Electrode design for soil decontamination with Radio-Frequency heating
Energy Technology Data Exchange (ETDEWEB)
Roland, U.; Holzer, F.; Kraus, M.; Trommler, U.; Kopinke, F.D. [Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Engineering, Leipzig (Germany)
2011-10-15
Radio-frequency heating to enhance soil decontamination requires adjusted solutions for the electrode design depending on scale and remediation technique. Parallel plate electrodes provide widely homogeneous field and temperature distributions and are, therefore, most suitable for supporting biodegradation processes. For thermally enhanced soil vapor extraction, certain temperature gradients can be accepted and, therefore, the less-demanding geometry of rod-shaped electrodes is usually applied. For electrode lengths of some meters, a design with an air gap has to be used in order to focus heating to the desired depth. Perforated rod electrodes may be simultaneously employed as extraction wells. Placing an oxidation catalyst in situ within the electrodes is an option for handling of highly loaded air flows. Coaxial antenna may be utilized to selectively heat soil compartments far from the surface of the soil. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
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
Theory of soil decontamination in mixing liquid
International Nuclear Information System (INIS)
Polyakov, A.S.; Emets, E.P.; Poluehktov, P.P.; Rybakov, K.A.
1997-01-01
The theory of soil decontamination from radioactive pollution in mixing liquid flow is described. It is shown that there exists the threshold intensity of liquid mixing up to which there is no decontamination. Beyond the threshold and by increasing the mixing intensity the decontamination of large soil fractions is allowable whereby the higher is the mixing intensity and lower is the soil contamination, the laser is the characteristic decontamination time. The above theory is related to cases of uniform pollution of the particles surface
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
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)
Particle Separation of Non-Decontamination Soil using Attrition and Washing
International Nuclear Information System (INIS)
Koo, Daeseo; Sung, Hyun-Hee; Kim, Seung-Soo; Hong, Sang Bum; Seo, Bum Kyoung; Choi, Jong-Won
2017-01-01
In this study, to improve the decontamination efficiency of uranium soil, a preliminary experiment on the particle separation of non-decontamination soil was carried out using attrition and washing. The characteristics of the attrition and washing system are investigated. A conditional experiment on particle separation of non-decontamination soil will be performed. A preliminary experiment on the particle separation of non-decontamination soil was carried out to improve the decontamination efficiency of uranium soil. This experiment was performed with the ratio of soil to water (1:4) for the particle separation of non-decontamination soil. The operations of all equipment such as attrition scrubber, ultrasonic reaction, vibrating screen, and hydro-cyclone were conducted and confirmed. In the future, the additional experiments will be conducted for optimal experimental condition.
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)
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)
Decontamination of Soil Contaminated with Bacillus anthracis ...
Technical Brief This technical summary will provide decontamination personnel rapid access to information on which decontamination approaches are most effective for soils contaminated with B anthracis.
Comparative scrub solution tests for decontamination of transuranic radionuclides from soils
International Nuclear Information System (INIS)
Stevens, J.R.; Kochen, R.L.; Rutherford, D.W.; Riordan, G.A.; Delaney, I.C.
1982-08-01
Soil decontamination tests were done using three scrubbing solutions on five different transuranic-contaminated soils from Department of Energy sites. The soils came from Rocky Flats, Colorado; Hanford, Washington; Mound Facility, Ohio; Idaho National Engineering Laboratory, Idaho; and Los Alamos National Laboratory, New Mexico. Decontamination was effected by physical and chemical means. A pH 12.5 scrub effected decontamination by serving as a hydraulic grading and attrition scrub medium; this solution did not solubilize the actinide contamination. A 2% HNO 3 , 0.2% HF, 2% pine oil, and 5% Calgon solution effected decontamination by physical and chemical means; this solution solubilized particulate actinide and actinide dispersed on the surface of soil particles. A 2N HCl scrub was also used to effect decontamination by physical and chemical means; this reagent solubilized soil constituents, removing contamination that had migrated into mineral surfaces. Only Rocky Flats soil was effectively decontaminated by the high pH solution although all soils had an enrichment of the activity in the -150 mesh fraction. Attrition scrubbing with both acid solutions had a better decontamination ability for the +150 mesh fraction for Hanford, INEL, and LANL soils. In addition, the acid solutions solubilized some of the plutonium and had a decontamination effect on the fine fractions
International Nuclear Information System (INIS)
Yoshino, Namiko; Takahashi, Yoshihiko; Kobayashi, Hiroyuki; Saitou, Kunihito
2015-01-01
Farms that were highly contaminated with radioactive materials following the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi nuclear power plant accident were decontaminated by removing topsoil and subsequently dressing with fresh soil. We investigated the chemical properties of soils following such decontamination on farms in Iitate village, Fukushima. The nitrogen content of dressed soil was considerably lower than that of the subsoil that was not stripped for decontamination, as a result of which the amount of dressed soil greatly affected the soil fertility of decontaminated farms. The potassium (K) content of soil differs markedly depending on the type of soil dressing material used; accordingly, the type of soil dressing material affected the soil K content on decontaminated farms. On most of the decontaminated farms where sandy soils were used as the soil dressing material, soil exchangeable K contents were less than 25 mg K_2O/100 g, which is the criterion value for inhibiting cesium absorption in rice and soybean cultivation. However, even in the soil dressing material from agricultural land, soil K content after soil dressing was generally lower than that before soil dressing. During fallow management and at the restart of cultivation on decontaminated farms, it is important to know in advance the chemical properties of soil and take the necessary measures based on this information. (author)
Pathogen Decontamination of Food Crop Soil: A Review.
Gurtler, Joshua B
2017-09-01
The purpose of this review is to delineate means of decontaminating soil. This information might be used to mitigate soil-associated risks of foodborne pathogens. The majority of the research in the published literature involves inactivation of plant pathogens in soil, i.e., those pathogens harmful to fruit and vegetable production and ornamental plants. Very little has been published regarding the inactivation of foodborne human pathogens in crop soil. Nevertheless, because decontamination techniques for plant pathogens might also be useful methods for eliminating foodborne pathogens, this review also includes inactivation of plant pathogens, with appropriate discussion and comparisons, in the hopes that these methods may one day be validated against foodborne pathogens. Some of the major soil decontamination methods that have been investigated and are covered include chemical decontamination (chemigation), solarization, steaming, biofumigation, bacterial competitive exclusion, torch flaming, microwave treatment, and amendment with biochar. Other innovative means of inactivating foodborne pathogens in soils may be discovered and explored in the future, provided that these techniques are economically feasible in terms of chemicals, equipment, and labor. Food microbiology and food safety researchers should reach out to soil scientists and plant pathologists to create links where they do not currently exist and strengthen relationships where they do exist to take advantage of multidisciplinary skills. In time, agricultural output and the demand for fresh produce will increase. With advances in the sensitivity of pathogen testing and epidemiological tracebacks, the need to mitigate preharvest bacterial contamination of fresh produce will become paramount. Hence, soil decontamination technologies may become more economically feasible and practical in light of increasing the microbial safety of fresh produce.
Soil decontamination at Rocky Flats
International Nuclear Information System (INIS)
Olsen, R.L.; Hayden, J.A.; Alford, C.E.; Kochen, R.L.; Stevens, J.R.
1979-01-01
A soils decontamination project was initiated, to remove actinides from soils at Rocky Flats. Wet screening, attrition scrubbing with Calgon at high pH, attrition scrubbing at low pH, and cationic flotation were investigated. Pilot plant studies were carried out. Conceptual designs have been generated for mounting the process in semi-trailers
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
Development of Decontamination Process for Soil Contaminated Uranium
International Nuclear Information System (INIS)
Kim, Gye-Nam; Kim, Seung-Soo; Park, Uk-Rang; Han, Gyu-Seong; Moon, Jei-Kwon
2014-01-01
Various experiments with full-scaled electrokinetic equipment, soil washing equipment, and gravel washing equipment were performed to remove 238 U from contaminated soils of below 0.4 Bq/g. The repetition number and the removal efficiencies of the soil and gravel washing equipment were evaluated. The decontamination periods by the soil and gravel electrokinetic equipment were evaluated. Finally, a work process of full-scaled decontamination equipment was developed. Contaminated soils were classified into soils and gravels using a 8.0 cm sieve. Soils were sent to the soil washing equipment, while gravels were sent to the gravel washing equipment. Soils sent to the soil washing equipment were sent to the soil electrokinetic equipment after soil washing. A repetition number of soil washing was two times. The washed gravels were sent to the gravel electrokinetic equipment. Gravel contaminated with a high concentration requires crushing after gravel washing
Development of Decontamination Process for Soil Contaminated Uranium
Energy Technology Data Exchange (ETDEWEB)
Kim, Gye-Nam; Kim, Seung-Soo; Park, Uk-Rang; Han, Gyu-Seong; Moon, Jei-Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2014-10-15
Various experiments with full-scaled electrokinetic equipment, soil washing equipment, and gravel washing equipment were performed to remove {sup 238}U from contaminated soils of below 0.4 Bq/g. The repetition number and the removal efficiencies of the soil and gravel washing equipment were evaluated. The decontamination periods by the soil and gravel electrokinetic equipment were evaluated. Finally, a work process of full-scaled decontamination equipment was developed. Contaminated soils were classified into soils and gravels using a 8.0 cm sieve. Soils were sent to the soil washing equipment, while gravels were sent to the gravel washing equipment. Soils sent to the soil washing equipment were sent to the soil electrokinetic equipment after soil washing. A repetition number of soil washing was two times. The washed gravels were sent to the gravel electrokinetic equipment. Gravel contaminated with a high concentration requires crushing after gravel washing.
Study of Soil Decontamination Method Using Supercritical Carbon Dioxide and TBP
International Nuclear Information System (INIS)
Park, Jihye; Park, Kwangheon; Jung, Wonyoung
2014-01-01
The result of this study means that we have a possible new method for cheap and less wasteful nuclear waste decontamination. When severe accidents such as the incident at the Fukushima nuclear site occur, the soil near the power plant is contaminated with fission products or the activation metal structure of the power plant. The soil pollution form depends on the environment and soil characteristics of the contaminated areas. Thus, a- single-decontamination method is not effective for site cleanup. In addition, some soil decontamination methods are expensive and large amounts of secondary waste are generated. Therefore, we need new soil decontamination methods. In this study, instead of using a conventional solvent method that generates secondary waste, supercritical carbon dioxide was used to remove metal ions from the soil. Supercritical carbon dioxide is known for good permeation characteristics. We expect that we will reduce the cost of soil pollution management. Supercritical carbon dioxide can decontaminate soil easily, as it has the ability to penetrate even narrow gaps with very good moisture permeability. We used TBP, which is a known for extractant of actinium metal. TBP is usually used for uranium and strontium extraction. Using TBP-HNO 3 complex and supercritical carbon dioxide, we did extraction experiments for several heavy metals in contaminated soil
Study of Soil Decontamination Method Using Supercritical Carbon Dioxide and TBP
Energy Technology Data Exchange (ETDEWEB)
Park, Jihye; Park, Kwangheon; Jung, Wonyoung [Kyunghee Univ., Yongin (Korea, Republic of)
2014-05-15
The result of this study means that we have a possible new method for cheap and less wasteful nuclear waste decontamination. When severe accidents such as the incident at the Fukushima nuclear site occur, the soil near the power plant is contaminated with fission products or the activation metal structure of the power plant. The soil pollution form depends on the environment and soil characteristics of the contaminated areas. Thus, a- single-decontamination method is not effective for site cleanup. In addition, some soil decontamination methods are expensive and large amounts of secondary waste are generated. Therefore, we need new soil decontamination methods. In this study, instead of using a conventional solvent method that generates secondary waste, supercritical carbon dioxide was used to remove metal ions from the soil. Supercritical carbon dioxide is known for good permeation characteristics. We expect that we will reduce the cost of soil pollution management. Supercritical carbon dioxide can decontaminate soil easily, as it has the ability to penetrate even narrow gaps with very good moisture permeability. We used TBP, which is a known for extractant of actinium metal. TBP is usually used for uranium and strontium extraction. Using TBP-HNO{sub 3} complex and supercritical carbon dioxide, we did extraction experiments for several heavy metals in contaminated soil.
Possibilities of soil washing for decontamination at Belgoprocess
Energy Technology Data Exchange (ETDEWEB)
Aerts, Wouter [Belgoprocess, Dessel, Antwerp (Belgium); De Bruecker, Thomas; Lytek, Anna [DEC - DEME Environmental Contractor, Zwijndrecht, Antwerp (Belgium)
2013-07-01
Contaminated soils form a large part of the nuclear waste arising from decommissioning activities. The storage and disposal of these large volumes of waste is costly. For this reason techniques which can decontaminate this waste stream to free release levels are economically very interesting. A feasibility study of the possibilities of soil washing to decontaminate such soils was ordered by NIRAS/ONDRAF and performed at Belgoprocess in collaboration with DEC. Initial contamination level and particle size distributions of contaminated soils from three different sources were determined. The main isotopes detected with gamma spectrometry contained in the waste were {sup 241}Am, {sup 137}Cs, {sup 226}Ra, {sup 60}Co and {sup 232}Th. The particle size distribution revealed that more than half of the mass of the quartz sand that makes up the soil has a particle size between 125 and 212 μm. This fraction is less contaminated than the fractions containing smaller particles. However, separation of the fines fraction (< 125 μm) was not enough to achieve the free release limit. Soil attrition was tested as an extra decontamination step for the sand fraction. The removal efficiencies for the different radionuclides contained in the soil were measured. The process conditions were optimized to achieve maximum removal and a treatment method for the secondary waste coming from this process step was determined. The soil washing process was not only performed with water but also with nitric acid to assess the possibilities of a combination of a mechanical and a chemical decontamination process. Reduction efficiencies of 60-80% for the most relevant radionuclides were recorded. (authors)
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.
Energy Technology Data Exchange (ETDEWEB)
Kim, Gyenam; Kim, Seungsoo; Park, Ukrang; Han, Gyuseong; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2014-05-15
The electrokinetic decontamination equipment and electrokinetic-elctrodialytic decontamination equipment were manufactured to decontaminate the contaminated soil. The removal efficiency according to the lapsed time by the electrokinetic decontamination equipment and the electrokinetic-elctrodialytic decontamination equipment was investigated through several experiments. The difference between the removal efficiency of the electrokinetic-elctrodialytic decontamination without anion exchange membrane and that of with anion exchange membrane was investigated through several experiments. In addition, the removal efficiency trend according to different cesium radioactivity of soil was drawn out through several experiments.
International Nuclear Information System (INIS)
Kim, Gyenam; Kim, Seungsoo; Park, Ukrang; Han, Gyuseong; Moon, Jeikwon
2014-01-01
The electrokinetic decontamination equipment and electrokinetic-elctrodialytic decontamination equipment were manufactured to decontaminate the contaminated soil. The removal efficiency according to the lapsed time by the electrokinetic decontamination equipment and the electrokinetic-elctrodialytic decontamination equipment was investigated through several experiments. The difference between the removal efficiency of the electrokinetic-elctrodialytic decontamination without anion exchange membrane and that of with anion exchange membrane was investigated through several experiments. In addition, the removal efficiency trend according to different cesium radioactivity of soil was drawn out through several experiments
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
Agricultural soils decontamination techniques: methods and results of tests realized near Chernobyl
International Nuclear Information System (INIS)
Maubert, H.; Jouve, A.; Mary, N.
1992-01-01
After a major nuclear accident, decontamination of agricultural soils would be necessary in order to reclaim the land. Specific techniques were studied in the framework of the European program for Rehabilitation of Soils and Surfaces after an Accident (RESSAC). Different ways to remove the top layer of soils are described, and especially the use of Decontaminating Vegetal Network (D.V.N.) combined with spraying of organic polymers. Real scale tests in the 30 km zone around the Chernobyl nuclear power plant showed that it is possible to achieve an excellent decontamination of agricultural fields (decontamination factor greater than 95%. (author)
Soil decontamination with Extraksol
International Nuclear Information System (INIS)
Paquin, J.; Mourato, D.
1989-01-01
The Extraksol process is a mobile decontamination technology which treats unconsolidated materials by solvent extraction. Treatment with Extraksol involves material washing, drying and solvent regeneration. Contaminant removal is achieved through desorption/dissolution mechanisms. The treated material is dry and acceptable to be reinstalled in its original location. The process provides a fast, efficient and versatile alternative for decontamination of soil and sludge. The organic contaminants extracted from the matrix are transferred to the extraction fluids. These are thereafter concentrated in the residues of distillation after solvent regeneration. Removal and concentration of the contaminants ensures an important waste volume reduction. This paper presents the process is operational principles and the steps involved in Extraksol's development with results of the pilot tests and full-scale demonstrations
Progress in decontamination by halophilic microorganisms in saline wastewater and soil
International Nuclear Information System (INIS)
Zhuang Xuliang; Han Zhen; Bai Zhihui; Zhuang Guoqiang; Shim Hojae
2010-01-01
Environments with high-salt concentrations are often populated by dense microbial communities. Halophilic microorganisms can be isolated from different saline environments and different strains even belonging to the same genus have various applications. Wastewater and soil rich in both organic matter and salt are difficult to treat using conventional microorganisms typically found in wastewater treatment and soil bioremediation facilities. Studies on decontaminative capabilities and decontamination pathways of organic contaminants (i.e., aromatic compounds benzoate, cinnamate, 3-phenylpropionate, 4-hydroxybenzoic acid), heavy metals (i.e., tellurium, vanadium), and nutrients in the biological treatment of saline wastewater and soil by halophilic microorganisms are discussed in this review. - Review on the decontaminative capabilities of halophilic microorganisms in saline wastewater and soil.
Progress in decontamination by halophilic microorganisms in saline wastewater and soil
Energy Technology Data Exchange (ETDEWEB)
Zhuang Xuliang, E-mail: xlzhuang@rcees.ac.c [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Bureau of Science and Technology for Resources and Environment, Chinese Academy of Sciences, Beijing 100864 (China); Han Zhen [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Bai Zhihui; Zhuang Guoqiang [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Shim Hojae [Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau (China)
2010-05-15
Environments with high-salt concentrations are often populated by dense microbial communities. Halophilic microorganisms can be isolated from different saline environments and different strains even belonging to the same genus have various applications. Wastewater and soil rich in both organic matter and salt are difficult to treat using conventional microorganisms typically found in wastewater treatment and soil bioremediation facilities. Studies on decontaminative capabilities and decontamination pathways of organic contaminants (i.e., aromatic compounds benzoate, cinnamate, 3-phenylpropionate, 4-hydroxybenzoic acid), heavy metals (i.e., tellurium, vanadium), and nutrients in the biological treatment of saline wastewater and soil by halophilic microorganisms are discussed in this review. - Review on the decontaminative capabilities of halophilic microorganisms in saline wastewater and soil.
International Nuclear Information System (INIS)
Oh, Won Zin; Lee, K. W.; Won, H. J.; Jung, C. H.; Choi, W. K.; Kim, G. N.
2001-08-01
A. Decontamination Technology Development of Uranium Conversion Facility. Understanding of uranium conversion facility and related decontamination technologies, and analysis of current status of decontamination technologies. Establishment of the objective and research items of the middle and long term R and D project. Discussion of the erformance plan and about the methodology for connection with the project of environmental restoration of uranium conversion facility B. Treatment Technology Development of Uranium Sludge Analysis of the domestic and overseas research development status. Suggestion of treatment methodology of uranium slurry and cooperative R and D among industries, universities and research institute. Establishment of the objective and research items of the middle and long term R and D project. Discussion about the performance plan and about the methodology for connection with the project of environmental restoration of uranium conversion facility C. Decommissioning Technology Development Analysis of the domestic and overseas research development status and the overview of decommissioning technologies. Establishment of the objective and research items of the middle and long term R and D project. Discussion about the performance plan and about the methodology for connection with the project of TRIGA decommissioning D. Evaluation of KAERI Soil Decontamination Technology. Evaluation of soil decontamination process and the liquid decontamination waste treatment technology. Performance of soil decontamination test using solvent flushing test equipment for evaluation of residual radioactivity after decontami- nation and modeling of the results
Energy Technology Data Exchange (ETDEWEB)
Oh, Won Zin; Lee, K. W.; Won, H. J.; Jung, C. H.; Choi, W. K.; Kim, G. N
2001-08-01
A. Decontamination Technology Development of Uranium Conversion Facility. Understanding of uranium conversion facility and related decontamination technologies, and analysis of current status of decontamination technologies. Establishment of the objective and research items of the middle and long term R and D project. Discussion of the erformance plan and about the methodology for connection with the project of environmental restoration of uranium conversion facility B. Treatment Technology Development of Uranium Sludge Analysis of the domestic and overseas research development status. Suggestion of treatment methodology of uranium slurry and cooperative R and D among industries, universities and research institute. Establishment of the objective and research items of the middle and long term R and D project. Discussion about the performance plan and about the methodology for connection with the project of environmental restoration of uranium conversion facility C. Decommissioning Technology Development Analysis of the domestic and overseas research development status and the overview of decommissioning technologies. Establishment of the objective and research items of the middle and long term R and D project. Discussion about the performance plan and about the methodology for connection with the project of TRIGA decommissioning D. Evaluation of KAERI Soil Decontamination Technology. Evaluation of soil decontamination process and the liquid decontamination waste treatment technology. Performance of soil decontamination test using solvent flushing test equipment for evaluation of residual radioactivity after decontami- nation and modeling of the results.
40 CFR 265.114 - Disposal or decontamination of equipment, structures and soils.
2010-07-01
... decontamination of equipment, structures and soils. During the partial and final closure periods, all contaminated... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Disposal or decontamination of equipment, structures and soils. 265.114 Section 265.114 Protection of Environment ENVIRONMENTAL PROTECTION...
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.
Sakai, Masaru; Gomi, Takashi; Nunokawa, Masanori; Wakahara, Taeko; Onda, Yuichi
2014-04-01
We investigated the biological accumulation of radiocesium in tadpoles [Rana (Pelophylax) porosa porosa] in rice paddies with and without decontamination practice at Fukushima. Radiocesium was accumulated in surface part of soils both in the control and decontaminated paddies one year after decontamination. Mean (134)Cs and (137)Cs concentrations in tadpoles in the control and decontaminated paddies were 3000 and 4500, and 600 and 890 Bq/kg dry weight, respectively. Radiocesium concentrations in surface soil (0-5 cm depth) and tadpoles in the decontaminated paddy were five times smaller than in the control paddy. These results suggest that decontamination practice can reduce radiocesium concentrations in both soil and tadpoles. However, at the decontaminated paddy, radiocesium concentrations in surface soils became 3.8 times greater one year after decontamination, which indicates that monitoring the subsequent movement of radiocesium in rice paddies and surrounding areas is essential for examining contamination propagation. Copyright © 2014 Elsevier Ltd. All rights reserved.
Magnetic separation for soil decontamination
International Nuclear Information System (INIS)
Avens, L.R.; Worl, L.A.; deAguero, K.J.; Padilla, D.D.; Prenger, F.C.; Stewart, W.F.; Hill, D.D.; Tolt, T.L.
1993-01-01
High gradient magnetic separation (HGMS) is a physical separation process that is used to extract magnetic particles from mixtures. The technology is used on a large scale in the kaolin clay industry to whiten or brighten kaolin clay and increase its value. Because all uranium and plutonium compounds are slightly magnetic, HGMS can be used to separate these contaminants from non-magnetic soils. A Cooperative Research and Development Agreement (CRADA) was signed in 1992 between Los Alamos National Laboratory (LANL) and Lockheed Environmental Systems and Technologies Company (LESAT) to develop HGMS for soil decontamination. This paper reports progress and describes the HGMS technology
[Thermodynamic forecasting of reagents composition for soils decontamination].
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.
Energy Technology Data Exchange (ETDEWEB)
Igarashi, Susumu, E-mail: igarashi@qb.see.eng.osaka-u.ac.jp; Nomura, Naoki; Mishima, Fumihito; Akiyama, Yoko, E-mail: yoko-ak@see.eng.osaka-u.ac.jp
2014-09-15
Highlights: • The method for the soil decontamination by the superconducting magnet is proposed. • Magnetic separation of clay minerals was performed by HGMS. • Soil separation ratio was evaluated by quantitative analysis using XRD. • It is expected that HGMS can be applied to the actual soil decontamination. - Abstract: The accident of Fukushima Daiichi nuclear power plant caused the diffusion of radioactive cesium over the wide area. We examined the possibility of applying magnetic separation method using the superconducting magnet, which can process a large amount of the soil in high speed, to the soil decontamination and volume reduction of the radioactive cesium contaminated soil. Clay minerals are classified as 2:1 and 1:1 types by the difference of their layer structures, and these types of minerals are respectively paramagnetic and diamagnetic including some exception. It is known that most of the radioactive cesium is strongly adsorbed on the clay, especially on 2:1 type clay minerals. It is expected that the method which can separate only 2:1 type clay minerals selectively from the mixture clay minerals can enormously contribute to the volume reduction of the contaminated soil. In this study, the components in the clay before and after separation were evaluated to estimate the magnetic separation efficiency by using X-ray diffraction. From the results, the decontamination efficiency and the volume reduction ratio were estimated in order to examine the appropriate separation conditions for the practical decontamination of the soil.
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
Selective Decontamination Effect of Metal Ions in Soil Using Supercritical CO2 and TBP Complex
International Nuclear Information System (INIS)
Park, Jihye; Park, Kwangheon; Jung, Wonyoung
2014-01-01
Decontamination of soil pollution is difficult because the type of contamination largely depends on the characteristics of the pollutant and the area. Also, existing soil decontamination methods generate large quantities of secondary waste and additional process costs. For this reason, new decontamination methods are always under active investigation. A method involving the use of supercritical carbon dioxide with excellent permeability in place of chemical solvents is currently being studied. Unlike other heavy metals in fission products, uranium is used as fuel, and must be handled carefully. Therefore, in this paper, we studied a supercritical carbon dioxide method for decontaminating heavy metal ions in soil using tri-n-butyl phosphate(TBP), which is well known as a ligand for the extraction of metal ions of actinium. We investigated the decontamination effect of heavy metal ions in the soil using TBP-HNO 3 Complex and supercritical carbon dioxide. The study results showed that when heavy metals in soil are extracted using supercritical carbon dioxide, the extraction efficiency is different according to the type of pollutant metal ions in the soil. When TBP-HNO 3 Complex is used with an extractant, uranium extraction is very effective, but lithium, strontium, and cesium extraction is not effective. Therefore, in the case of a mixture of uranium and other metals such as lithium, strontium, cesium, and so on in soil contaminated by fission product leaks from nuclear power plants, we can selectively decontaminate uranium with supercritical carbon dioxide and TBP-HNO 3 Complex
Influence of temperature and hydraulic conductivity of soil on electrokinetic decontamination
International Nuclear Information System (INIS)
Kim, Gye-Nam; Kim, Seung-Soo; Jeong, Jung-Whan; Choi, Jong-Won
2016-01-01
The electrokinetic process holds great promise for the decontamination of contaminated soil because it has a high removal efficiency and is time-effective for low permeability. Electrokinetic decontamination can be used to treat soil contaminated with inorganic species and radionuclides. The main mechanisms of a contaminant's movement in an electrical field involved in electrokinetic technology are the electro-migration of the ionic species and electro-osmosis. Electro-migration probably contributes significantly to the removal of contaminants, especially at high concentrations of ionic contaminants and/or a high hydraulic permeability of soil. The cathode reaction should be depolarized to avoid the generation of hydroxides and their transport in soil. The selected liquid, also known as a purging reagent, should induce favorable pH conditions in soil, and/or interact with the incorporated heavy metals so that these heavy metals are removed from the soil. The removal efficiencies of uranium from contaminated soil in manufactured laboratory electrokinetic decontamination equipment were proportional to the elapsed time. The removal efficiencies of uranium for 2 days were 77-87%. In addition, the removal efficiencies according to the elapsed time after 2 days were reduced. When 75, 80, and 85℃ electrolyte temperatures in the cathode chamber were applied, the time required for the removal efficiency of uranium to reach 92% was 6, 5 and 4 days
Influence of temperature and hydraulic conductivity of soil on electrokinetic decontamination
Energy Technology Data Exchange (ETDEWEB)
Kim, Gye-Nam; Kim, Seung-Soo; Jeong, Jung-Whan; Choi, Jong-Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2016-10-15
The electrokinetic process holds great promise for the decontamination of contaminated soil because it has a high removal efficiency and is time-effective for low permeability. Electrokinetic decontamination can be used to treat soil contaminated with inorganic species and radionuclides. The main mechanisms of a contaminant's movement in an electrical field involved in electrokinetic technology are the electro-migration of the ionic species and electro-osmosis. Electro-migration probably contributes significantly to the removal of contaminants, especially at high concentrations of ionic contaminants and/or a high hydraulic permeability of soil. The cathode reaction should be depolarized to avoid the generation of hydroxides and their transport in soil. The selected liquid, also known as a purging reagent, should induce favorable pH conditions in soil, and/or interact with the incorporated heavy metals so that these heavy metals are removed from the soil. The removal efficiencies of uranium from contaminated soil in manufactured laboratory electrokinetic decontamination equipment were proportional to the elapsed time. The removal efficiencies of uranium for 2 days were 77-87%. In addition, the removal efficiencies according to the elapsed time after 2 days were reduced. When 75, 80, and 85℃ electrolyte temperatures in the cathode chamber were applied, the time required for the removal efficiency of uranium to reach 92% was 6, 5 and 4 days.
International Nuclear Information System (INIS)
Imaizumi, Masayuki; Yoshimoto, Shuhei; Ishida, Satoshi; Okushima, Shuji; Yuuki, Youichi; Hirata, Ryoji
2016-01-01
The National Institute for Rural Engineering performed decontamination of radioactivity at the experimental sites in Iitate Village where paddy fields were contaminated by the Fukushima Daiichi nuclear power plant accident in March 2011 by means of three methods as follows; (1) topsoil removal using soil hardener, (2) removal of soil after paddling with water draining suspended contaminated soil by pumping without manual assistance, and (3) removal of soil after paddling with water draining suspended contaminated soil by pumping with manual assistance. The three methods were evaluated using decontamination factors (DFs) that were determined by applying a variant of inverse analysis using the calculation system for the estimation of decontamination effects (CDE). Input data were provided by surveys using a low-level balloon and a radio-controlled helicopter. The DF values of the three methods were determined on the basis of the Euclidean distances between the simulated and measured dose rates after decontamination. The resulting DFs were > 60 for topsoil removal using soil hardener, 1.4 for slurry pumping, and 2.2 for manually assisted slurry pumping. The area decontaminated by the soil hardening method may have been fully decontaminated, because the distribution of measured dose rates was consistent with the distribution of dose rates calculated for a fully decontaminated area within 20 m in radius. (author)
International Nuclear Information System (INIS)
Sugiura, Hiroyuki; Kawano, Keisuke; Kayama, Yukihiko; Koube, Nobuyuki
2012-01-01
Radioactivity decontamination by replacing soil and soil cover with deep-level soil and soil cover in flower beds and a vacant place in Northern Fukushima Prefecture were studied, which experienced radioactive contamination due to the accident at the TEPCO's Fukushima Daiichi Nuclear Power Plant. Radioactivity counting rate 1 cm above the soil surface after replacing surface soil with uncontaminated deep-level soil decreased to 13.7% of the control in gardens. The concentration of radioactive cesium in the cover soil increased after 132 days; however, it decreased in the old surface soil under the cover soil in flower beds. A 10 cm deep-level soil cover placed by heavy machinery decreased the radiation dose rate to 70.8% of the control and radioactivity counting rate to 24.6% in the vacant place. Replacing the radioactively contaminated surface soil and soil cover with a deep-level soil was a reasonable decontamination method for the garden and vacant place because it is quick, cost effective and labour efficient. (author)
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.
Decontamination of polluted soils in the new Federal States
International Nuclear Information System (INIS)
Burkhardt, K.
1993-01-01
In the course of the privatisation of companies by the Treuhandanstalt (THA), there is a financial risk involved for the property user which is hard to estimate, should the suspicion arise that the property is contaminated with soil pollutants of older origin. Both the Federal Government and the States are prepared to meet some of the costs of the required decontamination treatment in the new Federal States if certain conditions are fulfilled. The necessary inspection and decontamination measures must, in many cases, be cleared with the Treuhandanstalt beforehand. The experiences of the Thuga AG in the inspection and decontamination of pollutants of older origin, especially in the new Federal States, is introduced here. (orig.) [de
40 CFR 264.114 - Disposal or decontamination of equipment, structures and soils.
2010-07-01
... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Disposal or decontamination of equipment, structures and soils. 264.114 Section 264.114 Protection of Environment ENVIRONMENTAL PROTECTION... TREATMENT, STORAGE, AND DISPOSAL FACILITIES Closure and Post-Closure § 264.114 Disposal or decontamination...
A simplified in-situ electrochemical decontamination of lead from polluted soil (abstract)
International Nuclear Information System (INIS)
Ansari, T.M.; Ahmad, I.; Khan, Q.M.; Chaudhry, A.H.
2011-01-01
This paper reports a simplified In-Situ electrochemical method for remediation of field soil contaminated with lead. A series of electrochemical decontamination experiments including variable conditions such as operating duration and application of enhancement reagent were performed to demonstrate the efficiency of lead removal from spiked and polluted soil samples collected from Lahore, Pakistan. The results showed that the efficiency of lead removal from the contaminated soil increased with increasing the operating duration under a set of experimental conditions. The reagent used as complexing and solubilizing agent i.e. EDTA was found to be efficient in removing lead from the polluted soil. After 15 days duration, 85 % lead removal efficiency was observed in spiked soil under enhanced conditions , however, 63 % lead removal was achieved from the polluted soil samples by the simplified In-situ electrochemical decontamination method. The method is simple, rapid, cheaper and suitable for soil remediation purposes. (author)
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
Selective Decontamination Effect of Metal Ions in Soil Using Supercritical CO{sub 2} and TBP Complex
Energy Technology Data Exchange (ETDEWEB)
Park, Jihye; Park, Kwangheon; Jung, Wonyoung [Kyunghee Univ., Yongin (Korea, Republic of)
2014-10-15
Decontamination of soil pollution is difficult because the type of contamination largely depends on the characteristics of the pollutant and the area. Also, existing soil decontamination methods generate large quantities of secondary waste and additional process costs. For this reason, new decontamination methods are always under active investigation. A method involving the use of supercritical carbon dioxide with excellent permeability in place of chemical solvents is currently being studied. Unlike other heavy metals in fission products, uranium is used as fuel, and must be handled carefully. Therefore, in this paper, we studied a supercritical carbon dioxide method for decontaminating heavy metal ions in soil using tri-n-butyl phosphate(TBP), which is well known as a ligand for the extraction of metal ions of actinium. We investigated the decontamination effect of heavy metal ions in the soil using TBP-HNO{sub 3} Complex and supercritical carbon dioxide. The study results showed that when heavy metals in soil are extracted using supercritical carbon dioxide, the extraction efficiency is different according to the type of pollutant metal ions in the soil. When TBP-HNO{sub 3} Complex is used with an extractant, uranium extraction is very effective, but lithium, strontium, and cesium extraction is not effective. Therefore, in the case of a mixture of uranium and other metals such as lithium, strontium, cesium, and so on in soil contaminated by fission product leaks from nuclear power plants, we can selectively decontaminate uranium with supercritical carbon dioxide and TBP-HNO{sub 3} Complex.
International Nuclear Information System (INIS)
Kutlakhmedov, Y.; Zezina, N.; Micheev, A.; Jouve, A.; Perepelyatnikov, G.
1996-01-01
This paper represents our data of comparative analysis of efficacy of different countermeasures in decontamination of soils in Ukraine in total and in case study Milyachi. On this base it was created of optimal algorithm of strategy of decontamination of soils which is based on method of usage turf harvester for unploughed soils and method of phytodesactivation for ploughed soils of Ukraine after Chernobyl accident
Decontaminating soil organic pollutants with manufactured nanoparticles.
Li, Qi; Chen, Xijuan; Zhuang, Jie; Chen, Xin
2016-06-01
Organic pollutants in soils might threaten the environmental and human health. Manufactured nanoparticles are capable to reduce this risk efficiently due to their relatively large capacity of sorption and degradation of organic pollutants. Stability, mobility, and reactivity of nanoparticles are prerequisites for their efficacy in soil remediation. On the basis of a brief introduction of these issues, this review provides a comprehensive summary of the application and effectiveness of various types of manufactured nanoparticles for removing organic pollutants from soil. The main categories of nanoparticles include iron (oxides), titanium dioxide, carbonaceous, palladium, and amphiphilic polymeric nanoparticles. Their advantages (e.g., unique properties and high sorption capacity) and disadvantages (e.g., high cost and low recovery) for soil remediation are discussed with respect to the characteristics of organic pollutants. The factors that influence the decontamination effects, such as properties, surfactants, solution chemistry, and soil organic matter, are addressed.
Sampling design for use by the soil decontamination project
International Nuclear Information System (INIS)
Rutherford, D.W.; Stevens, J.R.
1981-01-01
This report proposes a general approach to the problem and discusses sampling of soil to map the contaminated area and to provide samples for characterizaton of soil components and contamination. Basic concepts in sample design are reviewed with reference to environmental transuranic studies. Common designs are reviewed and evaluated for use with specific objectives that might be required by the soil decontamination project. Examples of a hierarchial design pilot study and a combined hierarchial and grid study are proposed for the Rocky Flats 903 pad area
International Nuclear Information System (INIS)
Sobolev, I.A.; Prozorov, L.B.; Martyanov, V.V.
1995-01-01
The essence of methods for soil decontamination based on electrokinetic processes is that, in the field of constant current, contaminated particles-ions, depending on their charge mark, move to anode or cathode sides. If such a field is created in the soil containing ions of radionuclides or heavy metals, those ions-contaminants will begin to concentrated in the cathode or anode zone, i.e. soil decontamination with ion electric migration process takes place. During the recent tour years specialists from Mos RPA (Moscow Research-and-Production Association) Radon (Russia) have been conducting an extensive investigation on the utilization of electrokinetic processes for decontamination of soils from radionuclides and heavy metals
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
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)
Decontamination of soil from the research reactor site
International Nuclear Information System (INIS)
Won, H. Z.; Kim, K. N.; Choi, W. K.; Jeong, J. H.; Oh, W. J.
2002-01-01
The two research reactors (TRIGA MARK II and III) in Korea are to be decommissioned in the near future. When the reactors are completely dismantled, the site may remain contaminated due to the long period of operation. We assume that the site is radioactively contaminated by Co-60. Soils gathered from the research reactor site were artificially contaminated with Co 2+ ion. The desorption characteristics of Co 2+ ion from the soil surface by citric acid solution were investigated. Decontamination performances of citric acid and EDTA on soil stored in the radioactive waste drums was examined. The feasibility test of recycling the citric acid was also performed. We concluded that the radioactive waste volume could be reduced significantly by soil washing with a citric acid solution
Utilization of microwave energy for decontamination of oil polluted soils.
Iordache, Daniela; Niculae, Dumitru; Francisc, Ioan Hathazi
2010-01-01
Soil oil (petroleum) product pollution represents a great environmental threat as it may contaminate the neighboring soils and surface and underground water. Liquid fuel contamination may occur anywhere during oil (petroleum) product transportation, storing, handling and utilization. The polluted soil recovery represents a complex process due to the wide range of physical, chemical and biological properties of soils which should be analyzed in connection with the study of the contaminated soil behavior under the microwave field action. The soil, like any other non-metallic material, can be heated through microwave energy absorption due to the dielectric losses, expressed by its dielectric complex constant. Oil polluted soil behaves differently in a microwave field depending on the nature, structure and amount of the polluting fuel. Decontamination is performed through volatilization and retrieval of organic contaminant volatile components. After decontamination only a soil fixed residue remains, which cannot penetrate the underground anymore. In carrying out the soil recovery process by means of this technology we should also consider the soil characteristics such as: the soil type, temperature, moisture.The first part of the paper presents the theoretical aspects relating to the behavior of the polluted soil samples in the microwave field, as well as their relating experimental data. The experimental data resulting from the analysis of soils with a different level of pollution point out that the degree of pollutant recovery is high, contributing to changing the initial classification of soils from the point of view of pollution. The paper graphically presents the levels of microwave generated and absorbed power in soil samples, soil temperature during experimentations, specific processing parameters in a microwave field. It also presents the constructive solution of the microwave equipment designed for the contaminated soil in situ treatment.
Analysis on decontamination of contaminated soil with strontium using electrorestoration method
International Nuclear Information System (INIS)
Kim, K. N.; Won, H. J.; Kim, H. Y.; Kim, J. H.; Oh, W. J.
1999-01-01
The electrokinetic apparatus for remediation of the soil contaminated with Sr 2+ was designed. After kaolin clay compulsorily contaminated by Sr 2+ solution, the remediation characteristics by electrokinetic method were analyzed. Meanwhile, the numerical code for analysis of electrokinetic migration was developed for modelling of the soil remediation. And the input parameters needed for modelling were measured by laboratory experiment, or taken from literature. Experimental results are as follows : After 6 day remediation under 40 V, the front part of experimental cell was almost decontaminated, but the back part didn't almost be decontaminated. Consequently, the total remediation ratio of Sr 2+ from cell soil was about 84.8 %. The values calculated by the developed code almost agreed with experimental values. When voltages of electrode were increased by 10, 20, 40V, the total Sr 2+ remediation ratios were about 21.9%. 43.3%, 84.8 % , respectively, after 6 days
Biocompatible metal decontamination from soil using Ageratum conyzoides.
Sharma, Virbala; Pant, Deepak
2018-05-28
Metal pollution in soil is a serious problem among waste landfill sites and associated environment all over the globe. Amelioration of contaminated soil by plant bioaccumulation is an important strategy to protect the soil environment. Ageratum conyzoides is a common weed species that can grow easily in any contaminating site and bioaccumulate heavy metals present in the e-waste dumping/recycling sites as a natural scavenger. Soil selected for the study was contaminated with waste cathode ray tube (CRT) and printed circuit board (PCB) powder in the concentration range of 1-10 g/kg. Soil decontamination was achieved by using weed plants with ethylene diamine tetraacetic acid (EDTA, 0.1 g/kg) and kinetin (100 μM) combination in pot experiments. Fe, Mn, Zn, and Cu accumulation was found to be highest in leaves (6.51-38.58; 0.14-73.12; 5.24-269.07; 9.38-116.59%); Pb and Cr in stem (22.83-113.41; 21.05-500%), respectively, as compared with blank. Ion chromatography was used as a tool for the measurement of essential ions present in plant under different conditions. Plants showed better growth in terms of shoot, root length, biomass weight, and chlorophyll content with the proposed combination. EDTA allows the metals available for the accumulation through possible complexation. Also, the compatibility of kinetin to manage stress in plant is found to be enhanced in the presence of EDTA due to possible π-π interaction. Metal stress condition causes the deficiency of essential ions in the plants thereby disturbing its biochemistry and results in its eventual death. EDTA-kinetin hybrid treatment was found to be compatible for metal decontamination from soil, its detoxification in plants by changing its environment and restoring the essential ions for the survival of plant.
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
Texas market profile: soil and groundwater decontamination sector
International Nuclear Information System (INIS)
1998-12-01
The soil and groundwater decontamination market in Texas generated $7 billion in earnings in 1997 and should reach almost $9 billion in 2002. While Texas has introduced voluntary clean-up programs, decontamination is required at more than 200,000 sites. Pollution has arisen from such industrial sectors as chemicals, crude oil and natural gas. In Texas, government agency decontamination activities provide major business opportunities. As in the base of the environmental sector as a whole, economic factors are gradually taking over from regulation as the prime demand drivers. Cost and risk are major concerns for clients. Because the incentive to reduce costs and the trend toward contracting out and privatization are becoming stronger, companies with specialized technologies have opportunities in this market. The government is the main client for environmental restoration services, but the private sector is accounting for an increased share of the market. Aspects of market access discussed include: implications of NAFTA and 'Buy America', ATA carnets, the Environmental Technology Verification Program, centralized database, federal government contracting announcements, partnerships, and payment conditions
International Nuclear Information System (INIS)
Bazhenov, A.V.; Volobuev, P.V.; Isymov, M.A.
1996-01-01
The knowledge of coefficient of soil decontamination is necessary for predictions the dynamics in development of radioactive situation, for retrospective estimation and reconstruction of the initial radioactive contamination levels of territories. By effective coefficient of soil decontamination from radionuclides (CSD) we mean the multiple of a nuclide completely removed from the soil as a result of its physical decay, active removal of radionuclides from the ground into water ecosystems, as well as biogeochemical and wind migration beyond KURT borders. Its dimension can be expressed in the divisible relation (in how many times?), in percentage, as well as in periods of half-desintegration, if the process of desintegration is the exponent. The calculation is made on a complete nuclides supply in soil. The objective of the study is to calculate the effective coefficient of soil decontamination from 90 Sr on the basis of the analyzis of the experimental materials received at KURT territories in Sverdlovsk region. (author)
Phytoremediation: an overview of metallic ion decontamination from soil
Energy Technology Data Exchange (ETDEWEB)
Singh, O.V.; Labana, S.; Pandey, G.; Budhiraja, R.; Jain, R.K. [Inst. of Microbial Technology, Chandigarh (India)
2003-07-01
In recent years, phytoremediation has emerged as a promising ecoremediation technology, particularly for soil and water cleanup of large volumes of contaminated sites. The exploitation of plants to remediate soils contaminated with trace elements could provide a cheap and sustainable technology for bioremediation. Many modern tools and analytical devices have provided insight into the selection and optimization of the remediation process by plant species. This review describes certain factors for the phytoremediation of metal ion decontamination and various aspects of plant metabolism during metallic decontamination. Metal-hyperaccumulating plants, desirable for heavily polluted environments, can be developed by the introduction of novel traits into high biomass plants in a transgenic approach, which is a promising strategy for the development of effective phytoremediation technology. The genetic manipulation of a phytoremediator plant needs a number of optimization processes, including mobilization of trace elements/metal ions, their uptake into the root, stem and other viable parts of the plant and their detoxification and allocation within the plant. This upcoming science is expanding as technology continues to offer new, low-cost remediation options. (orig.)
Risoul, V; Pichon, C; Trouvé, G; Peters, W A; Gilot, P; Prado, G
1999-02-15
To determine decontamination behavior as affected by temperature, shallow beds of a clay-rich, a calcerous, and a sedimentary soil, artificially polluted with hexachlorobenzene, 4-chlorobiphenyl, naphthalene, or n-decane, were separately heated at 5 degrees C min-1 in a thermogravimetric analyzer. Temperatures for deep cleaning of the calcerous and the sedimentary soil increased with increasing boiling point (bp) of the aromatic contaminants, but removal efficiencies still approached 100% well below the bp. Decontamination rates were therefore modelled according to a pollutant evaporation-diffusion transport model. For the calcerous and sedimentary soils, this model reasonably correlated removal of roughly the first 2/3 of the naphthalene, but gave only fair predictions for hexachlorobenzene and 4-chlorobiphenyl. It was necessary to heat the clay soil above the aromatics bp to achieve high decontamination efficiencies. Weight loss data imply that for temperatures from near ambient to as much as 150 degrees C, interactions of each aromatic with the clay soil, or its decomposition products, result in lower net volatilization of the contaminated vs. neat clay. A similar effect was observed in heating calcerous soil polluted with hexachlorobenzene from near ambient to about 140 degrees C. Decontamination mechanisms remain to be established, although the higher temperatures needed to remove aromatics from the clay may reflect a more prominent role for surface desorption than evaporation. This would be consistent with our estimates that the clay can accommodate all of the initial pollutant loadings within a single surface monolayer, whereas the calcerous and sedimentary soils cannot.
Decontamination of Uranium-Contaminated Soil Sand Using Supercritical CO2 with a TBP–HNO3 Complex
Directory of Open Access Journals (Sweden)
Kwangheon Park
2015-09-01
Full Text Available An environmentally friendly decontamination process for uranium-contaminated soil sand is proposed. The process uses supercritical CO2 as the cleaning solvent and a TBP–HNO3 complex as the reagent. Four types of samples (sea sand and coarse, medium, and fine soil sand were artificially contaminated with uranium. The effects of the amount of the reagent, sand type, and elapsed time after the preparation of the samples on decontamination were examined. The extraction ratios of uranium in all of the four types of sand samples were very high when the time that elapsed after preparation was less than a few days. The extraction ratio of uranium decreased in the soil sand with a higher surface area as the elapsed time increased, indicating the possible formation of chemisorbed uranium on the surface of the samples. The solvent of supercritical CO2 seemed to be very effective in the decontamination of soil sand. However, the extraction of chemisorbed uranium in soil sand may need additional processes, such as the application of mechanical vibration and the addition of bond-breaking reagents.
Energy Technology Data Exchange (ETDEWEB)
Park, Jihye; Kim, Hakwon; Park, Kwangheon [Kyunghee University, Yongin (Korea, Republic of)
2015-10-15
The role of fuel cladding and reactor vessels is to help prevent the leakage of radioactive materials, including the fission products. However, if these shielding materials are damaged by a severe disaster such as the Fukushima Accident, radioactive materials could leak outside of a power plant site. Indeed, after the Fukushima Accident, radioactive materials have been detected in air and water samples. The air and water pollution lead to soil pollution, which is particularly difficult to decontaminate, as soil pollution has several types that vary according to the characteristics of a pollutant or its area. The existing decontamination methods generate a secondary waste owing to use of chemical toxicity solvents. It is also disadvantageous due to the additional cost of handling them. Therefore, new effective decontamination methods that reduce the use of toxicity solvents are necessary. For example, using supercritical CO{sub 2} has been studied as a new decontamination method. This study examines the method of decontaminating metallic ions inside of the soil using supercritical CO{sub 2} and a catecholamine compound. This study examined the effects of extracting metallic ions inside the soil using supercritical CO{sub 2} and catecholamine as the ligand. Based on these results, it is evident that when only the extraction agent was used, there was no extraction effect and that only when the ligand, co-ligand, and additive were used together was there an extraction effect. Following this, the optimal extraction-agent ratio was confirmed using varying amounts of extraction agents. The most effective extraction ratio of ligand to co-ligand was 1:2 in E-9 when 0.3 ml of H{sub 2}O were added.
International Nuclear Information System (INIS)
Haywood, F.F.
1986-01-01
In recent years, a number of soil decontamination studies have been carried out by investigators in the US and Canada. These investigations have included the segregation of potentially hazardous chemicals from uranium mill tailings, the use of various leaching agents for the selective removal of radium, thorium, and uranium from mine and mill tailings, the study of neutralization, fixation, and conditioning processes for tailings, the separation and removal of transuranium elements from contaminated soil and sediment, and finally studies of the cost effectiveness of various decontamination approaches. Remedial action programs for which soil decontamination may be an attractive alternative are those which include the cleanup of large open land areas since thousands of cubic years of material are generally involved. The practice of decontaminating or otherwise segregating contaminated and uncontaminated soil fractions before shipment to a final disposal site can only be done if it is economical to do so. This paper considers several techniques which have been reported in unclassified literature and includes a comparison of the authors' conclusions regarding the effectiveness of their investigations. The manuscript will include a comprehensive bibliography of references to techniques which appear to be feasible alternatives in remedial action programs
Gamma radiation for the decontamination of soil containing dioxin
International Nuclear Information System (INIS)
Chhor, M.P.; Wethington, J.A. Jr.
1986-01-01
Dioxin-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contamination poses an environmental danger. Different methods for the cleanup of contaminated sites have been proposed. The G value for dioxin dispersed in soil wetted with ethanol is much greater than G values for typical aromatic hydrocarbons. Doses > 6.24 x 10 23 eV/kg lead to decreasing rates of destruction of TCDD, and doses > 24.97 x 10 23 eV/kg are not very effective. Gamma irradiation of contaminated soil apparently will not result in large (powers of 10) decontamination factor. The concept of using gamma radiation for the degradation of TCDD in contaminated soil is about as good or as bad as other methods being tested
Alpha-beta-gamma spectrometer as an aid in directing decontamination of soils
International Nuclear Information System (INIS)
Berger, C.D.
1981-01-01
This technique permits rapid assessment of alpha-beta-gamma-emitter contamination in soils at sufficiently low concentrations to direct field operations. Of particular importance is its applicability during initial decommissioning and decontamination surveys when characterization of alpha and beta contamination in the presence of a high gamma background is necessary. This system has not yet been made portable for in-situ use, but it is expected that results willbe favorable when operated as a field instrument, resulting in simplified standard decontamination operation
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
International Nuclear Information System (INIS)
Ikeda, Yutaka; Akita, Hiroyuki; Kikawada, Kazuya
2013-01-01
The accident of Fukushima Daiichi nuclear energy plant by the tsunami resulting from the Great Eastern Japan Earthquake in 2011 caused the radiation contamination of cultivated field in Fukushima Prefecture. Some decontamination techniques such as surface soil grab, deep cultivation, and adding zeolite to the soil were tested in the rice fields of Fukushima Prefecture. Zeolite is usually used in the form of particle. It inhibits the transition of radioactive cesium from soil to plant bodies. Here, zeolite slurry was also used. The inhibition effect of the zeolite slurry was checked not only in the field but also in a laboratory experiment using some vegetables. The laboratory test results proved the effect of decontamination for vegetable; however, the field test showed uncertainness owing to the low passage coefficient of rice. (author)
Decontamination of radioactive cesium in soil using nano-size metallic calcium dispersing
International Nuclear Information System (INIS)
Mitoma, Yoshiharu; Fukuoka, Takezo; Matsue, Hideaki; Kobayashi, Hidemasa; Shiraishi, Hiroaki; Kajitani, Mikio
2013-01-01
In Japan, the major concern on radioactive cesium ( 134 Cs and 137 Cs) deposition and soil contamination due to the emission form the Fukushima Dai-ichi nuclear power plant showed up after a massive quake on March 11, 2011. Soil contamination with radioactive cesium has a long-term radiological impact due to its long half-life (30 years for 137 Cs) and its high biological hazard. Therefore, much attention has been paid to decontaminate Cs-contaminated soil with washing and/or extraction by adopting solvents. However, such wet methods have some disadvantages, i.e. forming of secondary effluents and additional cost for their treatment. We have recently shown that the nano-size metallic calcium/calcium oxide/iron dispersing mixture (Fe-nCa) is most effective for heavy metals immobilization and volume reduction method under dry condition. Thus, we applied this method to treat real radioactive cesium contaminated soils in dry condition. Simple stirring of the contaminated soil with Fe-nCa achieved about above 90% of radioactive Cs decontamination rate and the volume reduction level also reached around 50-60%. In this paper, we showed the effectiveness of a Fe-nCa method for the rapid remediation and volume reduction method of real radioactive cesium contaminated soils under dry conditions and our challenges for sophistication applying machine and reagents. (author)
International Nuclear Information System (INIS)
Omura, Tomomi
2011-01-01
At the stage of just eight months after the time when a large amount of radioactivity was discharged by the accident of the Fukushima Daiichi Nuclear Station of Tokyo Electric Power Company associated with the Great East Japan Earthquake, countermeasures for pollution due to radioactive substances have become the biggest challenge. The government made a cabinet decision on basic policy based on 'The Act on Special Measures concerning the Handling of Environmental Pollution by Radioactive Materials Discharged by the Nuclear Power Station Accident Associated with the Tohoku District - Off the Pacific Ocean Earthquake that Occurred on March 11, 2011 (The Act on Special Measures concerning the Handling of Radioactive Pollution).' By this, fiscal measures, regulatory measures, and role-sharing required for promoting the treatment of radioactivity-contaminated disaster waste and the decontamination measures of soil were clarified. At the same time as the enactment of the bill, 'Basic Policy for Emergency Response on Decontamination Work' and 'Guidelines for Municipal Decontamination Work' were issued, which helped a step toward full-scale decontamination activities with the backup of budgetary measures. This paper explains the following efforts of the government in implementing these actions. Installation of temporary storage sites for decontaminated soil, implementation of interim storage facilities, development of final disposal sites, and budgetary support. (O.A.)
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)
Prosopis juliflora--a green solution to decontaminate heavy metal (Cu and Cd) contaminated soils.
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.
Decontamination of metals and polycyclic aromatic hydrocarbons from slag-polluted soil.
Bisone, Sara; Mercier, Guy; Blais, Jean-François
2013-01-01
Metallurgy is an industrial activity that is one of the largest contributors to soil contamination by metals. This contamination is often associated with organic compound contamination; however, little research has been aimed at the development of simultaneous processes for decontamination as opposed to treatments to heavy metals or organic compounds alone. This paper presents an efficient process to decontaminate the soils polluted with smelting by-products rich in Cu, Zn and polycyclic aromatic hydrocarbons (PAHs). A simultaneous treatment for metals and PAHs was also tested. The process is mainly based on physical techniques, such as crushing, gravimetric separation and attrition. For the finest particle size fractions, an acid extraction with H2SO4 was used to remove metals. The PAH removal was enhanced by adding surfactant during attrition. The total metal removals varied from 49% to 73% for Cu and from 43% to 63% for Zn, whereas a removal yield of 92% was measured for total PAHs. Finally, a technical-economic evaluation was done for the two processes tested.
Removal of uranium from contaminated soil using indoor electrokinetic decontamination
International Nuclear Information System (INIS)
Gye-Nam Kim; Ilgook Kim; Seung-Soo Kim; Jong-Won Choi
2016-01-01
Indoor electrokinetic decontamination equipment was manufactured to treat 1.2 tons of uranium-contaminated soil. For a reduction of waste electrolyte and metal oxide, waste electrolyte was reused and the optimum pH was adjusted to minimize metal oxide volume in the cathode chamber. It was found that the optimum pH of the waste electrolyte in a cathode chamber was below 2.35 at 25 deg C. When the initial uranium concentrations in the soils were 7.0-27.0 Bq/g, the reuse periods of waste electrolyte required for uranium concentrations in the soils to reach below 5.0 Bq/g were 5-25 days. In addition, when the initial concentrations in the soils were 7.0-20.0 Bq/g, the periods required to reach below the clearance concentration level were 25-40 days.
International Nuclear Information System (INIS)
Ishii, K.; Terakawa, A.; Matsuyama, S.
2012-01-01
We studied the structure of radioactive cesium distribution in soil and found the exponential dependence. This behavior could be explained theoretically. We developed a useful method to decontaminate the soil contaminated with radioactive cesium atoms. We applied our method to the contaminated school yards of elementary schools of Marumori town and decontaminated total area of about 7000 m"2. (author)
Huang, Yu-Tuan; Hseu, Zeng-Yei; Hsi, Hsing-Cheng
2011-08-01
Thermal treatment is a useful tool to remove Hg from contaminated soils. However, thermal treatment may greatly alter the soil properties and cause the coexisting contaminants, especially trace metals, to transform and repartition. The metal repartitioning may increase the difficulty in the subsequent process of a treatment train approach. In this study, three Hg-contaminated soils were thermally treated to evaluate the effects of treating temperature and duration on Hg removal. Thermogravimetric analysis was performed to project the suitable heating parameters for subsequent bench-scale fixed-bed operation. Results showed that thermal decontamination at temperature>400°C successfully lowered the Hg content tosoil particle size was less significant, even when the soils were thermally treated to 550°C. Soil clay minerals such as kaolinite were shown to be decomposed. Aggregates were observed on the surface of soil particles after the treatment. The heavy metals tended to transform into acid-extractable, organic-matter bound, and residual forms from the Fe/Mn oxide bound form. These results suggest that thermal treatment may markedly influence the effectiveness of subsequent decontamination methods, such as acid washing or solvent extraction. Copyright © 2011 Elsevier Ltd. All rights reserved.
Electrokinetics and soil decontamination: concepts and overview (Review
Directory of Open Access Journals (Sweden)
Mohammed A. Karim
2014-12-01
Full Text Available Electrokinetic decontamination and extraction have been proven to be one of the most viable, cost effective and emerging techniques in removing contaminants, especially heavy metals from soils for about last five decades. Basic concepts and an overview of the electrokinetic extraction processes and their potential applications in geotechnical and geoenvironmental engineering have been reviewed based on the literature and presented in this paper. Primarily, theoretical and laboratory experimental studies related to electroreclamation of soils are summarised in brief with basic concepts of electrokinetic processes. The paper has been divided into different sections that include history of electrokinetics, background and concepts, modelling, parameter effects, instrumentation, contaminant extraction, field applications, and summary and recommendation. Based on the review it is obvious that the field application of electrokinetic technology to remediate heavy metal contaminated soils /sediments is very limited and site specific. Additional laboratory studies and more pilot- and full-scale information from field applications are critical to the further understanding of the technology and to customize the process in different field conditions.
International Nuclear Information System (INIS)
Tsubaki, Junichiro
2012-01-01
The new filtration and condensation techniques that decontaminate effectively the large quantity of contaminated soils, was developed. The facility treating the soils of 5 tons per day is being developed. (M.H.)
Dadhwal, M; Singh, A; Prakash, O; Gupta, S K; Kumari, K; Sharma, P; Jit, S; Verma, M; Holliger, C; Lal, R
2009-02-01
To locate a high-dose point hexachlorocyclohexane (HCH)-contaminated site, to identify HCH-degrading bacteria in it and assay HCH-decontamination by biostimulation. Bacteria were isolated by serial dilution method from HCH-contaminated soil samples collected from areas near an HCH-manufacturing unit and its dumpsite in North India. After confirming the presence of indigenous HCH-degraders (seven of 24 strains), an ex situ biostimulation experiment was conducted. For this, residue levels in soil were diluted by mixing with pristine garden soil and aeration, moisture and nutrients were provided intermittently. This soil was monitored for reduction in Sigma-HCH (sum of alpha-, beta-, gamma- and delta-HCH) levels and stimulation of HCH-degraders. Experiments were conducted twice, in March-April (c. 75 microg Sigma-HCH g(-1) soil) and October-November 2006 (c. 280 microg Sigma-HCH g(-1) soil) at 26-30 degrees C. Sigma-HCH levels were reduced to decontamination via aeration, addition of nutrients and moisture, of the indigenous population. The study demonstrates that biostimulation of indigenous HCH-degrading microbial population can be used for decontamination of chronically HCH-contaminated sites.
International Nuclear Information System (INIS)
Chirkst, D.Eh.; Chaliyan, K.N.; Chaliyan, A.G.
1994-01-01
Thermodynamic characteristics of the process of soil decontamination from 137 Cs by the their washing with eluting solution, Fe(3) and ammonium being included in its composition, have been determined. The decontamination process is 137 Cs desorption as a result of destruction of cesium chelate complexes with humic acids. Fe 3+ and Fe(OH) 2+ substitution for Cs + in the soils occurs spontaneously as a thermodynamically efficient process. 3 refs.; 1 fig
Development of Decontamination and Decommissioning Technologies for Nuclear Facilities
International Nuclear Information System (INIS)
Moon, Jei Kwon; Lee, Kune Woo; Won, Hui Jun
2010-04-01
A laser ablation decontamination technology which is reportedly effective for a removal of fixed contaminants has been developed for three years as the first stage of the development. Lab scale experimental equipment was fabricated and the process variables have been assessed for determination of appropriate decontamination conditions at the laser wave lengths of 1,064 nm and 532 nm, respectively. The decontamination tests using radioactive specimens showed that the decontamination efficiency was about 100 which is quite a high value. An electrokinetic-flushing, an agglomeration leaching and a supercritical CO 2 soil decontamination technology were development for a decontamination of radioactive soil wastes from the decommissioned sites of the TRIGA research reactor and the uranium conversion facilities. An electrokinetic-flushing process was found to be effective for soil wastes aged for a long time and an agglomeration leaching process was effective for soil wastes of surface contamination. On the other hand, a supercritical CO 2 soil decontamination technology was found to be applicable for U or TRU bearing soil wastes. The remediation monitoring key technologies such as a representative sample taking and a measurement concept for the vertical distribution of radionuclides were developed for an assessment of the site remediation. Also an One-Dimensional Water Flow and Contaminant Transport in Unsaturated Zone (FTUNS) code was developed to interpretate the radionuclide migration in the unsaturated zone
Energy Technology Data Exchange (ETDEWEB)
Temer, D.J.; Villarreal, R.; Smith, B.F. [Los Alamos National Lab., NM (United States)
1997-10-01
The decontamination of soils and/or materials from medium-fired plutonium oxide (PuO{sub 2}) with an effective and efficient decontamination agent that will not significantly dissolve the matrix requires a new and innovative technology. After testing several decontamination agents and solutions for dissolution of medium-fired PuO{sub 2}, the most successful decontamination solutions were fluoride compounds, which were effective in breaking the Pu-oxide bond but would not extensively dissolve soil constituents and other materials. The fluoride compounds, tetra fluoboric acid (HBF{sub 4}) and hydrofluorosilicic acid (H{sub 2}F{sub 6}Si), were effective in dissolving medium-fired PuO{sub 2}, and did not seem to have the potential to dissolve the matrix. In both compounds, the fluoride atom is attached to a boron or silicon atom that inhibits the reactivity of the fluoride towards other compounds or materials containing atoms less attracted to the fluoride atom in an acid solution. Because of this inhibition of the reactivity of the fluoride ion, these compounds are termed inhibited fluoride compounds or agents. Both inhibited fluorides studied effectively dissolved medium-fired PuO{sub 2} but exhibited a tendency to not attack stainless steel or soil. The basis for selecting inhibited fluorides was confirmed during leaching tests of medium-fired PuO{sub 2} spiked into soil taken from the Idaho National Engineering Laboratory (INEL). When dissolved in dilute HNO{sub 3}, HCl, or HBr, both inhibited fluoride compounds were effective at solubilizing the medium-fired PuO{sub 2} from spiked INEL soil.
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)
Potential of Biological Agents in Decontamination of Agricultural Soil
Directory of Open Access Journals (Sweden)
Muhammad Kashif Javaid
2016-01-01
Full Text Available Pesticides are widely used for the control of weeds, diseases, and pests of cultivated plants all over the world, mainly since the period after the Second World War. The use of pesticides is very extensive to control harm of pests all over the globe. Persistent nature of most of the synthetic pesticides causes serious environmental concerns. Decontamination of these hazardous chemicals is very essential. This review paper elaborates the potential of various biological agents in decontamination of agricultural soils. The agricultural crop fields are contaminated by the periodic applications of pesticides. Biodegradation is an ecofriendly, cost-effective, highly efficient approach compared to the physical and chemical methods which are expensive as well as unfriendly towards environment. Biodegradation is sensitive to the concentration levels of hydrogen peroxide and nitrogen along with microbial community, temperature, and pH changes. Experimental work for optimum conditions at lab scale can provide very fruitful results about specific bacterial, fungal strains. This study revealed an upper hand of bioremediation over physicochemical approaches. Further studies should be carried out to understand mechanisms of biotransformation.
Potential of Biological Agents in Decontamination of Agricultural Soil.
Javaid, Muhammad Kashif; Ashiq, Mehrban; Tahir, Muhammad
2016-01-01
Pesticides are widely used for the control of weeds, diseases, and pests of cultivated plants all over the world, mainly since the period after the Second World War. The use of pesticides is very extensive to control harm of pests all over the globe. Persistent nature of most of the synthetic pesticides causes serious environmental concerns. Decontamination of these hazardous chemicals is very essential. This review paper elaborates the potential of various biological agents in decontamination of agricultural soils. The agricultural crop fields are contaminated by the periodic applications of pesticides. Biodegradation is an ecofriendly, cost-effective, highly efficient approach compared to the physical and chemical methods which are expensive as well as unfriendly towards environment. Biodegradation is sensitive to the concentration levels of hydrogen peroxide and nitrogen along with microbial community, temperature, and pH changes. Experimental work for optimum conditions at lab scale can provide very fruitful results about specific bacterial, fungal strains. This study revealed an upper hand of bioremediation over physicochemical approaches. Further studies should be carried out to understand mechanisms of biotransformation.
GARDEC, Estimation of dose-rates reduction by garden decontamination
International Nuclear Information System (INIS)
Togawa, Orihiko
2006-01-01
1 - Description of program or function: GARDEC estimates the reduction of dose rates by garden decontamination. It provides the effect of different decontamination Methods, the depth of soil to be considered, dose-rate before and after decontamination and the reduction factor. 2 - Methods: This code takes into account three Methods of decontamination : (i)digging a garden in a special way, (ii) a removal of the upper layer of soil, and (iii) covering with a shielding layer of soil. The dose-rate conversion factor is defined as the external dose-rate, in the air, at a given height above the ground from a unit concentration of a specific radionuclide in each soil layer
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 soils containing PAHs by electroremediation: a review.
Pazos, M; Rosales, E; Alcántara, T; Gómez, J; Sanromán, M A
2010-05-15
During the last years, the anthropogenic sources have contributed to organic compound penetration into the environment. One large group of persistent and toxic contaminants is the hydrophobic organic contaminants. Among them, polycyclic aromatic hydrocarbons (PAHs) have been recognized as a representative group of these pollutants with low solubility. In this paper, it is showed the electroremediation of soil contaminated with PAHs as an alternative, to organic compound removal. This technique, mainly used for heavy metal extraction, applies the electric current to promote the movement of contaminants. Nowadays the application of this technique alone or combined with other techniques as for example Fenton or bioremediation is taking fine results to PAHs removal. Although the PAHs soil decontamination by means of the electric field is in an initial stage, many researchers have demonstrated the treatment effectiveness. This paper describes the foremost principles to carry out the electroremediation of soils contaminated with PAHs, just like the different alternatives to improve the electroremediation of PAHs and also the new methodologies of PAHs removal by using hybrid technologies. Copyright (c) 2009 Elsevier B.V. All rights reserved.
Radiological survey following decontamination activities near the TA-45 site
International Nuclear Information System (INIS)
Gunderson, T.; Buhl, T.; Romero, R.; Salazar, J.
1983-07-01
Three areas at the site of a former radioactive liquid waste treatment plant at Los Alamos National Laboratory were decontaminated during 1982 by Bechtel Corporation, with health physics support provided by Eberline Instrument Corporation, under the Department of Energy's Formerly Utilized Sites Remedial Action Program (FUSRAP). Before decontamination, there were above-background concentrations of gross alpha, gross beta, 238 Pu, 239 240 Pu, 241 Am, 90 Sr, and 137 Cs in the surface soils. These combined concentrations were above operational decontamination guidelines for surface soil contamination. After cleanup operations, radionuclide concentrations in surface soils at all three sites were within decontamination guidelines
Decontamination impacts on solidification
International Nuclear Information System (INIS)
Piciulo, P.L.; Davis, M.S.
1985-01-01
The increased occupational exposure resulting from the accumulation of activated corrosion products in the primary system of LWRs has led to the development of chemical methods to remove the contamination. In the past, the problem of enhanced migration of radionuclides away from trenches used to dispose of low-level radioactive waste, has been linked to the presence, at the disposal unit, of chelating or complexing agents such as those used in decontamination processes. These agents have further been found to reduce the normal sorptive capacity of soils for radionuclides. The degree to which these agents inhibit the normal sorptive processes is dependent on the type of complexing agent, the radionuclide of concern, the soil properties and whether the nuclide is present as a complex or is already sorbed to the soil. Since the quantity of reagent employed in a full system decontamination is large (200 to 25,000 kg), the potential for enhanced migration of radionuclides from a site used to dispose of the decontamination wastes should be addressed and guidelines established for the safe disposal of these wastes
PAHs soil decontamination in two steps: desorption and electrochemical treatment.
Alcántara, M Teresa; Gómez, Jose; Pazos, Marta; Sanromán, M Angeles
2009-07-15
The presence of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in soils poses a potential threat to human health if exposure levels are too high. Nevertheless, the removal of these contaminants presents a challenge to scientists and engineers. The high hydrophobic nature of PAHs enables their strong sorption onto soil or sediments. Thus, the use of surfactants could favour the release of sorbed hydrophobic organic compounds from contaminated soils. In this work, five surfactants, namely Brij 35, Tergitol NP10, Tween 20, Tween 80 and Tyloxapol, are evaluated on the desorption of PAHs [benzanthracene (BzA), fluoranthene (FLU), and pyrene (PYR), single and in mixture] from a model sample such as kaolin. In all cases, the best results were obtained when Tween 80 was employed. In order to obtain the global decontamination of PAHs, their electrochemical degradation is investigated. It is concluded that the order of increasing degradation for single compounds is BzA>FLU>PYR when they are subject to the same electrochemical treatment. In addition, there is a direct relationship between the ionization potential and the electrochemical degradation of PAH.
International Nuclear Information System (INIS)
Balanel, Vasile; Boldescu, Victoria; Mesina, Victor
2013-01-01
This paper presents research results of radiological samples taken from various media (water, soil, air and some food). The study showed that concentrations of radionuclides Cs 137 and Sr 90 did not exceed the maximum permissible. A high level of radionuclides but within the norm occurred in some imported food. The research describes methodology used in radioactive decontamination in practice of the modern world. (authors)
Soil surface decontamination and revegetation progress
International Nuclear Information System (INIS)
Graves, A.W.
1981-01-01
A review is given of work by Rockwell Hanford Operations related to large-area decontamination efforts. Rockwell has a Program Office which manages the decontamination and decommissioning (D and D) efforts. Part of the program is involved with large-surface area cleanup in conjunction with surveillance and maintenance of retired sites and facilities. The other part is the decontamination and decommissioning of structures. There are 322 surplus contaminated sites and facilities for which Rockwell has responsibility on the Hanford Site. A Program Office was established for a disciplined approach to cleanup of these retired sites. There are three major projects: the first is surveillance and maintenance of the sites prior to D and D, the project under which the radiation area cleanup is contained. Another project is for contaminated-equipment volume reduction; size reduction with arc saw cut-up and volume reduction with a vacuum furnace meltdown are being used. The third major project is structural D and D
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.
Special zone territory decontamination
International Nuclear Information System (INIS)
Samojlenko, Yu.N.; Golubev, V.V.
1989-01-01
Special zone is the Chernobyl' NPP operating site (OS). OS decontamination is described including reactor ruins from the accident moment. The process was begun from reactor bombardment with absorbing and filtering materials (sand, clay, lead, boron compounds). Then were produced soil shovelling, territory filling by dry concrete and laying concrete layer with thickness up to 300 mm. NPP room and equipment decontamination is described. 3 figs.; 3 tabs
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
Energy Technology Data Exchange (ETDEWEB)
Pauli, Mario
2011-07-01
The paper describes a system for the thermal decontamination of contaminated soils by microwaves. In addition to the determination of the dielectric material parameters of different soils, a focus is on antennas for the efficient coupling of the microwaves into the ground. The developed simulation model takes into account the electromagnetic-thermal interaction and makes it possible to predict optimal plant configuration, duration and costs of a sanitation measure in advance. [German] Die Arbeit beschreibt ein System zur thermischen Dekontaminierung verseuchter Boeden durch Mikrowellen. Neben der Bestimmung der dielektrischen Materialparameter verschiedener Boeden liegt ein Schwerpunkt auf Antennen zur effizienten Einkopplung der Mikrowellen in den Boden. Das entwickelte Simulationsmodell beruecksichtigt die elektromagnetisch-thermische Wechselwirkung und ermoeglicht es, bereits im Vorfeld optimale Anlagenkonfiguration, Dauer und Kosten einer Sanierungsmassnahme vorherzusagen.
Geographic assistance of decontamination strategy elaboration
International Nuclear Information System (INIS)
Davydchuk, V.; Arapis, G.
1996-01-01
Those who elaborates the strategy of decontamination of vast territories is to take into consideration the heterogeneity of such elements of landscape as relief, lithology, humidity and types of soils and, vegetation, both on local and regional level. Geographic assistance includes evaluation of efficacy of decontamination technologies in different natural conditions, identification of areas of their effective application and definition of ecological damage, estimation of balances of the radionuclides in the landscapes to create background of the decontamination strategy
Decontamination and decommissioning techniques for research reactors
International Nuclear Information System (INIS)
Oh, Won Zin; Won, H. J.; Jung, C. H.; Choi, W. K.; Kim, G. N.; Lee, K. W.
2002-05-01
Evaluation of soil decontamination process and the liquid decontamination waste treatment technology are investigation of organic acid as a decontamination agent, investigation of the liquid waste purification process and identification of recycling the decontamination agents. Participation on IAEA CRP meeting are preparation of IAEA technical report on 'studies on decommissioning of TRIGA reactors and site restoration technologies' and exchange the research result, technology, experience and safety regulation of the research reactor D and D of USA, Great Britain, Canada, Belgium, Italy, India and so forth
Testing of multistep soil washing for radiocesium-contaminated soil containing plant matter
International Nuclear Information System (INIS)
Funakawa, Masafumi; Tagawa, Akihiro; Okuda, Nobuyasu
2012-01-01
Decontamination work following radiocesium exposure requires a vast reduction in the amount of contaminated soil generated. The current study subjected 4 types of contaminated soil with different properties to multistep soil washing under the same conditions. This study also determined the effectiveness of radiocesium decontamination and the extent to which the amount of contaminated soil was reduced. In addition, the effectiveness of plant matter separation, adsorbent addition, and grinding as part of multistep soil washing was determined using the same contaminated soil. Results of testing indicated that the rate of radiocesium decontamination ranged from 73.6 to 89.2% and the recovery rate ranged from 51.5 to 84.2% for twice-treated soil, regardless of the soil properties or cesium level. Plant matter in soil had a high radiocesium level. However, there was little plant matter in our soil sample. Therefore, plant matter separation had little effect on the improvement in the percentage of radiocesium decontamination of twice-treated soil. Soil surface grinding improved the rate of radiocesium decontamination of twice-treated soil. However, radiocesium in soil tightly bound with minerals in the soil; thus, the addition of an adsorbent also failed to improve the rate of radiocesium decontamination. (author)
López-Vicente, Manuel; Onda, Yuichi; Takahashi, Junko; Kato, Hiroaki; Chayama, Shinya; Hisadome, Keigo
2018-08-01
Owing to the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident a vast amount of radiocesium was released polluting the land. Afterwards, a variety of decontamination practices has been done, reducing the ambient dose rates. In this study we evaluated the effectiveness of eight forest decontamination practices by means of monitoring the radiocesium ( 137 Cs) concentration in soil and leaf samples, and the daily discharge rates in ten plots during 27 months (May 2013-July 2015). A forest plantation located 16 km southwest to the FDNPP and within the exclusion area was selected. Radiocesium concentrations were analysed using a germanium gamma ray detector. The differences in radiocesium activities between the different plots were statistically significant (p soil and leaf fraction were 96.6% and 3.4%. Copyright © 2018 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
A. Comegna
2013-09-01
Full Text Available Contamination of soils with non-aqueous phase liquids (NAPL constitutes a serious geo-environmental problem, given the toxicity level and high mobility of these organic compounds. To develop effective decontamination methods, characterisation and identification of contaminated soils are needed. The objective of this work is to explore the potential of dielectric permittivity measurements to detect the presence of NAPLs in soils. The dielectric permittivity was measured by Time Domain Reflectometry method (TDR in soil samples with either different volumetric content of water (w and NAPL (NAPL or at different stages during immiscible displacement test carried out with two different flushing solutions. A mixing model proposed by Francisca and Montoro, was calibrated to estimate the volume fraction of contaminant present in soil. Obtained results, showed that soil contamination with NAPL and the monitoring of immiscible fluid displacement, during soil remediation processes, can be clearly identified from dielectric measurements.
International Nuclear Information System (INIS)
Samojlenko, Yu.N.; Nad''yarnykh, G.V.; Teplitskij, A.L.; Shilin, S.A.
1989-01-01
Data are presented on the radioactive contamination of the 30-km zone, on the radionuclide (RN) distribution in soils and on the RN migration in grounds. During 1986-1988 were tested over 20 techniques for territory decontamination and were found out the most optimal ones. The first stage of decontamination was removal of an upper contaminated soil layer. The second stage was prolonged chemical fixation of dusting decontaminated soil areas. 3 tabs
Decontamination of the site of an army gasoline service station
International Nuclear Information System (INIS)
Hoffmann, J.; Katzer, W.; Scheidt, M.; Roll, S.
1994-01-01
This is a report on the decontamination of the site of a gasoline service station at the Fuchsberg barracks at Salzwedel. Albeit that the accident is not spectacular for its magnitude, this case is interesting and exemplary because of the combined use of the most diverse decontamination methods. Soi air removal by suction, ground water decontamination, and microbiological soil decontamination were successfully used in conjunction. (orig.) [de
International Nuclear Information System (INIS)
Oh, Won Zin; Lee, K. W.; Won, H. J.; Jung, C. J.; Choi, W. K.; Kim, G. N.; Moon, J. K.
2001-04-01
The followings were studied through the project entitled 'Dry Decontamination Technology Development for Highly Radioactive Contaminants'. 1.Contaminant Characteristics Analysis of Domestic Nuclear Fuel Cycle Projects(NFCP) and Applicability Study of the Unit Dry-Decontamination Techniques A. Classification of contaminated equipments and characteristics analysis of contaminants B. Applicability study of the unit dry-decontamination techniques 2.Performance Evaluation of Unit Dry Decontamination Technique A. PFC decontamination technique B. CO2 decontamination technique C. Plasma decontamination technique 3.Development of Residual Radiation Assessment Methodology for High Radioactive Facility Decontamination A. Development of radioactive nuclide diffusion model on highly radioactive facility structure B. Obtainment of the procedure for assessment of residual radiation dose 4.Establishment of the Design Concept of Dry Decontamination Process Equipment Applicable to Highly Radioactive Contaminants 5.TRIGA soil unit decontamination technology development A. Development of soil washing and flushing technologies B. Development of electrokinetic soil decontamination technology
This treatability study report presents the results of laboratory and field tests on the effectiveness of a new decontamination process for soils containing 2,4-D/2,4,5-T and traces of dioxin. The process employs three operations, thermal desorption, condensation and absorp...
Schelkle, Bettina; Choi, Young; Baillie, Leslie W; Richter, William; Buyuk, Fatih; Celik, Elif; Wendling, Morgan; Sahin, Mitat; Gallagher, Theresa
2017-01-01
Remediation of Bacillus anthracis -contaminated soil is challenging and approaches to reduce overall spore levels in environmentally contaminated soil or after intentional release of the infectious disease agent in a safe, low-cost manner are needed. B. anthracis spores are highly resistant to biocides, but once germinated they become susceptible to traditional biocides or potentially even natural predators such as nematodes in the soil environment. Here, we describe a two-step approach to reducing B. anthracis spore load in soil during laboratory trials, whereby germinants and Caenorhabditis elegans nematodes are applied concurrently. While the application of germinants reduced B. anthracis spore load by up to four logs depending on soil type, the addition of nematodes achieved a further log reduction in spore count. These laboratory based results suggest that the combined use of nematodes and germinants could represent a promising approach for the remediation of B. anthracis spore contaminated soil. Originality-Significance Statement: This study demonstrates for the first time the successful use of environmentally friendly decontamination methods to inactivate Bacillus anthracis spores in soil using natural predators of the bacterium, nematode worms.
Energy Technology Data Exchange (ETDEWEB)
Bachmann, Guenther; Koenig, Wilhelm; Utermann, Jens (eds.)
2012-04-15
The 52th supplement consists of three main chapters. The first chapter is concerned to soil in the environmental policy, scientific basis, investigation and evaluation of soils and adverse soil alterations. The second chapter reports on fundamentals for measures of soil protection and soil decontamination, execution questions of the soil protection legislation. The third chapter contains the actual legislative provisions.
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 ...
Cravotto, Giancarlo; Di Carlo, Stefano; Ondruschka, Bernd; Tumiatti, Vander; Roggero, Carlo Maria
2007-10-01
The effect on halogenated aromatics of solid, non-toxic oxidants such as sodium percarbonate and the urea/hydrogen peroxide complex (Fenton-like reagents) was investigated. A microwaves-assisted, solvent-free method for soil decontamination is presented. It marks a considerable advance in the search of more efficient, environment-friendly procedures for the degradative oxidation of persistent organic pollutants. Residual pollutants in treated soil samples were determined by GC/MS analysis after solvent extraction or direct thermal desorption. Results showed that 4-chloronaphthol, 2,4-dichlorophenoxyacetic acid and p-nonylphenol had been degraded completely, 2,4-dibromophenol to a large extent.
Energy Technology Data Exchange (ETDEWEB)
Oh, Won Zin; Lee, K. W.; Won, H. J.; Jung, C. J.; Choi, W. K.; Kim, G. N.; Moon, J. K
2001-04-01
The followings were studied through the project entitled 'Dry Decontamination Technology Development for Highly Radioactive Contaminants'. 1.Contaminant Characteristics Analysis of Domestic Nuclear Fuel Cycle Projects(NFCP) and Applicability Study of the Unit Dry-Decontamination Techniques A. Classification of contaminated equipments and characteristics analysis of contaminants B. Applicability study of the unit dry-decontamination techniques 2.Performance Evaluation of Unit Dry Decontamination Technique A. PFC decontamination technique B. CO2 decontamination technique C. Plasma decontamination technique 3.Development of Residual Radiation Assessment Methodology for High Radioactive Facility Decontamination A. Development of radioactive nuclide diffusion model on highly radioactive facility structure B. Obtainment of the procedure for assessment of residual radiation dose 4.Establishment of the Design Concept of Dry Decontamination Process Equipment Applicable to Highly Radioactive Contaminants 5.TRIGA soil unit decontamination technology development A. Development of soil washing and flushing technologies B. Development of electrokinetic soil decontamination technology.
Assessing cost and effectiveness of radiation decontamination in Fukushima Prefecture, Japan
International Nuclear Information System (INIS)
Yasutaka, Tetsuo; Naito, Wataru
2016-01-01
Despite the enormous cost of radiation decontamination in Fukushima Prefecture, it is not clear what levels of reduction in external radiation exposure are possible in the Special Decontamination Area, the Intensive Contamination Survey Areas and the whole of Fukushima. The objective of this study was to evaluate the cost and effectiveness of radiation decontamination in Fukushima Prefecture in its entirety. Using a geographic information system, we calculated the costs of removal, storage containers, transport, and temporary and interim storage facilities as well as the reduction in air dose rate for a cumulative external exposure for 9000 1 km × 1 km mesh units incorporating 51 municipalities. The decontamination cost for the basic scenario, for which forested areas within 20 m of habitation areas were decontaminated, was JPY2.53–5.12 trillion; the resulting reduction in annual external dose was about 2500 person-Sv. The transport, storage, and administrative costs of decontamination waste and removed soil reached JPY1.55–2.12 trillion under this scenario. Although implementing decontamination of all forested areas provides some major reductions in the external radiation dose for the average inhabitant, decontamination costs could potentially exceed JPY16 trillion. These results indicate that technologies for reducing the volume of decontamination waste and removed soil should be considered to reduce storage costs and that further discussions about forest decontamination policies are needed. - Highlights: • Evaluation of cost and effectiveness of decontaminating Fukushima Prefecture. • Reductions in external exposure under various decontamination scenarios were similar. • Decontamination costs for the basic scenario were estimated at JPY2.53–5.12 trillion.
LASL experience in decontamination of the environment
International Nuclear Information System (INIS)
Ahlquist, A.J.
1981-01-01
This discussion represents one part of a major effort in soil decontamination at the Los Alamos site. A contaminated industrial waste line in the Los Alamos townsite was removed, and a plutonium incineration facility, and a filter building contaminated with actinium-227 were dismantled. The former plutonium handling facility has been decontaminated, and canyons and an old firing site contaminated with strontium-90 have been surveyed
Decontamination of Soils Contaminated with Co and Cs by Using an Acid Leaching Process
International Nuclear Information System (INIS)
Jung-Joon, Lee; Gye-Nam, Kim; Jei-Kwon, Moon; Kune-Woo, Lee
2009-01-01
Acid leaching process has been adapted for the remediation of soils contaminated with heavy metals and radionuclides. This method has been reported to be simple, and economically promising. Moreover it can be applicable for on-site and off-site remediations as well. Investigations were conducted on an acid leaching process using surrogate contaminated soils. Size sieving, agglomeration and column leaching were carried out with soils artificially contaminated with Co and Cs, respectively. Size distribution was analyzed for a determination of the particle size required to be agglomerated. Because of the low water permeability of the soils due to their fine particles, they were sieved by using a sieve with a 0.075 mm size (No. 200 mesh) for an agglomeration. The soils with a size smaller than 0.075 mm were agglomerated by using 2 % sodium silicate (Na 2 SiO 3 ), while the soils with a size larger than 0.075 mm were used directly for the column leaching test. From the preliminary test (the batch scale leaching test), 0.1 M of HCl was determined as the effective leaching agent for Co and Cs. Finally, the soils mixed with the coarse soil and the agglomerated soil were decontaminated with 0.1 M HCl within 11.3 days and the removal efficiencies of Co and Cs were 94.0 % and 82.8 %, respectively. In conclusion, an acid leaching process could be applied for a remediation of soils contaminated with radionuclides such as Co and Cs. (authors)
Assessing cost and effectiveness of radiation decontamination in Fukushima Prefecture, Japan.
Yasutaka, Tetsuo; Naito, Wataru
2016-01-01
Despite the enormous cost of radiation decontamination in Fukushima Prefecture, it is not clear what levels of reduction in external radiation exposure are possible in the Special Decontamination Area, the Intensive Contamination Survey Areas and the whole of Fukushima. The objective of this study was to evaluate the cost and effectiveness of radiation decontamination in Fukushima Prefecture in its entirety. Using a geographic information system, we calculated the costs of removal, storage containers, transport, and temporary and interim storage facilities as well as the reduction in air dose rate for a cumulative external exposure for 9000 1 km × 1 km mesh units incorporating 51 municipalities. The decontamination cost for the basic scenario, for which forested areas within 20 m of habitation areas were decontaminated, was JPY2.53-5.12 trillion; the resulting reduction in annual external dose was about 2500 person-Sv. The transport, storage, and administrative costs of decontamination waste and removed soil reached JPY1.55-2.12 trillion under this scenario. Although implementing decontamination of all forested areas provides some major reductions in the external radiation dose for the average inhabitant, decontamination costs could potentially exceed JPY16 trillion. These results indicate that technologies for reducing the volume of decontamination waste and removed soil should be considered to reduce storage costs and that further discussions about forest decontamination policies are needed. Copyright © 2015 Elsevier Ltd. All rights reserved.
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.)
Probabilistic frequency variations of structure-soil systems
International Nuclear Information System (INIS)
Hamilton, C.W.; Hadjian, A.H.
1976-01-01
During earthquakes, structure-soil systems act as filters greatly amplifying the response of equipment whose frequencies are at or near their natural frequencies. Thus, the estimation of these structure-soil system frequencies assumes significant importance both for safety and cost. Actual in-situ frequencies of structures differ from calculated frequencies due both to variations in mathematical modelling techniques and to variations of material properties. This paper studies the second source only. This variability is usually gauged by the 'worst case' analyses technique in which extreme high- and low- parameter values are assumed and the associated frequencies are used as upper and lower bounds. This approach is not entirely satisfactory because it does not provide any indication of the probability of these limits being exceeded, of the distribution between these limits, or of the level of conservation introduced into the design process. The present approach provides this additional information. The emphasis in this part is both on developing the methodology and on the results obtained. It covers both the fixed-base structure and the effects of soil-structure interaction. Empirical data on concrete proerties were obtained from previously published results. Much less is known about variability of soil properties, so the soil structure interaction coefficients are assumed to be normally distributed. As data on the variation of soil properties become available, they can be readily incorporated via the methodology developed here. (Auth.)
International Nuclear Information System (INIS)
Kim, Gye Nam; Yang, Byeong IL; Moon, Jei Kwon; Lee, Kune Woo
2009-01-01
Vertical electrokintic-flushing remediation equipment was developed for the remediation of a radioactive soil near nuclear facilities. An optimum reagent was selected to decontaminate the radioactive soil near nuclear facilities with the developed vertical electrokintic-flushing remediation equipment, and the optimum remediation conditions were established to obtain a higher remediation efficiency. Namely, acetic acid was selected as an optimum reagent due to its higher remediation efficiency. When the electrokinetic remediation and the electrokinetic-flushing remediation results were compared, the removal efficiency of 4.6% and the soil waste solution volume of 1.5 times were increased in the electrokinetic remediation. When the potential gradient within an electrokinetic soil cell was increased by two times (4.0 V/cm), the removal efficiencies of Co 2+ and Cs + were increased by about 4.3%( Co 2+ : 98.9%, Cs + : 96.7%). Also, when the reagent concentration was increased from 0.01 M to 0.05 M, the removal efficiency of Co 2+ was increased but that of Cs + was decreased. Therefore, the optimum remediation conditions were that the acetic concentration was 0.01 M ∼ 0.05 M, the potential gradient was 4 V/cm, the injection of reagent 2.4 ml/g, and the remediation period was 20 days.
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.
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)
Energy Technology Data Exchange (ETDEWEB)
Leglu, D.; Mulot, R.; Khalathari, A.; Lafon, B.; Stanley, T.; Linton, M.
2012-03-15
In a first part, the author describes how people living in the contaminated area around Fukushima try to deal with the difficult and almost impossible decontamination of their houses, gardens, schools, and so on. The destruction of forests is planned as they concentrate radioactivity. Thousands of inhabitants must wear dosimeters. An article comments the caesium activity measurements. Several data and figures are presented: evacuation areas, radioactive emissions and releases, doses received by emergency personnel, size of areas to be decontaminated, impact on the Japanese energy sector, contamination rates for soils and seawater, decontamination and dismantling costs, health impacts. An article proposes an overview of the different methods which are implemented and tested by the Japanese for large scale decontamination
Ayabe, Yoshiko; Hijii, Naoki; Takenaka, Chisato
2017-09-01
We investigated whether local-scale decontamination (removal of the litter layer, superficial soil layer, and understory) in a secondary forest contaminated by the Fukushima nuclear power plant accident reduced 137 Cs contamination of the soil and litter. We also measured 137 Cs concentrations in plants and in the web-building spider Nephila clavata (Nephilidae: Arachnida), as an indicator species, to examine 137 Cs contamination in arthropods. One month after decontamination, the total 137 Cs contamination (soil + litter) was reduced by 20% (100 kBq·m -2 ) relative to that in an adjacent untreated (i.e., contaminated) area, which was however not statistically significant. Four months after decontamination, 137 Cs in the decontaminated area had increased to a level similar to those in the untreated area, and the air radiation dose in the decontaminated area was about 2.1 μSv·h -1 , significantly higher than that in the untreated area (1.9 μSv·h -1 ). This may have been attributed to a torrential rain event. Although no statistically significant reduction was observed, most spiders had a lower 137 Cs contamination than that before the decontamination. This implied that the decontamination may have reduced 137 Cs transfer from soil via litter to N. clavata through the detrital food chains, but may not have reduced the amount of 137 Cs transfer through grazing food chains because the concentration of 137 Cs in living tree leaves was not reduced by the decontamination. In autumn, about 2 kBq·m -2 of 137 Cs was supplied from foliage to the ground by litterfall. The results suggested that removal of the litter and superficial soil layers in a contaminated forest may be ineffective. The present study suggests that the local-scale decontamination in a secondary forest had no effect on the reduction of 137 Cs contamination in the treated area. Copyright © 2017 Elsevier Ltd. All rights reserved.
Chen, A; Lin, C; Lu, W; Ma, Y; Bai, Y; Chen, H; Li, J
2010-03-15
A column leaching experiment was conducted to investigate the chemical dynamics of the percolating water and washed soil during decontamination of an acidic mine water-polluted soil. The results show that leaching of the contaminated soil with clean water rapidly reduced soluble acidity and ion concentrations in the soils. However, only soil column was eliminated after 30 leaching cycles. It is likely that the stored acidity continues to be released to the percolating water over a long period of time. During the column leaching, dissolved Cu and Pb were rapidly leached out, followed by mobilization of colloidal Cu and Pb from the exchangeable and the oxide-bound fractions as a result of reduced ionic strength in the soil solution. The soluble Fe contained in the soil was rare, probably because the soil pH was not sufficiently low; marked mobility of colloidal Fe took place after the ionic strength of the percolating water was weakened and the mobilized Fe was mainly derived from iron oxides. In contrast with Cu, Pb and Fe, the concentration of leachate Zn and Mn showed a continuously decreasing trend during the entire period of the experiment. (c) 2009 Elsevier B.V. All rights reserved.
Monitoring of electrokinetic in-situ-decontamination
Energy Technology Data Exchange (ETDEWEB)
Goldmann, T. [INTUS Inst. fuer Technologie und Umweltschutz e.V., Berlin (Germany)
2001-07-01
The need for a monitoring system for in-situ soil decontamination is two-fold: Firstly, to ensure that remediation is attained and secondly to minimize costs and treatment time. A further reason is the potential risk of unexpected mobilization or chemical generation of hazardous compounds which could result in an extension of the contamination into other regions of soil, the ground water or the atmosphere. Electrokinetic in-situ decontamination is based on transport processes in the ground that proceed with relatively low velocity. This results in treatment times of several months. Since the transport processes can be described by a mathematical model, monitoring should always be combined with qualified mathematical processing. This makes it possible to estimate treatment time and costs to be expected. The challenge of in-situ monitoring is to identify relevant parameters describing the state of the ground. These parameters must be independent from influences like weather but they must be sensitive to changes of soil characteristics. In the case of electrokinetic soil remediation, probes and sensors must be resistant to influences of electric fields. The function of sensors or measuring systems can be disturbed or even damaged or destroyed by electric fields (for example by electro-corrosion). (orig.)
Urban Decontamination Experience at Pripyat Ukraine - 13526
Energy Technology Data Exchange (ETDEWEB)
Paskevych, Sergiy [Institute for Safety Problems of Nuclear Power Plants, National Academy of Sciences of Ukraine, 36 a Kirova str. Chornobyl, Kiev region, 07200 (Ukraine); Voropay, Dmitry [Federal State Unitary Enterprise ' Russian State Center of Inventory and Registration and Real Estate - Federal Bureau of Technical Inventory' , 37-2 Bernadsky Prospekt, Moscow Russia 119415 (Russian Federation); Schmieman, Eric [Battelle Memorial Institute, PO Box 999 MSIN K6-90, Richland, WA 99352 (United States)
2013-07-01
This paper describes the efficiency of radioactive decontamination activities of the urban landscape in the town of Pripyat, Ukraine. Different methods of treatment for various urban infrastructure and different radioactive contaminants are assessed. Long term changes in the radiation condition of decontaminated urban landscapes are evaluated: 1. Decontamination of the urban system requires the simultaneous application of multiple methods including mechanical, chemical, and biological. 2. If a large area has been contaminated, decontamination of local areas of a temporary nature. Over time, there is a repeated contamination of these sites due to wind transport from neighboring areas. 3. Involvement of earth-moving equipment and removal of top soil by industrial method achieves 20-fold reduction in the level of contamination by radioactive substances, but it leads to large amounts of waste (up to 1500 tons per hectare), and leads to the re-contamination of treated areas due to scatter when loading, transport pollutants on the wheels of vehicles, etc.. (authors)
Decontamination of abandoned sites. An introduction into the problems of land decontamination
International Nuclear Information System (INIS)
Kundt, K.
1991-01-01
Starting from a brief overview of the history of origin of soil and ground water pollution in Berlin and its surroundings by gas, chemical, and petroleum works, old landfills, manufactories of arms and ammunition as well as gasoline depots or sites of gasoline depots, the brochure describes the legal situation and procedure (list of 'intervention' values) and goes on to outline the situation regarding the ground under Berlin, existing pollutants, and methods for dealing with land contamination. In five abandoned sites (waste oil refinery, copper refinery, waste solvent treatment plant, asphalt factory and drugs factory), different methods for eliminating soil and ground water contamination were used. Their efficacy is assessed on the basis of their soil and pollutant-specific suitability; the decontamination achieved is indicated. (BBR) [de
International Nuclear Information System (INIS)
Jouve, A.
1997-01-01
This thesis deals with the radiological consequences of a nuclear accident through the radioactive contamination of the food chain and the subsequent countermeasures for decreasing the fluxes of radionuclides and decontaminating agricultural lands. After a brief summary of the radioprotection ground and context in case of a nuclear accident, this work surveys existing data on the fluxes of radionuclides in soils and from soil to plants. The research work focuses on both the prediction of the fluxes of radionuclides and possible countermeasures: the measurement of the bioavailability of radionuclides in the soil solution, its use in a mathematical expression to quantify the soil-to-plant transfer of caesium and strontium, and the perspectives of an innovative technique of soil decontamination. The obtained results show that based on 4 coefficients, it is possible to predict crop contamination within a 3 % confidence interval: the fluid solid distribution coefficient of radionuclides kd, the amount of chemical analogues of caesium and strontium, i.e. potassium and calcium, respectively, soil pH and a constant characterising the plant species that is concerned. However, it generally appears from soil to plant transfer studies that the reduction of the fluxes of radionuclides is not a promising way of radiological exposure mitigation after a nuclear accident. The work performed shows that it is more efficient to tackle the source of the contamination, i.e. decontaminate the soil. The proposed technique of soil scraping using a turf harvester appears to be the most advantageous among the tested options, for the decontamination of peat-bog meadows. (author)
Energy Technology Data Exchange (ETDEWEB)
Cerre, P; Mestre, E; Kerdelleau, J de [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)
1962-07-01
A study was made of factors such as frequency, intensity, and time in the case of steel and of cotton cloth contaminated by fission products. Results show that the method is only of value in the case of steel and that it is necessary to operate at an optimum frequency of 80 khz and with an intensity of at least 4 W/cm{sup 2}. The difficulty of proposing a valid explanation for the decontamination mechanism is discussed. (authors) [French] Apres un examen des donnees theoriques du probleme, les auteurs font une etude systematique des facteurs frequence, intensite et temps dans le cas de l'acier et des tissus de coton contamines par des produits de fission. Ils montrent que la methode n'est interessante que pour l'acier qu'il faut operer a la frequence optimale de 80 kHz avec une intensite d'au moins 4 W/cm{sup 2}. Ils concluent en insistant sur la difficulte de proposer une explication valable pour le mecanisme de decontamination. (auteurs)
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
Possinger, A. R.; Inagaki, T.; Bailey, S. W.; Kogel-Knabner, I.; Lehmann, J.
2017-12-01
Soil carbon (C) interaction with minerals and metals through surface adsorption and co-precipitation processes is important for soil organic C (SOC) stabilization. Co-precipitation (i.e., the incorporation of C as an "impurity" in metal precipitates as they form) may increase the potential quantity of mineral-associated C per unit mineral surface compared to surface adsorption: a potentially important and as yet unaccounted for mechanism of C stabilization in soil. However, chemical, physical, and biological characterization of co-precipitated SOM as such in natural soils is limited, and the relative persistence of co-precipitated C is unknown, particularly under dynamic environmental conditions. To better understand the relationships between SOM stabilization via organometallic co-precipitation and environmental variables, this study compares mineral-SOM characteristics across a forest soil (Spodosol) hydrological gradient with expected differences in co-precipitation of SOM with iron (Fe) and aluminum (Al) due to variable saturation frequency. Soils were collected from a steep, well-drained forest soil transect with low, medium, and high frequency of water table intrusion into surface soils (Hubbard Brook Experimental Forest, Woodstock, NH). Lower saturation frequency soils generally had higher C content, C/Fe, C/Al, and other indicators of co-precipitation interactions resulting from SOM complexation, transport, and precipitation, an important process of Spodosol formation. Preliminary Fe X-ray Absorption Spectroscopic (XAS) characterization of SOM and metal chemistry in low frequency profiles suggest co-precipitation of SOM in the fine fraction (soils showed greater SOC mineralization per unit soil C for low saturation frequency (i.e., higher co-precipitation) soils; however, increased mineralization may be attributed to non-mineral associated fractions of SOM. Further work to identify the component of SOM contributing to rapid mineralization using 13C
International Nuclear Information System (INIS)
Oh, Won Zin; Jung, Ki Jung; Lee, Byung Jik
1997-01-01
This paper describes the introduction to research reactor decommissioning plan at KAERI, the background of technology development and demonstration, and the current status of the system decontamination technology for TRIGA reactors, concrete decontamination and dust treatment technologies, wall ranging robot and graphic simulation of dismantling processes, soil decontamination and restoration technology, recycling or reuse technologies for radioactive metallic wastes, and incineration technology demonstration for combustible wastes. 9 figs
International Nuclear Information System (INIS)
Orcutt, J.A.
1982-08-01
Areas 11 and 13 of the Nevada Test Site (NTS) are contaminated with varying concentrations of Pu-239, 240 and Am-241. An investigation of a vacuum method of soil removal, the Cleanup and Treatment (CAT) test, was conducted over a 3-month period in the plutonium safety shot or Plutonium Valley portion of Area 11. Soil in Plutonium Valley is of the Aridisol Order. The surface 0 to 10 cm is a gravelly loam, and is strongly alkaline (pH 8.8). A large truck-mounted vacuum unit, rather than conventional earth-moving equipment, was used as the primary soil collection unit. Effectiveness of the vacuum method of soil removal was evaluated in relation to conventional earthmoving procedures, particularly in terms of volume reduction of removed soil achieved over conventional techniques. Radiological safety considerations associated with use of the vacuum unit were evaluated in relation to their impact on a full-scale land decontamination program. Environmental and operational impacts of devegetation with retention of root crowns or root systems were investigated. It is concluded that the CAT test was successful under difficult environmental conditions
International Nuclear Information System (INIS)
Schilk, A.J.; Knopf, M.A.
1994-07-01
W tested a high-energy beta scintillation sensor to evaluate its efficacy in continually characterizing washed soils moving on a conveyor belt at Fernald's Soil Decontamination Pilot Plant (SDPP). This sensor was originally developed for monitoring uranium-contaminated soils in the field. It has a multi-layer design that enables it to discriminate against lower-energy beta particles from natural sources. It can also distinguish, to some extent, gamma rays and cosmic-induced species. The sensor detects uranium activity indirectly, based on the assumption that secular equilibrium exists between the targeted radionuclide ( 234m Pa) and its parent ( 238 U). Several 1-h background counts were made at the SDPP each day of the evaluation period. The average background count rate was found to be comparable to that observed under previous laboratory conditions. Static runs were performed on soils from SDPP test runs No. 1 and No. 17 to determine the extent of any residual activity following the decontamination process. Soils were found to contain 158±30 pCi/g and 114±25 pCi/g of 234 Th- 234m Pa ( 238 U?), respectively. But the soils had considerable moisture, and concern existed that this moisture would act as an additional beta attenuator and thereby give results that were erroneously low. Therefore, a soil sample was baked overnight, and the hard-baked clay that resulted was ground into small fragments and counted. This sample was counted for 30 min as before, and the total activity was determined to be 313±44 pCi/g of 234 Th 234m Pa ( 238 U?). Based on the test No. 1 results, a dry-to-wet activity ratio of 1.98 has been established. Hence, if the moisture content of test No. 17 was equivalent to that of test No. 1, the actual 234 Th- 234m Pa ( 238 U?) activity level is expected to be approximately 226 pCi/g
International Nuclear Information System (INIS)
Lee, Jeong Ken; Park, Kwang Heon
2010-01-01
Due to the increasing price of oil and coal and the tightening of regulations on greenhouse gases, nuclear power plants will become a more important source of electricity. Therefore, the number of nuclear power plants will constantly increase over the world. However, nuclear power plants have a disadvantage: they generate radioactive waste. Among radioactive waste, heavy metals in soil have a special feature: they change the form of contamination depending on the types and sizes of the soil. Therefore, diverse methods have to be used for decontamination. The current methods used for decontaminating heavy metals in soil are the electrokinetic method, the biodegradation method, and soil washing. Since soil washing in particular creates many secondary wastes, the cost of decontaminating soil has increased. In this case supercritical carbon dioxide (scCO 2 ) was used to reduce the secondary waste, and is expected to lower the cost as well
Separation of radiocaesium in soil using electric osmosis
International Nuclear Information System (INIS)
Ohtake, Yoshinori; Satou, Yukihiko; Sueki, Keisuke; Nakatani, Kiyoharu
2012-01-01
The environmental soil in central east Japan had been contaminated with radioactive nuclide by the Fukushima Nuclear Power Plant accident. The contaminated soil has been a target for decontamination work. In this work, we attempted to decontaminate in soil using an electroendosmose phenomenon which applied direct-current in soil include heavy metals such as cadmium and nickel. We performed which the rates of migrations for non-radioactive Cs in bentonite were measured with ICP-MS and for radioactive Cs in soil were measured germanium semiconductor detector, respectively. It is obtained which performance of separation was achieved 85-90% of decontamination rate in varied bentonite with the concentration of caesium nitrate solution. However, it was found slightly decontamination from contaminated Fukushima soil. We were obtained which it was hardly the movement of Cs in actual soil. It will improve the method for Cs movement in an actual soil and consider the mechanism of Cs adsorption in bentonite and soil. (author)
Japan, one year after. In Fukushima, a decontamination by forced march
International Nuclear Information System (INIS)
Leglu, D.; Mulot, R.; Khalathari, A.; Lafon, B.; Stanley, T.; Linton, M.
2012-01-01
In a first part, the author describes how people living in the contaminated area around Fukushima try to deal with the difficult and almost impossible decontamination of their houses, gardens, schools, and so on. The destruction of forests is planned as they concentrate radioactivity. Thousands of inhabitants must wear dosimeters. An article comments the caesium activity measurements. Several data and figures are presented: evacuation areas, radioactive emissions and releases, doses received by emergency personnel, size of areas to be decontaminated, impact on the Japanese energy sector, contamination rates for soils and seawater, decontamination and dismantling costs, health impacts. An article proposes an overview of the different methods which are implemented and tested by the Japanese for large scale decontamination
1995 Phase 1 concrete sampling at the decontaminated 183-H basins
International Nuclear Information System (INIS)
Kramer, C.D.
1996-01-01
This report provides a consolidated reference for 1995 concrete sampling data associated with the Hanford Site's 183-H Solar Evaporation Basins (located at the Hanford Site in Richland, Washington). In 1995, the basins were decontaminated and dismantled. Sampling efforts began after completion of concrete decontamination efforts. Soil and water samples were collected and are described in chronological order in this report
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.
International Nuclear Information System (INIS)
Dev, H.
1994-01-01
Over the last nine years IIT Research Institute (IITRI) has been developing and testing the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. The vaporized contaminants, water vapor and air are recovered from the heated zone by means of a vacuum manifold system which collects gases from below surface as well as from the soil surface. A vapor barrier is used to prevent fugitive emissions of the contaminants and to control air infiltration to minimize dilution of the contaminant gases and vapors. The recovered gases and vapors are conveyed to an on site vapor treatment system for the clean up of the vent gases. Electrical energy is applied to the soil by forming an array of electrodes in the soil which are electrically interconnected and supplied with power. The electrodes are placed in drilled bore holes which are made through the contaminated zone. There are two versions of the in situ heating and soil treatment process: the f irst version is called the In Situ Radio Frequency (RF) Soil Decontamination Process and the second version is called the In Situ Electromagnetic (EM) Soil Decontamination Process. The first version, the RF Process is capable of heating the soil in a temperature range of 100 degrees to 400 degrees C. The soil temperature in the second version, the EM Process, is limited to the boiling point of water under native conditions. Thus the soil will be heated to a temperature of about 85 degrees to 95 degrees C. In this project IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site due to the fact that most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85 degrees to 95 degrees C
Energy Technology Data Exchange (ETDEWEB)
Dev, H.
1994-08-16
Over the last nine years IIT Research Institute (IITRI) has been developing and testing the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. The vaporized contaminants, water vapor and air are recovered from the heated zone by means of a vacuum manifold system which collects gases from below surface as well as from the soil surface. A vapor barrier is used to prevent fugitive emissions of the contaminants and to control air infiltration to minimize dilution of the contaminant gases and vapors. The recovered gases and vapors are conveyed to an on site vapor treatment system for the clean up of the vent gases. Electrical energy is applied to the soil by forming an array of electrodes in the soil which are electrically interconnected and supplied with power. The electrodes are placed in drilled bore holes which are made through the contaminated zone. There are two versions of the in situ heating and soil treatment process: the f irst version is called the In Situ Radio Frequency (RF) Soil Decontamination Process and the second version is called the In Situ Electromagnetic (EM) Soil Decontamination Process. The first version, the RF Process is capable of heating the soil in a temperature range of 100{degrees} to 400{degrees}C. The soil temperature in the second version, the EM Process, is limited to the boiling point of water under native conditions. Thus the soil will be heated to a temperature of about 85{degrees} to 95{degrees}C. In this project IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site due to the fact that most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85{degrees} to 95{degrees}C.
Energy Technology Data Exchange (ETDEWEB)
Francis, C. W.
1993-09-01
To address the management of uranium-contaminated soils at Fernald and other DOE sites, the DOE Office of Technology Development formed the Uranium in Soils Integrated Demonstration (USID) program. The USID has five major tasks. These include the development and demonstration of technologies that are able to (1) characterize the uranium in soil, (2) decontaminate or remove uranium from the soil, (3) treat the soil and dispose of any waste, (4) establish performance assessments, and (5) meet necessary state and federal regulations. This report deals with soil decontamination or removal of uranium from contaminated soils. The report was compiled by the USID task group that addresses soil decontamination; includes data from projects under the management of four DOE facilities [Argonne National Laboratory (ANL), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL), and the Savannah River Plant (SRP)]; and consists of four separate reports written by staff at these facilities. The fundamental goal of the soil decontamination task group has been the selective extraction/leaching or removal of uranium from soil faster, cheaper, and safer than current conventional technologies. The objective is to selectively remove uranium from soil without seriously degrading the soil`s physicochemical characteristics or generating waste forms that are difficult to manage and/or dispose of. Emphasis in research was placed more strongly on chemical extraction techniques than physical extraction techniques.
Electrochemical Decontamination of Painted and Heavily Corroded Metals
International Nuclear Information System (INIS)
Marczak, S.; Anderson, J.; Dziewinski, J.
1998-01-01
The radioactive metal wastes that are generated from nuclear fuel plants and radiochemical laboratories are mainly contaminated by the surface deposition of radioactive isotopes. There are presently several techniques used in removing surface contamination involving physical and chemical processes. However, there has been very little research done in the area of soiled, heavily oxidized, and painted metals. Researchers at Los Alamos National Laboratory have been developing electrochemical procedures for the decontamination of bare and painted metal objects. These methods have been found to be effective on highly corroded as well as relatively new metals. This study has been successful in decontaminating projectiles and shrapnel excavated during environmental restoration projects after 40+ years of exposure to the elements. Heavily corroded augers used in sampling activities throughout the area were also successfully decontaminated. This process has demonstrated its effectiveness and offers several advantages over the present metal decontamination practices of media blasting and chemical solvents. These advantages include the addition of no toxic or hazardous chemicals, low operating temperature and pressure, and easily scaleable equipment. It is in their future plans to use this process in the decontamination of gloveboxes destined for disposal as TRU waste
DEFF Research Database (Denmark)
Hansen, Henrik; Ottosen, Lisbeth M.; Laursen, Søren
1997-01-01
Transport numbers in different metal chloride solutions were estimated using the emf method for two ion-exchange membranes: Ionics CR67 HMR412 (cation-exchange membrane) and Ionics AR204 SXRA 7639 (anion-exchange membrane). The cation-exchange membrane was found to work nearly ideally for Na...... experiments taken as a simplified simulation of the electrokinetic decontamination method showed that it was possible to remove all ions in the simulated soil volume, with a sharp increase in the potential difference over the soil volume as a result, and that it was possible to control the metal content...
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)
Wada, Koji; Yoshikawa, Toru; Murata, Masaru
2012-01-01
This article describes occupational health measures for workers involved in decontamination of radioactive material discharged around Fukushima Dai-ichi Nuclear Power Plant after the explosions in 2011. Decontamination is performed by removing radioactive particles (mainly cesium) from surfaces of soil, grass and trees, and buildings. Measurement of radiation doses is necessary to reduce exposure, and to determine whether workers can work below dose limits. Protective equipment for decontamination is determined based on the concentration of radiation in contaminated soil and the exposure to dust. Health examinations by physicians are mandated for decontamination workers upon hiring and every 6 months. While there is no possibility of acute radiation injury from decontamination, workers may be anxious about the unclear effects of chronic low level radiation exposure on health. Measures to protect the decontamination workers are the top priority.
The costs and effectiveness of various decontamination procedures
International Nuclear Information System (INIS)
Robinson, C.A.; Haywood, S.M.; Brown, J.
1991-01-01
Knowledge of the cost and effectiveness of decontamination techniques is necessary to optimise the implementation of this countermeasure. These factors vary depending upon the nature of the land affected. There is a great deal of data available on the cost and efficacy of specific decontamination techniques on particular surfaces, but little information for combinations of techniques in real environments. This paper describes the preliminary stages of a project, in progress at the National Radiological Protection Board (NRPB), aimed at providing this information, for inner city, residential and rural areas. The efficacies of individual decontamination processes on specific surfaces were from the available literature. The NRPB EXPURT (EXPosure from Urban Radionuclide Transfer) compartmental model was used to determine the effectiveness of a number of representative decontamination programmes; each programme represents a combination of common decontamination techniques which may be applied to the various surfaces comprising an inner-city, residential or rural environment, ie, paving, walls, roofs and soil. The effectiveness of each programme was measured in terms of the reduction in dose, or dose rate, to an individual in that environment, taking account of the building characteristics, and the occupancy of the population in these buildings. The costs of each programme were derived, based on data available in current literature on the cost of the constituent decontamination techniques. Representative cost and effectiveness data are presented and their application is discussed
Hseu, Zeng-Yei; Huang, Yu-Tuan; Hsi, Hsing-Cheng
2014-09-01
When a contaminated site contains pollutants including both nonvolatile metals and Hg, one single remediation technology may not satisfactorily remove all contaminants. Therefore, in this study, chemical extraction and thermal treatment were combined as a remediation train to remove heavy metals, including Hg, from contaminated soil. A 0.2 M solution of ethylenediamine tetraacetic acid (EDTA) was shown to be the most effective reagent for extraction of considerable amounts of Cu, Pb, and Zn (> 50%). Hg removal was ineffective using 0.2 M EDTA, but thermogravimetric analysis suggested that heating to 550 degrees C with a heating rate of 5 degrees C/min for a duration of 1 hr appeared to be an effective approach for Hg removal. With the employment of thermal treatment, up to 99% of Hg could be removed. However executing thermal treatment prior to chemical extraction reduced the effectiveness of the subsequent EDTA extraction because nonvolatile heavy metals were immobilized in soil aggregates after the 550 degrees C treatment. The remediation train of chemical extraction followed by thermal treatment appears to remediate soils that have been contaminated by many nonvolatile heavy metals and Hg. Implications: A remediation train conjoining two or more techniques has been initialized to remove multiple metals. Better understandings of the impacts of treatment sequences, namely, which technique should be employed first on the soil properties and the decontamination efficiency, are in high demand. This study provides a strategy to remove multiple heavy metals including Hg from a contaminated soil. The interactions between thermal treatment and chemical extraction on repartitioning of heavy metals was revealed. The obtained results could offer an integrating strategy to remediate the soil contaminated with both heavy metals and volatile contaminants.
Decontamination of soil washing wastewater using solar driven advanced oxidation processes.
Bandala, Erick R; Velasco, Yuridia; Torres, Luis G
2008-12-30
Decontamination of soil washing wastewater was performed using two different solar driven advanced oxidation processes (AOPs): the photo-Fenton reaction and the cobalt/peroxymonosulfate/ultraviolet (Co/PMS/UV) process. Complete sodium dodecyl sulphate (SDS), the surfactant agent used to enhance soil washing process, degradation was achieved when the Co/PMS/UV process was used. In the case of photo-Fenton reaction, almost complete SDS degradation was achieved after the use of almost four times the actual energy amount required by the Co/PMS/UV process. Initial reaction rate in the first 15min (IR15) was determined for each process in order to compare them. Highest IR15 value was determined for the Co/PMS/UV process (0.011mmol/min) followed by the photo-Fenton reaction (0.0072mmol/min) and the dark Co/PMS and Fenton processes (IR15=0.002mmol/min in both cases). Organic matter depletion in the wastewater, as the sum of surfactant and total petroleum hydrocarbons present (measured as chemical oxygen demand, COD), was also determined for both solar driven processes. It was found that, for the case of COD, the highest removal (69%) was achieved when photo-Fenton reaction was used whereas Co/PMS/UV process yielded a slightly lower removal (51%). In both cases, organic matter removal achieved was over 50%, which can be consider proper for the coupling of the tested AOPs with conventional wastewater treatment processes such as biodegradation.
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
Decontamination of hydrocarbon contaminated soil
International Nuclear Information System (INIS)
Smith, A.J.
1991-01-01
This patent describes the method of treating hydrocarbon contaminated soil. It comprises forming the soil into a flowing particulate stream, forming an aqueous liquid mixture of water and treating substance that reacts with hydrocarbon to form CO 2 and water, dispersing the liquid mixture into the particulate soil stream to wet the particulate, allowing the substance to react with the wetted soil particulate to thereby form CO 2 and water, thereby the resultant soil is beneficially treated, the stream being freely projected to dwell at a level and then fall, and the dispersing includes spraying the liquid mixture into the projected stream at the dwell, the substance consisting of natural bacteria, and at a concentration level in the mixture of between 100 to 3,000 PPM of bacteria to water, the soil forming step including impacting the soil to reduce it to particles less than about 1 inches in cross dimension, and including forming the wetting particulate into a first layer on a surface to allow the substance to react
Decontamination process development for gravels contaminated with uranium
Energy Technology Data Exchange (ETDEWEB)
Kim, Gye Nam; Park, Uk Ryang; Kim, Seung Su; Kim, Won Suk; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2013-10-15
It is impossible to scrub gravels in a washing tank, because gravels sinks to the bottom of the washing tank. In addition, when electrokinetic decontamination technology is applied to gravels larger than 10 cm, the removal efficiency of uranium from the gravels is reduced, because electro-osmotic flux at the surface of the gravel in electrokinetic cell reduces owing to a reduction of the particle surface area attributable to large-sized gravel. The volume ratio of gravel larger than10 cm in total volume of the soil in KAERI was about 20%. Therefore, it is necessary to study the decontamination process of gravels contaminated with radionuclides. The optimum number of washings for contaminated gravels is considered to be two. In addition, the removal efficiency of contaminated gravel was not related to its weight. For an electrokinetic-electrodialytic decontamination period of 5 days, 10 days, 15 days, and 20 days, {sup 238}U in gravel was removed by about 42%, 64%, 74%, and 80%, respectively. The more the decontamination time elapsed, the greater the reduction of the removal efficiency ratio of {sup 238}U. The decontamination process for gravels was generated on the basis of the results of washing and electrokinetic electrodialtic experiments.
Soil-structure interaction analysis of NPP containments: substructure and frequency domain methods
International Nuclear Information System (INIS)
Venancio-Filho, F.; Almeida, M.C.F.; Ferreira, W.G.; De Barros, F.C.P.
1997-01-01
Substructure and frequency domain methods for soil-structure interaction are addressed in this paper. After a brief description of mathematical models for the soil and of excitation, the equations for dynamic soil-structure interaction are developed for a rigid surface foundation and for an embedded foundation. The equations for the frequency domain analysis of MDOF systems are provided. An example of soil-structure interaction analysis with frequency-dependent soil properties is given and examples of identification of foundation impedance functions and soil properties are presented. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Dessi, R. [Progemisa SpA, Cagliari (Italy); Fadda, S.; Peretti, R.; Zucca, A. [CSGM, Centro Studi Germinerari e Mineralurgici del CNR, Cagliari (Italy); Serci, A. [Digita, Dipt. di Geoingegneria e Tecnologie Ambientali, Cagliari (Italy)
2000-12-01
The soils in the neighbourhood of the Rio Montevecchio-Sitzerri, a stream that flows in the valley below the tailings pond of the Montevecchio-Levante mineral processing plant (SW Sardinia, Italy) are severely contaminated by heavy metals, to the extent that traditional land uses are compromised. Consequently urgent measures are needed both to abate the pollution at source and rehabilitate the contaminated land. This paper is concerned with the problem of soil decontamination using washing and leaching techniques. Laboratory experiments have been conducted in mechanically agitated reactors, using citric acid and acetic acid solutions and brine of hydrochloric acid and calcium chloride. The influence of both reagent concentration and solid-to-liquid ratio has been assessed, and in the most significant cases, the attack kinetics has been determined. The tests showed the brine to be the most effective for removing metals from the soils. Based on the findings of the investigations, the possibility of decontamination by heap leaching has been simulated in the laboratory using the column technique. [Italian] I suoi circostanti il Rio Montevecchio-Sitzerri, che scorre a valle del bacino di decantazione degli sterili dell'impianto di trattamento dei minerali di Montevecchio-Levante (Sardegna Centro-Occidentale), sono caratterizzati da un elevato contenuto di metalli pesanti, che ne pregiudicano gli usi tradizionali. Si rende percio' improrogabile sia la necessita' di intervenire sulle cause all'origine della contaminazione, sia di bonificare i suoli in questione al fine di recuperarli a nuovi usi. La memoria intende portare un contributo alle relative problematiche affrontando la possibilita' di decontaminazione mediante tecniche di lavaggio e lisciviazione. La sperimentazione di laboratorio e' stata condotta in reattori ad agitazione meccanica, utilizzando soluzioni con acido citrico, acido acetico ed una salamoia costituita da acido
A direct method for soil-structure interaction analysis based on frequency-dependent soil masses
International Nuclear Information System (INIS)
Danisch, R.; Delinic, K.; Marti, J.; Trbojevic, V.M.
1993-01-01
In a soil-structure interaction analysis, the soil, as a subsystem of the global vibrating system, exerts a strong influence on the response of the nuclear reactor building to the earthquake excitation. The volume of resources required for dealing with the soil have led to a number of different types of frequency-domain solutions, most of them based on the impedance function approach. These procedures require coupling the soil to the lumped-mass finite-element model of the reactor building. In most practical cases, the global vibrating system is analysed in the time domain (i.e. modal time history, linear or non-linear direct time-integration). Hence, it follows that the frequency domain solution for soil must be converted to an 'equivalent' soil model in the time domain. Over the past three decades, different approaches have been developed and used for earthquake analysis of nuclear power plants. In some cases, difficulties experienced in modelling the soil have affected the methods of global analysis, thus leading to approaches like the substructuring technique, e.g. 3-step method. In the practical applications, the limitations of each specific method must be taken into account in order to avoid unrealistic results. The aim of this paper is to present the recent development on an equivalent SDOF system for soil including frequency-dependent soil masses. The method will be compared with the classical 3-step method. (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.)
Finding radiation hot-spots for a private residence/decontamination manual
International Nuclear Information System (INIS)
Nishizawa, Kunihide
2012-01-01
Since the Fukushima Daiichi Nuclear Power Station accident, the radio-iodine and cesium analysis group of ad hoc committee of safety measures has investigated initial screening monitor of the soils and examined contamination and experienced decontamination works. Existence of hot-spots where Cs 137 is concentrated is confirmed. The report makes a manual to find such a hot-spot in a private residence and how the decontamination should be carried out. Particularly, the report provides the definite examples of hot-spots, for instances, a roof, an eaves trough (a gutter), a side drain (a ditch), dead leaves (withered grass), surface land, a wood block, etc. and how the decontamination should be confirmed and the dusts be collected and kept. (S. Ohno)
Decontamination and decommissioning technology tree and the current status of the technologies
Energy Technology Data Exchange (ETDEWEB)
Oh, Won Zin; Won, H.J.; Kim, G.N.; Lee, K.W.; Chol, W.K.; Jung, C.H.; Kim, C.J.; Kim, S.H.; Kwon, S.O.; Chung, C.M
2001-03-01
A technology tree diagram was developed on the basis of the necessary technologies applicable to the decontamination and decommissioning of nuclear facilities. The technology tree diagram is consist of 6 main areas such as characterization, decontamination, decommissioning and remote technology, radwaste management, site restoration, and decommissioning plan and engineering. Characterization is divided into 4 regions such as sampling and data collection, general characterization, chemical analysis and radiological analysis. Decontamination is also divided into 4 regions such as chemical decontamination, mechanical decontamination, the other decontamination technologies and new decontamination technologies. Decommissioning and remote technology area is divided into 4 regions such as cutting techniques, decommissioning technologies, new developing technologies and remote technologies. Radwaste management area is divided into 5 regions such as solid waste treatment, sludge treatment, liquid waste treatment, gas waste treatment and thermal treatment. Site restoration area is divided into 3 regions such as the evaluation of site contamination, soil decontamination and ground water decontamination. Finally, permission, decommissioning process, cost evaluation, quality assurance and the estimation of radionuclide inventory were mentioned in the decommissioning plan and engineering area. The estimated items for each technology are applicable domestic D and D facilities, D and D problem area and contamination/requirement, classification of D and D technology, similar technology, principle and overview of technology, status, science technology needs, implementation needs, reference and contact point.
Decontamination and decommissioning technology tree and the current status of the technologies
International Nuclear Information System (INIS)
Oh, Won Zin; Won, H. J.; Kim, G. N.; Lee, K. W.; Chol, W. K.; Jung, C. H.; Kim, C. J.; Kim, S. H.; Kwon, S. O.; Chung, C. M.
2001-03-01
A technology tree diagram was developed on the basis of the necessary technologies applicable to the decontamination and decommissioning of nuclear facilities. The technology tree diagram is consist of 6 main areas such as characterization, decontamination, decommissioning and remote technology, radwaste management, site restoration, and decommissioning plan and engineering. Characterization is divided into 4 regions such as sampling and data collection, general characterization, chemical analysis and radiological analysis. Decontamination is also divided into 4 regions such as chemical decontamination, mechanical decontamination, the other decontamination technologies and new decontamination technologies. Decommissioning and remote technology area is divided into 4 regions such as cutting techniques, decommissioning technologies, new developing technologies and remote technologies. Radwaste management area is divided into 5 regions such as solid waste treatment, sludge treatment, liquid waste treatment, gas waste treatment and thermal treatment. Site restoration area is divided into 3 regions such as the evaluation of site contamination, soil decontamination and ground water decontamination. Finally, permission, decommissioning process, cost evaluation, quality assurance and the estimation of radionuclide inventory were mentioned in the decommissioning plan and engineering area. The estimated items for each technology are applicable domestic D and D facilities, D and D problem area and contamination/requirement, classification of D and D technology, similar technology, principle and overview of technology, status, science technology needs, implementation needs, reference and contact point
The project of decontamination of Tominari primary school in date city, Fukushima prefecture
International Nuclear Information System (INIS)
Katsumi, Satsuki
2013-01-01
The previous principal reports his concerned decontamination process of the school, localizing at 60 km distance from Fukushima Nuclear Power Plant, after its Accident (Mar. 2011). The school was defined as one of 11 with >3.8 mc-Sv/h ambient dose necessary for decontamination by Japanese Ministry of Education, Culture, Sports, Science an Technology (MEXT). Measurements of the dose by Date City and MEXT started from April, which revealed that it was 3.3-5.5 mc-Sv/h at 1 m height of the schoolyard. Decontamination was done by weeding, then removal of the ground soil at 3 ) and spreading a new soil, resulting in the reduction of the dose to 0.75 mc-Sv/h at 50 cm height. Unexpectedly, the removed soil was buried for tentative storage by wrapping with Volclay tarpaulin in a 140 cm deep hole at the corner of the yard, which was a result of residents' disagreement with the scheduled estate. Decontamination of school circumstances was conducted in July by experts, PTA voluntary parents and applied volunteers with their repeated meetings involving the radiological explanation of even radiation units. The classroom ambient dose at 50 cm height was declined from 0.11 to 0.06 mc-Sv, pavements from 2-3 to 0.7-1.0, plantings from 3.7 to 0.7, and the bank between the yard and schoolhouse from 4-5 to 1-1.5. The swimming pool water was first purified with zeolite, which made its radiocesium level below the standard limit <50 Bq/L, then was released out, and the pool was filled with fresh city water (<7 Bq/L). The ambient dose 6-8 mc-Sv/h around the pool at 50 cm height was reduced to 0.7-0.8 after decontamination. The project finished within July. Now the decontamination is still under progress for the forest and resident's houses; pupils are enjoying lessons, swimming and sports; and the author looks back the successful importance of experts' easy explanation about radiology. (T.T)
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 Methods using Liquid/Supercritical CO2
International Nuclear Information System (INIS)
Park, Kwang Heon; Koh, Moon Sung; Yoon, Chung Hyun; Kim, Hong Doo; Kim, Hak Won
1994-01-01
A major problem of nuclear energy is the production of radioactive wastes. Needs for more environmentally favorable method to decontaminate radioactive contaminants make the use of liquid/supercritical CO2 as a solvent medium. In removing radioactive metallic contaminants under CO2 solvent, two methods - use of chelating ligands and that of water in CO2 emulsion - are possible. In the chelating ligand method, a combination of ligands that can make synergistic effects seems important. We discuss about the properties of microemulsion formed by F-AOT. By adding acid in water core, decontamination of metallic parts, soils were possible
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.)
Changes in Soil Fungal Community Structure with Increasing Disturbance Frequency.
Cho, Hyunjun; Kim, Mincheol; Tripathi, Binu; Adams, Jonathan
2017-07-01
Although disturbance is thought to be important in many ecological processes, responses of fungal communities to soil disturbance have been little studied experimentally. We subjected a soil microcosm to physical disturbance, at a range of frequencies designed to simulate ecological disturbance events. We analyzed the fungal community structure using Illumina HiSeq sequencing of the ITS1 region. Fungal diversity was found to decline with the increasing disturbance frequencies, with no sign of the "humpback" pattern found in many studies of larger sedentary organisms. There is thus no evidence of an effect of release from competition resulting from moderate disturbance-which suggests that competition and niche overlap may not be important in limiting soil fungal diversity. Changing disturbance frequency also led to consistent differences in community composition. There were clear differences in OTU-level composition, with different disturbance treatments each having distinct fungal communities. The functional profile of fungal groups (guilds) was changed by the level of disturbance frequency. These predictable differences in community composition suggest that soil fungi can possess different niches in relation to disturbance frequency, or time since last disturbance. Fungi appear to be most abundant relative to bacteria at intermediate disturbance frequencies, on the time scale we studied here.
International Nuclear Information System (INIS)
Tagawa, Akihiro
2012-01-01
The Japan Atomic Energy Agency decontaminated schools, playgrounds, swimming pools, and houses in nonevacuated, less-contaminated areas in Fukushima for environmental restoration. A small, 150 m 2 playground lot in the residential area was chosen for decontamination demonstration, which used routinely available tools and commodities to carry out the work. The surfaces of playground lot equipment, such as swings, slides, and horizontal iron bars, were completely decontaminated by brushing with water and/or detergent. Side gutters around the playground lot were cleaned by removing the mud and then brushed and washed with a high-pressure water jet (7 MPa). The air dose rate at the playground lot was dominated by radiation from the ground surface and adjacent surroundings, such as apartments and rice fields. Two or three centimeters of the surface soil contaminated with cesium was removed manually with shovels, hoes, and other gardening tools. This significantly reduced the average air dose rate of the entire playground lot from 1.5 μSv/h before decontamination to 0.6 μSv/h. These results showed that ground surface decontamination can contribute measurably to the reduction in air dose rate in relatively small areas in residential areas. (author)
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
Independent verification of plutonium decontamination on Johnston Atoll (1992--1996)
International Nuclear Information System (INIS)
Wilson-Nichols, M.J.; Wilson, J.E.; McDowell-Boyer, L.M.; Davidson, J.R.; Egidi, P.V.; Coleman, R.L.
1998-05-01
The Field Command, Defense Special Weapons Agency (FCDSWA) (formerly FCDNA) contracted Oak Ridge National Laboratory (ORNL) Environmental Technology Section (ETS) to conduct an independent verification (IV) of the Johnston Atoll (JA) Plutonium Decontamination Project by an interagency agreement with the US Department of Energy in 1992. The main island is contaminated with the transuranic elements plutonium and americium, and soil decontamination activities have been ongoing since 1984. FCDSWA has selected a remedy that employs a system of sorting contaminated particles from the coral/soil matrix, allowing uncontaminated soil to be reused. The objective of IV is to evaluate the effectiveness of remedial action. The IV contractor's task is to determine whether the remedial action contractor has effectively reduced contamination to levels within established criteria and whether the supporting documentation describing the remedial action is adequate. ORNL conducted four interrelated tasks from 1992 through 1996 to accomplish the IV mission. This document is a compilation and summary of those activities, in addition to a comprehensive review of the history of the project
Koff, Matthew D; Brown, Jeremiah R; Marshall, Emily J; O'Malley, A James; Jensen, Jens T; Heard, Stephen O; Longtine, Karen; O'Neill, Melissa; Longtine, Jaclyn; Houston, Donna; Robison, Cindy; Moulton, Eric; Patel, Hetal M; Loftus, Randy W
2016-08-01
BACKGROUND Healthcare provider hands are an important source of intraoperative bacterial transmission events associated with postoperative infection development. OBJECTIVE To explore the efficacy of a novel hand hygiene improvement system leveraging provider proximity and individual and group performance feedback in reducing 30-day postoperative healthcare-associated infections via increased provider hourly hand decontamination events. DESIGN Randomized, prospective study. SETTING Dartmouth-Hitchcock Medical Center in New Hampshire and UMass Memorial Medical Center in Massachusetts. PATIENTS Patients undergoing surgery. METHODS Operating room environments were randomly assigned to usual intraoperative hand hygiene or to a personalized, body-worn hand hygiene system. Anesthesia and circulating nurse provider hourly hand decontamination events were continuously monitored and reported. All patients were followed prospectively for the development of 30-day postoperative healthcare-associated infections. RESULTS A total of 3,256 operating room environments and patients (1,620 control and 1,636 treatment) were enrolled. The mean (SD) provider hand decontamination event rate achieved was 4.3 (2.9) events per hour, an approximate 8-fold increase in hand decontamination events above that of conventional wall-mounted devices (0.57 events/hour); Phand hygiene system was not associated with a reduction in healthcare-associated infections (odds ratio, 1.07 [95% CI, 0.82-1.40], P=.626). CONCLUSIONS The hand hygiene system evaluated in this study increased the frequency of hand decontamination events without reducing 30-day postoperative healthcare-associated infections. Future work is indicated to optimize the efficacy of this hand hygiene improvement strategy. Infect Control Hosp Epidemiol 2016;37:888-895.
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)
International Nuclear Information System (INIS)
Yamamoto, Atsushi; Yoshida, Shigeru; Okumura, Hiroshi; Inagaki, Masayo; Yamanishi, Hirokuni; Ito, Tetsuo; Furukawa, Michio
2015-01-01
The most effective and widespread method to decontaminate radioactive cesium from the Fukushima Daiichi Nuclear Power Plant Disaster was peeling topsoil. But the method had problems, such as large amounts of discarded soil and large-scale work. In nature, cyanobacteria formed biomats on the ground surface and facilitated peeling topsoil when the biomats dried. The cyanobacteria-facilitating peeling decontamination method utilized these cyanobacterial properties. Cyanobacteria are located all over Japan and 'local' cyanobacteria could be used for decontamination without introducing new species. Utilizing cyanobacteria could decrease the amount of discarded soil to about 30% and downsize the execution-scale to individual locations. Cyanobacterial biomats were easily cultivated, especially in rice fields, by maintaining wet conditions and exposure to 100 - 83% solar radiation. Shading by a thin net was helpful in maintaining an environment suitable for cyanobacteria. Nowadays, to prevent uptake of radioactive cesium into rice, K + is usually added to fertilizer in rice fields. The K + fertilization in rice fields might also enhance cyanobacterial capture of radioactive cesium, because high concentrations of K + enhanced cyanobacterial uptake of Cs + . Cyanobacteria could also mitigate the risk of radioactive cesium moving away from a decontaminating rice field. Therefore, the cyanobacteria-facilitating peeling decontamination method was proposed as an easy and safe 'D.I.Y.' method for both farmers and the environment. Besides, plowing rice fields with water before peeling improved the efficiency of this method, because plowing increased the radioactive cesium concentration in the topsoil. (author)
Cs+ and Sr2+ adsorption selectivity of zeolites in relation to radioactive decontamination
Directory of Open Access Journals (Sweden)
M.W. Munthali
2015-09-01
Full Text Available Zeolites are used as adsorbents of cationic elements in the radioactive decontamination process of water, soil and others. We determined Cs+ and Sr2+ adsorption selectivity of some zeolites to know effective zeolite species for the decontamination of radioactive Cs and Sr. A 30 mL mixed solution containing up to 15 mg L−1 of non-radioactive Cs+ or Sr+ and up to 0.50 M of Na+ or K+ was mixed with 0.5 g of Linde-type A, Na-P1, faujasite X, faujasite Y and mordenite. Among the zeolites, mordenite had the highest Cs+ adsorption selectivity, and the selectivity had no correlation to the cation exchange capacity (CEC of the zeolites. In contrast, Sr2+ adsorption selectivity of the zeolites positively correlated with the CEC of the zeolites; Linde-type A with the highest CEC showed the highest adsorption selectivity, and its adsorption rate was more than 99.9% even in the presence of 0.5 M K+. A simulated soil decontamination experiment of Cs from a Cs-retaining vermiculite by using mordenite and that of Sr from a Sr-retaining vermiculite by using Linde-type A showed decontamination rates of more than 90%.
International Nuclear Information System (INIS)
Sugiura, Hiroyuki; Kawano, Keisuke; Kayama, Yukihiko
2012-01-01
Measurement and decontamination of surface of trees and surrounding wooden structures contaminated by radioactive substance were studied in the gardens and public parks of Northern Fukushima Prefecture which experienced radioactive contamination due to the accident at the TEPCO's Fukushima Daiichi Nuclear Power Plant. The counts per minute (CPM) above the centre surface of wooden garden tables in open air were 1.5 times higher than those of garden benches and 9 times higher than that of a garden bench in the square gazebo. Decontamination of wooden garden benches by high-pressure washing was more effective than planing. The counts per minute (CPM) above the soil around garden trees increased by 1.2 times after high-pressure washing. Radioactivity counting rate did not decrease when the leaves fallen from zelocova trees were removed; however, they decreased by about half when soil cover was installed at the base of the trees. Clearly, the upper surfaces of garden trees and wooden surrounding structures were strongly contaminated by radioactive substances, and they should be decontaminated by high-pressure washing before removing the surface soil. (author)
International Nuclear Information System (INIS)
Hans, J.M. Jr.; Hurst, T.L.
1981-01-01
Gamma radiation surveys and residual radium 226 soil samples were taken as part of the decontamination activities of the former Shiprock uranium mill site in New Mexico. In order to facilitate the decontamination activities, the mill site and its contaminated environs were divided into 6 major areas. Extensive data are presented in 2 appendices of the pre- and post-decontamination gamma ray exposure rates made on mill site, and of radium 226 concentrations in surface soil samples. A training program established on the mill site by the Navajo Engineering and Construction Authority is described
History of decontamination after the Great East Japan Earthquake
International Nuclear Information System (INIS)
Omura, Takashi; Onodera, Hideaki; Morishita, Satoru; Kato, Sei
2015-01-01
The magnitude 9.0 earthquake (the Great East Japan Earthquake) hit Japan on March 11, 2011 brought tsunami hazard as well as a nuclear accident in addition to the seismic hazard. A wide area of the eastern Japan was contaminated by radioactive materials released from the Fukushima Daiichi Nuclear Power Plant of the Tokyo Electric Power Company. In response to the unprecedented situation of the radioactive pollution after the accident, the Act on Special Measures Concerning the Handling of Radioactive Pollution was enacted in August 2011. The Ministry of the Environment (MOE) has formulated a set of guidelines by the end of 2011 to provide information on how to store and manage contaminated waste. In addition, the MOE established 'The Policies for the Decontamination of Specific Areas (Decontamination Roadmap)' in January 2012. As a result, the radiation dose rate has decreased by approximately 46% in the residential area of Naraha town. The MOE will have been promoting decontamination and construction of interim storage facilities which are able to store and manage the removed soils and incineration ashes generated from decontamination works. (author)
Decontamination of radioactive contaminated protective wear using dry cleaning solvent
International Nuclear Information System (INIS)
Muthiah, Pushpa; Chitra, S.; Paul, Biplob
2013-01-01
Liquid waste generated by conventional decontamination of radioactive contaminated cotton protective wear using detergent affects the chemical treatment of the plant. To reduce the generation of aqueous detergent waste, dry cleaning of cotton protective wear, highly soiled with oil and grease towards decontamination was tried with organic solvents. Mineral turpentine oil (MTO) among various other organic solvents was identified as a suitable organic solvent. As MTO leaves characteristic odour on the cloth, various commercial fragrances for the removal of the odour were tried. Application of the optimised dry cleaning solvent and commercial fragrance was adopted in plant scale operation. (author)
Vandermoere, Frédéric
2008-04-01
This case study examines the hazard and risk perception and the need for decontamination according to people exposed to soil pollution. Using an ecological-symbolic approach (ESA), a multidisciplinary model is developed that draws upon psychological and sociological perspectives on risk perception and includes ecological variables by using data from experts' risk assessments. The results show that hazard perception is best predicted by objective knowledge, subjective knowledge, estimated knowledge of experts, and the assessed risks. However, experts' risk assessments induce an increase in hazard perception only when residents know the urgency of decontamination. Risk perception is best predicted by trust in the risk management. Additionally, need for decontamination relates to hazard perception, risk perception, estimated knowledge of experts, and thoughts about sustainability. In contrast to the knowledge deficit model, objective and subjective knowledge did not significantly relate to risk perception and need for decontamination. The results suggest that residents can make a distinction between hazards in terms of the seriousness of contamination on the one hand, and human health risks on the other hand. Moreover, next to the importance of social determinants of environmental risk perception, this study shows that the output of experts' risk assessments-or the objective risks-can create a hazard awareness rather than an alarming risk consciousness, despite residents' distrust of scientific knowledge.
Comparative review of techniques used for in situ remediation of contaminated soils
International Nuclear Information System (INIS)
Escusol Tomey, M.; Rodriguez Abad, R.
2014-01-01
Soil pollution may influence the geotechnical parameters of the soil itself, properties such as solid particle density or water within its pores. It may also vary its friction angle, modify its structure and texture, or change the properties of its constitutive minerals due to the inclusion of polluting components. For these reasons, soil decontamination is an important factor to consider in geotechnics. This work focuses on those soil decontamination techniques carried out in situ, since they allow to eliminate soil pollutants in a less invasive way than confinement, containment or ex situ remediation techniques, causing a minor soil alteration and, therefore, affecting less to its mechanical properties. These factors should be taken into account when carrying out a geotechnical performance on a previously decontaminated soil. (Author)
Solid Waste Decontamination by Thermal Desorption and Catalytic Oxidation Methods
Czech Academy of Sciences Publication Activity Database
Šolcová, Olga; Topka, Pavel; Soukup, Karel; Jirátová, Květa; Váňová, H.; Kaštánek, František
2014-01-01
Roč. 68, č. 9 (2014), s. 1279-1282 ISSN 0366-6352 R&D Projects: GA MPO FR-TI1/059 Institutional support: RVO:67985858 Keywords : thermal desorption * catalytic oxidation * soil decontamination Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.468, year: 2014
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)
Electrodialytic Remediation of Soil Polluted with Copper from Wood Preservation
DEFF Research Database (Denmark)
Ottosen, Lisbeth M.; Hansen, Henrik; Laursen, Søren
1997-01-01
The principle of electrodialytic soil remediation was tested in six experiments on a copper polluted loamy sand. It was possible to decontaminate from 1360 to below 40 mg of Cu/kg of dry soil......The principle of electrodialytic soil remediation was tested in six experiments on a copper polluted loamy sand. It was possible to decontaminate from 1360 to below 40 mg of Cu/kg of dry soil...
Tomei, M Concetta; Mosca Angelucci, Domenica; Ademollo, Nicoletta; Daugulis, Andrew J
2015-03-01
Solid phase extraction performed with commercial polymer beads to treat soil contaminated by chlorophenols (4-chlorophenol, 2,4-dichlorophenol and pentachlorophenol) as single compounds and in a mixture has been investigated in this study. Soil-water-polymer partition tests were conducted to determine the relative affinities of single compounds in soil-water and polymer-water pairs. Subsequent soil extraction tests were performed with Hytrel 8206, the polymer showing the highest affinity for the tested chlorophenols. Factors that were examined were polymer type, moisture content, and contamination level. Increased moisture content (up to 100%) improved the extraction efficiency for all three compounds. Extraction tests at this upper level of moisture content showed removal efficiencies ≥70% for all the compounds and their ternary mixture, for 24 h of contact time, which is in contrast to the weeks and months, normally required for conventional ex situ remediation processes. A dynamic model characterizing the rate and extent of decontamination was also formulated, calibrated and validated with the experimental data. The proposed model, based on the simplified approach of "lumped parameters" for the mass transfer coefficients, provided very good predictions of the experimental data for the absorptive removal of contaminants from soil at different individual solute levels. Parameters evaluated from calibration by fitting of single compound data, have been successfully applied to predict mixture data, with differences between experimental and predicted data in all cases being ≤3%. Copyright © 2014 Elsevier Ltd. All rights reserved.
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.
An underestimated role of precipitation frequency in regulating summer soil moisture
International Nuclear Information System (INIS)
Wu Chaoyang; Chen, Jing M; Pumpanen, Jukka; Cescatti, Alessandro; Marcolla, Barbara; Blanken, Peter D; Ardö, Jonas; Tang, Yanhong; Magliulo, Vincenzo; Georgiadis, Teodoro; Soegaard, Henrik; Cook, David R; Harding, Richard J
2012-01-01
Soil moisture induced droughts are expected to become more frequent under future global climate change. Precipitation has been previously assumed to be mainly responsible for variability in summer soil moisture. However, little is known about the impacts of precipitation frequency on summer soil moisture, either interannually or spatially. To better understand the temporal and spatial drivers of summer drought, 415 site yr measurements observed at 75 flux sites world wide were used to analyze the temporal and spatial relationships between summer soil water content (SWC) and the precipitation frequencies at various temporal scales, i.e., from half-hourly, 3, 6, 12 and 24 h measurements. Summer precipitation was found to be an indicator of interannual SWC variability with r of 0.49 (p < 0.001) for the overall dataset. However, interannual variability in summer SWC was also significantly correlated with the five precipitation frequencies and the sub-daily precipitation frequencies seemed to explain the interannual SWC variability better than the total of precipitation. Spatially, all these precipitation frequencies were better indicators of summer SWC than precipitation totals, but these better performances were only observed in non-forest ecosystems. Our results demonstrate that precipitation frequency may play an important role in regulating both interannual and spatial variations of summer SWC, which has probably been overlooked or underestimated. However, the spatial interpretation should carefully consider other factors, such as the plant functional types and soil characteristics of diverse ecoregions. (letter)
Thermal remediation of tar-contaminated soil and oil-contaminated gravel
International Nuclear Information System (INIS)
Anthony, E.J.; Wang, J.
2005-01-01
High temperature treatments are commonly considered for the decontamination of soil as they have the advantages of reliability, high capacity, and effective destruction of hazardous materials with reduced long-term liability. This paper examined the remediation of soil contaminated by coal tar as well as gravel contaminated by oil. Pilot plant studies were conducted using 2 representative incineration technologies: rotary kiln and fluidized bed. The coal tar contaminated soil had accumulated over a few decades at a calcination plant in western Canada. The soil was sticky and could not be handled by conventional feeding and combustion systems. Crushed lignite was mixed with the soil as an auxiliary fuel and to reduce stickiness. A pilot plant furnace was used to evaluate the potential of decontamination in a rotary calciner. An analysis of both a modelling study and the test results showed that complete decontamination could be achieved in the targeted calciner. The results suggested that energy recovery was also possible, which could in turn make the remediation process more cost-effective. Decontamination of oil-contaminated gravel was conducted with a pilot plant fluidized bed combustor to study the feasibility of using incineration technology in the remediation of gravel and debris contaminated by oil spills. Results indicated that the gravel was decontaminated with acceptable emission performance. It was concluded that the study will be valuable to the application of commercial incineration processes for the remediation of polluted soils. It was observed that the weathering of the oiled gravel lowered the rate of decontamination. A small amount of salt water resulted in lowered decontamination rates, which may be an important factor for situations involving the remediation of shoreline gravel contaminated by oil. 24 refs., 6 tabs., 7 figs
Sampling and decontamination plan for the Transuranic Storage Area--1/-R container storage unit
International Nuclear Information System (INIS)
Barry, G.A.
1992-11-01
This document describes the sampling and decontamination of the Transuranic Storage Area (TSA)-l/-R container storage area and the earthen-covered portion of the TSA-2 container storage unit at the Radioactive Waste Management Complex. Stored containers from the earthen-covered asphalt pads will be retrieved from the TSA-l/-R and TSA-2 container storage units. Container retrieval will be conducted under the TSA retrieval enclosure, a fabricated steel building to be constructed over the earthen-covered pad to provide containment and weather protection. Following container retrieval, the TSA retrieval enclosure will be decontaminated to remove radioactive and hazardous contamination. The underlying soils will be sampled and analyzed to determine whether any contaminated soils require removal
Gagliano-Candela, R; Cammarota, R
2000-01-01
The excessive content of toxic elements in the human environment is associated with the etiology of a number of diseases. Soils' pollutants decontamination regards the main industrialised countries. Heavy metals represent the main problem for soil pollution characterisation. The first approach for pollution evaluation is the determination of total metal concentration; the evaluation of their bioavailability is required for a correct knowledge of the environmental risk. In the present work is shown the procedure to evaluate the sites, which require decontamination and which need the following data: knowledge of the threshold for each metal in the soil and its range, chemical analysis of the components, determination of bioavailability and soil destination. The bioavailability is easily calculated by the procedure of aimed extractions.
Advanced remediation of uranium-contaminated soil.
Kim, S S; Han, G S; Kim, G N; Koo, D S; Kim, I G; Choi, J W
2016-11-01
The existing decontamination method using electrokinetic equipment after acidic washing for uranium-contaminated soil requires a long decontamination time and a significant amount of electric power. However, after soil washing, with a sulfuric acid solution and an oxidant at 65 °C, the removal of the muddy solution using a 100 mesh sieve can decrease the radioactivity of the remaining coarse soil to the clearance level. Therefore, only a small amount of fine soil collected from the muddy solution requires the electrokinetic process for its decontamination. Furthermore, it is found that the selective removal of uranium from the sulfuric washing solution is not obtained using an anion exchanger but rather using a cation exchanger, unexpectedly. More than 90% of the uranium in the soil washing solutions is adsorbed on the S-950 resin, and 87% of the uranium adsorbed on S-950 is desorbed by washing with a 0.5 M Na 2 CO 3 solution at 60 °C. Copyright © 2016 Elsevier Ltd. All rights reserved.
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
International Nuclear Information System (INIS)
Blum, W.E.H.; Wenzel, W.W.
1989-01-01
Natural radioactivity - half-lifes and radiation type of man-made nuclides, radionuclide behaviour in soils, effects on soil condition and soil functions are described. The only mode of decontamination is by decay and thus primarily dependent on the half-life of nuclides
International Nuclear Information System (INIS)
Silva, S. da; Teixeira, M.V.
1986-06-01
The general methods of surface decontamination used in laboratory and others nuclear installations areas, as well as the procedures for handling radioactive materials and surfaces of work are presented. Some methods for decontamination of body external parts are mentioned. The medical supervision and assistance are required for internal or external contamination involving or not lesion in persons. From this medical radiation protection decontamination procedures are determined. (M.C.K.) [pt
Reactive decontamination formulation
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.
Reynier, Nicolas; Blais, Jean-François; Mercier, Guy; Besner, Simon
2014-01-01
In this paper, flotation in acidic conditions and alkaline leaching soil washing processes were compared to decontaminate four soils with variable contamination with metals, pentachlorophenol (PCP), and polychlorodibenzo dioxins and furans (PCDD/F). The measured concentrations of the four soils prior treatment were between 50 and 250 mg/kg for As, 35 and 220mg/kg for Cr, 80 and 350mg/kg for Cu, and 2.5 and 30mg/kg for PCP. PCDD/F concentrations reached 1394, 1375, 3730, and 6289ng/kg for F1, S1, S2, and S3 soils, respectively. The tests were carried out with masses of 100g of soil (fraction 0-2 mm) in a 2 L beaker or in a 1 L flotation cell. Soil flotation in sulphuric acid for 1 h at 60 degreeC with three flotation cycles using the surfactant cocamidopropyl betaine (BW) at 1% allows the solubilization of metals and PCP with average removal yields of 85%, 51%, 90%, and 62% for As, Cr, Cu, and PCP, respectively. The alkaline leaching for 2 h at 80 degreeC solubilizes As, Cr, Cu, and PCP with average removal yields of 60%, 32%, 77%, and 87%, respectively. Tests on PCDD/F solubilization with different surfactants were carried out in combination with the alkaline leaching process. PCDD/F removal yields of 25%, 72%, 70%, and 74% for F1, S1, S2, and S3 soils, respectively, were obtained using the optimized conditions.
International Nuclear Information System (INIS)
Obi, C.M.
2000-01-01
The Area 25 Reactor Maintenance, Assembly, and Disassembly Decontamination Facility is identified in the Federal Facility Agreement and Consent Order (FFACO) as Corrective Action Unit (CAU) 254. CAU 254 is located in Area 25 of the Nevada Test Site and consists of a single Corrective Action Site CAS 25-23-06. CAU 254 will be closed, in accordance with the FFACO of 1996. CAU 254 was used primarily to perform radiological decontamination and consists of Building 3126, two outdoor decontamination pads, and surrounding soil within an existing perimeter fence. The site was used to decontaminate nuclear rocket test-car hardware and tooling from the early 1960s through the early 1970s, and to decontaminate a military tank in the early 1980s. The site characterization results indicate that, in places, the surficial soil and building materials exceed clean-up criteria for organic compounds, metals, and radionuclides. Closure activities are expected to generate waste streams consisting of nonhazardous construction waste. petroleum hydrocarbon waste, hazardous waste, low-level radioactive waste, and mixed waste. Some of the wastes exceed land disposal restriction limits and will require off-site treatment before disposal. The recommended corrective action was revised to Alternative 3- ''Unrestricted Release Decontamination, Verification Survey, and Dismantle Building 3126,'' in an addendum to the Correction Action Decision Document
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
Magalhães, S M C; Ferreira Jorge, R M; Castro, P M L
2009-10-30
Bioventing has emerged as one of the most cost-effective in situ technologies available to address petroleum light-hydrocarbon spills, one of the most common sources of soil pollution. However, the major drawback associated with this technology is the extended treatment time often required. The present study aimed to illustrate how an intended air-injection bioventing technology can be transformed into a soil vapour extraction effort when the air flow rates are pushed to a stripping mode, thus leading to the treatment of the off-gas resulting from volatilisation. As such, a combination of an air-injection bioventing system and a biotrickling filter was applied for the treatment of contaminated soil, the latter aiming at the treatment of the emissions resulting from the bioventing process. With a moisture content of 10%, soil contaminated with toluene at two different concentrations, namely 2 and 14 mg g soil(-1), were treated successfully using an air-injection bioventing system at a constant air flow rate of ca. 0.13 dm(3) min(-1), which led to the removal of ca. 99% toluene, after a period of ca. 5 days of treatment. A biotrickling filter was simultaneously used to treat the outlet gas emissions, which presented average removal efficiencies of ca. 86%. The proposed combination of biotechnologies proved to be an efficient solution for the decontamination process, when an excessive air flow rate was applied, reducing both the soil contamination and the outlet gas emissions, whilst being able to reduce the treatment time required by bioventing only.
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.
Personnel protective equipment total-encapsulating suit decontamination study using shower systems
International Nuclear Information System (INIS)
Menkhaus, D.E.
1991-01-01
This report documents an experimental evaluation, conducted at the Idaho National Engineering Laboratory, of a shower-based decontamination station for personnel wearing a Level A, total- encapsulating, chemical-protective suit. The decontamination station is used by personnel when egressing a dry, dusty environment contaminated with transuranic radionuclides. This system has the potential to minimize the risk of spreading the contaminants to clean areas. Two types of shower systems were evaluated, a drench shower and a multi-nozzle shower. A total-encapsulating suit, worn by personnel. was contaminated with soil containing 239 Pu. Pre- shower and post-shower contamination samples were collected and visual observations were made to evaluate the ability of the shower system to remove the contaminated dust and to obtain baseline data useful in designing a shower-based personnel decontamination system. 12 figs., 7 tabs
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)
Screening for the next generation heavy metal hyperaccumulators for dryland decontamination
Ravanbakhsh, Mohammadhossein; Ronaghi, Abdol Majid; Taghavi, Seyed Mohsen; Jousset, Alexandre
2016-01-01
Heavy metal removal by plants bears a great potential to decontaminate soils. A major challenge remains to find plant species that accumulate heavy metal, harbor a sufficient biomass and grow in the desired environmental conditions. Here we present candidate plants for phytoremediation in arid
Removal of uranium from uranium-contaminated soils -- Phase 1: Bench-scale testing
International Nuclear Information System (INIS)
Francis, C.W.
1993-09-01
To address the management of uranium-contaminated soils at Fernald and other DOE sites, the DOE Office of Technology Development formed the Uranium in Soils Integrated Demonstration (USID) program. The USID has five major tasks. These include the development and demonstration of technologies that are able to (1) characterize the uranium in soil, (2) decontaminate or remove uranium from the soil, (3) treat the soil and dispose of any waste, (4) establish performance assessments, and (5) meet necessary state and federal regulations. This report deals with soil decontamination or removal of uranium from contaminated soils. The report was compiled by the USID task group that addresses soil decontamination; includes data from projects under the management of four DOE facilities [Argonne National Laboratory (ANL), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL), and the Savannah River Plant (SRP)]; and consists of four separate reports written by staff at these facilities. The fundamental goal of the soil decontamination task group has been the selective extraction/leaching or removal of uranium from soil faster, cheaper, and safer than current conventional technologies. The objective is to selectively remove uranium from soil without seriously degrading the soil's physicochemical characteristics or generating waste forms that are difficult to manage and/or dispose of. Emphasis in research was placed more strongly on chemical extraction techniques than physical extraction techniques
Solidification of metal oxide from electrokinetic-electrodialytic decontamination
Energy Technology Data Exchange (ETDEWEB)
Koo, Daeseo; Park, Uk-Ryang; Kim, Gye-Nam; Kim, Seung-Soo; Moon, Jei-Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2015-05-15
Electrokinectic-electrodialytic decontamination technology reduced 80% of the concentration of the uranium soil waste to below the concentration of self-disposal. After conducting electrokinectic-electrodialytic decontamination, more than 10% of the remainder of radioactive waste from the cathodes of electrokinectic-electrodialytic equipment were produced. To dispose of such waste, it is necessary to solidify second radioactive waste owing to the requirements of radioactive waste from public corporations. In this study, a solidification experiment was carried out using a polymer. At first, a sampling of second radioactive waste was conducted. Then, second radioactive waste and a polymer were mixed. Third, the solidified state between the second radioactive waste and polymer was checked. In our next study, an experiment for the requirements of a public radioactive waste corporation will be conducted.
An overview of plutonium-238 decontamination and decommissioning (D and D) projects at Mound
International Nuclear Information System (INIS)
Bond, W.H.; Davis, W.P.; Draper, D.G.; Geichman, J.R.; Harris, J.C.; Jaeger, R.R.; Sohn, R.L.
1987-01-01
Mound is currently decontaminating for restricted reuse and/or decommissioning for conditional release four major plutonium-238 contaminated facilities that contained 1700 linear feet of gloveboxes and associated equipment and services. Several thousand linear feet of external underground piping, associated tanks, and contaminated soil are being removed. Two of the facilities contain ongoing operations and will be reused for both radioactive and nonradioactive programs. Two others will be completely demolished and the land area will become available for future DOE building sites. An overview of the successful techniques and equipment used in the decontamination and decommissioning of individual pieces of equipment, gloveboxes, services, laboratories, sections of buildings, entire buildings, and external underground piping, tanks, and soil in a highly populated residential area is described and pictorially presented
International Nuclear Information System (INIS)
Allain, E.; Mignon, F.; Cessac, B.; Gallay, F.; Metivier, J.M.; Reales, N.; Gofette, R.; Mahot, M.
2004-01-01
From the beginning of 2002, Troyes prefecture has initiated a reflection about the management of a nuclear crisis caused by an accident at the Nogent-sur-Seine nuclear power plant. Five workshops have been created, dealing with the following themes: 'Administrative and economic organization', 'Health risk assessment and the epidemiology', 'Monitoring of environment', 'Movement in the contaminated area' and 'Decontamination of soil and Food chain'. The first results of the 'Decontamination of soil and Food chain' working group, which involves the District Agricultural and Forestry Department, the Farmer's Association, the Institute for Radiological Protection and Nuclear Safety and the Veterinary Division are presented in the poster. The scenario that had been developed for the accident considers the release of 3 radionuclides ( 131 I, 134 Cs and 137 Cs) in the environment. The scale of the crisis didn't require the evacuation and the sheltering of the population during the emergency phase. The consequences on the local agricultural products (cereal, beetroot, vine, milk, cow meat...) have been assessed up to 50 km and different strategies of agricultural countermeasures have been studied regarding to the local constraints (soil types, surfaces and quantities concerned) and to the consequences of their implementation (waste types and quantities, costs). Then, decision-making diagrams summed up the technical results and allowed to deepen the global thought. (author)
Statistical sampling method for releasing decontaminated vehicles
International Nuclear Information System (INIS)
Lively, J.W.; Ware, J.A.
1996-01-01
Earth moving vehicles (e.g., dump trucks, belly dumps) commonly haul radiologically contaminated materials from a site being remediated to a disposal site. Traditionally, each vehicle must be surveyed before being released. The logistical difficulties of implementing the traditional approach on a large scale demand that an alternative be devised. A statistical method (MIL-STD-105E, open-quotes Sampling Procedures and Tables for Inspection by Attributesclose quotes) for assessing product quality from a continuous process was adapted to the vehicle decontamination process. This method produced a sampling scheme that automatically compensates and accommodates fluctuating batch sizes and changing conditions without the need to modify or rectify the sampling scheme in the field. Vehicles are randomly selected (sampled) upon completion of the decontamination process to be surveyed for residual radioactive surface contamination. The frequency of sampling is based on the expected number of vehicles passing through the decontamination process in a given period and the confidence level desired. This process has been successfully used for 1 year at the former uranium mill site in Monticello, Utah (a CERCLA regulated clean-up site). The method forces improvement in the quality of the decontamination process and results in a lower likelihood that vehicles exceeding the surface contamination standards are offered for survey. Implementation of this statistical sampling method on Monticello Projects has resulted in more efficient processing of vehicles through decontamination and radiological release, saved hundreds of hours of processing time, provided a high level of confidence that release limits are met, and improved the radiological cleanliness of vehicles leaving the controlled site
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
Radiocesium decontamination of a riverside in Fukushima, Japan.
Nishikiori, Tatsuhiro; Suzuki, Satoshi
2017-10-01
Extensive decontamination measures have been implemented in the area affected by the Fukushima Dai-ichi nuclear disaster. Typical decontamination measures, such as removing topsoil of several centimeters in depth, are not suitable for rivers where contaminated sediments have been deposited. A decontamination measure was tested that considered the spatial distribution of radiocesium at the lower part of a tributary of the Abukuma River in Fukushima. The radiocesium distribution in the flood channel was vertically and horizontally highly heterogeneous. In some parts, the activity concentration was high (>10 kBq/kg for 137 Cs) even at depths of 25 cm in the sediment. This may be due to plant growth in the flood channel favoring the deposition of sediment with high activity concentration. On the basis of the radiocesium distribution, the flood channel sediment was removed to a depth of 15-35 cm, which accumulated the most radiocesium (>3.0 kBq/kg for the sum of 134 Cs and 137 Cs). The upper 5 cm of soil was removed from the dike slopes. The river bed was not decontaminated because the activity concentration was low (decontamination measure reduced the air dose rate by a factor of approximately two, demonstrating the effectiveness of our measures. Annual external doses were calculated for when this part of the dike and the flood channel is used for commuting to school and outdoor education. The doses during the activities at the test site accounted for only 1-2% of the value during daily life in the surrounding area, indicating that radiation exposure during riverside activities is limited. Copyright © 2017 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Fujinaka, Hiroyuki; Kubota, Mitsuru; Shibuya, Susumu; Kasai, Yoshimitsu
2013-01-01
The restore the normal life in the contaminated area, reconstruction of the infrastructure is necessary and early decontamination of roads and roadside slopes of highway are required. Decontamination work of roadside slopes is conducted only by hand working so far, but on the high and steep roadside slopes it is desirable to carry out decontamination work by an unmanned scraping machine to reduce working hours and improve safety. In this verification test, decontamination work of the roadside slope of highway, of which area was 20m W x 15m L and divided into two sections, was implemented by the machine or by hand, and working hours and radiation exposure dose were measured. As the results of the test, working hours and radiation exposure dose by the machine were 49% and 63% respectively compared to those by hand. Based on the results, cost and radiation dose for decontamination work on larger slopes were evaluated. Cost by the machine is estimated to be less than that by hand where the area is over 4,000m 2 . It is confirmed that the decontamination work of roadside slopes by the machine can be done more quickly and safely in comparison with hand working. (author)
Amin, Hira; Arain, Basir Ahmed; Abbasi, Muhammad Sadiq; Jahangir, Taj Muhammad; Amin, Farah
2018-02-01
Phytoextraction is a plant based-technique for removing toxic heavy metals from polluted soil. The experiment reported in this paper was undertaken to study the basic Cu phytoextraction potential of Sesamum indicum in comparison with Cyamopsis tetragonoloba for remediation of Cu contaminated soil in the framework of a pot-experiment. Plants were subjected to seven Cu concentrations (0, 25, 50, 100, 150, 200, and 300 mg kg-1 soil) for 12 weeks. The morphological (i.e. growth) and biochemical (i.e. chlorophyll) parameters of both the plant species were observed throughout the experimental period; the phytoextraction efficiency of S. indicum and C. tetragonoloba were also determined. Most growth parameters were reduced under high Cu stress. Our results shows that at low concentration (25 mg Cu kg-1) all the growth and biochemical parameters were increased but at elevated Cu concentrations, root length, shoot length, and biomass (fresh and dry) were all significantly decreased (p 1, bioaccumulation coefficient (BAC) > 1 and translocation factor (TF) > 1 established C. tetragonoloba as a potential candidate plant for the decontamination of slightly Cu-polluted soil where the growth of plants would not be impaired and the extraction of Cu could be maintained at satisfying levels. Therefore, the present study suggested that C. tetragonoloba could possibly be used as a viable tool for phytoextraction.
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.)
Removal of uranium from gravel using soil washing method
Energy Technology Data Exchange (ETDEWEB)
Kim, Ilgook; Kim, Kye-Nam; Kim, Seung-Soo; Choi, Jong-Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2015-10-15
The development of nuclear technology has led to increasing radioactive waste containing uranium being released and disposed in the nuclear sites. Fine grained soils with a size of less than 4 mm are normally decontaminated using soil washing and electro-kinetic technologies. However, there have been few studies on the decontamination of gravels with a size of more than 4 mm. Therefore, it is necessary to study the decontamination of gravel contaminated with radionuclides. The main objective of the present study on soil washing was to define the optimal condition for acid treatment of uranium-polluted gravel. In this study, soil washing method was applied to remove uranium from gravel. The gravel was crushed and classified as particle sizes. The gravel particles were treated with sulfuric acid in a shaking incubator at 60 .deg. C and 150 rpm for 3 h. The optimal particle size of gravel for soil washing in removal of uranium was between 0.45 and 2.0 mm.
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.
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)
International Nuclear Information System (INIS)
None
1997-01-01
OAK A271 Rockwell International Hot Laboratory decontamination and dismantlement interim progress report 1987-1996. The Rockwell International Hot Laboratory (RIHL) is one of a number of former nuclear facilities undergoing decontamination and decommissioning (D and D) at the Santa Susana Field Laboratory (SSFL). The RIHL facility is in the later stages of dismantlement, with the final objective of returning the site location to its original natural state. This report documents the decontamination and dismantlement activities performed at the facility over the time period 1988 through 1996. At this time, the support buildings, all equipment associated with the facility, and the entire above-ground structure of the primary facility building (Building 020) have been removed. The basement portion of this building and the outside yard areas (primarily asphalt and soil) are scheduled for D and D activities beginning in 1997
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)
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)
Tsujimura, Norio; Yoshida, Tadayoshi; Hoshi, Katsuya
To rationally judge the necessity of the contamination screening measurements required in the decontamination work regulations, a field study of the surface contamination density on the clothing of the workers engaged in decontamination operations was performed. The clothing and footwear of 20 workers was analyzed by high-purity germanium (HPGe) gamma-ray spectroscopy. The maximum radiocesium activities (134Cs + 137Cs) observed were 3600, 1300, and 2100 Bq for the work clothing, gloves, and boots, respectively, and the derived surface contamination densities were below the regulatory limit of 40 Bq/cm2. The results of this field study suggest that the upper bounds of the surface contamination density on the work clothing, gloves, and boots are predictable from the maximum soil loading density on the surface of clothing and footwear and the radioactivity concentration in soil at the site.
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.
Biofilm mediated decontamination of pollutants from the environment
Directory of Open Access Journals (Sweden)
Arindam Mitra
2016-01-01
Full Text Available In this review, we highlight beneficial use of microbial biofilms in remediation of environmental pollutants by bioremediation. Bioremediation is an environment friendly, cost effective, sustainable technology that utilizes microbes to decontaminate and degrade a wide variety of pollutants into less harmful products. Relative to free-floating planktonic cells, microbes existing in biofilm mode are advantageous for bioremediation because of greater tolerance to pollutants, environmental stress and ability to degrade varied harsh pollutants via diverse catabolic pathways. In biofilm mode, microbes are immobilized in a self-synthesized matrix which offers protection from stress, contaminants and predatory protozoa. Contaminants ranging from heavy metals, petroleum, explosives, pesticides have been remediated using microbial consortia of biofilms. In the industry, biofilm based bioremediation is used to decontaminate polluted soil and groundwater. Here we discuss conventional and newer strategies utilizing biofilms in environmental remediation.
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)
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.)
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
Modelling Mass Casualty Decontamination Systems Informed by Field Exercise Data
Directory of Open Access Journals (Sweden)
Richard Amlôt
2012-10-01
Full Text Available In the event of a large-scale chemical release in the UK decontamination of ambulant casualties would be undertaken by the Fire and Rescue Service (FRS. The aim of this study was to track the movement of volunteer casualties at two mass decontamination field exercises using passive Radio Frequency Identification tags and detection mats that were placed at pre-defined locations. The exercise data were then used to inform a computer model of the FRS component of the mass decontamination process. Having removed all clothing and having showered, the re-dressing (termed re-robing of casualties was found to be a bottleneck in the mass decontamination process during both exercises. Computer simulations showed that increasing the capacity of each lane of the re-robe section to accommodate 10 rather than five casualties would be optimal in general, but that a capacity of 15 might be required to accommodate vulnerable individuals. If the duration of the shower was decreased from three minutes to one minute then a per lane re-robe capacity of 20 might be necessary to maximise the throughput of casualties. In conclusion, one practical enhancement to the FRS response may be to provide at least one additional re-robe section per mass decontamination unit.
Combining different frequencies for electrical heating of saturated and unsaturated soil zones
Energy Technology Data Exchange (ETDEWEB)
Roland, U.; Holzer, F.; Kopinke, F.D. [Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Engineering, Leipzig (Germany)
2011-10-15
In situ electrical heating of soil was studied applying different frequencies: low-frequency energy for resistive heating and radio-frequency energy for dielectric heating. Steep temperature gradients were observed for each heating mode under the condition of the coexistence of saturated and unsaturated soil zones. By combining the two heating modes, this undesired effect can be avoided, thus allowing efficient soil remediation especially when organic phases are accumulated at the capillary fringe. A parallel application of both frequencies was demonstrated as the most suitable method to reduce temperature gradients. By using electronic filters, both electric fields can be established by only one electrode array. This innovative concept is especially applicable for optimizing thermal remediation of light non-aqueous phase liquid contaminations or realizing thermally-enhanced electrokinetic removal of heavy metals. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
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.)
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.)
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)
Transfer of radio-cesium from forest soil to woodchips using fungal activities
Kaneko, Nobuhiro; Huang, Yao; Tanaka, Yoichiro; Fujiwara, Yoshihiro; Sasaki, Michiko; Toda, Hiroto; Takahashi, Terumasa; Kobayashi, Tatsuaki; Harada, Naoki; Nonaka, Masahiro
2014-05-01
Raido-cesium released to terrestrial ecosystems by nuclear accidents is know to accumulate forest soil and organic layer on the soil. Forests in Japan are not exceptions. Practically it is impossible to decontaminate large area of forests. However, there is a strong demand from local people, who has been using secondary forests (Satoyama) around croplands in hilly areas, to decontaminate radio-cesium, because those people used to collect wild mushrooms and edible plants, and there are active cultures of mushrooms using logs and sawdusts. These natural resource uses consist substantial part of their economical activities, Therefore it is needed to decontaminate some selected part of forests in Japan to local economy. Clear cutting and scraping surface soil and organic matter are common methods of decontamination. However the efficiency of decontamination is up to 30% reduction of aerial radiation, and the cost to preserve contaminated debris is not affordable. In this study we used wood chips as a growth media for saprotrophic fungi which are known to accumulate redio-cesium. There are many studies indicated that mushrooms accumulated redio-cesium from forest soil and organic layer. It is not practical to collect mushrooms to decontaminate redio-cesium, because biomass of mushrooms are not enough to collect total contaminants. Mushrooms are only minor part of saprotrophic fungi. Fungal biomass in forest soil is about 1% of dead organic matter on forest floor. Our previous study to observe Cs accumulation to decomposing leaf litter indicated 18% absorption of total soil radio-Cs to litter during one year field incubation (Kaneko et al., 2013), and Cs concentration was proportional to fungal biomass on litter. This result indicated that fungi transferred radio-cesium around newly supplied leaf litter free of contamination. Therefore effective decontamination will be possible if we can provide large amount of growth media for saprotrophic fungi, and the media can be
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.)
Decommissioning and decontamination (burial ground stabilization) studies
International Nuclear Information System (INIS)
Cline, J.F.
1980-01-01
The decommissioning and decontamination of retired Hanford facilities and the future use of surrounding landscapes require isolation of contaminated wastes from the biosphere. Burial ground stabilization studies were conducted to determine the effectiveness of physical barriers for isolating contaminated wastes in shallow-land burial sites from plants and animals. This study was undertaken to determine the effectiveness of using a layer of loose rock between the waste and the surface soil covering to prevent both plant root and animal penetrations
Dwell time considerations for large area cold plasma decontamination
Konesky, Gregory
2009-05-01
Atmospheric discharge cold plasmas have been shown to be effective in the reduction of pathogenic bacteria and spores and in the decontamination of simulated chemical warfare agents, without the generation of toxic or harmful by-products. Cold plasmas may also be useful in assisting cleanup of radiological "dirty bombs." For practical applications in realistic scenarios, the plasma applicator must have both a large area of coverage, and a reasonably short dwell time. However, the literature contains a wide range of reported dwell times, from a few seconds to several minutes, needed to achieve a given level of reduction. This is largely due to different experimental conditions, and especially, different methods of generating the decontaminating plasma. We consider these different approaches and attempt to draw equivalencies among them, and use this to develop requirements for a practical, field-deployable plasma decontamination system. A plasma applicator with 12 square inches area and integral high voltage, high frequency generator is described.
Estimation of Soil Moisture Under Vegetation Cover at Multiple Frequencies
Jadghuber, Thomas; Hajnsek, Irena; Weiß, Thomas; Papathanassiou, Konstantinos P.
2015-04-01
Soil moisture under vegetation cover was estimated by a polarimetric, iterative, generalized, hybrid decomposition and inversion approach at multiple frequencies (X-, C- and L-band). Therefore the algorithm, originally designed for longer wavelength (L-band), was adapted to deal with the short wavelength scattering scenarios of X- and C-band. The Integral Equation Method (IEM) was incorporated together with a pedo-transfer function of Dobson et al. to account for the peculiarities of short wavelength scattering at X- and C-band. DLR's F-SAR system acquired fully polarimetric SAR data in X-, C- and L-band over the Wallerfing test site in Lower Bavaria, Germany in 2014. Simultaneously, soil and vegetation measurements were conducted on different agricultural test fields. The results indicate a spatially continuous inversion of soil moisture in all three frequencies (inversion rates >92%), mainly due to the careful adaption of the vegetation volume removal including a physical constraining of the decomposition algorithm. However, for X- and C-band the inversion results reveal moisture pattern inconsistencies and in some cases an incorrectly high inversion of soil moisture at X-band. The validation with in situ measurements states a stable performance of 2.1- 7.6vol.% at L-band for the entire growing period. At C- and X-band a reliable performance of 3.7-13.4vol.% in RMSE can only be achieved after distinct filtering (X- band) leading to a loss of almost 60% in spatial inversion rate. Hence, a robust inversion for soil moisture estimation under vegetation cover can only be conducted at L-band due to a constant availability of the soil signal in contrast to higher frequencies (X- and C-band).
International Nuclear Information System (INIS)
Tsujimura, Norio; Yoshida, Tadayoshi; Hoshi, Katsuya
2016-01-01
To rationally judge the necessity of the contamination screening measurements required in the decontamination work regulations, a field study of the surface contamination density on the clothing of the workers engaged in decontamination operations was performed. The clothing and footwear of 20 workers was analyzed by high-purity germanium (HPGe) gamma-ray spectroscopy. The maximum radiocesium activities ("1"3"4Cs + "1"3"7Cs) observed were 3600, 1300, and 2100 Bq for the work clothing, gloves, and boots, respectively, and the derived surface contamination densities were below the regulatory limit of 40 Bq/cm"2. The results of this field study suggest that the upper bounds of the surface contamination density on the work clothing, gloves, and boots are predictable from the maximum soil loading density on the surface of clothing and footwear and the radioactivity concentration in soil at the site. (author)
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
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)
International Nuclear Information System (INIS)
Ichikawa, Yujiro; Inoue, Tomohiro; Naito, Suekazu; Takahashi, Yoshihiko
2014-01-01
The efficacy of decontamination methods was evaluated with the measurement of 1cm dose equivalent rate and concentration of radioactive caesium in the soil, plants and water of the pond before and after decontamination at Japanese garden located in Chiba Prefectural Kashiwa-no-ha Park. Examined decontamination methods were: 1) The topsoil of walkway was stripped and removed to the depth of 10mm. 2) Washing the stone pavement walkway using high-pressure water jet washer. At the height of 50cm, we observed 45% and 36% of 1cm dose rate equivalent dose reduction rate (the natural dose rate derived from the ground was subtracted) for 1) and 2) decontamination methods respectively. Due to the decontamination process, the measurement value of 1cm equivalent dose rate decreased below 0.23μSv/h at most of the examined sites, which showed significant efficacy of decontamination methods performed at this Japanese garden. (author)
Impact of soil-structure interaction on the probabilistic frequency variation of concrete structures
International Nuclear Information System (INIS)
Hadjian, A.H.; Hamilton, C.W.
1975-01-01
Earthquake response of equipment in nuclear power plants is characterized by floor response spectra. Since these spectra peak at the natural frequencies of the structure, it is important, both from safety and cost standpoints, to determine the degree of the expected variability of the calculated structural frequencies. A previous work is extended on the variability of the natural frequencies of structures due to the variations of concrete properties and a rigorous approach is presented to evaluate frequency variations based on the probability distributions of both the structural and soil parameters and jointly determine the distributions of the natural frequencies. It is assumed that the soil-structure interaction coefficients are normally distributed. With the proper choice of coordinates, the simultaneous random variations of both the structural properties and the interaction coefficients can be incorporated in the eigenvalue problem. The key methodology problem is to obtain the probability distribution of eigenvalues of matrices with random variable elements. Since no analytic relation exists between the eigenvalues and the elements, a numerical procedure had to be designed. It was found that the desired accuracy can be best achieved by splitting the joint variation into two parts: the marginal distribution of soil variations and the conditional distribution of structural variations at specific soil fractiles. Then after calculating the actual eigenvalues at judiciously selected paired values of soil and structure parameters, this information is recombined to obtain the desired cumulative distribution of natural frequencies
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.)
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.)
Determining uranium speciation in Fernald soils by molecular spectroscopic methods
International Nuclear Information System (INIS)
Allen, P.G.; Berg, J.M.; Crisholm-Brause, C.J.; Conradson, S.D.; Donohoe, R.J.; Morris, D.E.; Musgrave, J.A.; Tait, C.D.
1994-07-01
This progress report describes new experimental results and interpretations for data collected from October 1, 1992, through September 30, 1993, as part of the Characterization Task of the Uranium in Soils Integrated Demonstration of the Office of Technology Development, Office of Environmental Restoration and Waste Management of the US Department of Energy. X-ray absorption, optical luminescence, and Raman vibrational spectroscopies were used to determine uranium speciation in contaminated soils from the US DOE's former uranium production facility at Fernald, Ohio. These analyses were carried out both before and after application of one of the various decontamination technologies being developed within the Integrated Demonstration. This year the program focused on characterization of the uranium speciation remaining in the soils after decontamination treatment. X-ray absorption and optical luminescence spectroscopic data were collected for approximately 40 Fernald soil samples, which were treated by one or more of the decontamination technologies
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)
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
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)
Decontamination of Radioactive Cesium Released from Fukushima Daiichi Nuclear Power Plant - 13277
Energy Technology Data Exchange (ETDEWEB)
Parajuli, Durga; Minami, Kimitaka; Tanaka, Hisashi; Kawamoto, Tohru [Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology - AIST (Japan)
2013-07-01
Peculiar binding of Cesium to the soil clay minerals remained the major obstacle for the immediate Cs-decontamination of soil and materials containing clay minerals like sludge. Experiments for the removal of Cesium from soil and ash samples from different materials were performed in the lab scale. For soil and sludge ash formed by the incineration of municipal sewage sludge, acid treatment at high temperature is effective while washing with water removed Cesium from ashes of plants or burnable garbage. Though total removal seems a difficult task, water-washing of wood-ash or garbage-ash at 40 deg. C removes >90% radiocesium, while >60% activity can be removed from soil and sludge-ash by acid washing at 95 deg. C. (authors)
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
International Nuclear Information System (INIS)
Suckel, R.A.
1984-11-01
This report describes the decontamination and decommissioning of the SPERT-I seepage pit. Prior to its decontamination and decommissioning, the seepage pit was surrounded by an earthen dike varying from 2 to 6 ft above the pit bottom. A 6-in., cast iron, underground waste line originated at the pit tank in the reactor building and ran approximately 68 ft to the seepage pit. The soil in the seepage pit contained low-level radioactive contamination. The soil surface was removed to a depth of 2.5 ft and shipped to the Radioactive Waste Management Complex (RWMC). The waste line that contained fixed contamination was removed and also sent to the RWMC. The pit was backfilled with radiologically clean soil, reducing the surface activity to background. A permanent marker was erected over the backfilled pit to indicate that presence of residual subsurface radioactive contamination. 5 references, 26 figures, 3 tables
Tromp-van Meerveld, I.; McDonnell, J.
2009-05-01
We present an assessment of electromagnetic induction (EM) as a potential rapid and non-invasive method to map soil moisture patterns at the Panola (GA, USA) hillslope. We address the following questions regarding the applicability of EM measurements for hillslope hydrological investigations: (1) Can EM be used for soil moisture measurements in areas with shallow soils?; (2) Can EM represent the temporal and spatial patterns of soil moisture throughout the year?; and (3) can multiple frequencies be used to extract additional information content from the EM approach and explain the depth profile of soil moisture? We found that the apparent conductivity measured with the multi-frequency GEM-300 was linearly related to soil moisture measured with an Aqua-pro capacitance sensor below a threshold conductivity and represented the temporal patterns in soil moisture well. During spring rainfall events that wetted only the surface soil layers the apparent conductivity measurements explained the soil moisture dynamics at depth better than the surface soil moisture dynamics. All four EM frequencies (7290, 9090, 11250, and 14010 Hz) were highly correlated and linearly related to each other and could be used to predict soil moisture. This limited our ability to use the four different EM frequencies to obtain a soil moisture profile with depth. The apparent conductivity patterns represented the observed spatial soil moisture patterns well when the individually fitted relationships between measured soil moisture and apparent conductivity were used for each measurement point. However, when the same (master) relationship was used for all measurement locations, the soil moisture patterns were smoothed and did not resemble the observed soil moisture patterns very well. In addition, the range in calculated soil moisture values was reduced compared to observed soil moisture. Part of the smoothing was likely due to the much larger measurement area of the GEM-300 compared to the Aqua
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
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
Czech Academy of Sciences Publication Activity Database
Heal, M. R.; Dickey, C. A.; Heal, K.V.; Stidson, R.T.; Matucha, Miroslav; Cape, J. N.
2010-01-01
Roč. 79, č. 4 (2010), s. 401-407 ISSN 0045-6535 Institutional research plan: CEZ:AV0Z50380511 Keywords : Trichloroacetic acid * TCA * Soil lysimeter Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides Impact factor: 3.155, year: 2010
McLauchlan, K. K.; Nelson, D. M.; Perakis, S.; Marcotte, A. L.
2017-12-01
Fire frequency is crucial for maintaining savannas in the transition between forests and grasslands. In general, increasing fire frequency has two effects: it increases herbaceous plant cover more than woody plant cover, and it lowers soil organic matter stocks. These effects have been demonstrated at a long-term prescribed fire experiment in an oak savanna ecosystem at Cedar Creek Ecosystem Science Reserve, Minnesota, U.S.A. The fire experiment began in 1964 and oak savannas are burned at various frequencies ranging from every year to not at all. This has led to changes in vegetation ranging from almost 100% grassland to 100% oak forest. Additionally, nitrogen stocks almost doubled in the sites that were not burned, as it accumulated in the trees, leaf litter, and soil. We addressed additional soil changes taking place at this experiment by asking the question: How have fire and oak-grass balance affected soil nutrients, specifically nitrogen and base cations? Surface soils were collected from 12 plots on the oak savanna burn experiment. Soils were collected in increments to 100 cm depth, from under grass-dominated vegetation and from under tree-dominated vegetation. We non-destructively estimated soil base cations by measuring elemental concentrations of dried soil subsamples with a handheld x-ray fluorescence analyzer. We also measured carbon and nitrogen concentrations and isotopic composition of the soil samples. Soils in plots with high fire frequency had higher concentrations of calcium than soils in unburned plots (low fire frequency). Similar trends were seen for soil potassium, magnesium, and phosphorus concentrations. In contrast, soils in plots with high fire frequency had dramatically lowered nitrogen cycling rates and stocks across the oak savanna. The contrast between the responses of different nutrients to changing fire frequency has important implications for the consequences of fire and tree-grass composition on nutrient cycling dynamics.
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)
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
Non-destructive decontamination of building materials
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.
Soil washing results for mixed waste pond soils at Hanford
International Nuclear Information System (INIS)
Gerber, M.A.; Freeman, H.D.; Baker, E.G.; Riemath, W.F.
1991-01-01
Soil washing technology was assessed as a means for remediating soil contaminated with mixed wastes primarily composed of heavy metals and radionuclides. The soils at the US Department of Energy's Hanford Site are considered suitable for soil washing because of their relatively low quantities of silt and clay. However, in a limited number of soil washing experiments using soils from different locations in the north pond of the 300 Area, the degree of decontamination achieved for the coarse fraction of the soil varied considerably. Part of this variation appears to be due to the presence of a discrete layer of contaminated sediment found in some of the samples
2015-06-19
decontamination strategies>> Maryline DEFEZ 1, Melissa HUNTER3J Susan WELKOS :~J Christopher COTE3 1 University Grenoble-Alpes, Grenoble, France. 1...inosine hydrolase and alanine racemase to enhance the germination of Bacillus anthracis Sterne spores potential spore decontamination strategies 5a...8217 • Accidentally in Humans • Natural reservoir is soil • Anthrax Disease Cycle: - animals infected by soilborne spores in food and water or bites from certain
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
Radiological decontamination, survey, and statistical release method for vehicles
International Nuclear Information System (INIS)
Goodwill, M.E.; Lively, J.W.; Morris, R.L.
1996-06-01
Earth-moving vehicles (e.g., dump trucks, belly dumps) commonly haul radiologically contaminated materials from a site being remediated to a disposal site. Traditionally, each vehicle must be surveyed before being released. The logistical difficulties of implementing the traditional approach on a large scale demand that an alternative be devised. A statistical method for assessing product quality from a continuous process was adapted to the vehicle decontamination process. This method produced a sampling scheme that automatically compensates and accommodates fluctuating batch sizes and changing conditions without the need to modify or rectify the sampling scheme in the field. Vehicles are randomly selected (sampled) upon completion of the decontamination process to be surveyed for residual radioactive surface contamination. The frequency of sampling is based on the expected number of vehicles passing through the decontamination process in a given period and the confidence level desired. This process has been successfully used for 1 year at the former uranium millsite in Monticello, Utah (a cleanup site regulated under the Comprehensive Environmental Response, Compensation, and Liability Act). The method forces improvement in the quality of the decontamination process and results in a lower likelihood that vehicles exceeding the surface contamination standards are offered for survey. Implementation of this statistical sampling method on Monticello projects has resulted in more efficient processing of vehicles through decontamination and radiological release, saved hundreds of hours of processing time, provided a high level of confidence that release limits are met, and improved the radiological cleanliness of vehicles leaving the controlled site
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
Disposal of decontaminated salts at the Savannah River Plant by solidification and burial
International Nuclear Information System (INIS)
Dukes, M.D.; Wolf, H.C.; Langton, C.A.
1983-01-01
The current plan for disposal of waste salt at the Savannah River Plant (SRP) is to immobilize the decontaminated salt solution by mixing with cement and SRP soil, and bury the resulting grout (saltstone) in a landfill. The grout which contains 37.8 wt % salt solution, 22.8 wt % Portland I-P cement, and 39.2 wt % SRP soil, was specially formulated to have a low permeability ( -10 cm/sec). This material will be mixed and placed in trenches. After setting, the saltstone will be covered with a clay cap, and an overburden of compacted native soil will be replaced. 6 references
Energy Technology Data Exchange (ETDEWEB)
Enokida, Y.; Tanada, Y.; Hirabayashi, D. [Graduate School of Engineering, 1 Furo-cho Nagoya-shi, Aichi-ken, 4648603 (Japan); Sawada, K. [EcoTopia Science Institute, Nagoya University, 1 Furo-cho Nagoya-shi, Aichi-ken, 4648603 (Japan)
2013-07-01
For the purpose of decontaminating radioactive cesium from a huge amount of soil, which has been estimated to be 1.2x10{sup 8} m{sup 3} by excavating to a 5-cm depth from the surface of Fukushima Prefecture where a severe nuclear accident occurred at TEPCO's power generating site and has emitted a significant amount of radioactive materials, mainly radioactive cesium, a wet sieving process was selected as one of effective methods available in Japan. Some private companies have demonstrated this process for soil treatment in the Fukushima area by testing at their plants. The results were very promising, and a full-fledged application is expected to follow. In the present study, we spiked several aqueous samples containing soil collected from an industrial wet sieving plant located near our university for the recycling of construction wastes with non-radioactive cesium hydroxide. The present study provides scientific data concerning the effectiveness in volume reduction of the contaminated soil by a wet sieving process as well as the cesium distribution between the liquid phase and clay minerals for each sub-process of the full-scale one, but a simulating plant equipped with a process of coagulating sedimentation and operational safety fundamentals for the plant. Especially for the latter aspect, the study showed that clay minerals of submicron size strongly bind a high content of cesium, which was only slightly removed by coagulation with natural sedimentation (1 G) nor centrifugal sedimentation (3,700 G) and some of the cesium may be transferred to the effluent or recycled water. By applying ultracentrifugation (257,000 G), most of submicron clay minerals containing cesium was removed, and the cesium amount which might be transferred to the effluent or recycled water, could be reduced to less than 2.3 % of the original design by the addition of a cesium barrier consisting of ultracentrifugation or a hollow fiber membrane. (authors)
Microbiological soil regeneration
International Nuclear Information System (INIS)
Behrens, D.; Wiesner, J.
1992-01-01
The Interdiciplinary Task Force ''Environmental Biotechnology - Soil'' of DECHEMA aims to pool the knowledge potential of the Dechema study committees on environmental biotechnology and soil protection with a view to the advancement of microbiological soil decontamination techniques. This conference volume on the 9th expert meeting of Dechema on environmental protection subjects entitled ''Microbiological Soil Regeneration'', held on February 27th and 28th, 1991, and the subsequent compilation of results give an intermediate account of the ongoing work of the Dechema Task Force. (orig.) [de
Chemical decontaminating method for stainless steel
International Nuclear Information System (INIS)
Onuma, Tsutomu; Akimoto, Hidetoshi.
1990-01-01
Radioactive metal wastes comprising passivated stainless steels are chemically decontaminated to such a radioactivity level as that of usual wastes. The present invention for chemically decontaminating stainless steels comprises a first step of immersing decontaminates into a sulfuric acid solution and a second step of immersing them into an aqueous solution prepared by adding oxidative metal salts to sulfuric acid, in which a portion of the surface of stainless steels as decontaminates are chemically ground to partially expose substrate materials and then the above-mentioned decontamination steps are applied. More than 90% of radioactive materials are removed in this method by the dissolution of the exposed substrate materials and peeling of cruds secured to the surface of the materials upon dissolution. This method is applicable to decontamination of articles having complicate shapes, can reduce the amount of secondary wastes after decontamination and also remarkably shorten the time required for decontamination. (T.M.)
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
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
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.)
Energy Technology Data Exchange (ETDEWEB)
Porcellini, A.; Talevi, N.; Marchetti-Rossi, M.T.; Palazzi, M.; Manna, A.; Sparaventi, G.; Delfini, C.; Valentini, M.
1987-11-01
To stimulate a leukemia remission marrow, cell suspensions of normal human bone marrow were mixed with human acute lymphoblastic or myelogenous leukemic cells of the CCRF-SF, Nalm-6, and K-562 lines. The cell mixtures were incubated in vitro with mafosfamide (AZ) or with the photoreactive dye merocyanine 540 (MC-540). A quantity of 10(4) cells of the treated suspensions was dispensed into microculture plates, and graded cell numbers of the line used to contaminate the normal marrow were added. Limiting-dilution analysis was used to estimate the frequency of leukemia cells persisting after treatment with the decontaminating agents. Treatment with AZ or MC-540 produced a total elimination (ie, 6 logs or 5.3 logs respectively) of B cell acute leukemia cells (CCRF-SB), whereas nearly 1.7 logs and 2 logs of K-562 acute myelogenous blasts were still present in the cell mixtures after treatment with MC-540 and AZ, respectively. Treatment of the Nalm-6-contaminated cell mixtures with AZ resulted in 100% elimination of clonogenic cells, whereas nearly 80% decontamination was obtained with MC-540. Our results suggest that treatment with AZ could be an effective method of eliminating clonogenic tumor cells from human bone marrow. MC-540, shown by previous studies to spare sufficient pluripotential stem cells to ensure hemopoietic reconstitution in the murine model and in clinical application, has comparable effects and merits trials for possible clinical use in autologous bone marrow transplantation.
International Nuclear Information System (INIS)
Porcellini, A.; Talevi, N.; Marchetti-Rossi, M.T.; Palazzi, M.; Manna, A.; Sparaventi, G.; Delfini, C.; Valentini, M.
1987-01-01
To stimulate a leukemia remission marrow, cell suspensions of normal human bone marrow were mixed with human acute lymphoblastic or myelogenous leukemic cells of the CCRF-SF, Nalm-6, and K-562 lines. The cell mixtures were incubated in vitro with mafosfamide (AZ) or with the photoreactive dye merocyanine 540 (MC-540). A quantity of 10(4) cells of the treated suspensions was dispensed into microculture plates, and graded cell numbers of the line used to contaminate the normal marrow were added. Limiting-dilution analysis was used to estimate the frequency of leukemia cells persisting after treatment with the decontaminating agents. Treatment with AZ or MC-540 produced a total elimination (ie, 6 logs or 5.3 logs respectively) of B cell acute leukemia cells (CCRF-SB), whereas nearly 1.7 logs and 2 logs of K-562 acute myelogenous blasts were still present in the cell mixtures after treatment with MC-540 and AZ, respectively. Treatment of the Nalm-6-contaminated cell mixtures with AZ resulted in 100% elimination of clonogenic cells, whereas nearly 80% decontamination was obtained with MC-540. Our results suggest that treatment with AZ could be an effective method of eliminating clonogenic tumor cells from human bone marrow. MC-540, shown by previous studies to spare sufficient pluripotential stem cells to ensure hemopoietic reconstitution in the murine model and in clinical application, has comparable effects and merits trials for possible clinical use in autologous bone marrow transplantation
Energy Technology Data Exchange (ETDEWEB)
Ouhadi, V.R., E-mail: vahidouhadi@yahoo.ca [Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Yong, R.N. [RNY Geoenvironmental Research, North Saanich (Canada); Shariatmadari, N. [Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Saeidijam, S.; Goodarzi, A.R.; Safari-Zanjani, M. [Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)
2010-01-15
While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of 'calcite or carbonate' (CaCO{sub 3}) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates.
International Nuclear Information System (INIS)
Ouhadi, V.R.; Yong, R.N.; Shariatmadari, N.; Saeidijam, S.; Goodarzi, A.R.; Safari-Zanjani, M.
2010-01-01
While the feasibility of using electrokinetics to decontaminate soils has been studied by several authors, the effects of soil composition on the efficiency of this method of decontamination has yet to be fully studied. This study focuses its attention on the effect of 'calcite or carbonate' (CaCO 3 ) on removal efficiency in electrokinetic soil remediation. Bench scale experiments were conducted on two soils: kaolinite and natural-soil of a landfill in Hamedan, Iran. Prescribed quantities of carbonates were mixed with these soils which were subsequently contaminated with zinc nitrate. After that, electrokinetic experiments were conducted to determine the efficiency of electrokinetic remediation. The results showed that an increase in the quantity of carbonate caused a noticeable increase on the contaminant retention of soil and on the resistance of soil to the contaminant removal by electrokinetic method. Because the presence of carbonates in the soil increases its buffering capacity, acidification is reduced, resulting in a decrease in the rate of heavy metal removed from the contaminant soil. This conclusion was validated by the evaluation of efficiency of electrokinetic method on a soil sample from the liner of a waste disposal site, with 28% carbonates.
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
Estimating decontamination efficiency of territory, adjoining to the Chernobyl' NPP
International Nuclear Information System (INIS)
Konstantinov, E.A.; Sanitarov, V.A.; Stepanov, I.K.; Senin, E.V.; Filippov, E.M.; Shiraj, A.P.; Umanets, M.P.
1989-01-01
The NPP territory decontamination was fulfilled according to the next scheme: 1) removal of the soil upper layer and its moving avay for burial; 2) concrete plate laying; 3) concreting seams between plates and piling up polymer coatings. The conclusion is made that substantial improvement of radiation situation at the operating site is possible only after removal of radiation sources at the machine room roofing. 1 ref.; 5 figs.; 2 tabs
Decontamination Data - Blister Agents
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...
Electrodialytic decontamination of heavy metal polluted soil
DEFF Research Database (Denmark)
Ottosen, Lisbeth M.; Hansen, Henrik K.; Karlsmose, Bodil
1996-01-01
Electrodialytic remediation of heavy metal polluted soil is a newly developed method, which combines the electrokinetic mevement of ions in soil with the principle of electrodialytis. The method has been proven to work in laboratory scale and at present two types of pilot plant tests are made....
Laboratory Experiment on Electrokinetic Remediation of Soil
Elsayed-Ali, Alya H.; Abdel-Fattah, Tarek; Elsayed-Ali, Hani E.
2011-01-01
Electrokinetic remediation is a method of decontaminating soil containing heavy metals and polar organic contaminants by passing a direct current through the soil. An undergraduate chemistry laboratory is described to demonstrate electrokinetic remediation of soil contaminated with copper. A 30 cm electrokinetic cell with an applied voltage of 30…
Soil washing results for mixed waste pond soils at Hanford
International Nuclear Information System (INIS)
Gerber, M.A.
1991-09-01
Soil washing technology was assessed as a means for remediating soil contaminated with mixed wastes primarily composed of heavy metals and radionuclides. The soils at the US Department of Energy's Hanford Site are considered suitable for soil washing because of their relatively low quantities of silt and clay. However, in a limited number of soil washing experiments using soils from different locations in the north pond of the 300 Area, the degree of decontamination achieved for the coarse fraction of the soil varied considerably. Part of this variation appears to be due to the presence of a discrete layer of contaminated sediment found in some of the samples. 7 refs., 2 figs., 4 tabs
Energy Technology Data Exchange (ETDEWEB)
Jouve, A. [CEA Centre d`Etudes Nucleaires de Cadarache, 13 -Saint-Paul-lez-Durance (France)]|[Universite de Provence, 13 - Marseille (France)
1997-12-31
This thesis deals with the radiological consequences of a nuclear accident through the radioactive contamination of the food chain and the subsequent countermeasures for decreasing the fluxes of radionuclides and decontaminating agricultural lands. After a brief summary of the radioprotection ground and context in case of a nuclear accident, this work surveys existing data on the fluxes of radionuclides in soils and from soil to plants. The research work focuses on both the prediction of the fluxes of radionuclides and possible countermeasures: the measurement of the bioavailability of radionuclides in the soil solution, its use in a mathematical expression to quantify the soil-to-plant transfer of caesium and strontium, and the perspectives of an innovative technique of soil decontamination. The obtained results show that based on 4 coefficients, it is possible to predict crop contamination within a 3 % confidence interval: the fluid solid distribution coefficient of radionuclides kd, the amount of chemical analogues of caesium and strontium, i.e. potassium and calcium, respectively, soil pH and a constant characterising the plant species that is concerned. However, it generally appears from soil to plant transfer studies that the reduction of the fluxes of radionuclides is not a promising way of radiological exposure mitigation after a nuclear accident. The work performed shows that it is more efficient to tackle the source of the contamination, i.e. decontaminate the soil. The proposed technique of soil scraping using a turf harvester appears to be the most advantageous among the tested options, for the decontamination of peat-bog meadows. (author).
Energy Technology Data Exchange (ETDEWEB)
Jouve, A [CEA Centre d` Etudes Nucleaires de Cadarache, 13 -Saint-Paul-lez-Durance (France); [Universite de Provence, 13 - Marseille (France)
1998-12-31
This thesis deals with the radiological consequences of a nuclear accident through the radioactive contamination of the food chain and the subsequent countermeasures for decreasing the fluxes of radionuclides and decontaminating agricultural lands. After a brief summary of the radioprotection ground and context in case of a nuclear accident, this work surveys existing data on the fluxes of radionuclides in soils and from soil to plants. The research work focuses on both the prediction of the fluxes of radionuclides and possible countermeasures: the measurement of the bioavailability of radionuclides in the soil solution, its use in a mathematical expression to quantify the soil-to-plant transfer of caesium and strontium, and the perspectives of an innovative technique of soil decontamination. The obtained results show that based on 4 coefficients, it is possible to predict crop contamination within a 3 % confidence interval: the fluid solid distribution coefficient of radionuclides kd, the amount of chemical analogues of caesium and strontium, i.e. potassium and calcium, respectively, soil pH and a constant characterising the plant species that is concerned. However, it generally appears from soil to plant transfer studies that the reduction of the fluxes of radionuclides is not a promising way of radiological exposure mitigation after a nuclear accident. The work performed shows that it is more efficient to tackle the source of the contamination, i.e. decontaminate the soil. The proposed technique of soil scraping using a turf harvester appears to be the most advantageous among the tested options, for the decontamination of peat-bog meadows. (author).
International Nuclear Information System (INIS)
Millar, J.S.; Pottmeyer, J.A.; Stratton, T.J.
1995-01-01
Purpose of the study was to estimate the amounts of equipment and other materials that are candidates for removal and subsequent processing in a solid waste facility when the Hanford Plutonium Finishing Plant is decontaminated and decommissioned. (Building structure and soil are not covered.) Results indicate that ∼5,500 m 3 of solid waste is expected to result from the decontamination and decommissioning of the Pu Finishing Plant. The breakdown of the volumes and percentages of waste by category is 1% dangerous solid waste, 71% low-level waste, 21% transuranic waste, 7% transuranic mixed waste
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)
Experience of soil rehabilitation in the scenario of Chernobyl
International Nuclear Information System (INIS)
Millan Gomez, R.; Ronero, L.; Jouve, A.
1996-01-01
The Chernobyl post-accident scenario became nowadays a natural radioecology laboratory, where a wide range of decontamination methods can be applied, validated or developed. This paper presents the application of a soil rehabilitation technique, the removal of vegetation and associated soil, in the experimental fields of Bourakovka and Chistogalovka surrounding the Chernobyl NPP. The results obtained have shown soil decontamination factors higher than 90% for caesium and strontium. This technique involves the removal of deposited hot particles released at the accident, and the experience allowed a detailed study of one of them corresponding to a nuclear fuel fragment, probably generated at the beginning of the breakdown. 16 refs. (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)
International Nuclear Information System (INIS)
Kawasaki, Kota
2016-01-01
This study discusses the current status and problems of decontamination by 52 municipalities out of 59 municipalities in Fukushima Prefecture, four and a half years after the Fukushima Daiichi Nuclear Power Plant accident, mainly based on the results of a questionnaire survey. The area corresponds to in all municipalities except for the 7 whose entire administrative area has been designated as Special Decontamination Area. This study reveals that (1) the number of municipalities which planned, ordered and implemented decontamination work has peaked although decontamination work of public facilities, housing, roads, farmland and forests has been still carried out in many municipalities, (2) about half of the municipalities have not secured enough temporary storage sites for contaminated soil and waste, (3) many municipalities recognize that construction of interim storage facilities, transfer of contaminated soil and waste from each municipality to interim storage facilities, and maintenance of temporary storage sites are major challenges concerning decontamination work, (4) about half of the municipalities regard efforts concerning decontamination work by the national government and the Fukushima prefectural government office as inadequate, (5) not a few municipalities recognize that residents cannot live their lives with a sense of safety and security unless air radiation dose is reduced to the level before the accident, and (6) most municipalities recognize that safe living environments can be recovered by decontamination work. Finally, based on these results, this study points out early completion of interim storage facilities and development of conditions to maintain and manage temporary storage sites, the end of decontamination work based on the air radiation dose rate, and establishment of decontamination policies concerning forests, rivers and waterways, as main future challenges concerning decontamination work by municipalities. (author)
International Nuclear Information System (INIS)
Sasaki, Kei; Okagawa, Masakazu; Takeno, Kenji; Shinkawa, Hidenori; Sasaki, Ken
2015-01-01
The soil pollution caused by radioactive substances released from the accident of TEPCO Fukushima Daiichi Nuclear Power Station has been still serious interference against agricultural reconstruction. This study used the soil contaminated with high radioactivity (13,602∼87,181 Bq/kg) in Namie Town, Fukushima Prefecture, and performed decontamination using photosynthetic bacteria in a simple outdoor practical test using a 60 L container. Using the soil after decontamination, the authors cultivated vegetables such as komatsuna (Japanese mustard spinach), and bok choy, the results of which are reported. As photosynthetic bacteria, Rhodobacter shaerodes SSI species was used. This paper describes the cultivation method of bacteria, preparation method of immobilization grain, decontamination method, and cultivation method of vegetables. As a result of the experiment, the decontamination efficient of the soil was between 59.5 to 73.3%, and cultured vegetables passed the edible reference value (edible criteria for infants: 50 Bq/kg FW), which was the success of the experiment. (A.O.)
International Nuclear Information System (INIS)
1995-08-01
This EA evaluates the proposed action to decontaminate and decommission GA's hot cell facility in northern San Diego, CA. This facility has been used for DOE and commercial nuclear R ampersand D for > 30 years. About 30,000 cubic feet of decontamination debris and up to 50,000 cubic feet of contaminated soil are to be removed. Low-level radioactive waste would be shipped for disposal. It was determined that the proposal does not constitute a major federal action significantly affecting the human environment according to NEPA; therefore, a finding of no significant impact is made, and an environmental impact statement is not required
Energy Technology Data Exchange (ETDEWEB)
NONE
1995-08-01
This EA evaluates the proposed action to decontaminate and decommission GA`s hot cell facility in northern San Diego, CA. This facility has been used for DOE and commercial nuclear R&D for > 30 years. About 30,000 cubic feet of decontamination debris and up to 50,000 cubic feet of contaminated soil are to be removed. Low-level radioactive waste would be shipped for disposal. It was determined that the proposal does not constitute a major federal action significantly affecting the human environment according to NEPA; therefore, a finding of no significant impact is made, and an environmental impact statement is not required.
International Nuclear Information System (INIS)
Nozaki, Atsuo; Kakuma, Takayuki; Narita, Yasunori; Yoshino, Hiroshi
2012-01-01
In present research, in order to clarify the actual condition of contamination, the radioactive concentration of the soil and the plant in Koriyama city was measured. It turned out that the radioactive concentration of soil or plants were heavily polluted by caesium-134 and 137, and iodine-131 was already disappeared by its lifetime. Especially, cesium-134 + 137 was ranged 3400 Bq/kg at the surface of soil in garden, however, it was remarkably decreased in the deeper point at 10 cm and ranged 23 Bq/kg, and we cannot detect the cesium at 15 cm. It is necessary for people in Fukushima to decontaminate for reducing radioactivity level. And it turned out that the evergreen plants have been polluted at high radioactive concentration and decontamination by cutting down the plant was decreased by 14% average. Most of radioactive material is removed by removing soils. (author)
Electrodialytic soil remediation enhanced by low frequency pulse current
DEFF Research Database (Denmark)
Sun, Tian R.; Ottosen, Lisbeth M.; Mortensen, John
2013-01-01
The effect of low frequency pulse current on decreasing the polarization and energy consumption during the process of electrodialytic soil remediation was investigated in the present work. The results indicated that the transportation of cations through the cation exchange membrane was the rate...
Microwave-Based Water Decontamination System
Arndt, G. Dickey (Inventor); Byerly, Diane (Inventor); Sognier, Marguerite (Inventor); Dusl, John (Inventor)
2016-01-01
A system for decontaminating a medium. The system can include a medium having one or more contaminants disposed therein. The contaminants can be or include bacteria, fungi, parasites, viruses, and combinations thereof. A microwave energy radiation device can be positioned proximate the medium. The microwave energy radiation device can be adapted to generate a signal having a frequency from about 10 GHz to about 100 GHz. The signal can be adapted to kill one or more of the contaminants disposed within the medium while increasing a temperature of the medium by less than about 10 C.
Long lasting decontamination foam
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 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
Decontamination manual of RI handling laboratory
International Nuclear Information System (INIS)
Wadachi, Yoshiki
2004-01-01
Based on experiences in Japan Atomic Energy Research Institute (JAERI), the essential and practical knowledge of radioactive contamination and its decontamination, and the method and procedure of floor decontamination are described for researcher and managing person in charge of handling radioisotopes (RI) in RI handling laboratories. Essential knowledge concerns the uniqueness of solid surface contamination derived from RI half lives and quantities, surface contamination density limit, and mode/mechanism of contamination. The principle of decontamination is a single conduct with recognition of chemical form of the RI under use. As the practical knowledge, there are physical and chemical methods of solid surface decontamination. The latter involves use of inorganic acids, chelaters and surfactants. Removal and replacement of contaminated solid like floor material are often effective. Distribution mapping of surface contamination can be done by measuring the radioactivity in possibly contaminated areas, and is useful for planning of effective decontamination. Floor surface decontamination is for the partial and spread areas of the floor. It is essential to conduct the decontamination with reagent from the highly to less contaminated areas. Skin decontamination with either neutral detergent or titanium oxide is also described. (N.I.)
Chemical decontamination: an overview
International Nuclear Information System (INIS)
Shaw, R.A.; Wood, C.J.
1985-01-01
The source of radioactive contamination in various types of power reactors is discussed. The methods of chemical decontamination vary with the manner in which the radioactive contaminants are deposited on the surface. Two types of dilute decontamination systems are available. One system uses organic acids and chelating agents, which are mildly reducing in nature. In this process, the oxide contaminants are removed by simple acidic dissolution and reductive dissolution. The second type of decontamination process is based on low oxidation state metal ions, which are more strongly reducing and do not require a corrosion inhibitor. All processes commercially available for decontamination of power reactors are not detailed here, but a few key issues to be considered in the selection of a process are highlighted. 2 figures, 2 tables
Energy Technology Data Exchange (ETDEWEB)
Baxter, Helen C; Richardson, Patricia R; Campbell, Gaynor A; Jones, Anita C; Baxter, Robert L [School of Chemistry, Joseph Black Chemistry Building, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ (United Kingdom); Kovalev, Valeri I; Maier, Robert; Barton, James S [School of Engineering and Physical Science, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); DeLarge, Greg [Plasma Etch Inc, 3522 Arrowhead Drive, Carson City, NV 89706 (United States); Casey, Mark [Sterile Services Department, Royal Infirmary of Edinburgh, Edinburgh EH16 4AS (United Kingdom)], E-mail: r.baxter@ed.ac.uk
2009-11-15
The development of methods for measuring the efficiency of gas-plasma decontamination has lagged far behind application. An approach to measuring the efficiency of protein removal from solid surfaces using fluorescein-labelled bovine serum albumin and epifluorescence scanning (EFSCAN) is described. A method for fluorescently labelling proteins, which are adsorbed and denatured on metal surfaces, has been developed. Both approaches have been used to evaluate the efficiency of radio frequency (RF) gas-plasma decontamination protocols. Examples with 'real' surgical instruments demonstrate that an argon-oxygen RF gas-plasma treatment can routinely reduce the protein load by about three orders of magnitude beyond that achieved by current decontamination methods.
International Nuclear Information System (INIS)
Baxter, Helen C; Richardson, Patricia R; Campbell, Gaynor A; Jones, Anita C; Baxter, Robert L; Kovalev, Valeri I; Maier, Robert; Barton, James S; DeLarge, Greg; Casey, Mark
2009-01-01
The development of methods for measuring the efficiency of gas-plasma decontamination has lagged far behind application. An approach to measuring the efficiency of protein removal from solid surfaces using fluorescein-labelled bovine serum albumin and epifluorescence scanning (EFSCAN) is described. A method for fluorescently labelling proteins, which are adsorbed and denatured on metal surfaces, has been developed. Both approaches have been used to evaluate the efficiency of radio frequency (RF) gas-plasma decontamination protocols. Examples with 'real' surgical instruments demonstrate that an argon-oxygen RF gas-plasma treatment can routinely reduce the protein load by about three orders of magnitude beyond that achieved by current decontamination methods.
Report on the Decontamination Site Tour in Fukushima Prefecture
International Nuclear Information System (INIS)
Knezevic, Z.; Miljanic, S.; Ranogajec-Komor, M.; Milkovic, D; Osvay, M.
2013-01-01
In the frame of Japanese-Croatian scientific-technical cooperation, our team visited Minamisoma city in Fukushima prefecture, Japan on Dec 3, 2012. The visit was organized for the foreign participants at the 8th International Workshop on Ionizing Radiation Monitoring held in Oarai, Japan. Minamisoma city is about 25 kilometres north from Fukushima Nuclear Power Plant. The city belonged to the evacuation zone and most of the residents were forced to leave immediately after the accident in 2011. In spring 2012 most of the people were able to return to their homes since dose rates were less than 20 mSv/y, the standard that Japanese government set as a temporary maximum radiation limit. Recently, a project of 'Decontaminating the Living Areas in Minamisoma City' was established. Enormous job has been carried out at the decontamination site (washing the houses, collection of soil, cutting trees, collecting the waste, etc). However, according to some experts, the cost-benefit effect of applied radiation protection principle is questionable. Our team with other participants visited one decontamination site and one temporary waste disposal site. After that a Satellite Meeting entitled 'What can be done for the reconstruction of Fukushima' was organized. In the discussion special attention was given to the public information and communication considering well known fear from radiation and its influence to the future of nuclear power program.(author)
Fire frequency drives decadal changes in soil carbon and nitrogen and ecosystem productivity
Pellegrini, Adam F. A.; Ahlström, Anders; Hobbie, Sarah E.; Reich, Peter B.; Nieradzik, Lars P.; Staver, A. Carla; Scharenbroch, Bryant C.; Jumpponen, Ari; Anderegg, William R. L.; Randerson, James T.; Jackson, Robert B.
2018-01-01
Fire frequency is changing globally and is projected to affect the global carbon cycle and climate. However, uncertainty about how ecosystems respond to decadal changes in fire frequency makes it difficult to predict the effects of altered fire regimes on the carbon cycle; for instance, we do not fully understand the long-term effects of fire on soil carbon and nutrient storage, or whether fire-driven nutrient losses limit plant productivity. Here we analyse data from 48 sites in savanna grasslands, broadleaf forests and needleleaf forests spanning up to 65 years, during which time the frequency of fires was altered at each site. We find that frequently burned plots experienced a decline in surface soil carbon and nitrogen that was non-saturating through time, having 36 per cent (±13 per cent) less carbon and 38 per cent (±16 per cent) less nitrogen after 64 years than plots that were protected from fire. Fire-driven carbon and nitrogen losses were substantial in savanna grasslands and broadleaf forests, but not in temperate and boreal needleleaf forests. We also observe comparable soil carbon and nitrogen losses in an independent field dataset and in dynamic model simulations of global vegetation. The model study predicts that the long-term losses of soil nitrogen that result from more frequent burning may in turn decrease the carbon that is sequestered by net primary productivity by about 20 per cent of the total carbon that is emitted from burning biomass over the same period. Furthermore, we estimate that the effects of changes in fire frequency on ecosystem carbon storage may be 30 per cent too low if they do not include multidecadal changes in soil carbon, especially in drier savanna grasslands. Future changes in fire frequency may shift ecosystem carbon storage by changing soil carbon pools and nitrogen limitations on plant growth, altering the carbon sink capacity of frequently burning savanna grasslands and broadleaf forests.
Cost studies of thermally enhanced in situ soil remediation technologies
International Nuclear Information System (INIS)
Bremser, J.; Booth, S.R.
1996-05-01
This report describes five thermally enhanced technologies that may be used to remediate contaminated soil and water resources. The standard methods of treating these contaminated areas are Soil Vapor Extraction (SVE), Excavate ampersand Treat (E ampersand T), and Pump ampersand Treat (P ampersand T). Depending on the conditions at a given site, one or more of these conventional alternatives may be employed; however, several new thermally enhanced technologies for soil decontamination are emerging. These technologies are still in demonstration programs which generally are showing great success at achieving the expected remediation results. The cost savings reported in this work assume that the technologies will ultimately perform as anticipated by their developers in a normal environmental restoration work environment. The five technologies analyzed in this report are Low Frequency Heating (LF or Ohmic, both 3 and 6 phase AC), Dynamic Underground Stripping (DUS), Radio Frequency Heating (RF), Radio Frequency Heating using Dipole Antennae (RFD), and Thermally Enhanced Vapor Extraction System (TEVES). In all of these technologies the introduction of heat to the formation raises vapor pressures accelerating contaminant evaporation rates and increases soil permeability raising diffusion rates of contaminants. The physical process enhancements resulting from temperature elevations permit a greater percentage of volatile organic compound (VOC) or semi- volatile organic compound (SVOC) contaminants to be driven out of the soils for treatment or capture in a much shorter time period. This report presents the results of cost-comparative studies between these new thermally enhanced technologies and the conventional technologies, as applied to five specific scenarios
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.)
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 evaluation based on radioactivity measurement instead of air dose rate
International Nuclear Information System (INIS)
Shozugawa, Katsumi
2013-01-01
Air dose rate at 1 m above the ground comes from gamma radiations emitted from vast area ranging over several ten meters of the contaminated field from the counter. After showing the actual example of the difference between air dose rate data and Cs 137 distribution map made by using a shielded NaI-scintillation counter within and around a contaminated sinkhole (a ditch or trench) near Fukushima Daiichi Nuclear Power Plants, the author proposes to make a decontamination program according to the radioactivity distribution measurement instead of air dose rate measurement. Furthermore, he explains some problems arising from a point and plane radiation source, and also difficulties accompanied by movement of Cs 137 atoms in the soils according to the absorption characteristics of the existing minerals but these are also important to consider for performing an effective decontamination. (S. Ohno)
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
Radiation survey and decontamination of cape Arza from depleted uranium
Directory of Open Access Journals (Sweden)
Vukotić Perko
2003-01-01
Full Text Available In the action of NATO A-10 airplanes in 1999, the cape Arza, Serbia and Montenegro was contaminated by depleted uranium. The clean-up operations were undertaken at the site, and 242 uranium projectiles and their 49 larger fragments were removed from the cape. That is about 85% of the total number of projectiles by which Arza was contaminated. Here are described details of the applied procedures and results of the soil radioactivity measurements after decontamination.
2014-01-01
SUMMARY There is increasing interest in the role of cleaning for managing hospital-acquired infections (HAI). Pathogens such as vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), multiresistant Gram-negative bacilli, norovirus, and Clostridium difficile persist in the health care environment for days. Both detergent- and disinfectant-based cleaning can help control these pathogens, although difficulties with measuring cleanliness have compromised the quality of published evidence. Traditional cleaning methods are notoriously inefficient for decontamination, and new approaches have been proposed, including disinfectants, steam, automated dispersal systems, and antimicrobial surfaces. These methods are difficult to evaluate for cost-effectiveness because environmental data are not usually modeled against patient outcome. Recent studies have reported the value of physically removing soil using detergent, compared with more expensive (and toxic) disinfectants. Simple cleaning methods should be evaluated against nonmanual disinfection using standardized sampling and surveillance. Given worldwide concern over escalating antimicrobial resistance, it is clear that more studies on health care decontamination are required. Cleaning schedules should be adapted to reflect clinical risk, location, type of site, and hand touch frequency and should be evaluated for cost versus benefit for both routine and outbreak situations. Forthcoming evidence on the role of antimicrobial surfaces could supplement infection prevention strategies for health care environments, including those targeting multidrug-resistant pathogens. PMID:25278571
Development of practical decontamination process for the removal of uranium from gravel.
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.
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.)
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.
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
Energy Technology Data Exchange (ETDEWEB)
Escusol Tomey, M.; Rodriguez Abad, R.
2014-07-01
Soil pollution may influence the geotechnical parameters of the soil itself, properties such as solid particle density or water within its pores. It may also vary its friction angle, modify its structure and texture, or change the properties of its constitutive minerals due to the inclusion of polluting components. For these reasons, soil decontamination is an important factor to consider in geotechnics. This work focuses on those soil decontamination techniques carried out in situ, since they allow to eliminate soil pollutants in a less invasive way than confinement, containment or ex situ remediation techniques, causing a minor soil alteration and, therefore, affecting less to its mechanical properties. These factors should be taken into account when carrying out a geotechnical performance on a previously decontaminated soil. (Author)
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)
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)
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.).
Heat transfer within a concrete slab applying the microwave decontamination process
International Nuclear Information System (INIS)
Li, W.; Ebadian, M.A.; White, T.L.; Grubb, R.G.
1993-01-01
Decontamination of a radioactive contaminated concrete surface is a new technology for the treatment of radioactive waste. In this paper, concrete decontamination using microwave technology is investigated theoretically. A plane wave assumption of microwave propagation has been employed to estimate the microwave field and power dissipation within the concrete. A one-dimensional, unsteady heat conduction model with microwave heat dissipation resulting from microwave-material interaction has been used to evaluate frequency, steel reinforcement within the concrete, and thermal boundary conditions are also considered in the present model. Four commonly used microwave frequencies of 0.896, 2.45, 10.6, and 18.0 GHz have been utilized in the analysis. The results revealed that as the microwave frequency increases to, or higher than 10.6 GHz, the microwave power dissipation shifts toward the front surface of the concrete. Furthermore, it was observed that use of a higher frequency microwave could reduce power intensity requirements needed to raise the temperature difference or thermal stress to the same value in the same period of time. It was found that the presence of reinforcing steel mesh causes part of the microwave energy to be blocked and reflected. Thus, the temperature or thermal stress of the concrete increases before the reinforcement, and decreases after the reinforcement. 16 refs., 6 figs., 3 tabs
Decontamination of electronic waste-polluted soil by ultrasound-assisted soil washing.
Chen, Fu; Yang, Baodan; Ma, Jing; Qu, Junfeng; Liu, Gangjun
2016-10-01
Laboratorial scale experiments were performed to evaluate the efficacy of a washing process using the combination of methyl-β-cyclodextrin (MCD) and tea saponin (TS) for simultaneous desorption of hydrophobic organic contaminants (HOCs) and heavy metals from an electronic waste (e-waste) site. Ultrasonically aided mixing of the field contaminated soil with a combination of MCD and TS solutions simultaneously mobilizes most of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and the analyte metal (Pb, Cu, and Ni) burdens. It is found that 15 g/L MCD and 10 g/L TS is an efficient reagent combination reconciling extraction performance and reagent costs. Under these conditions, the removal efficiencies of HOCs and heavy metals are 93.5 and 91.2 %, respectively, after 2 cycles of 60-min ultrasound-assisted washing cycles. By contrast, 86.3 % of HOCs and 88.4 % of metals are removed from the soil in the absence of ultrasound after 3 cycles of 120-min washing. The ultrasound-assisted soil washing could generate high removal efficiency and decrease the operating time significantly. Finally, the feasibility of regenerating and reusing the spent washing solution in extracting pollutants from the soil is also demonstrated. By application of this integrated technology, it is possible to recycle the washing solution for a purpose to reduce the consumption of surfactant solutions. Collectively, it has provided an effective and economic treatment of e-waste-polluted soil.
Microbial decontamination of polluted soil in a slurry process
International Nuclear Information System (INIS)
Geerdink, M.J.; Kleijntjens, R.H.; Loosdrecht, M.C.M. van; Luyben, K.C.A.M.
1996-01-01
Oil-contaminated soil (2.3--17 g/kg), even soil with high clay and silt content, was remediated microbiologically in a slurry reactor. The presence of soil, however, limits the degradation rate of oil. In contrast with results form experiments using oil dispersed in water, the relative composition of the oil components in a soil slurry after degradation was about the same as that of the original oil. Thus the composition of the degraded oil is the same as that of the original oil, which is indicative for a physical, rather than a (bio)chemical, limitation on the oil degradation rate. About 70% of the contaminant was readily available and was degraded in less than eight days. The dual injected turbulent suspension (DITS) reactor is able to combine remediation of part of the contaminated (polydisperse) soil with separation of the soil into a heavily and a lightly polluted fraction. In continuous operation, lowering the overall soil residence time from 200 to 100 h did not significantly increase the oil concentration in the effluent soil. Therefore a soil residence time of less than 100 h is feasible. With a residence time of 100 h, overall oil degradation rates at the steady state were more than 70 times faster than in a comparable land farm. After treatment in a DITS reactor, the remaining oil in the contaminated soil fraction is slowly released from the soil. From a batch experiment it was found that another 10 weeks were needed to reach the Dutch reference level of 50 mg/kg. This can be done in a process with a low energy input, such as a landfarm
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)
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.)
International Nuclear Information System (INIS)
Rao, K.S.; Chandra, G.; Rao, P.V.N.
1987-01-01
The analysis of brightness temperature data acquired from field and aircraft experiments demonstrates a linear relationship between soil moisture and brightness temperature. However, the analysis of brightness temperature data acquired by the Skylab radiometer demonstrates a non-linear relationship between soil moisture and brightness temperature. In view of the above and also because of recent theoretical developments for the calculation of the dielectric constant and brightness temperature under varying soil moisture profile conditions, an attempt is made to study the theoretical relationship between brightness temperature and soil moisture as a function of frequency. Through the above analysis, the appropriate microwave frequency range for soil moisture studies is recommended
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)
Energy Technology Data Exchange (ETDEWEB)
Song, Jong Soon; Shin, Seung Su; KIm, Sun Il [Chosun University, Gwangju (Korea, Republic of)
2016-09-15
Soil can be contaminated by radioactive materials due to nuclide leakage following unexpected situations during the decommissioning of a nuclear power plant. Soil decontamination is necessary if contaminated land is to be reused for housing or industry. The present study classifies various soil remediation technologies into biological, physics/chemical and thermal treatment and analyzes their principles and treatment materials. Among these methods, this study selects technologies and categorizes the economics, applicability and technical characteristics of each technology into three levels of high, medium and low by weighting the various factors. Based on this analysis, the most applicable soil decontamination technology was identified.
Plutonium mobility studies in soil sediment decontaminated by means of a soil-washing technology
International Nuclear Information System (INIS)
Negri, M.C.; Orlandini, K.A.; Swift, N.; Carfagno, D.
1995-01-01
The ACT*DE*CON SM process extracts plutonium from contaminated soils/sediments by means of a series of washings with a blend of chemicals, that includes a chelating agent, an oxidant, and carbonates. At the end of the process, the Pu level in the soil is lowered to 25-30 pCi/g from an initial contamination level averaging 500 pCi/g. The radionuclide still present in the soil at the end of the treatment must be strongly immobilized in or onto the soil particles to minimize the risk of its percolation to the aquifer and/or uptake by vegetation. This paper reports the investigation of residual Pu mobility as K d (distribution coefficient) in the treated soil/sediment. Six batches of contaminated soil were treated simultaneously by means of the ACT*DE*CON SM process. Some batches of the treated soil were amended with a standard fertilizer treatment of compost and nutrient and brought to pH 8.5. The treated soil, treated and fertilized soil, and the untreated controls were then incubated at 18 degrees C for 90 days. At four different times, a small aliquot of soil was retrieved from each of the batches and contacted with rainwater for six days to determine the Pu solid/liquid distribution and K d . Results indicated that a higher total amount of Pu was leached from the untreated soil, probably as a consequence of the higher content of available/exchangeable Pu in this soil compared with the treated ones. Treated/fertilized soils showed Pu leaching at intermediate levels between those for treated and untreated soils, at least for the first 30 days of incubation. K d values at the beginning of the incubation period were significantly lower in the untreated and treated/fertilized soils compared with those for the treated-only, but at 90 days, these values were substantially equal among the three different soils. Traces of the chelant were detectable only in treated, unfertilized soil
Decontamination of polyvinylchloride- and rubber type flooring
International Nuclear Information System (INIS)
Kunze, S.
1975-01-01
These types, fabricated by mixing of the basic components, showed no relation between content of fillers and decontamination results. Decontamination results are partly poorer, if the flooring contains a high concentration of the filler, especially if the latter consists mainly of hydrophilic materials. The coloring of the floorings seems to have no influence on the decontamination but floorings with clearly separated patterns can not be recommended for nuclear facilities. Fabricated by chemical reactions between polymeres, vulcanization materials and fillers, the decontamination results depend definitely from the proper choice of the filler. Flooring types, containing lampblack, graphite, kaoline, barium sulfate and titanium oxide are easy to decontamine. Again, increasing contents of hydrophilic filler cause a fall off in the decontamination results. (orig.) [de
Contamination and decontamination of skin
International Nuclear Information System (INIS)
Severa, J.; Knajfl, J.
1983-01-01
In external contamination the beta radiation dose is the prevalent component of the total dose absorbed by the skin. There exist four types of radionUclide bonds to the skin: mechanical retention of solid particles or solution on the surface and in the pores, physical adsorption of nondissociated molecules or colloids, the ion exchange effect, and chemisorption. Radionuclides then penetrate the skin by transfollicular transfer. The total amount of radioactive substances absorbed into the skin depends on the condition of the skin. Skin is decontaminated by washing with lukewarm water and soap or with special decontamination solutions. The most widely used components of decontamination solutions are detergents, chelaton, sodium hexametaphosphate, oxalic acid, citric acid. The main principles of the decontamination of persons are given. (M.D.)
Long-term decontamination engineering study. Volume 1
Energy Technology Data Exchange (ETDEWEB)
Geuther, W.J.
1995-04-03
This report was prepared by Westinghouse Hanford Company (WHC) with technical and cost estimating support from Pacific Northwest Laboratories (PNL) and Parsons Environmental Services, Inc. (Parsons). This engineering study evaluates the requirements and alternatives for decontamination/treatment of contaminated equipment at the Hanford Site. The purpose of this study is to determine the decontamination/treatment strategy that best supports the Hanford Site environmental restoration mission. It describes the potential waste streams requiring treatment or decontamination, develops the alternatives under consideration establishes the criteria for comparison, evaluates the alternatives, and draws conclusions (i.e., the optimum strategy for decontamination). Although two primary alternatives are discussed, this study does identify other alternatives that may warrant additional study. hanford Site solid waste management program activities include storage, special processing, decontamination/treatment, and disposal facilities. This study focuses on the decontamination/treatment processes (e.g., waste decontamination, size reduction, immobilization, and packaging) that support the environmental restoration mission at the Hanford Site.
Long-term decontamination engineering study. Volume 1
International Nuclear Information System (INIS)
Geuther, W.J.
1995-01-01
This report was prepared by Westinghouse Hanford Company (WHC) with technical and cost estimating support from Pacific Northwest Laboratories (PNL) and Parsons Environmental Services, Inc. (Parsons). This engineering study evaluates the requirements and alternatives for decontamination/treatment of contaminated equipment at the Hanford Site. The purpose of this study is to determine the decontamination/treatment strategy that best supports the Hanford Site environmental restoration mission. It describes the potential waste streams requiring treatment or decontamination, develops the alternatives under consideration establishes the criteria for comparison, evaluates the alternatives, and draws conclusions (i.e., the optimum strategy for decontamination). Although two primary alternatives are discussed, this study does identify other alternatives that may warrant additional study. hanford Site solid waste management program activities include storage, special processing, decontamination/treatment, and disposal facilities. This study focuses on the decontamination/treatment processes (e.g., waste decontamination, size reduction, immobilization, and packaging) that support the environmental restoration mission at the Hanford Site
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
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
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
Pulido, Manuel; Schnabel, Susanne; Francisco Lavado Contador, Joaquín; Miralles Mellado, Isabel
2016-04-01
Rangelands in SW Spain occupy a total surface area of approximately 6 million ha and constitute the most representative extensive ranching system of the Iberian Peninsula gathering more than 13 million livestock heads. They are characterised by an herbaceous layer, mostly composed of therophytic species, with a disperse tree cover, mainly holm oak and cork oak (Quercus ilex rotundifolia and Q. suber), interspersed with shrubs in many places. This type of land system is of ancient origin and experienced frequent changes in land use in the past, since agricultural, livestock and forestry activities have coexisted within the same farms. In recent decades, livestock farming has become dominant due, in part, to the subsidies of the Common Agriculture Policy. Since Spain joined the European Union in 1986 until the year 2000, the number of domestic animals doubled, particularly cattle, and consequently animal stocking rates have increased on average from 0.40 AU ha-1 up to 0.70 AU ha-1. This increase in animal stocking rates, along with a progressive substitution of cattle instead of sheep in many farms, has led to the occurrence of land degradation processes such as the reduction of grass cover or soil compaction in heavily grazed areas. Previous research has evidenced higher values of soil bulk density and resistance to penetration as well as larger bare surface areas in spring in fenced areas with animal stocking rates above 1 AU ha-1. However, a better understanding of how increasing bulk density or resistance to penetration influence the frequency of herbaceous roots and how a reduction in the frequency of roots affects soil organic matter content in rangelands is still unknown. Therefore, the main goal of this study was to determine possible relationships between the frequencies of herbaceous roots and soil organic matter content in order to understand the effect of excessive animal numbers on the depletion of soil fertility by reducing progressively the quantity of
Chemically reducing decontamination method for radioactive metal
International Nuclear Information System (INIS)
Tanaka, Akio; Onuma, Tsutomu; Sato, Hitoshi.
1994-01-01
The present invention concerns a decontamination method of electrolytically reducing radioactive metal wastes, then chemically dissolving the surface thereof with a strong acid decontaminating solution. This method utilizes dissolving characteristics of stainless steels in the strong acid solution. That is, in the electrolytic reduction operation, a portion of the metal wastes is brought into contact with a strong acid decontaminating solution, and voltage and current are applied to the portion and keep it for a long period of time so as to make the potential of the immersed portion of the metal wastes to an active soluble region. Then, the electrolytic reduction operation is stopped, and the metal wastes are entirely immersed in the decontaminating solution to decontaminate by chemical dissolution. As the decontaminating solution, strong acid such as sulfuric acid, nitric acid is used. Since DC current power source capacity required for causing reaction in the active soluble region can be decreased, the decontamination facility can be minimized and simplified, and necessary electric power can be saved even upon decontamination of radioactive metal wastes made of stainless steels and having a great area. Further, chemical dissolution can be conducted without adding an expensive oxidizing agent. (N.H.)
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.
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
The Frequency and Damping of Soil-Structure Systems with Embedded Foundation
International Nuclear Information System (INIS)
Ghannad, M. Ali; Rahmani, Mohammad T.; Jahankhah, Hossein
2008-01-01
The effect of foundation embedment on fundamental period and damping of buildings has been the title of several researches in three past decades. A review of the literature reveals some discrepancies between proposed formulations for dynamic characteristics of soil-embedded foundation-structure systems that raise the necessity of more investigation on this issue. Here, first a set of approximate polynomial equations for soil impedances, based on numerical data calculated from well known cone models, are presented. Then a simplified approach is suggested to calculate period and damping of the whole system considering soil medium as a viscoelastic half space. The procedure includes both material and radiation damping while frequency dependency of soil impedance functions is not ignored. Results show that soil-structure interaction can highly affect dynamic properties of system. Finally the results are compared with one of the commonly referred researches
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.)
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.)
Demonstration testing and evaluation of in situ soil heating
International Nuclear Information System (INIS)
Sresty, G.C.
1994-01-01
A Treatability Study planned for the demonstration of the in situ electromagnetic (EM) heating process to remove organic solvents is described in this Work Plan. The treatability study will be conducted by heating subsurface vadose-zone soils in an organic plume adjacent to the Classified Burial Ground K-1070-D located at K-25 Site, Oak Ridge. The test is scheduled to start during the fourth quarter of FY94 and will be completed during the first quarter of FY95. The EM heating process for soil decontamination is based on volumetric heating technologies developed during the '70s for the recovery of fuels from shale and tar sands by IIT Research Institute (IITRI) under a co-operative program with the US Department of Energy (DOE). Additional modifications of the technology developed during the mid '80s are currently used for the production of heavy oil and waste treatment. Over the last nine years, a number of Government agencies (EPA, Army, AF, and DOE) and industries sponsored further development and testing of the in situ heating and soil decontamination process for the remediation of soils containing hazardous organic contaminants. In this process the soil is heated in situ using electrical energy. The contaminants are removed from the soil due to enhanced vaporization, steam distillation and stripping. IITRI will demonstrate the EM Process for in situ soil decontamination at K-25 Site under the proposed treatability study. Most of the contaminants of concern are volatile organics which can be removed by heating the soil to a temperature range of 85 to 95 C. The efficiency of the treatment will be determined by comparing the concentration of contaminants in soil samples. Samples will be obtained before and after the demonstration for a measurement of the concentration of contaminants of concern
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.)
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
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
Removal of radiocesium from contaminated agricultural soil
International Nuclear Information System (INIS)
Oishi, Ayumi; Yanaga, Makoto
2012-01-01
The Fukushima Dai-ichi nuclear power plant accident occurred on March 11, 2011, led to emission of a great amount of radionuclides, and caused serious issues of contamination of our living environment. Two major radionuclides found to be widely deposited are Cs-134 and Cs-137. Because the half-lives of Cs-134 and Cs-137 are 2 years and 30 years, respectively, the decontamination of Cs is the crucial issue. Therefore, in the present work, the decontamination of Cs from the agricultural soil was attempted. For this purpose, we performed extractive test with 17 wt.% and 33 wt.% potassium iodide solution for agricultural soil collected on March 2012. The extraction rate was less than 2%, whereas the value of 20% was reported last year. This results might indicate that the cesium with soluble from have flowed or that cesium more strongly tied to soil. (author)
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.
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
DECONTAMINATION TECHNOLOGIES FOR FACILITY REUSE
International Nuclear Information System (INIS)
Bossart, Steven J.; Blair, Danielle M.
2003-01-01
As nuclear research and production facilities across the U.S. Department of Energy (DOE) nuclear weapons complex are slated for deactivation and decommissioning (D and D), there is a need to decontaminate some facilities for reuse for another mission or continued use for the same mission. Improved technologies available in the commercial sector and tested by the DOE can help solve the DOE's decontamination problems. Decontamination technologies include mechanical methods, such as shaving, scabbling, and blasting; application of chemicals; biological methods; and electrochemical techniques. Materials to be decontaminated are primarily concrete or metal. Concrete materials include walls, floors, ceilings, bio-shields, and fuel pools. Metallic materials include structural steel, valves, pipes, gloveboxes, reactors, and other equipment. Porous materials such as concrete can be contaminated throughout their structure, although contamination in concrete normally resides in the top quarter-inch below the surface. Metals are normally only contaminated on the surface. Contamination includes a variety of alpha, beta, and gamma-emitting radionuclides and can sometimes include heavy metals and organic contamination regulated by the Resource Conservation and Recovery Act (RCRA). This paper describes several advanced mechanical, chemical, and other methods to decontaminate structures, equipment, and materials
Liquid decontaminants for nuclear applications
International Nuclear Information System (INIS)
Henning, Klaus; Gojowczyk, Peter
2011-01-01
Decontaminants used in the nuclear field must meet a variety of requirements. On the one hand, the washing process must remove radioactive contamination and conventional dirt from the items washed. On the other hand, subsequent disposal of the washing water arisings must be feasible by the usual waste disposal pathway. One aspect of particular importance is unproblematic treatment of the radioactively contaminated waste water, as a rule low to medium active, whose final storage must be ensured. Decontaminants must not impair waste treatment processes, such as evaporation, filtration, and centrifuging, as well as further treatment of the concentrates and residues arising which are worked into matrix materials (cementation, bituminization), in drum drying or roller mill drying. For reasons of safety at work and environmental quality, also aspects of human toxicology and ecotoxicology must be taken into account. In this way, handling decontaminants will not jeopardize the health of personnel or cause potential long-term environmental damage. Liquid decontaminants, compared to powders, offer the advantage of automatic dosage. The liquid product is dosed accurately as a function of the washing program used. Liquid decontaminants can be handled safely in hot laundries without causing skin and eye contacts. (orig.)
Decontamination of skin in emergency situation
International Nuclear Information System (INIS)
Harase, Chieko
1988-01-01
The report briefly discusses the organization of decontamination personnel and facilities to be used for decontamination in the event of an emergency, and outlines the author's experience in carrying out decontamination of the skin of tourists who came back to Japan after staying in Kiev at the time of the accident at Chernobyl (about 150 km away from Kiev). In Japan at present, no nuclear facilities seem to have sufficient personnel who are in charge of skin decontamination activities required in the event of an emergency, and emergency measures are generally limited to the development of emergency plans and implementation of drills. It is necessary to establish training courses for medical doctors and other medical personnel. Each plant has plans for skin decontamination procedures designed for professional workers in the plant. Plans should also be established for general people who might suffer skin decontamination in the event of an accident. What is the most important is to ease their anxiety about the contamination of their skin. The procedures, including washing and shampooing, used for the tourist returning from Kiev are described, and some problems encountered or expected to occur in similar cases are outlined and discussed. (Nogami, K.)
Cost Savings through Innovation in Decontamination, Decommissioning, and Dismantlement
International Nuclear Information System (INIS)
Yancey, Neal A.
2003-01-01
/or safer. The technologies evaluated through the LSDDP have provided improvements in the following D and D areas: robotic underwater characterization of fuel storage pools, characterization of scrap metal for recycle, PCB and RCRA metals analysis in soil, water, paint, or sludge, subsurface characterization, personnel safety, waste disposal, scaffolding use, and remote radiation characterization of buildings and soil. It is estimated that the technologies demonstrated and deployed through this program will save more than $50 million dollars over the next 10 years at the INEEL alone. Of the $50 million estimated dollars saved, about 75% of the savings will come from characterization technologies, 11% from technologies associated with material dispositioning, 10% are associated with dismantlement technologies and the balance split between safety and decontamination
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)
National Research Council Canada - National Science Library
Colclough, Stephen
1998-01-01
The XM21 Decontaminant Pumper module of the Modular Decontamination System was analyzed using finite element analysis techniques to show why the first design iteration passed transportation vibration...
Decommissioning and Decontamination
International Nuclear Information System (INIS)
Massaut, V.
2000-01-01
The objectives of SCK-CEN's decommissioning and decontamination programme are (1) to develop, test and optimise the technologies and procedures for decommissioning and decontamination of nuclear installations in order to minimise the waste arising and the distributed dose; (2) to optimise the environmental impact; (3) to reduce the cost of the end-of-life of the installation; (4) to make these new techniques available to the industry; (5) to share skills and competences. The programme and achievements in 1999 are summarised
Nova target chamber decontamination study
International Nuclear Information System (INIS)
1979-05-01
An engineering study was performed to determine the most effective method for decontamination of the Nova target chamber. Manual and remote decontamination methods currently being used were surveyed. In addition, a concept that may not require in-situ decontamination was investigated. Based on the presently available information concerning material and system compatibility and particle penetration, it is recommended that a system of removable aluminum shields be considered. It is also recommended that a series of tests be performed to more precisely determine the vacuum compatibility and penetrability of other materials discussed in this report
Skin decontamination: principles and perspectives.
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.
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.
Wang, Ruzhen; Zhang, Yulan; Cerda Bolinches, Artemio; Cao, Mingming; Zhang, Yongyong; Yin, Jinfei; Jiang, Yong; Chen, Lijun
2017-01-01
Pyrogenic organic matter (PyOM) has long been used as a soil amendment to improve soil physicochemical properties. However, few studies simultaneously investigated both intensities and frequencies of PyOM addition on soil chemical properties of soil base cations, soil pH buffering capacity (pHBC),
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.
Classification and Reevaluation on Radionuclide and Activity of Contaminated Soil(I)
Energy Technology Data Exchange (ETDEWEB)
Kang, Il Sik; Shon, J. S.; Kim, K. J.; Kim, T. K.; Hong, D. S.; Lee, B. C.; Cho, H. S.; Je, W. G
2006-03-15
Radioactive wastes generated during the decommissioning process and contaminated soils were transported and have been stored at the waste storage facility. The radioactivity in the wastes has been decayed a lot. The radionuclide and the activity concentration of stored soil wastes were reevaluated. And using the reevaluation results, the soil wastes were classified as either a regulatory clearance wastes or a radioactive waste. The storage space can be secured by storing regulatory clearance wastes in the extra storage facility and self disposing them. Also, the objective is to protect the environment from contamination by observing the related nuclear regulation and managing the radioactive wastes. Through the reevaluation of radioactivity and classification of contaminated soils, the unnecessary decontamination of uncontaminated soil was prevented. It allowed us to save the cost for decontamination and disposal, also we could secure the pretreatment process techniques such as how to sample and analyze the nuclide.
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
Phytoremediation of Soil Trace Elements
Phytoremediation includes several distinct approaches to using plants to achieve soil remediation goals. Phytoextraction uses rare hyperaccumulator plants to accumulate in their shoots enough metals per year to achieve decontamination goals. Phytomining uses hyperaccumulators and biomass burn to pro...
Frequency of interaction-mediated triggering of antibiotic production among soil bacteria
Directory of Open Access Journals (Sweden)
Olaf eTyc
2014-10-01
Full Text Available Certain bacterial species produce antimicrobial compounds only in the presence of a competing species. However little is known on the frequency of interaction-mediated induction of antibiotic compound production in natural communities of soil bacteria. Here we developed a high-throughput method to screen for the production of antimicrobial activity by monocultures and pair-wise combinations of 146 phylogenetically different bacteria isolated from similar soil habitats. Growth responses of two human pathogenic model organisms, Escherichia coli WA321 and Staphylococcus aureus 533R4, were used to monitor antimicrobial activity. From all isolates, 33% showed antimicrobial activity only in monoculture and 42% showed activity only when tested in interactions. More bacterial isolates were active against S. aureus than against E. coli. The frequency of interaction-mediated induction of antimicrobial activity was 6% (154 interactions out of 2798 indicating that only a limited set of species combinations showed such activity. The screening revealed also interaction-mediated suppression of antimicrobial activity for 22% of all combinations tested. Whereas all patterns of antimicrobial activity (non-induced production, induced production and suppression were seen for various bacterial classes, interaction-mediated induction of antimicrobial activity was more frequent for combinations of Flavobacteria and alpha- Proteobacteria. The results of our study give a first indication on the frequency of interference competitive interactions in natural soil bacterial communities which may forms a basis for selection of bacterial groups that are promising for the discovery of novel, cryptic antibiotics.
New quaternary ammonium salts based decontaminants
Directory of Open Access Journals (Sweden)
Diana M. Popescu
2014-06-01
Full Text Available Decontamination after terrorist attacks or industrial accidents with biological and/or chemical agents („bio-chem“ must be fast and efficient, in order to reduce the number of victims and to eliminate the consequent damages. The decontamination of living biological agents (bacteria, viruses or nonliving ones (toxins, regulators and toxic chemicals could be accomplished by reactions of hydrolysis in various experimental conditions, in particular in alkaline medium, reactions with amines or ammonia, alcohols, phenols etc. and by their transformation into less toxic degradation products. “Bio-chem” intentional or unintentional contamination is a real risk, towards which an effective management must be available to prevent and control it. Decontamination is an essential measure to protect the personnel and the environment. Synthesis and testing of new „bio-chem“ decontaminants, based on quaternary ammonium salts, complete the arsenal of protection against chemical and biological agents. The most effective selected substances could be produced and used for decontamination in accordance with legal procedures
NRC regulations and positions concerning decontamination
International Nuclear Information System (INIS)
McCracken, C.
1982-09-01
The U.S. Nuclear Regulatory Commission encourages the use of decontamination to reduce man-rem exposure. The Commission feels that there are several processes developed to the point where soft decontamination can be applied to an entire plant in the near future. A utility can do a decontamination under its own licence without coming in for regulatory review if the process does not involve a change in technical specifications for the plant or does not involve unreviewed safety questions. Prior verbal notification is required for some steam generator secondary side cleaning or for decontamination of individual components that have not been removed from the reactor using chemicals not normally added to the reactor coolant. Prior written notification is required for steam generator secondary side crevice cleaning or sludge removal at a dented unit, or for chemical decontamination of reactor coolant systems or safety-related systems using chemicals not normally added to the coolant
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?
Frequency distribution of Radium-226, Thorium-228 and Potassium-40 concentration in ploughed soils
International Nuclear Information System (INIS)
Drichko, V.F.; Krisyuk, B.E.; Travnikova, I.G.; Lisachenko, E.P.; Dubenskaya, M.A.
1977-01-01
The results of studying Ra-226, Th-228 and K-40 concentration distribution laws in podsol, chernozem and saline soils are considered. Radionuclide concentrations were determined by gamma-spectrometric method in the samples chosen from arable soil layer according to the generally accepted agrotechnical procedure. Measuring procedure is described. The results show that frequency distributions of radionuclide concentrations transform from asymmetric form in normal coordinates into symmetric form in logarithmic coordinates. The usage of the lognormal law to describe frequency concentration distributions is substantiated. The values of concentration distribution parameters are given. The analysis of the data obtained permits to establish that Ra-226 and Th-228 concentrations in soils distribute lognormally and K-40 concentrations - normally and lognormally. According to the degree of decreasing mean concentrations of Ra-226 and Th-228, soils lie in line: chernozems=chernozem salterns > podsols; and according to the degree of decreasing mean quadratic deviation - in line: podsols>chernozems=salterns. It is necessary to determine the value of mean quadratic deviation and distribution type for full characteristics of the studied soil radioactivity
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 and decommissioning of the Organic Moderated Reactor Experiment facility (OMRE)
International Nuclear Information System (INIS)
Hine, R.E.
1980-09-01
This report describes the decontamination and decommissioning (D and D) of the Organic Moderated Reactor Experiment (OMRE) facility performed from October 1977 through September 1979. This D and D project included removal of all the facilities and as much contaminated soil and rock as practical. Removal of the reactor pressure vessel was an unusually difficult problem, and an extraordinary, unexpected amount of activated rock and soil was removed. After removal of all significantly contaminated material, the site consisted of a 20-ft deep excavation surrounded by backfill material. Before this excavation was backfilled, it and the backfill material were radiologically surveyed and detailed records made of these surveys. After the excavation was backfilled and graded, the site surface was surveyed again and found to be essentially uncontaminated
Energy Technology Data Exchange (ETDEWEB)
Abdel Sabour, M.F.; El-Naggar, H.A.; Soliman, S.M. (Atomic Energy Establishment, Cairo (Egypt). Nuclear Chemistry Dept.)
1991-01-01
Outdoor lysimeter experiments were carried out to elucidate the effect of 4 inorganic and 3 organic salts on {sup 60}Co and {sup 134}Cs uptake and dry matter yield of three cuts of clover in the soils of Inshas. A new concept was proposed for assessing the difference in capacity of soil to supply radionuclides to plants as affected by applied inorganic or organic compounds. A relation of plant tissue radionuclide content with time can be expressed in an exponential equation with corresponding regression coefficients. When the same plant species is grown on the same soil differing only in the applied compounds (e.g. Fe-EDDHA, Fe-DTPA, Fe-OAC, Fe(COO){sub 2}, Al(OH){sub 3}, Ca(H{sub 2}PO{sub 4}){sub 2}, Fe{sub 2}O{sub 3}) the derived equation will change. Differences of either Co or Cs accumulation with time between control and any other treatment were evaluated. The data also show that Fe-DTPA is preferred for {sup 60}Co as enhancing compound for plant uptake (for decontamination use), compared with other applied salts, on the other hand, any tested salts did not significantly effect {sup 134}Cs taken by clover. It was also found that more than 70% of the total cobalt uptake was accumulated in the roots which indicate that Co is less mobile in plants than Cs. (orig.).
International Nuclear Information System (INIS)
Abdel Sabour, M.F.; El-Naggar, H.A.; Soliman, S.M.
1991-01-01
Outdoor lysimeter experiments were carried out to elucidate the effect of 4 inorganic and 3 organic salts on 60 Co and 134 Cs uptake and dry matter yield of three cuts of clover in the soils of Inshas. A new concept was proposed for assessing the difference in capacity of soil to supply radionuclides to plants as affected by applied inorganic or organic compounds. A relation of plant tissue radionuclide content with time can be expressed in an exponential equation with corresponding regression coefficients. When the same plant species is grown on the same soil differing only in the applied compounds (e.g. Fe-EDDHA, Fe-DTPA, Fe-OAC, Fe(COO) 2 , Al(OH) 3 , Ca(H 2 PO 4 ) 2 , Fe 2 O 3 ) the derived equation will change. Differences of either Co or Cs accumulation with time between control and any other treatment were evaluated. The data also show that Fe-DTPA is preferred for 60 Co as enhancing compound for plant uptake (for decontamination use), compared with other applied salts, on the other hand, any tested salts did not significantly effect 134 Cs taken by clover. It was also found that more than 70% of the total cobalt uptake was accumulated in the roots which indicate that Co is less mobile in plants than Cs. (orig.) [de
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
Organic decontamination by ion exchange
International Nuclear Information System (INIS)
Wilson, T.R.
1994-01-01
This study has successfully identified ion exchanger media suitable for decontaminating the 5500-gallon organic layer in Tank 241-C-103. Decontamination of radionuclides is necessary to meet shipping, incinerator site storage, and incineration feed requirements. The exchanger media were identified through a literature search and experiments at the Russian Institute for Physical Chemistry. The principal radionuclides addressed are Cs-137 and Sr-90. Recommendations for an experimental program plan conclude the discussion. The experimental program would provide the data necessary for plant design specifications for a column and for ion exchange media to be used in decontaminating the organic layer
Amin, Hira; Arain, Basir Ahmed; Abbasi, Muhammad Sadiq; Jahangir, Taj Muhammad; Amin, Farah
2018-05-01
Phytoextraction is a plant based-technique for removing toxic heavy metals from polluted soil. The experiment reported in this paper was undertaken to study the basic Cu phytoextraction potential of Sesamum indicum in comparison with Cyamopsis tetragonoloba for remediation of Cu contaminated soil in the framework of a pot-experiment. Plants were subjected to seven Cu concentrations (0, 25, 50, 100, 150, 200, and 300 mg kg-1 soil) for 12 weeks. The morphological (i.e. growth) and biochemical (i.e. chlorophyll) parameters of both the plant species were observed throughout the experimental period; the phytoextraction efficiency of S. indicum and C. tetragonoloba were also determined. Most growth parameters were reduced under high Cu stress. Our results shows that at low concentration (25 mg Cu kg-1) all the growth and biochemical parameters were increased but at elevated Cu concentrations, root length, shoot length, and biomass (fresh and dry) were all significantly decreased ( p soil was noted for all tested treatments. In this study, both plant species showed quite high Cu tolerance and accumulation efficiency, even though C. tetragonoloba have higher Cu accumulation and tolerance indices than that of S . indicum. At 300 mg Cu kg-1, the highest Cu concentration was found in the root (282.08 mg Cu kg-1) followed by leaf (105.78 mg Cu kg-1), stem (65.30 mg Cu kg-1), and pod (8.13 mg Cu kg-1) of S. indicum. In contrast, C. tetragonoloba had highest Cu concentration primarily in the root (158.45 mg Cu kg-1) followed by the stem (154.73 mg Cu kg-1), leaf (152.32 mg Cu kg-1), and pod (8.13 mg Cu kg-1). Considering rapid growth, high biomass, tolerance, accumulation efficiency, bioconcentration factor (BCF) > 1, bioaccumulation coefficient (BAC) > 1 and translocation factor (TF) > 1 established C. tetragonoloba as a potential candidate plant for the decontamination of slightly Cu-polluted soil where the growth of plants would not be impaired and the extraction of Cu could
Advanced oxidation for groundwater remediation and for soil decontamination
International Nuclear Information System (INIS)
Gehringer, P.; Eschweiler, H.
2001-01-01
The advanced oxidation process (AOP) used in this paper is based on EB irradiation of water in the presence and absence of ozone. The paper describes two distinct sets of experiments, one dealing with groundwater contaminated with perchloroethylene (PCE) and some genotoxic compounds, and the other dealing with soil contaminated with polycyclic aromatic hydrocarbons (PAHs). The combination of ozone and EB irradiation has shown to be able to mineralize trace amounts of PCE contained in groundwater in a single stage process without formation of any by-product to be disposed of. Moreover, experiments performed with real groundwater have demonstrated that the combined ozone/EB irradiation process is also apt for total removal of some genotoxic compounds detected in groundwater contaminated with PCE. The design of an ozone/EB irradiation plant for treating 108 m 3 /h is presented. The issue concerning both the occurrences of genotoxic compounds in oxygen containing groundwater and possible processes for their removal is discussed. In the second part soil contaminated with PAHs has been treated in aqueous suspension using ozone and EB irradiation, respectively. Experiments were performed with low contaminated soil (total PAHs about 332 mg/kg soil). With an ozone consumption of 10 g C) 3 /kg soil a total PAH decomposition of about 21% was recorded. EB irradiation with a reasonable radiation dose of 100 kGy results in about 7% total PAH decomposition at room temperature and about 16%, respectively at 55-60 deg. C. It was recorded that almost no transfer of the PAH takes place from the soil into the water when soil is merely suspended in water. Ozone mainly attacked the high molecular fraction (i.e. consisting of 5 or 6 aromatic rings) of the PAHs investigated while EB irradiation of the aqueous soil suspension mostly decomposed the lower fraction (i.e. consisting up to 4 aromatic rings). (author)
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
Mechanical decontamination tests in areas affected by the Chernobyl accident
Energy Technology Data Exchange (ETDEWEB)
Roed, J.; Andersson, K.G.; Barkovsky, A.N.; Fogh, C.L.; Mishine, A.S.; Olsen, S.K.; Ponamarjov, A.V.; Prip, H.; Ramzaev, V.P.; Vorobiev, B.F
1998-08-01
Decontamination was carried out around three houses in Novo Bobovichi, Russia, in the summer of 1997. It was demonstrated that significant reductions in the dose rate both indoor (DRF = 0.27) and outdoor (DRF = 0.17) can be achieved when a careful cleaning is undertaken. This report describes the decontamination work carried out and the results obtained. The roof of one of the houses was replaced with a new roof. This reduced the Chernobyl related dose rate by 10% at the ground floor and by 27% at the first floor. The soil around the houses was removed by a bobcat, while carefully monitoring the ground for residual contamination with handheld dose meters. By monitoring the decline in the dose rate during the different stages of the work the dose reducing effect of each action has been estimated. This report also describes a test of a skim-and-burial plough developed especially for treatment of contaminated land. In the appendices of the report the measurement data is available for further analysis. (au) 24 tabs., 75 ills., 33 refs.
Mechanical decontamination tests in areas affected by the Chernobyl accident
International Nuclear Information System (INIS)
Roed, J.; Andersson, K.G.; Barkovsky, A.N.; Fogh, C.L.; Mishine, A.S.; Olsen, S.K.; Ponamarjov, A.V.; Prip, H.; Ramzaev, V.P.; Vorobiev, B.F.
1998-08-01
Decontamination was carried out around three houses in Novo Bobovichi, Russia, in the summer of 1997. It was demonstrated that significant reductions in the dose rate both indoor (DRF = 0.27) and outdoor (DRF = 0.17) can be achieved when a careful cleaning is undertaken. This report describes the decontamination work carried out and the results obtained. The roof of one of the houses was replaced with a new roof. This reduced the Chernobyl related dose rate by 10% at the ground floor and by 27% at the first floor. The soil around the houses was removed by a bobcat, while carefully monitoring the ground for residual contamination with handheld dose meters. By monitoring the decline in the dose rate during the different stages of the work the dose reducing effect of each action has been estimated. This report also describes a test of a skim-and-burial plough developed especially for treatment of contaminated land. In the appendices of the report the measurement data is available for further analysis. (au)
Development of a pilot size of electrochemical flushing equipment for radioactive soil and concrete
International Nuclear Information System (INIS)
Kim, Gye Nam; Moon, Jei Kwon; Choi, Wang Kyu; Yang, Byeong Il; Shon, Jong Sik; Hong, Dae Seok
2010-01-01
A pilot size of electrochemical flushing equipment will be manufactured suitable to the contamination characteristics of radioactive soil and concrete stored in KAERI radioactive waste storage. An optimal reagent and an optimal decontamination conditions should be decided through many experiments. - Contamination characterises analysis of TRIGA radioactive soil and concrete - Manufacture of pilot-scale electrochemical flushing equipment - Manufacture and improvement of suitable electrochemical flushing equipment for contamination characteristics in pilot size - Decontamination experiments of electrochemical flushing equipment in a pilot scale
Studies on residue-free decontaminants for chemical warfare agents.
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.
Electrochemical decontamination system for actinide processing gloveboxes
International Nuclear Information System (INIS)
Wedman, D.E.; Lugo, J.L.; Ford, D.K.; Nelson, T.O.; Trujillo, V.L.; Martinez, H.E.
1998-03-01
An electrolytic decontamination technology has been developed and successfully demonstrated at Los Alamos National Laboratory (LANL) for the decontamination of actinide processing gloveboxes. The technique decontaminates the interior surfaces of stainless steel gloveboxes utilizing a process similar to electropolishing. The decontamination device is compact and transportable allowing it to be placed entirely within the glovebox line. In this way, decontamination does not require the operator to wear any additional personal protective equipment and there is no need for additional air handling or containment systems. Decontamination prior to glovebox decommissioning reduces the potential for worker exposure and environmental releases during the decommissioning, transport, and size reduction procedures which follow. The goal of this effort is to reduce contamination levels of alpha emitting nuclides for a resultant reduction in waste level category from High Level Transuranic (TRU) to low Specific Activity (LSA, less than or equal 100 nCi/g). This reduction in category results in a 95% reduction in disposal and disposition costs for the decontaminated gloveboxes. The resulting contamination levels following decontamination by this method are generally five orders of magnitude below the LSA specification. Additionally, the sodium sulfate based electrolyte utilized in the process is fully recyclable which results in the minimum of secondary waste. The process bas been implemented on seven gloveboxes within LANL's Plutonium Facility at Technical Area 55. Of these gloveboxes, two have been discarded as low level waste items and the remaining five have been reused
New decontamination techniques: chemical gels, electropolishing and abrasives
International Nuclear Information System (INIS)
Brunel, G.; Gauchon, J.P.; Kervegant, Y.; Josso, F.
1991-01-01
The decommissioning of nuclear installations requires decontamination techniques that are efficient, simple to apply and producing a small amount of wastes, which are easy to process. With a view to this, three decontamination methods, which appear to be particularly suited to decommissioning, have been studied. These three methods are: - spraying of gels carrying chemical decontaminating agents, - electropolishing with a swab device, - abrasives blasting. After parametric tests on non-radioactive and active samples, the industrial application of these methods in the dismantling of installations was studied. These industrial applications concern: - decontamination of pieces coming from the German BWR ISAR by immersion and gel spraying, - decontamination, mainly by gel spraying, and dismantling of the BRENNILIS bituminisation plant, - decontamination of part of the cooling circuit of the graphite gas reactor G2 by gel spraying, - decontamination of a component of the FBR SuperPhenix, using dry abrasives blasting. During the first three applications, generated secondary wastes volume and form were determined. 33 tabs., 16 figs., 12 refs
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.)
The improvement of Pilot-scale Electrokinetic for Radioactive Soil Decontamination
International Nuclear Information System (INIS)
Park, Hye Min; Kim, Gye Nam; Kim, Wan Suk; Moon, Jai Kwon
2012-01-01
Most nuclear facility sites have been contaminated by leakage of radioactive waste-solution due to corrosion of the waste-solution tanks and connection pipes by their long-term operation, set up around underground nuclear facilities. Therefore it was needed that the method to remediate a large volume of radioactive soil should be developed. Until now the soil washing method has studied to remediate soil contaminated with uranium, cobalt, cesium, and so on. But it has a lower removal efficiency of nuclide from soils and generated a large volume of waste-solution. And its application to the soil composed of fine particle is impossible. So, the electrokinetic method has been studied as a new technology for soil remediation recently. In this study, the original electrokinetic equipment of 50L suitable to soil contamination characteristics of Korean nuclear facility sites was manufactured for the remediation of soil contaminated with uranium. During experiment with the original electrokinetic equipment, many metal oxides were generated and were stuck on the cathod plate. Several methods to reduce the generation quantity of metal oxides in the electrokinetic equipment and to take off metal oxides from the cathod plate were improved. The soil with uranium was remediated with the improved electrokinetic equipment. The required time to remediate a radioactive soil to under a clearance concentration level was yielded through demonstration experiment with the improved electrokinetic equipment for its different radioactivity concentration
The improvement of Pilot-scale Electrokinetic for Radioactive Soil Decontamination
Energy Technology Data Exchange (ETDEWEB)
Park, Hye Min; Kim, Gye Nam; Kim, Wan Suk; Moon, Jai Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2012-05-15
Most nuclear facility sites have been contaminated by leakage of radioactive waste-solution due to corrosion of the waste-solution tanks and connection pipes by their long-term operation, set up around underground nuclear facilities. Therefore it was needed that the method to remediate a large volume of radioactive soil should be developed. Until now the soil washing method has studied to remediate soil contaminated with uranium, cobalt, cesium, and so on. But it has a lower removal efficiency of nuclide from soils and generated a large volume of waste-solution. And its application to the soil composed of fine particle is impossible. So, the electrokinetic method has been studied as a new technology for soil remediation recently. In this study, the original electrokinetic equipment of 50L suitable to soil contamination characteristics of Korean nuclear facility sites was manufactured for the remediation of soil contaminated with uranium. During experiment with the original electrokinetic equipment, many metal oxides were generated and were stuck on the cathod plate. Several methods to reduce the generation quantity of metal oxides in the electrokinetic equipment and to take off metal oxides from the cathod plate were improved. The soil with uranium was remediated with the improved electrokinetic equipment. The required time to remediate a radioactive soil to under a clearance concentration level was yielded through demonstration experiment with the improved electrokinetic equipment for its different radioactivity concentration
Ultrasonic decontamination robot
International Nuclear Information System (INIS)
Patenaude, R.S.
1984-01-01
An ultrasonic decontamination robot removes radioactive contamination from the internal surface of the inlet and outlet headers, divider plate, tube sheet, and lower portions of tubes of a nuclear power plant steam generator. A programmable microprocessor controller guides the movement of a robotic arm mounted in the header manway. An ultrasonic transducer having a solvent delivery subsystem through which ultrasonic action is achieved is moved by the arm over the surfaces. A solvent recovery suction tube is positioned within the header to remove solvent therefrom while avoiding interference with the main robotic arm. The solvent composition, temperature, pressure, viscosity, and purity are controlled to optimize the ultrasonic scrubbing action. The ultrasonic transducer is controlled at a power density, frequency, and on-off mode cycle such as to optimize scrubbing action within the range of transducer-to-surface distance and solvent layer thickness selected for the particular conditions encountered. Both solvent and transducer control actions are optimized by the programmable microprocessor. (author)
Facility decontamination technology workshop
International Nuclear Information System (INIS)
1980-10-01
Purpose of the meeting was to provide a record of experience at nuclear facilities, other than TMI-2, of events and incidents which have required decontamination and dose reduction activities, and to furnish GPU and others involved in the TMI-2 cleanup with the results of that decontamination and dose reduction technology. Separate abstracts were prepared for 24 of the 25 papers; the remaining paper had been previously abstracted
Facility decontamination technology workshop
Energy Technology Data Exchange (ETDEWEB)
None
1980-10-01
Purpose of the meeting was to provide a record of experience at nuclear facilities, other than TMI-2, of events and incidents which have required decontamination and dose reduction activities, and to furnish GPU and others involved in the TMI-2 cleanup with the results of that decontamination and dose reduction technology. Separate abstracts were prepared for 24 of the 25 papers; the remaining paper had been previously abstracted. (DLC)
Criteria and evaluation of three decontamination techniques
Energy Technology Data Exchange (ETDEWEB)
Tripp, J.L.
1994-01-01
Past decontamination and solvent recovery activities at the Idaho Chemical Processing Plant (ICPP), which is part of the Idaho National Engineering Laboratory (INEL), have resulted in the accumulation of 1.5 million gallons of radioactively contaminated sodium-bearing liquid waste. Future decontamination activities at the ICPP could result in the production of 5 million gallons or more of sodium-bearing waste using the current decontamination techniques of chemical/water flushes and steam jet cleaning. This waste requires a large amount of cold chemical additive to process because the low melting temperatures of sodium and potassium salts cause agglomeration in the bed of the calciner vessel. Criteria have been established for evaluating methods and technologies available for decontaminating equipment and facilities. The criteria were weighted according to their relative importance using a Kepner-Tregoe Problem Solving process. These criteria were used to rank three decontamination techniques new to the ICPP: laser ablation, liquid abrasive blasting and CO{sub 2} pellet blasting, against the standard decontamination techniques of sodium-based chemical cleaning and water/steam jets used.
Criteria and evaluation of three decontamination techniques
International Nuclear Information System (INIS)
Tripp, J.L.
1994-01-01
Past decontamination and solvent recovery activities at the Idaho Chemical Processing Plant (ICPP), which is part of the Idaho National Engineering Laboratory (INEL), have resulted in the accumulation of 1.5 million gallons of radioactively contaminated sodium-bearing liquid waste. Future decontamination activities at the ICPP could result in the production of 5 million gallons or more of sodium-bearing waste using the current decontamination techniques of chemical/water flushes and steam jet cleaning. This waste requires a large amount of cold chemical additive to process because the low melting temperatures of sodium and potassium salts cause agglomeration in the bed of the calciner vessel. Criteria have been established for evaluating methods and technologies available for decontaminating equipment and facilities. The criteria were weighted according to their relative importance using a Kepner-Tregoe Problem Solving process. These criteria were used to rank three decontamination techniques new to the ICPP: laser ablation, liquid abrasive blasting and CO 2 pellet blasting, against the standard decontamination techniques of sodium-based chemical cleaning and water/steam jets used
Impedance matching of a coaxial antenna for microwave in-situ processing of polluted soils.
Pauli, Mario; Kayser, Thorsten; Wiesbeck, Werner; Komarov, Vyacheslav
2011-01-01
The present paper is focused on the minimization of return loss of a slotted coaxial radiator proposed for a decontamination system for soils contaminated by volatile or semi-volatile organic compounds such as oils or fuels. The antenna upgrade is achieved by coating it with a 5 mm thick Teflon layer. The electromagnetic characteristics reflection coefficient and power density distribution around the antenna surrounded by soils with different moisture levels are analyzed numerically. Simplified analytical approaches are employed to accelerate the optimization of the given antenna for microwave heating systems. The improved antenna design shows a good matching of the antenna to the surrounding soil with varying moisture levels. This ensures a high efficiency of the proposed in-situ soil decontamination system.
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 chemical and biological warfare agents].
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.
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 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 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)
International Nuclear Information System (INIS)
Kawasaki, Kota
2016-01-01
This study discusses opinions of 11 municipalities in Fukushima Prefecture designated as Special Decontamination Area as of the end of September 2015, about four and a half years afters the Fukushima Daiichi Nuclear Power Plant accident. This study shows that (1) more than half of the municipalities recognize that decontamination activities of the national government which is responsible for decontamination in Special Decontamination Area are inadequate, (2) most municipalities recognize that residents cannot live their lives with a sense of safety and security unless air radiation dose is reduced to the level before the accident or less than 0.23 μSv/h, (3) many municipalities recognize that residents will not be able to live their lives with a sense of safety and security even if the national government implements decontamination, (4) municipalities points out 'decontamination of forests or rivers and reconsideration of decontamination methods of forests or rivers', 'securement and maintenance of temporary storage site' and 'setting forth a numeric target concerning decontamination and implementation of additional decontamination after the first decontamination' as issues for the promotion of decontamination, and (5) all the municipalities recognize that that there are a lot of problems concerning the installation of interim storage facilities by the national government. (author)
Diversity and frequency of Nocardia spp. in the soil of Isfahan province, Iran.
Kachuei, R; Emami, M; Mirnejad, R; Khoobdel, M
2012-06-01
To isolate and identify Nocardia spp. from soil in different regions of Isfahan province in the center of Iran. This study was conducted in 32 districts (16 cities and 16 villages) in Isfahan province during two years. A total of 800 soil samples from these regions were studied by using kanamycin. The isolated Nocardia species were examined by gram and acid-fast staining and were identified biochemically and morphologically. The frequency and distribution of Nocardia spp. were determined in relation to different factors such as soil pH and temperate climate. From 153 (19.1%) Nocardia isolates identified, Nocardia asteroids (N. asteroids) complex (45.5%) and Nocardia brasiliensis (N. brasiliensis) (24.7%) were the most frequently isolated species, followed by Nocardia otitidiscaviarum (2.2%), Nocardiopsis dassonvillei, Actinomadura actinomadura (each 1.7%) and Nocardia transvalensis (1.1%) and also unknown spp. (23.0%). In this study, most species (54.4%) of Nocardia, especially N. asteroides complex were isolated from soils with pH: 7.01-8, whereas in pH: 8.01-9 more N. brasiliensis was isolated. The most Nocardia spp. was detected from regions with semi-nomadic and temperate climate (41.1%). N. asteroids complex is more prevalent in Isfahan province and soil can be a potential source of nocardiosis infections. It is to be considering that climate and soil pH are involved in the frequency and diversity of aerobic Actinomycetes.
System for chemical decontamination of nuclear reactor primary systems
International Nuclear Information System (INIS)
Schlonski, J.S.; McGiure, M.F.; Corpora, G.J.
1992-01-01
This patent describes a method of chemically decontaminating a nuclear reactor primary system, having a residual heat removal system with one or more residual heat removal heat exchangers, each having an upstream and a downstream side, at or above ambient pressure. It comprises: injecting decontamination chemicals using an injection means; circulating the injected decontamination chemicals throughout the primary system; directing the circulated decontamination chemicals and process fluids to a means for removing suspended solids and dissolved materials after the circulated chemicals and process fluids have passed through the residual heat removal heat exchanger; decontaminating the process fluids; and feeding the decontaminated process fluids to the injection means. This patent also describes a chemical decontamination system for use at, or above, ambient pressure in a nuclear reactor primary system having a residual heat removal system. It comprises: means for injecting decontamination chemicals into the primary system; means for removing dissolved and suspended materials and decontamination chemicals from the primary system; one or more residual heat removal pumps; means located downstream of one of the residual heat removal heat exchangers; and a return line connecting the means
The Development of Treatment Process Technology for Uranium Soil washing Leachate
Energy Technology Data Exchange (ETDEWEB)
Shon, Dong Bin; Kim, Gye Nam; Park, Hye Min; Kim, Ki Hong; Lee, Ki Won; Moon, Jeik won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2011-05-15
Electrokinetic treatment technology is a good method for removing radioactive substances such as U, Co, Cs: but it has a weakness. It takes a long time to get high removal efficiency. The Soil washing method compensates for this weak point with its short reaction time and with this method it is possible to remove a lot of uranium-contaminated soil. But a great deal of leachate is generated. That is, about more amounts of leachate are generated for the decontamination of the same volume of radioactive soil using the electrokinetic equipment. Therefore, the development of a treatment process for The Soil washing leachate is important so that there is a reduction of leachate waste volume and a choice of process. Previously, studies for liquid radioactive waste were in process at various nuclear facilities. Nuclear fuel plant survey appropriate cohesion quantity of liquid waste of radioactive. Nuclear power plants manage liquid radioactive waste with centrifugation equipment. In this study, the treatment technology for uranium Soil washing leachate generated on Soil washing decontamination for the soil contaminated with uranium was developed. A treatment process suitable to the contamination characteristics of Soil washing leachate was proposed
TECHNOLOGIES FOR BIOREMEDIATION OF SOILS CONTAMINATED WITH PETROLEUM PRODUCTS
Roxana Gabriela POPA
2012-01-01
Biological methods for remediation of soils is based on the degradation of pollutants due to activity of microorganisms (bacteria, fungi). Effectiveness of biological decontamination of soils depends on the following factors: biodegradation of pollutants, type of microorganisms used, choice of oxidant and nutrient and subject to clean up environmental characteristics. Ex situ techniques for bioremediation of soils polluted are: composting (static / mechanical agitation), land farming and biop...
International Nuclear Information System (INIS)
Brown, J.; Crick, M.J.; Hill, M.D.
1988-01-01
The NRPB has recently developed a dynamic model, EXPURT (EXPosure from Urban Radionuclide Transfer), that reflects the transfer processes that take place in the urban environment. Parameter values for the model have been derived from experiments performed in recent years in the United Kingdom and in Denmark. The model incorporates shielding properties of different types of buildings, and population habits to evaluate individual and population doses as a function of time after deposit. The original model has been extended to enable it to represent several techniques for decontaminating the various surfaces in the urban environment. These include hosing of impermeable surfaces, such as walls, roofs and paved areas, the removal or ploughing of soil/grass, and the replacement of building surfaces with new uncontaminated materials. The model has been used to examine the effectiveness of these various decontamination measures at reducing the external radiation doses to people living in urban areas. The importance of the time at which decontamination is performed is also discussed in this paper
Calculation of dose distribution above contaminated soil
Kuroda, Junya; Tenzou, Hideki; Manabe, Seiya; Iwakura, Yukiko
2017-07-01
The purpose of this study was to assess the relationship between altitude and the distribution of the ambient dose rate in the air over soil decontamination area by using PHITS simulation code. The geometry configuration was 1000 m ×1000 m area and 1m in soil depth and 100m in altitude from the ground to simulate the area of residences or a school grounds. The contaminated region is supposed to be uniformly contaminated by Cs-137 γ radiation sources. The air dose distribution and space resolution was evaluated for flux of the gamma rays at each altitude, 1, 5, 10, and 20m. The effect of decontamination was calculated by defining sharpness S. S was the ratio of an average flux and a flux at the center of denomination area in each altitude. The suitable flight altitude of the drone is found to be less than 15m above a residence and 31m above a school grounds to confirm the decontamination effect. The calculation results can be a help to determine a flight planning of a drone to minimize the clash risk.
Nuclear reactor vessel decontamination systems
International Nuclear Information System (INIS)
McGuire, P. J.
1985-01-01
There is disclosed in the present application, a decontamination system for reactor vessels. The system is operatable without entry by personnel into the contaminated vessel before the decontamination operation is carried out and comprises an assembly which is introduced into the vertical cylindrical vessel of the typical boiling water reactor through the open top. The assembly includes a circular track which is centered by guideways permanently installed in the reactor vessel and the track guides opposed pairs of nozzles through which water under very high pressure is directed at the wall for progressively cutting and sweeping a tenacious radioactive coating as the nozzles are driven around the track in close proximity to the vessel wall. The whole assembly is hoisted to a level above the top of the vessel by a crane, outboard slides on the assembly brought into engagement with the permanent guideways and the assembly progressively lowered in the vessel as the decontamination operation progresses. The assembly also includes a low pressure nozzle which forms a spray umbrella above the high pressure nozzles to contain radioactive particles dislodged during the decontamination
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.)
40 CFR 267.116 - What must I do with contaminated equipment, structure, and soils?
2010-07-01
... equipment, structure, and soils? 267.116 Section 267.116 Protection of Environment ENVIRONMENTAL PROTECTION..., structure, and soils? You must properly dispose of or decontaminate all contaminated equipment, structures, and soils during the partial and final closure periods. By removing any hazardous wastes or hazardous...
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
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)
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
Supercritical water decontamination of town gas soil
International Nuclear Information System (INIS)
Kocher, B.S.; Azzam, F.O.; Lee, S.
1994-01-01
Town gas sites represent a large environmental problem that exists in more than 2,000 sites across North America alone. The major contaminants in town gas sods are polycyclic aromatic hydrocarbons (PAHs). These are stable compounds that migrate deep into the soil and are traditionally very difficult to remove by conventional remediation processes. Supercritical fluids offer enhanced solvating properties along with reduced mass transfer resistances that make them ideal for removing compounds that are difficult or impossible to remove by conventional processes. Supercritical water is ideal for removing PAHs and other hydrocarbons from soil due to its high solvating power towards most hydrocarbon species. Supercritical water was investigated for its ability to remediate two different town gas sods containing from 3--20 wt% contamination. The sod was remediated in a 300-cc semi-continuous system to a more environmentally acceptable level
Method of decontaminating radioactive-contaminated instruments
Energy Technology Data Exchange (ETDEWEB)
Urata, M; Fujii, M; Kitaguchi, H
1982-03-29
Purpose: To enable safety processing of liquid wastes by recovering radioactive metal ions remaining in the electrolytes after the decontamination procedure thereby decreasing the radioactivity. Method: In a decontamination tank containing electrolytes consisting of diluted hydrochloric acid and diluted sulfuric acid, are provided a radioactive contaminated instrument connected to an anode and a collector electrode made of stainless steel connected to a cathode respectively. Upon applying electrical current, the portion of the mother material to be decontaminated is polished electrolytically into metal ions and they are deposited as metal on the collection electrode. After completion of the decontamination, an ultrasonic wave generator is operated to strip and remove the oxide films. Thereafter, the anode is replaced with the carbon electrode and electrical current is supplied continuously, whereby the remaining metal ions are deposited and recovered as the metal on the collection electrode.
Deactivation, Decontamination and Decommissioning Project Summaries
Energy Technology Data Exchange (ETDEWEB)
Peterson, David Shane; Webber, Frank Laverne
2001-07-01
This report is a compilation of summary descriptions of Deactivation, Decontamination and Decommissioning, and Surveillance and Maintenance projects planned for inactive facilities and sites at the INEEL from FY-2002 through FY-2010. Deactivations of contaminated facilities will produce safe and stable facilities requiring minimal surveillance and maintenance pending further decontamination and decommissioning. Decontamination and decommissioning actions remove contaminated facilities, thus eliminating long-term surveillance and maintenance. The projects are prioritized based on risk to DOE-ID, the public, and the environment, and the reduction of DOE-ID mortgage costs and liability at the INEEL.
Energy Technology Data Exchange (ETDEWEB)
Bregante, M.; Paganetto, A.; Magistrelli, P.; Martella, L.; Gambale, F. [Consiglio Nazionale delle Ricerche, Istituto di Cibernetica e Biofisica, Genoa (Italy); Sacchi, G.A.; Rivetta, A.; Cocucci, R. [Milan Univ., Milan (Italy). Dipt. di Produzione Vegetale
2001-12-01
The environmental pollution is continuously increasing owing to anthropic activity. High concentrations of heavy metals may have drastic consequences on human health, particularly on children development. Conventional approaches have high economical and environmental costs that do not allow soil decontamination unless sites are particularly valuable. Phytoextraction uses plants producing biomass to transfer metals from the soil to the aerial parts of the plants at the expenses of solar energy. This work illustrates the activity performed within a Life-Environment european project in order to verify whether phytoremediation can be transferred from the laboratory scale to the field scale. [Italian] L'inquinamento del suolo dovuto all'accumulo di metalli come conseguenza delle attivita' umane sta continuamente e drammaticamente aumentando. Principali cause di contaminazione sono l'accumulo di rifiuti urbani, l'utilizzo di fertilizzanti, il traffico motorizzato, gli inceneritori, le centrali termoelettriche, le emissiioni industriali nocive, lo sfruttamento e dismissione di miniere. La decontaminazione di suoli inquinati da metalli e' un problema estremamente difficile da trattare. La bonifica di suoli inquinati da metalli mediante l'utilizzo di piante metallofite e/o agronomiche (fitoestrazione) emerge quindi come una tecnica estremamente interessante. Viene percio' illustrato il progetto PhyLeS (Phytoextraction of Lead from Soil), un progetto pilota finanziato dal programma Europeo Life/Ambiente (DG XI), che si propone di verficare i potenziali vantaggi e la trasferibilita' della metodica di fitoestrazione assistita dalla scala di laboratorio a quella di campo.
Ecological evaluation of polluted soils from Sasa mine
Krstev, Boris; Golomeov, Blagoj; Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Aleksandar
2009-01-01
The paper presents various strategies developed to evaluate the quality of soils and sites correspond to three possible objectives: to establish references or criteria of soil quality, on chemical and/or ecotoxicological bases (to define thresholds), to develop methods of ranking to classify polluted sites for the purpose of their decontamination (to establish a classification), and to develop methods of risk evaluation. The paper presents result of ecological evaluation of polluted soils fro...
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
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
Decontamination of lead by fusion (1962); Decontamination du plomb par fusion (1962)
Energy Technology Data Exchange (ETDEWEB)
Boutot, P; Giachetto, L; Capitaine, A [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires
1962-07-01
Various attempts to decontaminate using mechanical and chemical methods having given questionable results, a fusion method has been developed. The apparatus consists of a propane-heated oven fitted with a steel crucible of 1 400 kg capacity, with two ventilation systems, and with a vacuum gauge for preventing the diffusion of toxic gases. There are three operational controls : 1. On the samples taken before during and after the operation, 2. On the plugs taken from the ingots, 3. On the ingot itself. The continuous sanitary control is done by a radioactive aerosol recorder and by periodic sampling. This decontamination process will be improved, especially as far as the productivity and the safety precautions are concerned. (authors) [French] Divers essais de decontamination par voies mecaniques et chimiques ayant donne des resultats discutables, un procede par fusion a ete mis au point. L'appareil se compose d'un four, chauffe au propane, muni d'un creuset en acier d'une capacite de 1 400 kg, de deux systemes de ventilation et d'un deprimometre afin d'eviter la diffusion de vapeurs nocives. Trois controles d'activite sont effectues: 1. sur des echantillons preleves avant, pendant et apres l'operation, 2. sur des carottages realises sur les lingots, 3. sur le lingot lui-meme. Le controle sanitaire permanent est assure par un enregistreur d'aerosols radioactifs et par des prelevements periodiques. Ce procede de decontamination doit encore etre ameliore, principalement en ce qui concerne la productivite et la securite. (auteurs)
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
Ioanid, E. G.; Dunca, S.; Rusu, D.; Tǎnase, C.
2012-04-01
Documents decontamination using dry methods, less invasive than the wet ones implying toxic nocuous substances for cellulose-based materials, has been the object of numerous studies. In recent years mixed researchers teams have been studying the possibility of one-step document decontamination performed by a dry treatment, the risks of repeated wet manipulation thus being reduced. Among physical methods appropriate to this end, high-frequency cold plasma and corona effect can be mentioned. Our studies were carried out on samples taken from ancient books with no cultural heritage value. The decontamination efficiency and the impact on paper of the two types of treatments were determined by: microbiological analysis, scanning electron microscopy, FTIR, chromatic alterations and gloss determination. The above-mentioned procedures eliminate the use of chemical conservation substances, nocuous for the paper support. At the same time the health risk for conservators, restorers, archivists or archive's users is removed.
Decontamination of 125I in Medical Laboratory
International Nuclear Information System (INIS)
Abdel Geleel, M.; Tawfeek, A.A.
2009-01-01
A radiological laboratory for diagnoses was contaminated by 125 I. A large-scale survey of gamma-radiation has been made in different locations of the floors and walls of the lab to determine the contaminated area and its activity. The activity level before decontamination for the wall and floor was 1400 and 2000 Bq/cm 2 respectively. Decontamination was carried out by using ethyl alcohol, potassium permanganate, ethylene diamine tetracetic acid and tissue papers. Decontamination factor has been calculated and it was 175 and 200 for the wall and floor respectively. D and D computer code has been used to calculate Total Effective Dose Equivalent (TEDE). TEDE from the wall and floor before decontamination were 3.05 and 4.35 ( mSv/yr ) while after decontamination were 18 and 23μSv/yr respectively. These results are lower than the Egyptian and the international regulations (10 mSv/y for the public ) according to International Atomic Energy agency, IAEA, Safety Series, SS, no. 115 (1994).
BIOREMEDIATION - TECHNOLOGY FOR DECONTAMINATION OF SOILS POLLUTED WITH PETROLEUM HYDROCARBONS
Directory of Open Access Journals (Sweden)
Irina-Ramona PECINGINĂ
2013-05-01
Full Text Available The pollution of soil with petroleum hydrocarbons prevents unfolding processes ofwater infiltration in soil, its circulation and the exchanges of the gaseous substances with theatmosphere. The biodegradation speed of the pollutants by the microorganisms is influenced ofsome factors: nutrients, soil type, humidity, temperature, pH, the type and the metabolism of themicroorganisms. The spill of the crude oil in the soil results in numerical growth of bacteriapopulations, with a concomitant reduction in their diversity, respectively with the predominantspecies that degrade hydrocarbons to simpler compounds, determining their gradualdisappearance.
EDF guide book for decontamination at power plant
International Nuclear Information System (INIS)
Glorennec, C.; Bemer, J.P.
1988-01-01
Nuclear Power Plant components or equipment often need to be more or less decontaminated before undergoing maintenance. In order to coordinate the activities of the different maintenance specialists belonging to the corporate or site organizations, the management of EDF/Nuclear and Fossil Division has created a decontamination task force. One of the objectives of this task force was to elaborate the present Guide Book for Decontamination at Power Plants. This paper provides assistance to nuclear plants operators in the very specific field of decontamination
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
International Nuclear Information System (INIS)
1996-08-01
This plan presents the strategy for the characterization of the Area 6 Decontamination Pond Facility at the Nevada Test Site which will be conducted for the US Department of Energy, Nevada Operations Office, Environmental Restoration Division. The objectives of the planned activities are to: obtain sufficient, sample analytical data from which further assessment, remediation, and/or closure strategies may be developed for the site; obtain sufficient, sample analytical data for management of investigation-derived waste. The scope of the characterization may include surface radiation survey(s), surface soil sampling, subsurface soil boring (i.e., drilling), and sampling of soil in and around the pond; in situ sampling of the soil within subsurface soil borings; and sample analysis for both site characterization and waste management purposes
Micelles as Soil and Water Decontamination Agents.
Shah, Afzal; Shahzad, Suniya; Munir, Azeema; Nadagouda, Mallikarjuna N; Khan, Gul Shahzada; Shams, Dilawar Farhan; Dionysiou, Dionysios D; Rana, Usman Ali
2016-05-25
Contaminated soil and water pose a serious threat to human health and ecosystem. For the treatment of industrial effluents or minimizing their detrimental effects, preventive and remedial approaches must be adopted prior to the occurrence of any severe environmental, health, or safety hazard. Conventional treatment methods of wastewater are insufficient, complicated, and expensive. Therefore, a method that could use environmentally friendly surfactants for the simultaneous removal of both organic and inorganic contaminants from wastewater is deemed a smart approach. Surfactants containing potential donor ligands can coordinate with metal ions, and thus such compounds can be used for the removal of toxic metals and organometallic compounds from aqueous systems. Surfactants form host-guest complexes with the hydrophobic contaminants of water and soil by a mechanism involving the encapsulation of hydrophobes into the self-assembled aggregates (micelles) of surfactants. However, because undefined amounts of surfactants may be released into the aqueous systems, attention must be paid to their own environmental risks as well. Moreover, surfactant remediation methods must be carefully analyzed in the laboratory before field implementation. The use of biosurfactants is the best choice for the removal of water toxins as such surfactants are associated with the characteristics of biodegradability, versatility, recovery, and reuse. This Review is focused on the currently employed surfactant-based soil and wastewater treatment technologies owing to their critical role in the implementation of certain solutions for controlling pollution level, which is necessary to protect human health and ensure the quality standard of the aquatic environment.
Volume reduction system by soil classifying. Soil-washing system and problems to be solved
International Nuclear Information System (INIS)
Oshino, Yoshio
2016-01-01
Radioactive contamination of ground surfaces, buildings and forests in a broad area was caused by the accident at the Fukushima Daiichi Nuclear Power Plant in Japan. The national government and municipalities have still been carrying out the decontamination works for livelihood areas after five years from the accident. The government estimated that the amounts of soils and wastes removed by the decontamination works would be about 28,000,000 cubic meters maximum including 20,000,000 cubic meters maximum of soils. The removed soils will be stored in “Interim Storage Facility” then will be finally disposed outside of Fukushima prefecture within 30 years. On the other hand, shortage of the soils as materials needed for the revitalization in Fukushima prefecture is expected. Technical Advisory Council on Remediation and Waste Management, which consists of about 90 companies, started a working group to investigate solutions to these problems. The working group focused on the investigation of the possibility to recycle the soils by washing and classification to use them as the materials for civil engineering works, and to reduce the volume of the interim storage. In the first part of this report, we have evaluated the applicability of various technologies for purification and volume reduction of the removed soils, and have researched usages, required quantities and specifications of the recycled soils. In the second part, we have made trial calculations of the volume reduction effects and costs using the washing and classification system. The calculated results showed the possibilities of reducing the storage capacity of the interim storage facility, as well as the construction and the operation costs by recycling the removed soils with the washing and classification system inside the interim storage facility. At the end of this report, we proposed problems to be solved in order to adopt the washing and classification system. (author)
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.)
Method of decontaminating radioactive-contaminated instruments
International Nuclear Information System (INIS)
Urata, Megumu; Fujii, Masaaki; Kitaguchi, Hiroshi.
1982-01-01
Purpose: To enable safety processing of liquid wastes by recovering radioactive metal ions remaining in the electrolytes after the decontamination procedure thereby decreasing the radioactivity. Method: In a decontamination tank containing electrolytes consisting of diluted hydrochloric acid and diluted sulfuric acid, are provided a radioactive contaminated instrument connected to an anode and a collector electrode made of stainless steel connected to a cathode respectively. Upon applying electrical current, the portion of the mother material to be decontaminated is polished electrolytically into metal ions and they are deposited as metal on the collection electrode. After completion of the decontamination, an ultrasonic wave generator is operated to strip and remove the oxide films. Thereafter, the anode is replaced with the carbon electrode and electrical current is supplied continuously, whereby the remaining metal ions are deposited and recovered as the metal on the collection electrode. (Yoshino, Y.)
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
Radioactive decontamination of equipment
International Nuclear Information System (INIS)
1982-03-01
After a recall of some definitions relating to decontamination techniques and of the regulation into effect, the principles to be respected to arrange rationally work zones are quoted while insisting more particularly on the types of coatings which facilitate maintenance operations and the dismantling of these installations. Then, the processes and equipments to use in decontamination units for routine or particular operations are described; the list of recommended chemical products to decontaminate the equipment is given. The influence of these treatments on the state and the duration of life of equipments is studied, and some perfectible methods are quoted. In the appendix, are given: the limits of surface contamination accepted in the centers; a standard project which defines the criteria of admissible residual contamination in wastes considered as cold wastes; some remarks on the interest that certain special ventilation and air curtain devices for the protection of operators working on apparatus generating contaminated dusts [fr
Decontamination and materials corrosion concerns in the BWR
International Nuclear Information System (INIS)
Gordon, B.M.; Gordon, G.M.
1988-01-01
The qualification of chemical decontamination processes to decontaminate complete systems or individual components in essential if effective inspection, maintenance, repair or replacement of plant components is to be achieved with minimum exposure of workers to ionizing radiation. However, it is critical that the benefits of decontamination processes are not overshadowed by deleterious materials/ corrosion side effects during the application of the process or during subsequent operation. This paper discusses such potential corrosion/materials problems in the BWR and presents relevant available corrosion data for the various commercial decontamination processes. (author)
Ficken, Cari D; Wright, Justin P
2017-01-01
Litter quality and soil environmental conditions are well-studied drivers influencing decomposition rates, but the role played by disturbance legacy, such as fire history, in mediating these drivers is not well understood. Fire history may impact decomposition directly, through changes in soil conditions that impact microbial function, or indirectly, through shifts in plant community composition and litter chemistry. Here, we compared early-stage decomposition rates across longleaf pine forest blocks managed with varying fire frequencies (annual burns, triennial burns, fire-suppression). Using a reciprocal transplant design, we examined how litter chemistry and soil characteristics independently and jointly influenced litter decomposition. We found that both litter chemistry and soil environmental conditions influenced decomposition rates, but only the former was affected by historical fire frequency. Litter from annually burned sites had higher nitrogen content than litter from triennially burned and fire suppression sites, but this was correlated with only a modest increase in decomposition rates. Soil environmental conditions had a larger impact on decomposition than litter chemistry. Across the landscape, decomposition differed more along soil moisture gradients than across fire management regimes. These findings suggest that fire frequency has a limited effect on litter decomposition in this ecosystem, and encourage extending current decomposition frameworks into disturbed systems. However, litter from different species lost different masses due to fire, suggesting that fire may impact decomposition through the preferential combustion of some litter types. Overall, our findings also emphasize the important role of spatial variability in soil environmental conditions, which may be tied to fire frequency across large spatial scales, in driving decomposition rates in this system.
Use of citric acid for large parts decontamination
International Nuclear Information System (INIS)
Holland, M.E.
1979-01-01
Laboratory and field studies have been performed to identify and evaluate chemical decontamination agents to replace ammonium carbonate, an environmentally unacceptable compound, in the decontamination facility for large process equipment at the Portsmouth Gaseous Diffusion Plant. Preliminary screening of over 40 possible decontamination agents on the basis of efficiency, availability, toxicity, cost, corrosiveness, and practicality indicated sodium carbonate and citric acid to be the most promising. Extensive laboratory studies were performed with these two reagents. Corrosion rates, decontamination factors, uranium recovery efficiencies, technetium ( 99 Tc)/ion exchange removal effects, and possible environmental impacts were determined or investigated. Favorable results were found in all areas. Detailed monitoring and analysis during two-week trial periods in which sodium carbonate and citric acid were used in the large parts decontamination facility resulted in similar evaluation and conclusions. Because it has cleaning properties not possessed by sodium carbonate, and because it eliminated several operational problems by incorporating two acidic decontamination reagents (citric and nitric acids) instead of one basic reagent (sodium or ammonium carbonate) and one acidic reagent (nitric acid), citric acid was selected for one-year field testing. On the basis of its excellent performance in the field tests, citric acid is recommended as a permanent replacement for ammonium carbonate in the decontamination facility for large process equipment
Development of calculation system for decontamination effect, CDE
International Nuclear Information System (INIS)
Satoh, Daiki; Kojima, Kensuke; Oizumi, Akito; Matsuda, Norihiro; Kugo, Teruhiko; Sakamoto, Yukio; Endo, Akira; Okajima, Shigeaki
2012-08-01
Large amount of radionuclides had been discharged to environment in the accident of the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant caused by the 2011 off the Pacific coast of Tohoku Earthquake. The radionuclides deposited on the ground elevate dose rates in large area around the Fukushima site. For the reduction of the dose rate and recovery of the environment, decontamination based on a rational plan is an important and urgent subject. A computer software, named CDE (Calculation system for Decontamination Effect), has been developed to support planning the decontamination. CDE calculates the dose rates before the decontamination by using a database of dose contributions by radioactive cesium. The decontamination factor is utilized in the prediction of the dose rates after the decontamination, and dose rate reduction factor is evaluated to express the decontamination effect. The results are visualized on the image of a target zone with color map. In this paper, the overview of the software and the dose calculation method are reported. The comparison with the calculation results by a three-dimensional radiation transport code PHITS is also presented. In addition, the source code of the dose calculation program and user's manual of CDE are attached as appendices. (author)
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)
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)
Soil science basis and the effect of oil contamination on chemical properties of soils
International Nuclear Information System (INIS)
Wagner, A.; Miehlich, G.
1993-01-01
The changes in soil chemistry properties due to oil contamination and decontamination are examined. One main point of the work is the determination of the effect of oil on the availability of nutrients in the soil. Nutrients are not only present dissolved in the soil solution, but are for the most part reversibly adsorbed by exchangers on loaded surfaces. The clay minerals, the organic substance and iron and manganese oxide act as exchangers. Knowledge on surface structure and reactions in soils contaminated by oil is to be obtained via examination of the exchange behaviour of different bio-elements. The results supply the basis for the cleaning up technique, the judgement of cleaned materials and their reusability. (orig.) [de
Decontamination system study for the Tank Waste Retrieval System
International Nuclear Information System (INIS)
Reutzel, T.; Manhardt, J.
1994-05-01
This report summarizes the findings of the Idaho National Engineering Laboratory's decontamination study in support of the Tank Waste Retrieval System (TWRS) development program. Problems associated with waste stored in existing single shell tanks are discussed as well as the justification for the TWRS program. The TWRS requires a decontamination system. The subsystems of the TWRS are discussed, and a list of assumptions pertinent to the TWRS decontamination system were developed. This information was used to develop the functional and operational requirements of the TWRS decontamination system. The requirements were combined with a comprehensive review of currently available decontamination techniques to produced a set of evaluation criteria. The cleaning technologies and techniques were evaluated, and the CO 2 blasting decontamination technique was chosen as the best technology for the TWRS
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
Pipe and hose decontamination apparatus
International Nuclear Information System (INIS)
Fowler, D.E.
1985-01-01
A pipe and hose decontamination apparatus is disclosed using freshly filtered high pressure Freon solvent in an integrated closed loop to remove radioactive particles or other contaminants from items having a long cylindrical geometry such as hoses, pipes, cables and the like. The pipe and hose decontamination apparatus comprises a chamber capable of accomodating a long cylindrical work piece to be decontaminated. The chamber has a downward sloped bottom draining to a solvent holding tank. An entrance zone, a cleaning zone and an exit drying zone are defined within the chamber by removable partitions having slotted rubber gaskets in their centers. The entrance and exit drying zones contain a horizontally mounted cylindrical housing which supports in combination a plurality of slotted rubber gaskets and circular brushes to initiate mechanical decontamination. Solvent is delivered at high pressure to a spray ring located in the cleaning zone having a plurality of nozzles surrounding the work piece. The solvent drains into a solvent holding tank located below the nozzles and means are provided for circulating the solvent to and from a solvent cleaning, distilling and filter unit
Manning, George C; Baer, Sara G; Blair, John M
2017-12-01
Fire and grazing are widely used to manage grasslands for conservation purposes, but few studies have evaluated the effects of these drivers on the conservation value of plant communities measured by the floristic quality index (FQI). Further, the influence of fire and grazing on soil properties and functions are difficult for land managers and restoration practitioners to assess. The objectives of this study were to: (1) quantify the independent and interactive effects of grazing and fire frequency on floristic quality in native tallgrass prairie to provide potential benchmarks for community assessment, and (2) to explore whether floristic quality can serve as an indicator of soil structure and function for more holistic ecosystem assessments. A factorial combination of fire frequencies (1-2, 4, and 20 years return intervals) and grazing (by bison or ungrazed) treatments were sampled for plant species composition, and for several indicators of soil quality in lowland tallgrass prairie. Floristic quality, diversity, and richness were higher in grazed than ungrazed prairie over all fire frequencies (P soil bulk density were also higher in grazed prairie soil over all fire frequencies (P soil N were positively correlated with FQI (P soil N pools are more strongly influenced by grazing than fire and that floristic quality can be an indicator of total soil C and N stocks in never cultivated lowland prairie.
International Nuclear Information System (INIS)
1998-01-01
This release of the Alberta Energy and Utilities Board (EUB) is intended to clarify the jurisdictional roles of Alberta Environmental Protection (AEP) and the EUB with regard to their respective responsibilities for the regulation of the suspension, abandonment, decontamination and surface land reclamation of active and inactive upstream oil and gas facilities. The EUB, AEP and industrial operators all have separate roles and responsibilities when active and inactive upstream facilities are suspended or reclaimed. In the future, industry operators will have more interaction with the AEP during the decontamination of a site, while the EUB will concentrate on pollution prevention and abandonment of non-economic facilities. All oilfield waste generated from suspension, abandonment, decontamination, and surface land reclamation of an active or inactive upstream oil and gas facility will fall under the jurisdiction of the EUB. Contaminated soils, sludges, and waters that are physically removed as a result of decontamination activities are considered to be oilfield wastes. The regulatory responsibility between the AEP and the EUB remains unchanged for the reclamation process of on-lease and off-lease spills, releases or pipeline breaks. Industry operators are no longer allowed to discharge any produced liquid to earthen pits or ponds and are encouraged to reclaim existing ones. 3 figs
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
Experience Practices on Decontamination Activity in NPP Decommissioning
Energy Technology Data Exchange (ETDEWEB)
Yoon, Suk Bon; Kim, Jeongju; Sohn, Wook [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)
2016-10-15
Decommissioning of a nuclear power plant (NPP) involves various technical and administrative activities for a utility to terminate its license, which allows the plant site to be released from the regulatory control (site release). Decontamination activity in NPP decommissioning is one of the main technical activities to be performed during the decommissioning. The decontamination at decommissioning sites is usually performed due to several reasons such as reducing personnel dose and disposal costs, and cleanup to meet license termination requirements by using physical or chemical removal techniques proven through the previous experience practices. This paper introduces the best and worst practices for the decontamination activities collected from the decommissioning operational experiences through the implementation of nuclear decommissioning projects around the world. Review of the experiences of decontamination shows that it is important to conduct an advanced planning for optimized implementation of decontamination taking into considering site specific conditions such as operating time, reactor type, system, and so on. Also, a review of newer decontamination methods is necessary to safely and economically decommission the nuclear facility.
Atmospheric-pressure plasma decontamination/sterilization chamber
Herrmann, Hans W.; Selwyn, Gary S.
2001-01-01
An atmospheric-pressure plasma decontamination/sterilization chamber is described. The apparatus is useful for decontaminating sensitive equipment and materials, such as electronics, optics and national treasures, which have been contaminated with chemical and/or biological warfare agents, such as anthrax, mustard blistering agent, VX nerve gas, and the like. There is currently no acceptable procedure for decontaminating such equipment. The apparatus may also be used for sterilization in the medical and food industries. Items to be decontaminated or sterilized are supported inside the chamber. Reactive gases containing atomic and metastable oxygen species are generated by an atmospheric-pressure plasma discharge in a He/O.sub.2 mixture and directed into the region of these items resulting in chemical reaction between the reactive species and organic substances. This reaction typically kills and/or neutralizes the contamination without damaging most equipment and materials. The plasma gases are recirculated through a closed-loop system to minimize the loss of helium and the possibility of escape of aerosolized harmful substances.
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.)
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
International Nuclear Information System (INIS)
Endo, Mitsuru; Endo, Mai; Kakizaki, Takao
2015-01-01
The Great East Japan Earthquake that occurred on March 11, 2011 resulted in the explosion of the TEPCO Fukushima 1st Nuclear Power Plant and the global dispersion of a large quantity of radioactive substances. A high radiation dose was particularly recorded in Fukushima prefecture several weeks after the accident, although the level is presently sufficiently low. However, considering that the adverse effects of low but extended exposure to radiation are yet to be negated, there is the urgent need for further decontamination. In our study, we focused on the efficient decontamination of radioactive substances in residential areas, for which we propose a high-pressure water jet system for washing road surfaces. The system differs from conventional systems of its type that were initially designed for use in the immediate environment of the nuclear reactors of the TEPCO Fukushima 1st Nuclear Power Plant. The proposed system consists of multiple washing, transporter, and server robots. The washing robots decontaminate the road surface using high-pressure water jets and are transported between washed and unwashed areas by the transporter robots. The server robots supply the water used for washing and absorb the polluted water together with ground dust. In this paper, we describe the concept of the system and present the results of decontamination experiments. Particular attention is given to the washing robot and its mechanism and control method. The results of the integration of the washing robot in an experimental system confirmed the feasibility of the proposed system. (author)
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
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.)
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
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
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 using the high-pressure wet jet system
International Nuclear Information System (INIS)
Brandt, D.
1985-01-01
For decontaminating machine components, tools, instruments and scrap in nuclear plants the most varying decontamination procedures are used. At the nuclear power plant Wuergassen a mobile high-pressure wet jet unit, developed by Ernst Schmutz GmbH, was successfully used for the first time in extensive decontamination work. The recycling system integrated in the decontamination unit substantially reduces secondary waste, which is usually produced in large quantities by the dry jet method, and continually extracts the contaminated dirt thus guaranteeing full utilisation of the jet agent while preventing secondary contamination of the components to be treated. (orig.) [de
Los Alamos DP West Plutonium Facility decontamination project
International Nuclear Information System (INIS)
Garde, R.; Cox, E.J.; Valentine, A.M.
1982-01-01
The DP West Plutonium Facility operated by the Los Alamos National Laboratory, Los Alamos, New Mexico, was decontaminated between April 1978 and April 1981. The facility was constructed in 1944 to 1945 to produce plutonium metal and fabricate parts for nuclear weapons. It was continually used as a plutonium processing and research facility until mid-1978. Decontamination operations included dismantling and removing gloveboxes and conveyor tunnels; removing process systems, utilities, and exhaust ducts; and decontaminating all remaining surfaces. This report describes glovebox and conveyor tunnel separations, decontamination techniques, health and safety considerations, waste management procedures, and costs of the operation
Doni, S; Macci, C; Peruzzi, E; Arenella, M; Ceccanti, B; Masciandaro, G
2012-05-01
In the past several years, industrial and agricultural activities have led to serious environmental pollution, resulting in a large number of contaminated sites. As a result, much recent research activity has focused on the application of bioremediation technologies as an environmentally friendly and economically feasible means for decontamination of polluted soil. In this study horse manure and Populus nigra (var. italica) (HM + P treatment) have been used, at real scale level, as an approach for bioremediation of a soil historically contaminated by metals (Pb, Cr, Cd, Zn, Cu and Ni) and organic contaminants, such as polychlorobiphenyls and petroleum hydrocarbon. After one year, the HM + P phytotreatment was effective in the reclamation of the polluted soil from both organic and inorganic contaminants. A reduction of about 80% in total petroleum hydrocarbon (TPH), and 60% in polychlorobiphenyls (PCBs) and total metals was observed in the HM + P treatment. In contrast, in the horse manure (HM) treatment, used as control, a reduction of only about 30% of TPH was obtained. In order to assess both effectiveness and evolution of the remediation system to a biologically active soil ecosystem, together with the pollution parameters, the parameters describing the evolution of the soil functionality (enzymatic activities and protein SDS-PAGE pattern) were investigated. A stimulation of the metabolic soil processes (increase in dehydrogenase activity) was observed in the HM + P compared to the HM treatment. Finally, preliminary protein SDS-PAGE results have permitted the identification of proteins that have been recovered in the HM + P soil with respect to the HM; this may become a basic tool for improving the biogeochemical status of soil during the decontamination through the identification of microbial populations that are active in soil decontamination.
Takahashi, Junko; Wakabayashi, Shokichi; Tamura, Kenji; Onda, Yuichi
2018-02-01
After the Fukushima Dai-ichi Nuclear Power Plant accident on March 2011, continuous monitoring of the detailed vertical distribution of radiocesium in soil is required to evaluate the fate of radiocesium and establish strategies for remediation and management of the contaminated land. It is especially important to investigate paddy soil because little knowledge has been accumulated for paddy soil and wetland rice is a major staple in Japan. Therefore, we monitored the vertical distribution of 137 Cs in abandoned paddy soil in a planned evacuation zone from June 2011 to March 2016. The decontamination works (i.e., 5 cm of surface soil removal and re-covering with uncontaminated soil) were conducted by the government in 2015. As a result of monitoring, the 137 Cs gradually migrated downward with time and the 137 Cs concentration in the 0-10 cm soil was almost homogenous in October 2014, although it was non-cultivated. The liner relationship was obtained between the median depth, which is the thickness of a soil layer containing half of the total 137 Cs inventory, and the time after the accident, indicating the migration rate was constant (1.3 cm y -1 ) before the decontamination works. After the decontamination works, the 137 Cs concentration in the uppermost surface layer was reduced by 90%, however the total 137 Cs inventory was reduced by only 50-70%. It was shown that the efficiency of 137 Cs removal by the decontamination works decrease linearly over time in fields like the studied paddy, in which the homogenization of 137 Cs concentration occurred. Conversely, the downward migration of 137 Cs to subsurface layers deeper than 10 cm (i.e., plowpan layer) with low permeability rarely occurred. It is expected that these unique trends in distribution and migration of 137 Cs would be found in abandoned paddy soils with properties similar to the studied soil, sandy loam but poorly drained because of the low permeable plowpan layer, although further validation is
Radiation decontamination of spices
International Nuclear Information System (INIS)
Jan, M.; Sattar, A.; Ahmad, W.A.; Khan, I.
1990-06-01
In this report radiation decontamination was initiated to investigate the red pepper, which is widely consumed in all parts of Pakistan. The samples were collected from local market and prepared for gamma radiation at dose level of 0, 2.5, 5.0, 7.5, and 10.0 kGy. The measurement of total fungal count was carried out immediately after irradiation and the at two months storage interval. It was reported that radiation dose 10.0 kGy is suitable for complete decontamination of red pepper. (A.B.)
RMDF leach-field decontamination. Final report
International Nuclear Information System (INIS)
Carroll, J.W.; Marzec, J.M.; Stelle, A.M.
1982-01-01
The objective of the decontamination effort was to place the Radioactive Materials Disposal Facility (RMDF) leach field in a condition suitable for release for unrestricted use. Radioactively contaminated soil was excavated from the leach field to produce a condition of contamination as low as reasonably achievable (ALARA). The contaminated soil was boxed and shipped to an NRC-licensed burial site at Beatty, Nevada, and to the DOE burial site at Hanford, Washington. The soil excavation project successfully reduced the contamination level in the leach field to background levels, except for less than 0.6 mCi of Sr-90 and trace amounts of Cs-137 that are isolated in cracks in the bedrock. The cracks are greater than 10 ft below the surface and have been sealed with a bituminous asphalt mastic. A pathways analysis for radiation exposure to humans from the remaining radionuclides was performed, assuming intensive home gardening, and the results show that the total first year whole body dose equivalent would be about 0.1 mrem/year. This dose equivalent is a projection for the hypothetical ingestion of vegetables grown on the site. Assuming that an average adult consumes 64 kg of green leafy vegetables per year and that the entire yearly supply could be grown on the site, the amount of ingested Sr-90 and Cs-137 is calculated to be 1100 pCi/year and 200 pCi/year. This ingested quantity would produce a total first year whole body dose equivalent of 0.10 mrem, using the accepted soil-to-plant transfer factors of 0.0172 and 0.010 for Sr-90 and Cs-137, respectively. The whole body dose equivalent exposure value of 0.1 mrem/year is far below the tentative limit established by NRC of 5 mrem/year for areas released for unrestricted use
Chemical Decontamination at Browns Ferry Unit 1
International Nuclear Information System (INIS)
Hartwig, Ed; Reid, Richard
2003-01-01
In May, 2002, the Tennessee Valley Authority's (TVA) Board of Directors approved the recovery and restart of Unit 1 at Browns Ferry Nuclear Station. As an initial step in the site characterization and restart feasibility review, a majority of the primary reactor circuit was chemically decontaminated. Close cooperation between TVA and vendor personnel resulted in project completion ahead of schedule with outstanding results. The final average decontamination factors were excellent, and the final dose rates were very low, with contact readings on most points between one and three mRem/hr. In addition to allowing TVA to do a complete and thorough job of determining the feasibility of the Unit 1 restart, the decontamination effort will greatly reduce personnel exposure during plant recovery, both whole body exposure to gamma radiation and airborne exposure during pipe replacement efforts. The implementation of lessons learned from previous decontamination work performed at Browns Ferry, as well as decontamination efforts at other plants aided greatly in the success. Specific items of note are: (1) The initial leak check of the temporary decontamination system should include ancillary systems such as the spent resin system, as well as the main circulation loop. This could save time and dose exposure if leaks are discovered before the use of such systems is required. (2) Due to the quick turnaround time from the award of contract, a vendor representative was onsite early in the project to help with engineering efforts and procedures. This aided greatly in completing preparations for the decontamination. (3) The work was performed under a single maintenance activity. This resulted in great craft and plant support. (4) The constant coverage by the site's decontamination flush directors provided timely plant support and interface. (5) The FPC system isolation and back flushing to prevent residual chemicals from being left in the FPC system should have been addressed in more
Darby, B.J.; Neher, D.A.; Housman, D.C.; Belnap, J.
2011-01-01
Frequent hydration and drying of soils in arid systems can accelerate desert carbon and nitrogen mobilization due to respiration, microbial death, and release of intracellular solutes. Because desert microinvertebrates can mediate nutrient cycling, and the autotrophic components of crusts are known to be sensitive to rapid desiccation due to elevated temperatures after wetting events, we studied whether altered soil temperature and frequency of summer precipitation can also affect the composition of food web consumer functional groups. We conducted a two-year field study with experimentally-elevated temperature and frequency of summer precipitation in the Colorado Plateau desert, measuring the change in abundance of nematodes, protozoans, and microarthropods. We hypothesized that microfauna would be more adversely affected by the combination of elevated temperature and frequency of summer precipitation than either effect alone, as found previously for phototrophic crust biota. Microfauna experienced normal seasonal fluctuations in abundance, but the effect of elevated temperature and frequency of summer precipitation was statistically non-significant for most microfaunal groups, except amoebae. The seasonal increase in abundance of amoebae was reduced with combined elevated temperature and increased frequency of summer precipitation compared to either treatment alone, but comparable with control (untreated) plots. Based on our findings, we suggest that desert soil microfauna are relatively more tolerant to increases in ambient temperature and frequency of summer precipitation than the autotrophic components of biological soil crust at the surface.
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
Decontamination of radioactively contaminated surfaces
International Nuclear Information System (INIS)
1986-10-01
By this standard objective conditions to evaluate and test the ease of decontamination of surfaces under laboratory conditions are to be laid down. Ease of decontamination in this context denotes the summed-up effect of two material properties: a) the capacity of the material for retaining radioactive substances at its surface; b) the ease with which these substances are given off again in the course of cleaning processes. (orig./HP) [de
Directory of Open Access Journals (Sweden)
Cari D Ficken
Full Text Available Litter quality and soil environmental conditions are well-studied drivers influencing decomposition rates, but the role played by disturbance legacy, such as fire history, in mediating these drivers is not well understood. Fire history may impact decomposition directly, through changes in soil conditions that impact microbial function, or indirectly, through shifts in plant community composition and litter chemistry. Here, we compared early-stage decomposition rates across longleaf pine forest blocks managed with varying fire frequencies (annual burns, triennial burns, fire-suppression. Using a reciprocal transplant design, we examined how litter chemistry and soil characteristics independently and jointly influenced litter decomposition. We found that both litter chemistry and soil environmental conditions influenced decomposition rates, but only the former was affected by historical fire frequency. Litter from annually burned sites had higher nitrogen content than litter from triennially burned and fire suppression sites, but this was correlated with only a modest increase in decomposition rates. Soil environmental conditions had a larger impact on decomposition than litter chemistry. Across the landscape, decomposition differed more along soil moisture gradients than across fire management regimes. These findings suggest that fire frequency has a limited effect on litter decomposition in this ecosystem, and encourage extending current decomposition frameworks into disturbed systems. However, litter from different species lost different masses due to fire, suggesting that fire may impact decomposition through the preferential combustion of some litter types. Overall, our findings also emphasize the important role of spatial variability in soil environmental conditions, which may be tied to fire frequency across large spatial scales, in driving decomposition rates in this system.
Studies of decontamination using easy removable coatings technique
International Nuclear Information System (INIS)
Oglaza, J.; Nowak, Z.
1991-01-01
The usefulness of removable coatings for decontamination of steel and epoxy-resin painted surfaces was examined. Natural latex, Revultex, butadiene-styrene latex as well as mixtures of latex with complexing agents and surfactants were used as decontaminating coats. The best decontamination was obtained by removable coatings of natural latex with EDTA additive for all surfaces and radionuclides tested. (author). 16 refs, 5 tabs
Manning, George C.; Baer, Sara G.; Blair, John M.
2017-12-01
Fire and grazing are widely used to manage grasslands for conservation purposes, but few studies have evaluated the effects of these drivers on the conservation value of plant communities measured by the floristic quality index (FQI). Further, the influence of fire and grazing on soil properties and functions are difficult for land managers and restoration practitioners to assess. The objectives of this study were to: (1) quantify the independent and interactive effects of grazing and fire frequency on floristic quality in native tallgrass prairie to provide potential benchmarks for community assessment, and (2) to explore whether floristic quality can serve as an indicator of soil structure and function for more holistic ecosystem assessments. A factorial combination of fire frequencies (1-2, 4, and 20 years return intervals) and grazing (by bison or ungrazed) treatments were sampled for plant species composition, and for several indicators of soil quality in lowland tallgrass prairie. Floristic quality, diversity, and richness were higher in grazed than ungrazed prairie over all fire frequencies ( P total N, and soil bulk density were also higher in grazed prairie soil over all fire frequencies ( P total organic C, and total soil N were positively correlated with FQI ( P quality and soil N pools are more strongly influenced by grazing than fire and that floristic quality can be an indicator of total soil C and N stocks in never cultivated lowland prairie.
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
TECHNOLOGIES FOR BIOREMEDIATION OF SOILS CONTAMINATED WITH PETROLEUM PRODUCTS
Directory of Open Access Journals (Sweden)
Roxana Gabriela POPA
2012-05-01
Full Text Available Biological methods for remediation of soils is based on the degradation of pollutants due to activity of microorganisms (bacteria, fungi. Effectiveness of biological decontamination of soils depends on the following factors: biodegradation of pollutants, type of microorganisms used, choice of oxidant and nutrient and subject to clean up environmental characteristics. Ex situ techniques for bioremediation of soils polluted are: composting (static / mechanical agitation, land farming and biopiles. Techniques in situ bioremediation of soils polluted are: bioventingul, biospargingul and biostimulation – bioaugumentarea.
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
Joly, François-Xavier; Kurupas, Kelsey L; Throop, Heather L
2017-09-01
Macroclimate has traditionally been considered the predominant driver of litter decomposition. However, in drylands, cumulative monthly or annual precipitation typically fails to predict decomposition. In these systems, the windows of opportunity for decomposer activity may rather depend on the precipitation frequency and local factors affecting litter desiccation, such as soil-litter mixing. We used a full-factorial microcosm experiment to disentangle the relative importance of cumulative precipitation, pulse frequency, and soil-litter mixing on litter decomposition. Decomposition, measured as litter carbon loss, saturated with increasing cumulative precipitation when pulses were large and infrequent, suggesting that litter moisture no longer increased and/or microbial activity was no longer limited by water availability above a certain pulse size. More frequent precipitation pulses led to increased decomposition at high levels of cumulative precipitation. Soil-litter mixing consistently increased decomposition, with greatest relative increase (+194%) under the driest conditions. Collectively, our results highlight the need to consider precipitation at finer temporal scale and incorporate soil-litter mixing as key driver of decomposition in drylands. © 2017 by the Ecological Society of America.
Decontamination around the site of Chernobylsk
International Nuclear Information System (INIS)
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.)
INTEGRATED VERTICAL AND OVERHEAD DECONTAMINATION SYSTEM
Energy Technology Data Exchange (ETDEWEB)
M.A. Ebadian, Ph.D.
1999-01-01
This report summarizes the activities performed during FY98 and describes the planned activities for FY99. Accomplishments for FY98 include identifying and selecting decontamination, the screening of potential characterization technologies, development of minimum performance factors for the decontamination technology, and development and identification of Applicable, Relevant and Appropriate Regulations (ARARs).
INTEGRATED VERTICAL AND OVERHEAD DECONTAMINATION SYSTEM
International Nuclear Information System (INIS)
Ebadian, M.A.
1999-01-01
This report summarizes the activities performed during FY98 and describes the planned activities for FY99. Accomplishments for FY98 include identifying and selecting decontamination, the screening of potential characterization technologies, development of minimum performance factors for the decontamination technology, and development and identification of Applicable, Relevant and Appropriate Regulations (ARARs)
Recent developments in chemical decontamination technology
Energy Technology Data Exchange (ETDEWEB)
Wood, C.J. [Electric Power Research Institute, Palo Alto, CA (United States)
1995-03-01
Chemical decontamination of parts of reactor coolant systems is a mature technology, used routinely in many BWR plants, but less frequently in PWRs. This paper reviews recent developments in the technology - corrosion minimization, waste processing and full system decontamination, including the fuel. Earlier work was described in an extensive review published in 1990.
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
Foam process for application of decontamination agents
International Nuclear Information System (INIS)
Harris, J.M.; Miller, J.R.; Frazier, R.S.; Walter, J.H.
1982-01-01
This paper presents the results and observations of a study performed by the authors to parametrically evaluate the performance characteristics of a foam process for application of decontamination agents. The initial tests were established to assess foam quality. Subsequent tests determined the ability of the foam as a carrier of chemical systems, and established system operating parameters. The technique was then applied in an actual decontamination task to verify effectiveness of these established parameters and to determine decontamination reduction factors. 4 figures, 5 tables
Decontamination of a canyon crane at the Savannah River Plant
International Nuclear Information System (INIS)
Stevenson, D.A.; Moore, D.B.; Bowers, J.W.; Brown, D.L.
1985-01-01
Decontamination of the crane is reviewed in terms of the health physics aspects, controls during decontamination efforts, and the resultant radiation exposure rates for decontamination efforts. 17 figs.,
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
Developments in Decontamination Technologies of Military Personnel and Equipment
Sata, Utkarsh R.; Ramkumar, Seshadri S.
Individual protection is important for warfighters, first responders and civilians to meet the current threat of toxic chemicals and chemical warfare (CW) agents. Within the realm of individual protection, decontamination of warfare agents is not only required on the battlefield but also in laboratory, pilot plants, production and agent destruction sites. It is of high importance to evaluate various decontaminants and decontamination techniques for implementing the best practices in varying scenarios such as decontamination of personnel, sites and sensitive equipment.
Morillas, Lourdes; Durán, Jorge; Rodríguez, Alexandra; Roales, Javier; Gallardo, Antonio; Lovett, Gary M; Groffman, Peter M
2015-10-01
Climate change and atmospheric nitrogen (N) deposition are two of the most important global change drivers. However, the interactions of these drivers have not been well studied. We aimed to assess how the combined effect of soil N additions and more frequent soil drying-rewetting events affects carbon (C) and N cycling, soil:atmosphere greenhouse gas (GHG) exchange, and functional microbial diversity. We manipulated the frequency of soil drying-rewetting events in soils from ambient and N-treated plots in a temperate forest and calculated the Orwin & Wardle Resistance index to compare the response of the different treatments. Increases in drying-rewetting cycles led to reductions in soil NO3- levels, potential net nitrification rate, and soil : atmosphere GHG exchange, and increases in NH4+ and total soil inorganic N levels. N-treated soils were more resistant to changes in the frequency of drying-rewetting cycles, and this resistance was stronger for C- than for N-related variables. Both the long-term N addition and the drying-rewetting treatment altered the functionality of the soil microbial population and its functional diversity. Our results suggest that increasing the frequency of drying-rewetting cycles can affect the ability of soil to cycle C and N and soil : atmosphere GHG exchange and that the response to this increase is modulated by soil N enrichment. © 2015 John Wiley & Sons Ltd.
Decontamination of CAGR gas circulator components
International Nuclear Information System (INIS)
Rogers, L.N.; Hooper, A.J.
1985-01-01
This paper describes the development and full-scale trial of two methods for removal of radioactive contamination on the surfaces of CAGR gas circulator components. The two methods described are a particle impact cleaning (PIC) decontamination technique and an electrochemical technique, 'electro-swabbing', which is based on the principle of decontamination by electro-polishing. In developing these techniques it was necessary to take account of the physical and chemical nature of the surface deposits on the gas circulator components; these were shown to consist of magnetite-type oxide and carbonaceous material. In order to follow the progress of the decontamination it was also necessary to develop a surface sampling technique which was effective and precise under these conditions; an electrochemical technique, employing similar principles to the electro-swabbing process, was developed for this purpose. The full-scale trial of the PIC decontamination technique was carried out on an inlet guide vane (IGV) assembly, this having been identified as the component from the gas circulator which contributes most to the radiation dose accumulated during routine circulator maintenance. The technique was shown to be practically viable and some 99% of the radioactive contamination was readily removed from the treated surfaces with only negligible surface damage being caused. The full-scale trial of the electro-swabbing decontamination technique was carried out on a gas circulator impeller. High decontamination factors were again achieved with ≥ 99% of the radioactive contamination being removed from the treated surfaces. The technique has practical limitations in terms of handling and treatment of waste-arisings. However, the use of specially-designed swabbing electrodes may allow the treatment of constricted geometries inaccessible to techniques such as PIC. The technique is also highly suitable for the treatment of soft-finish materials and of components fabricated from a
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
Pipe Decontamination Involving String-Foam Circulation
International Nuclear Information System (INIS)
Turchet, J.P.; Estienne, G.; Fournel, B.
2002-01-01
Foam applications number for nuclear decontamination purposes has recently increased. The major advantage of foam decontamination is the reduction of secondary liquid wastes volumes. Among foam applications, we focus on foam circulation in contaminated equipment. Dynamic properties of the system ensures an homogeneous and rapid effect of the foam bed-drifted chemical reagents present in the liquid phase. This paper describes a new approach of foam decontamination for pipes. It is based on an alternated air and foam injections. We called it 'string-foam circulation'. A further reduction of liquid wastes is achieved compared to continuous foam. Secondly, total pressure loss along the pipe is controlled by the total foam length in the pipe. It is thus possible to clean longer pipes keeping the pressure under atmospheric pressure value. This ensures the non dispersion of contamination. This study describes experimental results obtained with a neutral foam as well with an acid foam on a 130 m long loop. Finally, the decontamination of a 44 meters pipe is presented. (authors)
Experiences with decontaminating tritium-handling apparatus
International Nuclear Information System (INIS)
Maienschein, J.L.; Garcia, F.; Garza, R.G.; Kanna, R.L.; Mayhugh, S.R.; Taylor, D.T.
1991-07-01
Tritium-handling apparatus has been decontaminated as part of the shutdown of the LLNL Tritium Facility. Two stainless-steel gloveboxes that had been used to process lithium deuteride-tritide (LiDT) salt were decontaminated using the Portable Cleanup System so that they could be flushed with room air through the facility ventilation system. Further surface decontamination was performed by scrubbing the interior with paper towels and ethyl alcohol or Swish trademark. The surface contamination, as shown by swipe surveys, was reduced from 4x10 4 --10 6 disintegrations per minute (dpm)/cm 2 to 2x10 2 --4x10 4 dpm/cm 2 . Details on the decontamination operation are provided. A series of metal (palladium and vanadium) hydride storage beds have been drained of tritium and flushed with deuterium in order to remove as much tritium as possible. The bed draining and flushing procedure is described, and a calculational method is presented which allows estimation of the tritium remaining in a bed after it has been drained and flushed. Data on specific bed draining and flushing are given
Decontamination and decorporation: the clinical experience
International Nuclear Information System (INIS)
Poda, G.A.
1979-01-01
Decontamination and decorporation are quite interrelated when dealing with a contaminated person. Some clinical experiences from a transuranium production facility are offered. Skin decontamination is accomplished by washing with detergent and water. Stubborn cases are treated with sodium hypochlorite followed by rinsing, and emery cloth is used on more stubborn nail or finger pad contamination. If inhaled, the usual skin cleansing followed by nasal douche with normal saline decontaminates reachable areas and one of the DTPA salts given via aerosol both decontaminates and decorporates the inner recesses. Saline laxative reduces the time inhaled, and ingested particles remain in the gastro-intestinal tract. Conservatism prevails in general, but most persons found to have inhaled contamination are given a single chelation within the hour of discovery and if subsequently found to have over 10% M.P.P.B. of a soluble actinide are offered further chelation. Single dose chelation has been found to be relatively innocuous and usually sufficient. The longest case of chelation therapy spanned 2-1/4 years and encompassed 123 doses of CaNa-DTPA
Decontamination for radiators by friction effect
International Nuclear Information System (INIS)
Nojima, Takeshi; Yoshida, Yuji
2016-01-01
Radiators are equipped with cars, vending machines and outdoor units of air conditioners. Aluminum metal surfaces in their heat exchange part have been contaminated by radioactive material taking in dust after the nuclear accident. The dust adhering to the metal surface could be removed by flushing with water immediately after scattering radioactive material. But radioactive material such as cesium cannot be removed by water washing, because of growth of the oxide film and transfer of the nuclides in the metal surface due to aging. On the other hand, we have verified the effect of decontamination of radiators by friction cleaning using a cross flow shredder (CFS) and solvent washing of crushed metallic chips, as a different approach to high-pressure washing decontamination, and confirmed a certain decontamination effect. This paper describes the results of program, “Processing Technology of Radioactive Material Removal by Cross Flow Shredder,” in August to December 2015, on support of FY 2015 Demonstration Test Project for Decontamination and Volume Reduction of Ministry of the Environment. (author)
Electrokinetic decontamination of concrete
Energy Technology Data Exchange (ETDEWEB)
Lomasney, H. [ISOTRON Corp., New Orleans, LA (United States)
1995-10-01
The U.S. Department of Energy has assigned a priority to the advancement of technology for decontaminating concrete surfaces which have become contaminated with radionuclides, heavy metals, and toxic organics. This agency is responsible for decontamination and decommissioning of thousands of buildings. Electrokinetic extraction is one of the several innovative technologies which emerged in response to this initiative. This technique utilizes an electropotential gradient and the subsequent electrical transport mechanism to cause the controlled movement of ionics species, whereby the contaminants exit the recesses deep within the concrete. This report discusses the technology and use at the Oak Ridge k-25 plant.
Kessouri, P.; Buvat, S.; Tabbagh, A.
2012-12-01
Both electrical conductivity and dielectric permittivity of soil are influenced by its water content. Dielectric permittivity is usually measured in the high frequency range, using GPR or TDR, where the sensitivity to water content is high. However, its evaluation is limited by a low investigation depth, especially for clay rich soils. Electrical conductivity is closely related not only to soil water content, but also to clay content and soil structure. A simultaneous estimation of these electrical parameters can allow the mapping of soil water content variations for an investigation depth close to 1m. In order to estimate simultaneously both soil electrical conductivity and dielectric permittivity, an electromagnetic device working in the medium frequency range (between 100 kHz and 10 MHz) has been designed. We adopted Slingram geometry for the EM prototype: its PERP configuration (vertical transmission loop Tx and horizontal measuring loop Rx) was defined using 1D ground models. As the required investigation depth is around 1m, the coil spacing was fixed to 1.2m. This prototype works in a frequency range between 1 and 5 MHz. After calibration, we tested the response of prototype to objects with known properties. The first in situ measurements were led on experimental sites with different types of soils and different water content variations (artificially created or natural): sandy alluvium on a plot of INRA (French National Institute for Agricultural Research) in Orléans (Centre, France), a clay-loam soil on an experimental site in Estrée-Mons (Picardie, France) and fractured limestone at the vicinity of Grand (Vosges, France). In the case of the sandy alluvium, the values of dielectric permittivity measured are close to those of HF permittivity and allow the use of existing theoretical models to determine the soil water content. For soils containing higher amount of clay, the coupled information brought by the electrical conductivity and the dielectric
Cost effectiveness of dilute chemical decontamination
International Nuclear Information System (INIS)
LeSurf, J.E.; Weyman, G.D.
The basic principles of dilute chemical decontamination are described, as well as the method of application. Methods of computing savings in radiation dose and costs are presented, with results from actual experience and illustrative examples. It is concluded that dilute chemical decontamination is beneficial in many cases. It reduces radiation exposure of workers, saves money, and simplifies maintenance work
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
Mohammed, Priscilla N.; Piepmeier, Jeffrey R.; Johnson, Joel T.; Aksoy, Mustafa; Bringer, Alexandra
2015-01-01
The Soil Moisture Active Passive (SMAP) mission, launched in January 2015, provides global measurements of soil moisture using a microwave radiometer. SMAPs radiometer passband lies within the passive frequency allocation. However, both unauthorized in-band transmitters as well as out-of-band emissions from transmitters operating at frequencies adjacent to this allocated spectrum have been documented as sources of radio frequency interference (RFI) to the L-band radiometers on SMOS and Aquarius. The spectral environment consists of high RFI levels as well as significant occurrences of low level RFI equivalent to 0.1 to 10 K. The SMAP ground processor reports the antenna temperature both before and after RFI mitigation is applied. The difference between these quantities represents the detected RFI level. The presentation will review the SMAP RFI detection and mitigation procedure and discuss early on-orbit RFI measurements from the SMAP radiometer. Assessments of global RFI properties and source types will be provided, as well as the implications of these results for SMAP soil moisture measurements.