport mechanism to cause the controlled movement of ionics species, whereby the contaminants exit the recesses deep within the concrete. This report discusses the technology and use at the Oak Ridge k-25 plant.

  4. Electroosmotic decontamination of concrete

    International Nuclear Information System (INIS)

    Bostick, W.D.; Bush, S.A.; Marsh, G.C.; Henson, H.M.; Box, W.D.; Morgan, I.L.

    1993-03-01

    A method is described for the electroosmotic decontamination of concrete surfaces, in which an electrical field is used to induce migration of ionic contaminants from porous concrete into an electrolyte solution that may be disposed of as a low-level liquid radioactive waste (LLRW); alternately, the contaminants from the solution can be sorbed onto anion exchange media in order to prevent contaminant buildup in the solution and to minimize the amount of LLRW generated. We have confirmed the removal of uranium (and infer the removal of 99 Tc) from previously contaminated concrete surfaces. In a typical experimental configuration, a stainless steel mesh is placed in an electrolyte solution contained within a diked cell to serve as the negative electrode (cathode) and contaminant collection medium, respectively, and an existing metal penetration (e.g., piping, conduit, or rebar reinforcement within the concrete surface) serves as the positive electrode (anode) to complete the cell. Typically we have achieved 70 to >90% reductions in surface activity by applying 2 )

  5. Electrokinetic decontamination of concrete

    International Nuclear Information System (INIS)

    Lomasney, H.L.; SenGupta, A.K.; Yachmenev, V.

    1996-01-01

    ELECTROSORB Electrokinetic Extraction Technology, developed by ISOTRON Corp., offers a cost-effective approach to treating contaminated concrete. Heavy metals/radionuclides trapped in concrete can be extracted using this process if they are chemically solubilized; solubilizers used are citric acid alone and a mixture of citric and nitric acids. A DC electric field is applied across the contaminated concrete to electrokinetically transport the solubilized contaminants from the concrete pores to a collector on the concrete surface. The collector is an extraction pad laid on the surface. The pad provides confinement for a planar electrode and solubilizer solution; it is operated under a vacuum to hold the pad against the concrete surface. Operation requires little attendance, reducing the workers' health hazards. The process incorporates a mechanism for recycling the solubilizer solution. A field demonstration of the process took place in Building 21 of DOE's Mound facility in Miamisburg, OH, over 12 days in June 1996. The thorium species present in this building's concrete floors included ThO 2 and thorium oxalate. The nitric acid was found to facilitate Th extraction

  6. Proceedings of the concrete decontamination workshop

    International Nuclear Information System (INIS)

    Halter, J.M.; Sullivan, R.G.; Currier, A.J.

    1980-09-01

    Fourteen papers were presented. These papers describe concrete surface removal methods and equipment, as well as experiences in decontaminating and removing both power and experimental nuclear reactors

  7. Concrete decontamination and demolition methods

    International Nuclear Information System (INIS)

    LaGuardia, T.S.

    1980-01-01

    The US Department of Energy (DOE), Division of Environmental Control Technology, requested Nuclear Energy Services to prepare a handbook for the decontamination and decommissioning (D and D) of DOE-owned and commercially-owned radioactive facilities. the objective of the handbook is to provide the nuclear industry with guidance on the state-of-the-art methods and equipment available for decommissioning and to provide the means to estimate decommissioning costs and environmental impact. The methods available for concrete decontamination and demolition are summarized to provide an overview of some of the state-of-the-art techniques to be discussed at this workshop. The pertinent information on each method will include the selection factors such as the rate of performance in terms of concrete removal per unit time (cubic yards per day), manpower required by craft, unit cost (dollars per cubic yard) and the advantages and disadvantages. The methods included in this overview are those that have been routinely used in nuclear and nonnuclear applications or demonstrated in field tests. These methods include controlled blasting, wrecking ball or slab, backhoe mounted ram, flame torch, thermic lance, rock splitter, demolition compound, sawing, core stitch drilling, explosive cutting, paving breaker and power chisel, drill and spall, scarifying, water cannon and grinding

  8. Concrete decontamination by Electro-Hydraulic Scabbling (EHS)

    International Nuclear Information System (INIS)

    1994-11-01

    EHS is being developed for decontaminating concrete structures from radionuclides, organic substances, and hazardous metals. EHS involves the generation of powerful shock waves and intense cavitation by a strong pulsed electric discharge in a water layer at the concrete surface; high impulse pressure results in stresses which crack and peel off a concrete layer of controllable thickness. Scabbling produces contaminated debris of relatively small volume which can be easily removed, leaving clean bulk concrete. Objective of Phase I was to prove the technical feasibility of EH for controlled scabbling and decontamination of concrete. Phase I is complete

  9. Concrete decontamination by Electro-Hydraulic Scabbling (EHS)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-11-01

    EHS is being developed for decontaminating concrete structures from radionuclides, organic substances, and hazardous metals. EHS involves the generation of powerful shock waves and intense cavitation by a strong pulsed electric discharge in a water layer at the concrete surface; high impulse pressure results in stresses which crack and peel off a concrete layer of controllable thickness. Scabbling produces contaminated debris of relatively small volume which can be easily removed, leaving clean bulk concrete. Objective of Phase I was to prove the technical feasibility of EH for controlled scabbling and decontamination of concrete. Phase I is complete.

  10. Decontamination of large horizontal concrete surfaces outdoors

    International Nuclear Information System (INIS)

    Barbier, M.M.; Chester, C.V.

    1980-01-01

    A study is being conducted of the resources and planning that would be required to clean up an extensive contamination of the outdoor environment. As part of this study, an assessment of the fleet of machines needed for decontaminating large outdoor surfaces of horizontal concrete will be attempted. The operations required are described. The performance of applicable existing equipment is analyzed in terms of area cleaned per unit time, and the comprehensive cost of decontamination per unit area is derived. Shielded equipment for measuring directional radiation and continuously monitoring decontamination work are described. Shielding of drivers' cabs and remote control vehicles is addressed

  11. Biodegradation of concrete intended for their decontamination

    International Nuclear Information System (INIS)

    Jestin, A.

    2005-05-01

    The decontamination of sub-structural materials represents a stake of high importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those microorganisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

  12. Concrete decontamination by Electro-Hydraulic Scabbling (EHS). Topical report

    International Nuclear Information System (INIS)

    1996-01-01

    Electro-Hydraulic Scabbling (EHS) technology and equipment for decontaminating concrete structures from radionuclides, organic substances, and hazardous metals is being developed by Textron Systems Division (TSD). This wet scabbling technique involves the generation of powerful shock waves and intense cavitation by a strong pulsed electric discharge in a water layer at the concrete surface. The high pressure impulse results in stresses which crack and peel off a concrete layer of a controllable thickness. Scabbling produces contaminated debris of relatively small volume which can be easily removed, leaving clean bulk concrete. This new technology is being developed under Contract No. DE-AC21-93MC30164. The project objective is to develop and demonstrate a cost-efficient, rapid, controllable process to remove the surface layer of contaminated concrete while generating minimal secondary waste. The primary target of this program is uranium-contaminated concrete floors which constitute a substantial part of the contaminated area at DOE weapon facilities

  13. Concrete decontamination by electro-hydraulic scabbling (EHS). Final report

    International Nuclear Information System (INIS)

    1997-10-01

    Contamination of concrete structures by radionuclides, hazardous metals and organic substances (including PCB's) occurs at many DOE sites. The contamination of concrete structures (walls, floors, ceilings, etc.) varies in type, concentration, and especially depth of penetration into the concrete. In many instances, only the surface layer of concrete is contaminated, up to a depth of one inch, according to estimates provided in the R and D ID document. Then, removal of the concrete surface layer (scabbling) is considered to be the most effective decontamination method. Textron Systems Corp. (TSC) has developed a scabbling concept based on electro-mechanical phenomena accompanying strong electric pulses generated by applying high voltage at the concrete/water interface. Depending on the conditions, the electric discharge may occur either through a waste layer or through the concrete body itself. This report describes the development, testing, and results of this electro-mechanical process. Phase 1 demonstrated the feasibility of the process for the controlled removal of a thin layer of contaminated concrete. Phase 2 designed, fabricated, and tested an integrated subscale unit. This was tested at Fernald. In Phase 3, the scabbling unit was reconfigured to increase its power and processing rate. Technology transfer to an engineering contracting company is continuing

  14. Concrete decontamination by electro-hydraulic scabbling (EHS). Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    Contamination of concrete structures by radionuclides, hazardous metals and organic substances (including PCB`s) occurs at many DOE sites. The contamination of concrete structures (walls, floors, ceilings, etc.) varies in type, concentration, and especially depth of penetration into the concrete. In many instances, only the surface layer of concrete is contaminated, up to a depth of one inch, according to estimates provided in the R and D ID document. Then, removal of the concrete surface layer (scabbling) is considered to be the most effective decontamination method. Textron Systems Corp. (TSC) has developed a scabbling concept based on electro-mechanical phenomena accompanying strong electric pulses generated by applying high voltage at the concrete/water interface. Depending on the conditions, the electric discharge may occur either through a waste layer or through the concrete body itself. This report describes the development, testing, and results of this electro-mechanical process. Phase 1 demonstrated the feasibility of the process for the controlled removal of a thin layer of contaminated concrete. Phase 2 designed, fabricated, and tested an integrated subscale unit. This was tested at Fernald. In Phase 3, the scabbling unit was reconfigured to increase its power and processing rate. Technology transfer to an engineering contracting company is continuing.

  15. Contaminated concrete: Occurrence and emerging technologies for DOE decontamination

    International Nuclear Information System (INIS)

    Dickerson, K.S.; Wilson-Nichols, M.J.; Morris, M.I.

    1995-08-01

    The goals of the Facility Deactivation, Decommissioning, and Material Disposition Focus Area, sponsored by the US Department of Energy (DOE) Office of Technology Development, are to select, demonstrate, test, and evaluate an integrated set of technologies tailored to provide a complete solution to specific problems posed by deactivation, decontamination, and decommissioning, (D ampersand D). In response to these goals, technical task plan (TTP) OR152002, entitled Accelerated Testing of Concrete Decontamination Methods, was submitted by Oak Ridge National Laboratory. This report describes the results from the initial project tasks, which focused on the nature and extent of contaminated concrete, emerging candidate technologies, and matching of emerging technologies to concrete problems. Existing information was used to describe the nature and extent of contamination (technology logic diagrams, data bases, and the open literature). To supplement this information, personnel at various DOE sites were interviewed, providing a broad perspective of concrete contamination. Because characterization is in the initial stage at many sites, complete information is not available. Assimilation of available information into one location is helpful in identifying potential areas of concern in the future. The most frequently occurring radiological contaminants within the DOE complex are 137 Cs, 238 U (and it daughters), and 60 Co, followed closely by 90 Sr and tritium, which account for -30% of the total occurrence. Twenty-four percent of the contaminants were listed as unknown, indicating a lack of characterization information, and 24% were listed as other contaminants (over 100 isotopes) with less than 1% occurrence per isotope

  16. Demonstration recommendations for accelerated testing of concrete decontamination methods

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, K.S.; Ally, M.R.; Brown, C.H.; Morris, M.I.; Wilson-Nichols, M.J.

    1995-12-01

    A large number of aging US Department of Energy (DOE) surplus facilities located throughout the US require deactivation, decontamination, and decommissioning. Although several technologies are available commercially for concrete decontamination, emerging technologies with potential to reduce secondary waste and minimize the impact and risk to workers and the environment are needed. In response to these needs, the Accelerated Testing of Concrete Decontamination Methods project team described the nature and extent of contaminated concrete within the DOE complex and identified applicable emerging technologies. Existing information used to describe the nature and extent of contaminated concrete indicates that the most frequently occurring radiological contaminants are {sup 137}Cs, {sup 238}U (and its daughters), {sup 60}Co, {sup 90}Sr, and tritium. The total area of radionuclide-contaminated concrete within the DOE complex is estimated to be in the range of 7.9 {times} 10{sup 8} ft{sup 2}or approximately 18,000 acres. Concrete decontamination problems were matched with emerging technologies to recommend demonstrations considered to provide the most benefit to decontamination of concrete within the DOE complex. Emerging technologies with the most potential benefit were biological decontamination, electro-hydraulic scabbling, electrokinetics, and microwave scabbling.

  17. Demonstration recommendations for accelerated testing of concrete decontamination methods

    International Nuclear Information System (INIS)

    Dickerson, K.S.; Ally, M.R.; Brown, C.H.; Morris, M.I.; Wilson-Nichols, M.J.

    1995-12-01

    A large number of aging US Department of Energy (DOE) surplus facilities located throughout the US require deactivation, decontamination, and decommissioning. Although several technologies are available commercially for concrete decontamination, emerging technologies with potential to reduce secondary waste and minimize the impact and risk to workers and the environment are needed. In response to these needs, the Accelerated Testing of Concrete Decontamination Methods project team described the nature and extent of contaminated concrete within the DOE complex and identified applicable emerging technologies. Existing information used to describe the nature and extent of contaminated concrete indicates that the most frequently occurring radiological contaminants are 137 Cs, 238 U (and its daughters), 60 Co, 90 Sr, and tritium. The total area of radionuclide-contaminated concrete within the DOE complex is estimated to be in the range of 7.9 x 10 8 ft 2 or approximately 18,000 acres. Concrete decontamination problems were matched with emerging technologies to recommend demonstrations considered to provide the most benefit to decontamination of concrete within the DOE complex. Emerging technologies with the most potential benefit were biological decontamination, electro-hydraulic scabbling, electrokinetics, and microwave scabbling

  18. Testing and evaluation of electrokinetic decontamination of concrete

    International Nuclear Information System (INIS)

    DePaoli, D.W.; Harris, M.T.; Ally, M.R.

    1996-10-01

    The goals and objectives of the technical task plan (TTP) are to (1) describe the nature and extent of concrete contamination within the Department of Energy (DOE) complex and emerging and commercial technologies applicable to these problems; (2) to match technologies to the concrete problems and recommend up to four demonstrations; (3) to initiate recommended demonstrations; and (4) to continue investigation and evaluation of the application of electrokinetic decontamination processes to concrete. This document presents findings of experimental and theoretical studies of the electrokinetic decontamination (EK) process and their implications for field demonstrations. This effort is an extension of the work performed under TTP 142005, ''Electroosmotic Concrete Decontamination. The goals of this task were to determine the applicability of EK for treating contaminated concrete and, if warranted, to evaluate EK as a potential technology for demonstration. 62 refs

  19. Concrete decontamination by electro-hydraulic scabbling

    International Nuclear Information System (INIS)

    Goldfarb, V.; Gannon, R.

    1995-01-01

    Textron Defense Systems (TDS) is developing an electro-hydraulic device that has the potential for faster, safer, and less expensive scabbling of contaminated concrete surfaces. In the device, shock waves and cavitating bubbles are produced in water by the electric pulses, and the direct and reflected shock waves impinging on the concrete surface result in the crushing and cracking of the concrete. Pulse energy, frequency, and traverse speed control the depth of the scabbling action. Performance thus far has demonstrated the capability of a prototype unit to process a swath 24 inches wide, up to 3/4 inches deep at a linear velocity of up to 6 feet per hour, i.e., at a scabbling rate of 12 sq. ft. per hour

  20. Concrete decontamination by electro-hydraulic scabbling

    Energy Technology Data Exchange (ETDEWEB)

    Goldfarb, V.; Gannon, R. [Textron Defense System, Everett, MA (United States)

    1995-10-01

    Textron Defense Systems (TDS) is developing an electro-hydraulic device that has the potential for faster, safer, and less expensive scabbling of contaminated concrete surfaces. In the device, shock waves and cavitating bubbles are produced in water by the electric pulses, and the direct and reflected shock waves impinging on the concrete surface result in the crushing and cracking of the concrete. Pulse energy, frequency, and traverse speed control the depth of the scabbling action. Performance thus far has demonstrated the capability of a prototype unit to process a swath 24 inches wide, up to 3/4 inch deep at a linear velocity of up to 6 feet per hour, i.e., at a scabbling rate of 12 sq. ft. per hour.

  1. Salt decontamination demonstration test results

    International Nuclear Information System (INIS)

    Snell, E.B.; Heng, C.J.

    1983-06-01

    The Salt Decontamination Demonstration confirmed that the precipitation process could be used for large-scale decontamination of radioactive waste sale solution. Although a number of refinements are necessary to safely process the long-term requirement of 5 million gallons of waste salt solution per year, there were no observations to suggest that any fundamentals of the process require re-evaluation. Major accomplishments were: (1) 518,000 gallons of decontaminated filtrate were produced from 427,000 gallons of waste salt solution from tank 24H. The demonstration goal was to produce a minimum of 200,000 gallons of decontaminated salt solution; (2) cesium activity in the filtrate was reduced by a factor of 43,000 below the cesium activity in the tank 24 solution. This decontamination factor (DF) exceeded the demonstration goal of a DF greater than 10,000; (3) average strontium-90 activity in the filtrate was reduced by a factor of 26 to less than 10 3 d/m/ml versus a goal of less than 10 4 d/m/ml; and (4) the concentrated precipitate was washed to a final sodium ion concentration of 0.15 M, well below the 0.225 M upper limit for DWPF feed. These accomplishments were achieved on schedule and without incident. Total radiation exposure to personnel was less than 350 mrem and resulted primarily from sampling precipitate slurry inside tank 48. 3 references, 6 figures, 2 tables

  2. Contaminated concrete: Occurrence and emerging technologies for DOE decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, K.S.; Wilson-Nichols, M.J. [Oak Ridge National Lab., Grand Junction, CO (United States); Morris, M.I. [Oak Ridge National Lab., TN (United States)

    1995-08-01

    The goals of the Facility Deactivation, Decommissioning, and Material Disposition Focus Area, sponsored by the US Department of Energy (DOE) Office of Technology Development, are to select, demonstrate, test, and evaluate an integrated set of technologies tailored to provide a complete solution to specific problems posed by deactivation, decontamination, and decommissioning, (D&D). In response to these goals, technical task plan (TTP) OR152002, entitled Accelerated Testing of Concrete Decontamination Methods, was submitted by Oak Ridge National Laboratory. This report describes the results from the initial project tasks, which focused on the nature and extent of contaminated concrete, emerging candidate technologies, and matching of emerging technologies to concrete problems. Existing information was used to describe the nature and extent of contamination (technology logic diagrams, data bases, and the open literature). To supplement this information, personnel at various DOE sites were interviewed, providing a broad perspective of concrete contamination. Because characterization is in the initial stage at many sites, complete information is not available. Assimilation of available information into one location is helpful in identifying potential areas of concern in the future. The most frequently occurring radiological contaminants within the DOE complex are {sup 137}Cs, {sup 238}U (and it daughters), and {sup 60}Co, followed closely by {sup 90}Sr and tritium, which account for {minus}30% of the total occurrence. Twenty-four percent of the contaminants were listed as unknown, indicating a lack of characterization information, and 24% were listed as other contaminants (over 100 isotopes) with less than 1% occurrence per isotope.

  3. Summary review of Mound Facility's experience in decontamination of concrete

    International Nuclear Information System (INIS)

    Combs, A.B.; Davis, W.P.; Garner, J.M.; Geichman, J.R.

    1980-01-01

    Most of the current concrete decontamination work at Mound Facility involves surfaces that are contaminated with plutonium-238. Approximately 60,000 sq. ft. of concrete floors will have to be decontaminated in Mound's current Decontamination and Decommissioning (D and D) Project. Although most of these surfaces are partially protected by a barrier (tile or paint), contaminated water and acid have penetrated these barriers. The technique for decontaminating these floors is desribed. The initial cleaning of the floor involes standard water and detergent. Acids are not used in cleaning as they tend to drive the contamination deeper into the concrete surface. Next, the floor tile is manually removed inside a temporary enclosure under negative and filtered ventilation. Finally, layers of contaminated concrete are mechanically removed inside the ventilated enclosure. The suspected depth and surface area of contamination determines the type of mechanical tool used. In summary, several generic methods of concrete decontamination can be utilized: chemical, such as water, detergent, acids, paint remover, strippable paints, etc.; rotary using sanders, grinders, scarifiers, etc.; impact such as pressure washers (hydrolasers), particle blasters, scabblers, needlers, spallers, paving and rock breakers, ram hoes, etc. The particular method used depends on several factors: surface and area involved; depth of contamination; cost and availability of equipment; usage safety and radiological control; and waste generated

  4. Washing-electrokinetic Decontamination for Concrete Contaminated with Cobalt and Cesium

    International Nuclear Information System (INIS)

    Kim, Gye Nam; Yang, Byeong Il; Choi, Wang Kyu; Lee, Kune Woo; Hyeon, Jay Hyeok

    2009-01-01

    A great volume of radioactive concrete is generated during the operation and the decommissioning of nuclear facilities. The washing-electrokinetic technology in this study, which combined an electrokinetic method and a washing method, was developed to decontaminate the concrete generated in nuclear facilities. The results of only an electrokinetic decontamination for the concrete showed that cobalt was removed to below 1% from the concrete due to its high pH. Therefore, the washing electrokinetic technology was applied to lower the pH of the concrete. Namely, when the concrete was washed with 3 M of hydrochloric acid for 4 hours (0.17 day), the CaCO 3 in the concrete was decomposed into CO 2 and the pH of the concrete was reduced to 3.7, and the cobalt and cesium in the concrete were removed by up to 85.0% and 76.3% respectively. Next, when the washed concrete was decontaminated by the electrokinetic method with 0.01M of acetic acid in the 1L electrokinetic equipment for 14.83 days, the cobalt and the cesium in the concrete were both removed by up to 99.7% and 99.6% respectively. The removal efficiencies of the cobalt and cesium by 0.01M of acetic acid were increased more than those by 0.05M of acetic acid due to the increase of the concrete zeta potential. The total effluent volume generated from the washing-electrokinetic decontamination was 11.55L (7.2ml/g).

  5. Surface concrete decontamination equipment developed by Pacific Northwest Laboratory

    International Nuclear Information System (INIS)

    Halter, J.M.; Sullivan, R.G.; Bevan, J.L.

    1982-08-01

    This report documents a project that the Pacific Northwest Laboratory conducted to identify and develop techniques for removing contaminated concrete surfaces. A major problem associated with nuclear facility decontamination and decommissioning is how to economically demolish and dispose of contaminated concrete. Removing only the contaminated portion of the concrete can substantially reduce costs. Evaluation of various methods for removing concrete surfaces shows that several techniques presently used require excessive manpower, time, and energy. Many times more material is removed than necessary, increasing the quantity of waste that must be handled under controlled conditions. These evaluations generated the basic criteria for developing a suitable concrete removal technique: provide a convenient method for cleaning surfaces (such as those contaminated by a small spill); reduce the contaminated waste volume that has to be placed into controlled storage; remove surfaces quickly; and minimize personal exposure to potentially harmful radiation or toxic materials. Removal to 1/4 to 1/2 in. of contaminated surface layer is sufficient for cleanup of most facilities. Two unique decontamination methods have been developed: the concrete spaller and the water cannon. The concrete spaller is the most efficient technique: it removes the concrete surface faster than the water cannons and at a lower cost (as little as $3.00/ft 2 of concrete surface). However, the .458 magnum water cannon may be well suited for small or hard-to-reach locations

  6. Application of diamond tools when decontaminating concrete

    International Nuclear Information System (INIS)

    Woods, B.L.; Gossett, R.F.

    1980-01-01

    The utilization of diamond concrete cutting tools offers new potential approaches to the recurring problems of removing contaminated concrete. Innovative techniques can provide exacting removal within a dust-free environment. Present day technology allows remote control operated equipment to perform tasks heretofore considered impossible. Experience gained from years of removing concrete within the construction industry hopefully can contribute new and improved methods to D and D projects

  7. Decontamination of concrete, with particular reference to flame scarfing

    International Nuclear Information System (INIS)

    Ebeling, W.; Boedeker, B.; Rose, K.; Schaller, K.H.

    1984-01-01

    When decommissioned nuclear power stations are demolished, the contaminated surface layers must be removed, if it is not intended to dismantle and store the entire structure. The economies of this operation are important since the contaminated areas can be very large. The aim of this report is to give an outline of existing methods of concrete decontamination. Both stripping and non-stripping methods are described, though the latter are relatively unimportant for the purposes of demolition. Particular reference is made to flame scarfing, which has been tested by Salzgitter AG/Noell as part of the Community research programme 'Decommissioning of nuclear power plants'. The effectiveness of flame scarfing as a method of decontaminating concrete has been established by tests at the decommissioned nuclear power plant Gundremmingen KRB-A. (author)

  8. Biodegradation of concrete intended for their decontamination; Biodegradation de matrices cimentaires en vue de leur decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Jestin, A

    2005-05-15

    The decontamination of sub-structural materials represents a stake of high importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those microorganisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

  9. Heat transfer within a concrete slab applying the microwave decontamination process

    International Nuclear Information System (INIS)

    Li, W.; Ebadian, M.A.; White, T.L.; Grubb, R.G.

    1993-01-01

    Decontamination of a radioactive contaminated concrete surface is a new technology for the treatment of radioactive waste. In this paper, concrete decontamination using microwave technology is investigated theoretically. A plane wave assumption of microwave propagation has been employed to estimate the microwave field and power dissipation within the concrete. A one-dimensional, unsteady heat conduction model with microwave heat dissipation resulting from microwave-material interaction has been used to evaluate frequency, steel reinforcement within the concrete, and thermal boundary conditions are also considered in the present model. Four commonly used microwave frequencies of 0.896, 2.45, 10.6, and 18.0 GHz have been utilized in the analysis. The results revealed that as the microwave frequency increases to, or higher than 10.6 GHz, the microwave power dissipation shifts toward the front surface of the concrete. Furthermore, it was observed that use of a higher frequency microwave could reduce power intensity requirements needed to raise the temperature difference or thermal stress to the same value in the same period of time. It was found that the presence of reinforcing steel mesh causes part of the microwave energy to be blocked and reflected. Thus, the temperature or thermal stress of the concrete increases before the reinforcement, and decreases after the reinforcement. 16 refs., 6 figs., 3 tabs

  10. 1995 Phase 1 concrete sampling at the decontaminated 183-H basins

    International Nuclear Information System (INIS)

    Kramer, C.D.

    1996-01-01

    This report provides a consolidated reference for 1995 concrete sampling data associated with the Hanford Site's 183-H Solar Evaporation Basins (located at the Hanford Site in Richland, Washington). In 1995, the basins were decontaminated and dismantled. Sampling efforts began after completion of concrete decontamination efforts. Soil and water samples were collected and are described in chronological order in this report

  11. Development of Decontamination Technology for Separating Radioactive Constituents from Contaminated Concrete Waste

    International Nuclear Information System (INIS)

    Min, B. Y.; Kim, G. N.; Lee, G. W.; Choi, W. K.; Jung, U. S.

    2010-01-01

    The large amount of contaminated concrete produced during decommissioning procedures and available decontamination. In Korea, more than more than 60 tons of concrete wastes contaminated with uranium compounds have been generated from UCP (Uranium Conversion Plant) by dismantling. A recycling or a volume reduction of the concrete wastes through the application of appropriate treatment technologies have merits from the view point of an increase in a resource recycling as well as a decrease in the amount of wastes to be disposed of resulting in a reduction of a disposal cost and an enhancement of the disposal safety. For unconditional release of building and reduction of radioactive concrete waste, mechanical methods and thermal stress methods have been selected. In the advanced countries, such as France, Japan, Germany, Sweden, and Belgium, techniques for reduction and reuse of the decommissioning concrete wastes have applied to minimize the total radioactive concrete waste volume by thermal and mechanical processes. It was found that volume reduction of contaminated concrete can be achieved by separation of the fine cement stone and coarse gravel. Typically, the contaminated layer is only 1∼10mm thick because cementitious materials are porous media, the penetration of radionuclides may occur up to several centimenters from the surface of a material. Most of the dismantled concrete wastes are slightly contaminated rather than activated. This decontamination can be accomplished during the course of a separation of the concrete wastes contaminated with radioactive materials through a thermal treatment step of the radionuclide (e.g. cesium and strontium), transportation of the radionuclide to fine aggregates through a mechanical treatment step. Concrete is a structural material which generally consists of a binder (cement), water, and aggregate. The interaction between highly charged calcium silicate hydrate (C-S-H) particles in the presence of divalent calcium

  12. Training of skin decontamination and its results

    International Nuclear Information System (INIS)

    Yasunaka, Hideo; Wadachi, Yoshiki.

    1976-01-01

    In the nuclear power and radioisotope handling facilities, one of the most important problems is a radioactive contamination on skin. Hand skin contamination occurs very often in the operation area and such surface contamination must be removed as soon as possible to prevent an internal contamination. From 1967 to 1975, training courses for skin decontamination had been held with total 536 of trainee based on the radiation protection manual at the Oarai Research Establishment of JAERI. In the training courses, fresh pig skin samples used instead of human skin were contaminated with 137 Cs, 131 I, 85 Sr, 60 Co, 144 Ce, 88 Y, 239 Pu, fission products and activated metal corrosion particles, respectively. These samples were washed practically by each trainee with the skin decontamination method recommended in the manual. Results obtained in the training showed that such training itself is a significant work and this skin decontamination method is an excellent first aid. (auth.)

  13. Behavior of sulfur mustard in sand, concrete, and asphalt matrices: Evaporation, degradation, and decontamination.

    Science.gov (United States)

    Jung, Hyunsook; Choi, Seungki

    2017-10-15

    The evaporation, degradation, and decontamination of sulfur mustard on environmental matrices including sand, concrete, and asphalt are described. A specially designed wind tunnel and thermal desorber in combination with gas chromatograph (GC) produced profiles of vapor concentration obtained from samples of the chemical agent deposited as a drop on the surfaces of the matrices. The matrices were exposed to the chemical agent at room temperature, and the degradation reactions were monitored and characterized. A vapor emission test was also performed after a decontamination process. The results showed that on sand, the drop of agent spread laterally while evaporating. On concrete, the drop of the agent was absorbed immediately into the matrix while spreading and evaporating. However, the asphalt surface conserved the agent and slowly released parts of the agent over an extended period of time. The degradation reactions of the agent followed pseudo first order behavior on the matrices. Trace amounts of the residual agent present at the surface were also released as vapor after decontamination, posing a threat to the exposed individual and environment.

  14. Electrokinetic decontamination of concrete. Final report, August 3, 1993 - September 15, 1996

    International Nuclear Information System (INIS)

    1998-01-01

    The ELECTROSORB reg-sign open-quotes Cclose quotes process is an electrokinetic process for decontaminating concrete. ELECTROSORB reg-sign open-quotes Cclose quotes uses a carpet-like extraction pad which is placed on the contaminated concrete surface. An electrolyte solution is circulated from a supporting module. This module keeps the electrolyte solution clean. The work is advancing through the engineering development stage with steady progress toward a full scale demonstration unit which will be ready for incorporation in the DOE Large Scale Demonstration Program by Summer 1997. A demonstration was carried out at the Mound Facility in Miamisburg, Ohio, in June 1996. Third party verification by EG ampersand G verified the effectiveness of the process. Results of this work and the development work that proceeded are described herein

  15. Definition of a concrete bio-decontamination process in nuclear substructures; Biodegradation de matrices cimentaires en vue de leur decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Jestin, A

    2005-05-15

    The decontamination of sub-structural materials represents a stake of high-importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those micro-organisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

  16. Abrasive blasting, a technique for the industrial decontamination of metal components and concrete blocks from decommissioning to unconditional release levels

    International Nuclear Information System (INIS)

    Gills, R.; Lewandowski, P.; Ooms, B.; Reusen, N.; Van Laer, W.; Walthery, R.

    2007-01-01

    When decommissioning nuclear installations, large quantities of metal components are produced as well as significant amounts of other radioactive materials, which mostly show low surface contamination. Having been used or having been brought for a while in a controlled area marks them as 'suspected material'. In view of the very high costs for radioactive waste processing and disposal, alternatives have been considered, and much effort has gone to recycling through decontamination, melting and unconditional release of metals. In a broader context, recycling of materials can considered to be a first order ecological priority in order to limit the quantities of radioactive wastes for final disposal and to reduce the technical and economic problems involved with the management of radioactive wastes. It will help as well to make economic use of primary material and to conserve natural resources of basic material for future generations. In a demonstration programme, Belgoprocess has shown that it is economically interesting to decontaminate metal components to unconditional release levels using dry abrasive blasting techniques, the unit cost for decontamination being only 30 % of the global cost for radioactive waste treatment, conditioning, storage and disposal. As a result, an industrial dry abrasive blasting unit was installed in the Belgoprocess central decontamination infrastructure. At the end of December 2006, more than 1,128 Mg of contaminated metal has been treated as well as 313 Mg of concrete blocks. The paper gives an overview of the experience relating to the decontamination of metal material and concrete blocks at the decommissioning of the Eurochemic reprocessing plant in Dessel, Belgium as well from the decontamination of concrete containers by abrasive blasting. (authors)

  17. Demonstration experience with an abrasive blasting technique for decontaminating concrete pads

    International Nuclear Information System (INIS)

    Devgun, J.S.; Land, R.R.; Doane, R.W.

    1990-01-01

    A demonstration was performed for decontaminating a radioactivity contaminated concrete pad with a portable abrasive blasting system. The system utilizes a rotating blast wheel that scours the concrete surface with metal abrasive. The metal abrasive, pulverized concrete dust, and contaminants rebound into a separator chamber. The reusable metal abrasive is recycled, and the pulverized media are removed to an integral dust collection system. The exhaust is HEPA filtered to minimize release of airborne contaminants. However, the technique had limited success in reducing contamination around the cracks and seams in the concrete where the higher activity levels of contamination were detected during the radiological survey before the cleanup. The technique can be successful and cost-effective in decontaminating large areas of low contamination; however, careful characterization and planning are necessary. 3 refs., 3 figs., 1 tabs

  18. Decontamination of concrete surfaces in Building 3019, Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Parrott, J.R. Sr.

    1980-01-01

    This building was built in 1943 to serve as a pilot plant for separating isotopes from irradiated fuels. A chemical explosion leading to widespread Pu contamination occurred on Nov. 20, 1959, and the steps taken to treat the building afterwards are discussed, in particular the floor and the cells. The experience shows how hard it is to decontaminate concrete; smooth coatings should be utilized

  19. Decision Analysis Science Modeling for Application and Fielding Selection Applied to Concrete Decontamination Technologies

    International Nuclear Information System (INIS)

    Ebadian, M.A.; Ross, T.L.

    1998-01-01

    Concrete surfaces contaminated with radionuclides present a significant challenge during the decontamination and decommissioning (D and D) process. As structures undergo D and D, coating layers and/or surface layers of the concrete containing the contaminants must be removed for disposal in such a way as to present little to no risk to human health or the environment. The selection of a concrete decontamination technology that is safe, efficient, and cost-effective is critical to the successful D and D of contaminated sites. To support U.S. Department of Energy (DOE) Environmental Management objectives and to assist DOE site managers in the selection of the best-suited concrete floor decontamination technology(s) for a given site, two innovative and three baseline technologies have been assessed under standard, non-nuclear conditions at the Hemispheric Center for Environmental Technology (HCET) at Florida International University (FIU). The innovative technologies assessed include the Pegasus Coating Removal System and Textron's Electro-Hydraulic Scabbling System. The three baseline technologies assessed include: the Wheelabrator Blastrac model 1-15D, the NELCO Porta Shot Blast trademark model GPx-1O-18 HO Rider, and the NELCO Porta Shot Blasttrademark model EC-7-2. These decontamination technology assessments provide directly comparable performance data that have previously been available for only a limited number of technologies under restrictive site-specific constraints. Some of the performance data collected during these technology assessments include: removal capability, production rate, removal gap, primary and secondary waste volumes, and operation and maintenance requirements. The performance data generated by this project is intended to assist DOE site managers in the selection of the safest, most efficient, and cost-effective decontamination technologies to accomplish their remediation objectives

  20. Decontamination

    International Nuclear Information System (INIS)

    Montford, B.

    1975-01-01

    Development of special techniques has permitted the use of mild decontamination processes for the CANDU type reactor primary coolant circuit, overcoming many of the problems associated with conventional decontamination processes, which use strong, acidic reagents. (Author)

  1. Decontamination of paint-coated concrete in nuclear plants using laser technology

    Energy Technology Data Exchange (ETDEWEB)

    Anthofer, Anton; Lippmann, Wolfgang; Hurtado, Antonio [Technische Univ. Dresden (Germany). Chair of Hydrogen and Nuclear Technology

    2013-07-01

    A review of the state of the art shows the technical novelty of the combined project. The development of an all-in-one process for treatment hazard chemical contamination on concrete structures with online monitoring method reduces the laborious mechanic decontamination and post-treatment. For safe experimental investigations, a three-barrier-system was constructed and can be used for tests with - first - epoxy paint in order to analyze and optimize the process. Simulation models help to formulate a mathematic scheme of the decontamination process by laser technology. The goal is a decontamination system with an online analyzing system of the flue gas for a mobile and extensive component in nuclear and conventional decommission. (orig.)

  2. Definition of a concrete bio-decontamination process in nuclear substructures

    International Nuclear Information System (INIS)

    Jestin, A.

    2005-05-01

    The decontamination of sub-structural materials represents a stake of high-importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those micro-organisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

  3. Concrete decontamination: two innovative processes in response to surface or deep contamination

    International Nuclear Information System (INIS)

    CUER, F.; Nadai, A. de; Faure, S.

    2008-01-01

    To meet the future needs in the nuclear industry as regards dismantling and decommissioning, the LPAD (Laboratoire des Procedes Avances de Decontamination) develops new specific techniques to decontaminate concretes: the drying gel process adapted to surface contamination and the electrokinetics process to treat deep contamination. Indeed, because the concrete constitute a porous medium, two types of contamination can be met according to the environment to which is subjected the material. In the case of an accidental or dry contamination, radio elements do not penetrate beyond the first millimeters of the material. The contamination is then considered as surface. On the contrary, the contamination is considered as 'deep' when radioactive ions have diffused deeply under the effects of the natural diffusion. This is the case in fuel storage pond or other many nuclear infrastructures. (authors)

  4. Assessment of the Characteristic Aggregates during a Decontamination of Contaminated Concrete Waste

    International Nuclear Information System (INIS)

    Min, B. Y.; Choi, W. K.; Oh, W. Z.; Jung, C. H.; Park, J. W.

    2008-01-01

    During a decommissioning of nuclear plants and facilities, large quantities of slightly contaminated concrete wastes are generated. The exposure to radiation over many years could be hazardous to human health. In Korea, the decontamination and decommissioning of the retired TRIGA MARK II and III research reactors and a uranium conversion plant at the Korea Atomic Energy Research Institute (KAERI) has been under way. Hundreds of tons of concrete wastes are expected from the D and D of these facilities. Typically, the contaminated layer is only 1∼10mm thick because cementitious materials are porous media, the penetration of radionuclides may occur up to several centimeters from the surface of a material. Contaminated concrete waste can be of two forms, either a surface or bulk contamination. Bulk contamination usually arises from a neutron activation of nuclides during the service life on a component. Surface activity can be a loose contamination arising from a deposition of nuclides from an interfacing medium, and it also can be tightly bound. Most of the dismantled concrete wastes are slightly contaminated rather than activated. This decontamination can be accomplished during the course of a separation of the concrete wastes contaminated with radioactive materials through a thermal treatment step of the radionuclide (e.g. cesium and strontium), transportation of the radionuclide to fine aggregates through a mechanical treatment step such as a crushing, milling and sieving. Produced fine powder (paste) should be stabilized for the final disposal. Melting technology has been known as the one of the most effective technologies for a stabilization and volume reduction to the paste. Therefore, a melting may be a last step in the decontamination of a contaminated paste. The aim of this study was to establish the separation conditions for an optimum decontamination for the treatment of concrete wastes contaminated with radionuclides. The separation tests had been

  5. Decontamination and concrete core sampling by teleoperated robot at Fukushima Daiichi reactor buildings

    International Nuclear Information System (INIS)

    Watanabe, Masaru; Onitsuka, Hironori; Shimonabe, Noriaki; Fujita, Jun; Matsumura, Takumi; Okumura, Atsushi

    2015-01-01

    For decommissioning of Fukushima daiichi nuclear power station, reduction of the dose equivalent rates inside the reactor buildings is an important issue. Concrete core sampling from the buildings to investigate the contamination is necessary for study about effective decontamination. However, dose rate inside the reactor buildings is very high. For example, dose rate of 1st floor on the Unit 1 is 1.2 - 1820 [mSv / h], the Unit 2 is 2.5 - 220 [mSv / h] and Unit 3 is 2.2 - 4780 [mSv / h]. So it is difficult for workers to work long hours. Therefore, a teleoperated robot, named 'MHI-MEISTeR (Mitsubishi Heavy Industries - Maintenance Equipment Integrated System of Telecontrol Robot)', has been developed to conduct operations like concrete core samples from the reactor buildings. Actually, some concrete core samples from Fukushima daiichi were taken by MHI-MEISTeR. In addition, MHI-MEISTeR is designed as a versatile robot, and so it can conduct suction / blast decontamination works as well as concrete core sampling. The above operations were performed by MHI-MEISTeR in Fukushima daiichi nuclear power station. (author)

  6. Results of preliminary experiments on tritium decontamination by UV irradiation

    International Nuclear Information System (INIS)

    Oya, Yasuhisa; Shu, Wataru; O'hira, Shigeru; Hayashi, Takumi; Nishi, Masataka

    2000-03-01

    In the point of view of protection of workers from the radiation exposure and the limitation of the contamination with radioactive materials, it is important to decontaminate mobile tritium from plasma facing components of a nuclear fusion reactor at the beginning of their maintenance work. It is considered that the heating is the most effective method for decontamination. However, it is important to develop new decontamination method of adsorbed hydro-carbon based substances from the materials that cannot be heated or the inner pipe of double pipes. This report presents results of preliminary experiments performed for the development of the effective tritium decontamination technique pursuing under US/Japan collaborative program on technology for fusion-fuel processing (Annex IV). In the experiments, the effects of Ultra Violet (UV) irradiation on tritium removal from some kinds of materials, such as poly vinyl chloride -(CH 2 CHCl) n - film, polyethylene film and graphite samples coated by C 2 H 2 plasma were examined. As the result of UV irradiation, it was confined that hydrogen and carbon based compounds could be released from the specimen during UV irradiation. It is concluded that UV irradiation is one of the hopeful candidates for effective tritium decontamination. (author)

  7. The NEA co-operative programme on decommissioning decontamination and demolition of concrete structures

    International Nuclear Information System (INIS)

    Berton, Marie-Anne; Estivie, David; Cantrel, Eric; Moeller, Joerg; Ondaro, Manuel; Ooms, Bart; Wittenauer, Stefan; Burton, Bob

    2011-01-01

    In response to growing interest in the decommissioning of nuclear facilities, the OECD Nuclear Energy Agency set up the Co-operative Programme on Decommissioning in 1985. Its basic scope is to facilitate the exchange of scientific and technical information between major decommissioning projects. Participation in the Programme has expanded significantly over the years to include organisations from 13 countries. Currently, about 60 projects participate in the Programme. The Programme is executed under an agreement between the participating organisations and companies. A progress report is issued every five years on the CPD and includes a brief description of each project. The most recent report is entitled A Decade of Progress. The projects are divided into two groups: reactor projects (60%) and fuel facility projects (40%). A complete list of the different projects and their country of residence can be found in Annex 1. Many of the early projects in the Programme focused on experimental or prototype plants, however, a number of projects for the decommissioning of commercial facilities (power generation, fuel and reprocessing plants) have recently joined the Programme. Limited feedback on concrete clean-up operations has been available until now due to the lengthy time frame of decommissioning projects and the fact that building demolition occurs in the very late stages of the project. Some of the early projects in the Programme are now complete or nearing completion, making available significant data and experience. This experience and lessons learnt can be applied to the further development of decommissioning and dismantling (D and D) clean-up processes. This report aims to supplement the previous NEA report dedicated to decontamination techniques and to provide project engineers and/or project leaders involved in concrete infrastructure clean-up with: - Guidelines for setting up appropriate and adequate strategies, taking into consideration the international

  8. Abrasive-waterjet cutting of thick concrete and waterjet cleaning for nuclear facility decommissioning and decontamination

    International Nuclear Information System (INIS)

    Echert, D.C.; Hashish, M.; Marvin, M.H.

    1987-01-01

    Two tools have been developed for use by the nuclear industry: the Deep Kerf tool and the Cleaner/Scarifier tool. The Deep Kerf tool is designed to cut through thick, reinforced concrete structures to facilitate their decommissioning. It employs the abrasive-waterjet (AWJ) cutting technology. The basis of the system is a rotary nozzle that makes a slot in the concrete wide enough to accommodate the cutting tool as it advances. In this program, concrete as thick as 1.5 m was cut through from one side. A shroud and vacuum system covers the opening of the slot during cutting to contain the spoils with greater than 99% efficiency. The Cleaner/Scarifier tool was designed for removing the surface layers of contaminated concrete and decontaminating metal surfaces. It uses ultrahigh-pressure waterjets mounted on a rotating arm to remove or clean the target surface. Spoils recovery with a shroud and vacuum system is over 99% complete for both horizontal and vertical surfaces

  9. Radiological dose assessment for the decontaminated concrete removed from 183-H solar evaporation basins at the Hanford site, Richland, Washington

    International Nuclear Information System (INIS)

    Kamboj, S.; Faillace, E.; Yu, C.

    1997-01-01

    Potential maximum radiation dose rates over a 1,000-year time horizon were calculated for exposure to the decontaminated concrete removed from the 183-H Solar Evaporation Basins at the Hanford Site, Richland, Washington. The RESRAD computer code, Version 5.62, which implements the methodology described in the US Department of Energy's manual for developing residual radioactive material guidelines, was used in this evaluation. Currently, the concrete is not being used. Four potential exposure scenarios were developed for the land area where the decontaminated concrete will be stored. In Scenario A industrial use of the land is assumed; in Scenario B recreational use of the land is assumed; in Scenario C residential use of the land is assumed; and in Scenario D (a plausible but unlikely land-use scenario), the presence of a subsistence farmer in the immediate vicinity of the land is assumed. For Scenarios A and B, water used for drinking is assumed to be surface water from the Columbia River; for Scenarios C and D, groundwater drawn from a well located at the downgradient edge of the storage area is the only source of water for drinking, irrigation, and raising livestock. Conservative parameters values were used to estimate the radiation doses. The results of the evaluation indicate that the US Department of Energy's dose limit of 100 mrem/yr would not be exceeded for any of the scenarios analyzed. The potential maximum dose rates for Scenarios A, B, C, and D are 0.75, 0.022, 29, 29 mrem/yr, respectively. An uncertainty analysis was performed to determine which parameters have the greatest impact on the estimated doses. The doses in Scenarios C and D were found to be very sensitive to the magnitude of the irrigation rate

  10. PND fuel handling decontamination program: specialized techniques and results

    International Nuclear Information System (INIS)

    Pan, R.; Hobbs, K.; Minnis, M.; Graham, K.

    1995-01-01

    The use of various decontamination techniques and equipment has become a critical part of Fuel Handling maintenance work at the Pickering Nuclear Station, an eight unit CANDU station located about 30 km east of Toronto. This paper presents an overview of the set up and techniques used for cleaning in the PND Fuel Handling Maintenance Facility, and the results achieved. (author)

  11. Decision Analysis Modeling for Application and Fielding Selection Applied to Concrete Decontamination Technologies

    International Nuclear Information System (INIS)

    Ebadian, M.A.; Boudreaux, J.F.

    1998-01-01

    The purpose of this two-year investigation is to field test innovative technologies for coating and surface removal on concrete floors and compare the compiled data to baseline technologies, thereby ensuring that the best and most cost-effective options are developed and subsequently used during the decontamination and decommissioning (D and D) of U.S. Department of Energy Environmental Management (DOE-EM) sites. Comprehensive and comparable data will be collected in the areas of health and safety, operations, and secondary waste management. The technologies tested will include DOE-EM funded technologies and commercial non-nuclear technologies that have the potential to meet the environmental restoration objectives. This report summarizes the activities performed during Fiscal Year 1996 (FY96) and describes the planned activities for Fiscal Year 1997 (FY97). Accomplishments for FY96 include the completion of preparatory work to begin field testing of innovative technologies. A total of seven technologies will be tested during FY97. As a part of this project, interactive computer software will be developed during FY97, allowing site-specific parameters and technology performance data to be considered when determining the best option given site-specific conditions

  12. OIL DECONTAMINATION OF BOTTOM SEDIMENTS EXPERIMENTAL WORK RESULTS

    Directory of Open Access Journals (Sweden)

    Lushnikov Sergey V.

    2006-08-01

    Full Text Available This article presents the results of experimental work during 2004-2005 on oil decontamination of bottom sediments of Lake Schuchye, situated in the Komi Republic (Northern Russia. The cause of thecontamination were huge oil spills occurred after a series of accidental ruptures on the Harjaga-Usinsk and Vozej-Usinsk oil-pipe lines in 1994. Flotation technology was used for the cleaning of bottom sediments.157 tons of crude oil were removed during the course of 2-year experimental work from an area of 4,1 ha.The content of aliphatic and alicyclic oil hydrocarbons was reduced from 53,3 g/kg to 2,2 g/kg, on average.Hydrobiological investigations revealed that bottom sediments started to be inhabited by benthos organisms, dominantly Oligochaeta. Besides Oligochaeta, Chironomidae maggots and Bivalvia were detected. Theappearance of Macrozoobenthos organisms can serve as a bioindicator of water quality.

  13. Decontamination and demolition of concrete and metal structures during the decommissioning of nuclear facilities

    International Nuclear Information System (INIS)

    1988-01-01

    The objective of this report is to give a concise technical description of the techniques and equipment being used or developed for the decontamination and demolition of nuclear facilities in sufficient detail to assist Member States to plan decommissioning operations and make preliminary evaluations of techniques and equipment. This report also reviews new and/or different aspects which have not been well covered previously in readily available review documents or IAEA publications. This report is an up to date review of techniques and equipment being used or developed for decontamination or dismantling work during the decommissioning of all types of nuclear facility except mining and milling sites. Although the information presented is aimed at countries initiating decommissioning programmes, it should also be useful to others who are responsible for or interested in the planning and implementation of decommissioning tasks. This report describes the relevant techniques and equipment, their areas of application and degree of development and the conditions in which they are used, when these details are known. However, this publication should be used in conjunction with other published technical information on these topics, experience gained as a result of previous decommissioning operations and the assistance of experts in the appropriate areas are required. 64 refs, 33 figs, 5 tabs

  14. Verification of wet blasting decontamination technology

    International Nuclear Information System (INIS)

    Matsubara, Sachito; Murayama, Kazunari; Yoshida, Hirohisa; Igei, Shigemitsu; Izumida, Tatsuo

    2013-01-01

    Macoho Co., Ltd. participated in the projects of 'Decontamination Verification Test FY 2011 by the Ministry of the Environment' and 'Decontamination Verification Test FY 2011 by the Cabinet Office.' And we tested verification to use a wet blasting technology for decontamination of rubble and roads contaminated by the accident of Fukushima Daiichi Nuclear Power Plant of the Tokyo Electric Power Company. As a results of the verification test, the wet blasting decontamination technology showed that a decontamination rate became 60-80% for concrete paving, interlocking, dense-grated asphalt pavement when applied to the decontamination of the road. When it was applied to rubble decontamination, a decontamination rate was 50-60% for gravel and approximately 90% for concrete and wood. It was thought that Cs-134 and Cs-137 attached to the fine sludge scraped off from a decontamination object and the sludge was found to be separated from abrasives by wet cyclene classification: the activity concentration of the abrasives is 1/30 or less than the sludge. The result shows that the abrasives can be reused without problems when the wet blasting decontamination technology is used. (author)

  15. Concrete

    DEFF Research Database (Denmark)

    2015-01-01

    Concrete is a component of coherent transition between a concrete base and a wooden construction. The structure is based on a quantity of investigations of the design possibilities that arise when combining digital fabrication tools and material capacities. Through tangible experiments the project...... specific for this to happen. And the knowledge and intention behind the drawing becomes specialised through the understanding of the fabrication processes and their affect on the materials.The structure Concrete is a result of a multi-angled kerf series in ash wood and a concrete base. The ash wood is cut...... using a 5-axis CNC router with a thin saw blade attached. The programming of the machining results in variations of kerfs that lets the ash wood twist into unique shapes.The shapes of the revolving ash ribbons continue into the concrete creating a cohesive shape. The form for the concrete itself is made...

  16. Results of tritium tests performed on Sandia Laboratories decontamination system

    International Nuclear Information System (INIS)

    Gildea, P.D.; Wall, W.R.; Gede, V.P.

    1978-05-01

    The Tritium Research Laboratory (TRL), a facility for performing experiments using gram amounts of tritium, became operational on October 1, 1977. As secondary containment, the TRL employs sealed glove boxes connected on demand to two central decontamination systems, the Gas Purification System and the Vacuum Effluent Recovery System. Performance tests on these systems show the tritium removal systems can achieve concentration reduction factors (ratio of inlet to exhaust concentrations) much in excess of 1000 per pass at inlet concentrations of 1 part per million or less for both tritium and tritiated methane

  17. Economic analysis of recycling contaminated concrete

    Energy Technology Data Exchange (ETDEWEB)

    Stephen, A.; Ayers, K.W.; Boren, J.K.; Parker, F.L. [Vanderbilt Univ., Nashville, TN (United States)

    1997-02-01

    Decontamination and Decommissioning activities in the DOE complex generate large volumes of radioactively contaminated and uncontaminated concrete. Currently, this concrete is usually decontaminated, the contaminated waste is disposed of in a LLW facility and the decontaminated concrete is placed in C&D landfills. A number of alternatives to this practice are available including recycling of the concrete. Cost estimates for six alternatives were developed using a spreadsheet model. The results of this analysis show that recycling alternatives are at least as economical as current practice.

  18. Decontamination of steam generators at Loviisa NPS - The decision making and the results

    International Nuclear Information System (INIS)

    Wahlstroem, Bjoern G.

    1984-01-01

    In 1980, during the annual inspections at Loviisa 1, 440 MWe PWR unit, some minor faults in the welding seams of the water chambers in two of the six steam generators were indicated. This led to enlarged inspection work and to thousands of working hours inside the steam generators. The plant had been three years in operation, so the dose rates in the steam generators were rather high. In this case it turned out, that a formal radiation protection optimization procedure would not give the answer on how to go ahead, as there were several practical and psychological factors influencing the decision making process. Anyhow, the result was that a decontamination apparatus was urgently planned and constructed, and advice on tested decontamination chemicals was received from the plant supplier. Using the decontamination machine with alternating basic and acid solutions, a decontamination factor of DF = 300 was reached, and the repair work could be performed without any restrictions on working time. This paper points out some limiting factors in the decision making process and describes the decontamination equipment, the decontamination solutions and the programme. The cost per saved collective dose unit is also calculated. (author)

  19. Selective bowel decontamination results in gram-positive translocation.

    Science.gov (United States)

    Jackson, R J; Smith, S D; Rowe, M I

    1990-05-01

    Colonization by enteric gram-negative bacteria with subsequent translocation is believed to be a major mechanism for infection in the critically ill patient. Selective bowel decontamination (SBD) has been used to control gram-negative infections by eliminating these potentially pathogenic bacteria while preserving anaerobic and other less pathogenic organisms. Infection with gram-positive organisms and anaerobes in two multivisceral transplant patients during SBD led us to investigate the effect of SBD on gut colonization and translocation. Twenty-four rats received enteral polymixin E, tobramycin, amphotericin B, and parenteral cefotaxime for 7 days (PTA + CEF); 23 received parenteral cefotaxime alone (CEF), 19 received the enteral antibiotics alone (PTA), 21 controls received no antibiotics. Cecal homogenates, mesenteric lymph node (MLN), liver, and spleen were cultured. Only 8% of the PTA + CEF group had gram-negative bacteria in cecal culture vs 52% CEF, 84% PTA, and 100% in controls. Log Enterococcal colony counts were higher in the PTA + CEF group (8.0 + 0.9) vs controls (5.4 + 0.4) P less than 0.01. Translocation of Enterococcus to the MLN was significantly increased in the PTA + CEF group (67%) vs controls (0%) P less than 0.01. SBD effectively eliminates gram-negative organisms from the gut in the rat model. Overgrowth and translocation of Enterococcus suggests that infection with gram-positive organisms may be a limitation of SBD.

  20. Alpha detection for decontamination and decommissioning: Results and possibilities

    International Nuclear Information System (INIS)

    MacArthur, D.

    1995-01-01

    Alpha detectors based on the long-range alpha detection (LRAD) technology have numerous uses, both potential and demonstrated, in facility D ampersand D. These monitors operate by detecting the ions created by alpha particles interacting with ambient air. Thus, detection is not limited by the short range of the alpha particle and no window is required between the contamination and the detection region. These properties make LRAD-based detectors ideal for operation in field environments where complex objects to be monitored are the norm and reliability is crucial. Three monitors of particular interest in D ampersand D operations are the building surface monitor, the internal volume monitor for use on the inner surfaces of pipes, ducts, and tanks, and the conveyer belt monitor for concrete rubble and structural steel. Surface monitors have been used extensively, both in laboratory and field environments, internal volume monitors have been tested in the laboratory, and the conveyer system is still a conceptual design. These monitors and related applications demonstrate the utility of LRAD-based monitors for D ampersand D operations as well as exploring some of the new ways that fieldable monitoring systems can be used for D ampersand D. Ion collection sensing technology can be used to solve many of the alpha detection problems unique to the D ampersand D field

  1. Decontamination in preparation for dismantlement - AREVA's chemical decontamination technologies, projects performed and results obtained in the period 2011-2016

    International Nuclear Information System (INIS)

    Topf, C.; Sempere Belda, L.

    2017-01-01

    As a consequence of the nuclear phase-out decreed by the German government, several nuclear power plants in the country have already ceased operation. The remaining ones will cease operation by 2022. This has turned Germany into one of the most active regions worldwide in the field of nuclear decommissioning, with new and emerging technologies being deployed on the field, and already preexisting technologies being put to the test, optimized and developed into full maturity. The chemistry services division of AREVA GmbH has already performed 5 Full System Decontaminations (FSD) in preparation for decommissioning in this period - three in PWRs and two in BWRs - along with other international projects of relevance for decommissioning operations. During a FSD, the complete primary circuit of a nuclear power plant including auxiliary systems is subject to a chemical treatment; designed to remove radioactive matter accumulated onto system surfaces during operation. Through the effective removal of this radioactive accumulations contact dose rates on the different components of the primary circuit can be consistently reduced by factors larger than 50. This results in much lower ambient dose rates and, hence, in very significant dose savings for subsequent decommissioning activities. Additionally, dismantlement operations of large components are considerably simplified and can be performed under conditions that wouldn't have been possible before. The project specific objectives and challenges, the technologies employed, and the results obtained are presented and commented here. (authors)

  2. Bulk Building Material Characterization and Decontamination Using a Concrete Floor and Wall Contamination Profiling Technology

    International Nuclear Information System (INIS)

    Aggarwal, S.; Charters, G.; Blauvelt, D.

    2002-01-01

    The concrete profiling technology, RadPro(trademark) has four major components: a drill with a specialized cutting and sampling head, drill bits, a sample collection unit and a vacuum pump. The equipment in conjunction with portable radiometric instrumentation produces a profile of radiological or chemical contamination through the material being studied. The drill head is used under hammer action to penetrate hard surfaces. This causes the bulk material to be pulverized as the drill travels through the radioactive media efficiently transmitting to the sampling unit a representative sample of powdered bulk material. The profiling equipment is designed to sequentially collect all material from the hole. The bulk material samples are continuously retrieved by use of a specially designed vacuumed sample retrieval unit that prevents cross contamination of the clean retrieved samples. No circulation medium is required with this profiling process; therefore, the only by-product from drilling is the sample. The data quality, quantity, and representativeness may be used to produce an activity profile from the hot spot surface into the bulk building material. The activity data obtained during the profiling process is reduced and transferred to building drawings as part of a detailed report of the radiological problem. This activity profile may then be expanded to ultimately characterize the facility and expedite waste segregation and facility closure at a reduced cost and risk

  3. Effects of ground surface decontamination on the air radiation dose rate. Results of a decontamination trial at a playground lot in a Fukushima residential area

    International Nuclear Information System (INIS)

    Tagawa, Akihiro

    2012-01-01

    The Japan Atomic Energy Agency decontaminated schools, playgrounds, swimming pools, and houses in nonevacuated, less-contaminated areas in Fukushima for environmental restoration. A small, 150 m 2 playground lot in the residential area was chosen for decontamination demonstration, which used routinely available tools and commodities to carry out the work. The surfaces of playground lot equipment, such as swings, slides, and horizontal iron bars, were completely decontaminated by brushing with water and/or detergent. Side gutters around the playground lot were cleaned by removing the mud and then brushed and washed with a high-pressure water jet (7 MPa). The air dose rate at the playground lot was dominated by radiation from the ground surface and adjacent surroundings, such as apartments and rice fields. Two or three centimeters of the surface soil contaminated with cesium was removed manually with shovels, hoes, and other gardening tools. This significantly reduced the average air dose rate of the entire playground lot from 1.5 μSv/h before decontamination to 0.6 μSv/h. These results showed that ground surface decontamination can contribute measurably to the reduction in air dose rate in relatively small areas in residential areas. (author)

  4. Special zone territory decontamination

    International Nuclear Information System (INIS)

    Samojlenko, Yu.N.; Golubev, V.V.

    1989-01-01

    Special zone is the Chernobyl' NPP operating site (OS). OS decontamination is described including reactor ruins from the accident moment. The process was begun from reactor bombardment with absorbing and filtering materials (sand, clay, lead, boron compounds). Then were produced soil shovelling, territory filling by dry concrete and laying concrete layer with thickness up to 300 mm. NPP room and equipment decontamination is described. 3 figs.; 3 tabs

  5. Results of chemical decontamination of DOE`s uranium-enrichment scrap metal

    Energy Technology Data Exchange (ETDEWEB)

    Levesque, R.G.

    1997-02-01

    The CORPEX{reg_sign} Nuclear Decontamination Processes were used to decontaminate representative scrap metal specimens obtained from the existing scrap metal piles located at the Department of Energy (DOE) Portsmouth Gaseous Diffusion Plant (PORTS), Piketon, Ohio. In September 1995, under contract to Lockheed Martin Energy Systems, MELE Associates, Inc. performed the on-site decontamination demonstration. The decontamination demonstration proved that significant amounts of the existing DOE scrap metal can be decontaminated to levels where the scrap metal could be economically released by DOE for beneficial reuse. This simple and environmentally friendly process can be used as an alternative, or in addition to, smelting radiologically contaminated scrap metal.

  6. A thermodynamic study of decontamination of soils contaminated with 137Cs radionuclide as the results of accident at Chernobyl NPP

    International Nuclear Information System (INIS)

    Chirkst, D.Eh.; Chaliyan, K.N.; Chaliyan, A.G.

    1994-01-01

    Thermodynamic characteristics of the process of soil decontamination from 137 Cs by the their washing with eluting solution, Fe(3) and ammonium being included in its composition, have been determined. The decontamination process is 137 Cs desorption as a result of destruction of cesium chelate complexes with humic acids. Fe 3+ and Fe(OH) 2+ substitution for Cs + in the soils occurs spontaneously as a thermodynamically efficient process. 3 refs.; 1 fig

  7. Skin decontamination

    International Nuclear Information System (INIS)

    Moehrle, G.

    1975-01-01

    A general survey of skin decontamination is given. The success of every decontamination treatments depends mainly on the speed, but also on the care, with which the action is taken. The best way to remove the skin contaminants is thorough washing under lukewarm running water with mild soap and a soft brush. This washing is to be repeated several times for a period of several minutes. If results are not satisfactory, light duty detergents and wetting agents available commercially may also be used. Some solutions which have proved useful are mentioned. The decontamination solutions are best used in the order given. When one has no satisfactory decontamination effect, the next one is to be used. If necessary, these agents must be used several times in the stated order as long as this does not involve too much strain for the skin. All the decontamination measures mentioned refer, of course, to intact healthy skin. After decontamination has been completed, the skin should be treated with a protective cream

  8. Decontamination of radionuclides on construction materials

    International Nuclear Information System (INIS)

    Samuleev, P.V.; Andrews, W.S.; Creber, K.A.M.; Velicogna, D.

    2013-01-01

    A wide variety of materials can become contaminated by radionuclides, either from a terrorist attack or an industrial or nuclear accident. The final disposition of these materials depends, in large part, on the effectiveness of decontamination measures. This study reports on investigations into the decontamination of a selection of building materials. The aim has been to find an effective, easy-to-use and inexpensive decontamination system for radionuclides of cesium and cobalt, considering both the chemical and physical nature of these potential contaminants. The basic method investigated was surface washing, due to its ease and simplicity. In the present study, a basic decontamination formulation was modified by adding isotope-specific sequestering agents, to enhance the removal of cesium(I) and cobalt(II) from such construction materials as concrete, marble, aluminum and painted steel. Spiking solutions contained 134 Cs or 60 Co, which were prepared by neutron activation in the SLOWPOKE-2 nuclear reactor facility at the Royal Military College of Canada. Gamma spectroscopy was used to determine the decontamination efficiency. The results showed that the addition of sequestering agents generally improved the radiological decontamination. Although the washing of both cesium and cobalt from non-porous materials, such as aluminum and painted steel, achieved a 90-95 % removal, the decontamination of concrete and marble was more challenging, due to the porous nature of the materials. Nevertheless, the removal efficiency from 6-year-old concrete increased from 10 % to approximately 50 % for cobalt(II), and from 18 to 55 % for cesium(I), with the use of isotope binding agents, as opposed to a simple water wash. (author)

  9. Radioactive decontamination

    International Nuclear Information System (INIS)

    1983-07-01

    This Code of Practice covers: (a) the decontamination of plant items, buildings and associated equipment; (b) decontamination of protective clothing; (c) simple personal decontamination; and (d) the basic mechanisms of contamination and their influence on decontaminability. (author)

  10. Study on some factors affecting the results in the use of MIP method in concrete research

    International Nuclear Information System (INIS)

    Kumar, Rakesh; Bhattacharjee, B.

    2003-01-01

    Effects of rate of pressure application and forms and type of sample on porosity and pore size distribution of concrete estimated through mercury intrusion porosimetry (MIP) are presented in this experimental work. Two different forms of concrete sample, namely, crushed chunks of concrete and small core drilled out from the concrete beam specimens, were used for this study. The results exhibit that the rate of pressure application in mercury porosimetry has little effect on porosity and pore size distribution of concrete. It is also demonstrated that small cores drilled out from large concrete specimens are preferable as samples for performing porosimetry test on concrete

  11. Agricultural soils decontamination techniques: methods and results of tests realized near Chernobyl

    International Nuclear Information System (INIS)

    Maubert, H.; Jouve, A.; Mary, N.

    1992-01-01

    After a major nuclear accident, decontamination of agricultural soils would be necessary in order to reclaim the land. Specific techniques were studied in the framework of the European program for Rehabilitation of Soils and Surfaces after an Accident (RESSAC). Different ways to remove the top layer of soils are described, and especially the use of Decontaminating Vegetal Network (D.V.N.) combined with spraying of organic polymers. Real scale tests in the 30 km zone around the Chernobyl nuclear power plant showed that it is possible to achieve an excellent decontamination of agricultural fields (decontamination factor greater than 95%. (author)

  12. Technical Improvements to an Absorbing Supergel for Radiological Decontamination in Tropical Environments

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Michael D. [Argonne National Lab. (ANL), Argonne, IL (United States); Mertz, Carol J. [Argonne National Lab. (ANL), Argonne, IL (United States); Kivenas, Nadia [Argonne National Lab. (ANL), Argonne, IL (United States); demmer, Rick [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-01-01

    Argonne National Laboratory (Argonne) developed a superabsorbing gel-based process (SuperGel) for the decontamination of cesium from concrete and other porous building materials. Here, we report on results that tested the gel decontamination technology on specific concrete and ceramic formulations from a coastal city in Southeast Asia, which may differ significantly from some U.S. sources. Results are given for the evaluation of americium and cesium sequestering agents that are commercially available at a reasonable cost; the evaluation of a new SuperGel formulation that combines the decontamination properties of cesium and americium; the variation of the contamination concentration to determine the effects on the decontamination factors with concrete, tile, and brick samples; and pilot-scale testing (0.02–0.09 m2 or 6–12 in. square coupons).

  13. Concrete

    OpenAIRE

    Kruse Aagaard, Anders

    2015-01-01

    Concrete is a component of coherent transition between a concrete base and a wooden construction. The structure is based on a quantity of investigations of the design possibilities that arise when combining digital fabrication tools and material capacities.Through tangible experiments the project discusses materiality and digitally controlled fabrications tools as direct expansions of the architect’s digital drawing and workflow. The project sees this expansion as an opportunity to connect th...

  14. Pilot-scale decontamination solution test results HGTP-93-0702-02

    International Nuclear Information System (INIS)

    Clemmer, R.G.; Allen, R.P.; Bagaasen, L.M.; Fetrow, L.K.

    1993-05-01

    Decontamination solution testing constitutes a task of the Hanford Grout Technology Program (HGTP) at Pacific Northwest Laboratory (PNL). The HGTP provides technical support to the Westinghouse Hanford Company (WHC) Grout Disposal Program. Cementitious grout has been identified as the waste form for low-level radioactive waste. Grout processing equipment, including mixers, pumps, and piping, will require periodic maintenance. Decontamination of components is needed to reduce radiation dose to maintenance workers. The purpose of this work was to develop and test methods for decontaminating grout processing equipment. The proposed method of decontamination is to use a mild chemical solution, such as a 6 N citric acid to dissolve the grout. The method should effectively remove grout without causing degradation of grout processing equipment

  15. Environmental decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Cristy, G.A.; Jernigan, H.C. (eds.)

    1981-02-01

    The record of the proceedings of the workshop on environmental decontamination contains twenty-seven presentations. Emphasis is placed upon soil and surface decontamination, the decommissioning of nuclear facilities, and assessments of instrumentation and equipment used in decontamination. (DLS)

  16. Environmental decontamination

    International Nuclear Information System (INIS)

    Cristy, G.A.; Jernigan, H.C.

    1981-02-01

    The record of the proceedings of the workshop on environmental decontamination contains twenty-seven presentations. Emphasis is placed upon soil and surface decontamination, the decommissioning of nuclear facilities, and assessments of instrumentation and equipment used in decontamination

  17. Decontamination of a canyon crane at the Savannah River Plant

    International Nuclear Information System (INIS)

    Stevenson, D.A.; Moore, D.B.; Bowers, J.W.; Brown, D.L.

    1985-01-01

    Decontamination of the crane is reviewed in terms of the health physics aspects, controls during decontamination efforts, and the resultant radiation exposure rates for decontamination efforts. 17 figs.,

  18. Development of Practical Remediation Process for Uranium-Contaminated Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. S.; Kim, W. S.; Kim, G. N.; Moon, J. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    A volume reduction of the concrete waste by the appropriate treatment technologies will decrease the amount of waste to be disposed of and result in a reduction of the disposal cost and an enhancement of the efficiency of the disposal site. Our group has developed a 100 drums/year decontamination process and facilities for the decontamination of radioactive concrete. This practical scale process is little known. A practical decontamination process was developed to remove uranium from concrete pieces generated from the decommissioning of a uranium conversion plant. The concrete pieces are divided into two groups: concrete coated with and without epoxy. For the removal of epoxy from the concrete, direct burning by an oil flame is preferable to an electric heating method. The concrete blocks are crushed to below 30 mm and sifted to 1 mm. When the concrete pieces larger than 1 mm are sequentially washed with a clear washing solution and 1.0 M of nitric acid, most of their radioactivity reaches below the limit value of uranium for self-disposal. The concrete pieces smaller than 1 mm are decontaminated in a rotary washing machine by nitric acid, and an electrokinetic equipment is also used if their radioactivity is high.

  19. Development of Practical Remediation Process for Uranium-Contaminated Concrete

    International Nuclear Information System (INIS)

    Kim, S. S.; Kim, W. S.; Kim, G. N.; Moon, J. K.

    2013-01-01

    A volume reduction of the concrete waste by the appropriate treatment technologies will decrease the amount of waste to be disposed of and result in a reduction of the disposal cost and an enhancement of the efficiency of the disposal site. Our group has developed a 100 drums/year decontamination process and facilities for the decontamination of radioactive concrete. This practical scale process is little known. A practical decontamination process was developed to remove uranium from concrete pieces generated from the decommissioning of a uranium conversion plant. The concrete pieces are divided into two groups: concrete coated with and without epoxy. For the removal of epoxy from the concrete, direct burning by an oil flame is preferable to an electric heating method. The concrete blocks are crushed to below 30 mm and sifted to 1 mm. When the concrete pieces larger than 1 mm are sequentially washed with a clear washing solution and 1.0 M of nitric acid, most of their radioactivity reaches below the limit value of uranium for self-disposal. The concrete pieces smaller than 1 mm are decontaminated in a rotary washing machine by nitric acid, and an electrokinetic equipment is also used if their radioactivity is high

  20. Dry decontamination for tritiated wastes

    International Nuclear Information System (INIS)

    Shi Zhengkun; Wu Tao; Dan Guiping; Xie Yun

    2009-01-01

    To aim at decontamination of tritiated wastes, we have developed and fabricated a dry tritium decontamination system, which is designed to reduce tritium surface contamination of various alloy by UV, ozone and heating. The result indicates that the elevation of temperature can obviously improve decontamination effect. With 3 h irradiation by 365 nm UV at 220 degree C, it has a decontamination rate of 99% to stainless steel surface. Ozone can more obviously improve decontamination effect when metal was heated. Ozone has a decontamination effect beyond 95% to stainless steel, aluminum and brass at 220 degree C. Tritium surface concentration of metal has a little increase after decontamination. (authors)

  1. Methods for the decontamination of personnel recommended by a company doctor on the basis of recent research results

    International Nuclear Information System (INIS)

    Heinemann, G.

    1992-01-01

    There is no single panacea for all kinds of contamination and, thus, no standard procedure to be uniformly adopted in the decontamination of individuals. This means that methods of personnel decontamination vary according to the different working conditions encountered in research laboratories and units for the production of nuclear fuel and radionuclides on the one hand and nuclear power plants on the other hand. Some knowledge of the chemical properties of contaminating materials appears indispensable, but is mostly found wanting. A suitable method of personnel decontamination can by no means be defined as one that ensures the cleaning of contaminations from the skin surface. All decontamination measures, even the less aggressive ones, may result in incorporation. An intact skin offers the best protection against incorporation. It must be borne in mind that most contaminations occuring in nuclear power plants are of minor importance as regards dose. The damage to the affected individual from aggressive methods of removal will be much greater than that from any radioactivity remaining in the corneal layer. (orig.) [de

  2. The results of decontamination and decommissioning of experimental DUPIC equipment at PIEF 9405 hot cell

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H. H.; Park, J. J.; Shin, J. M.; Cho, K. H.; Yang, M. S.; Lee, E. P. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-02-01

    The characterization experiment for powder and sintered fuel had been performed using about 1 kg-U spent PWR fuel at No. 9405 hot-cell in PIEF(Post Irradiated Experiment Facility) since early in 1999. Currently, the experiments in PIEF have been completed. Since all DUPIC equipment in hot-cell are contaminated by high radioactive material, the decontamination and dismantlement must be performed remotely by M/S manipulator. During the radioactive waste packing and transportation, the reduction method of radiation exposure has to be considered. This report describes the basic plan for dismantlement/decontamination of the characterization equipment (power and sintered fuel). And methods of measurement/packing/transportation, method of dismantlement/decontamination of the experimental apparatus and the reduction method of radiation dose exposure, etc. are explained in order. 7 refs., 42 figs., 10 tabs. (Author)

  3. The feasibility of recycling contaminated concrete

    International Nuclear Information System (INIS)

    Ayers, K.W.; Corroon, W.; Parker, F.L.

    1999-01-01

    The changing mission of the Department of Energy along with the aging of many of its facilities has resulted in renewed emphasis on decontaminating and decommissioning surplus structures. Currently DOE is decontaminating some concrete and sending the clean material to C and D disposal facilities. In other instance, DOE is sending contaminated concrete to LLW disposal facilities. This paper examines the economic feasibility of decontaminating the concrete and recycling the rubble as clean aggregate. A probabilistic cost model was used to examine six potential recycling and disposal scenarios. The model predicted potential costs saving across the DOE complex of nearly one billion dollars. The ability of local markets to assimilate the recycled material was estimated for Washington, Idaho, Tennessee, New Mexico, and South Carolina. The relationships between a number of the economic model's variables were examined to develop operating ranges for initial managerial evaluation of recycling

  4. Simulation analysis of impact tests of steel plate reinforced concrete and reinforced concrete slabs against aircraft impact and its validation with experimental results

    International Nuclear Information System (INIS)

    Sadiq, Muhammad; Xiu Yun, Zhu; Rong, Pan

    2014-01-01

    Highlights: • Simulation analysis is carried out with two constitutive concrete models. • Winfrith model can better simulate nonlinear response of concrete than CSCM model. • Performance of steel plate concrete is better than reinforced concrete. • Thickness of safety related structures can be reduced by adopting steel plates. • Analysis results, mainly concrete material models should be validated. - Abstract: The steel plate reinforced concrete and reinforced concrete structures are used in nuclear power plants for protection against impact of an aircraft. In order to compare the impact resistance performance of steel plate reinforced concrete and reinforced concrete slabs panels, simulation analysis of 1/7.5 scale model impact tests is carried out by using finite element code ANSYS/LS-DYNA. The damage modes of all finite element models, velocity time history curves of the aircraft engine and damage to aircraft model are compared with the impact test results of steel plate reinforced concrete and reinforced concrete slab panels. The results indicate that finite element simulation results correlate well with the experimental results especially for constitutive winfrith concrete model. Also, the impact resistance performance of steel plate reinforced concrete slab panels is better than reinforced concrete slab panels, particularly the rear face steel plate is very effective in preventing the perforation and scabbing of concrete than conventional reinforced concrete structures. In this way, the thickness of steel plate reinforced concrete structures can be reduced in important structures like nuclear power plants against impact of aircraft. It also demonstrates the methodology to validate the analysis procedure with experimental and analytical studies. It may be effectively employed to predict the precise response of safety related structures against aircraft impact

  5. A decontamination technique for decommissioning waste

    International Nuclear Information System (INIS)

    Heki, H.; Hosaka, K.; Kuribayashi, N.; Ishikura, T.

    1993-01-01

    A large amount of radioactive metallic waste is generated from decommissioned commercial nuclear reactors. It is necessary from the point of environmental protection and resource utilization to decontaminate the contaminated metallic waste. A decommissioning waste processing system has been previously proposed considering such decommissioning waste characteristics as its large quantity, large radioactivity range, and various shapes and materials. The decontamination process in this system was carried out by abrasive blasting as pretreatment, electrochemical decontamination as the main process, and ultrasonic cleaning in water as post-treatment. For electrochemical decontamination, electrolytic decontamination for simple shaped waste and REDOX decontamination for complicated shaped waste were used as effective decontamination processing. This time, various kinds of actual radioactive contaminated samples were taken from operating power plants to simulate the decontamination of decommissioning waste. After analyzing the composition, morphogenesis and surface observation, electrolytic decontamination, REDOX decontamination, and ultrasonic cleaning experiments were carried out by using these samples. As a result, all the samples were decontaminated below the assumed exemption level(=4 x 10 -2 Bq/g). A maximum decontamination factor of over 104 was obtained by both electrolytic and REDOX decontamination. The stainless steel sample was easy to decontaminate in both electrochemical decontaminations because of its thin oxidized layer. The ultrasonic cleaning process after electrochemical decontamination worked effectively for removing adhesive sludge and the contaminated liquid. It has been concluded from the results mentioned above that electrolytic decontamination and REDOX decontamination are effective decontamination process for decontaminating decommissioning waste

  6. Concrete spaller. Innovative technology summary report

    International Nuclear Information System (INIS)

    1998-12-01

    The US Department of Energy (DOE) has numerous buildings and facilities that have become contaminated through operation of nuclear reactors, fuel fabrication processes, and research laboratory operations. These buildings and facilities, often constructed of concrete, need to be decontaminated before they can be safely decommissioned or demolished. Pacific Northwest National Laboratory's concrete spaller is a hand-held tool that can be used for decontaminating flat or slightly curved concrete surfaces, obtaining concrete samples, and in-depth removal from cracks in concrete. The concrete spaller includes a 9-ton hydraulic cylinder and spalling bit. It runs from a hydraulic pump that expands the spaller in pre-drilled holes in the concrete. The result is removal of concrete chunks that fall into the attached metal shroud. The concrete spaller is more efficient than traditional tools such as hand-held pneumatic scabblers and scalers. For example, the spaller is capable of spalling 1.3 m 3 /hr (0.23 ft 2 /min), compared to 1.1 m 2 /hr (0.20 ft 2 /min), for the baseline scabbler and scaler demonstrated at 3-mm (1/8-in.) depth. The spaller is also capable of removing concrete at a greater depth than traditional tools. Operating cost of the spaller ($128/m 2 or $11.93/ft 2 [optimum conditions]) is less than the baseline tools: scaler ($155/m 2 or $14.40/ft 2 ) and scabbler ($156/m 2 or $14.53/ft 2 )

  7. Results from the decontamination of and the shielding arrangements in the reactor pressure vessel in Oskarshamn 1-1994

    Energy Technology Data Exchange (ETDEWEB)

    Lowendahl, B. [OKG Aktiebolag, Figeholm (Sweden)

    1995-03-01

    In September 1992 Oskarshamn 1 was shut down in order to carry out measures to correct discovered deficiencies in the emergency cooling systems. Due to the results of a comprehensive non destructive test programme it was decided to perform a major replacement of pipes in the primary systems including a full system decontamination using the Siemens CORD process. The paper briefly presents the satisfying result of the decontamination performed in May-June 1993. When in late June 1993 cracks also were detected in the feed-water pipes situated inside the reactor pressure vessel (RPV) the plans were reconsidered and a large project was formed with the aim, in a first phase, to verify the integrity of the RPV. In order to make it possible to perform work manually inside the RPV special radiation protection measures had to be carried out. In January 1994 the lower region of the RPV was decontaminated, again using the CORD-process, followed by the installation of a special shielding construction in the RPV. The surprisingly good results of these efforts are also briefly described in the paper.

  8. Development of decontamination methods

    International Nuclear Information System (INIS)

    Kunze, S.; Dippel, T.; Hentschel, D.

    1976-01-01

    PVC floorings, fabricated by mixing of the basic components, showed no relation between content of fillers and decontamination results. Decontamination results are partly poorer, if the flooring contains a high concentration of the filler, especially if the latter consists mainly of hydrophilic materials. The coloring of the floorings seems to have no influence on the decontamination. Rubber floorings, fabricated by chemical reactions between polymers, vulcanization materials and fillers, show decontamination results depending definitely from the proper choice of the filler. Flooring types, containing lampblack, graphite, kaoline, barium sulfate and titanium oxide are easy to decontaminate. Increasing contents of hydrophilic filler cause a fall off in the decontamination results. The decontamination effectiveness and the homogenity of cleaning pastes based on hydrochloric acid, nitric acid, titanium oxide and polyethylene powders is strongly depended on the content of hydrochloric acid. Reduction of the content of this component to less than 2 w/O remains the effectiveness unchanged only if the titanium oxide-polyethylene powder mixture is substituted by a high density, highly surface active powder material. This type of paste containing no hydrochloric acid shows nearly the same decontamination effectiveness as standard pickling pastes containing about 30% hydrochlorid acid. Properly prepared salt powder turn out to be easily and successfully applied to metal surfaces by a flame spray technique. The thin layer of molten salts is a very effective decontamination to samples contaminated in the primary loop of a PWR. (orig.) [de

  9. Construction of Kashiwazaki-Kariwa Nuclear Power Station Results of manufacturing concrete

    International Nuclear Information System (INIS)

    Morishita, Hideki; Tsuchiya, Yoshimasa; Eguchi, Kiyoshi; Hosaka, Hiroshi

    1998-01-01

    The construction of Kashiwazaki-Kariwa Nuclear Power Station of Tokyo Electric Power Co., Inc. was completed in July, 1997. Seven nuclear power plants generate about 8.2 million kW, and it is the largest nuclear power station in the world. In the construction, from May, 1980 to August, 1996, the concrete of 2.42 million m 3 for architecture and 1.04 million m 3 for civil engineering, 3.46 million m 3 in total, and the mortar for artificial rock bed of 430,000 m 3 were manufactured and placed. The results of manufacturing concrete from beginning to finish are shown. The specification of concrete was different for No. 1 plant, No. 2 and 5 plants, No. 3 and 4 plants and No. 6 and 7 plants. As to the mixing of concrete, the specification and the materials used are reported. The features of the facilities for manufacturing concrete are explained. The flowchart of the quality control of materials and concrete is shown. The material testing of cement and aggregate, the test of water quality and the material testing of admixtures were carried out. As for concrete, the weight of unit volume, slump, air quantity, concrete temperature, chloride content, strength and alkali reactivity were examined. (K.I.)

  10. DECONTAMINATION TECHNOLOGIES FOR FACILITY REUSE

    International Nuclear Information System (INIS)

    Bossart, Steven J.; Blair, Danielle M.

    2003-01-01

    As nuclear research and production facilities across the U.S. Department of Energy (DOE) nuclear weapons complex are slated for deactivation and decommissioning (D and D), there is a need to decontaminate some facilities for reuse for another mission or continued use for the same mission. Improved technologies available in the commercial sector and tested by the DOE can help solve the DOE's decontamination problems. Decontamination technologies include mechanical methods, such as shaving, scabbling, and blasting; application of chemicals; biological methods; and electrochemical techniques. Materials to be decontaminated are primarily concrete or metal. Concrete materials include walls, floors, ceilings, bio-shields, and fuel pools. Metallic materials include structural steel, valves, pipes, gloveboxes, reactors, and other equipment. Porous materials such as concrete can be contaminated throughout their structure, although contamination in concrete normally resides in the top quarter-inch below the surface. Metals are normally only contaminated on the surface. Contamination includes a variety of alpha, beta, and gamma-emitting radionuclides and can sometimes include heavy metals and organic contamination regulated by the Resource Conservation and Recovery Act (RCRA). This paper describes several advanced mechanical, chemical, and other methods to decontaminate structures, equipment, and materials

  11. Monitoring of prestressed concrete pressure vessels. 1. An overview of concrete embedment strain instrumentation and calibration test results for selected concrete embedment strain meters

    International Nuclear Information System (INIS)

    Naus, D.J.; Hurtt, C.C.

    1978-01-01

    The report presents results of calibration tests on strain meters. The approach was divided into two phases: (1) an overview of meter performance criteria for PCPV applications and techniques for strain measurements in concrete and (2) procurement of commercially available gages and their evaluation to assess the reliability of manufacturer-supplied calibration factors. Calibration test results for gages embedded in 15.2-cm-diam by 54-cm cylindrical concrete specimens indicated that calibration factors should be determined (verified) by embedding samples of the gages in test specimens fabricated using a representative mix and that further research should be conducted on other measurement techniques based on inductance, capacitance, semiconductors, and fluidic principles

  12. Tensile strength of concrete under static and intermediate strain rates: Correlated results from different testing methods

    International Nuclear Information System (INIS)

    Wu Shengxing; Chen Xudong; Zhou Jikai

    2012-01-01

    Highlights: ► Tensile strength of concrete increases with increase in strain rate. ► Strain rate sensitivity of tensile strength of concrete depends on test method. ► High stressed volume method can correlate results from various test methods. - Abstract: This paper presents a comparative experiment and analysis of three different methods (direct tension, splitting tension and four-point loading flexural tests) for determination of the tensile strength of concrete under low and intermediate strain rates. In addition, the objective of this investigation is to analyze the suitability of the high stressed volume approach and Weibull effective volume method to the correlation of the results of different tensile tests of concrete. The test results show that the strain rate sensitivity of tensile strength depends on the type of test, splitting tensile strength of concrete is more sensitive to an increase in the strain rate than flexural and direct tensile strength. The high stressed volume method could be used to obtain a tensile strength value of concrete, free from the influence of the characteristics of tests and specimens. However, the Weibull effective volume method is an inadequate method for describing failure of concrete specimens determined by different testing methods.

  13. Development of System for Evaluating Concrete Strength Deterioration Due to Radiation and Resultant Heat

    International Nuclear Information System (INIS)

    Maruyama, I.; Kontani, O.; Ishizawa, A.; Takizawa, M.; Sato, O.

    2012-01-01

    Evaluation of the soundness of concrete exposed to irradiation has been studied within the framework of a project of the Nuclear and Industrial Safety Agency (NISA) 'Japan Ageing Management Program for System Safety'. This contribution presents the background to the existing evaluation processes, a review of the irradiation exposure effect on concrete and needs for irradiation testing. Based on results of this study, working assumptions for the development of an evaluation system are derived, and an overall picture of a numerical model as well as a framework for evaluating concrete soundness under irradiated conditions are proposed. (author)

  14. Surface decontamination

    International Nuclear Information System (INIS)

    Silva, S. da; Teixeira, M.V.

    1986-06-01

    The general methods of surface decontamination used in laboratory and others nuclear installations areas, as well as the procedures for handling radioactive materials and surfaces of work are presented. Some methods for decontamination of body external parts are mentioned. The medical supervision and assistance are required for internal or external contamination involving or not lesion in persons. From this medical radiation protection decontamination procedures are determined. (M.C.K.) [pt

  15. Experimental results on salt concrete for barrier elements made of salt concrete in a repository for radioactive waste in a salt mine

    International Nuclear Information System (INIS)

    Gutsch, Alex-W.; Preuss, Juergen; Mauke, Ralf

    2012-01-01

    The Bartensleben rock salt mine in Germany was used as a repository for low and intermediate level radioactive waste from 1971 to 1991 and from 1994 to 1998. The repository with an overall volume of about 6 million m 3 has to be closed. Salt concrete is used for the refill of the voids of the repository. The concrete mixtures contain crushed salt instead of natural aggregates as the void filling material should be as similar to the salt rock as possible. Very high requirements regarding low heat development and little or even no cracking during concrete hardening had to be fulfilled even for the barrier elements made from salt concrete which separate the radioactive waste from the environment. Requirements for the salt concrete were set up with regard to the fluidity of the fresh concrete during the hardening process and its durability. In the view of a comprehensive numerical calculations of the temperature development and thermal stresses in the massive salt concrete elements of the backfill of the voids, experimental results for material properties of the salt concrete are presented: mixture of the salt concrete, thermodynamic properties (adiabatic heat release, thermal dilatation, thermal conductivity and heat capacity), mechanical short term properties, creep (under tension, under compression), autogenous shrinkage

  16. New Trends for Reinforced Concrete Structures: Some Results of Exploratory Studies

    Directory of Open Access Journals (Sweden)

    Ricardo N. F. Carmo

    2017-10-01

    Full Text Available Today, the concrete sector is being pushed to innovate in order to better address current challenges with higher competitiveness and more sustainable solutions. Different research studies have been conducted all over the world in which novel approaches and paths were proposed. It is important to spread information to define new strategies for the future of this industry. The enhancement of concrete properties and the impact of these changes in structural design are some of the topics analysed in those studies. This paper presents four experimental studies conducted by the authors where different types of concrete and structural members were tested. The common goal of these studies was to develop innovative solutions with high performance and low environmental impact. The scope of the first study was the structural behaviour of members produced with lightweight aggregate concrete (LWAC. Results of several beams, ties, and slabs are herein presented and analysed. The advantage of using glass fibre–reinforced polymer (GFRP rebars was addressed in a second study, and main results obtained with this type of rebar are also herein presented. Recent advances in nanotechnology led to the development of concretes incorporating nanoparticles into the binder matrix. Typically, these nanoparticles have a diameter of 10–300 nanometers and are added to the mixture to reduce the porosity and increase the density of the binder matrix, improving the mechanical properties and durability. To analyse their influence on steel-to-concrete bonding and on the shear and flexural behaviour of the beams was the main goal of the third study herein described. Finally, a new concept to produce reinforced concrete members with high durability using a special concrete cover, which was the goal of the fourth study, is also herein presented.

  17. Non-destructive decontamination of building materials

    Science.gov (United States)

    Holecek, Josef; Otahal, Petr

    2015-11-01

    For nondestructive radiation decontamination of surfaces it is necessary to use varnishes, such as ARGONNE, DG1101, DG1108, etc. This text evaluates the use of manufactured strippable coatings for radiation decontamination. To evaluate decontamination capability of such coatings the following varnishes were selected and subsequently used: AZ 1-700 and AXAL 1807S. The varnishes were tested on different building materials surfaces contaminated by short-term radioisotopes of Na-24 or La-140, in water soluble or water insoluble forms. Decontamination quality was assessed by the decontamination efficiency value, defined as the proportion of removed activity to the applied activity. It was found that decontamination efficiency of both used varnishes depends not only on the form of contaminant, but in the case of application of AXAL 1807S varnish it also depends on the method of its application on the contaminated surface. The values of the decontamination efficiency for AZ1-700 varnish range from 46% for decontamination of a soluble form of the radioisotope from concrete surface to 98% for the decontamination of a soluble form of the radioisotope from ceramic tile surface. The decontamination efficiency values determined for AXAL 1807S varnish range from 48% for decontamination of a soluble form of the radioisotope from concrete surface to 96% for decontamination of an insoluble form of the radioisotope from ceramic tile surface. Comparing these values to the values given for the decontaminating varnishes we can conclude that AXAL 1807S varnish is possible to use on all materials, except highly porous materials, such as plasterboard or breeze blocks, or plastic materials. AZ 1-700 varnish can be used for all dry materials except plasterboard.

  18. Development of the Decontamination and Decommissioning Technology for Nuclear Facilities

    International Nuclear Information System (INIS)

    Lee, K. W.; Moon, J. K.; Won, C. H.

    2010-04-01

    The research results could be used for a design of a remote ablation decontamination system and ultimately applicable for an decontamination of high radiation facilities such as the DUPIC and PIEF. The evaluation technology of decommissioning process must be developed and will be used for the ALARA planning tool of decommissioning process and demonstrated for tools of decommissioning equipment. Also, this technology can be used for tools workplaces with high work difficulty such as large-scale chemical plant, under water and space. It is expected that the technology for a volume reduction and self-disposal of dismantled concrete wastes can be contributed to the establishment of a management plan for radioactive dismantled concrete wastes through the minimization of final waste volume

  19. Innovative technology summary report: Concrete grinder

    International Nuclear Information System (INIS)

    1998-09-01

    The Flex concrete grinder is a lightweight, hand-held concrete and coating removal system used for decontaminating or stripping concrete surfaces. The US Department of Energy has successfully demonstrated it for decontaminating walls and floors for free release surveys prior to demolition work. The grinder is an electric-powered tool with a vacuum port for dust extraction and a diamond grinding wheel. The grinder is suitable for flat or slightly curved surfaces and results in a smooth surface, which makes release surveys more reliable. The grinder is lightweight and produces very little vibration, thus reducing worker fatigue. The grinder is more efficient than traditional baseline, tools at removing contamination from concrete surfaces (more than four times faster than hand-held pneumatic scabbling and scaling tools). Grinder consumables (i.e., replacement diamond grinding wheel) are more expensive than the replacement carbide parts for the scaler and scabbler. However, operating costs are outweighed by the lower purchase price of the grinder (50% of the price of the baseline scaler and 8% of the price of the baseline scabbler). Overall, the concrete grinder is an attractive alternative to traditional scabbling and scaling pneumatic tools. To this end, in July 1998, the outer rod room exposed walls of the Safe Storage Enclosure (SSE), an area measuring approximately 150 m 2 , may be decontaminated with the hand-held grinder. This concrete grinder technology was demonstrated for the first time at the DOE's Hanford Site. Decontamination of a sample room walls was performed at the C Reactor to free release the walls prior to demolition. The demonstration was conducted by onsite D and D workers, who were instructed by the vendor prior to and during the demonstration

  20. Decontamination sheet

    International Nuclear Information System (INIS)

    Hirose, Emiko; Kanesaki, Ken.

    1995-01-01

    The decontamination sheet of the present invention is formed by applying an adhesive on one surface of a polymer sheet and releasably appending a plurality of curing sheets. In addition, perforated lines are formed on the sheet, and a decontaminating agent is incorporated in the adhesive. This can reduce the number of curing operation steps when a plurality steps of operations for radiation decontamination equipments are performed, and further, the amount of wastes of the cured sheets, and operator's exposure are reduced, as well as an efficiency of the curing operation can be improved, and propagation of contamination can be prevented. (T.M.)

  1. Facility decontamination technology workshop

    International Nuclear Information System (INIS)

    1980-10-01

    Purpose of the meeting was to provide a record of experience at nuclear facilities, other than TMI-2, of events and incidents which have required decontamination and dose reduction activities, and to furnish GPU and others involved in the TMI-2 cleanup with the results of that decontamination and dose reduction technology. Separate abstracts were prepared for 24 of the 25 papers; the remaining paper had been previously abstracted

  2. Facility decontamination technology workshop

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-10-01

    Purpose of the meeting was to provide a record of experience at nuclear facilities, other than TMI-2, of events and incidents which have required decontamination and dose reduction activities, and to furnish GPU and others involved in the TMI-2 cleanup with the results of that decontamination and dose reduction technology. Separate abstracts were prepared for 24 of the 25 papers; the remaining paper had been previously abstracted. (DLC)

  3. Decontamination method

    International Nuclear Information System (INIS)

    Tsujimura, Hiroshi; Ono, Shigeki; Tada, Nobuo; Tamai, Yasumasa; Okada, Masaya; Kurihara, Masayuki; Onuki, Toyomitsu; Toyota, Seiichi

    1998-01-01

    Before contamination of materials to be decontaminated, a surface of a region where a strippable paint is to be coated is smoothed by an epoxy resin previously. Then, a waterproof sheet is extended to the material to be decontaminated, and the strippable paint is applied to the periphery or the entire surface of the sheet. In order to facilitate peeling, the strippable paint is not applied to a portion of the outer circumference of the sheet. Even if the contaminating circumstance is an air atmosphere or a liquid such as reactor water, since the sheet itself has waterproofness and the strippable paint excellent in gas and water tightness is applied to the periphery, contamination is eliminated. When decontaminating the material to be decontaminated having contaminated surfaces, if the sheet for the start of peeling is picked up and the sheet is peeled, the strippable paint at the periphery thereof can be peeled off together with the sheet. (N.H.)

  4. Decontamination method

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimura, Hiroshi; Ono, Shigeki; Tada, Nobuo; Tamai, Yasumasa; Okada, Masaya; Kurihara, Masayuki [Hitachi Ltd., Tokyo (Japan); Onuki, Toyomitsu; Toyota, Seiichi

    1998-10-27

    Before contamination of materials to be decontaminated, a surface of a region where a strippable paint is to be coated is smoothed by an epoxy resin previously. Then, a waterproof sheet is extended to the material to be decontaminated, and the strippable paint is applied to the periphery or the entire surface of the sheet. In order to facilitate peeling, the strippable paint is not applied to a portion of the outer circumference of the sheet. Even if the contaminating circumstance is an air atmosphere or a liquid such as reactor water, since the sheet itself has waterproofness and the strippable paint excellent in gas and water tightness is applied to the periphery, contamination is eliminated. When decontaminating the material to be decontaminated having contaminated surfaces, if the sheet for the start of peeling is picked up and the sheet is peeled, the strippable paint at the periphery thereof can be peeled off together with the sheet. (N.H.)

  5. Cracked reinforced concrete walls of chimneys, silos and cooling towers as result of using formworks

    Directory of Open Access Journals (Sweden)

    Maj Marek

    2018-01-01

    Full Text Available There are presented in this paper some problems connected with reinforced concrete shell objects operation in the aggressive environment and built in method of formworks. Reinforced concrete chimneys, cooling towers, silos and other shells were built for decades. Durability of cracked shells are one of the most important parameters during process of designing, construction and exploitation of shells. Some reasons of appearance of horizontal and vertical cracks as temperature, pressure of stored material, live loads e.g. dynamic character of wind, moisture, influence of construction joints, thermal insulation, chemistry active environmental etc. reduce the carrying capacity of the walls. Formworks, as is occurred recently, are the reason for technological joints with leaking connection, imperfections of flexible formworks slabs and as result can initiate cracks. Cracked surface of this constructions causes decreasing capacity and lower the state of reliability. Horizontal, vertical cracks can caused corrosion of concrete and steel bars, decreasing stiffness of contraction, increasing of deflection and carbonation of concrete cover. Local and global imperfactions of concrete shells are increasing according to greater number of cracks...

  6. CO2 pellet blasting literature search and decontamination scoping tests report

    International Nuclear Information System (INIS)

    Archibald, K.E.

    1993-12-01

    Past decontamination and solvent recovery activities at the Idaho Chemical Processing Plant (ICPP) have resulted in the accumulation of 1.5 million gallons of radioactively contaminated sodium-bearing liquid waste. Future decontamination activities at the ICPP could result in the production of 5 million gallons or more of sodium-bearing waste using current decontamination techniques. Chemical decontamination flushes have provided a satisfactory level of decontamination. However, this method generates large amounts of sodium-bearing secondary waste. Steam jet cleaning has also been used with a great deal of success but cannot be used on concrete or soft materials. With the curtailment of reprocessing at the ICPP, the focus of decontamination is shifting from maintenance for continued operation of the facilities to decommissioning. Treatment of sodium-bearing waste is a particularly difficult problem due to the high content of alkali metals in the sodium-bearing liquid waste. It requires a very large volume of cold chemical additive for calcination. In addition, the sodium content of the sodium-bearing waste exceeds the limit that can be incorporated into vitrified waste without the addition of glass-forming compounds (primarily silicon) to produce an acceptable immobilized waste form. The primary initiatives of the Decontamination Development Program is the development of methods to eliminate/minimize the use of sodium-bearing decontamination chemicals and to minimize all liquid decontamination wastes. One method chosen for cold scoping studies during FY-93 was CO 2 pellet blasting. CO 2 pellet blasting has been used extensively by commercial industries for general cleaning. However, using this method for decontamination of nuclear materials is a fairly new concept. The following report discusses the research and scoping tests completed on CO 2 pellet blasting

  7. Coolant system decontamination

    International Nuclear Information System (INIS)

    Anstine, L.D.; James, D.B.; Melaika, E.A.; Peterson, J.P.

    1981-01-01

    An improved method for decontaminating the coolant system of water cooled nuclear power reactors and for regenerating the decontamination solution is described. A small amount of one or more weak-acid organic complexing agents is added to the reactor coolant, and the pH is adjusted to form a decontamination solution which is circulated throughout the coolant system to dissolve metal oxides from the interior surfaces and complex the resulting metal ions and radionuclide ions. The coolant containing the complexed metal ions and radionuclide ions is passed through a strong-base anion exchange resin bed which has been presaturated with a solution containing the complexing agents in the same ratio and having the same pH as the decontamination solution. As the decontamination solution passes through the resin bed, metal-complexed anions are exchanged for the metal-ion-free anions on the bed, while metal-ion-free anions in the solution pass through the bed, thus removing the metal ions and regenerating the decontamination solution. (author)

  8. Decontamination of nuclear facilities

    International Nuclear Information System (INIS)

    1982-01-01

    Thirty-seven papers were presented at this conference in five sessions. Topics covered include regulation, control and consequences of decontamination; decontamination of components and facilities; chemical and non-chemical methods of decontamination; and TMI decontamination experience

  9. Self-Placing Concrete

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Certain concrete pours have areas where the congestion of reinforcing bars make placement of concrete almost impossible. Using conventional placing and vibration techniques, the resulting concrete can have considerable honeycombing due to the development of voids. Self-placing concrete is a possible solution to the problem. Also known as self-compactable concrete, self-consolidating concrete, flowable concrete, and non-vibration concrete. These concretes eliminate the need for vibration in a ...

  10. Efficacy of liquid and foam decontamination technologies for chemical warfare agents on indoor surfaces.

    Science.gov (United States)

    Love, Adam H; Bailey, Christopher G; Hanna, M Leslie; Hok, Saphon; Vu, Alex K; Reutter, Dennis J; Raber, Ellen

    2011-11-30

    Bench-scale testing was used to evaluate the efficacy of four decontamination formulations on typical indoor surfaces following exposure to the liquid chemical warfare agents sarin (GB), soman (GD), sulfur mustard (HD), and VX. Residual surface contamination on coupons was periodically measured for up to 24h after applying one of four selected decontamination technologies [0.5% bleach solution with trisodium phosphate, Allen Vanguard Surface Decontamination Foam (SDF™), U.S. military Decon Green™, and Modec Inc. and EnviroFoam Technologies Sandia Decontamination Foam (DF-200)]. All decontamination technologies tested, except for the bleach solution, performed well on nonporous and nonpermeable glass and stainless-steel surfaces. However, chemical agent residual contamination typically remained on porous and permeable surfaces, especially for the more persistent agents, HD and VX. Solvent-based Decon Green™ performed better than aqueous-based bleach or foams on polymeric surfaces, possibly because the solvent is able to penetrate the polymer matrix. Bleach and foams out-performed Decon Green for penetrating the highly polar concrete surface. Results suggest that the different characteristics needed for an ideal and universal decontamination technology may be incompatible in a single formulation and a strategy for decontaminating a complex facility will require a range of technologies. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Study on LOMI decontamination technology

    International Nuclear Information System (INIS)

    Huang Fuduan; Yu Degui; Lu Jingju; Xie Yinyan

    1993-10-01

    The results of decontamination technique of Low-Oxidation-State Metal-Ion (LOMI) reagents developed from 1986 to 1991 in the laboratory are introduced. The experiments included preparation of LOMI reagents, de-filming efficiency, corrosion behavior of typical alloys, decontamination factors of reagents for contaminated materials and components have proved that the NP/LOMI decontamination method and treatment technique of waste water are feasible and have some advantages. The preparation of LOMI reagent with low concentration of formic acid by reduced pressure distilling technique and the utilization ratio of vanadium reached to 95% by second electrolysis are the main contributions of the study to the decontamination technique

  12. Decontamination of radioisotope production facility

    International Nuclear Information System (INIS)

    Daryoko, M.; Yatim, S.; Suseno, H.; Wiratmo, M.

    1998-01-01

    The strippable coating method use phosphoric glycerol and irradiated latex as supporting agents have been investigated. The investigation used some decontaminating agents: EDTA, citric acid, oxalic acid and potassium permanganate were combined with phosphoric glycerol supporting agent, then EDTA Na 2 , sodium citric, sodium oxalic and potassium permanganate were combined with irradiated latex supporting agent. The study was needed to obtain the representative operating data, will be implemented to decontamination the Hot Cell for radioisotope production. The experiment used 50x50x1 mm stainless steel samples and contaminated by Cs-137 about 1.1x10 -3 μCi/cm 2 . This samples according to inner cover of Hot Cell material, and Hot Cell activities. The decontamination factor results of the investigation were: phosphoric glycerol as supporting agent, about 20 (EDTA as decontaminating agent) to 47 (oxalic acid as decontaminating agent), and irradiated latex as supporting agent, about 11.5 (without decontamination agent) to 27 (KMnO 4 as decontaminating agent). All composition of the investigation have been obtained the good results, and can be implemented for decontamination of Hot Cell for radioisotope production. The irradiated latex could be recommended as supporting agent without decontaminating agent, because it is very easy to operate and very cheap cost. (author)

  13. New methods and techniques for decontamination in maintenance or decommissioning operations. Results of a co-ordinated research programme 1994-1998

    International Nuclear Information System (INIS)

    1998-06-01

    Decontamination of nuclear facilities is a subject of increasing importance as the nuclear community considers the issues related to the decommissioning of surplus or obsolete facilities and making modifications to operational facilities, or conducts the necessary inspections and maintenance to permit continued efficient and safe operation of existing facilities. Previous co-ordinated research programmes (CRP) conducted respectively from 1984 to 1987, and from 1989 to 1993, highlighted the role of decontamination within the overall domain of decommissioning. Having recognized technological progress in decontamination and the large potential for optimization, the CRP on New Methods and Techniques for Optimization of Decontamination for Maintenance or Decommissioning was launched and conducted by the IAEA from 1994 to 1998. Concluding reports that summarized the work undertaken under the aegis of the CRP were presented at the third and final Research Co-ordination Meeting (RCM) held in Mol, Belgium, 12-16 January 1998 and are collected in this Technical Document. Operating experience in real-scale applications, lessons learned, key results in laboratory scale or pilot scale research, and validation of mathematical models, are among the most significant achievements of the CRP and have been highlighted

  14. The results of the CCI-3 reactor material experiment investigating 2-D core-concrete interaction and debris coolability with a siliceous concrete crucible

    International Nuclear Information System (INIS)

    Farmer, M.T.; Basu, S.

    2006-01-01

    The OECD-sponsored Melt Coolability and Concrete Interaction (MCCI) program is conducting reactor material experiments and associated analysis with the objectives of resolving the ex-vessel debris coolability issue, and to address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two objectives will demonstrate the efficacy of severe accident management guidelines for existing plants and provide the technical basis for better containment designs for future plants. Despite years of international research, there are remaining uncertainties in the models that evaluate the lateral vs. axial power split during core-concrete interaction because of a lack of truly two-dimensional experiment data. As a result, there are differences in the 2-D cavity erosion predicted by codes such as MELCOR, WECHSL, and COSACO. In the continuing effort to bridge this data gap, the third in a series of large scale Core-Concrete Interaction experiments (CCI-3) has been conducted as part of the MCCI program. This test involved the interaction of a 375 kg core-oxide melt within a two-dimensional siliceous concrete crucible. The initial phase of the test was conducted under dry conditions. After a predetermined ablation depth was reached, the cavity was flooded to obtain data on the coolability of a core melt after core-concrete interaction has progressed for some time. This paper provides a summary description of the test facility and an overview of test results

  15. Remote methods for decontamination and decommissioning operations

    International Nuclear Information System (INIS)

    DeVore, J.R.

    1986-01-01

    Three methods for the decontamination and decommissioning of nuclear facilities are described along with operational experience associated with each method. Each method described in some way reduces radiation exposure to the operating personnel involved. Electrochemical decontamination of process tanks is described using an in-situ method. Descriptions of two processes, electropolishing and cerium redox decontamination, are listed. A method of essentially smokeless cutting of process piping using a plasma-arc cutting torch is described. In one technique, piping is cut remotely from a distance using a specially modified torch holder. In another technique, cutting is done with master-slave manipulators inside a hot cell. Finally, a method for remote cutting and scarification of contaminated concrete is described. This system, which utilizes high-pressure water jets, is coupled to a cutting head or rotating scarification head. The system is suited for cutting contaminated concrete for removal or removing a thin layer in a controlled manner for decontamination

  16. Site decontamination

    International Nuclear Information System (INIS)

    Bicker, A.E.

    1981-01-01

    Among the several DOE sites that have been radiologically decontaminated under the auspices of the Nevada Operations Office are three whose physical characteristics are unique. These are the Tatum Dome Test Site (TDTS) near Hattiesburg, Mississippi; a location of mountainous terrain (Pahute Mesa) on the Nevada Test Site; and the GNOME site near Carlsbad, New Mexico. In each case the contamination, the terrain, and the climate conditions were different. This presentation includes a brief description of each site, the methods used to perform radiological surveys, the logistics required to support the decontamination (including health physics and sample analysis), and the specific techniques used to reduce or remove the contamination

  17. Studies on residue-free decontaminants for chemical warfare agents.

    Science.gov (United States)

    Wagner, George W

    2015-03-17

    Residue-free decontaminants based on hydrogen peroxide, which decomposes to water and oxygen in the environment, are examined as decontaminants for chemical warfare agents (CWA). For the apparent special case of CWA on concrete, H2O2 alone, without any additives, effectively decontaminates S-2-(diisopropylamino)ethyl O-ethyl methylphosphonothioate (VX), pinacolyl methylphosphorofluoridate (GD), and bis(2-choroethyl) sulfide (HD) in a process thought to involve H2O2 activation by surface-bound carbonates/bicarbonates (known H2O2 activators for CWA decontamination). A plethora of products are formed during the H2O2 decontamination of HD on concrete, and these are characterized by comparison to synthesized authentic compounds. As a potential residue-free decontaminant for surfaces other than concrete (or those lacking adsorbed carbonate/bicarbonate) H2O2 activation for CWA decontamination is feasible using residue-free NH3 and CO2 as demonstrated by reaction studies for VX, GD, and HD in homogeneous solution. Although H2O2/NH3/CO2 ("HPAC") decontaminants are active for CWA decontamination in solution, they require testing on actual surfaces of interest to assess their true efficacy for surface decontamination.

  18. Comparison of vibration test results for Atucha II NPP and large scale concrete block models

    International Nuclear Information System (INIS)

    Iizuka, S.; Konno, T.; Prato, C.A.

    2001-01-01

    In order to study the soil structure interaction of reactor building that could be constructed on a Quaternary soil, a comparison study of the soil structure interaction springs was performed between full scale vibration test results of Atucha II NPP and vibration test results of large scale concrete block models constructed on Quaternary soil. This comparison study provides a case data of soil structure interaction springs on Quaternary soil with different foundation size and stiffness. (author)

  19. Results of polarization resistance and impedance of steel bars embedded in carbonated concrete contaminated with chlorides

    International Nuclear Information System (INIS)

    Andrade, C.; Alonso, C.; Gonzalez, J.A.

    1989-01-01

    Laboratory results of the corrosion rate of steel embedded in carbonated concrete contaminated with chlorides determined through the Polarization Resistance method are presented here as examples of the possibilities offered by this technique in order to monitor the reinforcement corrosion process. The Rp technique has the advantages of fast response, simple and relatively accurate. Contrasts with gravimetric losses are presented. The A.C. Impedance measurements determined on the same specimens are also presented. The difficulties found in the interpretation of the results are stressed. R T values cannot easily be obtained. Several electrical circuits which may model the behaviour of the steel/concrete system are discussed. Finally, comments on the basic criteria to interpret results of both techniques are given. (author) 4 refs., 6 figs

  20. Gentilly 1: decontamination program

    International Nuclear Information System (INIS)

    Le, H.; Denault, P.

    1985-01-01

    The Gentilly 1 station, a 250-MW(e) light-water-cooled and heavy-water-moderated nuclear reactor, is being decommissioned to a static state (variant of stage 1) condition by Atomic Energy of Canada Limited (AECL). The scope of the decontamination program at the Gentilly 1 site includes the fuel pool and associated systems, the decontamination center, the laundry, the feedwater pumps and piping systems, the service building ventilation and drainage systems, and miscellaneous floor and wall areas. After an extensive literature review for acceptable decontamination methods, it was decided that the decontamination equipment used at Gentilly 1 during the program would include a hydrolaser, a scarifier, chipping hammers, a steam cleaner, an ultrasonic bath, and cutting tools. In addition, various foams, acids, detergents, surfactants, and abrasives are used alone and in tandem with the above equipment. This paper highlights the result of these decontaminations, their effectiveness, and the recommendation for future application. The methodology in performing these operations are also presented

  1. A study on environmental pollution caused by radioactive substances and its countermeasure techniques. Part 3. Development on decontamination techniques with high pressure cleaning method

    International Nuclear Information System (INIS)

    Narita, Yasunori; Nozaki, Atsuo; Kakuma, Takayuki; Shinohara, Naohide; Yoshino, Hiroshi

    2012-01-01

    A huge area of Fukushima was contaminated by the radiation released from the nuclear disaster. As a result, decontamination has become an urgent task in densely populated area and developments of an effective decontamination method are desired. So, we carried out the plan of the decontamination methods with a high pressure cleaner in present study. Surface with covered with concrete materials at horizontal plane was washed with high pressure cleaner, consequently, radioactivity was approximately 80% decreased. Further, the wash act with brushing are raised efficiency by 10%. So, the case of washing with surfactant shows no increase efficiency. (author)

  2. On the Determination of Concrete Armour Unit Stress including Specific Results related to Dolosse

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Howell, G.L.; Liu, Z.

    1991-01-01

    Failures of rubble mound breakwaters armoured with complex types of unreinforced concrete armour units are often due to breakage. This happens when the stresses exceed the material strength. Sufficient parametric studies of the stresses are not yet available to produce design diagrams for structu......Failures of rubble mound breakwaters armoured with complex types of unreinforced concrete armour units are often due to breakage. This happens when the stresses exceed the material strength. Sufficient parametric studies of the stresses are not yet available to produce design diagrams...... and scale effects. Moreover, some results from the Crescent City Prototype Dolosse study are presented and related to results from small-de model tests. A preliminary design diagram for Dolosse ir presented as well....

  3. Full system decontamination. AREVAs experience in decontamination prior to decommissioning

    International Nuclear Information System (INIS)

    Topf, Christian

    2010-01-01

    Minimizing collective radiation exposure and producing free-release material are two of the highest priorities in the decommissioning of a Nuclear Power Plant (NPP). Full System Decontamination (FSD) is the most effective measure to reduce source term and remove oxide layer contamination within the plant systems. FSD is typically a decontamination of the primary coolant circuit and the auxiliary systems. In recent years AREVA NP has performed several FSDs in PWRs and BWRs prior to decommissioning by applying the proprietary CORD copyright family and AMDA copyright technology. Chemical Oxidation Reduction Decontamination or CORD represents the chemical decontamination process while AMDA stands for Automated Mobile Decontamination Appliance, AREVA NPs decontamination equipment. Described herein are the excellent results achieved for the FSDs applied at the German PWRs Stade in 2004 and Obrigheim in 2007 and for the FSDs performed at the Swedish BWRs, Barsebaeck Unit 1 in 2007 and Barsebaeck Unit 2 in 2008. All four FSDs were performed using the AREVA NP CORD family decontamination technology in combination with the AREVA NP decontamination equipment, AMDA. (orig.)

  4. On the Determination of Concrete Armour Unit Stress including Specific Results related to Dolosse

    OpenAIRE

    Burcharth, H. F.; Howell, G.L.; Liu, Z.

    1991-01-01

    Failures of rubble mound breakwaters armoured with complex types of unreinforced concrete armour units are often due to breakage. This happens when the stresses exceed the material strength. Sufficient parametric studies of the stresses are not yet available to produce design diagrams for structural integrity. The paper presents a general discussion of the problems related to stress etermination and describes the results and the analyses of model tests with 200 kg and 200 g load-cell instrume...

  5. Pervious Concrete

    OpenAIRE

    Torsvik, Øyvind André Hoff

    2012-01-01

    Pervious concrete is a material with a high degree of permeability but generally low strength. The material is primarily used for paving applications but has shown promise in many other areas of usage. This thesis investigates the properties of pervious concrete using normal Norwegian aggregates and practices. An overview of important factors when it comes to designing and producing pervious concrete is the result of this investigation. Several experiments have been performed in the concrete ...

  6. Examination of decontamination of various materials at houses in difficult-to-return zone

    International Nuclear Information System (INIS)

    Mori, Airi; Tanabe, Tsutomu; Kato, Mitsugu; Wada, Takao

    2017-03-01

    Large quantities of radioactive materials were released into the environment as a result of the TEPCO Fukushima Daiichi Nuclear Power Station accident. Residential areas and forest areas near the power station were contaminated with the radioactive materials. Outside of the houses, schools and the other buildings are being decontaminated by national authority and local government. On the other hand, the materials (such as walls, floors, or windows) which constitute the houses are not decontaminated officially. In order to prepare decontamination methods that can be applied easily, we conducted examinations of decontamination for various materials in houses. Fibrous materials, woods, glasses, concretes, plastics, vinyl chloride materials, metals and synthetic leathers were used in our examinations. These materials were collected from houses in difficult-to-return zone, and were contaminated by radioactive materials released by the accident. Dry methods (suction, wiping, adsorption and peelable coating), wet methods (wiping, brushing, polishing and washing) and physical method (peeling of materials) were used for decontamination. As a result of our examinations, materials with low water permeability, such as glasses, concretes, vinyl chloride materials and metals, were able to be decontaminated efficiently (about 90% reduction) by using wet methods. Materials with high water permeability like woods were relatively well decontaminated by peelable coating (about 60%–70% reduction). However, any methods except for physical method were not effective for tatami. It seems the most reasonable way to replace old surface of tatami with new one. In addition to the examination described above, the difference of contamination reduction effect between chemical properties of detergents and the effect of rubbing of peelable coating were also examined. Finally, the most effective method was summarized based on these examinations. (author)

  7. Pre-test analysis results of a PWR steel lined pre-stressed concrete containment model

    International Nuclear Information System (INIS)

    Basha, S.M.; Ghosh, Barnali; Patnaik, R.; Ramanujam, S.; Singh, R.K.; Kushwaha, H.S.; Venkat Raj, V.

    2000-02-01

    Pre-stressed concrete nuclear containment serves as the ultimate barrier against the release of radioactivity to the environment. This ultimate barrier must be checked for its ultimate load carrying capacity. BARC participated in a Round Robin analysis activity which is co-sponsored by Sandia National Laboratory, USA and Nuclear Power Engineering Corporation Japan for the pre-test prediction of a 1:4 size Pre-stressed Concrete Containment Vessel. In house finite element code ULCA was used to make the test predictions of displacements and strains at the standard output locations. The present report focuses on the important landmarks of the pre-test results, in sequential terms of first crack appearance, loss of pre-stress, first through thickness crack, rebar and liner yielding and finally liner tearing at the ultimate load. Global and local failure modes of the containment have been obtained from the analysis. Finally sensitivity of the numerical results with respect to different types of liners and different constitutive models in terms of bond strength between concrete and steel and tension-stiffening parameters are examined. The report highlights the important features which could be observed during the test and guidelines are given for improving the prediction in the post test computation after the test data is available. (author)

  8. Nuclear decontamination

    International Nuclear Information System (INIS)

    LeSurf, J.E.

    1981-01-01

    Decontamination may be accomplished by chemical, electrical, or mechanical means. Recently there have been significant developments in all three categories as well as an increased tendency to combine techniques, either simultaneously (e.g. by adding chemicals to water jets) or sequentially (e.g. by using a mechanical method to remove loose contamination, followed by a chemical method for more tightly bound activity). Some developments in the different techniques are discussed, together with typical applications of each. (author)

  9. Decontaminating method

    International Nuclear Information System (INIS)

    Furukawa, Toshiharu; Shibuya, Kiichiro.

    1985-01-01

    Purpose: To provide a method of eliminating radioactive contaminations capable of ease treatment for decontaminated liquid wastes and grinding materials. Method: Those organic grinding materials such as fine wall nuts shell pieces cause no secondary contaminations since they are softer as compared with inorganic grinding materials, less pulverizable upon collision against the surface to be treated, being capable of reusing and producing no fine scattering powder. In addition, they can be treated by burning. The organic grinding material and water are sprayed by a nozzle to the surface to be treated, and decontaminated liquid wastes are separated into solid components mainly composed of organic grinding materials and liquid components mainly composed of water by filtering. The thus separated solid components are recovered in a storage tank for reuse as the grinding material and, after repeating use, subjected to burning treatment. While on the other hand, water is recovered into a storage tank and, after repeating use, purified by passing through an ion exchange resin-packed column and decontaminated to discharge. (Horiuchi, T.)

  10. The Results of the CCI-3 Reactor Material Experiment Investigating 2-D Core-Concrete Interaction and Debris Coolability with a Siliceous Concrete Crucible

    International Nuclear Information System (INIS)

    Farmer, M.T.; Lomperski, S.; Basu, S.

    2006-01-01

    The OECD-sponsored Melt Coolability and Concrete Interaction (MCCI) program conducted reactor materials experiments and associated analysis to achieve the following two objectives: 1) resolve the ex-vessel debris coolability issue, and 2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs of future plants. With respect to the second objective, there are remaining uncertainties in the models that evaluate the lateral vs. axial power split during core-concrete interaction because of a lack of truly two-dimensional experiment data. As a result, there are differences in the 2-D cavity erosion profiles predicted by codes such as WECHSL, COSACO, TOLBIAC, MEDICIS, and MELCOR. In the continuing effort to bridge this data gap, the third in a series of large scale Core-Concrete Interaction experiments (CCI-3) has been conducted as part of the MCCI program. This test investigated the long-term interaction of a 375 kg core-oxide melt within a two-dimensional siliceous concrete crucible. The initial phase of the test was conducted under dry conditions. After a predetermined time interval, the cavity was flooded with water to obtain data on the coolability of a core melt after core-concrete interaction has progressed for some time. This paper provides a description of the facility and an overview of results from this test. (authors)

  11. Decontamination Data - Blister Agents

    Data.gov (United States)

    U.S. Environmental Protection Agency — Decontamination efficacy data for blister agents on various building materials using various decontamination solutions. This dataset is associated with the following...

  12. Decontamination of some urban surfaces

    International Nuclear Information System (INIS)

    Thornton, E.W.

    1988-04-01

    The long-term consequences of external radiation dose to the public could be a cause for concern in the event of a severe accident at a nuclear power plant leading to the release of fission products to the atmosphere and subsequent contamination of buildings, roads and other components of the urban environment. This study has concentrated on the decontamination of building materials contaminated under wet conditions with soluble, ionic radiocaesium. Results are given on the decontamination of building materials contaminated without run-off, on the effects of waiting between contamination and decontamination and on the effect of pre-treatment with an ammonium salt solution. (author)

  13. Cutting concrete with abrasion jet

    International Nuclear Information System (INIS)

    Yie, G.G.

    1982-01-01

    Fluidyne Corporation has developed a unique process and apparatus that allow selected abrasives to be introduced into high-speed waterjet to produce abrasive-entrained waterjet that has high material-cutting capabilities, which is termed by Fluidyne as the Abrasion Jet. Such Abrasion Jet has demonstrated capability in cutting hard rock and concrete at a modest pressure of less than 1360 bars (20,000 psi) and a power input of less than 45 kW (60 horsepower). Abrasion Jet cutting of concrete is characterized by its high rate of cutting, flexible operation, good cut quality, and relatively low costs. This paper presents a general description of this technology together with discussions of recent test results and how it could be applied to nuclear decontamination and decommissioning work. 8 references

  14. BR-5 primary circuit decontamination

    International Nuclear Information System (INIS)

    Efimov, I.A.; Nikulin, M.P.; Smirnov-Averin, A.P.; Tymosh, B.S.; Shereshkov, V.S.

    1976-01-01

    Results and methodology of steam-water and acid decontamination of the primary coolant circuit SBR-5 reactor in 1971 are discussed. Regeneration process in a cold trap of the primary coolant circuit is discussed

  15. Decontamination Technology Development for Nuclear Research Facilities

    International Nuclear Information System (INIS)

    Choi, W. K.; Jung, C. H.; Oh, W. Z.

    2007-06-01

    The originative CO 2 pellet blasting equipment was developed by improving additional components such as feed screw, idle roller and air-lock feeder to clear up the problems of freezing and discontinuity of blasting and by adopting pneumatically operated vacuum suction head and vacuum cup to prevent recontamination by collecting contaminant particulates simultaneously with the decontamination. The optimum decontamination process was established according to the kind of materials such as metal, concrete and plastic and the type of contaminants such as particulate, fixed chemical compound and oil. An excellent decontamination performances were verified by means of the lab-scale hot test with radioactive specimen and the technology demonstration in IMEF hot cell. The PFC dry decontamination equipment applicable to the surface contaminated with high radioactive particulate was developed. This equipment consists of the unit processes such as spray, collection, filtration and dry distillation designed originatively applicable to inside of dry hot cell. Through the demonstration of PFC spray decontamination process in IMEF hot cell, we secured on-site applicability and the decontamination efficiency more than 90 %. We investigated the characteristics of dismantled metal waste melting and the radionuclide(Co, Cs, U) distribution into ingot and slag by melting decontamination experiments using electric arc melter. We obtained the decontamination factors greater than 100 for Cs and of 10∼100 for uranium. The pilot scale(200 kg/batch) demonstration for melting decontamination was carried out successfully using high temperature melting facility at KAERI. The volume reduction factor of 1/7 and the economical feasibility of the melting decontamination were verified.

  16. The Overall Research Results of Prestressed I-beams Made of Ultra-high Performance Concrete

    Science.gov (United States)

    Tej, P.; Kolísko, J.; Kněž, P.; Čech, J.

    2017-09-01

    The design process of short-term and long-term loading of prestressed I-beams made of ultra-high performance concrete (UHPC) and the overall research results are presented in this article. The prestressed I-beams are intended and designed to replace steel HEB beams mainly in the construction of railway bridges with fully concreted height of the beams. These types of structures have the advantage of a low construction height. The prestressed I-beams were made of UHPC with dispersed steel fibres and are reinforced by prestressing cables in the bottom flange. Two specimens of 9 m span, three specimens of 7 m span and two specimens of 12 m span were made for the short-term loading. For the purpose of the long-term loading, two specimens of 12 m span were made and subsequently loaded for 450 days. All specimens were tested in four-point bending tests in the laboratory. The article presents also comparison of results of the experiments with computer simulations.

  17. Removal of contaminated concrete surfaces by microwave heating: Phase 1 results

    International Nuclear Information System (INIS)

    White, T.L.; Grubb, R.G.; Pugh, L.P.; Foster, D. Jr.; Box, W.D.

    1992-01-01

    Oak Ridge National Laboratory (ORNL) is developing a microwave heating process to remove radiologically contaminated surface layers from concrete. The microwave energy is directed at the concrete surface and heats the concrete and free water present in the concrete matrix. Continued heating produces steam-pressure-induced mechanical stresses that cause the concrete surface to burst. The concrete particles from this steam explosion are small enough to be removed by a vacuum system, yet less than 1% of the debris is small enough to pose an airborne contamination hazard. The first phase of this program has demonstrated reliable removal of noncontaminated concrete surfaces at frequencies of 2.45 GHz and 10.6 GHz. Continuous concrete removal rates of 1.07 cm 3 /s with 5.2 kW of 2.45.-GHz power and 2.11 cm 3 /s with 3.6 kW of 10.6-GHz power have been demonstrated. Figures-of-merit for microwave removal of concrete have been calculated to be 0.21 cm 3 /s/kW at 2.45 GHz and 0.59 cm 3 /s/kW at 10.6 GHz. The amount of concrete removed in a single pass can be controlled by choosing the frequency and power of the microwave system

  18. Solving decontaminable flooring problems

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Pennsylvania Power and Light wanted to cover deteriorating concrete in unit 2 of its Susquehanna BWR with a smooth, durable, decontaminable coating. Traditionally, floors in the plant had been coated with epoxy paint, but many of these floors suffered delamination, and failed in three to five years. Painting with epoxy would also interrupt operations for as much as three days while the floor dried, yet critical instruments in some areas had to be monitored at least once per shift. In addition, conventional floor surface preparation produced dust and vibration around sensitive equipment. The solution was a dustless scabbling system for surface preparation, followed by the installation of a high-strength acrylic industrial floor known as Silakal. The work was carried out by Pentek. Silikal bonds to the underlying concrete, so that delamination of the floor will not occur even under severe traffic conditions. Another advantage of this type of flooring is that it cures in one hour, so floor resurfacing has only minimal impact on plant operations. (author)

  19. Large scale sodium interactions. Part 2. Preliminary test results for limestone concrete

    International Nuclear Information System (INIS)

    Smaardyk, J.E.; Sutherland, H.J.; King, D.L.; Dahlgren, D.A.

    1977-01-01

    Any sodium cooled reactor system must consider the interaction of hot sodium with cell liners, and given either a failed liner or a hypothetical core disruptive accident, the interaction of hot sodium with concrete. The data base available for safety assessments involving these interactions is limited, especially for the concrete and failed liner interactions. To better understand what happens when hot sodium comes in contact with concrete, a series of tests is being carried out to investigate sodium-concrete reactions under conditions which are similar to actual reactor accident conditions. Tests cover the cases of sodium spills on bare concrete and on cells with defective steel liners. Specific objectives have been to obtain a complete description of the sodium/concrete interaction including heat balance, gas evolution and flow, movement and heat generation of the reaction zone, reaction product formation, and the layering or movement of the products

  20. A simplified model of aerosol scrubbing by a water pool overlying core debris interacting with concrete

    International Nuclear Information System (INIS)

    Powers, D.A.; Sprung, J.L.

    1993-11-01

    A classic model of aerosol scrubbing from bubbles rising through water is applied to the decontamination of gases produced during core debris interactions with concrete. The model, originally developed by Fuchs, describes aerosol capture by diffusion, sedimentation, and inertial impaction. This original model for spherical bubbles is modified to account for ellipsoidal distortion of the bubbles. Eighteen uncertain variables are identified in the application of the model to the decontamination of aerosols produced during core debris interactions with concrete by a water pool of specified depth and subcooling. These uncertain variables include properties of the aerosols, the bubbles, the water and the ambient pressure. Results are analyzed using a nonparametric, order statistical analysis that allows quantitative differentiation of stochastic and phenomenological uncertainty. The sampled values of the decontamination factors are used to construct estimated probability density functions for the decontamination factor at confidence levels of 50%, 90% and 95%. The decontamination factors for pools 30, 50, 100, 200, 300, and 500 cm deep and subcooling levels of 0, 2, 5, 10, 20, 30, 50, and 70 degrees C are correlated by simple polynomial regression. These polynomial equations can be used to estimate decontamination factors at prescribed confidence levels

  1. Decontamination strategies in contaminated settlement

    International Nuclear Information System (INIS)

    Hubert, P.; Jouve, A.; Tallec, V. Le

    1996-01-01

    Six years after the Chernobyl accident, decontamination actions had been completed in many places, the contamination could be considered as fixed, especially on urban surfaces and the social situation was felt to be stabilized. Under those conditions the efficiency of the 'classical' decontamination techniques was under question, it was worthwhile to look at new specific techniques. Besides it was necessary to discuss the interest of new decontamination actions in settlements. The European Union (EU) sponsored a project ECP 4 in order to look at the opportunities for further dose reduction actions in the contaminated territories of the three republics affected by the accident. The objective was to provide a local decision maker, faced with many alternatives for decontamination, with all the elements for determining what to do according to the various objectives he might pursue. The main results are presented here. (author)

  2. Decontamination of polyvinylchloride- and rubber type flooring

    International Nuclear Information System (INIS)

    Kunze, S.

    1975-01-01

    These types, fabricated by mixing of the basic components, showed no relation between content of fillers and decontamination results. Decontamination results are partly poorer, if the flooring contains a high concentration of the filler, especially if the latter consists mainly of hydrophilic materials. The coloring of the floorings seems to have no influence on the decontamination but floorings with clearly separated patterns can not be recommended for nuclear facilities. Fabricated by chemical reactions between polymeres, vulcanization materials and fillers, the decontamination results depend definitely from the proper choice of the filler. Flooring types, containing lampblack, graphite, kaoline, barium sulfate and titanium oxide are easy to decontamine. Again, increasing contents of hydrophilic filler cause a fall off in the decontamination results. (orig.) [de

  3. Concrete crushing and sampling, a methodology and technology for the unconditional release of concrete material from decommissioning

    International Nuclear Information System (INIS)

    Gills, R.; Lewandowski, P.; Ooms, B.; Reusen, N.; Van Laer, W.; Walthery, R.

    2007-01-01

    Belgoprocess started the industrial decommissioning of the main process building of the former Eurochemic reprocessing plant in 1990, after completion of a pilot project. Two small storage buildings for final products from reprocessing were dismantled to verify the assumptions made in a previous paper study on decommissioning, to demonstrate and develop dismantling techniques and to train personnel. Both buildings were emptied and decontaminated to background levels. They were demolished and the remaining concrete debris was disposed of as industrial waste and green field conditions restored. Currently, the decommissioning operations carried out at the main building have made substantial progress. They are executed on an industrial scale. In view of the final demolition of the building, foreseen to start in the middle of 2008, a clearance methodology for the concrete from the cells into the Eurochemic building has been developed. It considers at least one complete measurement of all concrete structures and the removal of all detected residual radionuclides. This monitoring sequence is followed by a controlled demolition of the concrete structures and crushing of the resulting concrete parts to smaller particles. During the crushing operations, metal parts are separated from the concrete and representative concrete samples are taken. The frequency of sampling meets the prevailing standards. In a further step, the concrete samples are milled, homogenised, and a smaller fraction is sent to the laboratory for analyses. The paper describes the developed concrete crushing and sampling methodology. (authors)

  4. FREEZE-THAW TEST RESULTS OF POROUS CONCRETE WITH CRUSHED SCALLOP SHELL MATERIAL ADDED

    OpenAIRE

    SUGIYAMA, Masashi

    2004-01-01

    This paper addresses the possibility of recycling an abundantly available byproduct of the fisheries industry, scallop shells, by adding it to porous concrete. If these shells, now discarded as refuse, can be used as an additive in porous concrete, this c

  5. Management of the post accidental situation applied to Nogent-Sur-Seine nuclear power plant environment. First results of the decontamination of soil and food chain working group

    International Nuclear Information System (INIS)

    Allain, E.; Mignon, F.; Cessac, B.; Gallay, F.; Metivier, J.M.; Reales, N.; Gofette, R.; Mahot, M.

    2004-01-01

    From the beginning of 2002, Troyes prefecture has initiated a reflection about the management of a nuclear crisis caused by an accident at the Nogent-sur-Seine nuclear power plant. Five workshops have been created, dealing with the following themes: 'Administrative and economic organization', 'Health risk assessment and the epidemiology', 'Monitoring of environment', 'Movement in the contaminated area' and 'Decontamination of soil and Food chain'. The first results of the 'Decontamination of soil and Food chain' working group, which involves the District Agricultural and Forestry Department, the Farmer's Association, the Institute for Radiological Protection and Nuclear Safety and the Veterinary Division are presented in the poster. The scenario that had been developed for the accident considers the release of 3 radionuclides ( 131 I, 134 Cs and 137 Cs) in the environment. The scale of the crisis didn't require the evacuation and the sheltering of the population during the emergency phase. The consequences on the local agricultural products (cereal, beetroot, vine, milk, cow meat...) have been assessed up to 50 km and different strategies of agricultural countermeasures have been studied regarding to the local constraints (soil types, surfaces and quantities concerned) and to the consequences of their implementation (waste types and quantities, costs). Then, decision-making diagrams summed up the technical results and allowed to deepen the global thought. (author)

  6. Soil decontamination with Extraksol

    International Nuclear Information System (INIS)

    Paquin, J.; Mourato, D.

    1989-01-01

    The Extraksol process is a mobile decontamination technology which treats unconsolidated materials by solvent extraction. Treatment with Extraksol involves material washing, drying and solvent regeneration. Contaminant removal is achieved through desorption/dissolution mechanisms. The treated material is dry and acceptable to be reinstalled in its original location. The process provides a fast, efficient and versatile alternative for decontamination of soil and sludge. The organic contaminants extracted from the matrix are transferred to the extraction fluids. These are thereafter concentrated in the residues of distillation after solvent regeneration. Removal and concentration of the contaminants ensures an important waste volume reduction. This paper presents the process is operational principles and the steps involved in Extraksol's development with results of the pilot tests and full-scale demonstrations

  7. Treatment of Uranium-Contaminated Concrete for Reducing Secondary Radioactive Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Soo; Han, G. S; Park, U. K; Kim, G. N.; Moon, J. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    A volume reduction of the concrete waste by appropriate treatment technologies will decrease the amount of waste to be disposed of and result in a reduction of the disposal cost and an enhancement of the efficiency of the disposal site. Our group has developed a decontamination process for uranium-contaminated (U-contaminated) concrete, and some experiments were performed to reduce the second radioactive waste. A decontamination process was developed to remove uranium from concrete waste. The yellow or brown colored surface of the wall brick with high concentration of uranium was removed by a chisel until the radioactivity of remaining block reached less than 1 Bq/g. The concrete waste coated with epoxy was directly burned by an oil flame, and the burned surface was then removed using the same method as the treatment of the brick. The selective mechanical removal of the concrete block reduced the amount of secondary radioactive waste. The concrete blocks without an epoxy were crushed to below 30 mm and sifted to 1 mm. When the concrete pieces larger than 1 mm were sequentially washed with a clear recycle solution and 1.0 M of nitric acid, their radioactivity reached below the limit value of uranium for self-disposal. For the concrete pieces smaller than 1 mm, a rotary washing machine and electrokinetic equipment were also used.

  8. Treatment of Uranium-Contaminated Concrete for Reducing Secondary Radioactive Waste

    International Nuclear Information System (INIS)

    Kim, Seung Soo; Han, G. S; Park, U. K; Kim, G. N.; Moon, J. K.

    2014-01-01

    A volume reduction of the concrete waste by appropriate treatment technologies will decrease the amount of waste to be disposed of and result in a reduction of the disposal cost and an enhancement of the efficiency of the disposal site. Our group has developed a decontamination process for uranium-contaminated (U-contaminated) concrete, and some experiments were performed to reduce the second radioactive waste. A decontamination process was developed to remove uranium from concrete waste. The yellow or brown colored surface of the wall brick with high concentration of uranium was removed by a chisel until the radioactivity of remaining block reached less than 1 Bq/g. The concrete waste coated with epoxy was directly burned by an oil flame, and the burned surface was then removed using the same method as the treatment of the brick. The selective mechanical removal of the concrete block reduced the amount of secondary radioactive waste. The concrete blocks without an epoxy were crushed to below 30 mm and sifted to 1 mm. When the concrete pieces larger than 1 mm were sequentially washed with a clear recycle solution and 1.0 M of nitric acid, their radioactivity reached below the limit value of uranium for self-disposal. For the concrete pieces smaller than 1 mm, a rotary washing machine and electrokinetic equipment were also used

  9. Local strategies for decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, P [Institut de Protection et de Surete Nucleaire, Fontenay-aux-Roses cedex (France); Ramzaev, V [Branch of Institute of Radiation Hygiene, Novozybkov, Bryansk region (Russian Federation); Antsypov, G [Chernnobyl State Committee of the Republic of Belarus, Minsk (Belarus); Sobotovich, E [Institute of Geochemistry, Mineralogy and Ore formation, Kiev (Ukraine); Anisimova, L [EMERCOM, Moscow (Russian Federation)

    1996-07-01

    The efficiencies of a great number of techniques for decontamination or dose reduction in contaminated areas have been investigated by several teams of E.C. and CIS scientists (ECP4 project). Modelling, laboratory and field experiments, t and return from experience allowed to assess radiological efficiencies (e.g. 'decontamination factor') and requirements for the operation of numerous practical solutions. Then, those data were supplemented with data on cost and waste generation in order to elaborate all the information for the optimization of decontamination strategies. Results will be presented for about 70 techniques. However, a technique cannot be compared to another from a generic point of view. Rather it is designed for a specific target and the best technology depends on the objectives. It has been decided to implement decision analyses on case studies, and the local conditions and objectives have been investigated. Individual doses ranged from 1 to 5 mSv, with contrasted contributions of internal and external doses. The desire to restore a normal activity in a partially depopulated settlement, and concerns about the recent increase in internal doses were typical incentives for action. The decision aiding analysis illustrated that actions can be usually recommended. Results are outlined here.

  10. Local strategies for decontamination

    International Nuclear Information System (INIS)

    Hubert, P.; Ramzaev, V.; Antsypov, G.; Sobotovich, E.; Anisimova, L.

    1996-01-01

    The efficiencies of a great number of techniques for decontamination or dose reduction in contaminated areas have been investigated by several teams of E.C. and CIS scientists (ECP4 project). Modelling, laboratory and field experiments, t and return from experience allowed to assess radiological efficiencies (e.g. 'decontamination factor') and requirements for the operation of numerous practical solutions. Then, those data were supplemented with data on cost and waste generation in order to elaborate all the information for the optimization of decontamination strategies. Results will be presented for about 70 techniques. However, a technique cannot be compared to another from a generic point of view. Rather it is designed for a specific target and the best technology depends on the objectives. It has been decided to implement decision analyses on case studies, and the local conditions and objectives have been investigated. Individual doses ranged from 1 to 5 mSv, with contrasted contributions of internal and external doses. The desire to restore a normal activity in a partially depopulated settlement, and concerns about the recent increase in internal doses were typical incentives for action. The decision aiding analysis illustrated that actions can be usually recommended. Results are outlined here

  11. Strength and deformability of hollow concrete blocks: correlation of block and cylindrical sample test results

    OpenAIRE

    Barbosa, C. S.; Hanai, J.B.

    2009-01-01

    This paper deals with correlations among mechanical properties of hollow blocks and those of concrete used to make them. Concrete hollow blocks and test samples were moulded with plastic consistency concrete, to assure the same material in all cases, in three diferente levels of strength (nominally 10 N/mm², 20 N/mm² and 30 N/mm²). The mechanical properties and structural behaviour in axial compression and tension tests were determined by standard tests in blocks and cylinders. Stress and str...

  12. Decontamination impacts on solidification

    International Nuclear Information System (INIS)

    Piciulo, P.L.; Davis, M.S.

    1985-01-01

    The increased occupational exposure resulting from the accumulation of activated corrosion products in the primary system of LWRs has led to the development of chemical methods to remove the contamination. In the past, the problem of enhanced migration of radionuclides away from trenches used to dispose of low-level radioactive waste, has been linked to the presence, at the disposal unit, of chelating or complexing agents such as those used in decontamination processes. These agents have further been found to reduce the normal sorptive capacity of soils for radionuclides. The degree to which these agents inhibit the normal sorptive processes is dependent on the type of complexing agent, the radionuclide of concern, the soil properties and whether the nuclide is present as a complex or is already sorbed to the soil. Since the quantity of reagent employed in a full system decontamination is large (200 to 25,000 kg), the potential for enhanced migration of radionuclides from a site used to dispose of the decontamination wastes should be addressed and guidelines established for the safe disposal of these wastes

  13. Excimer laser decontamination

    Science.gov (United States)

    Sentis, Marc L.; Delaporte, Philippe C.; Marine, Wladimir; Uteza, Olivier P.

    2000-04-01

    The application of excimer laser ablation process to the decontamination of radioactive surfaces is discussed. This technology is very attractive because it allows to efficiently remove the contaminated particles without secondary waste production. To demonstrate the capability of such technology to efficiently decontaminate large area, we studied and developed a prototype which include a XeCl laser, an optical fiber delivery system and an ablated particles collection cell. The main physical processes taking place during UV laser ablation will be explained. The influence of laser wavelength, pulse duration and absorption coefficient of material will be discussed. Special studies have been performed to understand the processes which limit the transmission of high average power excimer laser through optical fiber, and to determine the laser conditions to optimize the value of this transmission. An in-situ spectroscopic analysis of laser ablation plasma allows the real time control of the decontamination. The results obtained for painting or metallic oxides removal from stainless steel surfaces will be presented.

  14. Comparison of skin decontamination efficacy of commercial decontamination products following exposure to VX on human skin.

    Science.gov (United States)

    Thors, L; Koch, M; Wigenstam, E; Koch, B; Hägglund, L; Bucht, A

    2017-08-01

    The decontamination efficacy of four commercially available skin decontamination products following exposure to the nerve agent VX was evaluated in vitro utilizing a diffusion cell and dermatomed human skin. The products included were Reactive Skin Decontamination Lotion (RSDL), the Swedish decontamination powder 104 (PS104), the absorbent Fuller's Earth and the aqueous solution alldecontMED. In addition, various decontamination procedures were assessed to further investigate important mechanisms involved in the specific products, e.g. decontamination removal from skin, physical removal by sponge swabbing and activation of degradation mechanisms. The efficacy of each decontamination product was evaluated 5 or 30 min after dermal application of VX (neat or diluted to 20% in water). The RSDL-lotion was superior in reducing the penetration of VX through human skin, both when exposed as neat agent and when diluted to 20% in water. Swabbing with the RSDL-sponge during 2 min revealed decreased efficacy compared to applying the RSDL-lotion directly on the skin for 30 min. Decontamination with Fuller's Earth and alldecontMED significantly reduced the penetration of neat concentration of VX through human skin. PS104-powder was insufficient for decontamination of VX at both time-points, independently of the skin contact time of PS104. The PS104-slurry (a mixture of PS104-powder and water), slightly improved the decontamination efficacy. Comparing the time-points for initiated decontamination revealed less penetrated VX for RSDL and Fuller's Earth when decontamination was initiated after 5 min compared to 30 min post-exposure, while alldecontMED displayed similar efficacy at both time-points. Decontamination by washing with water only resulted in a significant reduction of penetrated VX when washing was performed 5 min after exposure, but not when decontamination was delayed to 30 min post-exposure of neat VX. In conclusion, early initiated decontamination with the

  15. Decontamination and decommissioning techniques for research reactors

    International Nuclear Information System (INIS)

    Oh, Won Zin; Won, H. J.; Jung, C. H.; Choi, W. K.; Kim, G. N.; Lee, K. W.

    2002-05-01

    Evaluation of soil decontamination process and the liquid decontamination waste treatment technology are investigation of organic acid as a decontamination agent, investigation of the liquid waste purification process and identification of recycling the decontamination agents. Participation on IAEA CRP meeting are preparation of IAEA technical report on 'studies on decommissioning of TRIGA reactors and site restoration technologies' and exchange the research result, technology, experience and safety regulation of the research reactor D and D of USA, Great Britain, Canada, Belgium, Italy, India and so forth

  16. Screening of mine dirt as addition to concrete. Description of testing plant. Results

    Energy Technology Data Exchange (ETDEWEB)

    Gnodtke, M

    1977-08-01

    An experimental facility for screening mine dirt during haulage operations is described. The screening material, adding sand and a binder, can be made into a concrete aggregate at low costs and used as backfilling material.

  17. Properties and solidification of decontamination wastes

    International Nuclear Information System (INIS)

    Davis, M.S.; Piciulo, P.L.; Bowerman, B.S.; Adams, J.W.; Milian, L.

    1983-01-01

    LWRs will require one or more chemical decontaminations to achieve their designed lifetimes. Primary system decontamination is designed to lower radiation fields in areas where plant maintenance personnel must work. Chemical decontamination methods are either hard (concentrated chemicals, approximately 5 to 25 weight percent) or soft (dilute chemicals less than 1 percent by weight). These methods may have different chemical reagents, some tailor-made to the crud composition and many methods are and will be proprietary. One factor common to most commercially available processes is the presence of organic acids and chelates. These types of organic reagents are known to enhance the migration of radionuclides after disposal in a shallow land burial site. The NRC sponsors two programs at Brookhaven National Laboratory that are concerned with the management of decontamination wastes which will be generated by the full system decontamination of LWRs. These two programs focus on potential methods for degrading or converting decontamination wastes to more acceptable forms prior to disposal and the impact of disposing of solidified decontamination wastes. The results of the solidification of simulated decontamination resin wastes will be presented. Recent results on combustion of simulated decontamintion wastes will be described and procedures for evaluating the release of decontamination reagents from solidified wastes will be summarized

  18. Overview of experimental results obtained under the Prestressed Concrete Nuclear Pressure Vessel Development Program at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Naus, D.J.

    1978-01-01

    Under the Prestressed Concrete Nuclear Pressure Vessel Development Program at the Oak Ridge National Laboratory, various aspects of Prestressed Concrete Pressure Vessels (PCPVs) are investigated and evaluated with respect to reliability, structural performance, constructability, and economy. Based upon identified needs, analytical and experimental investigations are conducted. Areas of interest include finite-element analysis development, materials and structural behavior tests, instrumentation evaluation and development, and structural model tests. Studies have been recently completed in the following areas: concrete embedment instrumentation systems for PCPVs, grouted-nongrouted prestressing systems, acoustic emission as a technique for structural integrity monitoring, and model tests of steam-generator cavity closure plugs for a Gas-Cooled Fast Reactor (GCFR). An overview of results is presented

  19. Biodecontamination of concrete

    International Nuclear Information System (INIS)

    Hamilton, M.A.; Rogers, R.D.; Benson, J.

    1996-01-01

    A novel technology for biologically decontaminating concrete is being jointly developed by scientists at the Idaho National Engineering Laboratory (INEL) and British Nuclear Fuels plc (BNFL). The technology exploits a naturally occurring phenomenon referred to as microbially influenced degradation (MID) in which bacteria produce acids that dissolve the cement matrix of concrete. Most radionuclide contamination of concrete is fixed in the outer few mm of the concrete surface. By capturing and controlling this natural process, a biological method of removing the surface of concrete to depths up to several mm is being developed. Three types of bacteria are known to be important in MID of concrete: nitrifying bacteria that produce nitric acid, sulfur oxidizing bacteria that produce sulfuric acid, and certain heterotrophic bacteria that produce organic acids. An investigation of natural environments demonstrated with scanning electron microscopy the presence of bacteria on concrete surfaces of a variety of structures, such as bridges and dams, where corrosion is evident. Enumeration of sulfur oxidizing and nitrifying bacteria revealed their presence and activity on structures to varying degrees in different environments. Under ideal conditions, Thiobacillus thiooxidans, a sulfur oxidizing bacteria, attached to and colonized the surface of concrete specimens. Over 1mm depth of material from a 10 cm x 10 cm square surface was removed in 68 days in the Thiobacillus treated specimen compared to a sterile control. Laboratory and field demonstrations are currently being conducted using experimental chambers designed to be mounted directly to concrete surfaces where radionuclide contamination exists. Data is being obtained in order to determine actual rates of surface removal and limitations to the system. This information will be used to develop a full scale decontamination technology

  20. Results from the preliminary conveyor evaluation of the high-energy beta scintillation sensor at the Fernald Soil Decontamination Pilot Plant

    International Nuclear Information System (INIS)

    Schilk, A.J.; Knopf, M.A.

    1994-07-01

    W tested a high-energy beta scintillation sensor to evaluate its efficacy in continually characterizing washed soils moving on a conveyor belt at Fernald's Soil Decontamination Pilot Plant (SDPP). This sensor was originally developed for monitoring uranium-contaminated soils in the field. It has a multi-layer design that enables it to discriminate against lower-energy beta particles from natural sources. It can also distinguish, to some extent, gamma rays and cosmic-induced species. The sensor detects uranium activity indirectly, based on the assumption that secular equilibrium exists between the targeted radionuclide ( 234m Pa) and its parent ( 238 U). Several 1-h background counts were made at the SDPP each day of the evaluation period. The average background count rate was found to be comparable to that observed under previous laboratory conditions. Static runs were performed on soils from SDPP test runs No. 1 and No. 17 to determine the extent of any residual activity following the decontamination process. Soils were found to contain 158±30 pCi/g and 114±25 pCi/g of 234 Th- 234m Pa ( 238 U?), respectively. But the soils had considerable moisture, and concern existed that this moisture would act as an additional beta attenuator and thereby give results that were erroneously low. Therefore, a soil sample was baked overnight, and the hard-baked clay that resulted was ground into small fragments and counted. This sample was counted for 30 min as before, and the total activity was determined to be 313±44 pCi/g of 234 Th 234m Pa ( 238 U?). Based on the test No. 1 results, a dry-to-wet activity ratio of 1.98 has been established. Hence, if the moisture content of test No. 17 was equivalent to that of test No. 1, the actual 234 Th- 234m Pa ( 238 U?) activity level is expected to be approximately 226 pCi/g

  1. CB decontamination for first responders

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, M.D.G.; Purdon, J.G.; Burczyk, A. [Defence Research and Development Canada Suffield, Ralston, AB (Canada)

    2006-07-01

    The Universal Containment System (UCS) is designed to contain, mitigate and decontaminate chemical, biological and radiological warfare agents. The UCS consists of a lightweight, tent-like enclosure filled with a water-based surface decontaminating foam (SDF). The Canadian government funded a project to advance the understanding of the behaviour of the UCS. This paper described the success of the project as well as the technological advances in the UCS formulation and equipment. Vapour desorption experiments were conducted in which SDF was applied onto 12 surfaces found in a typical office environment. Both mustard and nerve agent were studied on the test surfaces. Both scrubbing and non-scrubbing decontamination methods were tested. SDF effectively decontaminated the non-porous substances, particularly when the scrubbing procedure was used. Results were more complicated for the non-porous samples. A dye added to the agent was useful for determining the fate of the agent. Liquid phase studies were conducted in which the reaction between SDF and various agents were studied in the liquid phase in order to estimate the rate of reaction, the stoichiometry and the reaction products formed. Both SDF and the commercial decontamination agent CASCAD were found to effectively kill 100 per cent of anthrax spores. The significance of this project to first responders was considerable. Changes to the formulation and equipment of UCS will increase its usefulness and safety. Users will also have a better knowledge of the amount of decontamination needed for complete effectiveness in specific situations. Recommendations have been made for use of the product on a range of indoor surfaces. Field trials have shown the blast mitigation and agent decontamination ability of the foam under explosive situations. 15 refs., 4 tabs.

  2. Automatic detection and classification of EOL-concrete and resulting recovered products by hyperspectral imaging

    Science.gov (United States)

    Palmieri, Roberta; Bonifazi, Giuseppe; Serranti, Silvia

    2014-05-01

    The recovery of materials from Demolition Waste (DW) represents one of the main target of the recycling industry and the its characterization is important in order to set up efficient sorting and/or quality control systems. End-Of-Life (EOL) concrete materials identification is necessary to maximize DW conversion into useful secondary raw materials, so it is fundamental to develop strategies for the implementation of an automatic recognition system of the recovered products. In this paper, HyperSpectral Imaging (HSI) technique was applied in order to detect DW composition. Hyperspectral images were acquired by a laboratory device equipped with a HSI sensing device working in the near infrared range (1000-1700 nm): NIR Spectral Camera™, embedding an ImSpector™ N17E (SPECIM Ltd, Finland). Acquired spectral data were analyzed adopting the PLS_Toolbox (Version 7.5, Eigenvector Research, Inc.) under Matlab® environment (Version 7.11.1, The Mathworks, Inc.), applying different chemometric methods: Principal Component Analysis (PCA) for exploratory data approach and Partial Least Square- Discriminant Analysis (PLS-DA) to build classification models. Results showed that it is possible to recognize DW materials, distinguishing recycled aggregates from contaminants (e.g. bricks, gypsum, plastics, wood, foam, etc.). The developed procedure is cheap, fast and non-destructive: it could be used to make some steps of the recycling process more efficient and less expensive.

  3. Radioactive Decontamination by Strippable Paint

    International Nuclear Information System (INIS)

    Chantaraparprachoom, N.; Mishima, K.

    1998-01-01

    The strippable paint, one of the adhesion method, is to decontaminate solid surface of materials or/and a large area. Two kinds of specimen planchet, SUS 304 stainless steel and polycarbonate plastic, contaminated with radioactive 137 Cs were studied under various conditions. It included surface bottom types, the flat and convex concentric circle type, normal condition at room temperature and overheat condition (∼80 degree celsius). This method used coating paints which contains some elements to have a reaction with radioactive materials selectively. ALARA-Decon clear, Rempack-X200 clear, JD-P5-Mrs.Coat and Pro-Blue-color guard were selected to use as the coating paints. The contaminated surface was coated by the strippable paint under the optimum time, followed by peeling the paint seal. The Rempack-X200 showed the best result, the highest decontamination efficiency which are about 99-100% for all conditions of specimens. The JD-P5 and ALARA-Decon showed good results, which are 98-99% decontamination efficiency for the normal condition set of specimens and about 94-97% for the overheat set of specimens. They can decontaminate polycarbonate specimens better than stainless steel specimens. The Pro-Blue-color guard showed the lowest decontamination efficiency of which 60% for polycarbonate specimens at normal condition and 40%, 30% for stainless steel specimens at normal and overheat conditions respectively. There was no effects of surface bottom types significantly

  4. Phase 1 sampling and analysis plan for the 304 Concretion Facility closure activities

    International Nuclear Information System (INIS)

    Adler, J.G.

    1994-01-01

    This document provides guidance for the initial (Phase 1) sampling and analysis activities associated with the proposed Resource Conservation and Recovery Act of 1976 (RCRA) clean closure of the 304 Concretion Facility. Over its service life, the 304 Concretion Facility housed the pilot plants associated with cladding uranium cores, was used to store engineering equipment and product chemicals, was used to treat low-level radioactive mixed waste, recyclable scrap uranium generated during nuclear fuel fabrication, and uranium-titanium alloy chips, and was used for the repackaging of spent halogenated solvents from the nuclear fuels manufacturing process. The strategy for clean closure of the 304 Concretion Facility is to decontaminate, sample (Phase 1 sampling), and evaluate results. If the evaluation indicates that a limited area requires additional decontamination for clean closure, the limited area will be decontaminated, resampled (Phase 2 sampling), and the result evaluated. If the evaluation indicates that the constituents of concern are below action levels, the facility will be clean closed. Or, if the evaluation indicates that the constituents of concern are present above action levels, the condition of the facility will be evaluated and appropriate action taken. There are a total of 37 sampling locations comprising 12 concrete core, 1 concrete chip, 9 soil, 11 wipe, and 4 asphalt core sampling locations. Analysis for inorganics and volatile organics will be performed on the concrete core and soil samples. Separate concrete core samples will be required for the inorganic and volatile organic analysis (VOA). Analysis for inorganics only will be performed on the concrete chip, wipe, and asphalt samples

  5. Ontario Hydro decontamination experience

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, C S; Patterson, R W; Upton, M S [Chemistry and Metallurgy Department, Central Production Services, Ontario Hydro, ON (Canada)

    1991-04-01

    Ontario Hydro currently operates 18 nuclear electric generating units of the CANDU design with a net capacity of 12,402 MW(e). An additional 1,762 MW(e) is under construction. The operation of these facilities has underlined the need to have decontamination capability both to reduce radiation fields, as well as to control and reduce contamination during component maintenance. This paper presents Ontario Hydro decontamination experience in two key areas - full heat transport decontamination to reduce system radiation fields, and component decontamination to reduce loose contamination particularly as practised in maintenance and decontamination centres. (author)

  6. Reactive decontamination formulation

    Science.gov (United States)

    Giletto, Anthony [College Station, TX; White, William [College Station, TX; Cisar, Alan J [Cypress, TX; Hitchens, G Duncan [Bryan, TX; Fyffe, James [Bryan, TX

    2003-05-27

    The present invention provides a universal decontamination formulation and method for detoxifying chemical warfare agents (CWA's) and biological warfare agents (BWA's) without producing any toxic by-products, as well as, decontaminating surfaces that have come into contact with these agents. The formulation includes a sorbent material or gel, a peroxide source, a peroxide activator, and a compound containing a mixture of KHSO.sub.5, KHSO.sub.4 and K.sub.2 SO.sub.4. The formulation is self-decontaminating and once dried can easily be wiped from the surface being decontaminated. A method for decontaminating a surface exposed to chemical or biological agents is also disclosed.

  7. Ontario Hydro decontamination experience

    International Nuclear Information System (INIS)

    Lacy, C.S.; Patterson, R.W.; Upton, M.S.

    1991-01-01

    Ontario Hydro currently operates 18 nuclear electric generating units of the CANDU design with a net capacity of 12,402 MW(e). An additional 1,762 MW(e) is under construction. The operation of these facilities has underlined the need to have decontamination capability both to reduce radiation fields, as well as to control and reduce contamination during component maintenance. This paper presents Ontario Hydro decontamination experience in two key areas - full heat transport decontamination to reduce system radiation fields, and component decontamination to reduce loose contamination particularly as practised in maintenance and decontamination centres. (author)

  8. Survey results of corroding problems at biological treatment plants, Stage II Protection of concrete - State of the Art

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Ylva (CBI, Boraas (Sweden)); Henriksson, Gunilla (SP, Boraas (Sweden))

    2011-07-01

    A pilot study on the degradation and corrosion of concrete in biological treatment plants was conducted in 2009/2010 in a Waste Refinery Project WR-27 'Survey results of corroding problems at biological treatment plants'. The results showed that the concrete does not have sufficient resistance in the current aggressive plant environment. Furthermore, it is stated that some form of surface protection system is needed to ensure the good performance of concrete constructions, and that the system must withstand the aggressive environment and the traffic that occurs on site. Consequently, a new study was proposed in order to develop specifications for surface protection of concrete in aggressive food waste environments. Results from that study are presented in this report. The report includes various types of waterproofing/protection coating for concrete in biological treatment plants. A number of proposals from the industry are presented in the light of results from project WR-27, i.e., the materials must, among other things, withstand the aggressive leachate from waste food at temperatures up to 70 deg C, and some degree of wear. Some systems are compared in terms of technical material properties as reported by the manufacturer. It turns out that different testing methods were used, and the test results are thus generally not directly comparable. A proposal for a test program has been developed, focusing on chemical resistance and wear resistance. A test solution corresponding to leachate is specified. Laboratory tests for verification of the proposed methodology and future requirements are proposed, as well as test sites and follow-up in the field

  9. Electrochemical decontamination system for actinide processing gloveboxes

    International Nuclear Information System (INIS)

    Wedman, D.E.; Lugo, J.L.; Ford, D.K.; Nelson, T.O.; Trujillo, V.L.; Martinez, H.E.

    1998-03-01

    An electrolytic decontamination technology has been developed and successfully demonstrated at Los Alamos National Laboratory (LANL) for the decontamination of actinide processing gloveboxes. The technique decontaminates the interior surfaces of stainless steel gloveboxes utilizing a process similar to electropolishing. The decontamination device is compact and transportable allowing it to be placed entirely within the glovebox line. In this way, decontamination does not require the operator to wear any additional personal protective equipment and there is no need for additional air handling or containment systems. Decontamination prior to glovebox decommissioning reduces the potential for worker exposure and environmental releases during the decommissioning, transport, and size reduction procedures which follow. The goal of this effort is to reduce contamination levels of alpha emitting nuclides for a resultant reduction in waste level category from High Level Transuranic (TRU) to low Specific Activity (LSA, less than or equal 100 nCi/g). This reduction in category results in a 95% reduction in disposal and disposition costs for the decontaminated gloveboxes. The resulting contamination levels following decontamination by this method are generally five orders of magnitude below the LSA specification. Additionally, the sodium sulfate based electrolyte utilized in the process is fully recyclable which results in the minimum of secondary waste. The process bas been implemented on seven gloveboxes within LANL's Plutonium Facility at Technical Area 55. Of these gloveboxes, two have been discarded as low level waste items and the remaining five have been reused

  10. Cost effectiveness of dilute chemical decontamination

    International Nuclear Information System (INIS)

    LeSurf, J.E.; Weyman, G.D.

    The basic principles of dilute chemical decontamination are described, as well as the method of application. Methods of computing savings in radiation dose and costs are presented, with results from actual experience and illustrative examples. It is concluded that dilute chemical decontamination is beneficial in many cases. It reduces radiation exposure of workers, saves money, and simplifies maintenance work

  11. Gamma exposure rate reduction and residual radium-226 concentrations resulting from decontamination activities conducted at the former uranium millsite in Shiprock, New Mexico

    International Nuclear Information System (INIS)

    Hans, J.M. Jr.; Hurst, T.L.

    1981-01-01

    Gamma radiation surveys and residual radium 226 soil samples were taken as part of the decontamination activities of the former Shiprock uranium mill site in New Mexico. In order to facilitate the decontamination activities, the mill site and its contaminated environs were divided into 6 major areas. Extensive data are presented in 2 appendices of the pre- and post-decontamination gamma ray exposure rates made on mill site, and of radium 226 concentrations in surface soil samples. A training program established on the mill site by the Navajo Engineering and Construction Authority is described

  12. Concrete/Febex Bentonite Interaction: Results On Short-Term Column Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Escribano, A.; Turrero, M.J.; Torres, E.; Martin, P.L. [CIEMAT, Environmental Department, Avda. Complutense, 22, 28040 Madrid (Spain)

    2008-07-01

    Interaction between the alkaline pore fluids from the concrete engineered barriers and the bentonite at the repository conditions may generate products that can diffuse through the porous structure of the bentonite affecting their properties. A comprehensive study based on series of short term experiments is being performed to provide experimental evidences on the physical, chemical and mineralogical changes during the concrete-compacted bentonite interaction. Samples were analyzed by XRD, SEM-EDS and FTIR. Measurements of swelling capacity, specific surface area and chemical analysis for cation exchange capacity and soluble salts analyses were also performed. (authors)

  13. Concrete/Febex Bentonite Interaction: Results On Short-Term Column Experiments

    International Nuclear Information System (INIS)

    Escribano, A.; Turrero, M.J.; Torres, E.; Martin, P.L.

    2008-01-01

    Interaction between the alkaline pore fluids from the concrete engineered barriers and the bentonite at the repository conditions may generate products that can diffuse through the porous structure of the bentonite affecting their properties. A comprehensive study based on series of short term experiments is being performed to provide experimental evidences on the physical, chemical and mineralogical changes during the concrete-compacted bentonite interaction. Samples were analyzed by XRD, SEM-EDS and FTIR. Measurements of swelling capacity, specific surface area and chemical analysis for cation exchange capacity and soluble salts analyses were also performed. (authors)

  14. Remote methods for decontamination and decommissioning operations

    International Nuclear Information System (INIS)

    DeVore, J.R.

    1986-01-01

    Three methods for the decontamination and decommissioning of nuclear facilities are described along with operational experience associated with each method. Each method described in some way reduces radiation exposure to the operating personnel involved. Electrochemical decontamination of process tanks is described using an in-situ method. Descriptions of two processes, electropolishing and cerium redox decontamination, are listed. A method of essentially smokeless cutting of process piping using a plasma-arc cutting torch is described. In one technique, piping is cut remotely from a distance using a specially modified torch holder. In another technique, cutting is done with master-slave manipulators inside a hot cell. Finally, a method for remote cutting and scarification of contaminated concrete is described. This system, which utilizes high-pressure water jets, is coupled to a cutting head or rotating scarification head. The system is suited for cutting contaminated concrete for removal or removing a thin layer in a controlled manner for decontamination. 4 refs., 6 figs

  15. Non destructive multi elemental analysis using prompt gamma neutron activation analysis techniques: Preliminary results for concrete sample

    Energy Technology Data Exchange (ETDEWEB)

    Dahing, Lahasen Normanshah [School of Applied Physics, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia and Malaysian Nuclear Agency (Nuklear Malaysia), Bangi 43000, Kajang (Malaysia); Yahya, Redzuan [School of Applied Physics, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Yahya, Roslan; Hassan, Hearie [Malaysian Nuclear Agency (Nuklear Malaysia), Bangi 43000, Kajang (Malaysia)

    2014-09-03

    In this study, principle of prompt gamma neutron activation analysis has been used as a technique to determine the elements in the sample. The system consists of collimated isotopic neutron source, Cf-252 with HPGe detector and Multichannel Analysis (MCA). Concrete with size of 10×10×10 cm{sup 3} and 15×15×15 cm{sup 3} were analysed as sample. When neutrons enter and interact with elements in the concrete, the neutron capture reaction will occur and produce characteristic prompt gamma ray of the elements. The preliminary result of this study demonstrate the major element in the concrete was determined such as Si, Mg, Ca, Al, Fe and H as well as others element, such as Cl by analysis the gamma ray lines respectively. The results obtained were compared with NAA and XRF techniques as a part of reference and validation. The potential and the capability of neutron induced prompt gamma as tool for multi elemental analysis qualitatively to identify the elements present in the concrete sample discussed.

  16. Laser Decontamination of Surfaces Contaminated with Cs+ Ion

    International Nuclear Information System (INIS)

    Baigalmaaa, B.; Won, H. J.; Moon, J. K.; Jung, C. H.; Lee, K. W.; Hyun, J. H.

    2008-01-01

    Laser decontamination technology has been proven to be an efficient method for a surface modification of metals and concretes contaminated with radioactive isotopes. Furthermore, the generation of a secondary waste is negligible. The radioactivity of hot cells in the DFDF (Dupic Fuel Development Facility) is presumed to be very high and the predominant radionuclide is Cs-137. A series of laser decontamination studies by a fabricated Q-switched Nd:YAG laser system were performed on stainless steel specimens artificially contaminated with Cs+ ion. Decontamination characteristics of the stainless steel were analyzed by SEM and EPMA

  17. Decontamination Technology Development for Nuclear Research Facilities

    International Nuclear Information System (INIS)

    Oh, Won Zin; Jung, Chong Hun; Choi, Wang Kyu; Won, Hui Jun; Kim, Gye Nam

    2004-02-01

    Technology development of surface decontamination in the uranium conversion facility before decommissioning, technology development of component decontamination in the uranium conversion facility after decommissioning, uranium sludge treatment technology development, radioactive waste soil decontamination technology development at the aim of the temporary storage soil of KAERI, Optimum fixation methodology derivation on the soil and uranium waste, and safety assessment methodology development of self disposal of the soil and uranium waste after decontamination have been performed in this study. The unique decontamination technology applicable to the component of the nuclear facility at room temperature was developed. Low concentration chemical decontamination technology which is very powerful so as to decrease the radioactivity of specimen surface under the self disposal level was developed. The component decontamination technology applicable to the nuclear facility after decommissioning by neutral salt electro-polishing was also developed. The volume of the sludge waste could be decreased over 80% by the sludge waste separation method by water. The electrosorption method on selective removal of U(VI) to 1 ppm of unrestricted release level using the uranium-containing lagoon sludge waste was tested and identified. Soil decontamination process and equipment which can reduce the soil volume over 90% were developed. A pilot size of soil decontamination equipment which will be used to development of real scale soil decontamination equipment was designed, fabricated and demonstrated. Optimized fixation methodology on soil and uranium sludge was derived from tests and evaluation of the results. Safety scenario and safety evaluation model were development on soil and uranium sludge aiming at self disposal after decontamination

  18. Decontamination of the Douglas Point reactor, May 1983

    International Nuclear Information System (INIS)

    Lesurf, J.E.; Stepaniak, R.; Broad, L.G.; Barber, W.G.

    1983-01-01

    The Douglas Point reactor primary heat transport system including the fuel, was successfully decontaminated by the CAN-DECON process in 1975. A second decontamination, also using the CAN-DECON process, was successfully performed in May 1983. This paper outlines the need for the decontamination, the process used, the results obtained, and the benefits to the station maintenance and operation

  19. Provisional results from accelerated testing of ultra thin-layer reinforced concrete in South Africa

    CSIR Research Space (South Africa)

    Du Plessis, L

    2009-08-01

    Full Text Available The CSIR Built-Environment, in conjunction with the University of Pretoria and the Cement and Concrete Institute of South Africa, developed a low cost option for the upgrading of unsurfaced (gravel) roads. The proposed solution is the placing of a...

  20. Strength and deformability of hollow concrete blocks: correlation of block and cylindrical sample test results

    Directory of Open Access Journals (Sweden)

    C. S. Barbosa

    Full Text Available This paper deals with correlations among mechanical properties of hollow blocks and those of concrete used to make them. Concrete hollow blocks and test samples were moulded with plastic consistency concrete, to assure the same material in all cases, in three diferente levels of strength (nominally 10 N/mm², 20 N/mm² and 30 N/mm². The mechanical properties and structural behaviour in axial compression and tension tests were determined by standard tests in blocks and cylinders. Stress and strain analyses were made based on concrete’s modulus of elasticity obtained in the sample tests as well as on measured strain in the blocks’ face-shells and webs. A peculiar stress-strain analysis, based on the superposition of effects, provided an estimation of the block load capacity based on its deformations. In addition, a tentative method to preview the block deformability from the concrete mechanical properties is described and tested. This analysis is a part of a broader research that aims to support a detailed structural analysis of blocks, prisms and masonry constructions.

  1. Results of Laboratory Tests of the Filtration Characteristics of Clay-Cement Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Sol’skii, S. V., E-mail: solskiysv@vniig.ru; Lopatina, M. G., E-mail: LoptainaMG@vniig.ru; Legina, E. E.; Orishchuk, R. N.; Orlova, N. L. [B. E. Vedeneev All-Russia Research Institute of Hydraulic Engineering (VNIIG) (Russian Federation)

    2017-01-15

    Laboratory studies of the filtration characteristics of clay-cement concrete materials for constructing filtering diaphragms of earth dams by the method of secant piles are reported. Areas for further study aimed at improving the quality of construction, increasing operational safety, and developing a standards base for the design, construction, and operation of these systems are discussed.

  2. Radiological characterisation of contaminated concretes from the object 44/20 of NPP A1

    International Nuclear Information System (INIS)

    Slavik, O.; Listjak, M.; Pely, I.; Soos, F.

    2005-01-01

    Results of radiological characterisation of contaminated concretes from object 44/20 of the NPP A-1 Jaslovske Bohunice are summarized in this work. These works were carried out in VUJE in the laboratory of environmental dosimetry in 2004 and partially in 2005. The main results of radiological characterisation can be summarised as follow: (1) Contamination of concretes is in all cases surficial, it reaches up to 5-10 mm, the dominant contaminant is 137 Cs; (2) The spawn concrete is mostly contaminated only from one side (one being adjacent to the ceiling concrete), crucial part of them is even on this side contaminated in very low level complying with free release level; (3) The ceiling concrete blocks are contaminated mostly on one side, only (the inner side of shafts), their decontamination will require removing of about 5 mm thick surface layer. (4) The floor concrete is covered by heavily contaminated dust 137 CS, 100-500 Bq/g), originating from sorting of the wet RAW .Its decontamination will require removing of 10 mm thick surface concrete layer; (5) The core samples taken from the whole depth profile of the ceiling concrete show also only surface contamination, samples prepared from the deeper layers have not demonstrated any contamination in these layers. Control measurements of deeper concrete layers, however, went on with negative results also in year 2005; (6) The relative content for 90 Sr in these concretes is in average about 8%, for 241 Am determined by gamma-spectrometry is 0.4% and for 239 , 240 Pu determined radiochemically is 0.33% in comparison with the content of 137 Cs. (authors)

  3. Initial decontamination of the equipment decontamination room at the West Valley Demonstration Project. Topical report, September 1983-May 1985

    International Nuclear Information System (INIS)

    Meigs, R.A.

    1985-12-01

    The purpose of this report is to document the initial decontamination of the Equipment Decontamination Room (EDR). The effort spanned a two-year period and included packaging and removal of waste; grinding away contaminated concrete floors; pump-out and spraydown of an equipment soaking pit; washing and painting of walls, equipment, and floors; refurbishment of utilities and various pieces of equipment; and load tests of EDR and Chemical Process Cell (CPC) cranes. After decontamination, the EDR was converted into a waste handling area for the decommissioning of the CPC

  4. Recycled concrete aggregate in portland cement concrete.

    Science.gov (United States)

    2013-01-01

    Aggregates can be produced by crushing hydraulic cement concrete and are known as recycled concrete : aggregates (RCA). This report provides results from a New Jersey Department of Transportation study to identify : barriers to the use of RCA in new ...

  5. Recycled Concrete as Aggregate for Structural Concrete Production

    OpenAIRE

    Mirjana Malešev; Vlastimir Radonjanin; Snežana Marinković

    2010-01-01

    A comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement ratios of natural with recycled coarse aggregate is presented in the paper. Recycled aggregate was made by crushing the waste concrete of laboratory test cubes and precast concrete columns. Three types of concrete mixtures were tested: concrete made entirely with natural aggregate (NAC) as a control concrete and two types of concrete made with natural fine and recycle...

  6. Technology development and demonstration for TRIGA research reactor decontamination, decommissioning and site restoration

    International Nuclear Information System (INIS)

    Oh, Won Zin; Jung, Ki Jung; Lee, Byung Jik

    1997-01-01

    This paper describes the introduction to research reactor decommissioning plan at KAERI, the background of technology development and demonstration, and the current status of the system decontamination technology for TRIGA reactors, concrete decontamination and dust treatment technologies, wall ranging robot and graphic simulation of dismantling processes, soil decontamination and restoration technology, recycling or reuse technologies for radioactive metallic wastes, and incineration technology demonstration for combustible wastes. 9 figs

  7. Chemical decontamination method

    International Nuclear Information System (INIS)

    Nishiwaki, Hitoshi.

    1996-01-01

    Metal wastes contaminated by radioactive materials are contained in a rotational decontamination vessel, and the metal wastes are rotated therein while being in contact with a slight amount of a decontamination liquid comprising a mineral acid. As the mineral acid, a mixed acid of nitric acid, hydrochloric acid and fluoric acid is preferably used. Alternatively, chemical decontamination can also be conducted by charging an acid resistant stirring medium in the rotational decontamination vessel. The surface of the metal wastes is uniformly covered by the slight amount of decontamination liquid to dissolve the surface layer. In addition, heat of dissolution generated in this case is accumulated in the inside of the rotational decontamination vessel, the temperature is elevated with no particular heating, thereby enabling to obtain an excellent decontamination effect substantially at the same level as in the case of heating the liquid to 70degC in a conventional immersion decontamination method. Further, although contact areas between the metal wastes and the immersion vessel are difficult to be decontaminated in the immersion decontamination method, all of areas can be dissolved uniformly in the present invention. (T.M.)

  8. Lasers and high-energy light as a decontamination tool for nuclear applications

    International Nuclear Information System (INIS)

    Flesher, D.J.

    1993-12-01

    Light-aided decontamination (LAD) removal of paint and concrete layers is competitive with sand blasting rates. Remote operations, up to 137 m (450 ft), and lower waste volumes can provide cost, safety, and environmental advantages for nuclear facilities

  9. Decontamination technologies evaluations

    International Nuclear Information System (INIS)

    Tripp, J.

    1996-01-01

    Testing has been completed at the Idaho Chemical Processing Plant (ICPP) on in situ recyclable abrasives grit blasting, concrete cleaning (using scabbling, chemicals and electro-kinetics) and laser light ablation of metals. Several small scale tests have also been conducted with strippable coatings, CO 2 pellet blasting and various other techniques. The results of this testing is summarized in this paper

  10. Soil decontamination criteria report, November 1980

    International Nuclear Information System (INIS)

    Riordan, G.A.

    1980-01-01

    A program to access the extent of transuranic soil contamination at DOE sites and to develop methods for their decontamination is underway at Rocky Flats. As part of this program, acceptable soil contamination levels for plutonium proposed by a number of authorities over the past couple of decades were reviewed. From this review, goals for soil decontamination work are proposed. These goals, which relate to the disposition of the products of a decontamination process, are summarized as follows (dpm/g will refer to disintegrations per minute of transuranic nuclides per gram of soil): soil fractions having less than 30 dpm can be disposed of as surface soil with unrestricted usage. Fine soil fractions (less than 100 μm) that have less than 500 dpm and coarse soil fractions that have less than 1000 dpm can be disposed of as subsurface soil as long as usage is controlled to ensure compliance with EPA dosage guidance. Soil concentrates that have an activity greater than the above values but less than 22,000 dpm should be interred in an approved, low level waste burial site. Soil concentrates that are greater than 22,000 dpm should be stored as retrievable waste. Changes in the technical and legal areas of soil decontamination are rapid. Permissible soil decontamination levels will change as will decontamination technology and the ability to monitor the effectiveness of the decontamination processes. As a result, annual updates of decontamination criteria, goals, and monitoring are expected

  11. Experimental results of core-concrete interactions using molten steel with zirconium

    International Nuclear Information System (INIS)

    Copus, E.R.; Blose, R.E.; Brockmann, J.E.; Gomez, R.D.; Lucero, D.A.

    1990-07-01

    Four inductively sustained experiments, QT-D, QT-E, SURC-3, and SURC-3A, were performed in order to investigate the additional effects of zirconium metal oxidation on core debris-concrete interactions using molten stainless steel as the core debris simulant. The QT-D experiment ablated 18 cm of concrete axially during 50 minutes of interaction on limestone-common sand concrete using a 10 kg charge of 304 stainless steel to which 2 kg of zirconium metal was added subsequent to the onset of erosion. The QT-E experiment ablated 10 cm of limestone-common sand concrete axially and 10 cm radially during 35 minutes of sustained interaction using 50 kg of stainless steel and 10 kg of zirconium. The SURC-3 experiment had a 45 kg charge of stainless steel to which 1.1 kg of zirconium was subsequently added. SURC-3 axially eroded 33 cm of limestone concrete during two hours of interaction. The fourth experiment, SURC-3A, eroded 25 cm of limestone concrete axially and 9 cm radially during 90 minutes of sustained interaction. It utilized 40 kg of stainless steel and 2.2 kg of added zirconium as the charge material. All four experiments showed in a large increase in erosion rate, gas production, and aerosol release following the addition of Zr metal to the melt. In the SURC-3 and SURC-3A tests the measured erosion rates increased from 14 cm/hr to 27 cm/hr, gas release increased from 50 slpm to 100 slpm, and aerosol release increased from .02 q/sec to .04 q/sec. The effluent gas was composed of 80% CO, 10% CO 2 , and 2% H 2 before Zr addition and 92% CO, 4% CO 2 , 4% H 2 during the Zr interactions which lasted 10--20 minutes. Addition measurements indicated that the melt pool temperature ranged from 1600 degree C--1800 degree and that the aerosols produced were comprised primarily of Te and Fe oxides. 21 refs., 120 figs., 51 tabs

  12. Experimental results of core-concrete interactions using molten steel with zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Copus, E.R.; Blose, R.E.; Brockmann, J.E.; Gomez, R.D.; Lucero, D.A. (Sandia National Labs., Albuquerque, NM (USA))

    1990-07-01

    Four inductively sustained experiments, QT-D, QT-E, SURC-3, and SURC-3A, were performed in order to investigate the additional effects of zirconium metal oxidation on core debris-concrete interactions using molten stainless steel as the core debris simulant. The QT-D experiment ablated 18 cm of concrete axially during 50 minutes of interaction on limestone-common sand concrete using a 10 kg charge of 304 stainless steel to which 2 kg of zirconium metal was added subsequent to the onset of erosion. The QT-E experiment ablated 10 cm of limestone-common sand concrete axially and 10 cm radially during 35 minutes of sustained interaction using 50 kg of stainless steel and 10 kg of zirconium. The SURC-3 experiment had a 45 kg charge of stainless steel to which 1.1 kg of zirconium was subsequently added. SURC-3 axially eroded 33 cm of limestone concrete during two hours of interaction. The fourth experiment, SURC-3A, eroded 25 cm of limestone concrete axially and 9 cm radially during 90 minutes of sustained interaction. It utilized 40 kg of stainless steel and 2.2 kg of added zirconium as the charge material. All four experiments showed in a large increase in erosion rate, gas production, and aerosol release following the addition of Zr metal to the melt. In the SURC-3 and SURC-3A tests the measured erosion rates increased from 14 cm/hr to 27 cm/hr, gas release increased from 50 slpm to 100 slpm, and aerosol release increased from .02 q/sec to .04 q/sec. The effluent gas was composed of 80% CO, 10% CO{sub 2}, and 2% H{sub 2} before Zr addition and 92% CO, 4% CO{sub 2}, 4% H{sub 2} during the Zr interactions which lasted 10--20 minutes. Addition measurements indicated that the melt pool temperature ranged from 1600{degree}C--1800{degree} and that the aerosols produced were comprised primarily of Te and Fe oxides. 21 refs., 120 figs., 51 tabs.

  13. Corrective Action Investigation Plan for Corrective Action Unit 252: Area 25 Engine Test Stand 1 Decontamination Pad, Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    U.S. Department of Energy, Nevada Operations Office

    1999-08-20

    This Corrective Action Investigation Plan contains the U.S. Department of Energy, Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit 252 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 252 consists of Corrective Action Site (CAS) 25-07-02, Engine Test Stand-1 (ETS-1) Decontamination Pad. Located in Area 25 at the intersection of Road H and Road K at the Nevada Test Site, ETS-1 was designed for use as a mobile radiation checkpoint and for vehicle decontamination. The CAS consists of a concrete decontamination pad with a drain, a gravel-filled sump, two concrete trailer pads, and utility boxes. Constructed in 1966, the ETS-1 facility was part of the Nuclear Rocket Development Station (NRDS) complex and used to test nuclear rockets. The ETS-1 Decontamination Pad and mobile radiation check point was built in 1968. The NRDS complex ceased primary operations in 1973. Based on site history, the focus of the field investigation activities will be to determine if any primary contaminants of potential concern (COPCs) (including radionuclides, total volatile organic compounds, total semivolatile organic compounds, total petroleum hydrocarbons as diesel-range organics, Resource Conservation and Recovery Act metals, total pesticides, and polychlorinated biphenyls) are present at this site. Vertical extent of migration of suspected vehicle decontamination effluent COPCs is expected to be less than 12 feet below ground surface. Lateral extent of migration of COPCs is expected to be limited to the sump area or near the northeast corner of the decontamination pad. Using a biased sampling approach, near-surface and subsurface sampling will be conducted at the suspected worst-case areas including the sump and soil near the northeast corner of the decontamination pad. The results of this field investigation will support a defensible e

  14. Development of aerosol decontamination factor evaluation method for filtered containment venting system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae bong; Kim, Sung Il; Jung, Jaehoon; Ha, Kwang Soon; Kim, Hwan Yeol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Fission products would be released from molten corium pools which are relocated into the lower plenum of reactor pressure vessel, on the concrete pit and in the core catcher. In addition, steam, hydrogen and noncondensable gases such as CO and CO2 are generated during the core damage progression due to loss of coolant and the molten core-concrete interaction. Consequently, the pressure inside the containment could be increased continuously. Filtered containment venting is one action to prevent an uncontrolled release of radioactive fission products caused by an overpressure failure of the containment. After the Fukushima-Daiichi accident which was demonstrated the containment failure, many countries to consider the implementation of filtered containment venting system(FCVS) on nuclear power plant where these are not currently applied. In general evaluation for FCVS is conducted to determine decontamination factor on several conditions (aerosol diameter, submergence depth, water temperature, gas flow, steam flow rate, pressure, operating time,...). It is essential to quantify the mass concentration before and after FCVS for decontamination factor. This paper presents the development of the evaluation facility for filtered containment venting system at KAERI and an experimental investigation for aerosol removal performance. Decontamination factor for the FCVS is determined by filter measurement. The result of the aerosol size distribution measurement shows the aerosol removal performance by an aerosol size.

  15. Decontamination device for pipeline

    International Nuclear Information System (INIS)

    Harashina, Heihachi.

    1994-01-01

    Pipelines to be decontaminated are parts of pipelines contaminated with radioactive materials, and they are connected to a fluid transfer means (for example, a bladeless pump) and a ball collector by way of a connector. The fluid of a mixture of chemical decontaminating liquid and spheres is sent into pipelines to be decontaminated. The spheres are, for example, heat resistant porous hard or soft rubber spheres. The fluid discharged from the pipelines to be decontaminated are circulated by way of bypassing means. The inner surface of the pipelines is decontaminated by the circulation of the fluid. When the bypass means is closed, the fluid discharged from the pipelines to be decontaminated is sent to the ball collector, and the spheres are captured by a hopper. Further, the liquid is sent to the filtrating means to filter the chemical contaminating liquid, and sludges contained in the liquid are captured. (I.N.)

  16. Gross decontamination experiment report

    International Nuclear Information System (INIS)

    Mason, R.; Kinney, K.; Dettorre, J.; Gilbert, V.

    1983-07-01

    A Gross Decontamination Experiment was conducted on various levels and surfaces of the TMI - Unit 2 reactor building in March 1982. The polar crane, D-rings, missile shields, refueling canals, refueling bridges, equipment, and elevations 305' and 347'-6'' were flushed with low pressure water. Additionally, floor surfaces on elevation 305' and floor surfaces and major pieces of equipment on elevation 347'-6'' were sprayed with high pressure water. Selective surfaces were decontaminated with a mechanical scrubber and chemicals. Strippable coating was tested and evaluated on equipment and floor surfaces. The effectiveness, efficiency, and safety of several decontamination techniques were established for the large, complex decontamination effort. Various decontamination equipment was evaluated and its effectiveness was documented. Decontamination training and procedures were documented and evaluated, as were the support system and organization for the experiment

  17. Decontamination of radioactive isotopes

    International Nuclear Information System (INIS)

    Despotovic, R.; Music, S.; Subotic, B.; Wolf, R.H.H.

    1979-01-01

    Removal of radioactive isotopes under controlled conditions is determined by a number of physical and chemical properties considered radiocontaminating and by the characteristics of the contaminated object. Determination of quantitative and qualitative factors for equilibrium in a contamination-decontamination system provides the basis for rational and successful decontamination. The decontamination of various ''solid/liquid'' systems is interesting from the scientific and technological point of view. These systems are of great importance in radiation protection (decontamination of various surfaces, liquids, drinking water, fixation or collection of radiocontaminants). Different types of decontamination systems are discussed. The dependence of rate and efficiency of the preparation conditions and on the ageing of the scavenger is described. The influence of coagulating electrolyte on radioactive isotope fixation efficiency was also determined. The fixation of fission radionuclide on oxide scavengers has been studied. The connection between fundamental investigations and practical decontamination of the ''solid/liquid'' systems is discussed. (author)

  18. Gross decontamination experiment report

    Energy Technology Data Exchange (ETDEWEB)

    Mason, R.; Kinney, K.; Dettorre, J.; Gilbert, V.

    1983-07-01

    A Gross Decontamination Experiment was conducted on various levels and surfaces of the TMI - Unit 2 reactor building in March 1982. The polar crane, D-rings, missile shields, refueling canals, refueling bridges, equipment, and elevations 305' and 347'-6'' were flushed with low pressure water. Additionally, floor surfaces on elevation 305' and floor surfaces and major pieces of equipment on elevation 347'-6'' were sprayed with high pressure water. Selective surfaces were decontaminated with a mechanical scrubber and chemicals. Strippable coating was tested and evaluated on equipment and floor surfaces. The effectiveness, efficiency, and safety of several decontamination techniques were established for the large, complex decontamination effort. Various decontamination equipment was evaluated and its effectiveness was documented. Decontamination training and procedures were documented and evaluated, as were the support system and organization for the experiment.

  19. Failure conditions from push-out tests of a steel-concrete joint: experimental results

    Czech Academy of Sciences Publication Activity Database

    Helincks, P.; De Corte, W.; Klusák, Jan; Seitl, Stanislav; Boel, V.; De Schutter, G.

    488-489, - (2012), s. 714-717 ISSN 1013-9826. [International Conference on Fracture and Damage Mechanics - FDM 2011 /10./. Dubrovník, 19.09.2011-21.09.2011] R&D Projects: GA ČR GAP108/10/2049 Institutional research plan: CEZ:AV0Z20410507 Keywords : steel-concrete joint * push-out test * shear bond strength Subject RIV: JL - Materials Fatigue, Friction Mechanics

  20. How Concrete Is Concrete?

    Science.gov (United States)

    Gravemeijer, Koeno

    2011-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, "manipulatives", in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own,…

  1. Decontaminating reagents for radioactive systems

    International Nuclear Information System (INIS)

    Seddon, W.A.

    1982-01-01

    A decontaminating reagent composition has been developed comprising EDTA, citric acid, oxalic acid, and formic acid. Formic acid inhibits the decomposition of both EDTA and citric acid, and yields oxalic acid as a result of its own radiolysis. The invention includes the improvement of initially incorporating formic acid in the mixture and maintaining the presence of formic acid by at least one further addition

  2. Decontamination of body surface

    International Nuclear Information System (INIS)

    Harase, Chieko.

    1989-01-01

    There are two important points for an effective application of decontamination procedures. One is the organizing method of responsible decontamination teams. The team should be directed by medical doctor with the knowledge of decontamination of radionuclides. The other point is the place of application of the decontamination. Hospitals and clinics, especially with a department of nuclear medicine, or specialized units such as an emergency medical center are preferable. Before decontamination procedures are initiated, adequate monitoring of the body surface should be undertaken by a competent person in order to demarcate the areas which are contaminated. There are fundamental principles which are applicable to all decontamination procedures. (1) Precautions must always be taken to prevent further spread of contamination during decontamination operations. (2) Mild decontamination methods should be tried before resorting to treatment which can damage the body surface. The specific feature of each contamination varies widely in radionuclides involved, place and area of the contamination, condition of the contaminated skin such as whether the skin is wounded or not, and others. Soap and water are usually good detergents in most cases. If they fail, orange oil cream (SUPERDECONCREAM, available from Tokyo Engineering Co.) specially prepared for decontamination of radionuclides of most fission and corrosion products may be used. Contaminated hair should be washed several times with an efficient shampoo. (author)

  3. Estimating decontamination efficiency of territory, adjoining to the Chernobyl' NPP

    International Nuclear Information System (INIS)

    Konstantinov, E.A.; Sanitarov, V.A.; Stepanov, I.K.; Senin, E.V.; Filippov, E.M.; Shiraj, A.P.; Umanets, M.P.

    1989-01-01

    The NPP territory decontamination was fulfilled according to the next scheme: 1) removal of the soil upper layer and its moving avay for burial; 2) concrete plate laying; 3) concreting seams between plates and piling up polymer coatings. The conclusion is made that substantial improvement of radiation situation at the operating site is possible only after removal of radiation sources at the machine room roofing. 1 ref.; 5 figs.; 2 tabs

  4. Comparison between theoretical and experimental results of the 1/6 scale concrete model under internal pressure

    International Nuclear Information System (INIS)

    Riviere, J.; Barbe, B.; Millard, A.; Koundy, V.

    1988-01-01

    The prevision of the behavior of the 1/6 scale concrete model under internal pressure was realized by means of two computations, the first one with an infinite soil rigidity, the second one with a soil rigidity equal to 61.26 MPa/m. These two computations, that assumed a perfectly axisymetric structure gave theoretical and experimental results in good agreement, except the raft of which the theoretical uplift was three times higher than the experimental one. The main conclusions of this study are as follow: the soil stiffness has no influence on the ultimate behavior of the model, the dead concrete rigidity decreases the raft uplift in an important way, the model is destroyed because the hoop stress reaches the ultimate strength

  5. Decontamination tests on cotton materials; Essais de decontamination sur tissus de coton

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, P; Pelletier, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    It is shown that versene gives the best decontamination results on cotton materials soiled by a mixture of fission products. (author) [French] On a montre que le versene donne les meilleurs resultats de decontamination sur des tissus de coton souilles par un melange de produits de fission. (auteur)

  6. Decontamination of floor surfaces

    International Nuclear Information System (INIS)

    Smirous, F.

    1983-01-01

    Requirements are presented put on the surfaces of floors of radiochemical workplaces. The mechanism is described of retaining the contaminant in the surface of the flooring, ways of reducing the hazards of floor surface contamination, decontamination techniques and used decontamination agents. (J.P.)

  7. Review of the sodium fire experiments including sodium-concrete-reactions and summary of the results

    International Nuclear Information System (INIS)

    Cherdron, W.

    1996-01-01

    In the technical and design concept of containment systems of sodium cooled breeder reactors it has to be considered, that leakages in sodium pipes lead to sodium fires. The temperature and pressure rise caused by sodium fires makes it indispensable to analyse these accidents to be able to assess the safety of the whole system. Generally sodium leakages may lead to three different types of fires with different consequences. The main influences are the geometry of the leakage, shape, size, location, and the sodium conditions, such as temperature, flow rate and velocity. It must be also considered the reaction of sodium with surfaces like concrete. The paper gives an overview over all the sodium fire experiments performed in the FAUNA-facility (220 m 3 ) of the Forschungszentrum Karlsruhe in the years 1979 to 1993. The experimental program started with the investigation of pool fires on burning areas between 2 and 12 m 2 with up to 500 kg of Sodium. The experiments had been continued with 3 combined fires and 40 experiments on spray fires. 7 experiments on sodium-concrete reactions completed the program. (author)

  8. ANALYTICAL RESULTS OF MOX COLEMANITE CONCRETE SAMPLE PBC-44.2

    Energy Technology Data Exchange (ETDEWEB)

    Best, D.; Cozzi, A.; Reigel, M.

    2012-12-20

    The Mixed Oxide Fuel Fabrication Facility (MFFF) will use colemanite bearing concrete neutron absorber panels credited with attenuating neutron flux in the criticality design analyses and shielding operators from radiation. The Savannah River National Laboratory is tasked with measuring the total density, partial hydrogen density, and partial boron density of the colemanite concrete. Sample PBC-44.2 was received on 9/20/2012 and analyzed. The average total density measured by the ASTM method C 642 was 2.03 g/cm{sup 3}, within the lower bound of 1.88 g/cm3. The average partial hydrogen density was 6.64E-02 g/cm{sup 3} as measured using method ASTM E 1311 and met the lower bound of 6.04E-02 g/cm{sup 3}. The average measured partial boron density was 1.70E-01 g/cm{sup 3} which met the lower bound of 1.65E-01 g/cm{sup 3} measured by the ASTM C 1301 method.

  9. ANALYTICAL RESULTS OF MOX COLEMANITE CONCRETE SAMPLES POURED AUGUST 29, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Best, D.; Cozzi, A.; Reigel, M.

    2012-12-20

    The Mixed Oxide Fuel Fabrication Facility (MFFF) will use colemanite bearing concrete neutron absorber panels credited with attenuating neutron flux in the criticality design analyses and shielding operators from radiation. The Savannah River National Laboratory is tasked with measuring the total density, partial hydrogen density, and partial boron density of the colemanite concrete. Samples poured 8/29/12 were received on 9/20/2012 and analyzed. The average total density of each of the samples measured by the ASTM method C 642 was within the lower bound of 1.88 g/cm{sup 3}. The average partial hydrogen density of samples 8.6.1, 8.7.1, and 8.5.3 as measured using method ASTM E 1311 met the lower bound of 6.04E-02 g/cm{sup 3}. The average measured partial boron density of each sample met the lower bound of 1.65E-01 g/cm{sup 3} measured by the ASTM C 1301 method. The average partial hydrogen density of samples 8.5.1, 8.6.3, and 8.7.3 did not meet the lower bound. The samples, as received, were not wrapped in a moist towel as previous samples and appeared to be somewhat drier. This may explain the lower hydrogen partial density with respect to previous samples.

  10. Results of fission product release from intermediate-scale MCCI [molten core-concrete interaction] tests

    International Nuclear Information System (INIS)

    Spencer, B.W.; Thompson, D.H.; Fink, J.K.; Gunther, W.H.; Sehgal, B.R.

    1988-01-01

    A program of reactor-material molten core-concrete interaction (MCCI) tests and related analyses are under way at Argonne National Laboratory under sponsorship of the Electric Power Research Institute (EPRI). The particular objective of these tests is to provide data pertaining to the release of nonvolatile fission products such as La, Ba, and Sr, plus other aerosol materials, from the coupled thermal-hydraulic and chemical processes of the MCCI. The first stages of the program involving small and intermediate-scale tests have been completed. Three small-scale tests (/approximately/5 kg corium) and nine intermediate-scale tests (/approximately/30 kg corium) were performed between September 1985 and September 1987. Real reactor materials were used in these tests. Sustained internal heat generation at nominally 1 kW per kg of melt was provided by direct electrical heating of the corium mixture. MCCI tests were performed with both fully and partially oxidized corium mixtures that contained a variety of nonradioactive materials such as La 2 O 3 , BaO, and SrO to represent fission products. Both limestone/common sand and basaltic concrete basemats were used. The system was instrumented for characterization of the thermal hydraulic, chemical, gas release, and aerosol release processes

  11. Separations canyon decontamination facilities

    International Nuclear Information System (INIS)

    Hershey, J.H.

    1975-01-01

    Highly radioactive process equipment is decontaminated at the Savannah River Plant in specially equipped areas of the separations canyon building so that direct mechanical repairs or alterations can be made. Using these facilities it is possible to decontaminate and repair equipment such as 10- x 11-ft storage tanks, 8- x 8-ft batch evaporator pots and columns, 40-in. Bird centrifuges, canyon pumps and agitators, and various canyon piping systems or ''jumpers.'' For example, centrifuge or evaporator pots can be decontaminated and rebuilt for about 60 percent of the 1974 replacement cost. The combined facilities can decontaminate and repair 6 to 10 pieces of major equipment per year. Decontamination time varies with type of equipment and radioactivity levels encountered

  12. Separations canyon decontamination facilities

    International Nuclear Information System (INIS)

    Hershey, J.H.

    1975-05-01

    Highly radioactive process equipment is decontaminated at the Savannah River Plant in specially equipped areas of the separations canyon buildings so that direct mechanical repairs or alterations can be made. Using these facilities it is possible to decontaminate and repair equipment such as 10- x 11-ft storage tanks, 8- x 8-ft batch evaporator pots and columns, 40-in. Bird centrifuges, canyon pumps and agitators, and various canyon piping systems or ''jumpers.'' For example, centrifuge or evaporator pots can be decontaminated and rebuilt for about 60 percent of the 1974 replacement cost. The combined facilities can decontaminate and repair 6 to 10 pieces of major equipment per year. Decontamination time varies with type of equipment and radioactivity levels encountered. (U.S.)

  13. Influence of Decontamination

    International Nuclear Information System (INIS)

    Knaack, Michael

    2016-01-01

    This paper describes the influence of several decontamination techniques on the decommissioning of nuclear facilities. There are different kinds of decontamination methods like mechanical and chemical processes. The techniques specified, and their potential to change measured characteristics like the isotope vector of the contamination is demonstrated. It is common for all these processes, that the contamination is removed from the surface. Slightly adhered nuclides can be removed more effectively than strongly sticking nuclides. Usually a mixture of these nuclides forms the contamination. Problematically any kind of decontamination will influence the nuclide distribution and the isotope vector. On the one hand it is helpful to know the nuclide distribution and the isotope vector for the radiological characterization of the nuclear facility and on the other hand this information will be changed in the decontamination process. This is important especially for free release procedures, radiation protection and waste management. Some questions on the need of decontamination have been discussed. (authors)

  14. Guide for decontaminating swimming pool at schools

    International Nuclear Information System (INIS)

    Matsuhashi, Shimpei; Kurikami, Hiroshi; Yasuda, Ryo; Takano, Takao; Seko, Noriaki; Naganawa, Hirochika; Kuroki, Ryota; Saegusa, Jun

    2012-07-01

    Because of TEPCO Fukushima Dai-ichi Nuclear Power Plant accident due to the Great East Japan Earthquake, a huge amount of radioactive materials was widely dispersed and precipitated into the environment. Swimming pools in Fukushima prefectures were contaminated with the radioactives. We JAEA carried out several demonstration tests to decontaminate the radioactives and discharge the pool water safely. We concluded the results obtained from the tests as 'Guide for decontaminating Swimming Pool at School' and released it quickly. Following this, we also released the guide in English. This manuscript, as an experimental report of the swimming pool water decontamination, is consisted from the guide in Japanese and English prepared. (author)

  15. Guide for decontaminating swimming pool at schools

    Energy Technology Data Exchange (ETDEWEB)

    Matsuhashi, Shimpei; Kurikami, Hiroshi; Yasuda, Ryo; Takano, Takao; Seko, Noriaki; Naganawa, Hirochika; Kuroki, Ryota; Saegusa, Jun

    2012-07-15

    Because of TEPCO Fukushima Dai-ichi Nuclear Power Plant accident due to the Great East Japan Earthquake, a huge amount of radioactive materials was widely dispersed and precipitated into the environment. Swimming pools in Fukushima prefectures were contaminated with the radioactives. We JAEA carried out several demonstration tests to decontaminate the radioactives and discharge the pool water safely. We concluded the results obtained from the tests as 'Guide for decontaminating Swimming Pool at School' and released it quickly. Following this, we also released the guide in English. This manuscript, as an experimental report of the swimming pool water decontamination, is consisted from the guide in Japanese and English prepared. (author)

  16. Foam process for application of decontamination agents

    International Nuclear Information System (INIS)

    Harris, J.M.; Miller, J.R.; Frazier, R.S.; Walter, J.H.

    1982-01-01

    This paper presents the results and observations of a study performed by the authors to parametrically evaluate the performance characteristics of a foam process for application of decontamination agents. The initial tests were established to assess foam quality. Subsequent tests determined the ability of the foam as a carrier of chemical systems, and established system operating parameters. The technique was then applied in an actual decontamination task to verify effectiveness of these established parameters and to determine decontamination reduction factors. 4 figures, 5 tables

  17. Chemical decontamination for decommissioning purposes. (Vigorous decontamination tests of steel samples in a special test loop)

    International Nuclear Information System (INIS)

    Bregani, F.; Pascali, R.; Rizzi, R.

    1984-01-01

    The aim of the research activities described was to develop vigorous decontamination techniques for decommissioning purposes, taking into account the cost of treatment of the radwaste, to achieve possibly unrestricted release of the treated components, and to obtain know-how for in situ hard decontamination. The decontamination procedures for strong decontamination have been optimized in static and dynamic tests (DECO-loop). The best values have been found for: (i) hydrochloric acid: 4 to 5% vol. at low temperature, 0.7 to 1% vol. at high temperature (80 0 C); (ii) hydrofluoric plus nitric acid: 1.5% vol. HF + 5% vol. HNO 3 at low temperature; 0.3 to 0.5% vol. HF + 2.5 to 5% vol. HNO 3 at high temperature. High flow rates are not necessary, but a good re-circulation of the solution is needed. The final contamination levels, after total oxide removal, are in accordance with limits indicated for unrestricted release of materials in some countries. The arising of the secondary waste is estimated. Decontamination of a 10 m 2 surface would typically produce 0.5 to 3.0 kg of dry waste, corresponding to 1.6 to 10 kg of concrete conditioned waste

  18. Decontamination technology assessment

    International Nuclear Information System (INIS)

    Allen, R.P.; Konzek, G.J.; Schneider, K.R.; Smith, R.I.

    1988-10-01

    This study identifies and technically assesses foreign decontamination and decommissioning (D and D) technology developments that may represent significant improvements over D and D technology currently available or under development in the United States. Technology need areas for nuclear power reactor decommissioning operations were identified and prioritized using the results of past light water reactor (LWR) decommissioning studies to quantitatively evaluate the potential for reducing cost and decommissioning worker radiation dose for each major decommissioning activity. Based on these identified needs, current foreign D and D technologies of potential interest to the US were identified through personal contacts and the collection and review of an extensive body of D and D literature. These technologies were then assessed qualitatively to evaluate their uniqueness, potential for a significant reduction in D and D costs and/or worker radiation dose, development status, and other factors affecting their value and applicability to US needs. 4 refs

  19. Oxidative Tritium Decontamination System

    International Nuclear Information System (INIS)

    Gentile, Charles A.; Parker, John J.; Guttadora, Gregory L.; Ciebiera, Lloyd P.

    2002-01-01

    The Princeton Plasma Physics Laboratory, Tritium Systems Group has developed and fabricated an Oxidative Tritium Decontamination System (OTDS), which is designed to reduce tritium surface contamination on various components and items. The system is configured to introduce gaseous ozone into a reaction chamber containing tritiated items that require a reduction in tritium surface contamination. Tritium surface contamination (on components and items in the reaction chamber) is removed by chemically reacting elemental tritium to tritium oxide via oxidation, while purging the reaction chamber effluent to a gas holding tank or negative pressure HVAC system. Implementing specific concentrations of ozone along with catalytic parameters, the system is able to significantly reduce surface tritium contamination on an assortment of expendable and non-expendable items. This paper will present the results of various experimentation involving employment of this system

  20. Use of a multi-process phytoremediation system for decontamination of petroleum impacted soils : results of successful field trials

    International Nuclear Information System (INIS)

    Greenberg, B.M.; Gurska, J.; Huang, X.D.; Gerhardt, K.E.; Yu, X.M.; Nykamp, J.; MacNeill, G.; Yang, S.; Lu, X.; Glick, B.; Wang, W.; Knezevich, N.; Reid, N.

    2008-01-01

    The multi-process phytoremediation system (MPPS) was developed to degrade petroleum hydrocarbons (PHCs) in impacted soils. Phytoremediation of persistent contaminants in soils holds significant promise for rapid remediation kinetics. MPPS effectively removes polycyclic aromatic hydrocarbons (PAHs), total petroleum hydrocarbons (TPHs) and chlorinated hydrocarbons (CHCs) from soils. A plant growth promoting rhizobacteria interaction is the main element for success as it mitigates stress ethylene effects in plants, leading to high root biomass which, in turn, promotes growth of rhizosphere organisms. Field tests of the MPPS were initiated at a farm site in Sarnia, Ontario in the summer of 2004. The field was contaminated with petroleum hydrocarbons from refinery oil sludge. The second field trial was performed for 3 consecutive years at a petroleum contaminated biopile in Turner Valley, Alberta. The paper presented the results of the successful field tests of the MPPS. It was concluded that increased root biomass is achieved in the contaminated soils, which leads to more efficient and complete removal of TPHs in the field. Three years of field trials of the MPPS showed that remediation continues with successive seasons. 28 refs., 1 tab., 3 figs

  1. Decontamination Efficacy and Skin Toxicity of Two Decontaminants against Bacillus anthracis.

    Directory of Open Access Journals (Sweden)

    Chad W Stratilo

    Full Text Available Decontamination of bacterial endospores such as Bacillus anthracis has traditionally required the use of harsh or caustic chemicals. The aim of this study was to evaluate the efficacy of a chlorine dioxide decontaminant in killing Bacillus anthracis spores in solution and on a human skin simulant (porcine cadaver skin, compared to that of commonly used sodium hypochlorite or soapy water decontamination procedures. In addition, the relative toxicities of these decontaminants were compared in human skin keratinocyte primary cultures. The chlorine dioxide decontaminant was similarly effective to sodium hypochlorite in reducing spore numbers of Bacillus anthracis Ames in liquid suspension after a 10 minute exposure. After five minutes, the chlorine dioxide product was significantly more efficacious. Decontamination of isolated swine skin contaminated with Bacillus anthracis Sterne with the chlorine dioxide product resulted in no viable spores sampled. The toxicity of the chlorine dioxide decontaminant was up to two orders of magnitude less than that of sodium hypochlorite in human skin keratinocyte cultures. In summary, the chlorine dioxide based decontaminant efficiently killed Bacillus anthracis spores in liquid suspension, as well as on isolated swine skin, and was less toxic than sodium hypochlorite in cultures of human skin keratinocytes.

  2. Reactive skin decontamination lotion (RSDL) for the decontamination of chemical warfare agent (CWA) dermal exposure.

    Science.gov (United States)

    Schwartz, M D; Hurst, C G; Kirk, M A; Reedy, S J D; Braue, E H

    2012-08-01

    Rapid decontamination of the skin is the single most important action to prevent dermal absorption of chemical contaminants in persons exposed to chemical warfare agents (CWA) and toxic industrial chemicals (TICs) as a result of accidental or intentional release. Chemicals on the skin may be removed by mechanical means through the use of dry sorbents or water. Recent interest in decontamination systems which both partition contaminants away from the skin and actively neutralize the chemical has led to the development of several reactive decontamination solutions. This article will review the recently FDA-approved Reactive Skin Decontamination Lotion (RSDL) and will summarize the toxicity and efficacy studies conducted to date. Evidence of RSDL's superior performance against vesicant and organophosphorus chemical warfare agents compared to water, bleach, and dry sorbents, suggests that RSDL may have a role in mass human exposure chemical decontamination in both the military and civilian arenas.

  3. Pervious concrete fill in Pearl-Chain Bridges: Using small-scale results in full-scale implementation

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Hansen, Kurt Kielsgaard; Truelsen, R.

    2016-01-01

    distribution and strength properties is determined for 800 mm high blocks cast in different numbers of layers, and (2) full-scale implementation in a 26 m long Pearl-Chain Bridge. With a layer thickness of 27 cm, the small-scale tests indicated homogenous results; however, for the full-scale implementation......Pearl-Chain Bridge technology is a new prefabricated arch solution for highway bridges. This study investigates the feasibility of pervious concrete as a filling material in Pearl-Chain Bridges. The study is divided into two steps: (1) small-scale tests where the variation in vertical void...

  4. PWR decontamination feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Silliman, P.L.

    1978-12-18

    The decontamination work which has been accomplished is reviewed and it is concluded that it is worthwhile to investigate further four methods for decontamination for future demonstration. These are: dilute chemical; single stage strong chemical; redox processes; and redox/chemical in combination. Laboratory work is recommended to define the agents and processes for demonstration and to determine the effect of the solvents on PWR materials. The feasibility of Indian Point 1 for decontamination demonstrations is discussed, and it is shown that the system components of Indian Point 1 are well suited for use in demonstrations.

  5. Long lasting decontamination foam

    Science.gov (United States)

    Demmer, Ricky L.; Peterman, Dean R.; Tripp, Julia L.; Cooper, David C.; Wright, Karen E.

    2010-12-07

    Compositions and methods for decontaminating surfaces are disclosed. More specifically, compositions and methods for decontamination using a composition capable of generating a long lasting foam are disclosed. Compositions may include a surfactant and gelatin and have a pH of less than about 6. Such compositions may further include affinity-shifting chemicals. Methods may include decontaminating a contaminated surface with a composition or a foam that may include a surfactant and gelatin and have a pH of less than about 6.

  6. PWR decontamination feasibility study

    International Nuclear Information System (INIS)

    Silliman, P.L.

    1978-01-01

    The decontamination work which has been accomplished is reviewed and it is concluded that it is worthwhile to investigate further four methods for decontamination for future demonstration. These are: dilute chemical; single stage strong chemical; redox processes; and redox/chemical in combination. Laboratory work is recommended to define the agents and processes for demonstration and to determine the effect of the solvents on PWR materials. The feasibility of Indian Point 1 for decontamination demonstrations is discussed, and it is shown that the system components of Indian Point 1 are well suited for use in demonstrations

  7. Full system decontamination (FSD) for sustainable dose reduction

    International Nuclear Information System (INIS)

    Stiepani, Christoph; Sempere-Belda, Luis; Topf, Christian; Basu, Ashim

    2012-09-01

    Nuclear power plants experience an increase in dose rates during operation due to the build-up of the activity inventory. The activity build-up is influenced by the construction materials, past and present water chemistries, and the individual operating history of the plant. Depending on these factors the dose levels in an operating plant may reach a point in which concrete actions to reduce the overall radiation exposure become necessary. In the past dose reduction plans were performed, based on - Modification in coolant water chemistry - Substitution of Cobalt containing materials - Outage optimization program - Installation of permanent shielding - Decontamination The dose rate reduction took several years and today a stagnation of further dose rate reduction can be seen. Therefore AREVA has developed the Concept for Sustainable Dose Reduction in Operating BWRs and PWRs. This is a program of joint corrective measures to minimize dose levels rapidly and keep them low for continued operation. It can be applied in plants from all constructors and designs. The concept is based fully on the application of proven technologies, including: - Full System Decontamination with AREVA's decontamination process HP/CORD UV to minimize the activity inventory - The formation of new, very stable protective oxides on the system surfaces including injection of depleted zinc - Introduction of advanced water chemistry for maintaining the low dose levels achieved during ongoing operation The implementation of this program is particularly interesting for plants with a long operation history, especially when considering life extension. The latest application was performed successfully at the German PWR Grafenrheinfeld in 2010. In this paper the concept for sustainable dose reduction will be outlined and the site application detailed and the achieved results at PWR Grafenrheinfeld will be described. The recontamination after one cycle will be outlined in a second paper. (authors)

  8. Final programmatic environmental impact statement related to decontamination and disposal of radioactive wastes resulting from March 28, 1979 accident, Three Mile Island Nuclear Station, Unit 2, Docket No. 50-320

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1981-03-01

    A Final Programmatic Environmental Impact Statement (PEIS) related to the decontamination and disposal of radioactive wastes resulting from the March 28, 1979, accident at Three Mile Island Nuclear Station, Unit 2 (Docket No. 50-320) has been prepared by the Office of Nuclear Reactor Regulation of the Nuclear Regulatory Commission in response to a directive issued by the Commission on November 21, 1979. This statement is an overall study of the activities necessary for decontamination of the facility, defueling, and disposition of the radioactive wastes. The available alternatives considered ranged from implementation of full cleanup to no action other than continuing to maintain the reactor in a safe shutdown condition. Also included are comments of governmental agencies, other organizations, and the general public on the Draft PEIS on this project, and staff responses to these comments. (author)

  9. TRANSPARENT CONCRETE

    OpenAIRE

    Sandeep Sharma*, Dr. O.P. Reddy

    2017-01-01

    Transparent concrete is the new type of concrete introduced in todays world which carries special property of light transmitting due to presence of light Optical fibres. Which is also known as translucent concrete or light transmitting concrete, it is achieved by replacing coarse aggregates with transparent alternate materials (Optical fibres). The binding material in transparent concrete may be able to transmit light by using clear resins the concrete mix. The concrete used in industry in pr...

  10. Development of strippable gel for surface decontamination applications

    International Nuclear Information System (INIS)

    Banerjee, D.; Sandhya, U.; Khot, S.A.; Srinivas, C.

    2015-07-01

    Strippable gels are an attractive option for decontamination of surfaces particularly when materials are to be reused after decontamination. The process in general results in good decontamination performance with minimal secondary waste generation. This paper reports on development of strippable gel formulation using polyvinyl alcohol as the gel former. Peeling behavior of the gel film improved when glycerol was used as plasticizer. Incorporation of decontaminating agents is essential for the gel to be effective, so a number of decontaminating agents were screened based on their miscibility with the gel, smooth peeling, and good decontamination performance. Based on this study, a strippable gel, ‘INDIGEL’ was formulated as a potential candidate for surface decontamination applications. Extensive trials on evaluation of decontamination performance of Indigel were done on simulated surfaces like stainless steel tray, stainless steel fume hood, PVC floor, granite and ceramic table tops. Results show that Indigel is highly effective for decontamination of surfaces contaminated with all types of radionuclides. Simplicity of its use coupled with good decontamination ability will find application in nuclear and other chemical industries. (author)

  11. Decontamination experiments for stainless steel decommissioned components

    International Nuclear Information System (INIS)

    Stefanescu, D.; Radulescu, M.; Dragomir, M.; Velciu, L.; Dinu, A.

    2001-01-01

    This paper presents the factors which influence the decontamination conditions using the steps of CONAP process. This four phases process (alkaline pre-treatment , an oxidation phase with potassium permanganate in acid environment, a dissolution phase using a complexing agent, a rinsing phase) has been used for decontamination to recycle the stainless steel 304 L and 403 m. The attraction of this process results from the following reasons: - the volume of radioactive sludge is low comparatively with the original volume of the solutions; - the separation of the activity from the solution is very effective; - time of exposure is reduced; - it is not necessary to process the solution through evaporators. During decommissioning decontamination is used to reduce radiation field by removing some of the fission and activation products contained in deposits and oxide films to minimize the radiation exposure of the personnel and public. In this context, this hard decontamination yields the materials at a radioactivity level fulfilling the repository requirements. (authors)

  12. Chemical Decontamination at Browns Ferry Unit 1

    International Nuclear Information System (INIS)

    Hartwig, Ed; Reid, Richard

    2003-01-01

    In May, 2002, the Tennessee Valley Authority's (TVA) Board of Directors approved the recovery and restart of Unit 1 at Browns Ferry Nuclear Station. As an initial step in the site characterization and restart feasibility review, a majority of the primary reactor circuit was chemically decontaminated. Close cooperation between TVA and vendor personnel resulted in project completion ahead of schedule with outstanding results. The final average decontamination factors were excellent, and the final dose rates were very low, with contact readings on most points between one and three mRem/hr. In addition to allowing TVA to do a complete and thorough job of determining the feasibility of the Unit 1 restart, the decontamination effort will greatly reduce personnel exposure during plant recovery, both whole body exposure to gamma radiation and airborne exposure during pipe replacement efforts. The implementation of lessons learned from previous decontamination work performed at Browns Ferry, as well as decontamination efforts at other plants aided greatly in the success. Specific items of note are: (1) The initial leak check of the temporary decontamination system should include ancillary systems such as the spent resin system, as well as the main circulation loop. This could save time and dose exposure if leaks are discovered before the use of such systems is required. (2) Due to the quick turnaround time from the award of contract, a vendor representative was onsite early in the project to help with engineering efforts and procedures. This aided greatly in completing preparations for the decontamination. (3) The work was performed under a single maintenance activity. This resulted in great craft and plant support. (4) The constant coverage by the site's decontamination flush directors provided timely plant support and interface. (5) The FPC system isolation and back flushing to prevent residual chemicals from being left in the FPC system should have been addressed in more

  13. The characterization of cement waste form for final disposal of decommissioned concrete waste

    International Nuclear Information System (INIS)

    Lee, K.W.; Lee, Y.J.; Hwang, D.S.; Moon, J.K.

    2015-01-01

    Since the decommissioning of nuclear plants and facilities, large quantities of slightly contaminated concrete waste have been generated. In Korea, the decontamination and decommissioning of the KRR-1, 2 at the KAERI have been under way. In addition, 83 drums of 200 l, and 41 containers of 4 m 3 of concrete waste were generated. Conditioning of concrete waste is needed for final disposal. Concrete waste is conditioned as follows: mortar using coarse and fine aggregates is filled into a void space after concrete rubble pre-placement into 200 l drums. Thus, this research developed an optimizing mixing ratio of concrete waste, water, and cement, and evaluated the characteristics of a cement waste form to meet the requirements specified in the disposal site specific waste acceptance criteria. The results obtained from compressive strength test, leaching test, and thermal cycling test of cement waste forms conclude that the concrete waste, water, and cement have been suggested to have 75:15:10 as the optimized mixing ratio. In addition, the compressive strength of cement waste form was satisfied, including fine powder up to a maximum 40 wt% in concrete debris waste of about 75%. (authors)

  14. Fatal and nonfatal risk associated with recycle of D&D-generated concrete

    Energy Technology Data Exchange (ETDEWEB)

    Boren, J.K.; Ayers, K.W.; Parker, F.L. [Vanderbilt Univ., Nashville, TN (United States)

    1997-02-01

    As decontamination and decommissioning activities proceed within the U.S. Department of Energy Complex, vast volumes of uncontaminated and contaminated concrete will be generated. The current practice of decontaminating and landfilling the concrete is an expensive and potentially wasteful practice. Research is being conducted at Vanderbilt University to assess the economic, social, legal, and political ramifications of alternate methods of dealing with waste concrete. An important aspect of this research work is the assessment of risk associated with the various alternatives. A deterministic risk assessment model has been developed which quantifies radiological as well as non-radiological risks associated with concrete disposal and recycle activities. The risk model accounts for fatal as well as non-fatal risks to both workers and the public. Preliminary results indicate that recycling of concrete presents potentially lower risks than the current practice. Radiological considerations are shown to be of minor importance in comparison to other sources of risk, with conventional transportation fatalities and injuries dominating. Onsite activities can also be a major contributor to non-fatal risk.

  15. Advance in radioactive decontamination

    International Nuclear Information System (INIS)

    Basteris M, J. A.; Farrera V, R.

    2010-09-01

    The objective of the present work was to determine if the application of the Na hypochlorite has some utility in the radioactive decontamination, in comparison with the water, detergent and alcohol. Several methods were compared for decontaminate the iodine 131 and technetium 99, the work table and the skin it was carried out an initial count with the Geiger Muller. Later on, in a single occasion, the areas were washed with abundant water, alcohol, clothes detergent and sodium hypochlorite (used commercially as domestic bleacher) without diluting. Observing that the percentage in the decrease of the counted radioactivity by the Geiger Muller, decreased in the following way: It was demonstrated that the Na hypochlorite presents the highest index of radioactive decontamination with 100% of effectiveness. The Na hypochlorite is an excellent substance that can be used with effectiveness and efficiency like decontamination element in the accident cases of radioactive contamination in the clinical laboratories of nuclear medicine. (Author)

  16. Recommendations for skin decontamination

    International Nuclear Information System (INIS)

    1989-01-01

    Further to the reecommendations for determining the surface contamination of the skin and estimating the radiation exposure of the skin after contamination (SAAS-Mitt--89-16), measures for skin decontamination are recommended. They are necessary if (1) after simple decontamination by means of water, soap and brush without damaging the skin the surface contamination limits are exceeded and the radiation exposure to be expected for the undamaged healthy skin is estimated as to high, and if (2) a wound is contaminated. To remove skin contaminations, in general universally applicable, non-aggressive decontamination means and methods are sufficient. In special cases, nuclide-specific decontamination is required taking into account the properties of the radioactive substance

  17. Some remarks about decontamination

    International Nuclear Information System (INIS)

    Bertini, A.

    1990-01-01

    Decontamination in itself is not the elimination of a problem, but corresponds to move that problem from one place to another. It is beneficial only if the contamination is less of a nuisance when moved to the ''other place''. Therefore any prospective decontamination process is to be considered essentially in terms of cost-benefit, and in particular in terms of reducing the burden on the waste management systems. The paper is not intended to deal with and to review critically the technical aspects of the various decontamination processes which are currently available. Its aim is to call the attention of those who may be faced with the problem of large-scale decontamination, so that this operation is carried out after all practical aspects have been examined. (author)

  18. Chemical decontamination: an overview

    International Nuclear Information System (INIS)

    Shaw, R.A.; Wood, C.J.

    1985-01-01

    The source of radioactive contamination in various types of power reactors is discussed. The methods of chemical decontamination vary with the manner in which the radioactive contaminants are deposited on the surface. Two types of dilute decontamination systems are available. One system uses organic acids and chelating agents, which are mildly reducing in nature. In this process, the oxide contaminants are removed by simple acidic dissolution and reductive dissolution. The second type of decontamination process is based on low oxidation state metal ions, which are more strongly reducing and do not require a corrosion inhibitor. All processes commercially available for decontamination of power reactors are not detailed here, but a few key issues to be considered in the selection of a process are highlighted. 2 figures, 2 tables

  19. Food decontamination using nanomaterials

    Science.gov (United States)

    The research indicates that nanomaterials including nanoemulsions are promising decontamination media for the reduction of food contaminating pathogens. The inhibitory effect of nanoparticles for pathogens could be due to deactivate cellular enzymes and DNA; disrupting of membrane permeability; and/...

  20. Decommissioning and Decontamination

    International Nuclear Information System (INIS)

    Massaut, V.

    2000-01-01

    The objectives of SCK-CEN's decommissioning and decontamination programme are (1) to develop, test and optimise the technologies and procedures for decommissioning and decontamination of nuclear installations in order to minimise the waste arising and the distributed dose; (2) to optimise the environmental impact; (3) to reduce the cost of the end-of-life of the installation; (4) to make these new techniques available to the industry; (5) to share skills and competences. The programme and achievements in 1999 are summarised

  1. Evaluation of Cost and Effectiveness of Decontamination Scenarios on External Radiation Exposure in Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Yasutaka, T.; Naito, W. [National Institute of Advanced Industrial Science and Technology (Japan)

    2014-07-01

    Despite the enormous cost associated with radiation decontamination, almost no quantitative assessment has been performed on the relationship between the potential reduction in long-term radiation exposure and the costs of the various decontamination strategies considered for the decontamination areas in Fukushima. In order to establish effective and pragmatic decontamination strategies for use in the radiation contaminated areas in Fukushima, a holistic approach for assessing decontamination strategies, their costs, and long-term external radiation doses is needed. The objective of the present study is to evaluate the cost and effectiveness of decontamination scenarios in the decontamination areas in Fukushima in regard to external radiation exposure. The choice of decontamination strategies in the decontamination areas should be based on a comprehensive analysis of multiple attributes such as radiological, economic, and socio-psychological attributes. The cost and effectiveness of the different decontamination strategies is not sole determinant of the decontamination strategies of the special decontamination area but is one of the most important attributes when making the policy decision. In the current study, we focus on radiological and economic attributes in determining decontamination strategies. A geographical information system (GIS) was used to relate the predicted external dose in the affected areas to the number of potential inhabitants and the land use in the areas. A comprehensive review of the costs of various decontamination methods was conducted as part of the analysis. The results indicate that aerial decontamination in the special decontamination areas in Fukushima would be effective for reducing the air dose rate to the target level in a short period of time in some but not all of the areas. In a standard scenario, the analysis of cost suggests that decontamination costs of decontamination in Fukushima was estimated to be up to approximately 5

  2. Criteria and evaluation of three decontamination techniques

    Energy Technology Data Exchange (ETDEWEB)

    Tripp, J.L.

    1994-01-01

    Past decontamination and solvent recovery activities at the Idaho Chemical Processing Plant (ICPP), which is part of the Idaho National Engineering Laboratory (INEL), have resulted in the accumulation of 1.5 million gallons of radioactively contaminated sodium-bearing liquid waste. Future decontamination activities at the ICPP could result in the production of 5 million gallons or more of sodium-bearing waste using the current decontamination techniques of chemical/water flushes and steam jet cleaning. This waste requires a large amount of cold chemical additive to process because the low melting temperatures of sodium and potassium salts cause agglomeration in the bed of the calciner vessel. Criteria have been established for evaluating methods and technologies available for decontaminating equipment and facilities. The criteria were weighted according to their relative importance using a Kepner-Tregoe Problem Solving process. These criteria were used to rank three decontamination techniques new to the ICPP: laser ablation, liquid abrasive blasting and CO{sub 2} pellet blasting, against the standard decontamination techniques of sodium-based chemical cleaning and water/steam jets used.

  3. Criteria and evaluation of three decontamination techniques

    International Nuclear Information System (INIS)

    Tripp, J.L.

    1994-01-01

    Past decontamination and solvent recovery activities at the Idaho Chemical Processing Plant (ICPP), which is part of the Idaho National Engineering Laboratory (INEL), have resulted in the accumulation of 1.5 million gallons of radioactively contaminated sodium-bearing liquid waste. Future decontamination activities at the ICPP could result in the production of 5 million gallons or more of sodium-bearing waste using the current decontamination techniques of chemical/water flushes and steam jet cleaning. This waste requires a large amount of cold chemical additive to process because the low melting temperatures of sodium and potassium salts cause agglomeration in the bed of the calciner vessel. Criteria have been established for evaluating methods and technologies available for decontaminating equipment and facilities. The criteria were weighted according to their relative importance using a Kepner-Tregoe Problem Solving process. These criteria were used to rank three decontamination techniques new to the ICPP: laser ablation, liquid abrasive blasting and CO 2 pellet blasting, against the standard decontamination techniques of sodium-based chemical cleaning and water/steam jets used

  4. How Concrete is Concrete

    OpenAIRE

    Koeno Gravemeijer

    2010-01-01

    If we want to make something concrete in mathematics education, we are inclined introduce, what we call, ‘manipulatives’, in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own, abstract, knowledge; in the latter, we try to find an example that the others will be familiar with. This article first looks at the tension between these two diff...

  5. Treatment of wastes arising from decontamination process using citric acid as a decontaminate agent

    International Nuclear Information System (INIS)

    Mierzwa, J.C.; Riella, H.G.; Carvalho, E.U. de

    1993-01-01

    Wastes arising from equipment decontamination processes from nuclear fuel cycle facilities at Coordenacao de Projetos Especiais - Comissao Nacional de Energia Nuclear, Sao Paulo (COPESP-CNEN/SP) has been studied after using citric acid as a decontaminate agent. Precipitation of uranium and metallic impurities resulted from use of sodium hydroxide or calcium oxide plus a flocculation agent. The removal efficient of uranium was 95% and 99% for sodium hydroxide and calcium oxide respectively. The results shows that this process can be used to test wastes from decontamination processes which use citric acid. (B.C.A.). 03 refs, 08 figs, 04 tabs

  6. Lessons Learned from Decontamination Experiences

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, JH

    2000-11-16

    This interim report describes a DOE project currently underway to establish what is known about decontamination of buildings and people and the procedures and protocols used to determine when and how people or buildings are considered ''clean'' following decontamination. To fulfill this objective, the study systematically examined reported decontamination experiences to determine what procedures and protocols are currently employed for decontamination, the timeframe involved to initiate and complete the decontamination process, how the contaminants were identified, the problems encountered during the decontamination process, how response efforts of agencies were coordinated, and the perceived social psychological effects on people who were decontaminated or who participated in the decontamination process. Findings and recommendations from the study are intended to aid decision-making and to improve the basis for determining appropriate decontamination protocols for recovery planners and policy makers for responding to chemical and biological events.

  7. How Concrete is Concrete

    Directory of Open Access Journals (Sweden)

    Koeno Gravemeijer

    2010-07-01

    Full Text Available If we want to make something concrete in mathematics education, we are inclined introduce, what we call, ‘manipulatives’, in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own, abstract, knowledge; in the latter, we try to find an example that the others will be familiar with. This article first looks at the tension between these two different ways of making things concrete. Next another role of manipulatives, will be discussed, namely that of means for scaffolding and communication. In this role, manipulatives may function as means of support in a process that aims at helping students to build on their own thinking while constructing more sophisticated mathematics

  8. Impact of decontamination on LWR radioactive waste treatment systems

    International Nuclear Information System (INIS)

    Hoenes, G.R.; Perrigo, L.D.; Divine, J.R.; Faust, L.G.

    1979-01-01

    Only at N-Reactor is there a means to accommodate radwaste produced during decontamination. The Dresden system is expected to be ready to accommodate such solutions by the summer of 1979. Solidification of the processed decontamination waste may be a significant problem. There is doubt that the materials in current radwaste treatment systems can handle chemicals from a concentrated process. The total storage volume, for concentrated decontamination, is not sufficient in existing radwaste treatment systems. Greater attention should be placed on designing reactors and radwaste treatment systems for decontamination. A means of handling waste material resulting from leaks in the primary system during the decontamination must be developed. On-site storage of solidified decontamination wastes may be a viable option, but license amendments will be necessary

  9. Decontamination of radionuclides in food

    Energy Technology Data Exchange (ETDEWEB)

    Ohmomo, Yoichiro [Institute for Environmental Sciences, Aomori (Japan)

    1994-03-01

    The release of radionuclides arising from the Chernobyle accident led to widespread contamination of the northern hemisphere through fallout. This accident provided again an opportunity to investigate how and to what extent the radionuclides contamination in crops and animal derived foods could be reduced. The following topics are included in this paper. (1) How to reduce the transfer of radiostrontium and/or cesium from soil to crops: A pH increase of soil is effective for reducing their plant uptake. (2) How to reduce the transfer of radiocesium to animal derived foods: Ammonium-ferric-cyanoferrate (AFCF) should be the most effective compound for radiocesium excretion in the feces. Experiments with lactating cows and/or poultry gave extremely good results with respect to low radiocesium concentrations in milk, meat and eggs. (3) Removal coefficients of radiostrontium, cesium and iodine from contaminated leaf vegetables and cereals during food processing and culinary preparation: Though different by species, more than 80% of cesium and about 50% of strontium and iodine can be removed during culinary preparation of washing and boiling. (4) Simultaneous decontamination of radiocesium and iodine from drinking water and liquid milk: Metal ferrocyanide-anion exchange resin, specifically Fe ferrocyanide one, was successfully used for a rapid and simple decontamination of radiocesium and iodine in the liquid samples arising from the Chernobyle accident. (5) Removal of radiocesium from meat: The meat structurally contaminated with radiocesium is easily and very successfully decontaminated by pickling in NaCl solution and the decontamination is much speeded up by freezing meat before pickling. (author).

  10. Decontamination of radionuclides in food

    International Nuclear Information System (INIS)

    Ohmomo, Yoichiro

    1994-01-01

    The release of radionuclides arising from the Chernobyle accident led to widespread contamination of the northern hemisphere through fallout. This accident provided again an opportunity to investigate how and to what extent the radionuclides contamination in crops and animal derived foods could be reduced. The following topics are included in this paper. (1) How to reduce the transfer of radiostrontium and/or cesium from soil to crops: A pH increase of soil is effective for reducing their plant uptake. (2) How to reduce the transfer of radiocesium to animal derived foods: Ammonium-ferric-cyanoferrate (AFCF) should be the most effective compound for radiocesium excretion in the feces. Experiments with lactating cows and/or poultry gave extremely good results with respect to low radiocesium concentrations in milk, meat and eggs. (3) Removal coefficients of radiostrontium, cesium and iodine from contaminated leaf vegetables and cereals during food processing and culinary preparation: Though different by species, more than 80% of cesium and about 50% of strontium and iodine can be removed during culinary preparation of washing and boiling. (4) Simultaneous decontamination of radiocesium and iodine from drinking water and liquid milk: Metal ferrocyanide-anion exchange resin, specifically Fe ferrocyanide one, was successfully used for a rapid and simple decontamination of radiocesium and iodine in the liquid samples arising from the Chernobyle accident. (5) Removal of radiocesium from meat: The meat structurally contaminated with radiocesium is easily and very successfully decontaminated by pickling in NaCl solution and the decontamination is much speeded up by freezing meat before pickling. (author)

  11. Influence Of The Gripping Fixture On The Modified Compact Tension Test Results: Evaluation Of The Experiments On Cylindrical Concrete Specimens

    Directory of Open Access Journals (Sweden)

    Holušová Táňa

    2015-12-01

    Full Text Available The modified compact tension test (MCT might become in the future a stable test configuration for the evaluation of fracture-mechanics parameters or also for description of fatigue behavior of composites materials such as concrete. Core drilling is used for sampling of existing structures. These samples have cylindrical shape with the selected thickness to avoid the stress concentration. This contribution focuses on the evaluation of the fracture behavior during static and quasi static tests. Static tests are performed on standard specimen with diameter 150 mm and length 300 mm. The quasi-static tests are performed using two different gripping fixtures. The results for quasi-static tests are represented as L-COD diagrams (i.e. load vs. crack opening displacement measured on the loading axis. The comparison of results and discussion of advantages and disadvantages are introduced.

  12. Concrete crushing and sampling, a methodology and technology for the unconditional release of concrete material from decommissioning

    International Nuclear Information System (INIS)

    Baumann, S.; Teunckens, L.; Walthery, R.; Lewandowski, P.; Millen, D.

    2002-01-01

    Belgoprocess started the industrial decommissioning of the main process building of the former Eurochemic reprocessing plant in 1990, after completion of a pilot project. Two small storage buildings for final products from reprocessing were dismantled to verify the assumptions made in a previous paper study on decommissioning, to demonstrate and develop dismantling techniques and to train personnel. Both buildings were emptied and decontaminated to background levels. They were demolished and the remaining concrete debris was disposed of as industrial waste and green field conditions restored. Currently, the decommissioning operations carried out at the main building have made substantial progress. They are executed on an industrial scale and will continue till the end of 2005. In view of the final demolition of the building, a clearance methodology has to be proposed. Application of the methodology applied for the storage buildings of the pilot project is complicated for several reasons. Although this methodology is not rejected as such, an alternative has been studied thoroughly. It considers at least one complete measurement of all concrete structures and the removal of all detected residual radioactivity. This monitoring sequence is followed by a controlled demolition of the concrete structures and crushing of the resulting concrete parts to smaller particles. During the crushing operations, metal parts are separated from the concrete and representative concrete samples are taken. The frequency of sampling meets the prevailing standards. In a further step, the concrete samples are milled, homogenised, and a smaller fraction is sent to the laboratory for analyses. The paper describes the developed concrete crushing and sampling methodology. (authors)

  13. Pickering emulsions for skin decontamination.

    Science.gov (United States)

    Salerno, Alicia; Bolzinger, Marie-Alexandrine; Rolland, Pauline; Chevalier, Yves; Josse, Denis; Briançon, Stéphanie

    2016-08-01

    This study aimed at developing innovative systems for skin decontamination. Pickering emulsions, i.e. solid-stabilized emulsions, containing silica (S-PE) or Fuller's earth (FE-PE) were formulated. Their efficiency for skin decontamination was evaluated, in vitro, 45min after an exposure to VX, one of the most highly toxic chemical warfare agents. Pickering emulsions were compared to FE (FE-W) and silica (S-W) aqueous suspensions. PE containing an oil with a similar hydrophobicity to VX should promote its extraction. All the formulations reduced significantly the amount of VX quantified on and into the skin compared to the control. Wiping the skin surface with a pad already allowed removing more than half of VX. FE-W was the less efficient (85% of VX removed). The other formulations (FE-PE, S-PE and S-W) resulted in more than 90% of the quantity of VX removed. The charge of particles was the most influential factor. The low pH of formulations containing silica favored electrostatic interactions of VX with particles explaining the better elimination from the skin surface. Formulations containing FE had basic pH, and weak interactions with VX did not improve the skin decontamination. However, these low interactions between VX and FE promote the transfer of VX into the oil droplets in the FE-PE. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Flow induced particle migration in fresh concrete: Theoretical frame, numerical simulations and experimental results on model fluids

    DEFF Research Database (Denmark)

    Spangenberg, J.; Roussel, N.; Hattel, J.H.

    2012-01-01

    In this paper, we describe and compare the various physical phenomena which potentially lead to flow induced particle migration in concrete. We show that, in the case of industrial casting of concrete, gravity induced particle migration dominates all other potential sources of heterogeneities ind...

  15. A novel self-embrittling strippable coating for radioactive decontamination based on silicone modified styrene-acrylic emulsion

    Science.gov (United States)

    Wang, Jing; Wang, Jianhui; Zheng, Li; Li, Jian; Cui, Can; Lv, Linmei

    2017-03-01

    Silicone modified styrene-acrylic emulsion and butyl acrylate were used as a main film-forming agent and an additive respectively to synthesize a self-embrittling strippable coating. The doping mass-ratio of butyl acrylate was adjusted at 0, 5%, 10%, 15%, 20%, and the results indicated the optimized doping ratio was 10%. Ca(OH)2 was used to promote the coating film self-embrittling at a moderate doping mass-ratio of 20%. The synthesized coating’s coefficients of α and β decontamination on concrete, marble, glass and stainless steel surfaces were both greater than 85%, which indicated the synthesized coating is a promising cleaner for radioactive decontamination.

  16. Research and development activities of the Institut fuer Nukleare Entsorgungstechnik on the decontamination of surfaces

    International Nuclear Information System (INIS)

    Dippel, T.; Hentschel, D.; Kunze, S.

    1983-06-01

    After developing a procedure for the ''Testing of Surface Coating Materials for the Decontamination'' about 900 different surface coating materials had been tested and evaluated for the domestic and foreign industry. The results prove the following basic facts: Surface coatings, low in porosity, forming a smooth surface and containing limited amounts of filler are in the majority very effectively decontaminated if they are prepared of chemically stable, water repellent materials; Decontamination results are drastically poorer if the degree of filling of the materials is high especially if hygroscopic fillers and/or hygroscopic colouring matters are used. Currently available cleansers and washing powders used for decontamination did not fulfill the three basic demands for a decontamination agent: high efficiency, small foam generation and sufficient thermal stability. Therefore for the decontamination of walls, floors, etc. a water delutable, liquid cleanser was developed. In the same context a washing powder was optimized for the decontamination of contaminated clothing. The experiments on the decontamination of stainless steels ended up with the formulation of a pickling paste. Furthermore all investigations were aimed at a minimization of the waste generation by the decontamination process. This resulted in decontamination techniques, in which the decontaminating agents were applied in thin layers. A comparison of the currently practiced dipping technique with the coating technique showed that the latter one gave the better decontamination results and that the amount of decontamination waste was reduced. (orig./HP) [de

  17. TMI-2 containment decontamination plans

    International Nuclear Information System (INIS)

    McDougall, F.

    1980-01-01

    Because of other priorities such as reentry, purging, and recovery, containment decontamination is only in the preliminary planning stages. This paper summarizes the study with emphasis on the remote decontamination techniques

  18. Decontamination and winter conditions

    International Nuclear Information System (INIS)

    Quenild, C.; Tveten, U.

    1984-12-01

    The report deals with two decontamonation experiments under winter conditions. A snow-covered parking lot was contaminated, and the snow was subsequently removed using standard snow-moving equipment. The snow left behind was collected and the content of contaminant was determined. A non-radioactive contaminant was used. A decontamination factor exceeding 100 was obtained. Although the eksperimental conditions were close to ideal, it is reason to believe that extremely efficient removal of deposited materials on a snow surface is achivable. In another investigation, run-off from agricultural surface, contaminated while covered with snow, was measured A lycimeter was used in this experiment. A stable layer of ice and snow was allowed to form before contamination. The run-off water was collected at each thaw period until all snow and ice was gone. Cs-134 was used as contaminant. Roughly 30% of the Cs-134 with which the area was contaminated ran off with the melt water. Following a reactor accident situation, this would have given a corresponding reduction in the long term doses. Both of these experiments show that consequence calculation assumptions, as they are currently applied to large accident assessment, tend to overestimate the consequences resulting from accidents taking place under winter conditions

  19. Decontamination technology assessment

    International Nuclear Information System (INIS)

    Allen, R.P.; Konzek, G.J.; Schneider, K.J.; Smith, R.I.

    1988-01-01

    This study was conducted by the Pacific Northwest Laboratory (PNL) for the U.S. Department of Energy (DOE) to identify and technically assess foreign decontamination and decommissioning (D and D) technology developments that may represent significant improvements over D and D technology currently available or under development in the United States. Technology need areas for nuclear power reactor decommissioning operations were identified and prioritized using the results of past light water rector (LWR) decommissioning studies to quantitatively evaluate the potential for reducing cost and decommissioning worker radiation dose for each major decommissioning activity. Based on these identified needs, current foreign D and D technologies of potential interest to the U.S. were identified through personal contacts and the collection and review of an extensive body of D and D literature. These technologies were then assessed qualitatively to evaluate their uniqueness, potential for a significant reduction in D and D costs and/or worker radiation dose, development status, and other factors affecting their value and applicability to U.S. needs

  20. Radioactive decontamination of equipment

    International Nuclear Information System (INIS)

    1982-03-01

    After a recall of some definitions relating to decontamination techniques and of the regulation into effect, the principles to be respected to arrange rationally work zones are quoted while insisting more particularly on the types of coatings which facilitate maintenance operations and the dismantling of these installations. Then, the processes and equipments to use in decontamination units for routine or particular operations are described; the list of recommended chemical products to decontaminate the equipment is given. The influence of these treatments on the state and the duration of life of equipments is studied, and some perfectible methods are quoted. In the appendix, are given: the limits of surface contamination accepted in the centers; a standard project which defines the criteria of admissible residual contamination in wastes considered as cold wastes; some remarks on the interest that certain special ventilation and air curtain devices for the protection of operators working on apparatus generating contaminated dusts [fr

  1. Decontamination of main coolant pumps

    International Nuclear Information System (INIS)

    Roofthooft, R.

    1988-01-01

    Last year a number of main coolant pumps in Belgian nuclear power plants were decontaminated. A new method has been developed to reduce the time taken for decontamination and the volume of waste to be treated. The method comprises two phases: Oxidation with permanganate in nitric acid and dissolution in oxalic acid. The decontamination of main coolant pumps can now be achieved in less than one day. The decontamination factors attained range between 15 and 150. (orig.) [de

  2. Properties of high-workability concrete with recycled concrete aggregate

    OpenAIRE

    Safiuddin,; Alengaram,Ubagaram Johnson; Salam,Abdus; Jumaat,Mohd Zamin; Jaafar,Fahrol Fadhli; Saad,Hawa Binti

    2011-01-01

    This study presents the effects of recycled concrete aggregate (RCA) on the key fresh and hardened properties of concrete. RCA was used to produce high-workability concrete substituting 0-100% natural coarse aggregate (NCA) by weight. The slump and slump flow of fresh concretes were determined to ensure high workability. In addition, the compressive, flexural and splitting tensile strengths, modulus of elasticity, and permeable voids of hardened concretes were determined. The test results rev...

  3. Experiments to determine the efficiency of two standard decontamination procedures for radiocarbon samples

    International Nuclear Information System (INIS)

    Currie, D.R.

    1980-02-01

    Laboratory tests were made to decontaminate radiocarbon samples containing known amounts of contamination. Results for both acid-alkali treatment and acid hydrolysis indicate that decontamination is not 100% efficient

  4. Radiation decontamination of spices

    International Nuclear Information System (INIS)

    Jan, M.; Sattar, A.; Ahmad, W.A.; Khan, I.

    1990-06-01

    In this report radiation decontamination was initiated to investigate the red pepper, which is widely consumed in all parts of Pakistan. The samples were collected from local market and prepared for gamma radiation at dose level of 0, 2.5, 5.0, 7.5, and 10.0 kGy. The measurement of total fungal count was carried out immediately after irradiation and the at two months storage interval. It was reported that radiation dose 10.0 kGy is suitable for complete decontamination of red pepper. (A.B.)

  5. Decontamination and radioactivity measurement on building surfaces related to dismantling of Japan power demonstration reactor (JPDR)

    International Nuclear Information System (INIS)

    Hatakeyama, Mutsuo; Tachibana, Mitsuo; Yanagihara, Satoshi

    1997-12-01

    In the final stage of dismantling activities for decommissioning a nuclear power plant, building structures have to be demolished to release the site for unrestricted use. Since building structures are generally made from massive reinforced concrete materials, it is not a rational way to treat all concrete materials arising from its demolition as radioactive waste. Segregation of radioactive parts from building structures is therefore indispensable. The rational procedures were studied for demolition of building structures by treating arising waste as non-radioactive materials, based on the concept established by Nuclear Safety Commission, then these were implemented in the following way by the JPDR dismantling demonstration project. Areas of the JPDR facilities are categorized into two groups : possibly contaminated areas, and possibly non-contaminated areas, based on the document of the reactor operation. Radioactivity on the building surfaces was then measured to confirm that the qualitative categorization is reasonable. After that, building surfaces were decontaminated in such a way that the contaminated layers were removed with enough margin to separate radioactive parts from non-radioactive building structures. Thought it might be possible to demolish the building structures by treating arising waste as non-radioactive materials, confirmation survey for radioactivity was conducted to show that there is no artificial radioactive nuclides produced by operation in the facility. This report describes the procedures studied on measurement of radioactivity and decontamination, and the results of its implementation in the JPDR dismantling demonstration project. (author)

  6. Heat and mass transfer in a contaminated porous concrete slab with variable dielectric properties

    International Nuclear Information System (INIS)

    Li, W.; Ebadian, M.A.

    1994-01-01

    The effect of temperature dependent dielectric properties on concrete decontamination and decommissioning using microwave technology is investigated theoretically in this paper. The concrete is treated as a porous material, which has residual water and air within the pores. A one-dimensional model of unsteady heat and mass transport in the porous concrete with temperature dependent dielectric properties is developed. Based on this model, temperature and pressure with different microwave frequencies are predicted, the effects of the temperature dependent dielectric properties on microwave power dissipation, the temperature and pressure distributions for different microwave frequencies, and the different microwave power intensities are analyzed in detail. Four available industrial microwave frequencies of 0.896, 2.45, 10.6 and 18.0 GHz are used in the analysis. As a result of the dielectric properties varying with temperature, the power dissipation also varies with the heating times. Comparing the results for both temperature dependent and constant dielectric properties reveals that the variation of dielectric permittivity with temperature must be considered in a theoretical model of the concrete decontamination and decommissioning process for a low microwave frequency (f <2.45 GHz). (Author)

  7. Loop cleanup with redox decontamination technique

    International Nuclear Information System (INIS)

    Ren Xian Wen; Zhang Yuan

    1998-01-01

    The corrosion rate of stainless steel in nitric acid solution will be enhanced by existence of Ce 4+ . The goal of this study is to develop a circular decontamination process in medium of nitric acid, in order to use it in a loop clean up. That needs a specially designed electrolytic cell to oxidize the Ce 3+ into Ce 4+ . This regenerator's structure should be simple and easy to operate, and can meet the requirements of practical decontamination operation. The concentration of Ce 4+ in the nitric acid solution was selected to provide a suitable corrosion rate to contaminated stainless steel. The total concentration of cerium (III+IV) was also optimized to ensure that the regeneration rate of Ce 4+ could satisfy the consumption rate of Ce 4+ during decontaminating process. The operation parameters were selected strictly on the basis of our experimental results, so that the regeneration rate of Ce 4+ can be higher reasonably in proper operation conditions and not arise any problem related to safety of operation and nuclear aspects. It is considered that this decontamination process could be applied into either decommissioning or maintenance stage of nuclear facilities. The concentration of Ce 4+ and temperature are the main factors for corrosion rate, other factors should also be considered during decision of decontamination process. With the regenerator developed under contract No 7959/RB could obtain sufficient decontamination factors, when use following conditions: concentration of Ce 4+ is higher than 0.2 mol/1, the total concentration of cerium (III+IV) is higher than 0.4 mol/1, concentration of nitric acid is higher than 2 mol/1, temperature of decontamination operation is within 25 deg. C - 40 deg. C and temperature of regeneration is within 40 deg C - 50 deg.C

  8. OECD MCCI project 2-D Core Concrete Interaction (CCI) tests : CCI-3 test data report-thermalhydraulic results. Rev. 0 October 15, 2005.

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, M. T.; Lomperski, S.; Kilsdonk, D. J.; Aeschlimann, R. W.; Basu, S. (Nuclear Engineering Division); (NRC)

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following objectives: (1) resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two program objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of satisfying these objectives, the Management Board (MB) approved the conduct of a third long-term 2-D Core-Concrete Interaction (CCI) experiment designed to provide information in several areas, including: (i) lateral vs. axial power split during dry core-concrete interaction, (ii) integral debris coolability data following late phase flooding, and (iii) data regarding the nature and extent of the cooling transient following breach of the crust formed at the melt-water interface. This data report provides thermal hydraulic test results from the CCI-3 experiment, which was conducted on September 22, 2005. Test specifications for CCI-3 are provided in Table 1-1. This experiment investigated the interaction of a fully oxidized 375

  9. Programmatic environmental impact statement related to decontamination and disposal of radioactive wastes resulting from March 28, 1979 accident, Three Mile Island Nuclear Station, Unit 2 (Docket No. 50-320): Draft

    International Nuclear Information System (INIS)

    1986-12-01

    In accordance with the National Environmental Policy Act and the Commission's implementing regulations and its April 27, 1981 Statement of Policy, the Programmatic Environmental Impact Statement related to decontamination and disposal of radioactive wastes resulting from March 28, 1979, accident Three Mile Island Nuclear Station, Unit 2 NUREG-0683 (PEIS) is being supplemented. This draft supplement updates the environmental evaluation of accident-generated water disposal alternatives published in the PEIS, utilizing more complete and current information. Also, the draft supplement includes a specific environmental evaluation of the licensee's recently submitted proposal for water disposition

  10. Safety aspects in decontamination operations: Lessons learned during the decommissioning of a small PWR reactor

    International Nuclear Information System (INIS)

    Klein, M.; Ponnet, M.; Emond, O.

    2002-01-01

    Decontamination operations are generally executed during the decommissioning of nuclear installations for different objectives: decontamination of loops or large pieces to reduce the dose rate inside a contaminated plant or decontamination to minimize the amount of radioactive waste. These decontamination operations raise safety issues such as radiological exposure, classical safety, environmental releases, production and management of secondary waste, management of primary resources, etc. This paper presents the return of experience from decontamination operations performed during the dismantling of the BR3 PWR reactor. The safety issues are discussed for 3 types of decontamination operations: full system decontamination of the primary loop with a chemical process to reduce the dose rate by a factor of 10; thorough decontamination with an aggressive chemical process of dismantled pieces to reach the unconditional clearance values; and thorough decontamination processes with physical processes of metals and of concrete to reach the unconditional clearance values. For the protection of the workers, we must consider the ALARA aspects and the classical safety issues. During the progress of our dismantling operations, the dose rate issue was becoming less important but the classical safety issues were becoming preponderant due to the use of very aggressive techniques. For the protection of the environment, we must take all the precautions to avoid any leakages from the plant and we must use processes which minimize the use of toxic products and which minimize the production of secondary wastes. We therefore promote the use of regenerative processes. (author)

  11. Radiation decontamination of frozen chicks

    International Nuclear Information System (INIS)

    Khan, M.; Akhtar, T.; Sattar, A.; Khan, I.

    1992-07-01

    In this report decontamination of frozen chicken has been discussed. The pathogenic bacteria present in poultry meats causes food infectious diseases. The spoilage microorganisms in poultry meat quickly render the meat unacceptable due to decomposition of the products resulting in off-odour and development of slime. Irradiation (2-5 kGy) and freezing has been found effective in eliminating various pathogens. These combination treatments were tested in local environment. The results indicated that radiation followed by freezing greatly protected quality of poultry meat during storage for 6 months. (A.B.)

  12. How Concrete is Concrete?

    Directory of Open Access Journals (Sweden)

    Koeno Gravemeijer

    2011-01-01

    Full Text Available If we want to make something concrete in mathematics education, we are inclined introduce, what we call, ‘manipulatives’, in the form of tactile objects or visual representations. If we want to make something concrete in a everyday-life conversation, we look for an example. In the former, we try to make a concrete model of our own, abstract, knowledge; in the latter, we try to find an example that the others will be familiar with. This article first looks at the tension between these two different ways of making things concrete. Next another role of manipulatives, will be discussed, namely that of means for scaffolding and communication. In this role, manipulatives may function as means of support in a process that aims at helping students to build on their own thinking while constructing more sophisticated mathematics.Key words:  Conceret Learning Materials, School Math, Common Sense, Scaffolding, Communication DOI: http://dx.doi.org/10.22342/jme.2.1.780.1-14

  13. Radioactive contamination of some rubber or plastic surfaces by fission products. Decontamination tests

    International Nuclear Information System (INIS)

    Mestre, E.; Sautiez, N.

    1957-10-01

    With the objective of notably addressing the contamination and decontamination of gloves and floor covering, this report first presents some characteristics of contaminating radioactive materials (nature, physical and chemical condition), of contaminated surfaces (surface condition, surface nature), and of decontamination processes (physical, chemical or mechanical action). It describes the operational modality implemented to test decontamination processes on various glove or flooring materials: sample preparation, counting, decontamination, reproducibility of decontamination tests, results in terms of activity reduction. It more precisely describes the tested samples: short gloves, gloves from glove boxes, floor and wall coverings. Results are presented and discussed in terms of sample susceptibility to contamination, and of decontamination, but also for re-contamination tests after a Nab-based decontamination (susceptibility to contamination, decontamination gain)

  14. Decontamination Project for Cell G of the Metal Recovery Facility at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Mandry, G.J.; Grisham, R.W.

    1994-02-01

    The goal of the decontamination effort in Cell G at the Metal Recovery Facility, Building 3505, located at the Oak Ridge National Laboratory, was two-fold: to determine the effectiveness of the dry decontamination technique employed and to provide data required to assess whether additional decontamination using this method would be beneficial in the eventual decommissioning of the facility. Allied Technology Group (ATG) was contracted to remove a portion of the concrete surface in Cell G by a technique known as scabbling. Some metallic cell components were also scabbled to remove paint and other surface debris. Generally, the scabbling operation was a success. Levels of contamination were greatly reduced. The depth of contaminant penetration into the concrete surfaces of certain areas was much greater than had been anticipated, necessitating the removal of additional concrete and extending ATG's period of performance. Scabbling and other related techniques will be extremely useful in the decontamination and decommissioning of other nuclear facilities with similar radiological profiles

  15. Decontamination by shotblasting of radioactivity deposited on an asphalt road

    International Nuclear Information System (INIS)

    Warming, L.

    1987-01-01

    Long-lived fission products may be deposited in the environment after a serious reactor accident. From previous experiments it is known that if firehosing is to be used for decontamination it has to be done soon after the deposition. It is therefore worthwhile to study another decontamination method. An experimental study has been conducted of how well shotblasting can remove contamination from an asphalt road. In shotblasting a thin layer of the surface is loosened by the impact of small steel balls, and in the same procedure the surface dust is vacuumed up and the steel balls recovered. The contaminant was 86 Rb, which behaves as caesium. As reference, the weathering of identical contamination on an asphalt road, a concrete road and a road covered with small concrete stones was studied concurrently. (author)

  16. Laser-based characterization and decontamination of contaminated facilities

    International Nuclear Information System (INIS)

    Leong, K.H.; Hunter, B.V.; Grace, J.E.; Pellin, M.J.; Leidich, H.F.; Kugler, T.R.

    1996-01-01

    This study examines the application of laser ablation to the characterization and decontamination of painted and unpainted concrete and metal surfaces that are typical of many facilities within the US Department of Energy complex. The utility of this promising technology is reviewed and the essential requirements for efficient ablation extracted. Recent data obtained on the ablation of painted steel surfaces and concrete are presented. The affects of beam irradiance, ablation speed and efficiency, and characteristics of the aerosol effluent are discussed. Characterization of the ablated components of the surface offers the ability of concurrent determination of the level of contamination. This concept can be applied online where the ablation endpoint can be determined. A conceptual system for the characterization and decontamination of surfaces is proposed

  17. Remediation of 137Cs contaminated concrete using electrokinetic phenomena and ionic salt washes in nuclear energy contexts.

    Science.gov (United States)

    Parker, Andrew J; Joyce, Malcolm J; Boxall, Colin

    2017-10-15

    This work describes the first known the use of electrokinetic treatments and ionic salt washes to remediate concrete contaminated with 137 Cs. A series of experiments were performed on concrete samples, contaminated with K + and 137 Cs, using a bespoke migration cell and an applied electric field (60V potential gradient and current limit of 35mA). Additionally, two samples were treated with an ionic salt wash (≤400molm -3 of KCl) alongside the electrokinetic treatment. The results show that the combined treatment produces removal efficiencies three times higher (>60%) than the electrokinetic treatment alone and that the decontamination efficiency appears to be proportional to the initial degree of contamination. Furthermore, the decontamination efficiencies are equivalent to previous electrokinetic studies that utilised hazardous chemical enhancement agents demonstrating the potential of the technique for use on nuclear licensed site. The results highlight the relationship between the initial contamination concentration within the concrete and achievable removal efficiency of electrokinetic treatment and other treatments. This information would be useful when selecting the most appropriate decontamination techniques for particular contamination scenarios. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Final programmatic environmental impact statement related to decontamination and disposal of radioactive wastes resulting from March 28, 1979 accident, Three Mile Island Nuclear Station, Unit 2, Docket No. 50-320

    International Nuclear Information System (INIS)

    1981-03-01

    The appendices included in this report include the following: Comments on the Draft Programmatic Environmental Impact Statement (A-1); Commission's Statement of Policy and Notice of Intent to Prepare a Programmatic Environmental Impact Statement (B-1); 'Final Environmental Assessment for Decontamination of the Three Mile Island Unit 2 Reactor Building Atmosphere, Final NRC Staff Report,' US Nuclear Regulatory Commission, NUREG-0662, May 1980 (C-1); 'Environmental Assessment for Use of EPICOR-Il at Three Mile Island Unit 2,' US Nuclear Regulatory Commission, NUREG-0591, October 3, 1979 (D-1); Fish and Fisheries of York Haven Pond and Conowingo Pond of the Susquehanna River and Upper Chesapeake Bay (E1); Reuse of Accident Water (F-1); Engineering Considerations for Treatment of TMI-2 Accident-Generated Liquid Waste G-1); Engineering Considerations Related to Immobilization of Radioactive Wastes (H-1); Justification for Radiation Fields Used in Section 6 I-1); Economic Cost Basis (K-1); Average Individual Quarterly Dose Limits Used in Determinations of Work Force Estimates (L-1); 'Long-Term Environmental Radiation Surveillance Plan for Three Mile Island,' US Environmental Protection Agency, 1981 (M-1); Occupational Radiation Exposure during Onsite Waste Handling (N-1); Decontamination Status of Auxiliary and Fuel Handling Buildings (0-1); Chemical Systems for Decontamination of Primary System Components (P-1); Onsite Storage Facility (Q-1); Proposed Additions to Technical Specifications for TMI-2 Cleanup Program (R-1); Calculations of Discharge of Processed Accident Water to the Atmosphere (S-1); The Behavior of Sorbable Radionuclides in the Susquehanna River and Chesapeake Bay (T-1); Decommissioning of TMI-2 (U-1); Assessment of Groundwater Liquid Pathway from Leakage of Containment Water at Three Mile Island, Unit 2 (V-1); Calculation Models and Parameters Used in Estimating Doses, and Interpretation of Model Results (W-1); Contributors to the PEIS X-1); Scheduled

  19. Decontamination between dismantling of the Rapsodie primary coolant circuit

    International Nuclear Information System (INIS)

    Costes, J.R.; Gauchon, J.P.; Antoine, P.

    1991-01-01

    The large-scale decontamination of FBR sodium loops is a novel task, as only a limited number of laboratory-scale results are available to date. The principal objective of this work is to develop a suitable decontamination procedure for application to the primary loops of the RAPSODIE fast breeder reactor as part of decommissionning to Stage 2

  20. The characterization of cement waste form for final disposal of decommissioning concrete wastes

    International Nuclear Information System (INIS)

    Lee, Yoon-ji; Lee, Ki-Won; Min, Byung-Youn; Hwang, Doo-Seong; Moon, Jei-Kwon

    2015-01-01

    Highlights: • Decommissioning concrete waste recycling and disposal. • Compressive strength of cement waste form. • Characteristic of thermal resistance and leaching of cement waste form. - Abstract: In Korea, the decontamination and decommissioning of KRR-1, 2 at KAERI have been under way. The decommissioning of the KRR-2 was finished completely by 2011, whereas the decommissioning of KRR-1 is currently underway. A large quantity of slightly contaminated concrete waste has been generated from the decommissioning projects. The concrete wastes, 83ea of 200 L drums, and 41ea of 4 m 3 containers, were generated in the decommissioning projects. The conditioning of concrete waste is needed for final disposal. Concrete waste is conditioned as follows: mortar using coarse and fine aggregates is filled with a void space after concrete rubble pre-placement into 200 L drums. Thus, this research developed an optimizing mixing ratio of concrete waste, water, and cement, and evaluated the characteristics of a cement waste form to meet the requirements specified in the disposal site specific waste acceptance criteria. The results obtained from a compressive strength test, leaching test, and thermal cycling test of cement waste forms conclude that the concrete waste, water, and cement have been suggested as an optimized mixing ratio of 75:15:10. In addition, the compressive strength of the cement waste form was satisfied, including a fine powder up to a maximum of 40 wt% in concrete debris waste of about 75%. According to the scale-up test, the mixing ratio of concrete waste, water, and cement is 75:10:15, which meets the satisfied compressive strength because of an increase in the particle size in the waste

  1. Monitoring work at decontamination in Fukushima city

    International Nuclear Information System (INIS)

    Mori, Kazuyuki

    2013-01-01

    The author has been working at the decontamination site of Fukushima residences as a radiation monitor since Feb. 2012 for about 1 year, of which experiences are reported here. The decontamination conducted was legally based on the Act on Special Measures concerning the contamination by Fukushima Nuclear Power Plant Accident in Mar. 2011, and on other national, municipal related laws and guidelines. Fukushima city planned to conduct the decontamination for coming 5 years from Oct. 2011 to reduce its ambient dose rate to 9 sites within a residence. The work was managed with monitoring result cards and photographs. The definition of contamination to be cleared was against the dose rate of garden ground surface >30 Bq/cm 2 and of ambient at 1 m height 0.5-2 mc-Sv/h, the latter of which was aimed at reducing to <1 mc-Sv/h and the ambient at 1 cm height, to <0.4 mc-Sv. The ambient dose rate after decontamination of 717 residences has been found decreased to about a half (36-73% of doses before the work). Radiation hazard protection of workers was managed with the health examination defined by the law, education and pocket dosimeter: the exposure dose of the decontamination workers has been found to be about 5 mc-Sv/day. Finally, the report presents comments of thoughts and resolves of the city, executing trader, executer and monitoring staff. (T.T.)

  2. General recommendations for decontamination procedures to individuals

    International Nuclear Information System (INIS)

    Ohlenschlaeger, L.; Messerschmidt, J.P.

    1989-04-01

    The fundamental criteria in handling radioactive contaminated persons are discussed and methods of monitoring, including monitoring of contaminated wounds, as well as decontamination measures with reference to particularly exposed regions of the body are described. Each decontamination procedure has to be carried out cautiously and has to be stopped as soon as skin lesion would be ensured from too strong mechanical cleansing, in order to avoid any additional incorporation by an injured skin. As a rule, any residual radioactivity still adherent to the skin surface can be neglected as soon as avoidance of spreading of the contamination to surrounding areas is assured. Experience showed that contaminations with radioactive dust can be removed from the skin surface quite easily by such simple means like water and soap. Radioisotopes, however, as used in nuclear medicine, usually are having a higher adhesive effect to the skin surface, thus making conditions for decontamination more difficult. Measures related to the decontamination procedure such as monitoring, mode of sampling for bioassay in case of incidents, handling of waste resulting from decontamination, as well as self-protective aspects are discussed in the annex. (orig.) [de

  3. Decontamination of 125I in Medical Laboratory

    International Nuclear Information System (INIS)

    Abdel Geleel, M.; Tawfeek, A.A.

    2009-01-01

    A radiological laboratory for diagnoses was contaminated by 125 I. A large-scale survey of gamma-radiation has been made in different locations of the floors and walls of the lab to determine the contaminated area and its activity. The activity level before decontamination for the wall and floor was 1400 and 2000 Bq/cm 2 respectively. Decontamination was carried out by using ethyl alcohol, potassium permanganate, ethylene diamine tetracetic acid and tissue papers. Decontamination factor has been calculated and it was 175 and 200 for the wall and floor respectively. D and D computer code has been used to calculate Total Effective Dose Equivalent (TEDE). TEDE from the wall and floor before decontamination were 3.05 and 4.35 ( mSv/yr ) while after decontamination were 18 and 23μSv/yr respectively. These results are lower than the Egyptian and the international regulations (10 mSv/y for the public ) according to International Atomic Energy agency, IAEA, Safety Series, SS, no. 115 (1994).

  4. Mechanical decontamination techniques for floor drain systems

    International Nuclear Information System (INIS)

    Palau, G.L.

    1987-01-01

    The unprecedented nature of cleanup activities at Three Mile Island Unit 2 (TMI-2) following the 1979 accident has necessitated the development of new techniques to deal with radiation and contamination in the plant. One of these problems was decontamination of floor drain systems, which had become highly contaminated with various forms of dirt and sludge containing high levels of fission products and fuel from the damaged reactor core. The bulk of this contamination is loosely adherent to the drain pipe walls; however, significant amounts of contamination have become incorporated into pipe wall oxide and corrosion layers and embedded in microscopic pits and fissures in the pipe wall material. The need to remove this contamination was recognized early in the TMI-2 cleanup effort. A program consisting of development and laboratory testing of floor drain decontamination techniques was undertaken early in the cleanup with support from the Electric Power Research Institute (EPRI). Based on this initial research, two techniques were judged to show promise for use at TMI-2: a rotating brush hone system and a high-pressure water mole nozzle system. Actual use of these devices to clean floor drains at TMI-2 has yielded mixed decontamination results. The decontamination effectiveness that has been obtained is highly dependent on the nature of the contamination in the drain pipe and the combination of decontamination techniques used

  5. The Effect of Specimen Size on the Results of Concrete Adiabatic Temperature Rise Test with Commercially Available Equipment

    Directory of Open Access Journals (Sweden)

    Byung Jae Lee

    2014-12-01

    Full Text Available In this study, adiabatic temperature rise tests depending on binder type and adiabatic specimen volume were performed, and the maximum adiabatic temperature rises and the reaction factors for each mix proportion were analyzed and suggested. The results indicated that the early strength low heat blended cement mixture had the lowest maximum adiabatic temperature rise (Q∞ and the ternary blended cement mixture had the lowest reaction factor (r. Also, Q and r varied depending on the adiabatic specimen volume even when the tests were conducted with a calorimeter, which satisfies the recommendations for adiabatic conditions. Test results show a correlation: the measurements from the 50 L specimens were consistently higher than those from the 6 L specimens. However, the Q∞ and r values of the 30 L specimen were similar to those of the 50 L specimen. Based on the above correlation, the adiabatic temperature rise of the 50 L specimen could be predicted using the results of the 6 L and 30 L specimens. Therefore, it is thought that this correlation can be used for on-site concrete quality control and basic research.

  6. The Effect of Specimen Size on the Results of Concrete Adiabatic Temperature Rise Test with Commercially Available Equipment.

    Science.gov (United States)

    Lee, Byung Jae; Bang, Jin Wook; Shin, Kyung Joon; Kim, Yun Yong

    2014-12-08

    In this study, adiabatic temperature rise tests depending on binder type and adiabatic specimen volume were performed, and the maximum adiabatic temperature rises and the reaction factors for each mix proportion were analyzed and suggested. The results indicated that the early strength low heat blended cement mixture had the lowest maximum adiabatic temperature rise ( Q ∞ ) and the ternary blended cement mixture had the lowest reaction factor ( r ). Also, Q and r varied depending on the adiabatic specimen volume even when the tests were conducted with a calorimeter, which satisfies the recommendations for adiabatic conditions. Test results show a correlation: the measurements from the 50 L specimens were consistently higher than those from the 6 L specimens. However, the Q ∞ and r values of the 30 L specimen were similar to those of the 50 L specimen. Based on the above correlation, the adiabatic temperature rise of the 50 L specimen could be predicted using the results of the 6 L and 30 L specimens. Therefore, it is thought that this correlation can be used for on-site concrete quality control and basic research.

  7. Dry Ice Blast Decontamination to in-service equipment in Japanese PWR plant

    International Nuclear Information System (INIS)

    2016-01-01

    MHI had developed several mechanical decontamination methods. Mechanical decontamination is beneficial when it is applied to equipment whose surface is narrow. Especially in terms of secondary waste reduction, MHI started the study of application of Dry Ice Blast Decontamination to actual PWR plant. This paper provides an introduction to Dry Ice Blast Decontamination principle, its system and actual application result to PWR plant. (J.P.N.)

  8. Soil removal as a decontamination practice and radiocesium accumulation in tadpoles in rice paddies at Fukushima.

    Science.gov (United States)

    Sakai, Masaru; Gomi, Takashi; Nunokawa, Masanori; Wakahara, Taeko; Onda, Yuichi

    2014-04-01

    We investigated the biological accumulation of radiocesium in tadpoles [Rana (Pelophylax) porosa porosa] in rice paddies with and without decontamination practice at Fukushima. Radiocesium was accumulated in surface part of soils both in the control and decontaminated paddies one year after decontamination. Mean (134)Cs and (137)Cs concentrations in tadpoles in the control and decontaminated paddies were 3000 and 4500, and 600 and 890 Bq/kg dry weight, respectively. Radiocesium concentrations in surface soil (0-5 cm depth) and tadpoles in the decontaminated paddy were five times smaller than in the control paddy. These results suggest that decontamination practice can reduce radiocesium concentrations in both soil and tadpoles. However, at the decontaminated paddy, radiocesium concentrations in surface soils became 3.8 times greater one year after decontamination, which indicates that monitoring the subsequent movement of radiocesium in rice paddies and surrounding areas is essential for examining contamination propagation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Study of decontamination and waste management technologies for contaminated rural and forest environment

    International Nuclear Information System (INIS)

    Grebenkov, A.; Davydchuk, V.; Firsakova, S.; Jouve, A.; Kutlakhmedov, Y.; Rose, K.; Zhouchenko, T.; Antzypaw, G.

    1996-01-01

    Pilot and demonstrative scale in situ trials of several decontamination technologies proposed in the framework of ECP-4 project were carried out in real conditions of Chernobyl Zone. Their results proved that industrial scale decontamination of various types of land is feasible. The management of radioactive waste arising from decontamination techniques can be provided by ecologically sound and efficient technologies

  10. Concrete laying laboratory

    International Nuclear Information System (INIS)

    Bastlova, K.

    1986-01-01

    The task of the concrete laying laboratory established within a special department for quality control and assurance at the Dukovany nuclear power plant, is to check the composition of concrete mixes produced by the central concrete production plant on the site, and the shipment, laying and processing of concrete. The composition is given of special barite and serpentinite concretes designed for biological shields. The system of checks and of filing the results is briefly described. Esperience is summed up from the operation of the concrete laying laboratory, and conclusions are formulated which should be observed on similar large construction sites. They include the precise definition of the designer's requirements for the quality of concrete, the surface finish of concrete surfaces, the method of concreting specific structures around bushings, increased density reinforcements and various technological elements, and requirements for shipment to poorly accessible or remote places. As for the equipment of the laboratory, it should be completed with an instrument for the analysis of fresh concrete mixes, a large capacity drying kiln, etc. (Z.M.)

  11. OECD MCCI 2-D Core Concrete Interaction (CCI) tests : CCI-2 test data report-thermalhydraulic results, Rev. 0 October 15, 2004.

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, M. T.; Lomperski, S.; Kilsdonk, D. J.; Aeschlimann, R. W.; Basu, S. (Nuclear Engineering Division); (NRC)

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following objectives: (1) resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten core-concrete interactions under both wet and dry cavity conditions. Achievement of these two program objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of satisfying these objectives, the Management Board (MB) approved the conduct of two long-term 2-D Core-Concrete Interaction (CCI) experiments designed to provide information in several areas, including: (i) lateral vs. axial power split during dry core-concrete interaction, (ii) integral debris coolability data following late phase flooding, and (iii) data regarding the nature and extent of the cooling transient following breach of the crust formed at the melt-water interface. This data report provides thermal hydraulic test results from the CCI-2 experiment, which was conducted on August 24, 2004. Test specifications for CCI-2 are provided in Table 1-1. This experiment investigated the interaction of a fully oxidized 400 kg

  12. Decontamination and disposal of radioactive wastes resulting from the March 28, 1979 accident, Three-Mile Island Nuclear Station, Unit 2, Pennsylvania-Docket No. 50-320 (final supplement 2 to the final environmental impact statement of March 1981)

    International Nuclear Information System (INIS)

    1987-06-01

    Implementation of actions necessary for decontamination of the facility, defueling of the reactor, and disposition of the radioactive wastes that resulted from the accident on March 28, 1979 at Unit 2 of the Three-Mile Island Nuclear Station in Dauphin County, Pennsylvania are discussed. This second final supplement to the final environmental impact statement, filed in March 1981 on facility decontamination, reevaluates the environmental impacts of accident-generated water disposal alternatives, using more complete and current information. This supplement also includes a specific evaluation of the recently submitted proposal for water disposition. The project would alleviate a radiological hazard that threatens the well-being of the surrounding population and downstream communities. Risks to the general public have been estimated to be very small fractions of the estimated normal incidence of cancer fatalities and genetic disorders. The most significant potential impact is the risk of physical injury associated with transportation accidents. Social impacts during the operation could result in reduced property values, competition between the work force and tourists for temporary housing, and congestion of local traffic arteries. Some psychological stress would experienced by area residents. Economic effects could include increased electricity rates, reduced tourism, and possible resistance to consumption of area goods that consumers might mistakenly think are contaminated

  13. Decontamination/decommissioning of the Princeton Pennsylvania Accelerator Facility

    International Nuclear Information System (INIS)

    Bair, W.A.

    1990-01-01

    The Princeton Pennsylvania Accelerator Facility was a 3 GeV proton synchrotron operated jointly by Princeton University and the University of Pennsylvania from 1962 to 1972 on Princeton University's Forrestal Campus. During synchrotron operations, certain portions of the PPA central accelerator chamber and structural members became neutron activated. Upon termination of accelerator operations due to funding problems, Princeton desired to utilize the PPA site for other purposes, and commissioned a study to investigate Decommissioning and Decontamination options and methodologies. The study investigated several methods for in-place, surgically removing the neutron activated from the uncontaminated concrete. Since each technique produced different volumes of removed concrete all methods investigated were studied from the total economics of the problem and the cost of limiting and clean-up of secondary contamination. The decontamination method selected used a diamond wire cutting technique to sever in-place, the activated concrete from the uncontaminated. Large, intact, activated structural segments were cut and removed from the central accelerator chamber's floor, outer walls, internal columns and ceiling. Nonactivated portions of the structure, and the remainder of the central chamber were subsequently razed by conventional demolition methods. The paper describes the decontamination methodology, its effectiveness, disposal economics and radiological safety problems related thereto

  14. Decontamination tests on tritium-contaminated materials

    International Nuclear Information System (INIS)

    Boutot, P.; Schipfer, P.

    1967-01-01

    These tests are designed to try out various processes liable to be applied to the decontamination of a material contaminated with tritium. The samples are thin stainless- steel slabs contaminated in the laboratory with elements extracted from industrial installations. The measurement of the initial and residual activities is carried out using an open-window BERTHOLD counter. The best results are obtained by passing a current of pre-heated (300 deg. C) air containing water vapour. This process makes it possible to reach a decontamination factor of 99.5 per cent in 4 hours. In a vacuum, the operation has to be prolonged to 100 hours in order to obtain a decontamination factor of 99.2 per cent. Wet-chemical or electrolytic treatments are efficient but their use is limited by the inherent corrosion risks. A study of the reappearance of the contamination has made it possible to observe that this phenomenon occurs whatever the process used. (authors) [fr

  15. Modification of the Decontamination Facility at the Kruemmel NPP - 13451

    Energy Technology Data Exchange (ETDEWEB)

    Klute, Stefan; Kupke, Peter [Siempelkamp Nukleartechnik GmbH Am Taubenfeld 25/1, 69123 Heidelberg (Germany)

    2013-07-01

    In February 2009, Siempelkamp Nukleartechnik GmbH was awarded the contract for the design, manufacture, delivery and construction of a new Decontamination Facility in the controlled area for Kruemmel NPP. The new decontamination equipment has been installed according to the state of art of Kruemmel NPP. The existing space required the following modification, retrofitting and reconstruction works: - Demounting of the existing installation: to create space for the new facility it was necessary to dismantle the old facility. The concrete walls and ceilings were cut into sizes of no more than 400 kg for ease of handling. This enabled decontamination so largest possible amount could be released for recycling. All steel parts were cut into sizes fitting for iron-barred boxes, respecting the requirement to render the parts decontaminable and releasable. - Reconstructing a decontamination facility: Reconstruction of a decontamination box with separate air lock as access area for the decontamination of components and assemblies was conducted using pressurized air with abrasives (glass beads or steel shots). The walls were equipped with sound protection, the inner walls were welded gap-free to prevent the emergence of interstices and were equipped with changeable wear and tear curtains. Abrasive processing unit positioned underneath the dry blasting box adjacent to the two discharge hoppers. A switch has been installed for the separation of the glass beads and the steel shot. The glass beads are directed into a 200 l drum for the disposal. The steel shot was cleaned using a separator. The cleaned steel shot was routed via transportation devices to the storage container, making it available for further blasting operations. A decontamination box with separate air lock as access area for the decontamination of components and assemblies using high pressure water technology was provided by new construction. Water pressures between 160 bar and 800 bar can be selected. The inner

  16. Modification of the Decontamination Facility at the Kruemmel NPP - 13451

    International Nuclear Information System (INIS)

    Klute, Stefan; Kupke, Peter

    2013-01-01

    In February 2009, Siempelkamp Nukleartechnik GmbH was awarded the contract for the design, manufacture, delivery and construction of a new Decontamination Facility in the controlled area for Kruemmel NPP. The new decontamination equipment has been installed according to the state of art of Kruemmel NPP. The existing space required the following modification, retrofitting and reconstruction works: - Demounting of the existing installation: to create space for the new facility it was necessary to dismantle the old facility. The concrete walls and ceilings were cut into sizes of no more than 400 kg for ease of handling. This enabled decontamination so largest possible amount could be released for recycling. All steel parts were cut into sizes fitting for iron-barred boxes, respecting the requirement to render the parts decontaminable and releasable. - Reconstructing a decontamination facility: Reconstruction of a decontamination box with separate air lock as access area for the decontamination of components and assemblies was conducted using pressurized air with abrasives (glass beads or steel shots). The walls were equipped with sound protection, the inner walls were welded gap-free to prevent the emergence of interstices and were equipped with changeable wear and tear curtains. Abrasive processing unit positioned underneath the dry blasting box adjacent to the two discharge hoppers. A switch has been installed for the separation of the glass beads and the steel shot. The glass beads are directed into a 200 l drum for the disposal. The steel shot was cleaned using a separator. The cleaned steel shot was routed via transportation devices to the storage container, making it available for further blasting operations. A decontamination box with separate air lock as access area for the decontamination of components and assemblies using high pressure water technology was provided by new construction. Water pressures between 160 bar and 800 bar can be selected. The inner

  17. Decontamination of the activation product based on a legal revision of the cyclotron vault room on the non-self-shield compact medical cyclotron

    International Nuclear Information System (INIS)

    Komiya, Isao; Umezu, Yoshiyuki; Fujibuchi, Toshiou; Nakamura, Kazumasa; Baba, Shingo; Honda, Hiroshi

    2016-01-01

    The non-self-shield compact medical cyclotron and the cyclotron vault room were in operation for 27 years. They have now been decommissioned. We efficiently implemented a technique to identify an activation product in the cyclotron vault room. Firstly, the distribution of radioactive concentrations in the concrete of the cyclotron vault room was estimated by calculation from the record of the cyclotron operation. Secondly, the comparison of calculated results with an actual measurement was performed using a NaI scintillation survey meter and a high-purity germanium detector. The calculated values were overestimated as compared to the values measured using the Nal scintillation survey meter and the high-purity germanium detector. However, it could limit the decontamination area. By simulating the activation range, we were able to minimize the concrete core sampling. Finally, the appropriate range of radioactivated area in the cyclotron vault room was decontaminated based on the results of the calculation. After decontamination, the radioactive concentration was below the detection limit value in all areas inside the cyclotron vault room. By these procedures, the decommissioning process of the cyclotron vault room was more efficiently performed. (author)

  18. Uranium City radiation reduction program: further efforts at remedial measures for houses with block walls, concrete porosity test results, and intercomparison of Kuznetz method and Tsivoglau method

    International Nuclear Information System (INIS)

    Haubrich, E.; Leung, M.K.; Mackie, R.

    1980-01-01

    An attempt was made to reduce the levels of radon in a house in Uranium City by mechanically venting the plenums in the concrete block basement walls, with little success. A table compares the results obtained by measuring the radon WL using the Tsivoglau and the Kuznetz methods

  19. High pressure freon decontamination of remote equipment

    International Nuclear Information System (INIS)

    Wilson, C.E.

    1987-01-01

    A series of decontamination tests using high pressure FREON 113 was conducted in the 200 Area of the Hanford site. The intent of these tests was to evaluate the effectiveness of FREON 113 in decontamination of manipulator components, tools, and equipment items contaminated with mixed fission products. The test results indicated that high pressure FREON 113 is very effective in removing fissile material from a variety of objects and can reduce both the quantity and the volume of the radioactive waste material presently being buried

  20. Green coffee decontamination by electron beam irradiation

    International Nuclear Information System (INIS)

    Nemtanu, Monica R.; Brasoveanu, Mirela; Grecu, Maria Nicoleta; Minea, R.

    2005-01-01

    Microbiological load of green coffee is a real problem considering that it is extremely sensitive to contamination. Irradiation is a decontamination method for a lot of foodstuffs, being a feasible, very effective and environment friendly one. Beans and ground green coffee were irradiated with electron beams up to 40 kGy. Microbial load, rheological behavior, electron paramagnetic resonance (EPR) and visible spectroscopy were carried out. The results show that electron beam irradiation of green coffee could decontaminate it without severe changes in its properties

  1. Recycled Concrete as Aggregate for Structural Concrete Production

    Directory of Open Access Journals (Sweden)

    Mirjana Malešev

    2010-04-01

    Full Text Available A comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement ratios of natural with recycled coarse aggregate is presented in the paper. Recycled aggregate was made by crushing the waste concrete of laboratory test cubes and precast concrete columns. Three types of concrete mixtures were tested: concrete made entirely with natural aggregate (NAC as a control concrete and two types of concrete made with natural fine and recycled coarse aggregate (50% and 100% replacement of coarse recycled aggregate. Ninety-nine specimens were made for the testing of the basic properties of hardened concrete. Load testing of reinforced concrete beams made of the investigated concrete types is also presented in the paper. Regardless of the replacement ratio, recycled aggregate concrete (RAC had a satisfactory performance, which did not differ significantly from the performance of control concrete in this experimental research. However, for this to be fulfilled, it is necessary to use quality recycled concrete coarse aggregate and to follow the specific rules for design and production of this new concrete type.

  2. Experiment on electrolysis decontamination of stainless steel pipes

    International Nuclear Information System (INIS)

    Wang Dongwen; Dou Tianjun; Zhao Yujie

    2004-01-01

    A new electrolytic decontamination method used metal balls as conducting anode was investigated. The influences of current density, solution property and diameter of pipes on efficiency of electrolytic decontamination were examined and the efficiency of this method was compared with that of common electrolytic method under the same experimental conditions. Decontamination of samples of stainless steel pipes contaminated by plutonium was performed. Experimental results indicate that decontamination of stainless steel pipes contaminated by plutonium can be achieved at the optimum conditions of greater than 0.2 A·cm -2 current density, 5% sulfuric acid electrolyte and 5 min electrolysis. This method can be used in the decontamination of a wide variety of decommissioned metal materials. (author)

  3. Effect of decontamination on nuclear power plant primary circuit materials

    International Nuclear Information System (INIS)

    Brezina, M.; Kupca, L.

    1991-01-01

    The effect of repeated decontamination on the properties of structural materials of the WWER-440 primary coolant circuit was examined. Three kinds of specimens of 08Kh18Ni10T steel were used for radioactivity-free laboratory experiments; they included material obtained from assembly additions to the V-2 nuclear power plant primary piping, and a sheet of the CSN 17247 steel. Various chemical, electrochemical and semi-dry electrochemical decontamination procedures were tested. Chemical decontamination was based on the conventional AP(20/5)-CITROX(20/20) procedure and its variants; NP-CITROX type procedures with various compositions were also employed. Solutions based on oxalic acid were tested for the electrochemical and semi-dry electrochemical decontamination. The results of measurements of mass losses of the surfaces, of changes in the corrosion resistance and in the mechanical properties of the materials due to repeated decontamination are summarized. (Z.S.). 12 figs., 1 tab., 8 refs

  4. Decontamination for free release

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, K A; Elder, G R [Bradtec Ltd., Bristol (United Kingdom)

    1997-02-01

    Many countries are seeking to treat radioactive waste in ways which meet the local regulatory requirements, but yet are cost effective when all contributing factors are assessed. In some countries there are increasing amounts of waste, arising from nuclear plant decommissioning, which are categorized as low level waste: however with suitable treatment a large part of such wastes might become beyond regulatory control and be able to be released as non-radioactive. The benefits and disadvantages of additional treatment before disposal need to be considered. Several processes falling within the overall description of decontamination for free release have been developed and applied, and these are outlined. In one instance the process seeks to take advantage of techniques and equipment used for decontaminating water reactor circuits intermittently through reactor life. (author). 9 refs, 1 fig., 3 tabs.

  5. Sunflowers to decontaminate water

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    Sunflowers offer a new method of decontamination. 55 kilograms (dry weight) of sunflowers are able to decontaminate all the cesium 137 and the strontium 90 polluting a pond situated at one kilometer from Tchernobyl. These flowers are able to decrease 95% in 24 hours the uranium concentration in the american site of Ashtabula in Ohio getting this water from 350 parts by milliards to less than 5 parts by milliards. The radioactivity should stocked in the roots at concentrations 5 000 to 10 000 times higher than water concentration. The cost is cheaper than micro filtration and precipitation (2-6 dollars for 4 000 liters of water against 80 dollars for others technologies). when sunflowers are radioactive they can be reduced in dust and vitrified and stocked as solid radioactive wastes. (N.C.)

  6. OPO fabric decontamination

    International Nuclear Information System (INIS)

    Severa, J.; Bar, J.; Grujbar, V.

    1978-01-01

    Samples of five polypropylene-based man-made fabrics were studied with regard to the degree of contamination and possibilities of decontamination in order to assess their suitability as material for protective clothing in the nuclear industry. The contamination degree of the fabrics in an aqueous solution of a fission product mixture was found to be low. Soaking in a mixture of the Sapon detergent and sodium hexametaphosphate at a concentration of both materials of 1 g/l with subsequent washing in a solution of the Zenit detergent at a concentration of 3 g/l was suggested as the most suitable decontamination procedure. It reduces the initial contamination by almost 99%. (Z.M.)

  7. Development of decommissioning, decontamination and reuse technology for nuclear facilities

    International Nuclear Information System (INIS)

    Lee, K. W.; Moon, J. K.; Choi, B. S.

    2012-03-01

    In this project, the foundation of decommissioning technology through the development of core technologies applied to maintenance and decommissioning of nuclear facility was established. First of all, we developed the key technology such as safety assessment technology for decommissioning work needed at the preparatory stage of decommissioning of the highly contaminated facilities and simultaneous measurement technology of the high-level alpha/beta contamination applicable to the operation and decommissioning of the nuclear facilities. Second, we developed a remotely controlled laser ablation decontamination system which is useful for a removal of fixed contaminants and developed a chemical gel decontamination technology for a removal of non-fixed contaminants during the maintenance and decommissioning works of high radiation hot cells which have been used for a recycling or treatment of spent fuels. Third, we developed a volume reduction and self-disposal technology for dismantled concrete wastes. Also, the technology for volume reduction and stabilization of the peculiar wastes(HEPA filter and organic mixed wastes), which have been known to be very difficult to treat and manage, generated from the high radioactive facilities in operation, improvement and repair and under decommissioning was developed. Finally, this research project was developed a system for the reduction of radiotoxicity of several uranium mixtures generated in the front- and back-end nuclear fuel cycles with characteristics of highly enhanced proliferation-resistance and more environmental friendliness, which can make the uranium to be recovered or separated from the mixtures with a high purity level enough for the uranium to be reused and to be classified as C-class level for burial near the surface, and then which result in the much reduction in volume of the uranium mixture wastes

  8. Decontamination of latex gloves; Decontamination de gants en latex

    Energy Technology Data Exchange (ETDEWEB)

    Boutot, P; Schipfer, P; Blachere, A [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

    1969-07-01

    Initially the latex gloves used in controlled zones were processed after use as radioactive waste. In view of the continually increasing number used, however, the persons in charge of the SPRAR have considered the possibility of decontaminating the gloves and using them again after control. The recovery installations which have been developed were initially designed rather crudely and operated irregularly; they have been progressively improved as a result of the experience acquired; today they are more really an industrial concern, equipped with automatic machinery. In 1967 it has been possible with this set-up to recover 247000 pairs of gloves, representing nearly 70 per cent of the number treated. (author) [French] Initialement, les gants de latex utilises dans les zones controlees etaient conditionnes apres emploi comme dechets radioactifs. Mais, devant l'augmentation sans cesse croissante des quantites employees, les responsables du SPRAR ont envisage leur decontamination et leur recyclage apres controles. Les installations de recuperation mises au point, de conception artisanale et fonctionnant de maniere episodique au depart, se sont progressivement ameliorees au fur et a mesure de l'experience acquise; elles revetent aujourd'hui le caractere d'une exploitation industrielle equipee de machines automatiques. En 1967, ces nouvelles installations ont permis de recuperer 247000 paires de gants, ce qui represente pres de 70 pour cent des quantites traitees. (auteur)

  9. Economics and risks of recycling radioactively contaminated concrete

    International Nuclear Information System (INIS)

    Parker, F.L.; Ayers, K.W.

    1997-01-01

    As Decontamination and Decommissioning activities proceed within the DOE complex, tremendous volumes of both radioactively contaminated and non-contaminated concrete will be processed for disposal. Current practice is to decontaminate the concrete, dispose of the contamination at LLW facilities and ship the concrete rubble to C ampersand D landfills for disposal. This study evaluates the economic, health and safety, legal, and social aspects of recycling radioactively contaminated concrete. Probabilistic models were used to estimate costs and risks. The model indicates that the radioactively contaminated concrete can be recycled at the same or lower cost than current or alternative practices. The risks associated with recycling were consistently less than or equal to the other alternatives considered

  10. Sensitive Equipment Decontamination

    Science.gov (United States)

    2017-10-01

    a ceramic-like material Polonium - 210 Metallic foil Radium-226 Radium bromide or radium chloride Strontium-90 Metallic strontium, strontium...extremely toxic toxins. 3.1.1.5 Routes of Infection Pathogenic microorganisms are transferred to human beings largely via air and food (including...regularly in the pharmaceutical industry to decontaminate manufacturing clean rooms. It is also used to sterilize packages used to store foods . It has

  11. Decommissioning and decontamination

    International Nuclear Information System (INIS)

    Dadoumont, J.; Cantrel, E.; Valenduc, P.; Noynaert, L.

    2009-01-01

    The SCK-CEN has built a large know-how in decommissioning and decontamination, thanks to its BR3 decommissioning project. In 2007, the decommissioning activities at BR3 have been continued according to the strategy. This article discusses main realisations the following domains: decommissioning of the neutron shield tank and installation of new ventilation for the controlled area, dismantling of the former one and characterization of the stack

  12. Programmatic Environmental Impact Statement: related to decontamination and disposal of radioactive wastes resulting from March 28, 1979 accident Three Mile Island Nuclear Station, Unit 2 (Docket No. 50-320). Final supplement dealing with occupational radiation dose. Supplement No. 1

    International Nuclear Information System (INIS)

    1984-10-01

    In accordance with the National Environmental Policy Act, the Programmatic Environmental Impact Statement Related to Decontamination and Disposal of Radioactive Wastes Resulting from March 28, 1979 Accident Three Mile Island Nuclear Station, Unit 2 has been supplemented. The supplement was required because current information indicates that cleanup may entail substantially more occupational radiation dose to the cleanup work force than originally anticipated. Cleanup was originally estimated to result in from 2000 to 8000 person-rem of occupational radiation dose. Although nearly 2000 person-rem have resulted from cleanup operations performed up to now, current estimates now indicate that between 13,000 and 46,000 person-rem are expected to be required. Alternative cleanup methods considered in the supplement either did not result in appreciable dose savings or were not known to be technically feasible

  13. Structural Precast Concrete Handbook

    DEFF Research Database (Denmark)

    Kjærbye, Per Oluf H

    Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly.......Structural concept for precast concrete systems. Design og precast reinforced concrete components. Design of precast concrete connections. Illustrations on design of precast concrete buildings. Precast concrete assembly....

  14. Laser decontamination device

    International Nuclear Information System (INIS)

    Michishita, Shizuo; Akagawa, Katsuhiko.

    1997-01-01

    One end of an optical fiber inserted into an inner cylinder is opposed to a wall surface to be decontaminated, and an opened top end of an intermediate cylinder circumferentially surrounding the inner cylinder is tightly in contact with the wall surface to be decontaminated, an open end of an outer cylinder circumferentially surrounding the intermediate cylinder is tightly in contact with the wall surface to be decontaminated. Dust removing holes are perforated in the vicinity of the top end of the intermediate cylinder while being in communication with the inside and the outside of the intermediate cylinder, and one end of an air supply tube is in communication with the space between the outer circumferential surface of the inner cylinder and the inner circumferential surface of the intermediate cylinder. The other end of the air supply tube is connected to an air supply device, one end of a sucking tube is in communication with the space between the outer circumferential surface of the intermediate cylinder and the inner circumferential surface of the outer cylinder, the other end of the sucking tube is connected to a sucking device, and the other end of the optical fiber is connected to a laser generation device. The laser generation device is operated while determining the air sucking amount increased than the air supply amount, the materials deposited on the wall surface are crushed and peeled off, and the peeled off materials are transferred by air flow to a filter and collected. (N.H.)

  15. Building surface decontamination for chemical counter-terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, S.; Thouin, G.; Kuang, W. [SAIC Canada, Ottawa, ON (Canada); Volchek, K.; Fingas, M.; Li, K. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Division, Environmental Technology Centre, Science and Technology Branch

    2006-07-01

    A test method to compare and evaluate surface decontamination methods for buildings affected by chemical attacks was developed. Decontamination techniques generally depend on the nature and quantity of the weapon agent, the type of construction material and the location. Cleanup methods can be either physical, chemical or biological. This paper addressed chemical decontamination methods which use reactants to change the molecular structure of the contaminant. Peroxycarboxylic and peroxyacetic acids (PAA) are being used increasingly for both disinfection and environmental protection. In this study, 4 materials were chosen to represent common building materials. Samples were spiked with 10 mg of pesticides such as malathion and diazinon. Decontamination agents included the commercial decontamination agent CASCAD prepared in liquid form, a chemical preparation of PAA, and reagent grade peroxypropionic acid (PPA). The newly developed surface decontamination procedure can evaluate and compare the effectiveness of different chemical decontamination agents. The procedures were used on porous ceiling tile and carpet as well as on non-porous floor tile and painted steel surfaces. Rinse water was collected and analyzed in order to determine if decontamination was a result of chemical destruction or mechanical removal. The extraction efficiencies were found to be acceptable for all materials, with the exception of the highly porous ceiling tile. The extraction of diazinon from all surfaces was less efficient than the extraction of malathion. Results suggest that the performance of decontamination agents can be improved by repeated application of the decontamination agent, along with greater volumes and a combination of chemical and mechanical actions. It was also suggested that breakdown methods and wastewater treatment procedures should be developed because hazardous byproducts were detected in many samples. 18 refs., 1 tab., 17 figs.

  16. Chemical and mechanical decontamination processes to minimize secondary waste decommissioning

    International Nuclear Information System (INIS)

    Enda, M.; Ichikawa, N.; Yaita, Y.; Kanasaki, T.; Sakai, H.

    2008-01-01

    In the decommissioning of commercial nuclear reactors in Japan, prior to the dismantling of the nuclear power plants, there are plans to use chemical techniques to decontaminate reactor pressure vessels (RPVs), internal parts, primary loop recirculation systems (PLRs), reactor water clean up systems (RWCUs), etc., so as to minimize radiation sources in the materials to be disposed of. After dismantling the nuclear power plants, chemical and mechanical decontamination techniques will then be used to reduce the amounts of radioactive metallic waste. Toshiba Corporation has developed pre-dismantling and post-dismantling decontamination systems. In order to minimize the amounts of secondary waste, the T-OZON process was chosen for decontamination prior to the dismantling of nuclear power plants. Dismantling a nuclear power plant results in large amounts of metallic waste requiring decontamination; for example, about 20,000 tons of such waste is expected to result from the dismantling of a 110 MWe Boiling Water Reactor (BWR). Various decontamination methods have been used on metallic wastes in preparation for disposal in consideration of the complexity of the shapes of the parts and the type of material. The materials in such nuclear power plants are primarily stainless steel and carbon steel. For stainless steel parts having simple shapes, such as plates and pipes, major sources of radioactivity can be removed from the surface of the parts by bipolar electrolysis (electrolyte: H 2 SO 4 ). For stainless steel parts having complicated shapes, such as valves and pumps, major sources of radioactivity can be removed from the surfaces by redox chemical decontamination treatments (chemical agent: Ce(IV)). For carbon steel parts having simple shapes, decontamination by blasting with zirconia grit is effective in removing major sources of radioactivity at the surface, whereas for carbon steel parts having complicated shapes, major sources of radioactivity can be removed from

  17. Overview of nonchemical decontamination techniques

    International Nuclear Information System (INIS)

    Allen, R.P.

    1984-09-01

    The decontamination techniques summarized in this paper represent a variety of surface cleaning methods developed or adapted for component and facility-type decontamination applications ranging from small hand tools to reactor cavities and other large surface areas. The major conclusion is that decontamination is a complex, demanding technical discipline. It requires knowledgeable, experienced and well-trained personnel to select proper techniques and combinations of techniques for the varied plant applications and to realize their full performance potential. Unfortunately, decontamination in many plants has the lowest priority of almost any activity. Operators are unskilled and turnover is so frequent that expensive decontamination capabilities remain unused while decontamination operations revert to the most rudimentary type of hand scrubbing and water spray cleaning

  18. Development of a pilot size of electrochemical flushing equipment for radioactive soil and concrete

    International Nuclear Information System (INIS)

    Kim, Gye Nam; Moon, Jei Kwon; Choi, Wang Kyu; Yang, Byeong Il; Shon, Jong Sik; Hong, Dae Seok

    2010-01-01

    A pilot size of electrochemical flushing equipment will be manufactured suitable to the contamination characteristics of radioactive soil and concrete stored in KAERI radioactive waste storage. An optimal reagent and an optimal decontamination conditions should be decided through many experiments. - Contamination characterises analysis of TRIGA radioactive soil and concrete - Manufacture of pilot-scale electrochemical flushing equipment - Manufacture and improvement of suitable electrochemical flushing equipment for contamination characteristics in pilot size - Decontamination experiments of electrochemical flushing equipment in a pilot scale

  19. OECD MMCI 2-D Core Concrete Interaction (CCI) tests : CCCI-1 test data report-thermalhydraulic results. Rev 0 January 31, 2004.

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, M. T.; Lomperski, S.; Aeschlimann, R. W.; Basu, S. (Nuclear Engineering Division)

    2011-05-23

    The Melt Attack and Coolability Experiments (MACE) program addressed the issue of the ability of water to cool and thermally stabilize a molten core-concrete interaction when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. As a follow-on program to MACE, The Melt Coolability and Concrete Interaction Experiments (MCCI) project is conducting reactor material experiments and associated analysis to achieve the following objectives: (1) resolve the ex-vessel debris coolability issue through a program that focuses on providing both confirmatory evidence and test data for the coolability mechanisms identified in MACE integral effects tests, and (2) address remaining uncertainties related to long-term two-dimensional molten coreconcrete interactions under both wet and dry cavity conditions. Achievement of these two program objectives will demonstrate the efficacy of severe accident management guidelines for existing plants, and provide the technical basis for better containment designs for future plants. In terms of satisfying these objectives, the Management Board (MB) approved the conduct of two long-term 2-D Core-Concrete Interaction (CCI) experiments designed to provide information in several areas, including: (i) lateral vs. axial power split during dry core-concrete interaction, (ii) integral debris coolability data following late phase flooding, and (iii) data regarding the nature and extent of the cooling transient following breach of the crust formed at the melt-water interface. This data report provides thermal hydraulic test results from the CCI-1 experiment, which was conducted on December 19, 2003. Test specifications for CCI-1 are provided in Table 1-1. This experiment investigated the interaction of a fully oxidized 400 kg

  20. Advance Organizers: Concret Versus Abstract.

    Science.gov (United States)

    Corkill, Alice J.; And Others

    1988-01-01

    Two experiments examined the relative effects of concrete and abstract advance organizers on students' memory for subsequent prose. Results of the experiments are discussed in terms of the memorability, familiarity, and visualizability of concrete and abstract verbal materials. (JD)

  1. Programmatic environmental impact statement related to decontamination and disposal of radioactive wastes resulting from March 28, 1979 accident, Three Mile Island Nuclear Station, Unit 2 (Docket No. 50-320). Draft supplement dealing with occupational radiation dose. Supplement No. 1

    International Nuclear Information System (INIS)

    1983-12-01

    In accordance with the National Environmental Policy Act, the Programmatic Environmental Impact Statement Related to Decontamination and Disposal of Radioactive Waste for the 1979 Accident at Three Mile Island Nuclear Station Unit 2 has been supplemented. The supplement was required because current information indicates that cleanup will entail substantially more occupational radiation dose to the cleanup work force than originally anticipated. Cleanup was originally estimated to result in from 2000 to 8000 person-rem of occupational radiation dose. Although only 1700 person-rem have resulted from cleanup operations performed up to now, current estimates now indicate that between 13,000 and 46,000 person-rem are expected to be required. Alternate cleanup methods considered in the supplement either did not result in appreciable dose savings or were not known to be technically feasible

  2. Manual on decontamination of surfaces

    International Nuclear Information System (INIS)

    1979-01-01

    The manual is intended for those who are responsible for the organization and implementation of decontamination programmes for facilities where radioactive materials are handled mainly on a laboratory scale. It contains information and guidelines on practical methods for decontaminating working spaces, equipment, laboratory benches and protective clothing. Useful information is also provided on the removal of loose skin contamination from personnel by mild, non-medical processes. Methods of removing skin contamination needing medical supervision, or of internal decontamination, which is entirely a medical process, are not covered in this manual. Large-scale decontamination of big nuclear facilities is also considered as outside its scope

  3. Decontamination of TRU glove boxes

    International Nuclear Information System (INIS)

    Crawford, J.H.

    1978-03-01

    Two glove boxes that had been used for work with transuranic nuclides (TRU) for about 12 years were decontaminated in a test program to collect data for developing a decontamination facility for large equipment highly contaminated with alpha emitters. A simple chemical technique consisting of a cycle of water flushes and alkaline permanganate and oxalic acid washes was used for both boxes. The test showed that glove boxes and similar equipment that are grossly contaminated with transuranic nuclides can be decontaminated to the current DIE nonretrievable disposal guide of <10 nCi TRU/g with a moderate amount of decontamination solution and manpower. Decontamination of the first box from an estimated 1.3 Ci to about 5 mCi (6 nCi/g) required 1.3 gallons of decontamination solution and 0.03 man-hour of work for each square foot of surface area. The second box was decontaminated from an estimated 3.4 Ci to about 2.8 mCi (4.2 nCi/g) using 0.9 gallon of decontamination solution and 0.02 man-hour for each square foot of surface area. Further reductions in contamination were achieved by repetitive decontamination cycles, but the effectiveness of the technique decreased sharply after the initial cycle

  4. Concrete release protocol case studies for decommissioning work at the Idaho National Engineering and Environmental Laboratory

    International Nuclear Information System (INIS)

    Kamboj, S.; Arnish, J.; Chen, S-Y; Parker, F. L.; Phillips, A. M.; Tripp, J. L.; Meservey, R. H.

    2000-01-01

    The US Department of Energy (DOE) Order 5400.5, ''Radiation Protection of the Public and Environment'' contains provisions pertinent to releasing potentially radioactive materials from DOE facilities for reuse or recycle. A process of authorized release for materials recovered from radiation areas is permitted under Order 5400.5 and the proposed rule in Title 10, Part 834, of the Code of Federal Regulations (10 CFR Part 834). A generic disposition protocol to facilitate release of concrete under these provisions has been developed. This report analyzes the application of that generic protocol to site-specific cases at the Idaho National Engineering and Environmental Laboratory (INEEL). The potential radiological doses and costs for several concrete disposition alternatives for the sewage treatment plant (STP) at the Central Facilities Area (CFA) of INEEL were evaluated in this analysis. Five disposition alternatives were analyzed for the concrete: (A) decontaminate, crush, and reuse; (B) crush and reuse without decontamination; (C) decontaminate, demolish, and dispose of at a nonradiological landfill; (D) demolish and dispose of at a nonradiological landfill without decontamination; and (E) demolish and dispose of at a low-level radioactive waste (LLW) facility. The analysis was performed for disposition of concrete from four INEEL structures: (1) trickle filter, (2) primary clarifier, (3) secondary clarifier, and (4) CFA-691 pumphouse for a generic case (based on default parameters from the disposition protocol) and an INEEL-specific case (based on INEEL-specific parameters). The results of the analysis indicated that Alternatives B and D would incur the lowest cost and result in a dose less than 1 mrem/yr (except for the trickle filter, the dose for which was estimated at 1.9 mrem/yr) for nonradiological workers. The analysis indicated that the main contributor to the radiological dose would be cobalt-60 contamination in the concrete. A characterization conducted

  5. 75 FR 47260 - Certain Steel Concrete Reinforcing Bars from Turkey: Notice of Amended Final Results Pursuant to...

    Science.gov (United States)

    2010-08-05

    ... concrete reinforcing bars (rebar) from Turkey. See Nucor Corporation, Gerdau Ameristeel, Inc., and... calculated for Ekinciler to the Department. See Nucor Corporation, Gerdau Ameristeel Corporation, and Commercial Metals Company v. United States, Court No. 07-00457 (Apr. 14, 2009) (Nucor). On May 14, 2009, the...

  6. Glazed Concrete

    DEFF Research Database (Denmark)

    Bache, Anja Margrethe

    2010-01-01

    Why glazed concrete? Concrete hardens and finds its strength at room temperature whereas clay products must first be fired before they achieve this strength. They are stronger and three times as durable as clay products, which is a weighty reason for choosing concrete.5 Another reason, which....... If this succeeds, it will be possible to manufacture thin, large-scale glazed concrete panels comparable in size to concrete sandwich construction and larger which, with or without back-casting, can work as load-bearing construction elements....

  7. Usage of Crushed Concrete Fines in Decorative Concrete

    Science.gov (United States)

    Pilipenko, Anton; Bazhenova, Sofia

    2017-10-01

    The article is devoted to the questions of usage of crushed concrete fines from concrete scrap for the production of high-quality decorative composite materials based on mixed binder. The main problem in the application of crushed concrete in the manufacture of decorative concrete products is extremely low decorative properties of crushed concrete fines itself, as well as concrete products based on them. However, crushed concrete fines could have a positive impact on the structure of the concrete matrix and could improve the environmental and economic characteristics of the concrete products. Dust fraction of crushed concrete fines contains non-hydrated cement grains, which can be opened in screening process due to the low strength of the contact zone between the hydrated and non-hydrated cement. In addition, the screening process could increase activity of the crushed concrete fines, so it can be used as a fine aggregate and filler for concrete mixes. Previous studies have shown that the effect of the usage of the crushed concrete fines is small and does not allow to obtain concrete products with high strength. However, it is possible to improve the efficiency of the crushed concrete fines as a filler due to the complex of measures prior to mixing. Such measures may include a preliminary mechanochemical activation of the binder (cement binder, iron oxide pigment, silica fume and crushed concrete fines), as well as the usage of polycarboxylate superplasticizers. The development of specific surface area of activated crushed concrete fines ensures strong adhesion between grains of binder and filler during the formation of cement stone matrix. The particle size distribution of the crushed concrete fines could achieve the densest structure of cement stone matrix and improve its resistance to environmental effects. The authors examined the mechanisms of structure of concrete products with crushed concrete fines as a filler. The results of studies of the properties of

  8. Build-up Factor Calculation for Ordinary Concrete, Baryte Concrete and Blast-furnace Slugges Concrete as γ Radiation Shielding

    International Nuclear Information System (INIS)

    Isman MT; Elisabeth Supriatni; Tochrul Binowo

    2002-01-01

    Calculation of build up factor ordinary concrete, baryte concrete and blast-furnace sludge concrete have been carried out. The calculations have been carried out by dose rate measurement of Cs 137 source before and after passing through shielding. The investigated variables were concrete type, thickness of concrete and relative possession of concrete. Concrete type variables are ordinary concrete, baryte concrete and blast sludge furnace concrete. The thickness variables were 6, 12, 18, 24, 30 and 36 cm. The relative position variables were dose to the source and close to detector. The result showed that concrete type and position did not have significant effect to build-up factor value, while the concrete thickness (r) and the attenuation coefficient (μ) were influenced to the build-up factor. The higher μr value the higher build-up factor value. (author)

  9. Concrete with onyx waste aggregate as aesthetically valued structural concrete

    Science.gov (United States)

    Setyowati E., W.; Soehardjono, A.; Wisnumurti

    2017-09-01

    The utillization of Tulungagung onyx stone waste as an aggregate of concrete mixture will improve the economic value of the concrete due to the brighter color and high aesthetic level of the products. We conducted the research of 75 samples as a test objects to measure the compression stress, splits tensile stress, flexural tensile stress, elasticity modulus, porosity modulus and also studied 15 test objects to identify the concrete micro structures using XRD test, EDAX test and SEM test. The test objects were made from mix designed concrete, having ratio cement : fine aggregate : coarse aggregate ratio = 1 : 1.5 : 2.1, and W/C ratio = 0.4. The 28 days examination results showed that the micro structure of Tulungagung onyx waste concrete is similar with normal concrete. Moreover, the mechanical test results proved that Tulungagung onyx waste concretes also have a qualified level of strength to be used as a structural concrete with higher aesthetic level.

  10. Concrete Hinges

    DEFF Research Database (Denmark)

    Halding, Philip Skov; Hertz, Kristian Dahl; Schmidt, Jacob Wittrup

    2014-01-01

    In the first part of the 20th century concrete hinges developed by Freyssinet and Mesnager were widely tested and implemented in concrete structures. The concrete hinges were used a great deal in closed-spandrel arch bridges. Since such a bridge type has not been competitive for the past 40 years......, the research in concrete hinges has not evolved significantly in that period. But introducing a new state-of-the-art concrete arch bridge solution (Pearl-Chain arches invented at the Technical University of Denmark) creates a necessity of a concrete hinge research based on modern standards. Back when research...... in concrete hinges was more common different designs were proposed for the geometry and reinforcement. Previous research focused on fatigue, multi-axial stresses around the hinge throat, and the relation between rotation- and moment. But many different test-setups were proposed by different researchers...

  11. Concrete structures

    CERN Document Server

    Setareh, Mehdi

    2017-01-01

    This revised, fully updated second edition covers the analysis, design, and construction of reinforced concrete structures from a real-world perspective. It examines different reinforced concrete elements such as slabs, beams, columns, foundations, basement and retaining walls and pre-stressed concrete incorporating the most up-to-date edition of the American Concrete Institute Code (ACI 318-14) requirements for the design of concrete structures. It includes a chapter on metric system in reinforced concrete design and construction. A new chapter on the design of formworks has been added which is of great value to students in the construction engineering programs along with practicing engineers and architects. This second edition also includes a new appendix with color images illustrating various concrete construction practices, and well-designed buildings. The ACI 318-14 constitutes the most extensive reorganization of the code in the past 40 years. References to the various sections of the ACI 318-14 are pro...

  12. Shear reinforced beams in autoclaved aerated concrete

    DEFF Research Database (Denmark)

    Cornelius, Thomas

    2010-01-01

    Shear behaviour in concrete materials is very well documented, for normal density concrete materials. In this paper results of various tests on low density concrete materials like aerated autoclaved concrete (in the following denoted aircrete) will be presented and analyzed for different combinat....... Codes for designing prefabricated reinforced components of aircrete structures have adopted these recently developed approaches.......Shear behaviour in concrete materials is very well documented, for normal density concrete materials. In this paper results of various tests on low density concrete materials like aerated autoclaved concrete (in the following denoted aircrete) will be presented and analyzed for different...

  13. Magnesium oxychloride cement concrete

    Indian Academy of Sciences (India)

    The durability of MOC concrete compositions against extreme environmental conditions viz. heating–cooling, freezing–thawing, wetting–drying and penetration and deposition of salts etc were investigated. The results reveal that MOC concrete has high compressive strength associated with high flexural strength and the ...

  14. Danish High Performance Concretes

    DEFF Research Database (Denmark)

    Nielsen, M. P.; Christoffersen, J.; Frederiksen, J.

    1994-01-01

    In this paper the main results obtained in the research program High Performance Concretes in the 90's are presented. This program was financed by the Danish government and was carried out in cooperation between The Technical University of Denmark, several private companies, and Aalborg University...... concretes, workability, ductility, and confinement problems....

  15. Characterisation and management of concrete grinding residuals.

    Science.gov (United States)

    Kluge, Matt; Gupta, Nautasha; Watts, Ben; Chadik, Paul A; Ferraro, Christopher; Townsend, Timothy G

    2018-02-01

    Concrete grinding residue is the waste product resulting from the grinding, cutting, and resurfacing of concrete pavement. Potential beneficial applications for concrete grinding residue include use as a soil amendment and as a construction material, including as an additive to Portland cement concrete. Concrete grinding residue exhibits a high pH, and though not hazardous, it is sufficiently elevated that precautions need to be taken around aquatic ecosystems. Best management practices and state regulations focus on reducing the impact on such aquatic environment. Heavy metals are present in concrete grinding residue, but concentrations are of the same magnitude as typically recycled concrete residuals. The chemical composition of concrete grinding residue makes it a useful product for some soil amendment purposes at appropriate land application rates. The presence of unreacted concrete in concrete grinding residue was examined for potential use as partial replacement of cement in new concrete. Testing of Florida concrete grinding residue revealed no dramatic reactivity or improvement in mortar strength.

  16. Concrete shaver. Innovative technology summary report

    International Nuclear Information System (INIS)

    1998-12-01

    The US Department of Energy (DOE) is in the process of decontamination and decommissioning (D and D) for many of its nuclear facilities throughout the United States. These facilities must be dismantled and the demolition waste sized into manageable pieces for handling and disposal. The facilities undergoing D and D are typically chemically and/or radiologically contaminated. To facilitate this work, DOE requires a tool capable of removing the surface of radiologically contaminated concrete floors. Operating requirements for the tool include simple and economical operation, the capability of operating in ambient temperatures from 3 C to 40 C (37 F to 104 F), and the ability to be easily decontaminated. The tool also must be safe for workers. The Marcrist Industries Limited concrete shaver is an electrically driven, self-propelled concrete and coating removal system. This technology consists of a 25-cm (10-in.)-wide diamond impregnated shaving drum powered by an electric motor and contains a vacuum port for dust extraction. The concrete shaver is ideal for use on open, flat, floor areas. The shaver may also be used on slightly curved surfaces. This shaver is self-propelled and produces a smooth, even surface with little vibration. The concrete shaver is an attractive alternative to traditional pneumatic scabbling tools, which were considered the baseline in this demonstration. The use of this tool reduces worker fatigue (compared to the baseline) due to lower vibration. The shaver is more than five times faster than the five-piston pneumatic scabbler at removing contamination from concrete. Because of this increased productivity, the shaver is 50% less costly to operate than baseline technologies. The DOE has successfully demonstrated the concrete shaver for decontaminating floors for free-release surveys prior to demolition work

  17. Biodecontamination of concrete surfaces: Occupational and environmental benefits

    International Nuclear Information System (INIS)

    Johnson, L.; Rogers, R.; Hamilton, M.; Nelson, L.

    1996-01-01

    Managers and engineers around the globe are presently challenged by high estimated costs for the decontamination and decommissioning of nuclear facilities which are no longer needed or are abandoned. It has been estimated that more than 73 Km 2 of contaminated concrete currently exists in the USDOE complex and is increased many fold when similar facilities are accounted for in other countries. Needs for the decontamination of concrete have been identified as: more cost effective decontamination methods, reduction of secondary wastes, minimized worker radiation exposures and, contaminant containment. Recently environmental microbes have been harnessed to remove the surface of concrete as a technique for decontamination and decommissioning (D and D). This biodecontamination technology has been tested by INEL and BNFL scientists and engineers in both US and United Kingdom nuclear facilities. Biodecontamination field tests at a shutdown nuclear reactor facility (EBR-I) have shown radioactively contaminated surface removed at rates of 4--8 mm/yr, thus validating the feasibility of this technology. Engineering economic analyses indicate two attractive benefits embedded in this approach to concrete D and D: (1) due to the passive nature of the technique, a cost savings of more than an order of magnitude is projected compared to the current labor intensive physical decontamination techniques; and (2) the exposure to humans and the natural environment is greatly reduced due to the unattended, highly contained biodecontamination process

  18. Use of fiber reinforced concrete for concrete pavement slab replacement.

    Science.gov (United States)

    2014-03-01

    Unlike ordinary concrete pavement, replacement concrete slabs need to be open to traffic within 24 hours (sooner in : some cases). Thus, high early-strength concrete is used; however, it frequently cracks prematurely as a result of high : heat of hyd...

  19. Decontamination of Soil Contaminated with Bacillus anthracis ...

    Science.gov (United States)

    Technical Brief This technical summary will provide decontamination personnel rapid access to information on which decontamination approaches are most effective for soils contaminated with B anthracis.

  20. LIGHTWEIGHT CONCRETE BASED GRANSHLAK

    Directory of Open Access Journals (Sweden)

    NETESA M. I.

    2016-02-01

    Full Text Available Raising of problem. Concrete advisable to obtain a low strength with local secondary resources for recycling and reduce the environmental burden on the environment. But it is important to design such concrete compositions with a reduced flow of cement. It is known that the coefficient of efficiency of use of cement in the concrete of the heavy and B10 is less than about 0.5, which is almost two times smaller than in class B15 concrete and above. Even lower coefficient of efficiency in light concrete cement low strength. Therefore, it is important to find patterns determining the composition of lightweight concrete based on local-products industry with more efficient use of cement in them. Purpose.. Based on the analysis of earlier research results, including with the use of methods of mathematical planning of experiments to determine the concrete contents, which can provide the requirements for the underlying layers of the floor, the compressive strength of which should correspond to the class B5. It is important to provide the required strength at minimum flow of the cement, which is the most expensive and energy-intensive part of concrete. Conclusion. Analysis of the test results of control samples of concrete in 28-day-old, the following laws. The required tensile strength of concrete compressive strength of 7.0 MPa can be obtained in the test range when used in formulations as a filler as the Dnieper hydroelectric power station fly ash and tailings Krivoy Rog iron ore YuGOK. To ensure providing the required characteristic strength of the concrete in the underlying layers of the floor is advisable to use a nominal composition per cubic meter of concrete: cement 160 kg granshlaka Plant named after Petrovsky, 675 kg of fly ash Dnieper HPP 390 kg, 400 kg of sand, 230 liters of water. Thus, while ensuring rational grain composition components can obtain the desired strength lightweight concrete based granshlaka plant Petrovsky, using as fillers

  1. Survey of decontamination and decommissioning techniques

    International Nuclear Information System (INIS)

    Kusler, L.E.

    1977-01-01

    Reports and articles on decommissioning have been reviewed to determine the current technology status and also attempt to identify potential decommissioning problem areas. It is concluded that technological road blocks, which limited decommissioning facilities in the past have been removed. In general, techniques developed by maintenance in maintaining the facility have been used to decommission facilities. Some of the more promising development underway which will further simplify decommissioning activities are: electrolytic decontamination which simplifies some decontaminating operations; arc saw and vacuum furnace which reduce the volume of metallic contaminated material by a factor of 10; remotely operated plasma torch which reduces personnel exposure; and shaped charges, water cannon and rock splitters which simplify concrete removal. Areas in which published data are limited are detailed costs identifying various components included in the total cost and also the quantity of waste generated during the decommissioning activities. With the increased awareness of decommissioning requirements as specified by licensing requirements, design criteria for new facilities are taking into consideration final decommissioning of buildings. Specific building design features will evolve as designs are evaluated and implemented

  2. Electro-decontamination of cementitious materials

    International Nuclear Information System (INIS)

    Ben-Hadj-Hassine, S.

    2012-01-01

    The end of operations in nuclear facilities is followed by various decontamination and decommissioning operations. Similar to other electrochemical techniques such as re-alkalinisation and chloride extraction, an electrokinetic remediation process is being developed as a specific method for deeply contaminated concrete structures. Two cements, an ordinary Portland and a 30% slag cement, have been chosen for the conducted work.Mortars and concretes are contaminated by adding non-radioactive cesium in the batch water, cesium being a representative specie of deep encountered contaminants. The conducted experimental and numerical work have focused on three main aspects: characterizing and understanding the cesium transport mechanisms, assessing the electro-remediation process at lab-scale and evaluating the real scale constraints. Using existing knowledge of chloride transport mechanisms, experiments have been conducted to characterize the cesium interactions with cementitious phase and ionic transport in saturated materials. A numerical model have then been developed to describe the cesium transport, taking into account the ionic activity coefficients and interactions with solid phases. Indeed, lab-scale experiments have demonstrated that electro-remediation reduced to 20-50% the initially contained cesium after a three weeks treatment. Treated samples analysis confirmed that deeply diffused cesium is migrating to the surface. Moreover, conducted experiments showed the consistency between the different materials properties, applied currents and decontamination efficiency. A comparative analysis of experiments carried on samples with different shapes, formulations and contamination modes helped assessing and optimizing the process efficiency for various continuous and variable applied currents. Finally, electro-remediation experiments have also been carried on 1m 2 concrete slabs. Liquid catholyte and anolyte solutions are replaced by alumina gels and cellulose pastes

  3. Electrolytic decontamination of the 3013 inner can

    International Nuclear Information System (INIS)

    Wedman, D.E.; Nelson, T.O.; Rivera, Y.; Weisbrod, K.; Martinez, H.E.; Limback, S.

    1998-01-01

    Disposition of plutonium recovered from nuclear weapons or production residues must be stored in a manner that ensures safety. The criteria that has been established to assure the safety of stored materials for a minimum of 50 years is DOE-STD-3013. This standard specifies both the requirements for containment and furthermore specifies that the inner container be decontaminated to a level of ≤20 dpm/100 cm 2 swipable and ≤500 dpm/100 cm 2 direct alpha such that a failure of the outer containment barrier will have a lower probability of resulting in a spread of contamination. The package consists of an optional convenience (food pack) can, a welded type 304L stainless steel inner (primary) can, and a welded type 304L stainless steel outer (secondary) can. Following the welding process, the can is checked for leaks and then sent down the line for decontamination. Once decontaminated, the sealed primary can may be removed from the glove box line. Welding of the secondary container takes place outside the glove box line. The highly automated decontamination process that has been developed to support the packaging of Special Nuclear Materials is based on an electrolytic process similar to the wide spread industrial technique of electropolishing. The can is placed within a specially designed stainless steel fixture built within a partition of a glove box. The passage of current through this electrolytic cell results in a uniform anodic dissolution of the surface metal layers of the can. This process results in a rapid decontamination of the can. The electrolyte is fully recyclable, and the separation of the chromium from the actinides results in a compact, non RCRA secondary waste product

  4. Decontamination of the Warm Aisles at the West Valley Demonstration Project. Final topical report, January 1985-February 1986

    International Nuclear Information System (INIS)

    Allen, J.C.

    1986-06-01

    The West Valley Demonstration Project is a DOE project to solidify in a glass form the 2,120 m 3 (560,000 gallons) of liquid high-level waste stored in two underground steel tanks at the site of the world's first commercial nuclear fuel reprocessing plant, West Valley, New York. One project objective is to utilize as much of the existing plant areas as practical for the installation of solidification support systems. Previously, Extraction Cell Three (XC3) and the Product Purification Cell (PPC) had been chosen as the location of the Liquid Waste Treatment System (LWTS). Subsequently, it was decided that areas of the Upper Warm Aisle (UWA) and the Lower Warm Aisle (LWA) which are located adjacent to the south wall of XC3 and PPC would also be needed for the installation of LWTS equipment. Shielded concrete niches which contained pumps and valve manifolds are located in the warm aisles. One pump niche and one valve manifold niche in the UWA and one pump niche in the LWA were identified as needed for the LWTS. Also, it was necessary to remove some equipment which was located outside the niches. Subsequently, decontamination plans were made and carried out to prepare these areas for modification and installation activities. Predecontamination survey activities began in January 1985, and decontamination operations were completed in February 1986. Decontamination efforts, results, and lessons learned are reported

  5. Programmatic Environmental Impact Statement related to decontamination and disposal of radioactive wastes resulting from March 28, 1979 accident at Three Mile Island Nuclear Station, Unit 2 (Docket No. 50-320): Final report

    International Nuclear Information System (INIS)

    1987-06-01

    In accordance with the National Environmental Policy Act, the Commission's implementing regulations, and the Commission's April 27, 1981 Statement of Policy, the Programmatic Environmental Impact Statement related to decontamination and disposal of radioactive wastes resulting from March 28, 1979, accident Three Mile Island Nuclear Station, Unit 2 NUREG-0683 (PEIS) is being supplemented. This supplement updates the environmental evaluation of accident-generated water disposal alternatives published in the PEIS, utilizing more complete and current information. Also, the supplement includes a specific environmental evaluation of the licensee's proposal for water disposition. Although no clearly preferable water disposal alternative was identified, the supplement concluded that a number of alternatives could be implemented without significant environmental impact. The NRC staff has concluded that the licensee's proposed disposal of the accident-generated water by evaporation will not significantly affect the quality of the human environment. Further, any impacts from the disposal program are outweighed by its benefits

  6. Development of calculation system for decontamination effect, CDE

    International Nuclear Information System (INIS)

    Satoh, Daiki; Kojima, Kensuke; Oizumi, Akito; Matsuda, Norihiro; Kugo, Teruhiko; Sakamoto, Yukio; Endo, Akira; Okajima, Shigeaki

    2012-08-01

    Large amount of radionuclides had been discharged to environment in the accident of the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant caused by the 2011 off the Pacific coast of Tohoku Earthquake. The radionuclides deposited on the ground elevate dose rates in large area around the Fukushima site. For the reduction of the dose rate and recovery of the environment, decontamination based on a rational plan is an important and urgent subject. A computer software, named CDE (Calculation system for Decontamination Effect), has been developed to support planning the decontamination. CDE calculates the dose rates before the decontamination by using a database of dose contributions by radioactive cesium. The decontamination factor is utilized in the prediction of the dose rates after the decontamination, and dose rate reduction factor is evaluated to express the decontamination effect. The results are visualized on the image of a target zone with color map. In this paper, the overview of the software and the dose calculation method are reported. The comparison with the calculation results by a three-dimensional radiation transport code PHITS is also presented. In addition, the source code of the dose calculation program and user's manual of CDE are attached as appendices. (author)

  7. Use of citric acid for large parts decontamination

    International Nuclear Information System (INIS)

    Holland, M.E.

    1979-01-01

    Laboratory and field studies have been performed to identify and evaluate chemical decontamination agents to replace ammonium carbonate, an environmentally unacceptable compound, in the decontamination facility for large process equipment at the Portsmouth Gaseous Diffusion Plant. Preliminary screening of over 40 possible decontamination agents on the basis of efficiency, availability, toxicity, cost, corrosiveness, and practicality indicated sodium carbonate and citric acid to be the most promising. Extensive laboratory studies were performed with these two reagents. Corrosion rates, decontamination factors, uranium recovery efficiencies, technetium ( 99 Tc)/ion exchange removal effects, and possible environmental impacts were determined or investigated. Favorable results were found in all areas. Detailed monitoring and analysis during two-week trial periods in which sodium carbonate and citric acid were used in the large parts decontamination facility resulted in similar evaluation and conclusions. Because it has cleaning properties not possessed by sodium carbonate, and because it eliminated several operational problems by incorporating two acidic decontamination reagents (citric and nitric acids) instead of one basic reagent (sodium or ammonium carbonate) and one acidic reagent (nitric acid), citric acid was selected for one-year field testing. On the basis of its excellent performance in the field tests, citric acid is recommended as a permanent replacement for ammonium carbonate in the decontamination facility for large process equipment

  8. Fuel decontamination at Ringhals 1 with the new decontamination process IcedecTM

    International Nuclear Information System (INIS)

    Fredriksson, E.; Ivars, R.; Rosengren, A.; Granath, G.

    2003-01-01

    The new fuel decontamination technique ICEDEC TM , which has been developed by Westinghouse, is based on abrasion of fuel crud with ice particles. A mixture of ice and water is led continuously through the fuel assembly, which is placed in a specially designed fuel decontamination container connected to a closed loop recirculation system. The ice particles scrape off the loose crud from the fuel surfaces and a mixture of crud and water from the melted ice is then led to a filter unit were the crud is separated from the water. In this paper results of fuel decontamination tests of two-year-old and spent fuel assemblies during spring 2001 at Ringhals 1 are presented. The fuel crud was only released when ice particles passed through the fuel assembly and stopped within ten seconds after the feeding of ice particles had ceased. The activity release from the fuel could thus be performed in a controlled way making the process easy to manage and survey. Activity measurements confirmed that about 50% of the loose crud was removed from the fuel surfaces of the two-year-old assembly. Fuel inspection after the decontamination process showed no influence on the fuel integrity. Furthermore, no enhanced personnel radiation dose was involved with the fuel decontamination compared to normal fuel services. (authors)

  9. Unit for air decontamination

    International Nuclear Information System (INIS)

    Mariano H, E.

    1991-02-01

    To fulfill the applicable requirements of safety to the ventilation systems in nuclear facilities, it is necessary to make a cleaning of the air that hurtles to the atmosphere. For that which was designed and it manufactured an unit for decontamination of the air for the Pilot plant of production of Nuclear Fuel that this built one with national parts, uses Hepa national filters and the design can adapt for different dimensions of filters, also can be added a lodging for a prefilter or to adopt two Hepa filters. (Author)

  10. Decontamination solution development studies

    International Nuclear Information System (INIS)

    Allen, R.P.; Fetrow, L.K.; Kjarmo, H.E.; Pool, K.H.

    1993-09-01

    This study was conducted for the Westinghouse Hanford Company (WHC) by Pacific Northwest Laboratory (PNL) as part of the Hanford Grout Technology Program (HGTP). The objective of this study was to identify decontamination solutions capable of removing radioactive contaminants and grout from the Grout Treatment Facility (GTF) process equipment and to determine the impact of these solutions on equipment components and disposal options. The reference grout used in this study was prepared with simulated double-shell slurry feed (DSSF) and a dry blend consisting of 40 wt % limestone flour, 28 wt % blast furnace slag, 28 wt % fly ash, and 4 wt % type I/II Portland cement

  11. Ultrasonic decontamination of nuclear fuel. Feasibility study

    International Nuclear Information System (INIS)

    Berg, A.; Libal, A.; Norbaeck, J.; Wegemar, B.

    1995-05-01

    Ultrasonic decontamination of nuclear fuel is an expeditious way to reduce radiation exposures resulting in a minimal volume of waste. The fuel assemblies are set up in the fuel preparation machine one at a time and treated without prior disassemblage. By decontaminating 20% of the BWR fuel assemblies annually, there is a potential to reduce the collective dose by approximately 40-50%. Including also improved reactivity of the fuel, this amounts to an economic benefit of about 4 MSEK per reactor and year. The costs for performing the decontamination can be economically justified if the plants do not plan for short outages each year. The decontamination method could also be used for the purpose of removing tramp Uranium following a fuel failure or minor core accident. An additional benefit is removal of loosely adherent crud. The waste produced will be handled in a closed filtering circuit. The method is suggested to be verified in a test on discharged burnt-up fuel at site. The next step will be to develop the method further in order to be able to remove also tenacious crud. 12 refs, 4 tabs

  12. MOBILE PHONES– DO WE NEED DECONTAMINATION?

    Directory of Open Access Journals (Sweden)

    Ketaki Prakash Ghatole

    2018-01-01

    Full Text Available BACKGROUND Mobile phones have become a necessity in the present scenario. They are extensively used for communication, internet, images, education, you tube, banking, for sharing reports, X-rays in healthcare settings. On the other hand they are reported to be contaminated by micro-organisms and may act as source of infection. In our study we analysed the mobile phones of healthcare workers (HCW and college students for microbial contamination and also efficacy of sanitizers, wet wipes for decontamination. MATERIALS AND METHODS A total of 220 swabs were collected from 110 mobile phones of HCWs and 110 students. Swabs were cultured on 5% sheep blood agar; MacConkey agar and isolates were identified by standard protocol. RESULTS 91.8% of students and 89.1% of HCWs mobiles were contaminated. Organisms like Staphylococcus aureus, CONS, E. coli, Klebsiella aerogenes were isolated. HCWs mobiles showed higher number of potential pathogens. Decontamination by absolute alcohol, alcohol-based hand sanitizers decontaminated 96% of the mobile phones. Nonalcohol-based hand sanitizers and wet wipes were able to decontaminate 88% and 96% of the mobiles respectively. CONCLUSION Mobile phones of healthcare workers and also students were contaminated. Absolute alcohol could clean 96% mobiles of HCWs and 92% of students. Alcohol based hand sanitizers eliminated the organisms (96% as against non-alcohol-based sanitizers. (88%. It was also observed that wet wipes were effective in students’ groups. (96%.

  13. Decontamination for radiators by friction effect

    International Nuclear Information System (INIS)

    Nojima, Takeshi; Yoshida, Yuji

    2016-01-01

    Radiators are equipped with cars, vending machines and outdoor units of air conditioners. Aluminum metal surfaces in their heat exchange part have been contaminated by radioactive material taking in dust after the nuclear accident. The dust adhering to the metal surface could be removed by flushing with water immediately after scattering radioactive material. But radioactive material such as cesium cannot be removed by water washing, because of growth of the oxide film and transfer of the nuclides in the metal surface due to aging. On the other hand, we have verified the effect of decontamination of radiators by friction cleaning using a cross flow shredder (CFS) and solvent washing of crushed metallic chips, as a different approach to high-pressure washing decontamination, and confirmed a certain decontamination effect. This paper describes the results of program, “Processing Technology of Radioactive Material Removal by Cross Flow Shredder,” in August to December 2015, on support of FY 2015 Demonstration Test Project for Decontamination and Volume Reduction of Ministry of the Environment. (author)

  14. Pipe Decontamination Involving String-Foam Circulation

    International Nuclear Information System (INIS)

    Turchet, J.P.; Estienne, G.; Fournel, B.

    2002-01-01

    Foam applications number for nuclear decontamination purposes has recently increased. The major advantage of foam decontamination is the reduction of secondary liquid wastes volumes. Among foam applications, we focus on foam circulation in contaminated equipment. Dynamic properties of the system ensures an homogeneous and rapid effect of the foam bed-drifted chemical reagents present in the liquid phase. This paper describes a new approach of foam decontamination for pipes. It is based on an alternated air and foam injections. We called it 'string-foam circulation'. A further reduction of liquid wastes is achieved compared to continuous foam. Secondly, total pressure loss along the pipe is controlled by the total foam length in the pipe. It is thus possible to clean longer pipes keeping the pressure under atmospheric pressure value. This ensures the non dispersion of contamination. This study describes experimental results obtained with a neutral foam as well with an acid foam on a 130 m long loop. Finally, the decontamination of a 44 meters pipe is presented. (authors)

  15. Decontamination of operational nuclear power plants

    International Nuclear Information System (INIS)

    1981-06-01

    In order to reduce the radiation fields around nuclear power plants, and, consequently, to limit the radiation exposure of and dose commitments to the operating and maintenance personnel, the contamination build-up should be kept to a minimum. The most fruitful approach, from the point of view of economics and efficiency, is to tackle the problems of contamination and decontamination in the design and construction phases of the reactor. To do this, knowledge gained from the operation of existing power reactors should be used to make improvements in new designs. New structural materials with low corrosion rates or whose constituents are not activated by neutrons should also be used. For older reactors, in most cases it is already too late to incorporate design changes without extensive and expensive modifications. For these plants, decontamination remains the most efficient way to reduce radiation fields. The aim of this report is to deal with the different decontamination methods that may be applied to nuclear power plant circuits and equipment during operation. The factors that have to be considered in determining the type and the extent of the methods used are the engineering and the planning of the decontamination operation and the treatment of the resulting waste generated during the process are also discussed

  16. Investigation on safety of gel decontamination technology

    International Nuclear Information System (INIS)

    Liu Zhihui; Song Fengli; Wang Yongxian; Zhang Taoge

    2014-01-01

    Gel decontamination technology is an advanced decontamination process of metal contaminated by radionuclide. It has the advantages such as simple operation process, high decontaminating factor, etc. But the disadvantages are that it has high spraying pressure and is strongly corrosive, which has safety risk to the operator and equipment. The effect of such factors as spraying pressure on operators was analyzed based on process feature, and it is proposed that it be worthwhile to make further study on the corrosion of gels to spraying equipment, taking into account corrosion feature of gels to stainless steel. Meanwhile, the safety issue was demonstrated on collecting and handling wastes from gel decontamination process. And then, protective measures, study methods, and solutions are put forward. The results show that protection should be strengthened during spraying to reduce the effect of splashing and fogging on workers; the equipment should be cleaned in time to reduce the effect of corrosion, and reducers should be added into waste liquid to eliminate the effect of residual detergent. (authors)

  17. Thermal decontamination of transformers: A new technology

    International Nuclear Information System (INIS)

    Colak, P.Z.

    1992-01-01

    After evaluating a number of methods for decontaminating or disposing of transformers that contained polychlorinated biphenyls (PCB), it was concluded that no entirely satisfactory procedure or technology was yet available which was permanent, effective, safe, relatively simple, and based on proven technology or conventional practice. The most desirable compromise appears to be thermal decontamination. It is proposed to decontaminate transformers by controlled incineration in a specially designed, indirect-fired furnace which resembles the conventional bell-type, vertical elevator, metal heat treating type of furnace. The design differs in the incorporation of those essential features required to achieve oxidation of the organic components, to provide internal air circulation needed to ensure efficient heat and mass transfer, and other factors. The most appropriate decontamination facility would provide for implementation of the following procedures: draining of PCB-containing liquids from the transformer; limited disassembly of the transformer, which in most instances would imply only removal of the top cover to expose the insides; and controlled incineration with any vapors generated being conducted to a secondary combustion chamber. Experiments were conducted in a kiln to simulate the proposed transformer incinerator. Results show that exposure of the transformer segments to a temperature in the 950-1,000 degree C range for over 90 min is generally sufficient to reduce the PCB content to under 1 ppM. Based on the work conducted, a suitable bell furnace was constructed and added to the Swan Hills (Alberta) waste treatment facility. 2 figs., 3 tabs

  18. Cleaning and decontamination: Experimental feedback from PHENIX

    International Nuclear Information System (INIS)

    Masse, F.; Rodriguez, G.

    1997-01-01

    After the first few years of operation of PHENIX, it proved necessary to clean, then decontaminate sodium-polluted components, particularly large components such as the intermediate heat exchangers (IHX) and the primary pumps (PP). Ibis document presents the evolution of the cleaning and decontamination processes used, and specifies the reasons for this evolution. As regards the cleaning, experimental feedback and a greater rigour with respect to the hydrogen hazard have resulted in a modification of the process. The new cleaning process used at present (since 1994) is described in greater detail in this document. The main steps are: cold CO 2 bubbling in water, followed by hot CO 2 bubbling, spraying phase, then drying for inspection before immersion. In order to optimize and validate the process, the cleaning and decontamination plant has been highly instrumented, which, in particular, has allowed confirmation of the contention that the major part of the sodium is eliminated during the bubbling phases. With respect to decontamination, the objective is to perfect an efficient process that allows both human intervention with no particular biological shield for repair or maintenance of the components, and requalification of the materials after the decontamination operation. Owing to the high operating temperature of Fast Breeder Reactor components (400 to 550 deg. C), the activated corrosion products deposited on the components melt into the metal. The decontamination process therefore consists in either dissolving the deposits on the surface, or dissolving a thickness of about less than ten micrometers of the base metal. The reference process for austenitic-type steels is the SPm process, which consists in immersing the component in a sulphuric-phosphoric bath (sulphuric acid and phosphoric acid) at a temperature of 60 deg. C for 6 hours. The problem linked to this process is the treatment of the effluents that are produced, particularly phosphate releases. A

  19. Decontamination of Rooibostea by radurization

    International Nuclear Information System (INIS)

    Holzapfel, W.H.

    1985-01-01

    The microbiological quality of a 'raw' agricultural commodity such as Rooibos tea is determined by a set of factors during harvesting and processing. Results suggest that a fermentation process takes place during processing, with members of the Enterobacteriaceae playing a dominant role. Against this background, as well as fluctuating hygienic conditions during processing, the high microbial population (10 7 to 5 x 10 8 /g) and even the possible presence of food-borne pathogens such as salmonellae, may be explaned. No real quarantee for the microbiological status of the product can be given, unless it is subjected to a terminal decontamination process (preferably after final packaging). Radurisation appears to be an ideal process for this purpose, and treatment at 8 kGy resulted in more than a 5000-fold (>99,9%) reduction of the microbial population. This was sufficient to eliminate all pathogens without harming the organoleptic quality of the product

  20. Dilute chemical decontamination program review

    International Nuclear Information System (INIS)

    Anstine, L.D.; Blomgren, J.C.; Pettit, P.J.

    1980-01-01

    The objective of the Dilute Chemical Decontamination Program is to develop and evaluate a process which utilizes reagents in dilute concentrations for the decontamination of BWR primary systems and for the maintenance of dose rates on the out-of-core surfaces at acceptable levels. A discussion is presented of the process concept, solvent development, advantages and disadvantages of reagent systems, and VNC loop tests. Based on the work completed to date it is concluded that (1) rapid decontamination of BWRs using dilute reagents is feasible; (2) reasonable reagent conditions for rapid chemical decontamination are: 0.01M oxalic acid + 0.005M citric acid, pH3.0, 90/degree/C, 0.5 to 1.0 ppm dissolved oxygen; (3) control of dissolved oxygen concentration is important, since high levels suppress the rate of decontamination and low levels allow precipitation of ferrous oxalate. 4 refs

  1. Soil removal as a decontamination practice and radiocesium accumulation in tadpoles in rice paddies at Fukushima

    International Nuclear Information System (INIS)

    Sakai, Masaru; Gomi, Takashi; Nunokawa, Masanori; Wakahara, Taeko; Onda, Yuichi

    2014-01-01

    We investigated the biological accumulation of radiocesium in tadpoles [Rana (Pelophylax) porosa porosa] in rice paddies with and without decontamination practice at Fukushima. Radiocesium was accumulated in surface part of soils both in the control and decontaminated paddies one year after decontamination. Mean 134 Cs and 137 Cs concentrations in tadpoles in the control and decontaminated paddies were 3000 and 4500, and 600 and 890 Bq/kg dry weight, respectively. Radiocesium concentrations in surface soil (0–5 cm depth) and tadpoles in the decontaminated paddy were five times smaller than in the control paddy. These results suggest that decontamination practice can reduce radiocesium concentrations in both soil and tadpoles. However, at the decontaminated paddy, radiocesium concentrations in surface soils became 3.8 times greater one year after decontamination, which indicates that monitoring the subsequent movement of radiocesium in rice paddies and surrounding areas is essential for examining contamination propagation. - Highlights: • Surface soil removal in a rice paddy reduced the radiocesium concentration in soil. • The radiocesium concentration in tadpoles decreased following decontamination. • Radiocesium levels in soil increased at 1 year following decontamination practice. • Reduction of radiocesium of soil can propagate to biota in rice paddies. - Decontamination practice reduced radiocesium concentrations in both soil and tadpoles that suggests reduction of radiocesium of soil can propagate to biota in rice paddies

  2. Statistical sampling method for releasing decontaminated vehicles

    International Nuclear Information System (INIS)

    Lively, J.W.; Ware, J.A.

    1996-01-01

    Earth moving vehicles (e.g., dump trucks, belly dumps) commonly haul radiologically contaminated materials from a site being remediated to a disposal site. Traditionally, each vehicle must be surveyed before being released. The logistical difficulties of implementing the traditional approach on a large scale demand that an alternative be devised. A statistical method (MIL-STD-105E, open-quotes Sampling Procedures and Tables for Inspection by Attributesclose quotes) for assessing product quality from a continuous process was adapted to the vehicle decontamination process. This method produced a sampling scheme that automatically compensates and accommodates fluctuating batch sizes and changing conditions without the need to modify or rectify the sampling scheme in the field. Vehicles are randomly selected (sampled) upon completion of the decontamination process to be surveyed for residual radioactive surface contamination. The frequency of sampling is based on the expected number of vehicles passing through the decontamination process in a given period and the confidence level desired. This process has been successfully used for 1 year at the former uranium mill site in Monticello, Utah (a CERCLA regulated clean-up site). The method forces improvement in the quality of the decontamination process and results in a lower likelihood that vehicles exceeding the surface contamination standards are offered for survey. Implementation of this statistical sampling method on Monticello Projects has resulted in more efficient processing of vehicles through decontamination and radiological release, saved hundreds of hours of processing time, provided a high level of confidence that release limits are met, and improved the radiological cleanliness of vehicles leaving the controlled site

  3. Surface activity and radiation field measurements of the TMI-2 reactor building gross decontamination experiment

    International Nuclear Information System (INIS)

    McIsaac, C.V.

    1983-10-01

    Surface samples were collected from concrete and metal surfaces within the Three Mile Island Unit 2 Reactor Building on December 15 and 17, 1981 and again on March 25 and 26, 1982. The Reactor Building was decontaminated by hydrolasing during the period between these dates. The collected samples were analyzed for radionuclide concentration at the Idaho National Engineering Laboratory. The sampling equipment and procedures, and the analysis methods and results are discussed. The measured mean surface concentrations of 137 Cs and 90 Sr on the 305-ft elevation floor before decontamination were, respectively, 3.6 +- 0.9 and 0.17 +- 0.04 μCi/cm 2 . Their mean concentrations on the 347-ft elevation floor were about the same. On both elevations, walls were found to be considerably less contaminated than floors. The fractions of the core inventories of 137 Cs, 90 Sr, and 129 I deposited on Reactor Building surfaces prior to decontamination were calculated using their mean concentrations on various types of surfaces. The calculated values for these three nuclides are 3.5 +- 0.4 E-4, 2.4 +- 0.8 E-5, and 5.7 +- 0.5 E-4, respectively. The decontamination operations reduced the 137 Cs surface activity on the 305- and 347-ft elevations by factors of 20 and 13, respectively. The 90 Sr surface activity reduction was the same for both floors, that being a factor of 30. On the whole, decontamination of vertical surfaces was not achieved. Beta and gamma exposure rates that were measured during surface sampling were examined to determine the degree to which they correlated with measured surface activities. The data were fit with power functions of the form y = ax/sup b/. As might be expected, the beta exposure rates showed the best correlation. Of the data sets fit with the power function, the set of December 1981 beta exposure exhibited the least scatter. The coefficient of determination for this set was calculated to be 0.915

  4. Experimental studies on decontamination in first aid for contaminated wounds

    International Nuclear Information System (INIS)

    Kusama, Tomoko; Ogaki, Kazushi; Yoshizawa, Yasuo

    1982-01-01

    The present study was designed to investigate the decontamination procedures in first aid for wounds contaminated with radionuclides. Abrasion of mouse skin was contaminated with 58 CoCl 2 . Irrigation by decontamination fluids began at 2 min after administration of the radionuclide and continued for 14 min. Tap water, 0.5% Hyamine solution or 10% Ca-DTPA solution were used as the decontamination fluids. Radioactivities of whole body, wounded skin surface and washed solution were measured with an animal counter with 5 cm NaI(Tl) and a well-type auto-gamma-counter. Decontamination effectiveness were expressed as follows: (1) absorption rate of radionuclide through the wound and (2) residual rate of radionuclide on the wound. More than 20% of the radionuclide applied on the wounded skin was absorbed in 15 min after contamination. The absorption rate decreased to 2% by the decontamination procedures. The Ca-DTPA solution reduced the residual rate of radionuclide on the wounds. The results suggested that the decontamination for the contaminated wounds should begin as soon as possible. Irrigation with 0.5% Hyamine solution has been advocated for the decontamination in the first aid. (author)

  5. Methods and techniques for decontamination design and construction of facilities

    International Nuclear Information System (INIS)

    Augustin, X.; Cohen, S.

    1986-01-01

    TECHNICATOME and STMI have jointly solved a wide range of problems specific to decontamination from the very design studies up to operation. TECHNICATOME has brought its expertise in the design and construction of nuclear facilities concerned in particular with decontamination and radwaste management. STMI is an experienced operator with expertise in designing tools and developing advanced techniques in the same fields. The expertise of both companies in this field cumulated for many years has resulted in developing techniques and tools adapted to most of the decontamination problems including specific cases [fr

  6. ASTM STANDARD GUIDE FOR EVALUATING DISPOSAL OPTIONS FOR REUSE OF CONCRETE FROM NUCLEAR FACILITY DECOMMISSIONING

    International Nuclear Information System (INIS)

    Phillips, Ann Marie; Meservey, Richard H.

    2003-01-01

    Within the nuclear industry, many contaminated facilities that require decommissioning contain huge volumes of concrete. This concrete is generally disposed of as low-level waste at a high cost. Much of the concrete is lightly contaminated and could be reused as roadbed, fill material, or aggregate for new concrete, thus saving millions of dollars. However, because of the possibility of volumetric contamination and the lack of a method to evaluate the risks and costs of reusing concrete, reuse is rarely considered. To address this problem, Argonne National Laboratory-East (ANL-E) and the Idaho National Engineering and Environmental Laboratory teamed to write a ''concrete protocol'' to help evaluate the ramifications of reusing concrete within the U.S. Department of Energy (DOE). This document, titled the Protocol for Development of Authorized Release Limits for Concrete at U.S. Department of Energy Site (1) is based on ANL-E's previously developed scrap metal recycle protocols; on the 10-step method outlined in DOE's draft handbook, Controlling Release for Reuse or Recycle of Property Containing Residual Radioactive Material (2); and on DOE Order 4500.5, Radiation Protection of the Public and the Environment (3). The DOE concrete protocol was the basis for the ASTM Standard Guide for Evaluating Disposal Options for Concrete from Nuclear Facility Decommissioning, which was written to make the information available to a wider audience outside DOE. The resulting ASTM Standard Guide is a more concise version that can be used by the nuclear industry worldwide to evaluate the risks and costs of reusing concrete from nuclear facility decommissioning. The bulk of the ASTM Standard Guide focuses on evaluating the dose and cost for each disposal option. The user calculates these from the detailed formulas and tabulated data provided, then compares the dose and cost for each disposal option to select the best option that meets regulatory requirements. With this information

  7. Concrete Fibrations

    OpenAIRE

    Pagnan, Ruggero

    2017-01-01

    As far as we know, no notion of concrete fibration is available. We provide one such notion in adherence to the foundational attitude that characterizes the adoption of the fibrational perspective in approaching fundamental subjects in category theory and discuss it in connection with the notion of concrete category and the notions of locally small and small fibrations. We also discuss the appropriateness of our notion of concrete fibration for fibrations of small maps, which is relevant to a...

  8. Recycling of concrete waste generated from nuclear power plant dismantling

    International Nuclear Information System (INIS)

    Ogawa, Hideo; Nagase, Takahiro; Tanaka, Hiroaki; Nawa, Toyoharu

    2012-01-01

    Non-radioactive concrete waste generated from dismantling of a standard large nuclear power plant is estimated to be about 500,000 tons in weight. Using such waste as recycled aggregate within the enclosure of the plant requires a new manufacturing technology that generates a minimal amount of by-product powder. Recycled aggregate has brittle parts with defects such as cracks, pores, and voids in residual paste from original concrete. This study presents a method of selectively removing the defective parts during manufacture to improve the quality of the recycled fine aggregate. With this selective removal method used, the amount of by-product powder can be reduced by half as compared to that by a conventional method. The influences of the characteristics of the recycled fine aggregate on the flowability and strength of the mortar using recycled fine aggregate were evaluated by multiple linear regression analysis. The results clearly showed that the flowability was primarily affected by the filling fraction of recycled fine aggregate, while the compressive strength of mortar was primarily affected by the fraction of defects in the aggregate. It was also found that grains produced by a granulator have more irregularities in the surfaces than those produced by a ball mill, providing an increased mortar strength. Using these findings from this study, efforts are also being made to develop a mechanical technology that enables simultaneous processing of decontamination and recycling. The granulator under consideration is capable of grinding the surfaces of irregularly shaped particles and may be used successfully, under optimal conditions, for the surface decontamination of concrete waste contaminated with radioactive materials. (author)

  9. Chemical decontamination of metals

    International Nuclear Information System (INIS)

    Partridge, J.A.; Lerch, R.E.

    1979-10-01

    A metal decontamination process based upon removal of contamination by treatment with a cerium (IV)-nitric acid solution (or other redox agent in nitric acid) is feasible and highly promising. The technique is effective in dissolving the surface layer of stainless steel. Dissolution rates of approximately 1.5 mils/h were demonstrated with cerium (IV)-nitric acid solutions. Removal of plutonium contamination from stainless steel was demonstrated in laboratory tests, in which activity levels were reduced from greater than 5 x 10 5 counts per minute to nondetectable levels in approximately one hour at 90 0 C. Removal of paint from stainless steel surfaces was also demonstrated. Advantages of this process over other chemical solutions include: (1) The solutions are not high salt systems; therefore, there is potentially less waste generated. (2) Cerium(IV) in nitric acid is a good dissolution agent for plutonium oxide. (3) Regeneration of Ce(IV) during the decontamination is accomplished by electrolysis. (4) The process should be effective for irregularly shaped equipment. (5) It could be effective as a spray or a flow-through system. 13 figures

  10. Concrete produced with recycled aggregates

    Directory of Open Access Journals (Sweden)

    J. J. L. Tenório

    Full Text Available This paper presents the analysis of the mechanical and durable properties of recycled aggregate concrete (RAC for using in concrete. The porosity of recycled coarse aggregates is known to influence the fresh and hardened concrete properties and these properties are related to the specific mass of the recycled coarse aggregates, which directly influences the mechanical properties of the concrete. The recycled aggregates were obtained from construction and demolition wastes (CDW, which were divided into recycled sand (fine and coarse aggregates. Besides this, a recycled coarse aggregate of a specific mass with a greater density was obtained by mixing the recycled aggregates of the CDW with the recycled aggregates of concrete wastes (CW. The concrete was produced in laboratory by combining three water-cement ratios, the ratios were used in agreement with NBR 6118 for structural concretes, with each recycled coarse aggregates and recycled sand or river sand, and the reference concrete was produced with natural aggregates. It was observed that recycled aggregates can be used in concrete with properties for structural concrete. In general, the use of recycled coarse aggregate in combination with recycled sand did not provide good results; but when the less porous was used, or the recycled coarse aggregate of a specific mass with a greater density, the properties of the concrete showed better results. Some RAC reached bigger strengths than the reference concrete.

  11. Radioactive contamination of some rubber or plastic surfaces by fission products. Decontamination tests; Contamination radioactive de quelques surfaces en caoutchouc ou en matiere plastique par des produits de fission. Essais de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Mestre, E.; Sautiez, N.

    1957-10-15

    With the objective of notably addressing the contamination and decontamination of gloves and floor covering, this report first presents some characteristics of contaminating radioactive materials (nature, physical and chemical condition), of contaminated surfaces (surface condition, surface nature), and of decontamination processes (physical, chemical or mechanical action). It describes the operational modality implemented to test decontamination processes on various glove or flooring materials: sample preparation, counting, decontamination, reproducibility of decontamination tests, results in terms of activity reduction. It more precisely describes the tested samples: short gloves, gloves from glove boxes, floor and wall coverings. Results are presented and discussed in terms of sample susceptibility to contamination, and of decontamination, but also for re-contamination tests after a Nab-based decontamination (susceptibility to contamination, decontamination gain)

  12. Determination of in-depth contamination in concrete using a non-destructive technique

    International Nuclear Information System (INIS)

    Boden, S.; Cantrel, E.

    2007-01-01

    The decommissioning of the BR3 (Belgian Reactor 3) approaches its final phase, in which the building structures are being decontaminated and either denuclearized for possible reuse or demolished. Apart from the presence of naturally occurring radionuclides in building materials, other radionuclides might be present due to activation or contamination. The BR3 bioshield has been exposed to rather high neutron leakage fluxes during the reactor operation and is therefore activated. Building structure contamination usually results from leakages during reactor operation, releases due to maintenance works or even dismantling operations. In case of in-depth contamination in concrete it is important to know the exact in-depth profile before decontamination, in order to minimize the amount of radioactive waste that will be produced during the decontamination process and to optimize both the decontamination process and the final control measurements. Common non-destructive analyses used in decommissioning are usually based on the measurement of beta radiation, using e.g. hand-held plastic scintillators. This kind of measurement technique can not be used to determine in-depth contamination. Therefore, most of the decontamination specialists currently base themselves on the results of the radiological analysis of samples taken by core drilling. The use of such a destructive method implies a number of disadvantages: it is time consuming and therefore costly and the different sample preparation steps can conceivably lead to cross-contamination. Moreover, one only receives results of a limited number of points, while the in-depth contamination is usually very inhomogeneously distributed and the relationship between in-depth contamination and surface contamination and/or dose rate (hotspot detection) is generally rather poor.The objective therefore is to test the use of the ISOCS (In Situ Object Counting System) for the determination of contamination depth

  13. Chemical Decontamination of Metallic Waste from Uranium Conversion Plant Dismantling

    International Nuclear Information System (INIS)

    Hwang, D. S.; Choi, Y. D.; Hwang, S. T.; Park, J. H.; Byun, J. I.; Jang, N. S.

    2005-01-01

    Korea Atomic Energy Research Institute (KAERI) started a decommissioning program of the uranium conversion plant. Pre-work was carried as follows; installation of the access control facility, installation of a changing room and shower room, designation of an emergency exit way and indicating signs, installation of a radiation management facility, preparation of a storage area for tools and equipments, inspection and load test of crane, distribution and packaging of existing waste, and pre-decontamination of the equipment surface and the interior. First, decommissioning work was performed in kiln room, which will be used for temporary radioactive waste storage room. Kiln room housed hydro fluorination rotary kiln for production of uranium tetra-fluoride. The kiln is about 0.8 m in diameter and 5.5 m long. The total dismantled waste was 6,690 kg, 73 % of which was metallic waste and 27 % the others such as cable, asbestos, concrete, secondary waste, etc. And effluent treatment room and filtration room were dismantled for installation of decontamination equipment and lagoon sludge treatment equipment. There were tanks and square mixer in these rooms. The total dismantled waste was 17,250 kg, 67% of which was metallic waste and 33% the others. These dismantled metallic wastes consist of stainless and carbon steel. In this paper, the stainless steel plate and pipe were decontaminated by the chemical decontamination with ultrasonic

  14. An overview of experimental results obtained under the prestressed concrete nuclear pressure vessel development program at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Naus, D.J.

    1979-01-01

    Under the Prestressed Concrete Nuclear Pressure Development Program at the Oak Ridge National Laboratory, various aspects of Prestressed Concrete Pressure Vessels (PCPVs) are investigated with respect to reliability, structural performance, constructability, and economy. These investigations are conducted under the High-Temperature Gas-Cooled Reactor (HTGR) Program and the Gas-Cooled Fast Reactor (GCFR) Program. The objectives are to: (1) provide technical support to ongoing PCPV design activities, (2) contribute to the overall technological data base, and (3) provide independent review and evaluations. Specific areas of interest at present include finite-element analysis development, materials and structural behaviour tests, instrumentation evaluations and development, and structural model tests. The following provides an overview of both the HTGR and GCFR PCPV activities and a summary of recent experimental results

  15. A study on implementation plan of decontamination and decommissioning R and D and evaluation of KAERI soil decontamination process

    International Nuclear Information System (INIS)

    Oh, Won Zin; Lee, K. W.; Won, H. J.; Jung, C. H.; Choi, W. K.; Kim, G. N.

    2001-08-01

    A. Decontamination Technology Development of Uranium Conversion Facility. Understanding of uranium conversion facility and related decontamination technologies, and analysis of current status of decontamination technologies. Establishment of the objective and research items of the middle and long term R and D project. Discussion of the erformance plan and about the methodology for connection with the project of environmental restoration of uranium conversion facility B. Treatment Technology Development of Uranium Sludge Analysis of the domestic and overseas research development status. Suggestion of treatment methodology of uranium slurry and cooperative R and D among industries, universities and research institute. Establishment of the objective and research items of the middle and long term R and D project. Discussion about the performance plan and about the methodology for connection with the project of environmental restoration of uranium conversion facility C. Decommissioning Technology Development Analysis of the domestic and overseas research development status and the overview of decommissioning technologies. Establishment of the objective and research items of the middle and long term R and D project. Discussion about the performance plan and about the methodology for connection with the project of TRIGA decommissioning D. Evaluation of KAERI Soil Decontamination Technology. Evaluation of soil decontamination process and the liquid decontamination waste treatment technology. Performance of soil decontamination test using solvent flushing test equipment for evaluation of residual radioactivity after decontami- nation and modeling of the results

  16. A study on implementation plan of decontamination and decommissioning R and D and evaluation of KAERI soil decontamination process

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Won Zin; Lee, K. W.; Won, H. J.; Jung, C. H.; Choi, W. K.; Kim, G. N

    2001-08-01

    A. Decontamination Technology Development of Uranium Conversion Facility. Understanding of uranium conversion facility and related decontamination technologies, and analysis of current status of decontamination technologies. Establishment of the objective and research items of the middle and long term R and D project. Discussion of the erformance plan and about the methodology for connection with the project of environmental restoration of uranium conversion facility B. Treatment Technology Development of Uranium Sludge Analysis of the domestic and overseas research development status. Suggestion of treatment methodology of uranium slurry and cooperative R and D among industries, universities and research institute. Establishment of the objective and research items of the middle and long term R and D project. Discussion about the performance plan and about the methodology for connection with the project of environmental restoration of uranium conversion facility C. Decommissioning Technology Development Analysis of the domestic and overseas research development status and the overview of decommissioning technologies. Establishment of the objective and research items of the middle and long term R and D project. Discussion about the performance plan and about the methodology for connection with the project of TRIGA decommissioning D. Evaluation of KAERI Soil Decontamination Technology. Evaluation of soil decontamination process and the liquid decontamination waste treatment technology. Performance of soil decontamination test using solvent flushing test equipment for evaluation of residual radioactivity after decontami- nation and modeling of the results.

  17. Cost and effectiveness of decontamination strategies in radiation contaminated areas in Fukushima in regard to external radiation dose.

    Science.gov (United States)

    Yasutaka, Tetsuo; Naito, Wataru; Nakanishi, Junko

    2013-01-01

    The objective of the present study is to evaluate the cost and effectiveness of decontamination strategies in the special decontamination areas in Fukushima in regard to external radiation dose. A geographical information system (GIS) was used to relate the predicted external dose in the affected areas to the number of potential inhabitants and the land use in the areas. A comprehensive review of the costs of various decontamination methods was conducted as part of the analysis. The results indicate that aerial decontamination in the special decontamination areas in Fukushima would be effective for reducing the air dose rate to the target level in a short period of time in some but not all of the areas. In a standard scenario, analysis of cost and effectiveness suggests that decontamination costs for agricultural areas account for approximately 80% of the total decontamination cost, of which approximately 60% is associated with storage. In addition, the costs of decontamination per person per unit area are estimated to vary greatly. Appropriate selection of decontamination methods may significantly decrease decontamination costs, allowing more meaningful decontamination in terms of the limited budget. Our analysis can help in examining the prioritization of decontamination areas from the viewpoints of cost and effectiveness in reducing the external dose. Decontamination strategies should be determined according to air dose rates and future land-use plans.

  18. Considerations about house decontamination in Goiania: limits and consequences

    International Nuclear Information System (INIS)

    Silva, C.J. da; Delgado, J.U.; Luiz, M.T.B.; Cunha, P.G.; Barros, P.D. de

    1988-01-01

    We are considering some aspects related to the decontamination activities about 50 houses affected by Cs-137 in Goiania city. We described the way these contaminations occurred, the instruments used and the procedures. We also discuss the dose limits establised in the decontamination and the consequences resulting from this action. We call attention to the fact that not only the technical aspects in such activities bu also the psycho-social implications resulting from them are specially important. (author) [pt

  19. NANOMODIFIED CONCRETE

    Directory of Open Access Journals (Sweden)

    B. M. Khroustalev

    2015-01-01

    Full Text Available One of the main directions in construction material science is the development of  next generation concrete that is ultra-dense, high-strength, ultra-porous, high heat efficient, extra corrosion-resistant. Selection of such direction is caused by extreme operational impacts on the concrete, namely: continuously increasing load on the concrete and various dynamics of such loads; the necessity in operation of concrete products in a wide temperature range and their exposure to various chemical and physical effects.The next generation concrete represents high-tech concrete mixtures with additives that takes on and retain the required properties when hardening and being used under any operational conditions. A differential characteristic of the next generation concrete is its complexity that presumes usage of various mineral dispersed components, two- and three fractional fine and coarse aggregates, complex chemical additives, combinations of polymer and iron reinforcement.Design strength and performance properties level of the next generation concrete is achieved by high-quality selection of the composition, proper selection of manufacturing techniques, concrete curing, bringing the quality of concrete items to the required level of technical condition during the operational phase. However, directed formation of its structure is necessary in order to obtain high-tech concrete.Along with the traditional methods for regulation of the next generation concrete structure, modification of concrete while using silica nanoparticles is also considered as a perspective one because the concrete patterning occurs due to introduction of a binder in a mineral matrix. Due to this it is possible to obtain nano-modified materials with completely new properties.The main problem with the creation of nano-modified concrete is a uniform distribution of nano-materials in the volume of the cement matrix which is particularly important in the cases of adding a modifier in

  20. Development of contaminated concrete removing system 'Clean cut method'

    International Nuclear Information System (INIS)

    Kinoshita, Takehiko; Tanaka, Tsutomu; Funakawa, Naoyoshi; Idemura, Hajime; Sakashita, Fumio; Tajitsu, Yoshiteru

    1989-01-01

    In the case of decommissioning nuclear facilities such as nuclear power stations, nuclear fuel facilities and RI handling facilities and carrying out reconstruction works, if there is radioactive contamination on the surfaces of concrete structures such as the floors and walls of the buildings for nuclear facilities, it must be removed. Since concrete is porous, contamination infiltrates into the inside of concrete, and the wiping of surfaces only or chemical decontamination cannot remove it, therefore in most cases, contaminated concrete must be removed. The removal of concrete surfaces has been carried out with chipping hammers, grinders and so on, but many problems arise due to it. In order to solve these problems, the mechanical cutting method was newly devised, and clean cut method (CCRS) was completed. The depth of cutting from concrete surface is set beforehand, and the part to be removed is accurately cut, at the same time, the concrete powder generated is collected nearly perfectly, and recovered into a drum. The outline of the method and the constitution of the system, the features of the clean cut method, the development of the technology for cutting concrete and the technology for recovering concrete powder, and the test of verifying decontamination are reported. (K.I.)

  1. Chemical decontamination method in nuclear facility system

    International Nuclear Information System (INIS)

    Takahashi, Ryota; Sakai, Hitoshi; Oka, Shigehiro.

    1996-01-01

    Pumps and valves in a closed recycling loop system incorporating materials to be chemically decontaminated are decomposed, a guide plate having the decomposed parts as an exit/inlet of a decontaminating liquid is formed, and a decontaminating liquid recycling loop comprising a recycling pump and a heater is connected to the guide plate. Decontaminating liquid from a decontaminating liquid storage tank is supplied to the decontaminating liquid recycling loop. With such constitutions, the decontaminating liquid is filled in the recycling closed loop system incorporating materials to be decontaminated, and the materials to be decontaminated are chemically decontaminated. The decontaminating liquid after the decontamination is discharged and flows, if necessary, in a recycling system channel for repeating supply and discharge. After the decontamination, the guide plate is removed and returned to the original recycling loop. When pipelines of a reactor recycling system are decontaminated, the amount of decontaminations can be decreased, and reforming construction for assembling the recycling loop again, which requires cutting for pipelines in the system is no more necessary. Accordingly, the amount of wastes can be decreased, and therefore, the decontamination operation is facilitated and radiation dose can be reduced. (T.M.)

  2. Concrete = aggregate, cement, water?

    International Nuclear Information System (INIS)

    Jelinek, J.

    1990-01-01

    Concrete for the Temelin nuclear power plant is produced to about 70 different formulae. For quality production, homogeneous properties of aggregates, accurate proportioning devices, technological discipline and systematic inspections and tests should be assured. The results are reported of measuring compression strength after 28 days for different concrete samples. The results of such tests allow reducing the proportion of cement, which brings about considerable savings. Reduction in cement quantities can also be achieved by adding ash to the concrete mixes. Ligoplast, a plasticizer addition is used for improving workability. (M.D). 8 figs

  3. Decontamination Technologies, Task 3, Urban Remediation and Response Project

    International Nuclear Information System (INIS)

    Heiser, J.; Sullivan, T.

    2009-01-01

    In the aftermath of a Radiological Dispersal Device (RDD, also known as a dirty bomb) it will be necessary to remediate the site including building exteriors and interiors, equipment, pavement, vehicles, personal items etc. Remediation will remove or reduce radioactive contamination from the area using a combination of removing and disposing of many assets (including possible demolition of buildings), decontaminating and returning to service other assets, and fixing in place or leaving in place contamination that is deemed 'acceptable'. The later will require setting acceptable dose standards, which will require negotiation with all involved parties and a balance of risk and cost to benefit. To accomplish the first two, disposal or decontamination, a combination of technologies will be deployed that can be loosely classified as: Decontamination; Equipment removal and size reduction; and Demolition. This report will deal only with the decontamination technologies that will be used to return assets to service or to reduce waste disposal. It will not discuss demolition, size reduction or removal technologies or equipment (e.g., backhoe mounted rams, rock splitter, paving breakers and chipping hammers, etc.). As defined by the DOE (1994), decontamination is removal of radiological contamination from the surfaces of facilities and equipment. Expertise in this field comes primarily from the operation and decommissioning of DOE and commercial nuclear facilities as well as a small amount of ongoing research and development closely related to RDD decontamination. Information related to decontamination of fields, buildings, and public spaces resulting from the Goiania and Chernobyl incidents were also reviewed and provide some meaningful insight into decontamination at major urban areas. In order to proceed with decontamination, the item being processed needs to have an intrinsic value that exceeds the cost of the cleaning and justifies the exposure of any workers during the

  4. Decontamination Technologies, Task 3, Urban Remediation and Response Project

    Energy Technology Data Exchange (ETDEWEB)

    Heiser,J.; Sullivan, T.

    2009-06-30

    In the aftermath of a Radiological Dispersal Device (RDD, also known as a dirty bomb) it will be necessary to remediate the site including building exteriors and interiors, equipment, pavement, vehicles, personal items etc. Remediation will remove or reduce radioactive contamination from the area using a combination of removing and disposing of many assets (including possible demolition of buildings), decontaminating and returning to service other assets, and fixing in place or leaving in place contamination that is deemed 'acceptable'. The later will require setting acceptable dose standards, which will require negotiation with all involved parties and a balance of risk and cost to benefit. To accomplish the first two, disposal or decontamination, a combination of technologies will be deployed that can be loosely classified as: Decontamination; Equipment removal and size reduction; and Demolition. This report will deal only with the decontamination technologies that will be used to return assets to service or to reduce waste disposal. It will not discuss demolition, size reduction or removal technologies or equipment (e.g., backhoe mounted rams, rock splitter, paving breakers and chipping hammers, etc.). As defined by the DOE (1994), decontamination is removal of radiological contamination from the surfaces of facilities and equipment. Expertise in this field comes primarily from the operation and decommissioning of DOE and commercial nuclear facilities as well as a small amount of ongoing research and development closely related to RDD decontamination. Information related to decontamination of fields, buildings, and public spaces resulting from the Goiania and Chernobyl incidents were also reviewed and provide some meaningful insight into decontamination at major urban areas. In order to proceed with decontamination, the item being processed needs to have an intrinsic value that exceeds the cost of the cleaning and justifies the exposure of any workers

  5. Examples of processing problematic waste and material. A-3. Processing of lead by mechanical decontamination at UKAEA Harwell

    International Nuclear Information System (INIS)

    2006-01-01

    The UKAEA and its contractor (NNC) have decontaminated lead blocks arising from the decommissioning of a metallurgical site that comprised three concrete shielded remote handling cells and 36 lead shielded enclosures. The primary decommissioning and dismantling work entailed the dismantling of the 36 lead enclosures, which were expected to yield over 1000 t of lead shielding bricks as waste. During the initial dismantling of the lead shielded enclosures, all the lead bricks were monitored for radioactive contamination; clean items were segregated and set aside for detailed clearance and assurance checks. The contaminated blocks were sent for assessment and decontamination treatment, as necessary. The decontamination process utilized a purpose built partitioned containment tent, ventilated with a HEPA filtration system, so that the receipt, decontamination and radiological monitoring of individual items could be segregated in order to minimize any cross-contamination. The dismantled lead blocks comprised a range of standard thicknesses (2, 4, 9 and 10 in, or 3, 8, 13 and 15 cm) and incorporated a variety of chevron, concave and convex shapes, which are utilized to avoid weaknesses within the assembled shielding. The primary technical issues for the mechanical processing of the contaminated lead blocks were consideration of the individual lead brick shapes (i.e. the bricks were contoured) and the individual weight of the bricks, which had a range of 10-75 kg. The preferred option was a manual dry cutting technique using a handheld rotary industrial planer (the selected planer is normally associated with the joinery trade). The dry cutting option considered the malleability of the lead, which under certain circumstances during dry cutting could give rise to localized heating effects, leading to melted lead over the cutting surface, resulting in limited effectiveness in the removal of the contaminated layer. To mitigate this effect the planer was set to take cuts

  6. RILEM technical committee 195-DTD recommendation for test methods for AD and TD of early age concrete Round Robin documentation report : program, test results and statistical evaluation

    CERN Document Server

    Bjøntegaard, Øyvind; Krauss, Matias; Budelmann, Harald

    2015-01-01

    This report presents the Round-Robin (RR) program and test results including a statistical evaluation of the RILEM TC195-DTD committee named “Recommendation for test methods for autogenous deformation (AD) and thermal dilation (TD) of early age concrete”. The task of the committee was to investigate the linear test set-up for AD and TD measurements (Dilation Rigs) in the period from setting to the end of the hardening phase some weeks after. These are the stress-inducing deformations in a hardening concrete structure subjected to restraint conditions. The main task was to carry out an RR program on testing of AD of one concrete at 20 °C isothermal conditions in Dilation Rigs. The concrete part materials were distributed to 10 laboratories (Canada, Denmark, France, Germany, Japan, The Netherlands, Norway, Sweden and USA), and in total 30 tests on AD were carried out. Some supporting tests were also performed, as well as a smaller RR on cement paste. The committee has worked out a test procedure recommenda...

  7. Radioactive decontamination apparatus and process

    International Nuclear Information System (INIS)

    Jackson, O.L.

    1983-01-01

    Apparatus for removing radioactive contamination from metal objects is disclosed, consisting of three of three separate pieces. The first is an electro- polishing tank, pump and filter assembly, ventilation duct and filter assembly, and DC power supply. The second is a rinse tank and a pump and filter assembly therefor. The third is a divot crane. The electro-polishing tank assembly and the rinse tank assembly are each separately mounted on pallets to facilitate moving. The filter systems of the electro-polishing tank and the rinse tank are designed to remove the radioactive contamination from the fluids in those tanks. Heavy items or highly contaminated items are handled with the divot crane constructed of stainless steel. The electro- polishing tank and the rinse tank are also made of stainless steel. The ventilation system on the electro- polishing tank exhausts acid fumes resulting from the tank heaters and the electro-polishing process. Inside the electro-polishing tank are two swinging arms that carry two stainless steel probes that hang down in the electrolyte fluid. These negative DC probes and are electrically isolated from the tank and the rest of the system. Across the top center of the tank is a copper pipe, which is also electrically isolated from the tank. This is the positive side of the DC system. To decontaminate a metal object, it is suspended from the positive copper pipe, with good electrical contact, into the electrolyte fluid. The negative probes are then moved on their swinging arms to a close proximity to the object being decontaminated, without making contact

  8. The International Atomic Energy Agency's program on decontamination and decommissioning

    International Nuclear Information System (INIS)

    Feraday, M.A.

    1989-01-01

    The International Atomic energy Agency (IAEA) is developing an integrated information base that will systematically cover the technical, regulatory, radiation protection, planning, and economic aspects related to the decontamination and decommissioning (D/D) of nuclear facilities. The object of this program is to assist member states in developing the required expertise, equipment, and programs so that they can decommission their nuclear facilities in a safe, timely, and cost-effective manner. In addition to providing information, the IAEA encourages research and provides technical assistance in the form of expert missions, equipment design and procurement, etc., to assist member states in implementing their D/D programs. The technology contained in some recent IAEA reports is reviewed, including the decontamination, segmentation, and demolition of concrete and steel; the recycle/reuse of components from decommissioning; and the reduction of occupational exposures in D/D and the regulatory process in decommissioning. The IAEA's future program is briefly reviewed

  9. Recycling of concrete generated from Nuclear Power Plant dismantling

    International Nuclear Information System (INIS)

    Ogawa, Hideo; Nawa, Toyoharu; Ishikura, Takeshi; Tanaka, Hiroaki

    2013-01-01

    Reactor decommissioning required various technologies such as dismantling of facilities, decontamination, radioactivity measurement and recycling of dismantling wastes. This article discussed recycling of demolished concrete wastes. Dismantling of reactor building of large one unit of nuclear power plants would generate about 500 K tons of concrete wastes, about 98% of which was non-radioactive and could be used as base course material or backfill material after crushed to specified particle size. Since later part of 1990s, high quality recycled aggregate with specified limit of bone-dry density, water absorptivity and amount of fine aggregate had been developed from demolished concrete with 'Heat and rubbing method', 'Eccentric rotor method' and 'Screw grinding method' so as to separate cements attached to aggregate. Recycled aggregates were made from concrete debris with 'Jaw crusher' to particle size less than 40 mm and then particle size control or grinded by various grinding machines. Recycled fine aggregates made from crushing would have fragile site with cracks, air voids and bubbles. The author proposed quality improvement method to selectively separate fragile defects from recycled aggregates using weak grinding force, leaving attached pastes much and preventing fine particle generation as byproducts. This article outlined experiments to improve quality of recycled fine aggregates and their experimental results confirmed improvement of flow ability and compressive strength of mortal using recycled fine aggregates using 'Particle size selector' and 'Ball mill' so as to remove their fragile parts less than 2%. Mortal made from recycled fine aggregate could also prevent permeation of chloride ion. Recycled aggregate could be used for concrete instead of natural aggregate. (T. Tanaka)

  10. Estimating Durability of Reinforced Concrete

    Science.gov (United States)

    Varlamov, A. A.; Shapovalov, E. L.; Gavrilov, V. B.

    2017-11-01

    In this article we propose to use the methods of fracture mechanics to evaluate concrete durability. To evaluate concrete crack resistance characteristics of concrete directly in the structure in order to implement the methods of fracture mechanics, we have developed special methods. Various experimental studies have been carried out to determine the crack resistance characteristics and the concrete modulus of elasticity during its operating. A comparison was carried out for the results obtained with the use of the proposed methods and those obtained with the standard methods for determining the concrete crack resistance characteristics.

  11. Nova target chamber decontamination study

    International Nuclear Information System (INIS)

    1979-05-01

    An engineering study was performed to determine the most effective method for decontamination of the Nova target chamber. Manual and remote decontamination methods currently being used were surveyed. In addition, a concept that may not require in-situ decontamination was investigated. Based on the presently available information concerning material and system compatibility and particle penetration, it is recommended that a system of removable aluminum shields be considered. It is also recommended that a series of tests be performed to more precisely determine the vacuum compatibility and penetrability of other materials discussed in this report

  12. Skin decontamination: principles and perspectives.

    Science.gov (United States)

    Chan, Heidi P; Zhai, Hongbo; Hui, Xiaoying; Maibach, Howard I

    2013-11-01

    Skin decontamination is the primary intervention needed in chemical, biological and radiological exposures, involving immediate removal of the contaminant from the skin performed in the most efficient way. The most readily available decontamination system on a practical basis is washing with soap and water or water only. Timely use of flushing with copious amounts of water may physically remove the contaminant. However, this traditional method may not be completely effective, and contaminants left on the skin after traditional washing procedures can have toxic consequences. This article focuses on the principles and practices of skin decontamination.

  13. Organic decontamination by ion exchange

    International Nuclear Information System (INIS)

    Wilson, T.R.

    1994-01-01

    This study has successfully identified ion exchanger media suitable for decontaminating the 5500-gallon organic layer in Tank 241-C-103. Decontamination of radionuclides is necessary to meet shipping, incinerator site storage, and incineration feed requirements. The exchanger media were identified through a literature search and experiments at the Russian Institute for Physical Chemistry. The principal radionuclides addressed are Cs-137 and Sr-90. Recommendations for an experimental program plan conclude the discussion. The experimental program would provide the data necessary for plant design specifications for a column and for ion exchange media to be used in decontaminating the organic layer

  14. Decontamination and coating of lead

    International Nuclear Information System (INIS)

    Rankin, W.N.; Bush, S.P.; Lyon, C.E.; Walker, V.

    1988-01-01

    Technology is being developed to decontaminate lead used in shielding applications in contaminated environments for recycle as shieldings. Technology is also being developed to coat either decontaminated lead or new lead before it is used in contaminated environments. The surface of the coating is expected to be much easier to decontaminate than the original lead surface. If contamination becomes severely embedded in the coating and cannot be removed, it can be easily cut with a knife and removed from the lead. The used coating can be disposed of as radioactive (hot hazardous) waste. The lead can then be recoated for further use as a shielding material

  15. Steel fiber reinforced concrete

    International Nuclear Information System (INIS)

    Baloch, S.U.

    2005-01-01

    Steel-Fiber Reinforced Concrete is constructed by adding short fibers of small cross-sectional size .to the fresh concrete. These fibers reinforce the concrete in all directions, as they are randomly oriented. The improved mechanical properties of concrete include ductility, impact-resistance, compressive, tensile and flexural strength and abrasion-resistance. These uniqlte properties of the fiber- reinforcement can be exploited to great advantage in concrete structural members containing both conventional bar-reinforcement and steel fibers. The improvements in mechanical properties of cementitious materials resulting from steel-fiber reinforcement depend on the type, geometry, volume fraction and material-properties of fibers, the matrix mix proportions and the fiber-matrix interfacial bond characteristics. Effects of steel fibers on the mechanical properties of concrete have been investigated in this paper through a comprehensive testing-programme, by varying the fiber volume fraction and the aspect-ratio (Lid) of fibers. Significant improvements are observed in compressive, tensile, flexural strength and impact-resistance of concrete, accompanied by marked improvement in ductility. optimum fiber-volume fraction and aspect-ratio of steel fibers is identified. Test results are analyzed in details and relevant conclusions drawn. The research is finally concluded with future research needs. (author)

  16. Full system decontamination (FSD) at NPP Stade prior to dismantling activities

    International Nuclear Information System (INIS)

    Christoph Stiepani; Karl Seidelmann

    2006-01-01

    Full text of publication follows: Introduction: Minimization of personnel dose rates and generation of material free for release is of the highest priority and requires Full System Decontamination (FSD) as a first and important measure when decommissioning Nuclear Power Plants. Framatome ANP has many years experience with Full System Decontaminations for operating nuclear power plants in general and for decommissioning in particular. The latest decommissioning project was the FSD at the PWR Stade which was permanently shut down in November 2003 after 31 years of operation. FSD was scheduled within a short period after shutdown and prior to decommissioning activities. Full System Decontamination at Stade: The PWR Stade is a 4 loop design. FSD included the entire primary circuit with RPV and the auxiliary systems (RHR, VCS and RWCU). The decontamination circuit had a total volume of ∼310 m 3 and an overall surface of ∼17000 m 2 . The Framatome ANP decontamination process HP/CORD R UV was selected for application. The decontamination was performed by using NPP systems in combination with the Framatome mobile decontamination equipment AMDA R (Automated Mobile Decontamination Appliance). A total of 4 decontamination cycles were performed and excellent results were obtained. The average decontamination factor (DF) was 160 for the steam generators with an outstanding ambient dose reduction factor (DRF) of 75. Conclusions: FSD at the PWR Stade has shown that the HP/CORD UV process yields excellent results in primary and auxiliary systems. The significant ambient dose reduction factor of 75 is remarkable. This very high DRF, no other decontamination application came even close, will result in excellent cost-benefit ratios for additional decommissioning activities at Stade. The applied HP/CORD UV process is not a specific decontamination process for decommissioning. Therefore the obtained decontamination and dose reduction factors demonstrate the advantage/potential for

  17. Decontamination of surfaces (1961)

    International Nuclear Information System (INIS)

    Mestre, E.

    1961-01-01

    The continued expansion of atomic Energy has led the S.C.R.G.R. to extend simultaneously the recovery of materials contaminated by use in radio-active media. The importance of this aspect of atomic Energy was not immediately obvious to those concerned but is now fully recognized due to the cost of the materials and installations, and also to the time required for the construction of special equipment for the C.E.A. Another very important reason is the dangers associated with the handling of contaminated material. The S.C.R.G.R. attacked this problem from the point of view of these dangers. It later became apparent to the users, once the decontamination methods had proved their worth, that the process presented advantages from the material and cost-saving point of view. (author) [fr

  18. Ultrasonic decontamination robot

    International Nuclear Information System (INIS)

    Patenaude, R.S.

    1984-01-01

    An ultrasonic decontamination robot removes radioactive contamination from the internal surface of the inlet and outlet headers, divider plate, tube sheet, and lower portions of tubes of a nuclear power plant steam generator. A programmable microprocessor controller guides the movement of a robotic arm mounted in the header manway. An ultrasonic transducer having a solvent delivery subsystem through which ultrasonic action is achieved is moved by the arm over the surfaces. A solvent recovery suction tube is positioned within the header to remove solvent therefrom while avoiding interference with the main robotic arm. The solvent composition, temperature, pressure, viscosity, and purity are controlled to optimize the ultrasonic scrubbing action. The ultrasonic transducer is controlled at a power density, frequency, and on-off mode cycle such as to optimize scrubbing action within the range of transducer-to-surface distance and solvent layer thickness selected for the particular conditions encountered. Both solvent and transducer control actions are optimized by the programmable microprocessor. (author)

  19. Stainless steel decontamination manipulators

    International Nuclear Information System (INIS)

    Sullivan, R.J.

    1986-01-01

    Three, large-volume coverage manipulator systems were designed and built for the Defense Water Processing Facility at the Savannah River Laboratory. These stainless steel systems will be used for high-pressure spray decontamination of waste containers and large process equipment modules. Each system has a manipulator arm, folding boom, and vertical drive and guide structure. Handling capacity is 45 kg, horizontal reach is 4.6 m with a 180-deg swing motion, and the vertical travel is 6 m. The system is remotely removable and replaceable in modules using an overhead crane and an impact wrench. The manipulator arm has seven motions: Shoulder rotation and pivot, elbow pivot, wrist pivot and rotation, and grip open-close. All motions are variable speed and are slip-clutch protected to prevent overloading from external forces (collisions)

  20. Granulated decontamination formulations

    Science.gov (United States)

    Tucker, Mark D.

    2007-10-02

    A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a sorbent additive, and water. A highly adsorbent sorbent additive (e.g., amorphous silica, sorbitol, mannitol, etc.) is used to "dry out" one or more liquid ingredients into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.

  1. Decontamination & decommissioning focus area

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    In January 1994, the US Department of Energy Office of Environmental Management (DOE EM) formally introduced its new approach to managing DOE`s environmental research and technology development activities. The goal of the new approach is to conduct research and development in critical areas of interest to DOE, utilizing the best talent in the Department and in the national science community. To facilitate this solutions-oriented approach, the Office of Science and Technology (EM-50, formerly the Office of Technology Development) formed five Focus AReas to stimulate the required basic research, development, and demonstration efforts to seek new, innovative cleanup methods. In February 1995, EM-50 selected the DOE Morgantown Energy Technology Center (METC) to lead implementation of one of these Focus Areas: the Decontamination and Decommissioning (D & D) Focus Area.

  2. Decontamination of organic waste

    International Nuclear Information System (INIS)

    Schulz, W.

    1977-01-01

    Decontamination stands for the sack collecting of wc-waste water of nuclear-medical tracts and especially the collecting of primary urine and primary faeces of patients after application of radio-isotopes (e.g. iodine 131). They are tied up in the sacks, treated with antiseptic and decomposition-preventing agents, and finally stored in a decupation depot over the time constant. The decupation depot can, for example, be a deep-freezor with separations and clocks, which is radiation-isolated. After the time constant a chemical and/or physical destruction (e.g. comminution) takes place, with simultaneous disinfection and thawing (vapour heating) and the transfer to the canalization. (DG) [de

  3. Glovebox decontamination technology comparison

    International Nuclear Information System (INIS)

    Quintana, D.M.; Rodriguez, J.B.; Cournoyer, M.E.

    1999-01-01

    Reconfiguration of the CMR Building and TA-55 Plutonium Facility for mission requirements will require the disposal or recycle of 200--300 gloveboxes or open front hoods. These gloveboxes and open front hoods must be decontaminated to meet discharge limits for Low Level Waste. Gloveboxes and open front hoods at CMR have been painted. One of the deliverables on this project is to identify the best method for stripping the paint from large numbers of gloveboxes. Four methods being considered are the following: conventional paint stripping, dry ice pellets, strippable coatings, and high pressure water technology. The advantages of each technology will be discussed. Last, cost comparisons between the technologies will be presented

  4. An experimental study on decontamination by surface condition

    International Nuclear Information System (INIS)

    Lee, Young Hae

    1974-01-01

    Surface decontamination is one of the very important problem to be completely solved in the isotope laboratory where there is always the possibility of radioactive contamination, i.e., on the floors, walls, working tables and benches etc., Isotope laboratories require surface covering of material which can be easily and effectively decontaminated. These experiment were done to find an effective decontamination procedure for kind of surfaces which usually are found in radioisotope laboratories and the best type of surface material, that is, one which is easily decontaminated from the point of view of radiation health and safely. This study is presented to guide radioisotope laboratories in Korea which may need to renovate existing unsafe facilities. In some contaminated facilities entirely new installations may be required. Twelve types of surface material are used for study in this experiment. These include 10 cm square of stainless steel, aluminum, ceramic and mosaic tiles, glass, acrylic, formica board, asphalt tile and coated wood with 4 kinds of paints. Stepwise decontamination was performed with various decontamination procedures following a spill of I 1 31 on the center of the surface material being tested. Twelve different decontamination procedures were tested. These included wet wiping with water and detergent, or dry wiping, or removing with gummed paper. Additional chemical procedures used 10% solution of hydrochloric acid, or surface acid, or ammonium citrate, or potassium iodide, or acetone or carbon tetrachloride. The final testing method was abrasion of the test surfaces. Brief analysis of experimental results on the decontaminability on the tested surface showed: 1. Metallic surfaces such as stainless steel or aluminum, or glass, or a piece of ceramic tile or acrylic are recommended as the surface materials for isotope laboratories because these are easily decontaminated by wet wiping only. 2. Formica board, asphalt tile and wood are not easily

  5. Evaluation of destructive methods for managing decontamination wastes

    International Nuclear Information System (INIS)

    Piciulo, P.L.; Adams, J.W.

    1986-01-01

    Results are discussed of a laboratory evaluation of destructive methods for processing chemical decontamination wastes. Incineration, acid digestion and wet-air oxidation are capable of degrading decontamination reagents and organic ion-exchange resins. The extent of destruction as a function of operating parameters was waste specific. The reagents used in the testing were: EDTA, oxalic acid, citric acid, picolinic acid and LND-101A

  6. Decontamination of process equipment using recyclable chelating solvent

    Energy Technology Data Exchange (ETDEWEB)

    Jevec, J.; Lenore, C.; Ulbricht, S. [Babcock & Wilcox, Co., R& DD, Alliance, OH (United States)

    1995-10-01

    The Department of Energy (DOE) is now faced with the task of meeting decontamination and decommissioning obligations at numerous facilities by the year 2019. Due to the tremendous volume of material involved, innovative decontamination technologies are being sought that can reduce the volumes of contaminated waste materials and secondary wastes requiring disposal. This report describes the results of the performance testing of chelates and solvents for the dissolution of uranium.

  7. Radiation level assessment of the Dresden-1 decontamination pilot loop

    International Nuclear Information System (INIS)

    1978-05-01

    The radionuclide concentrations of the Dresden-1 decontamination pilot loop were determined by gamma spectroscopy. The General Electric Ge(Li)pipe gamma scanning system was utilized to take measurements at eight locations both before and after the pilot demonstration of decontamination process. Dose rate measrurements were taken with a portable gamma monitor at 30 additional locations. The percentage of Co-60 removed was calculated and the results were interpreted

  8. Study of decontamination and radiation resistance properties of Indian paints

    International Nuclear Information System (INIS)

    Shah, S.M.; Gopinathan, E.; Bhagwath, A.M.

    1976-01-01

    A brief introduction to the study of contamination and radiation resistance properties of Indian paints used as coating for structural materials in the nuclear industry is given. The general composition of paints such as epoxy, vinyl, alkyd, phenolic, chlesimated rubber, etc. is given. Method of sample preparation, processing and actual evaluation of decontaminability are described. The results have been discussed in terms of decontamination factors. Some recommendations based on the performance of the paints studied are also included. (K.B.)

  9. Assessing cost and effectiveness of radiation decontamination in Fukushima Prefecture, Japan.

    Science.gov (United States)

    Yasutaka, Tetsuo; Naito, Wataru

    2016-01-01

    Despite the enormous cost of radiation decontamination in Fukushima Prefecture, it is not clear what levels of reduction in external radiation exposure are possible in the Special Decontamination Area, the Intensive Contamination Survey Areas and the whole of Fukushima. The objective of this study was to evaluate the cost and effectiveness of radiation decontamination in Fukushima Prefecture in its entirety. Using a geographic information system, we calculated the costs of removal, storage containers, transport, and temporary and interim storage facilities as well as the reduction in air dose rate for a cumulative external exposure for 9000 1 km × 1 km mesh units incorporating 51 municipalities. The decontamination cost for the basic scenario, for which forested areas within 20 m of habitation areas were decontaminated, was JPY2.53-5.12 trillion; the resulting reduction in annual external dose was about 2500 person-Sv. The transport, storage, and administrative costs of decontamination waste and removed soil reached JPY1.55-2.12 trillion under this scenario. Although implementing decontamination of all forested areas provides some major reductions in the external radiation dose for the average inhabitant, decontamination costs could potentially exceed JPY16 trillion. These results indicate that technologies for reducing the volume of decontamination waste and removed soil should be considered to reduce storage costs and that further discussions about forest decontamination policies are needed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Volume reduction and material recirculation by freon decontamination

    International Nuclear Information System (INIS)

    Berners, O.; Buhmann, D.; Yamashita, Y.; Yoshiaki, M.

    1989-01-01

    This paper discusses the use of freon in a large variety of decontamination in the nuclear and non-nuclear fields. As far as the contamination is loose or smerable, surfaces of nearly all materials can be decontaminated. Freon is electrically non-conductive, chemically neutral and has a low surface tension. So it is capable of creeping under the contaminant and loosening or dissolving it. Used freon can be collected, cleaned and recirculated. Its cleaning can be done easily by evaporation at its lower vapor point of about 48 degrees C (104 degrees F). Good decontamination results could be achieved, expensive materials, tools and equipment could be recirculated. Big volumes of materials could get separated from their contaminants, which is the real radioactive waste. Freon decontamination is an effective, overall economical and approved technology to volume reduction and material recirculation

  11. Chemical hazards from decontamination solutions in low level waste

    International Nuclear Information System (INIS)

    Leventhal, L.; Miller, A.; Turney, J.; Naughton, M.; IMPELL Corp., Walnut Creek, CA; Electric Power Research Inst., Palo Alto, CA)

    1985-01-01

    Recent regulations are focussing more attention on the non-radioactive matrix materials associated with radioactive wastes. Decontamination of operating facilities is becoming a more significant source of low-level waste. This study reviewed the chemical and biological hazards of over 50 decontamination processes. Seventeen of the most prominent hard and soft decontamination processes were examined in detail. The chemical and biological hazards of these seventeen are presented in this paper. These hazards influence the choice of radwaste processing and packaging operations and methods. Federal, state and local regulations further impact on operations and waste disposal. Hazards to personnel, in plant and off-site, resulting from the decontamination cycle are evaluated. 1 fig., 5 tabs

  12. Guide for decontamination in P.W.R. power plants

    International Nuclear Information System (INIS)

    Herisson, J.; Glorennec, C.

    1992-01-01

    Nuclear power plant components or equipment often need to be more ore less decontaminated before maintenance. In order to coordinate the activities of the various maintenance specialists belonging to the corporate or Site Organizations, the Management of EDF/Nuclear and Fossil Division has created a 'Decontamination Task Force'. The first objective of this Task Force was to prepare this 'Decontamination Guide for Nuclear Power Plants'. This document is the result of a close collaboration, within a specific working group, between representatives of Nuclear Fossil Division (from Nuclear Power Plants and Corporate Departments) and EDF Project and Construction Group. It will provide assistance to Nuclear Plants Operators in the very specific field of decontamination. (author)

  13. System decontamination as a tool to control radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Riess, R.; Bertholdt, H.O. [Siemens Power Generation Group, Erlangen (Germany)

    1995-03-01

    Since chemical decontamination of the Reactor Coolant Systems (RCS) and subsystems has the highest potential to reduce radiation fields in a short term this technology has gained an increasing importance. The available decontamination process at Siemens, i.e., the CORD processes, will be described. It is characterized by using permanganic acid for preoxidation and diluted organic acid for the decontamination step. It is a regenerative process resulting in very low waste volumes. This technology has been used frequently in Europe and Japan in both RCS and subsystems. An overview will be given i.e. on the 1993 applications. This overview will include plant, scope, date of performance, system volume specal features of the process removed activities, decon factor time, waste volumes, and personnel dose during decontamination. This overview will be followed by an outlook on future developments in this area.

  14. Decontamination of outdoor school swimming pools in Fukushima

    International Nuclear Information System (INIS)

    Saegusa, Jun

    2013-01-01

    After the Fukushima Daiichi NPP accident following the Great East Japan Earthquake, many school swimming pools in Fukushima have suspended water discharge, due to concerns that pool water which contains radioactive fallout is discharged into a river or waterway for agricultural use. The Japan Atomic Energy Agency conducted researches and examinations on the existing absorbent method and the flocculation method as ways for decontaminating pool water. By reviewing and improving these methods through decontamination demonstrations at eight pools in Fukushima, a practical decontamination method for outdoor pools has been established. This report summarizes the methods and results of the decontamination demonstrations carried out at the schools. Also, the surface density of fallout estimated at one of the pools is also presented and discussed in connection with the overall collection ratio of radiocesium at the pool. (author)

  15. Review of decontamination technologies for chemical counter-terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Volchek, K.; Boudreau, L.; Hornof, M. [SAIC Canada, Ottawa, ON (Canada); Fingas, M.F.; Gamble, R.L. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Div]|[Environment Canada, Ottawa, ON (Canada). River Road Environmental Technology Centre

    2004-07-01

    The two categories of chemical agents that could be used in acts of chemical terrorism are conventional chemical warfare agents and commercial toxic chemicals. Industrial chemicals are easier to access than warfare agents, and must therefore be considered when evaluating decontamination techniques. This study involved a search of public-domain documents to identify decontamination technologies including: physical/mechanical treatment or removal; chemical treatment; and, biological methods including natural degradation and attenuation. The technologies were analyzed with reference to their effectiveness for specific groups of chemical agents, state of development, availability and costs. Results indicate that there are many decontamination methods available, both developed and under development, that work effectively for most agents. The two most common decontamination methods are oxidation and alkali hydrolysis followed by dehalogenation. Technology limitations and gaps were also identified, suggesting a need for more research to further the development of promising processes. 31 refs., 2 tabs.

  16. Magnetite Dissolution Performance of HYBRID-II Decontamination Process

    International Nuclear Information System (INIS)

    Kim, Seonbyeong; Lee, Woosung; Won, Huijun; Moon, Jeikwon; Choi, Wangkyu

    2014-01-01

    In this study, we conducted the magnetite dissolution performance test of HYBRID-II (Hydrazine Based Reductive metal Ion Decontamination with sulfuric acid) as a part of decontamination process development. Decontamination performance of HYBRID process was successfully tested with the results of the acceptable decontamination factor (DF) in the previous study. While following-up studies such as the decomposition of the post-decontamination HYBRID solution and corrosion compatibility on the substrate metals of the target reactor coolant system have been continued, we also seek for an alternate version of HYBRID process suitable especially for decommissioning. Inspired by the relationship between the radius of reacting ion and the reactivity, we replaced the nitrate ion in HYBRID with bigger sulfate ion to accommodate the dissolution reaction and named HYBRID-II process. As a preliminary step for the decontamination performance, we tested the magnetite dissolution performance of developing HYBRID-II process and compared the results with those of HYBRID process. HYBRID process developed previously is known have the acceptable decontamination performance, but the relatively larger volume of secondary waste induced by anion exchange resin to treat nitrate ion is the one of the problems related in the development of HYBRID process to be applicable. Therefore we alternatively devised HYBRID-II process using sulfuric acid and tested its dissolution of magnetite in numerous conditions. From the results shown in this study, we can conclude that HYBRID-II process improves the decontamination performance and potentially reduces the volume of secondary waste. Rigorous tests with metal oxide coupons obtained from reactor coolant system will be followed to prove the robustness of HYBRID-II process in the future

  17. Assessing cost and effectiveness of radiation decontamination in Fukushima Prefecture, Japan

    International Nuclear Information System (INIS)

    Yasutaka, Tetsuo; Naito, Wataru

    2016-01-01

    Despite the enormous cost of radiation decontamination in Fukushima Prefecture, it is not clear what levels of reduction in external radiation exposure are possible in the Special Decontamination Area, the Intensive Contamination Survey Areas and the whole of Fukushima. The objective of this study was to evaluate the cost and effectiveness of radiation decontamination in Fukushima Prefecture in its entirety. Using a geographic information system, we calculated the costs of removal, storage containers, transport, and temporary and interim storage facilities as well as the reduction in air dose rate for a cumulative external exposure for 9000 1 km × 1 km mesh units incorporating 51 municipalities. The decontamination cost for the basic scenario, for which forested areas within 20 m of habitation areas were decontaminated, was JPY2.53–5.12 trillion; the resulting reduction in annual external dose was about 2500 person-Sv. The transport, storage, and administrative costs of decontamination waste and removed soil reached JPY1.55–2.12 trillion under this scenario. Although implementing decontamination of all forested areas provides some major reductions in the external radiation dose for the average inhabitant, decontamination costs could potentially exceed JPY16 trillion. These results indicate that technologies for reducing the volume of decontamination waste and removed soil should be considered to reduce storage costs and that further discussions about forest decontamination policies are needed. - Highlights: • Evaluation of cost and effectiveness of decontaminating Fukushima Prefecture. • Reductions in external exposure under various decontamination scenarios were similar. • Decontamination costs for the basic scenario were estimated at JPY2.53–5.12 trillion.

  18. Contamination and decontamination of skin

    International Nuclear Information System (INIS)

    Severa, J.; Knajfl, J.

    1983-01-01

    In external contamination the beta radiation dose is the prevalent component of the total dose absorbed by the skin. There exist four types of radionUclide bonds to the skin: mechanical retention of solid particles or solution on the surface and in the pores, physical adsorption of nondissociated molecules or colloids, the ion exchange effect, and chemisorption. Radionuclides then penetrate the skin by transfollicular transfer. The total amount of radioactive substances absorbed into the skin depends on the condition of the skin. Skin is decontaminated by washing with lukewarm water and soap or with special decontamination solutions. The most widely used components of decontamination solutions are detergents, chelaton, sodium hexametaphosphate, oxalic acid, citric acid. The main principles of the decontamination of persons are given. (M.D.)

  19. Decontaminating method for radioactive contaminant

    International Nuclear Information System (INIS)

    Suzuki, Ken-ichi.

    1994-01-01

    After decontamination of radioactive contaminates with d-limonene, a radioactive material separating agent not compatible with liquid wastes caused by decontamination is added to the liquid wastes. Then after stirring, they are stood still to be separated into two phases, and the radioactive materials in the liquid waste phase caused by decontamination are transferred to the phase of the radioactive material separating agent. With such procedures, they can satisfactorily be separated into two phases of d-limonene and the radioactive material separating agent. Further, d-limonene remaining after the separation can be used again as a decontaminating agent for radioactive contaminates. Therefore, the amount of d-limonene to be used can be reduced, to lower the cost for cleaning, thereby enabling to reduce the amount of radioactive wastes formed. (T.M.)

  20. Road surface washing system for decontaminating radioactive substances. Experiment of radioactive decontamination

    International Nuclear Information System (INIS)

    Endo, Mitsuru; Endo, Mai; Kakizaki, Takao

    2015-01-01

    The Great East Japan Earthquake that occurred on March 11, 2011 resulted in the explosion of the TEPCO Fukushima 1st Nuclear Power Plant and the global dispersion of a large quantity of radioactive substances. A high radiation dose was particularly recorded in Fukushima prefecture several weeks after the accident, although the level is presently sufficiently low. However, considering that the adverse effects of low but extended exposure to radiation are yet to be negated, there is the urgent need for further decontamination. In our study, we focused on the efficient decontamination of radioactive substances in residential areas, for which we propose a high-pressure water jet system for washing road surfaces. The system differs from conventional systems of its type that were initially designed for use in the immediate environment of the nuclear reactors of the TEPCO Fukushima 1st Nuclear Power Plant. The proposed system consists of multiple washing, transporter, and server robots. The washing robots decontaminate the road surface using high-pressure water jets and are transported between washed and unwashed areas by the transporter robots. The server robots supply the water used for washing and absorb the polluted water together with ground dust. In this paper, we describe the concept of the system and present the results of decontamination experiments. Particular attention is given to the washing robot and its mechanism and control method. The results of the integration of the washing robot in an experimental system confirmed the feasibility of the proposed system. (author)

  1. Large-bore pipe decontamination

    International Nuclear Information System (INIS)

    Ebadian, M.A.

    1998-01-01

    The decontamination and decommissioning (D and D) of 1200 buildings within the US Department of Energy-Office of Environmental Management (DOE-EM) Complex will require the disposition of miles of pipe. The disposition of large-bore pipe, in particular, presents difficulties in the area of decontamination and characterization. The pipe is potentially contaminated internally as well as externally. This situation requires a system capable of decontaminating and characterizing both the inside and outside of the pipe. Current decontamination and characterization systems are not designed for application to this geometry, making the direct disposal of piping systems necessary in many cases. The pipe often creates voids in the disposal cell, which requires the pipe to be cut in half or filled with a grout material. These methods are labor intensive and costly to perform on large volumes of pipe. Direct disposal does not take advantage of recycling, which could provide monetary dividends. To facilitate the decontamination and characterization of large-bore piping and thereby reduce the volume of piping required for disposal, a detailed analysis will be conducted to document the pipe remediation problem set; determine potential technologies to solve this remediation problem set; design and laboratory test potential decontamination and characterization technologies; fabricate a prototype system; provide a cost-benefit analysis of the proposed system; and transfer the technology to industry. This report summarizes the activities performed during fiscal year 1997 and describes the planned activities for fiscal year 1998. Accomplishments for FY97 include the development of the applicable and relevant and appropriate regulations, the screening of decontamination and characterization technologies, and the selection and initial design of the decontamination system

  2. Decontamination of radioactively contaminated surfaces

    International Nuclear Information System (INIS)

    1986-10-01

    By this standard objective conditions to evaluate and test the ease of decontamination of surfaces under laboratory conditions are to be laid down. Ease of decontamination in this context denotes the summed-up effect of two material properties: a) the capacity of the material for retaining radioactive substances at its surface; b) the ease with which these substances are given off again in the course of cleaning processes. (orig./HP) [de

  3. Evaluation of a decontamination model

    International Nuclear Information System (INIS)

    Rippin, D.W.T.; Hanulik, J.; Schenker, E.; Ullrich, G.

    1981-02-01

    In the scale-up of a laboratory decontamination process difficulties arise due to the limited understanding of the mechanisms controlling the process. This paper contains some initial proposals which may contribute to the quantitative understanding of the chemical and physical factors which influence decontamination operations. General features required in a mathematical model to describe a fluid-solid reaction are discussed, and initial work is presented with a simple model which has had some success in describing the observed laboratory behaviour. (Auth.)

  4. Presolidification treatment of decontamination wastes

    International Nuclear Information System (INIS)

    Habayeb, M.A.

    1982-02-01

    Unsatisfactory leaching performance of several solidified decontamination solutions indicated a need for presolidification treatments to reduce the water sensitivity of the active chemicals. Chemical treatments examined in this work include pH adjustment, precipitation and oxidation-reduction reactions. The reactions involved in these treatments are discussed. The most suitable presolidification treatment for each decontamination solution has been identified. Further research is needed to test the effectivenss of these treatments

  5. Concrete and criticality

    International Nuclear Information System (INIS)

    Carter, R.D.

    1978-01-01

    Concrete is a widely used structural material which occurs frequently in systems requiring criticality analyses. Ordinarily, we give little thought to what its actual composition is (as compared to reference compositions), yet in criticality safety, differences in composition can cause large changes in k-effective and it may not be easy to predict in which direction the change will occur. Concrete composition is quite variable with differences in the aggregate used in the concrete in various parts of the country providing relative large differences in k-effective. The water content of concrete can also strongly affect the reactivity of a system in which it acts as a reflector or is interspersed between fissile units. Because concrete is so common and is often (but not always) a better reflector than water, one must know the concrete compositions or be prepared to use a ''worst case'' composition. It may be a problem, however, to determine just what is the worst case. At the Hanford Plant, the aggregate normally used is basalt, which gives a composition very low in carbon as opposed to those areas (e.g., Oak Ridge) where the use of limestone aggregate will result in concrete with a high carbon content. The data presented show some of the effects found in situations using ''Hanford'' concrete, but similar effects might be found with other compositions. In some cases, the use of concrete may be incidental to the effects shown. While the numbers shown are those for actual systems, the primary intent is to alert the reader that these effects can occur. In applying this information, the analyst should use material specific to the systems being analyzed

  6. Life Cycle Assessment of Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Sjunnesson, Jeannette

    2005-09-15

    This is an environmental study on concrete that follows the standard protocol of life cycle assessment (LCA). The study is done for two types of concrete, ordinary and frost-resistant concrete, and has an extra focus on the superplasticizers used as admixtures. The utilization phase is not included in this study since the type of construction for which the concrete is used is not defined and the concrete is assumed to be inert during this phase. The results show that it is the production of the raw material and the transports involved in the life cycle of concrete that are the main contributors to the total environmental load. The one single step in the raw material production that has the highest impact is the production of cement. Within the transportation operations the transportation of concrete is the largest contributor, followed by the transportation of the cement. The environmental impact of frost-resistant concrete is between 24-41 % higher than that of ordinary concrete due to its higher content of cement. Superplasticizers contribute with approximately 0.4-10.4 % of the total environmental impact of concrete, the least to the global warming potential (GWP) and the most to the photochemical ozone creation potential (POCP). Also the toxicity of the superplasticizers is investigated and the conclusion is that the low amount of leakage of superplasticizers from concrete leads to a low risk for the environment and for humans.

  7. Decontaminating lead bricks and shielding

    International Nuclear Information System (INIS)

    Lussiez, G.W.

    1993-01-01

    Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium trader pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of contaminated lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling

  8. Chemical Gel for Surface Decontamination

    International Nuclear Information System (INIS)

    Jung, Chong Hun; Moon, J. K.; Won, H. J.; Lee, K. W.; Kim, C. K.

    2010-01-01

    Many chemical decontamination processes operate by immersing components in aggressive chemical solutions. In these applications chemical decontamination technique produce large amounts of radioactive liquid waste. Therefore it is necessary to develop processes using chemical gels instead of chemical solutions, to avoid the well-known disadvantages of chemical decontamination techniques while retaining their high efficiency. Chemical gels decontamination process consists of applying the gel by spraying it onto the surface of large area components (floors, walls, etc) to be decontaminated. The gel adheres to any vertical or complex surface due to their thixotropic properties and operates by dissolving the radioactive deposit, along with a thin layer of the gel support, so that the radioactivity trapped at the surface can be removed. Important aspects of the gels are that small quantities can be used and they show thixitropic properties : liquid during spraying, and solid when stationary, allowing for strong adherence to surfaces. This work investigates the decontamination behaviors of organic-based chemical gel for SS 304 metallic surfaces contaminated with radioactive materials

  9. Random Vibration Analysis of the XM2l Decontaminant Pumper Module of the Modular Decontamination System

    National Research Council Canada - National Science Library

    Colclough, Stephen

    1998-01-01

    The XM21 Decontaminant Pumper module of the Modular Decontamination System was analyzed using finite element analysis techniques to show why the first design iteration passed transportation vibration...

  10. Shippingport Station Decommissioning Project: Contaminated concrete removal: Topical report

    International Nuclear Information System (INIS)

    1989-01-01

    This Topical Report is a synopsis of the removal of contaminated concrete from the Shippingport Station Decommissioning Project (SSDP). The information is provided as a part of the Technology Transfer Program to document the decontamination activities in support of site release in the decommissioning of a nuclear power reactor. 4 refs., 8 figs., 2 tabs

  11. Innovative technologies for recycling contaminated concrete and scrap metal

    International Nuclear Information System (INIS)

    Bossart, S.J.; Moore, J.

    1993-01-01

    Decontamination and decommissioning of US DOE's surplus facilities will generate enormous quantities of concrete and scrap metal. A solicitation was issued, seeking innovative technologies for recycling and reusing these materials. Eight proposals were selected for award. If successfully developed, these technologies will enable DOE to clean its facilities by 2019

  12. Activation experiment for concrete blocks using thermal neutrons

    Science.gov (United States)

    Okuno, Koichi; Tanaka, Seiichiro

    2017-09-01

    Activation experiments for ordinary concrete, colemanite-peridotite concrete, B4C-loaded concrete, and limestone concrete are carried out using thermal neutrons. The results reveal that the effective dose for gamma rays from activated nuclides of colemanite-peridotite concrete is lower than that for the other types of concrete. Therefore, colemanite-peridotite concrete is useful for reducing radiation exposure for workers.

  13. Development of treatment technology for radioactive concrete wastes

    Energy Technology Data Exchange (ETDEWEB)

    Min, B. Y.; Choi, W. K.; Lee, K. W., E-mail: bymin@kaeri.re.k [Korea Atomic Energy Research Institute, 1045 Daeduk-daero, Yuseong-gu, Daejeon, 305-353 Republic of Korea (Korea, Republic of)

    2010-10-15

    The aim of this study was the separation of clean aggregates from contaminated dismantling concrete wastes by thermal and mechanical processes. In Korea, the decontamination and decommissioning of the retired Korea research reactor (KRR) and a uranium conversion plant (UCP) at the Korea Atomic Energy Research Institute (KAERI) has been under way. Hundreds of tons of concrete wastes are expected from these facilities. The KAERI has developed volume reduction technology applicable to an activated heavy concrete waste generated by dismantling KRR-2 and a uranium contaminated light weight concrete produced from a UCP. Contamination level of the gravel and sand aggregates was remarkably decreased by thermal and mechanical process. The volume reduction rate could be achieved above 70% for KRR-2 concrete waste and above to 80% for the UCP concrete waste. (Author)

  14. Efficacy of scalp hair decontamination following exposure to vapours of sulphur mustard simulants 2-chloroethyl ethyl sulphide and methyl salicylate.

    Science.gov (United States)

    Spiandore, Marie; Piram, Anne; Lacoste, Alexandre; Prevost, Philippe; Maloni, Pascal; Torre, Franck; Asia, Laurence; Josse, Denis; Doumenq, Pierre

    2017-04-01

    Chemical warfare agents are an actual threat and victims' decontamination is a main concern when mass exposure occurs. Skin decontamination with current protocols has been widely documented, as well as surface decontamination. However, considering hair ability to trap chemicals in vapour phase, we investigated hair decontamination after exposure to sulphur mustard simulants methyl salicylate and 2-chloroethyl ethyl sulphide. Four decontamination protocols were tested on hair, combining showering and emergency decontamination (use of Fuller's earth or Reactive Skin Decontamination Lotion RSDL ® ). Both simulants were recovered from hair after treatment, but contents were significantly reduced (42-85% content allowance). Showering alone was the least efficient protocol. Concerning 2-chloroethyl ethyl sulphide, protocols did not display significant differences in decontamination efficacy. For MeS, use of emergency decontaminants significantly increased showering efficacy (10-20% rise), underlining their usefulness before thorough decontamination. Our results highlighted the need to extensively decontaminate hair after chemical exposure. Residual amounts after decontamination are challenging, as their release from hair could lead to health issues. Copyright © 2016. Published by Elsevier B.V.

  15. Decontamination of polypropylene fabrics by dry cleaning

    International Nuclear Information System (INIS)

    Severa, J.; Knajfl, J.

    1983-01-01

    Polypropylene fabrics can efficiently be decontaminated by dry cleaning in benzine or perchloroethylene, this also in case the fabric was greased in addition to radioactive contamination. For heavily soiled fabric, it is advantageous to first dry clean it and then wash it. The positive effect was confirmed of intensifiers on the cleaning process, especially of benzine soap. In practice, its concentration should be selected within 1 and 10 g.dm - 3 . Decontamination by dry cleaning and subsequent washing is advantageous in that that the resulting activity of waste water from the laundry is low. Radioactive wastes from the dry cleaning process have a low weight and can be handled as solid waste. (M.D.)

  16. Decontamination of lead by fusion (1962)

    International Nuclear Information System (INIS)

    Boutot, P.; Giachetto, L.; Capitaine, A.

    1962-01-01

    Various attempts to decontaminate using mechanical and chemical methods having given questionable results, a fusion method has been developed. The apparatus consists of a propane-heated oven fitted with a steel crucible of 1 400 kg capacity, with two ventilation systems, and with a vacuum gauge for preventing the diffusion of toxic gases. There are three operational controls : 1. On the samples taken before during and after the operation, 2. On the plugs taken from the ingots, 3. On the ingot itself. The continuous sanitary control is done by a radioactive aerosol recorder and by periodic sampling. This decontamination process will be improved, especially as far as the productivity and the safety precautions are concerned. (authors) [fr

  17. Technology for treatment of decontamination products

    International Nuclear Information System (INIS)

    Kavkhuta, G.A.; Rozdzyalovskaya, L.F.

    1994-01-01

    The research concerning the methods of management and processing of products generated as the result of post Chernobyl decontamination activities is being carried out by the Institute of Radioecological Problems of Belarus Academy of Science (IRP) in the framework of the Belarus National Programme. The main goal of this work is choice and development of an appropriate system for treatment of the decontamination radwastes, based on currently available information and experimental studies. This paper presents the technological schemes being studied for treating the post-Chernobyl liquid and solid wastes and will also briefly discuss the approach being used to settle a problem on collecting/management of low-level radioactive ash wastes, generated from the use of contaminated fuel

  18. Concrete domains

    OpenAIRE

    Kahn, G.; Plotkin, G.D.

    1993-01-01

    This paper introduces the theory of a particular kind of computation domains called concrete domains. The purpose of this theory is to find a satisfactory framework for the notions of coroutine computation and sequentiality of evaluation.

  19. Investigation of electro-kinetic methods for soil decontamination

    International Nuclear Information System (INIS)

    Shabanova, A.N.

    2000-01-01

    The choices of effective methods for ecological system decontamination, their perfection and introduction into practical use have been actual tasks for the Ural region. The objective of this work has been to study the potentials of electrical kinetics method of ISOTRON Corporation (US) for decontamination of the Urals soils. Results obtained have shown the method proposed to be usable for decontaminating some types of soils from strontium and plutonium; it is low effective for decontamination in the area of South-Urals radioactive plume. Thus, a low effectiveness can be expected in podsolic and leached laterite characterized by a high content of loamy sand and sandy soils, as well as for sobby-podsolic ones. The method can be promising for decontamination of soils and wastes from chemical contaminants, such as Zn, Ni, Cu, Pb, Hg, and others. Important advantages of this method compared to others have been its simplicity, small amount of wastes, and feasibility of decontamination in areas difficult to access. (authors)

  20. Decontamination of the RA reactor heavy water system, Annex 9

    International Nuclear Information System (INIS)

    Maksimovic, Z.B.; Nikolic, R.M.; Marinkovic, M.D.; Jelic, Lj.M.

    1963-01-01

    Both stainless steel and aluminium parts of the RA reactor heavy water system system were decontaminated as well as the heavy water itself. System was contaminated with 60 Co. Decontamination factor was determined by activity measurements during distillation. Concentration of the corrosion products in the heavy water was measured by spectrochemical analysis, and found to be 0.1 - 1 mg/l. Chemical analyses of the aluminium and stainless steel surfaces showed that cobalt was adsorbed on the aluminium oxide layer. Water solution of 7%H 3 PO 4 + 2% CrO 3 was used for decontamination of the heavy water system and distillation device. This was found to be the most efficient solvent which does not affect stainless steel corrosion. Decontamination factors achieved were from 60 - 100. Decontamination results enabled determining the distribution of cobalt in the system: 10 Ci on the stainless steel parts, 50 Ci in the heavy water; and above 600 Ci on the fuel and experimental channels. Specific activity of 60 Co was calculated to be 15 Ci/g on the reactor channels, 8 Ci/g on the stainless steel parts and 3 Ci/g in the heavy water. Decontamination of the aluminium parts was not done because it was considered it could initiate corrosion. Since the efficiency of distillation is increased it was expected that permanent distillation would remove most of the activity in the reactor channels

  1. Photocatalyticpaving concrete

    OpenAIRE

    Lyapidevskaya Ol'ga Borisovna; Fraynt Mikhail Aleksandrovich

    2014-01-01

    Today bituminous concrete is a conventional paving material. Among its advantages one can name dustlessness and noiselessness, fine wear (up to 1 mm a year) and fine maintainability. As the main disadvantages of this material one can name high slipperiness under humidification, low durability and weather resistance. Besides that, during placement of the bituminous concrete a lot of different air pollutants are emitted, which are harmful for environment and human’s health (they are listed in t...

  2. Photocatalyticpaving concrete

    Directory of Open Access Journals (Sweden)

    Lyapidevskaya Ol'ga Borisovna

    2014-02-01

    Full Text Available Today bituminous concrete is a conventional paving material. Among its advantages one can name dustlessness and noiselessness, fine wear (up to 1 mm a year and fine maintainability. As the main disadvantages of this material one can name high slipperiness under humidification, low durability and weather resistance. Besides that, during placement of the bituminous concrete a lot of different air pollutants are emitted, which are harmful for environment and human’s health (they are listed in the paper according to the US Environmental Protection Agency materials. As an alternative, one can use cement-concrete pavement, which is in many ways more efficient than the bituminous concrete. It is proposed to enhance environmental performance of the cement-concrete pavement via usage of photocatalysis. The mechanism of different photocatalytic reactions is described in the paper, namely heterogeneous and homogeneous photocatalysis, photo-induces, photoactivated catalysis and catalytical photoreactions. It is pro-posed to use heterogeneous photocatalysis with titanium dioxide as a photocatalyst. The mechanism of photo oxidation of air contaminants, with the usage of titanium dioxide is2described. The paper sets problems, connected with the sensibilization of TiOto thevisible light (it is proposed to use titanium dioxide, doped with the atoms of certain elements to increase its sensibility to the visible light and with the development of a new photocatalytic paving concrete, which will meet the requirements, specified for paving in the climatic and traffic conditions of the Russian Federation.

  3. A State of the Art on the Technology for Recycling and Reuse of the Decommissioning Concrete Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Chung Hun; Choi, Wang Kyu; Min, Byung Youn; Oh, Won Zin; Lee, Kun Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-02-15

    This report describes the reduction and recycling technology of decommissioning concrete waste. Decontamination and decommissioning (D and D) becomes one of the most important nuclear markets especially in the developed countries including USA, UK and France where lots of the retired nuclear facilities have been waiting for decommissioning. In our country the KAERI has been carrying out the decommissioning of the retired TRIGA MARK II and III research reactors and an uranium conversion plant as the first national decommissioning project since 1998. One of the most important areas of the decommissioning is a management of a huge amount of a decommissioning waste the cost of which is more than half of the total decommissioning cost. Therefore reduction in decommissioning waste by a reuse or a recycle is an important subject of decommissioning technology development in the world. Recently much countries pay attention to recycle the large amount of concrete dismantling waste resulted from both a nuclear and a non nuclear industries. In our country, much attention was taken in a recycle of concrete dismantling waste as a concrete aggregate, but a little success has been resulted due to the disadvantages such as a weakness of hardness and surface mortar contamination. A recycle in nuclear industry and a self disposal of the radioactively contaminated concrete wastes are main directions of concrete wastes resulted from a nuclear facility decommissioning. In this report it was reviewed the state of art of the related technologies for a reduction and a recycle of concrete wastes from a nuclear decommissioning in the country and abroad. Prior to recycle and reuse in the nuclear sector, however, the regulatory criteria for the recycle and reuse of concrete waste should be established in parallel with the development of the recycling technology.

  4. A State of the Art on the Technology for Recycling and Reuse of the Decommissioning Concrete Wastes

    International Nuclear Information System (INIS)

    Jung, Chung Hun; Choi, Wang Kyu; Min, Byung Youn; Oh, Won Zin; Lee, Kun Woo

    2008-02-01

    This report describes the reduction and recycling technology of decommissioning concrete waste. Decontamination and decommissioning (D and D) becomes one of the most important nuclear markets especially in the developed countries including USA, UK and France where lots of the retired nuclear facilities have been waiting for decommissioning. In our country the KAERI has been carrying out the decommissioning of the retired TRIGA MARK II and III research reactors and an uranium conversion plant as the first national decommissioning project since 1998. One of the most important areas of the decommissioning is a management of a huge amount of a decommissioning waste the cost of which is more than half of the total decommissioning cost. Therefore reduction in decommissioning waste by a reuse or a recycle is an important subject of decommissioning technology development in the world. Recently much countries pay attention to recycle the large amount of concrete dismantling waste resulted from both a nuclear and a non nuclear industries. In our country, much attention was taken in a recycle of concrete dismantling waste as a concrete aggregate, but a little success has been resulted due to the disadvantages such as a weakness of hardness and surface mortar contamination. A recycle in nuclear industry and a self disposal of the radioactively contaminated concrete wastes are main directions of concrete wastes resulted from a nuclear facility decommissioning. In this report it was reviewed the state of art of the related technologies for a reduction and a recycle of concrete wastes from a nuclear decommissioning in the country and abroad. Prior to recycle and reuse in the nuclear sector, however, the regulatory criteria for the recycle and reuse of concrete waste should be established in parallel with the development of the recycling technology

  5. Characterization and improvement of coatings protecting concrete against contamination

    International Nuclear Information System (INIS)

    Bernard, A.; Gerland, H.

    1985-01-01

    A new type of coatings has been developped for the protection of concrete structures which simplifies the dismantling of nuclear power reactors and decreases the risks of getting a huge volume of wastes. These coatings are decontaminable, resistant, adherent and, if necessary, strippable. They usually consist of composite systems, in order to perfectly fulfill the often contradicting functions. This made difficult the development of such a material. Different tests have been performed on many systems using such a type of painting: decontamination test (standard NF T 30 901), artificial aging (standard NF T 30 049), peeling tests, chemical corrosion tests. Some of these coatings have been selected. Each of them is an example of a given configuration - one layer strippable coating, composite system, etc... Many other coatings although not reported, gave encouraging results. Although in apparent contradiction with the present subject, an other property of these removable coatings has been studied, namely the fixing of contamination. This could also give interesting results. A prototype of such a coating has been qualified. We also present here a device developed by the STMI company. This device would allow taking off the contaminated coatings in case of a problem with the normal removal. Using peeling coatings in the Nuclear Power Reactors in the CEE seems to be an interesting possibility for the future

  6. New decontamination technologies for environmental applications

    International Nuclear Information System (INIS)

    Allen, R.P.; Arrowsmith, H.W.; McCoy, M.W.

    1981-01-01

    The technologies discussed represent a versatile collection of tools and approaches for environmental decontamination applications. The fixatives provide a means for gaining and maintaining control of large contaminated areas, for decontaminating large surface areas, and for protecting equipment and supplies used in decontamination operations. The other decontamination techniques together provide a method for removing loose surface contamination from almost all classes of materials and surfaces. These techniques should have wide application both as direct decontamination processes and for the cleaning of tools and equipment used in the decontamination operations

  7. A rapid and inexpensive bioassay to evaluate the decontamination of organophosphates.

    Science.gov (United States)

    Claborn, David M; Martin-Brown, Skylar A; Sagar, Sanjay Gupta; Durham, Paul

    2012-01-01

    An inexpensive and rapid bioassay using adult red flour beetles was developed for use in assessing the decontamination of environments containing organophosphates and related chemicals. A decontamination protocol was developed which demonstrated that 2 to 3 applications of 5% bleach solution were required to obtain nearly complete decontamination of malathion. The bioassay was also used to screen common household cleaners as potential decontaminating agents, but only 5% bleach was effective at improving survival of insects on steel plates treated with 25% malathion. A toxic degradation product (malaoxon) was detected using gas chromatography/mass spectrophotometry; this toxin affected the decontamination efficacy and resulted in continued toxicity to the beetles until subsequent decontaminations. The bioassay provides evidence to support the use of red flour beetles as a sensitive, less expensive method for determining safety levels of environments contaminated with malathion and other toxins, and may have application in the study of chemical warfare agents.

  8. Actual situation on the field of decontamination in Slovak and Czech NPPs

    International Nuclear Information System (INIS)

    Prazska, M.; Rezbarik, J.; Solcanyi, M.; Trtilek, R.

    2002-01-01

    Many decontamination methods for various applications have proved to provide good results at Slovak and Czech nuclear power plants. A number of mechanical, chemical and electrochemical decontamination methods are available. The selection of a suitable method and decontamination technology is the result of a multicriterial optimization. The plants use the decontamination procedures described in the design documentation. New decontamination procedures aiming to minimize secondary radioactive wastes and corrosion attack on the basic material are being developed. No standardized qualification process, however, exists for such new procedures and large efforts are to be made to introduce them into practice. Methods for decommissioning purposes are based on static or dynamic application of decontamination solutions such as a mixture of formic acid + complexing agent + corrosion inhibitor or dilute HNO 3 . A process consisting in treatment in a solution containing formic acid + complexing agent + corrosion inhibitor (total concentration 3 - 4 mass %, temperature 30 - 35 deg C), whose effect is enhanced by the application of ultrasound (0.4 - 0.5 W per cm 2 decontaminated area) in a specially designed bath, is recommended for segmented metallic parts, which can be then released into the environment and recycled. Electrochemical decontamination in a bath is another efficient decontamination method to achieve unrestricted release of the material into the environment. Efficient decontamination of various highly contaminated materials can be attained by using an electrolyte solution based on citric acid (100 g.dm -3 ) + nitric acid (20 g.dm -3 ) + NH 4 NO 3 (50 g.dm -3 ) and applying a current density of 100 - 200 mA.cm -2 , electrolyte temperature 25 - 50 deg C, with one decontamination cycle period not exceeding 30 minutes. The best results are obtained by electrolysis followed by mechanical treatment using ultrasound. Electrochemical decontamination using a spraying

  9. Metallic surfaces decontamination by using laser light

    International Nuclear Information System (INIS)

    Moggia, Fabrice; Lecardonnel, Xavier

    2013-01-01

    Metal surface cleaning appears to be one of the major priorities for industries especially for nuclear industries. The research and the development of a new technology that is able to meet the actual requirements (i.e. waste volume minimization, liquid effluents and chemicals free process...) seems to be the main commitment. Currently, a wide panel of technologies already exists (e.g. blasting, disk sander, electro-decontamination...) but for some of them, the efficiency is limited (e.g, Dry Ice blasting) and for others, the wastes production (liquid and/or solid) remains an important issue. One answer could be the use of a LASER light process. Since a couple of years, the Clean- Up Business Unit of the AREVA group investigates this decontamination technology. Many tests have been already performed in inactive (i.e. on simulants such as paints, inks, resins, metallic oxides) or active conditions (i.e. pieces covered with a thick metallic oxide layer and metallic pieces covered with grease). The paper will describe the results obtained in term of decontamination efficiency during all our validation process. Metallographic characterizations (i.e. SEM, X-ray scattering) and radiological analysis will be provided. We will also focus our paper on the future deployment of the LASER technology and its commercial use at La Hague reprocessing facility in 2013. (authors)

  10. [Decontamination of chemical warfare agents by photocatalysis].

    Science.gov (United States)

    Hirakawa, Tsutomu; Mera, Nobuaki; Sano, Taizo; Negishi, Nobuaki; Takeuchi, Koji

    2009-01-01

    Photocatalysis has been widely applied to solar-energy conversion and environmental purification. Photocatalyst, typically titanium dioxide (TiO(2)), produces active oxygen species under irradiation of ultraviolet light, and can decompose not only conventional pollutants but also different types of hazardous substances at mild conditions. We have recently started the study of photocatalytic decontamination of chemical warfare agents (CWAs) under collaboration with the National Research Institute of Police Science. This article reviews environmental applications of semiconductor photocatalysis, decontamination methods for CWAs, and previous photocatalytic studies applied to CWA degradation, together with some of our results obtained with CWAs and their simulant compounds. The data indicate that photocatalysis, which may not always give a striking power, certainly helps detoxification of such hazardous compounds. Unfortunately, there are not enough data obtained with real CWAs due to the difficulty in handling. We will add more scientific data using CWAs in the near future to develop useful decontamination systems that can reduce the damage caused by possible terrorism.

  11. Decontamination of high-level waste canisters

    International Nuclear Information System (INIS)

    Nesbitt, J.F.; Slate, S.C.; Fetrow, L.K.

    1980-12-01

    This report presents evaluations of several methods for the in-process decontamination of metallic canisters containing any one of a number of solidified high-level waste (HLW) forms. The use of steam-water, steam, abrasive blasting, electropolishing, liquid honing, vibratory finishing and soaking have been tested or evaluated as potential techniques to decontaminate the outer surfaces of HLW canisters. Either these techniques have been tested or available literature has been examined to assess their applicability to the decontamination of HLW canisters. Electropolishing has been found to be the most thorough method to remove radionuclides and other foreign material that may be deposited on or in the outer surface of a canister during any of the HLW processes. Steam or steam-water spraying techniques may be adequate for some applications but fail to remove all contaminated forms that could be present in some of the HLW processes. Liquid honing and abrasive blasting remove contamination and foreign material very quickly and effectively from small areas and components although these blasting techniques tend to disperse the material removed from the cleaned surfaces. Vibratory finishing is very capable of removing the bulk of contamination and foreign matter from a variety of materials. However, special vibratory finishing equipment would have to be designed and adapted for a remote process. Soaking techniques take long periods of time and may not remove all of the smearable contamination. If soaking involves pickling baths that use corrosive agents, these agents may cause erosion of grain boundaries that results in rough surfaces

  12. AREVA NP decontamination concept for decommissioning. A comprehensive approach based on over 30 years experience

    International Nuclear Information System (INIS)

    Stiepani, Christoph

    2011-01-01

    decontamination is tailored to the given boundaries and desired goals to ensure the best results with the lowest waste generation. This includes lower source term by oxide film, thus corrosion product, removal; controlled base metal attack to remove embedded activity; increased gamma/alpha ratios; and alpha contamination removal. This paper will describe the AREVA NP Decontamination Concept for Decommissioning (DCD) and present highlights of previous FSDs performed prior to decommissioning using the CORD/AMDA technology. (author)

  13. Residual radioactivity investigation and radiological assessments for self-disposal of concrete waste in nuclear fuel processing facility

    International Nuclear Information System (INIS)

    Seol, Jeung Gun; Ryu, Jae Bong; Cho, Suk Ju; Yoo, Sung Hyun; Song, Jung Ho; Baek, Hoon; Kim, Seong Hwan; Shin, Jin Seong; Park, Hyun Kyoun

    2007-01-01

    In this study, domestic regulatory requirement was investigated for self-disposal of concrete waste from nuclear fuel processing facility. And after self-disposal as landfill or recycling/reuse, the exposure dose was evaluated by RESRAD Ver. 6.3 and RESRAD BUILD Ver. 3.3 computing code for radiological assessments of the general public. Derived clearance level by the result of assessments for the exposure dose of the general public is 0.1071Bq/g (3.5% enriched uranium) for landfill and 0.05515 Bq/cm 2 (5% enriched uranium) for recycling/reuse respectively. Also, residual radioactivity of concrete waste after decontamination was investigated in this study. The result of surface activity is 0.01Bq/cm 2 for emitter and the result of radionuclide analysis for taken concrete samples from surface of concrete waste is 0.0297Bq/g for concentration of 238 U, below 2w/o for enrichment of 235 U and 0.0089Bq/g for artificial contamination of 238 U respectively. Therefore, radiological hazard of concrete waste by self-disposal as landfill and recycling/reuse is below clearance level to comply with clearance criterion provided for Notice No. 2001-30 of the MOST and Korea Atomic Energy Act

  14. Mitigation of Hexavalent Chromium in Storm Water Resulting from Demolition of Large Concrete Structure at the East Tennessee Technology Park - 12286

    Energy Technology Data Exchange (ETDEWEB)

    Britto, Ronnie; Brown, Bridget; Hale, Timothy B.; Hensley, Janice L.; Johnson, Robert T.; Patel, Madhu [Tetra Tech, Inc. (United States); Emery, Jerry A. [Energy Solutions, Inc. (United States); Gaston, Clyde [LATA-SHARP Remediation Services - LSRS (United States); Queen, David C. [U.S. DOE-ORO (United States)

    2012-07-01

    American Recovery and Reinvestment Act (ARRA) funding was provided to supplement the environmental management program at several DOE sites, including the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. Demolition of the ETTP K-33 Building, the largest building to be demolished to date in Oak Ridge, was awarded to LSRS in FY-2010 under the ARRA program. The K-33 building was an 82 foot tall 2-story structure covering approximately 32 acres. Once this massive building was brought down to the ground, the debris was segregated and consolidated into piles of concrete rubble and steel across the remaining pad. The process of demolishing the building, tracking across concrete debris with heavy equipment, and stockpiling the concrete rubble caused it to become pulverized. During and after storm events, hexavalent chromium leached from the residual cement present in the large quantities of concrete. Storm water control measures were present to preclude migration of contaminants off-site, but these control measures were not designed to control hexavalent chromium dissolved in storm water from reaching nearby receiving water. The following was implemented to mitigate hexavalent chromium in storm water: - Steel wool was distributed around K-33 site catch basins and in water pools as an initial step in addressing hexavalent chromium. - Since the piles of concrete were too massive and unsafe to tarp, they were placed into windrows in an effort to reduce total surface area. - A Hach colorimetric field meter was acquired by the K-33 project to provide realtime results of hexavalent chromium in site surface water. - Three hexavalent chromium treatment systems were installed at three separate catch basins that receive integrated storm water flow from the K-33 site. Sodium bisulfite is being used as a reducing agent for the immobilization of hexavalent chromium while also assisting in lowering pH. Concentrations initially were 310 - 474 ppb of hexavalent chromium in

  15. Liquid abrasive grit blasting literature search and decontamination scoping tests report

    International Nuclear Information System (INIS)

    Ferguson, R.L.

    1993-10-01

    Past decontamination and solvent recovery activities at the Idaho Chemical Processing Plant (ICPP) have resulted in the accumulation of 1.5 million gallons of radioactively contaminated sodium-bearing liquid waste. Future decontamination activities at the ICPP could result in the production of 5 million gallons or more of sodium-bearing waste using the current decontamination techniques of chemical/water flushes and steam jet cleaning. With the curtailment of reprocessing at the ICPP, the focus of decontamination is shifting from maintenance for continued operation of the facilities to decommissioning. As decommissioning plans are developed, new decontamination methods must be used which result in higher decontamination factors and generate lower amounts of sodium-bearing secondary waste. The primary initiative of the WINCO Decontamination Development Program is the development of methods to eliminate/minimize the use of sodium-bearing decontamination chemicals. One method that was chosen for cold scoping studies during FY-93 was abrasive grit blasting. Abrasive grit blasting has been used in many industries and a vast amount of research and development has already been conducted. However, new grits, process improvements and ICPP applicability was investigated. This evaluation report is a summary of the research efforts and scoping tests using the liquid abrasive grit blasting decontamination technique. The purpose of these scoping tests was to determine the effectiveness of three different abrasive grits: plastic beads, glass beads and alumina oxide

  16. Toshiba's decontamination technologies for the decommissioning

    International Nuclear Information System (INIS)

    Inoue, Yuki; Yaita, Yumi; Sakai, Hitoshi

    2011-01-01

    For the decommissioning, two types of decontamination process are necessary, 1) system decontamination before dismantling and 2) decontamination of dismantling waste. Toshiba has been developing the decontamination technologies for the both purposes from the viewpoint of minimizing the secondary waste. For the system decontamination before dismantling, chemical decontamination process, such as T-OZON, can be applicable for stainless steel or carbon steel piping. For the decontamination of dismantling waste, several types of process have been developed to apply variety of shapes and materials. For the simple shape materials, physical decontamination process, such as blast decontamination, is effective. We have developed new blast decontamination process with highly durable zirconia particle. It can be used repeatedly and secondary waste can be reduced compared with conventional blast particle. For the complex shape materials, chemical decontamination process can be applied that formic acid decontamination process for carbon steel and electrolytic reduction decontamination process with organic acid for stainless steel. These chemicals can be decomposed to carbon dioxide and water and amount of secondary waste can be small. (author)

  17. Decontaminating products for routine decontamination in nuclear power plants

    International Nuclear Information System (INIS)

    Henning, K.

    2001-01-01

    Routine decontamination work that has to be carried out in practical operation includes the cleaning of all kinds of surfaces such as floors, walls and apparatus, the decontamination of professional clothes and of the personnel. In order to ensure a trouble-free functioning of plants for the treatment of waste water and concentrate in nuclear power plants, radioactive liquid wastes appearing in the controlled area should be compatible with the treatment methods in practice. Radioactive concentrates and resides obtained from the treatment methods are mixed with matrix materials like cement or bitumen or treated by roller frame drying and thus are conditioned for intermediate or final storage. Several requirements should be made on decontaminating agents used in the controlled area. Some of these physical-chemical criteria will be described in detail. (R.P.)

  18. Development of Nuclear Decontamination Technology Using Supercritical Fluid

    International Nuclear Information System (INIS)

    Jung, Wonyoung; Park, Kwangheon; Park, Jihye; Lee, Donghee

    2014-01-01

    Soil cleaning technologies that have been developed thus far increase treatment costs in contaminated soil recovery processes because they generate large amounts of secondary wastes. In this respect, this study is intended to develop soil decontamination methods using CO 2 , which is a nontoxic, environmentally friendly substance, in order to fundamentally suppress the generation of secondary wastes from the decontamination process and to create high added values. In this study, to develop decontamination methods for uranium-contaminated soil using supercritical CO 2 , a soil decontamination system using supercritical CO 2 was constructed. In addition, the basic principle of supercritical CO 2 decontamination using a TBP-HNO3 complex was explained. According to the results of the study, sea-sand samples having the same degree of contamination showed different results of decontamination according to the quantities of the TBP-HNO3 complex used as an extraction agent, which resulted in high extraction rates. Thus far, a most widely used method of extracting uranium has been the dissolving of uranium in acids. However, this method has the large adverse effect of generating strong acidic wastes that cannot be easily treated. On the other hand, supercritical CO 2 requires critical conditions that are no more difficult to meet than those of other supercritical fluids, since its density can be changed from a very low state close to that of an ideal gas to a high state close to that of liquids. The critical gas conditions are a pressure of 71 bar and a temperature of 31 .deg. C, both of which are inexpensive to achieve. Moreover, CO 2 is a solvent that is not harmful to the human body and few effects on environmental pollution. Therefore, nontoxic and environment friendly processes can be developed using supercritical CO 2 . Supercritical CO 2 's advantages over prevailing methods suggest its potential for developing innovative decontamination methods, as demonstrated

  19. Performance of "Waterless Concrete"

    Science.gov (United States)

    Toutanji, H. A.; Grugel, R. N.

    2009-01-01

    Waterless concrete consists of molten elementary sulfur and aggregate. The aggregates in a lunar environment will be lunar rocks and soil. Sulfur is present on the Moon in Troilite soil (FeS) and, by oxidation of the soil, iron and sulfur can be produced. Sulfur concrete specimens were cycled between liquid nitrogen (approx.]91 C) and room temperature (^21 C) to simulate exposure to a lunar environment. Cycled and control specimens were subsequently tested in compression at room temperatures (^21 C) and ^-101 C. Test results showed that due to temperature cycling, the compressive strength of cycled specimens was 20% of those non-cycled. This reduction in strength can be attributed to the large differences in thermal coefficients of expansion of the materials constituting the concrete which promoted cracking. Similar sulfur concrete mixtures were strengthened with short and long glass fibres. The lunar regolith simulant was melted in a 25 cc Pt- Rh crucible in a Sybron Thermoline high temperature MoSi2 furnace at melting temperatures of 1450 to 1600 C for times of 30 min to i hour. Glass fibres and small rods were pulled from the melt. The glass fibres were used to reinforce sulfur concrete plated to improve the flexural strength of the sulfur concrete. Beams strengthened with glass fibres showed to exhibit an increase in the flexural strength by as much as 45%.

  20. Fracture Mechanics of Concrete

    DEFF Research Database (Denmark)

    Ulfkjær, Jens Peder

    Chapter 1 Chapter l contains the introduction to this thesis. The scope of the thesis is partly to investigate different numerical and analytical models based on fracture mechanical ideas, which are able to predict size effects, and partly to perform an experimental investigation on high-strength......Chapter 1 Chapter l contains the introduction to this thesis. The scope of the thesis is partly to investigate different numerical and analytical models based on fracture mechanical ideas, which are able to predict size effects, and partly to perform an experimental investigation on high......-strength concrete. Chapter 2 A description of the factors which influence the strength and cracking of concrete and high strength concrete is made. Then basic linear fracture mechanics is outlined followed by a description and evaluation of the models used to describe concrete fracture in tension. The chapter ends...... and the goveming equations are explicit and simple. These properties of the model make it a very powerful tool, which is applicable for the designing engineer. The method is also extended to reinforced concrete, where the results look very promising. The large experimental investigation on high-strength concrete...

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

    International Nuclear Information System (INIS)

    Sutoto

    2007-01-01

    The abrasive decontamination of the stainless steel valve using 12 bar pressurized CO 2 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)

  2. New decontamination process using foams containing particles

    International Nuclear Information System (INIS)

    Guignot, S.; Faure, S.

    2008-01-01

    One key point in the dismantling of nuclear facilities is the thorough cleaning of radiation- exposed surfaces on which radioactive deposits have formed. This cleaning step is often achieved by successive liquid rinses with specific solutions containing alkaline, acidic, or even oxidizing species depending on whether the aim is to dissolve greasy deposits (like ter-butylphosphate) or to corrode surfaces on micrometric thicknesses. An alternative process to reduce the amount of chemicals and the volume of the resulting nuclear wastes consists in using the same but foamed solutions (1). Carrying less liquid, the resulting foams still display similar kinetics of dissolution rates and their efficiency is determined by their ability to hold sufficient wetnesses during the time required for the decontamination. Classical foam decontamination process illustrated by foam pulverization or circulation in the 90 turned five years ago into a specific static process using high-lifetime viscosified foam at a steady state. One way to slow down the liquid drainage is to raise liquid viscosity by adding organic viscosifiers like xanthan gum (2). In 2005, new studies started on an innovative process proposed by S. Faure and based on triphasic foams containing particles [3]. The aim is to generate new decontamination foams containing less quantities of organics materials (surfactants and viscosifiers). Silica particles are obviously known to stabilize or destabilize foams (4). In the frame of S. Guignot Ph.D., new fundamental studies are initiated in order to clarify the role of silica solid microparticles in these foams. Our final goal is to determine whether this kind of new foam can be stable for several hours for a decontamination process. The results we will report focus on wet foams used for nuclear decontamination and incorporating fumed silica. The study is conducted on a vertical foam column in a pseudo-free drainage configuration, and aims at investigating the influence of

  3. Decontaminating lead bricks and shielding

    International Nuclear Information System (INIS)

    Lussiez, G.

    1994-01-01

    Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially of planned decommissioning operations. Thus lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for contaminated lead is removing the superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a scaled-off area. The slurry of abrasive and particles of lead falls through a floor and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling

  4. Decontaminating lead bricks and shielding

    International Nuclear Information System (INIS)

    Lussiez, G.W.

    1993-01-01

    Lead used for shielding is often surface contaminated with radionuclides and is therefore a Resource Conservation and Recovery Act (RCRA) D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Lab. decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 100 metric tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 280 kPa (40 psig) rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a pump. A pump sends the slurry mixture back to the spray gun, creating a continuous process

  5. Liquid decontaminants for nuclear applications

    International Nuclear Information System (INIS)

    Henning, Klaus; Gojowczyk, Peter

    2011-01-01

    Decontaminants used in the nuclear field must meet a variety of requirements. On the one hand, the washing process must remove radioactive contamination and conventional dirt from the items washed. On the other hand, subsequent disposal of the washing water arisings must be feasible by the usual waste disposal pathway. One aspect of particular importance is unproblematic treatment of the radioactively contaminated waste water, as a rule low to medium active, whose final storage must be ensured. Decontaminants must not impair waste treatment processes, such as evaporation, filtration, and centrifuging, as well as further treatment of the concentrates and residues arising which are worked into matrix materials (cementation, bituminization), in drum drying or roller mill drying. For reasons of safety at work and environmental quality, also aspects of human toxicology and ecotoxicology must be taken into account. In this way, handling decontaminants will not jeopardize the health of personnel or cause potential long-term environmental damage. Liquid decontaminants, compared to powders, offer the advantage of automatic dosage. The liquid product is dosed accurately as a function of the washing program used. Liquid decontaminants can be handled safely in hot laundries without causing skin and eye contacts. (orig.)

  6. Full system decontamination feasibility studies

    International Nuclear Information System (INIS)

    Denault, R.P.; LeSurf, J.E.; Walschot, F.W.

    1988-01-01

    Many chemical decontaminations have been performed on subsystems in light water reactors (BWRs and PWRs) but none on the full system (including the fuel) of large, (>500 MWe) investor owned reactors. Full system decontaminations on pressure-tubed reactors have been shown to facilitate maintenance, inspection, repair and replacement of reactor components. Further advantages are increased reactor availability and plant life extension. A conceptual study has been performed for EPRI (for PWRs) and Commonwealth Edison Co (for BWRs) into the applicability and cost benefit of full system decontaminations (FSD). The joint study showed that FSDs in both PWRs and BWRs, with or without the fuel included in the decontamination, are feasible and cost beneficial provided a large amount of work is to be done following the decontamination. The large amounts of radioactive waste generated can be managed using current technologies. Considerable improvements in waste handling, and consequent cost savings, can be obtained if new techniques which are now reaching commercial application are used. (author)

  7. Application of a modified electrochemical system for surface decontamination of radioactive metal waste

    International Nuclear Information System (INIS)

    Lee, J.H.; Lim, Y.K.; Yang, H.Y.; Shin, S.W.; Song, M.J.

    2003-01-01

    Conventional and modified electrolytic decontamination experiments were performed in a solution of sodium sulfate for the decontamination of carbon steel as the simulated metal wastes which are generated in large amounts from nuclear power plants. The effect of reaction time, current density and concentration of electrolytes in the modified electrolytic decontamination system were examined to remove the surface contamination of the simulated radioactive metal wastes. As for the results of this research, the modified electrochemical decontamination process can decontaminate more effectively than the conventional decontamination process by applying different anode material which causes higher induced electro-motive forces. When 0.5 M sodium sulfate, 0.4 A/cm 2 current density and 30 minutes reaction time were applied in the modified process, a 16 μm thickness change that is expected to remove most surface contamination in radioactive metal wastes was achieved on carbon steel which is the main material of radioactive metal waste in nuclear power plants. The decontamination efficiency of metal waste showed similar results with the small and large lab-scale modified electrochemical system. The application of this modified electrolytic decontamination system is expected to play a considerable role for decontamination of radioactive metal waste in nuclear power plants in the near future. (author)

  8. Decontamination of transvaginal ultrasound probes: Review of national practice and need for national guidelines

    International Nuclear Information System (INIS)

    Gray, R.A.; Williams, P.L.; Dubbins, P.A.; Jenks, P.J.

    2012-01-01

    Aim: To determine the national practice of transvaginal ultrasound (TVUS) probe decontamination in English hospitals and to develop recommendations for guidance. Materials and methods: A literature review was undertaken to clarify best practice and evaluate methods of decontamination of TVUS probes. A questionnaire was developed to ascertain TVUS probe decontamination programmes in current use within English hospitals. This was sent to ultrasound leads of 100 English hospitals; 68 hospitals responded. Results: There is a wide variation in TVUS probe decontamination across English hospitals. Although the majority of respondents (87%, 59/68) reported having clear and practical written guidelines for TVUS decontamination, the frequency, methods, and types of decontamination solutions utilized were widely variable and none meet the standards required to achieve high-level disinfection. Conclusion: While the decontamination of other endoluminal medical devices (e.g., flexible endoscopes) is well defined and regulated, the decontamination of TVUS probes has no such guidance. There appears to be incomplete understanding of the level of risk posed by TVUS probes, and in some cases, this has resulted in highly questionable practices regarding TVUS hygiene. There is an urgent need to develop evidence-based national guidance for TVUS probe decontamination.

  9. Research on working property and early age mechanical property of self-compacting concrete used in steel-concrete structure

    International Nuclear Information System (INIS)

    Zhao Yongguang

    2013-01-01

    Background: Self-compacting concrete that has good working property is the prerequisite of steel-concrete structure. The early age mechanical property of self-compacting concrete is the important parameter when design steel-concrete structure. Purpose: This paper attempts to research the working property and early age mechanical property of self-compacting concrete. Methods: Test is used to research the working property and early age mechanical property of self-compacting concrete. Results: Self-compacting concrete that could meet the requirement of steel-concrete structure has been mixed and parameters of early age mechanical property of self-compacting concrete which is necessary for design of steel-concrete structure have been presented. Conclusions: Base on the results, this paper can guide the construction of self-compacting concrete in steel-concrete structure and the design and construction of steel-concrete structure. (author)

  10. Chemical decontaminating method for stainless steel

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Akimoto, Hidetoshi.

    1990-01-01

    Radioactive metal wastes comprising passivated stainless steels are chemically decontaminated to such a radioactivity level as that of usual wastes. The present invention for chemically decontaminating stainless steels comprises a first step of immersing decontaminates into a sulfuric acid solution and a second step of immersing them into an aqueous solution prepared by adding oxidative metal salts to sulfuric acid, in which a portion of the surface of stainless steels as decontaminates are chemically ground to partially expose substrate materials and then the above-mentioned decontamination steps are applied. More than 90% of radioactive materials are removed in this method by the dissolution of the exposed substrate materials and peeling of cruds secured to the surface of the materials upon dissolution. This method is applicable to decontamination of articles having complicate shapes, can reduce the amount of secondary wastes after decontamination and also remarkably shorten the time required for decontamination. (T.M.)

  11. Precipitation process for supernate decontamination

    International Nuclear Information System (INIS)

    Lee, L.M.; Kilpatrick, L.L.

    1982-11-01

    A precipitation and adsorption process has been developed to remove cesium, strontium, and plutonium from water-soluble, high-level radioactive waste. An existing waste tank serves as the reaction vessel and the process begins with the addition of a solution of sodium tetraphenylborate and a slurry of sodium titanate to the contained waste salt solution. Sodium tetraphenylborate precipitates the cesium and sodium titanate adsorbs the strontium and plutonium. The precipitate/adsorbate is then separated from the decontaminated salt solution by crossflow filtration. This new process offers significant capital savings over an earlier ion exchange process for salt decontamination. Chemical and small-scale engineering studies with actual waste are reported. The effect of many variables on the decontamination factors and filter performance are defined

  12. A scaffold easy to decontaminate

    International Nuclear Information System (INIS)

    Mourek, D.

    1992-01-01

    The conventional scaffold used in the assembling work and in revisions of technological facilities at nuclear power plants has many drawbacks. The most serious of them are a high amount of radioactive waste arising from the decontamination (planing) of the floor timber and from the discarding of damaged irreparable parts, and a considerable corrosion of the carbon steel supporting structure after the decontamination. A detailed description is given of a novel scaffold assembly which can be decontaminated and which exhibits many assets, in particular a good mechanical resistance (also to bad weather), a lower weight, and the use of prepreg floor girders for the construction of service platforms or scaffold bridges which can readily be assembled from the pressed pieces in a modular way. (Z.S.). 4 figs., 4 refs

  13. Chemical decontamination of stainless steel

    International Nuclear Information System (INIS)

    Onuma, Tsutomu; Akimoto, Hidetoshi

    1991-01-01

    The present invention concerns a method for chemical decontamination of radioactive metal waste materials contaminated with radioactive materials on the surface, generated in radioactive materials-handling facilities. The invention is comprised of a method of chemical decontamination of stainless steel, characterized by comprising a first process of immersing a stainless steel-based metal waste material contaminated by radioactive materials on the surface in a sulfuric acid solution and second process of immersing in an aqueous solution of sulfuric acid and oxidizing metal salt, in which a portion of the surface of the stainless steel to be decontaminated is polished mechanically to expose a portion of the base material before the above first and second processes. 1 figs., 2 tabs

  14. RSDL decontamination of human skin contaminated with the nerve agent VX.

    Science.gov (United States)

    Thors, L; Lindberg, S; Johansson, S; Koch, B; Koch, M; Hägglund, L; Bucht, A

    2017-03-05

    Dermal exposure to low volatile organophosphorus compounds (OPC) may lead to penetration through the skin and uptake in the blood circulation. Skin decontamination of toxic OPCs, such as pesticides and chemical warfare nerve agents, might therefore be crucial for mitigating the systemic toxicity following dermal exposure. Reactive skin decontamination lotion (RSDL) has been shown to reduce toxic effects in animals dermally exposed to the nerve agent VX. In the present study, an in vitro flow-through diffusion cell was utilized to evaluate the efficacy of RSDL for decontamination of VX exposed to human epidermis. In particular, the impact of timing in the initiation of decontamination and agent dilution in water was studied. The impact of the lipophilic properties of VX in the RSDL decontamination was additionally addressed by comparing chemical degradation in RSDL and decontamination efficacy between the VX and the hydrophilic OPC triethyl phosphonoacetate (TEPA). The epidermal membrane was exposed to 20, 75 or 90% OPC diluted in deionized water and the decontamination was initiated 5, 10, 30, 60 or 120min post-exposure. Early decontamination of VX with RSDL, initiated 5-10min after skin exposure, was very effective. Delayed decontamination initiated 30-60min post-exposure was less effective but still the amount of penetrated agent was significantly reduced, while further delayed start of decontamination to 120min resulted in very low efficacy. Comparing RSDL decontamination of VX with that of TEPA showed that the decontamination efficacy at high agent concentrations was higher for VX. The degradation mechanism of VX and TEPA during decontamination was dissected by 31 P NMR spectroscopy of the OPCs following reactions with RSDL and its three nucleophile components. The degradation rate was clearly associated with the high pH of the specific solution investigated; i.e. increased pH resulted in a more rapid degradation. In addition, the solubility of the OPC in RSDL

  15. A study on sodium-concrete reaction

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jae Heum; Min, Byong Hun [Suwon University, Suwon (Korea, Republic of)

    1997-07-01

    A small sodium-concrete reaction facility was designed, manufactured and installed. this facility has been operated under inert gas(N{sub 2}) with different experimental variables such as sodium injection temperature, injection amount of sodium, aging period of concrete, sodium reservoir temperature. As a result, it was found that sodium injection temperature and injected amount of sodium has little effect on sodium-concrete reaction. However, sodium reservoir temperature and aging period of concrete has relatively high impact on sodium-concrete reaction. Sodium-concrete reaction model has also been developed and compared with experimental results. (Author) 51 refs., 16 tabs., 64 figs.

  16. Study of tritium decontamination of stainless steel, copper, aluminum metals by tritium dry desorption

    International Nuclear Information System (INIS)

    Xie Yun; Shi Zhengkun; Wu Tao

    2014-01-01

    In order to study the decontamination efficiency of stainless steel, copper, aluminum metals contaminated by tritium, the metals were decontaminated by exposing to UV, ozone, heating, and the combination of heating, UV and ozone. The result indicates that the elevation of temperature can obviously improve decontamination. While irradiated by 172 nm UV, the decontamination efficiency is low, but it is better while heated and irradiated by 172 nm UV. If the stainless steel is irradiated by 172 nm UV and heated at 500℃ for 4 h, the decontamination efficiency is 99.2%. There is better decontamination efficiency of copper while exposed to ozone. While exposed to ozone and heated at 500℃, the decontamination efficiencies of stainless steel, copper and aluminum are higher than 99.2%. The decontamination efficiency can more obviously improve when metal is heated at high temperature (500℃) than low temperature (300℃). The surface tritium of metal placed at 30 d after decontamination increases because of diffusion and penetration of the tritium. Resolution spectra of tritium show that there are four kinds of contamination adsorbed tritium of stainless steel. (authors)

  17. Concrete durability

    OpenAIRE

    Gaspar Tébar, Demetrio

    1991-01-01

    The evidence that the concrete is not a material for ever was noticed from the beginning of its industrial use. In the present work, the author describes the studies carried out during the last century and the early ages of the present one, mainly devoted to the study of the durability in sea water. At the present days, and in spite of the numerous papers published from then, the study of the concrete durability continues focusing the research priorities and economical resources of rese...

  18. Prediction of concrete strength in massive structures

    International Nuclear Information System (INIS)

    Sakamoto, T.; Makino, H.; Nakane, S.; Kawaguchi, T.; Ohike, T.

    1989-01-01

    Reinforced concrete structures of a nuclear power plant are mostly of mass concrete with cross-sectional dimensions larger than 1.0 m. The temperature of concrete inside after placement rises due to heat of hydration of cement. It is well known that concrete strengths of mass concrete structure subjected to such temperature hysteresis are generally not equal to strengths of cylinders subjected to standard curing. In order to construct a mass concrete structure of high reliability in which the specified concrete strength is satisfied by the specified age, it is necessary to have a thorough understanding of the strength gain property of concrete in the structure and its relationships with the water-cement ratio of the mix, strength of standard-cured cylinders and the internal temperature hysteresis. This report describes the result of studies on methods of controlling concrete strength in actual construction projects

  19. Historic Concrete : From Concrete Repair to Concrete Conservation

    NARCIS (Netherlands)

    Heinemann, H.A.

    2013-01-01

    Concrete like materials were already applied during the Roman Empire. After the decline of the Roman Empire, a wide scale application of concrete only reappeared in the 19th century. Here lies also the origin of modern (reinforced) concrete. Since then, both concrete application and composition have

  20. Heat transfer within a concrete slab with a finite microwave heating source

    International Nuclear Information System (INIS)

    Lagos, L.E.; Li, W.; Ebadian, M.A.; Grubb, R.G.

    1995-01-01

    In the present paper, the concrete decontamination and decommissioning process with a finite microwave heating source is investigated theoretically. For the microwave induced heating pattern, a multilayer concrete slab, which includes steel reinforcement mesh, is assumed to be exposed to a finite plane microwave source at normal incidence. Two-dimensional heat transport within the concrete is also considered to evaluate the variations of temperature with heating time at different frequencies with and without the presence of the reinforcement bars. Four commonly used industrial microwave frequencies of 0.896, 2.45, 10.6 and 18.0 GHz have been selected. The results revealed that as the microwave frequency increases to, or higher than 10.6 GHz, the maximum temperature shifts toward the front surface of the concrete. It was found that the presence of a steel reinforcement mesh causes part of the microwave energy to be blocked and reflected. Furthermore, it was observed that the temperature distribution is nearly uniform within the dimensions of the microwave applicator for a high microwave power intensity and a short heating time. (author)

  1. Ultrasonic imaging in concrete

    International Nuclear Information System (INIS)

    Ribay, G.; Paris, O.; Rambach, J.M.

    2009-01-01

    The third and final protection barrier confining nuclear reactors is usually a concrete containment structure. Monitoring the structural integrity of these barriers is critical in ensuring the safety of nuclear power plants. The Institute for Radiological Protection and Nuclear Safety (IRSN) in France in collaboration with the French Atomic commission (CEA/LIST) has developed an ultrasonic phased-array technique capable of inspecting thick concrete walls. The non-destructive method is dedicated to detect cracks and bulk defects. Given the thickness of the structure (1.2 m) undergoing inspection and the heterogeneity of the concrete, the optimal frequency lies in the 50-300 kHz range. At these frequencies, the ultrasonic beam profiles are widespread (non-directive) with poor signal-to-noise ratio. Previous studies have shown the potential of using phased-array techniques (i.e., beam focusing and beam steering) in order to improve detection resolution and sizing accuracy. In this paper we present experimental studies performed with array up to 16 transducers working at 200 kHz. Experiments are carried out on representative concrete blocks containing artificial defects. One is a reinforced mock-up representative of the first reinforcing mesh of wall containment. Experimental results show that in spite of the reinforcement, artificial defects deep as half a meter can be detected. Reconstructed images resulting from phased array acquisitions on an artificial crack embedded in a concrete block are also presented and discussed. The presented method allows detecting oriented defects in concrete with improved signal to noise ratio and sensibility. A simulation model of the interaction of ultrasound with a heterogeneous medium like concrete is briefly commented. (authors)

  2. Report on practical use of new decontamination technology

    International Nuclear Information System (INIS)

    Nitta, Hideyuki; Ono, Masahiro

    2000-03-01

    For removing surface contamination of a solid waste with radioactivity, technology of laser cleaning and vacuum arc cleaning has the possibility to obtain the high decontamination rate. We made a research for practical uses of these methods as a new cleaning technology from published papers and patents. From these results, we discussed about an applicability of laser cleaning and vacuum arc cleaning to decontaminate a body of centrifugal separator. At first, we investigate the solid surface cleaning technology with a laser or a vacuum arc from published papers in the world and the patents in Japan. The results were listed in tables. Each information was abstracted into a technical data sheet and sorted into a related technology (system or equipment). We also investigate the decontamination technology by the same way and the results were abstracted into technical data sheets and sorted into related technologies, too. As an application of the above research, we considered the process and the system for decontaminating a body of centrifugal separators (cylinders). In the system, the cleaning head is set inside the cylinder and the inner surface contaminated by radioactivity is removed by the irradiation of a YAG laser, a CO2 laser or a vacuum arc. The cylinder is rotated by rotational rings and moved towards the direction of the central axis and the whole inner surface of the cylinder is cleaned with a constant cleaning rate. We also estimated the costs of each decontamination technology. (author)

  3. Report of concrete pavement evaluation : project 105 C-4181-01 Donahoo Road, Wyandotte County.

    Science.gov (United States)

    2013-12-01

    The physical properties of hardened concrete cores and fresh concrete test results were compared with aggregate : gradation workability differences. The concrete cores were taken from a rural two-lane concrete road in northeastern Kansas : constructe...

  4. Study of technological features of tubular compressed concrete members in concreting

    Directory of Open Access Journals (Sweden)

    Voskobiinyk Olena

    2017-01-01

    Full Text Available The technological features of core concreting were analyzed as the main factor in ensuring of strength and reliability of compressed concrete-filled steel tubular (CFST members. We have conducted the analysis of existing concreting methods of CFST members. In this respect, the most dangerous types of possible technological defects of concrete core of CFST members are inhomogeneity along the height, voids, caverns, and concrete “weak spots”. The authors considered the influence of such technological factors of concreting: placeability, time, concrete mixture compaction method, concreting height on the concrete core strength of CFST members. Based on the experimental studies conducted we suggested the regression correlations for determining the concrete strength of CFST members of different length depending on the movability of concrete mixture and a time for its compaction. The authors performed the correlation analysis of technological factors of concreting on the strength of the concrete core. We carried out the comparison of data on the concrete core strength of CFST members, that were determined by non-destructive methods (sclerometer test results, ultrasonic method and direct compression strength tests. We experimentally proved that using movable mixtures with the slump of about 4 – 9 cm the overall variation coefficient of concrete core strength of CFST members along the height reaches nearly 13%. Based on the experimental studies conducted we suggested the guidelines on optimal regimes of concrete compaction during manufacturing CFST members at a construction site environment.

  5. An appraisal of existing decontamination technology used in the United States of America

    International Nuclear Information System (INIS)

    Domenech, J.S.; Frost, F.; Curran, A.R.; Grave, M.J.

    1984-01-01

    This report is a review of decontamination technology applied by industry to radioactively contaminated components in the U.S.A. In addition some newer techniques under development or recently emerging are discussed. Mechanical, chemical, manual and other techniques such as electropolishing and ultrasonics are reviewed. Whilst the emphasis is mainly on non-destructive techniques for components some discussion of segmentation is included as this is inevitable during concrete decontamination; and also when decontamination of components occurs as part of a decommissioning programme the use of segmentation techniques may facilitate the process. A bibliography has been included to facilitate further reading. It is important to consider the relevance of the US data in this report to the United Kingdom both to the learning curve of development and the different nuclear reactor systems in the respective countries. The authors have therefore listed some conclusions and recommendations which have become apparent to them whilst undertaking the study. (U.K.)

  6. Mobile worksystems for decontamination and dismantlement

    International Nuclear Information System (INIS)

    Osborn, J.; Bares, L.C.; Thompson, B.R.

    1995-01-01

    Many DOE nuclear facilities have aged beyond their useful lifetimes. They need to be decommissioned in order to be safe for human presence in the short term, to eventually recover valuable materials they contain, and ultimately to be transitioned to alternative uses or green field conditions. Decontamination and dismantlement are broad classes of activities that will enable these changes to occur. Most of these facilities - uranium enrichment plants, weapons assembly plants, research and production reactors, and fuel recycling facilities - are dormant, though periodic inspection, surveillance and maintenance activities within them are on-going. DOE estimates that there are over 5000 buildings that require deactivation to reduce the costs of performing such work with manual labor. In the long term, 1200 buildings will be decommissioned, and millions of metric tons of metal and concrete will have to be recycled or disposed of The magnitude of the problem calls for new approaches that are far more cost effective than currently available techniques. This paper describes two technologies that are viable solutions for facility D ampersand D

  7. Mobile worksystems for decontamination and dismantlement

    Energy Technology Data Exchange (ETDEWEB)

    Osborn, J. [Carnegie Mellon Univ., Pittsburgh, PA (United States); Bares, L.C.; Thompson, B.R. [RedZone Robotics, Inc., Pittsburgh, PA (United States)

    1995-10-01

    Many DOE nuclear facilities have aged beyond their useful lifetimes. They need to be decommissioned in order to be safe for human presence in the short term, to eventually recover valuable materials they contain, and ultimately to be transitioned to alternative uses or green field conditions. Decontamination and dismantlement are broad classes of activities that will enable these changes to occur. Most of these facilities - uranium enrichment plants, weapons assembly plants, research and production reactors, and fuel recycling facilities - are dormant, though periodic inspection, surveillance and maintenance activities within them are on-going. DOE estimates that there are over 5000 buildings that require deactivation to reduce the costs of performing such work with manual labor. In the long term, 1200 buildings will be decommissioned, and millions of metric tons of metal and concrete will have to be recycled or disposed of. The magnitude of the problem calls for new approaches that are far more cost effective than currently available techniques. This paper describes a mobile workstation termed ROSIE, which provides remote work capabilities for D&D activities.

  8. Evaluation of ilmenite serpentine concrete and ordinary concrete as nuclear reactor shielding

    International Nuclear Information System (INIS)

    Abulfaraj, W.H.; Kamal, S.M.

    1994-01-01

    The present study involves adapting a formal decision methodology to the selection of alternative nuclear reactor concrete shielding. Multiattribute utility theory is selected to accommodate decision maker's preferences. Multiattribute utility theory (MAU) is here employed to evaluate two appropriate nuclear reactor shielding concretes in terms of effectiveness to determine the optimal choice in order to meet the radiation protection regulations. These concretes are Ordinary concrete (O.C.) and Illmenite Serpentile concrete (I.S.C.). These are normal weight concrete and heavy weight heat resistive concrete, respectively. The effectiveness objective of the nuclear reactor shielding is defined and structured into definite attributes and subattributes to evaluate the best alternative. Factors affecting the decision are dose received by reactor's workers, the material properties as well as cost of concrete shield. A computer program is employed to assist in performing utility analysis. Based upon data, the result shows the superiority of Ordinary concrete over Illmenite Serpentine concrete. (Author)

  9. Radiological decontamination, survey, and statistical release method for vehicles

    International Nuclear Information System (INIS)

    Goodwill, M.E.; Lively, J.W.; Morris, R.L.

    1996-06-01

    Earth-moving vehicles (e.g., dump trucks, belly dumps) commonly haul radiologically contaminated materials from a site being remediated to a disposal site. Traditionally, each vehicle must be surveyed before being released. The logistical difficulties of implementing the traditional approach on a large scale demand that an alternative be devised. A statistical method for assessing product quality from a continuous process was adapted to the vehicle decontamination process. This method produced a sampling scheme that automatically compensates and accommodates fluctuating batch sizes and changing conditions without the need to modify or rectify the sampling scheme in the field. Vehicles are randomly selected (sampled) upon completion of the decontamination process to be surveyed for residual radioactive surface contamination. The frequency of sampling is based on the expected number of vehicles passing through the decontamination process in a given period and the confidence level desired. This process has been successfully used for 1 year at the former uranium millsite in Monticello, Utah (a cleanup site regulated under the Comprehensive Environmental Response, Compensation, and Liability Act). The method forces improvement in the quality of the decontamination process and results in a lower likelihood that vehicles exceeding the surface contamination standards are offered for survey. Implementation of this statistical sampling method on Monticello projects has resulted in more efficient processing of vehicles through decontamination and radiological release, saved hundreds of hours of processing time, provided a high level of confidence that release limits are met, and improved the radiological cleanliness of vehicles leaving the controlled site

  10. A Survey and Evaluation of Chemical Warfare Agent-Decontaminants and Decontamination

    Science.gov (United States)

    1984-10-15

    Biological Methods. The use of a cell-free enzymatic system, microorganisms, algae, and the state-of-the-art genetic engineering approach for decontaminating...many organic and inorganic materials might react with agents in a manner similar to complex enzymatic reactions. However. experimental data were not...28). XXCC3 was further tested for use in a microencapsulation concept. Pre- liminary results indicated that O.30g of ethyl cellulose 21 microcapsules

  11. Soil decontamination at Rocky Flats

    International Nuclear Information System (INIS)

    Olsen, R.L.; Hayden, J.A.; Alford, C.E.; Kochen, R.L.; Stevens, J.R.

    1979-01-01

    A soils decontamination project was initiated, to remove actinides from soils at Rocky Flats. Wet screening, attrition scrubbing with Calgon at high pH, attrition scrubbing at low pH, and cationic flotation were investigated. Pilot plant studies were carried out. Conceptual designs have been generated for mounting the process in semi-trailers

  12. ORNL decontamination and decommissioning program

    International Nuclear Information System (INIS)

    Bell, J.P.

    1980-01-01

    A program has been initiated at ORNL to decontaminate and decommission surplus or abandoned nuclear facilities. Program planning and technical studies have been performed by UCC-ND Engineering. A feasibility study for decommissioning the Metal Recovery Facility, a fuel reprocessing pilot plant, has been completed

  13. Decontamination in a Russian settlement

    DEFF Research Database (Denmark)

    Fogh, C.L.; Andersson, Kasper Grann; Barkovsky, A.N.

    1999-01-01

    Decontamination was carried out in an area with three houses in Novo Bobovichi, Bryansk region, Russia, in the autumn of 1995. It was demonstrated that significant reductions in the dose rate both indoor (DRF = 0.34) and outdoor (DRF = 0.20) can be achieved when a controlled cleaning is undertake...

  14. Nuclear reactor vessel decontamination systems

    International Nuclear Information System (INIS)

    McGuire, P. J.

    1985-01-01

    There is disclosed in the present application, a decontamination system for reactor vessels. The system is operatable without entry by personnel into the contaminated vessel before the decontamination operation is carried out and comprises an assembly which is introduced into the vertical cylindrical vessel of the typical boiling water reactor through the open top. The assembly includes a circular track which is centered by guideways permanently installed in the reactor vessel and the track guides opposed pairs of nozzles through which water under very high pressure is directed at the wall for progressively cutting and sweeping a tenacious radioactive coating as the nozzles are driven around the track in close proximity to the vessel wall. The whole assembly is hoisted to a level above the top of the vessel by a crane, outboard slides on the assembly brought into engagement with the permanent guideways and the assembly progressively lowered in the vessel as the decontamination operation progresses. The assembly also includes a low pressure nozzle which forms a spray umbrella above the high pressure nozzles to contain radioactive particles dislodged during the decontamination

  15. Radioactive decontamination through UV laser

    International Nuclear Information System (INIS)

    Delaporte, Ph.; Gastaud, M.; Sentis, M.; Uteza, O.; Marine, W.; Thouvenot, P.; Alcaraz, J.L.; Le Samedy, J.M.; Blin, D.

    2003-01-01

    A device allowing the radioactive decontamination of metal surfaces through the use of a pulsed UV laser has been designed and tested. This device is composed of a 1 kW excimer laser linked to a bundle of optic fibers and of a system to recover particles and can operate in active zones. Metal surfaces have the peculiarities to trap radio-elements in a superficial layer of oxide that can be eaten away by laser radiation. Different contaminated metals (stainless steels, INCONEL and aluminium) issued from the nuclear industry have been used for the testing. The most important contaminants were 60 Co, 137 Cs, 154-155 Eu and 125 Sb. The ratio of decontamination was generally of 10 and the volume of secondary wastes generating during the process was very low compared with other decontamination techniques. A decontamination speed of 1 m 2 /h has been reached for aluminium. The state of the surface is an important parameter because radio-elements trapped in micro-cracks are very difficult to remove. (A.C.)

  16. Pipe and hose decontamination apparatus

    International Nuclear Information System (INIS)

    Fowler, D.E.

    1985-01-01

    A pipe and hose decontamination apparatus is disclosed using freshly filtered high pressure Freon solvent in an integrated closed loop to remove radioactive particles or other contaminants from items having a long cylindrical geometry such as hoses, pipes, cables and the like. The pipe and hose decontamination apparatus comprises a chamber capable of accomodating a long cylindrical work piece to be decontaminated. The chamber has a downward sloped bottom draining to a solvent holding tank. An entrance zone, a cleaning zone and an exit drying zone are defined within the chamber by removable partitions having slotted rubber gaskets in their centers. The entrance and exit drying zones contain a horizontally mounted cylindrical housing which supports in combination a plurality of slotted rubber gaskets and circular brushes to initiate mechanical decontamination. Solvent is delivered at high pressure to a spray ring located in the cleaning zone having a plurality of nozzles surrounding the work piece. The solvent drains into a solvent holding tank located below the nozzles and means are provided for circulating the solvent to and from a solvent cleaning, distilling and filter unit

  17. Remote Decontamination Facility and Repair Station for hot-cell manipulators

    International Nuclear Information System (INIS)

    Ryz, M.A.

    1977-01-01

    Increasingly high radiation levels on manipulators at the Whiteshell Nuclear Research Establishment, Pinawa, Manitoba, Canada, necessitated design and construction of a Remote Decontamination Facility and Repair Station. This facility reduces radiation levels on manipulators by an order of magnitude over previous hand decontamination techniques. The reduced radiation levels have allowed superior manipulator repair and maintenance, resulting in 50% fewer manipulator breakdowns

  18. Developing technique for waste water cleaning of a division for equipment decontamination

    International Nuclear Information System (INIS)

    Gromoglasov, A.A.; Solyakov, V.K.; Novikov, V.N.; Pil'shchikov, A.P.; Chekalov, A.G.; Sinyukov, M.A.; Pshenichnykh, V.N.

    1989-01-01

    Results are described of developing technique for radionuclide cleaning solutions after metal product decontamination. The method is based on the adagulation with usage of quicklime. The conclusion is method permits to consider it as the main technique for waste water decontamination. 3 refs.; 2 figs.; 3 tabs

  19. The use of ultrasound for decontamination of tools and equipment in nuclear power plant Krshko

    International Nuclear Information System (INIS)

    Erman, R.

    1987-01-01

    This paper describes the main principles of the ultrasonic generator functioning and the use of ultrasound for decontamination of tools and equipment in nuclear power plant Krshko. The paper gives the operating procedure and presents decontamination results of tools and equipment fabricated from various materials. (author) 3 refs.; 1 tab

  20. Decontamination processes for waste glass canisters

    International Nuclear Information System (INIS)

    Rankin, W.N.

    1981-06-01

    The process which will be used to decontaminate waste glass canisters at the Savannah River Plant consists of: decontamination (slurry blasting); rinse (high-pressure water); and spot decontamination (high-pressure water plus slurry). No additional waste will be produced by this process because glass frit used in decontamination will be mixed with the radioactive waste and fed into the glass melter. Decontamination of waste glass canisters with chemical and abrasive blasting techniques was investigated. The ability of a chemical technique with HNO 3 -HF and H 2 C 2 O 4 to remove baked-on contamination was demonstrated. A correlation between oxide removal and decontamination was observed. Oxide removal and, thus, decontamination by abrasive blasting techniques with glass frit as the abrasive was proposed and demonstrated