Electrolytic decontamination of the 3013 inner can

International Nuclear Information System (INIS)

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

1998-01-01

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

A decontamination system for chemical weapons agents using a liquid solution on a solid sorbent.

Science.gov (United States)

Waysbort, Daniel; McGarvey, David J; Creasy, William R; Morrissey, Kevin M; Hendrickson, David M; Durst, H Dupont

2009-01-30

A decontamination system for chemical warfare agents was developed and tested that combines a liquid decontamination reagent solution with solid sorbent particles. The components have fewer safety and environmental concerns than traditional chlorine bleach-based products or highly caustic solutions. The liquid solution, based on Decon Greentrade mark, has hydrogen peroxide and a carbonate buffer as active ingredients. The best solid sorbents were found to be a copolymer of ethylene glycol dimethacrylate and n-lauryl methacrylate (Polytrap 6603 Adsorber); or an allyl methacrylate cross-linked polymer (Poly-Pore E200 Adsorber). These solids are human and environmentally friendly and are commonly used in cosmetics. The decontaminant system was tested for reactivity with pinacolyl methylphosphonofluoridate (Soman, GD), bis(2-chloroethyl)sulfide (Mustard, HD), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX) by using NMR Spectroscopy. Molybdate ion (MoO(4)(-2)) was added to the decontaminant to catalyze the oxidation of HD. The molybdate ion provided a color change from pink to white when the oxidizing capacity of the system was exhausted. The decontaminant was effective for ratios of agent to decontaminant of up to 1:50 for VX (t(1/2) decontamination solution were measured to show that the sorbent decreased the vapor concentration of GD. The E200 sorbent had the additional advantage of absorbing aqueous decontamination solution without the addition of an organic co-solvent such as isopropanol, but the rate depended strongly on mixing for HD.

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

Decontamination method for radiation contaminated metal

International Nuclear Information System (INIS)

Enda, Masami; Hosaka, Katsumi; Sakai, Hitoshi.

1997-01-01

An organic acid solution is used as a decontamination liquid, and base materials of radiation contaminated metals are dissolved in the solution. The concentration of the organic acid is measured, and the organic acid is supplied by an amount corresponding to the lowering of the concentration. The decontamination liquid wastes generated during the decontamination step are decomposed, and metals leached in the organic acid solution are separated. With such procedures, contamination intruded into the inside of the mother materials of the metals can be removed, and radioactivity of the contaminated metals such as stainless steels and carbon steels can be eliminated, or the radiation level thereof can be reduced. In addition, the amount of secondary wastes generated along with the decontamination can be suppressed. (T.M.)

Study on decontamination of radioactive ruthenium by steel wool in waste solution

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, S; Sakaki, T [Radia Industry Co. Ltd., Takasaki, Gunma (Japan)

1979-06-01

Tracer experiments were done in order to establish a decontamination process of /sup 106/Ru in radioactive waste solution by column method paying special attention on the solution of nitrato-nitrosyl complex of Ru which is often encountered as a low level radioactive solution. It turned out that metallic iron was the most effective decontaminating agent among the several tens of materials tested. The decontamination factor (DF) of /sup 106/Ru increased in proportion to the total surface area of iron and it sensitively depended on the oxidation state of the surface as revealed by the batchwise and columnwise tests. Iron samples with high corrosiveness gave a much larger DF than those with low corrosiveness. The decontamination process proceeded as iron was being oxidized via Fe(metal) ..-->.. Fe(II) ..-->.. Fe(III). As the results, the DF initially increased after initiating the passage of water through the column but it then decreased as the oxidation process became inactive. An excellent durability up to 10000 bed volumes was demonstrated by the column method at a high average DF of 150.

Precipitation-filtering technology for uranium waste solution generated on washing-electrokinetic decontamination

Energy Technology Data Exchange (ETDEWEB)

Kim, Gye-Nam, E-mail: kimsum@kaeri.re.kr; Park, Uk-Ryang; Kim, Seung-Soo; Moon, Jei-Kwon

2015-05-15

Graphical abstract: A recycling process diagram for the volume reduction of waste solution generated from washing-electrokinetic decontamination. - Highlights: • A process for recycling a waste solution generated was developed. • The total metal precipitation rate by NaOH in a supernatant after precipitation was the highest at pH 9. • The uranium radioactivity in the treated solution upon injection of 0.2 g of alum was lower. • After drying, the volume of sludge was reduced to 35% of the initial sludge volume. - Abstract: Large volumes of uranium waste solution are generated during the operation of washing-electrokinetic decontamination equipment used to remove uranium from radioactive soil. A treatment technology for uranium waste solution generated upon washing-electrokinetic decontamination for soil contaminated with uranium has been developed. The results of laboratory-size precipitation experiments were as follows. The total amount of metal precipitation by NaOH for waste solution was highest at pH 11. Ca(II), K(I), and Al(III) ions in the supernatant partially remained after precipitation, whereas the concentration of uranium in the supernatant was below 0.2 ppm. Also, when NaOH was used as a precipitant, the majority of the K(I) ions in the treated solution remained. The problem of CaO is to need a long dissolution time in the precipitation tank, while Ca(OH){sub 2} can save a dissolution time. However, the volume of the waste solution generated when using Ca(OH){sub 2} increased by 8 mL/100 mL (waste solution) compared to that generated when using CaO. NaOH precipitant required lower an injection volume lower than that required for Ca(OH){sub 2} or CaO. When CaO was used as a precipitant, the uranium radioactivity in the treated solution at pH 11 reached its lowest value, compared to values of uranium radioactivity at pH 9 and pH 5. Also, the uranium radioactivity in the treated solution upon injection of 0.2 g of alum with CaO or Ca(OH){sub 2} was

A decontamination system for chemical weapons agents using a liquid solution on a solid sorbent

International Nuclear Information System (INIS)

Waysbort, Daniel; McGarvey, David J.; Creasy, William R.; Morrissey, Kevin M.; Hendrickson, David M.; Durst, H. Dupont

2009-01-01

A decontamination system for chemical warfare agents was developed and tested that combines a liquid decontamination reagent solution with solid sorbent particles. The components have fewer safety and environmental concerns than traditional chlorine bleach-based products or highly caustic solutions. The liquid solution, based on Decon Green TM , has hydrogen peroxide and a carbonate buffer as active ingredients. The best solid sorbents were found to be a copolymer of ethylene glycol dimethacrylate and n-lauryl methacrylate (Polytrap 6603 Adsorber); or an allyl methacrylate cross-linked polymer (Poly-Pore E200 Adsorber). These solids are human and environmentally friendly and are commonly used in cosmetics. The decontaminant system was tested for reactivity with pinacolyl methylphosphonofluoridate (Soman, GD), bis(2-chloroethyl)sulfide (Mustard, HD), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX) by using NMR Spectroscopy. Molybdate ion (MoO 4 -2 ) was added to the decontaminant to catalyze the oxidation of HD. The molybdate ion provided a color change from pink to white when the oxidizing capacity of the system was exhausted. The decontaminant was effective for ratios of agent to decontaminant of up to 1:50 for VX (t 1/2 ≤ 4 min), 1:10 for HD (t 1/2 1/2 < 2 min). The vapor concentrations of GD above the dry sorbent and the sorbent with decontamination solution were measured to show that the sorbent decreased the vapor concentration of GD. The E200 sorbent had the additional advantage of absorbing aqueous decontamination solution without the addition of an organic co-solvent such as isopropanol, but the rate depended strongly on mixing for HD

Decontamination of waste radioactive polluted solutions in radiation treatment

International Nuclear Information System (INIS)

Simova, G.; Boyadzhiev, A.; Mikhajlov, M.G.; Shopov, N.

1979-01-01

The decontamination capacity of solutions of the trivial cleaning Bulgarian preparations ''Mipro'', ''Sana'', ''Synthek'' and ''Univer'' for different surfaces (steel, glass, PVC and linoleum) contaminated with cesium-134, strontium-85 or cerium-144 chlorides, was studied. Concentrations from 5 to 15 g/l of the solutions used in this study displayed a degree of cleaning over 90%. Higher concentration of the solution does not improve its cleaning capacity. For evaluation of foam formation by the solutions, the so called ''foam column stability coefficient'' has been adopted. This coefficient represents the ratio between the height of the foam column and the time of its half life, referred to the time for the foam column formation when blown through with a constant air current. On the basis of this index, solutions of the preparation ''Mipro'' proved to be the best ones for decontamination - in the whole investigated concentration span, the foam column stability coefficient for the solutions of this preparation is with two orders lower than the respective coefficient of the other preparations. It was experimentally established that radiation treatment of radio-contaminated solutions reduces the foam column stability coefficient. Radiation treatment should be carried out in a gamma field, realizing at least one megarad within an acceptable for the liquid wastes time period. (A.B.)

A decontamination system for chemical weapons agents using a liquid solution on a solid sorbent

Energy Technology Data Exchange (ETDEWEB)

Waysbort, Daniel [Israel Institute for Biological Research, PO Box 19, Ness-Ziona 74100 (Israel); McGarvey, David J. [R and T Directorate, Edgewood Chemical and Biological Center (ECBC), Aberdeen Proving Ground-Edgewood Area, MD 21010 (United States)], E-mail: david.mcgarvey@us.army.mil; Creasy, William R.; Morrissey, Kevin M.; Hendrickson, David M. [SAIC, P.O. Box 68, Gunpowder Branch, Aberdeen Proving Ground, MD 21010 (United States); Durst, H. Dupont [R and T Directorate, Edgewood Chemical and Biological Center (ECBC), Aberdeen Proving Ground-Edgewood Area, MD 21010 (United States)

2009-01-30

A decontamination system for chemical warfare agents was developed and tested that combines a liquid decontamination reagent solution with solid sorbent particles. The components have fewer safety and environmental concerns than traditional chlorine bleach-based products or highly caustic solutions. The liquid solution, based on Decon Green{sup TM}, has hydrogen peroxide and a carbonate buffer as active ingredients. The best solid sorbents were found to be a copolymer of ethylene glycol dimethacrylate and n-lauryl methacrylate (Polytrap 6603 Adsorber); or an allyl methacrylate cross-linked polymer (Poly-Pore E200 Adsorber). These solids are human and environmentally friendly and are commonly used in cosmetics. The decontaminant system was tested for reactivity with pinacolyl methylphosphonofluoridate (Soman, GD), bis(2-chloroethyl)sulfide (Mustard, HD), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX) by using NMR Spectroscopy. Molybdate ion (MoO{sub 4}{sup -2}) was added to the decontaminant to catalyze the oxidation of HD. The molybdate ion provided a color change from pink to white when the oxidizing capacity of the system was exhausted. The decontaminant was effective for ratios of agent to decontaminant of up to 1:50 for VX (t{sub 1/2} {<=} 4 min), 1:10 for HD (t{sub 1/2} < 2 min with molybdate), and 1:10 for GD (t{sub 1/2} < 2 min). The vapor concentrations of GD above the dry sorbent and the sorbent with decontamination solution were measured to show that the sorbent decreased the vapor concentration of GD. The E200 sorbent had the additional advantage of absorbing aqueous decontamination solution without the addition of an organic co-solvent such as isopropanol, but the rate depended strongly on mixing for HD.

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)

Preparation of SiO2-KCoFC composite ion-exchanger for removal of Cs in the soil decontamination waste solution

International Nuclear Information System (INIS)

Lee, Jung Joon; Moon, Jei kwon; Lee, Kune Woo

2009-01-01

The soil decontamination process has been developed for remediate the soil wastes excavated from the TRIGA research reactor sites. Even though the process was proven to be very effective for decontaminate the radioactive nuclides such as cesium and cobalt, the secondary spent solution should be treated with an appropriate method to minimize the waste volume. There are mainly two components in the spent decontamination solution of Cs and Co. The Co in the waste solution can be removed easily by precipitation under a basic condition. However, since the Cs is hardly removed by precipitation, an appropriate selective removal method should be employed. In this study, an inorganic composite ion exchanger of SiO 2 -KCoFC was prepared by sol-gel method for a removal of Cs in the decontamination waste solution. An optimum condition for a preparation of the composite ion exchanger and the adsorption performances of the prepared composite ion exchangers were evaluated

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

Determination of trace amounts of chemical warfare agent degradation products in decontamination solutions with NMR spectroscopy.

Science.gov (United States)

Koskela, Harri; Rapinoja, Marja-Leena; Kuitunen, Marja-Leena; Vanninen, Paula

2007-12-01

Decontamination solutions are used for an efficient detoxification of chemical warfare agents (CWAs). As these solutions can be composed of strong alkaline chemicals with hydrolyzing and oxidizing properties, the analysis of CWA degradation products in trace levels from these solutions imposes a challenge for any analytical technique. Here, we present results of application of nuclear magnetic resonance spectroscopy for analysis of trace amounts of CWA degradation products in several untreated decontamination solutions. Degradation products of the nerve agents sarin, soman, and VX were selectively monitored with substantially reduced interference of background signals by 1D 1H-31P heteronuclear single quantum coherence (HSQC) spectrometry. The detection limit of the chemicals was at the low part-per-million level (2-10 microg/mL) in all studied solutions. In addition, the concentration of the degradation products was obtained with sufficient confidence with external standards.

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

Process to decontaminate a superficial soil layer contaminated with radioactive particles and decontaminating solution

International Nuclear Information System (INIS)

Jouve, A.; Mary, N.

1993-01-01

The process consists to dissolve a micronised powder of anionic and crosslinked polyacrilamide, to spray the obtained decontamination solution on the floor to be traited allowing to dry to form a dry polyacrilamide film, to rehydrate the film by spraying with water and to recover the film bonded to the floor particles and the polluting particles by cleaning means. 1 fig

Corrosion Compatibility Studies on Inconel-600 in NP Decontamination Solution

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Yoon; Jung, Jun Young; Won, Huijun; Choi, Wangkyu; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

It is well known that corrosion and contamination process in the primary cooling circuit of nuclear reactors are essentially interrelated: the contaminant isotopes are mostly corrosion products activated in the reactor core, and the contamination takes place on the out-core of Inconel-600 surface. This radionuclide uptake takes place up to the inner oxide layer and oxide/metal interface. So, it is necessary to remove inner oxide layer as well as outer oxide layer for excellent decontamination effects. The outer oxide layers are composed of Fe{sub 3}O{sub 4} and NiFe{sub 2}O{sub 4}. On the other hand, the inner oxide layers are composed of Cr{sub 2}O{sub 3}, (Ni{sub 1-x}Ni{sub x})(Cr{sub 1-y}Fe{sub y}){sub 2}O{sub 4}, and FeCr{sub 2}O{sub 4}. Because of chromium in the trivalent oxidation state which is difficult to dissolve, the oxide layer has an excellent protectiveness and become hard to be decontaminated. Alkaline permanganate (AP) or nitric permanganate (NP) oxidative phase has been used to dissolve the chromium-rich oxide. A disadvantage of AP process is the generation of a large volume of secondary waste. On the other hand, that of NP process is the high corrosion rate for Ni-base alloys. Therefore, for the safe use of oxidative phase in PWR system decontamination, it is necessary to reformulate the NP chemicals for decrease of corrosion rate. This study describes the corrosion compatibility on Inconel-600 and type 304 stainless steel in NP decontamination solution for PWR applications. To evaluate the general corrosion properties, weight change of NP treated specimens was measured. NP treated specimen surface was observed using optical microscope (OM) and scanning electron microscopy (SEM) for the evaluation of the localized corrosion. The effect of additives on the corrosion of the specimens was also evaluated. This study describes the corrosion compatibility on Inconel-600 and type 304 stainless steel in NP decontamination solution for PWR applications

Corrosion Compatibility Studies on Inconel-600 in NP Decontamination Solution

International Nuclear Information System (INIS)

Park, Sang Yoon; Jung, Jun Young; Won, Huijun; Choi, Wangkyu; Moon, Jeikwon

2013-01-01

It is well known that corrosion and contamination process in the primary cooling circuit of nuclear reactors are essentially interrelated: the contaminant isotopes are mostly corrosion products activated in the reactor core, and the contamination takes place on the out-core of Inconel-600 surface. This radionuclide uptake takes place up to the inner oxide layer and oxide/metal interface. So, it is necessary to remove inner oxide layer as well as outer oxide layer for excellent decontamination effects. The outer oxide layers are composed of Fe 3 O 4 and NiFe 2 O 4 . On the other hand, the inner oxide layers are composed of Cr 2 O 3 , (Ni 1-x Ni x )(Cr 1-y Fe y ) 2 O 4 , and FeCr 2 O 4 . Because of chromium in the trivalent oxidation state which is difficult to dissolve, the oxide layer has an excellent protectiveness and become hard to be decontaminated. Alkaline permanganate (AP) or nitric permanganate (NP) oxidative phase has been used to dissolve the chromium-rich oxide. A disadvantage of AP process is the generation of a large volume of secondary waste. On the other hand, that of NP process is the high corrosion rate for Ni-base alloys. Therefore, for the safe use of oxidative phase in PWR system decontamination, it is necessary to reformulate the NP chemicals for decrease of corrosion rate. This study describes the corrosion compatibility on Inconel-600 and type 304 stainless steel in NP decontamination solution for PWR applications. To evaluate the general corrosion properties, weight change of NP treated specimens was measured. NP treated specimen surface was observed using optical microscope (OM) and scanning electron microscopy (SEM) for the evaluation of the localized corrosion. The effect of additives on the corrosion of the specimens was also evaluated. This study describes the corrosion compatibility on Inconel-600 and type 304 stainless steel in NP decontamination solution for PWR applications. It is revealed that Inconel-600 specimen is more

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.)

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

Investigations regarding the wet decontamination of fluorescent lamp waste using iodine in potassium iodide solutions

International Nuclear Information System (INIS)

Tunsu, Cristian; Ekberg, Christian; Foreman, Mark; Retegan, Teodora

2015-01-01

Highlights: • A wet-based decontamination process for fluorescent lamp waste is proposed. • Mercury can be leached using iodine in potassium iodide solution. • The efficiency of the process increases with an increase in leachant concentration. • Selective leaching of mercury from rare earth elements is achieved. • Mercury is furthered recovered using ion exchange, reduction or solvent extraction. - Abstract: With the rising popularity of fluorescent lighting, simple and efficient methods for the decontamination of discarded lamps are needed. Due to their mercury content end-of-life fluorescent lamps are classified as hazardous waste, requiring special treatment for disposal. A simple wet-based decontamination process is required, especially for streams where thermal desorption, a commonly used but energy demanding method, cannot be applied. In this study the potential of a wet-based process using iodine in potassium iodide solution was studied for the recovery of mercury from fluorescent lamp waste. The influence of the leaching agent’s concentration and solid/liquid ratio on the decontamination efficiency was investigated. The leaching behaviour of mercury was studied over time, as well as its recovery from the obtained leachates by means of anion exchange, reduction, and solvent extraction. Dissolution of more than 90% of the contained mercury was achieved using 0.025/0.05 M I 2 /KI solution at 21 °C for two hours. The efficiency of the process increased with an increase in leachant concentration. 97.3 ± 0.6% of the mercury contained was dissolved at 21 °C, in two hours, using a 0.25/0.5 M I 2 /KI solution and a solid to liquid ratio of 10% w/v. Iodine and mercury can be efficiently removed from the leachates using Dowex 1X8 anion exchange resin or reducing agents such as sodium hydrosulphite, allowing the disposal of the obtained solution as non-hazardous industrial wastewater. The extractant CyMe 4 BTBP showed good removal of mercury, with an

Investigations regarding the wet decontamination of fluorescent lamp waste using iodine in potassium iodide solutions

Energy Technology Data Exchange (ETDEWEB)

Tunsu, Cristian, E-mail: tunsu@chalmers.se; Ekberg, Christian; Foreman, Mark; Retegan, Teodora

2015-02-15

Highlights: • A wet-based decontamination process for fluorescent lamp waste is proposed. • Mercury can be leached using iodine in potassium iodide solution. • The efficiency of the process increases with an increase in leachant concentration. • Selective leaching of mercury from rare earth elements is achieved. • Mercury is furthered recovered using ion exchange, reduction or solvent extraction. - Abstract: With the rising popularity of fluorescent lighting, simple and efficient methods for the decontamination of discarded lamps are needed. Due to their mercury content end-of-life fluorescent lamps are classified as hazardous waste, requiring special treatment for disposal. A simple wet-based decontamination process is required, especially for streams where thermal desorption, a commonly used but energy demanding method, cannot be applied. In this study the potential of a wet-based process using iodine in potassium iodide solution was studied for the recovery of mercury from fluorescent lamp waste. The influence of the leaching agent’s concentration and solid/liquid ratio on the decontamination efficiency was investigated. The leaching behaviour of mercury was studied over time, as well as its recovery from the obtained leachates by means of anion exchange, reduction, and solvent extraction. Dissolution of more than 90% of the contained mercury was achieved using 0.025/0.05 M I{sub 2}/KI solution at 21 °C for two hours. The efficiency of the process increased with an increase in leachant concentration. 97.3 ± 0.6% of the mercury contained was dissolved at 21 °C, in two hours, using a 0.25/0.5 M I{sub 2}/KI solution and a solid to liquid ratio of 10% w/v. Iodine and mercury can be efficiently removed from the leachates using Dowex 1X8 anion exchange resin or reducing agents such as sodium hydrosulphite, allowing the disposal of the obtained solution as non-hazardous industrial wastewater. The extractant CyMe{sub 4}BTBP showed good removal of mercury

SODIUM ALUMINOSILICATE FOULING AND CLEANING OF DECONTAMINATED SALT SOLUTION COALESCERS

International Nuclear Information System (INIS)

Poirier, M.; Thomas Peters, T.; Fernando Fondeur, F.; Samuel Fink, S.

2008-01-01

During initial non-radioactive operations at the Modular Caustic Side Solvent Extraction Unit (MCU), the pressure drop across the decontaminated salt solution coalescer reached ∼10 psi while processing ∼1250 gallons of salt solution, indicating possible fouling or plugging of the coalescer. An analysis of the feed solution and the 'plugged coalescer' concluded that the plugging was due to sodium aluminosilicate solids. MCU personnel requested Savannah River National Laboratory (SRNL) to investigate the formation of the sodium aluminosilicate solids (NAS) and the impact of the solids on the decontaminated salt solution coalescer. Researchers performed developmental testing of the cleaning protocols with a bench-scale coalescer container 1-inch long segments of a new coalescer element fouled using simulant solution. In addition, the authors obtained a 'plugged' Decontaminated Salt Solution coalescer from non-radioactive testing in the MCU and cleaned it according to the proposed cleaning procedure. Conclusions from this testing include the following: (1) Testing with the bench-scale coalescer showed an increase in pressure drop from solid particles, but the increase was not as large as observed at MCU. (2) Cleaning the bench-scale coalescer with nitric acid reduced the pressure drop and removed a large amount of solid particles (11 g of bayerite if all aluminum is present in that form or 23 g of sodium aluminosilicate if all silicon is present in that form). (3) Based on analysis of the cleaning solutions from bench-scale test, the 'dirt capacity' of a 40 inch coalescer for the NAS solids tested is calculated as 450-950 grams. (4) Cleaning the full-scale coalescer with nitric acid reduced the pressure drop and removed a large amount of solid particles (60 g of aluminum and 5 g of silicon). (5) Piping holdup in the full-scale coalescer system caused the pH to differ from the target value. Comparable hold-up in the facility could lead to less effective cleaning and

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

Structural characterization of chemical warfare agent degradation products in decontamination solutions with proton band-selective (1)H-(31)P NMR spectroscopy.

Science.gov (United States)

Koskela, Harri; Hakala, Ullastiina; Vanninen, Paula

2010-06-15

Decontamination solutions, which are usually composed of strong alkaline chemicals, are used for efficient detoxification of chemical warfare agents (CWAs). The analysis of CWA degradation products directly in decontamination solutions is challenging due to the nature of the matrix. Furthermore, occasionally an unforeseen degradation pathway can result in degradation products which could be eluded to in standard analyses. Here, we present the results of the application of proton band-selective (1)H-(31)P NMR spectroscopy, i.e., band-selective 1D (1)H-(31)P heteronuclear single quantum coherence (HSQC) and band-selective 2D (1)H-(31)P HSQC-total correlation spectroscopy (TOCSY), for ester side chain characterization of organophosphorus nerve agent degradation products in decontamination solutions. The viability of the approach is demonstrated with a test mixture of typical degradation products of nerve agents sarin, soman, and VX. The proton band-selective (1)H-(31)P NMR spectroscopy is also applied in characterization of unusual degradation products of VX in GDS 2000 solution.

Chemical decontamination method for stainless steel

International Nuclear Information System (INIS)

Yomo, Nobuo; Onuma, Tsutomu; Akimoto, Hidetoshi.

1991-01-01

In a case where an object to be decontaminated has a restricted portion in which the passage of liquids is difficult, decontamination liquids are not circulated effectively upon decontamination for the inner surfaces, and it requires a quite long period of time. In view of the above, through holes are perforated by, for example, a drill in the restricted portion of metal wastes made of stainless steels. Then, they are immersed in a sulfuric acid solution, and further immersed in an aqueous solution in which oxidative metal salts are added to the sulfuric acid. With such procedures, substrates are exposed at the inner circumference of the holes even if they are fine holes, and a local cell is formed between the substrate and an oxidized membranes, which may cause dissolution due to the reduction of the oxidized membranes. Further, since it is possible to discharge bubbles formed upon the solution, even from such fine holes, decontamination can be conducted effectively. (T.M.)

Polysaccharide-thickened aqueous fluoride solutions for rapid destruction of the nerve agent VX. Introducing the opportunity for extensive decontamination scenarios.

Science.gov (United States)

Elias, Shlomi; Saphier, Sigal; Columbus, Ishay; Zafrani, Yossi

2014-01-01

Among the chemical warfare agents, the extremely toxic nerve agent VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothioate) is a target of high importance in the development of decontamination methods, due to its indefinite persistence on common environmental surfaces. Liquid decontaminants are mostly characterized by high corrosivity, usually offer poor coverage, and tend to flow and accumulate in low areas. Therefore, the development of a noncorrosive decontaminant, sufficiently viscous to resist dripping from the contaminated surface, is necessary. In the present paper we studied different polysaccharides-thickened fluoride aqueous solutions as noncorrosive decontaminants for rapid and efficient VX degradation to the nontoxic product EMPA (ethyl methylphosphonic acid). Polysaccharides are environmentally benign, natural, and inexpensive. Other known decontaminants cannot be thickened by polysaccharides, due to the sensitivity of the latter toward basic or oxidizing agents. We found that the efficiency of VX degradation in these viscous solutions in terms of kinetics and product identity is similar to that of KF aqueous solutions. Guar gum (1.5 wt %) with 4 wt % KF was chosen for further evaluation. The benign nature, rheological properties, adhering capabilities to different surfaces, and decontamination from a porous matrix were examined. This formulation showed promising properties for implementation as a spray decontaminant for common and sensitive environmental surfaces.

Decontamination and decommissioning of laboratory solutions enriched uranium (IR-01 b)

International Nuclear Information System (INIS)

Diaz Arocas, P. P.; Sama Colao, J.; Garcia Diaz, A.; Torre Rodriguez, J.; Martinez, A.; Argiles, E.; Garrido Delgado, C.

2010-01-01

Completed actions decontamination and decommissioning of the Laboratory of Enriched Uranium Solutions, attached to the Radioactivity lR-0l CIEMAT, was carried out final radiological control of the laboratory. From the documentation generated proceeded to request modification of the IR-01 installation by closing its laboratory IR-01 b.

Investigations regarding the wet decontamination of fluorescent lamp waste using iodine in potassium iodide solutions.

Science.gov (United States)

Tunsu, Cristian; Ekberg, Christian; Foreman, Mark; Retegan, Teodora

2015-02-01

With the rising popularity of fluorescent lighting, simple and efficient methods for the decontamination of discarded lamps are needed. Due to their mercury content end-of-life fluorescent lamps are classified as hazardous waste, requiring special treatment for disposal. A simple wet-based decontamination process is required, especially for streams where thermal desorption, a commonly used but energy demanding method, cannot be applied. In this study the potential of a wet-based process using iodine in potassium iodide solution was studied for the recovery of mercury from fluorescent lamp waste. The influence of the leaching agent's concentration and solid/liquid ratio on the decontamination efficiency was investigated. The leaching behaviour of mercury was studied over time, as well as its recovery from the obtained leachates by means of anion exchange, reduction, and solvent extraction. Dissolution of more than 90% of the contained mercury was achieved using 0.025/0.05 M I2/KI solution at 21 °C for two hours. The efficiency of the process increased with an increase in leachant concentration. 97.3 ± 0.6% of the mercury contained was dissolved at 21 °C, in two hours, using a 0.25/0.5M I2/KI solution and a solid to liquid ratio of 10% w/v. Iodine and mercury can be efficiently removed from the leachates using Dowex 1X8 anion exchange resin or reducing agents such as sodium hydrosulphite, allowing the disposal of the obtained solution as non-hazardous industrial wastewater. The extractant CyMe4BTBP showed good removal of mercury, with an extraction efficiency of 97.5 ± 0.7% being achieved in a single stage. Better removal of mercury was achieved in a single stage using the extractants Cyanex 302 and Cyanex 923 in kerosene, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bioremediation of 60Co from simulated spent decontamination solutions

International Nuclear Information System (INIS)

Rashmi, K.; Naga Sowjanya, T.; Maruthi Mohan, P.; Balaji, V.; Venkateswaran, G.

2004-01-01

Bioremediation of 60 Co from simulated spent decontamination solutions by utilizing different biomass of (Neurospora crassa, Trichoderma viridae, Mucor recemosus, Rhizopus chinensis, Penicillium citrinum, Aspergillus niger and, Aspergillus flavus) fungi is reported. Various fungal species were screened to evaluate their potential for removing cobalt from very low concentrations (0.03-0.16 μM) in presence of a high background of iron (9.33 mM) and nickel (0.93 mM) complexed with EDTA (10.3 mM). The different fungal isolates employed in this study showed a pickup of cobalt in the range 8-500 ng/g of dry biomass. The [Fe]/[Co] and [Ni]/[Co] ratios in the solutions before and after exposure to the fungi were also determined. At micromolar level the cobalt pickup by many fungi especially the mutants of N. crassa is seen to be proportional to the initial cobalt concentration taken in the solution. However, R. chinensis exhibits a low but iron concentration dependent cobalt pickup. Prior saturating the fungi with excess of iron during their growth showed the presence of selective cobalt pickup sites. The existence of cobalt specific sorption sites is shown by a model experiment with R. chinensis wherein at a constant cobalt concentration (0.034 μM) and varying iron concentrations so as to yield [Fe/Co] initial ratios in solution of 10, 100, 1000 and 287 000 have all yielded a definite Co pickup capacity in the range 8-47 ng/g. The presence of Cr(III)EDTA (3 mM) in solution along with complexed Fe and Ni has not influenced the cobalt removal. The significant feature of this study is that even when cobalt is present in trace level (sub-micromolar) in a matrix of high concentration (millimolar levels) of iron, nickel and chromium, a situation typically encountered in spent decontamination solutions arising from stainless steel based primary systems of nuclear reactors, a number of fungi studied in this work showed a good sensitivity for cobalt pickup

Experiment on electrolysis decontamination of stainless steel pipes

International Nuclear Information System (INIS)

Wang Dongwen; Dou Tianjun; Zhao Yujie

2004-01-01

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

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.)

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

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...

Chemical decontamination method for radioactive metal waste

International Nuclear Information System (INIS)

Onuma, Tsutomu; Tanaka, Akio; Shibuya, Sadao.

1991-01-01

When contaminants mainly composed of copper remained on the surface of stainless steel wastes sent from an electrolytic reduction as a first step are chemically decontaminated, metal wastes are discriminated to carbon steel wastes and stainless steel wastes. Then, the carbon steel wastes are applied only with the first step of immersing in a sulfuric acid solution, and stainless steel wastes are applied with a first step of immersing into a sulfuric acid solution for electrolytic reduction for a predetermined period of time and a second step of immersing into a liquid in which an oxidative metal salt is added to sulfuric acid. The decontamination liquid which is used for immersing the stainless steel wastes in the second step and the oxidation force of which is lowered is used as the sulfuric acid solution in the first step for the carbon steel wastes. In view of the above, the decontamination liquid of the second step can be utilized most effectively, enabling to greatly decrease the secondary wastes and to improve decontamination efficiency. (T.M.)

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.)

Radioactive contamination of protective clothes made of textile and their decontamination in aqueous solutions

International Nuclear Information System (INIS)

Fukumori, D.T.

1989-01-01

This dissertation deals with the radioactive contamination, its prevention, control and decontamination, related to protective clothing made of textile and usually weared in normal working conditions, within the installations where radioactive materials are handled or processed, especially as unsealed sources. The features of textile materials and contaminants, contamination mechanisms, risks related to contaminated clothes, planning of working areas, monitoring and surface contamination limits are described. Concerning to decontamination, the reagents, their action mechanisms and methods of efficiency evaluation are emphasized. The selected reagents were experimentally tested and their efficiencies in decontaminating cotton cloth samples, contaminated with uranyl nitrate solution, were evaluated by means of counting rate determined with a Geiger-Muller provided counting system. In this way, complexing agents, surfactants and commercial cleanning products were tested. The results were analysed and interpreted considering statistical, radiochemical and Radiation Protection aspects. Both, the radiactive contamination and decontamination of protective clothes are extensive matters and they still could be developed and improved; thus, many suggestions were presented as further studies. (author) [pt

Bioremediation of {sup 60}Co from simulated spent decontamination solutions

Energy Technology Data Exchange (ETDEWEB)

Rashmi, K.; Naga Sowjanya, T.; Maruthi Mohan, P.; Balaji, V.; Venkateswaran, G

2004-07-26

Bioremediation of {sup 60}Co from simulated spent decontamination solutions by utilizing different biomass of (Neurospora crassa, Trichoderma viridae, Mucor recemosus, Rhizopus chinensis, Penicillium citrinum, Aspergillus niger and, Aspergillus flavus) fungi is reported. Various fungal species were screened to evaluate their potential for removing cobalt from very low concentrations (0.03-0.16 {mu}M) in presence of a high background of iron (9.33 mM) and nickel (0.93 mM) complexed with EDTA (10.3 mM). The different fungal isolates employed in this study showed a pickup of cobalt in the range 8-500 ng/g of dry biomass. The [Fe]/[Co] and [Ni]/[Co] ratios in the solutions before and after exposure to the fungi were also determined. At micromolar level the cobalt pickup by many fungi especially the mutants of N. crassa is seen to be proportional to the initial cobalt concentration taken in the solution. However, R. chinensis exhibits a low but iron concentration dependent cobalt pickup. Prior saturating the fungi with excess of iron during their growth showed the presence of selective cobalt pickup sites. The existence of cobalt specific sorption sites is shown by a model experiment with R. chinensis wherein at a constant cobalt concentration (0.034 {mu}M) and varying iron concentrations so as to yield [Fe/Co]{sub initial} ratios in solution of 10, 100, 1000 and 287 000 have all yielded a definite Co pickup capacity in the range 8-47 ng/g. The presence of Cr(III)EDTA (3 mM) in solution along with complexed Fe and Ni has not influenced the cobalt removal. The significant feature of this study is that even when cobalt is present in trace level (sub-micromolar) in a matrix of high concentration (millimolar levels) of iron, nickel and chromium, a situation typically encountered in spent decontamination solutions arising from stainless steel based primary systems of nuclear reactors, a number of fungi studied in this work showed a good sensitivity for cobalt pickup.

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

Decontaminating lead bricks and shielding

International Nuclear Information System (INIS)

Lussiez, G.W.

1993-01-01

Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium trader pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of contaminated lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling

Actual situation on the field of decontamination in Slovak and Czech NPPs

International Nuclear Information System (INIS)

Prazska, M.; Rezbarik, J.; Solcanyi, M.; Trtilek, R.

2002-01-01

Many decontamination methods for various applications have proved to provide good results at Slovak and Czech nuclear power plants. A number of mechanical, chemical and electrochemical decontamination methods are available. The selection of a suitable method and decontamination technology is the result of a multicriterial optimization. The plants use the decontamination procedures described in the design documentation. New decontamination procedures aiming to minimize secondary radioactive wastes and corrosion attack on the basic material are being developed. No standardized qualification process, however, exists for such new procedures and large efforts are to be made to introduce them into practice. Methods for decommissioning purposes are based on static or dynamic application of decontamination solutions such as a mixture of formic acid + complexing agent + corrosion inhibitor or dilute HNO 3 . A process consisting in treatment in a solution containing formic acid + complexing agent + corrosion inhibitor (total concentration 3 - 4 mass %, temperature 30 - 35 deg C), whose effect is enhanced by the application of ultrasound (0.4 - 0.5 W per cm 2 decontaminated area) in a specially designed bath, is recommended for segmented metallic parts, which can be then released into the environment and recycled. Electrochemical decontamination in a bath is another efficient decontamination method to achieve unrestricted release of the material into the environment. Efficient decontamination of various highly contaminated materials can be attained by using an electrolyte solution based on citric acid (100 g.dm -3 ) + nitric acid (20 g.dm -3 ) + NH 4 NO 3 (50 g.dm -3 ) and applying a current density of 100 - 200 mA.cm -2 , electrolyte temperature 25 - 50 deg C, with one decontamination cycle period not exceeding 30 minutes. The best results are obtained by electrolysis followed by mechanical treatment using ultrasound. Electrochemical decontamination using a spraying

Impact of decontamination on LWR radioactive waste treatment systems

International Nuclear Information System (INIS)

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

1979-01-01

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

Decontaminating lead bricks and shielding

International Nuclear Information System (INIS)

Lussiez, G.

1994-01-01

Lead used for shielding is often surface contaminated with radioisotopes and is therefore a RCRA D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Laboratory decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 50 tons and likely to grow substantially of planned decommissioning operations. Thus lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for contaminated lead is removing the superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 40 psig rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a scaled-off area. The slurry of abrasive and particles of lead falls through a floor and is collected in a sump. A pump sends the slurry mixture back to the spray gun, creating a continuous process. The process generates small volumes of lead slurry that can be solidified and, because it passes the TCLP, is not a mixed waste. The decontaminated lead can be released for recycling

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

Prosopis juliflora--a green solution to decontaminate heavy metal (Cu and Cd) contaminated soils.

Science.gov (United States)

Senthilkumar, P; Prince, W S P M; Sivakumar, S; Subbhuraam, C V

2005-09-01

Soil and plant samples (root and shoot) of Prosopis juliflora were collected in the vicinity of metal based foundry units in Coimbatore and assessed for their heavy metal content (Cu and Cd) to ascertain the use of P. juliflora as a green solution to decontaminate soils contaminated with Cu and Cd. The results showed that Cu and Cd content was much higher in plant components compared to their extractable level in the soil. Furthermore, there exist a strong correlation between the distance of the sources of industrial units and accumulation of heavy metals in plants. Accumulation of Cd in roots is comparatively higher than that of shoots. However, in case of Cu no such clear trend is seen. Considering the accumulation efficiency and tolerance of P. juliflora to Cd and Cu, this plant can be explored further for the decontamination of metal polluted soils. On the other hand, in view of heavy metal accumulate the practice of providing foliage and pods as fodder for live stock should be avoided.

Salt decontamination demonstration test results

International Nuclear Information System (INIS)

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

1983-06-01

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

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.

Precipitation process for supernate decontamination

International Nuclear Information System (INIS)

Lee, L.M.; Kilpatrick, L.L.

1982-11-01

A precipitation and adsorption process has been developed to remove cesium, strontium, and plutonium from water-soluble, high-level radioactive waste. An existing waste tank serves as the reaction vessel and the process begins with the addition of a solution of sodium tetraphenylborate and a slurry of sodium titanate to the contained waste salt solution. Sodium tetraphenylborate precipitates the cesium and sodium titanate adsorbs the strontium and plutonium. The precipitate/adsorbate is then separated from the decontaminated salt solution by crossflow filtration. This new process offers significant capital savings over an earlier ion exchange process for salt decontamination. Chemical and small-scale engineering studies with actual waste are reported. The effect of many variables on the decontamination factors and filter performance are defined

Application of Ultrasonic for Decontamination of Contaminated Soil - 13142

International Nuclear Information System (INIS)

Vasilyev, A.P.; Lebedev, N.M.; Savkin, A.E.

2013-01-01

The trials of soil decontamination were carried out with the help of a pilot ultrasonic installation in different modes. The installation included a decontamination bath equipped with ultrasonic sources, a precipitator for solution purification from small particles (less than 80 micrometer), sorption filter for solution purification from radionuclides washing out from soil, a tank for decontamination solution, a pump for decontamination solution supply. The trials were carried out on artificially contaminated sand with specific activity of 4.5 10 5 Bk/kg and really contaminated soil from Russian Scientific Center 'Kurchatovsky Institute' (RSC'KI') with specific activity of 2.9 10 4 Bk/kg. It was established that application of ultrasonic intensify the process of soil reagent decontamination and increase its efficiency. The decontamination factor for the artificially contaminated soil was ∼200 and for soil from RSC'KI' ∼30. The flow-sheet diagram has been developed for the new installation as well as determined the main technological characteristics of the equipment. (authors)

A study on dry decontamination using ion exchange polymer

International Nuclear Information System (INIS)

Jung, Ki Jung; Ahn, Byung Gil

1997-12-01

Through the project of A study on dry decontamination using ion exchange polymer , the followings were investigated. 1. Highly probable decontamination technologies for the decontamination were investigated. 2. Development of gel type decontamination agent using ion-exchange resin powder (mixed type) as an ion exchanger. 3. Manufacturing of contaminated specimens (5 kinds) with Cs-137 solution and dust / Cs-137 solution. 4. Decontamination performance evaluation of the manufactured agent. 5. Analysis of composition (XRF) and the structure of surface of specimens (optic micrography). (author). 20 refs., 11 figs

Presolidification treatment of decontamination wastes

International Nuclear Information System (INIS)

Habayeb, M.A.

1982-02-01

Unsatisfactory leaching performance of several solidified decontamination solutions indicated a need for presolidification treatments to reduce the water sensitivity of the active chemicals. Chemical treatments examined in this work include pH adjustment, precipitation and oxidation-reduction reactions. The reactions involved in these treatments are discussed. The most suitable presolidification treatment for each decontamination solution has been identified. Further research is needed to test the effectivenss of these treatments

A study on Cs decontamination characterisitcs of radioactively contaminated soil using soil washing

International Nuclear Information System (INIS)

Lee, K. W.; Son, J. K.; Kim, K. D.; Kim, H. S.; Choi, Y. C.; Kang, K. D.; Sin, S. W.

2002-01-01

To decontaminate radioactively contaminated soil, various characteristics of soil were investigated, and applied for the best decontamination method and requirement. The effects of several conditions such as decontamination solutions, temperature and time was investigated. Na 2 CO 3 , which is not toxic to environment, was used as primary decontamination solution. The efficiency of decontamination was increased approximately 9% when decontamination time was increased from 30 min to 120 min. The efficiency of decontamination was increased approximately 10% when decontamination temperature was increased from 25 .deg. C to 70 .deg. C. The efficiency of decontamination was increased approximately 7% when the ratio of decontamination solution and soil was increased from 5:1 to 10:1

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)

Application of Ultrasonic for Decontamination of Contaminated Soil - 13142

Energy Technology Data Exchange (ETDEWEB)

Vasilyev, A.P. [JRC ' NIKIET' , Moscow (Russian Federation); Lebedev, N.M. [LLC ' Aleksandra-Plus' , Vologda (Russian Federation); Savkin, A.E. [SUE SIA ' Radon' , Moscow (Russian Federation)

2013-07-01

The trials of soil decontamination were carried out with the help of a pilot ultrasonic installation in different modes. The installation included a decontamination bath equipped with ultrasonic sources, a precipitator for solution purification from small particles (less than 80 micrometer), sorption filter for solution purification from radionuclides washing out from soil, a tank for decontamination solution, a pump for decontamination solution supply. The trials were carried out on artificially contaminated sand with specific activity of 4.5 10{sup 5} Bk/kg and really contaminated soil from Russian Scientific Center 'Kurchatovsky Institute' (RSC'KI') with specific activity of 2.9 10{sup 4} Bk/kg. It was established that application of ultrasonic intensify the process of soil reagent decontamination and increase its efficiency. The decontamination factor for the artificially contaminated soil was ∼200 and for soil from RSC'KI' ∼30. The flow-sheet diagram has been developed for the new installation as well as determined the main technological characteristics of the equipment. (authors)

Model decontamination of PVC flooring specimens by wet method

International Nuclear Information System (INIS)

Severa, J.; Knajfl, J.; Bar, J.

1981-01-01

PVC flooring samples of 29 mm in diameter were used in experiments. The samples were degreased. Tested were the dependence of the degree of contamination on the duration of contact with the contaminant and the efficacy of decontamination by wiping with tampons and immersing in solutions. A mixture of fission products of 80 kBq/ml in specific activity was used for contamination. Higher decontamination efficacy was achieved by immersing the samples in decontamination solutions. Water was found to be the least efficacious medium; a high degree was only attained in the case when decontamination was effected within 1 minute after contamination. The highest decontamination values were achieved using solutions containing a chelating agent and a surfactant. The most efficacious solutions contained 0.5% of citric acid and 0.5% of detergents which are very potent at a concentration as low as 2 g/l. (J.P.)

Chemical decontamination of stainless steel

International Nuclear Information System (INIS)

Onuma, Tsutomu; Akimoto, Hidetoshi

1991-01-01

The present invention concerns a method for chemical decontamination of radioactive metal waste materials contaminated with radioactive materials on the surface, generated in radioactive materials-handling facilities. The invention is comprised of a method of chemical decontamination of stainless steel, characterized by comprising a first process of immersing a stainless steel-based metal waste material contaminated by radioactive materials on the surface in a sulfuric acid solution and second process of immersing in an aqueous solution of sulfuric acid and oxidizing metal salt, in which a portion of the surface of the stainless steel to be decontaminated is polished mechanically to expose a portion of the base material before the above first and second processes. 1 figs., 2 tabs

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.)

Development of decontamination technology for the decommissioned Bohunice A-1 nuclear power plant

International Nuclear Information System (INIS)

Krejci, F.; Majersky, D.; Solcanyi, M.; Sekely, S.; Kucharik, D.

1991-01-01

The main results of investigation into the decontamination technology for the equipment and buildings of the decommissioned A-1 nuclear power plant, achieved by the Nuclear Power Plants Research Institute in Trnava over the 1988-1990 period, are summarized. Mobile decontamination and recirculation equipment has been developed for pre-disassembling decontamination. A solution containing formic acid (19 g/l), EDTA-Na 4 (6 g/l) and thiourea (0.5 g/l) was used for decontamination of low-alloy steels; for materials from the steam generators and turbo-compressors, the decontamination factor (DF) of this solution was 30 to 150 per decontamination cycle. For high-alloy steels, a two-stage process comprising the use of an oxidation solution and a reduction solution appeared suitable. The oxidation solution contained potassium permanganate (0.6 g/l) and nitric acid (0.4 g/l), whereas the reduction solution, viz. Citrox 21, contained citric acid (0.5 g/l), oxalic acid (1.0 g/l) and EDTA-NA 4 (2.5 g/l). The DF is 10 to 50 in one oxidation-reduction cycle and 50-100 in two cycles. For the post-disassembling chemical decontamination, the contaminated material was cut into pieces 70 to 80 cm long, freed from grease and decontaminated chemically by submerging in the solution while applying treatment by ultrasound. A technology of electrochemical decontamination has also been developed. It appeared particularly suitable for structural materials of the primary coolant circuit comprising austenitic stainless steels and low-alloy steels after pre-disassembling chemical decontamination with remainders of the corrosion layer, and for structural materials of the secondary coolant circuit after chemical post-disassembling decontamination. Research in the field of decontamination of the building parts and of the outer surfaces of the structural materials concentrated mainly on the use of decontamination foams. Foaming solutions have been developed for the decontamination of PESL floors and

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)

Decontamination of process equipment using recyclable chelating solvent

International Nuclear Information System (INIS)

Jevec, J.; Lenore, C.; Ulbricht, S.

1995-01-01

The Department of Energy (DOE) is now faced with the task of meeting decontamination and decommissioning obligations at numerous facilities by the year 2019. Due to the tremendous volume of material involved, innovative decontamination technologies are being sought that can reduce the volumes of contaminated waste materials and secondary wastes requiring disposal. With sufficient decontamination, some of the material from DOE facilities could be released as scrap into the commercial sector for recycle, thereby reducing the volume of radioactive waste requiring disposal. Although recycling may initially prove to be more costly than current disposal practices, rapidly increasing disposal costs are expected to make recycling more and more cost effective. Additionally, recycling is now perceived as the ethical choice in a world where the consequences of replacing resources and throwing away reusable materials are impacting the well-being of the environment. Current approaches to the decontamination of metals most often involve one of four basic process types: (1) chemical, (2) manual and mechanical, (3) electrochemical, and (4) ultrasonic. open-quotes Hardclose quotes chemical decontamination solutions, capable of achieving decontamination factors (Df's) of 50 to 100, generally involve reagent concentrations in excess of 5%, tend to physically degrade the surface treated, and generate relatively large volumes of secondary waste. open-quotes Softclose quotes chemical decontamination solutions, capable of achieving Df's of 5 to 10, normally consist of reagents at concentrations of 0.1 to 1%, generally leave treated surfaces in a usable condition, and generate relatively low secondary waste volumes. Under contract to the Department of Energy, the Babcock ampersand Wilcox Company is developing a chemical decontamination process using chelating agents to remove uranium compounds and other actinide species from process equipment

OPO fabric decontamination

International Nuclear Information System (INIS)

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

1978-01-01

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

Decontamination experiments for stainless steel decommissioned components

International Nuclear Information System (INIS)

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

2001-01-01

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

Decontamination of Metal Ions in Soil by Supercritical CO2 Extraction with Crown Ether

Energy Technology Data Exchange (ETDEWEB)

Park, Jihe; Park, Kwangheon [Kyunghee University, Yongin (Korea, Republic of)

2015-05-15

Previous decontamination methods have shortcomings in that they produce additional waste due to the usage of solutions with chemical toxicity. Hence, demand is strong for new decontamination methods that can guarantee effective decontamination while decreasing the chemical solution. In particular, methods using supercritical CO2 as a means of decontamination are currently in progress. This study examines the method of decontaminating metallic ions inside soil using supercritical CO2. This paper examined the effects of extracting metallic ions inside soil using supercritical CO2 and crown ether as the ligand. It was confirmed that extraction effectiveness increases following greater usage of ligand and co-ligand, with a drastic increase in extraction effectiveness when using extracts over a certain dose. Moreover, it was shown that if the usage of ligand and additive decreases, the extraction ratio also decreases.

Decontamination of Metal Ions in Soil by Supercritical CO2 Extraction with Crown Ether

International Nuclear Information System (INIS)

Park, Jihe; Park, Kwangheon

2015-01-01

Previous decontamination methods have shortcomings in that they produce additional waste due to the usage of solutions with chemical toxicity. Hence, demand is strong for new decontamination methods that can guarantee effective decontamination while decreasing the chemical solution. In particular, methods using supercritical CO2 as a means of decontamination are currently in progress. This study examines the method of decontaminating metallic ions inside soil using supercritical CO2. This paper examined the effects of extracting metallic ions inside soil using supercritical CO2 and crown ether as the ligand. It was confirmed that extraction effectiveness increases following greater usage of ligand and co-ligand, with a drastic increase in extraction effectiveness when using extracts over a certain dose. Moreover, it was shown that if the usage of ligand and additive decreases, the extraction ratio also decreases

Studies on residue-free decontaminants for chemical warfare agents.

Science.gov (United States)

Wagner, George W

2015-03-17

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

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.)

Melting decontamination and recycling of radioactive polluted metals from uranium mining and metallurgy

International Nuclear Information System (INIS)

Chen Anquan

2011-01-01

Melting method is a primary method used for decontamination of radioactive polluted metal from uranium mining and metallurgy. The decontamination mechanism of the method, the way selection and its features are introduced. Taking the ten year's work of CNNC Uranium Mining and Metallurgy Radioactive Polluted Metal Melting Processing Center as example, the effects of processing radioactive polluted metals by smelting method are discussed. The surface pollution levels of radioactive polluted metal from uranium mining and metallurgy decreased from 4-48 Bq/cm 2 before decontamination to 0.004-0.016 Bq/cm 2 after decontamination, and the specific activity of its metal is less than 1 Bq/g, which is below the solution control level proposed by IAEARS-G1.7 'the application of the concepts of exclusion, immunity and solution control'. The metals after decontamination can be recycled by producing tooth plate and bucket teeth of excavator used in mines. (authors)

Decontamination of Belarus research reactor installation by strippable coatings

International Nuclear Information System (INIS)

Voronik, N.I.; Shatilo, N.N.

2002-01-01

The goal of this study was to develop new strippable coatings using water-based solutions of polyvinyl alcohol and active additives for decontamination of research reactor equipment. The employment of strippable coatings makes it possible to minimize the quantity of liquid radioactive waste. The selection of strippable decontaminating coatings was carried out on the basis of general requirements to decontaminating solutions: successfully dissolve corrosion deposits; ensure the desorption of radionuclides from the surfaces and the absence of resorption; introduce minimal corrosion effect of construction materials; to be relatively cheap and available in reagents. The decontaminating ability and adhesion properties of these coatings depending on metal and deposit sorts were investigated. Research on the chemical stability of solid wastes was carried out. The data obtained were the base for recommendations on waste management procedure for used films and pastes. A full-scale case-study analysis was performed for comparing strippable coatings with decontaminating solutions. (author)

Surface decontamination using dry ice snow

International Nuclear Information System (INIS)

Ryu, Jungdong; Park, Kwangheon; Lee, Bumsik; Kim Yangeun

1999-01-01

An adjustable nozzle for controlling the size of dry ice snow was developed. The converging/diverging nozzle can control the size of snows from sub-microns to 10 micron size. Using the nozzle, a surface decontamination device was made. The removal mechanisms of surface contaminants are mechanical impact, partial dissolving and evaporation process, and viscous flow. A heat supply system is added for the prevention of surface ice layer formation. The cleaning power is slightly dependent on the size of snow. Small snows are the better in viscous flow cleaning, while large snows are slightly better in dissolving and sublimation process. Human oils like fingerprints on glass were easy to remove. Decontamination ability was tested using a contaminated pump-housing surface. About 40 to 80% of radioactivity was removed. This device is effective in surface-decontamination of any electrical devices like detector, controllers which cannot be cleaned in aqueous solution. (author)

The ultrasonic copper and brass decontamination study; Etude de la decontamination du cuivre et des laitons en presence d'ultra-sons

Energy Technology Data Exchange (ETDEWEB)

Courtault, J; Kerdelleau, J de; Mestre, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

The use of ultra-sounds as a decontamination technic does not bring an absolute solution. As a function of the materials it seemed necessary to find what was the optimum conditions for using the ultra-sounds and to define not only the ultra-sonic factors but also the chemical solutions which bring some appreciable decontamination factors without bringing any too important corrosion processus. This report gives the results of this study applied to copper and brass. This study allowed to select some effective treatment baths on the two types of contamination: plutonium and fission products. (authors) [French] L'emploi des ultra-sons comme technique de decontamination n'amene pas une solution absolue. Il est apparu necessaire de rechercher en fonction de la nature du materiau a decontaminer quelles etaient les conditions optimales d'utilisation des ultra-sons et de definir alors non seulement les facteurs ultrasoniques mais encore les solutions chimiques qui apportent des facteurs de decontamination appreciables sans amener des phenomenes de corrosion trop importants. Ce rapport donne les resultats de cette etude appliquee au cuivre et aux laitons. Cette etude a permis de selectionner des bains de traitement efficaces dans les deux cas de contamination: plutonium et produits de fission. (auteurs)

New decontamination processes for liquid effluents and solid materials

International Nuclear Information System (INIS)

Faure, S.

2008-01-01

New decontamination processes are being studied in order to protect workers and to reduce strongly the quantity of secondary wastes produced. 2 decontamination processes for liquid nuclear wastes are under studies. First, the coprecipitation process whose improvement is based on a better control of the 2 coupled mechanisms involved in the process: the formation of adsorbent particles and the uptake of radionuclides. Secondly, the column process whose development focuses on new materials that can be used to absorb cesium in a reversible way. 3 new decontamination processes for solid materials are being developed. First, processes using drying gels are under investigation in order to treat materials like lead, aluminium, iron and stainless steel. Real decontamination of hot cells by drying gel process has been performed and a decontamination factor between 16 and 25 has been obtained on stainless steels. Secondly, new foam decontamination processes have been developed, they are based on the use of new foams stabilized by biodegradable non-ionic surfactants: alkyl-poly-glucosides and viscofiers or nano-particles. The aim is to increase the foam lifetime. Thirdly, new surfactants in solution decontamination processes have been studied, the aim is to decontaminate through degreasing by using acidic surfactants. The idea is to combine emulsification and wetting power. (A.C.)

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.

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)

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.)

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

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.

Study to produce polymer gel for decontamination on the surface of steel, ceramic, plastic, glass

International Nuclear Information System (INIS)

Pham Quynh Luong; Nguyen Van Chinh; Nguyen Thu Trang; Nguyen An Thai; Nguyen Dinh Lam

2015-01-01

Strippable polymer coating is one of the methods for effective surface decontamination. A gel solution of a water soluble polymer, preferably polyvinyl alcohol (PVA) and chelating agent is applied to remove radioisotopes of Cs"1"3"7, Sr"8"5, I"1"3"1, P"3"2 and Tc"9"9"m on the surface of stainless steel, mild steel, ceramic, PVC plastic. After cleaning is completed, the gel solution is dried, formed a strong thin film, which is easily peeled off from a contaminated surface and can be disposed of as radioactive solid waste. Decontamination efficient of this gel polymer for radioisotopes have been studied on the surfaces and compared with Decongel 1101. The influence of decontamination agents, activity, film thickness to decontamination factor have been studied. The infrared spectrophotometer has been conducted to study mechanism of the decontamination for this radioisotope. (author)

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

The characteristics of per-fluorocarbon compounds (PFC) are colorless, non-toxic, easily vaporized and nonflammable. Also, some of them are liquids of a high density, low surface tension, low latent heat and low specific heat. These particular chemical and physical properties of fluoro-organic compounds permit their use in very different fields such as electronics, medicine, tribology, nuclear and material science. The Sonatol process was developed under a contract with the DOE. The Sonatol process uses an ultrasonic agitation in a PFC solution that contains a fluorinated surfactant to remove radioactive particles from surfaces. Filtering the suspended particles allows the solutions to be reused indefinitely. They applied the Sonatol process to the decontamination of a heterogeneous legacy Pu-238 waste that exhibited an excessive hydrogen gas generation, which prevents a transportation of such a waste to a Waste Isolation Pilot Plant. Korea Atomic Energy Research Institute (KAERI) is developing dry decontamination technologies applicable to a decontamination of a highly radioactive area loosely contaminated with radioactive particles. This contamination has occurred as a result of an examination of a post-irradiated material or the development of the DUPIC process. The dry decontamination technologies developed are the carbon dioxide pellet spray method and the PFC spray method. As a part of the project, PFC ultrasonic decontamination technology was developed in 2004. The PFC spray decontamination method which is based on the test results of the PFC ultrasonic method has been under development since 2005. The developed PFC spray decontamination equipment consists of four modules (spray, collection, filtration and distillation). Vacuum cup of the collection module gathers the contaminated PFC solution, then the solution is moved to the filtration module and it is recycled. After a multiple recycling of the spent PFC solution, it is purified in the distillation

Decontamination of radionuclides on construction materials

International Nuclear Information System (INIS)

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

2013-01-01

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

Decontamination of the equipment in the acids recovery cell in the fuel reprocessing plant

International Nuclear Information System (INIS)

Maki, Akira; Kusano, Toshitsugu

1985-01-01

In the cell where an acids recovery evaporator tank is set, there are also installed its associated components such as the solution feed system and a receiving tank. When maintenance etc. are to be conducted within the cell, the equipment etc. must be decontaminated to eliminate the personnel exposure. In the acid recovery process, there is involved ruthenium-106, for which the decontamination reagents must be selected. As such, the decontamination proceeded first with nitric acid + sodium hydroxide solution and then alkaline potassium permanganate solution + nitric acid + EDTA.2Na. Decontamination was made twice in 1979 and 1983. Described are the selection of decontamination reagents and decontamination works performed in the acids recovery cell. (Mori, K.)

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.

Development of practical decontamination process for the removal of uranium from gravel.

Science.gov (United States)

Kim, Ilgook; Kim, Gye-Nam; Kim, Seung-Soo; Choi, Jong-Won

2018-01-01

In this study, a practical decontamination process was developed to remove uranium from gravel using a soil washing method. The effects of critical parameters including particle size, H 2 SO 4 concentration, temperature, and reaction time on uranium removal were evaluated. The optimal condition for two-stage washing of gravel was found to be particle size of 1-2 mm, 1.0 M H 2 SO 4 , temperature of 60°C, and reaction time of 3 h, which satisfied the required uranium concentration for self-disposal. Furthermore, most of the extracted uranium was removed from the waste solution by precipitation, implying that the treated solution can be reused as washing solution. These results clearly demonstrated that our proposed process can be indeed a practical technique to decontaminate uranium-polluted gravel.

Method of chemical decontamination of stainless steel

International Nuclear Information System (INIS)

Onuma, Tsutomu; Akimoto, Hidetoshi.

1989-01-01

The present invention concerns a decontamination method of chemically decontaminating radioactive metal wastes of passivated stainless steels to a radioactivity level identical with usual wastes, in which the amount of oxidizable metal salts used is decreased. Metal wastes of stainless steels contaminated at their surface with radioactive materials are immersed in a sulfuric acid solution. In this case, a voltage is applied for a certain period of time so that the potential of the stainless steels comes to an active region. Then, oxidizable metal salt (tetravalent cerium) is added into the sulfuric acid solution. According to this method, since most of radioactive materials are removed in the immersing step to the sulfuric acid solution, the amount of the tetravalent cerium used is as less as 1/700 and the decontamination time is as short as 1/4 as compared with those in the conventional method. (K.M.)

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.)

Decontamination of some urban surfaces

International Nuclear Information System (INIS)

Thornton, E.W.

1988-04-01

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

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)

Precipitation-adsorption process for the decontamination of nuclear waste supernates

Science.gov (United States)

Lee, L.M.; Kilpatrick, L.L.

1982-05-19

High-level nuclear waste supernate is decontaminated of cesium by precipitation of the cesium and potassium with sodium tetraphenyl boron. Simultaneously, strontium-90 is removed from the waste supernate sorption of insoluble sodium titanate. The waste solution is then filtered to separate the solution decontaminated of cesium and strontium.

Decontaminated salt disposal as saltcrete in a landfill. Technical data summary

International Nuclear Information System (INIS)

1982-01-01

This technical data summary presents a reference process for immobilizing decontaminated salt solution from the 200-Area waste storage tanks with cement, and disposing of the final waste material (called saltcrete) by burial in trenches. The saltcrete will be protected from leaching by clay and will be placed at least 3 meters above the historic high water table and beneath at least 5 meters of soil overburden. The decontaminated salt solution is a waste material which remains after the bulk of the radionuclides have been removed from waste tank supernate. This removal is effected by contacting the waste supernate with sodium tetraphenyl boron (Na-TPB) and sodium titanate (NaTi 2 O 5 H). These materials remove (by precipitation) most of the 137 Cs and 90 Sr as well as many other radioactive and non-radioactive elements. These precipitates, along with many other sludges which reside in the HLW tanks will be incorporated in borosilicate glass for eventual disposal in a geologic repository. An ion exchange process will also be used for removal of 99 Tc. The decontaminated salt solution has sufficiently low levels of radioactivity that it can be disposed of on-site. The scope of the curent effort is to describe a process for blending decontaminated salt solution with cement to form a saltcrete product which has dimensional stability and relatively low leachability. The process is to be capable of solidifying 10 gpm of supernate. About 100 million gallons of salt solution is to be solidified

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

Chemical decontamination of metals

International Nuclear Information System (INIS)

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

1979-10-01

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

Development and assessment of two decontamination processes: closed electropolishing system for decontamination of underwater surfaces -vibratory decontamination with abrasives

International Nuclear Information System (INIS)

Benavides, E.; Fajardo, M.

1992-01-01

Two decontamination processes have been developed to decontaminate the stainless steel components of nuclear power plants. The first process uses an underwater closed electropolishing system for the decontamination of large stainless steel surfaces in flooded systems without loss of electrolyte. Large underwater contaminated areas can be treated with an electropolishing head covering an area of 2 m 2 in one step. The decontamination factors achieved with this technique range between 100 and 1000. The second process consists in the decontamination of nuclear components using vibratory equipment with self-cleaning abrasives generating a minimum quantity of waste. This technique may reach contamination factors similar to those obtained with other abrasive methods (brush abrasion, abrasive blasting, etc...). The obtained decontamination factors range between 5 and 50. Only a small quantity of waste is generated, which is treated and reduced in volume by filtration and evaporation

Decontamination liquid waste processing method

International Nuclear Information System (INIS)

Enda, Masami; Hosaka, Katsumi.

1992-01-01

Liquid wastes after electrolytic reduction are caused to flow through an anionic exchange membrane in a diffusion dialysis step, and liquid wastes and dialyzed water are passed in a countercurrent manner. Since acids in the liquid wastes transfer on the side of the dialyzed water due to the difference of concentration between the liquid wastes and the dialyzed water, acids can be easily recovered from the liquid wastes. If the acid-removed liquid wastes are put to electrodeposition in an electrodepositing step, the electrodepositing reactions between radioactive materials such as Co ion, Mn ion and leached metals such as Fe ions and Cr ions are caused preferentially to hydrogen generation reaction on a metal deposition cathode. Accordingly, metal ions can be easily separated from the liquid wastes. Since the separated liquid wastes are an aqueous solution in which cerium ions as a decontaminant and an acid at low concentration are dissolved, the concentration thereof is controlled by mixing them to acid recovering water after the diffusion dialysis and they can be reused as the decontaminant. (T.M.)

Mechanical and chemical decontamination of surfaces

International Nuclear Information System (INIS)

Kienhoefer, M.

1982-01-01

Decontamination does not mean more than a special technique of cleaning surfaces by methods well known in the industry. The main difference consists in the facts that more than just the visible dirt is to be removed and that radioactive contamination cannot be seen. Especially, intensive mechanical and chemical carry-off methods are applied to attack the surfaces. In order to minimize damages caused to the surfaces, the decontamination method is to adapt to the material and the required degree of decontamination. The various methods, their advantages and disadvantages are described, and the best known chemical solutions are shown. (orig./RW)

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.)

Magnetite Dissolution Performance of HYBRID-II Decontamination Process

International Nuclear Information System (INIS)

Kim, Seonbyeong; Lee, Woosung; Won, Huijun; Moon, Jeikwon; Choi, Wangkyu

2014-01-01

In this study, we conducted the magnetite dissolution performance test of HYBRID-II (Hydrazine Based Reductive metal Ion Decontamination with sulfuric acid) as a part of decontamination process development. Decontamination performance of HYBRID process was successfully tested with the results of the acceptable decontamination factor (DF) in the previous study. While following-up studies such as the decomposition of the post-decontamination HYBRID solution and corrosion compatibility on the substrate metals of the target reactor coolant system have been continued, we also seek for an alternate version of HYBRID process suitable especially for decommissioning. Inspired by the relationship between the radius of reacting ion and the reactivity, we replaced the nitrate ion in HYBRID with bigger sulfate ion to accommodate the dissolution reaction and named HYBRID-II process. As a preliminary step for the decontamination performance, we tested the magnetite dissolution performance of developing HYBRID-II process and compared the results with those of HYBRID process. HYBRID process developed previously is known have the acceptable decontamination performance, but the relatively larger volume of secondary waste induced by anion exchange resin to treat nitrate ion is the one of the problems related in the development of HYBRID process to be applicable. Therefore we alternatively devised HYBRID-II process using sulfuric acid and tested its dissolution of magnetite in numerous conditions. From the results shown in this study, we can conclude that HYBRID-II process improves the decontamination performance and potentially reduces the volume of secondary waste. Rigorous tests with metal oxide coupons obtained from reactor coolant system will be followed to prove the robustness of HYBRID-II process in the future

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

Strippable gel for decontamination of contaminated metallic surfaces

International Nuclear Information System (INIS)

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

2013-01-01

Periodic decontamination of radioactive laboratories including fume hoods, glove boxes and all surfaces used for handling, processing and transporting radioactive materials is mandatory in all nuclear installations as this reduces spread of contamination and decreases total man rem exposure. Conventionally, chemical decontaminating agents or surfactant solutions are used for this purpose. However, this approach leads to generation of large volume of secondary radioactive waste. The use of strippable gel is an attractive alternative with low secondary waste generation particularly where removal of loose or weakly fixed contamination is necessary and also when the decontaminated material are to be reused, for e.g. decontamination of fume hoods, glove boxes, transport casks, spent fuel storage racks, control rod drive transport containers etc. Literature on gel formulations is scarce and mostly in the patent form. The sustained effort on gel formulation development has resulted in a basic gel formulation. The gel is a highly viscous water-based organic polymer, particularly suitable for application on vertical surfaces including difficult to reach metallic surfaces of complex geometry and not just limited to horizontal surfaces. The gel can be easily applied on contaminated surfaces by brushing or spraying. Curing of the gel is complete within 16-24 hours under ambient conditions and can then be removed by peeling as a dry sheet. While curing, the contaminants are trapped in gel either physically or chemically depending upon the nature of the contaminant. Salient features of cured gel include that it is water soluble and can be disposed off after immobilization in cement. Decontamination performance of the gel was initially evaluated by applying it on SS planchettes contaminated with known amount of radionuclides such as Cs(I), Co(II) and Ce(III). The measured decontamination factor was found to be in the range of 50-500, lowest for Ce(III) and highest for Co

Decontamination effectiveness of mixtures of citric acid, oxalic acid and EDTA

International Nuclear Information System (INIS)

Speranzini, R.A.

1990-01-01

An experimental study of the decontamination effectiveness of citric acid, oxalic acid and EDTA mixtures was conducted to assess whether oxalic acid could be removed from decontamination solutions to minimize corrosion. In loop experiments, radioactive specimens from two boiling water reactors and one pressurized water reactor were suspended in solutions of single acids or in mixtures of reagents at total reagent concentrations of less than 0.1 wt% under conditions similar to those used to decontaminate reactor systems. Rate constants for dissolution of oxides and decontamination factors were measured. Based on the results, it was concluded that under certain conditions, oxalic acid was the most effective reagent for the dissolution of oxides. It was also found, however, that conditions under which effective dissolution occurred in solutions of oxalic acid and/or citric acid were difficult to define and control. EDTA was found to be an effective reagent for dissolution of oxides such that rates of dissolution in EDTA containing solutions at 117 degrees Celsius were comparable to rates in oxalic acid containing solutions. At 90 degrees Celsius, EDTA acted synergistically with oxalic acid such that the rate of dissolution of oxides in citric-acid/oxalic-acid/EDTA solutions was higher than in citric-acid/EDTA solutions. The rates of dissolution of oxides were significantly reduced when 60 mg/kg of ferric ion was added to the citric-acid/oxalic-acid, citric-acid/EDTA and citric-acid/oxalic-acid/EDTA solutions. It was concluded that effective decontaminations of BWR and PWR systems could be achieved with mixtures of citric acid and EDTA

Evaluation of six decontamination processes on actinide and fission product contamination

International Nuclear Information System (INIS)

Conner, C.; Chamberlain, D.B.; Chen, L.

1995-01-01

In-situ decontamination technologies were evaluated for their ability to: (1) reduce equipment contamination levels to allow either free release of the equipment or land disposal, (2) minimize residues generated by decontamination, and (3) generate residues that are compatible with existing disposal technologies. Six decontamination processes were selected. tested and compared to 4M nitric acid, a traditional decontamination agent: fluoroboric acid (HBF 4 ), nitric plus hydrofluoric acid, alkaline persulfate followed by citric acid plus oxalic acid, silver(II) plus sodium persulfate plus nitric acid, oxalic acid plus hydrogen peroxide plus hydrofluoric acid, and electropolishing using nitric acid electrolyte. The effectiveness of these solutions was tested using prepared 304 stainless steel couponds contaminated with uranium, plutonium, americium, or fission products. The decontamination factor for each of the solutions and tests conditions were determined; the results of these experiments are presented

Decontaminating lead bricks and shielding

International Nuclear Information System (INIS)

Lussiez, G.W.

1993-01-01

Lead used for shielding is often surface contaminated with radionuclides and is therefore a Resource Conservation and Recovery Act (RCRA) D008 mixed waste. The technology-based standard for treatment is macroencapsulation. However, decontaminating and recycling the clean lead is a more attractive solution. Los Alamos National Lab. decontaminates material and equipment contaminated with radioisotopes. Decontaminating lead poses special problems because of the RCRA hazard classification and the size of the inventory, now about 100 metric tons and likely to grow substantially because of planned decommissioning operations. This lead, in the form of bricks and other shield shapes, is surface contaminated with fission products. One of the best methods for decontaminating lead is removing the thin superficial layer of contamination with an abrasive medium under pressure. For lead, a mixture of alumina with water and air at about 280 kPa (40 psig) rapidly and effectively decontaminates the lead. The abrasive medium is sprayed onto the lead in a sealed-off area. The slurry of abrasive and particles of lead falls through a floor grating and is collected in a pump. A pump sends the slurry mixture back to the spray gun, creating a continuous process

Intervention and decontamination of hardware contaminated by tritium

International Nuclear Information System (INIS)

Cerre, Pierre; Mestre, Emile

1964-10-01

This report first describes the intervention process for teams intervening, either in case of accident or to modify or repair installations in which tritium is handled, i.e. in both cases in a contaminated atmosphere. Three main aspects are addressed: how to prepare and insulate the work place from the rest of the installation, how to protect the intervening personnel, and how to perform decontamination. The authors then present the various available decontamination techniques: decontamination bath at different temperatures and use of different chemical solutions at different temperatures, the degassing technique (temperature increase and vacuum, temperature hold during 30 to 45 minutes, return to atmospheric pressure), and mercury-based decontamination

Chemical decontamination of reactor components

International Nuclear Information System (INIS)

Riess, R.; Berthold, H.O.

1977-08-01

A solution for the decontamination of reactor components of the primary system was developed. This solution is a modification of the APAC- (Alkaline Permanganate Ammonium Citrate) system described in the literature. The most important advantage of the present solution over the APAC-method is that it does not induce any selective corrosion attack on materials like stainless steel (austenitic), Inconel 600 and Incoloy 800. (orig.) [de

Application of a modified electrochemical system for surface decontamination of radioactive metal waste

International Nuclear Information System (INIS)

Lee, J.H.; Lim, Y.K.; Yang, H.Y.; Shin, S.W.; Song, M.J.

2003-01-01

Conventional and modified electrolytic decontamination experiments were performed in a solution of sodium sulfate for the decontamination of carbon steel as the simulated metal wastes which are generated in large amounts from nuclear power plants. The effect of reaction time, current density and concentration of electrolytes in the modified electrolytic decontamination system were examined to remove the surface contamination of the simulated radioactive metal wastes. As for the results of this research, the modified electrochemical decontamination process can decontaminate more effectively than the conventional decontamination process by applying different anode material which causes higher induced electro-motive forces. When 0.5 M sodium sulfate, 0.4 A/cm 2 current density and 30 minutes reaction time were applied in the modified process, a 16 μm thickness change that is expected to remove most surface contamination in radioactive metal wastes was achieved on carbon steel which is the main material of radioactive metal waste in nuclear power plants. The decontamination efficiency of metal waste showed similar results with the small and large lab-scale modified electrochemical system. The application of this modified electrolytic decontamination system is expected to play a considerable role for decontamination of radioactive metal waste in nuclear power plants in the near future. (author)

Equipment decontamination: A brief survey of the DOE complex

International Nuclear Information System (INIS)

Conner, C.; Chamberlain, D.B.; Chen, L.; Vandegrift, G.F.

1995-03-01

Deactivation at DOE facilities has left a tremendous amount of contaminated equipment behind. In-situ methods are needed to decontaminate the interiors of the equipment sufficiently to allow either free release or land disposal. A brief survey was completed of the DOE complex on their needs for equipment decontamination with in-situ technology to determine (1) the types of contamination problems within the DOE complex, (2) decontamination processes that are being used or are being developed within the DOE, and (3) the methods that are available to dispose of spent decontamination solutions. In addition, potential sites for testing decontamination methods were located. Based on the information obtained from these surveys, the Rocky Flats Plant and the Idaho National Engineering Laboratory appear to be best suited to complete the initial testing of the decontamination processes

Electroosmotic decontamination of concrete

International Nuclear Information System (INIS)

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

1993-03-01

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

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

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)

Decontamination of radionuclides in food

Energy Technology Data Exchange (ETDEWEB)

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

1994-03-01

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

Decontamination of radionuclides in food

International Nuclear Information System (INIS)

Ohmomo, Yoichiro

1994-01-01

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

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

International Nuclear Information System (INIS)

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

1984-01-01

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

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

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)

PROCESS OF DECONTAMINATING MATERIAL CONTAMINATED WITH RADIOACTIVITY

Science.gov (United States)

Overholt, D.C.; Peterson, M.D.; Acken, M.F.

1958-09-16

A process is described for decontaminating metallic objects, such as stainless steel equipment, which consists in contacting such objects with nltric acid in a concentration of 35 to 60% to remove the major portion of the contamination; and thereafter contacting the partially decontaminated object with a second solution containing up to 20% of alkali metal hydroxide and up to 20% sodium tartrate to remove the remaining radioactive contaminats.

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

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.

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.)

Decontamination method and device for radiation contaminated product

International Nuclear Information System (INIS)

Morikawa, Kenji; Ohinata, Hiroshi; Omata, Kazuo; Sato, Toshihiko; Nakajima, Yoshihiko; Ichikawa, Seigo.

1996-01-01

In the present invention, radiation contaminated products generated during shot peening are decontaminated by a chelating agent, and the chelating agent is removed from the radiation contaminated products. Then the temperature of the radiation contaminated products is elevated by hot blowing at a temperature higher than a boiling point of the solvent. Then, a solvent is added to the radiation contaminated products and the solvent is evaporated abruptly. The solution of the chelating agent remained while being deposited thereto is removed by evaporation to remove it from the radiation contaminated products together with the solvent. With such procedures, all of the decontamination steps can be completed in one device without requiring a large space or not moving the radiation contaminated products on every step. (T.M.)

Evaluation of commercially available decontamination chemicals

International Nuclear Information System (INIS)

Shurte, E.A.; Rankin, W.N.

1988-01-01

The effectiveness of commercially available decontamination solutions was compared with the effectiveness of 10% oxalic acid in controlled laboratory tests. Type 304L stainless steel and Inconel 625 specimens were used. Contamination was sludge from Savannah River Plant (SRP) high level waste tanks. Measured amounts of contamination were placed on each specimen. They were then heated to bond the contamination to the surface and cleaned according to the manufacturer's directions. The effectiveness of the product was determined by monitoring specimens before and after cleaning. Four of the 16 solutions evaluated removed all the contamination from Type 304L stainless steel. Inconel 625 was more difficult to decontaminate. Further tests are planned with the chemicals that were most effective in this test. 4 refs., 6 tabs

Evaluation of commercially available decontamination chemicals

International Nuclear Information System (INIS)

Shurte, E.A.

1988-01-01

The effectiveness of commercially available decontamination solutions was compared with the effectiveness of 10% oxalic acid in controlled lab. tests. Type 304L stainless steel and Inconel 625 specimens were used. Contamination was sludge from Savannah River Plant (SRP) high level waste tanks. Measured amounts of contamination were placed on each specimen. They were then heated to bond the contamination to the surface and cleaned according to the manufacturer's directions. The effectiveness of the produce was determined by monitoring specimens before and after cleaning. Four of the 16 solutions evaluated removed all the contamination from Type 304L stainless steel. Inconel 625 was more difficult to decontaminate. Further tests are planned with the chemicals that were most effective in this test

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

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

Decontamination of plutonium-contaminated surfaces; Essais de decontamination des surfaces contaminees par du plutonium

Energy Technology Data Exchange (ETDEWEB)

Bertrand, J; Clouet d' Orval, Ch; Tachon, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The measure of the neutron distribution in the core of 'Proserpine', by means of activation detectors, requires no contact between the plutonium sulfate solution and the detectors. These detectors are put into PVC or polyethylene bags. This report describes the process used to decontaminate these bags. A washing by nitric acid followed by coating with plexiglass is kept, with this process we have no contamination on the detectors. (author) [French] La mesure de la distribution de neutrons par detecteurs a activation dans le coeur de Proserpine exige de proteger ces detecteurs contre tout contact avec la solution de plutonium. Les detecteurs sont places dans des gaines en polyvinyle ou en polyethylene. Ce rapport decrit le procede utilise pour decontaminer ces gaines. On a retenu un lavage a l'acide nitrique suivi du revetement d'une meme couche de plexiglass, ce qui permet d'eviter la contamination des detecteurs. (auteur)

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)

New decontamination process using foams containing particles

International Nuclear Information System (INIS)

Guignot, S.; Faure, S.

2008-01-01

One key point in the dismantling of nuclear facilities is the thorough cleaning of radiation- exposed surfaces on which radioactive deposits have formed. This cleaning step is often achieved by successive liquid rinses with specific solutions containing alkaline, acidic, or even oxidizing species depending on whether the aim is to dissolve greasy deposits (like ter-butylphosphate) or to corrode surfaces on micrometric thicknesses. An alternative process to reduce the amount of chemicals and the volume of the resulting nuclear wastes consists in using the same but foamed solutions (1). Carrying less liquid, the resulting foams still display similar kinetics of dissolution rates and their efficiency is determined by their ability to hold sufficient wetnesses during the time required for the decontamination. Classical foam decontamination process illustrated by foam pulverization or circulation in the 90 turned five years ago into a specific static process using high-lifetime viscosified foam at a steady state. One way to slow down the liquid drainage is to raise liquid viscosity by adding organic viscosifiers like xanthan gum (2). In 2005, new studies started on an innovative process proposed by S. Faure and based on triphasic foams containing particles [3]. The aim is to generate new decontamination foams containing less quantities of organics materials (surfactants and viscosifiers). Silica particles are obviously known to stabilize or destabilize foams (4). In the frame of S. Guignot Ph.D., new fundamental studies are initiated in order to clarify the role of silica solid microparticles in these foams. Our final goal is to determine whether this kind of new foam can be stable for several hours for a decontamination process. The results we will report focus on wet foams used for nuclear decontamination and incorporating fumed silica. The study is conducted on a vertical foam column in a pseudo-free drainage configuration, and aims at investigating the influence of

Effect of Cerium(IV)-Surfactant Reaction in Foam Decontamination

Energy Technology Data Exchange (ETDEWEB)

Yang, Han Beom; Jung, Chong-Hun; Yoon, In-Ho; Kim, Chorong; Choi, Wang-Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

Using foams allows the decommissioning of complex shaped facilities. The decontamination foam comprises at least one surfactant to generate the foam and one or more chemical reactants to achieve the dissolution of the contaminants at the solid surface. In order to improve the efficiency of decontamination foam, the present study attempts to find the optimum condition of chemical reagents to the foaming solution. The corrosion rate of radioactive nuclides contaminated stainless steel metal is very important factor for the foam decontamination process. The goal of this study is to develop the decontamination process for contaminated stainless steel in medium of nitric acid. Stainless steel needs a strong oxidizing agent such as Ce(IV) ion and the effects of cerium(IV). Surfactant interaction involved in foam decontamination and finally the improvement brought by formulation science. The formulation of foams loaded with strong oxidizing reagents such as Ce(IV) is an important factor. The enhanced decontamination properties of nitric acid with Ce(IV) additive on stainless steel is well known in liquid mediums. stainless steel metal is an important aspect in the foam decontamination process.

Effect of Cerium(IV)-Surfactant Reaction in Foam Decontamination

International Nuclear Information System (INIS)

Yang, Han Beom; Jung, Chong-Hun; Yoon, In-Ho; Kim, Chorong; Choi, Wang-Kyu

2015-01-01

Using foams allows the decommissioning of complex shaped facilities. The decontamination foam comprises at least one surfactant to generate the foam and one or more chemical reactants to achieve the dissolution of the contaminants at the solid surface. In order to improve the efficiency of decontamination foam, the present study attempts to find the optimum condition of chemical reagents to the foaming solution. The corrosion rate of radioactive nuclides contaminated stainless steel metal is very important factor for the foam decontamination process. The goal of this study is to develop the decontamination process for contaminated stainless steel in medium of nitric acid. Stainless steel needs a strong oxidizing agent such as Ce(IV) ion and the effects of cerium(IV). Surfactant interaction involved in foam decontamination and finally the improvement brought by formulation science. The formulation of foams loaded with strong oxidizing reagents such as Ce(IV) is an important factor. The enhanced decontamination properties of nitric acid with Ce(IV) additive on stainless steel is well known in liquid mediums. stainless steel metal is an important aspect in the foam decontamination process

Efficacy studies of Reactive Skin Decontamination Lotion, M291 Skin Decontamination Kit, 0.5% bleach, 1% soapy water, and Skin Exposure Reduction Paste Against Chemical Warfare Agents, part 2: guinea pigs challenged with soman.

Science.gov (United States)

Braue, Ernest H; Smith, Kelly H; Doxzon, Bryce F; Lumpkin, Horace L; Clarkson, Edward D

2011-03-01

, the calculated LT(50) (the delayed-decontamination time at which 50% of the animals die in the test population following a 5-LD(50) challenge) value for RSDL was only 4.0 minutes. Several conclusions can be drawn from this study: 1) Reactive Skin Decontamination Lotion provided superior protection against GD compared with the other products tested; 2) The 0.5% bleach solution, the 1% soapy water solution, and the M291 SDK were less effective than RSDL, but still provided modest (2 Decontamination Lotion, the best product tested, did not provide significant protection against GD when decontamination was delayed for more than 3 minutes; 4) Skin Exposure Reduction Paste Against Chemical Warfare Agents provided significant, but modest, protection against GD; 5) There was good correlation between using the rabbit model and the guinea pig model for decontamination efficacy evaluations; and 6) Soman (GD) is an agent of real concern because it is very difficult to decontaminate and the effects of exposure are difficult to treat.

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)

Attapulgite, a decontaminating medium, research tool in the radioprotection field

International Nuclear Information System (INIS)

Panciatici, G.; Belfiore, A.; Poggianti, M.

1993-01-01

Gels based on attapulgite, obtained by mixing attapulgite, a clay, with water or chemicals have been used as decontaminating agents. The method has been optimized through extensive scale laboratory experiments carried out under standard conditions. A wide variety of materials, used in nuclear technologies, and significant radionuclides have been tested. Gels obtained with water only in some cases allow full decontamination, when acids are added to clay, complete contamination removal, is possible except for extreme pHs radionuclides solution and on non-passivated or porous surfaces. The optimized decontaminating technique has successively been set up and applied on materials contaminated by routine or accident. Laboratory scale results have been confirmed through practical use. Process data are reported. This method is simple to perform and requires no special equipment. No liquid radioactive waste arises from the process and the resulting solid waste can be conditioned with cement

Decontamination by cleaning with fluorocarbon surfactant solutions

International Nuclear Information System (INIS)

Kaiser, R.; Benson, C.E.; Meyers, E.S.; Vaughen, V.C.A.

1994-02-01

In the nuclear industry, facilities and their components inevitably become contaminated with radioactive materials. This report documents the application of a novel particle-removal process developed by Entropic Systems, Inc. (ESI), to decontaminate critical instruments and parts that are contaminated with small radioactive particles that adhere to equipment surfaces. The tests were performed as a cooperative effort between ESI and the Chemical Technology Division of the Oak Ridge National Laboratory (ORNL). ESI developed a new, environmentally compatible process to remove small particles from solid surfaces that is more effective than spraying or sonicating with CFC-113. This process uses inert perfluorinated liquids as working media; the liquids have zero ozone-depleting potential, are nontoxic and nonflammnable, and are generally recognized as nonhazardous materials. In the ESI process, parts to be cleaned are first sprayed or sonicated with a dilute solution of a high-molecular-weight fluorocarbon surfactant in an inert perfluorinated liquid to effect particle removal. The parts are then rinsed with the perfluorinated liquid to remove the fluorocarbon surfactant applied in the first step, and the residual rinse liquid is then evaporated from the parts into an air or nitrogen stream from which it is recovered. Nuclear contamination is inherently a surface phenomenon. The presence of radioactive particles is responsible for all ''smearable'' contamination and, if the radioactive particles are small enough, for some of the fixed contamination. Because radioactivity does not influence the physical chemistry of particle adhesion, the ESI process should be just as effective in removing radioactive particles as it is in removing nonradioactive particles

Low concentration NP preoxidation condition for PWR decontamination

International Nuclear Information System (INIS)

Huang Fuduan; Yu Degui; Lu Jingju; Ding Dejun; Zhao Yukun

1991-02-01

To use preoxidation condition with low concentration NP (nitric acid permanganate) instead of conventional high concentration AP (alkline permanganate ) for PWR oxidation decontamination (POD) was summarized. Experiments including three parts have been performed. The defilming performance and decontamination factor of preoxidation with low concentration NP, which is 100, 10 times lower than that of AP are better than that with high concentration AP. The reason has been studied with the aid of prefilmed specimens of corrosion potential measuring in NP solution and chromium release in NP and AP solutions. The behaviour of alloy 13 prefilmed specimen in NP preoxidation solution is different from 18-8 ss and Incoloy 800. In the low acidity, the corrosion potential moves toward positive direction as the acidity becomes high

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)

Personnel decontamination and preventive skin care

International Nuclear Information System (INIS)

Henning, Klaus; Gojowczyk, Peter

2010-01-01

Skin contamination arises from contact with contaminated aqueous solutions and from transmission of radioactively contaminated dirt particles. As long as the surface of the skin is neither inflamed nor showing any lesions, normally only a limited part of the top layer (epidermis), i.e. the upper layers of the stratum corneum, is contaminated. The intact horny layer has a barrier function protecting against the penetration of chemicals and dirt particles. The horny layer can be damaged by water, solvents, alkaline substances, and acids. In general, it is safe to say that the horny layer acts as a natural barrier to the penetration of liquid and particulate impurities into lower layers of the skin. As long as the horny layer is intact and free from lesions, the risk of incorporation can be considered low. When decontaminating and cleansing the skin, also in daily skin cleansing, care must be taken to prevent the acid protective layer and the horny layer from being compromised. Daily cleansing and cleansing for decontamination must be carried out with a mild, weakly acidic detergent. In addition, prevention should be achieved daily by applying a non-greasy skin lotion to protect the skin. Following a systematic regular regimen in skin cleansing and preventive skin care as well as a specific approach in skin decontamination and cleansing will avoid damage to the skin and remove any contamination incurred. This approach comprises a three-pronged concept, namely skin protection, cleansing and care. (orig.)

Active Waste Materials Corrosion and Decontamination Tests

International Nuclear Information System (INIS)

Danielson, M.J.; Elmore, M.R.; Pitman, S.G.

2000-01-01

Stainless steel alloys, 304L and 316L, were corrosion tested in representative radioactive samples of three actual Hanford tank waste solutions (Tanks AW-101, C-104, AN-107). Both the 304L and 316L exhibited good corrosion performance when immersed in boiling waste solutions. The maximum general corrosion rate was 0.015 mm/y (0.60 mils per year). Generally, the 304L had a slightly higher rate than the 316L. No localized attack was observed after 122 days of testing in the liquid phase, liquid/vapor phase, or vapor phase. Radioactive plate-out decontamination tests indicated that a 24-hour exposure to 1 und M HNO 3 could remove about 99% of the radioactive components in the metal film when exposed to the C-104 and AN-107 solutions. The decontamination results are less certain for the AW-101 solution, since the initial contamination readings exceeded the capacity of the meter used for this test

Decontamination and coating of lead

International Nuclear Information System (INIS)

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

1988-01-01

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

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

Comparison of four different fuller's earth formulations in skin decontamination.

Science.gov (United States)

Roul, Annick; Le, Cong-Anh-Khanh; Gustin, Marie-Paule; Clavaud, Emmanuel; Verrier, Bernard; Pirot, Fabrice; Falson, Françoise

2017-12-01

Industrial accidents, wars and terrorist threats are potential sources of skin contamination by highly toxic chemical warfare agents and manufacturing compounds. We have compared the time-dependent adsorption capacity and decontamination efficiency of fuller's earth (FE) for four different formulations for the molecular tracer, 4-cyanophenol (4-CP), in vitro and ex vivo using water decontamination as standard. The adsorption capacity of FE was assessed in vitro for 4-CP aqueous solutions whereas decontamination efficiency was investigated ex vivo by tracking porcine skin 4-CP content using attenuated total reflectance Fourier transform infrared spectroscopy. Decontamination was performed on short time, exposed porcine skin to 4-CP by application of FE: (1) as free powder; (2) loaded on adhesive tape; (3) on powdered glove; or (4) in suspension. Removal rate of 4-CP from aqueous solutions correlates with the amount of FE and its contact time. Decontamination efficiency estimated by the percentage of 4-CP recovery from contaminated porcine skin, achieved 54% with water, ranged between ~60 and 70% with dry FE and reached ~90% with FE suspension. Successful decontamination of the FE suspension, enabling a dramatic reduction of skin contamination after a brief exposure scenario, appears to be rapid, reliable and should be formulated in a new device ready to use for self-application. Copyright © 2017 John Wiley & Sons, Ltd.

A Simple Decontamination Approach Using Hydrogen ...

Science.gov (United States)

Journal article To evaluate the use of relatively low levels of hydrogen peroxide vapor (HPV) for the inactivation of Bacillus anthracis spores within an indoor environment. Methods and Results: Laboratory-scale decontamination tests were conducted using bacterial spores of both B. anthracis Ames and Bacillus atrophaeus inoculated onto several types of materials. Pilot-scale tests were also conducted using a larger chamber furnished as an indoor office. Commercial off-the-shelf (COTS) humidifiers filled with aqueous solutions of 3% or 8% hydrogen peroxide were used to generate the HPV inside the mock office. The spores were exposed to the HPV for periods ranging from 8 hours up to one week. Conclusions: Four to seven day exposures to low levels of HPV (average air concentrations of approximately 5-10 parts per million) were effective in inactivating B. anthracis spores on multiple materials. The HPV can be generated with COTS humidifiers and household H2O2 solutions. With the exception of one test/material, B. atrophaeus spores were equally or more resistant to HPV inactivation compared to those from B. anthracis Ames. Significance and Impact of Study: This simple and effective decontamination method is another option that could be widely applied in the event of a B. anthracis spore release.

Verification of wet blasting decontamination technology

International Nuclear Information System (INIS)

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

2013-01-01

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

[Decontamination of chemical and biological warfare agents].

Science.gov (United States)

Seto, Yasuo

2009-01-01

Chemical and biological warfare agents (CBWA's) are diverse in nature; volatile acute low-molecular-weight toxic compounds, chemical warfare agents (CWA's, gaseous choking and blood agents, volatile nerve gases and blister agents, nonvolatile vomit agents and lacrymators), biological toxins (nonvolatile low-molecular-weight toxins, proteinous toxins) and microbes (bacteria, viruses, rickettsiae). In the consequence management against chemical and biological terrorism, speedy decontamination of victims, facilities and equipment is required for the minimization of the damage. In the present situation, washing victims and contaminated materials with large volumes of water is the basic way, and additionally hypochlorite salt solution is used for decomposition of CWA's. However, it still remains unsolved how to dispose large volumes of waste water, and the decontamination reagents have serious limitation of high toxicity, despoiling nature against the environments, long finishing time and non-durability in effective decontamination. Namely, the existing decontamination system is not effective, nonspecifically affecting the surrounding non-target materials. Therefore, it is the urgent matter to build up the usable decontamination system surpassing the present technologies. The symposiast presents the on-going joint project of research and development of the novel decontamination system against CBWA's, in the purpose of realizing nontoxic, fast, specific, effective and economical terrorism on-site decontamination. The projects consists of (1) establishment of the decontamination evaluation methods and verification of the existing technologies and adaptation of bacterial organophosphorus hydrolase, (2) development of adsorptive elimination technologies using molecular recognition tools, and (4) development of deactivation technologies using photocatalysis.

Corrosion Characteristics of Inconel-600 at the NP(Cu)-HYBRID Decontamination Demonstration Test with HANARO FTL Specimen

Energy Technology Data Exchange (ETDEWEB)

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

2013-10-15

An alkaline permanganate (AP) or nitric permanganate (NP) oxidative phase has been generally used to dissolve the chromium-rich oxide. AP is advantageous for the corrosion resistance, but increases the volume of secondary waste during the decontamination procedure. On the other hand, NP has a high corrosion rate but reduces secondary waste. For the safe use of an oxidative decontamination solution with high corrosive resistance and less amount of secondary waste are required. In this study, we modified NP oxidative decontamination solution by adding Cu{sup 2+} to reduce the corrosion rate. To evaluate the general corrosion characteristics, we measured the weight losses of selected specimens in an NP(Cu) and other solutions. The localized corrosion was observed using an optical microscope (OM). To compare the decontamination performance, we measured the contact dose rate of specimens treated in NP-HYBRID and NP(Cu)-HYBRID systems. The reduced corrosion characteristics of the Inconel-600 specimen in a NP(Cu) oxidative solution was observed in terms of generalized corrosion as well as localized corrosion. Less corrosion characteristics do not affect the performance of the overall decontamination compared to the NP-HYBRID process. Therefore, our results support that the NP(Cu)-HYBRID decontamination process is appropriate for the decontamination of the primary coolant system in a nuclear reactor.

Aggressive chemical decontamination tests on small valves from the Garigliano BWR

International Nuclear Information System (INIS)

Bregani, F.

1990-01-01

In order to check the effectiveness of direct chemical decontamination on small and complex components, usually considered for storage without decontamination because of the small amount, some tests were performed on the DECO experimental loop. Four small stainless steel valves from the primary system of the Garigliano BWR were decontaminated using mainly aggressive chemicals such as HC1, HF, HNO 3 and their mixtures. On two valves, before the treatment with aggressive chemicals, a step with soft chemical (oxalic and citric acid mixture) was performed in order to see whether a softening action enhances the following aggressive decontamination. Moreover, in order to increase as much as possible the decontamination effectiveness, a decontamination process using ultrasounds jointly with aggressive chemicals was investigated. After an intensive laboratory testing programme, two smaller stainless steel valves from the primary system of the Garigliano BWR were decontaminated using ultrasounds in aggressive chemical solutions

The separation of silica nanoparticle by cetyltrimethylammonium bromide from decontamination foam waste

International Nuclear Information System (INIS)

Choi, Man Soo; Yoon, In Ho; Jung, Chong Hun; Moon, Jei Kwon; Choi, Wang Kyu

2016-01-01

Decontamination foam has been considered as a potential application for the cleaning of radioactive contaminant in the field of metallic walls, overhead surfaces, and complex components. Moreover, foam decontamination could generate the low secondary waste amount owing to its volume expansion. In order to increase the decontamination efficiency, it is essential to improve the foam stability with low amount of chemical decontamination agent. Yoon et al. reported that the silica nanoparticle containing surfactant increased the foam stability compared to only surfactant solution[3]. Nanoparticle has been used with surfactant, which they adsorb at fluid/fluid interface, to stabilize emulsions or bubbles in foams. Despite of improving foam stability, they still used the surfactant, silica nanoparticle (1 wt%), and viscosifier. In addition, it is difficult to separate silica nanoparticle from decontamination solution. Because nanoparticles differ from classical solid particles due to smaller particle size and their specific properties. Thus, the separation method for nanoparticle should be also developed with high recovery rates. The flocculation of silica nanoparticle added by CTAB could be quickly achieved for only 30 min. The particle size of SiO_2 was larger as CTAB amount increased, and SiO_2 contents in the top solution were decreased after centrifugation

The separation of silica nanoparticle by cetyltrimethylammonium bromide from decontamination foam waste

Energy Technology Data Exchange (ETDEWEB)

Choi, Man Soo; Yoon, In Ho; Jung, Chong Hun; Moon, Jei Kwon; Choi, Wang Kyu [KAERI, Daejeon (Korea, Republic of)

2016-05-15

Decontamination foam has been considered as a potential application for the cleaning of radioactive contaminant in the field of metallic walls, overhead surfaces, and complex components. Moreover, foam decontamination could generate the low secondary waste amount owing to its volume expansion. In order to increase the decontamination efficiency, it is essential to improve the foam stability with low amount of chemical decontamination agent. Yoon et al. reported that the silica nanoparticle containing surfactant increased the foam stability compared to only surfactant solution[3]. Nanoparticle has been used with surfactant, which they adsorb at fluid/fluid interface, to stabilize emulsions or bubbles in foams. Despite of improving foam stability, they still used the surfactant, silica nanoparticle (1 wt%), and viscosifier. In addition, it is difficult to separate silica nanoparticle from decontamination solution. Because nanoparticles differ from classical solid particles due to smaller particle size and their specific properties. Thus, the separation method for nanoparticle should be also developed with high recovery rates. The flocculation of silica nanoparticle added by CTAB could be quickly achieved for only 30 min. The particle size of SiO{sub 2} was larger as CTAB amount increased, and SiO{sub 2} contents in the top solution were decreased after centrifugation.

Treatment of Soil Decontamination Solution by the Cs{sup +} Ion Selective Ion Exchange Resin

Energy Technology Data Exchange (ETDEWEB)

Won, Hui Jun; Kim, Gye Nam; Jung, Chung Hun; Oh, Won Zin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2005-07-01

Occasionally, radioactively contaminated soils have been excavated and stored at the temporary storage facility. Cesium as a radionuclide is one of the most toxic elements and it has a long half decay life. During the operation of nuclear facility, soils near the facility would be contaminated with radioactive cesium and it will cause the deleterious effect to human body and environment. In this study, Cs{sup +} ion selective ion exchange resin was prepared by changing the functional group of commercial anion exchange resin for a ferrocyanide ion. Ion exchange capability of using the soil decontamination solution was investigated. We also performed the feasibility test of recycling the spent Cs ion selective ion exchange resin.

Surface decontamination by heterogeneous foams and suspensions

International Nuclear Information System (INIS)

Polyakov, A.; Poluektov, P.; Emets, E.; Kuchumov, V.; Rybakov, K.; Teterin, E.

2000-01-01

A variety of methods was used to investigate the surface of stainless steel as delivered or treated (electrochemically polished, machine ground). Micro X-ray spectral analysis evidenced a uniform distribution of alloying elements. Auger spectroscopy revealed the layer-by-layer composition by elements and the thickness of the superficial oxide film. The distribution of heterogeneous uranium dioxide powders on the stainless steel surface was examined by microprobe analysis (using Comebax). In the order of increasing contamination by uranium dioxide, the surfaces can be arranged as: untreated - polished - ground. The behaviour of hydrogen peroxide in alkaline solutions was studied by spectrophotometry and laser analysis. Decontamination of stainless steel surfaces from UO 2 by microgaseous emulsions in alkaline media with surfactants present was tested. The decontamination factor was determined as a function of the size and volume of gas bubbles. It was shown to rise with increasing gas content. (author)

Factors determining the stainless steel decontamination efficiency for the steam generator heat exchanger tubes at NPPs with the WWERs

International Nuclear Information System (INIS)

Kamenskij, A.N.; Balaban-Irmenin, Yu.V.

1983-01-01

To raise the efficiency of the redox method and decrease the amount of radioactive wastes, a possibility of improving the decontamination process for NPP heat exchanger tubes made of stainless steel is studied. In the home practice the redox method of equipment decontamination is carried out as a multi-cycle process. In each cycle the surface is treated first with a permanganate alkaline solution ther with an oxalic acid solution, with a condensate washing-at between the treatments. Using samples cut out of the steam generator pipelines of the first and third power units of the Novovoronezh NPP the effect of the oXalic acid concentration, as well as washout time and conditions on the decontamination factor are studied. On the basis of analysis of the obtained data a conclusion is drawn that using oxalic acid of low concentrations and increasing its concentrations from cycle to cycle maximum decontamination factor values can be obtained at a minimum salt content in radioactive wastes

Method of heat decomposition for chemical decontaminating resin waste

International Nuclear Information System (INIS)

Kikuchi, Akira.

1988-01-01

Purpose: To make resin wastes into non-deleterious state, discharge them into a resin waste storage tank of existent radioactive waste processing facility and store and dispose them. Constitution: In the processing of chemical decontaminating resin wastes, iron exchange resins adsorbing chemical decontaminating agents comprising a solution of citric acid, oxalic acid, formic acid and EDTA alone or as a mixture of them are heated to dry, thermally decomposed and then separated from the ion exchange resins. That is, the main ingredients of the chemical decontaminating agents are heat-decomposed when heated and dried at about 250 deg C in air and converted into non-toxic gases such as CO, CO 2 , NO, NO 2 or H 2 O. Further, since combustion or carbonization of the basic materials for the resin is not caused at such a level of temperature, the resin wastes removed with organic acid and chelating agents are transferred to an existent resin waste storage tank and stored therein. In this way, facility cost and radiation exposure can remarkably be decreased. (Kamimura, M.)

Immobilization of citric acid solutions in portland cement

International Nuclear Information System (INIS)

Lopes, Valdir M.; Rzyski, Barbara M.

1997-01-01

Decontamination processes by using citric acid on certain items used in the nuclear area, can result in large volumes of liquid wastes with low activity or effluents, contaminated with uranium and some elements dangerous to the environment. A great number of installations that have decontamination processes adopt the zero discharge philosophy. So, one of the forms to isolate the solutions is by reducing its volume through the evaporation process. The generated must can be neutralized and encapsulated or immobilized in Portland cement. This work propose a chemical technique to destroy the citric acid in the decontamination solutions instead of neutralization and, depending on the installation convenience, a direct cement immobilization of these solutions or of the evaporation mud. The results obtained in this work involve data about the workability, setting time and mechanical resistance, after 28 days of sealed cure, for samples with water-cement ratios of 4, 0.5 and 0.6, by weight. (author). 5 refs., 2 tabs

New sorption-reagent materials for decontamination of liquid radioactive waste

International Nuclear Information System (INIS)

Avramenko, V.A.; Golikov, A.P.; Zheleznov, V.V.; Kaplun, E.V.; Marinin, D.V.; Sokolnitskaya, T.A.

2001-01-01

Full text: Use of selective sorbents in liquid radioactive waste (LRW) management is widely spread in the field of nuclear power objects liquid waste decontamination, since the main objective there is to remove long-lived radionuclides of the nuclear cycle. The latter include, first of all, cesium-137, strontium-90, cobalt-60 and a number of α-irradiators. In this case LRW composition for most of the nuclear power objects is rather simple, except acidic deactivation solutions. At the same time, liquid radioactive wastes of different research centers have a variable chemical and radiochemical composition depending on objectives and tasks of a given center research activities. As a result, application of sorption technologies in such waste decontamination determines special requirements to these sorbents selectivity: a wide spectrum of radionuclides that can be removed and fairly high selectivity enabling to remove radionuclides from solutions of complex chemical composition (containing surfactants, complexing agents etc.). This paper is concerned with studying properties of new materials selective to different radionuclides. These materials are capable to interact with solution components whether already contained in the waste or deliberately added into resulting solution. Such sorption-reagent materials combine universal character of co-precipitation methods with simplicity of sorption methods. In this work we studied sorption-reagent inorganic ion-exchange materials interacting with sulfate-, carbonate-, oxalate-, sulfide-, and permanganate-ions. Insoluble compounds formed as a result of this interaction increase tens- and hundreds-fold the sorption selectivity of different radionuclides - strontium, cobalt, mercury, iron, and manganese as compared to conventional ion-exchange system. By means of X-ray phase analysis, IR-spectroscopy, chemical and radiochemical analysis, we have studied the mechanism of radionuclide sorption on different sorption

Treatment of Simulated Soil Decontamination Waste Solution by Ferrocyanide-Anion Exchange Resin Beads

Energy Technology Data Exchange (ETDEWEB)

Won, Hui Jun; Kim, Min Gil; Kim, Gye Nam; Jung, Chung Hun; Park, Jin Ho; Oh, Won Zin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2005-03-15

Preparation of ferrocyanide-anion exchange resin and adsorption test of the prepared resin on the Cs{sup -} ion were performed. Adsorption capability of the prepared resin on the Cs{sup -} ion in the simulated citric acid based soil decontamination waste solution was 4 times greater than that of the commercial cation exchange resin. Adsorption equilibrium of the prepared resin on the Cs{sup -} ion reached within 360 minutes. Adsorption capability on the Cs{sup -} ion became to decrease above the necessary Co{sup 2-} ion concentration in the experimental range. Recycling test of the spent ion exchange resin by the successive application of hydrogen peroxide and hydrazine was also performed. It was found that desorption of Cs{sup -} ion from the resin occurred to satisfy the electroneutrality condition without any degradation of the resin.

Decontamination of adsorbed chemical warfare agents on activated carbon using hydrogen peroxide solutions.

Science.gov (United States)

Osovsky, Ruth; Kaplan, Doron; Nir, Ido; Rotter, Hadar; Elisha, Shmuel; Columbus, Ishay

2014-09-16

Mild treatment with hydrogen peroxide solutions (3-30%) efficiently decomposes adsorbed chemical warfare agents (CWAs) on microporous activated carbons used in protective garments and air filters. Better than 95% decomposition of adsorbed sulfur mustard (HD), sarin, and VX was achieved at ambient temperatures within 1-24 h, depending on the H2O2 concentration. HD was oxidized to the nontoxic HD-sulfoxide. The nerve agents were perhydrolyzed to the respective nontoxic methylphosphonic acids. The relative rapidity of the oxidation and perhydrolysis under these conditions is attributed to the microenvironment of the micropores. Apparently, the reactions are favored due to basic sites on the carbon surface. Our findings suggest a potential environmentally friendly route for decontamination of adsorbed CWAs, using H2O2 without the need of cosolvents or activators.

Treatability studies for decontamination of Melton Valley Storage Tank supernate

International Nuclear Information System (INIS)

Arnold, W.D.; Fowler, V.L.; Perona, J.J.; McTaggart, D.R.

1992-08-01

Liquid low-level waste, primarily nitric acid contaminated with radionuclides and minor concentrations of organics and heavy metals, is neutralized with sodium hydroxide, concentrated by evaporation, and stored for processing and disposal. The evaporator concentrate separates into sludge and supernate phases upon cooling. The supernate is 4 to 5 mol/L sodium nitrate contaminated with soluble radionuclides, principally 137 Cs, 90 Sr, and 14 C, while the sludge consists of precipitated carbonates and hydroxides of metals and transuranic elements. Methods for treatment and disposal of this waste are being developed. In studies to determine the feasibility of removing 137 Cs from the supernates before solidification campaigns, batch sorption measurements were made from four simulated supernate solutions with four different samples of potassium hexacyanocobalt ferrate (KCCF). Cesium decontamination factors of 1 to 8 were obtained with different KCCF batches from a highly-salted supernate at pH 13. Decontamination factors as high as 50 were measured from supernates with lower salt content and pH, in fact, the pH had a greater effect than the solution composition on the decontamination factors. The decontamination factors were highest after 1 to 2 d of mixing and decreased with longer mixing times due to decomposition of the KCCF in the alkaline solution. The decontamination factors decreased with settling time and were lower for the same total contact time (mixing + settling) for the longer mixing times, indicating more rapid KCCF decomposition during mixing than during settling. There was no stratification of cesium in the tubes as the KCCF decomposed

Cadmium decontamination using in-house resin

International Nuclear Information System (INIS)

Pal, Sangita; Thalor, K.L; Prabhakar, S.; Srivastava, V.K.; Goswami, J.L.; Tewari, P.K.; Dhanpal, Pranav; Goswami, J.L.

2010-01-01

A selective and strong in-house chelator has been studied w.r.t. basic parameters like concentration, time, and elution. De-contamination of cadmium, mercury, chromium, lead etc by using high uptake values fro cadmium ions proves its selectivity with high elution ratio ensures further decontamination of run-off water during natural calamities. In three step cascade use the concentration of original cadmium solution (500 ppm) decocted to safe disposable attribute. This polymeric ligand exchanger displayed outlet effluent concentration to 1 ppm and less than 200 ppb when treated for inlet feed concentration of 50 ppm and 500 ppm respectively. (author)

Decontamination Study for Mixed Waste Storage Tanks RCRA Closure

International Nuclear Information System (INIS)

Leaphart, D.M.; Reed, S.R.; Rankin, W.N.

1995-01-01

The Savannah River Site (SRS) plans to close six underground tanks storing mixed waste under RCRA regulations. In support of this closure effort, a study was performed to determine the optimal method of decontaminating these tanks to meet the closure requirements. Items consaidered in the evaluation of the decontamination methods included effectiveness, compatibility with existing waste residues, possible cleaning solution disposal methods, and cost

Electrochemical decontamination of metallic surfaces by means of a movable electrode

International Nuclear Information System (INIS)

Mihai, F.; Nicu, M.; Cazan, L.; Turcanu, C.

1998-01-01

Electrochemical decontamination can be considered to be a decontamination assisted by an electrochemical field. The method is applied to the metallic surface decontamination for contaminants of any physico-chemical nature. The physico-chemical phenomenon that is the basis for the electrochemical methods is the anodic layer dissolution. By dissolution of the superficial layer any radioactive contaminant on the surface or entrapped within the surface oxide is eliminated. Electrochemical decontamination, also known as electropolishing, involves the use of the object to be cleaned as an anode in an electrochemical cell. The passage of current results in anodic dissolution of the surface material. Generally, there are many methods of application for electropolishing. The most common method is immersing the object to be decontaminated in a tank filled with a suitable electrolyte. The electrochemical method with movable electrode involves the use of 'in situ' mobile devices that are able to electropolish punctual surfaces in places difficult to access. The advantages are the simplicity of the setup, short times of application and reduced waste volumes. Phosphoric and sulphuric acid mixture is used as the electrolyte in electropolishing because of its stability, safety and applicability to a variety of alloy systems. The method was applied to decontaminate carbon steel, aluminium and copper. Used contaminants are mixtures of 60 Co and 134 Cs; 60 Co and 65 Zn; 60 Co, 65 Zn and 134 Cs. After preparation, the samples were kept in laboratory conditions about one month, to simulate real conditions and to let the chemical reactions between contaminant and sample material constitution to complete. To calculate decontamination factor characteristic for each studied decontamination method the following radiometric measurements are necessary: - activity measurement after radioisotope solution contamination representing initial activity Λ in ; - activity measurement after

The Efficiency of Strontium-90 Desorption Using Iron (III) Solutions in the Decontamination Process of Radioactive Soils

OpenAIRE

Olga Vladimirovna Cheremisina; Vasiliy Sergeev; Varvara Alabusheva; Alexander Fedorov; Alexandra Iliyna

2018-01-01

The paper presents the investigation on the estimated efficiency of iron (III) chloride solutions in the decontamination process of radioactive soils with 90 Sr, according to kinetic and thermodynamic characteristics of the desorption process. The specific 90 Sr radioactivity of soil samples was (3.9±0.3)·104 Bq·g. The adsorption isotherms of Sr 2+ and Fe 3+ are described with the Langmuir equation. The values of Gibbs energy G0298 = -4.65 kJ·mol -1 and equilibrium ion exchange constant ...

Organophosphate degrading microorganisms and enzymes as biocatalysts in environmental and personal decontamination applications.

Science.gov (United States)

Yair, Simo; Ofer, Butnaro; Arik, Eisenkraft; Shai, Shrot; Yossi, Rosman; Tzvika, Dushnitsky; Amir, Krivoy

2008-01-01

One of the major challenges in dealing with chemical warfare agent (CWA) dispersal, whether in the battlefield or after a terror act, is decontamination and rehabilitation of any contaminated area. Organophosphates (OPs) are considered to be among the deadliest CWAs to date. Other OPs are used as pesticides in modern agriculture, and are considered environmentally hazardous. Current methods for OP decontamination are either dangerous or insufficiently effective. As a promising solution for this problem, bioremediation--the use of biocomponents for environmental remediation--is a potentially effective, safe, and environment-friendly method. The technology relies on several enzymatic mechanisms, and can be applied in various ways. We will review recent achievements and potential applications, such as biocatalyst-containing foams and an enzymatic sponge, for environmental as well as personal exterior decontamination.

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

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

Surface Decontamination Studies of Cs-137 and Sr-85 Using Polymer Gel

International Nuclear Information System (INIS)

Pham, L.; Nguyen, C.; Nguyen, L.

2015-01-01

Strippable polymer coating is one of the methods for effective surface decontamination to remove isotopes on the contaminated surface. This method is applying in nuclear facilities on the World. In this paper, we present the results obtained in our laboratory from product the polymer coating to apply to remove radioisotopes of "1"3"7Cs and "8"5Sr from surface of glass, stainless steel, mild steel, ceramic, PVC plastic. This polymer gel solution consist of water soluble polymer preferably polyvinyl alcohol (PVA), plasticizing agent (glycerine) and chelating agents, (citric acid) which can be sprayed or pasted on to contaminated surface. After some hours, these gel solutions was dried to form a strong thin film and it was easily peeled off from a contaminated surface with the radioactive isotopes and can be disposed off as radioactive solid waste. In this study infrared spectrophotometry technique was used to examine the interaction of the cesium and strontium ions with polyvinyl alcohol (PVA), polymer gel and the results of the study were also presented. The results showed that decontamination efficiency of "1"3"7Cs and "8"5Sr strongly depended on property, porosity and smoothness of the contaminated surface and obtained from 95-99% on glass and stainless steel, ceramic and PVC plastic surfaces. The decontamination efficiency also depended on activity and coating thickness. Optimization of film thickness is around 0.2 mm. Decontamination efficiency of Polymer gel were compared with Decongel 1101 (product from USA) on surfaces. IR spectra studies indicated that Cs and Sr ions interacted with PVA and citric acid in Polymer gel through cacboxyl (C = O) group. Polymer gel could remove of "1"3"7Cs and "8"5Sr better than PVA gel does because of citric acid, which can form chelating complex with Cs and Sr ion. (author)

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.

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)

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

Reaction-diffusion models of decontamination

DEFF Research Database (Denmark)

Hjorth, Poul G.

A contaminant, which also contains a polymer is in the form of droplets on a solid surface. It is to be removed by the action of a decontaminant, which is applied in aqueous solution. The contaminant is only sparingly soluble in water, so the reaction mechanism is that it slowly dissolves...

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

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)

Testing of methods for decontamination of stainless steels and carbon steels conformably to demountable equipment of nuclear power plant with WWR type reactor

International Nuclear Information System (INIS)

Dergunova, G.M.; Nazarov, V.K.; Ozolin, A.B.; Smirnov, L.M.; Stel'mashuk, V.P.; Yulikov, E.I.; Vlasov, I.N.

1978-01-01

Results are given of experiments on decontamination of stainless steel by the oxidation-reduction method and also results of decontamination of carbon steel by means of solutions based on oxalic acid, citric acid and phosphoric acid. Investigations of efficiency of oxidation-reduction treatment were done on samples of stainless steel cut from the pipeline of the primary coolant circuit of reactor. Comparison is given of efficiency of oxidation-reduction methods of contamination of stainless steel in the case of application of different compositions of decontaminating solutions. Dependences are given for decontamination completeness on duration of operations, on temperature and on ratio of volume of decontaminating solutions to surface are of the sample. For carbon steels parameters are given for decontamination process by means of oxalic, citric and phosphoric acid solutions. (I.T.) [ru

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

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.)

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.)

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.)

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)

Developing technique for waste water cleaning of a division for equipment decontamination

International Nuclear Information System (INIS)

Gromoglasov, A.A.; Solyakov, V.K.; Novikov, V.N.; Pil'shchikov, A.P.; Chekalov, A.G.; Sinyukov, M.A.; Pshenichnykh, V.N.

1989-01-01

Results are described of developing technique for radionuclide cleaning solutions after metal product decontamination. The method is based on the adagulation with usage of quicklime. The conclusion is method permits to consider it as the main technique for waste water decontamination. 3 refs.; 2 figs.; 3 tabs

Method of recovering phosphoric acid type decontaminating electrolytes by electrodeposition

International Nuclear Information System (INIS)

Sasaki, Takashi; Wada, Koichi; Kobayashi, Toshio.

1985-01-01

Purpose: To recoving phosphoric acid type highly concentrated decontaminating liquid used for the electrolytic decontamination of contaminated equipments, components, etc in nuclear power plants or the like through electrodeposition by diaphragm electrolysis. Method: Before supplying phosphoric acid decontaminating liquid at high concentration used in the electrolytic decontaminating step to an electrodeposition recovering tank, phosphoric acid in the decontaminating electrolyte is extracted with solvents and decomposed liquid extracts (electrolyte reduced with the phosphoric acid component) are supplied to the cathode chamber of the electrodeposition recovering tank, where phosphoric acid is back-extracted with water from the solvents after extraction of phosphoric acid. Then, the back-extracted liquids (aqueous phosphoric acid solution scarcely containing metal ions) are sent to the anode chamber of the electrodeposition recovering tank. Metal ions in the liquid are captured by electrodeposition in the cathode chamber, as well as phosphoric acid in the liquids is concentrated to the initial concentration of the electrolyte in the anode chamber for reuse as the decontaminating electrolyte. As the phosphoric acid extracting agent used in the electrodeposition recovering step for the decontaminating electrolyte, water-insoluble and non-combustible tributyl phosphate (TBP) is most effective. (Horiuchi, T.)

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

[Thermodynamic forecasting of reagents composition for soils decontamination].

Science.gov (United States)

Nikolaev, V P; Nikolaevskiĭ, V B; Chirkina, I V; Shcheglov, M Iu

2009-01-01

Based on thermodynamic studies, the authors conducted laboratory experiments on searching optimal composition of leaching reagents solution for soils decontamination, when contaminated with Cs-137, of activity coefficient for caesium sulfate microquantities in macrocomponents solutions. The method could be used for modelling the radionuclides phase equillibrium and relocations in soils.

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

Development of complex electrokinetic decontamination method for soil contaminated with uranium

International Nuclear Information System (INIS)

Kim, Gye-Nam; Kim, Seung-Soo; Park, Hye-Min; Kim, Wan-Suk; Moon, Jei-Kwon; Hyeon, Jay-Hyeok

2012-01-01

520L complex electrokinetic soil decontamination equipment was manufactured to clean up uranium contaminated soils from Korean nuclear facilities. To remove uranium at more than 95% from the radioactive soil through soil washing and electrokinetic technology, decontamination experiments were carried out. To reduce the generation of large quantities of metal oxides in cathode, a pH controller is used to control the pH of the electrolyte waste solution between 0.5 and 1 for the formation of UO 2+ . More than 80% metal oxides were removed through pre-washing, an electrolyte waste solution was circulated by a pump, and a metal oxide separator filtered the metal oxide particles. 80–85% of the uranium was removed from the soil by soil washing as part of the pre-treatment. When the initial uranium concentration of the soil was 21.7 Bq/g, the required electrokinetic decontamination time was 25 days. When the initial concentration of 238 U in the soil was higher, a longer decontamination time was needed, but the removal rate of 238 U from the soil was higher.

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

Science.gov (United States)

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

2011-11-30

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

A rapid and inexpensive bioassay to evaluate the decontamination of organophosphates.

Science.gov (United States)

Claborn, David M; Martin-Brown, Skylar A; Sagar, Sanjay Gupta; Durham, Paul

2012-01-01

An inexpensive and rapid bioassay using adult red flour beetles was developed for use in assessing the decontamination of environments containing organophosphates and related chemicals. A decontamination protocol was developed which demonstrated that 2 to 3 applications of 5% bleach solution were required to obtain nearly complete decontamination of malathion. The bioassay was also used to screen common household cleaners as potential decontaminating agents, but only 5% bleach was effective at improving survival of insects on steel plates treated with 25% malathion. A toxic degradation product (malaoxon) was detected using gas chromatography/mass spectrophotometry; this toxin affected the decontamination efficacy and resulted in continued toxicity to the beetles until subsequent decontaminations. The bioassay provides evidence to support the use of red flour beetles as a sensitive, less expensive method for determining safety levels of environments contaminated with malathion and other toxins, and may have application in the study of chemical warfare agents.

Method to chemically decontaminate nuclear reactor components

International Nuclear Information System (INIS)

Bertholdt, H.O.

1984-01-01

The large decontamination of components of the primary circuit of activated corrosion products in the oxide layer of the structure materials firstly involves an approx. 1 hour oxidation treatment with alkali permanganate solution. Following intermediate rinsing with deionate, they are etched with an inhibited citrate-oxalate solution for 5-20 hours. This is followed by post-treatment with a citric acid/H2O2 solution containing suspended fiber particles. (orig./PW)

Decontamination Experiments on Intact Pig Skin Contaminated with Beta-Gamma- Emitting Nuclides

Energy Technology Data Exchange (ETDEWEB)

Edvardsson, K A; Hagsgaard, S [AB Atomenergi, Nykoeping (Sweden); Swensson, A [Dept. of Occupational Medicine, Karolinska Sjukhuset, Stockholm (Sweden)

1966-11-15

A number of decontamination experiments have been performed on intact pig skin. In most of the experiments NaI-131 in water solution has been utilized because this nuclide is widely used within the Studsvik research establishment, is easy to detect and relatively harmless, and is practical to use in these experiments. Among the {beta} {gamma}-nuclides studied 1-131 has furthermore proved to be the one most difficult to remove from the skin. The following conclusions and recommendations regarding the decontamination of skin are therefore valid primarily for iodine in the form of Nal, but are probably also applicable to many other {beta} {gamma}-nuclides. a) A prolonged interval between contamination and decontamination has a negative effect on the result of the decontamination. Therefore start decontamination as soon as possible after the contamination. b) Soap and water has proved to be the most suitable decontamination agent. A number of other agents have appeared to be harmful to the skin. Therefore, first of all use only soap and water in connection with gentle rubbing. c) No clear connection between the temperature of the water for washing and the result of the decontamination has been demonstrated. d) Skin not degreased before the contamination seems to be somewhat easier to decontaminate than degreased skin, particularly if the activity has been on the skin for a long time. Therefore do not remove the sebum of the skin when engaged on radioactive work involving contamination risks. e) Irrigation of the contaminated surface with a solution containing the corresponding inactive ions or ordinary water in large quantities may considerably decrease the skin contamination. f) In radioactive work of long duration involving high risks of contamination prophylactic measures in the form of a protective substance ('invisible glove'), type Kerodex, may make decontamination easier.

Decontamination Experiments on Intact Pig Skin Contaminated with Beta-Gamma- Emitting Nuclides

International Nuclear Information System (INIS)

Edvardsson, K.A.; Hagsgaard, S.; Swensson, A.

1966-11-01

A number of decontamination experiments have been performed on intact pig skin. In most of the experiments NaI-131 in water solution has been utilized because this nuclide is widely used within the Studsvik research establishment, is easy to detect and relatively harmless, and is practical to use in these experiments. Among the β γ-nuclides studied 1-131 has furthermore proved to be the one most difficult to remove from the skin. The following conclusions and recommendations regarding the decontamination of skin are therefore valid primarily for iodine in the form of Nal, but are probably also applicable to many other β γ-nuclides. a) A prolonged interval between contamination and decontamination has a negative effect on the result of the decontamination. Therefore start decontamination as soon as possible after the contamination. b) Soap and water has proved to be the most suitable decontamination agent. A number of other agents have appeared to be harmful to the skin. Therefore, first of all use only soap and water in connection with gentle rubbing. c) No clear connection between the temperature of the water for washing and the result of the decontamination has been demonstrated. d) Skin not degreased before the contamination seems to be somewhat easier to decontaminate than degreased skin, particularly if the activity has been on the skin for a long time. Therefore do not remove the sebum of the skin when engaged on radioactive work involving contamination risks. e) Irrigation of the contaminated surface with a solution containing the corresponding inactive ions or ordinary water in large quantities may considerably decrease the skin contamination. f) In radioactive work of long duration involving high risks of contamination prophylactic measures in the form of a protective substance ('invisible glove'), type Kerodex, may make decontamination easier

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.

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)

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

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.)

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.)

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)

Effect of decontamination on nuclear power plant primary circuit materials

International Nuclear Information System (INIS)

Brezina, M.; Kupca, L.

1991-01-01

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

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.

Development of peelable films for decontamination and their performances

International Nuclear Information System (INIS)

Yang Enbo; Xu Baolan; Zhao Xiuyan

1990-01-01

Two kinds of peelable films have been developed which can be coated on surface contaminated by radioactivity for decontamination purposes. Very high levels of radioactive decontamination, especially on smooth surface, are obtained after one application. 90-99% decontamination based on initial activity can be obtained for stainless steel, PVC floor and glass

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.)

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.)

Investigation of electro-kinetic methods for soil decontamination

International Nuclear Information System (INIS)

Shabanova, A.N.

2000-01-01

The choices of effective methods for ecological system decontamination, their perfection and introduction into practical use have been actual tasks for the Ural region. The objective of this work has been to study the potentials of electrical kinetics method of ISOTRON Corporation (US) for decontamination of the Urals soils. Results obtained have shown the method proposed to be usable for decontaminating some types of soils from strontium and plutonium; it is low effective for decontamination in the area of South-Urals radioactive plume. Thus, a low effectiveness can be expected in podsolic and leached laterite characterized by a high content of loamy sand and sandy soils, as well as for sobby-podsolic ones. The method can be promising for decontamination of soils and wastes from chemical contaminants, such as Zn, Ni, Cu, Pb, Hg, and others. Important advantages of this method compared to others have been its simplicity, small amount of wastes, and feasibility of decontamination in areas difficult to access. (authors)

Chemical decontamination and melt densification of chop-leach fuel hulls

International Nuclear Information System (INIS)

Dillon, R.L.; Griggs, B.; Kemper, R.S.; Nelson, R.G.

1976-01-01

This paper reports on decontamination and densification studies of chop-leach fuel hull residues designed to minimize the transuranic element (TRU) contaminated waste stream. Decontamination requirements have been established from studies of TRU element distribution in the fuel hull residues. Effective surface decontamination of Zircaloy requires removal of zirconium oxide corrosion products. Good decontamination factors have been achieved with aqueous solutions following high temperature HF conditioning of oxide films. Molten fluoride salt mixtures are effective decontaminants, but pose problems in metal loss and salt dragout. Molten metal decontamination methods are highly preliminary, but may be required to reduce TRU originating from tramp uranium in Zircaloy. Low melting (1300 0 C) alloy of Zircaloy, stainless steel, and Inconel have been prepared in induction heated graphite crucibles. High quality ingots of Zircaloy-2 have been prepared directly from short sections of descaled fuel clad tubing using the Inductoslag process. This material is readily capable of refabrication. Inductoslag melts have also been prepared from heavily oxidized Zircaloy tubing demonstrating melt densification without prior decontamination is technically feasible. Hydrogen absorption kinetics have been demonstrated with cast Zircaloy-2 and cast Zircaloy-stainless steel-Inconel alloys. Metallic fuel hull residues have been proposed as a storage medium for tritium released from fuel during reprocessing. (author)

Polymeric compositions for “dry” decontamination of NPP equipment and premises

International Nuclear Information System (INIS)

Voronik, N.I.; Toropova, V.V.

2015-01-01

In JIPNR – “Sosny” NASB developed decontaminating polymeric compositions based on binder – polyvinyl alcohol solution with active additives such as nitric and borohydrofluoric acids, 1-hydroxyethylidene diphosphonic acid and its salts, detergents and fillers - natural tripoli; tripoli modified by ferrocyanides of nickel and copper; pulverized dolomite modified by manganese oxides, ferrocyanides of nickel and copper; clinoptilolite modified by iron chlorides (III) and calcium sodium phosphate and potassium ferrocyanide; hydrolytic lignin. It is shown that the developed decontaminating polymeric compositions (pastes) possess high decontaminating capacity (FD 102 – 103) and low adhesion to the surfaces of stainless and carbon steels, including painted, plastic, self-leveling floors, teflon-surface. Prolonged leaching method allowed determine the chemical resistance of “dry” decontamination wastes, strength of "1"3"7Cs and "6"0Co fixations in wastes obtained in result of using new decontamination pastes [ru

A scaffold easy to decontaminate

International Nuclear Information System (INIS)

Mourek, D.

1992-01-01

The conventional scaffold used in the assembling work and in revisions of technological facilities at nuclear power plants has many drawbacks. The most serious of them are a high amount of radioactive waste arising from the decontamination (planing) of the floor timber and from the discarding of damaged irreparable parts, and a considerable corrosion of the carbon steel supporting structure after the decontamination. A detailed description is given of a novel scaffold assembly which can be decontaminated and which exhibits many assets, in particular a good mechanical resistance (also to bad weather), a lower weight, and the use of prepreg floor girders for the construction of service platforms or scaffold bridges which can readily be assembled from the pressed pieces in a modular way. (Z.S.). 4 figs., 4 refs

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

Electrolytic decontamination of conductive materials for hazardous waste management

International Nuclear Information System (INIS)

Wedman, D.E.; Martinez, H.E.; Nelson, T.O.

1996-01-01

Electrolytic removal of plutonium and americium from stainless steel and uranium surfaces has been demonstrated. Preliminary experiments were performed on the electrochemically based decontamination of type 304L stainless steel in sodium nitrate solutions to better understand the metal removal effects of varying cur-rent density, pH, and nitrate concentration parameters. Material removal rates and changes in surface morphology under these varying conditions are reported. Experimental results indicate that an electropolishing step before contamination removes surface roughness, thereby simplifying later electrolytic decontamination. Sodium nitrate based electrolytic decontamination produced the most uniform stripping of material at low to intermediate pH and at sodium nitrate concentrations of 200 g L -1 and higher. Stirring was also observed to increase the uniformity of the stripping process

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

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 some liquid wastes of medium activity with a new solvent type

International Nuclear Information System (INIS)

Gasparini, G.

1986-01-01

The decontamination of a reference MAWsub(s) (an alkaline solution coming from the solvent washing and an acidic solution consisting of the mixture of aqueous raffinates deriving from uranium and plutonium purification cycles) by hydroxamic acid is reported. The results of the ''in batch'' decontamination tests, using extraction chromatography techniques, are given. The extraction chromatography techniques do not give the expected performances for the tests in column. Discontinuous liquid extraction tests using traced solutions show that Pu, Am, Zr, Nb are extracted but not U and Ru. The strip of Pu, Am and Zr with an oxalic acid solution is quantitative. Continuous tests using mixer settler batteries, and a simulated alkaline solution and complete extraction-reextraction runs using a simulated solution are conducted. The results of a discontinuous conclusive experiments using a true alkaline solution coming from a reprocessing plant are given

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?

Decontamination before dismantling a fast breeder reactor primary cooling system

International Nuclear Information System (INIS)

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

1997-01-01

The large-scale decontamination of FBR sodium loops is a novel task, as only a limited number of laboratory-scale results are available to date. The principal objective of this work is to develop a suitable decontamination procedure for application to the primary loops of the RAPSODIE fast breeder reactor as part of decommissioning to Stage 2. After disconnecting the piping from the main vessel, the pipes were treated by circulating chemical solutions and the vessels by spraying. The dose rate in the areas to be dismantled was divided by ten. A decontamination factor of about 300 was obtained, and should allow austenitic steel parts to be melted in special furnaces for unrestricted release. (author)

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.)

Volume reduction and material recirculation by freon decontamination

International Nuclear Information System (INIS)

Berners, O.; Buhmann, D.; Yamashita, Y.; Yoshiaki, M.

1989-01-01

This paper discusses the use of freon in a large variety of decontamination in the nuclear and non-nuclear fields. As far as the contamination is loose or smerable, surfaces of nearly all materials can be decontaminated. Freon is electrically non-conductive, chemically neutral and has a low surface tension. So it is capable of creeping under the contaminant and loosening or dissolving it. Used freon can be collected, cleaned and recirculated. Its cleaning can be done easily by evaporation at its lower vapor point of about 48 degrees C (104 degrees F). Good decontamination results could be achieved, expensive materials, tools and equipment could be recirculated. Big volumes of materials could get separated from their contaminants, which is the real radioactive waste. Freon decontamination is an effective, overall economical and approved technology to volume reduction and material recirculation

Decontamination Efficacy Testing of COTS SteriFx Prodcuts for Mass Personnel and Casualty Decontamination

Science.gov (United States)

2011-09-01

amounts of water for at least 15 min. Ingestion : If alert give several glasses of water or milk . Do not induce vomiting. Contact poison control center...strong oxidants that can harm skin and eyes. A safe, easily disseminated and effective alternative biological decontamination agent is needed to address...outlined in our preliminary work, shows that the technology has a very low risk of doing harm to personnel in decontamination scenarios, or that

Oxidation of Ce(III) in Foam Decontaminant by Ozone

Energy Technology Data Exchange (ETDEWEB)

Jung, Chong Hun; Yoon, I. H.; Choi, W. K.; Moon, J. K.; Yang, H. B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, J. S. [Gachon University, Seongnam (Korea, Republic of)

2016-10-15

A nanoparticle-based foam decontaminant is composed of a surfactant and nanoparticles for the generation and maintenance of foam, and a chemical decontamination agent made of Ce(IV) dissolved in nitric acid. Ce(IV) will be reduced to Ce(III) through the decontamination process. Oxidizing cerium(III) can be reused as a decontamination agent, Ce(IV). Oxidation treatment technology by ozone uses its strong oxidizing power. It can be regarded as an environmentally friendly process, because ozone cannot be stored and transported like other industrial gases (because it quickly decays into diatomic oxygen) and must therefore be produced on site, and used ozone can decompose immediately. The ozonation treatment of Ce(III) in foam decontaminant containing a surfactant is necessary for the effective regeneration of Ce(III). Thus, the present study was undertaken to determine the optimal conditions for ozonation treatment in the regeneration of Ce(III) into Ce(IV) in the nanoparticle-based foam decontaminant containing surfactant. This study was undertaken to determine the optimal conditions for ozonation treatment in the regeneration of Ce(III) to Ce(IV) in nanoparticle-based foam decontaminant containing a TBS surfactant. The oxidation conversion rate of Ce(III) was increased with an increase in the flow rate of the gas mixture and ozone injection amount. The oxidation time required for the 100% oxidation conversion of Ce(III) to Ce(IV) at a specific ozone injection amount can be predicted from these experimental data.

Oxidation of Ce(III) in Foam Decontaminant by Ozone

International Nuclear Information System (INIS)

Jung, Chong Hun; Yoon, I. H.; Choi, W. K.; Moon, J. K.; Yang, H. B.; Lee, J. S.

2016-01-01

A nanoparticle-based foam decontaminant is composed of a surfactant and nanoparticles for the generation and maintenance of foam, and a chemical decontamination agent made of Ce(IV) dissolved in nitric acid. Ce(IV) will be reduced to Ce(III) through the decontamination process. Oxidizing cerium(III) can be reused as a decontamination agent, Ce(IV). Oxidation treatment technology by ozone uses its strong oxidizing power. It can be regarded as an environmentally friendly process, because ozone cannot be stored and transported like other industrial gases (because it quickly decays into diatomic oxygen) and must therefore be produced on site, and used ozone can decompose immediately. The ozonation treatment of Ce(III) in foam decontaminant containing a surfactant is necessary for the effective regeneration of Ce(III). Thus, the present study was undertaken to determine the optimal conditions for ozonation treatment in the regeneration of Ce(III) into Ce(IV) in the nanoparticle-based foam decontaminant containing surfactant. This study was undertaken to determine the optimal conditions for ozonation treatment in the regeneration of Ce(III) to Ce(IV) in nanoparticle-based foam decontaminant containing a TBS surfactant. The oxidation conversion rate of Ce(III) was increased with an increase in the flow rate of the gas mixture and ozone injection amount. The oxidation time required for the 100% oxidation conversion of Ce(III) to Ce(IV) at a specific ozone injection amount can be predicted from these experimental data

A study of the decontamination effect of commercial detergents on the skin

International Nuclear Information System (INIS)

Takasaki, Koji; Miyabe, Kenjiro

2003-01-01

Titanium dioxide paste is generally used as the radiological skin decontaminant in the radiation control area at Japan Nuclear Cycle Development Institute (JNC) Tokai works. It is a typical and proven skin decontaminant in the nuclear industry, but there is a disadvantage in that it has a short shelf life. Recently, many detergents applicable as skin decontaminants have become available in non-nuclear industries such as cosmetics and sanitation. They are easily acquired and have an advantage in that stimulus to the skin is mild, because these products have been developed for the human body. In this study, the decontamination factor of the commercial detergents for each nuclide was examined using imitation skin. Sheets of raw pig skins were contaminated with a nitric-acid solution containing 144 Ce, 137 Cs, 106 Ru or 60 Co, and then washed with various detergents such as a neutral detergent, cleansing cream and orange oil. The nuclide removal rates of some of the commercial detergents examined were nearly equal to that of titanium dioxide, thus proving that they show satisfactory decontamination performance as a skin decontaminant. (author)

Decontamination of transvaginal ultrasound probes: Review of national practice and need for national guidelines

International Nuclear Information System (INIS)

Gray, R.A.; Williams, P.L.; Dubbins, P.A.; Jenks, P.J.

2012-01-01

Aim: To determine the national practice of transvaginal ultrasound (TVUS) probe decontamination in English hospitals and to develop recommendations for guidance. Materials and methods: A literature review was undertaken to clarify best practice and evaluate methods of decontamination of TVUS probes. A questionnaire was developed to ascertain TVUS probe decontamination programmes in current use within English hospitals. This was sent to ultrasound leads of 100 English hospitals; 68 hospitals responded. Results: There is a wide variation in TVUS probe decontamination across English hospitals. Although the majority of respondents (87%, 59/68) reported having clear and practical written guidelines for TVUS decontamination, the frequency, methods, and types of decontamination solutions utilized were widely variable and none meet the standards required to achieve high-level disinfection. Conclusion: While the decontamination of other endoluminal medical devices (e.g., flexible endoscopes) is well defined and regulated, the decontamination of TVUS probes has no such guidance. There appears to be incomplete understanding of the level of risk posed by TVUS probes, and in some cases, this has resulted in highly questionable practices regarding TVUS hygiene. There is an urgent need to develop evidence-based national guidance for TVUS probe decontamination.

A decontamination technique for decommissioning waste

International Nuclear Information System (INIS)

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

1993-01-01

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

Decontamination by ultrafiltration of low radioactivity waste water from fuel element fabrication

International Nuclear Information System (INIS)

Muller, H.M.

1984-01-01

It could be demonstrated that waste waters which contain uranium in a filterable form, such as laundry and floor-cleaning waste, can be sufficiently decontaminated by means of ultra-filtration. In the case of process waste solutions, which contain uranium in a dissolved form, high decontamination factors could be achieved by means of flocculation or coprecipitation. The following methods were tested: - flocculation with Fe (OH) 3 , - coprecipitation with CaHPO 4 , - precipitation with K 4 (Fe(CN) 6 ). The phosphate precipitation, whereby the uranium is probably coprecipitated as Ca(UO 2 ) 2 (PO 4 ) 2 , was found to be the most reliable method. Difficulties were encountered when complex-forming anions, notably carbonate, oxalate and fluoride were present. These necessitate specific pretreatment steps. Whether ultrafiltration then still remains an economical option must be judged in each individual case. The application of the methods so far developed on combined waste streams remains an object for further research. In combination with a phosphate precipitation, ultrafiltration is a suitable method for the decontamination of low-activity, uranium-contaminated waste waters

Decontamination of CANDU primary coolant system

International Nuclear Information System (INIS)

Pettit, P.J.

1975-01-01

Decontamination of radioactive systems is necessary to reduce personnel radiation exposures and also to reduce exposure during special work. Mechanical decontamination methods are sometimes useful, but most contaminated surfaces are inaccessible, so chemical decontamination often is preferred. The A-P Citrox method will remove most contaminants from CANDU systems, but is costly and long, damages components, and produces large quantities of radioactive liquid waste. The Redox cycling process is fast and inexpensive, produces only solid wastes, but removes small quantities of deposit from Monel only. The CAN-DECON process removes deposits from most materials including fuel cladding and has many other advantages. (author)

General recommendations for decontamination procedures to individuals

International Nuclear Information System (INIS)

Ohlenschlaeger, L.; Messerschmidt, J.P.

1989-04-01

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

Decontamination of plutonium-contaminated surfaces

International Nuclear Information System (INIS)

Bertrand, J.; Clouet d'Orval, Ch.; Tachon, J.

1958-01-01

The measure of the neutron distribution in the core of 'Proserpine', by means of activation detectors, requires no contact between the plutonium sulfate solution and the detectors. These detectors are put into PVC or polyethylene bags. This report describes the process used to decontaminate these bags. A washing by nitric acid followed by coating with plexiglass is kept, with this process we have no contamination on the detectors. (author) [fr

Contamination, decontamination and radiochemical safety analyses of the RA reactor (Report 1966)

International Nuclear Information System (INIS)

Maksimovic, Z.

1966-12-01

This contract is concerned with development of methods for detection of fission products i the heavy water and quantitative radiochemical analysis for detecting one fission product which enables reliable verification of heavy water contamination by fission products and estimation of contamination level. Qualitative and quantitative radiometry measurements of fission products in water are shown on page 4. Page 6 shows study of contamination and decontamination of water on the laboratory level. Experiments have shown that the majority of fission products was adsorbed on the uranium oxide and that the iodine isotopes are partly in water (non-adsorbed). Gamma spectrometry analyses showed 131 I moves to distillate with the initial quantities of distilled water. decontamination factors compared to the total activity of fission products in distillator and distillate are not higher than ∼10 3 . Decontamination of water contaminated by uranium oxide and fission products in the distillation device of the RA reactor is shown on page 8. Experiments demanded special preparation due to high activity of uranium (1.7 g of uranium irradiated in the reactor for 10 days at neutron flux 1.10 13 n.cm 2 /s. Prior preparations for transport and dissolution of irradiated metal uranium as well as sampling were needed. Distillation was done under lower pressure and temperature to avoid possible contamination of the environment bu fission products and iodine. Decontamination factors are shown in Table. Contamination and decontamination of stainless steel on the laboratory level are described on page 5. It was found that the deposition of activity on the stainless steel plates is inhomogeneous showing that the uranium oxide and fission products are deposited on the rough metal surfaces. According to literature data and our laboratory studies decontamination was done by nitric acid solution (2MHNO 3 ). Since the heavy water system of the RA reactor was made of stainless teel (except the

Studies of radioactive deposition on farm buildings and testing of some methods for decontamination

International Nuclear Information System (INIS)

Andersson, Inger; Erlandsson, B.; Hansson, J.; Dolby, C.M.

1993-01-01

Studies were made of radioactive fallout on roofs of farm buildings and of some methods of decontamination. The aim was to find ways of reducing the external radiation dose to farmers working and farm animals housed in stables in a fallout situation. The roof material studied was steel plate (A) and tile (B,C, D), each with four sample areas of ca. 1 m 2 . The roof samples were collected at three places and from totally four building in regions which in 1986 (after the Chernobyl fallout) has a 137 Cs ground depositions of 3040 kBq/m 2 (A, B, C) and > 100 kBq/m 2 (D). Four different decontamination methods were tested: 1. High pressure washing with water. 2. Repeated high pressure washing with water. 3. Application of foam of a sanitizing chemical for livestock buildings followed by high pressure washing with water. 4. Application of a solution of KCl followed by high pressure washing with water. In C, the effect of decontamination expressed as the percentage decrease of the 137 Cs activity was on average for all methods, 55%. This material was coated before the decontamination by a marked growth of algae or moss, which was effectively washed off during the sanitizing procedure. In B, the average activity decontamination effect was 25%, while in D (with the highest original activity, but without growth of organic material) the effect was very small, 3%. In A, the activity level before decontamination was so low that measurements after decontamination were considered unnecessary. Method number 4 was the most effective in B and C, 32% and 64%, respectively, while method number 3 was the most effective in D, 5.7%. The results indicate that good effects can be achieved in radioactivity decontamination of roof material with equipment and chemicals which are normally available on farms

Effect of HNO3-cerium(IV) decontamination on stainless steel canister materials

International Nuclear Information System (INIS)

Westerman, R.E.; Mackey, D.B.

1991-01-01

Stainless steel canisters will be filled with vitrified radioactive waste at the West Valley Demonstration Project (WVDP), West Valley, NY. After they are filled, the sealed canisters will be decontaminated by immersion in a HNO 3 -Ce(IV) solution, which will remove the oxide film and a small amount of metal from the surface of the canisters. Studies were undertaken in support of waste form qualification activities to determine the effect of this decontamination treatment on the legibility of the weld-bead canister identification label, and to determine whether this decontamination treatment could induce stress-corrosion cracking (SCC) in the AISI 304L stainless steel (SS) canister material. Neither the label legibility nor the canister integrity with regard to SCC were found to be prejudiced by the simulated decontamination treatment

The Efficiency of Strontium-90 Desorption Using Iron (III Solutions in the Decontamination Process of Radioactive Soils

Directory of Open Access Journals (Sweden)

Olga Vladimirovna Cheremisina

2018-03-01

Full Text Available The paper presents the investigation on the estimated efficiency of iron (III chloride solutions in the decontamination process of radioactive soils with 90 Sr, according to kinetic and thermodynamic characteristics of the desorption process. The specific 90 Sr radioactivity of soil samples was (3.9±0.3·104 Bq·g. The adsorption isotherms of Sr 2+ and Fe 3+ are described with the Langmuir equation. The values of Gibbs energy G0298 = -4.65 kJ·mol -1 and equilibrium ion exchange constant Keq = 6,5 confirm the hypothesis of strontium removal from soils with iron (III cations. The effectiveness of the method is substantiated by experimental and calculated results of this study samples of radioactive soils are deactivated in 90% after 9.5 hours, whereas the kinetic constant is 6.77·10 s -1 . The suggested method of soil cleanup with 0.2 M Fe 3+ solutions is optimal and complies with the environmental requirements.

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.

Basic study on decontamination of TRU wastes with cerium mediated electrolytic oxidation method

International Nuclear Information System (INIS)

Ishii, Junichi; Kobayashi, Fuyumi; Uchida, Shoji; Sumiya, Masato; Kida, Takashi; Shirahashi, Koichi; Umeda, Miki; Sakuraba, Koichi

2010-03-01

At Nuclear Fuel Cycle Safety Engineering Research Facility (NUCEF), the cerium mediated electrolytic oxidation method which is a decontamination technique to decrease the radioactivity of TRU wastes to the clearance-level has been developed for the effective reduction of TRU wastes generated from the decommissioning of a nuclear fuel reprocessing facility and so on. This method corrodes the oxide layer and the surface of metallic TRU metal wastes by the strong oxidation power of Ce 4+ in nitric acid. In this study, parameter tests were conducted to optimize the solution condition of Ce 3+ initial concentrations and nitric acid concentrations. The target corrosion rate of metallic TRU wastes set to be 2 - 4 μm/h for the practical use of this method. Under the optimized solution condition, a dissolution test of stainless steel simulating wastes was carried out. From the result of the dissolution test, the average corrosion rate was 3.3 μm/h during the test time of 90 hours. Based on the supposition that the corrosion depth of metallic TRU wastes was 20 μm enough to achieve the clearance-level, the treatment time for the decontamination was about 6 hours. It was confirmed from the result that the decontamination could be performed within one day and the decontamination solution could repeatedly reuse 15 times. (author)

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

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.

Performance test of wet type decontamination device

International Nuclear Information System (INIS)

Lee, E. P.; Kim, E. G.; Min, D. K.; Jun, Y. B.; Lee, H. K.; Seu, H. S.; Kwon, H. M.; Hong, K.P.

2003-01-01

The intervention area located at rear hot cell can be contaminated by hot cell maintenance work. For effective decontamination of the intervention floor a wet type decontamination device was developed. The device was assembled with a brush rotating part, a washing liquid supplying part, an intake part for recovering contaminated liquid and a device moving cart part. The device was made of stainless steel for easy decontamination and corrosion resistance. The function test carried out at intervention area of the PIE facility showed good performance

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)

Method of bituminization equipment decontamination

International Nuclear Information System (INIS)

Alexa, J.

1982-01-01

Overheated water vapour is fed into the contaminated area containing substances insoluble in water but soluble in organic solvents. Prior to entry into the decontaminated area the vapour bubbles through the aqueous solution layer of suitable detergents and a layer of suitable organic solvent. In this process the distillation takes place of the solvent and the aerosols of the aqueous solution are carried away with the vapour stream, condense on the inner surface of the vessel and thus wash it. The condensate flows down the walls and in its place condense other fractions of pure solvent and the aqueous solution. The walls of the vessel are slowly heated and the liquid waste is discharged via a mud discharge pipe. (J.B.)

Decontamination process and device of a radioactive surface with a coherent light beam. Procede et installation de decontamination d'une surface radioactive au moyen d'un faisceau de lumiere coherente

Energy Technology Data Exchange (ETDEWEB)

Gauchon, J.P.; Bournot, P.; Caminat, P.; Dupont, A.

1994-07-29

To decontaminate a radioactive surface, this one is swept with a focused laser beam and a liquid such as water or preferably a nitric acid solution on the whole surface. The liquid may be a film running on the surface and is recycled advantageously. The resulting decontamination is very efficient. 6 refs., 2 figs., 5 tabs.

Decontamination impacts on solidification and waste disposal

International Nuclear Information System (INIS)

Kempf, C.R.; Soo, P.

1988-01-01

Research to determine chemical and physical conditions which could lead to thermal excursions, gas generation, and/or general degradation of decontamination-reagent-loaded resins has shown that IRN-78, IONAC A-365, and IRN-77 organic ion exchange resin moisture contents vary significantly depending on the counter ion ''loading.'' The extent/vigor of the reaction is very highly dependent on the degree of dewatering of the resins and on the method of solution addition. The heat generation may be due, in part, to the heat of neutralization. In studies of the long-term compatibility effects of decontamination waste resins in contact with waste package container materials in the presence of decontamination reagents, radiolysis products and gamma irradiation, it has been found that the corrosion of carbon steel and austenitic stainless steel in mixed bed resins is enhanced by gamma irradiation. However, cracking in high density polyethylene is essentially eliminated because of the rapid removal of oxygen from the environment by gamma-induced oxidation of the large resin mass. 13 refs., 10 figs., 3 tabs

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.

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

Energy Technology Data Exchange (ETDEWEB)

Levesque, R.G.

1997-02-01

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

Decontamination method for radiation-contaminated metal waste

International Nuclear Information System (INIS)

Suwa, Takeshi; Kuribayashi, Nobuhide; Yasumune, Taketoshi.

1991-01-01

In immersing radiation-contaminated metal wastes into a sulfuric acid solution thereby peeling and removing radioactive deposition cruds and dissolving the surface of the matrix metals to eliminate radioactive contaminants, when the potential of the sulfuric acid solution is shifted to a higher direction by more than a certain level due to the increase of the amount of metal ions leached from the cruds and the matrix material, the leached metal ions are electrolytically reduced to control the potential of the sulfuric acid solution to less than a predetermined potential level. Although the dissolving rate is increased as the concentration of the sulfuric acid solution is higher, it is preferably from 0.5 to 2 mol/l, since higher concentration increases the load on the waste liquid processing. Further, the temperature for solution is set to higher than a room temperature and, preferably from 50 to 90degC. Further, the potential level of the solution, although varies somewhat depending on the concentration of the leached metal ions and the temperature, is preferably controlled to less than 0.1 to 0.2 V. This can attain high decontaminating effect in a short period of time by using a sulfuric acid solution alone. (T.M.)

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

Reactor component chemical decontamination-developments in waste handling and disposal

International Nuclear Information System (INIS)

Papesch, R.; Atwood, K.L.

1989-01-01

Because of restrictive limits on man-rem exposure in European nuclear plants, a company has developed and applied a number of chemical decontamination techniques for components that must be periodically maintained. These techniques are particularly effective for components that can be placed in a decontamination bath for dose reduction prior to performing maintenance. The cleaning technique has the ability to achieve decontamination factors of at least 20 and in some cases much greater. For components with before cleaning dose rates of between 1 to as high as 80 R/hr, significant man-rem reductions are achieved when hundreds of manhours may be required to complete required component maintenance. Transferring this solvent technology to the U.S. required a program to develop solidification formulas to allow the solvent wastes to be disposed of in accordance with regulations and in a cost effective manner. This paper demonstrates in chemical decontaminations with small liquid volume systems that concentrated decontamination solvents can be employed to achieve high decontamination factors

Method of processing decontaminating liquid waste

International Nuclear Information System (INIS)

Kusaka, Ken-ichi

1989-01-01

When decontaminating liquid wastes are processed by ion exchange resins, radioactive nuclides, metals, decontaminating agents in the liquid wastes are captured in the ion exchange resins. When the exchange resins are oxidatively deomposed, most of the ingredients are decomposed into water and gaseous carbonic acid and discharged, while sulfur ingredient in the resins is converted into sulfuric acid. In this case, even less oxidizable ingredients in the decontaminating agent made easily decomposable by oxidative decomposition together with the resins. The radioactive nuclides and a great amount of iron dissolved upon decontamination in the liquid wastes are dissolved in sulfuric acid formed. When the sulfuric acid wastes are nuetralized with sodium hydroxide, since they are formed into sodium sulfate, which is most popular as wastes from nuclear facilities, they can be condensated and solidified by existent waste processing systms to thereby facilitate the waste processing. (K.M.)

Reconventionalization following antibiotic decontamination in man and animals

NARCIS (Netherlands)

Waaij, D. van der; Vossen, J.M.; Korthals Altes, C.; Hartgrink, C.

1977-01-01

Antibiotic decontamination of the digestive tract can suppress or eliminate all microorganisms in this tract that are sensitive to the antibiotics used for decontamination. Experimental work in animals has indicated that colonization resistance (CR) decreases to extremely low values during

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.)

A simple and feasible method of effectiveness evaluation on radioactive decontamination action

International Nuclear Information System (INIS)

Chen Lin; Geng Xiaobing; Sun Jian; Wang Jihong; Guo Lijun

2012-01-01

Radioactive decontamination is a vital task in nuclear emergency response. The assessment of decontamination effectiveness is of great importance to decision-making. An index system for effectiveness evaluation of radioactive decontamination action in nuclear emergency response is produced. A method of decontamination effectiveness evaluation based on analytic hierarchy process and fuzzy comprehensive evaluation is presented. Index weights are determined through analytic hierarchy process. And scores of objects in each hierarchy are judged by fuzzy comprehensive evaluation. Then comprehensive effectiveness of the top object can be obtained, which can offer a basis for decision-making of decontamination action. (authors)

Decontamination factor of the commercial detergents for the skin (part 3)

Energy Technology Data Exchange (ETDEWEB)

Miyabe, Kenjiro; Takasaki, Koji [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan); Yasunaka, Hideo; Izumi, Yuichi [Japan Environment Research Corporation, Tokyo (Japan)

2000-08-01

The commercial detergents, which are cleansing cream, shampoo, neutral detergent, etc., were examined in order to select the body cleaners that are substitutes for the titanium dioxide paste. JNC entrusted Japan Environment Research Corporation Limited with these examinations since 1997. In 1997 and 1998, the commercial detergents were examined for Ce-144, Cs-137 and Ru-106. In 1999, 22 detergents were examined for Co-60 from the result of the past examinations. In this examination, the radioactive solution of Co-60 was dropped on the pig-skin samples. These samples were washed with each detergent after 5 minutes and 40 minutes. The decontamination factors of detergents were estimated by the radioactive ratio of the samples before and after washing. As a result of this examination, the decontamination factors for Co-60 was the same as the decontamination factors for Ce-144 and Cs-137, and 11 detergents were nominated as the cleaner that have the decontamination factor more than that of titanium dioxide paste. (author)

Decontamination efficiency of detergents on the market for the skin contaminated with radioactive materials. The comparative test (1)

International Nuclear Information System (INIS)

Miyabe, Kenjiro; Ninomiya, Kazushi; Takasaki, Koji; Horiuchi, Nobuharu; Yasunaka, Hideo; Izumi, Yuichi

1999-04-01

Contamination incidence on human body and skin happens sometimes during radiation works in controlled area. The radioactive surface contamination should be removed from the skin as soon as possible for radiation control and exposure management. Titanium oxide paste, which is reserved as a detergent for decontamination, has a satisfactory and reliable result for decontamination effects. The titanium oxide paste, however, has a short preservation period, and must be updated and supplied every serenal months. Decontamination tests for about 60 kinds of detergents on the market were carried out with swine and radioactive material, Ce-144. Radioactive solution of Ce-144 was dropped on the test samples of swine skin, which were left for 5 min or 40 min as it is. Radioactivities of the samples were measured before and after washing by the detergents. As a result of the decontamination tests, 22 kinds of detergents on the market which have a similar decontamination efficiency to the titanium oxide paste were selected. It was also ascertained that the decontamination efficiency of all the detergents decreased on the test samples which were immersed in the radioactive solution for 40 min and wounded on skin surface. (Suetake, M.)

Composition of CBRN Decontamination Effluent and Development of Surrogate Mixtures for Testing Effluent Treatment Technologies

Science.gov (United States)

2016-07-01

possible, the site around the wash stations is graded to allow the wash water to run off to a pit, where it can seep into the earth or be collected...Caustic soda solution Radioisotopes /Nuclear Residuals Soap with warm water DS2 = Decontamination Solution 2 STB = Super Tropical bleach HTH = High... DATE (DD-MM-YYYY) 2. REPORT TYPE 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

Decontamination of radioactive clothing using microemulsion in carbon dioxide

Energy Technology Data Exchange (ETDEWEB)

Yoo, Jaeryong; Jang, Jina; Park, Kwangheon; Kim, Hongdoo; Kim, Hakwon [Kyunghee Univ., Seoul (Korea, Republic of); Yim, Sanghak; Yoon, Weonseob [Ulchin Nuclear Power Site, Ulchin (Korea, Republic of)

2006-07-01

Nuclear power is intrinsically a clean energy source due to its high energy density and low generation of waste. However, as the nuclear industry grows, a variety of radioactive wastes are increased gradually. Major subjects include contaminated components, tools, equipment, containers and facilities as well as nuclear waste such as uranium scrap and radioactive clothing. The radioactive waste can be classified by its creation. There are Trans-Uranium Nuclides (TRU), Fission Products (FP) and corrosion products. Nuclear decontamination has become an important issue in the nuclear industry. The conventional methods have some problems such as the production of secondary wastes and the use of toxic solvents. We need to develop a new method of decontamination and suggest a use of microemulsion in carbon dioxide to overcome these disadvantages. The microemulsion is the clear solution that contains the water, surfactant and carbon dioxide. The surfactant surrounded the droplet into carbon dioxide and this state is thermodynamically stable. That is, the microemulsion has a structure similar to that of a conventional water-based surfactant system. Generally, the size of droplet is about 5 {approx} 10nm. The microemulsion is able to decontaminate radioactive waste so that the polar substance is removed by water and the non-polar substance is removed by carbon dioxide. After the decontamination process, the microemulsion is separated easily to surfactant and water by decreasing the pressure under the cloud point. This way, only radioactive wastes are left in the system. Cleaned carbon dioxide is then collected and reused. Thus, there are no secondary wastes. Carbon dioxide is considered an alternative process medium. This is because it is non-toxic, non-flammable, inexpensive and easy to handle. Additionally, the tunable properties of carbon dioxide through pressure and temperature control are versatile for use in extracting organic materials. In this paper, we examine the

Decontamination of radioactive clothing using microemulsion in carbon dioxide

International Nuclear Information System (INIS)

Yoo, Jaeryong; Jang, Jina; Park, Kwangheon; Kim, Hongdoo; Kim, Hakwon; Yim, Sanghak; Yoon, Weonseob

2006-01-01

Nuclear power is intrinsically a clean energy source due to its high energy density and low generation of waste. However, as the nuclear industry grows, a variety of radioactive wastes are increased gradually. Major subjects include contaminated components, tools, equipment, containers and facilities as well as nuclear waste such as uranium scrap and radioactive clothing. The radioactive waste can be classified by its creation. There are Trans-Uranium Nuclides (TRU), Fission Products (FP) and corrosion products. Nuclear decontamination has become an important issue in the nuclear industry. The conventional methods have some problems such as the production of secondary wastes and the use of toxic solvents. We need to develop a new method of decontamination and suggest a use of microemulsion in carbon dioxide to overcome these disadvantages. The microemulsion is the clear solution that contains the water, surfactant and carbon dioxide. The surfactant surrounded the droplet into carbon dioxide and this state is thermodynamically stable. That is, the microemulsion has a structure similar to that of a conventional water-based surfactant system. Generally, the size of droplet is about 5 ∼ 10nm. The microemulsion is able to decontaminate radioactive waste so that the polar substance is removed by water and the non-polar substance is removed by carbon dioxide. After the decontamination process, the microemulsion is separated easily to surfactant and water by decreasing the pressure under the cloud point. This way, only radioactive wastes are left in the system. Cleaned carbon dioxide is then collected and reused. Thus, there are no secondary wastes. Carbon dioxide is considered an alternative process medium. This is because it is non-toxic, non-flammable, inexpensive and easy to handle. Additionally, the tunable properties of carbon dioxide through pressure and temperature control are versatile for use in extracting organic materials. In this paper, we examine the

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)

Decontamination of the RA reactor heavy water system, Annex 9

International Nuclear Information System (INIS)

Maksimovic, Z.B.; Nikolic, R.M.; Marinkovic, M.D.; Jelic, Lj.M.

1963-01-01

Both stainless steel and aluminium parts of the RA reactor heavy water system system were decontaminated as well as the heavy water itself. System was contaminated with 60 Co. Decontamination factor was determined by activity measurements during distillation. Concentration of the corrosion products in the heavy water was measured by spectrochemical analysis, and found to be 0.1 - 1 mg/l. Chemical analyses of the aluminium and stainless steel surfaces showed that cobalt was adsorbed on the aluminium oxide layer. Water solution of 7%H 3 PO 4 + 2% CrO 3 was used for decontamination of the heavy water system and distillation device. This was found to be the most efficient solvent which does not affect stainless steel corrosion. Decontamination factors achieved were from 60 - 100. Decontamination results enabled determining the distribution of cobalt in the system: 10 Ci on the stainless steel parts, 50 Ci in the heavy water; and above 600 Ci on the fuel and experimental channels. Specific activity of 60 Co was calculated to be 15 Ci/g on the reactor channels, 8 Ci/g on the stainless steel parts and 3 Ci/g in the heavy water. Decontamination of the aluminium parts was not done because it was considered it could initiate corrosion. Since the efficiency of distillation is increased it was expected that permanent distillation would remove most of the activity in the reactor channels

An electrochemical and high-speed imaging study of micropore decontamination by acoustic bubble entrapment.

Science.gov (United States)

Offin, Douglas G; Birkin, Peter R; Leighton, Timothy G

2014-03-14

Electrochemical and high-speed imaging techniques are used to study the abilities of ultrasonically-activated bubbles to clean out micropores. Cylindrical pores with dimensions (diameter × depth) of 500 μm × 400 μm (aspect ratio 0.8), 125 μm × 350 μm (aspect ratio 2.8) and 50 μm × 200 μm (aspect ratio 4.0) are fabricated in glass substrates. Each pore is contaminated by filling it with an electrochemically inactive blocking organic material (thickened methyl salicylate) before the substrate is placed in a solution containing an electroactive species (Fe(CN)6(3-)). An electrode is fabricated at the base of each pore and the Faradaic current is used to monitor the decontamination as a function of time. For the largest pore, decontamination driven by ultrasound (generated by a horn type transducer) and bulk fluid flow are compared. It is shown that ultrasound is much more effective than flow alone, and that bulk fluid flow at the rates used cannot decontaminate the pore completely, but that ultrasound can. In the case of the 125 μm pore, high-speed imaging is used to elucidate the cleaning mechanisms involved in ultrasonic decontamination and reveals that acoustic bubble entrapment is a key feature. The smallest pore is used to explore the limits of decontamination and it is found that ultrasound is still effective at this size under the conditions employed.

RSDL decontamination of human skin contaminated with the nerve agent VX.

Science.gov (United States)

Thors, L; Lindberg, S; Johansson, S; Koch, B; Koch, M; Hägglund, L; Bucht, A

2017-03-05

Dermal exposure to low volatile organophosphorus compounds (OPC) may lead to penetration through the skin and uptake in the blood circulation. Skin decontamination of toxic OPCs, such as pesticides and chemical warfare nerve agents, might therefore be crucial for mitigating the systemic toxicity following dermal exposure. Reactive skin decontamination lotion (RSDL) has been shown to reduce toxic effects in animals dermally exposed to the nerve agent VX. In the present study, an in vitro flow-through diffusion cell was utilized to evaluate the efficacy of RSDL for decontamination of VX exposed to human epidermis. In particular, the impact of timing in the initiation of decontamination and agent dilution in water was studied. The impact of the lipophilic properties of VX in the RSDL decontamination was additionally addressed by comparing chemical degradation in RSDL and decontamination efficacy between the VX and the hydrophilic OPC triethyl phosphonoacetate (TEPA). The epidermal membrane was exposed to 20, 75 or 90% OPC diluted in deionized water and the decontamination was initiated 5, 10, 30, 60 or 120min post-exposure. Early decontamination of VX with RSDL, initiated 5-10min after skin exposure, was very effective. Delayed decontamination initiated 30-60min post-exposure was less effective but still the amount of penetrated agent was significantly reduced, while further delayed start of decontamination to 120min resulted in very low efficacy. Comparing RSDL decontamination of VX with that of TEPA showed that the decontamination efficacy at high agent concentrations was higher for VX. The degradation mechanism of VX and TEPA during decontamination was dissected by 31 P NMR spectroscopy of the OPCs following reactions with RSDL and its three nucleophile components. The degradation rate was clearly associated with the high pH of the specific solution investigated; i.e. increased pH resulted in a more rapid degradation. In addition, the solubility of the OPC in RSDL

Chemical and mechanical decontamination processes to minimize secondary waste decommissioning

International Nuclear Information System (INIS)

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

2008-01-01

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

Instructions for RA reactor decontamination - Annex 10; Prilog 10 - Uputstvo za dekontaminaciju Reaktora RA

Energy Technology Data Exchange (ETDEWEB)

NONE

1963-12-15

Instructions for RA reactor decontamination includes: action plan for decontamination of the heavy water system by 7% water solution of H{sub 3}PO{sub 4} + 2% CrO{sub 3} acid; description of the preparatory work including calculation of the pipes volume and installation of special pipes; detailed instructions for decontamination procedure. [Serbo-Croat] Uputstvo za dekontaminaciju Reaktora RA sadrzi: plan operacija za dekontaminaciju sistema teske vode 7% vodenim rastvorom kiseline H{sub 3}PO{sub 4} + 2% CrO{sub 3}; opis pripremnih radova ukljucujuci proracun zapremine covovoda i montiranje posebnih cevovoda; detaljno uputstvo za izvodjenje operacija pri dekontaminaciji.

Radioactive Decontamination by Strippable Paint

International Nuclear Information System (INIS)

Chantaraparprachoom, N.; Mishima, K.

1998-01-01

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

The dissolution of metal decontamination sludges stored in tanks and their management

Energy Technology Data Exchange (ETDEWEB)

Prokopowicz, R.A.; Phillips, B. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

2011-07-01

The decontamination of stainless steel components is accomplished by the use of alkaline permanganate solutions, followed by an application of solutions of complexing agents such as citric acid or oxalic acid. Spent decontamination solutions comprising residues from both steps were combined in several waste storage tanks, where they have been in storage for several years. In those tanks, a reaction between residual permanganate and unreacted complexing agents produced sludges, consisting mainly of manganese dioxide, that reside in the tanks along with supernatant liquid. In a campaign that was conducted a few years ago, the accumulated waste solution was partially treated and disposed. This treatment consisted of decanting only the supernatant liquid and transporting it to a liquid waste treatment facility that employed a Thin Film Evaporator (TFE) to concentrate the liquid and ultimately produce a bitumen-encapsulated solidified waste form for storage. A study of treatment options for the remaining sludge is reported here. The requirement was to determine a simple means of treating the sludge using existing routine processes and equipment. This will be a significant step toward the decommissioning of the decontamination waste storage tanks. The available equipment at the liquid waste treatment facility was not designed to process sludge or slurries containing a large volume fraction of solids. Laboratory testing was carried out to find a means of dissolving the decontamination waste sludges, preferably in situ, and filtering undissolved solids to meet the feed requirements of the TFE in the liquid waste treatment facility. A concentrated citric acid solution was applied to sludge samples, without the use of externally applied mixing of the reagent and sludge. In all of the samples of actual decontamination waste sludge that were tested, a quantity of undissolved material remained after treatment with citric acid. The quantities were relatively small in volume, and

The dissolution of metal decontamination sludges stored in tanks and their management

International Nuclear Information System (INIS)

Prokopowicz, R.A.; Phillips, B.

2011-01-01

The decontamination of stainless steel components is accomplished by the use of alkaline permanganate solutions, followed by an application of solutions of complexing agents such as citric acid or oxalic acid. Spent decontamination solutions comprising residues from both steps were combined in several waste storage tanks, where they have been in storage for several years. In those tanks, a reaction between residual permanganate and unreacted complexing agents produced sludges, consisting mainly of manganese dioxide, that reside in the tanks along with supernatant liquid. In a campaign that was conducted a few years ago, the accumulated waste solution was partially treated and disposed. This treatment consisted of decanting only the supernatant liquid and transporting it to a liquid waste treatment facility that employed a Thin Film Evaporator (TFE) to concentrate the liquid and ultimately produce a bitumen-encapsulated solidified waste form for storage. A study of treatment options for the remaining sludge is reported here. The requirement was to determine a simple means of treating the sludge using existing routine processes and equipment. This will be a significant step toward the decommissioning of the decontamination waste storage tanks. The available equipment at the liquid waste treatment facility was not designed to process sludge or slurries containing a large volume fraction of solids. Laboratory testing was carried out to find a means of dissolving the decontamination waste sludges, preferably in situ, and filtering undissolved solids to meet the feed requirements of the TFE in the liquid waste treatment facility. A concentrated citric acid solution was applied to sludge samples, without the use of externally applied mixing of the reagent and sludge. In all of the samples of actual decontamination waste sludge that were tested, a quantity of undissolved material remained after treatment with citric acid. The quantities were relatively small in volume, and

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

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

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

Decontamination of liquid radioactive wastes using seeded ultrafiltration

International Nuclear Information System (INIS)

Kavanagh, P.; Goldsmith, A.

1997-01-01

A number of techniques may be used to treat radioactive wastes. This paper presents a discussion of the relative merits of two of these: ion exchange and membrane filtration, and discusses the overall benefit of using seeded filtration to combine the advantages of each, with selected examples of where these techniques have been used. Evaporation is another technique that can be used, however, because of its high capital and operating costs its use is limited and it is not discussed here. Examples of the decontamination of standard solutions by novel materials tested by the Novel Absorber Evaluation Club are presented, and the advantages of the new PAN-based absorbers discussed

Possibility of Localized Corrosion of PWR primary side materials in oxidative decontamination condition

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Yoon; Jung, Jun Young; Won, Huijun; Kim, Seon Byeong; Choi, Wangkyu; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

can conclude the following. The corrosion characteristics of a classical NP process rely highly on the acidity of the decontamination solution, and the typical process performed around a pH of 3 needs to be improved since it is vulnerable to corrosion. A small amount of copper (II) ion works as a corrosion inhibitor in the oxidative process and by the addition of 0.5mM copper (II) ion the general corrosion dropped to a level of 25% and local corrosion was completely inhibited. This modified nitric acid permanganate process was named MONAP.

Development of chemical decontamination for low level radioactive wastes

International Nuclear Information System (INIS)

Ichikawa, Seigo; Omata, Kazuo; Obinata, Hiroshi; Nakajima, Yoshihiko; Kanamori, Osamu.

1995-01-01

During routine intermittent inspection and maintenance at nuclear power plants, a considerable quantity of low level radioactive waste is generated requiring release from the nuclear site or treating additionally. To decontaminate this waste for safe release from the nuclear power plant, the first step could be washing the waste in Methylene chloride, CH 2 Cl 2 , to remove most of the paint coating. However, CH 2 Cl 2 washing does not completely remove the paint coating from the waste, which in the next step is shot blasted with plastic bead media to loose and remove the remaining paint coating. Following in succession, in the third step, the waste is washed in a chelate solution, after which most waste is decontaminated and suitable to be released for recycling. The residual chelate solution may be decomposed into nontoxic carbon dioxide and water by an electrolysis process and then safely discharged into the environment. (author)

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

Project n.4: local strategies for decontamination

Energy Technology Data Exchange (ETDEWEB)

Hubert, Ph. [CEA Centre d`Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire; Ramzaev, V. [Branch of Institute of Radiation Hygiene, Karchovka, Bryandk (Russian Federation); Antsypov, G. [Chernobyl State Committee of the Republic of Belarus, (Belarus); Sobotovich, E. [Institute of Geochemistry, Mineralogy and Ore formation, Kiev (Ukraine); Anisimova, L. [EMERCOM, Moscow (Russian Federation)

1995-12-31

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, and a return from experience from the area contaminated by the Chernobyl accident allowed to assess radiological efficiencies 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 optimisation of decontamination strategies. Results are 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 the 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. (authors). 23 refs.

Project n.4: local strategies for decontamination

Energy Technology Data Exchange (ETDEWEB)

Hubert, Ph [CEA Centre d` Etudes de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire; Ramzaev, V [Branch of Institute of Radiation Hygiene, Karchovka, Bryandk (Russian Federation); Antsypov, G [Chernobyl State Committee of the Republic of Belarus, (Belarus); Sobotovich, E [Institute of Geochemistry, Mineralogy and Ore formation, Kiev (Ukraine); Anisimova, L [EMERCOM, Moscow (Russian Federation)

1996-12-31

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, and a return from experience from the area contaminated by the Chernobyl accident allowed to assess radiological efficiencies 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 optimisation of decontamination strategies. Results are 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 the 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. (authors). 23 refs.

Project n.4: local strategies for decontamination

International Nuclear Information System (INIS)

Hubert, Ph.; Antsypov, G.; Sobotovich, E.; Anisimova, L.

1995-01-01

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, and a return from experience from the area contaminated by the Chernobyl accident allowed to assess radiological efficiencies 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 optimisation of decontamination strategies. Results are 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 the 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. (authors)

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

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.

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)

Separation of cobalt from synthetic intermediate and decontamination radioactive wastes using polyurethane foam

International Nuclear Information System (INIS)

Rao, S.V.S.; Lal, K.B.; Narasimhan, S.V.; Ahmed, J.

1997-01-01

Studies have been carried out on the removal of radioactive cobalt ( 60 Co) from synthetic intermediate level waste (ILW) and decontamination waste using neat polyurethane (PU) foam as well as n-tributyl phosphate-polyurethane (TBP-PU) foam. The radioactive cobalt has been extracted on the PU foam as cobalt thiocyanate from the ILW. Maximum removal of cobalt has been observed when the concentration of thiocyanate in the solution is about 0.4 M. Cobalt can be separated from decontamination waste containing ethylenediaminetetraacetic acid (EDTA) and iron(II). The extent of extraction of cobalt is slow and the separation of iron and cobalt is better with the neat PU foam compared to the TBP-PU foam. The presence of iron in the decontamination waste facilitates the extraction of cobalt thiocyanate on the PU foam. Column studies have been carried out in order to extend these studies to the plant scale. The capacities of the PU foams for cobalt have been determined. The effect of density and the surface area of PU foam have been investigated. Fourier Transform Infrared (FT-IR) spectral studies have been conducted to find out the interaction between PU foam and cobalt thiocyanate species

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

Method for electrochemical decontamination of radioactive metal

Science.gov (United States)

Ekechukwu, Amy A [Augusta, GA

2008-06-10

A decontamination method for stripping radionuclides from the surface of stainless steel or aluminum material comprising the steps of contacting the metal with a moderately acidic carbonate/bicarbonate electrolyte solution containing sodium or potassium ions and thereafter electrolytically removing the radionuclides from the surface of the metal whereby radionuclides are caused to be stripped off of the material without corrosion or etching of the material surface.

Determination of overall decontamination factors for common impurity elements in PHWR spent fuel reprocessing

International Nuclear Information System (INIS)

Pant, D.K.; Bhalerao, B.A.; Gupta, K.K.; Kulkarni, P.G.; Gurba, P.B.; Janardan, P.; Changrani, R.D.; Dey, P.K.

2009-01-01

An attempt has been made to determine overall decontamination factors for elemental impurities normally encountered in the U 3 O 8 product obtained by reprocessing of PHWR spent fuel. The solution obtained by dissolution of spent fuel and corresponding U 3 O 8 product were analyzed for 24 elemental impurities by ICP-AES for this purpose. Decontamination factors achieved for major neutron poisons are in the range of 200-400. (author)

Nuclear criticality safety evaluation of the passage of decontaminated salt solution from the ITP filters into tank 50H for interim storage

International Nuclear Information System (INIS)

Hobbs, D.T.; Davis, J.R.

1994-01-01

This report assesses the nuclear criticality safety associated with the decontaminated salt solution after passing through the In-Tank Precipitation (ITP) filters, through the stripper columns and into Tank 50H for interim storage until transfer to the Saltstone facility. The criticality safety basis for the ITP process is documented. Criticality safety in the ITP filtrate has been analyzed under normal and process upset conditions. This report evaluates the potential for criticality due to the precipitation or crystallization of fissionable material from solution and an ITP process filter failure in which insoluble material carryover from salt dissolution is present. It is concluded that no single inadvertent error will cause criticality and that the process will remain subcritical under normal and credible abnormal conditions

Decontamination processes for waste glass canisters

International Nuclear Information System (INIS)

Rankin, W.N.

1981-06-01

The process which will be used to decontaminate waste glass canisters at the Savannah River Plant consists of: decontamination (slurry blasting); rinse (high-pressure water); and spot decontamination (high-pressure water plus slurry). No additional waste will be produced by this process because glass frit used in decontamination will be mixed with the radioactive waste and fed into the glass melter. Decontamination of waste glass canisters with chemical and abrasive blasting techniques was investigated. The ability of a chemical technique with HNO 3 -HF and H 2 C 2 O 4 to remove baked-on contamination was demonstrated. A correlation between oxide removal and decontamination was observed. Oxide removal and, thus, decontamination by abrasive blasting techniques with glass frit as the abrasive was proposed and demonstrated

Decontamination processes for waste glass canisters

International Nuclear Information System (INIS)

Rankin, W.N.

1981-01-01

The process which will be used to decontaminate waste glass canisters at the Savannah River Plant consists of: decontamination (slurry blasting); rinse (high-pressure water); and spot decontamination (high-pressure water plus slurry). No additional waste will be produced by this process because glass frit used in decontamination will be mixed with the radioactive waste and fed into the glass melter. Decontamination of waste glass canisters with chemical and abrasive blasting techniques was investigated. The ability of a chemical technique with HNO 3 -HF and H 2 C 2 O 4 to remove baked-on contamination was demonstrated. A correlation between oxide removal and decontamination was observed. Oxide removal and, thus, decontamination by abrasive blasting techniques with glass frit as the abrasive was proposed and demonstrated

Comparison of four decontamination treatments on porcine renal decellularized extracellular matrix structure, composition, and support of human renal cortical tubular epithelium cells.

Science.gov (United States)

Poornejad, Nafiseh; Nielsen, Jeffery J; Morris, Ryan J; Gassman, Jason R; Reynolds, Paul R; Roeder, Beverly L; Cook, Alonzo D

2016-03-01

Engineering whole organs from porcine decellularized extracellular matrix and human cells may lead to a plentiful source of implantable organs. Decontaminating the porcine decellularized extracellular matrix scaffolds is an essential step prior to introducing human cells. However, decontamination of whole porcine kidneys is a major challenge because the decontamination agent or irradiation needs to diffuse deep into the structure to eliminate all microbial contamination while minimizing damage to the structure and composition of the decellularized extracellular matrix. In this study, we compared four decontamination treatments that could be applicable to whole porcine kidneys: 70% ethanol, 0.2% peracetic acid in 1 M NaCl, 0.2% peracetic acid in 4% ethanol, and gamma (γ)-irradiation. Porcine kidneys were decellularized by perfusion of 0.5% (w/v) aqueous solution of sodium dodecyl sulfate and the four decontamination treatments were optimized using segments (n = 60) of renal tissue to ensure a consistent comparison. Although all four methods were successful in decontamination, γ-irradiation was very damaging to collagen fibers and glycosaminoglycans, leading to less proliferation of human renal cortical tubular epithelium cells within the porcine decellularized extracellular matrix. The effectiveness of the other three optimized solution treatments were then all confirmed using whole decellularized porcine kidneys (n = 3). An aqueous solution of 0.2% peracetic acid in 1 M NaCl was determined to be the best method for decontamination of porcine decellularized extracellular matrix. © The Author(s) 2015.

Immobilization of citric acid solutions in portland cement; Imobilizacao de solucoes de acido citrico em cimento Portland

Energy Technology Data Exchange (ETDEWEB)

Lopes, Valdir M.; Rzyski, Barbara M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

1997-12-01

Decontamination processes by using citric acid on certain items used in the nuclear area, can result in large volumes of liquid wastes with low activity or effluents, contaminated with uranium and some elements dangerous to the environment. A great number of installations that have decontamination processes adopt the zero discharge philosophy. So, one of the forms to isolate the solutions is by reducing its volume through the evaporation process. The generated must can be neutralized and encapsulated or immobilized in Portland cement. This work propose a chemical technique to destroy the citric acid in the decontamination solutions instead of neutralization and, depending on the installation convenience, a direct cement immobilization of these solutions or of the evaporation mud. The results obtained in this work involve data about the workability, setting time and mechanical resistance, after 28 days of sealed cure, for samples with water-cement ratios of 4, 0.5 and 0.6, by weight. (author). 5 refs., 2 tabs.

Microbial decontamination of dried date by Gamma-irradiation

International Nuclear Information System (INIS)

Majd, F.; Motamedi, F.; Abhari, M.

2000-01-01

Dried date is one of the export item from Iran. It can be contaminated during the processing and storage using nuclear techniques such as irradiation of food can increase the shelf life of agricultural products and improve their quality. This technique can be used for food decontamination of dried fruits according the standard authorized limitation. In this research different doses of Gamma Irradiation were used for microbial decontamination.he rest indicates that the optimum dose to reduce microbial contamination and increase shelf life is 5 kGy

Gentilly 1: decontamination program

International Nuclear Information System (INIS)

Le, H.; Denault, P.

1985-01-01

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

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)

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.)

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

Development of remote electrochemical decontamination for hot cell applications

International Nuclear Information System (INIS)

Turner, A.D.; Junkison, A.R.; Pottinger, J.S.; Lain, M.J.; Neville, M.D.; Dawson, R.K.; Fletcher, P.A.; Fenn-Tye, I.A.

1993-01-01

Electrochemical dissolution into nitric acid has been developed as a decontamination process for metallic items, both for immersion and in-situ use. Not only is the spent electrolyte compatible with existing waste treatment routes, potentially yielding an immobilized product volume of 0.6 dm 3 /m 2 area treated, but it also suppresses any hydrogen production. Both processes have been developed from laboratory to microprocessor-controlled pilot-scale units, which have been demonstrated successfully for the treatment of genuine waste, reducing activity levels to background. For stainless steel substrates, the immersion tank process uses low current densities (10-50 A/m 2 ) in 1-5M HN0 3 for the treatment of extended areas. Decontamination factors > 10 4 can be achieved in two hours. The in-situ technique uses electropolishing in 6M HN0 3 at 1-2 A/cm 2 in an engineered head. Decontamination factors > 10 3 can be achieved in only 20 seconds. This device has also shown potential for incorporation into an integrated monitoring/decontaminating system under robotic control. Both techniques may be used remotely as a way of reducing man-dose and improving productivity during decontamination. Additional cost savings can be made over currently used techniques through the decategorization of the bulk of the waste volume, and the volume reduction of waste for interim storage and geological disposal

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)

Role of alkyl alcohol on viscosity of silica-based chemical gels for decontamination of highly radioactive nuclear facilities

International Nuclear Information System (INIS)

Choi, B. S.; Yoon, S. B.; Jung, C. H.; Lee, K. W.; Moon, J. K.

2012-01-01

Silica-based chemical gel for the decontamination of nuclear facilities was prepared by using fumed silica as a viscosifier, a 0.5 M Ce (IV) solution dissolved in concentrated nitric acid as a chemical decontamination agent, and tripropylene glycol butyl ether (TPGBE) as a co-viscosifier. A new effective strategy for the preparation of the chemical gel was investigated by introducing the alkyl alcohols as organic solvents to effectively dissolve the co-viscosifier. The mixture solution of the co-viscosifier and alkyl alcohols was more effective in the control of viscosity than that of the co-viscosifier only in gel. Here, the alkyl alcohols played a key role as an effective dissolution solvent for the co-viscosifier in the preparation of the chemical gel, resulting in a reducing of the amount of the co-viscosifier and gel time compared with that of the chemical gel prepared without the alkyl alcohols. It was considered that the alkyl alcohols contributed to the effective dissolution of the co-viscosifier as well as the homogeneous mixing in the formation of the gel, while the co-viscosifier in an aqueous media of the chemical decontamination agent solution showed a lower solubility. The decontamination efficiency of the chemical gels prepared in this work using a multi-channel analyzer (MCA) showed a high decontamination efficiency of over ca. 94% and ca. 92% for Co-60 and Cs-137 contaminated on surface of the stainless steel 304, respectively. (authors)

Decontamination Options for Drinking Water Contaminated with Bacillus anthracis Spores

Energy Technology Data Exchange (ETDEWEB)

Raber, E; Burklund, A

2010-02-16

Five parameters were evaluated with surrogates of Bacillus anthracis spores to determine effective decontamination options for use in a contaminated drinking water supply. The parameters were: (1) type of Bacillus spore surrogate (B. thuringiensis or B. atrophaeus); (2) spore concentration in suspension (10{sup 2} to 10{sup 6} spores/ml); (3) chemical characteristics of decontaminant [sodium dicholor-s-triazinetrione dihydrate (Dichlor), hydrogen peroxide, potassium peroxymonosulfate (Oxone), sodium hypochlorite, and VirkonS{reg_sign}]; (4) decontaminant concentration (0.01% to 5%); and (5) decontaminant exposure time (10 min to 24 hr). Results from 162 suspension tests with appropriate controls are reported. Hydrogen peroxide at a concentration of 5%, and Dichlor and sodium hypochlorite at a concentration of 2%, were effective at spore inactivation regardless of spore type tested, spore exposure time, or spore concentration evaluated. This is the first reported study of Dichlor as an effective decontaminant for B. anthracis spore surrogates. Dichlor's desirable characteristics of high oxidation potential, high level of free chlorine, and more neutral pH than that of other oxidizers evaluated appear to make it an excellent alternative. All three oxidizers were effective against B. atrophaeus spores in meeting EPA's biocide standard of greater than a 6 log kill after a 10-minute exposure time and at lower concentrations than typically reported for biocide use. Solutions of 5% VirkonS{reg_sign} and Oxone were less effective decontaminants than other options evaluated in this study and did not meet the EPA's efficacy standard for biocides. Differences in methods and procedures reported by other investigators make quantitative comparisons among studies difficult.

Measurement of Ce(IV) Concentration in Foam Decontaminant containing Fluorosurfactant

Energy Technology Data Exchange (ETDEWEB)

Jung, Chong Hun; Yang, H. B.; Yoon, I. H.; Choi, W. K.; Moon, J. K. [KAERI, Daejeon (Korea, Republic of); Lee, J. S. [Gachon University, Seongnam (Korea, Republic of)

2016-05-15

To improve the stability of the foam, surfactants and inorganic materials such as nanoparticles can be added. A nanoparticle-based foam decontaminant is composed of a surfactant and nanoparticles for the generation and maintenance of foam, and a chemical decontamination agent made of Ce(IV) dissolved in nitric acid. Ce(IV) will be reduced to Ce(III) through the decontamination process. Oxidizing the cerium (III) can be reused as a decontamination agent, Ce(IV). Oxidation treatment technology by ozone uses its strong oxidizing power. It can be regarded as an environmentally friendly process, because ozone cannot be stored and transported like other industrial gases (because it quickly decays into diatomic oxygen) and must therefore be produced on site, and used ozone can be decomposed immediately. A concentration analysis of Ce(IV) in foam decontaminant containing a surfactant is necessary prior to the derivation of optimal conditions for the regeneration of Ce(III) through ozonation treatment. A UV spectrometric method using the absorbance or potentiometric method with a potential difference in Ce(III)/Ce(IV), or a potentiometric titration method using Fe (II), can be used for a Ce(IV) concentration analysis. A UV spectrometric method has a problem receiving the influence of the surfactant, and a potentiometric method is difficult to use because of the problem of an insignificant change in the potential difference value of the Ce(III)/Ce(IV). Thus, the present study was undertaken to determine whether the potentiometric titration method can be used for an analysis of the Ce(IV) concentration in the nanoparticle-based foam decontaminant containing surfactant. It will be effectively used for the Ce(IV) concentration measurement, in relation to the subsequent research on the derivation of optimal conditions for the regeneration of Ce(III) through ozonation treatment.

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

Radiation decontamination (hygienisation) of cosmetic raw materials and products

International Nuclear Information System (INIS)

Malec-Czechowska, K.; Migdal, W.; Owczarczyk, H.B.

1998-01-01

Microbiological purity of cosmetics is a problem of today because of growing hygienic requirements to these products. The demand for high hygienic purity from one side and the limitation in the use of conservants to cosmetics from the other side stimulate the research activity, the aim of which is to satisfy present requirements in this field. The application of radiation decontamination (hygienisation) seems to be one of solutions. In present report were present the results of the study on the effect of electron beam irradiation on microbial contamination of selected cosmetics and some raw materials used in cosmetic industry. Radiation doses applied were not higher than 6.0 kGy. The level of microbial contamination in both unirradiated and irradiated samples was determined by applying the standard microbiological methods. In addition, the quality and usefulness of irradiated cosmetics were examined by methods used in cosmetic industry. The results obtained show conclusively that radiation treatment can be successfully used for the decontamination (hygienisation) of cosmetics and some raw materials used in their production, without changing the quality and the usefulness of the product released. (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

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)

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)

Post-Decontamination Vapor Sampling and Analytical Test Methods

Science.gov (United States)

2015-08-12

is decontaminated that could pose an exposure hazard to unprotected personnel. The chemical contaminants may include chemical warfare agents (CWAs... decontamination process. Chemical contaminants can include chemical warfare agents (CWAs) or their simulants, nontraditional agents (NTAs), toxic industrial...a range of test articles from coupons, panels, and small fielded equipment items. 15. SUBJECT TERMS Vapor hazard; vapor sampling; chemical warfare

Efficacy studies of Reactive Skin Decontamination Lotion, M291 Skin Decontamination Kit, 0.5% bleach, 1% soapy water, and Skin Exposure Reduction Paste Against Chemical Warfare Agents, part 1: guinea pigs challenged with VX.

Science.gov (United States)

Braue, Ernest H; Smith, Kelly H; Doxzon, Bryce F; Lumpkin, Horace L; Clarkson, Edward D

2011-03-01

This report, first in a series of five, directly compares the efficacy of 4 decontamination products and Skin Exposure Reduction Paste Against Chemical Warfare Agents (SERPACWA) in the haired guinea pig model following exposure to VX. In all experiments, guinea pigs were close-clipped and given anesthesia. In the decontamination experiments, the animals were challenged with VX and decontaminated after a 2-minute delay for the standard procedure or at longer times for the delayed-decontamination experiments. Skin Exposure Reduction Paste Against Chemical Warfare Agents was applied as a thin coating (0.1 mm thick), allowed to dry for 15 minutes, and challenged with VX. After a 2-hour challenge, any remaining VX was blotted off the animal, but no additional decontamination was done. Positive control animals were challenged with VX in the same manner as the treated animals, except that they received no treatment. In addition, the positive control animals were always challenged with 5% VX in isopropyl alcohol (IPA) solution, whereas the treatment animals received either neat (undiluted) VX or 5% VX in IPA solution. All animals were observed during the first 4 hours and again at 24 hours after exposure for signs of toxicity and death. The protective ratio (PR, defined as the median lethal dose [LD(50)] of the treatment group divided by the LD(50) of the untreated positive control animals) was calculated from the probit dose-response curves established for each treatment group and nontreated control animals. Significance in this report was defined as p decontamination experiments, the calculated PRs for Reactive Skin Decontamination Lotion (RSDL), 0.5% bleach, 1% soapy water, and the M291 Skin Decontamination Kit (SDK) were 66, 17, 16, and 1.1, respectively. Reactive Skin Decontamination Lotion was by far the most effective decontamination product tested and was significantly better than any of the other products. Bleach and soapy water provided equivalent and good (PR

[Decontamination of chemical warfare agents by photocatalysis].

Science.gov (United States)

Hirakawa, Tsutomu; Mera, Nobuaki; Sano, Taizo; Negishi, Nobuaki; Takeuchi, Koji

2009-01-01

Photocatalysis has been widely applied to solar-energy conversion and environmental purification. Photocatalyst, typically titanium dioxide (TiO(2)), produces active oxygen species under irradiation of ultraviolet light, and can decompose not only conventional pollutants but also different types of hazardous substances at mild conditions. We have recently started the study of photocatalytic decontamination of chemical warfare agents (CWAs) under collaboration with the National Research Institute of Police Science. This article reviews environmental applications of semiconductor photocatalysis, decontamination methods for CWAs, and previous photocatalytic studies applied to CWA degradation, together with some of our results obtained with CWAs and their simulant compounds. The data indicate that photocatalysis, which may not always give a striking power, certainly helps detoxification of such hazardous compounds. Unfortunately, there are not enough data obtained with real CWAs due to the difficulty in handling. We will add more scientific data using CWAs in the near future to develop useful decontamination systems that can reduce the damage caused by possible terrorism.

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

Development of haemostatic decontaminants for the treatment of wounds contaminated with chemical warfare agents. 2: evaluation of in vitro topical decontamination efficacy using undamaged skin.

Science.gov (United States)

Dalton, Christopher H; Hall, Charlotte A; Lydon, Helen L; Chipman, J K; Graham, John S; Jenner, John; Chilcott, Robert P

2015-05-01

The risk of penetrating, traumatic injury occurring in a chemically contaminated environment cannot be discounted. Should a traumatic injury be contaminated with a chemical warfare (CW) agent, it is likely that standard haemostatic treatment options would be complicated by the need to decontaminate the wound milieu. Thus, there is a need to develop haemostatic products that can simultaneously arrest haemorrhage and decontaminate CW agents. The purpose of this study was to evaluate a number of candidate haemostats for efficacy as skin decontaminants against three CW agents (soman, VX and sulphur mustard) using an in vitro diffusion cell containing undamaged pig skin. One haemostatic product (WoundStat™) was shown to be as effective as the standard military decontaminants Fuller's earth and M291 for the decontamination of all three CW agents. The most effective haemostatic agents were powder-based and use fluid absorption as a mechanism of action to sequester CW agent (akin to the decontaminant Fuller's earth). The envisaged use of haemostatic decontaminants would be to decontaminate from within wounds and from damaged skin. Therefore, WoundStat™ should be subject to further evaluation using an in vitro model of damaged skin. Copyright © 2014 Crown copyright. Journal of Applied Toxicology © 2014 John Wiley & Sons, Ltd.

Study of tritium decontamination of stainless steel, copper, aluminum metals by tritium dry desorption

International Nuclear Information System (INIS)

Xie Yun; Shi Zhengkun; Wu Tao

2014-01-01

In order to study the decontamination efficiency of stainless steel, copper, aluminum metals contaminated by tritium, the metals were decontaminated by exposing to UV, ozone, heating, and the combination of heating, UV and ozone. The result indicates that the elevation of temperature can obviously improve decontamination. While irradiated by 172 nm UV, the decontamination efficiency is low, but it is better while heated and irradiated by 172 nm UV. If the stainless steel is irradiated by 172 nm UV and heated at 500℃ for 4 h, the decontamination efficiency is 99.2%. There is better decontamination efficiency of copper while exposed to ozone. While exposed to ozone and heated at 500℃, the decontamination efficiencies of stainless steel, copper and aluminum are higher than 99.2%. The decontamination efficiency can more obviously improve when metal is heated at high temperature (500℃) than low temperature (300℃). The surface tritium of metal placed at 30 d after decontamination increases because of diffusion and penetration of the tritium. Resolution spectra of tritium show that there are four kinds of contamination adsorbed tritium of stainless steel. (authors)

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)

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.

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

Control of radiation exposures by decontamination

International Nuclear Information System (INIS)

LeSurf, J.E.

1981-01-01

The radiation exposures of workers at light water and heavy water cooled reactors can be reduced by dilute chemical decontamination as exemplified by the CAN-DECON process. The cost effectiveness of the CAN-DECON process is illustrated by actual service experience and by hypothetical cases

Development of Nuclear Decontamination Technology Using Supercritical Fluid

Energy Technology Data Exchange (ETDEWEB)

Jung, Wonyoung; Park, Kwangheon; Park, Jihye; Lee, Donghee [Kyunghee Univ., Yongin (Korea, Republic of)

2014-05-15

Soil cleaning technologies that have been developed thus far increase treatment costs in contaminated soil recovery processes because they generate large amounts of secondary wastes. In this respect, this study is intended to develop soil decontamination methods using CO{sub 2}, which is a nontoxic, environmentally friendly substance, in order to fundamentally suppress the generation of secondary wastes from the decontamination process and to create high added values. In this study, to develop decontamination methods for uranium-contaminated soil using supercritical CO{sub 2}, a soil decontamination system using supercritical CO{sub 2} was constructed. In addition, the basic principle of supercritical CO{sub 2} decontamination using a TBP-HNO3 complex was explained. According to the results of the study, sea-sand samples having the same degree of contamination showed different results of decontamination according to the quantities of the TBP-HNO3 complex used as an extraction agent, which resulted in high extraction rates. Thus far, a most widely used method of extracting uranium has been the dissolving of uranium in acids. However, this method has the large adverse effect of generating strong acidic wastes that cannot be easily treated. On the other hand, supercritical CO{sub 2} requires critical conditions that are no more difficult to meet than those of other supercritical fluids, since its density can be changed from a very low state close to that of an ideal gas to a high state close to that of liquids. The critical gas conditions are a pressure of 71 bar and a temperature of 31 .deg. C, both of which are inexpensive to achieve. Moreover, CO{sub 2} is a solvent that is not harmful to the human body and few effects on environmental pollution. Therefore, nontoxic and environment friendly processes can be developed using supercritical CO{sub 2}. Supercritical CO{sub 2}'s advantages over prevailing methods suggest its potential for developing innovative

Development of Nuclear Decontamination Technology Using Supercritical Fluid

International Nuclear Information System (INIS)

Jung, Wonyoung; Park, Kwangheon; Park, Jihye; Lee, Donghee

2014-01-01

Soil cleaning technologies that have been developed thus far increase treatment costs in contaminated soil recovery processes because they generate large amounts of secondary wastes. In this respect, this study is intended to develop soil decontamination methods using CO 2 , which is a nontoxic, environmentally friendly substance, in order to fundamentally suppress the generation of secondary wastes from the decontamination process and to create high added values. In this study, to develop decontamination methods for uranium-contaminated soil using supercritical CO 2 , a soil decontamination system using supercritical CO 2 was constructed. In addition, the basic principle of supercritical CO 2 decontamination using a TBP-HNO3 complex was explained. According to the results of the study, sea-sand samples having the same degree of contamination showed different results of decontamination according to the quantities of the TBP-HNO3 complex used as an extraction agent, which resulted in high extraction rates. Thus far, a most widely used method of extracting uranium has been the dissolving of uranium in acids. However, this method has the large adverse effect of generating strong acidic wastes that cannot be easily treated. On the other hand, supercritical CO 2 requires critical conditions that are no more difficult to meet than those of other supercritical fluids, since its density can be changed from a very low state close to that of an ideal gas to a high state close to that of liquids. The critical gas conditions are a pressure of 71 bar and a temperature of 31 .deg. C, both of which are inexpensive to achieve. Moreover, CO 2 is a solvent that is not harmful to the human body and few effects on environmental pollution. Therefore, nontoxic and environment friendly processes can be developed using supercritical CO 2 . Supercritical CO 2 's advantages over prevailing methods suggest its potential for developing innovative decontamination methods, as demonstrated

The recuperation of sulphuric acid out of contaminated solutions by electro electrodialysis

International Nuclear Information System (INIS)

Cattoir, S.

1997-05-01

The dismantling of a nuclear reactor results in large amounts of contaminated waste. The amount of waste is minimized by so-called decontamination processes. These decontamination processes result in decontaminated metal as well as contaminated effluents, containing acid and metal salts. Standard treatment of these effluents involves neutralisation of the acid using sodium hydroxide, resulting in the precipitation of hydroxides; and evaporation of the solvent. However, if the acid is extracted out of the decontamination effluents prior to neutralisation, this acid can be re-used in the decontamination process, substantially reducing the final waste. This report investigates the possibility of using Electro Electrodialysis (EED) for the extraction of 900 moles of sulphuric acid out of a 1 m 3 contaminated solution, containing 22 kg of ferrous, chromous, cerous and nickel ions and 1000 moles of sulphuric acid. EED removes acids out of acid/salts solutions, using an electrolyser equipped with an anionic membrane: the acid-anion is displaced by migration through the membrane while the proton is displaced by electrolysis. This report gives a full description of the technique, the lab-scale apparatus, the analyses involved in studying the technique on lab-scale or monitoring it on full scale, the choice of electrode and membrane and of process parameters such as temperature and current density. On lab scale, EED can displace 90% of the acid out of the acid/salt solution just described, at a current density as high as 0.14 A.cm -2 , at 50 degrees Celsius, if the cathode and the anode are of smoothed platina or of platinised titanium, and the anion selective membrane is the Neosepta AMH -membrane of Tokuyama. The study of EED still needs to be completed with a further study of metal deposition on the cathode, and a comparison of the technique to other (electro)membrane techniques

The possibility of precipitating thorium soap from aqueous solutions

International Nuclear Information System (INIS)

Drathen, H.

1975-01-01

The purpose of the analysis was firstly to determine the precipitation process of thorium with soap and the influence of foreign ions, secondly to explain the conditions for the best method of decontaminating waste waters contaminated by thoriuum. The result was that if thorium is precipitated with soap both thorium soaps and thorium hydroxide are formed. The proportion of each substance depends considerably upon the pH value. All the precipitation compounds exist independently. No adsorption or mixed crystal formation took place. By adding bivalent or multivalent cations the one-step decontamination factor increases to more than 20. Quantitatively, the decontamination of thorium contaminated waste waters can be carried out down to a thorium concentration of 10 -5 mol/1. Technical soaps provide the least expensive solution without displaying any qualitative disadvantages. The only disadvantage is that this method cannot be used continuously. Therefore ion exchangers provide a great advantage, although they are very expensive and have a limited capacity. The best solution, then, is a combination of ion exchangers and precipitation with soap. (orig.) [de

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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.)

SAFETY STUDIES TO MEASURE EXOTHERMIC REACTIONS OF SPENT PLUTONIUM DECONTAMINATION CHEMICALS USING WET AND DRY DECONTAMINATION METHODS

International Nuclear Information System (INIS)

HOPKINS, A.M.; JACKSON, G.W.; MINETTE, M.; EWALT, J.; COOPER, T.; SCOTT, P.; JONES, S.; SCHEELEY, R.

2005-01-01

The Plutonium Finishing Plant (PFP) at the Hanford site in Eastern Washington is currently being decommissioned by Fluor Hanford. Chemicals being considered for dccontamination of gloveboxes in PFP include cerium (IV) nitrate in a nitric acid solution, and proprietary commercial solutions that include acids and sequestering agents. Aggressive chemicals are commonly used to remove transuranic contaminants from process equipment to allow disposal of the equipment as low level waste. Fluor's decontamination procedure involves application of chemical solutions as a spray on the contaminated surfaces, followed by a wipe-down with rags. Alternatively, a process of applying oxidizing Ce IV ions contained in a gel matrix and vacuuming a dry gel material is being evaluated. These processes effectively transfer the transuranic materials to rags or a gel matrix which is then packaged as TRU waste and disposed

Sunflowers to decontaminate water

International Nuclear Information System (INIS)

Anon.

1996-01-01

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

Radiation decontamination of dry food ingredients and processing aids

Energy Technology Data Exchange (ETDEWEB)

Farkas, J

1984-01-01

Radiation decontamination of dry ingredients, herbs and enzyme preparations is a technically feasible, economically viable and safe physical process. The procedure is direct, simple, requires no additives and is highly efficient. Its dose requirement is moderate. Radiation doses of 3-10 kGy (0.3-1 mrad) have proved sufficient to reduce the viable counts to a satisfactory level. Ionising radiations do not cause any significant rise in temperature. The flavour, texture or other important technological or sensory properties of most ingredients are not influenced at radiation doses necessary for satisfactory decontamination, and radiation obviates the chemical residue problem. The microflora surviving radiation decontamination of dry ingredients are more susceptible to subsequent antimicrobial treatments. Recontamination can be prevented as the product can be irradiated in its final packaging. Irradiation could be carried out in commercial containers and would result in considerable savings of energy and labour as compared to alternative decontamination techniques. Radiation processing of these commodities is an established technology in several countries and more clearances on irradiated foods are expected to be granted in the near future.

Influence of antimicrobial solutions in the decontamination and adhesion of glass-fiber posts to root canals

Science.gov (United States)

HARAGUSHIKU, Gisele Aihara; BACK, Eduardo Donato Eing Engelke; TOMAZINHO, Paulo Henrique; BARATTO, Flares; FURUSE, Adilson Yoshio

2015-01-01

Objective This study evaluated the effect of root canal disinfectants on the elimination of bacteria from the root canals, as well as their effect on glass-fiber posts bond strength. Material and Methods Fifty-three endodontically treated root canals had post spaces of 11 mm in length prepared and contaminated with E. faecalis. For CFU/ml analysis, eight teeth were contaminated for 1 h or 30 days (n=4). Teeth were decontaminated with 5% NaOCl, 2% CHX, or distilled water. As control, no decontamination was conducted. After decontamination, sterile paper points were used to collect samples, and CFU/ml were counted. For push-out, three groups were evaluated (n=15): irrigation with 2.5% NaOCl, 2% CHX, or sterile distilled water. A bonding agent was applied to root canal dentin, and a glass-fiber post was cemented with a dual-cured cement. After 24 h, 1-mm-thick slices of the middle portion of root canals were obtained and submitted to the push-out evaluation. Three specimens of each group were evaluated in scanning electron microscopy (SEM). Data were analyzed with one-way ANOVA and Dunnett’s T3 test (α=0.05). Results The number of CFU/ml increased from 1 h to 30 days of contamination in control and sterile distilled water groups. Decontamination with NaOCl was effective only when teeth were contaminated for 1 h. CHX was effective at both contamination times. NaOCl did not influence the bond strength (p>0.05). Higher values were observed with CHX (pcontaminated root canals both in reducing the bacterial contamination and in improving the glass-fiber post bonding. PMID:26398518

Resorption of radionuclides through the surface of thermal burns and problems of decontamination

International Nuclear Information System (INIS)

Il'in, L.A.; Ivannikov, A.T.; Popov, B.A.; Parfenova, I.M.

1981-01-01

Resorption of sup(137)Cs, sup(89)Sr, sup(131)I, sup(241)Am during thermal burns of 1-3 degrees and choice of a decontamination method used simultaneously for decontamination and disinfection of burn wounds were studied. It is shown that a degree of burns effects in a certain form on skin penetrability: through burns of 1-2 degrees the resorption increases 1 5-3 times, through burns of the thir degree the resorption decreases slightly as compared to the resorption through intact skin. High efficiency of 3% soap solution for removing radionuclides from burn csurfae of skin has been established. For burns accompanied with the disturbance of epidermis integrality, when considerable absorption of radionuclides is possible, decontamination must be accomplished as soon and complete as possible [ru

Selection and development of an easy to process electrolyte for decontamination by electropolishing

International Nuclear Information System (INIS)

Steringer, A.; Moser, T.

1989-01-01

Three different organic electrolytes: formic acid (E 1), oxalic acid (E 2) and acetylacetone (E 3) using potassium bromide (KBr) as the auxiliary electrolyte, were tested in the laboratory for electrochemically dissolving steel and stainless steel. The best results in the preliminary test series were attained with acetylacetone. It ranks among the first for current efficiency, with the produced acetylacetonates having the lowest solubility and thus they settle out of the solution in the form of coarse crystalline products. Tests were made on radioactive reactor components using acetylacetone in a 400 A test facility, to verify and optimize the decontamination factors, the electrolyte service life and the produced waste volume, as well as the respective process parameters. The surface activity of the components ranged from 2 to 10 Bq/cm 2 , and a decontamination factor of 30 was attained. The obtained specific waste volume is 1.1 litre/m 2 of decontaminated surface. A gamma-spectrometric evaluation revealed that the activity in the settled-out metallic acetylacetonate is five times higher than that in the electrolyte. It is only necessary to refill the spent acetylacetonate which makes it then possible to continue to use the electrolyte solution almost unrestrictedly

Designing of a mobile decontamination facility (MDF) for preparedness and response to nuclear/radiological emergencies

International Nuclear Information System (INIS)

Joshi, G.H.; Garai, S.K.; Chatterjee, M.K.; Pradeepkumar, K.S.; Sharma, D.N.

2005-01-01

During a radiological emergency in public domain, likelihood of radioactive contamination cannot be completely ruled out. Timely and effective decontamination can significantly reduce possible external and internal radiation exposure to public. The objective of designing of a mobile decontamination facility is to develop the capability for decontaminating affected persons in case of any radiological emergency in public domain. A fully equipped decontamination facility on the wheels will be able to reach at the scene and will be able to decontaminate a large number of victims with the help of optimized decontamination procedures in short duration avoiding unwanted radiation exposure. This self-supporting decontamination facility is designed to be equipped with sufficient number of radiation monitoring instruments, equipments for decontamination, decontamination agents etc. (author)

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

Decontamination by water jet, chemical and electrochemical methods

International Nuclear Information System (INIS)

Gauchon, J.P.; Mordenti, P.; Bezia, C.; Fuentes, P.; Kervegant, Y.; Munoz, C.; Pierlas, C.

1986-01-01

The decontamination tests have been carried out on samples coming from representative specimens from primary circuit of the PWR and on samples coming from the emergency feed water piping of the German BWR (Isar). The oxide found in PWR primary loops can only be removed by a two steps process. The initial embrittling step is particularly effective in hot alkaline permanganate medium. Oxidation by ozone treatment is less effective. The second step involves chemical erosion of the metal in nitrofluoric acid in conjonction with ultrasonic agitation. Among the reagents used, only oxalic acid is suitable for electrolytic decontamination. Among the reagents possible for decontamination of the Isar specimens (ferritic steel lined with hematite) halogenous acid in mixture without or with oxygenated water, sulfuric acid, the formic acid/formaldehyde mixture are chosen. Metal erosion with high pressure jet as well as the decontamination efficiency on parts lined with hematite have made possible to determine the best conditions. 33 figs, 29 refs

Advance in radioactive decontamination; Avances en descontaminacion radiactiva

Energy Technology Data Exchange (ETDEWEB)

Basteris M, J. A. [Universidad Autonoma de Yucatan, Facultad de Medicina, Departamento de Diagnostico por Laboratorio y Gabinete, Av. Cupules No. 232, Col. Garcia Gineres, 97070 Merida, Yucatan (Mexico); Farrera V, R., E-mail: basteris@prodigy.net.m [Hospital de Especialidades de la UMAE, Centro Medico Nacional Ignacio Garcia Tellez, Departamento de Medicina Nuclear, Calle 34 x 41, Exterrenos el Fenix s/n, Col. Industrial, 91750 Merida, Yucatan (Mexico)

2010-09-15

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 removal of Cs-137 from soil using washing-electrokinetic decontamination equipment

International Nuclear Information System (INIS)

Kim, Gyenam; Kim, Seungsoo; Kim, Geunho; Park, Hyemin; Kim, Wansuk; Park, Ukryang; Kwon, Hyeokju; Ryu, Ohha; Moon, Jeikwon

2012-01-01

The radioactive soil at the KAERI radioactive waste storage facility has slightly high hydro-conductivity, and was mainly contaminated with 137 Cs 30-35 years ago. Recently, a soil washing method has been applied to remove 137 Cs from radioactive soil, but it appears that the removal efficiency of 137 Cs had low and a lot of waste solution was generated. Meanwhile, an electrokinetic decontamination method provides high removal efficiency of 137 Cs and generates little waste effluent. Thus, it is suggested that an electrokinetic decontamination method is a suitable technology in consideration of the soil characteristics near South Korean nuclear facilities

A comparison of decontamination effects of commercially available detergents in rats pre-exposed to topical sulphur mustard.

Science.gov (United States)

Misik, Jan; Jost, Petr; Pavlikova, Ruzena; Vodakova, Eva; Cabal, Jiri; Kuca, Kamil

2013-06-01

The genotoxic vesicant sulphur mustard [bis-2-(chloroethyl)sulphide] is a chemical warfare agent which is easily available due to its relatively simple synthesis. Thus, sulphur mustard is a potential agent for mass contamination. In this study, we focused on sulphur mustard toxicity and decontamination in a rat model using commercially available detergent mixtures for dermal decontamination. Male Wistar rats were percutaneously treated with sulphur mustard and subjected to wet decontamination 2 min postexposure. Commercially produced detergents Neodekont™, Argos™, Dermogel™ and FloraFree™ were tested for their decontamination efficacy against an exposed group and their protective ratios determined. The results showed that all tested detergent solutions produced an increase in the median lethal dose [LD(50) = 9.83 (5.87-13.63) mg·kg(-1)] in comparison to controls, which led to increased survival of experimental animals. In general, all tested detergents provided modest decontamination efficacy (PR = 2.0-5.7). The highest protective ratio (5.7) was consistently achieved with Argos™. Accordingly, Argos™ should be considered in further investigation of mass casualty decontamination.

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

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 of process equipment using recyclable chelating solvent

Energy Technology Data Exchange (ETDEWEB)

Jevec, J.; Lenore, C.; Ulbricht, S. [Babcock & Wilcox, Co., R& DD, Alliance, OH (United States)

1995-10-01

The Department of Energy (DOE) is now faced with the task of meeting decontamination and decommissioning obligations at numerous facilities by the year 2019. Due to the tremendous volume of material involved, innovative decontamination technologies are being sought that can reduce the volumes of contaminated waste materials and secondary wastes requiring disposal. This report describes the results of the performance testing of chelates and solvents for the dissolution of uranium.

A Sandia National Laboratories decontamination and demolition success story

International Nuclear Information System (INIS)

Miller, D.R.; Barber, D.S.; Lipka, G.

1994-01-01

Sandia National Laboratories/New Mexico (SNL/NM) has established a formal facility assessment, decontamination and demolition oversight process with the goal of ensuring that excess or contaminated facilities are managed in a cost-effective manner that is protective of human health and the environment. The decontamination and demolition process is designed so that all disciplines are consulted and have input from the initiation of a project. The committee consists of all essential Environmental, Safety and Health (ES and H) and Facilities disciplines. The interdisciplinary-team approach has provided a mechanism that verifies adequate building and site assessment activities are conducted. This approach ensures that wastes generated during decontamination and demolition activities are handled and disposed according to Department of Energy (DOE), Federal, state, and local requirements. Because of the comprehensive nature of the SNL decontamination and demolition process, the strategy can be followed for demolition, renovation and new construction projects, regardless of funding source. An overview of the SNL/NM decontamination and demolition process is presented through a case study which demonstrates the practical importance of the formal process

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)

Technical soaps - a possibility of decontaminating thorium-contaminated waste waters

International Nuclear Information System (INIS)

Drathen, H.; Erichsen, L. v.

1977-01-01

Thorium-contaminated waste waters showing a concentration of thorium higher than 10sup(-5) mol/l can be quantitatively decontaminated by adding soaps. Concentrations of impurity ions of both tap and sea waters have been taken into consideration. As there is no difference between soaps and soap mixtures concerning the quantity of precipitation rates, technical soaps are from the economic point of view best suited for decontaminating thorium-contaminated waste waters. Having a soap concentration of 200% of the stoichiometric amount of thorium and a concentration of impurity ions of 10sup(-2) mol/l, it is assumed that decontamination factors of more than 20 can be reached in one step. (orig.) [de

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)

Financial assurance for decontamination and decommissioning: a Texas perspective

International Nuclear Information System (INIS)

Rao, C.D.; Etter, S.D.; Dziuk, T.W.

1986-01-01

The Texas Department of Health (TDH) has the regulatory responsibility to ensure that funds are available for decontamination, decommissioning, and reclamation of uranium recovery facilities in Texas. Uranium recovery licensees are required to post financial security with the Agency for that purpose. Texas uranium facilities include (1) conventional surface mining and milling plants, including tailings ponds, and (2) in situ solution mining plants, each with somewhat different cost elements for decontamination, decommissioning, reclamation, and closure. Cost estimates for decontamination, decommissioning, and reclamation, along with a facility closure plan, are initially submitted to the Agency by the licensees. These are verified and compared with detailed independent cost estimates prepared by Agency staff. Significant differences between the two estimates are examined and resolved by negotiation and/or recalculation to the satisfaction of the state. The Texas philosophy for maintaining financial security permits flexibility in the closure plan without jeopardizing or compromising the ultimate long-term objectives of closure. Review of closure plans incorporates new technological developments In contrast, financial security is established expeditiously by applying the best available cost data to necessarily conservative estimates of the work involved. Financial security cost estimates are subject to annual review and adjustment

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.)

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)

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

Use of complexones solutions in liquid carbon dioxide for cleaning of materials contaminated with heavy and radioactive metals

International Nuclear Information System (INIS)

Shadrin, A.Yu.; Kamachev, V.A.; Kiseleva, R.N.; Murzin, A.A.; Shafikov, D.N.; Bondin, V.V.; Efremov, I.V.; Kovalev, D.N.; Podoinitsyn, S.V.

2003-01-01

I n this paper liquid carbon dioxide (pressure 50-70 atm) was used for decontamination. The performed experiments on removal of cobalt, nickel, uranium and americium nitrates and carbonates by different solutions have shown that the solutions of such complexing agents as hexafluoroacetylacetone (HFA), tributylphosphate (TBP), di-2-ethylhexylphosphoric acid (D2EHPA) in liquid CO 2 can be used for purification of pulps, metals, paper and fabrics. Liquid CO 2 is high viscosity of the medium and hence low diffusion coefficients and long duration of the processes. It is known that 20 minutes are sufficient to attain equilibrium in supercritical CO 2 medium on metal removal by HFA solutions. During the experiments it was established that with the use of liquid CO 2 the keeping time should be increased to 40 min, which is acceptable from the standpoint of technical feasibility of decontamination processes in these solutions. Experiments on really contaminated samples of pulps, metals and fabrics have confirmed that the decontamination coefficients of 30-100 can be easily obtained by 2-3 fold material treatment operations. The secondary waste volume therewith is less by a factor of 20-200 than that of traditional techniques. (authors)

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)

Influence of antimicrobial solutions in the decontamination and adhesion of glass-fiber posts to root canals

Directory of Open Access Journals (Sweden)

Gisele Aihara HARAGUSHIKU

2015-08-01

Full Text Available AbstractObjective This study evaluated the effect of root canal disinfectants on the elimination of bacteria from the root canals, as well as their effect on glass-fiber posts bond strength.Material and Methods Fifty-three endodontically treated root canals had post spaces of 11 mm in length prepared and contaminated with E. faecalis. For CFU/ml analysis, eight teeth were contaminated for 1 h or 30 days (n=4. Teeth were decontaminated with 5% NaOCl, 2% CHX, or distilled water. As control, no decontamination was conducted. After decontamination, sterile paper points were used to collect samples, and CFU/ml were counted. For push-out, three groups were evaluated (n=15: irrigation with 2.5% NaOCl, 2% CHX, or sterile distilled water. A bonding agent was applied to root canal dentin, and a glass-fiber post was cemented with a dual-cured cement. After 24 h, 1-mm-thick slices of the middle portion of root canals were obtained and submitted to the push-out evaluation. Three specimens of each group were evaluated in scanning electron microscopy (SEM. Data were analyzed with one-way ANOVA and Dunnett’s T3 test (α=0.05.Results The number of CFU/ml increased from 1 h to 30 days of contamination in control and sterile distilled water groups. Decontamination with NaOCl was effective only when teeth were contaminated for 1 h. CHX was effective at both contamination times. NaOCl did not influence the bond strength (p>0.05. Higher values were observed with CHX (p<0.05. SEM showed formation of resin tags in all groups.Conclusion CHX showed better results for the irrigation of contaminated root canals both in reducing the bacterial contamination and in improving the glass-fiber post bonding.

High pressure freon decontamination of remote equipment

International Nuclear Information System (INIS)

Wilson, C.E.

1987-01-01

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

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.).

Ultrasonic decontamination of nuclear fuel. Feasibility study

International Nuclear Information System (INIS)

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

1995-05-01

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

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.

Decontamination of stainless steel canisters that contain high-level waste

International Nuclear Information System (INIS)

Bray, L.A.

1987-01-01

At the West Valley Nuclear Services Company (WVNSC) in West Valley, New York, high-level radioactive waste (HLW) will be vitrified into a borosilicate glass form and poured into large, stainless steel canisters. During the filling process, volatile fission products, principally 137 Cs, condense on the exterior of the canisters. The smearable contamination that remains on the canisters after they are filled and partially cooled must be removed from the canisters' exterior surfaces prior to their storage and ultimate shipment to a US Department of Energy (DOE) repository for disposal. A simple and effective method was developed for decontamination of HLW canisters. This method of chemical decontamination is applicable to a wide variety of contaminated equipment found in the nuclear industry. The process employs a reduction-oxidation system [Ce(III)/Ce(IV)] in nitric acid solution to chemically mill the surface of stainless steel, similar to the electropolishing process, but without the need for an applied electrical current. Contaminated canisters are simply immersed in the solution at controlled temperature and Ce(IV) concentration levels

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)

Fate of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX) on soil following accelerant-based fire and liquid decontamination.

Science.gov (United States)

Gravett, M R; Hopkins, F B; Self, A J; Webb, A J; Timperley, C M; Riches, J R

2014-08-01

In the event of alleged use of organophosphorus nerve agents, all kinds of environmental samples can be received for analysis. These might include decontaminated and charred matter collected from the site of a suspected chemical attack. In other scenarios, such matter might be sampled to confirm the site of a chemical weapon test or clandestine laboratory decontaminated and burned to prevent discovery. To provide an analytical capability for these contingencies, we present a preliminary investigation of the effect of accelerant-based fire and liquid decontamination on soil contaminated with the nerve agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX). The objectives were (a) to determine if VX or its degradation products were detectable in soil after an accelerant-based fire promoted by aviation fuel, including following decontamination with Decontamination Solution 2 (DS2) or aqueous sodium hypochlorite, (b) to develop analytical methods to support forensic analysis of accelerant-soaked, decontaminated and charred soil and (c) to inform the design of future experiments of this type to improve analytical fidelity. Our results show for the first time that modern analytical techniques can be used to identify residual VX and its degradation products in contaminated soil after an accelerant-based fire and after chemical decontamination and then fire. Comparison of the gas chromatography-mass spectrometry (GC-MS) profiles of VX and its impurities/degradation products from contaminated burnt soil, and burnt soil spiked with VX, indicated that the fire resulted in the production of diethyl methylphosphonate and O,S-diethyl methylphosphonothiolate (by an unknown mechanism). Other products identified were indicative of chemical decontamination, and some of these provided evidence of the decontaminant used, for example, ethyl 2-methoxyethyl methylphosphonate and bis(2-methoxyethyl) methylphosphonate following decontamination with DS2. Sample preparation

Removal of radioactive cesium from surface soils solidified using polyion complex. Rapid communication for decontamination test at Iitate-mura in Fukushima Prefecture

International Nuclear Information System (INIS)

Naganawa, Hirochika; Yanase, Nobuyuki; Mitamura, Hisayoshi; Nagano, Tetsushi; Yoshida, Zenko; Kumazawa, Noriyuki; Saitoh, Hiroshi; Kashima, Kaoru; Fukuda, Tatsuya; Tanaka, Shun-ichi

2011-01-01

We tried the decontamination of surface soils for three types of agricultural land at Nagadoro district of Iitate-mura (village) in Fukushima Prefecture, which is highly contaminated by deposits of radionuclides from the plume released from the Fukushima Daiichi nuclear power plant. The decontamination method consisted of the peeling of surface soils solidified using a polyion complex, which was formed from a salt solution of polycations and polyanions. Two types of polyion complex solution were applied to an upland field in a plastic greenhouse, a pasture, and a paddy field. The decontamination efficiency of the surface soils reached 90%, and dust release was effectively suppressed during the removal of surface soils. (author)

Chemical, biological, radiological, and nuclear decontamination: Recent trends and future perspective

Directory of Open Access Journals (Sweden)

Vinod Kumar

2010-01-01

Full Text Available Chemical, biological, radiological, and nuclear (CBRN decontamination is the removal of CBRN material from equipment or humans. The objective of the decontamination is to reduce radiation burden, salvage equipment, and materials, remove loose CBRN contaminants, and fix the remaining in place in preparation for protective storage or permanent disposal work activities. Decontamination may be carried out using chemical, electrochemical, and mechanical means. Like materials, humans may also be contaminated with CBRN contamination. Changes in cellular function can occur at lower radiation doses and exposure to chemicals. At high dose, cell death may take place. Therefore, decontamination of humans at the time of emergency while generating bare minimum waste is an enormous task requiring dedication of large number of personnel and large amount of time. General principles of CBRN decontamination are discussed in this review with emphasis on radiodecontamination.

The reuse of scrap and decontamination waste water from decommissioning

International Nuclear Information System (INIS)

Deng Junxian; Li Xin; Xie Xiaolong

2010-01-01

Huge amount of radioactive scrap with low activity will be generated from reactor decommissioning; the decontamination is concentrated in the surface layer of the scrap. The decontaminated substance can be removed by high pressure water jet to appear the base metal and to reuse the metal. Big amount of radioactive waste water will be generated by this decontamination technology; the radioactive of the waste water is mainly caused by the solid particle from decontamination. To remove the solid particle as clean as possible, the waste water can be reused. Different possible technology to remove the solid particle from the water had been investigated, such as the gravity deposit separation, the filtration and the centrifugal separation etc. The centrifugal separation technology is selected; it includes the hydraulic vortex, the centrifugal filtration and the centrifugal deposit. After the cost benefit analysis at last the centrifugal deposit used butterfly type separator is selected. To reuse the waste water the fresh water consumption and the cost for waste water treatment can be reduced. To reuse the radioactive scrap and the waste water from decommissioning will minimize the radioactive waste. (authors)

Progress in the development and application of methods for cleaning and decontamination of components exposed to sodium

International Nuclear Information System (INIS)

Msika, D.; Lafon, A.

1978-01-01

In the technology of liquid sodium cooled fast reactors, the necessary processes for washing and decontamination have been demonstrated. For sodium removal, different solutions have been considered and tested in France. The studies have been progressively oriented toward defining a process using a fine dispersion of water in a gas (atomization). The results obtained by that method on non-radioactive components were satisfactory insofar as the efficiency and safety of the operation was concerned. The purpose of decontaminating components from the reactor primary circuits is to reduce the level of surface activity to a level compatible with personnel access without biological shielding. The treatment Is comprised of two stages: (i) washing, to remove any residual sodium, and (ii) decontamination which alternately applies alkaline and acid solutions, to dissolve the deposited radionuclides without significant attack on the surface. The treatment, recently applied to components from in-service reactors, generally met the design objective. (author)

Decontamination of polypropylene fabrics by dry cleaning

International Nuclear Information System (INIS)

Severa, J.; Knajfl, J.

1983-01-01

Polypropylene fabrics can efficiently be decontaminated by dry cleaning in benzine or perchloroethylene, this also in case the fabric was greased in addition to radioactive contamination. For heavily soiled fabric, it is advantageous to first dry clean it and then wash it. The positive effect was confirmed of intensifiers on the cleaning process, especially of benzine soap. In practice, its concentration should be selected within 1 and 10 g.dm - 3 . Decontamination by dry cleaning and subsequent washing is advantageous in that that the resulting activity of waste water from the laundry is low. Radioactive wastes from the dry cleaning process have a low weight and can be handled as solid waste. (M.D.)

UV-decontamination of potable and sewage water in the city with population over one million

Directory of Open Access Journals (Sweden)

Smirnov Aleksandr

2016-01-01

Full Text Available The waterworks system in a modern city is a complex challenge. From the one hand, it is necessary to provide high-quality potable water to the residents with observance of all sanitary and hygienic requirements; from the other hand, the sewage water discharged from the city should not affect the environment. Meanwhile, the microbiological safety is the top-priority and crucial parameter for evaluation of any work and any project. In Novosibirsk, solutions have been found for both of them by using the cutting-edge approaches in the decontamination technologies. The UV-decontamination enabled to create a multi-barrier efficient protection when dealing with the potable water treatment and ensure environmentally-friendly decontamination of the sewage water.

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

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

The removal of Cs-137 from soil using washing-electrokinetic decontamination equipment

Energy Technology Data Exchange (ETDEWEB)

Kim, Gyenam; Kim, Seungsoo; Kim, Geunho; Park, Hyemin; Kim, Wansuk; Park, Ukryang; Kwon, Hyeokju; Ryu, Ohha; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-10-15

The radioactive soil at the KAERI radioactive waste storage facility has slightly high hydro-conductivity, and was mainly contaminated with {sup 137}Cs 30-35 years ago. Recently, a soil washing method has been applied to remove {sup 137}Cs from radioactive soil, but it appears that the removal efficiency of {sup 137}Cs had low and a lot of waste solution was generated. Meanwhile, an electrokinetic decontamination method provides high removal efficiency of {sup 137}Cs and generates little waste effluent. Thus, it is suggested that an electrokinetic decontamination method is a suitable technology in consideration of the soil characteristics near South Korean nuclear facilities.

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

Commercial Cleaning Products for Chemical Decontamination: A Scoping Study

Science.gov (United States)

2014-05-01

and may injure human skin without dilution), although this approach is less favoured in a mass casualty decontamination situation than soap and water...commercial cleaning products, full strength K-O-K® liquid bleach (5.25% aqueous solution of NaOCl), dish-washing detergent Cascade® with Extra...Bleach Action Gel, OxiClean® Versatile Stain Remover Powder, and ZEP® Industrial Purple liquid cleaner (proprietary caustic cleaner containing

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.

Decontamination of radioruthenium from TRUEX Solvent

International Nuclear Information System (INIS)

Kumaresan, R.; Nayak, Prasant; Venkatesan, K.A.; Antony, M.P.; Rao, P.R. Vasudeva

2012-01-01

A procedure has been developed for the decontamination of radioruthenium from the lean organic phase composed of a solution 0.2 M n-octyl(phenyl)-N,N-diisobutylcarbamoylmethylyphosphineoxide (CMPO) and 1.2 M tri-n-butylphosphate (TBP) in n-dodecane (n-DD), which was used for the partitioning of minor actinides from actual high active waste solution (155 GWd/Te). For this purpose, the stripping behavior of radioruthenium from 0.2 M CMPO-1.2 M TBP in n-DD was studied at 298 K by using various aqueous reagents and adsorbents. Among the different reagents investigated, the aqueous solution of sodium hydroxide and sodium carbonate and adsorbents such as neutral alumina and anion exchange resin (OH - form) were identified as the promising candidates. Nearly 90-95% of radioruthenium was removed from the lean organic phase in seven contacts using sodium carbonate or sodium hydroxide solution. The residual radioactivity in the organic phase was removed by treatment with neutral alumina or anion exchange resin. The quality of the organic phase was ascertained by 241 Am(III) retention test. (orig.)

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

International Nuclear Information System (INIS)

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

1996-01-01

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

An evaluation of selected methods for the decontamination of cattle hides prior to skinning.

Science.gov (United States)

Small, A; Wells-Burr, B; Buncic, S

2005-02-01

The effectiveness of different decontamination treatments in reducing microbial loads on cattle hides was assessed. The 10-s hide treatments were conducted using a wet-and-dry vacuum cleaner filled with one of the liquids (heated to 50 °C) indicated below, followed or not by 10-min drying in the air. Also, the hide was clipped, followed or not by 10-s singeing using a hand-held blowtorch. Before and after each decontamination treatment, the hide was sampled (100 cm(2) areas) by a sponge-swabbing method to compare the total viable counts of bacteria (TVC). The largest bacterial reduction (Psanitizer solution (10% Betane Plus) resulted in significant reductions of 1.80 (Peffects. Since hide contamination is associated with microbial contamination of the carcasses, the results indicate that post-killing/pre-skinning hide decontamination (used alone, or in combination with carcass decontamination) has a potential to improve microbial meat safety. Nevertheless, further research is required to optimise the efficacy of these treatments in the reduction of specific pathogens under commercial conditions.

Complexing properties of the main organic acids used in decontamination solutions and reactions involved in their degradation or elimination

International Nuclear Information System (INIS)

Noel, D.; Kerrec, O.; Lantes, B.; Rosset, R.; Bayri, B.; Desbarres, J.; Jardy, A.

1994-09-01

This paper presents a study that, parallel with the industrial development of the decontamination chemical process, has been performed more fundamentally on the chemical properties of used products: degradation reaction during process or after decontamination and during wastes treatment. In particular, results show that the organic compounds used have no interaction with resins during radioactive wastes storage and therefore they do not present leaching risk. (authors). 8 refs., 3 figs., 4 tabs

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

Design of a tritium decontamination workstation based on plasma cleaning

International Nuclear Information System (INIS)

Antoniazzi, A.B.; Shmayda, W.T.; Fishbien, B.F.

1993-01-01

A design for a tritium decontamination workstation based on plasma cleaning is presented. The activity of tritiated surfaces are significantly reduced through plasma-surface interactions within the workstation. Such a workstation in a tritium environment can routinely be used to decontaminate tritiated tools and components. The main advantage of such a station is the lack of low level tritiated liquid waste. Gaseous tritiated species are the waste products with can with present technology be separated and contained

Removal of Uranium in Soil Using Large-scale Electrokinetic Decontamination Equipment

Energy Technology Data Exchange (ETDEWEB)

Kim, Gye Nam; Kim, Il gook; Jeong, Jung Whan; Kim, Seung Soo; Choi, Jong Won [KAERI, Daejeon (Korea, Republic of)

2016-05-15

A method to remediate a large volume of radioactive soil should be developed. Until now the soil washing method has been studied to remediate soil contaminated with uranium, cobalt, cesium, and so on. However, it has a lower removal efficiency of nuclide from soils and generated a large volume of waste-solution. In addition, its application to the soil composed of fine particle is impossible. Thus, the electrokinetic method has been studied as a new technology for soil remediation recently. In this study, for a reduction of the waste electrolyte volume, the reuse period of waste electrolyte in the electrokinetic decontamination experiment through several experiments with the manufactured 1.2 ton electrokinetic decontamination equipment. In addition, the time required to reach below the clearance concentration level for self- disposal was estimated through several experiments using the manufactured electrokinetic decontamination equipment. When the initial uranium concentrations in the soils were 7.0-20.0 Bq/g, the times required to reach below the clearance concentration level for self-disposal were 25-40 days with the waste and reclaimed electrolytes.

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

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

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.)

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

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

Application of gamma irradiation in ginseng for both photodegradation of pesticide pentachloronitrobenzene and microbial decontamination

Energy Technology Data Exchange (ETDEWEB)

Wen, Hsiao-Wei [Department of Food Science and Biotechnology, National Chung Hsing University, 250, Kuo Kuang Road, Taichung 402, Taiwan (China); Hsieh, Ming-Fa [Department of Biomedical Engineering, Chung Yuan Christian University, 200, Chung Pei Road, Chungli 320, Taiwan (China); Wang, Ya-Ting; Chung, Hsiao-Ping [Nuclear Science and Technology Development Center, National Tsing Hua University, 101 Section 2, Kuang Fu Road, Hsinchu 300, Taiwan (China); Hsieh, Po-Chow; Lin, I-Hsin [Committee on Chinese Medicine and Pharmacy, Department of Health, Executive Yuan, Taipei 104, Taiwan (China); Chou, Fong-In, E-mail: fichou@mx.nthu.edu.tw [Nuclear Science and Technology Development Center, National Tsing Hua University, 101 Section 2, Kuang Fu Road, Hsinchu 300, Taiwan (China); Institute of Nuclear Engineering and Science, National Tsing Hua University, 101 Section 2, Kuang Fu Road, Hsinchu 300, Taiwan (China)

2010-04-15

This study investigates the feasibility of using gamma irradiation for photodegradation of a common residual fungicide, pentachloronitrobenzene (PCNB), in ginseng, and for microbial decontamination. American ginseng, Panax quinquefolius, was subjected to gamma irradiation. PCNB residues were analyzed by gas chromatography with electron capture detection and mass spectrometry. Eighty percent of PCNB (100 ppm) in a methanol aqueous solution was degraded by 5 kGy irradiation, and the primary degradation product was pentachloroaniline. Furthermore, contaminated PCNB (3.7 ppm) in ginseng were reduced to 0.2 ppm after 20 kGy irradiation. The IC{sub 50} for treatment of Sclerotium rolfsii with 20 kGy irradiated PCNB was about 2.7 times higher than that for treatment with unirradiated PCNB. The survival rate of mouse fibroblast L929 cells treated with 20 kGy irradiated PCNB was about 12.9% higher than that of L929 cells treated with unirradiated PCNB. Additionally, after 20 kGy irradiation, less than 5% reduction of contents of ginsenoside Rb1 and Re were observed, and amounts of ginsenosides Rc, Rd, and Rg1 were not reduced significantly. The minimal gamma dose for microbial decontamination was 10 kGy. Therefore, gamma irradiation can be used for both PCNB photodegradation and microbial decontamination of ginseng without obvious loses of ginsenoside contents.

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.

The pharmacological activity of medical herbs after microbiological decontamination by irradiation

Science.gov (United States)

Owczarczyk, H. B.; Migdał, W.; K ȩdzia, B.

2000-03-01

In the Institute of Nuclear Chemistry and Technology research on microbiological decontamination of medicinal herbs by irradiation has been carried out since 1996. It was shown that using ionizing radiation (a dose of 10 kGy) can obtain satisfactory results of microbiological decontamination of these products. The content of essential biologically active substances such as essential oils, flavonoids, glycosides, anthocyans, antra-compounds, poliphenoloacids, triterpene saponins, oleanosides and plants mucus did not change significantly after irradiation. Pharmacological activity of medicinal herbs has been found satisfactory after microbiological decontamination by irradiation.

The pharmacological activity of medical herbs after microbiological decontamination by irradiation

International Nuclear Information System (INIS)

Owczarczyk, H.B.; Migdal, W.; Kedzia, B.

2000-01-01

In the Institute of Nuclear Chemistry and Technology research on microbiological decontamination of medicinal herbs by irradiation has been carried out since 1996. It was shown that using ionizing radiation (a dose of 10 kGy) can obtain satisfactory results of microbiological decontamination of these products. The content of essential biologically active substances such as essential oils, flavonoids, glycosides, anthocyans, antra-compounds, poliphenoloacids, triterpene saponins, oleanosides and plants mucus did not change significantly after irradiation. Pharmacological activity of medicinal herbs has been found satisfactory after microbiological decontamination by irradiation

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.)

Concrete decontamination by Electro-Hydraulic Scabbling (EHS)

International Nuclear Information System (INIS)

1994-11-01

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

Concrete decontamination by Electro-Hydraulic Scabbling (EHS)

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-11-01

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

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)

Decontamination in a Russian settlement

DEFF Research Database (Denmark)

Fogh, C.L.; Andersson, Kasper Grann; Barkovsky, A.N.

1999-01-01

Decontamination was carried out in an area with three houses in Novo Bobovichi, Bryansk region, Russia, in the autumn of 1995. It was demonstrated that significant reductions in the dose rate both indoor (DRF = 0.34) and outdoor (DRF = 0.20) can be achieved when a controlled cleaning is undertake...

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...

Electrocoagulation applied to the decontamination of stainless steel parts contaminated with uranium

International Nuclear Information System (INIS)

Pujol P, A. A.; Monroy G, F.; Bustos B, E.

2017-09-01

The decontamination of non-compact able radioactive waste, such as tools and equipment, has the purpose of removing surface radioactive waste from waste, in order to reduce its volume to be conditioned and stored. The application of treatment techniques based on electrochemistry, such as electro-coagulation (Ec) in the decontamination of waste or non-compact able radioactive materials of stainless steel containing uranium, was studied in the present work and its technical feasibility was evaluated. For this, tests were carried out, first with stainless steel plates coated with WO 3 , to simulate a fixed contamination and to determine the best conditions of tungsten removal by Ec as: ph, support electrolyte, cell potential, type of counter electrode material and distance between the anode/cathode electrodes. In addition, different arrangements of configurations were tested for a rectangular acrylic cell and for a circular configuration cell, using flat plate electrodes and cylindrical electrodes to perform the removal process of the contaminant with the best conditions. In the case of the Ec, the mechanism that occurs is an electrodisolution of the iron plate, with the release of oxygen at the anode and detachment of the WO 3 layer, all the material passing to the solution with the formation of iron hydroxides. Subsequently, from the best experimental conditions to remove WO 3 , UO 2 (NO 3 ) 2 was used as radioactive contaminant to evaluate the feasibility of the decontamination process. Removal efficiencies of 90% uranium were obtained in 1 hour, ph = 1, using a molar solution of H 2 SO 4 as support electrolyte and potential of 2.4 V. Finally, after testing the different electrochemical cell (Ec) arrays at the laboratory level, radioactive decontamination of real pieces contaminated with U-238 was performed using the circular configuration arrangement under the best experimental conditions previously determined. (Author)

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

Binding affinity and decontamination of dermal decontamination gel to model chemical warfare agent simulants.

Science.gov (United States)

Cao, Yachao; Elmahdy, Akram; Zhu, Hanjiang; Hui, Xiaoying; Maibach, Howard

2018-05-01

Six chemical warfare agent simulants (trimethyl phosphate, dimethyl adipate, 2-chloroethyl methyl sulfide, diethyl adipate, chloroethyl phenyl sulfide and diethyl sebacate) were studied in in vitro human skin to explore relationship between dermal penetration/absorption and the mechanisms of simulant partitioning between stratum corneum (SC) and water as well as between dermal decontamination gel (DDGel) and water. Both binding affinity to and decontamination of simulants using DDGel were studied. Partition coefficients of six simulants between SC and water (Log P SC/w ) and between DDGel and water (Log P DDGel/w ) were determined. Results showed that DDGel has a similar or higher binding affinity to each simulant compared to SC. The relationship between Log P octanol/water and Log P SC/w as well as between Log P octanol/water and Log P DDGel/w demonstrated that partition coefficient of simulants correlated to their lipophilicity or hydrophilicity. Decontamination efficiency results with DDGel for these simulants were consistent with binding affinity results. Amounts of percentage dose of chemicals in DDGel of trimethyl phosphate, dimethyl adipate, 2-chloroethyl methyl sulfide, diethyl adipate, chloroethyl phenyl sulfide and diethyl sebacate were determined to be 61.15, 85.67, 75.91, 53.53, 89.89 and 76.58, with corresponding amounts absorbed in skin of 0.96, 0.65, 1.68, 0.72, 0.57 and 1.38, respectively. In vitro skin decontamination experiments coupled with a dermal absorption study demonstrated that DDGel can efficiently remove chemicals from skin surface, back-extract from the SC, and significantly reduced chemical penetration into skin or systemic absorption for all six simulants tested. Therefore, DDGel offers a great potential as a NextGen skin Decon platform technology for both military and civilian use. Copyright © 2018 John Wiley & Sons, Ltd.

Decontamination of Hetron Tank from Decominissioning of Phosphate Acid Purification Instalation

International Nuclear Information System (INIS)

Sutoto

2008-01-01

To decreasing quantity of the contaminated equipment from the nuclear installation decommissioning activity, it can be done by decontamination. Its process must be done by considering of radiation safety so that not dangerous to worker and environment. Effectively method must be chosen so that not generate high of secondary wastes. To primary decontamination of HETRON tank with a chemical method is not effectively to used because its a reinforcement thermoplastic materials. These material has high resistance for chemical compound. Therefore selected methods of physical-mechanical decontamination, that is can to removal of contaminants from the surface by scrubbing and swabbing with used of wet cloth have been tried and effective to decreasing of β/γ radiation rate until about (0.04 - 0.06 mR/h), its value is equal to background rate and the level of α/β radiation activity contamination is about (1.07 - 2.03 Bq/cm 2 ), so that it can be out grouping as radioactive waste. For the equipment of which cannot decontaminated, it grouped as solid radioactive waste and together with secondary waste will be sent to PTLR-BATAN. (author)

Study of Thorium Phosphate Diphosphate (TPD) formation in nitric medium for the decontamination of high activity actinides bearing effluents

International Nuclear Information System (INIS)

Rousselle, Jerome

2004-01-01

Considering several activities in the nuclear industry and research, several low-level liquids wastes (LLLW) containing actinides in nitric medium must be decontaminated before being released in the environment. These liquid wastes mainly contain significant amounts of uranium(VI), neptunium(V) and plutonium(IV). In this work, two chemical ways were studied to decontaminate LLLW then to incorporate simultaneously uranium, neptunium and plutonium in the Thorium Phosphate Diphosphate (TPD). Both ways started from a nitric solution containing thorium and the actinides considered, present at their lower stable oxidation state. The first way consisted in the initial precipitation of actinide and thorium mixed oxalate. After drying the mixture containing the powder and phosphoric acid under dried argon, a poly-phase system was obtained. It was mainly composed by a thorium-actinide oxalate-phosphate. This mixture was transformed into a TPDAn solid solution (An = U, Np and/or Pu) by heating treatment at 1200 deg. C under inert atmosphere. The second way consisted in the precipitation of a precursor of TPD, identified as the Thorium Phosphate Hydrogen Phosphate loaded with the actinides considered. The gel initially formed by mixing concentrated phosphoric acid solution with the nitric actinide solution was heated at 90 - 160 deg. C in a closed PTFE container for several weeks. It led to the TPDAn solid solutions after heating at 1100 deg. C in air or under inert argon. The efficiency of both processes was evaluated through the determination of the decontamination for each actinide considered. Considering the encouraging results obtained for both kinds of processes, some complementary studies are now required before performing the effective decontamination of real Low-Level Liquid Waste using one of the methods proposed. (author) [fr

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

trillion JPY. Our results suggest that the cost of removal was estimated to account for approximately 60% of the total cost in the decontamination implementation areas, while the cost of storage and transport was estimated to account for more than 70% in the special decontamination areas. In addition, the costs of decontamination per person per unit area are estimated to vary greatly. Appropriate selection of decontamination methods may significantly decrease decontamination costs, allowing more meaningful decontamination in terms of the limited budget. Our analysis can help in examining the prioritization of decontamination areas from the viewpoints of cost and effectiveness in reducing the external dose. Decontamination strategies should be determined according to air dose rates and future land-use plans. Document available in abstract form only. (authors)

Safety analysis report for packaging (onsite) decontaminated equipment self-container

International Nuclear Information System (INIS)

Boehnke, W.M.

1998-01-01

The purpose of this Safety Analysis Report for Packaging (SARP) is to demonstrate that specific decontaminated equipment can be safely used as its own self-container. As a Decontaminated Equipment Self-Container (also referred to as a self-container), no other packaging, such as a burial box, would be required to transport the equipment onsite. The self-container will consist of a piece of equipment or apparatus which has all readily removable interior contamination removed, all of its external openings sealed, and all external surfaces decontaminated to less than 2000 dpm/100 cm for gamma-emitting radionuclides and less than 220 dpm/100 CM2 for alpha-emitting radionuclides

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 of transuranic contaminated metals by melt refining

International Nuclear Information System (INIS)

Heshmatpour, B.; Copeland, G.L.; Heestand, R.L.

1983-01-01

Melt refining of transuranic contaminated metals is a possible decontamination process with the potential advantages of producing metal for reuse and of simplifying chemical analyses. By routinely achieving the 10 nCi/g( about0.1ppm) level by melt refining, scrap metal can be removed from the transuranic waste category. (To demonstrate the effectiveness of this melt refining process, mild steel, stainless steel, nickel, and copper were contaminated with 500 ppm (μg/g) PuO 2 and melted with various fluxes. The solidified slags and metals were analyzed for their plutonium contents, and corresponding partition ratios for plutonium were calculated. Some metals were double refined in order to study the effect of secondary slag treatment. The initial weight of the slags was also varied to investigate the effect of slag weight on the degree of plutonium removal. In general, all four metals could be decontaminated below 1 ppm (μg/g) Pu ( about100 nCi/g) by a single slag treatment. Doubling the slag weight did not improve decontamination significantly; however, double slag treatment using 5 wt.% slag did decontaminate the metals to below 0.1 ppm (μg/g) Pu (10 nCi/g).)

Comprehensive investigation of the corrosion and surface chemical effects of the decontamination technologies

International Nuclear Information System (INIS)

Szabo-Nagy, Andrea; Varga, Kalman; Deak-Horvath, Emese; Nemeth, Zoltan; Horvath, David; Schunk, Janos; Patek, Gabor

2012-09-01

Decontamination technologies are mainly developed to reduce the collective dose of the maintenance personnel at NPPs. The highest efficiency (i.e., the highest DF values) available without detrimental modification of the treated surface of structural material is the most important goal in the course of the application of a decontamination technology. A so-called 'soft' chemical decontamination technology has been developed - supported by the Paks Nuclear Power Plant - at the Institute of Radiochemistry and Radioecology of the University of Pannonia. The novel base technology can be effectively applied for the decontamination of the heat exchanger tubes of steam generators. In addition, by optimizing the main technological parameters (temperature, concentration of the liquid chemicals, flow rates, contact time, etc.) it can be utilized for specific applications such as decontamination of some dismountable devices and separable equipment or the total decontamination prior to plant dismantling (decommissioning) in the future. The aim of this work is to compare the efficiency, corrosion and surface chemical effects of some improved versions of the novel base-technology elaborated for decontamination of austenitic stainless steel surfaces. The experiments have been performed at laboratory conditions in decontamination model systems. The applied methods: γ-spectrometry, ICP-OES, voltammetry and SEM-EDX. The experimental results revealed that the efficiency of the base-technology mainly depends on the surface features of the stainless steel samples such as the chemical composition and thickness of the oxide layer, the nature (quantity, morphology and chemical composition) of the crystalline deposits. It has been documented that the improved version of the base-technology are suitable for the decontamination of both steel surfaces covered by chemically resistant large Cr-content crystals and that having compact oxide-layers (up to a thickness of 10 �

A study on the decontamination of the gravels contaminated by uranium

Energy Technology Data Exchange (ETDEWEB)

Park, Ukryang; Kim, Gyenam; Kim, Seungsoo; Moon, Jaikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

The amount of gravels contaminated by uranium is usually about 10% of the contaminated soil. Since such contaminated gravels show different kinds and volumes, it would cost a considerable amount of money if they are to be disposed of without going through any special process. Also, there has not been any particular way or technology for processing the gravels contaminated by uranium. Therefore, various fundamental experiments and researches have been carried out for the decontamination of the gravels contaminated by uranium. Through such experiments and researches, it has been possible to obtain some significant results. The acid cleaning process, which is based on the application of the soil cleaning method, can be regarded as one of the major ways used for decontamination. When the gravels contaminated by uranium are cleaned as they are, most of them tend to show an extremely-low level of decontamination. Therefore, it could be said that the inside of each gravel is also contaminated by uranium. As a result, the gravels contaminated by uranium need to be crushed before being cleaned, which would result in a higher level of efficiency for decontamination compared to the previous way. Therefore, it is more effective to crush the subject gravels before cleaning them in terms of decontamination. However, such test results can only be applied to the gravels contaminated by an average level of uranium concentration. Regarding the gravels showing a higher level of uranium concentration than the average, it is still necessary to carry out more researches. Therefore, this study focused on the level of efficiency for decontamination after the contaminated gravels were crushed before being cleaned, in order to find a way to effectively dispose of the gravels contaminated by high-concentration uranium and secure a high level of efficiency for decontamination. In order to decontaminate the gravels which were contained in the soil contaminated by uranium and showed a higher

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

Low corrosive chemical decontamination method using pH control. 1. Basic system

International Nuclear Information System (INIS)

Nagase, Makoto; Ishida, Kazushige; Uetake, Naohito; Anazawa, Kazumi; Nakamura, Fumito; Yoshikawa, Hiroo; Tamagawa, Tadashi; Furukawa, Kiyoharu

2001-01-01

A new low corrosive decontamination method was developed which uses both oxalic acid and hydrazine as the reducing agent and potassium permanganate as the oxidizing agent. Less corrosion of structural materials during the decontamination is realized by pH control of the reducing agent. The pH of 2.5, attained by adding hydrazine to oxalic acid, was the optimum pH for maintaining a high decontamination effect and lowering the corrosion at the same time. As this reducing agent can be decomposed into carbon dioxide, nitrogen and water by using a catalyst column with hydrogen peroxide, the amount of secondary radioactive waste is small. These good features were demonstrated through actual plant decontamination tasks. (author)