Refractory, Abrasive and Other Industrial Mineral Operations

Data.gov (United States)

Department of Homeland Security — This map layer includes refractory, abrasive, and other industrial minerals operations in the United States. The data represent commodities covered by the Minerals...

Steam Generator Group Project. Task 6. Channel head decontamination

International Nuclear Information System (INIS)

Allen, R.P.; Clark, R.L.; Reece, W.D.

1984-08-01

The Steam Generator Group Project utilizes a retired-from-service pressurized-water-reactor steam generator as a test bed and source of specimens for research. An important preparatory step to primary side research activities was reduction of the radiation field in the steam generator channel head. This task report describes the channel head decontamination activities. Though not a programmatic research objective it was judged beneficial to explore the use of dilute reagent chemical decontamination techniques. These techniques presented potential for reduced personnel exposure and reduced secondary radwaste generation, over currently used abrasive blasting techniques. Two techniques with extensive laboratory research and vendors prepared to offer commercial application were tested, one on either side of the channel head. As indicated in the report, both techniques accomplished similar decontamination objectives. Neither technique damaged the generator channel head or tubing materials, as applied. This report provides details of the decontamination operations. Application system and operating conditions are described

Comparison of thorough decontamination techniques on dismantled pieces of a PWR reactor

International Nuclear Information System (INIS)

Klein, M.; Rahier, A.; Mandoki, R.; Ponnet, M.

1998-01-01

The decontamination experience gained during the BR3 dismantling project is developed. This started with the full system decontamination of the primary loop and was followed by R and D on thorough decontamination projects. First, a wet abrasive installation has been installed and is now in operation for the thorough cleaning of metallic pieces of simple geometry. Afterwards, the chemical cerium process has been developed. The results of the regeneration with ozone and with electrochemistry are presented in detail. The ozone regeneration process has been selected for the industrial installation of which the construction is foreseen in 1998. (author)

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

Decontamination processes for waste glass canisters

International Nuclear Information System (INIS)

Rankin, W.N.

1982-01-01

A Defense Waste Processing Facility (DWPF) is currently being designed to convert Savannah River Plant liquid, high-level radioactive waste into a solid form, such as borosilicate glass. To prevent the spread of radioactivity, the outside of the canisters of waste glass must have very low levels of smearable radioactive contamination before they are removed from the DWPF. Several techniques were considered for canister decontamination: high-pressure water spray, electropolishing, chemical dissolution, and abrasive blasting. An abrasive blasting technique using a glass frit slurry has been selected for use in the DWPF. No additional equipment is needed to process waste generated from decontamination. Frit used as the abrasive will be mixed with the waste and fed to the glass melter. In contrast, chemical and electrochemical techniques require more space in the DWPF, and produce large amounts of contaminated by-products, which are difficult to immobilize by vitrification

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

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

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

Decontamination of Savannah River Plant waste glass canisters

International Nuclear Information System (INIS)

Rankin, W.N.

1982-01-01

A Defense Waste Processing Facility (DWPF) is currently being designed to convert Savannah River Plant (SRP) liquid, high-level radioactive waste into a solid form, such as borosilicate glass. The outside of the canisters of waste glass must have very low levels of smearable radioactive contamination before they are removed from the DWPF to prevent the spread of radioactivity. Several techniques were considered for canister decontamination: high-pressure water spray, electropolishing, chemical dissolution, and abrasive blasting. An abrasive blasting technique using a glass frit slurry has been selected for use in the DWPF. No additional equipment is needed to process waste generated from decontamination. Frit used as the abrasive will be mixed with the waste and fed to the glass melter. In contrast, chemical and electrochemical techniques require more space in the DWPF, and produce large amounts of contaminated byproducts which are difficult to immobilize by vitrification

Dry blasting decontaminating method for radioactive waste

International Nuclear Information System (INIS)

Nishiwaki, Hitoshi.

1993-01-01

In the present invention, when abrasives are dry blasted on the surface of radioactive wastes and the recovered abrasives are classified for re-use, abrasives having a microvicker's hardness (HMV) of greater than 600 and a grain size of greater than 1mm are used in a case where the radioactive wastes to be abraded are stainless steels. This enables dry blasting decontamination for stainless steels which has been considered to be impossible. In addition since the amount of secondary wastes are reduced, it is extremely effective. (T.M.)

Research on operation mode of abrasive grain during grinding

Science.gov (United States)

Ivanova, T. N.; Dement’ev, V. B.; Nikitina, O. V.

2018-03-01

The processing of materials by cutting with an abrasive tool is carried out by means of thousands of grains bonded together as a single whole. The quality of the abrasive tool is defined by cutting properties of abrasive grains and depends on features of spreading the temperature field in time and in the abrasive grain volume. Grains are exposed to heating and cooling during work. It leads to undesired effects such as a decrease of durability of grain retention in the binder, hardness, intensification of diffusion and oxidation processes between the binder and the grain, the occurrence of considerable temperature stresses in the grain itself. The obtained equation which allows calculation of temperature field of grain for one rotation of grinding wheel shows that the temperature of the wheel depends on grinding modes and thermophysical properties of abrasive material. Thus, as the time of contact of grain with processed material increases, the temperature in the cutting area rises. As thermophysical properties increase, the temperature in cutting area decreases. Thermal working conditions are determined to be different from each other depending on contact time of the grain and the material. For example, in case of creep-feed grinding, the peak value of temperature is higher than during multistep grinding; the depth of expansion is greater. While the speed of the thermal process in creep-feed grinding is 2-3 times lower than in multistep grinding, the gradient reduces 3-4 times. The analysis of machining methods shows that creep-feed grinding ensures greater depth of grain heating, a smaller heating rate and a reduced velocity gradient. It causes a decrease of probable allotropic modifications and prevents from occurring of heat strokes - cracking of grains due to high temperature falls. Consequently, it is necessary to employ creep-feed grinding to increase the efficiency of abrasive tool employing. Three operation modes of grinding wheel including blunting, full

Decontamination of material in the Marcoule plutonium producing centre (1961); La decontamination du materiel dans le centre de production du plutonium de Marcoule (1961)

Energy Technology Data Exchange (ETDEWEB)

Rodier, J; Bouzigues, H; Boutot, P [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1961-07-01

The decontamination of material in an atomic centre is an essential operation in view of the cost and the difficulties of replacement. It also makes it possible to reduce the storage of radio-active materials always an expensive task. Surfaces are contaminated by retention of radioactive products and the mechanism of the bounding forces can be explained in terms of chemical, mechanical, electrostatic and surface tension phenomena. The methods used for decontamination are either physical (section, abrasion, steam, ultrasonics) or chemical (acids, alkalis, detergents, reducing and oxidising agents). At Marcoule, chemical methods of treatment are used. This is effected in tanks, the exact composition of the liquids being regulated from a control panel. Working experience has shown that the fact of operating in humid conditions eliminates all problems of atmospheric contamination; as a result it is possible for the personnel to work without any special protective devices. Almost all the material can be re-utilized and the operations produce only a small volume of liquid waste. The decontamination workshop is operated by a small number of workers. The working costs, including capital repayment and treatment of the waste, do not exceed 15 per cent of the value of the apparatus treated. (authors) [French] La decontamination du materiel dans un centre atomique est une operation indispensable etant donne le cout et les difficultes du remplacement. Elle contribue aussi a diminuer les stockages toujours onereux des materiaux radioactifs. Les surfaces se contaminent par retention de corps radioactifs, l'origine des forces de liaison devant etre recherchee dans les phenomenes chimiques, mecaniques, electro-statiques ou de tensions superficielles. Les methodes de decontamination peuvent etre physiques (aspiration, abrasion, vapeur, ultra-sons) ou chimiques (acides, alcalins, detergents, reducteurs, oxydants). Sur le centre de Marcoule, la methode des traitements chimiques a ete

Decontamination of material in the Marcoule plutonium producing centre (1961)

International Nuclear Information System (INIS)

Rodier, J.; Bouzigues, H.; Boutot, P.

1961-01-01

The decontamination of material in an atomic centre is an essential operation in view of the cost and the difficulties of replacement. It also makes it possible to reduce the storage of radio-active materials always an expensive task. Surfaces are contaminated by retention of radioactive products and the mechanism of the bounding forces can be explained in terms of chemical, mechanical, electrostatic and surface tension phenomena. The methods used for decontamination are either physical (section, abrasion, steam, ultrasonics) or chemical (acids, alkalis, detergents, reducing and oxidising agents). At Marcoule, chemical methods of treatment are used. This is effected in tanks, the exact composition of the liquids being regulated from a control panel. Working experience has shown that the fact of operating in humid conditions eliminates all problems of atmospheric contamination; as a result it is possible for the personnel to work without any special protective devices. Almost all the material can be re-utilized and the operations produce only a small volume of liquid waste. The decontamination workshop is operated by a small number of workers. The working costs, including capital repayment and treatment of the waste, do not exceed 15 per cent of the value of the apparatus treated. (authors) [fr

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

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

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.

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

Decontamination and decommissioning of the Chemical Process Cell (CPC): Topical report for the period January 1985-March 1987

International Nuclear Information System (INIS)

Meigs, R.A.

1987-07-01

To support interim storage of vitrified High-Level Waste (HLW) at the West Valley Demonstration Project, the shielded, remotely operated Chemical Process Cell (CPC) was decommissioned and decontaminated. All equipment was removed, packaged and stored for future size reduction and decontamination. Floor debris was sampled, characterized, and vacuumed into remotely handled containers. The cell walls, ceiling, and floor were decontaminated. Three 20 Mg (22.5 ton) concrete neutron absorber cores were cut with a high-pressure water/abrasive jet cutting system and packaged for disposal. All operations were performed remotely using two overhead bridge cranes which included two 1.8 Mg (2 ton) hoists, one 14.5 Mg (16 ton) hoist, and an electromechanical manipulator or an industrial robot mounted on a mobile platform. Initial general area dose rates in the cell ranged from 1 to 50 R/h. Target levels of less than 10 mR/h general area readings were established before decontamination and decommissioning was initiated; general area dose rates between 200 mR/h and 1200 mR/h were obtained at the completion of the decontamination work. 4 refs., 11 figs., 8 tabs

Abrasive wear based predictive maintenance for systems operating in sandy conditions

NARCIS (Netherlands)

Woldman, M.; Tinga, T.; Heide, E. van der; Masen, M.A.

2015-01-01

Machines operating in sandy environments are damaged by the abrasive action of sand particles that enter the machine and become entrapped between components and contacting surfaces. In the case of the military services the combination of a sandy environment and the wide range of tasks to be

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)

The abrasive blasting technique. Matching the waste minimisation precept

International Nuclear Information System (INIS)

Welbers, Philipp; Noll, Thomas; Braehler, Georg; Sohnius, Bern

2010-01-01

Nowadays main challenges in the nuclear industry are, besides the development and design of new facilities, the dismantling of outlived nuclear installations and subsequent waste handling. Not only Germany but all countries and institutions which are involved in our business face similar problems: A large quantity of slightly contaminated waste, equipment and civil structures, arise inevitably during operation and, especially, during dismantling. This waste occurs in a huge amount due to its bulky nature, e.g. pipe-work. Storage of bulky items is very expensive and would not be compatible with the waste minimisation precept. Treatment in an ecological correct and economical beneficial way is the key factor in dealing with this waste. This means decontamination of the waste up to clearance levels where possible. A suitable solution is the Abrasive Blasting Technique. (orig.)

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)

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

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

Abrasive water jets for controlled demolition and dismantling

International Nuclear Information System (INIS)

Abudaka, M.; Crofton, P.S.J.

1988-01-01

Abrasive water jets offer an efficient high speed cutting tool for hard materials such as reinforced concrete, tool steel and armour plate. Cutting by abrasive water jets is often described as a cold cutting operation since no heat is developed and any increase in local temperature is immediately cooled by the water jet. Moreover no sparks are generated to ignite a potentially inflammable atmosphere. Mass flow rates of water and abrasive are small (typically 4 litres/min.water and 1 kg/min abrasive) and hence are easy to collect and to dispose of. For these reasons abrasive water jets offer certain advantages in cutting difficult materials in hazardous environments such as in the nuclear industry, offshore oil rigs and petrochemical plant. Available portable cutting systems are described and the advantages of using abrasive water jets are discussed as well as some of the parameters involved in the cutting operation. Finally a description is presented of some typical applications of abrasive water jet cutting. (author)

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.)

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)

Electropolishing as a decontamination process: progress and applications

International Nuclear Information System (INIS)

Allen, R.P.; Arrowsmith, H.W.; Charlot, L.A.; Hooper, J.L.

1978-04-01

Research studies demonstrated the ability of electropolishing to reduce the radiation levels of steel tools and stainless steel vacuum system components, which were heavily contaminated with plutonium oxide, from 1 million dis/min x 100 cm 2 to background in less than 10 min. Other examples of objects that have been decontaminated within minutes using electropolishing include hot cell manipulator assemblies, analytical instrument components, laboratory transfer containers, offsite shipping containers, fission product storage capsules, laboratory animal cages, and nuclear reactor process tube components. One of the major activities of this research has been the establishment and intensive operation of a 400-gal immersion electropolishing system. Progress has also been made in developing in situ electropolishing techniques that can be used to decontaminate metallic surfaces that cannot readily be transported to or immersed in a conventional electropolishing tank. Sectioning/pretreatment studies are under way to develop and demonstrate optimum disassembly, sectioning, surface preparation, and gross contamination removal procedures. Arc saw, plasma arc torch, and explosive cutting techniques are being evaluated in terms of the thickness and characteristics of the disturbed metal layer. Some of the pretreatment methods under consideration for removal of paint, grease, corrosion layers, and gross contamination include vibratory finishing, ultrasonics, dry and liquid abrasive blasting, and high-pressure spray systems. Other supporting studies are also in progress to provide a sound technical basis for scale-up and widespread application of this new decontamination process. 44 figures

Decontamination and recovery of a nuclear facility to allow continued operation

International Nuclear Information System (INIS)

Cavaghan, Josh

2017-01-01

A power supply failure caused a loss of power to key ventilation systems in an operating nuclear facility. The in-cell depression was lost, which led to an egress of activity through prepared areas and into the normal operating areas. After an initial programme of radiological monitoring to quantify and categorise the activity in the operating areas, a plan was developed for the decontamination and remediation of the plant. The scope of the recovery plan was substantial and featured several key stages. The contamination was almost entirely "1"3"7Cs, reflecting the α:β/γ ratio for the facility. In addition to the physical remediation work, several administrative controls were introduced such as new local rules, safety signage to indicate abnormal radiological conditions in certain areas and training of the decontamination teams. All areas of plant, which were contaminated, were returned to normal access arrangements and the plant was successfully returned to full operational capability, <12 months from the date of the event. (authors)

Room source management decontamination in Uruguay

International Nuclear Information System (INIS)

Blanco, D.; Montanez, Osvaldo

1998-01-01

A surface,work materials and tools contamination it produced for Ra-226 sources management in des use in Uruguayan radioactive waste and sources management and storage room specifically in the Uruguay Republic University in Nuclear Search Center. A surface contamination direct was performed measurement with Eberline alpha particles Contamat FHT 111M with 42 496/30 sounder. It found greater and least contamination grade in all cement floor as well as in tables where was managed with Ra-226 sources. A value measured surface contamination can see in the Room scheme with more 200 Bq/cm in extension small places. A segregation between work materials and tools considerate d free contamination was realized. The contaminated objects was separated for a future treatment. A proceeding followed in the decontamination was inhale, abrasion,sweep essays in different representative zones, obtain decontamination factors and residual activity

Cleaning, abrasion, and polishing effect of novel perlite toothpaste abrasive.

Science.gov (United States)

Wang, Bo

2013-01-01

This study was intended to optimize perlite particle size and morphology for better tooth cleaning and lower tooth abrasion, and to evaluate the performance of a whitening toothpaste containing the optimized perlite abrasive for tooth cleaning, abrasion, and polishing. Perlite toothpaste abrasive samples were prepared by air classifying a commercial expanded perlite product. The tooth cleaning and abrasion properties for these classified perlite samples were reported via the pellicle cleaning ratio (PCR) and relative dentin abrasion (RDA). Performance of the whitening toothpaste containing the optimized perlite abrasive in tooth cleaning, polishing, and abrasion was evaluated against a widely used synthetic high-cleaning silica. Air classification removes large perlite particles and also physically changes perlite particle morphology from mostly three dimensional and angular particles to mainly two dimensional and platy particles. All the classified samples show good tooth cleaning effect, but tooth abrasion decreases significantly with decreasing particle size. Compared to high-cleaning silica whitening toothpaste, the whitening toothpaste containing the optimized perlite abrasive (PerlClean) is slightly better at tooth cleaning, lower in tooth abrasion, and significantly better at tooth polishing. Fine platy perlite particles are effective in tooth cleaning with low tooth abrasion. The enhanced performance of optimized perlite toothpaste abrasive compared to high-cleaning silica in a whitening toothpaste is attributed to the optimized particle size distribution and the unique platy particle geometry.

Assessment of mechanical and three-body abrasive wear peculiarity ...

Indian Academy of Sciences (India)

The three-body abrasive wear characteristic of fabricated composites has been assessed under different operating conditions. For this, the three-body abrasion test is done on dry abrasion test rig (TR-50)and analysed using Taguchi's experimental design scheme and analysis of variance. The results obtained from these ...

Planning of decontamination and bleaching of textiles in an industrial cycle; Programmation des operations de decontamination et de blanchissage du linge dans un cycle industriel

Energy Technology Data Exchange (ETDEWEB)

Boutot, Pierre; Schipfer, Pierre [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre de Production de Plutonium de Marcoule, Service de Protection contre les Radiations (France)

1964-10-15

This note describes the operational planning for the decontamination and bleaching of textiles (clothes, protections, etc.) worn by personnel, in industrial-type washing machines. Various tests have been conducted with contaminated cotton samples using different cleaning products (and quantities) and various temperature cycles. The performance of the washing cycle (soaking, pre-washing, washing, rinsing) is discussed in terms of decontamination and washing efficiency, textile wear and resistance to shrinkage, whiteness, etc. The experimental washing machine is described [French] Cette etude programme les operations de decontamination et de blanchissage du linge au sein d'un cycle de traitement tel qu'il apparait dans les machines a laver industrielles a fort indice de production. Les echantillons de cotonnade, contamines au moyen de produits de fission, sont de meme nature que le tissu des vetements de protection. En matiere de decontamination les meilleurs resultats sont obtenus apres un trempage faiblement acide et un prelavage au moyen d'un sequestrant. Dans le cadre du blanchissage, seule une lessive industrielle employee dans la phase de lavage peut conferer aux tissus la luminance que requiert leur bonne presentation. Les taches persistantes sont effacees par blanchiment au cours du rincage tiede. Une analyse terminale permet de constater que l'usure des vetements est davantage liee aux conditions d'utilisation qu'aux operations de lavage et de decontamination. (auteurs)

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)

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)

Study on operational condition of electro-decontamination by computer simulation

International Nuclear Information System (INIS)

Amamoto, Ippei; Sato, Koji; Kawabe, Akihiro; Fujita, Reiko; Terai, Takayuki

2005-01-01

The molten-salt electro-decontamination method can be taken up as adecontamination method for contaminated metal systems generated in the reprocessing using the fluoride volatility method, etc. This method makes a small amount of secondary waste and is able to construct a small-size process in which a critical state is easily controlled. It can be further expected that an electrolytic current penetrates inside contaminated substances of complex shape. In this report, an appropriate operational condition was theoretically obtained by the simulation on the applicability of this method to decontamination of metal materials, and it was confirmed by a fundamental testing that the simulation result is reasonable. (M.H.)

Dual-arm manipulation module for use in decontamination and decommissioning operations

International Nuclear Information System (INIS)

Hamel, W.R.; Haley, D.C.; Dixon, W.E.

1994-01-01

A dual-arm manipulation module is under development for application in decontamination and decommissioning (D ampersand D) tasks. The development is led by Oak Ridge National Laboratory with support from Sandia National Laboratories, and with university and industry participation. The project is part of the Robotics Technology Development Program funded by the US Department of Energy, Environmental Restoration and Waste Management, Office of Technology Development. The dual-arm module is designed to provide dexterous manipulation capability for remote characterization, decontamination, and dismantlement operations, and the module is reconfigurable to meet various deployment requirements. Remote manipulation capability can benefit D ampersand D activities through reduced worker exposure to both contaminant and industrial hazards. When tasks conditions permit, increased use of robotic features reduce costs by increased efficiency of operation

Life cycle and sustainability of abrasive tools

CERN Document Server

Linke, Barbara

2016-01-01

This monograph focuses on abrasive tools for grinding, polishing, honing, and lapping operations. The book describes the life cycle of abrasive tools from raw material processing of abrasive grits and bonding, manufacturing of monolithic or multi-layered tools, tool use to tool end-of-life. Moreover, this work highlights sustainability challenges including economic, environmental, social and technological aspects. The target audience primarily comprises research and industry experts in the field of manufacturing, but the book may also be beneficial for graduate students.

Optimization of Nonambulant Mass Casualty Decontamination Protocols as Part of an Initial or Specialist Operational Response to Chemical Incidents.

Science.gov (United States)

Chilcott, Robert P; Mitchell, Hannah; Matar, Hazem

2018-05-30

The UK's Initial Operational Response (IOR) is a new process for improving the survival of multiple casualties following a chemical, biological, radiological or nuclear incident. Whilst the introduction of IOR represents a patient-focused response for ambulant casualties, there is currently no provision for disrobe and dry decontamination of nonambulant casualties. Moreover, the current specialist operational response (SOR) protocol for nonambulant casualty decontamination (also referred to as "clinical decontamination") has not been subject to rigorous evaluation or development. Therefore, the aim of this study was to confirm the effectiveness of putatively optimized dry (IOR) and wet (SOR) protocols for nonambulant decontamination in human volunteers. Dry and wet decontamination protocols were objectively evaluated using human volunteers. Decontamination effectiveness was quantified by liquid chromatography-mass spectrometry analysis of the recovery of a chemical warfare agent simulant (methylsalicylate) from skin and hair of volunteers, with whole-body fluorescence imaging to quantify the skin distribution of residual simulant. Both the dry and wet decontamination processes were rapid (3 and 4 min, respectively) and were effective in removing simulant from the hair and skin of volunteers, with no observable adverse effects related to skin surface spreading of contaminant. Further studies are required to assess the combined effectiveness of dry and wet decontamination under more realistic conditions and to develop appropriate operational procedures that ensure the safety of first responders.

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

Skin decontamination of G, V, H L agents by Canadian reactive skin decontaminant lotion

Energy Technology Data Exchange (ETDEWEB)

Bide, R.W.; Sawyer, T.W.; DiNinno, V.L.; Armour, S.J.; Risk, D.J.

1993-05-13

The Canadian Reactive Skin Decontaminant Lotion (RSDL) is a reactive solution designed to be applied directly to skin for the decontamination and destruction of the classical chemical warfare agents. The solvent of the RSDL is very effective in dissolving liquid agents from the skin surface and the differential solubility of agents in the RSDL and the skin strongly favors retention of agents in the lotion. The active ingredient in the RSDL reacts rapidly and completely with G-agents, V-agents, mustard Lewisite producing relatively nontoxic products. The RSDL will dissolve and destroy agent thickened with acrylate polymers. The lotion is water soluble and readily removed from the skin. Since the RSDL is water soluble, it is active against water soluble agents even at high dilutions. For water insoluble agents, the activity is reduced as the water content rises above abrasive 50% due to insolubility of the agents. Skin and eye irritancy trials indicate that the RSDL is only a mild irritant to the eyes (equivalent to a chlorinated swimming pool) and to abraded skin. Acute toxicity trials showed that large oral and intraperitoneal doses were essentially non-toxic. The RSDL was fielded by the Canadian Forces for the Gulf Conflict. The RSDL may be used in open wounds for short periods. Wound decontamination and irrigation with RSDL diluted 1:1 with isotonic saline was recommended for the Gulf conflict.

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

Chemical decontamination method for radioactive metal waste

International Nuclear Information System (INIS)

Tanaka, Akio; Onuma, Tsutomu; Yamazaki, Sei; Miura, Haruki.

1993-01-01

The present invention provides a chemical decontamination method for radioactive metal wastes, which are generated from radioactive material handling facilities and the surfaces of which are contaminated by radioactive materials. That is, it has a feature of applying acid dissolution simultaneously with mechanical grinding. The radioactive metal wastes are contained in a vessel such as a barrel together with abrasives in a sulfuric acid solution and rotated at several tens rotation per minute. By such procedures for the radioactive metal wastes, (1) cruds and passive membranes are mechanically removed, (2) exposed mother metal materials are uniformly brought into contact with sulfuric acid and further (3) the mother metal materials dissolve the cruds and the passive membranes also chemically by a reducing dissolution (so-called local cell effect). According to the method of the present invention, stainless steel metal wastes having cruds and passive membranes can rapidly and efficiently be decontaminated to a radiation level equal with that of ordinary wastes. (I.S.)

Process and device for fabrication of ice beads and application to abrasive blasting with ice beads for surface treatments

International Nuclear Information System (INIS)

Barnier, M.; Manificat, A.; Perroud, P.

1989-01-01

A device is described for cleaning and decontamination by abrasive blasting with ice beads. It comprises a water injector, with many holes, at the top of a column feeded with cold gas where solidification of water droplets begins, solidification is completed in a cooling liquids, ice is extracted by a screw and pushed to the projection nozzle with cold gas [fr

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)

EDF/CIDEN - ONECTRA: PWR decontamination

International Nuclear Information System (INIS)

Fayolle, P.; Orcel, H.; Wertz, L.

2010-01-01

In the context of PWR circuit renewal (expected in 2011) and their decontamination, an analysis of data coming from cartography and on site decontamination measurements as well as from premise modelling by means of the PANTHERE radioprotection code, is presented. Several French PWRs have been studied. After a presentation of code principles and operation, the authors discuss the radiological context of a workstation, and give an assessment of the annual dose associated with maintenance operations with or without decontamination

Air Abrasion

Science.gov (United States)

... Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air ... will perform any procedures that use air-abrasion technology. Ask your dentist if he or she uses ...

Interim report on the activity hold-up and ease of decontamination of permanent coatings and surface treatments incorporated in a glove box floor

International Nuclear Information System (INIS)

Dalton, J.T.; Eccles, E.W.; Sutcliffe, P.W.; Turner, A.D.; Dawson, R.K.

1987-12-01

A commercial GRP glove box has been equipped with 1 square foot tiles of alternative flooring materials. These comprise highly polished GRP, PEEK, electropolished stainless steel, cold-rolled stainless steel foil, bright nickel electroplate on stainless steel and hard chrome electroplate on stainless steel. The natural GRP finish was used as a reference surface. Standard PuO 2 handling and floor abrasion operations have been carried out on a regular basis. Subsequently, the floor tiles have been decontaminated by swabbing with Arklone soaked tissues and a mass balance has determined the fraction of PuO 2 unaccounted to be about 1%. Hard, smooth surfaces are promising to give the best performance in minimising activity retention under these abrasive conditions to ∼ 100 μg cm -2 . Glove box aerosol concentrations have also been monitored as a function of time after the completion of handling operations by air sampling and by gravity settling. After an initial rapid decrease over ∼ 2 hours, a steady state is reached corresponding to ∼ 1 ng/l of PuO 2 . (author)

BNL Building 650 lead decontamination and treatment feasibility study. Final report

International Nuclear Information System (INIS)

Kalb, P.D.; Cowgill, M.G.; Milian, L.W.

1995-10-01

Lead has been used extensively at Brookhaven National Laboratory (BNL) for radiation shielding in numerous reactor, accelerator and other research programs. A large inventory of excess lead (estimated at 410,000 kg) in many shapes and sizes is currently being stored. Due to it's toxicity, lead and soluble lead compounds are considered hazardous waste by the Environmental Protection Agency. Through use at BNL, some of the lead has become radioactive, either by contamination of the surface or through activation by neutrons or deuterons. This study was conducted at BNL's Environmental and Waste Technology Center for the BNL Safety and Environmental Protection Division to evaluate feasibility of various treatment options for excess lead currently being stored. The objectives of this effort included investigating potential treatment methods by conducting a review of the literature, developing a means of screening lead waste to determine the radioactive characteristics, examining the feasibility of chemical and physical decontamination technologies, and demonstrating BNL polyethylene macro-encapsulation as a means of treating hazardous or mixed waste lead for disposal. A review and evaluation of the literature indicated that a number of physical and chemical methods are available for decontamination of lead. Many of these techniques have been applied for this purpose with varying degrees of success. Methods that apply mechanical techniques are more appropriate for lead bricks and sheet which contain large smooth surfaces amenable to physical abrasion. Lead wool, turnings, and small irregularly shaped pieces would be treated more effectively by chemical decontamination techniques. Either dry abrasion or wet chemical methods result in production of a secondary mixed waste stream that requires treatment prior to disposal

Study of the rheological properties and the finishing behavior of abrasive gels in abrasive flow machining

Energy Technology Data Exchange (ETDEWEB)

Wang, A. C.; Liu, C. H.; Liang, K. Z.; Pai, S. H. [Ching Yun University, Taipei (China)

2007-10-15

Abrasive flow machining (AFM) is an effective method to finish the smooth surface in the complex holes. Abrasive media are key elements which dominate the polished results in AFM. But it is hard to develop the machining model of these abrasive gels because of its complicated mechanism. In this research, a non-Newtonian flow is used to set up the abrasive mechanism of the abrasive media in AFM. Power law is a main equation of the non-Newtonian flow to describe the motion of the abrasive media. Viscosities vs. shear rates of different abrasive gels are used to establish the power law in CFD-ACE{sup +} software first. And the working parameters of AFM were applied as input to study the properties of the abrasive gels in AFM. Finally, the relationships between the simulations and the experiments were found. And the abrasive mechanism of the abrasive gels was set up in AFM. The simulated results show that the abrasive gel with high viscosity can entirely deform in the complex hole than the abrasive gel with low viscosity. And the abrasive gel with high viscosity generates a larger shear force than the abrasive gel with low viscosity in the same area. Moreover, the strain rate is seriously changed when the abrasive gel cross over the narrow cross-section of the complex hole. It also means that abrasive gel will produce large finish force in that area. And these results indeed consist with the experiments in AFM.

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

Preliminary design and estimate of capital and operating costs for a production scale application of laser decontamination technology

International Nuclear Information System (INIS)

Pang, Ho-ming; Edelson, M.C.

1994-01-01

The application of laser ablation technology to the decontamination of radioactive metals, particularly the surfaces of equipment, is discussed. Included is information related to the design, capital and operating costs, and effectiveness of laser ablation technology, based on commercial excimer and Nd:YAG lasers, for the decontamination of production scale equipment

Robotic edge machining using elastic abrasive tool

Science.gov (United States)

Sidorova, A. V.; Semyonov, E. N.; Belomestnykh, A. S.

2018-03-01

The article describes a robotic center designed for automation of finishing operations, and analyzes technological aspects of an elastic abrasive tool applied for edge machining. Based on the experimental studies, practical recommendations on the application of the robotic center for finishing operations were developed.

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

Reduced abrasion drilling fluid

NARCIS (Netherlands)

2010-01-01

A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

Reduced abrasion drilling fluid

NARCIS (Netherlands)

2012-01-01

A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

Los Alamos DP West Plutonium Facility decontamination project

International Nuclear Information System (INIS)

Garde, R.; Cox, E.J.; Valentine, A.M.

1982-01-01

The DP West Plutonium Facility operated by the Los Alamos National Laboratory, Los Alamos, New Mexico, was decontaminated between April 1978 and April 1981. The facility was constructed in 1944 to 1945 to produce plutonium metal and fabricate parts for nuclear weapons. It was continually used as a plutonium processing and research facility until mid-1978. Decontamination operations included dismantling and removing gloveboxes and conveyor tunnels; removing process systems, utilities, and exhaust ducts; and decontaminating all remaining surfaces. This report describes glovebox and conveyor tunnel separations, decontamination techniques, health and safety considerations, waste management procedures, and costs of the operation

Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

International Nuclear Information System (INIS)

Milly, Hussam; Andiappan, Manoharan; Thompson, Ian; Banerjee, Avijit

2014-01-01

The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

Synthesis CNTs Particle Based Abrasive Media for Abrasive Flow Machining Process

International Nuclear Information System (INIS)

Kumar, Sonu; Walia, R.S; Dhull, S.; Murtaza, Q.; Tyagi, P. K.

2016-01-01

Abrasive flow machining (AFM) is a modem fine finishing process used for intricate and internal finishing of components or parts. It is based on flowing of viscoelastic abrasive media over the surface to be fine finished. The abrasive media is the important parameter in the AFM process because of its ability to accurately abrade the predefined area along it flow path. In this study, an attempt is made to develop a new abrasive, alumina with Carbon nanotubes (CNTs) in viscoelastic medium. CNT s in house produced through chemical vapour deposition technique and characterize through TEM. Performance evaluation of the new abrasive media is carried out by increasing content of CNT s with fixed extrusion pressure, viscosity of media and media flow rate as process parameters and surface finish improvement and material removal as process responses in AFM setup. Significantly improvement has been observed in material removal and maximum improvement of 100% has been observed in the surface finish on the inner cylindrical surface of the cast iron work piece. (paper)

Interim report on the activity hold-up, and ease of decontamination of permanent coatings and surface treatments incorporated in a glove box floor

International Nuclear Information System (INIS)

Dalton, J.T.; Eccles, E.W.; Sutcliffe, P.W.; Turner, A.D.; Dawson, R.K.

1987-11-01

A commercial glass reinforced plastic (GRP) glove box has been equipped with 1 square foot tiles of alternative flooring materials. These comprise highly polished GRP, poly-ether-ether-ketone (PEEK), electropolished stainless steel, cold-rolled stainless steel foil, bright nickel electroplate on stainless steel and hard chrome electroplate on stainless steel. The natural GRP finish was used as a reference surface. Standard PuO 2 handling and floor abrasion operations have been carried out on a regular basis. Subsequently, the floor tiles have been decontaminated by swabbing with Arklone soaked tissues and a mass balance has determined the fraction of PuO 2 unaccounted to be about 1%. Hard, smooth surfaces are promising to give the best performance in minimizing activity retention under these abrasive conditions to ∼ 100 μg cm -2 . Glove box aerosol concentrations have also been monitored as a function of time after the completion of handling operations by air sampling and by gravity settling. After an initial rapid decrease over ∼ 2 hours, a steady state is reached corresponding to ∼ 1 ng/l of PuO 2 . (author)

Machining with abrasives

CERN Document Server

Jackson, Mark J

2011-01-01

Abrasive machining is key to obtaining the desired geometry and surface quality in manufacturing. This book discusses the fundamentals and advances in the abrasive machining processes. It provides a complete overview of developing areas in the field.

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)

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

Chemically reducing decontamination method for radioactive metal

International Nuclear Information System (INIS)

Tanaka, Akio; Onuma, Tsutomu; Sato, Hitoshi.

1994-01-01

The present invention concerns a decontamination method of electrolytically reducing radioactive metal wastes, then chemically dissolving the surface thereof with a strong acid decontaminating solution. This method utilizes dissolving characteristics of stainless steels in the strong acid solution. That is, in the electrolytic reduction operation, a portion of the metal wastes is brought into contact with a strong acid decontaminating solution, and voltage and current are applied to the portion and keep it for a long period of time so as to make the potential of the immersed portion of the metal wastes to an active soluble region. Then, the electrolytic reduction operation is stopped, and the metal wastes are entirely immersed in the decontaminating solution to decontaminate by chemical dissolution. As the decontaminating solution, strong acid such as sulfuric acid, nitric acid is used. Since DC current power source capacity required for causing reaction in the active soluble region can be decreased, the decontamination facility can be minimized and simplified, and necessary electric power can be saved even upon decontamination of radioactive metal wastes made of stainless steels and having a great area. Further, chemical dissolution can be conducted without adding an expensive oxidizing agent. (N.H.)

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

Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

Energy Technology Data Exchange (ETDEWEB)

Milly, Hussam [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Andiappan, Manoharan [Unit of Dental Public Health, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Thompson, Ian [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Banerjee, Avijit, E-mail: avijit.banerjee@kcl.ac.uk [Biomaterials, Biomimetics and Biophotonics Research Group, Kings College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom); Unit of Conservative Dentistry, King' s College London Dental Institute at Guy' s Hospital, King' s Health Partners, London (United Kingdom)

2014-06-01

The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required “time taken”. BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

Health physics and industrial hygiene aspects of decontamination as a precursor to decontamination

International Nuclear Information System (INIS)

Card, C.J.; Hoenes, G.R.; Munson, L.F.; Halseth, G.A.

1982-06-01

The Pacific Northwest Laboratory is conducting a comprehensive study of the impacts, benefits and effects of decontamination as a precursor to decommissioning for the US Nuclear Regulatory Commission. The program deals primarily with chemical cleaning of light-water reactor (LWR) systems that will not be returned to operation. A major section of this study defines the health physics and industrial hygiene and safety concerns during decontamination operations. The primary health physics concerns include providing adequate protection for workers from radiation sources which are transported by the decontamination processes, estimating and limiting radioactive effluents to the environment and maintaining operations in accordance with the ALARA philosophy. Locating and identifying the areas of contamination and measuring the radiation exposure rates throughout the reactor primary system are fundamental to implementing these health physics goals. The principal industrial hygiene and safety concerns stem from the fact that a nuclear power plant is being converted for a time to a chemical plant which will contain large volumes of chemical solutions

Force-feedback tele operation of industrial robots a cost effective solution for decontamination of nuclear plants

International Nuclear Information System (INIS)

Desbats, P.; Andriot, C.; Gicquel, P.; Viallesoubranne, J.P.; Souche, C.

1998-01-01

Decontamination and maintenance in hot cells are some new emerging applications of industrial robots in the nuclear fuel cycle plants. Industrial robots are low cost, accurate and reliable manipulator arms which are used in manufacturing industries usually. Thanks to the recent evolution of robotics technologies, some industrial robots may be adapted to nuclear environment. These robots are transportable, sealed and can be decontaminated, and they may be 'hardened' up to a level of irradiation dose sufficient for operation in low and medium irradiating/contaminating environments. Although industrial robots are usually programmed to perform specific and repetitive tasks, they may be remotely tele-operated by human operators as well. This allows industrial robots to perform usual tele-manipulation tasks encountered in the nuclear plants and more. The paper presents the computer based tele-operation control system TAO2000 TM , developed by the Tele-operation and Robotics Service of CEA, which has been applied to the RX90 TM industrial robot from ST-UBLI company. This robot has been selected in order to perform various maintenance and decontamination tasks in COGEMA plants. TAO2000 provides the overall tele-robotic and robotic functions necessary to perform any remote tele-operation application in hostile environment: force-feedback master-slave control; computer- assisted tele-operation of mechanical processes; trajectory programming as well as various robotics functions; graphical modelling of working environment and simulation; automatic path planning with obstacle avoidance; man-machine interface for tasks programming and mission execution. Experimental results reported in the paper demonstrate the feasibility of force-feedback master-slave control of standard industrial robots. Finally, the design of new, cost effective. tele-operation systems based on industrial robots may be intended for nuclear plants maintenance. (author)

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.)

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.)

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)

Mobile workstation for decontamination and decommissioning operations

Energy Technology Data Exchange (ETDEWEB)

Whittaker, W.L.; Osborn, J.F.; Thompson, B.R. [Carnegie-Mellon Univ., Pittsburgh, PA (United States). Robotics Inst.

1993-10-01

This project is an interdisciplinary effort to develop effective mobile worksystems for decontamination and decommissioning (D&D) of facilities within the DOE Nuclear Weapons Complex. These mobile worksystems will be configured to operate within the environmental and logistical constraints of such facilities and to perform a number of work tasks. Our program is designed to produce a mobile worksystem with capabilities and features that are matched to the particular needs of D&D work by evolving the design through a series of technological developments, performance tests and evaluations. The project has three phases. In this the first phase, an existing teleoperated worksystem, the Remote Work Vehicle (developed for use in the Three Mile Island Unit 2 Reactor Building basement), was enhanced for telerobotic performance of several D&D operations. Its ability to perform these operations was then assessed through a series of tests in a mockup facility that contained generic structures and equipment similar to those that D&D work machines will encounter in DOE facilities. Building upon the knowledge gained through those tests and evaluations, a next generation mobile worksystem, the RWV II, and a more advanced controller will be designed, integrated and tested in the second phase, which is scheduled for completion in January 1995. The third phase of the project will involve testing of the RWV II in the real DOE facility.

Mobile workstation for decontamination and decommissioning operations

International Nuclear Information System (INIS)

Whittaker, W.L.; Osborn, J.F.; Thompson, B.R.

1993-10-01

This project is an interdisciplinary effort to develop effective mobile worksystems for decontamination and decommissioning (D ampersand D) of facilities within the DOE Nuclear Weapons Complex. These mobile worksystems will be configured to operate within the environmental and logistical constraints of such facilities and to perform a number of work tasks. Our program is designed to produce a mobile worksystem with capabilities and features that are matched to the particular needs of D ampersand D work by evolving the design through a series of technological developments, performance tests and evaluations. The project has three phases. In this the first phase, an existing teleoperated worksystem, the Remote Work Vehicle (developed for use in the Three Mile Island Unit 2 Reactor Building basement), was enhanced for telerobotic performance of several D ampersand D operations. Its ability to perform these operations was then assessed through a series of tests in a mockup facility that contained generic structures and equipment similar to those that D ampersand D work machines will encounter in DOE facilities. Building upon the knowledge gained through those tests and evaluations, a next generation mobile worksystem, the RWV II, and a more advanced controller will be designed, integrated and tested in the second phase, which is scheduled for completion in January 1995. The third phase of the project will involve testing of the RWV II in the real DOE facility

Summary of decontamination cover manufacturing experience

International Nuclear Information System (INIS)

Ulrich, G.B.; Berry, H.W.

1995-02-01

Decontamination cover forming cracks and vent cup assembly leaks through the decontamination covers were early manufacturing problems. The decontamination cover total manufacturing process yield was as low as 55%. Applicable tooling and procedures were examined. All manufacturing steps from foil fabrication to final assembly leak testing were considered as possible causes or contributing factors to these problems. The following principal changes were made to correct these problems: (1) the foil annealing temperature was reduced from 1375 degrees to 1250 degrees C, (2) the decontamination cover fabrication procedure (including visual inspection for surface imperfections and elimination of superfluous operations) was improved, (3) the postforming dye penetrant inspection procedure was revised for increased sensitivity, (4) a postforming (prewelding) 1250 degrees C/1 h vacuum stress-relief operation was added, (5) a poststress relief (prewelding) decontamination cover piece-part leak test was implemented, (6) the hold-down fixture used during the decontamination cover-to-cup weld was modified, and concomitantly, and (7) the foil fabrication process was changed from the extruding and rolling of 63-mm-diam vacuum arc-remelted ingots (extrusion process) to the rolling of 19-mm-square arc-melted drop castings (drop cast process). Since these changes were incorporated, the decontamination cover total manufacturing process yield has been 91 %. Most importantly, more than 99% of the decontamination covers welded onto vent cup assemblies were acceptable. The drastic yield improvement is attributed primarily to the change in the foil annealing temperature from 1375 degrees to 1250 degrees C and secondarily to the improvements in the decontamination cover fabrication procedure

Project gnome decontamination and decommissioning plan

International Nuclear Information System (INIS)

1979-04-01

The document presents the operational plan for conducting the final decontamination and decommissioning work at the site of the first U.S. nuclear detonation designed specifically for peaceful purposes and the first underground event on the Plowshare Program to take place outside the Nevada Test Site. The plan includes decontamination and decommissioning procedures, radiological guidelines, and the NV concept of operations

Abrasives and possibilities of increase in efficiency of abrasive waterjets

Czech Academy of Sciences Publication Activity Database

Sitek, Libor; Martinec, Petr

2016-01-01

Roč. 9, March 2016 (2016), s. 877-881 ISSN 1805-0476 R&D Projects: GA MŠk(CZ) LO1406; GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : high-speed waterjets * abrasive waterjets * abrasives * garnet * zirconia Subject RIV: JQ - Machines ; Tools http://www.mmscience.eu/content/file/archives/MM_Science_201603.pdf

Atmospheric particulate emissions from dry abrasive blasting using coal slag

Energy Technology Data Exchange (ETDEWEB)

Bhaskar Kura; Kalpalatha Kambham; Sivaramakrishnan Sangameswaran; Sandhya Potana [University of New Orleans, New Orleans, LA (United States). Department of Civil and Environmental Engineering

2006-08-15

Coal slag is one of the widely used abrasives in dry abrasive blasting. Atmospheric emissions from this process include particulate matter (PM) and heavy metals, such as chromium, lead, manganese, nickel. Quantities and characteristics of PM emissions depend on abrasive characteristics and process parameters. Emission factors are key inputs to estimate emissions. Experiments were conducted to study the effect of blast pressure, abrasive feed rate, and initial surface contamination on total PM (TPM) emission factors for coal slag. Rusted and painted mild steel surfaces were used as base plates. Blasting was carried out in an enclosed chamber, and PM was collected from an exhaust duct using U.S. Environment Protection Agency source sampling methods for stationary sources. Results showed that there is significant effect of blast pressure, feed rate, and surface contamination on TPM emissions. Mathematical equations were developed to estimate emission factors in terms of mass of emissions per unit mass of abrasive used, as well as mass of emissions per unit of surface area cleaned. These equations will help industries in estimating PM emissions based on blast pressure and abrasive feed rate. In addition, emissions can be reduced by choosing optimum operating conditions. 40 refs., 5 figs., 2 tabs.

Abrasion Testing of Products Containing Nanomaterials, SOP-R-2: Scientific Operating Procedure Series: Release (R)

Science.gov (United States)

2016-04-01

Nanotechnologies -- Terminology and definitions for nano-objects -- Nanoparticle, nanofibre and nanoplate Definitions Abrasion - wearing away...ER D C SR -1 6- 2 Environmental Consequences of Nanotechnologies Abrasion Testing of Products Containing Nanomaterials, SOP-R-2...ERDC online library at http://acwc.sdp.sirsi.net/client/default. Environmental Consequences of Nanotechnologies ERDC SR-16-2 April 2016

Decontamination of lead by fusion (1962); Decontamination du plomb par fusion (1962)

Energy Technology Data Exchange (ETDEWEB)

Boutot, P; Giachetto, L; Capitaine, A [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1962-07-01

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) [French] Divers essais de decontamination par voies mecaniques et chimiques ayant donne des resultats discutables, un procede par fusion a ete mis au point. L'appareil se compose d'un four, chauffe au propane, muni d'un creuset en acier d'une capacite de 1 400 kg, de deux systemes de ventilation et d'un deprimometre afin d'eviter la diffusion de vapeurs nocives. Trois controles d'activite sont effectues: 1. sur des echantillons preleves avant, pendant et apres l'operation, 2. sur des carottages realises sur les lingots, 3. sur le lingot lui-meme. Le controle sanitaire permanent est assure par un enregistreur d'aerosols radioactifs et par des prelevements periodiques. Ce procede de decontamination doit encore etre ameliore, principalement en ce qui concerne la productivite et la securite. (auteurs)

Cutting and decontamination technologies for nuclear facility dismantling; Technologien zur Zerlegung und zur Dekontamination von kerntechnischen Anlagen

Energy Technology Data Exchange (ETDEWEB)

Huebner, Felix; Grone, Georg von; Schultmann, Frank

2017-03-15

The German Government's decision to phase-out nuclear power will lead to a substantial increase of the number of nuclear decommissioning and dismantling projects. The decommissioning of nuclear facilities must meet the requirements of the radiation protection ordinance. This study deals with the decontamination and dismantling technologies available to meet radiation protection requirements. The aim of this study is to determine the state of the art in the field of decommissioning and dismantling technologies. Furthermore, future trends in the development and application of such technologies should be identified. A detailed study of current literature provides an overview of established decommissioning technologies. Moreover, experts were consulted in order to facilitate a practical assessment. The experts' statements indicate that (apart from the chemical decontamination of the primary circuit) the use of mechanical methods is generally preferred. Abrasive methods are rated as particularly efficient. According to the experts, the development of new decontamination technologies may allow a more efficient decontamination. However, the success of a new technology will be subject to its application costs. Mechanical technologies are preferred for the dismantling of nuclear facilities. The band saw has been identified as a standard tool in nuclear dismantling. The survey has concluded that there is no need for new dismantling technologies. The potential lies in the optimization of existing processes and techniques. With regard to remotely operated systems, experts' opinions vary on whether the use of these systems will increase in future. Most areas inside a nuclear facility have low radiation levels that allow the use of human labour for the dismantling. However, there is a need for an improvement in the allocation and management of decommissioning projects.

Operation of the radiation dose registration system for decontamination and related works

International Nuclear Information System (INIS)

Ogawa, Tsubasa; Yasutake, Tsuneo; Itoh, Atsuo; Miyabe, Kenjiro

2017-01-01

The radiation dose registration system for decontamination and related works was established on 15 November 2013. Radiation dose registration center and primary contractors of decontamination and related works manage decontamination registration and management system. As of 31 March 2017, 384 primary contractors joined in the radiation dose registration system for decontamination and related works. 383,087 quarterly exposure dose records for decontamination and related works were registered. Based on the registered data provided by the primary contractors, radiation dose registration center has released the statistical data that represent the radiation control status for workers engaged in radiation work at the work areas of decontamination and related works, etc. The statistical data shows that there were 40,377 workers engaged in decontamination and related works in 2015. The average exposure dose for workers was 0.6 mSv in 2015. The maximum exposure dose for workers was 7.8 mSv in 2015. Dose distribution by age of workers shows the range of 60 to 64 years old were most engaged in decontamination and related works in 2015. Dose distribution by gender of workers shows 97% of workers were male in 2015. From 2012 to 2015, about 95% of workers were exposed to radiation less than 3 mSv. And about 80% of workers were exposed to radiation less than 1 mSv. The average exposure dose per year was ranged from 0.5 to 0.7 mSv. (author)

Measurement of Radioactive Contamination on Work Clothing of Workers Engaged in Decontamination Operations

Science.gov (United States)

Tsujimura, Norio; Yoshida, Tadayoshi; Hoshi, Katsuya

To rationally judge the necessity of the contamination screening measurements required in the decontamination work regulations, a field study of the surface contamination density on the clothing of the workers engaged in decontamination operations was performed. The clothing and footwear of 20 workers was analyzed by high-purity germanium (HPGe) gamma-ray spectroscopy. The maximum radiocesium activities (134Cs + 137Cs) observed were 3600, 1300, and 2100 Bq for the work clothing, gloves, and boots, respectively, and the derived surface contamination densities were below the regulatory limit of 40 Bq/cm2. The results of this field study suggest that the upper bounds of the surface contamination density on the work clothing, gloves, and boots are predictable from the maximum soil loading density on the surface of clothing and footwear and the radioactivity concentration in soil at the site.

Decontamination measures for Fukushima prefecture. Fukushima prefecture measures for promoting decontamination

International Nuclear Information System (INIS)

Endo, Kouzou

2013-01-01

For Fukushima prefecture having suffered from significant damage associated with the Great East Japan Earthquake and the nuclear power plant accident, the decontamination work is the most urgent issue. The paper reports the present situation of the remediation acts of Fukushima Government done since the accident, particular emphasis on the removal of radioactive substances due to cesium 137 in the residential area. Government supports to promote the decontamination work and its operators, and encourages employers and employees in their efforts, to set up temporary storages of the produced radioactive wastes, to cultivate and improve technical supports for decontamination work and strengthen understanding and support of the local resident, thus providing the training course for the site supervisors, the person engaged in the work and management. (S. Ohno)

CFD Based Erosion Modelling of Abrasive Waterjet Nozzle using Discrete Phase Method

International Nuclear Information System (INIS)

Kamarudin, Naqib Hakim; Prasada Rao, A K; Azhari, Azmir

2016-01-01

In Abrasive Waterjet (AWJ) machining, the nozzle is the most critical component that influences the performance, precision and economy. Exposure to a high speed jet and abrasives makes it susceptible to wear erosion which requires for frequent replacement. The present works attempts to simulate the erosion of the nozzle wall using computational fluid dynamics. The erosion rate of the nozzle was simulated under different operating conditions. The simulation was carried out in several steps which is flow modelling, particle tracking and erosion rate calculation. Discrete Phase Method (DPM) and K-ε turbulence model was used for the simulation. Result shows that different operating conditions affect the erosion rate as well as the flow interaction of water, air and abrasives. The simulation results correlates well with past work. (paper)

Decontamination of a rotating cutting tool during operation by means of atmospheric pressure plasmas

DEFF Research Database (Denmark)

Leipold, Frank; Kusano, Yukihiro; Hansen, F.

2010-01-01

, is used for the experiments. A rotating knife was inoculated with L. innocua. The surface of the rotating knife was partly exposed to an atmospheric pressure dielectric barrier discharge operated in air, where the knife itself served as a ground electrode. The rotation of the knife ensures a treatment...... of the whole cutting tool. A log 5 reduction of L. innocua is obtained after 340 s of plasma operation. The temperature of the knife after treatment was found to be below 30 °C. The design of the setup allows a decontamination during slicing operation....

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

Los Alamos DP West Plutonium Facility decontamination project, 1978-1981

International Nuclear Information System (INIS)

Garde, R.; Cox, E.J.; Valentine, A.M.

1982-09-01

The DP West Plutonium Facility operated by the Los Alamos National Laboratory, Los Alamos, New Mexico was decontaminated between April 1978 and April 1981. The facility was constructed in 1944 to 1945 to produce plutonium metal and fabricate parts for nuclear weapons. It was continually used as a plutonium processing and research facility until mid-1978. Decontamination operations included dismantling and removing gloveboxes and conveyor tunnels; removing process systems, utilities, and exhaust ducts; and decontaminating all remaining surfaces. This report describes glovebox and conveyor tunnel separations, decontamination techniques, health and safety considerations, waste management procedures, and costs of the operation

Development of a robot for decontamination of reactor well and maintenance pit wall surfaces

International Nuclear Information System (INIS)

Miyakawa, Minoru; Nozawa, Katsuro; Mizutani, Takeshi; Onozuka, Kazuaki; Morita, Isamu

1984-01-01

A robot has been developed at Hamaoka BWR Power Plant of Chubu Electric Power Company, Inc., which performs the decontamination of the wall surfaces of reactor wells and maintenance pits. The robot is controlled with a control box through a micro-computer. The mechanical structure and working principle of this robot is explained. One of the special features of this robot is that it perceives the steps on a wall, and washes the vertical and horizontal surfaces with two different types of brushes. As the material for the bristles of the brushes, nylon with alumina as abrasive (TAINEX-A made by Dupont Ltd.) was selected after some experience. The design specifications of the brushes were determined, based on the results of intensive performance test, which are shown in this report. The efficiency of this robot was proved by applying it to the decontamination of the reactor wells in the periodic inspection and maintenance of Unit 1 and Unit 2 in the Hamaoka BWR Power Plant. As the result of this decontamination, the contamination level was reduced from about 10 -3 μCi/cm 2 to about 10 -5 μCi/cm 2 . The measured results of contamination after the first and third decontamination works are listed for various parts of the well surfaces. (Aoki, K.)

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

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

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

Measurement of radioactive contamination on work clothing of workers engaged in decontamination operations

International Nuclear Information System (INIS)

Tsujimura, Norio; Yoshida, Tadayoshi; Hoshi, Katsuya

2016-01-01

To rationally judge the necessity of the contamination screening measurements required in the decontamination work regulations, a field study of the surface contamination density on the clothing of the workers engaged in decontamination operations was performed. The clothing and footwear of 20 workers was analyzed by high-purity germanium (HPGe) gamma-ray spectroscopy. The maximum radiocesium activities ("1"3"4Cs + "1"3"7Cs) observed were 3600, 1300, and 2100 Bq for the work clothing, gloves, and boots, respectively, and the derived surface contamination densities were below the regulatory limit of 40 Bq/cm"2. The results of this field study suggest that the upper bounds of the surface contamination density on the work clothing, gloves, and boots are predictable from the maximum soil loading density on the surface of clothing and footwear and the radioactivity concentration in soil at the site. (author)

Membrane treatment of liquid wastes from radiological decontamination operations.

Science.gov (United States)

Svittsov, A A; Khubetsov, S B; Volchek, K

2011-01-01

The paper focuses on the evaluation of membrane filtration for the treatment of liquid radioactive streams generated in area decontamination operations. In this work, semi-permeable membranes were demonstrated to be effective reducing the volume of wastewater containing cesium and cobalt by two orders of a magnitude. The efficiency of membrane separation was enhanced by employing additives that enlarged the size of target radionuclide species and improved their rejection by the membranes. This was achieved by chelation with synthetic water-soluble polymers and by adsorption on micro particles of adsorbent coupled with micelle formation. The effect of wastewater composition and that of the radionuclide-binding additives on the volume reduction was investigated. Membrane treatment is expected to help simplify further processing and decrease disposal costs.

Experience Practices on Decontamination Activity in NPP Decommissioning

Energy Technology Data Exchange (ETDEWEB)

Yoon, Suk Bon; Kim, Jeongju; Sohn, Wook [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

2016-10-15

Decommissioning of a nuclear power plant (NPP) involves various technical and administrative activities for a utility to terminate its license, which allows the plant site to be released from the regulatory control (site release). Decontamination activity in NPP decommissioning is one of the main technical activities to be performed during the decommissioning. The decontamination at decommissioning sites is usually performed due to several reasons such as reducing personnel dose and disposal costs, and cleanup to meet license termination requirements by using physical or chemical removal techniques proven through the previous experience practices. This paper introduces the best and worst practices for the decontamination activities collected from the decommissioning operational experiences through the implementation of nuclear decommissioning projects around the world. Review of the experiences of decontamination shows that it is important to conduct an advanced planning for optimized implementation of decontamination taking into considering site specific conditions such as operating time, reactor type, system, and so on. Also, a review of newer decontamination methods is necessary to safely and economically decommission the nuclear facility.

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

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)

Abrasion Properties of Steel Fiber Reinforced Silica Fume Concrete According to Los Angeles and Water Abrasion Tests

Directory of Open Access Journals (Sweden)

Tsan-Ching CHENG

2014-12-01

Full Text Available The current study mainly investigated the influence of different tests on the abrasion resistance of concrete mixed with steel fibers and silica fume. The abrasion resistance was assessed at 28, 56 and 91 days on concretes with water-binder ratios of 0.35 and 0.55 where in some mixes silica fume was substituted by 5 % of cement by weight. Steel fibers of 0.5 % and 1.0 % of concrete volume were also added into the test concrete by replacement of coarse and fine aggregates. The results showed that concrete with higher compressive strength in Los Angeles abrasion tests also had better abrasion resistance. The inclusion of steel fibers into test concrete with a water-binder ratio of 0.35 resulted in a significant increase in compressive strength. This concrete also displayed better abrasion resistance and splitting tensile strength than reference concrete; in the test sample with a water-binder ratio of 0.55, the added steel fibers was unable to effectively produce cementation with the concrete. The inclusion of silica fume improved the abrasion resistance of concretes. In water abrasion testing, the abrasion resistance of concrete containing steel fiber was worse than that of concrete without steel fibers. In the water abrasion testing, the surface of steel fiber reinforced concrete was eroded by water and steel balls, and the impact caused the steel fibers to separate from the concrete and led to higher wear loss. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6460

Usage of abrasion-resistant materials in agriculture

Directory of Open Access Journals (Sweden)

J Votava

2014-06-01

Full Text Available Agricultural soil-processing machines are subject to an extensive abrasive wear. This paper analyses technical materials and their fitness to exchangeable parts of plough bottoms, such as edge-tools and whole plough cutting edges. There were tested abrasion-resistant steels with different microstructures: austenite, martensite-bainite, and carbide. Steel with the pearlite-ferrite structure was used as an etalon. Abrasion resistance tests were processed in compliance with the norm CSN 01 5084, which is a test of abrasion wear on abrasive cloth.

Depressurized pipes decontamination by using circulation foam

International Nuclear Information System (INIS)

Damerval, Frederique; Belz, Jacques; Renouf, Marjorie; Janneau, Patrice

2012-09-01

Decontamination of pipes remains a necessity in order to reduce the radiation level during maintenance or dismantling operations but it is not so easy to do it, especially in case of a long pipe network. To achieve this operation, the use of chemistry is one of the more relevant methods; moreover, the liquid waste production still remains an issue that it can be avoided by the use of decontamination foams. (authors)

Sustainability of abrasive processes

DEFF Research Database (Denmark)

Aurich, J.C.; Linke, B.; Hauschild, Michael Zwicky

2013-01-01

, the content of technical presentations in STC G, and the results of a comprehensive literature study. The approach to sustainability includes environmental, social, and economic sustainability in accordance with the definition proposed in the Brundtland Report of the United Nations [156]. The main focus......This paper presents an overview of research on sustainability of abrasive processes. It incorporates results from a round robin study on ‘‘energy-efficiency of abrasive processes’’ which has been carried out within the scientific technical committee ‘‘abrasive processes’’ (STC G) of CIRP...... is on environmental and social sustainability. Economic sustainability will be considered as manufacturing productivity. © 2013 CIRP....

Development of a robot for decontamination of reactor well and maintenance pit wall surfaces

Energy Technology Data Exchange (ETDEWEB)

Miyakawa, Minoru; Nozawa, Katsuro; Mizutani, Takeshi; Onozuka, Kazuaki; Morita, Isamu

1984-03-01

A robot has been developed at Hamaoka BWR Power Plant of Chubu Electric Power Company, Inc., which performs the decontamination of the wall surfaces of reactor wells and maintenance pits. The robot is controlled with a control box through a micro-computer. The mechanical structure and working principle of this robot is explained. One of the special features of this robot is that it perceives the steps on a wall, and washes the vertical and horizontal surfaces with two different types of brushes. As the material for the bristles of the brushes, nylon with alumina as abrasive (TAINEX-A made by Dupont Ltd.) was selected after some experience. The design specifications of the brushes were determined, based on the results of intensive performance test, which are shown in this report. The efficiency of this robot was proved by applying it to the decontamination of the reactor wells in the periodic inspection and maintenance of Unit 1 and Unit 2 in the Hamaoka BWR Power Plant. As the result of this decontamination, the contamination level was reduced from 10/sup 3/ ..mu..Ci/cm/sup 2/ to about 10/sup 5/ ..mu..Ci/cm/sup 2/. The measured results of contamination after the first and third decontamination works are listed for various parts of the well surfaces.

Radiological survey following decontamination activities near the TA-45 site

International Nuclear Information System (INIS)

Gunderson, T.; Buhl, T.; Romero, R.; Salazar, J.

1983-07-01

Three areas at the site of a former radioactive liquid waste treatment plant at Los Alamos National Laboratory were decontaminated during 1982 by Bechtel Corporation, with health physics support provided by Eberline Instrument Corporation, under the Department of Energy's Formerly Utilized Sites Remedial Action Program (FUSRAP). Before decontamination, there were above-background concentrations of gross alpha, gross beta, 238 Pu, 239 240 Pu, 241 Am, 90 Sr, and 137 Cs in the surface soils. These combined concentrations were above operational decontamination guidelines for surface soil contamination. After cleanup operations, radionuclide concentrations in surface soils at all three sites were within decontamination guidelines

Progress in abrasive and grinding technology

CERN Document Server

Xu, Xipeng

2009-01-01

The grinding and abrasive processing of materials are machining techniques which use bonded or loose abrasives to remove material from workpieces. Due to the well-known advantages of grinding and abrasive processes, advances in abrasive and grinding technology are always of great import in enhancing both productivity and component quality. In order to highlight the recent progress made in this field, the editor invited 21 world-wide contributions with the aim of gathering together all of the achievements of leading researchers into a single publication. The authors of the 21 invited papers, of

EDF guide book for decontamination at power plant

International Nuclear Information System (INIS)

Glorennec, C.; Bemer, J.P.

1988-01-01

Nuclear Power Plant components or equipment often need to be more or less decontaminated before undergoing maintenance. In order to coordinate the activities of the different maintenance specialists belonging to the corporate or site organizations, the management of EDF/Nuclear and Fossil Division has created a decontamination task force. One of the objectives of this task force was to elaborate the present Guide Book for Decontamination at Power Plants. This paper provides assistance to nuclear plants operators in the very specific field of decontamination

RA Reactor operation and maintenance (I-IX), part VIII, Task 3.08/05, Decontamination of the reactor

International Nuclear Information System (INIS)

Zecevic, V.

1963-12-01

Permanent increase of radiation in the heavy water system was noticed during first three year of the RA reactor operation, even when the reactor was shutdown. It was found that there was no failure of the fuel element cladding. Radioactive cobalt was found in the heavy water which was rather strange. During repair of the heavy water system, it has been found that stellite was used for coating the heavy water pumps. Since stellite is a cobalt alloy, this could have been the source of radioactive cobalt in the heavy water. The stellite coating was damaged due to friction and particle of cobalt appeared in the coolant, they were activated since they were in the core. decontamination of the heavy water and the heavy water coolant loop was a must . Beside the detailed report on the contamination and decontamination of the heavy water system this volume includes 14 annexes describing the investigation of the event and the whole procedure of decontamination

Nuclear decontamination and decommissioning operations at the Idaho National Engineering and Environmental Laboratory (INEEL)

International Nuclear Information System (INIS)

Meservey, R.H.; Kenoyer, D.J.; Frazee, B.J.

1997-01-01

The Idaho National engineering and Environmental Laboratory (INEEL) is home of the largest concentration of nuclear reactors in the world. In addition to the reactors, many fuel reprocessing, laboratory, and other nuclear support facilities have been operated at the INEEL. Many have already been decontaminated and decommissioned (D and D) and many more are in the planning stages for such activities. A full time D and D program has been in existence at the INEEL for the past 20 years. Starting with a long range plan for D and D of all surplus contaminated facilities at the INEEL, and ending with the verification of the free release of those facilities after decommissioning, all aspects of D and D activities are covered. Topics covered in this paper include the INEEL D and D Long Range Plan, the D and D Porject Managers Handbook, the use of ASTM Standard Guides in decommissioning operations, and the INEEL D and D Technology Logic Diagrams. The identification and preparation of safety plans, environmental documentation, and operational procedures will also be covered in the presentation. The selection and use of advanced technologies to improve safety, reduce costs, and shorten D and D schedules is very important to the nuclear industry. In addition to a discussion of the D and D Technology Logic Diagrams, a discussion of new and improved technologies in use at the INEEL and other department of energy facilities will be presented. This will include brief discussions of work being performed at three Department of Energy Large Scale D and D Technology Demonstration projects. These include technology demonstrations at a Test Reactor, Uranium Fabrication Plant, and a large Production Reactor. Unique technologies which have been developed and tested at the INEEL will also be covered in the presentation. These include the biological decontamination of concrete, a laser enhanced zero added waste cutting, abraiding, and drilling technology, and the development of an

Properties, structure and machnining capabilities sintered corundum abrasives

Directory of Open Access Journals (Sweden)

Cz.J. Niżankowski

2010-07-01

Full Text Available The diversity of sintered corundum abrasives used in both bonded and in the embankment of abrasive tools currently poses substantialproblems for their choice of technology to specific tasks. Therefore performed a comparative study of ownership structures and capacitiesof elected representatives machnining sintered corundum abrasives of different generations, and this is normal sintered alumina,submicrocrystalline alumina sintered and nanocrystalline alumina sintered. Were studied some properties of a set of abrasive particles,physicochemical properties and structural and mechanical and technological properties. The studies used the method of microscopicmeasurement to determine the shape of abrasive particles, the pycnometer to determine the density of abrasive, a spectrometer todetermine the chemical composition of the magnetic analyzer for determining the magnetic fraction, scanning electron microscope toanalysis of abrasive grains and a special position to designate the machining capacity abrasive grains. The results showed a significantincrease in machining capacity sintered corundum abrasives with increasing degree of fragmentation of the crystallites sintered corundum abrasives and distinctive bands in the emerging microchip. The originality of the development provides a comparative summary ofproperties of sintered corundum abrasives of different generations and functions obtained by the author making the change in value indexof machininhcapacity grit from cutting speeds for different generations of sintered corundum.

Pleurectomy versus pleural abrasion for primary spontaneous pneumothorax in children.

Science.gov (United States)

Joharifard, Shahrzad; Coakley, Brian A; Butterworth, Sonia A

2017-05-01

Primary spontaneous pneumothorax (PSP) represents a common indication for urgent surgical intervention in children. First episodes are often managed with thoracostomy tube, whereas recurrent episodes typically prompt surgery involving apical bleb resection and pleurodesis, either via pleurectomy or pleural abrasion. The purpose of this study was to assess whether pleurectomy or pleural abrasion was associated with lower postoperative recurrence. The records of patients undergoing surgery for PSP between February 2005 and December 2015 were retrospectively reviewed. Recurrence was defined as an ipsilateral pneumothorax requiring surgical intervention. Bivariate logistic regressions were used to identify factors associated with recurrence. Fifty-two patients underwent 64 index operations for PSP (12 patients had surgery for contralateral pneumothorax, and each instance was analyzed separately). The mean age was 15.7±1.2years, and 79.7% (n=51) of patients were male. In addition to apical wedge resection, 53.1% (n=34) of patients underwent pleurectomy, 39.1% (n=25) underwent pleural abrasion, and 7.8% (n=5) had no pleural treatment. The overall recurrence rate was 23.4% (n=15). Recurrence was significantly lower in patients who underwent pleurectomy rather than pleural abrasion (8.8% vs. 40%, p<0.01). In patients who underwent pleural abrasion without pleurectomy, the relative risk of recurrence was 2.36 [1.41-3.92, p<0.01]. Recurrence of PSP is significantly reduced in patients undergoing pleurectomy compared to pleural abrasion. Level III, retrospective comparative therapeutic study. Copyright © 2017 Elsevier Inc. All rights reserved.

Decontamination and materials corrosion concerns in the BWR

International Nuclear Information System (INIS)

Gordon, B.M.; Gordon, G.M.

1988-01-01

The qualification of chemical decontamination processes to decontaminate complete systems or individual components in essential if effective inspection, maintenance, repair or replacement of plant components is to be achieved with minimum exposure of workers to ionizing radiation. However, it is critical that the benefits of decontamination processes are not overshadowed by deleterious materials/ corrosion side effects during the application of the process or during subsequent operation. This paper discusses such potential corrosion/materials problems in the BWR and presents relevant available corrosion data for the various commercial decontamination processes. (author)

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)

Damage to the edge of steel stampings and abrasive during ultrasonic hydroabrasive machining

International Nuclear Information System (INIS)

Dokuchaeva, V.A.; Chernov, A.P.

1976-01-01

Principles have been established explaining the fracture of abrasive material in the process of ultrasonic hydroabrasive treatment, and a method is proposed suitable for the calculation of steel barb erosion in the hydroabrasive flux. It is assumed that fracture occurs along the entire edge surface and that the losses caused by plastic deformation are small. Conclusion has been made as to the governing the change of the abrasive particle size in the time of treatment. It is shown that the most serious fracture takes place at initial stage of the treatment, terminating practically after 60 minutes of operation. Curves showing the distribution of boron carbide abrasive particles are presented

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

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

CONTROL SYSTEM EVALUATION AND IMPLEMENTATION FOR THE ABRASIVE MACHINING PROCESS ON WOOD

Directory of Open Access Journals (Sweden)

Stephen Jackson

2011-06-01

Full Text Available Continuous process improvement and automation have proven to be powerful tools for the wood processing industries in order to obtain better final product quality and thus increase profits. Abrasive machining represents an important and relevant process in the manufacturing and processing of wood products, which also implies high cost of materials and labor; therefore, special attention to this process is necessary. The objective of this work was to evaluate and demonstrate a process control system for use in the abrasive machining of wood and wood-based products. A control system was created on LabView® to integrate the monitoring process and the actions required, depending on the abrasive machining process conditions. The system acquires information from the optical sensor to detect loading and activate the cleaning system. The system continuously monitors the condition of the abrasive belt (tool wear by using an acoustic emission sensor and alerts the operator of the status of the belt (green, yellow, and red lights indicating satisfactory, medium, and poor belt condition. The system also incorporates an additional safety device, which helps prevent permanent damage to the belt, equipment, or workpiece by alerting the operator when an excessive temperature has been reached. The process control system proved that automation permits enhancement in the consistency of the belt cleaning technique by the elimination of the human errors. Furthermore, this improvement also affects the cost by extending the life of the belt, which reduces setup time, belt cost, operation cost, as well as others.

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

Study on design of light-weight super-abrasive wheel

Science.gov (United States)

Nohara, K.; Yanagihara, K.; Ogawa, M.

2018-01-01

Fixed-abrasive tool, also called a grinding wheel, is produced by furnacing abrasive compound which contains abrasive grains and binding powder such as vitrified materials or resins. Fixed-abrasive tool is installed on spindle of grinding machine. And it is given 1,800-2,000 min-1 of spindle rotation for the usage. The centrifugal fracture of the compound of fixed- abrasive tool is one of the careful respects in designing. In recent years, however, super-abrasive wheel as a fixed-abrasive tool has been developed and applied widely. One of the most characteristic respects is that metal is applied for the body of grinding-wheel. The strength to hold abrasive grain and the rigidity of wheel become stronger than those of general grinding wheel, also the lifespan of fixed-abrasive tool becomes longer. The weight of fixed-abrasive tool, however, becomes heavier. Therefore, when the super-abrasive wheel is used, the power consumption of spindle motor becomes larger. It also becomes difficult for the grinding-wheel to respond to sudden acceleration or deceleration. Thus, in order to reduce power consumption in grinding and to obtain quicker frequency response of super-abrasive wheel, the new wheel design is proposed. The design accomplishes 46% weight reduction. Acceleration that is one second quicker than that of conventional grinding wheel is obtained.

Method of decontaminating radioactive-contaminated instruments

Energy Technology Data Exchange (ETDEWEB)

Urata, M; Fujii, M; Kitaguchi, H

1982-03-29

Purpose: To enable safety processing of liquid wastes by recovering radioactive metal ions remaining in the electrolytes after the decontamination procedure thereby decreasing the radioactivity. Method: In a decontamination tank containing electrolytes consisting of diluted hydrochloric acid and diluted sulfuric acid, are provided a radioactive contaminated instrument connected to an anode and a collector electrode made of stainless steel connected to a cathode respectively. Upon applying electrical current, the portion of the mother material to be decontaminated is polished electrolytically into metal ions and they are deposited as metal on the collection electrode. After completion of the decontamination, an ultrasonic wave generator is operated to strip and remove the oxide films. Thereafter, the anode is replaced with the carbon electrode and electrical current is supplied continuously, whereby the remaining metal ions are deposited and recovered as the metal on the collection electrode.

Decontamination demonstration facility (D.D.F) modularization/mobility study

International Nuclear Information System (INIS)

FitzPatrick, V.F.; Butts, H.L.; Moles, R.G.; Lundgren, R.A.

1980-11-01

The component decontamination technology, developed under the DOE sponsored TRU Waste Decontamination Program, has potential benefits to nuclear utility owners in four strategic areas: (1) Meeting ALARA Criteria for Maintenance/Operations; (2) Management of wastes and waste forms; (3) Accident Response; (4) Decommissioning. The most significant step in transferring this technology directly to the nuclear industry is embodied in the TMI Decontamination Demonstration Facility

Decontamination of two filter boxes after a fire

International Nuclear Information System (INIS)

Cerre, P.; Mestre, E.; Lafitte, T.

1961-01-01

As a primary filter of the venting system caught fire in a hot cell of the Laboratory of Examination of Irradiated Fuels, this filter (as well as the secondary filter) has been removed, wrapped in polyvinyl sheets, and transported into the decontamination station. The authors report the details of the handling and decontamination operations: modifications to the station arrangement, measures of radiation protection, decontamination and measurements, observations made when disassembling the filter and filter-boxes [fr

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.)

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

Cleaning power and abrasivity of European toothpastes.

Science.gov (United States)

Wülknitz, P

1997-11-01

For 41 toothpastes available to European consumers in 1995, the cleaning efficacy was evaluated in comparison with abrasivity on dentin (RDA value). For cleaning power assessment, a modified pellicle cleaning ratio (PCR) measurement method was developed. The method is characterized by a five-day tea-staining procedure on bovine front teeth slabs on a rotating wheel, standardized brushing of the slabs in a V8 cross-brushing machine, and brightness measurement by a chromametric technique. All tested products were in accordance with the new DIN/ISO standard 11,609 for toothpastes in terms of dentin abrasivity. Not a single product exceeded an RDA value of 200. The majority of toothpastes (80%) had an RDA value below 100. Only three products surpassed the reference in cleaning power. Most products (73%) had a cleaning power (PCR value) between 20 and 80. The correlation between cleaning power and dentin abrasion was low (r = 0.66), which can be explained with the different influence on dentin and stains by factors like abrasive type, particle surface and size, as well as the chemical influence of other toothpaste ingredients. Some major trends could be shown on the basis of abrasive types. The ratio PCR to RDA was rather good in most silica-based toothpastes. A lower ratio was found in some products containing calcium carbonate or aluminum trihydrate as the only abrasive. The addition of other abrasives, such as polishing alumina, showed improved cleaning power. Some active ingredients, especially sequenstrants such as sodium tripolyphosphate or AHBP, also improve the PCR/RDA ratio by stain-dissolving action without being abrasive. The data for some special anti-stain products did not differ significantly from standard products. Compared with data measured in 1988, a general trend toward reduced abrasivity without loss of cleaning efficacy could be noticed on the European toothpaste market. This may be mostly due to the increased use of high-performance abrasives such

Decontamination of Battelle-Columbus' Plutonium Facility. Final report

International Nuclear Information System (INIS)

Rudolph, A.; Kirsch, G.; Toy, H.L.

1984-01-01

The Plutonium Laboratory, owned and operated by Battelle Memorial Institute's Columbus Division, was located in Battelle's Nuclear Sciences area near West Jefferson, Ohio, approximately 17 miles west of Columbus, Ohio. Originally built in 1960 for plutonium research and processing, the Plutonium Laboratory was enlarged in 1964 and again in 1967. With the termination of the Advanced Fuel Program in March, 1977, the decision was made to decommission the Plutonium Laboratory and to decontaminate the building for unrestricted use. Decontamination procedures began in January, 1978. All items which had come into contact with radioactivity from the plutonium operations were cleaned or disposed of through prescribed channels, maintaining procedures to ensure that D and D operations would pose no risk to the public, the environment, or the workers. The entire program was conducted under the cognizance of DOE's Chicago Operations Office. The building which housed the Plutonium Laboratory has now been decontaminated to levels allowing it to house ordinary laboratory and office operations. A ''Finding of No Significant Impact'' (FNSI) was issued in May, 1980

Decontamination system study for the Tank Waste Retrieval System

International Nuclear Information System (INIS)

Reutzel, T.; Manhardt, J.

1994-05-01

This report summarizes the findings of the Idaho National Engineering Laboratory's decontamination study in support of the Tank Waste Retrieval System (TWRS) development program. Problems associated with waste stored in existing single shell tanks are discussed as well as the justification for the TWRS program. The TWRS requires a decontamination system. The subsystems of the TWRS are discussed, and a list of assumptions pertinent to the TWRS decontamination system were developed. This information was used to develop the functional and operational requirements of the TWRS decontamination system. The requirements were combined with a comprehensive review of currently available decontamination techniques to produced a set of evaluation criteria. The cleaning technologies and techniques were evaluated, and the CO 2 blasting decontamination technique was chosen as the best technology for the TWRS

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.

Ceramic-bonded abrasive grinding tools

Science.gov (United States)

Holcombe, Jr., Cressie E.; Gorin, Andrew H.; Seals, Roland D.

1994-01-01

Abrasive grains such as boron carbide, silicon carbide, alumina, diamond, cubic boron nitride, and mullite are combined with a cement primarily comprised of zinc oxide and a reactive liquid setting agent and solidified into abrasive grinding tools. Such grinding tools are particularly suitable for grinding and polishing stone, such as marble and granite.

Ceramic-bonded abrasive grinding tools

Science.gov (United States)

Holcombe, C.E. Jr.; Gorin, A.H.; Seals, R.D.

1994-11-22

Abrasive grains such as boron carbide, silicon carbide, alumina, diamond, cubic boron nitride, and mullite are combined with a cement primarily comprised of zinc oxide and a reactive liquid setting agent and solidified into abrasive grinding tools. Such grinding tools are particularly suitable for grinding and polishing stone, such as marble and granite.

Volunteer trials of a novel improvised dry decontamination protocol for use during mass casualty incidents as part of the UK'S Initial Operational Response (IOR.

Directory of Open Access Journals (Sweden)

Richard Amlôt

Full Text Available Previous studies have demonstrated that rapid evacuation, disrobing and emergency decontamination can enhance the ability of emergency services and acute hospitals to effectively manage chemically-contaminated casualties. The purpose of this human volunteer study was to further optimise such an "Initial Operational Response" by (1 identifying an appropriate method for performing improvised skin decontamination and (2 providing guidance for use by first responders and casualties. The study was performed using two readily available, absorbent materials (paper towels and incontinence pads. The decontamination effectiveness of the test materials was measured by quantifying the amount of a chemical warfare agent simulant (methyl salicylate removed from each volunteer's forearm skin. Results from the first study demonstrated that simulant recovery was lower in all of the dry decontamination conditions when compared to matched controls, suggesting that dry decontamination serves to reduce chemical exposure. Blotting in combination with rubbing was the most effective form of decontamination. There was no difference in effectiveness between the two absorbent materials. In the following study, volunteers performed improvised dry decontamination, either with or without draft guidelines. Volunteers who received the guidance were able to carry out improvised dry decontamination more effectively, using more of the absorbent product (blue roll to ensure that all areas of the body were decontaminated and avoiding cross-contamination of other body areas by working systematically from the head downwards. Collectively, these two studies suggest that absorbent products that are available on ambulances and in acute healthcare settings may have generic applicability for improvised dry decontamination. Wherever possible, emergency responders and healthcare workers should guide casualties through decontamination steps; in the absence of explicit guidance and

Volunteer trials of a novel improvised dry decontamination protocol for use during mass casualty incidents as part of the UK'S Initial Operational Response (IOR).

Science.gov (United States)

Amlôt, Richard; Carter, Holly; Riddle, Lorna; Larner, Joanne; Chilcott, Robert P

2017-01-01

Previous studies have demonstrated that rapid evacuation, disrobing and emergency decontamination can enhance the ability of emergency services and acute hospitals to effectively manage chemically-contaminated casualties. The purpose of this human volunteer study was to further optimise such an "Initial Operational Response" by (1) identifying an appropriate method for performing improvised skin decontamination and (2) providing guidance for use by first responders and casualties. The study was performed using two readily available, absorbent materials (paper towels and incontinence pads). The decontamination effectiveness of the test materials was measured by quantifying the amount of a chemical warfare agent simulant (methyl salicylate) removed from each volunteer's forearm skin. Results from the first study demonstrated that simulant recovery was lower in all of the dry decontamination conditions when compared to matched controls, suggesting that dry decontamination serves to reduce chemical exposure. Blotting in combination with rubbing was the most effective form of decontamination. There was no difference in effectiveness between the two absorbent materials. In the following study, volunteers performed improvised dry decontamination, either with or without draft guidelines. Volunteers who received the guidance were able to carry out improvised dry decontamination more effectively, using more of the absorbent product (blue roll) to ensure that all areas of the body were decontaminated and avoiding cross-contamination of other body areas by working systematically from the head downwards. Collectively, these two studies suggest that absorbent products that are available on ambulances and in acute healthcare settings may have generic applicability for improvised dry decontamination. Wherever possible, emergency responders and healthcare workers should guide casualties through decontamination steps; in the absence of explicit guidance and instructions, improvised

Determination of vibration frequency depending on abrasive mass flow rate during abrasive water jet cutting

Czech Academy of Sciences Publication Activity Database

Hreha, P.; Radvanská, A.; Hloch, Sergej; Peržel, V.; Krolczyk, G.; Monková, K.

2014-01-01

Roč. 77, 1-4 (2014), s. 763-774 ISSN 0268-3768 Institutional support: RVO:68145535 Keywords : Abrasive water jet * Abrasive mass flow rate * Vibration Subject RIV: JQ - Machines ; Tools Impact factor: 1.458, year: 2014 http://link.springer.com/article/10.1007%2Fs00170-014-6497-9#page-1

Decontamination of Savannah River Plant H-Area hot-canyon crane

International Nuclear Information System (INIS)

Rankin, W.N.; Sims, J.R.

1985-01-01

Decontamination techniques applicable to the remotely operated bridge cranes in canyon buildings at the Savannah River Plant (SRP) were identified and were evaluated in laboratory-scale tests. High pressure Freon blasting was found to be the most attractive process available for this application. Strippable coatings were selected as an alternative technique in selected applications. The ability of high pressure Freon blasting plus two strippable coatings (Quadcoat 100 and Alara 1146) to remove the type of contamination expected on SRP cranes was demonstrated in laboratory-scale tests. Quadrex HPS was given a contract to decontaminate the H-Area hot canyon crane. Decontamination operations were successfully carried out within the specified time-frame window. The radiation level goals specified by SRP were met and decontamination was accomplished with 85% less personnel exposure than estimated by SRP before the job started. This reduction is attributed to the increased efficiency of the new decontamination techniques used. 6 refs., 1 tab

Method of decontaminating radioactive-contaminated instruments

International Nuclear Information System (INIS)

Urata, Megumu; Fujii, Masaaki; Kitaguchi, Hiroshi.

1982-01-01

Purpose: To enable safety processing of liquid wastes by recovering radioactive metal ions remaining in the electrolytes after the decontamination procedure thereby decreasing the radioactivity. Method: In a decontamination tank containing electrolytes consisting of diluted hydrochloric acid and diluted sulfuric acid, are provided a radioactive contaminated instrument connected to an anode and a collector electrode made of stainless steel connected to a cathode respectively. Upon applying electrical current, the portion of the mother material to be decontaminated is polished electrolytically into metal ions and they are deposited as metal on the collection electrode. After completion of the decontamination, an ultrasonic wave generator is operated to strip and remove the oxide films. Thereafter, the anode is replaced with the carbon electrode and electrical current is supplied continuously, whereby the remaining metal ions are deposited and recovered as the metal on the collection electrode. (Yoshino, Y.)

A remotely operated robot for decontamination tasks

International Nuclear Information System (INIS)

Dudar, A.M.; Vandewalle, R.C.

1994-01-01

Engineers in the Robotics Development Group at the Westinghouse Savannah River Company (WSRC) have developed a robot which will be used to decontaminate a pipe gallery of a tank farm used for nuclear waste storage. Personnel access is required into this pipe gallery to inspect existing pipes and perform repairs to secondary containment walls around the tank farm. Presently, the pipe gallery is littered with debris of various sizes and its surface is contaminated with activity levels up to 2.5E6 DPM (disintegrations per minute) alpha and exposure levels as high as 20 Rad/hr. Cleaning up this pipe gallery win be the mission of an all-hydraulic robotic vehicle developed in-house at WSRC caged the ''Remote Decon'' robot. The Remote Decon is a tracked vehicle which utilizes skid steering and features a six-degree-of-freedom (DOF) manipulator arm, a five-DOF front end loader type bucket with a rotating brush for scrubbing and decontaminating surfaces, and a three-DOF pan/tilt mechanism with cameras and lights. The Remote Decon system is connected to a control console via a 200 foot tethered cable. The control console was designed with ergonomics and simplicity as the main design factors and features three joysticks, video monitors, LED panels, and audible alarms

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

Evaluation of absorbent materials for use as ad hoc dry decontaminants during mass casualty incidents as part of the UK's Initial Operational Response (IOR.

Directory of Open Access Journals (Sweden)

Nick Kassouf

Full Text Available The UK's Initial Operational Response (IOR is a revised process for the medical management of mass casualties potentially contaminated with hazardous materials. A critical element of the IOR is the introduction of immediate, on-scene disrobing and decontamination of casualties to limit the adverse health effects of exposure. Ad hoc cleansing of the skin with dry absorbent materials has previously been identified as a potential means of facilitating emergency decontamination. The purpose of this study was to evaluate the in vitro oil and water absorbency of a range of materials commonly found in the domestic and clinical environments and to determine the effectiveness of a small, but representative selection of such materials in skin decontamination, using an established ex vivo model. Five contaminants were used in the study: methyl salicylate, parathion, diethyl malonate, phorate and potassium cyanide. In vitro measurements of water and oil absorbency did not correlate with ex vivo measurements of skin decontamination. When measured ex vivo, dry decontamination was consistently more effective than a standard wet decontamination method ("rinse-wipe-rinse" for removing liquid contaminants. However, dry decontamination was ineffective against particulate contamination. Collectively, these data confirm that absorbent materials such as wound dressings and tissue paper provide an effective, generic capability for emergency removal of liquid contaminants from the skin surface, but that wet decontamination should be used for non-liquid contaminants.

Impact Capacity Reduction in Railway Prestressed Concrete Sleepers with Surface Abrasions

Science.gov (United States)

Ngamkhanong, Chayut; Li, Dan; Kaewunruen, Sakdirat

2017-10-01

Railway sleepers (also called ‘railroad tie’ in North America) embedded in ballasted railway tracks are a main part of railway track structures. Its important role is to transfer the loads evenly from the rails to a wider area of ballast bed and to secure rail gauge and enable safe passages of rolling stocks. By nature, railway infrastructure is nonlinear, evidenced by its behaviours, geometry and alignment, wheel-rail contact and operational parameters such as tractive efforts. Based on our critical review, the dynamic behaviour of railway sleepers has not been fully investigated, especially when the sleepers are deteriorated by excessive wears. In fact, the ballast angularity causes differential abrasions on the soffit or bottom surface of sleepers (especially at railseat zone). Furthermore, in sharp curves and rapid gradient change, longitudinal and lateral dynamics of rails increase the likelihood of railseat abrasions in concrete sleepers due to the unbalanced loading conditions. This paper presents a structural capacity of concrete sleepers under dynamic transient loading. The modified compression field theory for ultimate strength design of concrete sleepers under impact loading will be highlighted in this study. The influences of surface abrasions, including surface abrasion and soffit abrasion, on the dynamic behaviour of prestressed concrete sleepers, are firstly highlighted. The outcome of this study will improve the rail maintenance and inspection criteria in order to establish appropriate and sensible remote track condition monitoring network in practice. Moreover, this study will also improve the understanding of the fundamental dynamic behaviour of prestressed concrete sleepers with surface abrasions. The insight into these behaviours will not only improve safety and reliability of railway infrastructure but will enhance the structural safety of other concrete structures.

Research and development of treatment techniques for LLW from decommissioning: Decontamination and volume reduction techniques

International Nuclear Information System (INIS)

Hirabayashi, T.; Kameo, Y.; Nakashio, N.

2001-01-01

For the purpose of reducing the amount and/or volume of low-level radioactive waste (LLW) arising from decommissioning of nuclear reactor, the Japan Atomic Energy Research Institute (JAERI) has been developing four decontamination techniques. They are: (a) Gas-carrying abrasive method, (b) In-situ remote electropolishing method for pipe system before dismantling, (c) Bead reaction - thermal shock method, and (d) Laser induced chemical method for components after dismantling. JAERI in developing techniques are also carrying out melting tests of metal and non-metal. Melting was confirmed to be effective in reducing the volume, homogenizing, and furthermore stabilizing non-metallic wastes. (author)

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.)

Development of filtration equipment to reuse PFC decontamination wastewater

International Nuclear Information System (INIS)

Kim, Gye Nam; Lee, Sung Yeol; Won, Hui Jun; Jung Chong Hun; Oh, Won Zin; Park, Jin Ho

2005-01-01

When PFC(Perfluorocarbonate) decontamination technology is applied to removal of radioactive contaminated particulate adhered at surface during the operation of nuclear research facilities, it is necessary to develop a filtration equipment to reuse of PFC solution due to high price, also to minimize the volume of second wastewater. Contaminated characteristics of hot particulate was investigated and a filtration process was presented to remove suspended radioactive particulate from PFC decontamination wastewater generated on PFC decontamination

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

Effect of Organic Solvents in Preparation of Silica-Based Chemical Gel Decontaminates for Decontamination of Nuclear Facilities

International Nuclear Information System (INIS)

Yoon, Suk Bon; Jung, Chong Hun; Kim, Chang Ki; Choi, Byung Seon; Lee, Kune Woo; Moon, Jei Kwon

2011-01-01

Decontamination of nuclear facilities is necessary to reduce the radiation field during normal operations and decommissioning of complex equipment such as stainless steel components, other iron-based steel and alloys, metal surfaces, structural materials and so on. Chemical decontamination technology in particular is a highly effective method to remove the radioactive contamination through a chemical dissolution or a redox reaction. However, this method has the serious drawback due to the generation of large amounts of the radioactive liquid wastes. Recently, a few literatures have been reported for the preparation of the chemical gel decontaminants to reduce the amount of the radioactive liquid wastes and to enhance the decontamination efficiency through increasing the contact time between the gels and the radioactive contaminants. In the preparation of the chemical gels, the control of the viscosity highly depends on the amount of a coviscosifier used among the components of the chemical gels consisted of a viscosifier, a coviscosifier, and a chemical decontaminant. In this works, a new effective method for the preparation of the chemical gel was investigated by introducing the organic solvents. The mixture solution of the coviscosifier and organic solvent was more effective in the control of the viscosity compared with that of the coviscosifier only in gels. Furthermore, the decontamination efficiency of the chemical gels measured by using the multi-channel analyzer (MCA) showed the high decontamination factor for Co-60 and Cs-137 contaminated on the surface of the stainless steel 304

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)

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

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.)

Ultrasonic Abrasive Removal Of EDM Recast

Science.gov (United States)

Mandel, Johnny L.; Jacobson, Marlowe S.

1990-01-01

Ultrasonic abrasive process removes layer of recast material generated during electrical-discharge machining (EDM) of damper pocket on turbine blade. Form-fitted tool vibrated ultrasonically in damper pocket from which material removed. Vibrations activate abrasive in pocket. Amount of material removed controlled precisely.

Volunteer trials of a novel improvised dry decontamination protocol for use during mass casualty incidents as part of the UK’S Initial Operational Response (IOR)

Science.gov (United States)

Riddle, Lorna; Larner, Joanne

2017-01-01

Previous studies have demonstrated that rapid evacuation, disrobing and emergency decontamination can enhance the ability of emergency services and acute hospitals to effectively manage chemically-contaminated casualties. The purpose of this human volunteer study was to further optimise such an “Initial Operational Response” by (1) identifying an appropriate method for performing improvised skin decontamination and (2) providing guidance for use by first responders and casualties. The study was performed using two readily available, absorbent materials (paper towels and incontinence pads). The decontamination effectiveness of the test materials was measured by quantifying the amount of a chemical warfare agent simulant (methyl salicylate) removed from each volunteer’s forearm skin. Results from the first study demonstrated that simulant recovery was lower in all of the dry decontamination conditions when compared to matched controls, suggesting that dry decontamination serves to reduce chemical exposure. Blotting in combination with rubbing was the most effective form of decontamination. There was no difference in effectiveness between the two absorbent materials. In the following study, volunteers performed improvised dry decontamination, either with or without draft guidelines. Volunteers who received the guidance were able to carry out improvised dry decontamination more effectively, using more of the absorbent product (blue roll) to ensure that all areas of the body were decontaminated and avoiding cross-contamination of other body areas by working systematically from the head downwards. Collectively, these two studies suggest that absorbent products that are available on ambulances and in acute healthcare settings may have generic applicability for improvised dry decontamination. Wherever possible, emergency responders and healthcare workers should guide casualties through decontamination steps; in the absence of explicit guidance and instructions

Particle Separation of Non-Decontamination Soil using Attrition and Washing

International Nuclear Information System (INIS)

Koo, Daeseo; Sung, Hyun-Hee; Kim, Seung-Soo; Hong, Sang Bum; Seo, Bum Kyoung; Choi, Jong-Won

2017-01-01

In this study, to improve the decontamination efficiency of uranium soil, a preliminary experiment on the particle separation of non-decontamination soil was carried out using attrition and washing. The characteristics of the attrition and washing system are investigated. A conditional experiment on particle separation of non-decontamination soil will be performed. A preliminary experiment on the particle separation of non-decontamination soil was carried out to improve the decontamination efficiency of uranium soil. This experiment was performed with the ratio of soil to water (1:4) for the particle separation of non-decontamination soil. The operations of all equipment such as attrition scrubber, ultrasonic reaction, vibrating screen, and hydro-cyclone were conducted and confirmed. In the future, the additional experiments will be conducted for optimal experimental condition.

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

Model for analyzing decontamination process systems

International Nuclear Information System (INIS)

Boykin, R.F.; Rolland, C.W.

1979-06-01

Selection of equipment and the design of a new facility in light of minimizing cost and maximizing capacity, is a problem managers face many times in the operations of a manufacturing organization. This paper deals with the actual analysis of equipment facility design for a decontamination operation. Discussions on the selection method of the equipment and the development of the facility design criteria are presented along with insight into the problems encountered in the equipment analysis for a new decontamination facility. The presentation also includes a review of the transition from the old facility into the new facility and the process used to minimize the cost and conveyance problems of the transition

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.)

New Rock Abrasivity Test Method for Tool Life Assessments on Hard Rock Tunnel Boring: The Rolling Indentation Abrasion Test (RIAT)

Science.gov (United States)

Macias, F. J.; Dahl, F.; Bruland, A.

2016-05-01

The tunnel boring machine (TBM) method has become widely used and is currently an important presence within the tunnelling industry. Large investments and high geological risk are involved using TBMs, and disc cutter consumption has a great influence on performance and cost, especially in hard rock conditions. Furthermore, reliable cutter life assessments facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory tests for rock abrasivity assessments are needed. A new abrasivity test method by rolling disc named Rolling Indentation Abrasion Test (RIAT) has been developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods. Wear by rolling contact on intact rock samples is introduced and several rock types, covering a wide rock abrasiveness range, have been tested by RIAT. The RIAT procedure indicates a great ability of the testing method to assess abrasive wear on rolling discs. In addition and to evaluate the newly developed RIAT test method, a comprehensive laboratory testing programme including the most commonly used abrasivity test methods and the mineral composition were carried out. Relationships between the achieved results from conventional testing and RIAT results have been analysed.

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

Optimization of the decontamination in EDF PWR power plants

International Nuclear Information System (INIS)

Gosset, P.; Dupin, M.; Buisine, D.; Buet, J.F.; Brunel, V.

2002-01-01

The optimisation of decontamination in EDF PWR power plants is the result of a permanent collaborative work between the plant operators, the subcontractors, central services of nuclear power division of EDF. This collaborative work enables the saving of all the feedback experience. The main operations carried out on nuclear sites like mechanical decontamination of valves, use of the ''EMMAC'' process on big components (replacement of steam generator, hydraulic parts of the reactor coolant pumps), use of foam on pools walls and divers in highly contaminated pools have been discussed. This paper shows that the choice of decontamination processes is very dependant on the components, on the dose rate reduction to be aimed and on the possibility to treat the waste on site. (authors)

Experimental Rock-on-Rock Abrasive Wear Under Aqueous Conditions: its Role in Subglacial Abrasion

Science.gov (United States)

Rutter, E. H.; Lee, A. G.

2003-12-01

We have determined experimentally the rate of abrasive wear of rock on rock for a range of rock types as a function of normal stress and shear displacement. Unlike abrasive wear in fault zones, where wear products accumulate as a thickening gouge zone, in our experiments wear particles were removed by flowing water. The experiments are thus directly pertinent to one of the most important processes in subglacial erosion, and to some extent in river incision. Wear was produced between rotating discs machined from rock samples and measured from the progressive approach of the disc axes towards each other under various levels of normal load. Shear displacements of several km were produced. Optical and scanning electron microscopy were used to study the worn rock surfaces, and particle size distributions in wear products were characterized using a laser particle size analyzer. Rock types studied were sandstones of various porosities and cement characteristics, schists and a granite. In all cases abrasion rate decreased logarithmically with displacement by up to 2 orders of magnitude until a steady state was approached, but only after at least 1 km displacement. The more porous, less-well cemented rocks wore fastest. Amount of abrasion could be characterized quantitatively using an exponentially decaying plus a steady-state term. Wear rate increased non-linearly with normal contact stress, apparently to an asymptote defined by the unconfined compressive strength. Microstructural study showed that the well-cemented and/or lowest porosity rocks wore by progressive abrasion of grains without plucking, whereas whole grains were plucked out of weakly-cemented and/or more porous rocks. This difference in behavior was reflected in wear-product particle size distributions. Where whole-grain plucking was possible, wear products were dominated by particles of the original grain size rather than finer rock flour. Comparison of our results to glacier basal abrasive wear estimated

Recent Developments in Abrasive Hybrid Manufacturing Processes

Directory of Open Access Journals (Sweden)

Ruszaj Adam

2017-06-01

Full Text Available Recent dynamic development of abrasive hybrid manufacturing processes results from application of a new difficult for machining materials and improvement of technological indicators of manufacturing processes already applied in practice. This tendency also occurs in abrasive machining processes which are often supported by ultrasonic vibrations, electrochemical dissolution or by electrical discharges. In the paper we present the review of new results of investigations and new practical applications of Abrasive Electrodischarge (AEDM and Electrochemical (AECM Machining.

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)

Sandstone Turning by Abrasive Waterjet

Czech Academy of Sciences Publication Activity Database

Hlaváček, Petr; Cárach, J.; Hloch, Sergej; Vasilko, K.; Klichová, Dagmar; Klich, Jiří; Lehocká, D.

2015-01-01

Roč. 48, č. 6 (2015), s. 2489-2493 ISSN 0723-2632 R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : turning away from the jet * conventional turning towards the jet * sandstone * abrasive water jet Subject RIV: JQ - Machines ; Tools Impact factor: 2.386, year: 2015 http://www.springerprofessional.de/sandstone-turning-by-abrasive-waterjet/6038028.html

Metal segmenting using abrasive and reciprocating saws

International Nuclear Information System (INIS)

Allen, R.P.; Fetrow, L.K.; Haun, F.E. Jr.

1987-06-01

This paper evaluates a light-weight, high-power abrasive saw for segmenting radioactively contaminated metal components. A unique application of a reciprocating mechanical saw for the remote disassembly of equipment in a hot cell also is described. The results of this work suggest that use of these techniques for selected remote sectioning applications could minimize operational and access problems and be very cost effective in comparison with other inherently faster sectioning methods. 2 refs., 7 figs

Management of Retrograde Peri-Implantitis Using an Air-Abrasive Device, Er,Cr:YSGG Laser, and Guided Bone Regeneration

Directory of Open Access Journals (Sweden)

Nikolaos Soldatos

2018-01-01

Full Text Available Background. The placement of an implant in a previously infected site is an important etiologic factor contributing to implant failure. The aim of this case report is to present the management of retrograde peri-implantitis (RPI in a first maxillary molar site, 2 years after the implant placement. The RPI was treated using an air-abrasive device, Er,Cr:YSGG laser, and guided bone regeneration (GBR. Case Description. A 65-year-old Caucasian male presented with a draining fistula associated with an implant at tooth #3. Tooth #3 revealed periapical radiolucency two years before the implant placement. Tooth #3 was extracted, and a ridge preservation procedure was performed followed by implant rehabilitation. A periapical radiograph (PA showed lack of bone density around the implant apex. The site was decontaminated with an air-abrasive device and Er,Cr:YSGG laser, and GBR was performed. The patient was seen every two weeks until suture removal, followed by monthly visits for 12 months. The periapical X-rays, from 6 to 13 months postoperatively, showed increased bone density around the implant apex, with no signs of residual clinical or radiographic pathology and probing depths ≤4 mm. Conclusions. The etiology of RPI in this case was the placement of an implant in a previously infected site. The use of an air-abrasive device, Er,Cr:YSGG, and GBR was utilized to treat this case of RPI. The site was monitored for 13 months, and increased radiographic bone density was noted.

Comparing the Air Abrasion Cutting Efficacy of Dentine Using a Fluoride-Containing Bioactive Glass versus an Alumina Abrasive: An In Vitro Study

Directory of Open Access Journals (Sweden)

Melissa H. X. Tan

2015-01-01

Full Text Available Air abrasion as a caries removal technique is less aggressive than conventional techniques and is compatible for use with adhesive restorative materials. Alumina, while being currently the most common abrasive used for cutting, has controversial health and safety issues and no remineralisation properties. The alternative, a bioactive glass, 45S5, has the advantage of promoting hard tissue remineralisation. However, 45S5 is slow as a cutting abrasive and lacks fluoride in its formulation. The aim of this study was to compare the cutting efficacy of dentine using a customised fluoride-containing bioactive glass Na0SR (38–80 μm versus the conventional alumina abrasive (29 μm in an air abrasion set-up. Fluoride was incorporated into Na0SR to enhance its remineralisation properties while strontium was included to increase its radiopacity. Powder outflow rate was recorded prior to the cutting tests. Principal air abrasion cutting tests were carried out on pristine ivory dentine. The abrasion depths were quantified and compared using X-ray microtomography. Na0SR was found to create deeper cavities than alumina (p<0.05 despite its lower powder outflow rate and predictably reduced hardness. The sharper edges of the Na0SR glass particles might improve the cutting efficiency. In conclusion, Na0SR was more efficacious than alumina for air abrasion cutting of dentine.

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

Experiences with decontaminating tritium-handling apparatus

International Nuclear Information System (INIS)

Maienschein, J.L.; Garcia, F.; Garza, R.G.; Kanna, R.L.; Mayhugh, S.R.; Taylor, D.T.

1992-01-01

Tritium-handling apparatus has been decontaminated as part of the downsizing of the LLNL Tritium Facility. Two stainless-steel glove boxes that had been used to process lithium deuteride-tritide (LiDT) slat were decontaminated using the Portable Cleanup System so that they could be flushed with room air through the facility ventilation system. In this paper the details on the decontamination operation are provided. A series of metal (palladium and vanadium) hydride storage beds have been drained of tritium and flushed with deuterium, in order to remove as much tritium as possible. The bed draining and flushing procedure is described, and a calculational method is presented which allows estimation of the tritium remaining in a bed after it has been drained and flushed. Data on specific bed draining and flushing are given

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)

Anti-abrasive nanocoatings current and future applications

CERN Document Server

2015-01-01

This book provides an overview of the fabrication methods for anti-abrasive nanocoatings. The connections among fabrication parameters, the characteristics of nanocoatings and the resulting properties (i.e. nanohardness, toughness, wear rate, load-bearing ability, friction coefficient, and scratch resistance) are discussed. Size-affected mechanical properties of nanocoatings are examined, including their uses. Anti-abrasive nanocoatings, including metallic-, ceramic-, and polymeric-based layers, as well as different kinds of nanostructures, such as multi-layered nanocomposites and thin films, are reviewed. * Provides a comprehensive overview of the fabrication methods for anti-abrasive nanocoatings* Discusses the connections among fabrication parameters, the characteristics of nanocoatings and the resulting properties* Reviews advantages and drawbacks of fabrication methods for anti-abrasive nanocoatings and clarifies the place of these nanocoatings in the world of nanotechnology

Experiences with decontaminating tritium-handling apparatus

International Nuclear Information System (INIS)

Maienschein, J.L.; Garcia, F.; Garza, R.G.; Kanna, R.L.; Mayhugh, S.R.; Taylor, D.T.

1991-07-01

Tritium-handling apparatus has been decontaminated as part of the shutdown of the LLNL Tritium Facility. Two stainless-steel gloveboxes that had been used to process lithium deuteride-tritide (LiDT) salt were decontaminated using the Portable Cleanup System so that they could be flushed with room air through the facility ventilation system. Further surface decontamination was performed by scrubbing the interior with paper towels and ethyl alcohol or Swish trademark. The surface contamination, as shown by swipe surveys, was reduced from 4x10 4 --10 6 disintegrations per minute (dpm)/cm 2 to 2x10 2 --4x10 4 dpm/cm 2 . Details on the decontamination operation are provided. A series of metal (palladium and vanadium) hydride storage beds have been drained of tritium and flushed with deuterium in order to remove as much tritium as possible. The bed draining and flushing procedure is described, and a calculational method is presented which allows estimation of the tritium remaining in a bed after it has been drained and flushed. Data on specific bed draining and flushing are given

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)

Abrasive wear of intermetallics

International Nuclear Information System (INIS)

Hawk, J.A.; Alman, D.E.; Wilson, R.D.

1995-01-01

The US Bureau of Mines is investigating the wear behavior of a variety of advanced materials. Among the many materials under evaluation are intermetallic alloys based on the compounds: Fe 3 Al, Ti 3 Al, TiAl, Al 3 Ti, NiAl and MoSi 2 . The high hardness, high modulus, low density, and superior environmental stability of these compounds make them attractive for wear materials. This paper reports on the abrasive wear of alloys and composites based on the above compounds. The abrasive wear behavior of these alloys and composites are compared to other engineering materials used in wear applications

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

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

Summary of sodium removal and decontamination programs in the USA

International Nuclear Information System (INIS)

Steele, O.P.; Brehm, W.F.

1978-01-01

The goals of the United States Department of Energy sodium removal and decontamination programs are: 1) to identify plant requirements and develop safe effective processes for sodium removal, both for experimental facilities and for reactor components; 2) to develop effective decontamination processes for removing deposited radioactivity; 3) to establish and put into use a set of workable criteria for requalification and return to service of components after sodium removal and decontamination; 4) to design, build and operate facilities in which to perform the sodium removal and decontamination operations. This paper gives a summary of progress toward each of these goals; details will be presented in other papers at this meeting. Three basic processes for sodium removal have been investigated extensively: the use of water vapor in an inert carrier gas, the use of an alcohol-type reagent, and evaporation. The process development work on the first two processes has been essentially completed. The evaporative process is still under development, but preliminary parameters have been established

Abrasive water jet: a complementary tool

International Nuclear Information System (INIS)

Duarte, J.P.; Pecas, P.; Nunes, E.; Gouveia, H.

1998-01-01

The abrasive water jet is a powerful cutting tool, whose main advantages lie in the absence of thermal effects and the capability of cutting highly thick materials. Compared with Laser, the abrasive water jet allows the cutting of a larger range of thicknesses and a wider variety of materials such as: ornamental stones, metals, polymers, composites, wood, glass ceramics. The application of this technology has suffered and extensive growth, with successful applications in varied industrial sectors like the automotive, aerospace, textile, metalworking, ornamental stones, etc. The present communication aims at introducing the abrasive water jet as a complementary tool to laser cutting, presenting its advantages by showing some documented examples of pieces cut for different industries. (Author) 5 refs

Decontamination analysis of a radiologically contaminated site

International Nuclear Information System (INIS)

Tawil, J.J.; Strenge, D.L.

1984-02-01

This paper presents an analysis of decontamination options at the NUWAZX-83 exercise site. Held in May 1983, the purpose of the exercise was to evaluate the ability of federal, state and local officials to respond to a radiological accident involving nuclear weapons. A computer program developed by Pacific Northwest Laboratory was used to conduct the decontamination analysis. The program, called DECON, was designed to assist personnel engaged in the planning of decontamination activities. The many features of DECON that are demonstrated in this paper contribute to its potential usefulness as a planning tool for site restoration. Strategies that are analyzed with DECON include: (1) using a Quick-Vac option, under which exterior surfaces are vacuumed before it rains; (2) protecting surfaces against precipitation; (3) prohibiting specific operations on selected surfaces; (4) requiring that specific methods be used on selected surfaces; (5) evaluating the trade-off between cleanup standards and decontamination costs; and (6) varying clean-up standards according to expected human exposure to the surface

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

Safety analysis report. Decontamination and decommissioning of the EBR-I Complex

International Nuclear Information System (INIS)

Commander, J.C.; Macbeth, P.J.; Michels, D.E.

1975-06-01

The safety aspects of the planned EBR-I Complex decontamination and decommissioning operations are assessed. The major operations are: (1) removal of NaK from the EBR-I primary and secondary coolant systems, (2) processing of the NaK to produce solid caustic for disposal, (3) decontamination of contaminated areas of EBR-I and ZPR-III, (4) removal of items that cannot be decontaminated economically to acceptably safe levels, (5) isolation of contaminated areas, (6) demolition of the AFSR Shielding, and (7) removal of contaminated vessels from the NaK storage pit. It may be concluded that although potential hazards do exist from explosion, chemical burns and low-level radioactive exposure from the D and D operation, these hazards represent acceptable risks provided that the established procedures and precautions are followed. (U.S.)

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.

Impact of LWR decontamination on radwaste systems

International Nuclear Information System (INIS)

Perrigo, L.D.; Divine, J.R.

1979-01-01

Increased radiation levels around certain reactors in the United States and accompanying increases in personnel exposures are causing a reexamination of options available to utilities to continue operation. One of the options is decontamination of the primary system to reduce radiation levels. The Battelle-Northwest study of decontamination and its impact on radwaste systems has been directed towards existing reactors and allied systems as they are employed during their operational lifetimes. Decommissioning and cleanup during such work are not within the scope of this project although certain processes and waste systems might be similar. Rupture debris cleanup represents a special situation that requires different design features and concepts and it is not a part of this study

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)

Decontamination laboratory design for iron pipes contaminated with uranium and thorium series

International Nuclear Information System (INIS)

Sahyun, Adelia; Sordi, Gian M.; Ghobril, Carlos N.; Puga Sanches, Matias; Rodrigues, Demerval L.

2008-01-01

The Brazilian soil is very rich in the ore processing, after some time, the pipes are contaminated with trace levels of uranium and thorium. When the pipes are exchanged, to recovery the funds, the best is to sell them as scrap, however, because they are contaminated and present a considerable amount of dose can not be marketed until they are decontaminated. The question is that the tube is incrusted with the contaminated material, and is difficult to remove it. For the removal this material, that comes to be 2 inches thick, for the larger pipes diameter, requires special equipment as a motor-pump units with ultra high pressure water jetting, of the order of 40000 psi. The purpose of this paper is to suggest a design of one laboratory able to perform the decontamination avoiding large scale production of radioactive wastes. The solids and liquids wastes produced during the process of decontamination will be collected in different containers and classified according to their contamination level. The laboratory was designed to facilitate its decontamination with a minimum dose for their operators. The most difficult question to be solved during the project, was to perform the laboratory decontamination during the pipe decontamination in continuous operation since we can't stop the process for the reason of it expensive cost. The paper will show how will be made all the steps of the tubes decontamination and the laboratory decontamination. It will be shown how we collect the liquids and solids wastes, separate, for their classification. After the pipe, decontamination we show as will be measure the dose to release or to return for the laboratory to development a further decontamination. At last, it will show the temporary storage place for the decontaminated pipes that will be later collected as scrap. (author)

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

21 CFR 872.6030 - Oral cavity abrasive polishing agent.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oral cavity abrasive polishing agent. 872.6030... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6030 Oral cavity abrasive polishing agent. (a) Identification. An oral cavity abrasive polishing agent is a device in paste or powder form...

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

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.

Radiation protection procedures for the dismantling and decontamination of nuclear facility

International Nuclear Information System (INIS)

Almeida, C.C.; Garcia, R.H.L.; Cambises, P.B.S.; Silva, T.M. da; Paiva, J.E.; Carneiro, J.C.G.G.; Rodrigues, D.L.

2013-01-01

This work presents the operational procedures and conditions to ensure the required level of protection and safety during the dismantling and decontamination of a natural uranium purification facility at IPEN-CNEN/SP, Brazil. The facility was designed for chemical processing of natural uranium, aiming to obtain the uranyl nitrate, nuclear-grade. Afterwards, the installation operated in treatment and washing of thorium sulfate and thorium oxycarbonate dissolution, to get thorium nitrate as final product. A global evaluation of the potential exposure situation was carried out by radioprotection team in order to carry out the operations planned. For the facility dismantling, was established both measures to control the radiation exposure at workplace and individual monitoring of workers. A combination of physical, chemical and mechanical methods was used in the decontamination procedure applied in this unit. Concerning the internal operation procedures of IPEN-CNEN/SP, the radioactive waste control, the transport of the radioactive materials and authorization of use of decontaminated equipment were also subject of study. (author)

Abrasion of 6 dentifrices measured by vertical scanning interference microscopy.

Science.gov (United States)

Pascaretti-Grizon, Florence; Mabilleau, Guillaume; Chappard, Daniel

2013-01-01

The abrasion of dentifrices is well recognized to eliminate the dental plaque. The aims of this study were to characterize the abrasive powders of 6 dentifrices (3 toothpastes and 3 toothpowders) and to measure the abrasion on a test surface by Vertical Scanning Interference microscopy (VSI). Bright field and polarization microscopy were used to identify the abrasive particles on the crude dentifrices and after prolonged washes. Scanning electron microscopy and microanalysis characterized the shape and nature of the particles. Standardized and polished blocks of poly(methylmethacrylate) were brushed with a commercial electric toothbrush with the dentifrices. VSI quantified the mean roughness (Ra) and illustrated in 3D the abraded areas. Toothpastes induced a limited abrasion. Toothpowders induced a significantly higher roughness linked to the size of the abrasive particles. One powder (Gencix® produced a high abrasion when used with a standard testing weight. However, the powder is based on pumice particles covered by a plant homogenate that readily dissolves in water. When used in the same volume, or after dispersion in water, Ra was markedly reduced. Light and electron microscopy characterize the abrasive particles and VSI is a new tool allowing the analysis of large surface of abraded materials.

Basics of cutting and abrasive processes

CERN Document Server

Toenshoff, Hans Kurt

2013-01-01

Manufacturing is the basic industrial activity generating real value. Cutting and abrasive technologies are the backbone of precision production in machine, automotive and aircraft building as well as of production of consumer goods. We present the knowledge of modern manufacturing in these technologies on the basis of scientific research. The theory of cutting and abrasive processes and the knowledge about their application in industrial practice are a prerequisite for the studies of manufacturing science and an important part of the curriculum of the master study in German mechanical engineering. The basis of this book is our lecture “Basics of cutting and abrasive processes” (4 semester hours/3 credit hours) at the Leibniz University Hannover, which we offer to the diploma and master students specializing in manufacturing science.

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)

The separation of particulate within PFC decontamination wastewater generated by PFC decontamination

International Nuclear Information System (INIS)

Kim, Gye Nam; Lee, Sung Yeol; Won, Hui Jun; Jung, Chong Hun; Oh, Won Zin; Park, Jin Ho; Narayan, M.

2005-01-01

When PFC(Perfluoro carbonate) decontamination technology is applied to removal of radioactive contaminated particulate adhered at surface during the operation of nuclear research facilities, it is necessary to develop a filtration equipment to reuse of PFC solution due to high price, also to minimize the volume of second wastewater. Contaminated characteristics of hot particulate was investigated and a filtration process was presented to remove suspended radioactive particulate from PFC decontamination wastewater generated on PFC decontamination. The range of size of hot particulate adhered at the surface of research facilities measured by SEM was 0.1∼10μm. Hot particulate of more than 2μm in PFC contamination wastewater was removed by first filter and then hot particulate of more than 0.2μm was removed by second filter. Results of filter experiments showed that filtration efficiency of PVDF(Poly vinylidene fluoride), PP(Polypropylene), Ceramic filter was 95∼97%. A ceramic filter showed a higher filtration efficiency with a little low permeate volume. Also, a ceramic of inorganic compound could be broken easily on experiment and has a high price but was highly stable at radioactivity in comparison of PVDF and PP of a macromolecule which generate H 2 gas in alpha radioactivity environment

Mobile worksystems for decontamination and decommissioning operations. Final report

International Nuclear Information System (INIS)

1997-02-01

This project is an interdisciplinary effort to develop effective mobile worksystems for decontamination and decommissioning (D ampersand D) of facilities within the DOE Nuclear Weapons Complex. These mobile worksystems will be configured to operate within the environmental and logistical constraints of such facilities and to perform a number of work tasks. Our program is designed to produce a mobile worksystem with capabilities and features that are matched to the particular needs of D ampersand D work by evolving the design through a series of technological developments, performance tests and evaluations. The Phase I effort was based on a robot called the Remote Work Vehicle (RWV) that was previously developed by CMU for use in D ampersand D operations at the Three Mile Island Unit 2 Reactor Building basement. During Phase I of this program, the RWV was rehabilitated and upgraded with contemporary control and user interface technologies and used as a testbed for remote D ampersand D operations. We established a close working relationship with the DOE Robotics Technology Development Program (RTDP). In the second phase, we designed and developed a next generation mobile worksystem, called Rosie, and a semi-automatic task space scene analysis system, called Artisan, using guidance from RTDP. Both systems are designed to work with and complement other RTDP D ampersand D technologies to execute selective equipment removal scenarios in which some part of an apparatus is extricated while minimally disturbing the surrounding objects. RTDP has identified selective equipment removal as a timely D ampersand D mission, one that is particularly relevant during the de-activation and de-inventory stages of facility transitioning as a means to reduce the costs and risks associated with subsequent surveillance and monitoring. In the third phase, we tested and demonstrated core capabilities of Rosie and Artisan; we also implemented modifications and enhancements that improve their

Decontamination analysis of a radiologically contaminated site

International Nuclear Information System (INIS)

Tawil, J.J.; Strenge, D.L.

1984-01-01

This paper presents a post-exercise analysis of decontamination options for the NUWAX-83 exercise site. Held in May 1983, the purpose of NUWAX-83 was to evaluate the ability of federal, state and local officials to respond to an accident involving nuclear weapons. A computer program, called DECON, was developed by Pacific Northwest Laboratory and used to conduct the decontamination analysis in November 1983. DECON was designed to assist personnel engaged in the planning of decontamination activities. The many features of DECON that are demonstrated in this paper contribute to its potential usefulness as a planning tool for site restoration. Strategies that are analyzed with DECON include: 1) using a Quick-Vac option, under which exterior surfaces are vacuumed before it rains; 2) protecting surfaces against precipitation; 3) prohibiting specific operations on selected surfaces; 4) requiring that specific methods be used on selected surfaces; 5) evaluating the trade-off between cleanup standards and decontamination costs; and 6) varying clean-up standards according to expected human exposure to the surface

Performance Evaluation of Abrasive Grinding Wheel Formulated ...

African Journals Online (AJOL)

This paper presents a study on the formulation and manufacture of abrasive grinding wheel using locally formulated silicon carbide abrasive grains. Six local raw material substitutes were identified through pilot study and with the initial mix of the identified materials, a systematic search for an optimal formulation of silicon ...

Alpha-beta-gamma spectrometer as an aid in directing decontamination of soils

International Nuclear Information System (INIS)

Berger, C.D.

1981-01-01

This technique permits rapid assessment of alpha-beta-gamma-emitter contamination in soils at sufficiently low concentrations to direct field operations. Of particular importance is its applicability during initial decommissioning and decontamination surveys when characterization of alpha and beta contamination in the presence of a high gamma background is necessary. This system has not yet been made portable for in-situ use, but it is expected that results willbe favorable when operated as a field instrument, resulting in simplified standard decontamination operation

Dentifrice fluoride and abrasivity interplay on artificial caries lesions.

Science.gov (United States)

Nassar, Hani M; Lippert, Frank; Eckert, George J; Hara, Anderson T

2014-01-01

Incipient caries lesions on smooth surfaces may be subjected to toothbrushing, potentially leading to remineralization and/or abrasive wear. The interplay of dentifrice abrasivity and fluoride on this process is largely unknown and was investigated on three artificially created lesions with different mineral content/distribution. 120 bovine enamel specimens were randomly allocated to 12 groups (n = 10), resulting from the association of (1) lesion type [methylcellulose acid gel (MeC); carboxymethylcellulose solution (CMC); hydroxyethylcellulose gel (HEC)], (2) slurry abrasive level [low (REA 4/ RDA 69); high (REA 7/RDA 208)], and (3) fluoride concentration [0/275 ppm (14.5 mM) F as NaF]. After lesion creation, specimens were brushed in an automated brushing machine with the test slurries (50 strokes 2×/day). Specimens were kept in artificial saliva in between brushings and overnight. Enamel surface loss (SL) was determined by optical profilometry after lesion creation, 1, 3 and 5 days. Two enamel sections (from baseline and post-brushing areas) were obtained and analyzed microradiographically. Data were analyzed by analysis of variance and Tukey's tests (α = 5%). Brushing with high-abrasive slurry caused more SL than brushing with low-abrasive slurry. For MeC and CMC lesions, fluoride had a protective effect on SL from day 3 on. Furthermore, for MeC and CMC, there was a significant mineral gain in the remaining lesions except when brushed with high-abrasive slurries and 0 ppm F. For HEC, a significant mineral gain took place when low-abrasive slurry was used with fluoride. The tested lesions responded differently to the toothbrushing procedures. Both slurry fluoride content and abrasivity directly impacted SL and mineral gain of enamel caries lesions.

Sliding-gate valve for use with abrasive materials

Science.gov (United States)

Ayers, Jr., William J.; Carter, Charles R.; Griffith, Richard A.; Loomis, Richard B.; Notestein, John E.

1985-01-01

The invention is a flow and pressure-sealing valve for use with abrasive solids. The valve embodies special features which provide for long, reliable operating lifetimes in solids-handling service. The valve includes upper and lower transversely slidable gates, contained in separate chambers. The upper gate provides a solids-flow control function, whereas the lower gate provides a pressure-sealing function. The lower gate is supported by means for (a) lifting that gate into sealing engagement with its seat when the gate is in its open and closed positions and (b) lowering the gate out of contact with its seat to permit abrasion-free transit of the gate between its open and closed positions. When closed, the upper gate isolates the lower gate from the solids. Because of this shielding action, the sealing surface of the lower gate is not exposed to solids during transit or when it is being lifted or lowered. The chamber containing the lower gate normally is pressurized slightly, and a sweep gas is directed inwardly across the lower-gate sealing surface during the vertical translation of the gate.

29 CFR 1910.215 - Abrasive wheel machinery.

Science.gov (United States)

2010-07-01

... be securely fastened to the spindle and the bearing surface shall run true. When more than one wheel... 29 Labor 5 2010-07-01 2010-07-01 false Abrasive wheel machinery. 1910.215 Section 1910.215 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery. (a...

Electrochemical Decontamination of Painted and Heavily Corroded Metals

International Nuclear Information System (INIS)

Marczak, S.; Anderson, J.; Dziewinski, J.

1998-01-01

The radioactive metal wastes that are generated from nuclear fuel plants and radiochemical laboratories are mainly contaminated by the surface deposition of radioactive isotopes. There are presently several techniques used in removing surface contamination involving physical and chemical processes. However, there has been very little research done in the area of soiled, heavily oxidized, and painted metals. Researchers at Los Alamos National Laboratory have been developing electrochemical procedures for the decontamination of bare and painted metal objects. These methods have been found to be effective on highly corroded as well as relatively new metals. This study has been successful in decontaminating projectiles and shrapnel excavated during environmental restoration projects after 40+ years of exposure to the elements. Heavily corroded augers used in sampling activities throughout the area were also successfully decontaminated. This process has demonstrated its effectiveness and offers several advantages over the present metal decontamination practices of media blasting and chemical solvents. These advantages include the addition of no toxic or hazardous chemicals, low operating temperature and pressure, and easily scaleable equipment. It is in their future plans to use this process in the decontamination of gloveboxes destined for disposal as TRU waste

Anisotropy abrasive wear behavior of bagasse fiber reinforced ...

African Journals Online (AJOL)

parallel orientation (APO) and normal orientation (NO) by using a two body abrasion wear tester. Three different types of abrasives wear behaviour have been observed in the composite in three orientations and follow the following trends: WNO ...

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

Soil surface decontamination and revegetation progress

International Nuclear Information System (INIS)

Graves, A.W.

1981-01-01

A review is given of work by Rockwell Hanford Operations related to large-area decontamination efforts. Rockwell has a Program Office which manages the decontamination and decommissioning (D and D) efforts. Part of the program is involved with large-surface area cleanup in conjunction with surveillance and maintenance of retired sites and facilities. The other part is the decontamination and decommissioning of structures. There are 322 surplus contaminated sites and facilities for which Rockwell has responsibility on the Hanford Site. A Program Office was established for a disciplined approach to cleanup of these retired sites. There are three major projects: the first is surveillance and maintenance of the sites prior to D and D, the project under which the radiation area cleanup is contained. Another project is for contaminated-equipment volume reduction; size reduction with arc saw cut-up and volume reduction with a vacuum furnace meltdown are being used. The third major project is structural D and D

Planning guidance for nuclear-power-plant decontamination. [PWR; BWR

Energy Technology Data Exchange (ETDEWEB)

Munson, L.F.; Divine, J.R.; Martin, J.B.

1983-06-01

Direct and indirect costs of decontamination are considered in the benefit-cost analysis. A generic form of the benefit-cost ratio is evaluated in monetary and nonmonetary terms, and values of dollar per man-rem are cited. Federal and state agencies that may have jurisiction over various aspects of decontamination and waste disposal activities are identified. Methods of decontamination, their general effectiveness, and the advantages and disadvantages of each are outlined. Dilute or concentrated chemical solutions are usually used in-situ to dissolve the contamination layer and a thin layer of the underlying substrate. Electrochemical techniques are generally limited to components but show high decontamination effectiveness with uniform corrosion. Mechanical agents are particularly appropriate for certain out-of-system surfaces and disassembled parts. These processes are catagorized and specific concerns are discussed. The treatment, storage, and disposal or discharge or discharge of liquid, gaseous, and solid wastes generated during the decontamination process are discussed. Radioactive and other hazardous chemical wastes are considered. The monitoring, treatment, and control of radioactive and nonradioactive effluents, from both routine operations and possible accidents, are discussed. Protecting the health and safety of personnel onsite during decontamination is of prime importance and should be considered in each facet of the decontamination process. The radiation protection philosophy of reducing exposure to levels as low as reasonably achievable should be stressed. These issues are discussed.

Surface decontamination of Type 304L stainless steel with electrolytically generated hydrogen: Design and operation of the electrolyzer

International Nuclear Information System (INIS)

Bellanger, G.

1993-01-01

The surface of tritiated Type 304L stainless steel is decontaminated by isotopic exchange with the hydrogen generated in an electrolyzer. This steel had previously been exposed to tritium in a tritium gas facility for several years. The electrolyzer for the decontamination uses a conducting solid polymer electrolyte made of a Nafion membrane. The cathode where the hydrogen is formed is nickel deposited on one of the polymer surfaces. This cathode is placed next to the region of the steel to be decontaminated. The decontamination involves, essentially, the tritiated oxide layers of which the initial radioactivity is ∼ 5 kBq/cm 2 . After treatment for 1 h, the decontamination factor is 8. 9 refs., 16 figs., 2 tabs

Decontaminating agents and decontamination processes for nuclear industry and for plant demolition

International Nuclear Information System (INIS)

Henning, Klaus; Gojowczyk, Peter

2012-01-01

Decontamination of surfaces of materials in nuclear facilities or in nuclear power plants under demolition can be carried out successfully if surface treatment is performed by dipping or in an ultrasonic bath by alternating between alkaline and acid baths with intermediate rinsing in demineralized water. Decontaminating aluminium surfaces sensitive to corrosion requires further treatment in an ultrasonic bath, after the first 2 ultrasonic baths, with a weak alkaline decontaminating agent. This applies alike to components to be decontaminated for re-use and parts of materials to be disposed of. The decontamination action depends on the surfaces either being free from corrosion or else showing pronounced corrosion. (orig.)

Transition metal carbide and boride abrasive particles

International Nuclear Information System (INIS)

Valdsaar, H.

1978-01-01

Abrasive particles and their preparation are discussed. The particles consist essentially of a matrix of titanium carbide and zirconium carbide, at least partially in solid solution form, and grains of crystalline titanium diboride dispersed throughout the carbide matrix. These abrasive particles are particularly useful as components of grinding wheels for abrading steel. 1 figure, 6 tables

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.

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

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

Dismantling and decontamination of Piver prototype vitrification plant

International Nuclear Information System (INIS)

Jouan, A.; Roudil, S.; Thomas, F.

1991-01-01

The PIVER prototype was targeted for dismantling in order to install a new pilot facility for the french continuous vitrification process. Most of the work involved the vitrification cell containing the process equipments, which had to be cleared out and thoroughly decontaminated; this implied disassembling, cutting up, conditioning and removing all the equipment installed in the cell. Remote manipulation, handling and cutting devices were used and some prior modifications were implemented in the cell environment. The dismantling procedure was conducted under a detailed programme defining the methodology for each operation. After equipment items and active zones were identified, the waste materials were removed, and several liquid decontamination operations were implemented. Removed activity, levels of irradiation in the cell and doses integrated by personnel were monitored to control progress and to adapt procedures to the conditions encountered. At the end of December 1989, the PIVER cleanup programme was at 87% complete and the total activity removed was 2.11 X 10 14 Bq (5712 Ci). The objective now is to obtain suitable working conditions in order to allow operators to enter the cell to remove items that are inaccessible or which cannot be dismantled by remote manipulators and to complete the decontamination procedure

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.

Abrasive water jet: a complementary tool

OpenAIRE

Duarte, J. P.; Peças, P.; Nunes, E.; Gouveia, H.

1998-01-01

The abrasive water jet is a powerful cutting tool, whose main advantages lie in the absence of thermal effects and the capability of cutting highly thick materials. Compared with Laser, the abrasive water jet allows the cutting of a larger range of thicknesses and a wider variety of materials such as: ornamental stones, metals, polymers, composites, wood, glass and ceramics. The application of this technology has suffered an extensive growth, with successful applications in varied industrial ...

Wear of dentine in vitro by toothpaste abrasives and detergents alone and combined.

Science.gov (United States)

Moore, C; Addy, M

2005-12-01

To measure in vitro the abrasion of dentine by toothpaste detergents and abrasives alone and combined. Detergents used were tego betain, sodium lauryl sulphate (SLS), adinol and pluronic diluted to 1% w/v. Abrasives were three artificial silicas, tixosil 73 and 123 and Zeodent 113, and calcium carbonate used at 2.5% w/v. Flat human dentine specimens were brushed with aqueous detergent solutions or abrasive slurries, detergent abrasive slurries and water for 20,000 brush strokes. Dentine loss was measured by non-contacting profilometry at 10,000 and 20,000 strokes. Silica particle size distribution was measured by laser deflection. Loss of dentine occurred with all detergents, abrasives and detergent abrasion combinations, but was not linear with number of brush strokes. Water appeared to remove the smear layer only, but all detergents exceeded the predicted smear layer thickness. The silica abrasives differed in abrasion properties despite similar particle size distribution. Different detergents modulated the abrasives actions in mainly positive or mainly negative directions. Detergents appear able to attack the dentine surface to produce wear. Abrasives vary considerably in wear produced under similar conditions. Detergents modulate the effect of abrasives in a way that may reflect the rheological properties of the mixture.

Abrasive water jet cutting technique for biological shield concrete dismantlement

International Nuclear Information System (INIS)

Konno, T.; Narazaki, T.; Yokota, M.; Yoshida, H.; Miura, M.; Miyazaki, Y.

1987-01-01

The Japan Atomic Energy Research Institute (JAERI) is developing the abrasive-water jet cutting system to be applied to dismantling the biological shield walls of the JPDR as a part of the reactor dismantling technology development project. This is a total system for dismantling highly activated concrete. The concrete biological shield wall is cut into blocks by driving the abrasive-water jet nozzle, which is operated with a remote, automated control system. In this system, the concrete blocks are removed to a container, while the slurry and dust/mist which are generated during cutting are collected and treated, both automatically. It is a very practical method and will quite probably by used for actual dismantling of commercial power reactors in the future because it can minimize workers' exposure to radioactivity during dismantling, contributes to preventing diffusion of radiation, and reduces the volume of contaminated secondary waste

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)

The feasibility study of hot cell decontamination by the PFC spray method

International Nuclear Information System (INIS)

Hui-Jun Won; Chong-Hun Jung; Jei-Kwon Moon

2008-01-01

module. A performance test on each module was executed and the results have been reported. A combined test of the four modules, however, has not been performed as yet. The main objective of the present study is to demonstrate the feasibility of the full PFC spray decontamination process. Decontamination of the inside of the IMEF hot cell by the PFC spray method was also performed. PFC spray decontamination process was demonstrated by using a surrogate wall contaminated with Eu 2 O 3 powder. The spray pressure was 41 kgf/cm 2 , the orifice diameter was 0.2 mm and the spray velocity was 0.2 L/min. And, the decontaminated area was 100 cm 2 . From previous test results, we found that the decontamination factor of the PFC spray method was in the range from 9.6 to 62.4. When the decontamination efficiency of Co-60 was high, then the decontamination efficiency of Cs-137 was also high. As the surface roughness of the specimen increased, the PFC spray decontamination efficiency decreased. Inferring from the previous results, the surface of the surrogate wall was cleaned by the PFC spray method. The vacuum cup of the collection module operated well and gathered more than 99 % of the PFC solution. Also, filtration and distillation modules operated well. All the filtered PFC solution flowed to the storage chamber where some of the PFC solution was distilled. The coolant of the distillation module was a dry ice. And, the recycled solution was transferred to the spray module by a high pressure pump. To evaluate the PFC spray decontamination efficiency, a smear device was fabricated and operated by a manipulator. Before and after decontamination, a smear test was performed. The tested area was 100 cm 2 and the radioactivity was estimated indirectly by measuring the radioactivity of the filter paper. The average decontamination factor was in the range between 10 and 15. One application time was 2 minutes. The sprayed PFC solution was collected by the vacuum cup and it was stored in the

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

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.

Decontamination process applied to radioactive solid wastes from nuclear power plants

International Nuclear Information System (INIS)

Franco, Milton B.; Kastner, Geraldo F.; Monteiro, Roberto Pellacani G.

2009-01-01

The process of decontamination is an important step in the economic operation of nuclear facilities. A large number of protective clothing, metallic parts and equipment get contaminated during the handling of radioactive materials in laboratory, plants and reactors. Safe and economic operation of these nuclear facilities will have a bearing on the extent to which these materials are reclaimed by the process of decontamination. The most common radioactive contaminants are fission products, corrosion products, uranium and thorium. The principles involved in decontamination are the same as those for an industrial cleaning process. However, the main difference is in the degree of cleaning required and at times special techniques have to be employed for removing even trace quantities of radioactive materials. This paper relate decontaminations experiences using acids and acids mixtures (HCl, HF, HNO 3 , KMnO 4 , C 2 H 2 O 4 , HBF 4 ) in several kinds of radioactive solid wastes from nuclear power plants. The result solutions were monitored by nuclear analytical techniques, in order to contribute for radiochemical characterization of these wastes. (author)

A Study on Decontamination Process Using Atmospheric Pressure Plasma

International Nuclear Information System (INIS)

Kim, Yong Soo; Jeon, Sang Hwan; Jin, Dong Sik; Park, Dong Min

2010-05-01

Radioactive decontamination process using atmospheric pressure plasma which can be operated parallel with low vacuum cold plasma processing is studied. Two types of cold plasma torches were designed and manufactured. One of them is the cylindrical type applicable to the treatment of three-dimensional surfaces. The other is the rectangular type for the treatment of flat and large surface areas. Ar palsam was unstable but using He as a carrier gas, discharge condition was improved. Besides filtering module using pre, medium, charcoal, and HEPA filter was designed and manufactured. More intensive study for developing filtering system will be followed. Atmospheric pressure plasma decontamination process can be used to the equipment and facility wall decontamination

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)

Development of decontamination system for radioactive matter on paved road using dry ice blast method

International Nuclear Information System (INIS)

Nagamine, Haruo; Wakayama, Masanori; Nakamura, Hiroshi

2014-01-01

As a decontamination method for paved road surface, the 'Dry Ice Blast Decontamination System' has been developed. This decontamination system has characteristic as follows; 1) Generation of decontamination waste is extremely small, 2) not using water, 3) not damaging the pavement surface. In actual decontamination work, more than 60% average (maximum 84%) reduction rate of the radiation counting rate has been achieved. In addition to these features, this system prevent the diffusion into the surrounding and the radiation exposure of workers by sucking waste quickly using attached dust collecting function. This system is also characterized in that it does not cause a difference in skill by the operator because of faceted decontamination using repetitive motion by concatenating three pellet injection nozzle and self-propelled decontamination machine. (author)

Preconceptual design of the gas-phase decontamination demonstration cart

International Nuclear Information System (INIS)

Munday, E.B.

1993-12-01

Removal of uranium deposits from the interior surfaces of gaseous diffusion equipment will be a major portion of the overall multibillion dollar effort to decontaminate and decommission the gaseous diffusion plants. Long-term low-temperature (LTLT) gas-phase decontamination is being developed at the K-25 Site as an in situ decontamination process that is expected to significantly lower the decontamination costs, reduce worker exposure to radioactive materials, and reduce safeguard concerns. This report documents the preconceptual design of the process equipment that is necessary to conduct a full-scale demonstration of the LTLT method in accordance with the process steps listed above. The process equipment and method proposed in this report are not intended to represent a full-scale production campaign design and operation, since the gas evacuation, gas charging, and off-gas handling systems that would be cost effective in a production campaign are not cost effective for a first-time demonstration. However, the design presented here is expected to be applicable to special decontamination projects beyond the demonstration, which could include the Deposit Recovery Program. The equipment will therefore be sized to a 200 ft size 1 converter (plus a substantial conservative design margin), which is the largest item of interest for gas phase decontamination in the Deposit Recovery Program. The decontamination equipment will allow recovery of the UF 6 , which is generated from the reaction of ClF 3 with the uranium deposits, by use of NaF traps

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

Method of forming an abrasive compact of cubic boron nitride

International Nuclear Information System (INIS)

Bell, F.R.

1976-01-01

This patent concerns an abrasive compact comprising diamond or cubic boron nitride or mixtures thereof held in a matrix of a refractory substance and a substance which dissolves the abrasive particle to at least a limited extent. The compact may be made by subjecting a powdered mixture of the ingredients to conditions of temperature and pressure at which the abrasive particle is crystallographically stable and the solvent substance acts to dissolve the abrasive particle. The refractory substance and solvent substance are preferably so chosen that during compact manufacture there is interaction resulting in the formation of a hard material

LITERATURE SURVEY ON ABRASION PROBLEM IN CHENILLE YARNS

Directory of Open Access Journals (Sweden)

Erhan Kenan ÇEVEN

2006-01-01

Full Text Available Chenille yarns are traditionally used in the manufacture of furnishing fabrics, fashion knitwear, and as decorative threads in many types of broad and narrow fabrics. Chenille yarn has a very distinct weakness-it does not have very good inherent abrasion resistance. When the yarns are in use, clearly the abrasion resistance of the chenille yarn is crucially important. Either during further processing or during the eventual end-use, any removal of the effect yarn forming the beard will expose the ground yarns, which in turn will result in a bare appearance. To avoid this undesirable result, several options are available. Therefore, the studies on this area are about the investigation of the influences of some material types and machine parameters on the abrasion resistance of chenille yarns and fabrics produced with these yarns. In this paper, the experimental studies about the abrasion properties of chenille yarns in yarn, knitted and woven fabric forms are summarized.

A study on practical use of underwater abrasive water jet cutting

Science.gov (United States)

Yamaguchi, Hitoshi; Demura, Kenji

1993-09-01

The practicality of underwater abrasive water jet cutting technology was studied in experiments. A study of abrasives in slurried form showed that optimum polymer concentration can be selected to suit underwater conditions. For the long-distance transport of slurry from the ocean surface to the ocean floor, a direct supply system by hose proved to be practical. This system takes advantage of the insolubility of the slurry in water due to a difference in specific gravity. For cutting thick steel plate at great ocean depths, a simulation with a pressurized container revealed the requirements for actual cutting. Confirmation of remote cutting operations will become the most important technology in field applications. Underwater sound vibration characteristics were found to change significantly in direct response to modifications in cutting conditions. This will be important basic data to develop an effective sensoring method.

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.)

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.)

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)

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 prior to Decommissioning and Dismantlement is imperative. Not only does it provide for minimization of personnel dose exposure but also maximization of the material volume available for free release. Since easier dismantling techniques in lower dose areas can be applied, the licensing process is facilitated and the scheduling and budgeting effort is more reliable. The most internationally accepted approach for Decontamination prior to Decommissioning projects is the Full System Decontamination (FSD). FSD is defined as the chemical decontamination of the primary cooling circuit, in conjunction with the main auxiliary systems. AREVA NP has long-term experience with Full System Decontamination for return to service of operating nuclear power plants as well as for decommissioning after shutdown. Since 1976, AREVA NP has performed over 500 decontamination applications and, from 1986, Decontaminations prior to Decommissioning projects which comprise virtually all NPP designs and plant conditions were performed: NPP designs: HPWR, PWR, and BWR by AREVA, Westinghouse, ABB and GE. Decontaminations performed shortly after final shutdown or several years later, and even after re-opening Safe Enclosure. High Alpha inventory and or low gamma/alpha ratio. Main Coolant chemistry (e.g., with and without Zn injection during operation). Fifteen Decontaminations prior to Decommissioning Projects have been performed successfully to date and the sixteenth FSD is now in the detailed engineering phase and is scheduled to commence late 2010. AREVA NP has developed a fully comprehensive approach for decontamination based on the CORD® (Chemical Oxidation Reduction Decontamination) Family, applied using the in-house designed decontamination equipment AMDA TM (Automatic Modular Decontamination Appliance). Based on the vast experience of AREVA NP in the field of decontamination, the Decontamination Concept for Decommissioning was developed. This concept ensures that the

Decontamination of Surfaces by Ultrasonics; La decontamination des surfaces par l'emploi des ultra-sons

Energy Technology Data Exchange (ETDEWEB)

Cerre, P; Mestre, E; Kerdelleau, J de [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

1962-07-01

A study was made of factors such as frequency, intensity, and time in the case of steel and of cotton cloth contaminated by fission products. Results show that the method is only of value in the case of steel and that it is necessary to operate at an optimum frequency of 80 khz and with an intensity of at least 4 W/cm{sup 2}. The difficulty of proposing a valid explanation for the decontamination mechanism is discussed. (authors) [French] Apres un examen des donnees theoriques du probleme, les auteurs font une etude systematique des facteurs frequence, intensite et temps dans le cas de l'acier et des tissus de coton contamines par des produits de fission. Ils montrent que la methode n'est interessante que pour l'acier qu'il faut operer a la frequence optimale de 80 kHz avec une intensite d'au moins 4 W/cm{sup 2}. Ils concluent en insistant sur la difficulte de proposer une explication valable pour le mecanisme de decontamination. (auteurs)

Control technology for crystalline silica exposures in construction: wet abrasive blasting.

Science.gov (United States)

Golla, Vijay; Heitbrink, William

2004-03-01

This study was designed to document the effect that wet abrasive blasting has on reducing worker exposure to crystalline silica, which has been associated with silicosis and premature death. In this study, worker exposure to respirable crystalline silica was monitored during wet abrasive blasting on the exterior walls of a parking garage to remove surface concrete and expose the underlying aggregate. In this process a wet sand mix comprised of 80% dry sand and 20% water was used. Sampling and analysis revealed that the geometric mean respirable quartz concentration was 0.2 mg/m(3) for workers conducting abrasive blasting and 0.06 mg/m(3) for helpers. When abrasive blasting was conducted in areas that apparently had reduced natural ventilation, dust exposures appeared to increase. When compared with other published data, this case study suggests that wet abrasive blasting causes less exposure to crystalline silica than dry abrasive blasting.

Concept for Sustainable Dose Reduction in Operating BWRs and PWRs with FSD (Full System decontamination)

Energy Technology Data Exchange (ETDEWEB)

Sempere Belda, L.; Stiepani, C.; Topf, C.

2011-07-01

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. 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 and keep them low for continued operation. It can be applied in plants from all constructors and designs. The concept is put into practice through the coordinated application of proven technologies, including: . Full System Decontamination 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. A description of the activities involved is provided, including an approximate timeline for the implementation from the initial planning stages until completion.

Concept for Sustainable Dose Reduction in Operating BWRs and PWRs with FSD (Full System decontamination)

International Nuclear Information System (INIS)

Sempere Belda, L.; Stiepani, C.; Topf, C.

2011-01-01

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. 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 and keep them low for continued operation. It can be applied in plants from all constructors and designs. The concept is put into practice through the coordinated application of proven technologies, including: . Full System Decontamination 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. A description of the activities involved is provided, including an approximate timeline for the implementation from the initial planning stages until completion.

Electrical resistivity measurements to predict abrasion resistance of ...

Indian Academy of Sciences (India)

WINTEC

increasing expansion of highway and other construction works and decreasing natural aggregate resources in the world, the demand for crushed stone aggregates has in- creased from day-to-day. One of the important properties of rock aggregates is abrasion resistance. The abrasion resistance of aggregates is generally ...

Chemical decontamination solutions: Effects on PWR equipment

International Nuclear Information System (INIS)

Pezze, C.M.; Colvin, E.R.; Aspden, R.G.

1992-01-01

A critical objective for the nuclear industry is the reduction of personnel exposure to radiation. Reductions have been achieved through industry's radiation management programs including training and radiation awareness concepts. Increased plant maintenance and higher radiation fields at many sites continue to raise concerns. To alleviate the radiation exposure problem, the sources of radiation which contribute to personnel exposure must be removed from the plant. A feasible was of significantly reducing these sources from a Pressurized Water Reactor (PWR) is to chemically decontaminate the entire reactor coolant system (RCS). A program was conducted to determine the technical acceptability of using certain dilute chemical solvent processes for full RCS chemical decontamination. The two processes evaluated were CAN-DEREM and LOMI. The purpose of the program was to define and complete a systematic evaluation of the major issues that need to be addressed for the successful decontamination of the entire RCS and affected portions of the auxiliary systems of a four-loop PWR system. A test program was designed to evaluate the corrosion effects of the two decontamination processes under expected plant conditions. Materials and sample configurations dictated by generic PWR components were evaluated. The testing also included many standard corrosion coupons. The test data were then used to assess the impact of chemical decontamination on the physical condition and operability of the components, equipment and mechanical systems that make up the RCS. An overview of the test program, sample configurations, data and engineering evaluations is presented. The data demonstrate that through detailed engineering evaluations of corrosion data and equipment function, the impact of full RCS chemical decontamination on plant equipment is established

Comparison and Evaluation of Various Tritium Decontamination Techniques and Processes

International Nuclear Information System (INIS)

Gentile, C.A.; Langish, S.W.; Skinner, C.H.; Ciebiera, L.P.

2004-01-01

In support of fusion energy development, various techniques and processes have been developed over the past two decades for the removal and decontamination of tritium from a variety of items, surfaces, and components. Tritium decontamination, by chemical, physical, mechanical, or a combination of these methods, is driven by two underlying motivational forces. The first of these motivational forces is safety. Safety is paramount to the established culture associated with fusion energy. The second of these motivational forces is cost. In all aspects, less tritium contamination equals lower operational and disposal costs. This paper will discuss and evaluate the various processes employed for tritium removal and decontamination

Comparison and Evaluation of Various Tritium Decontamination Techniques and Processes

International Nuclear Information System (INIS)

Gentile, C.A.; Langish, S.W.; Skinner, C.H.; Ciebiera, L.P.

2005-01-01

In support of fusion energy development, various techniques and processes have been developed over the past two decades for the removal and decontamination of tritium from a variety of items, surfaces, and components. The motivational force for tritium decontamination by chemical, physical, mechanical, or a combination of these methods, is driven by two underlying forces. The first of these motivational forces is safety. Safety is paramount to the established culture associated with fusion energy. The second of these motivational forces is cost. In all aspects, less tritium contamination equals lower operational and disposal costs. This paper will discuss and evaluate the various processes employed for tritium removal and decontamination

UK fast reactor components. Sodium removal decontamination and requalification

International Nuclear Information System (INIS)

Donaldson, D.M.; Bray, J.A.; Newson, I.H.

1978-01-01

Extensive experience gained at the U.K.A.E.A. Dounreay Nuclear Power Development Establishment is being applied to form the basis of the plant to be provided for sodium removal, decontamination, and requalification of components in future commercial fast reactors. In the first part of a three part paper, the factors to be taken into account, showing the UK philosophy and approach to maintenance and repair operations are discussed. In the second part, PFR facilities for sodium removal and decontamination are described and some examples are given of cleaning components such as pumps, charge machine, cold trap baskets, and steam generator units. Similar facilities at DFR are briefly described. In the third part of the paper a short description is given of the Harwell mass transfer loop, currently used to study the deposition of activated stainless steel corrosion products. Decontamination method for pipework specimens cut from the loop are described and results of first screening tests of various chemical decontaminants are presented. (U.K.)

Submerged cutting characteristics of abrasive suspension jet

International Nuclear Information System (INIS)

Shimizu, Seiji; Peng, Guoyi; Oguma, Yasuyuki; Nishikata, Hiroki

2015-01-01

An abrasive suspension jet (ASJ) formed by propelling abrasive suspension through a nozzle has a greater cutting capability than the conventional abrasive water jet. However the cutting capability of submerged ASJs decreases drastically with increasing the standoff distance and the pressure around the jet. A sheathed nozzle nozzle with ventilation for ASJs has been developed as a mean of extending the effective stand-off distance and improving the cutting capabilities under submerged condition. In the present investigation, cutting tests by ASJs in air and under submerged condition are conducted with specimens of aluminum alloy. Air coated ASJs are formed by using a sheathed nozzle with ventilation. The relative cutting depth is defined as the cutting depth is arranged effectually by the cavitation number based on the cavity pressure measured at the sheath. (author)

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.)

Abrasive wear of ceramic wear protection at ambient and high temperatures

Science.gov (United States)

Varga, M.; Adam, K.; Tumma, M.; Alessio, K. O.

2017-05-01

Ceramic wear protection is often applied in abrasive conditions due to their excellent wear resistance. This is especially necessary in heavy industries conveying large amounts of raw materials, e.g. in steel industry. Some plants also require material transport at high temperatures and velocities, making the need of temperature stable and abrasion resistant wear protection necessary. Various types and wear behaviour of ceramic protection are known. Hence, the goal of this study is to identify the best suitable ceramic materials for abrasive conditions in harsh environments at temperatures up to 950°C and severe thermal gradients. Chamottes, known for their excellent thermal shock resistance are compared to high abrasion resistant ceramic wear tiles and a cost efficient cement-bounded hard compound. Testing was done under high-stress three-body abrasion regime with a modified ASTM G65 apparatus enabling for investigations up to ~950°C. Thereto heated abrasive is introduced into the wear track and also preheated ceramic samples were used and compared to ambient temperature experiments. Results indicate a significant temperature influence on chamottes and the hard compound. While the chamottes benefit from temperature increase, the cement-bounded hard compound showed its limitation at abrasive temperatures of 950°C. The high abrasion resistant wear tiles represented the materials with the best wear resistance and less temperature influence in the investigated range.

Influence of martensitic phase in abrasion behaviour of stainless steel 304 L

International Nuclear Information System (INIS)

Ruzzante, J.; Alvarez, P.; Hey, A.; Gestido, G.D.; Vosen, J.H.; Fernandez, H.A.

1986-01-01

Abrasion behaviour is studied in commercial stainless steels of different class compositions by standard. The work achieved guieds in structural analysis of superficial coat formed and its relation with abrasion variables, load and velocity. The abrasion is made in an equipment LF WK of high velocity with friction powers, abrasion velocity and temperature variation registered on the tested piece. The abrasion zone is studied with scanning electron microscope (SEM). The deformed superficial zone nature is studied relationing its microstructure with profile corresponding of microhardness. (C.M.C.T.R.) [pt

Transportation cask decontamination and maintenance at the potential Yucca Mountain repository

International Nuclear Information System (INIS)

Hartman, D.J.; Miller, D.D.; Hill, R.R.

1992-04-01

This study investigates spent fuel cask handling experience at existing nuclear facilities to determine appropriate cask decontamination and maintenance operations at the potential Yucca Mountain repository. These operations are categorized as either routine or nonroutine. Routine cask decontamination and maintenance tasks are performed in the cask preparation area at the repository. Casks are taken offline to a separate cask maintenance area for major nonroutine tasks. The study develops conceptual designs of the cask preparation area and cask maintenance area. The functions, layouts, and major features of these areas are also described

PNL size reduction and decontamination facilities and capabilities

International Nuclear Information System (INIS)

Allen, R.P.; Fetrow, L.K.; McCoy, M.W.

1983-07-01

Studies sponsored by the US Department of Energy at Pacific Northwest Laboratory (PNL) have resulted in the development of an effective, integrated size reduction and decontamination system for transuranically contaminated components. Using this system, a reduction of more than 95% in the volume of transuranic waste requiring interim storage and eventual geologic disposal has been achieved for typical plutonium contaminated glove boxes. This paper describes the separate preparation, size reduction, decontamination and waste treatment operations and facilities that have been developed and demonstrated as part of this work

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)

Proposed draft standard ANS 11.18: recommendations to facilitate decontamination and decommissioning

International Nuclear Information System (INIS)

Jenkins, C.E.; LaGuardia, T.S.; Jones, J.W.

1981-01-01

The purpose of ANS Standard 11.18 is to recommend design guides to facilitate decontamination and eventual decommissioning of a remotely operated radioactive facility. This design guide contains generic recommendations to assist in the planning, selection and arrangement of equipment and materials, and the protection of surfaces to enhance system decontamination and disassembly

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

Development of remote control decontamination machines for BWR nuclear power plants

International Nuclear Information System (INIS)

Miyakawa, Minoru; Nozawa, Katsuro; Yamada, Masuji; Mizutani, Takeshi; Onozuka, Kazuaki

1981-01-01

The dose rate of radiation on the surfaces of equipments and in rooms tends to increase as radioactive substances accumulate with the continuous operation of nuclear power stations. The decontamination works to remove radioactive substances are carried out to prevent the exposure of workers in the case of inspection and repair. In order to reduce the exposure of decontamination workers, to save labor and to shorten decontamination time, Chubu Electric Power Co., Inc., has developed the decontamination machines for the walls of reactor wells, the walls and bottoms of equipment pits, the internal surfaces of suppression chambers, and the internal surfaces of tanks. The decontamination machines have several remote-handling functions: (a) brushing up with sprinkling against complicate surface such as a wall with step, (b) vertical transfer of brushing position with sucking force, (c) sucking out slurries under the water of storage pool or inside the pressure-supression pool, (d) horizontal transfer of suction position with electric motors. (J.P.N.)

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)

Plasma decontamination during ergodic divertor experiments in TORE SUPRA

International Nuclear Information System (INIS)

Monier-Garbet, P.; DeMichelis, C.; Fall, T.; Ghendrih, Ph.; Goniche, M.; Grosman, A.; Hess, W.; Mattioli, M.

1991-01-01

In Tore Supra an ergodic divertor (ED) has been integrated in the machine design and successfully operated, as already reported. This paper analyses the decontamination effect resulting from the creation of an ergodic boundary zone. Two plasma geometrical configurations (outboard and inboard) are studied, the plasma being limited respectively either, on the low field side (lfs), by an outboard limiter (3 to 5 cm ahead of the ED modules) or, on the high field side (hfs), by the graphite inner wall. Strong decontamination effects have already been reported for the first configuration by observing line emission of the intrinsic (carbon and oxygen) and purposely injected (nitrogen) impurities. When limited by the inner wall, the plasma is several centimeters farther from the ED modules than in the lfs configuration. The magnetic perturbation is then greatly reduced, and much smaller decontamination effects should be expected. In this paper, the hfs configuration data is compared with that from the lfs configuration. Preliminary experiments combining lower hybrid current drive and ED operation in the hfs configuration are also reported. (author) 5 refs., 4 figs

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.)

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.)

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

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.)

Decontamination methods in nuclear power plants after incidents and in the case of decommissioning

International Nuclear Information System (INIS)

Dippel, T.; Hentschel, D.

1975-01-01

Tabellary survey on various decontamination methods with regard to criteria such as decontaminating materials, handling, duration, operating temperature etc. which help to get a clear description of the individual methods that is still as simple as possible. (RW/AK) [de

Functional and operational design requirements for decontamination and decommissioning of the EBR-I Mark-II NaK: Final report

International Nuclear Information System (INIS)

Brown, B.W.; Crandall, D.L.; Dafoe, R.E.; Dolenc, M.R.; LaRue, D.M.

1987-09-01

Approximately 180 gal of sodium/potassium (NaK) eutectic liquid metal were severely radioactively contaminated during a meltdown of the Mark-II core of the Experimental Breeder Reactor-I (EBR-I) in November 1955. This contaminated NaK, which is contained in four vessels, is currently stored in an underground bunker located at the Army Reentry Vehicle Facility Site (ARVFS) located approximately at the center of the Idaho National Engineering Laboratory (INEL). This document presents the Functional and Operational Requirements (F and ORs) for the D and D of the contaminated NaK and the ARVFS bunker site. This project will chemically deactivate the NaK; dispose of the radioactively contaminated product at a designated burial site; chemically deactivate any residual NaK in the containers, and dispose of the containers at a designated burial site; decontaminate and decommission any contaminated process equipment used in these operations, and decontaminate and decommission the ARVFS bunker site. Completion of the above technical objectives will allow for the effective disposition of the NaK, and will return the ARFVS bunker and immediate area to a reusable condition. Upon completion, the ARVFS NaK, which is now considered a significant potential hazard, will be removed from the Surplus Facilities Management Program priority listing of projects. 33 refs., 8 figs

Solidification structure and abrasion resistance of high chromium white irons

Science.gov (United States)

Doğan, Ö. N.; Hawk, J. A.; Laird, G.

1997-06-01

Superior abrasive wear resistance, combined with relatively low production costs, makes high Cr white cast irons (WCIs) particularly attractive for applications in the grinding, milling, and pumping apparatus used to process hard materials. Hypoeutectic, eutectic, and hypereutectic cast iron compositions, containing either 15 or 26 wt pct chromium, were studied with respect to the macrostructural transitions of the castings, solidification paths, and resulting microstructures when poured with varying superheats. Completely equiaxed macrostructures were produced in thick section castings with slightly hypereutectic compositions. High-stress abrasive wear tests were then performed on the various alloys to examine the influence of both macrostructure and microstructure on wear resistance. Results indicated that the alloys with a primarily austenitic matrix had a higher abrasion resistance than similar alloys with a pearlitic/bainitic matrix. Improvement in abrasion resistance was partially attributed to the ability of the austenite to transform to martensite at the wear surface during the abrasion process.

Modeling of Micro Deval abrasion loss based on some rock properties

Science.gov (United States)

Capik, Mehmet; Yilmaz, Ali Osman

2017-10-01

Aggregate is one of the most widely used construction material. The quality of the aggregate is determined using some testing methods. Among these methods, the Micro Deval Abrasion Loss (MDAL) test is commonly used for the determination of the quality and the abrasion resistance of aggregate. The main objective of this study is to develop models for the prediction of MDAL from rock properties, including uniaxial compressive strength, Brazilian tensile strength, point load index, Schmidt rebound hardness, apparent porosity, void ratio Cerchar abrasivity index and Bohme abrasion test are examined. Additionally, the MDAL is modeled using simple regression analysis and multiple linear regression analysis based on the rock properties. The study shows that the MDAL decreases with the increase of uniaxial compressive strength, Brazilian tensile strength, point load index, Schmidt rebound hardness and Cerchar abrasivity index. It is also concluded that the MDAL increases with the increase of apparent porosity, void ratio and Bohme abrasion test. The modeling results show that the models based on Bohme abrasion test and L type Schmidt rebound hardness give the better forecasting performances for the MDAL. More models, including the uniaxial compressive strength, the apparent porosity and Cerchar abrasivity index, are developed for the rapid estimation of the MDAL of the rocks. The developed models were verified by statistical tests. Additionally, it can be stated that the proposed models can be used as a forecasting for aggregate quality.

Effect of nanofillers' size on surface properties after toothbrush abrasion.

Science.gov (United States)

Cavalcante, Larissa M; Masouras, Konstantinos; Watts, David C; Pimenta, Luiz A; Silikas, Nick

2009-02-01

To investigate the effect of filler-particle size of experimental and commercial resin composites, undergoing toothbrush abrasion, on three surface properties: surface roughness (SR), surface gloss (G) and color stability (CS). Four model (Ivoclar/Vivadent) and one commercial resin composite (Tokuyama) with varying filler-size from 100-1000 nm were examined. Six discs (10 mm x 2 mm) from each product were prepared and mechanically polished. The samples were then submitted to 20,000 brushing strokes in a toothbrush abrasion machine. SR parameters (Ra, Rt and RSm), G, and CS were measured before and after toothbrush abrasion. Changes in SR and G were analyzed by 2-way ANOVA, with Bonferroni post hoc test. CS values were submitted to one-way ANOVA and Bonferroni post hoc test (alpha=0.05). Initial G values ranged between 73-87 gloss units (GU) and were reduced after toothbrush abrasion to a range of 8-64 GU. Toothbrush abrasion resulted in significant modifications in SR and G amongst the materials tested, attributed to filler sizes. There was statistically significant difference in color (delta E* ranged from 0.38-0.88). Filler size did not affect color stability. Toothbrush abrasion resulted in rougher and matte surfaces for all materials tested. Although the individual differences in surface roughness among filler sizes were not always significant, the correlation showed a trend that larger filler sizes resulted in higher surface roughness after abrasion for the SR parameters Ra and Rt (r = 0.95; r = 0.93, respectively). RSm showed an increase after toothbrush abrasion for all resin composites, however no significant correlation was detected (r = 0.21).There was a significant correlation between G and Ra ratios (r = - 0.95).

Neuro - Fuzzy Analysis for Silicon Carbide Abrasive Grains ...

African Journals Online (AJOL)

Grinding wheels are made of very small, sharp and hard abrasive materials or grits held together by strong porous bond. Abrasive materials are materials of extreme hardness that are used to shape other materials by a grinding or abrading action and they are used either as loose grains, as grinding wheels, or as coatings ...

Third abrasive wear mode: is it possible?

Directory of Open Access Journals (Sweden)

Ronaldo Câmara Cozza

2014-04-01

Full Text Available The objective of this paper is to propose an initial discussion on the characterization of a third abrasive wear mode. The results obtained in a previous work [1] under different test conditions revealed the occurrence of the superposition of the “rolling” and “grooving” abrasive wear modes. This phenomenon was denoted “micro-rolling abrasion” due to the observation that “rolling abrasion” was found to act on “grooving abrasion”.

Chemical decontamination method for radioactive metal waste

International Nuclear Information System (INIS)

Onuma, Tsutomu; Akimoto, Hidetoshi

1991-01-01

The invention relates to a decontamination method for radioactive metal waste products derived from equipment that handles radioactive materials whose surfaces have been contaminated; in particular it concerns a decontamination method that reduces the amount of radioactive waste by decontaminating radioactive waste substances to a level of radioactivity in line with normal waste products. In order to apply chemical decontamination to metal waste products whose surfaces are divided into carbon steel waste and stainless steel waste; the carbon steel waste is treated using only a primary process in which the waste is immersed in a sulfuric acid solution, while the stainless steel waste must be treated with both the primary process and then electrolytically reduces it for a specific length of time and a secondary process that uses a solution of sulfuric acid mixed with oxidizing metal salts. The method used to categorize metal waste into carbon steel waste and stainless steel waste involves determining the presence, or absence, of magnetism. Voltage is applied for a fixed duration; once that has stopped, electrolytic reduction repeats the operative cycle of applying, then stopping voltage until the potential of the radioactive metal waste is retained in the active region. 1 fig. 2 tabs

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

Gas phase decontamination of gaseous diffusion process equipment

International Nuclear Information System (INIS)

Bundy, R.D.; Munday, E.B.; Simmons, D.W.; Neiswander, D.W.

1994-01-01

D ampersand D of the process facilities at the gaseous diffusion plants (GDPs) will be an enormous task. The EBASCO estimate places the cost of D ampersand D of the GDP at the K-25 Site at approximately $7.5 billion. Of this sum, nearly $4 billion is associated with the construction and operation of decontamination facilities and the dismantlement and transport of contaminated process equipment to these facilities. In situ long-term low-temperature (LTLT) gas phase decontamination is being developed and demonstrated at the K-25 site as a technology that has the potential to substantially lower these costs while reducing criticality and safeguards concerns and worker exposure to hazardous and radioactive materials. The objective of gas phase decontamination is to employ a gaseous reagent to fluorinate nonvolatile uranium deposits to form volatile LJF6, which can be recovered by chemical trapping or freezing. The LTLT process permits the decontamination of the inside of gas-tight GDP process equipment at room temperature by substituting a long exposure to subatmospheric C1F for higher reaction rates at higher temperatures. This paper outlines the concept for applying LTLT gas phase decontamination, reports encouraging laboratory experiments, and presents the status of the design of a prototype mobile system. Plans for demonstrating the LTLT process on full-size gaseous diffusion equipment are also outlined briefly

Abrasive water jet cutting

International Nuclear Information System (INIS)

Leist, K.J.; Funnell, G.J.

1988-01-01

In the process of selecting a failed equipment cut-up tool for the process facility modifications (PFM) project, a system using an abrasive water jet (AWJ) was developed and tested for remote disassembly of failed equipment. It is presented in this paper

Decontamination of medical radioisotopes from hard surfaces using peelable polymer-based decontamination agents

International Nuclear Information System (INIS)

Draine, Amanda E.; Walter, Ken J.; Johnson, Thomas E.

2008-01-01

Full text: Medical radioisotopes used to treat and diagnose patients often contaminate surfaces in patient treatment rooms. They are typically short-lived and decay within a matter of days or weeks. However, down time in a medical facility related to radioisotope contamination is costly and can impact patient care. Most liquid or solid spills can be contained and disposed in radioactive wastes fairly completely and quickly; however residual contamination may remain on the contacted surface. Although liquid decontamination agents can be used to address the issue of residual contamination, they often require multiple applications with attendant scrubbing and wiping. Liquid decontamination can also produce large volumes of low-level radioactive waste. To look at reducing radioactive waste volumes, research was conducted on the efficacy of three low-volume peel able decontamination agents. Testing was performed on hard surfaces, such as vinyl composition floor tiles and stainless steel, which are found in many hospitals, research laboratories, and universities. The tiles were contaminated with the medical use isotopes of 99m Tc, Tl-201, and I-131 and subsequently decontaminated with one of the three decontamination agents. Quantitative and qualitative data were obtained for each of three different peel able decontamination agent formulations. Quantitative data included environmental temperature and relative humidity, application thickness, dry time, contact time, and decontamination efficacy of the agents on the tested surfaces. Qualitative factors included ease of application and pee lability, as well as sag resistance and odor of each agent. Initial studies showed that under standard conditions there were reproducible differences in the decontamination efficacies among the three different decontamination formulations. (author)

Microbial decontamination of cosmetic raw materials and personal care products by irradiation

International Nuclear Information System (INIS)

Katusin-Razem, B.; Mihaljevic, B.; Razem, D.

2005-01-01

Typical levels of sporadically occurring (dynamic) microbial contamination of cosmetic raw materials: pigments, abrasives and liposomes, as well as of final products for personal care, i.e. toothpaste, crayons, shampoos, cleansers and creams, were evaluated. In most cases, contamination was dominated by a single population of microorganisms, either Gram-negative bacteria or molds. The feasibility of microbial decontamination by irradiation was studied by determining the resistance to gamma radiation of contaminating microflora in situ. It was expressed as a dose required for the first 90% reduction, D first 9 0% red. The values in the range 1-2 kGy for molds and 0.1-0.6 kGy for Gram-negative bacteria were obtained. This relatively high susceptibility to irradiation allowed inactivation factors close to 6 to be achieved with doses generally not exceeding 3 kGy, and yielding endpoint contamination less than 10 g -1 . (author)

Microbial decontamination of cosmetic raw materials and personal care products by irradiation

International Nuclear Information System (INIS)

Katusin-Razem, Branka; Mihaljevic, Branka; Razem, D.

2003-01-01

Typical levels of sporadically occurring (dynamic) microbial contamination of cosmetic raw materials: pigments, abrasives and liposomes, as well as of final products for personal care: toothpaste, crayons, shampoos, cleansers and creams, were evaluated. In most cases the contamination was dominated by a single population of microorganisms, either Gram-negative bacteria or molds. The feasibility of microbial decontamination by irradiation was studied by determining the resistance to gamma radiation of contaminating microflora in situ. It was expressed as a dose required for the first 90% reduction, D first 9 0% r ed . The values in the range 1-2 kGy for molds and 0.1-0.6 kGy for Gram-negative bacteria were obtained. This relatively high susceptibility to irradiation allowed inactivation factors close to 6 to be achieved with doses generally not exceeding 3 kGy, and yielding endpoint contamination less than 10/g

Decontamination chamber for the maintenance of DUPIC nuclear fuel fabrication and process equipment

International Nuclear Information System (INIS)

Kim, K. H.; Park, J. J.; Yang, M. S.; Lee, H. H.; Shin, J. M.

2000-10-01

This report presents the decontamination chamber of being capable of decontaminating and maintaining DUPIC nuclear fuel fabrication equipment contaminated in use. The decontamination chamber is a closed room in which contaminated equipment can be isolated from a hot-cell, be decontaminated and be reparired. This chamber can prevent contamination from spreading over the hot-cell, and it can also be utilized as a part of the hot-cell after maintenance work. The developed decontamination chamber has mainly five sub-modules - a horizontal module for opening and closing a ceil of the chamber, a vertical module for opening and closing a side of the chamber, a subsidiary door module for enforcing the vertical opening/closing module, a rotary module for rotating contaminated equipment, and a grasping module for holding a decontamination device. Such sub-modules were integrated and installed in the M6 hot-cell of the IMEF at the KAERI. The mechanical design considerations of each modules and the arrangement with hot-cell facility, remote operation and manipulation of the decontamination chamber are also described

Decontamination chamber for the maintenance of DUPIC nuclear fuel fabrication and process equipment

Energy Technology Data Exchange (ETDEWEB)

Kim, K. H.; Park, J. J.; Yang, M. S.; Lee, H. H.; Shin, J. M

2000-10-01

This report presents the decontamination chamber of being capable of decontaminating and maintaining DUPIC nuclear fuel fabrication equipment contaminated in use. The decontamination chamber is a closed room in which contaminated equipment can be isolated from a hot-cell, be decontaminated and be reparired. This chamber can prevent contamination from spreading over the hot-cell, and it can also be utilized as a part of the hot-cell after maintenance work. The developed decontamination chamber has mainly five sub-modules - a horizontal module for opening and closing a ceil of the chamber, a vertical module for opening and closing a side of the chamber, a subsidiary door module for enforcing the vertical opening/closing module, a rotary module for rotating contaminated equipment, and a grasping module for holding a decontamination device. Such sub-modules were integrated and installed in the M6 hot-cell of the IMEF at the KAERI. The mechanical design considerations of each modules and the arrangement with hot-cell facility, remote operation and manipulation of the decontamination chamber are also described.

Bioinspired Surface Treatments for Improved Decontamination: Handling andDecontamination Considerations

Science.gov (United States)

2018-03-16

and Decontamination Considerations Brandy J. White Martin H. Moore Brian J. Melde Laboratory for the Study of Molecular Interfacial Interactions...Decontamination Considerations Brandy J. White, Martin H. Moore, Brian J. Melde, Anthony P. Malanoksi, and Chanté Campbell1 Center for Bio/Molecular

Erosion and abrasion on dental structures undergoing at-home bleaching

Directory of Open Access Journals (Sweden)

Tarquinio SBC

2011-07-01

Full Text Available Flávio Fernando Demarco1, Sônia Saeger Meireles2, Hugo Ramalho Sarmento1, Raquel Venâncio Fernandes Dantas1, Tatiana Botero3, Sandra Beatriz Chaves Tarquinio11Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Brazil; 2Department of Operative Dentistry, Federal University of Paraíba, Brazil; 3Cariology, Restorative Science, and Endodontics Department, School of Dentistry, University of Michigan, MI, USAAbstract: This review investigates erosion and abrasion in dental structures undergoing at-home bleaching. Dental erosion is a multifactorial condition that may be idiopathic or caused by a known acid source. Some bleaching agents have a pH lower than the critical level, which can cause changes in the enamel mineral content. Investigations have shown that at-home tooth bleaching with low concentrations of hydrogen or carbamide peroxide have no significant damaging effects on enamel and dentin surface properties. Most studies where erosion was observed were in vitro. Even though the treatment may cause side effects like sensitivity and gingival irritation, these usually disappear at the end of treatment. Considering the literature reviewed, we conclude that tooth bleaching agents based on hydrogen or carbamide peroxide have no clinically significant influence on enamel/dentin mineral loss caused by erosion or abrasion. Furthermore, the treatment is tolerable and safe, and any adverse effects can be easily reversed and controlled.Keywords: peroxide, tooth bleaching, enamel, dentin, erosion, abrasion

New techniques available for decontamination

International Nuclear Information System (INIS)

Costes, J.R.; Cochaux, C.

1996-01-01

As nuclear industry dismantling operations become more widespread, one naturally sees the growth of specific needs in decontamination techniques. In this paper, the authors present two applications involving the decategorization of wastes from dismantling. Decategorization means using decontamination to transform the wastes into a lower, and thus cheaper, category. The first application is in decategorizing large mild steel pipes, which come from the stage decommissioning of the G2/G3 graphite gas reactors at Marcoule. A large number of these pipes (4000 t) have been contaminated by deposits and encrustations of 60 Co (95%) and 137 Cs (5%) to the extent of 200 Bq/cm 2 . The objective was to avoid having to store them on surface sites for 300 yr. This is achieved by decontaminating them to a level that enables the metal to be reused. The other application involves stainless steel waste cut into small sections, which comes from the stage decommissioning of a radiometallurgy laboratory (RM2) at Fontenay aux Roses. This waste was not acceptable to the surface storage center due to high levels of alpha contamination. A decategorization technique has been developed for part of the 13 tonnes of waste concerned, which avoids the need for it to be disposed of in extremely costly geologic repositories

Decontamination and decommissioning focus area. Technology summary

International Nuclear Information System (INIS)

1995-06-01

This report presents details of the facility deactivation, decommissioning, and material disposition research for development of new technologies sponsored by the Department of Energy. Topics discussed include; occupational safety, radiation protection, decontamination, remote operated equipment, mixed waste processing, recycling contaminated metals, and business opportunities

Submerged cutting characteristics of abrasive suspension jet

International Nuclear Information System (INIS)

Shimizu, Seiji; Peng, Guoyi; Oguma, Yasuyuki; Nishikata, Hiroyuki

2015-01-01

An abrasive suspension jet (ASJ) formed by propelling abrasive suspension through a nozzle has a greater cutting capability than the conventional abrasive water jet. However the cutting capability of submerged ASJs decreases drastically with increasing the standoff distance and the pressure around the jet. A sheathed nozzle with ventilation for ASJs has been developed as a mean of extending the effective stand-off distance and improving the cutting capabilities under submerged condition. In the present investigation, cutting tests by ASJs in air and under submerged condition are conducted with specimens of aluminum alloy. Air coated ASJs are formed by using a sheathed nozzle with ventilation. The relative cutting depth is defined as the cutting depth under submerged condition divided by the cutting depth in air at the same standoff distance. The relative cutting depth is arranged effectually by the cavitation number based on the cavity pressure measured at the sheath. (author)

Method for decontaminating radiation metal waste

International Nuclear Information System (INIS)

Onuma, Tsutomu; Tanaka, Akio; Akimoto, Hidetoshi

1991-01-01

This report describes a method for decontaminating radiation metal waste characterized by the following properties: in order to decontaminate radiation metal waste of various shapes produced by facilities involved with radioactive substances, non-complex shapes are decontaminated by electropolishing the materials in a neutral saline solution. Complex shapes are chemically decontaminated by means of an acid solution containing permanganic acid or an alkaline solution and a mineral acid solution. After neutralizing the solutions used for chemical decontamination, the radioactive material is separated and removed. Further, in the decontamination method for radioactive metal waste, a supernatant liquid is reused as the electrolyte in electropolishing decontamination. Permanganic ions (MnO 4 - ) are reduced to manganese dioxide (MnO 2 ) and deposited prior to neutralizing the solution used for chemical decontamination. Once manganese dioxide (MnO 2 ) has been separated and removed, it is re-used as the electrolyte in electropolishing decontamination by means of a process identical to the separation process for radioactive substances. 3 figs

Experience with cleaning of sodium-wetted components and decontamination at Nuclear Research Centre Karlsruhe

Energy Technology Data Exchange (ETDEWEB)

Menzenhauer, P; Borgstedt, U; Stamm, H H; Dippel, Th; Kunze, S; Hentschel, D [Kernforschungszentrum Karlsruhe, Karlsruhe (Germany)

1978-08-01

Within the framework of the Fast Breeder Project various institutes of the KarIsruhe Nuclear Research Center operate sodium loops for corrosion studies and component tests under sodium. The operation of these loops has led to extensive experience in cleaning sodium-wetted components. This experience relates to the alcohol method, the removal of sodium by melting, storage in air, and to cleaning by means of steam. Deposition samples from radioactive sodium loops were used for decontamination experiments employing various decontaminating agents. The department concerned with the treatment of radioactive waste studied the use of molten salts and paste type cleansers for components unsuitable for mechanical decontamination, primarily with the objective to reduce the amount of radioactive waste. (author)

Experience with cleaning of sodium-wetted components and decontamination at Nuclear Research Centre Karlsruhe

International Nuclear Information System (INIS)

Menzenhauer, P.; Borgstedt, U.; Stamm, H.H.; Dippel, Th.; Kunze, S.; Hentschel, D.

1978-01-01

Within the framework of the Fast Breeder Project various institutes of the KarIsruhe Nuclear Research Center operate sodium loops for corrosion studies and component tests under sodium. The operation of these loops has led to extensive experience in cleaning sodium-wetted components. This experience relates to the alcohol method, the removal of sodium by melting, storage in air, and to cleaning by means of steam. Deposition samples from radioactive sodium loops were used for decontamination experiments employing various decontaminating agents. The department concerned with the treatment of radioactive waste studied the use of molten salts and paste type cleansers for components unsuitable for mechanical decontamination, primarily with the objective to reduce the amount of radioactive waste. (author)

Analysis of coarse aggregate performance based on the modified Micro Deval abrasion test

Directory of Open Access Journals (Sweden)

Jiangfeng Wu

2018-03-01

Full Text Available The anti-abrasion property of aggregate significantly affects the performance of the pavement. In this research, the quartzite and gneiss which were produced in Lincheng County, Xingtai City, Hebei Province were selected as test samples. According to the American Society for Testing and Materials standard, the Micro-Deval abrasion test was taken every 1000 rotation times until 20,000 times, and the change trend of the Micro-Deval abrasion value was obtained. Results showed that the abrasion values were in the exponential growth rate rather than linear rate. Their R-Square coefficient was 0.99142 and 0.99916 respectively. The gravel information such as area, roundness, diameter, perimeter and so on were calculated and analyzed by Image-Pro Plus software, which provided a rapid way for the 2D morphology characteristics analysis of the coarse aggregate. Keywords: Micro-Deval abrasion test, Coarse aggregate, Anti-abrasion property, Abrasion values

Abrasive wear of WC-NiMoCrFeCo thermally sprayed coatings in dependence on different types of abrasive sands

Czech Academy of Sciences Publication Activity Database

Kašparová, M.; Zahálka, F.; Houdková, Š.; Ctibor, Pavel

2010-01-01

Roč. 48, č. 1 (2010), s. 75-85 ISSN 0023-432X R&D Projects: GA AV ČR 1QS200430560 Institutional research plan: CEZ:AV0Z20430508 Keywords : WC-Hastelloy * abrasive wear * Al2O3 sand * SiO2 sand * braun size * abrasive efficiency Subject RIV: JG - Metallurgy Impact factor: 0.471, year: 2010 http://kovmat.sav.sk/abstract.php?rr=48&cc=1&ss=73

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

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

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.

Decontamination of the main circulation loap equipment together with the core of a boiling channel-type reactor

International Nuclear Information System (INIS)

Boguslavskij, V.B.; Gruzdev, N.I.; Kocharin, V.E.; Matskevich, G.V.; Mel'nikov, A.P.; Petrov, V.A.; Petukhov, Yu.I.; Sklyarov, V.P.; Shiryaev, V.N.; Shchapov, G.A.

1977-01-01

Presented herein are the results of decontamination of the main circulation loop together with the core in Beloyarskaya nuclear power plant. A double-bath reduction-oxidation decontamination process has been employed by alternately using alkaline solution of potassium permanganate and oxalic acid at 90 deg C. Standard cation-exchange filters, filled with Ky-2 resin, have been used to purify the acid solutions at all the stages of decontamination from s.lurry and radionuclide 60 Co. The total quantity of corrosion products removed from the loop in the decontamination cycles amountes cobalt-60 - 2340 c; chrome-51 - 275 c; magnanese-54 - 12 c; iron-59 - 65 c; cobalt-58 - 50 c; zinc-65 - 13 c. The new adopted technology of decontamination together with purification of the decontaminating solution enables to remove practically all the metal oxide deposits from fuel elements, to enhance operational reliability of the evaporative channels and improve the radiation conditions in the unit as well as reduce the operational duty as compared to the conventional technology

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

Mangrove Cultivation For Dealing With Coastal Abrasion Case Study Of Karangsong

Science.gov (United States)

Fatimatuzzahroh, Feti; Hadi, Sudharto P.; Purnaweni, Hartuti

2018-02-01

Coastal abrasion is consequence from destructive waves and sea current. One of cause is human intervention. The effort to solve of abrasion is by mangrove cultivation. Mangroves are halophyte plant that can restrain the sea wave. Mangrove cultivation required participation community that give awareness the importance of mangrove in coastal sustainability. Mangroves in coastal Karangsong, Indramayu west java, in 2007 was through abrasion approximately 127.30 ha. Mangrove cultivation in Karangsong has been replanting since 1998 to 2003, but there was no maintenance and management. In 2007 until 2015 Karangsong replanting mangroves and has been succeed. Karangsong became the center of mangrove study for west java area in 2015. This achievement is result of cooperation between community, NGO, and local government. In addition, this effort made not only overcome the abrasion problem but also give community awareness about the importance of mangrove cultivation in preventing coastal abrasion throughout community development. This paper reviews abrasion in Karangsong and the impact for local community and empowerment in mangrove cultivation. To achieve the success mangrove cultivation required community development approach from planning process, planting, maintenance and management.

Radiation decontamination unit for the community hospital

International Nuclear Information System (INIS)

Waldron, R.L. II; Danielson, R.A.; Shultz, H.E.; Eckert, D.E.; Hendricks, K.O.

1981-01-01

Freestanding radiation decontamination units including surgical capability can be developed and made operational in small/medium sized community hospitals at relatively small cost and with minimal plant reconstrution. The Radiological Assistance Program of the United States Department of Energy and the Radiation Emergency Assistance Center Training Site of Oak Rige Associated Universities are ready to support individual hospitals and physicians in this endeavor. Adequate planning rather than luck, should be used in dealing with potential radiation accident victims. The radiation emergency team is headed by a physician on duty in the hospital. The senior administrative person on duty is responsible for intramural and extramural communications. Rapid mobilization of the radiation decontamination unit is important

New techniques for cutting and decontamination for decommissioning of nuclear research reactors with consideration of cost reduction. Final report

International Nuclear Information System (INIS)

Bach, W.; Redeker, C.F.; Versemann, R.

2003-06-01

In decommissioning of research reactors, specific boundary conditions, such as special materials, nuclides, geometries, spatial circumstances exist. This project aims on the development and adaptation of progressive procedures for decommissioning tasks with respect to economical aspects (cost reduction). Explored are Laser Cutting techniques, especially the cutting of aluminium in atmosphere and under water, remote- and manually controlled; decontamination and removal of concrete and ceramics by a combined diodelaser / cryogenic carbon dioxide thermal shock treatment (dry ice blasting) as well as cutting with the water-abrasive-suspension-jet and the plasma beam. The project will lead to application in the decommissioning of PTB's FRMB (research reactor of Physikalisch Technische Bundesanstalt, Braunschweig, Germany). (orig.) [de

Experimental Research into Technology of Abrasive Flow Machining Nonlinear Tube Runner

Directory of Open Access Journals (Sweden)

Junye Li

2014-06-01

Full Text Available In the fields of military and civil uses, some special passages exist in many major parts, such as non-linear tubes. The overall performance is usually decided by the surface quality. Abrasive flow machining (AFM technology can effectively improve the surface quality of the parts. In order to discuss the mechanism and technology of abrasive flow machining nonlinear tube, the nozzle is picked up as the researching object, and the self-designed polishing liquid is employed to make research on the key technological parameters of abrasive flow machining linear tube. Technological parameters’ impact on surface quality of the parts through the nozzle surface topography and scanning electron microscopy (SEM map is explored. It is experimentally confirmed that abrasive flow machining can significantly improve surface quality of nonlinear runner, and experimental results can provide technical reference to optimizing study of abrasive flow machining theory.

Area 6 Decontamination Pond Corrective Action Unit 92 Post-Closure Inspection Annual Report for the Period January 2000-December 2000

International Nuclear Information System (INIS)

Traynor, J. L.

2001-01-01

The Area 6 Decontamination Pond, Corrective Action Unit 92, was closed in accordance with the Resource Conservation and Recovery Act (RCRA) Part B Operational Permit (Nevada Division of Environmental Protection [NDEP, 1995]) and the Federal Facility Agreement and Consent Order (NDEP, 1996) on May 11, 1999. Historically the Decontamination Pond was used for the disposal of partially treated liquid effluent discharged from the Decontamination Facility (Building 6-05) and the Industrial Laundry (Building 6-07) (U.S. Department of Energy, Nevada Operations Office [DOE/NV], 1996). The Decontamination Pond was constructed and became operational in 1979. Releases of RCRA-regulated hazardous waste or hazardous waste constituents have not been discharged to the Decontamination Pond since 1988 (DOE/NV, 1996). The pipe connecting the Decontamination Pond and Decontamination Facility and Industrial Laundry were cut and sealed at the Decontamination Pad Oil/Water Separator in 1992. The Decontamination Pond was closed in place by installing a RCRA cover. Fencing was installed around the periphery to prevent accidental damage to the cover. Post-closure monitoring at the site consists of quarterly inspections of the RCRA cover and fencing, and a subsidence survey. Additional inspections are conducted if: Precipitation occurs in excess of 1.28 centimeters (cm) (0.50 inches [in]) in a 24-hour period, or An earthquake occurs with a magnitude exceeding 4.5 on the Richter scale within 100 kilometers (km) (62 miles [mi]) of the closure

Area 6 Decontamination Pond Corrective Action Unit 92 Post-Closure Inspection Annual Report for the Period January 2000-December 2000

Energy Technology Data Exchange (ETDEWEB)

J. L. Traynor

2001-03-01

The Area 6 Decontamination Pond, Corrective Action Unit 92, was closed in accordance with the Resource Conservation and Recovery Act (RCRA) Part B Operational Permit (Nevada Division of Environmental Protection [NDEP, 1995]) and the Federal Facility Agreement and Consent Order (NDEP, 1996) on May 11, 1999. Historically the Decontamination Pond was used for the disposal of partially treated liquid effluent discharged from the Decontamination Facility (Building 6-05) and the Industrial Laundry (Building 6-07) (U.S. Department of Energy, Nevada Operations Office [DOE/NV], 1996). The Decontamination Pond was constructed and became operational in 1979. Releases of RCRA-regulated hazardous waste or hazardous waste constituents have not been discharged to the Decontamination Pond since 1988 (DOE/NV, 1996). The pipe connecting the Decontamination Pond and Decontamination Facility and Industrial Laundry were cut and sealed at the Decontamination Pad Oil/Water Separator in 1992. The Decontamination Pond was closed in place by installing a RCRA cover. Fencing was installed around the periphery to prevent accidental damage to the cover. Post-closure monitoring at the site consists of quarterly inspections of the RCRA cover and fencing, and a subsidence survey. Additional inspections are conducted if: Precipitation occurs in excess of 1.28 centimeters (cm) (0.50 inches [in]) in a 24-hour period, or An earthquake occurs with a magnitude exceeding 4.5 on the Richter scale within 100 kilometers (km) (62 miles [mi]) of the closure.

Development of CDE (calculation system for decontamination effect) for the support of decontamination to restore the environment. Software visually depicting the effect of decontamination Work

International Nuclear Information System (INIS)

Satoh, Daiki

2012-01-01

CDE in the title developed by Japan Atomic Energy Agency (JAEA) is explained for its use to support the cleaning work of the environment contaminated by the Fukushima Daiichi Nuclear Power Plant Accident (Mar. 11, 2011). With this CDE software (available at http://nsed.jaea.go.jp/josen, from Nov. 2, 2011), the effect of decontamination schedule/work can be evaluable rapidly and accurately by calculating the ambient dose rates before and after the work. Access number to the CDE site until Jan., 2012, amounts to 402, for the purposes of ambient dose assessment (20%), planning of decontamination (15%), study/investigation (15%), etc. The system software is operable in Microsoft Excel with Graphical User Interface (GUI) described by VBA (Visual Basic for Applications). To be inputted in CDE are the map of the region subjected to decontamination, data of surface contamination density and of decontamination coefficients for the area relief, all of which are available through the internet and actual measurement, which is then followed by output as tables and figures of distribution of the ambient dose rate before and after the work, and of the rate reduction coefficient. Radiation subjected to calculation is from radiocesium ( 134 Cs and 137 Cs). When the software is compared for its accuracy with those by previous software Particle and Heavy Ion Transport Code System (PHITS) and by actual measurement, their results all show a virtually satisfactory agreement, and the time necessary for calculation is over several-ten hours in PHITS, and within about 10 seconds, in CDE. Updated information of CDE is available at the above mentioned site and twitter.com/JAEA_nsed. (T.T.)

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

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

Heavy metal decontamination of sludges and soils. Pt. 2

International Nuclear Information System (INIS)

Niemann, J.

1993-06-01

This research project deals with decontamination technology for contaminated soil and sediments. A pilot plant for the decontamination of soil contaminated with heavy metals has been erected and is operated. The process is arranged in two steps: - heavy metal contaminated solid is decontaminted with acidic extraction. - the heavy metals are separated in a recyclable formation from the process solution you gain in the first process step. Heavy metal contaminated soil, heavy metal contaminated sediments (habour sediments) as well as residue from a soil regeneration plant have been successfully decontaminated in the pilot plan. An adaption of the process is necessary for various materials. High rates of mobilisation of heavy metals (e.g. lead, cadmium, chromium, copper, nickel, zinc) were obtained, especially with soil which contains less organic matter. (orig.). 54 figs., 30 tabs., 45 refs [de

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.)

Tests of the use of cation exchange organic resins for the decontamination of radioactive aqueous effluents; Essais d'emploi des resines organiques echangeuses de cations pour la decontamination des effluents aqueux radioactifs

Energy Technology Data Exchange (ETDEWEB)

Bourdrez, Jean; Girault, Jacques; Wormser, Gerald

1962-12-14

The authors report tests performed in laboratory and results obtained during an investigation of the use of synthetic ion exchangers for the decontamination of radioactive effluents of moderate activity level and with a non neglectable salt loading. Resins are used under sodium form and regenerated after each fixing operation. Once decontaminated and free of its disturbing ions, the regenerating agent (NaCl) is used for several operations. The authors present the used resins, the treated effluents, describe the tests, and discuss the obtained results [French] Dans ce rapport nous faisons le point des essais et resultats obtenus au laboratoire au cours d'une etude concernant l'utilisation des echangeurs d'ions synthetiques pour la decontamination des effluents radioactifs de niveau d'activite moyenne et de charge en sels non negligeable. Les resines sont employees sous forme sodique et regenerees apres chaque operation de fixation. Le regenerant decontamine et debarrasse de ses ions genants est utilise pour plusieurs operations d'elution. Les seuls residus a stocker proviennent d'une part eventuellement d'un pretraitement de l'effluent, d'autre part, dans tous les cas des precipites consecutifs a la purification de l'eluant dont le traitement chimique est plus aise et donne lieu a des boues beaucoup moins volumineuses qu'une coprecipitation effectuee sur la totalite de l'effluent. (auteurs)

Assessment of microwave-based clinical waste decontamination unit.

Science.gov (United States)

Hoffman, P N; Hanley, M J

1994-12-01

A clinical waste decontamination unit that used microwave-generated heat was assessed for operator safety and efficacy. Tests with loads artificially contaminated with aerosol-forming particles showed that no particles were detected outside the machine provided the seals and covers were correctly seated. Thermometric measurement of a self-generated steam decontamination cycle was used to determine the parameters needed to ensure heat disinfection of the waste reception hopper, prior to entry for maintenance or repair. Bacterial and thermometric test pieces were passed through the machine within a full load of clinical waste. These test pieces, designed to represent a worst case situation, were enclosed in aluminium foil to shield them from direct microwave energy. None of the 100 bacterial test pieces yielded growth on culture and all 100 thermal test pieces achieved temperatures in excess of 99 degrees C during their passage through the decontamination unit. It was concluded that this method may be used to render safe the bulk of of ward-generated clinical waste.

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

Main approaches to choice of decontamination methods in case of nuclear power plant shutdown

International Nuclear Information System (INIS)

Tarasov, V.M.; Syrkus, M.N.

1991-01-01

Selection criteria for optimal decontamination technology in case of nuclear power plant shutdown are considered. It is shown that technology evaluation from the viewpoint of observance of required precautionary measures is performed during the first stage of operation followed by analysis of process operational characteristics. The next stage relates to risk analysis of equipment, technological process and structure failures. The selection process is followed then according to criteria of decontamination duration, complexity level of control process and availability of qualified personnel, as well as complexity and composition of radioactive waste conditioning. Further follows decontamination technology evaluation from the viewpoint of its impact on personnal health and enviroment. Cost-benefit ratio resulting from introduction of technologies under consideration are determined at the final stage

Performance tests of an abrasive cut-off systems for the finishing of high-precision casts

Directory of Open Access Journals (Sweden)

A. Fedoryszyn

2008-10-01

Full Text Available The paper summarizes the performance data of a newly designed and engineered grinding and cut-off system. The machine is used forseparation of models manufactured by the investment casting method. The machine comprises the following units:- base supporting other assemblies and elements: abrasive disc holder and drives; this solution enables an easy replacement and access toholding elements while a belt transmission allows the disc rpm to be varied,- mechanism moving the spindle in the horizontal, hence the abrasive disc position with respect to the batch can be precisely controlled,depending on the cast position and their shape,- holding and positioning-control of the batch to enable the fore and aft movements and rotations,- guide systems ensuring the travel of the batch in the specified direction and adjusting the travel speed to the required cutting rate,- centering, control, exhaust system, housing.Extensive tests were performed, including the tests of operating parameters of abrasive discs depending on the cast material, cyclograms ofthe applied treatment are obtained accordingly.

Performance tests of an abrasive cut-off systems for the finishing of high-precision casts

Directory of Open Access Journals (Sweden)

A. Fedoryszyn

2008-07-01

Full Text Available The paper summarizes the performance data of a newly designed and engineered grinding and cut-off system. The machine is used for separation of models manufactured by the investment casting method. The machine comprises the following units:- base supporting other assemblies and elements: abrasive disc holder and drives; this solution enables an easy replacement and access to holding elements while a belt transmission allows the disc rpm to be varied,- mechanism moving the spindle in the horizontal, hence the abrasive disc position with respect to the batch can be precisely controlled, depending on the cast position and their shape,- holding and positioning-control of the batch to enable the fore and aft movements and rotations,- guide systems ensuring the travel of the batch in the specified direction and adjusting the travel speed to the required cutting rate,- centering, control, exhaust system, housingExtensive tests were performed, including the tests of operating parameters of abrasive discs depending on the cast material, cyclograms of the applied treatment are obtained accordingly.

A Review on Parametric Analysis of Magnetic Abrasive Machining Process

Science.gov (United States)

Khattri, Krishna; Choudhary, Gulshan; Bhuyan, B. K.; Selokar, Ashish

2018-03-01

The magnetic abrasive machining (MAM) process is a highly developed unconventional machining process. It is frequently used in manufacturing industries for nanometer range surface finishing of workpiece with the help of Magnetic abrasive particles (MAPs) and magnetic force applied in the machining zone. It is precise and faster than conventional methods and able to produce defect free finished components. This paper provides a comprehensive review on the recent advancement of MAM process carried out by different researcher till date. The effect of different input parameters such as rotational speed of electromagnet, voltage, magnetic flux density, abrasive particles size and working gap on the performances of Material Removal Rate (MRR) and surface roughness (Ra) have been discussed. On the basis of review, it is observed that the rotational speed of electromagnet, voltage and mesh size of abrasive particles have significant impact on MAM process.

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

Mechanical and abrasive wear characterization of bidirectional and chopped E-glass fiber reinforced composite materials

International Nuclear Information System (INIS)

Siddhartha,; Gupta, Kuldeep

2012-01-01

Highlights: ► Bi-directional and chopped E-glass fiber reinforced epoxy composites are fabricated. ► Three body abrasive wear behavior of fabricated composites has been assessed. ► Results are validated against existing microscopic models of Lancaster and Wang. ► Tensile strength of bi-directional E-glass fiber reinforced composites increases. ► Chopped glass fiber composites are found better in abrasive wear situations. -- Abstract: Bi-directional and chopped E-glass fiber reinforced epoxy composites are fabricated in five different (15, 20, 25, 30 and 35) wt% in an epoxy resin matrix. The mechanical characterization of these composites is performed. The three body abrasive wear behavior of fabricated composites has been assessed under different operating conditions. Abrasive wear characteristics of these composites are successfully analysed using Taguchi’s experimental design scheme and analysis of variance (ANOVA). The results obtained from these experiments are also validated against existing microscopic models of Ratner-Lancaster and Wang. It is observed that quite good linear relationships is held between specific wear rate and reciprocal of ultimate strength and strain at tensile fracture of these composites which is an indicative that the experimental results are in fair agreement with these existing models. Out of all composites fabricated it is found that tensile strength of bi-directional E-glass fiber reinforced composites increases because of interface strength enhancement. Chopped glass fiber reinforced composites are observed to perform better than bi-directional glass fiber reinforced composites under abrasive wear situations. The morphology of worn composite specimens has been examined by scanning electron microscopy (SEM) to understand about dominant wear mechanisms.

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...

Evaluation of laryngoscopes decontamination practices in different hospitals

International Nuclear Information System (INIS)

Ahmad, M.; Hussain, W.; Saleem, A.; Saqib, M

2014-01-01

To find disinfection and sterilization practices of laryngoscope in different hospitals. Study Design: Descriptive study. Materials and Methods: Laryngoscope decontamination practices in different hospitals were evaluated in this study which was based on a telephonic structured questionnaire. Preset questions were asked on phone from operation room technicians of 50 different hospitals. For clarification and confirmation of procedure anesthesiologist of the hospital was contracted. Laryngoscope decontamination practices were asked as per questionnaire and data collected was recorded and analyzed. Results were documented and compared with studies regarding laryngoscope decontamination practices of different countries. Results: Most exercised methods were manual decontamination with simple gauze (50%), alcohol gauze (11%) or tap water (27%). The use of disposable blades and sheathing of blades was not practiced by any of the hospitals. Similarly chemical disinfectants were used rarely (2%). Rinsing laryngoscopes with water (always 27%, sometimes 23%) was very common while, autoclaving or sheathing of blades was not done in any of the hospital. Conclusion: The rate of different postoperative infection is on the increase in our hospitals and one likely contributing source is contaminated laryngoscopes. Lack of awareness and poor practices among health care professionals, over work and economic constraints are the major contributing factors which need to be controlled by adhering to international standards. (author)

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)

Leach studies on cement-solidified ion exchange resins from decontamination processes at operating nuclear power stations

International Nuclear Information System (INIS)

McIsaac, C.V.; Akers, D.W.; McConnell, J.W.; Morcos, N.

1992-01-01

The effects of varying pH and leachant compositions on the physical stability and leachability of radionuclides and chelating agents were determined for cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small scale waste-form specimens were collected during waste solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station. The collected specimens were leach tested, and their compressive strength was measured in accordance with the Nuclear Regulatory Commission's ''Technical Position on Waste Form'' (Revision 1), from the Low-Level Waste Management Branch. Leachates from these studies were analyzed for radionuclides, selected transition metals, and chelating agents to assess the leachability of these waste form constituents. Leachants used for the study were deionized water, simulated seawater, and groundwater compositions similar to those found at Barnwell, South Carolina and Hanford, Washington. Results of this study indicate that initial leachant pH does not affect leachate pH or releases from cement-solidified decontamination ion-exchange resin waste forms. However, differences in leachant composition and the presence of chelating agents may affect the releases of radionuclides and chelating agents. In addition, results from this study indicate that the cumulative releases of radionuclides and chelating agents observed for forms that disintegrated were similar to those for forms that maintained their general physical integrity

Abrasive wear of enamel by bioactive glass-based toothpastes.

Science.gov (United States)

Mahmood, Asad; Mneimne, Mohammed; Zou, Li Fong; Hill, Robert G; Gillam, David G

2014-10-01

To determine the abrasivity of a 45S5 bioactive glass based toothpaste on enamel as a function of the particle size and shape of the glass. 45S5 glass was synthesized ground and sieved to give various particle sized fractions toothpastes and their tooth brush abrasivity measured according to BS EN ISO11609 methodology. Enamel loss increased with increasing particle size. The percussion milled powder exhibited particles that had sharp edges and the pastes were significantly more abrasive than the pastes made with round ball milled powders. One interesting observation made during the present study was that there was preferential wear of the enamel at the dentin-enamel junction (DEJ), particularly with the coarse particle sized pastes.

Environmental and occupational hazards associated with decontamination solutions (a)

International Nuclear Information System (INIS)

Levanthal, L.

1985-01-01

Some of the reagents employed in the decontamination of reactor coolant systems are potentially hazardous. Potential exposure to decontamination agents by operating personnel, or members of the general population, could occur during use, processing, transportation to, or disposal at a low-level waste site. Federal and state agencies have promulgated regulations relevant to the disposal of decontamination solution waste to prevent acute or chronic exposures. In particular, the Nuclear Regulatory Commission (NRC), U.S. Environmental Protection Agency (EPA), Department of Transportation (DOT), Department of Labor - Occupational Safety and Health Administration (OSHA), State of South Carolina, State of Nevada, and the State of Washington have such regulations. These regulations may impact on the choice of decontamination solutions, operations procedures, processing methods, or disposal methods. Laws and regulations relate to both chemically hazardous, or toxic materials and to radioactive hazards. Laws which regulate the exposure of workers and the general public to effluents and emissions during processing, disposal and transport have been abstracted. As a result of these regulations, utilities are required to obtain permits to perform monitoring and sampling of personnel and the on-site and off-site environment, provide proper protective clothing and ventilation, make certain the solutions are properly contained during use, storage and processing, and destroy and/or properly immobilize the residues for disposal. Waste treatment processes such as neutralization, ion exchange, evaporation, incineration, etc., must not produce, nor result in hazardous emissions, effluents, residues, or hazards to workers. The laws also stipulate record keeping and documentation

Correlation Study of Magnetite Dissolution in Hybrid Decontamination Process

Energy Technology Data Exchange (ETDEWEB)

Kim, Seon-Byeong; Won, Hui-Jun; Park, Jung-Sun; Park, Sang-Yoon; Moon, Jei-Kwon; Choi, Wang-Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

In the operating plants, the localized corrosion on SG tubes which are transporters of thermal energy to the secondary side lowers the reduction heat transfer efficiency as well as degrades the lifetime of SG. Magnetite, Fe3O4, is a commonly found corrosion product on the inner surface of reactor coolant system. Simply magnetite can be reduced to hematite, Fe{sub 2}O{sub 3}, and further to iron when oxygen is limited or ample reducing agents are supplied. Along this line, number of decontamination processes has been developed since 1970s and most of them contain organic acid and additive chelating agents. However, many reports have pointed out the negative environmental effect of those chemicals, and currently there are new approaches to overcome the limited decontamination efficiency and large volume of secondary waste from other alternate processes without using such those organic chemicals. In present study, we investigated the magnetite dissolution in HyBRID solution as newly developing decontamination process. As a preliminary study for empirical modeling of decontamination by HyBRID solution, simply correlation study between variable and magnetite dissolution was introduced with studied mechanism and experimental results.

OECD/NEA Aagesta decontamination project. Phase 1, final report

International Nuclear Information System (INIS)

1982-12-01

The objective of the project is to utilize the four primary loops of the Aagesta reactor to demonstrate decontamination methods for PWR primary systems. The first phase of the project consisted of laboratory scale tests. The methods tested were developed at a) Studsvik Energiteknik AB, Sweden (a soft chemistry). b) Kraftwerk Union AG, Federal Republic of Germany, (two chemistries, one soft and one hard). c) Swiss Federal Institute of Reactor Research (two chemistries, one soft and one hard). d) Berkeley Nuclear Laboratories, United Kingdom, (a soft chemistry). The test programme consisted of decontamination tests on steam generator tubing and other active material from Aagesta and a number of operating reactors as well as material compatibility tests on standardized samples of a representative selection of modern PWR primary system materials. Six countries have participated in Phase I of the project - the four countries named above as well as the United States of America and Italy. Studsvik Energiteknik AB was appointed Project leader. The results show that all six processes in general met the acceptance criteria both regarding decontamination and corrosion. The decontamination results with the hard chemistries were rather uneven. (Author)

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

Decontamination in the Republic of Belarus

International Nuclear Information System (INIS)

Antsipov, G.V.; Matveenko, S.A.; Mirkhaidarov, A.Kh.

2002-01-01

To continue the decontamination work in the Republic of Belarus, which was carried out by the military troops, the state specialized enterprises were formed in Gomel and Mogilev in 1991. The organization and regulations were developed inside the country: instructions, rules, radiological and hygienic criteria and norms. The enterprises concentrated on decontamination of the most socially significant facilities: kindergartens, schools, medical institutions and industrial enterprises. During 9 years Gomel State Specialized Enterprise 'Polessje' decontaminated 130 kindergartens, schools and hospitals. The total decontaminated area was 450 000 m 2 . The ventilation systems and equipment at 27 industrial enterprises in Gomel were decontaminated. The practical decontamination methods for areas, buildings, roofs, industrial equipment, ventilation systems were developed and tested. The special rules for handling wastes contaminated with Cs were elaborated. The paper analyzes and sums up the acquired experience which is important for implementation of rehabilitation programs and improvement of decontamination methods. (author)

Decontamination and management of human remains following incidents of hazardous chemical release.

Science.gov (United States)

Hauschild, Veronique D; Watson, Annetta; Bock, Robert

2012-01-01

To provide specific guidance and resources for systematic and orderly decontamination of human remains resulting from a chemical terrorist attack or accidental chemical release. A detailed review and health-based decision criteria protocol is summarized. Protocol basis and logic are derived from analyses of compound-specific toxicological data and chemical/physical characteristics. Guidance is suitable for civilian or military settings where human remains potentially contaminated with hazardous chemicals may be present, such as sites of transportation accidents, terrorist operations, or medical examiner processing points. Guidance is developed from data-characterizing controlled experiments with laboratory animals, fabrics, and materiel. Logic and specific procedures for decontamination and management of remains, protection of mortuary affairs personnel, and decision criteria to determine when remains are sufficiently decontaminated are presented. Established procedures as well as existing materiel and available equipment for decontamination and verification provide reasonable means to mitigate chemical hazards from chemically exposed remains. Unique scenarios such as those involving supralethal concentrations of certain liquid chemical warfare agents may prove difficult to decontaminate but can be resolved in a timely manner by application of the characterized systematic approaches. Decision criteria and protocols to "clear" decontaminated remains for transport and processing are also provided. Once appropriate decontamination and verification have been accomplished, normal procedures for management of remains and release can be followed.

Comparative evaluation of enamel abrasivity of different commercially available dentifrices – An In vitro Study

Directory of Open Access Journals (Sweden)

Rupali Athawale

2018-01-01

Full Text Available Background: Toothbrushing with toothpaste is a major contributor to dental abrasion. A number of factors such as abrasivity and concentration of the toothpaste, brushing frequency, brushing duration, force of brushing, and toothbrush bristle stiffness have a potential impact on the abrasion process of dental hard tissue. However, the abrasivity of the toothpaste is the most important parameter that affects the abrasion process of dental hard tissue. Aims: This study aims to evaluate the maximum and mean enamel abrasivity of commercially available dentifrices such as Colgate total®, Pepsodent whitening®, Vicco vajradanti®, Dabur red® in primary and permanent teeth. Materials and Methods: Human extracted 60 primary and 60 permanent teeth were randomly selected based on the inclusion criteria. Teeth were sectioned at cementoenamel junction using diamond disc and mounted in an acrylic resin blocks. Baseline profilometric measurements were recorded for all the samples. Four commonly used dentifrices were selected and labeled as Group A (Colgate Total®, B (Pepsodent Whitening®, C (Vicco Vajradanti®, and D (Dabur Red®. Toothpaste slurry was prepared. Tooth specimens were brushed in vitro using a customized brushing machine. After toothbrushing, profilometric measurements were obtained, and the differences in readings served as proxy measure to assess surface abrasion. Data were collected and analyzed using student t-test and ANOVA test. Student t-test was used to compare the enamel abrasivity prebrushing and postbrushing, and ANOVA was used to compare the enamel abrasivity among the four different commercially available toothpastes. Results: In permanent teeth, all the toothpastes were found to cause significant enamel abrasion (P = 0.000 and a significant variation was observed when maximum (P = 0.008 and mean (P = 0.036 enamel abrasivity of these toothpastes were compared. In primary teeth also, all the toothpastes caused significant abrasion

Pilot plant for the radioactive decontamination of spent oils

International Nuclear Information System (INIS)

Flores E, R.M.; Ortiz O, H.V.; Cisneros L, L.; Lopez G, R.

2002-01-01

In this work the operation parameters obtained in the laboratory of oil storage are presented, as well as the operations which shape the pilot plant, the design criteria and the basic design of the core equipment of the developed process. Finally, the comparative results obtained the decontamination process of oil are given as well as laboratory scale. (Author)

A State of the Art Report on the Case Study of Hot Cell Decontamination and Refurbishment

Energy Technology Data Exchange (ETDEWEB)

Won, H. J.; Jung, C. H.; Moon, J. K.; Park, G. I.; Song, K. C

2008-08-15

As the increase of the operation age of the domestic high radiation facilities such as IMEF, PIEF and DFDF, the necessity of decontamination and refurbishment of hot cells in these facilities is also increased. In the near future, the possibilities of refurbishment of hot cells in compliance with the new regulations, the reuse of hot cells for the other purposes and the decommissioning of the facilities also exist. To prepare against the decontamination and refurbishment of hot cells, the reports on the refurbishment, decommissioning and decontamination experiences of hot cells in USA, Japan, France, Belgium and Great Britain were investigated. ANL of USA performed the project on the decontamination of hot cells. The purpose of the project was to practically eliminate the radioactive emissions of Rn-220 to the environment and to restore the hot cells to an empty restricted use condition. The five hot cells were emptied and decontaminated for restricted use. Chemical processing facility in JAEA of Japan was used for the reprocessing study of spent fuels, hot cells in CPF were refurbished from 1995 for the tests of the newly developed reprocessing process. In a first stage, decommissioning and decontamination were fully performed by the remote operation Then, decommissioning and decontamination were performed manually. By the newly developed process, they reported that the radiation exposure of workers were satisfactorily reduced. In the other countries, they also make an effort for the refurbishment and decontamination of hot cells and it is inferred that they accumulate experiences in these fields.

Projectile Nose Mass Abrasion of High-Speed Penetration into Concrete

Directory of Open Access Journals (Sweden)

Haijun Wu

2012-01-01

Full Text Available Based on the dynamic spherical cavity expansion theory of concrete and the analysis of experimental data, a mass abrasion model of projectile considering the hardness of aggregates, the relative strength of target and projectile, and the initial impact velocity is constructed in this paper. Furthermore, the effect of mass abrasion on the penetration depth of projectile and the influence of hardness of aggregates and strength of projectile on penetration depth and mass loss are also analyzed. The results show that, for the ogive-nose projectile with the CRH of 3 and aspect ratio of 7 penetrating the concrete of 35 MPa, the “rigid-body penetration” model is available when the initial impact velocity is lower than 800 m/s. However, when the initial impact velocity is higher than 800 m/s, the “deforming/eroding body penetration” model should be adopted. Through theoretical analysis and numerical calculation, the results indicate that the initial impact velocity is the most important factor of mass abrasion. The hardness of aggregates and the strength of projectile are also significant factors. But relatively speaking, the sensitivity of strength of projectile to mass abrasion is higher, which indicates that the effect of projectile material on mass abrasion is more dramatic than the hardness of aggregates.

Decontamination of the chemical crane room and decontamination and decommissioning of the extraction chemical room at the West Valley Demonstration Project

International Nuclear Information System (INIS)

Phillips, E.C.; Golden, M.P.

1986-01-01

This paper describes the decontamination of the Chemical Crane Room (CCR) of the West Valley Plant and the Extraction Chemical Room (XCR) from radioactively contaminated conditions to essentially shirt sleeve environments. In both cases, subsequent use re-contaminated the rooms. Prior to decontamination, general exposure rates in the CCR were 50 to 100 mR/hr with hot spots as high as 2000 mR/hr. Smearable levels on the floor were in the range of 10 5 to 10 6 dpm per 100/cm 2 . Respiratory protection was mandatory for entry. In the Extraction Chemical Room (XCR) prior to decontamination and decommissioning (D/D), radiological surveys indicated a maximum radiation field of 5 mR/hr, due to sources internal to the room, and 20,000 dpm beta/100 cm 2 surface contamination. A radiation source external to the XCR caused a hot spot with a 9 mR/hr exposure rate inside the XCR. The CCR, located at the north end of the Chemical Process Cell (CPC) is for the storage and servicing of two bridge cranes used in the CPC. Decontamination and exposure reduction in the CCR has been completed using vacuum cleaning, damp wipe down, and surface grinding followed by shielding and painting. The decontamination and decommissioning of the Extraction Chemical Room (XCR), located on the fifth floor elevation (160') of the reprocessing plant at the WVDP, has been completed. D/D operations included removal of piping, tanks, supports, and equipment to provide a clean work area of about 3000 square feet and 17 feet high

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.

Anlagen- und Kraftwerksrohrleitungsbau Greifswald GmbH plan and build wet decontamination plant for disposal of components of Russian nuclear submarines

International Nuclear Information System (INIS)

Schneider, Jan; Konitzer, Arnold; Luedeke, Michael

2010-01-01

Anlagen- und Kraftwerksrohrleitungsbau Greifswald, on behalf of Energiewerke Nord GmbH, Lubmin, plan and build a wet decontamination facility for the waste management center at Saida Bay, Russia (EZS). The plant is part of a large project with a total volume on the order of 3-digit millions funded by the German Federal Ministry for Economics and Technology. This project involves construction at Saida Bay near the port city of Murmansk of a complete waste management center and a long-term interim store for radioactively contaminated components. These components are mainly parts of decommissioned nuclear vessels and submarines whose metals, after decontamination, can be returned to economic use. The basis of the wet decontamination plant is a former AKB project for disposal and re-use of contaminated metal components of Energiewerke Nord GmbH at Lubmin, which is being adapted and developed further. The plant is to allow unrestricted re-use of the metals after surface cleaning and surface abrasion, respectively. For this purpose, the contaminated layer is removed far enough for the clearance limits under the Radiation Protection Ordinance to be met. A large fraction of the metals can be re-used after cleaning and do not have to be stored in a financially and logistically expensive process. The contract gives AKB an excellent opportunity to demonstrate its capabilities in plant construction, especially in the very sensitive area of disposal of radioactively contaminated objects. (orig.)

Surface characterization of current composites after toothbrush abrasion.

Science.gov (United States)

Takahashi, Rena; Jin, Jian; Nikaido, Toru; Tagami, Junji; Hickel, Reinhard; Kunzelmann, Karl-Heinz

2013-01-01

The present study was designed to evaluate the surface roughness and the gloss of current composites before and after toothbrush abrasion. We assessed forty dimensionally standardized composite specimens (n=8/group) from five composites: two nanohybrids (i. e., IPS Empress Direct Enamel and IPS Empress Direct Dentin), two microhybrids (i. e., Clearfil AP-X and Filtek Z250) and one organically modified ceramics (Admira). All of the specimens were polished with 4000-grid silicon carbide papers. Surface roughness was measured with a profilometer and gloss was measured with a glossmeter before and after powered toothbrush abrasion with a 1:1 slurry (dentifrice/tap water) at 12,000 strokes in a toothbrush simulator. There was a significant increase in the surface roughness and a reduction in gloss after toothbrush abrasion in all of the composites except Clearfil AP-X (pgloss (R(2)=0.191, p<0.001).

Decontamination manual of RI handling laboratory

International Nuclear Information System (INIS)

Wadachi, Yoshiki

2004-01-01

Based on experiences in Japan Atomic Energy Research Institute (JAERI), the essential and practical knowledge of radioactive contamination and its decontamination, and the method and procedure of floor decontamination are described for researcher and managing person in charge of handling radioisotopes (RI) in RI handling laboratories. Essential knowledge concerns the uniqueness of solid surface contamination derived from RI half lives and quantities, surface contamination density limit, and mode/mechanism of contamination. The principle of decontamination is a single conduct with recognition of chemical form of the RI under use. As the practical knowledge, there are physical and chemical methods of solid surface decontamination. The latter involves use of inorganic acids, chelaters and surfactants. Removal and replacement of contaminated solid like floor material are often effective. Distribution mapping of surface contamination can be done by measuring the radioactivity in possibly contaminated areas, and is useful for planning of effective decontamination. Floor surface decontamination is for the partial and spread areas of the floor. It is essential to conduct the decontamination with reagent from the highly to less contaminated areas. Skin decontamination with either neutral detergent or titanium oxide is also described. (N.I.)

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

Baking soda as an abrasive in toothpastes: Mechanism of action and safety and effectiveness considerations.

Science.gov (United States)

Hara, Anderson T; Turssi, Cecilia P

2017-11-01

Toothpastes can be formulated with different abrasive systems, depending on their intended clinical application. This formulation potentially affects their effectiveness and safety and, therefore, requires proper understanding. In this article, the authors focused on abrasive aspects of toothpastes containing sodium bicarbonate (baking soda), which have gained considerable attention because of their low abrasivity and good compatibility, while providing clinical effectiveness (further detailed in the other articles of this special issue). The authors first appraised the role of toothpaste abrasivity on tooth wear, exploring some underlying processes and the existing methods to determine toothpaste abrasivity. The authors reviewed the available data on the abrasivity of toothpastes containing baking soda and reported a summary of findings highlighting the clinical implications. On the basis of the collected evidence, baking soda has an intrinsic low-abrasive nature because of its comparatively lower hardness in relation to enamel and dentin. Baking soda toothpastes also may contain other ingredients, which can increase their stain removal effectiveness and, consequently, abrasivity. Even those formulations have abrasivity well within the safety limit regulatory agencies have established and, therefore, can be considered safe. Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.

Abrasive Wear of Four Direct Restorative Materials by Standard and Whitening Dentifrices

Science.gov (United States)

2013-06-01

Weader, E., Liscombe, C., & Holt, J.S. (2005). The measurement of enamel and dentine abrasion by tooth - whitening products using an in situ model...ABRASION OF TOOTH STRUCTURE Hard tissue abrasion is a familiar consequence of toothbrushing. Enamel , dentin, and cementum differ in their...LESIONS Cervical enamel wear is common; however, relatively few epidemiologic studies have distinguished between cervical enamel wear and tooth wear in

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

Abrasion behavior of graphite pebble in lifting pipe of pebble-bed HTR

Energy Technology Data Exchange (ETDEWEB)

Shen, Ke; Su, Jiageng [Institute of Nuclear and New Energy Technology, Advanced Nuclear Energy Technology Cooperation Innovation Center, The Key Laboratory of Advanced Nuclear Engineering and Safety, Ministry of Education, Beijing 10084 (China); Zhou, Hongbo [Institute of Nuclear and New Energy Technology, Advanced Nuclear Energy Technology Cooperation Innovation Center, The Key Laboratory of Advanced Nuclear Engineering and Safety, Ministry of Education, Beijing 10084 (China); Chinergy Co., LTD., Beijing 100193 (China); Peng, Wei; Liu, Bing [Institute of Nuclear and New Energy Technology, Advanced Nuclear Energy Technology Cooperation Innovation Center, The Key Laboratory of Advanced Nuclear Engineering and Safety, Ministry of Education, Beijing 10084 (China); Yu, Suyun, E-mail: suyuan@tsinghua.edu.cn [Center for Combustion Energy, The Key Laboratory for Thermal Science and Power Engineering, Ministry of Educations, Tsinghua University, Beijing 10084 (China)

2015-11-15

Highlights: • Quantitative determination of abrasion rate of graphite pebbles in different lifting velocities. • Abrasion behavior of graphite pebble in helium, air and nitrogen. • In helium, intensive collisions caused by oscillatory motion result in more graphite dust production. - Abstract: A pebble-bed high-temperature gas-cooled reactor (pebble-bed HTR) uses a helium coolant, graphite core structure, and spherical fuel elements. The pebble-bed design enables on-line refueling, avoiding refueling shutdowns. During circulation process, the pebbles are lifted pneumatically via a stainless steel lifting pipe and reinserted into the reactor. Inevitably, the movement of the fuel elements as they recirculate in the reactor produces graphite dust. Mechanical wear is the primary source of graphite dust production. Specifically, the sources are mechanisms of pebble–pebble contact, pebble–wall (structural graphite) contact, and fuel handling (pebble–metal abrasion). The key contribution to graphite dust production is from the fuel handling system, particularly from the lifting pipe. During pneumatic lift, graphite pebbles undergo multiple collisions with the stainless steel lifting pipe, thereby causing abrasion of the graphite pebbles and producing graphite dust. The present work explored the abrasion behavior of graphite pebble in the lifting pipe by measuring the abrasion rate at different lifting velocities. The abrasion rate of the graphite pebble in helium was found much higher than those in air and nitrogen. This gas environment effect could be explained by either tribology behavior or dynamic behavior. Friction testing excluded the possibility of tribology reason. The dynamic behavior of the graphite pebble was captured by analysis of the audio waveforms during pneumatic lift. The analysis results revealed unique dynamic behavior of the graphite pebble in helium. Oscillation and consequently intensive collisions occur during pneumatic lift, causing

Lung scintigraphy evaluation in workers exposed to abrasive dusts

International Nuclear Information System (INIS)

Terra Filho, Mario

1995-01-01

The production process of abrasives use aluminium, or silicon carbide a synthetic material with a hardness only slightly less than that of a diamond. It is popularly known as carborundum since it was first manufactured as an abrasive in 1891, produced by the fusion of high grade silica and petroleum coke with sawdust. For many years silicon carbide was thought not to give rise to pulmonary lesions. Recently several researchers suggested the existence of a carborundum pneumoconiosis. The aim of this study was to evaluate the role of the pulmonary clearance of 99m Technetium chelated to diethylene-triamine penta-acetate ( 99m Tc DTPA), and 67 Gallium lung scanning in workers exposed to abrasive dusts. Thirty seven subjects, 13 smokers and 24 nonsmokers and ex smokers were studied. In 32 (86,48%) 67 Gallium lung scanning was positive including 13 (40,62%) retired workers. We conclude that non smoking workers of abrasives plants have a pulmonary alveolar epithelial permeability disturbance similar as observed in smoking workers and smoking controls. Most workers, ex-workers of these industries and in patients with carborundum pneumoconiosis there is an evidence of pulmonary inflammation measured with abnormal 67 Gallium lung scan. (author)

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)

Decontamination of injured persons in the hospital in case of NBC hazards

International Nuclear Information System (INIS)

Martens, Frank

2009-01-01

Prompt recognition of contaminated people is a prerequisite for the activation of a decontamination plan. Because simple detection methods are missing, the clinical awareness for such events has to be raised. The objectives of such a plan are protection of the hospital and its staff due to secondary contamination, the rapid termination of the exposure of casualties and their treatment, if necessary. The response plan should account for exposed individuals whose contamination has been noticed in the emergency department (contaminated E.D.) as well as for the announced influx of such persons. The implementation of such a plan and its elements are not necessarily expensive and decontamination can be realized with a few employees. Personal protective equipment (PPE) is indispensable and frequent exercises are necessary to keep its protective effect. Donning and doffing PPE should be easy and personnel in different physical conditions should be able to wear it. Waterproof, chemical-resistant suits, full-face masks and powered air purifying respirators with particle filters and absorbent cartridges are necessary. Decontamination consists of undressing clothes, showers with warm water and cleaning the skin with soap. Abrasions may be cleaned in the same way whereas complex wounds should be irrigated with sterile isotonic solution and dressed with waterproof adhesive bandage before showering. Presumably, waste water may be drained into sewer system without endangering people or environment. Mutual agreements between hospitals and water authorities are recommended. To achieve the concept described, a group of interested, knowledgeable employees should compile all details specifically for their hospital. Suggestions and ideas how to realize this goal are given in this report. Good cooperation of all participants in the chain of treatment may reduce the risk for affected people, but these links between hospitals, emergency medical services, fire services and police

Measurement of nanoparticle removal by abrasion

International Nuclear Information System (INIS)

Guiot, Arnaud; Golanski, Luana; Tardif, Francois

2009-01-01

A strong release limitation of single nanoparticles from commercial manufactured 'nanoproducts' is necessary to decrease potential exposure risks of consumers and represents also a pragmatic way to facilitate acceptance for nanomaterial commercialization before obtaining definitive toxicological results. So, it is of prime importance to know how to characterize the release of small materials during usage solicitations such as mechanical, thermal, UV stress: are they single nanoparticles, aggregates or nanoparticles included in a bigger piece of the matrix? In the frame of NanoSafe2 project, CEA developed and qualified a specific bench test where the material to be tested is mechanically solicited by abrasion using a normalized Taber equipment. The first results show that nanofillers can be released in usage by abrasion for non optimised nanoproducts.

Situations of decontamination promotion activities. Efforts by Tokyo Electric Power Company, Fukushima Revitalization Headquarters, Decontamination Promotion Office

International Nuclear Information System (INIS)

Takano, Takahiko; Ito, Kei; Takizawa, Koichi

2015-01-01

As for the decontamination of the soil contaminated with radioactive materials, decontamination is on the way in compliance with the 'Act on Special Measures Concerning the Handling of Environmental Pollution by Radioactive Materials by the NPS Accident Associated with the Tohoku District - Off the Pacific Ocean' (hereinafter, the Act on Special Measures). Tokyo Electric Power Company (TEPCO), as the party concerned to the accident, is cooperating with decontamination activities conducted by countries and municipalities under the Act on Special Measures. Total number of people cooperated by the Decontamination Promotion Office amounts to about 120,000 people. The cooperation to the decontamination by countries and municipalities covers the following fields: provision of knowledge of radiation, training of site management and supervisors, and proposal such as the decontamination method suitable for the site. As cooperation to various monitoring, there is a traveling monitoring that performs radiation measurement from the vehicles. As cooperation in the farming and industrial resumption toward the reconstruction, the group has implemented support for the distribution promotion of the holdup that was stuck in distribution due to contamination with radioactive substances. As decontamination related technology, the following are performed: (1) preparation of radiation understanding promotion tool, (2) development of precise individual dose measurement technology, and (3) development and utilization of decontamination effect analysis program. In the future, this group will perform the follow-up for decontamination, and measures toward the lifting of evacuation order. It will install the basis to perform various technical analyses on decontamination, and will further intensify technical cooperation. (A.O.)

ORO scrap metal decontamination program

International Nuclear Information System (INIS)

Jugan, M.

1987-01-01

The Oak Ridge Operations Office (ORO) of the US Department of Energy (DOE) has approximately 80,000 tons of contaminated scrap metal at the Oak Ridge Gaseous Diffusion Plant in Oak Ridge, Tennessee; Paducah Gaseous Diffusion Plant in Paducah, Kentucky; Portsmouth Gaseous Diffusion Plant in Piketon, Ohio; and the Feed Materials Production Center in Fernald, Ohio. After unsuccessful in-house attempts to eliminate/recycle the contaminated metal, DOE is allowing private enterprise the opportunity to participate in this program. DOE is making this opportunity available under a two-phase approach, which is being supported by two separate and corresponding Request for Proposals. Phase I, which is nearing completion, is a demonstration phase to establish a group of companies that the DOE will consider qualified to eliminate the scrap at one or more sites. In Phase I, the companies decontaminated 25-50 tons of scrap to demonstrate capabilities to DOE and to gain the knowledge required to plan/bid on elimination of the scrap at one or more sites. Phase II will request proposals for elimination of the total scrap at one or more of the above noted sites. Multiple awards for Phase II are also anticipated. Companies participating in Phase II will be required to take title to the contaminated scrap and decontaminate/process the scrap for beneficial reuse. Radioactive wastes and metal that cannot be successfully decontaminated/processed will be returned to DOE

Numerical analysis of special-shaped surface in abrasive flow machining

Science.gov (United States)

Li, Junye; Zhou, Zengwei; Wu, Guiling; Lu, Hui; Sun, Zhihuai

2018-03-01

Solid-liquid two-phase abrasive flow machining is a method to effectively polish the surface of Special-shaped surface parts. Based on the processing characteristics of the abrasive flow machining. The standard model and the pressure-coupled SIMPLEC algorithm are used. The shear force and velocity of the near-wall surface of the runner of the solid-liquid two-phase abrasive machining with different inlet pressure are analyzed. The numerical simulation results show that the inlet pressure has little effect on the velocity, and the shear force has a linear relationship with the inlet pressure. To obtain a better polishing effect, the outlet pressure can be appropriately increased.

Influence of Corrosion on the Abrasion of Cutter Steels Used in TBM Tunnelling

Science.gov (United States)

Espallargas, N.; Jakobsen, P. D.; Langmaack, L.; Macias, F. J.

2015-01-01

Abrasion on tunnel boring machine (TBM) cutters may be critical in terms of project duration and costs. Several researchers are currently studying the degradation of TBM cutter tools used for excavating hard rock, soft ground and loose soil. So far, the primary focus of this research has been directed towards abrasive wear. Abrasive wear is a very common process in TBM excavation, but with a view to the environment in which the tools are working, corrosion may also exert an influence. This paper presents a selection of techniques that can be used to evaluate the influence of corrosion on abrasion on TBM excavation tools. It also presents the influence of corrosion on abrasive wear for some initial tests, with constant steel and geomaterial and varying properties of the excavation fluids (soil conditioners, anti-abrasion additives and water). The results indicate that the chloride content in the water media greatly influences the amount of wear, providing evidence of the influence of corrosion on the abrasion of the cutting tools. The presence of conditioning additives tailored to specific rock or soil conditions reduces wear. However, when chloride is present in the water, the additives minimise wear rates but fail to suppress corrosion of the cutting tools.

Shoe heel abrasion and its possible biomechanical cause: a transversal study with infantry recruits.

Science.gov (United States)

Baumfeld, Daniel; Raduan, Fernando C; Macedo, Benjamim; Silva, Thiago Alexandre Alves; Baumfeld, Tiago; Favato, Danilo Fabrino; de Andrade, Marco Antonio Percope; Nery, Caio

2015-11-19

Excessive shoe heel abrasion is of concern to patients and shoe manufacturers, but little scientific information is available about this feature and its possible causes. The purpose of this study was to relate this phenomenon with biomechanical factors that could predispose to shoe heel abrasion. Ninety-seven recruits (median age 25) were enrolled in this study. Shoe abrasion was assessed manually with a metric plastic tape on the posterior part of the heel that comes in contact with the ground. The number of sprains, foot alignment, and calf muscle shortening (Silfverskiold test) was also assessed in order to relate it with shoe heel abrasion. After using our exclusion criteria, 86 recruits and 172 were considered for this study. The most common abrasion site was the lateral portion of the heel surface (50 %). Forty-four percent of the participants had neutral hind-foot alignment and 39 % had valgus alignment. Twenty-six (30 %) patients have had previous ankle or foot sprains. Neutral foot was related with less calf muscle shortening. On the other hand, valgus hind-foot alignment was more associated with Achilles shortening (p study was able to correlate shoe heel abrasion with biomechanical causes (neutral alignment-uniform abrasion/varus alignment-central and lateral abrasion). More effort has to be done to continue evaluating outsole abrasion with its possible biomechanical cause in order to predict and treat possible associated injuries.

Chemical decontamination process and device therefor

International Nuclear Information System (INIS)

Takahashi, Ryota; Sakai, Hitoshi

1998-01-01

The present invention provides a process and a device for chemical decontamination, which can suppress corrosion of low corrosion resistant materials, keep decontamination properties substantially as same as before and further, reduce the volume of secondary wastes. In a step of reductively melting oxide membranes on an objective material to be decontaminated, a mixture of oxalic acid and a salt thereof is used as a reducing agent, and the reductive melting is conducted while suppressing hydrogen ion concentration of an aqueous liquid system. In order to enhance the reducibility of the oxalic acid ions, it is desirable to add a cyclic hetero compound thereto. The device of the present invention comprises, a decontamination loop including a member to be decontaminated, a heater and a pH meter, a medical injection pump for injecting a reducing agent to the decontamination loop, a metal ion recovering loop including an ion exchange resin tower, a reducing agent decomposing loop including an electrolytic vessel and/or a UV ray irradiation cell, a circulation pump for circulating the decontamination liquid to each of the loops and a plurality of opening/closing valves for switching the loop in which the decontamination liquid is circulated. (T.M.)

Submerged cutting of steel by abrasive water jets

International Nuclear Information System (INIS)

Haferkamp, H.; Louis, H.; Meier, G.

1990-01-01

A special cutting head for underwater use was designed and built. Tests were carried out to find out useful parameters for submerged cutting. With regard to the production of secondary waste the abrasive flow rate had to be minimized. This was achieved by using a small water jet nozzle (up to 0.4 mm diameter) and a high pressure (up to 4000 bar) with an optimal abrasive flow rate of about 5 g/s. In the case of a higher ambient pressure a decrease of the cutting performance was measured. But this decrease is not important regarding decommissioning because the ambient pressure is less than 2 bar. An air mantle nozzle was adapted to the cutting head to improve the working distance under water. The air mantle surrounding the abrasive jet lowers the friction between jet and surrounding water and increases the cutting efficiency in the case of greater working distances. (author)

Technology of magnetic abrasive finishing in machining of difficult-to-machine alloy complex surface

Directory of Open Access Journals (Sweden)

Fujian MA

2016-10-01

Full Text Available The technology of magnetic abrasive finishing is one of the important finishing technologies. Combining with low-frequency vibration and ultrasonic vibration, it can attain higher precision, quality and efficiency. The characteristics and the related current research of magnetic abrasive finishing, vibration assisted magnetic abrasive finishing and ultrasonic assisted magnetic abrasive finishing are introduced. According to the characteristics of the difficult-to-machine alloy's complex surface, the important problems for further study are presented to realize the finishing of complex surface with the technology of magnetic abrasive finishing, such as increasing the machining efficiency by enhancing the magnetic flux density of machining gap and compounding of magnetic energy and others, establishing of the control function during machining and the process planning method for magnetic abrasive finishing of complex surface under the space geometry restraint of complex surface on magnetic pole, etc.

Study of Effect of Impacting Direction on Abrasive Nanometric Cutting Process with Molecular Dynamics.

Science.gov (United States)

Li, Junye; Meng, Wenqing; Dong, Kun; Zhang, Xinming; Zhao, Weihong

2018-01-11

Abrasive flow polishing plays an important part in modern ultra-precision machining. Ultrafine particles suspended in the medium of abrasive flow removes the material in nanoscale. In this paper, three-dimensional molecular dynamics (MD) simulations are performed to investigate the effect of impacting direction on abrasive cutting process during abrasive flow polishing. The molecular dynamics simulation software Lammps was used to simulate the cutting of single crystal copper with SiC abrasive grains at different cutting angles (0 o -45 o ). At a constant friction coefficient, we found a direct relation between cutting angle and cutting force, which ultimately increases the number of dislocation during abrasive flow machining. Our theoretical study reveal that a small cutting angle is beneficial for improving surface quality and reducing internal defects in the workpiece. However, there is no obvious relationship between cutting angle and friction coefficient.

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.

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

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

On-Site Decontamination System for Liquid Low Level Radioactive Waste - 13010

Energy Technology Data Exchange (ETDEWEB)

OSMANLIOGLU, Ahmet Erdal [Cekmece Nuclear Research and Training Center, Kucukcekmece Istanbul (Turkey)

2013-07-01

This study is based on an evaluation of purification methods for liquid low-level radioactive waste (LLLW) by using natural zeolite. Generally the volume of liquid low-level waste is relatively large and the specific activity is rather low when compared to other radioactive waste types. In this study, a pilot scale column was used with natural zeolite as an ion exchanger media. Decontamination and minimization of LLLW especially at the generation site decrease operational cost in waste management operations. Portable pilot scale column was constructed for decontamination of LLW on site. Effect of temperature on the radionuclide adsorption of the zeolite was determined to optimize the waste solution temperature for the plant scale operations. In addition, effect of pH on the radionuclide uptake of the zeolite column was determined to optimize the waste solution pH for the plant scale operations. The advantages of this method used for the processing of LLLW are discussed in this paper. (authors)

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

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

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)

Decontamination and remote dismantling tests in the Itrec reprocessing plant

International Nuclear Information System (INIS)

Candelieri, T.; Gerardi, A.; Soffietto, G.

1993-01-01

The scope of this research is to evaluate the advantages of the rack removal system in the dismantling of reprocessing installations. The objective of this work is to verify experimentally the possibility of the decontamination of any particular module and the capability of the remote dismantling of components installed in the mobile rack. In particular, the main objective is to develop remotely operated equipment for the dismantling of centrifugal contactors. The decontamination of the equipment which represents the most important preliminary phase of the decommissioning operation, allowed to obtain low-level radioactivity. A supporting programme has been performed in order to collect sufficient data for the project and design of the remote dismantling machine. On the basis of technological cold test results, the project of the dismantling machine's construction has been optimized. Positive results obtained during the hot dismantling operations on the Rack 6 bis attested the effectiveness of the rack removal system as an original design which facilitates decommissioning of reprocessing plants. 2 tabs., 18 figs

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.)

An experience of cleaning and decontamination of the BN-350 reactor components

International Nuclear Information System (INIS)

Vasilenko, K.T.; Kochetkov, L.A.; Arkhipov, V.M.; Baklushin, R.P.; Gorlov, A.I.; Kiselev, G.V.; Rezinkin, P.S.; Samarkin, A.A.; Tverdovsky, N.D.

1978-01-01

In the course of start-up, adjustment and operation of the BN-350 reactor there arose a need for cleaning from sodium and decontamination of primary and secondary equipment components. Design schemes of the systems provided for this purpose as well as those specially designed for cleaning of steam generator evaporators are considered. Technological processes of cleaning and decontamination for some reactor components (removable parts of circulating pumps, evaporators, valves) are described, the results are presented. (author)

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.

Chemical decontamination of the residual heat removal system (RHRS) of Flamanville 1

International Nuclear Information System (INIS)

Steinkuhler, Claude; Coomans, Reginald; Koen, Lenie

2007-01-01

The purpose of the decontamination of the RHRS at Flamanville 1 was the reduction of the general dosimetry and the elimination of hot spots. This was done to allow the maintenance on the RHRS equipment. The main challenge of this project was the execution of a complicated operation on the critical path of a shutdown. The redox attack of the oxides at the surface of the circuit in Flamanville, was performed by an EDF qualified process of the EMMAC family. The functions required by the decontamination system were very diverse and therefore an existing decontamination loop, which was previously developed for the decontamination of small system volumes, was re-developed and adapted for bigger circuits. Due to different reasons, an important delay on the planning happened. Therefore, only one cycle EMMAg was performed, totalling 2 hours of decontamination. Despite this, a DRRF (dose rate reduction factor) of 3,7 average was reached. The re-designed equipment and a shortened process were validated during this project. An acceptable DRRF was reached with no delay on the critical path. The capability of maintenance on the RHRS equipment is recovered with a gain of factor 5 on dosimetry. (authors)

STUDY OF POLISHING AISI 316L WITH STRUCTURED ABRASIVE

Directory of Open Access Journals (Sweden)

François GOOSSENS

2015-05-01

Full Text Available Finishing process like polishing is usually used to obtain high quality mechanical surface characteristics such as texture and roughness. These operations are mainly handmade and need highly trained operators thus limiting their repeatability and profitability. To optimize the industrialization of the polishing process, it is therefore necessary to modelize the process to built efficient parameter database. The aim of this study is to characterise the polishing of 316L stainless steel with structured abrasive belts. The geometric data of the belts are given, and we then propose a model to determine material removal. An experimental test bench is set up to test this model and characterise the polishing process in terms of forces. It produces samples for different polishing conditions. The different polished surfaces are then analyzed thanks to the roughness and the wettability. Using experimental designs, we are able to validate the proposed model and identify the parameters that influence a polishing operation.

Decontamination of surfaces by blasting with crystals of H2O and CO2

International Nuclear Information System (INIS)

Benson, C.E.; Parfitt, J.E.; Patton, B.D.

1995-02-01

A major mission of the US Department of Energy during the 1990s is site and environmental cleanup. In pursuit of this mission, numerous remediation projects are under way and many others are being planned at Oak Ridge National Laboratory (ORNL). In this report, tests using two proposed methods for decontaminating surfaces one using water ice crystals [Crystalline Ice Blast (CIB)], the other using dry ice crystals (CO 2 Cleanblast trademark) -- are described. Both methods are adaptations of the commonly used sand blasting technology. The two methods tested differ from sand blasting in that the particles are not particularly abrasive and do not accumulate as particles in the wastes. They differ from each other in that the CO 2 particles sublime during and after impact and the ice particles melt. Thus, the two demonstrations provide important information about two strong candidate decontamination methodologies. Each process was tested at ORNL using contaminated lead bricks and contaminated tools and equipment. Demonstrations with the prototype Crystalline Ice Blast and the CO 2 Cleanblast systems showed that paint, grease, and oil can be removed from metal, plastic, asphalt, and concrete surfaces. Furthermore, removal of contamination from lead bricks was highly effective. Both processes were found to be less effective, under the conditions tested, with contaminated tools and equipment that had chemically bonded contamination or contamination located in crevices since neither technology abrades the substrates or penetrates deeply into crevices to remove particulates. Some process improvements are recommended

Processes of elimination of activated corrosion products. Chemical decontamination - fuel cleaning

International Nuclear Information System (INIS)

Viala, C.; Brun, C.; Neuhaus, R.; Richier, S.; Bachet, M.

2007-01-01

The abatement of the individual and collective dose of a PWR imposes to control the source term through different processes implemented during the plant exploitation. When the limits of these different optimization processes are reached, the abatement of dose rates requires the implementation of curative processes. The objective is thus to eliminate the contaminated oxides and deposits present on surfaces free of radiation flux, and eventually on surfaces under radiation flux and on the fuel itself. The chemical decontamination of equipments and systems is the main and universal remedy implemented at different levels. On the other hand, the ultrasonic cleaning of fuel assemblies is a promising process. This paper aims at illustrating these different techniques using concrete examples of application in France and abroad (decontamination during steam generator replacement, decontamination of primary pump scroll in hot workshop, decontamination of loop sections, ultrasonic cleaning of fuel). The description of these different operations stresses on their efficiency in terms of dosimetric gain, duration of implementation, generation of wastes, and recontamination following their implementation. (J.S.)

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)

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

Decontamination of radioactive contaminated protective wear using dry cleaning solvent

International Nuclear Information System (INIS)

Muthiah, Pushpa; Chitra, S.; Paul, Biplob

2013-01-01

Liquid waste generated by conventional decontamination of radioactive contaminated cotton protective wear using detergent affects the chemical treatment of the plant. To reduce the generation of aqueous detergent waste, dry cleaning of cotton protective wear, highly soiled with oil and grease towards decontamination was tried with organic solvents. Mineral turpentine oil (MTO) among various other organic solvents was identified as a suitable organic solvent. As MTO leaves characteristic odour on the cloth, various commercial fragrances for the removal of the odour were tried. Application of the optimised dry cleaning solvent and commercial fragrance was adopted in plant scale operation. (author)

Experimental Investigation on the Material Removal of the Ultrasonic Vibration Assisted Abrasive Water Jet Machining Ceramics

Directory of Open Access Journals (Sweden)

Tao Wang

2017-01-01

Full Text Available The ultrasonic vibration activated in the abrasive water jet nozzle is used to enhance the capability of the abrasive water jet machinery. The experiment devices of the ultrasonic vibration assisted abrasive water jet are established; they are composed of the ultrasonic vibration producing device, the abrasive supplying device, the abrasive water jet nozzle, the water jet intensifier pump, and so on. And the effect of process parameters such as the vibration amplitude, the system working pressure, the stand-off, and the abrasive diameter on the ceramics material removal is studied. The experimental result indicates that the depth and the volume removal are increased when the ultrasonic vibration is added on abrasive water jet. With the increase of vibration amplitude, the depth and the volume of material removal are also increased. The other parameters of the ultrasonic vibration assisted abrasive water jet also have an important role in the improvement of ceramic material erosion efficiency.

Decontamination around the site of Chernobylsk; Decontamination autour du site de Tchernobyl

Energy Technology Data Exchange (ETDEWEB)

Manesse, D; Rzepka, J P; Maubert, H

1990-12-01

This report describes the decontamination of the site around the nuclear plant of Chernobylsk after the reactor accident of 1986. The work of decontamination in urban areas, buildings, fields and vegetation are detailed. The interventions to reduce the contamination of surface waters and to protect ground waters are also given. (N.C.).

Recycling decontaminated scrap metal from the nuclear industry

International Nuclear Information System (INIS)

Bordas, F.

2000-01-01

The Commissariat a l'Energie Atomique (CEA) has set up a pilot program for recycling decontaminated scrap metal. In decommissioning its enriched uranium production facilities at Pierrelatte, the CEA has accumulated some 700 metric tons of scrap metal from dismantled uranium hexafluoride transport containers. The containers were decontaminated by SOCATRI at the Tricastin site, then cut up and recycled by a steelmaker. The project was submitted to the Ionizing Radiation Protection Office, the Nuclear Facilities Safety Division and the Regional Directorate for Industry, Research and Environmental Protection for approval. It was also submitted to the Ministry of Industry's Nuclear Information and Safety Council and to the Permanent Secretariat for Industrial Pollution Problems (an informational group chaired by the Prefect of the Provence Alpes-Cote d Azur region and including representatives of local and regional authorities, associations, elected officials and the media). The permit was granted for this program under the terms of a prefectorial decree stipulating additional requirements for the steelmaker, and contingent on the demonstration of full control over the operations, demonstrated traceability and the absence of any significant harmful effects. The key elements of this demonstration include the choice of operators, identification of the objects, itemization of the operations, discrimination of operators, the contractual framework of the operations, the signature of agreements by the CEA with SOCATRI and with the steelmaker, documentary monitoring of the operations, contradictory inspections and measurements, second-level inspection by the CEA/Valrho, audits of the operators and impact assessments. All the procedures of operations related to the scrap metal are described in quality assurance documents. (author)

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)

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.)

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)

The new gamma sterilisation and decontamination plant, Queensland

International Nuclear Information System (INIS)

West, G.; Robotham, R.

2003-01-01

Steritech Pty Ltd operates the only three industrial gamma sterilisation and decontamination plants in Australia. A plant in Dandenong Victoria has operated since 1971 and a second in Wetherill Park from 1985. In August 2003, a third facility started commercial operation in Narangba, 40km north of Brisbane. Each plant represents a generational change in operating features, although the basic design of the irradiation room, storage pool and shielding remains substantially the same. This paper discusses some of the key design features of the Queensland plant, the complex approval and licensing process and some of the complications caused by perceived terrorist threats

Innovative ways of decontaminating nuclear facilities

International Nuclear Information System (INIS)

Bremmer, Jan; Gentes, Sascha; Ambos, Frank

2009-01-01

The great variety of surfaces to be decontaminated in a nuclear power plant increases demand for economic solutions and efficient processing systems. The Institute for Technology and Management in Building (TMB) of the University of Karlsruhe (TH) is working on this task in the new professorship of Sascha Gentes and, together with sat Kerntechnik GmbH, developing innovative techniques and tools for surface decontamination. In this effort, sat.Kerntechnik GmbH contributes 50% to the funding of the new professorship at the Karlsruhe Institute of Technology, the merger of the University of Karlsruhe and the Karlsruhe Research Center. The new professorship will extend its work also to various other innovative concepts to be employed not only in demolition but also in maintenance and operation of nuclear facilities. Above and beyond theoretical approaches, practical solutions are in the focus of work. For this reason, new developments are elaborated in close cooperation with the respective users. (orig.)

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

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

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.)

Long-term decontamination engineering study. Volume 1

Energy Technology Data Exchange (ETDEWEB)

Geuther, W.J.

1995-04-03

This report was prepared by Westinghouse Hanford Company (WHC) with technical and cost estimating support from Pacific Northwest Laboratories (PNL) and Parsons Environmental Services, Inc. (Parsons). This engineering study evaluates the requirements and alternatives for decontamination/treatment of contaminated equipment at the Hanford Site. The purpose of this study is to determine the decontamination/treatment strategy that best supports the Hanford Site environmental restoration mission. It describes the potential waste streams requiring treatment or decontamination, develops the alternatives under consideration establishes the criteria for comparison, evaluates the alternatives, and draws conclusions (i.e., the optimum strategy for decontamination). Although two primary alternatives are discussed, this study does identify other alternatives that may warrant additional study. hanford Site solid waste management program activities include storage, special processing, decontamination/treatment, and disposal facilities. This study focuses on the decontamination/treatment processes (e.g., waste decontamination, size reduction, immobilization, and packaging) that support the environmental restoration mission at the Hanford Site.

Long-term decontamination engineering study. Volume 1

International Nuclear Information System (INIS)

Geuther, W.J.

1995-01-01

This report was prepared by Westinghouse Hanford Company (WHC) with technical and cost estimating support from Pacific Northwest Laboratories (PNL) and Parsons Environmental Services, Inc. (Parsons). This engineering study evaluates the requirements and alternatives for decontamination/treatment of contaminated equipment at the Hanford Site. The purpose of this study is to determine the decontamination/treatment strategy that best supports the Hanford Site environmental restoration mission. It describes the potential waste streams requiring treatment or decontamination, develops the alternatives under consideration establishes the criteria for comparison, evaluates the alternatives, and draws conclusions (i.e., the optimum strategy for decontamination). Although two primary alternatives are discussed, this study does identify other alternatives that may warrant additional study. hanford Site solid waste management program activities include storage, special processing, decontamination/treatment, and disposal facilities. This study focuses on the decontamination/treatment processes (e.g., waste decontamination, size reduction, immobilization, and packaging) that support the environmental restoration mission at the Hanford Site

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

Radiation decontamination unit for the community hospital.

Science.gov (United States)

Waldron, R L; Danielson, R A; Shultz, H E; Eckert, D E; Hendricks, K O

1981-05-01

"Freestanding" radiation decontamination units including surgical capability can be developed and made operational in small/medium sized community hospitals at relatively small cost and with minimal plant reconstruction. Because of the development of nuclear power plants in relatively remote areas and widespread transportation of radioactive materials it is important for hospitals and physicians to be prepared to handle radiation accident victims. The Radiological Assistance Program of the United States Department of Energy and the Radiation Emergency Assistance Center Training Site of Oak Ridge Associated Universities are ready to support individual hospitals and physicians in this endeavor. Adequate planning rather than luck, should be used in dealing with potential radiation accident victims. The radiation emergency team is headed by a physician on duty in the hospital. It is important that the team leader be knowledgeable in radiation accident management and have personnel trained in radiation accident management as members of this team. The senior administrative person on duty is responsible for intramural and extramural communications. Rapid mobilization of the radiation decontamination unit is important. Periodic drills are necessary for this mobilization and the smooth operation of the unit.

Quantitative characterization of agglomerate abrasion in a tumbling blender by using the Stokes number approach.

Science.gov (United States)

Willemsz, Tofan A; Nguyen, Tien Thanh; Hooijmaijers, Ricardo; Frijlink, Henderik W; Vromans, Herman; van der Voort Maarschalk, Kees

2013-03-01

Removal of microcrystalline cellulose agglomerates in a dry-mixing system (lactose, 100 M) predominantly occurs via abrasion. The agglomerate abrasion rate potential is estimated by the Stokes abrasion (StAbr) number of the system. The StAbr number equals the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. Basically, the StAbr number concept describes the blending condition of the dry-mixing system. The concept has been applied to investigate the relevance of process parameters on agglomerate abrasion in tumbling blenders. Here, process parameters such as blender rotational speed and relative fill volumes were investigated. In this study, the StAbr approach revealed a transition point between abrasion rate behaviors. Below this transition point, a blending condition exists where agglomerate abrasion is dominated by the kinetic energy density of the powder blend. Above this transition point, a blending condition exists where agglomerates show (undesirable) slow abrasion rates. In this situation, the blending condition is mainly determined by the high fill volume of the filler.

Dismantling and decontamination of the PIVER prototype vitrification facility

International Nuclear Information System (INIS)

Jouan, A.

1989-01-01

The PIVER facility was dismantled for replacement by a new continuous pilot plant. The more important operation concerns the vitrification cell, containing equipments of the process, for complete disposal and maximum decontamination, requiring dismantling, cutting, conditioning and removal of equipment inside the cell. Manipulators, handling and cutting tools were used. Activity of removed material and irradiation of personal are followed during the work for matching intervention means to operation conditions [fr

Full system chemical decontamination used in nuclear decommissioning

International Nuclear Information System (INIS)

Elder, George; Rottner, Bernard; Braehler, Georg

2012-01-01

The decommissioning of nuclear power stations at the end of the operational period of electricity generation offers technical challenges in the safe dismantling of the facility and the minimization of radioactive waste arising from the decommissioning activities. These challenges have been successfully overcome as demonstrated by decommissioning of the first generation of nuclear power plants. One of the techniques used in decommissioning is that of chemical decontamination which has a number of functions and advantages as given here: 1. Removal of contamination from metal surfaces in the reactors cooling systems. 2. Reduction of radioactive exposure to decommissioning workers 3. Minimization of metal waste by decontamination and recycling of metal components 4. Control of contamination when dismantling reactor and waste systems 5. Reduction in costs due to lower radiation fields, lower contamination levels and minimal metal waste volume for disposal. One such chemical decontamination technology was developed for the Electric Power Research Institute (EPRI) by Bradtec (Bradtec is an ONET Technologies subsidiary) and is known as the EPRI DFD system. This paper gives a description of the EPRI DFD system, and highlights the experience using the system. (orig.)

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

Neural network approximation of tip-abrasion effects in AFM imaging

International Nuclear Information System (INIS)

Bakucz, Peter; Dziomba, Thorsten; Koenders, Ludger; Krüger-Sehm, Rolf; Yacoot, Andrew

2008-01-01

The abrasion (wear) of tips used in scanning force microscopy (SFM) directly influences SFM image quality and is therefore of great relevance to quantitative SFM measurements. The increasing implementation of automated SFM measurement schemes has become a strong driving force for increasing efforts towards the prediction of tip wear, as it needs to be ensured that the probe is exchanged before a level of tip wear is reached that adversely affects the measurement quality. In this paper, we describe the identification of tip abrasion in a system of SFM measurements. We attempt to model the tip-abrasion process as a concatenation of a mapping from the measured AFM data to a regression vector and a nonlinear mapping from the regressor space to the output space. The mapping is formed as a basis function expansion. Feedforward neural networks are used to approximate this mapping. The one-hidden layer network gave a good quality of fit for the training and test sets for the tip-abrasion system. We illustrate our method with AFM measurements of both fine periodic structures and randomly oriented sharp features and compare our neural network results with those obtained using other methods

Neural network approximation of tip-abrasion effects in AFM imaging

Science.gov (United States)

Bakucz, Peter; Yacoot, Andrew; Dziomba, Thorsten; Koenders, Ludger; Krüger-Sehm, Rolf

2008-06-01

The abrasion (wear) of tips used in scanning force microscopy (SFM) directly influences SFM image quality and is therefore of great relevance to quantitative SFM measurements. The increasing implementation of automated SFM measurement schemes has become a strong driving force for increasing efforts towards the prediction of tip wear, as it needs to be ensured that the probe is exchanged before a level of tip wear is reached that adversely affects the measurement quality. In this paper, we describe the identification of tip abrasion in a system of SFM measurements. We attempt to model the tip-abrasion process as a concatenation of a mapping from the measured AFM data to a regression vector and a nonlinear mapping from the regressor space to the output space. The mapping is formed as a basis function expansion. Feedforward neural networks are used to approximate this mapping. The one-hidden layer network gave a good quality of fit for the training and test sets for the tip-abrasion system. We illustrate our method with AFM measurements of both fine periodic structures and randomly oriented sharp features and compare our neural network results with those obtained using other methods.

Decontamination of burns contaminated with radioactive materials

International Nuclear Information System (INIS)

Vykouril, L.

1986-01-01

The suitability of various solutions for the decontamination of burnt skin and their efficiency were tested by experiments on rats. Tested was the decontamination of undisturbed skin, second degree skin burns and third degree skin burns. Decontamination solutions used included: distilled water, jodonal (an aqueous solution of iodine, ethoxylated nonylphenols, the copolymer of ethylene oxide with propylene oxide, and phosphoric acid) and a decontamination mixture of Sapon, Komplexon (trade names of detergents) and sodium hexametaphosphate. Decontamination efficiency was 68.4% for second degree burns and 47.1% for third degree burns. Most effective was the decontamination solution with an efficiency of 72%; the efficiency of jodonal was 67% and of water - 54%. Jodonal is the most suitable: in addition, it acts as a disinfectant and antiseptic. (M.D.)

Low level radioactive liquid waste decontamination by electrochemical way

International Nuclear Information System (INIS)

Tronche, E.

1994-10-01

As part of the work on decontamination treatments for low level radioactive aqueous liquid wastes, the study of an electro-chemical process has been chosen by the C.E.A. at the Cadarache research centre. The first part of this report describes the main methods used for the decontamination of aqueous solutions. Then an electro-deposition process and an electro-dissolution process are compared on the basis of the decontamination results using genuine radioactive aqueous liquid waste. For ruthenium decontamination, the former process led to very high yields (99.9 percent eliminated). But the elimination of all the other radionuclides (antimony, strontium, cesium, alpha emitters) was only favoured by the latter process (90 percent eliminated). In order to decrease the total radioactivity level of the waste to be treated, we have optimized the electro-dissolution process. That is why the chemical composition of the dissolved anode has been investigated by a mixture experimental design. The radionuclides have been adsorbed on the precipitating products. The separation of the precipitates from the aqueous liquid enabled us to remove the major part of the initial activity. On the overall process some operations have been investigated to minimize waste embedding. Finally, a pilot device (laboratory scale) has been built and tested with genuine radioactive liquid waste. (author). 77 refs., 41 tabs., 55 figs., 4 appendixes

Analytical cell decontamination and shielding window refurbishment. Final report, March 1984-March 1985

International Nuclear Information System (INIS)

Smokowski, R.T.

1985-01-01

This is a report on the decontamination and refurbishment of five inactive contaminated analytical cells and six zinc bromide filled shielding windows. The analytical cells became contaminated during the nuclear fuel reprocessing carried out by Nuclear Fuel Services from 1966 to 1972. The decontamination and decommissioning (D and D) work was performed in these cells to make them useful as laboratories in support of the West Valley Demonstration Project. To accomplish this objective, unnecessary equipment was removed from these cells. Necessary equipment and the interior of each cell were decontaminated and repaired. The shielding windows, essentially tanks holding zinc bromide, were drained and disassembled. The deteriorated, opaque zinc bromide was refined to optical clarity and returned to the tanks. All wastes generated in this operation were characterized and disposed of properly. All the decontamination and refurbishment was accomplished within 13 months. The Analytical Hot Cell has been turned over to Analytical Chemistry for the performance high-level waste (HLW) characterization analysis

Mass Casualty Decontamination in a Chemical or Radiological/ Nuclear Incident: Further Guiding Principles

Science.gov (United States)

Carter, Holly; Amlôt, Richard; Williams, Richard; Rubin, G. James; Drury, John

2016-01-01

This short report presents a response to an article written by Cibulsky et al. (2016). The paper by Cibulsky et al. presents a useful and timely overview of the evidence surrounding the technical and operational aspects of mass casualty decontamination. It identifies three priority targets for future research, the third of which is how casualties' needs can be met in ways that best support compliance with and effectiveness of casualty decontamination. While further investigation into behavioural, communication and privacy issues during mass decontamination is warranted, there is now a substantial body of research in this area which is not considered in detail in the succinct summary provided by Cibulsky et al. (2016). In this short report, we summarise the available evidence around likely public behaviour during mass decontamination, effective communication strategies, and potential issues resulting from a lack of privacy. Our intention is to help further focus the research needs in this area and highlight topics on which more research is needed. PMID:27790381

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.)

Tests of the use of cation exchange organic resins for the decontamination of radioactive aqueous effluents

International Nuclear Information System (INIS)

Bourdrez, Jean; Girault, Jacques; Wormser, Gerald

1962-01-01

The authors report tests performed in laboratory and results obtained during an investigation of the use of synthetic ion exchangers for the decontamination of radioactive effluents of moderate activity level and with a non neglectable salt loading. Resins are used under sodium form and regenerated after each fixing operation. Once decontaminated and free of its disturbing ions, the regenerating agent (NaCl) is used for several operations. The authors present the used resins, the treated effluents, describe the tests, and discuss the obtained results [fr

Decontamination flowsheet development for a waste oil containing mixed radioactive contaminants

International Nuclear Information System (INIS)

Vijayan, S.; Buckley, L.P.

1993-01-01

The majority of waste oils contaminated with both radioactive and hazardous components are generated in nuclear power plant, research lab. and uranium-refinery operations. The waste oils are complex, requiring a detailed examination of the waste management strategies and technology options. It may appear that incineration offers a total solution, but this may not be true in all cases. An alternative approach is to decontaminate the waste oils to very low contaminant levels, so that the treated oils can be reused, burned as fuel in boilers, or disposed of by commercial incineration. This paper presents selected experimental data and evaluation results gathered during the development of a decontamination flowsheet for a specific waste oil stores at Chalk River Labs. (CRL). The waste oil contains varying amounts of lube oils, grease, paint, water, particulates, sludge, light chloro- and fluoro-solvents, polychlorinated biphenyls (PCB), complexing chemicals, uranium, chromium, iron, arsenic and manganese. To achieve safe management of this radioactive and hazardous waste, several treatment and disposal methods were screened. Key experiments were performed at the laboratory-scale to confirm and select the most appropriate waste-management scheme based on technical, environmental and economic criteria. The waste-oil-decontamination flowsheet uses a combination of unit operations, including prefiltration, acid scrubbing, and aqueous-leachage treatment by precipitation, microfiltration, filter pressing and carbon adsorption. The decontaminated oil containing open-quotes de minimisclose quotes levels of contaminants will undergo chemical destruction of PCBs and final disposal by incineration. The recovered uranium will be recycled to a uranium milling process

Feasibility Study on Cutting HTPB Propellants with Abrasive Water Jet

Science.gov (United States)

Jiang, Dayong; Bai, Yun

2018-01-01

Abrasive water jet is used to carry out the experiment research on cutting HTPB propellants with three components, which will provide technical support for the engineering treatment of waste rocket motor. Based on the reliability theory and related scientific research results, the safety and efficiency of cutting sensitive HTPB propellants by abrasive water jet were experimentally studied. The results show that the safety reliability is not less than 99.52% at 90% confidence level, so the safety is adequately ensured. The cooling and anti-friction effect of high-speed water jet is the decisive factor to suppress the detonation of HTPB propellant. Compared with pure water jet, cutting efficiency was increased by 5% - 87%. The study shows that abrasive water jets meet the practical use for cutting HTPB propellants.

Quantitative characterization of agglomerate abrasion in a tumbling blender by using the Stokes number approach

NARCIS (Netherlands)

Willemsz, Tofan A.; Nguyen, Tien Thanh; Hooijmaijers, Ricardo; Frijlink, Henderik W.; Vromans, Herman; van der Voort Maarschalk, Kees

2013-01-01

Removal of microcrystalline cellulose agglomerates in a dry-mixing system (lactose, 100 M) predominantly occurs via abrasion. The agglomerate abrasion rate potential is estimated by the Stokes abrasion (StAbr) number of the system. The StAbrnumber equals the ratio between the kinetic energy density

Specific decontamination methods: water nozzle, cavitation erosion

International Nuclear Information System (INIS)

Boulitrop, D.; Gauchon, J.P.; Lecoffre, Y.

1984-05-01

The erosion and decontamination tests carried out in the framework of this study, allowed to specify the fields favourable to the use of the high pressure jet taking into account the determinant parameters that are the pressure and the target-nozzle distance. The previous spraying of gels with chemical reagents (sulfuric acid anf hydrazine) allows to get better decontamination factors. Then, the feasibility study of a decontamination method by cavitation erosion is presented. Gelled compounds for decontamination have been developed; their decontamination quality has been evaluated by comparative contamination tests in laboratory and decontamination tests of samples of materials used in nuclear industry; this last method is adapted to remote handling devices and produces a low quantity of secondary effluents, so it allows to clean high contaminated installation on the site without additional exposure of the personnel [fr

On the abrasion of heat-treated 2.8C21Cr1Mo white cast iron

Energy Technology Data Exchange (ETDEWEB)

Al-Rubaie, Kassim S.; Preti, Orlando [Centro Universitario SOCIESC, Joinville (Brazil). Engenharia Mecanica; Pohl, Michael [Bochum Univ. (Germany). Inst. fuer Werkstoffe

2016-09-15

The abrasion behaviour of heat-treated 2.8C21Cr1Mo cast iron was studied. The specimens were destabilised at two temperatures, 980 and 1050 C, for 4 h, air hardened, and then tempered at five temperatures, 220, 320, 400, 500, and 620 C, for 2 h followed by air cooling. Using a pin-on-plate abrasion apparatus, the specimens were abraded on four types of bonded abrasives (silicon carbide, corundum, flint, and glass). The effect of work hardening on the abrasion resistance was investigated. It was found that the increase in alloy hardness produced by heat treatment had little effect on the abrasion resistance against silicon carbide or corundum; the inverse was true against flint or glass. The as-hardened structure containing 40% retained austenite gave the best abrasion resistance, whereas the hardened and tempered at 620 C showed the worst. Both bulk hardness and matrix hardness before wear correlated poorly with the abrasion resistance. Therefore, a general model ''equivalent hardness'' was developed, in which the hardness of the abraded matrix was considered. With this model, the abrasion behaviour can be clearly analysed.

New decontamination techniques generating a low volume of effluent

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

This document presents some decontamination techniques, their principles, characteristics and advantages and provides references on the subject. Techniques as foam and spray foam decontamination, dry steam decontamination, electro-decontamination and gel decontamination are presented. A presentation of TRIADE, cleanup dismantling servicing, is also provided. (A.L.B.)

New decontamination techniques generating a low volume of effluent

International Nuclear Information System (INIS)

2002-01-01

This document presents some decontamination techniques, their principles, characteristics and advantages and provides references on the subject. Techniques as foam and spray foam decontamination, dry steam decontamination, electro-decontamination and gel decontamination are presented. A presentation of TRIADE, cleanup dismantling servicing, is also provided. (A.L.B.)

Vigorous decontamination tests of steel samples

International Nuclear Information System (INIS)

Agostinelli, A.; Bregani, F.; Pascali, R.; Ronchetti, C.

1982-01-01

Among operative deCommissioning problems, the chemical decontamination of metallic surfaces of LWR, mainly with the use of high vigorous reagents, is being studied in particular. ENEL research activities, partially financed by the European Community Commission, began at the end of 1980, and are being developed by CRTN, Centro di Ricerca Termica e Nucleare, in close connection with ENEL-DPT and CISE. The main aim is the identification, development, and assessment of vigorous decontamination techniques taking into account the amount and disposal cost of liquid radwaste. The test materials come from the primary loop of the BWR-Garigliano plant. Activity levels, mainly due to 60 Co, range from about 0.01 μCi/cm 2 for predecontaminated material to some μCi/cm 2 for virgin material. Moreover, traces of 90 Sr-Y beta pure emitter and alpha emitters are monitored. Research is at first carried out by screening static tests for the optimization of etching static parameters (time, temperature, reagent concentrations). Reagent effectiveness will then be tested in a special experimental loop (DECO), in dynamic conditions simulating in-situ real procedures of decontamination. Hydrofluoric, nitric and hydrochloric acids and mixtures of them have been used for the first tests. Sometimes total oxide removal is possible, and when this takes place, the final contamination levels are in accordance with limits indicated for unrestricted release materials in some countries. 18 references, 13 figures, 5 tables

Laser Decontamination of Type 304 Stainless Steel Contaminated with Co2+ and CeO2

International Nuclear Information System (INIS)

Won, Hui Jun; Baigalmaa, Byambatseren; Moon, Jei Kwon; Jung, Chong Hun; Lee, Kune Woo

2009-01-01

The merits of laser decontamination are a remote operation, a short application time, and the high removal efficiency. And also, generation of the secondary waste is negligible. A series of laser decontamination test by Qswitched Nd:YAG laser at 532 nm were performed on stainless steel specimens artificially contaminated with the Co 2+ and CeO 2 , respectively. Test results were examined by SEM and EPMA

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

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.

National demonstration of full reactor coolant system (RCS) chemical decontamination at Indian Point 2

Energy Technology Data Exchange (ETDEWEB)

Trovato, S.A.; Parry, J.O. [Consolidated Edison Co., New York, NY (United States)

1995-03-01

Key to the safe and efficient operation of the nation`s civilian nuclear power plants is the performance of maintenance activities within regulations and guidelines for personnel radiation exposure. However, maintenance activities, often performed in areas of relatively high radiation fields, will increase as the nation`s plant age. With the Nuclear Regulatory Commission (NRC) lowering the allowable radiation exposure to plant workers in 1994 and considering further reductions and regulations in the future, it is imperative that new techniques be developed and applied to reduce personnel exposure. Full primary system chemical decontamination technology offers the potential to be single most effective method of maintaining workers exposure {open_quotes}as low as reasonably achievable{close_quotes} (ALARA) while greatly reducing plant operation and maintenance (O&M) costs. A three-phase program underway since 1987, has as its goal to demonstrate that full RCS decontamination is a visible technology to reduce general plant radiation levels without threatening the long term reliability and operability of a plant. This paper discusses research leading to and plans for a National Demonstration of Full RCS Chemical Decontamination at Indian Point 2 nuclear generating station in 1995.

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

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.)

Decontamination of skin in emergency situation

International Nuclear Information System (INIS)

Harase, Chieko

1988-01-01

The report briefly discusses the organization of decontamination personnel and facilities to be used for decontamination in the event of an emergency, and outlines the author's experience in carrying out decontamination of the skin of tourists who came back to Japan after staying in Kiev at the time of the accident at Chernobyl (about 150 km away from Kiev). In Japan at present, no nuclear facilities seem to have sufficient personnel who are in charge of skin decontamination activities required in the event of an emergency, and emergency measures are generally limited to the development of emergency plans and implementation of drills. It is necessary to establish training courses for medical doctors and other medical personnel. Each plant has plans for skin decontamination procedures designed for professional workers in the plant. Plans should also be established for general people who might suffer skin decontamination in the event of an accident. What is the most important is to ease their anxiety about the contamination of their skin. The procedures, including washing and shampooing, used for the tourist returning from Kiev are described, and some problems encountered or expected to occur in similar cases are outlined and discussed. (Nogami, K.)

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)

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...

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

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

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.

Experiences from Loviisa Nuclear Power Station concerning the decontamination of steam generators and primary system components

International Nuclear Information System (INIS)

Jaernstroem, R.

1989-01-01

Loviisa 1 and 2 are 465 MWe PWR units of the Soviet type VVER-440. Loviisa 1 has been in commercial operation since spring 1977 and Loviisa 2 from the beginning of 1980. Decontamination of primary circuit components - even big ones as steam generators - can be performed in an efficient and quick way with good results and resonable expences. Total costs for decontamination of the two steam generators including planning, construction, documentation, operation, chemicals etc. did not rise above 100,000.00 dollars. (author) 6 figs., 2 tabs

Photochemical surface modification of PP for abrasion resistance

International Nuclear Information System (INIS)

Bahners, Thomas; Haessler, Ruediger; Gao Shanglin; Maeder, Edith; Wego, Andreas; Schollmeyer, Eckhard

2009-01-01

The potential of a photo-chemical approach to increase the surface hardness of polypropylene (PP) has been studied. Using a 222 nm excimer lamp, fibers and film were irradiated in the presence of multi-functional substances diallylphthalate (DAP), tetraallyloxyethane (TAE), and pentaerithritoltriacylate (PETA) and characterized with regard to the resulting effect on abrasion resistance. AFM-based methods were employed to analyze thermo-mechanical surface properties. Nanoindentation and microthermal analyses of the outermost surface layers of UV treated fibers gave clear indications of an effective cross-linking of reactive substances present during irradiation. One may assume that the reactive media polymerize on top of the surface of the PP substrate and form a thin-layer. The abrasion resistance of the PP fibers was tested by applying stress through a rotating and axially oscillating roller of defined roughness and measuring the mass loss as a function of time. The abrasion resistance was found to be remarkably improved compared to the untreated fiber. Best effects were achieved using PETA as reactive substance. The experiments clearly showed the influence of processing conditions, namely with regard to homogeneous coverage of the substrate surface with the reactive medium.

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.

Experimental Study of the Ultrasonic Vibration-Assisted Abrasive Waterjet Micromachining the Quartz Glass

Directory of Open Access Journals (Sweden)

Rongguo Hou

2018-01-01

Full Text Available The ultrasonic vibration is used to enhance the capability of the abrasive water micromachining glass. And, the ultrasonic vibration is activated on the abrasive waterjet nozzle. The quality of the flow is improved, and the velocity of the abrasive is increased because of the addition of the ultrasonic energy. The relevant experimental results indicate that the erosion depth and the material volume removal of the glass are obviously increased when ultrasonic vibration is working. As for the influence of process parameters on the material removal of the glass such as vibration amplitude, system pressure, distance of the standoff, and abrasive size, the experimental results indicate that the system pressure and vibration contribute greatly to the glass material removal. Also, the erosion depth and the volume of material removal are increased with the increase in the vibration amplitude and system pressure. There are some uplifts found at the edge of erosion pit. Then, it can be inferred that the plastic method is an important material removal method during the machining process of ultrasonic vibration-assisted abrasive waterjet.

A new method to test rock abrasiveness based on physico-mechanical and structural properties of rocks

Directory of Open Access Journals (Sweden)

V.N. Oparin

2015-06-01

Full Text Available A new method to test rock abrasiveness is proposed based upon the dependence of rock abrasiveness on their structural and physico-mechanical properties. The article describes the procedure of presentation of properties that govern rock abrasiveness on a canonical scale by dimensionless components, and the integrated estimation of the properties by a generalized index. The obtained results are compared with the known classifications of rock abrasiveness.

Decontamination factors of ceramic filter in radioactive waste incineration system

International Nuclear Information System (INIS)

Kanbe, Hiromi; Mayuzumi, Masami; Ono, Tetsuo; Yoshiki, Shinya; Kouyama, Hiroaki; Nagae, Madoka; Sekiguchi, Ryosaku; Takaoku, Yoshinobu; Hozumi, Masahiro.

1987-01-01

A suspension-firing type radioactive waste incineration system is developed and cold demonstration testing of ceramic filters for the system are carried out. The incineration system, which is useful for a wide variety of waste materials, can serve to simplify the facilities and to reduce the costs for waste disposal. The incineration system can be used for drying-processing of concentrated waste liquids and disposal of flame resistant materials including ion exchange resins and rubber, as well as for ordinary combustible solid materials. An on-line backwash system is adopted to allow the ceramic filters to operate stably for a long period of time. For one-step filtering using the ceramic filter, the decontamination factor is greater than 10 5 for the processing of various wastes. In a practical situation, there exist vapor produced by the spray drier and the cladding in used ion exchange resin, which act to increase the decontamination performance of the ceramic filters to ensure safe operation. For the waste incineration system equipped with a waste gas processing apparatus consisting of a ceramic filter and HEPA filter, the overall decontamination factor is expected to be greater than 10 6 at portions down to the outlet of the ceramic filter and greater than 10 8 at portions down to the outlet of the HEPA filter. (Nogami, K.)

Exposure management in a hot-cell decontamination and refurbishment campaign

International Nuclear Information System (INIS)

Courtney, J.C.; Ferguson, K.R.; Chesnovar, D.L.; Huebner, M.F.

1984-01-01

We developed a minicomputer-based system to provide rapid access to personnel dosimetry data during a campaign to decontaminate and refurbish a hot-cell at the Hot Fuel Examination Facility (HFEF) Complex. This system allows project management to estimate doses for future tasks, assess the effectiveness of decontamination and personnel protection techniques, and balance exposures among members of various skill groups. As the campaign progresses, projected total exposures can be minimized by tradeoffs between estimated doses during decontamination and estimated dose savings during the refurbishment phase. The effectiveness of various dose-reduction procedures can be compared on the basis of data from a few cell entries before more extensive routine operations are scheduled. Because the radiation fields vary significantly with location in the cell, we find that measurements of whole-body, skin, and extremity doses are more valuable than dose-rate information. Penetrating and skin radiation doses to personnel can be compared to administrative guidelines. This helps us to select the most effective combination of protective clothing. For example, leaded gauntlets reduce the dose rate to the workers' hands, but their use can increase the time required for some in-cell tasks. Hence, use of gauntlets can lead to higher whole-body and skin doses. The program is written for the HFEF Complex Harris/6 minimainframe computer with a disk-monitor operating system

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.

Kinetic energy density and agglomerate abrasion rate during blending of agglomerates into powders.

Science.gov (United States)

Willemsz, Tofan A; Hooijmaijers, Ricardo; Rubingh, Carina M; Tran, Thanh N; Frijlink, Henderik W; Vromans, Herman; van der Voort Maarschalk, Kees

2012-01-23

Problems related to the blending of a cohesive powder with a free flowing bulk powder are frequently encountered in the pharmaceutical industry. The cohesive powder often forms lumps or agglomerates which are not dispersed during the mixing process and are therefore detrimental to blend uniformity. Achieving sufficient blend uniformity requires that the blending conditions are able to break up agglomerates, which is often an abrasion process. This study was based on the assumption that the abrasion rate of agglomerates determines the required blending time. It is shown that the kinetic energy density of the moving powder bed is a relevant parameter which correlates with the abrasion rate of agglomerates. However, aspects related to the strength of agglomerates should also be considered. For this reason the Stokes abrasion number (St(Abr)) has been defined. This parameter describes the ratio between the kinetic energy density of the moving powder bed and the work of fracture of the agglomerate. The St(Abr) number is shown to predict the abrasion potential of agglomerates in the dry-mixing process. It appeared possible to include effects of filler particle size and impeller rotational rate into this concept. A clear relationship between abrasion rate of agglomerates and the value of St(Abr) was demonstrated. Copyright © 2011 Elsevier B.V. All rights reserved.

Decontamination of stainless steel using cerium(IV): Material recycle and reuse

International Nuclear Information System (INIS)

Kurath, D.E.; Bray, L.A.; Jarrett, J.H.

1997-01-01

It has been demonstrated that the Cerium(IV) process can effectively remove radioactive contamination from stainless steel. Ce(IV) is a powerful oxidizing agent that is applied in an inorganic acid solution or as an atomized spray by injection into steam directed at the contaminated surface. Ce(IV) attacks the oxide layer and underlying metal surface to remove a 0.5-μm to 3-μm layer. This process has been implemented in a number of actual operations. In one application, a Ce(IV) steam decontamination process was instrumental in renovating hot cells at the High-Level Radiochemistry Facility (325-A building) at the Hanford site. The initial dose rate of approximately 100,000 mR/h was reduced to <50 mR/h and allowed manned entry during hot cell renovation activities. These valuable facilities have been returned to full operation. In an application at the West Valley Nuclear Services Co., Inc., the surfaces of stainless steel canisters that had been filled with vitrified high-level waste have been decontaminated. In some cases the free release levels for surface contamination have been achieved. In another application, five plutonium contaminated stainless steel vessels were decontaminated during decommissioning of the Critical Mass Facility at Hanford

Testing and evaluation of eight decontamination chemicals

International Nuclear Information System (INIS)

Demmer, R.

1994-09-01

This report covers experimental work comparing eight different decontamination chemicals. Seven of these chemicals have some novelty, or are not currently in use at the ICPP. The eighth is a common ICPP decontamination reagent used as a baseline for effective comparison. Decontamination factors, waste generation values, and corrosion rates are tabulated for these chemicals. Recommendations are given for effective methods of non-sodium or low-sodium decontamination chemicals. The two most effective chemical for decontamination found in these test were a dilute hydrofluoric and nitric acid (HF/HNO 3 ) mixture and a fluoroboric acid solution. The fluoroboric acid solution (1 molar) was by far the most effective decontamination reagent, but suffered the problem of generating significant final calcine volume. The HF/HNO 3 solution performed a very good decontamination of the SIMCON coupons while generating only small amounts of calcine volume. Concentration variables were also tested, and optimized for these two solutions. Several oxidation/reduction decon chemical systems were also tested. These systems were similar to the TURCO 4502 and TURCO 4521 solutions used for general decontamination at the ICPP. A low sodium alternative, nitric acid/potassium permanganate, to the ''high sodium'' TURCO 4502 was tested extensively, optimized and recommended for general ICPP use. A reductive chemical solution, oxalic acid/nitric acid was also shown to have significant advantages

Idaho National Engineering Laboratory decontamination and decommissioning summary

International Nuclear Information System (INIS)

Chapin, J.A.

1981-01-01

Topics covered concern the decontamination and decommissioning (D and D) work performed at the Idaho National Engineering Laboratory (INEL) during FY 1979 and include both operations and development projects. Briefly presented are the different types of D and D projects planned and the D and D projects completed. The problems encountered on these projects and the development program recommended are discussed

Post-accident TMI-2 (Three Mile Island-Unit 2) decontamination and defueling

International Nuclear Information System (INIS)

Hofstetter, K.J.; Baston, V.F.

1986-01-01

Following the accident at Three Mile Island-Unit 2 (TMI-2), a substantial quantity of fission products was distributed throughout various plant systems and areas. The control of further migration of these radionuclides was accomplished by various physical and chemical means. The decontamination and defueling activities have proceeded within specific regulatory, administrative, and hardware restrictions. A summary of the post-accident status of the plant systems, the decontamination methods used, and the end-point criteria will be discussed. The hardware installed or utilized to perform the cleanup operations will be described. The methods and progress of defueling will also be presented. The development of detailed water chemistry requirements and their effects on systems and decontamination efforts are discussed. The planning, scheduling, and performance of specific recovery tasks are presented along with a general overview of water and chemical management at TMI-2

New quaternary ammonium salts based decontaminants

Directory of Open Access Journals (Sweden)

Diana M. Popescu

2014-06-01

Full Text Available Decontamination after terrorist attacks or industrial accidents with biological and/or chemical agents („bio-chem“ must be fast and efficient, in order to reduce the number of victims and to eliminate the consequent damages. The decontamination of living biological agents (bacteria, viruses or nonliving ones (toxins, regulators and toxic chemicals could be accomplished by reactions of hydrolysis in various experimental conditions, in particular in alkaline medium, reactions with amines or ammonia, alcohols, phenols etc. and by their transformation into less toxic degradation products. “Bio-chem” intentional or unintentional contamination is a real risk, towards which an effective management must be available to prevent and control it. Decontamination is an essential measure to protect the personnel and the environment. Synthesis and testing of new „bio-chem“ decontaminants, based on quaternary ammonium salts, complete the arsenal of protection against chemical and biological agents. The most effective selected substances could be produced and used for decontamination in accordance with legal procedures

NRC regulations and positions concerning decontamination

International Nuclear Information System (INIS)

McCracken, C.

1982-09-01

The U.S. Nuclear Regulatory Commission encourages the use of decontamination to reduce man-rem exposure. The Commission feels that there are several processes developed to the point where soft decontamination can be applied to an entire plant in the near future. A utility can do a decontamination under its own licence without coming in for regulatory review if the process does not involve a change in technical specifications for the plant or does not involve unreviewed safety questions. Prior verbal notification is required for some steam generator secondary side cleaning or for decontamination of individual components that have not been removed from the reactor using chemicals not normally added to the reactor coolant. Prior written notification is required for steam generator secondary side crevice cleaning or sludge removal at a dented unit, or for chemical decontamination of reactor coolant systems or safety-related systems using chemicals not normally added to the coolant

Performance Enhancement of Abrasive Waterjet Cutting

NARCIS (Netherlands)

2008-01-01

Abrasive Waterjet (AWJ) Machining is a recent non-traditional machining process. This technology is widely used in industry for cutting difficult-to-machine-materials, milling slots, polishing hard materials etc. AWJ machining has many advantages, e.g. it can cut net-shape parts, no heat is

Anthrax Sampling and Decontamination: Technology Trade-Offs

Energy Technology Data Exchange (ETDEWEB)

Price, Phillip N.; Hamachi, Kristina; McWilliams, Jennifer; Sohn, Michael D.

2008-09-12

The goal of this project was to answer the following questions concerning response to a future anthrax release (or suspected release) in a building: 1. Based on past experience, what rules of thumb can be determined concerning: (a) the amount of sampling that may be needed to determine the extent of contamination within a given building; (b) what portions of a building should be sampled; (c) the cost per square foot to decontaminate a given type of building using a given method; (d) the time required to prepare for, and perform, decontamination; (e) the effectiveness of a given decontamination method in a given type of building? 2. Based on past experience, what resources will be spent on evaluating the extent of contamination, performing decontamination, and assessing the effectiveness of the decontamination in abuilding of a given type and size? 3. What are the trade-offs between cost, time, and effectiveness for the various sampling plans, sampling methods, and decontamination methods that have been used in the past?

Analysis of waste management issues arising from a field study evaluating decontamination of a biological agent from a building.

Science.gov (United States)

Lemieux, P; Wood, J; Drake, J; Minamyer, S; Silvestri, E; Yund, C; Nichols, T; Ierardi, M; Amidan, B

2016-01-01

The Bio-response Operational Testing and Evaluation (BOTE) Project was a cross-government effort designed to operationally test and evaluate a response to a biological incident (release of Bacillus anthracis [Ba] spores, the causative agent for anthrax) from initial public health and law enforcement response through environmental remediation. The BOTE Project was designed to address site remediation after the release of a Ba simulant, Bacillus atrophaeus spp. globigii (Bg), within a facility, drawing upon recent advances in the biological sampling and decontamination areas. A key component of response to a biological contamination incident is the proper management of wastes and residues, which is woven throughout all response activities. Waste is generated throughout the response and includes items like sampling media packaging materials, discarded personal protective equipment, items removed from the facility either prior to or following decontamination, aqueous waste streams, and materials generated through the application of decontamination technologies. The amount of residual contaminating agent will impact the available disposal pathways and waste management costs. Waste management is an integral part of the decontamination process and should be included through "Pre-Incident" response planning. Overall, the pH-adjusted bleach decontamination process generated the most waste from the decontamination efforts, and fumigation with chlorine dioxide generated the least waste. A majority of the solid waste generated during pH-adjusted bleach decontamination was the nonporous surfaces that were removed, bagged, decontaminated ex situ, and treated as waste. The waste during the two fumigation rounds of the BOTE Project was associated mainly with sampling activities. Waste management activities may represent a significant contribution to the overall cost of the response/recovery operation. This paper addresses the waste management activities for the BOTE field test

Experience with dilute chemical decontamination in Indian Pressurized Heavy Water Reactors

International Nuclear Information System (INIS)

Velmurugan, S.; Rufus, A.L.; Sathyaseelan, V.S.; Subramanian, Veena; Mittal, V.K.; Narasimhan, S.V.

2010-01-01

Dilute Chemical Decontamination (DCD) process has been used in several full system and components of nuclear coolant systems to effectively remove the radioactive contaminants that causes radiation field and consequent MANREM problem. The DCD process uses chemicals in very low concentrations (millimolar) and dissolves the oxide film along with the activity incorporated in the oxide film. In DCD process operated under the regenerative mode, the chemical formulation spent in the process of oxide dissolution is replenished by passing through cation exchange columns. Finally, after achieving sufficient decontamination of the system/component, the added decontamination chemicals along with the activities and metal ions released during the process are removed by mixed bed ion exchange columns and the system is restored to normal operating condition in few days time. In PHWRs, the regenerative DCD process is applied for full primary coolant system decontamination. The chemicals are added directly to the heavy water coolant with the fuel in the core. In Indian PHWRs (MAPS-1 and 2, RAPS-1 and 2, NAPS-1 and 2 and KAPS-1), the process has been applied eleven times. A chemical formulation based on NTA, Citric acid and Ascorbic acid has been applied seven times with good results. Decontamination factors in the range 2-30 have been obtained in different components with good MANREM savings in the subsequent maintenance works. Efforts are on to modify the process to take care of the challenges posed by antimony isotope. An inhibitor (Rodine-92B) based process was successfully tested in NAPS-2 for removing antimony isotopes ( 122 Sb and 124 Sb). Further refining of the antimony removal process is being worked out. Similarly, the process is being modified to effectively remove the hotspot causing stellite particles in the moderator system of PHWRs. A permanganate based process has been developed and tested in several adjustor rod drive mechanisms in KAPS and NAPS. The experience of

Decontamination and decommissioning techniques for research reactors