Electrolyze radioactive contamination away

International Nuclear Information System (INIS)

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

1996-01-01

The Los Alamos National Laboratory Plutonium Facility is using electrolysis to clean the surfaces of hazardous materials. In the past, contaminated metals were cleaned with concentrated acids. Although these treatments make the surfaces safer, they produce other radioactive and toxic wastes in turn. Anodic current passes through a piece of stainless steel submersed in a sodium nitrate solution, and steel dissolves at the surfaces. Surface contamination strips away along with the surface layers. The authors are using this electrolysis approach to remove plutonium and americium from stainless steel and uranium. Unlike acid washing processes, electrolytic decontamination can be accomplished quickly. Little waste is generated regardless of how much material has to be removed from the surface. Material removal is proportional to the applied current, which gives the operator control over the rate and extent of decontamination

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

Bonding of radioactive contamination. III. Auger electron spectroscopic investigation

International Nuclear Information System (INIS)

Rankin, W.N.; Whitkop, P.G.

1983-01-01

The mechanisms by which radioactive contamination would be bonded to a DWPF canister surface are being investigated. Tests with low pressure water and air-injected water decontamination of radioactive specimens showed that bonding of contamination increases rapidly with postoxidation temperature. Even with the least severe temperature conditions expected on the waste glass canister, bonding is so great that decontamination cannot be affected by water-only techniques. A preoxidation film increased rather than decreased bonding. This memorandum describes detailed surface analyses of coupons simulating DWPF canister surfaces. Based on this examination we conclude: contamination will be dispersed throughout the oxide film on DWPF canisters. Contamination is concentrated at the surface, decreasing farther into the oxide film; some samples contain sludge contamination at the steel/oxide interface. This was not the case for semi-volatile (Cs 2 O) contamination; in samples with contamination at the steel/oxide interface, at least 80% of the contamination is usually in the oxide layer; no difference in contamination dispersion between preoxidized and non-preoxidized samples was found; and postoxidation atmosphere had no effect on the contamination dispersion within the oxide layer. 6 references, 9 figures

A model to determine the radiological implications of non-fixed radioactive contamination on the surfaces of packages and conveyances

International Nuclear Information System (INIS)

Hughes, J.S.; Warner Jones, S.M.; Lizot, M.T.; Perrin, M.L.; Thierfeld, S.; Schroedl, E.; Schwarz, G.; Rawl, R.; Munakata, M.; Hirose, M.

2004-01-01

The surfaces of packages and conveyances used to transport radioactive materials can sometimes become contaminated with radioactive material. This usually occurs as a result of the transfer of radioactive material from areas in which these packages and conveyances are handled. This contamination may subsequently be transferred to transport equipment, workers and to areas accessible to the public. This can represent a significant radiation safety issue that requires careful management. The current regulatory limits for non-fixed contamination on packages and conveyances have been in use for over 40 years, and are based on a simple exposure model. However, the bases on which these limits were derived have been subject to changes, as a result of successive revisions of international recommendations. In recognition of this need for a review and analysis of the current contamination limits an IAEA Co-ordinated Research Project (CRP) on the ''Radiological Aspects of Package and Conveyance Non-Fixed Contamination'' was initiated to review the scientific basis for the current regulatory limits for surface contamination. The CRP was also to develop guidance material for evaluating the radiological significance of surface contamination to workers and the public in light of state-of-the-art research, technical developments and current transport practices. The specific objectives of the work undertaken within this multi-national CRP were, in accordance with the terms of reference: To ensure that appropriate models exist for all package types including consideration of the aspects pertinent for assessing and revising a surface contamination model for transport. To collect - where possible - contamination, operational and dosimetric data to ensure modelling consistency. To use models for assessing the limitations and optimisation of radiation doses incurred in transport operations, and to consider preventive methods for package and conveyance contamination

Process for cleaning radioactively contaminated metal surfaces

International Nuclear Information System (INIS)

Mihram, R.G.; Snyder, G.A.

1975-01-01

A process is described for removing radioactive scale from a ferrous metal surface, including the steps of initially preconditioning the surface by contacting it with an oxidizing solution (such as an aqueous solution of an alkali metal permanganate or hydrogen peroxide), then, after removal or decomposition of the oxidizing solution, the metallic surface is contacted with a cleaning solution which is a mixture of a mineral acid and a complexing agent (such as sulfuric acid and oxalic acid), and which preferably contains a corrosion inhibitor. A final step in the process is the treatment of the spent cleaning solution containing radioactive waste materials in solution by adding a reagent selected from the group consisting of calcium hydroxide or potassium permanganate and an alkali metal hydroxide to thereby form easily recovered metallic compounds containing substantially all of the dissolved metals and radioactivity. (auth)

The development of the American national standard, ''control of radioactive surface contamination on materials, equipment and facilities to be released for uncontrolled use''

International Nuclear Information System (INIS)

Shapiro, J.

1980-01-01

The American National Standard, Control of Radioactive Surface Contamination on Materials, Equipment and Facilities to be Released for Uncontrolled Use, was developed under the procedures of ANSI for ANSI Main Committee N13 (Radiation Protection) by a working group of the Health Physics Society Standards Committee. This standard provides criteria for the control of materials, equipment and facilities contaminated with radioactivity proposed to be released for uncontrolled use. Permissible contamination limits are specified as well as methods assessing the levels of contamination. This paper reviews the proceedings of the Subcommittee on Radioactive Surface Contamination, the comments received by reviewers of the standard, the resolution of the committee, and the bases for reaching the final limits, recommendations, and measurement procedures. (H.K.)

Decontamination method for radioactively contaminated material

International Nuclear Information System (INIS)

Shoji, Yuichi; Mizuguchi, Hiroshi; Sakai, Hitoshi; Komatsubara, Masaru

1998-01-01

Radioactively contaminated materials having surfaces contaminated by radioactive materials are dissolved in molten salts by the effect of chlorine gas. The molten salts are brought into contact with a low melting point metal to reduce only radioactive materials by substitution reaction and recover them into the low melting point metal. Then, a low melting point metal phase and a molten salt phase are separated. The low melting point metal phase is evaporated to separate the radioactive materials from molten metals. On the other hand, other metal ions dissolved in the molten salts are reduced into metals by electrolysis at an anode and separated from the molten salts and served for regeneration. The low melting point metals are reutilized together with contaminated lead, after subjected to decontamination, generated from facilities such as nuclear power plant or lead for disposal. Since almost all materials including the molten salts and the molten metals can be enclosed, the amount of wastes can be reduced. In addition, radiation exposure of operators who handle them can be reduced. (T.M.)

Organization of work for prevention of propagation of radioactive contamination, for decontamination of the premise surfaces and individual protective means in case of radiation accident

International Nuclear Information System (INIS)

Klochkov, V.N.; Vas'kin, A.G.; Filatova, V.M.

1995-01-01

Radiation accident results in radioactive contamination of the surface, clothes and other property. If proper measures are taken, it will prevent propagation of contamination. Decontamination of surfaces - is a complicated and tedious process. The paper has examined the measures of organization and technical aspects of prevention of propagation of radioactive contamination. Methods of decontamination of internal surfaces of premises are demonstrated, organization of the individual protective means is determined. 9 refs

Technologies for remediation of radioactively contaminated sites

International Nuclear Information System (INIS)

1999-06-01

This report presents particulars on environmental restoration technologies (control and treatment) which can be applied to land based, radioactively contaminated sites. The media considered include soils, groundwater, surface water, sediments, air, and terrestrial and aquatic vegetation. The technologies addressed in this report can be categorized as follows: self-attenuation (natural restoration); in-situ treatment; removal of contamination; ex-situ treatment; and transportation and final disposal. The report provides also background information about and a general approach to remediation of radioactively contaminated sites as well as some guidance for the selection of a preferred remediation technology. Examples of remediation experience in Australia and Canada are given it annexes

Technologies for remediation of radioactively contaminated sites

Energy Technology Data Exchange (ETDEWEB)

1999-06-01

This report presents particulars on environmental restoration technologies (control and treatment) which can be applied to land based, radioactively contaminated sites. The media considered include soils, groundwater, surface water, sediments, air, and terrestrial and aquatic vegetation. The technologies addressed in this report can be categorized as follows: self-attenuation (natural restoration); in-situ treatment; removal of contamination; ex-situ treatment; and transportation and final disposal. The report provides also background information about and a general approach to remediation of radioactively contaminated sites as well as some guidance for the selection of a preferred remediation technology. Examples of remediation experience in Australia and Canada are given it annexes Refs, figs, tabs

Radioactive contamination level of vehicles resulted from transporting fine rare-earth minerals by rail

International Nuclear Information System (INIS)

Han Kaichun; Yu Boyong; Gao Shengwei

1997-01-01

This paper presents monitoring results of radioactive contamination level of steel open wagon surface resulted from transporting fine rare-earth minerals. Under promising transport conditions (the packaging consists of two layers of plastic bags and two layers of plastic net sacks, each package contains 50 kg of minerals, each vehicle carries 60 t), the surface radioactivity (total α and total β) of 16 vehicles on two lines from Baotou to Wujiachuan (924 km) and from Baotou to Sankeshu (2236 km) was measured before loading, after unloading and washing, using α and β surface contamination detector. The results showed that the radioactive contamination level of the vehicle surface after unloading appeared significantly different. The contamination level of vehicle bases was higher than that of both sides, long distance vehicles was higher than that of short distance vehicles. The radioactive contamination level of vehicles surface after washing was below the standard limits, these vehicles can be used for ordinary goods transport

Trench 'bathtubbing' and surface plutonium contamination at a legacy radioactive waste site.

Science.gov (United States)

Payne, Timothy E; Harrison, Jennifer J; Hughes, Catherine E; Johansen, Mathew P; Thiruvoth, Sangeeth; Wilsher, Kerry L; Cendón, Dioni I; Hankin, Stuart I; Rowling, Brett; Zawadzki, Atun

2013-01-01

Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (~12 Bq/L of (239+240)Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest (239+240)Pu soil activity was 829 Bq/kg in a shallow sample (0-1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the 'bathtub' effect.

ASSESSMENT OF RADIOACTIVE AND NON-RADIOACTIVE CONTAMINANTS FOUND IN LOW LEVEL RADIOACTIVE WASTE STREAMS

International Nuclear Information System (INIS)

R.H. Little, P.R. Maul, J.S.S. Penfoldag

2003-01-01

This paper describes and presents the findings from two studies undertaken for the European Commission to assess the long-term impact upon the environment and human health of non-radioactive contaminants found in various low level radioactive waste streams. The initial study investigated the application of safety assessment approaches developed for radioactive contaminants to the assessment of nonradioactive contaminants in low level radioactive waste. It demonstrated how disposal limits could be derived for a range of non-radioactive contaminants and generic disposal facilities. The follow-up study used the same approach but undertook more detailed, disposal system specific calculations, assessing the impacts of both the non-radioactive and radioactive contaminants. The calculations undertaken indicated that it is prudent to consider non-radioactive, as well as radioactive contaminants, when assessing the impacts of low level radioactive waste disposal. For some waste streams with relatively low concentrations of radionuclides, the potential post-closure disposal impacts from non-radioactive contaminants can be comparable with the potential radiological impacts. For such waste streams there is therefore an added incentive to explore options for recycling the materials involved wherever possible

Evaluation of indigenously developed plastic scintillator sheet detector for surface radioactive contamination monitoring application

International Nuclear Information System (INIS)

Sahani, R.M.; Chaudhary, H.S.; Mahala, V.K.; Senwar, K.R.; Meena, J.P.

2018-01-01

Radioactive contamination may be caused by release of radioactivity in the environment due to accident at nuclear plant/reactor or spillage of loose radioactive materials in a laboratory. The protection of workers from potentially hazardous radiations emitted by the contaminants is a matter of prime concern. The detection of such radiations requires a monitoring system capable of measuring the level of radioactivity at the contaminated site. Plastic scintillators are widely used for large area radiation monitoring due to the ease of preparation in different shape and sizes. These detectors are sensitive to beta and gamma radiation therefore can be used for monitoring of beta and gamma contamination. In this paper, performance results of indigenously developed plastic scintillator sheet of area 800 cm 2 are reported

Characteristics of radioactive contamination of vegetables derived from the Fukushima nuclear accident

International Nuclear Information System (INIS)

Shiba, Kazuhiro; Kitamura, Yoji; Kozaka, Takashi; Uno, Izumi; Shimizu, Kikuo; Hirota, Masahiro; Higaki, Shogo; Masumoto, Kazuyoshi

2012-01-01

We examined the characteristics of the radioactive contamination and the physical removal of radioactivity from contaminated cabbage and spinach. In a distribution imaging study, there were two types of contamination, spot type and spread type, of cabbage and spinach. The relative radioactivity (PSL) of the face of the leaf was much higher than that of the back of a leaf of cabbage. The ratio of relative radioactivity (PSL) between spot contamination and spread contamination in a leaf of spinach was 9.4% and 90.6%, respectively. More than 80% of radioactivity attaches to the surface of leaves of spinach. There was no significant difference of radioactivity removal between hand-washing and rinsing with running water. The degree of removal of radioactivity from contaminated spinach depended on the length of time between contamination and rinsing. When contaminated spinach was rinsed within 1 week after contamination, the removal ratio of 131 I and 137 Cs was high, with 50% and 70%, respectively. When rinsing contaminated spinaches more than 2 weeks after contamination, the removal ratio of 131 I and 137 Cs was low, approximately 34% and 69%, respectively. (author)

Low-waste technology of prevention, decontamination and localization of radioactive contamination

International Nuclear Information System (INIS)

Kizhnerov, L. V.; Konstantinov, Ye. A.; Prokopenko, V. A.; Sorokin, N. M.

1997-01-01

The report presents the results of research in developing a low-waste technology of prevention, decontamination and localization of radioactive contamination founded on the of easily removed protective polymeric coating based on water and alcohol latexes and dispersion of polymers with special activating additives. The developed technology provides for the reduction of weakly fixed radioactive contamination of non-painted and painted surfaces to admissible levels (as a rule), it securely prevents and localizes contamination and does not generate secondary liquid radioactive wastes

Radioactive contamination in imported foods

International Nuclear Information System (INIS)

Kan, Kimiko; Maki, Toshio; Nagayama, Toshihiro; Hashimoto, Hideki; Kawai, Yuka; Kobayashi, Maki; Shioda, Hiroko; Nishima, Taichiro

1990-01-01

On April 26, 1986, explosion occurred in Chernobyl nuclear power station in USSR, and radioactivity contamination was brought about in almost all countries in the world. In European countries, crops were contaminated directly with radioactive fallout to high concentration. Also in Japan, after one week the radioactivity higher than usual was detected in environment, and also in vegetables, milk, tea leaves and others. Thereafter, in order to cope with the import of contaminated foods, inspection and watch system was strengthened by deciding the interim limit of radioactive concentration. However the cases of exceeding the interim limit were often reported. In order to remove the harmful foods due to radioactive contamination and to meet the fear of consumers, the authors measured the radioactive concentration in foods distributed in Tokyo and investigated the actual state of contamination. The samples were 920 imported foods. The experimental method, the preparation of samples, the method of analysis and the results are reported. The samples in which the radioactive concentration exceeding 50 Bq/kg was detected were 25 cases. The food having the high frequency of detection was flavors. (K.I.)

Surface contamination technology in decommissioning of nuclear fuel cycle

International Nuclear Information System (INIS)

Ishiguro, Hideharu

2012-01-01

Surface contamination measurement is the most basic technology in radiation control of the nuclear and radiation facilities. Loose surface contamination causes internal exposure through airborne contamination. Surface contamination measurement is recently more important in the waste management such as confirmation of decontamination factor, contamination survey of carried-out materials from radioactive control area, and application of clearance level. This report describes the base of surface contamination standards, meaning of contamination in decommissioning, relationship between clearance level and surface contamination, and current technology of surface contamination measurement. (author)

49 CFR 175.705 - Radioactive contamination.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Radioactive contamination. 175.705 Section 175.705... Regulations Applicable According to Classification of Material § 175.705 Radioactive contamination. (a) A... (radioactive) materials that may have been released from their packagings. (b) When contamination is present or...

Substantiation of the permissible radioactive contamination of working clothes

International Nuclear Information System (INIS)

Shcherbakov, V.L.; Korostin, A.S.

1977-01-01

A permissible level of working clothes contamination was determined on the base of the main migration routes of radioactive contaminants: permeation directly through the clothes into subclothes space on skin surface, emission into the air with amount of contaminants subsequently got by the organism of a working person through inhalation as well as transfer in the process of contacting of contaminated working clothes and surfaces of premises equipment, working person hands with amount of contaminants posteriorly got by the organism by alimentary or inhalation ways. Using the experimental and literature data available the permissible levels of working clothes contamination for the mentioned migration routes of radioactive materials have been calculated. According to the data obtained the permissible levels of working clothes contamination must not exceed 4 alpha-part/(cm 2 xmin) for contamination with high-tonic isotopes, 20 alpha-part./(cm 2 xmin) with other alpha-detine isotopes, 1000 beta-part./(cm 2 xmin) with beta-active ones. The permissible level of contamination of additional materials of the individual protection in the case of their contamination with high-tonic alpha-actine isotopes must not exceed 50 alpha-part./(cm 2 xmin), 200 alpha-part./(cm 2 xmin) for contamination th other alpha-active isotopes and 400 beta-part./(cm 2 xmin) with beta-active isotopes

Surface soil contamination standards

International Nuclear Information System (INIS)

Boothe, G.F.

1979-01-01

The purpose of this document is to define surface soil contamination limits for radioactive materials below which posting, restrictions and environmental controls are not necessary in order to protect personnel and the environment. The standards can also be used to determine if solid waste or other material is contaminated relative to disposal requirements. The derivation of the standards is given

Early-stage bioassay for monitoring radioactive contamination in living livestock.

Science.gov (United States)

Yamaguchi, Toshiro; Sawano, Kaita; Kishimoto, Miori; Furuhama, Kazuhisa; Yamada, Kazutaka

2012-12-01

Soil samples from the ground surface and feces and blood from a mixed-breed male pig were collected on April 10, 2011 at a farm within 20 km of the Fukushima Daiichi nuclear power plant. The radioactivity of each sample was measured using a Ge semiconductor detector. Despite the fact that the pig had been fed non-contaminated imported feed, (131)I, (134)Cs and (137)Cs were detected in the feces, and (134)Cs and (137)Cs were detected in the blood clots. Because it is considerably difficult to measure radioactive contamination in the edible muscle of living livestock, bioassays are an option for the screening of radioactive contamination in living livestock to ensure food safety.

A model for evaluating the radioactive contamination in the urban environment

International Nuclear Information System (INIS)

Hwang, Won Tae; Kim, Eun Han; Jeong, Hyo Joon; Suh, Kyung Suk; Han, Moon Hee

2005-01-01

A model for evaluating radioactive contamination in the urban environment, named METRO-K, was developed as a basic step for accident consequence analysis in case of an accidental release. The three kind of radionuclides ( 137 Cs, 106 Ru, 131 I) and the different chemical forms of iodine (particulate, organic and elemental forms) are considered in the model. The radioactive concentrations are evaluated for the five types of surface (roof, paved road, wall, lawn/soil, tree) as a function of time. Using the model, the contaminative impacts of the surfaces were intensively investigated with respect to with and without precipitation during the measurement periods of radionuclides in air. In addition, a practical application study was conducted using 137 Cs concentration in air and precipitation measured in an European country at the Chernobyl accident. As a result, precipitation was an influential factor in surface contamination. The degree of contamination was strongly dependent on the types of radionuclide and surface. Precipitation was more influential in contamination of 137 Cs than that of 131 I (elemental form)

Radiation exposure to skin following radioactive contamination

International Nuclear Information System (INIS)

Baumann, H.; Beyermann, M.; Kraus, W.

1989-01-01

In the case of skin contamination intensive decontamination measures should not be carried out until the potential radiation exposure to the basal cell layer of the epidermis was assessed. Dose equivalent rates from alpha-, beta- or photon-emitting contaminants were calculated with reference to the surface activity for different skin regions as a function of radiation energy on the condition that the skin was healthy and uninjured and the penetration of contaminants through the epidermis negligible. The results have been presented in the form of figures and tables. In the assessment of potential skin doses, both radioactive decay and practical experience as to the decrease in the level of surface contamination by natural desquamation of the stratum corneum were taken into account. 9 figs., 5 tabs., 46 refs. (author)

Trench ‘Bathtubbing’ and Surface Plutonium Contamination at a Legacy Radioactive Waste Site

Science.gov (United States)

2013-01-01

Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (∼12 Bq/L of 239+240Pu in 0.45 μm-filtered water), and there is an associated contamination of Pu in surface soils. The highest 239+240Pu soil activity was 829 Bq/kg in a shallow sample (0–1 cm depth) near the trench sampling point. Away from the trenches, the elevated concentrations of Pu in surface soils extend for tens of meters down-slope. The broader contamination may be partly attributable to dispersion events in the first decade after disposal, after which a layer of soil was added above the trenched area. Since this time, further Pu contamination has occurred near the trench-sampler within this added layer. The water level in the trench-sampler responds quickly to rainfall and intermittently reaches the surface, hence the Pu dispersion is attributed to saturation and overflow of the trenches during extreme rainfall events, referred to as the ‘bathtub’ effect. PMID:24256473

Radioactive air and surface contamination in Czechia and Slovakia

International Nuclear Information System (INIS)

Rumyantsev, V.V.

1992-01-01

Data are presented on the radioactive substance effluents into the environment in conditions of NPP normal operation and on the air contamination by 85 Kr due to operation of the European and Soviet plants for reprocessing spent nuclear fuel. Data are given on the dosage of the Czechoslovakia population due to the Chernobyl NPP accident

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.)

Radioactive contamination in imported foods (II)

International Nuclear Information System (INIS)

Kan, Kimiko; Maki, Toshio; Hashimoto, Hideki; Kawai, Yuka; Nagayama, Toshihiro; Kobayashi, Maki; Shioda, Hiroko; Nishima, Taichiro

1991-01-01

Five years have elapsed since the Chernobyl accident, but the effect of radioactivity contamination to foods has continued. Also in Japan, the imported foods which were ordered by the Ministry of Health and Welfare to be sent back due to radioactivity contamination do not cease. In fiscal year 1990, three cases occurred: tea from Albania, mushrooms from Yugoslavia and spices from france. If those are not checked at quarantines, it is feared that such foods are distributed in Japan. Among the foods which were ordered to be sent back in the past, there were those from Brazil and Hong Kong where the effect of the Chernobyl accident is little, and the foods contaminated with radioactivity spread worldwide through import and export. Therefore, attention must be paid to the foods from the countries where radioactivity contamination is little. Also it is feared that Japanese foods may be contaminated by being cultivated with imported feed, soil and fertilizer, for which there is no regulation. In this report, the radioactivity contamination of imported foods in fiscal year 1990 is described, and the experimental method and the results are reported. (K.I.)

Examination of a measuring method for fallout radioactivity released by the accident of the Fukushima Dai-ichi NPS. Surface contamination measurement

International Nuclear Information System (INIS)

Yoshii, Taiki; Kawasaki, Satoru

2013-08-01

Radioactive nuclides were released in the atmosphere by the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Station in March, 2011, and they are detected on the materials that had no artificial radioactive nuclides before the accident. Confronted with this situation, NISA issued a guideline titled 'A guideline regarding treatment of materials in nuclear facilities considering the influence of fallout released from the accident of TEPCO's Fukushima Dai-ichi Nuclear Power Station' on March 30, 2012. Nuclear Regulatory Authority refers to applying the existing bylaw until the time to make decision of the updated bylaw. The guideline shows that after judging whether there is the influence of fallout or not, the conventional clearance and NR systems can be used when there is no influence of fallout. On the other hand, the special treatment is required when it is judged that there is the influence. This report describes a specific example of measuring method to evaluate the influence of fallout, in case of surface contamination. This report focused surface contamination of flat object as target. Preliminary investigation shows that the distribution of surface contamination due to fallout is near to lognormal distribution. Therefore, the sampling measurement can be adopted. The average surface contamination of target is decided from sampling data by using 90% upper confidence limit of Chebyshev inequality. Also, the minimum sampling number is decided. The evaluation of the influence of fallout is judged from the result of surface contamination measurement, weight of target and surface area of target. (author)

Method of electrolytic decontamination of contaminated metal materials for radioactivity

International Nuclear Information System (INIS)

Harada, Yoshio; Ishibashi, Masaru; Matsumoto, Hiroyo.

1985-01-01

Purpose: To electrolytically eliminate radioactive materials from metal materials contaminated with radioactive materials, as well as efficiently remove metal ions leached out in an electrolyte. Method: In the case of anodic dissolution of metal materials contaminated with radioactivity in an electrolyte to eliminate radioactive contaminating materials on the surface of the metal materials, a portion of an electrolytic cell is defined with partition membranes capable of permeating metal ions therethrough. A cathode connected to a different power source is disposed to the inside of the partition membranes and fine particle of metals are suspended and floated in the electrolyte. By supplying an electric current between an insoluble anode disposed outside of the partition membranes and the cathode, metal ions permeating from the outside of the partition membranes are deposited on the fine metal particles. Accordingly, since metal ions in the electrolyte are removed, the electrolyte can always be kept clean. (Yoshihara, H.)

Predicting the radioactive contamination of the surroundings near a nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Khristova, M; Paskalev, Z

1975-01-01

Predicting the radioactive contamination requires determining the concentration of radioactive material emitted from the stack of a nuclear power plant into the air and deposited on the earth's surface. The main factors determining the degree of contamination are the distance from the stack, the wind velocity and air turbulence. Formulas are presented for predicting the amount of radioactivity as a function of the initial concentration of activity, the distance from the stack and the meteorological condition. Formulas are given for the maximum deposition of radioactive aerosols at a distance R from the stack under wet and dry condtions. 2 refs. (SJR)

Development of portable and automatic smear sampler for measuring surface contamination

Energy Technology Data Exchange (ETDEWEB)

Lee, Bong Jae; Chang, S. Y.; Kim, B. H.; Kim, J. S.; Lee, H. S.; Kim, C. K.; Swol, C. W

2000-12-01

In measuring radioactive contamination in radiation controlled area of nuclear facility, the technical criteria to evaluate surface contamination level and to sample by indirect method was established in this paper. Radioactive materials always present on surface within operating nuclear facilities. Because of the presence of interfering radiation field, health physicists take smear samples to monitoring surface contamination according to routine monitoring program. But there are some problems like great errors and difference of personnel. Then, to solve them, The portable and automatic smear sampling apparatus was designed and fabricated.

Development of portable and automatic smear sampler for measuring surface contamination

International Nuclear Information System (INIS)

Lee, Bong Jae; Chang, S. Y.; Kim, B. H.; Kim, J. S.; Lee, H. S.; Kim, C. K.; Swol, C. W.

2000-12-01

In measuring radioactive contamination in radiation controlled area of nuclear facility, the technical criteria to evaluate surface contamination level and to sample by indirect method was established in this paper. Radioactive materials always present on surface within operating nuclear facilities. Because of the presence of interfering radiation field, health physicists take smear samples to monitoring surface contamination according to routine monitoring program. But there are some problems like great errors and difference of personnel. Then, to solve them, The portable and automatic smear sampling apparatus was designed and fabricated

Survey of radioactive contamination for foodstuffs

International Nuclear Information System (INIS)

Lee, Wan No; Lee, Chang Wu; Choi, Geun Sik; Cho, Yeong Hyeon; Kang, Mun Ja; Cheong, Geun Ho; Kim, Hui Ryeong; Park, Du Won; Park, Hyo Guk; Kwak, Ji Yeon

2006-11-01

After the Chernobyl nuclear accident in 1986, a lot of countries including EU, Japan, USA are to strengthen survey of radioactive contamination for foodstuffs. Our country has also surveyed radioactive contamination of the imported foodstuffs and started to check continuously the radioactivity contamination of the open market foodstuffs since 2003. In this year, imported foodstuffs(130 samples) and domestic foodstuffs(10 samples) are analyzed to investigate the radioactive contamination. Sampled foodstuffs items are collected from the open markets; one group is the imported foodstuffs and the other group is the domestic foodstuffs producted around nuclear facilities and northeast of Sokcho city concerning recent situations. Samples are usually bought from traditional markets, mart, department store or the Internet. After pretreatments such as drying, ashing, and homogenization, all samples were analyzed by gamma spectrometer system for survey and assessment of radioactive contamination. The 131 I radionuclide isn't detected among all foodstuffs(imported and domestic). The 137 Cs radionuclide among the regulation radionuclides( 137 Cs, 13 4 C s, 131 I) of food code is only detected at the imported foodstuffs but its level is far below the maximum permitted level. For the improvement of measurement confidence, the developed analysis method is tested by the participation of the national and international intercomparison. The developed method based on test results and international standard would be used at radioactive analysis as well as an education of relative workers. It could be applied as the basis data for amending the analysis method of food code. It is technically supported for radioactive analysis of commercial company and the government including KFDA. Finally these results would be used to solve an ambiguous anxiety of a people for radiation exposure by foodstuffs intake and help the KFDA to manage systematically the radioactive contamination and to give

Soil magnetic susceptibility as indicator of radioactive contamination

International Nuclear Information System (INIS)

Curda, S.

2006-01-01

Measurement of magnetic susceptibility is a method, which is used in many areas of research. The locality Ak-Tjuz is typical example of old ecological load. One of the negative effects represents radioactive contamination. This situation is caused by environmental disaster in 1964. For useful reparation it is really necessary to determinate the surface range of contamination. And measurement of the magnetic susceptibility could be the suitable method for that kind of monitoring. (author)

Final report: survey and removal of radioactive surface contamination at environmental restoration sites, Sandia National Laboratories/New Mexico. Volume 1

International Nuclear Information System (INIS)

Lambert, K.A.; Mitchell, M.M.; Jean, D.; Brown, C.; Byrd, C.S.

1997-09-01

This report describes the survey and removal of radioactive surface contamination at Sandia's Environmental Restoration (ER) sites. Radiological characterization was performed as a prerequisite to beginning the Resource Conservation and Recovery Act (RCRA) corrective action process. The removal of radioactive surface contamination was performed in order to reduce potential impacts to human health and the environment. The predominant radiological contaminant of concern was depleted uranium (DU). Between October 1993 and November 1996 scanning surface radiation surveys, using gamma scintillometers, were conducted at 65 sites covering approximately 908 acres. A total of 9,518 radiation anomalies were detected at 38 sites. Cleanup activities were conducted between October 1994 and November 1996. A total of 9,122 anomalies were removed and 2,072 waste drums were generated. The majority of anomalies not removed were associated with a site that has subsurface contamination beyond the scope of this project. Verification soil samples (1,008 total samples) were collected from anomalies during cleanup activities and confirm that the soil concentration achieved in the field were far below the target cleanup level of 230 pCi/g of U-238 (the primary constituent of DU) in the soil. Cleanup was completed at 21 sites and no further radiological action is required. Seventeen sites were not completed since cleanup activities wee precluded by ongoing site activity or were beyond the original project scope

Final report: survey and removal of radioactive surface contamination at environmental restoration sites, Sandia National Laboratories/New Mexico. Volume 1

Energy Technology Data Exchange (ETDEWEB)

Lambert, K.A.; Mitchell, M.M. [Brown and Root Environmental, Albuquerque, NM (United States); Jean, D. [MDM/Lamb, Inc., Albuquerque, NM (United States); Brown, C. [Environmental Dimensions, Inc., Albuquerque, NM 87109 (United States); Byrd, C.S. [Sandia National Labs., Albuquerque, NM (United States)

1997-09-01

This report describes the survey and removal of radioactive surface contamination at Sandia`s Environmental Restoration (ER) sites. Radiological characterization was performed as a prerequisite to beginning the Resource Conservation and Recovery Act (RCRA) corrective action process. The removal of radioactive surface contamination was performed in order to reduce potential impacts to human health and the environment. The predominant radiological contaminant of concern was depleted uranium (DU). Between October 1993 and November 1996 scanning surface radiation surveys, using gamma scintillometers, were conducted at 65 sites covering approximately 908 acres. A total of 9,518 radiation anomalies were detected at 38 sites. Cleanup activities were conducted between October 1994 and November 1996. A total of 9,122 anomalies were removed and 2,072 waste drums were generated. The majority of anomalies not removed were associated with a site that has subsurface contamination beyond the scope of this project. Verification soil samples (1,008 total samples) were collected from anomalies during cleanup activities and confirm that the soil concentration achieved in the field were far below the target cleanup level of 230 pCi/g of U-238 (the primary constituent of DU) in the soil. Cleanup was completed at 21 sites and no further radiological action is required. Seventeen sites were not completed since cleanup activities wee precluded by ongoing site activity or were beyond the original project scope.

The development of the American National Standard 'control of radioactive surface contamination on materials equipment and facilities to be released for uncontrolled use'

International Nuclear Information System (INIS)

Shapiro, J.

1980-01-01

A new standard submitted by the Health Physics Society Standards Committee to the American National Standards Institute concerning radioactive surface contamination of materials and equipment is discussed. The chronological events in the development of this standard are given. The standard provides criteria for the release for uncontrolled use of materials, equipment and facilities contaminated or potentially contaminated with radioactivity. Permissible contamination limits are specified for: 1) long lived alpha emitters except natural uranium and thorium, 2) more hazardous beta-gamma emitters, 3) less hazardous beta-gamma emitters and 4) natural uranium and thorium. A contamination reference level of 1000 dpm/100 cm 2 for 90 Sr was set as the basis for assigning limits to radionuclides presenting an ingestion hazard and other radionuclides were grouped based on the values of their maximum permissible concentration (MPC) in water relative to 90 Sr. The contamination limit for 239 Pu was chosen as the basis for assigning limits based on MPC in air to radionuclides presenting an inhalation hazard; a value of 100 dpm/100 cm 2 was adopted in the standard. An upper limit of 5000 dpm/100 cm 2 for surface contamination was selected for the standard. (UK)

Internal radioactive contamination treatment

International Nuclear Information System (INIS)

Tobajas, L. M.

1998-01-01

In a radiological emergency, the internal radioactive contamination becomes a therapeutic urgency and must be established as fast as possible. Just when a radioactive contamination accident occurs, it is difficult to know exactly the amount of radioactive materials absorbed and to estimate the dose received.. The decision to be taken after the incorporation of the radioactive material depends on the method and on the Radiological Protection Department collaboration. Any treatment achieving a reduction of the doses received or expected will be useful. The International Radiological Protection Commission doesn't recommend the use of the dose limit, to decide about the intervention necessity. However the LIA can be used as the reference point to establish the necessity and reach of the treatment. The object of the present work, is to introduce the general principles to carry out the internal people decontamination, under the last international recommendations. (Author) 4 refs

Transboundary Movement of Radioactively Contaminated Scrap Metal - Lessons Learned

Energy Technology Data Exchange (ETDEWEB)

Nizamska, M., E-mail: m.nimzamska@bnra.bg [Emergency Planning and Preparedness Division, Bulgarian Nuclear Regulatory Agency, Sofia (Bulgaria)

2011-07-15

Starting in 1989, Bulgaria has undergone a comprehensive transformation of its economy and social conditions. Part of this process is related to the intensive privatization that started in 2001. This privatization included facilities, as well as sites that use radioactive material for different applications - industry, medicine, agriculture, science, etc. The rapid change of property ownership and, in some cases, the resulting bankruptcy, has caused difficulties in tracing and identifying radioactive sources and materials and a deterioration of the system of safety, physical protection, etc. of radioactive material. In some cases, radioactive sources were stolen because of the value of their protective containers and sold for scrap metal. This led to the occurrence of different types of radiation incidents, mainly related to the discovery of radioactive sources in scrap metal. The consequences of these incidents include the risk of radiation exposure of the workers at scrap metal yards or reprocessing facilities and of members of the public and, in addition, radioactive contamination of the environment. The Bulgarian Nuclear Regulatory Agency (BNRA) has been responding to these incidents and has carried out a series of measures to improve the control over materials (e.g. activated or surface contaminated materials) and radioactive sources and to strengthen the preventive, monitoring, emergency preparedness and mitigating measures at facility, national and transboundary levels. This paper presents an analysis of the lessons learned by the BNRA and of the control of the transboundary movement of radioactively contaminated scrap metal through the territory of Bulgaria. (author)

10 CFR 39.69 - Radioactive contamination control.

Science.gov (United States)

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Radioactive contamination control. 39.69 Section 39.69... Radiation Safety Requirements § 39.69 Radioactive contamination control. (a) If the licensee detects evidence that a sealed source has ruptured or licensed materials have caused contamination, the licensee...

Decontamination of radioactively contaminated surfaces - Testing of decontamination agents for textiles. 1. ed.

International Nuclear Information System (INIS)

1992-01-01

The present International Standard provides an experimental method for determining the efficiency of the agents for removal radionuclides deposited on textile materials. It applies to testing the detergents which might be used in water solution for cleaning textiles contaminated by radioactive elements. It is applicable for testing the efficiency of detergents for eliminating non-radioactive dirt

Analysis of surface contributions to external doses in a radioactively contaminated urban environment designed by the EMRAS-2 Urban Areas Working Group

International Nuclear Information System (INIS)

Hwang, Won Tae; Jeong, Hae Sun; Jeong, Hyo Joon; Kim, Eun Han; Han, Moon Hee; Kim, In Gyu

2013-01-01

Highlights: ► External dose and contribution from radio-activated surface were evaluated for EMRAS-2 Urban Areas Working Group scenarios. ► The external doses showed a distinctive difference with the locations and precipitation. ► The contribution of contaminated surfaces for external dose depends on locations and precipitation. ► These results provide the essential information for decision-making support of countermeasures. - Abstract: The EMRAS-2 Urban Areas Working Group, which is supported by the IAEA, has designed a variety of accidental scenarios to test and improve the capabilities of the models used for an evaluation of radioactive contamination in an urban environment. A variety of models including a Korean model, METRO-K, are used for predictive results on the hypothetical scenarios. This paper describes the predictive results of METRO-K for the hypothetical scenarios designed in the Working Group. The external dose resulting from the air contamination of Co-60 was evaluated, and its contribution was analyzed with time as a function of the location of a receptor and precipitation conditions at the time of the contamination event. As a result, the external doses showed a distinctive difference with the locations to be evaluated and the precipitation conditions. Moreover, the contribution of contaminated surfaces for external doses was strongly dependent on the locations to be evaluated and the precipitation conditions. These results will provide essential information to assist the decision-making of appropriate countermeasures in an emergency situation of a radioactively contaminated urban environment

Remediation of sites with dispersed radioactive contamination

International Nuclear Information System (INIS)

2004-01-01

disciplines, including the health sciences, chemistry, physics, geology, microbiology and environmental engineering, is necessary in order to develop technical solutions. It is also necessary to include information on the political, social and economic context. This report describes remediation techniques that are applicable to dispersed radioactive contamination at a variety of sites, including surface soil, the vadose zone, surface water, sediments and groundwater

use of the RESRAD-BUILD code to calculate building surface contamination limits

International Nuclear Information System (INIS)

Faillace, E.R.; LePoire, D.; Yu, C.

1996-01-01

Surface contamination limits in buildings were calculated for 226 Ra, 230 Th, 232 Th, and natural uranium on the basis of 1 mSv y -1 (100 mrem y -1 ) dose limit. The RESRAD-BUILD computer code was used to calculate these limits for two scenarios: building occupancy and building renovation. RESRAD-BUILD is a pathway analysis model designed to evaluate the potential radiological dose incurred by individuals working or living inside a building contaminated with radioactive material. Six exposure pathways are considered in the RESRAD-BUILD code: (1) external exposure directly from the source; (2) external exposure from materials deposited on the floor; (3) external exposure due to air submersion; (4) inhalation of airborne radioactive particles; (5) inhalation of aerosol indoor radon progeny; and (6) inadvertent ingestion of radioactive material, either directly from the sources or from materials deposited on the surfaces. The code models point, line, area, and volume sources and calculates the effects of radiation shielding, building ventilation, and ingrowth of radioactive decay products. A sensitivity analysis was performed to determine how variations in input parameters would affect the surface contamination limits. In most cases considered, inhalation of airborne radioactive particles was the primary exposure pathway. However, the direct external exposure contribution from surfaces contaminated with 226 Ra was in some cases the dominant pathway for building occupancy depending on the room size, ventilation rates, and surface release fractions. The surface contamination limits are most restrictive for 232 Th, followed by 230 Th, natural uranium, and 226 Ra. The results are compared with the surface contamination limits in the Nuclear Regulatory Commission's Regulatory Guide 1.86, which are most restrictive for 226 Ra and 230 Th, followed by 232 Th, and are least restrictive for natural uranium

Radioactive contamination of the Guatemalan marine environment

International Nuclear Information System (INIS)

Perez-Sabino, J.F.; Oliva de Sandoval, B.E.; Orozco-Chilel, R.M.; Aguilar-Sandoval, E.

1999-01-01

As part of the IAEA TC project GUA/2/005 'Radioactivity and Contamination of the Marine Environment in Guatemala', concentrations of artificial and natural radionuclides have been determined in marine water and sediments, giving important information to establish the base line of the natural radioactivity and the radioactive contamination in this area that not have been studying

Environmental radioactivity and water supply. Pt. 3. The contamination of surface waters in Germany after the Chernobyl reactor accident

International Nuclear Information System (INIS)

Haberer, K.

1988-03-01

After the reactor accident, german surface waters have been monitored in numerous positions over a long period of time. The highest concentrations of iodine 131 occurred in the lower german region of the Danube river with more than 200 Bg/l whereas the Rhine river had the lowest concentrations. The sudden rise of the radioactivity of the river water have been followed by a slower decrease but nevertheless much faster than the radioactive decay. Probably this is caused by the interaction with river sediments. For the german lakes and reservoirs it was very important whether the water masses have been stratified or not when the radioactive cloud arrived. Where this was the case, the radioactive contaminants remained predominantly in the upper layer, the epilimnion for a long period of time [fr

Measurement of radioactive contamination and decontamination on wooden exteriors and garden trees in Northern Fukushima Prefecture

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)

Radioactive contamination of recycled metals

International Nuclear Information System (INIS)

Lubenau, J.O.; Cool, D.A.; Yusko, J.G.

1996-01-01

Radioactive sources commingled with metal scrap have become a major problem for the metals recycling industry worldwide. Worldwide there have been 38 confirmed reports of radioactive sources accidentally smelted with recycled metal. In some instances, contaminated metal products were subsequently distributed. The metal mills, their products and byproducts from the metal making process such as slags, crosses and dusts from furnaces can become contaminated. In the U.S., imported ferrous metal products such as reinforcement bars, pipe flanges, table legs and fencing components have been found contaminated with taco. U.S. steel mills have unintentionally smelted radioactive sources on 16 occasions. The resulting cost for decontamination waste disposal and temporary closure of the steel mill is typically USD 10,000,000 and has been as much as USD 23,000,000. Other metal recycling industries that have been affected by this problem include aluminum, copper, zinc, gold, lead and vanadium. (author)

Measurement of radioactive soil contamination from the air

International Nuclear Information System (INIS)

Loman, A.C.; Kuile, C.R. ter; Slaper, H.

1990-09-01

In-situ gamma spectrometry can be used to determine the qualitative and quantitative deposition of radioactive materials on the ground surface. By applying the in-situ spectrometry method using either a helicopter or an airplane, large areas can be scanned in a short period of time. In this report the results of in-situ gamma spectroscopic measurements taken from a helicopter are described. Measurements were carried out using a single point source, a field of 36 point sources, and using the present ground contamination due to fall-out from the Chernobyl accident and atom bombs. The results of these measurements were used to determine calibration factors, which were in agreement with a calibration obtained using more simple (and less expensive) laboratory measurements in combination with flux calculations. Detection limits for the measurement of surface contamination were determined. At a height of 50 meters above the surface and using a measurement time of 2 minutes, the minimally detectable surface contamination was 1.1 kBqm -2 for a Cs-137 contamination and 2.1 kBqm -2 for I-131 contamination. Fall-out determinations based on measurements taken at a height of 50 meters were in agreement with determinations taken at a height of 1 meter, and with the results obtained measuring soil samples. The in-situ gamma spectroscopy, using helicopter or airplane, is a fast and powerful method for mapping surface contamination. (author). 13 refs.; 18 figs.; 13 tabs

Radioactive contamination of the Guatemalan marine environment

Energy Technology Data Exchange (ETDEWEB)

Perez-Sabino, J F; Oliva de Sandoval, B E; Orozco-Chilel, R M; Aguilar-Sandoval, E [Universidad de San Carlos de Guatemala, Facultad de Ciencias Quimicas y Farmacia, Unidad de Analisis Instrumental, Guatemala C.A. (Guatemala)

1999-07-01

As part of the IAEA TC project GUA/2/005 `Radioactivity and Contamination of the Marine Environment in Guatemala`, concentrations of artificial and natural radionuclides have been determined in marine water and sediments, giving important information to establish the base line of the natural radioactivity and the radioactive contamination in this area that not have been studying 4 refs, 1 fig., 4 tabs

Criteria for the designation of radioactively contaminated land

International Nuclear Information System (INIS)

Titley, J.; Mobbs, S.; Burgess, P.; Hitchins, G.; Sinclair, P.

1999-01-01

This report examines the criteria for the designation of radioactively contaminated land. It should be read in conjunction with reference to another output from the project i.e. Environment Agency report, Technical Support Material for the Regulation of Radioactively Contaminated Land 1999. This report deals with the intervention on radioactively contaminated sites i.e. where no change of land use is anticipated and where the land has become contaminated as a result of previous land use and not current practices. (author)

The total amounts of radioactively contaminated materials in forests in Fukushima, Japan

Science.gov (United States)

Hashimoto, Shoji; Ugawa, Shin; Nanko, Kazuki; Shichi, Koji

2012-01-01

There has been leakage of radioactive materials from the Fukushima Daiichi Nuclear Power Plant. A heavily contaminated area (≥ 134, 137Cs 1000 kBq m−2) has been identified in the area northwest of the plant. The majority of the land in the contaminated area is forest. Here we report the amounts of biomass, litter (small organic matter on the surface of the soil), coarse woody litter, and soil in the contaminated forest area. The estimated overall volume and weight were 33 Mm3 (branches, leaves, litter, and coarse woody litter are not included) and 21 Tg (dry matter), respectively. Our results suggest that removing litter is an efficient method of decontamination. However, litter is being continuously decomposed, and contaminated leaves will continue to fall on the soil surface for several years; hence, the litter should be removed promptly but continuously before more radioactive elements are transferred into the soil. PMID:22639724

Application of autonomous robotics to surveillance of waste storage containers for radioactive surface contamination

International Nuclear Information System (INIS)

Sweeney, F.J.; Beckerman, M.; Butler, P.L.; Jones, J.P.; Reister, D.B.

1991-01-01

This paper describes a proof-of-principal demonstration performed with the HERMIES-III mobile robot to automate the inspection of waste storage drums for radioactive surface contamination and thereby reduce the human burden of operating a robot and worker exposure to potentially hazardous environments. Software and hardware for the demonstration were developed by a team consisting of Oak Ridge National Laboratory, and the Universities of Florida, Michigan, Tennessee, and Texas. Robot navigation, machine vision, manipulator control, parallel processing and human-machine interface techniques developed by the team were demonstrated utilizing advanced computer architectures. The demonstration consists of over 100,000 lines of computer code executing on nine computers

Measurement and removal of surface contamination

International Nuclear Information System (INIS)

Neider, M.; Tamberg, T.

1990-01-01

This is a critical reappraisal of the sampling factor which is important for indirect contamination measurement. The factor gives the radioactivity collected by means of a wipe sample as a fraction of the total loose radioactivity i.e. without firm adhesion. It is used in national and international standard specifications and stated, frequently with excessive conservatism, as 0.1. Secondly, the standard specifications for the testing and appraisal of surface materials in relation to their decontamination capacity and for testing the effect of decontamination agents hitherto bond and Co-60 and Cs-137 are to be expanded to include radioactive iodine, which is important in nuclear medicine. The selection of optimum surface materials will thus be put on an improved basis. (orig./DG) [de

Investigation of radioactive contamination at non-radioactive drains of the Tsuruga Nuclear Power Station

International Nuclear Information System (INIS)

Koide, Hiroaki; Imanaka, Tetsuji; Ebisawa, Toru; Kawano, Shinji; Kobayashi, Keiji.

1982-05-01

In April, 1981, it was disclosed that a drainage area at the Tsuruga Nuclear Power Station was so much contaminated with radioactivites. Although Ministry of International Trade and Industry (MITI) officially provided an explanation of a process that resulted in the contamination, many problems remain unsolved on account of insufficient and limited investigations. The authors collected mud samples from contaminated manholes and examined radioactivities in them through the measurement of #betta#- and #betta#-spectra. Chemical separation of the samples was carried out in order to obtain precise concentration of radioactive cesium. Results are as follows: i) the concentration of radioactivities does not show monotonous decrease along the stream line but an anomalous peak at downstream manholes, ii) at the manhole specified No. 6 located rather downstream, 137 Cs concentration is significantly high and the composition of radioactive nuclides is quite different from that in the other manholes, and iii) additional radioactive contamination was observed in other manholes of non-radioactive drains which would not be influenced by the accident explained by MITI. Our present work has provided much more data than by MITI and made it clear that the overall data cnnot be consistent with the simple MITI explanation; a single radioactive release accident caused the disclosed contamination. It is concluded that non-radioactive water drains at the Tsuruga Nuclear Power Station had been under continual contamination. (author)

Processing method for contaminated water containing radioactive waste

International Nuclear Information System (INIS)

Tahara, Toshiaki; Fukagawa, Ken-ichiro.

1994-01-01

For absorbing contaminated water containing radioactive substances, a sheet is prepared by covering water absorbing pulps carrying an organic water absorbent having an excellent water absorbability is semi-solidified upon absorption water with a water permeable cloth, such as a non-woven fabric having a shape stability. As the organic water absorbent, a hydrophilic polymer which retains adsorbed water as it is used. In particular, a starch-grafted copolymer having an excellent water absorbability also for reactor water containing boric acid is preferred. The organic water absorbent can be carried on the water absorbing pulps by scattering a granular organic water absorbent to the entire surface of the water absorbing cotton pulp extended thinly to carry it uniformly and putting them between thin absorbing paper sheets. If contaminated water containing radioactive materials are wiped off by using such a sheet, the entire sheet is semi-solidified along with the absorption with no leaching of the contaminated water, thereby enabling to move the wastes to a furnace for applying combustion treatment. (T.M.)

Decoding Environmental Processes Using Radioactive Isotopes for the Post-Radioactive Contamination Recovery Assessment

Science.gov (United States)

Yasumiishi, Misa; Nishimura, Taku; Osawa, Kazutoshi; Renschler, Chris

2017-04-01

The continual monitoring of environmental radioactive levels in Fukushima, Japan following the nuclear plant accident in March 2011 provides our society with valuable information in two ways. First, the collected data can be used as an indicator to assess the progress of decontamination efforts. Secondly, the collected data also can be used to understand the behavior of radioactive isotopes in the environment which leads to further understanding of the landform processes. These two aspects are inseparable for us to understand the effects of radioactive contamination in a dynamic environmental system. During the summer of 2016, 27 soil core samples were collected on a farmer's land (rice paddies and forest) in Fukushima, about 20 km northwest of the nuclear plant. Each core was divided into 2.0 - 3.0 cm slices for the Cs-134, Cs-137, and I-131 level measurement. The collected data is being analyzed from multiple perspectives: temporal, spatial, and geophysical. In the forest area, even on the same hillslope, multiple soil types and horizon depths were observed which indicates the challenges in assessing the subsurface radioactive isotope movements. It appears that although highly humic soils show higher or about the same level of radioactivity in the surface layers, as the depth increased, the radioactivity decreased more in those samples compared with more sandy soils. With regard to the direction a slope faces and the sampling altitudes, the correlation between those attributes and radioactivity levels is inconclusive at this moment. The altitude might have affected the fallout level on a single hillslope-basis. However, to determine the correlation, further sampling and the detailed analysis of vegetation and topography might be necessary. Where the surface soil was scraped and new soil was brought in, former rice paddy surface layers did show three-magnitude levels lower of radioactivity in the top layer when compared with forest soils. At the foot of forest

Contamination of foods by radioactive rains

Energy Technology Data Exchange (ETDEWEB)

Obo, F; Wakamatsu, C; Nakae, Y; Higasayama, S

1955-01-01

The radioactivities of various vegetable foods contaminated by radioactive rains in May, 1954, in the Kagoshima Area were detected. Tea showed especially high radioactivities which could be extracted with hot water. Radioactive Nb, Zr, Hf, Ce, Y, Pr, and La were detected in the hot water extractions of tea by ion-exchange chromatography. The partial contribution of /sup 40/K in these radioactive vegetables was critically examined.

Laser Decontamination of Surfaces Contaminated with Cs+ Ion

International Nuclear Information System (INIS)

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

2008-01-01

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

Protection of environmental contamination by radioactive materials and remediation of environment

International Nuclear Information System (INIS)

2003-05-01

This report consisted of the environmental contamination of radioactive and non-radioactive materials. 38 important accident examples of environmental contamination of radioactive materials in the world from 1944 to 2001 are stated. Heavily polluted areas by accidents are explained, for example, Chernobyl, atomic reactor accidents, development of nuclear weapon in USA and USSR, radioactive waste in the sea. The environmental contamination ability caused by using radioactive materials, medical use, operating reactor, disposal, transferring, crashing of airplane and artificial satellite, release are reported. It contains measurements and monitor technologies, remediation technologies of environmental contamination and separation and transmutation of radioactive materials. On the environmental contamination by non-radioactive materials, transformation of the soil contamination in Japan and its control technologies are explained. Protection and countermeasure of environmental contamination of radioactive and non-radioactive materials in Japan and the international organs are presented. There are summary and proposal in the seventh chapter. (S.Y.)

Economics and risks of recycling radioactively contaminated concrete

International Nuclear Information System (INIS)

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

1997-01-01

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

Residual radioactive contamination from decommissioning: Technical basis for translating contamination levels to annual dose

International Nuclear Information System (INIS)

Kennedy, W.E. Jr.; Peloquin, R.A.

1990-01-01

This document describes the generic modeling of the total effective dose equivalent (TEDE) to an individual in a population from a unit concentration of residual radioactive contamination. Radioactive contamination inside buildings and soil contamination are considered. Unit concentration TEDE factors by radionuclide, exposure pathway, and exposure scenario are calculated. Reference radiation exposure scenarios are used to derive unit concentration TEDE factors for about 200 individual radionuclides and parent-daughter mixtures. For buildings, these unit concentration factors list the annual TEDE for volume and surface contamination situations. For soil, annual TEDE factors are presented for unit concentrations of radionuclides in soil during residential use of contaminated land and the TEDE per unit total inventory for potential use of drinking water from a ground-water source. Because of the generic treatment of potentially complex ground-water systems, the annual TEDE factors for drinking water for a given inventory may only indicate when additional site data or modeling sophistication are warranted. Descriptions are provided of the models, exposure pathways, exposure scenarios, parameter values, and assumptions used. An analysis of the potential annual TEDE resulting from reference mixtures of residual radionuclides is provided to demonstrate application of the TEDE factors. 62 refs., 5 figs., 66 tabs

Radioactive contamination in the Arctic - Present situation and future challenges

International Nuclear Information System (INIS)

Strand, P.

2002-01-01

There is currently a focus on radioactivity and the Arctic region. The reason for this is the high number of nuclear sources in parts of the Arctic and the vulnerability of Arctic systems to radioactive contamination. The Arctic environment is also perceived as a wilderness and the need for the protection of this wilderness against contamination is great. In 1991, the International Arctic Environmental Protection Strategy (IAEPS) was launched and the Arctic Monitoring and Assessment Programme (AMAP) established. AMAP is undertaking an assessment of the radioactive contamination of the Arctic and its radiological consequences. This paper summarises some of current knowledge about sources of radioactive contamination, vulnerability, exposure of man, and potential sources for radioactive contamination within Arctic and some views on the future needs for work concerning radioactivity in Arctic. (author)

Treatment of Uranium-Contaminated Concrete for Reducing Secondary Radioactive Waste

Energy Technology Data Exchange (ETDEWEB)

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

2014-10-15

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

Treatment of Uranium-Contaminated Concrete for Reducing Secondary Radioactive Waste

International Nuclear Information System (INIS)

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

2014-01-01

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

Issues in recycling and disposal of radioactively contaminated materials

International Nuclear Information System (INIS)

Kluk, A.F.; Hocking, E.K.; Roberts, R.; Phillips, J.W.

1993-01-01

The Department of Energy's present stock of potentially re-usable and minimally radioactively contaminated materials will increase significantly as the Department's remediation activities expand. As part of its effort to minimize wastes, the Department is pursuing several approaches to recover valuable materials such as nickel, copper, and steel, and reduce the high disposal costs associated with contaminated materials. Key approaches are recycling radioactively contaminated materials or disposing of them as non-radioactive waste. These approaches are impeded by a combination of potentially conflicting Federal regulations, State actions, and Departmental policies. Actions to promote or implement these approaches at the Federal, State, or Departmental level involve issues which must be addressed and resolved. The paramount issue is the legal status of radioactively contaminated materials and the roles of the Federal and State governments in regulating those materials. Public involvement is crucial in the debate surrounding the fate of radioactively contaminated materials

Radiological Risk Assessment and Survey of Radioactive Contamination for Foodstuffs

International Nuclear Information System (INIS)

Lee, W.R.; Lee, C.W.; Choi, K.S.

2007-11-01

After the Chernobyl nuclear accident in 1986, a radiological dose assessment and a survey of a radioactive contamination for foodstuffs have been investigated by many countries such as EU, Japan, USA. In the case of Japan which is similar to our country for the imported regions of foodstuffs, there were some instances of the excess for regulation on the maximum permitted levels of radioactive contamination among some imported foodstuffs. Concerns about the radioactive contamination of foodstuffs are increased because of the recently special situation (Nuclear test of North Korea). The purpose of this study is a radiological dose assessment and a survey of a radioactive contamination for foodstuffs in order to reduce the probability of intake of contaminated foodstuffs. Analytical results of the collected samples are below MDA. In this project, the model of radiological dose assessment via the food chain was also developed and radiological dose assessment was conducted based on surveys results of a radioactive contamination for foodstuffs in the Korean open markets since 2002. The results of radiological dose assessment are far below international reference level. It shows that public radiation exposure via food chain is well controlled within the international guide level. However, the radioactive contamination research of imported foodstuffs should be continuous considering the special situation(nuclear test of North Korea). These results are used to manage the radioactive contamination of the imported foodstuffs and also amend the regulation on the maximum permitted levels of radioactive contamination of foodstuffs

Technologies for remediating radioactively contaminated land

International Nuclear Information System (INIS)

Pearl, M.

2000-01-01

This paper gives an overview of technologies that can be used for the remediation of radioactively contaminated ground. There are a wide variety of techniques available -most have established track records for contaminated ground, though in general many are only just being adapted to use for radioactively contaminated ground. 1) Remediation techniques for radioactively contaminated ground involve either removal of the contamination and transfer to a controlled/contained facility such as the national LLW repository at Drigg, or 2) immobilization, solidification and stabilization of the contamination where the physical nature of the soil is changed, or an 'agent' is added to the soil, to reduce the migration of the contaminants, or 3) isolation and containment of the contaminated ground to reduce contaminant migration and control potential detrimental effects to human health. Where contamination has to be removed, ex situ and in situ techniques are available which minimize the waste requiring disposal to an LLW repository. These techniques include: 1) detector-based segregation 2) soil washing by particle separations 3) oil washing with chemical leaching agents 4) electro remediation 5) phyto remediation. Although many technologies are potentially applicable, their application to the remediation of a specific contaminated site is dependent on a number of factors and related to detailed site characterization studies, results from development trials and BPEO (best practicable environmental option) studies. Those factors considered of particular importance are: 1) the clean-up target 2) technical feasibility relative to the particular site, soil and contaminant characteristics, and time frame 3) site infrastructure arrangements and needs, the working life of the site and the duration of institutional care 4) long-term monitoring arrangements for slow remedial techniques or for immobilization and containment techniques 5) validation of the remediation 6) health and

Method of melting decontamination of radioactive contaminated metals

International Nuclear Information System (INIS)

Uda, Tatsuhiko; Miura, Noboru; Tsuchiya, Hiroyuki.

1984-01-01

Purpose: To improve the transfer efficiency of radioactive materials into slags. Method: Contaminated metals are melt with adding slagging agent in order to transfer the radioactive materials into the slag, where the slagging agent holds less free energy than that of metal oxides contaminated with radioactive materials in order to promote the transfer of the contaminated materials into the slag layer. This effect can also be attained on metals or alloys other than iron contaminated with radioactive materials. In the case of alloy, the slagging agent is to containing such metal oxide that free energy is less than that of the oxide of metal being the main ingredient element of the alloy. The decontamination effect can further be improved by containing halogenide such as calcium fluoride together with the metal oxide into the slagging agent. (Ikeda, J.)

Environmental radioactive contamination and its control for nuclear power plants

International Nuclear Information System (INIS)

Shi Zhongqi; Qu Jingyuan; Cui Yongli

1998-01-01

The environmental radioactive releases and exposure to human being due to operation of nuclear power plants in the world and in China, environmental contamination and consequences caused by severe nuclear power plant accidents in the history, control of the radioactive contamination in China, and some nuclear laws on the radioactive contamination control established by international organizations and USA etc. are described according to literature investigation and research. Some problems and comments in radioactive contamination control for nuclear power plants in China are presented. Therefore, perfecting laws and regulations and enhancing surveillances on the contamination control are recommended

Methods for removing radioactive isotopes from contaminated streams

International Nuclear Information System (INIS)

Hoy, D.R.; Hickey, T.N.; Spulgis, I.S.; Parish, H.C.

1979-01-01

Methods for removing radioactive isotopes from contaminated gas streams for use in atmospheric containment and cleanup systems in nuclear power plants are provided. The methods provide for removal of radioactive isotopes from a first portion of the contaminated stream, separated from the remaining portion of the stream, so that adsorbent used to purify the first portion of the contaminated stream by adsorption of the radioactive isotopes therefrom can be tested to determine the adsorbing efficacy of the generally larger portion of adsorbent used to purify the remaining portion of the stream

Characterizing, for packaging and transport, large objects contaminated by radioactive material having a limited A2 value

International Nuclear Information System (INIS)

Pope, R.B.; Shappert, L.B.; Michelhaugh, R.D.; Cash, J.M.; Best, R.E.

1998-02-01

The International Atomic Energy Agency (IAEA) Regulations for the safe packaging and transportation of radioactive materials follow a graded approach to the requirements for both packaging and controls during transport. The concept is that, the lower the risk posed to the people and the environment by the contents, (1) the less demanding are the packaging requirements and (2) the smaller in number are the controls imposed on the transport of the material. There are likely to be a great number of situations arising in coming years when large objects, contaminated with radioactive material having unlimited A 2 values will result from various decommissioning and decontamination (D and D) activities and will then require shipment from the D and D site to a disposal site. Such situations may arise relatively frequently during the cleanup of operations involving mining, milling, feedstock, and uranium enrichment processing facilities. Because these objects are contaminated with materials having an unlimited A 2 value they present a low radiological risk to worker and public safety and to the environment during transport. However, when these radioactive materials reside on the surfaces of equipment and other large objects, where the equipment and objects themselves are not radioactive, the radioactive materials appear as surface contamination and, if the contaminated object is categorized as a surface contaminated object, it would need to be packaged for shipment according to the requirements of the Regulations for SCO. Despite this categorization, alternatives may be available which will allow these contaminants, when considered by themselves for packaging and transport, to be categorized as either (1) a limited quantity of radioactive material to be shipped in an excepted package or (2) low specific activity (LSA) materials to be shipped in an IP-1 package or possibly even shipped unpackaged. These options are discussed in this paper

Decontamination of radioactively contaminated surfaces - Method for testing and assessing the ease of decontamination (International Standard Publication ISO 8690:1988)

International Nuclear Information System (INIS)

Stefanik, J.

2001-01-01

The specifications laid down in this International Standard apply to the testing of surfaces which may become contaminated by radioactive materials. Decontaminability data obtained using this test method are not applicable to technical systems where layers of contaminating materials are formed as a result of long-term application of higher temperatures and pressures (for example primary circuits of nuclear reactors). The purpose of the test is to assess the ease of decontamination of surfaces under laboratory conditions. In practical applications, it may be important to consider other qualities, such as chemical, mechanical and radiation resistance and long-term stability in the selection of the materials to be used. It should be recognized that further decontamination tests under simulated service conditions may be needed

Automatic Measurement of Low Level Contamination on Concrete Surfaces

International Nuclear Information System (INIS)

Tachibana, M.; Itoh, H.; Shimada, T.; Yanagihara, S.

2002-01-01

Automatic measurement of radioactivity is necessary for considering cost effectiveness in final radiological survey of building structures in decommissioning nuclear facilities. The RAPID (radiation measuring pilot device for surface contamination) was developed to be applied to automatic measurement of low level contamination on concrete surfaces. The RAPID has a capability to measure contamination with detection limit of 0.14 Bq/cm2 for 60Co in 30 seconds of measurement time and its efficiency is evaluated to be 5 m2/h in a normal measurement option. It was confirmed that low level contamination on concrete surfaces could be surveyed by the RAPID efficiently compared with direct measurement by workers through its actual application

Laser techniques for radioactive decontamination gives metallic surfaces

International Nuclear Information System (INIS)

Escobar Alracon, L.; Molina, G.; Vizuet Gonzalez, J.

1998-01-01

In this work it presented the prototype for system decontamination at diverse component with removable superficial contamination, using the technique gives laser ablation, for the evaporation at the pollutant. It discusses the principle in the fact that system, as well as the different elements that compose it. The are presented the obtained results when irradiating with a laser a surface without radioactive contamination to verify the system operation

Radioactive contamination in Arctic - present situation and future challenges

International Nuclear Information System (INIS)

Strand, Per

2002-01-01

There is currently a focus on radioactivity and the Arctic region. The reason for this is probably the high number of nuclear sources in parts of the Arctic and the vulnerability of Arctic systems to radioactive contamination. The Arctic environment is also perceived as a wilderness and the need for the protection of this wilderness against contamination is great. In the last decade information has also been released concerning the nuclear situation which has caused concern in many countries. Due to such concerns, the International Arctic Environmental Protection Strategy (IAEPS) was launched in 1991 and the Arctic Monitoring and Assessment Programme (AMAP) was established. AMAP is undertaking an assessment of the radioactive contamination of the Arctic and its radiological consequences. In 1996 IAEPS became part of the Arctic Council. AMAP presented one main report in 1997 and another in 1998. There are also several other national, bilateral and international programmes in existence which deal with this issue. This paper summarises some of current knowledge about sources of radioactive contamination, vulnerability, exposure of man, and potential sources for radioactive contamination within Arctic and some views on the future needs for work concerning radioactivity in Arctic. (au)

Fluctuating asymmetry of shape in rodents from radioactively contaminated environments at Chernobyl

International Nuclear Information System (INIS)

Smith, M.H.; Novak, J.M.; Oleksyk, T.K.; Purdue, J.R.; Gashchak, S.

2002-01-01

In this study we addressed the question of whether levels of fluctuating symmetry (FA) were elevated in the radioactively contaminated populations compared to reference populations of an abundant rodent living in both environments: the yellow - necked mouse (Apodemus flavicollis). We used six populations of these animals from both inside the radioactively contaminated area close to the failed Chornobyl reactor in Ukraine and in reference areas with no apparent contamination by radionuclides. Twenty-four landmarks on the ventral surface of the rodent's skulls were used to calculate the amounts of FA of shape using Procrustes methods. A higher level of FA was documented for the populations in closest proximity to the failed Chornobyl Nuclear Plant. This index was significantly higher in populations from the most contaminated locations in the Chornobyl Exclusion Zone than in the reference areas. On the other hand, populations from the less contaminated areas inside the Chornobyl Exclusion Zone did not express FA values different from those in the reference populations

Measurement of radioactivity in contaminated crops

Energy Technology Data Exchange (ETDEWEB)

Yamada, Y; Hasegawa, M; Kihara, T

1956-01-01

A method called the Direct Method was developed to correct for natural /sup 40/K radiation in plant samples. The K content of the ashed sample is determined by flamephotometry. The radioactivity in a 100 mg sample is measured and the natural radioactivity from /sup 40/K determined by calculation subtracted. Tea samples tested gave evidence of contamination by radioactive fallout.

Process for reducing radioactive contamination in phosphogypsum

International Nuclear Information System (INIS)

Palmer, J.W.; Gaynor, J.C.

1983-01-01

In a process for reducing radioactive contamination of phosphogypsum, anhydrite crystals are obtained through dehydration of the phosphogypsum in strong sulfuric acid: a portion of the anhydrite crystals is converted to subtantially radiation free gypsum by crystallizing out on radiation free gypsum seed crystals. These coarse radiation free gypsum crystals are then separated from the small anhydrite crystal relics containing substantially all of the radioactive contamination

Ways for forestry management in radioactive contamination zone

International Nuclear Information System (INIS)

Kaletnik, N.N.; Pasternak, P.S.; Kiselevskij, R.G.; Molotkov, P.I.; Kuchma, N.D.; Landin, V.P.; Matukhno, Yu.D.; Shlonchak, G.L.; Podkur, P.P.; Khudolej, V.I.

1989-01-01

The necessity of realization of forestry protection measures in the radioactive contamination zone is determined by the forest ecological part and the problems of elimination of the territory secondary contamination in the process of radionuclide migration. The damage of forest tracts in the zone is analyzed. The data on pine surface contamination levels, needles appearance in forests with different degree of damage and crown phytomass, growth for pines 20 years old in forests with different damage degrees are considered. The index of pine forest state is obtained. The data discussed reveal the complicated situation, which takes place in the 30-km zone forests. It is shown that the depth of radionuclide migration into soil for forest areas is twice lower as compared with that for open places. 6 tabs

A Novel Method for Remote Depth Estimation of Buried Radioactive Contamination.

Science.gov (United States)

Ukaegbu, Ikechukwu Kevin; Gamage, Kelum A A

2018-02-08

Existing remote radioactive contamination depth estimation methods for buried radioactive wastes are either limited to less than 2 cm or are based on empirical models that require foreknowledge of the maximum penetrable depth of the contamination. These severely limits their usefulness in some real life subsurface contamination scenarios. Therefore, this work presents a novel remote depth estimation method that is based on an approximate three-dimensional linear attenuation model that exploits the benefits of using multiple measurements obtained from the surface of the material in which the contamination is buried using a radiation detector. Simulation results showed that the proposed method is able to detect the depth of caesium-137 and cobalt-60 contamination buried up to 40 cm in both sand and concrete. Furthermore, results from experiments show that the method is able to detect the depth of caesium-137 contamination buried up to 12 cm in sand. The lower maximum depth recorded in the experiment is due to limitations in the detector and the low activity of the caesium-137 source used. Nevertheless, both results demonstrate the superior capability of the proposed method compared to existing methods.

Strippable gel for decontamination of contaminated metallic surfaces

International Nuclear Information System (INIS)

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

2013-01-01

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

Phytoremediation of water bodies contaminated with radioactive heavy metal

International Nuclear Information System (INIS)

Yan Zhen; Yuan Shichao; Ling Hui; Xie Shuibo

2012-01-01

The sources of the radioactive heavy metal in the water bodies were analyzed. The factors that affect phyto remediation of water contaminated with radioactive heavy metal were discussed. The plant species, mechanism and major technology of phyto remediation of water contaminated with radioactive heavy metal were particularly introduced. The prospective study was remarked. (authors)

Radioactive contamination in environment and food in Poland in 1992

International Nuclear Information System (INIS)

Grabowski, D.; Muszynski, W.; Petrykowska, M.; Rubel, B.; Smagala, G.; Wilgos, J.

1993-01-01

The level analysis of the level of radioactive contamination in environment and food samples was carried out in Poland in 1992. The results were compared to the data from 1985-1991 period. Since the Chernobyl accident gradual decrease of contamination level has been stated. The gamma dose rate and the contamination of air, fallout, tap and surface water were at the level of 1985. Still higher contamination level of cesium isotopes in soil has been reported and as a consequence food contamination was higher particularly the animal food. Actually, the source of additional dose is ingestion of artificial isotopes with food as a result of food contamination. The average effective dose equivalent, due to the contaminated food consumption, was estimated at the level 15 μSv for a Pole in 1992. (author). 13 refs, 6 figs, 20 tabs

Radioactive waste management for a radiologically contaminated hospitalized patient

International Nuclear Information System (INIS)

Pina Jomir, G.; Michel, X.; Lecompte, Y.; Chianea, N.; Cazoulat, A.

2015-01-01

Radioactive waste management in the post-accidental phase following caring for a radiologically contaminated patient in a hospital decontamination facility must be anticipated at a local level to be truly efficient, as the volume of waste could be substantial. This management must comply with the principles set out for radioactive as well as medical waste. The first step involves identification of radiologically contaminated waste based on radioactivity measurement for volume reduction. Then, the management depends on the longest radioactive half-life of contaminative radionuclides. For a half-life inferior to 100 days, wastes are stored for their radioactivity to decay for at least 10 periods before disposal like conventional medical waste. Long-lived radioactive waste management implies treatment of liquid waste and special handling for sorting and packaging before final elimination at the French National Agency for Radioactive Waste Management (ANDRA). Following this, highly specialized waste management skills, financial responsibility issues and detention of non-medical radioactive sources are questions raised by hospital radioactive waste management in the post-accidental phase. (authors)

Radioactive releases from a thorium-contaminated site in Wayne, New Jersey

International Nuclear Information System (INIS)

Wang, J.; Yang, J.; Merry-Libby, P.

1985-01-01

Various residues and wastes from the production of thorium and rare earths from monazite ore are buried on a hillside in Wayne, New Jersey. In addition, contaminated materials (primarily soils) from nearby vicinity properties are being consolidated onto the Wayne site. The US Department of Energy plans to stabilize all the contaminated materials on an interim basis (20 years) until funding is available to remove them to another location. In order to evaluate the effectiveness of interim stabilization measures, pre-remedial action radioactive releases are compared to estimated releases under a reference stabilization option (one meter of soil cover). Two potential pathways are examined: (1) airborne radioactive gases (thoron and radon) and particulates, and (2) seepage into the near-surface groundwater. The relative reduction of releases into the air and groundwater for the reference stabilization option is analyzed using mathematical models for radioactive gas fluxes and atmospheric dispersion as well as groundwater transport and dispersion. The consequent health implications for nearby individuals and the general population are also estimated. Health effects due to radioactive releases are estimated to be insignificant

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

Science.gov (United States)

Tsujimura, Norio; Yoshida, Tadayoshi; Hoshi, Katsuya

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

Process for reducing radioactive contamination in waste product gypsum

International Nuclear Information System (INIS)

Lange, P.H. Jr.

1979-01-01

A process is described for reducing the radioactive contamination in waste product gypsum in which waste product gypsum is reacted with a dilute sulfuric acid containing barium sulfate to form an acid slurry at an elevated temperature, the slurry is preferably cooled, the acid component is separated from the solid, and the resulting solid is separated into a fine fraction and a coarse fraction. The fine fraction predominates in barium sulfate and radioactive contamination. The coarse fraction predominates in a purified gypsum product of reduced radioactive contamination

Establishing community trust at radioactively contaminated sites

International Nuclear Information System (INIS)

Simpson, E.

1999-01-01

Establishing community trust is an essential element in the successful remediation of a radioactively contaminated site. The US Environmental Protection Agency (EPA), Region 2 has been involved in the clean up of numerous radioactively contaminated Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), Resource Conservation Recovery Act (RCRA), and Formerly Utilized Site Remedial Action Program (FUSRAP) sites in New Jersey and New York. Each site presented a unique challenge which centered around establishing and, often, re-establishing the trust of the surrounding community. Thanks to the United States government's history regarding the use of radioactive materials, people question whether governmental regulators could possibly have the public's best interests in mind when it comes to addressing radioactively contaminated sites. It has been our experience that EPA can use its position as guardian of the environment to help establish public confidence in remedial actions. The EPA can even use its position to lend credibility to remedial activities in situations where it is not directly responsible for the clean-up. Some ways that we have found to instill community confidence are: establishing radioanalytical cross-check programs using EPA's National Air and Radiation Environmental Laboratory to provide analytical quality assurance; and establishing an environmental radiation monitoring program for the contaminated site and surrounding community. (author)

The Barents Sea, distribution and fate of radioactive contaminants

International Nuclear Information System (INIS)

Foeyn, L.; Heldal, H.E.; Svaeren, I.

1999-01-01

Possible contamination in the marine food webs of the Barents Sea may be a problem for a rational harvest of the area. Radioactive contamination has in this context a special public impact as even traces of radioactivity seems to be considered by the public to be a real danger. It is therefor of special importance, from a regulatory and fisheries point of view, to accumulate knowledge of the behaviour of radioactive elements in the marine ecosystems of the Barents Sea in order to place this contamination in proper and realistic proportions

Contamination of fodder and radioactivity in turkeys

International Nuclear Information System (INIS)

Kossakowski, S.; Olszewska, K.

1985-01-01

Radioactivity was determined in mixed fodder (IB, IC, IE) and in turkeys which were given that feeding stuff. In animals (25 males and 25 females) fed with the above mixed fodder for 16-24 weeks radioactivity was assessed in internal organs and in their tissues. It was found that radioactivity ranged from 322.2 Bq/kg to 190.6 Bq/kg. In males the highest contamination was found in the spleen (average 0.108 Bq/g), in skeletal muscles (0.082 Bq/g), and in the liver (0.080 Bq/g), and the lowest in the skin (0.046 Bq per 1 g). The findings indicate that radioactivity of carcasses and internal organs in turkeys fed with contamined fodder was much lower than that in fodder. 6 refs., 1 tab. (author)

Radioactive contamination mapping system detailed design report

International Nuclear Information System (INIS)

Bauer, R.G.; O'Callaghan, P.B.

1996-08-01

The Hanford Site's 100 Area production reactors released radioactively and chemically contaminated liquids into the soil column. The primary source of the contaminated liquids was reactor coolant and various waste waters released from planned liquid discharges, as well as pipelines, pipe junctions, and retention basins leaking into the disposal sites. Site remediation involves excavating the contaminated soils using conventional earthmoving techniques and equipment, treating as appropriate, transporting the soils, and disposing the soils at ERDF. To support remediation excavation, disposal, and documentation requirements, an automated radiological monitoring system was deemed necessary. The RCMS (Radioactive Contamination Mapping System) was designed to fulfill this need. This Detailed Design Report provides design information for the RCMS in accordance with Bechtel Hanford, Inc. Engineering Design Project Instructions

Analysis on the influence of forest soil characteristics on radioactive Cs infiltration and evaluation of residual radioactive Cs on surfaces.

Science.gov (United States)

Mori, Yoshitomo; Yoneda, Minoru; Shimada, Yoko; Fukutani, Satoshi; Ikegami, Maiko; Shimomura, Ryohei

2018-03-29

We investigated the depth profiles of radioactive Cs, ignition loss, and cation exchange capacity (CEC) in five types of forest soils sampled using scraper plates. We then simulated the monitored depth profiles in a compartment model, taking ignition loss as a parameter based on experimental results showing a positive correlation between ignition loss and the CEC. The calculated values were comparable with the monitored values, though some discrepancy was observed in the middle of the soil layer. Based on decontamination data on the surface dose rate and surface contamination concentration, we newly defined a surface residual index (SRI) to evaluate the residual radioactive Cs on surfaces. The SRI value tended to gradually decrease in forests and unpaved roads and was much smaller in forests and on unpaved roads than on paved roads. The radioactive Cs was assumed to have already infiltrated underground 18 months after the nuclear power plant accident, and the sinking was assumed to be ongoing. The SRI values measured on paved roads suggested that radioactive Cs remained on the surfaces, though a gradual infiltration was observed towards the end of the monitoring term. The SRI value is thought to be effective in grasping the rough condition of residual radioactive Cs quickly at sites of decontamination activity in the field. The SRI value may be serviceable for actual contamination works after further research is done to elucidate points such as the relation between the SRI and the infiltration of radioactive Cs in various types of objects.

Risk assessment methodology for evaluating releases of radioactively contaminated materials

International Nuclear Information System (INIS)

Chen, S.Y.

1993-01-01

Extensive decontamination and decommissioning (D ampersand D) activities are expected to be required in the near future in association with license termination of nuclear power facilities and cleanup efforts at the U.S. Department of Energy's (DOE's) weapons production facilities. In advance of these D ampersand D activities, it is becoming increasingly urgent that standards be established for the release of materials with residual radioactive contamination. The only standards for unrestricted release that currently exist address surface contamination. The methods used to justify those standards were developed some 20 yr ago and may not satisfy today's criteria. Furthermore, the basis of setting standards has moved away from the traditional open-quotes instrumentation-basedclose quotes concept toward a open-quotes risk-basedclose quotes approach. Therefore, as new release standards are developed, it will be necessary that risk assessment methodology consistent with modern concepts be incorporated into the process. This paper discusses recent developments in risk methodology and issues and concerns regarding the future development of standards for the release of radioactively contaminated materials

Cleanup of radioactivity contamination in environment

International Nuclear Information System (INIS)

Kosako, Toshiso

1994-01-01

Environmental radioactivity cleanup is needed under a large scale accident in a reactor or in an RI irradiation facility which associates big disperse of radioactivities. Here, the fundamental concept including a radiation protection target, a period classification, planning, an information data base, etc. Then, the methods and measuring instruments on radioactivity contamination and the cleanup procedure are explained. Finally, the real site examples of accidental cleanup are presented for a future discussion. (author)

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

International Nuclear Information System (INIS)

Tsujimura, Norio; Yoshida, Tadayoshi; Hoshi, Katsuya

2016-01-01

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

Assessment and prediction of the scales of radioactive contamination of the environment by emissions from a nuclear power plant

International Nuclear Information System (INIS)

Elokhin, A.P.; Solovei, A.F.

1995-01-01

The assessment of radioactive contamination of the air basin and underlying surface in the direction of emission reduces to determining the volume activity of the radioactive impurity in air, the surface activity on the underlying surface of the radioactive impurity is known at least approximately (for example, it can be set on the basis of the technological regulations at the nuclear power plant or according to the criterion of levels during an accident), by using exposure-dose-rate sensors in a network of posts of the automatic system for monitoring the radiation environment (ASMRE), which are placed on the industrial area of the nuclear power plant, in the shielded zone and in the observation zone, it is possible to determine more accurately the magnitude of the emission and, therefore, to estimate the scale of the radioactive contamination of the medium

Experimental study on source efficiencies for estimating surface contamination level

International Nuclear Information System (INIS)

Ichiji, Takeshi; Ogino, Haruyuki

2008-01-01

Source efficiency was measured experimentally for various materials, such as metals, nonmetals, flooring materials, sheet materials and other materials, contaminated by alpha and beta emitter radioactive nuclides. Five nuclides, 147 Pm, 60 Co, 137 Cs, 204 Tl and 90 Sr- 90 Y, were used as the beta emitters, and one nuclide 241 Am was used as the alpha emitter. The test samples were prepared by placing drops of the radioactive standardized solutions uniformly on the various materials using an automatic quantitative dispenser system from Musashi Engineering, Inc. After placing drops of the radioactive standardized solutions, the test materials were allowed to dry for more than 12 hours in a draft chamber with a hood. The radioactivity of each test material was about 30 Bq. Beta rays or alpha rays from the test materials were measured with a 2-pi gas flow proportional counter from Aloka Co., Ltd. The source efficiencies of the metals, nonmetals and sheet materials were higher than 0.5 in the case of contamination by the 137 Cs, 204 Tl and 90 Sr- 90 Y radioactive standardized solutions, higher than 0.4 in the case of contamination by the 60 Co radioactive standardized solution, and higher than 0.25 in the case of contamination by the alpha emitter the 241 Am radioactive standardized solution. These values were higher than those given in Japanese Industrial Standards (JIS) documents. In contrast, the source efficiencies of some permeable materials were lower than those given in JIS documents, because source efficiency varies depending on whether the materials or radioactive sources are wet or dry. This study provides basic data on source efficiency, which is useful for estimating the surface contamination level of materials. (author)

Contamination detector for inner surface of container

International Nuclear Information System (INIS)

Watanabe, Tadao.

1995-01-01

The present invention concerns a device for detecting contamination of radioactive materials on the inner surface of a vessel upon reutilizing the vessel for containing solidified radioactive wastes and transporting them. Namely, the detecting device has following functions. (1) A radiation detector detects the radioactive materials on the inner surface of the vessel. (2) A plurality of proximity switches measure the distance from the radiation detector to the wall surface of the vessel and are actuated if the distance is decreased to a predetermined value, (3) A vessel inner surface position calculation mechanism calculates the position of the inner surface of the vessel based on the information from a direction indicator and a height indicator. (4) A frontal limit detector detects the limit for allowing the radiation detector to proceed. (5) A vessel inner shape judging mechanism for judging the shape of the inner side of the vessel based on the signals from the proximity switches in a state where the frontal limit detector is operated and a vessel inner surface position signal outputted from the vessel inner surface position calculation mechanism. As a result, the shape of the inner side of the vessel can accurately be recognized, thereby improving accuracy of radiation measurement. (I.S.)

Radioactive standards and calibration methods for contamination monitoring instruments

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Makoto [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1997-06-01

Contamination monitoring in the facilities for handling unsealed radioactive materials is one of the most important procedures for radiation protection as well as radiation dose monitoring. For implementation of the proper contamination monitoring, radiation measuring instruments should not only be suitable to the purpose of monitoring, but also be well calibrated for the objective qualities of measurement. In the calibration of contamination monitoring instruments, quality reference activities need to be used. They are supplied in different such as extended sources, radioactive solutions or radioactive gases. These reference activities must be traceable to the national standards or equivalent standards. On the other hand, the appropriate calibration methods must be applied for each type of contamination monitoring instruments. In this paper, the concepts of calibration for contamination monitoring instruments, reference sources, determination methods of reference quantities and practical calibration methods of contamination monitoring instruments, including the procedures carried out in Japan Atomic Energy Research Institute and some relevant experimental data. (G.K.)

Assessment of sites concerning radioactive contamination during preparation of a Contamination Site Register

International Nuclear Information System (INIS)

Gellermann, Rainer; Flesch, Klaus

2014-01-01

Experience gained since 1990 in the new, but also old German Federal States has shown that there are radioactive contaminated sites beside the legacies of uranium mining in Germany which caused exposures exceeding the radiation protection limits for members of the public. The reason for this situation is that radioactivity has been excluded in the compilation of the register for potentially hazardous sites that are prepared routinely in the context of soil protection assessments. Moreover, the information contained in these registers is not yet evaluated regarding aspects of radioactivity. In many cases, the information existing at the soil protection authorities needs only to be additionally filtered in order to identify potentially hazardous sites for radioactive contamination. For that reason, the working group ''Natural radioactivity'' (AKNAT) of the German-Swiss Radiation Protection Association developed a specific catalogue of business branches that provides indications for radioactive legacies.

On-site radioactive soil contamination at the Andreeva Bay shore technical base, Northwest Russia.

Science.gov (United States)

Reistad, O; Dowdall, M; Selnaes, Ø G; Standring, W J F; Hustveit, S; Steenhuisen, F; Sørlie, A

2008-07-01

The radioactive waste (RAW) storage site at Andreeva Bay in the Russian Northwest has experienced radioactive contamination both as a result of activities carried out at the site and due to incidents that have occurred there in the past such as accidental releases of radioactive materials. The site is an interesting case study for decommissioning due to the extremely large amounts of radioactivity present at the site and the conditions under which it is stored; very little has been previously published in the scientific literature about this site. This paper complements the paper describing dose rates at Andreeva Bay which is published in this issue of Journal of Environmental Radioactivity by the same authors. This study presents new data related to the activity concentrations of (137)Cs and (90)Sr in surface soils and measurements of alpha- and beta-particle fluxes taken at different areas around the site. Limited data on 60Co is also presented. The results of the study indicate that the main areas of site contamination are associated with the former spent nuclear fuel storage facility at Building 5, due to accidental discharges which began in 1982. Substantial contamination is also observed at the solid radioactive waste storage facilities, probably due to the ingress of water into these facilities. More than 240 samples were measured: maximum contamination levels were 1 x 10(6)Bq/kg (137)Cs (mean value 4.1 x 10(5)Bq/kg) and 4 x 10(6)Bq/kg (90)Sr (mean value 1.2 x1 0(5)Bq/kg). Localised patches of alpha and beta contamination were also observed throughout the site.

Radioactive contamination in monitors received for calibration

International Nuclear Information System (INIS)

Dias, Paulo S.; Santos, Gilvan C. dos; Brunelo, Maria Antonieta G.; Paula, Tiago C. de; Pires, Marina A.; Borges, Jose C.

2013-01-01

The Calibration Laboratory - LABCAL, from the Research Center for Metrology and Testing - METROBRAS, MRA Comercio de Instrumentos Eletronicos Ltda., began activities in October 2008 and, in August 2009, decided to establish a procedure for monitoring tests, external and internal, of all packages received from customers, containing instruments for calibration. The aim was to investigate possible contamination radioactive on these instruments. On July 2011, this procedure was extended to packagings of personal thermoluminescent dosemeters - TLD, received by the newly created Laboratory Laboratorio de Dosimetria Pessoal - LDP . In the monitoring procedure were used monitors with external probe, type pancake, MRA brand, models GP - 500 and MIR 7028. During the 37 months in which this investigation was conducted, were detected 42 cases of radioactive contamination, with the following characteristics: 1) just one case was personal dosimeter, TLD type; 2) just one case was not from a packing from nuclear medicine service - was from a mining company; 3) contamination occurred on packs and instruments, located and/or widespread; 4) contamination values ranged from slightly above the level of background radiation to about a thousand fold. Although METROBRAS has facilities for decontamination, in most cases, especially those of higher contamination, the procedure followed was to store the contaminated material in a room used for storage of radioactive sources. Periodically, each package and/or instrument was monitored, being released when the radiation level matched the background radiation. Every contamination detected, the client and/or owner of the instrument was informed. The Brazilian National Energy Commission - CNEN, was informed, during your public consultation for reviewing the standard for nuclear medicine services, held in mid-2012, having received from METROBRAS the statistical data available at the time. The high frequency of contamination detected and the high

Health assessment for Monticello Radioactive Contaminated Properties, Monticello, Utah, Region 8. CERCLIS No. UTD980667208. Preliminary report

International Nuclear Information System (INIS)

1989-01-01

The Monticello Mill Site (MMS) is on the National Priorities List. The site is located in Monticello (San Juan County), Utah. MMS includes properties contaminated with radioactive ore wastes from a former uranium mill located near the town. The mill was formerly operated by the Atomic Energy Commission and is now the responsibility of the Department of Energy. Radioactive contaminants (uranium, radium, thorium, and radon) are present in mine tailings, soil, ground water, and surface water on-site and also in ground water, surface water, and soil off-site. Based on available information, the site is considered to be of public health concern because of the risk to human health caused by the likelihood of human exposure to hazardous substances. The possibility exists that human exposure could occur from domestic use of contaminated ground water, consumption of commercial crops, garden vegetables grown in contaminated soil, and consumption of commercial livestock that graze on contaminated soil, grasses, and feed

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

International Nuclear Information System (INIS)

Fukumori, D.T.

1989-01-01

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

Development of high-level radioactive waste treatment and conversion technologies 'Dry decontamination technology development for highly radioactive contaminants'

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

The iron waste from thermal power plant (t.p.p.) as the source of radioactive contamination

International Nuclear Information System (INIS)

Kovacevic, M.; Todorovic, D.; Radenkovic, M.; Joksic, J.; Vukcevic, M.

2006-01-01

The radioactivity control of the iron waste (tubes) raised from the regular maintenance of the Gacko thermo power plant has shown the allocated spots of relatively high surface contamination, mainly beta, and no enhanced levels of absorbed radiation dose in the air. Further laboratory examination of the contaminated tube samples (10- 15 cm length) determined the level and source of contamination. Gamma spectrometry (H.P. Ge, efficiency 23%) has shown the presence of 210 Pb isotope, beta-emitting radionuclide with 47 keV X-ray emission, the member of the 238 U series. The surface contamination and concentration values, determined after samples dissolution in mineral acids, are 2.4 Bq/cm 2 and 0.6 Bq/g, respectively. The radioactivity of the tubes originate from the naturally occurring radionuclides in coal, with 210 Pb activities mostly within 0.01-0.05 Bq/g. During the T.P.P. work, radioactivity is deposed with ash, flying ash and slag and partly released into atmosphere. But, the part of radioactivity is deposited at the tubes and cauldron with gases emanated during the coal combustion. In this way, the iron becomes contaminated by the natural radionuclide during the technological process. Since there are no legislative stipulations about such cases, we have applied the international recommendations saying that dose limit should not be higher than 10 Micro Sv/year for individuals. On this basis T.E.C.D.O.C. 855 define different use of metals contaminated with natural or man-made radionuclides. According this document the contaminated iron with activity lower than 0.7 Bq/g may be further processed in the steel works that is the case with the iron waste produced in the T.P.P. Gacko. (authors)

Radioactive contamination of the Yenisei River

International Nuclear Information System (INIS)

Vakulovsky, S.M.; Kryshev, I.I.; Nikitin, A.I.; Savitsky, Y.V.; Malyshev, S.V.; Tertyshnik, E.G.

1995-01-01

Based on observational data in the period 1971-1993, radioactive contamination of the Yenisei River ecosystem was analysed within 2000 km of the site of discharges from the Krasnoyarsk Mining and Chemical Industrial Complex. Data on the content of 24 Na, 32 P, 46 Sc, 51 Cr, 54 Mn, 56 Mn, 58 Co, 60 Co, 59 Fe, 65 Zn, 90 Sr, 95 Zr, 95 Nb, 103 Ru, 106 Ru, 134 Cs, 137 Cs, 140 Ba, 141 Ce, 144 Ce and 239 Np in the river ecosystem components were generalised. Radioactive contamination of water in the near zone of discharges (within 15 km) was shown to be determine mainly by the short-lived nuclides, such as 24 Na, 32 P, 56 Mn and 239 Np, as well as 51 Cr. Outside the near zone the water contamination level decreased appreciably. According to observational data of 1973, the total contamination inventory of the river bottom in the near zone was as great as 5800 kBq m -2 . More than half was accounted for by two radionuclides: 51 Cr and 65 Zn. At a distance of 1930 km from the site of discharges a technogenic activity of bottom sediments amounted to 5 kBq m -2 and was accounted for by 137 Cs and 65 Zn. The main radionuclide accumulated in fish was 32 P. Exposure doses to aquatic organisms and population were assessed in the near and far zones of the Krasnoyarsk radioactive contamination trace. Within 250 km of the site of discharges the exposure dose to the population from a consumption of 1 kg of fish was shown to amount to an average of 10 μSv. (author)

The major regularities of the air radioactive contamination of Belarus territory after the Chernobyl accident

International Nuclear Information System (INIS)

Konoplya, E. F.; Mironov, V. P.; Drugachenok, M. A.; Kudryashov, V.P; Grushevich, L.E; Adamovich, A.A.

2001-01-01

In the first days after the Chernobyl accident the radioactivity of surface air in different regions of Belarus has increased in tens and hundred thousand time. The regular control of air radioactive contamination in the zone of alienation and nearest to it is carried out from the end 1989. The radioactive air monitoring carried out in territories with various contamination density (from 0,2 up to 9,6 MBq/m 2 on Cs-137). The measurements of the Cs-137 contents in ashes of air sampler filters were carried out by gamma - spectrometer ADCAM-300 MCA. The measurement of the Pu-240,239 and Sr-90 contents was carried out by usual radiochemical techniques. The used techniques and equipment allow to define in a sample of the minimal activity: Pu-239,240 - 0,001 Bq, Cs-137 - 0,5 Bq, Sr-90 - 0,1 Bq. The initial contamination of ground happened a near zone within approximately first 2 weeks after accident. Since the end of May, 1986 till present time the air radioactive contamination is formed under action of processes of secondary wind rise and carry of radioactive particles with contaminated territories, which depends from a number factors of both natural and anthropogenous origin. The relations of Pu-238/Pu-239 and Sr-90/Pu-239 in aerosol particles practically coincide with the same relations in fuel blown up reactor. The ratio of Cs-137/Pu-239 activities in aerosols considerably exceeds the resettlement ratio for fuel. Strontium and plutonium are in structure of fuel particles, and cesium aerosol have other origin. The analysis of changes annual radioisotopes concentration in air of towns of Belarus specifies existence of the tendency to slow decrease of contamination of atmosphere by radioisotopes of industrial origins. The basic tendency of formation of air radioactive contamination is determined by the contents of a dust at surface layer of an atmosphere and its specific activity. Annual average dust content of air in a zone resettlement was least and made about 10 mk g

Status on contamination monitoring in China

Energy Technology Data Exchange (ETDEWEB)

Quanlu, Gou [China Institute for Radiation Protection, Taiyuan (China)

1997-06-01

The air contaminated by radioactive materials in nuclear enterprises and radioactive workplaces and forming radioactive aerosol and the leakage of radioactive materials in operation cause internal exposure damage in workers. It is necessary and important to monitor air and surface contaminations for the health of public and workers, and for protecting environment. At present, many institutes engage in the studies on surface contamination monitoring in China, and the government has formulated the control limits of surface contamination in the Regulations of Radiation Protection. The monitors for surface contamination monitoring are almost home-made. The methods being used often are smear test and placing surface sample test. Scintillation counters, semiconductor detectors and G-M counters have been used for detecting alpha surface contamination. Plastic scintillator meters and thin wall/window G-M counters are used for beta surface contamination. Special detectors have been designed for monitoring low energy nuclides. The status of airborne contamination monitoring in China is reported. As the studies for future, the development of the surface contamination monitor for low energy beta nuclides, especially H-3, the monitoring methods for the special shapes of surfaces, the technology of decontamination and the calibration method and device for on-line radioactive aerosol continuous monitors are taken up. (K.I.)

Radioactive contamination in metal recycling industry - an environmental issue

International Nuclear Information System (INIS)

Agarwal, S.P.

2012-01-01

Metal recycling has become an important industrial activity worldwide; it is seen as being socially and environmentally beneficial because it conserves natural ore resources and saves energy. However, there have been several accidents over the past decades involving orphan radioactive sources or other radioactive material that were inadvertently collected as metal scrap that was destined for recycling. The consequences of these accidents have been serious with regard to the protection of people and the environment from the harmful effects of ionizing radiation as well as from an economic point of view. India produces and exports steel products to various countries. In the recent years there were rejection and return of steel products as they were found to be contaminated with trace quantities of radioactive materials. During investigation of incidents of radioactive contamination in steel products exported from India, it was observed that steel products are contaminated with low level radioactivity. Though radioactivity level in steel products is found to be too low to pose any significant hazards to the handling personnel or to the users or the public at large, its presence is undesirable and need to be probed as to how it has entered in the steel products. Atomic Energy Regulatory Board (AERB) has investigated the incidents of such nature in the recent past and it is gathered that the steel products are made out of steel produced in a foundry where metal scrap containing radioactive material has been used. In this talk, incidents of radioactive contamination, its roots cause, and its radiological impact on person, property and environment, lessons learnt, remedial measures and international concerns will be discussed

The radioactive contamination level in Croatia by means of radioactive rainwaters, caused by the accident in NPP 'Lenin'

International Nuclear Information System (INIS)

Barishicj, D.; Koshuticj, K.; Kvastek, K.; Lulicj, S.; Tuta, J.; Vertachnik, A.; Vrhovac, A.

1987-01-01

In this paper, the radioactive contamination level in Croatia by means of radioactive rainwaters, caused by the accident in NPP 'Lenin', has been described. The results represent the sum of measured and evaluated data, the map of the radioactive contamination in Croatia caused by radioactive rainwaters between April, 28 to May, 20 1986 has been constructed. (author) 3 tabs.; 5 figs

REAL-TIME IDENTIFICATION AND CHARACTERIZATION OF ASBESTOS AND CONCRETE MATERIALS WITH RADIOACTIVE CONTAMINATION

International Nuclear Information System (INIS)

XU, X. George; Zhang, X.C.

2002-01-01

Concrete and asbestos-containing materials were widely used in DOE building construction in the 1940s and 1950s. Over the years, many of these porous materials have been contaminated with radioactive sources, on and below the surface. To improve current practice in identifying hazardous materials and in characterizing radioactive contamination, an interdisciplinary team from Rensselaer has conducted research in two aspects: (1) to develop terahertz time-domain spectroscopy and imaging system that can be used to analyze environmental samples such as asbestos in the field, and (2) to develop algorithms for characterizing the radioactive contamination depth profiles in real-time in the field using gamma spectroscopy. The basic research focused on the following: (1) mechanism of generating of broadband pulsed radiation in terahertz region, (2) optimal free-space electro-optic sampling for asbestos, (3) absorption and transmission mechanisms of asbestos in THz region, (4) the role of asbestos sample conditions on the temporal and spectral distributions, (5) real-time identification and mapping of asbestos using THz imaging, (7) Monte Carlo modeling of distributed contamination from diffusion of radioactive materials into porous concrete and asbestos materials, (8) development of unfolding algorithms for gamma spectroscopy, and (9) portable and integrated spectroscopy systems for field testing in DOE. Final results of the project show that the combination of these innovative approaches has the potential to bring significant improvement in future risk reduction and cost/time saving in DOE's D and D activities

General radioactive contamination of the biosphere measurements in the Netherlands 1974. Annual report Coordination Commission radioactivity measurements and Coordination Commission for the measurements of radioactivity and xenobiotic materials

Energy Technology Data Exchange (ETDEWEB)

1975-07-01

For several years, measurements have been performed in the Netherlands to determine radioactive contamination of the biosphere. These measurements are carried out by various institutes responsible to three ministries: the Ministery of 'Health and Environmental Protection', of 'Agriculture and Fisheries' and of 'Transport and Water', (Dutch: 'Verkeer en Waterstaat', under the supervision of the Coordination Commission Radioactive Measurements (CCRA)). Besides radionuclides, many other elements and compounds are considered harmful for man, animal and the environment. A systematic control of the extent of the contamination of the biosphere, in the same way as is in operation for radionuclides, has been proposed for a number of the most harmful contaminants of the biosphere. The measurements are divided into measurements for the National Measuring Programme and additional Measurements. The former include the analyses essential for an efficacious control of the radioactivity of the biosphere. Measurements are performed in air, soil, surface water, milk and in deposition on the surface of the earth. Besides the determination of the usual radionuclides, as performed up to 1970, deposited radioactivity and surface water are also tested for some other specific radionuclides which may be set free at nuclear installations. Finally, samples of milk and grass from the surroundings of nuclear reactors and water from drinking-waterreservoirs have been analysed. Results are given of determination of tritium in drinking water of four big cities, and of radionuclides in some fishery products from the Dutch coastal waters in view of the potential of some marine organisms to concentrate fission products and especially activated corrosion products from nuclear installations. Adiitionally are given the results of measurements by the licensees of the Dutch nuclear installations of samples from the surroundings of their plants.

Method of melt-decontaminating alumium contaminated with radioactivity

International Nuclear Information System (INIS)

Uda, Tatsuhiko; Iba, Hajime; Miura, Noboru; Kawasaki, Katsuo.

1986-01-01

Purpose: To enable optimum deontamination for radioactive-contaminated aluminum by further improving the decontaminating effect of the slag agent added to radioactive contaminated materials. Method: The slag agent is mainly composed of chloride type slags having a high reactivity for mainly incorporating uranium compounds and easily reacting near the melting point of aluminum and incorporated with fluorides for weakening the deliquescent characteristic to the chloride materials. Further, those slag agents are selected which can be treated at a low temperature in order to prevent the uranium compounds once incorporated into the slags from re-melting into the molten aluminum. Typically, a slag agent comprising 14 LiF, 76 KCl - 10 BaCl 2 is preferred. The basicity of the slag agent ranges from 0.5 to 2 and the melting point is 700 deg C. The melting decontaminating efficiency for the radioactive-contaminated aluminum can thus be improved. (Horiuchi, T.)

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Structure and dimensions of radioactive contamination caused by use of nuclear weapons

International Nuclear Information System (INIS)

Ilijas, B.

1996-01-01

Radioactive contamination is one of unavoidable consequences of nuclear burst. Its structure and dimensions are depended of many factors connected with type of weapon, with meteorological conditions and location of burst and characteristics of area involved. Contamination manifests in two ways - as induced radioactivity in the nearness of the center of explosion and as radioactive fallout. Induced radioactivity originates from interaction of neutrons from primary beam with elements naturally presents in environment, which results in creating radionuclides and area of radioactive contamination. Radioactive fallout consists of material formed or collected in the explosion that falls on earth in form of small particles. This contaminant contains α, β and γ sources with structure dependent of explosive energy and location of burst. Some radionuclides, often present in fallout, are very dangerous as internal sources ( 90 Sr, 131 I, 137 Cs, 239 Pu). Dimension of contaminated area varies widely, but if one has Knowledge of enough parameters, it is possible to predict its shape, as well as dose rate on some distance from zero point. Preciseness of this work is essentially affected by credibility of data involved and by kind of selected model. Using of well-chosen model enables on-time evaluation of risk from radioactive contamination and planning adequate protection. (author)

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

International Nuclear Information System (INIS)

Hatakeyama, Mutsuo; Tachibana, Mitsuo; Yanagihara, Satoshi

1997-12-01

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

Evaluating factors affecting the permeability of emulsions used to stabilize radioactive contamination from a radiological dispersal device.

Science.gov (United States)

Fox, Garey A; Medina, Victor F

2005-05-15

Present strategies for alleviating radioactive contamination from a radiological dispersal device (RDD) or dirty bomb involve either demolishing and removing radioactive surfaces or abandoning portions of the area near the release point. In both cases, it is imperative to eliminate or reduce migration of the radioisotopes until the cleanup is complete or until the radiation has decayed back to acceptable levels. This research investigated an alternative strategy of using emulsions to stabilize radioactive particulate contamination. Emergency response personnel would coat surfaces with emulsions consisting of asphalt or tall oil pitch to prevent migration of contamination. The site can then be evaluated and cleaned up as needed. In order for this approach to be effective, the treatment must eliminate migration of the radioactive agents in the terror device. Water application is an environmental condition that could promote migration into the external environment. This research investigated the potential for water, and correspondingly contaminant, migration through two emulsions consisting of Topein, a resinous byproduct during paper manufacture. Topein C is an asphaltic-based emulsion and Topein S is a tall oil pitch, nonionic emulsion. Experiments included water adsorption/ mobilization studies, filtration tests, and image analysis of photomicrographs from an environmental scanning electron microscope (ESEM) and a stereomicroscope. Both emulsions were effective at reducing water migration. Conductivity estimates were on the order of 10(-80) cm s(-1) for Topein C and 10(-7) cm s(-1) for Topein S. Water mobility depended on emulsion flocculation and coalescence time. Photomicrographs indicate that Topein S consisted of greater and more interconnected porosity. Dilute foams of isolated spherical gas cells formed when emulsions were applied to basic surfaces. Gas cells rose to the surface and ruptured, leaving void spaces that penetrated throughout the emulsion. These

Treatment of radioactive contaminated water in nuclear power plants

International Nuclear Information System (INIS)

1978-12-01

This rule is to be applied to the design, construction, and operation of facilities for treatment of water contaminated with radioactive material in stationary nuclear power plants with LWRs and HTRs. According to the requirements of the rule these facilities are to be designed, constructed, and operated in such a way that a) uncontrolled discharge of water contaminated with radioactive material is avoided, b) the activity discharged with water is as low as possible, c) water contaminated with radioactive material will not reach the ground, d) the radiation exposure as a consequence of direct radiation, contamination, and inhalation of the persons occupied in the facilities is as low as possible and as a maximum corresponds to the values laid down in the radiation protection regulation or to the values of the operating license. This rule is not to be applied to facilities for coolant and storage pit clean-up as well as facilities for the treatment of concentrates produced during the contamination of the water. (orig./HP) [de

Control System Radioactive Contamination in Food Samples in Poland

International Nuclear Information System (INIS)

Grabowski, D.; Kurowski, W.; Muszynski, W.; Rubel, B.; Smagala, G.; Swietochowska, J.

2001-01-01

Full text: The analyses of the level of radioactive contamination in food samples are carried out by the Service for Measurements of Radioactive Contamination (SMRC) in Poland. The Service was brought into existence in 1961. The Service comprises of a network of measurement stations and the Centre of Radioactive Contamination Measurements (CRCM). The duty of the Centre is being executed by the Central Laboratory for Radiological Protection (CLRP). The uniform methods of sampling are used in measurement stations. All important foodstuff: milk, meat, vegetables, fruit, cereals are controlled in the Service stations. The radiochemical and spectrometric methods are used to determine the activity of radioactive isotopes. The standard equipment of the measurement station is the measurement system type SAPOS-90 and multichannel analyser with scintillation or germanium detector. The structure of the Service, kinds of samples tested by each station, program of sampling in normal and during accident situation are presented in this paper. (author)

Radioactivity measurement of radioactive contaminated soil by using a fiber-optic radiation sensor

Science.gov (United States)

Joo, Hanyoung; Kim, Rinah; Moon, Joo Hyun

2016-06-01

A fiber-optic radiation sensor (FORS) was developed to measure the gamma radiation from radioactive contaminated soil. The FORS was fabricated using an inorganic scintillator (Lu,Y)2SiO5:Ce (LYSO:Ce), a mixture of epoxy resin and hardener, aluminum foil, and a plastic optical fiber. Before its real application, the FORS was tested to determine if it performed adequately. The test result showed that the measurements by the FORS adequately followed the theoretically estimated values. Then, the FORS was applied to measure the gamma radiation from radioactive contaminated soil. For comparison, a commercial radiation detector was also applied to measure the same soil samples. The measurement data were analyzed by using a statistical parameter, the critical level to determine if net radioactivity statistically different from background was present in the soil sample. The analysis showed that the soil sample had radioactivity distinguishable from background.

Characterization of radioactive contamination inside pipes with the Pipe Explorer trademark system

International Nuclear Information System (INIS)

Lowry, W.

1994-01-01

The objective for the development of the Pipe Explorer trademark radiological characterization system is to achieve a cost effective, low risk means of characterizing gamma radioactivity on the inside surface of pipes. The unique feature of this inspection system is the use of a pneumatically inflated impermeable membrane which transports the detector into the pipe as it inverts. The membrane's internal air pressure tows the detector and tether through the pipe. This mechanism isolates the detector and its cabling from the contaminated surface, yet allows measurement of radioactive emissions which can readily penetrate the thin plastic membrane material (such as gamma and high energy beta emissions). In Phase 1, an initial survey of DOE facilities was conducted to determine the physical and radiological characteristics of piping systems. The inverting membrane deployment system was designed and extensively tested in the laboratory. A range of membrane materials was tested to evaluate their ruggedness and deployment characteristics. Two different sizes of gamma scintillation detectors were procured and tested with calibrated sources. Radiation transport modeling evaluated the measurement system's sensitivity to detector position relative to the contaminated surface, the distribution of the contamination, background gamma levels, and gamma source energy levels. In the culmination of Phase 1, a field demonstration was conducted at the Idaho National Engineering Laboratory's Idaho Chemical Processing Plant. The project is currently in transition from Phase 1 to Phase 2, where more extensive demonstrations will occur at several sites. Results to date are discussed

Environmental radioactive contamination

International Nuclear Information System (INIS)

Saucedo, Edgardo

2000-01-01

The environmental radioactive contamination with the scientific and technological advances can produce big benefits or damages to the human beings or the environment. The approval of national or international laws in the population's education so that it can face the topic critically and the scientific formation of human resources and ethically for application of the ionizing radiations, they are the best road to take advantage to the maximum of benefits of these radiations, reducing to the minimum the risks on the man and the environment

Ecological Role of Soils upon Radioactive Contamination

Science.gov (United States)

Tsvetnov, Evgeny; Shcheglov, Alexei; Tsvenova, Olga

2016-04-01

The ecological role of soils upon radioactive contamination is clearly manifested in the system of notions about ecosystems services, i.e., benefits gained by humans from ecosystems and their components, including soils (Millennium Ecosystem Assessment, 2005). For the soils, these services are considered on the basis of soil functions in the biosphere that belong to the protective ecosystem functions within the group of soil functions known under the names of "Buffer and protective biogeocenotic shield" (at the level of particular biogeocenoses) and "Protective shield of the biosphere" (at the global biospheric level) (according to Dobrovol'skii & Nikitin, 2005). With respect to radionuclides, this group includes (1) the depositing function, i.e., the accumulation and long-term sequestration of radioactive substances by the soil after atmospheric fallout; (2) the geochemical function, i.e., the regulation of horizontal and vertical fluxes of radionuclides in the system of geochemically conjugated landscapes and in the soil-groundwater and soil-plant systems; and (3) the dose-forming function that is manifested by the shielding capacity of the soil with respect to the external ionizing radiation (lowering of the dose from external radiation) and by the regulation of the migration of radionuclides in the trophic chain (lowering of the dose from internal radiation). The depositing and geochemical functions of the soils are interrelated, which is seen from quantitative estimates of the dynamics of the fluxes of radionuclides in the considered systems (soil-plant, soil-groundwater, etc.). The downward migration of radionuclides into the lower soil layers proceeds very slowly: for decades, more than 90% of the pool of radionuclides is stored in the topmost 10 cm of the soil profile. In the first 3-5 years after the fallout, the downward migration of radionuclides with infiltrating water flows decreases from several percent to decimals and hundredths of percent from the

Micro-PIXE evaluation of radioactive cesium transfer in contaminated soil samples

International Nuclear Information System (INIS)

Fujishiro, F.; Ishii, K.; Matsuyama, S.; Arai, H.; Ishizaki, A.; Osada, N.; Sugai, H.; Kusano, K.; Nozawa, Y.; Yamauchi, S.; Karahashi, M.; Oshikawa, S.; Kikuchi, K.; Koshio, S.; Watanabe, K.; Suzuki, Y.

2014-01-01

Highlights: • There are radioactively contaminated soils having a radioactive cesium transfer of 0.01. • Micro-PIXE analysis has revealed an existence of phosphorus in a contaminated soil. • Radioactive cesium captured by phosphorus compound would be due to radioactive transfer. -- Abstract: Micro-PIXE analysis has been performed on two soil samples with high cesium activity concentrations. These soil samples were contaminated by fallout from the accident at Fukushima Daiichi Nuclear Power Plant. One exhibits a radioactive cesium transfer of ∼0.01, and the other shows a radioactive cesium transfer of less than 0.001, even though both samples have high cesium activity concentrations exceeding 10,000 Bq/kg. X-ray spectra and elemental images of the soil samples revealed the presence of chlorine, which can react with cesium to produce an inorganic soluble compound, and phosphorus-containing cesium-capturable organic compounds

Development of maintenance procedure for plate type heat exchanger taking into account preventing radioactive contamination

International Nuclear Information System (INIS)

Terai, Kensuke; Someki, Hiroyuki; Ueda, Yuya

2017-01-01

In Japanese pressurized water reactors (PWR), heat loads of spent fuel pools (SFP) is increasing due to rising spent fuels and use of mixed oxide (MOX) fuels. Therefore, SFP cooling capacities are necessary to be enhanced, and replacement of SFP coolers or installation of additional coolers is needed. On the other hand, installation spaces of SFP coolers are limited in existing buildings. Therefore, plate type heat exchangers which can be designed to be compact because of the high heat efficiency have often been adopted for SFP coolers instead of shell and tube type heat exchangers in general use. Plate type heat exchangers have to be overhauled periodically for inspection and gasket replacement. However, in plate type SFP coolers, radioactive SFP water and non-radioactive component cooling water (CCW) alternately run through between each plate. Thus there is a concern that the CCW system may be contaminated by radioactive materials from the SFP water during overhaul of the SFP cooler. In order to solve this problem, we have developed the maintenance procedure of the plate type SFP coolers to prevent CCW side contamination by coating the contaminated surfaces with strippable paint prior to disassembly. Before applying this developed maintenance procedure to actual equipment, we have performed the following verification tests. (1) Confirmation of fundamental characteristics for strippable paint. Firstly, we selected both water-based and solvent-based strippable paints. Secondly, we tested and confirmed the detachability and the drying time of the selected strippable paints respectively. Moreover we also confirmed that the selected strippable paints are appropriate materials from the viewpoint of chemical composition restriction of consumable materials used in nuclear power plant. (2) Confirmation of workability for paint filling, drying and peeling off. The strippable paints need to be peeled off after filling into plate type heat exchanger and draining

Radioactivity of some alpha, beta and gamma emitting radionuclides in surface marine sediments of different bays in Algeria

International Nuclear Information System (INIS)

Noureddine, A.; Baggoura, B.

1999-01-01

Samples of surface (0-15) cm marine sediments of different grain sizes, namely sand, muddy and fine sand, were collected in the western, central and east coast of Algeria, to measure concentrations of natural and artificial radioactivity. The aim of this study is to detect any radioactive contamination, its origin and also to determine the uptake of radioactivity by marine surface sediments

Radioactive contamination of sewage sludge

International Nuclear Information System (INIS)

Soeder, C.J.; Zanders, E.; Raphael, T.

1986-01-01

Because of the radioactivity released through the explosion of the nuclear reactor near Chernobyl radionuclides have been accumulated to a significant extent in sewage sludge in the Federal Republic of Germany. This is demonstrated for samples from four activated sludge plants according to a recent recommendation of the German Commission for Radiation Protection, there is until now no reason to deviate from the common practices of sludge disposal or incineration. The degree of radioactive contamination of plant materials produced on farm lands on which sewage sludge is being spread cannot be estimated with sufficient certainty yet. Additional information is required. (orig.) [de

The inhalation of radioactive materials as related to hand contamination

Energy Technology Data Exchange (ETDEWEB)

Bailey, J.C.; Rohr, R.C.

1953-09-15

Tests performed to determine the hazard associated with the inhalation of radioactive materials as the result of smoking with contaminated hands indicate that for dry uranium compounds adhering to the palmar surfaces of the hands, approximately 1.0% of the material may be transferred to a cigarette, and that of this approximately 0.2% may appear in the smoke which is inhaled. Most of the contamination originally placed in a cigarette was found in the ash, and only 11% of the material was not recovered following burning; approximately half of this loss may be attributed to normal losses inherent in the analytical process, the recovery efficiency for which was found by supplementary experiments to be 95%.

Development of high-level radioactive waste treatment and conversion technologies 'Dry decontamination technology development for highly radioactive contaminants'

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.

Radioactive contamination of workers. General recommendation and procedures

International Nuclear Information System (INIS)

Mastro, N.L. del; Santos, O.R. dos; Silva, E.N.D.; Santos, A.J. dos.

1987-09-01

The present publication has an objective to provide data and information to be used by workers who handle with or eventually could enter in touch with radioactives substances. The authors have made a compilation of subjects got from the literature on several aspects about radiocontamination, physical and chemical characteristics of radioisotopes, main sources of radioactive contamination, biological basis and treatement of internal and external decontamination. Special attention was paid to iodine and actinides contamination, particularly to uranium and plutonium. The conclusion are presented as general recommendation and synoptic tables. (Author) [pt

Radioactive contamination of environment and food in Poland in 1998

International Nuclear Information System (INIS)

Grabowski, D.; Kurowski, W.; Muszynski, W.; Rubel, B.; Smagala, G.; Swietochowska, J.

1999-01-01

The analysis of the level of radioactive contamination in environmental and food samples was carried out in Poland in 1998. The results were compared to the data from the period 1985-1997. Since the Chernobyl accident gradual decrease of contamination level has been observed. The gamma dose rate and the contamination of air, fallout, tape and surface water were at the level of 1985. The only contamination enhanced in relation to pre-Chernobyl period was the content of cesium isotopes in soil and as a consequence food contamination was higher particularly milk and meat. At present, the source of additional dose is ingestion of artificial isotopes with food as a result of food contamination. No significant regional differences in the distribution of the level of cesium in food over the territory of Poland has been registered. Milk can be assumed as the main contributor of cesium to the diet, its share is about 33% of annual intake of cesium. The average effective dose, resulting from the contaminated food consumption, was estimated to be at the level of 13 μSv per capita of the Polish population in 1998. (author)

Radioactive contamination of environment and food in Poland in 1997

International Nuclear Information System (INIS)

Grabowski, D.; Kurowski, W.; Muszynski, W.; Rubel, B.; Smagala, G.; Swietochowska, J.; Wilgos, J.

1998-01-01

The analysis of the level of radioactive contamination in environmental and food samples was carried out in Poland in 1997. The results were compared to the data from the period 1985-1996. Since the Chernobyl accident gradual decrease of contamination level has been observed. The gamma dose rate and the contamination of air, fallout, tape and surface water were at the level of 1985. The only contamination enhanced in relation to pre-Chernobyl period was the content of cesium isotopes in soil and as a consequence food contamination was higher particularly milk and meat. At present, the source of additional dose is ingestion of artificial isotopes with food as a result of food contamination. No significant regional differences in the distribution of the level of cesium in food over the territory of Poland has been registered. Milk can be assumed as the main contributor of cesium to the diet, its share is about 35% of annual intake of cesium. The average effective dose equivalent, resulting from the contaminated food consumption, was estimated to be at the level of 13 μSv per capita of the Polish population in 1997. (author)

Radioactive contamination of environment and food in Poland in 1996

International Nuclear Information System (INIS)

Grabowski, D.; Kurowski, W.; Muszynski, W.; Rubel, B.; Smagala, G.; Swietochowska, J.; Wilgos, J.

1997-01-01

The analysis of the level of radioactive contamination in environmental and food samples was carried out in Poland in 1996. The results were compared to the data from the period 1985-1995. Since the Chernobyl accident gradual decrease of contamination level has been observed. The gamma dose rate and the contamination of air, fallout, tape and surface water were at the level of 1985. The only contamination enhanced in relation to pre-Chernobyl period was the content of cesium isotopes in soil and as a consequence food contamination was higher particularly milk and meat. At present, the source of additional dose is ingestion of artificial isotopes with food as a result of food contamination. No significant regional differences in the distribution of the level of cesium in food over the territory of Poland has been registered. Milk can be assumed as the main contributor of cesium to the diet, its share is about 40% of annual intake of cesium. The average effective dose equivalent, resulting from the contaminated food consumption, was estimated to be at the level of 14 μSv per capita of the Polish population in 1996. (author)

Radioactive contamination of food and the intake by man

International Nuclear Information System (INIS)

Frissel, M.J.; Blaauboer, R.O.; Koester, H.W.; Leenhouts, H.P.; Stoutjesdijk, J.F.; Vaas, L.H.

1989-01-01

This paper describes the different pathways by which food is contaminated after a release of radionuclides into the environment. Equations to calculate the contamination level, as well as the most important parameters used in these equations, are included. Thereupon is explained how the radiation dose can be calculated from the intake of radioactivity. The principles which are used to derive criteria for the amounts of radioactivity which are allowed in food are described. (author)

An overview of sites contaminated by radioactivity

International Nuclear Information System (INIS)

Eisenbud, M.

1991-01-01

This paper discusses contamination of land and water by radioactive material which is a subject that has been receiving widespread media attention, and has become the cause of much public anxiety. The contaminated sites can be divided broadly into three groups: Those that are quite old, relatively small in size, and the legacy of non-nuclear industrial activities involved with natural radioactivity, mostly in the early part of the century; the chain of uranium extraction plants used during and shortly after World War II, and the plants and laboratories that comprise the Department of Energy (DOE) research and weapons production complex today. It is the latter group that is the focus of greatest public attention at the present time

Mapping the radioactive contamination in urban environments after nuclear emergencies

International Nuclear Information System (INIS)

Kaiser, Jan Christian; Proehl, Gerhard; Woda, Clemens

2008-01-01

Full text: In the event of a nuclear emergency in an urban environment a reliable overview on the radioactive contamination is crucial for decision making. To assess the radiological situation both measurements of the gamma dose or dose rate (GDR) and results from urban dispersion and deposition models are used. Measurements may arrive from various sources like car-borne detectors or man-borne radiation-sensitive materials embedded in cell phones, flash memory devices or RFID chips. The measurements depend strongly on the detector environment. To account for this dependence each signal is multiplied by a location factor, which quantifies the deviation of the recorded signal from the hypothetical signal of a reference surface of infinitely extended lawn. Furthermore, the data originate from geo-referenced points or lines but do not provide full spatial information. We present here two approaches to produce maps of the reference GDR or surface contamination in urban areas, which are implemented in the Inhabited Areas Monitoring Module (IAMM) as part of the European decision support systems RODOS and ARGOS. Immediately after the accident, a few measurements are combined with the predictions of urban models using data assimilation. If enough measurements are available they are regionalised with geo-statistical interpolation algorithms like inverse distance weighting or kriging. Both approaches are demonstrated in hypothetical scenarios based on the explosion of a radioactive dispersion device. (author)

Development of an automatic smear sampler and evaluation of surface contamination

International Nuclear Information System (INIS)

Seo, B. K.; Lee, B. J.; Lee, K. W.; Park, J. H.

2004-01-01

The surface contamination level of a radiation-controlled area is measured periodically according to atomic energy law and connection regulations. The measurement of surface contamination by an indirect method is subject to various kinds of error depending on the sampling person and consumes much time and effort in the sampling of large nuclear facilities. In this research, an automatic smear sampler is developed to solve these problems. The developed equipment is composed of a rotating sampling part, a sample transferring part, a power supply part a control part, and vacuum part. It improved the efficiency of estimation of the surface contamination level achieved periodically in a radiation-controlled area. Using an automatic smear sampler developed in this research, it is confirmed that radioactive contaminated materials are uniformly transferred to smear paper more than any sampling method by an operator. (authors)

Distinguishing method for contamination/radio-activation of radioactive wastes

International Nuclear Information System (INIS)

Fukazawa, Takuji; Kato, Keiichiro; Koda, Satoshi.

1994-01-01

The present invention concerns a method of distinguishing the contamination/radio-activation of radioactive wastes used in processing wastes generated upon dismantling of exhausted nuclear reactors. Especially, contaminated/radio-activation is distinguished for wastes having openings such as pipes and valves, by utilizing scattering of γ-rays or γ-ray to β-ray ratio. That is, ratio of scattered γ-rays and direct γ-rays or ratio of β-rays and γ-rays from radioactive wastes are measured and compared by a radiation detector, to distinguish whether the radioactive wastes contaminated materials or radio-activated materials. For example, when an object to be measured having an opening is contaminated at the inner side, the radiation detector facing to the opening mainly detects high direct γ-rays emitted from the object to be measured while a radiation detector not facing the opening mainly detects high scattered γ-rays relatively. On the other hand, when the object is a radio-activated material, any of the detectors detect scattered γ-rays, so that they can be distinguished by these ratios. (I.S.)

Development of RadRob15, A Robot for Detecting Radioactive Contamination in Nuclear Medicine Departments

Directory of Open Access Journals (Sweden)

Shafe A.

2016-09-01

Full Text Available Accidental or intentional release of radioactive materials into the living or working environment may cause radioactive contamination. In nuclear medicine departments, radioactive contamination is usually due to radionuclides which emit high energy gamma photons and particles. These radionuclides have a broad range of energies and penetration capabilities. Rapid detection of radioactive contamination is very important for efficient removing of the contamination without spreading the radionuclides. A quick scan of the contaminated area helps health physicists locate the contaminated area and assess the level of activity. Studies performed in IR Iran shows that in some nuclear medicine departments, areas with relatively high levels of activity can be found. The highest contamination level was detected in corridors which are usually used by patients. To monitor radioactive contamination in nuclear medicine departments, RadRob15, a contamination detecting robot was developed in the Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC. The motor vehicle scanner and the gas radiation detector are the main components of this robot. The detection limit of this robot has enabled it to detect low levels of radioactive contamination. Our preliminary tests show that RadRob15 can be easily used in nuclear medicine departments as a device for quick surveys which identifies the presence or absence of radioactive contamination.

Some problems of risk assessment in cases of environmental radioactive and chemical contamination in regions of the Ural radioactive trail

International Nuclear Information System (INIS)

Kryshev, I.I.; Isaeva, L.N.; Sazykina, T.G.

1995-01-01

A methodology of risk assessment if being developed to permit the analysis of possible consequences of radioactive and chemical environment contamination on the territory of the Urals radioactive trail. The assessment of hazards from radioactive contamination of the Techa river (Muslyumovo) has been carried out. A comparison of radioactive and chemical risks for the population of Kasli has been made

Contamination and decontamination of vehicles driven in radioactive areas

International Nuclear Information System (INIS)

Ulvsand, T.; Nygren, U.

1999-03-01

There is reason to ask whether it is beneficial to decontaminate vehicles, in view of the great effort applied. If the level of contamination is low before the decontamination process, then the cost is not motivated, even if the decontamination is shown to be effective in relative terms. The report describes two trials at the National NBC Defence School in Umeaa and one trial at the French test site in Bourges. The aim is to investigate how vehicles are contaminated and at which ground deposition levels troublesome levels of contamination will arise. In the trials, a non-radioactive agent substituting real radioactivity was used. The trials in Sweden so far have used the oversnow vehicle BV 206, during both winter and summer conditions. The vehicles were driven a specific distance along a road on which a known amount of the test substance had been dispersed. Samples were taken on pre-determined areas on one side of the vehicles to measure the amount of test substance. Later, the vehicles continued along a 'clean' road where additional samples were taken, but on the other side of the vehicles. The largest amount of test substance was collected on the tracks and on the back of the vehicle. The tracks and mud-flaps were effectively decontaminated when the vehicles were driven along a clean road, while most of the contamination remained on the backside. The purpose of the trials in France was to compare the results from our non-radioactive and their radioactive method, based on the radioactive La-140. Due to ground conditions, the level of contamination on the vehicles was much less than in the trials in Umeaa, but the effect decontamination could be measured after all

Modelling of contamination of surface atmosphere for deflation of Cesium-137 on contaminated territories

International Nuclear Information System (INIS)

Bogdanov, A.P.; Zhmura, G.M.

1994-01-01

Presence of Cesium 137 in near land air is caused at the contaminated territories by 'local' dusting and transport of the dust from the zone of strong contamination. For large distance is it caused by resuspension of radioactive dust from the surface in the given region. In accordance with the models of dusting round square sources based on Gauss statistical model of dissemination of admixtures in the atmosphere, the contaminated areas of european part of the former of USSR with the density of contamination over 1 Ci/km 2 with Cesium 137 were represented by 30 round square sources covering the main spots of contamination. The results of calculation of contamination of the atmosphere for several cities of Belarus, Russia and Ukraine, where there are the permanent points of observation for the content of radionuclides in the air, have shown that the proposed model of dusting sources describes the contamination of near land air with Cesium 137 reasonably well. 7 refs., 3 tabs

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

International Nuclear Information System (INIS)

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

1999-04-01

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

Radioactive contamination of oil produced from nuclear-broken shale

International Nuclear Information System (INIS)

Arnold, W.D.; Crouse, D.J.

1970-01-01

The results of small-scale exposure and retorting tests indicate that oil recovered from shale that has been broken with nuclear explosives will be contaminated with tritium. When oil shale was heated in sealed flasks with tritiated water vapor or with tritiated hydrogen, both the shale and the oil subsequently retorted from the shale contained tritium. There was much less contamination of the shale or oil, however, when the shale was exposed to tritiated methane and ethane. Contamination of shale and oil with tritium, as the result, of exposure to tritiated water, increased as the exposure temperature, exposure pressure, and the tritium concentration in the water were increased. This contamination also increased as the exposure time was increased up to 25 days, but not significantly thereafter. More than 90% of the tritium was removed from contaminated shale by treating the shale with moist air at elevated temperatures. Only small amounts of the tritium were removed from crude oil by contacting it with solid drying agents or with water. When tritium-contaminated shale oil was distilled, the tritium contents of the recovered fractions were found to be approximately equal. After being heated with a sample of underground test-shot debris, liquid shale oil became contaminated with radioactive fission products. Most of the radioactivity of the oil was due to finely dispersed solids rather than to dissolved radionuclides. Filtration of the oil removed a major fraction of the radioactive material. When the contaminated oil was distilled, more than 99% of the radionuclides remained in the pot residue. (author)

Radioactive contamination of oil produced from nuclear-broken shale

Energy Technology Data Exchange (ETDEWEB)

Arnold, W D; Crouse, D J

1970-05-15

The results of small-scale exposure and retorting tests indicate that oil recovered from shale that has been broken with nuclear explosives will be contaminated with tritium. When oil shale was heated in sealed flasks with tritiated water vapor or with tritiated hydrogen, both the shale and the oil subsequently retorted from the shale contained tritium. There was much less contamination of the shale or oil, however, when the shale was exposed to tritiated methane and ethane. Contamination of shale and oil with tritium, as the result, of exposure to tritiated water, increased as the exposure temperature, exposure pressure, and the tritium concentration in the water were increased. This contamination also increased as the exposure time was increased up to 25 days, but not significantly thereafter. More than 90% of the tritium was removed from contaminated shale by treating the shale with moist air at elevated temperatures. Only small amounts of the tritium were removed from crude oil by contacting it with solid drying agents or with water. When tritium-contaminated shale oil was distilled, the tritium contents of the recovered fractions were found to be approximately equal. After being heated with a sample of underground test-shot debris, liquid shale oil became contaminated with radioactive fission products. Most of the radioactivity of the oil was due to finely dispersed solids rather than to dissolved radionuclides. Filtration of the oil removed a major fraction of the radioactive material. When the contaminated oil was distilled, more than 99% of the radionuclides remained in the pot residue. (author)

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Influence of radioactive contaminants on absorbed dose estimates for radiopharmaceuticals

International Nuclear Information System (INIS)

Watson, E.E.; Stabin, M.G.

1986-01-01

Several popular radiopharmaceutical products contain low levels of radioactive contaminants. These contaminants increase the radiation absorbed dose to the patient without any increased benefit and, in some cases, with a decrease in image quality. The importance of a contaminant to the radiation dosimetry picture is a function of 1) the contaminant level, 2) the physical half-life of the contaminant, 3) the organ uptake and the biological half-time of the contaminant in the various body systems, and 4) the decay mode, energy, etc. of the contaminant. The general influence of these parameters is discussed in this paper; families of curves are included that reflect the changing importance of contaminant dosimetry with respect to the primary radionuclide as a function of these variables. Several specific examples are also given of currently used radiopharmaceutical products which can contain radioactive contaminants (I-123, In-111, Tl-201, Ir-191m, Rb-82, Au-195m). 7 references, 8 figures, 4 tables

Contamination due to radioactive materials

International Nuclear Information System (INIS)

Woodhead, D.S.

1984-01-01

The peaceful exploitation of radioactivity and the expansion of the nuclear power programme ensure that the disposal of radioactive wastes will cause contamination of the marine environment in the foreseeable future. The exposure of marine organisms to radioactivity from wastes has been studied in depth and related to exposure to natural background radiation. Concentrations of natural radionuclides and those from marine waste disposal have been measured at various stations in the oceans and seas around the world. The fate of radionuclides at four representative sites has been studied and the concentrations of radionuclides in oysters, porphyra, plaice in the Windscale discharge area have been measured. The extent of human exposure, particularly with reference to seafood consumption in local fishing communities, has been assessed. Effects of radiation on developing fish embryos and eggs and genetic radiation effects in aquatic organisms has been studied. The above studies reveal that the controls applied to the discharge of radioactive wastes to limit hazards to humans also provide adequate protection for populations of marine organisms. (U.K.)

Waste processing system for product contaminated with radioactivity

International Nuclear Information System (INIS)

Sotoyama, Koichi; Takaya, Jun-ichi; Takahashi, Suehiro.

1987-01-01

Purpose: To enable to processing contaminated products while separating them into metals at high contamination level and non-metals at low contamination level. Constitution: Pulverized radioactive wastes conveyed on a conveyor belt are uniformly irradiated by a ring-illumination device and then they are picked-up by a television camera or the like. The picked-up signals are sent to an image processing device, applied with appropriate binarization and metal objects are separated by utilizing the light absorbing property of non-metal and light reflection property of metals. The graviational center for the metal object is calculated from the binarized image, the positional information is provided to a robot controller and the metal object is transferred to another position by a robot. Since only the metal object at high radioactive contamination level can be taken out separately, it is no more necessary to process the entire wastes as the high level decontamination products, to thereby provide an economical advantage. (Sekiya, K.)

Comparison between ex situ and in situ measurement methods for the assessment of radioactively contaminated land. Comparison between measurement methods for the characterisation of radioactively contaminated land

International Nuclear Information System (INIS)

Rostron, Peter D.; Ramsey, Michael H.; Heathcote, John A.

2012-01-01

In the UK, it is estimated that there may be 20,000,000 cubic metres of contaminated land at Sellafield alone. Harwell and Dounreay are known to have significant amounts of radioactive or nonradioactive contaminated land (NDA, 2006). It is therefore important to devise optimal methods for the characterisation of areas of land for radionuclide content, in order to enable cost-effective decommissioning. With chemical contaminants, ex situ measurements are made on a larger volume of soil than are in situ measurements, such as PXRF. However, the opposite is often true for the characterisation of radioactive contamination, when this involves the detection of penetrating radiation from γ-emitting radionuclides. This means that when investigating for hotspots of radioactive contamination at or near the ground surface, better coverage can be obtained using in situ methods. This leads to the question, what is the optimal strategy (e.g. percentage coverage, counting time) for in situ characterisation of radioactively contaminated land' Surveys on light-moderate contaminated areas of ground were conducted at Dounreay in order to compare the relative effectiveness of in situ and ex situ methods, both for the detection of radioactive hotspots and also for estimating the average radionuclide content of an area of ground. These surveys suggest that continuous coverage by in situ devices is more effective at hotspot detection, with ex situ laboratory measurements being less effective, although in one case elevated activity below 10 cm depth that was identified by ex situ measurement was not located by in situ measurement. The surveys also highlighted that careful choice of an appropriate spatial model is critical to the estimation of activity concentrations over averaging areas. Whereas continuous coverage may be considered necessary for hotspot identification, in the particular case of the detection of hot particles (where the particle is very small compared to the sampling

Some bioindicators of radioactive contamination

International Nuclear Information System (INIS)

Cosma, C.; Cozmuta, I.; Micu, C.

1996-01-01

The lessons that could be learned from the Chernobyl accident were numerous and encompassed all areas. One of those lead to the discovery of new monitoring methods which also supply to cost-effective solutions to control contaminant radioactive discharges in the environment. Through the measurements performed, we discovered that some samples, because of their radioactive content restrained also for long periods of time, can be used as bioindicators. Hen eggs between May 1-30 1986 were analysed (identification of radionuclides with a Ge(Li) detector and measuring of total gamma activity with NaI(T1)). Various aspects pursued revealed that eggs are precious witness of vegetable food contamination with fission products, especially Ba-140 and I-131, behaving as radionuclide separators (Ba-140 in egg shell -301 Bq/egg and I-131 in the content - 182 Bq/egg). Some of the most important pharmaceutical plants from Transylvania measured during 1986-1994 period presents high cesium radioactivity. The perennial plants (as Lichen Islandicus) for the same period accumulated a greater activity that the annual ones. Especially the lichen, because of the their slow decreasing activity are suitable as biological detectors also in retrospective measurements. Measuring the activity of some pollen samples was rediscovered. The pollen grains, during their transport in air by the bees, are acting like a filter for radionuclides so that we could use they to monitor the deliverance of these substances in air. (author)

Management of commercial high-level and transuranium-contaminated radioactive wastes. Environmental statement

International Nuclear Information System (INIS)

1974-09-01

This Draft Environmental Statement is issued to assess the environmental impact of the AEC's program to manage commercial high-level and transuranium-contaminated radioactive wastes. These are the types of commercial radioactive wastes for which AEC custody is required by present or anticipated regulations. The program consists of three basic parts: development of a Retrievable Surface Storage Facility (RSSF) for commercial high-level waste, using existing technology; evaluating geological formations and sites for the development of a Geological Disposal Pilot Plant (GDPP) which would lead to permanent disposal; and providing retrievable storage for the transuranium-contaminated waste pending availability of permanent disposal. Consideration has been given to all environmental aspects of the program, using waste generation projections through the year 2000. Radiological and other impacts of implementing the program are expected to be minimal, but will be discussed in further environmental statements which will support budget actions for specific repositories. The alternatives discussed in this Draft Environmental Statement are presented. (U.S.)

Control of the surface radioactive contamination in the field of biological research; Control de la contaminacion radiactiva superficial en el ambito de la investigacion biologica

Energy Technology Data Exchange (ETDEWEB)

Calvo, S.; Encina, A. de la; Gaspar, J.; Macias, M. T.; Sanchez, A.; Usera, F.

2012-11-01

The manipulation of unsealed sources in biomedical research involves significant risk of radioactive contamination. the aim of this study has been to analyze the radioactive contamination occurring in the field of biomedical research, assessing its magnitude, identifying the equipment that can be contaminated with higher probability and monitoring the evolution of the contaminations production taking into account the radioisotopes and the activities uses, and the radiation protection control applied. The data used for this study correspond to a very lengthy period of time and it have been collected in the radioactive facility, of the Centro Nacional de Biotecnologia (CSIC), a very large biological research centre that can be used perfectly as a reference for this area. The results obtained show a gradual and significant decrease in the incidence of the radioactive contamination. This is due to the optimization of radiation protection standards applied and the implementation or a systematic operational radiation protection program. (Author) 13 refs.

Experiment on Physical Desalinisation of Uranium-contaminated Gravel Surface

International Nuclear Information System (INIS)

Park, Uk-Ryang; Kim, Gye-Nam; Kim, Seung-Soo; Han, Gyu-Seong; Moon, Jai-Kwon

2014-01-01

As a result, the method to wash uranium-contaminated gravels could not get satisfactory desalinization rate. During the long oxidization process it was judged that uranium penetrated inside the gravels, so we tried to increase the desalinization rate by fragmentizing them into pieces and then washing them. The desalinization rate after fragmentizing the gravels into pieces and washing them brought a satisfactory result.. However, we could obtain desired concentration for gravels with high uranium concentration by fragmentizing them and breaking them further into even smaller pieces. Likewise, desalinization using soil washing process is complicated and has to go through multiple washing steps, resulting in too much of waste fluid generated accordingly. The increase of waste fluid generated leads to the increase in by-products of the final disposal process later on, bringing a not good economic result. Furthermore, taking into account that the desalinization rate is 65% during soil washing process, it is expected that gravel washing will show a similar desalinization result; it is considered uneasy to have a perfect desalinization only by soil washing. The grinding method is actually used in the primary desalinization process in order to desalinize radioactivity-contaminated concrete. This method does desalinization by grinding the radioactivity-contaminated area of the concrete surface with desalinization equipment, which enables a near-to-perfect desalinization for relatively thinly contaminated surface. Likewise, this research verified the degree of desalinization by applying the grinding method and comparing it to the fragmentizing-washing method, and attempted to find a method to desalinize uranium-contaminated gravels more effectively. In order to desalinize uranium-contaminated gravels more effectively and compare to the existing washing-desalinization method, we conducted a desalinization experiment with grinding method that grinds gravel surface. As a

Microfiltration of radioactive contaminants

Energy Technology Data Exchange (ETDEWEB)

Buckley, L P; Slade, J A; Vijayan, S; Wong, C F

1993-04-01

Cross-flow microfiltration processing of radioactive liquids has been in use at Chalk River Laboratories for about four years. The separation process removes suspended particles from radioactive waste solutions. The clean liquid can then be treated with conventional reverse osmosis membranes to achieve volume reduction factors approaching 100. Microfiltration removes particles below the rating of 0.2 microns, in part from particle agglomeration. Operating experience relating to a 15 USGPM unit is presented. Coupling microfiltration technology with chemical treatment enhances the removal of soluble species. Research and development experience with the removal of soluble contaminants found in ground water and waste water will be discussed. The technology has advantages over other membrane technologies, namely lower energy costs, a lesser degree of fouling, and a higher recovery of processed solution. Future applications of the technology are addressed. (author). 10 refs., 3 tabs., 4 figs.

Microfiltration of radioactive contaminants

International Nuclear Information System (INIS)

Buckley, L.P.; Slade, J.A.; Vijayan, S.; Wong, C.F.

1993-04-01

Cross-flow microfiltration processing of radioactive liquids has been in use at Chalk River Laboratories for about four years. The separation process removes suspended particles from radioactive waste solutions. The clean liquid can then be treated with conventional reverse osmosis membranes to achieve volume reduction factors approaching 100. Microfiltration removes particles below the rating of 0.2 microns, in part from particle agglomeration. Operating experience relating to a 15 USGPM unit is presented. Coupling microfiltration technology with chemical treatment enhances the removal of soluble species. Research and development experience with the removal of soluble contaminants found in ground water and waste water will be discussed. The technology has advantages over other membrane technologies, namely lower energy costs, a lesser degree of fouling, and a higher recovery of processed solution. Future applications of the technology are addressed. (author). 10 refs., 3 tabs., 4 figs

Description of measurement techniques for surface contaminations

International Nuclear Information System (INIS)

Bourrez, E.

2001-01-01

The needs of evaluation of the surface contamination are numerous in the processes of production and management of radioactive waste. The market of radiation protection materials proposes a lot of devices answering to the almost all these needs. These device have however their conditions and particular limits for use. To realize correct measurements it is use the device, the technique and the methods adapted to the need, by taking into account the optimization of economical aspect. (N.C.)

Investigation to radioactive contamination of pool water in IMEF

International Nuclear Information System (INIS)

Song, Ung Sup; Jung, Yang Hong; Lee, J. H.; Lee, H. K.

2003-06-01

The pool (3x6x10) in irradiated materials examination facility is usually used for the purpose of taking the specimen out of cask loaded into the pool, and carrying in/out the specimen to/ from the hot cell. Always, it must be cared for the water into the pool to be fine condition because all operation are worked with the naked eye during taking an irradiated materials out of the cask and plunging them in the bucket-elevator. In the aspects of the radioactive remained substances in the water must be controlled so that the amount of substances to be lower than the standard amount prescribed by RCA Korea Activity in a part of radioactive contamination control. In consequence, an expertness of status and a practical use of skill make possible the prevention of radioactive material's diffusion or the radioactive contamination of pool water and safety work

A feasibility study for decision-making support of a radioactive contamination model in an urban environment (METRO-K)

International Nuclear Information System (INIS)

Hwang, Won Tae; Han, Moon Hee; Jeong, Hyo Joon; Kim, Eun Han; Lee, Chang Woo

2008-01-01

A Korean urban contamination model METRO-K (Model for Estimates the Transient behavior of RadiOactive materials in the Korean urban environment), which is capable of calculating the exposure doses resulting from radioactive contamination in an urban environment, is taking part in a model testing program EMRAS (Environmental Modelling for RAdiation Safety) organized by the IAEA (International Atomic Energy Agency). For radioactive contamination scenarios of Pripyat districts and a hypothetical RDD (Radiological Dispersal Device), the predicted results using METRO-K were submitted to the EMRAS's urban contamination working group. In this paper, the predicted results for the contamination scenarios of a pripyat district were shown in case of both without remediation measures and with ones. Comparing with the predicted results of the models that have taken part in EMRAS program, a feasibility for decision-making support of METRO-K was investigated. As a predicted result of METRO-K, to take immediately remediation measures following a radioactive contamination, if possible, might be one of the best ways to reduce exposure dose. It was found that the discrepancies of predicted results among the models are resulted from 1) modeling approaches and applied parameter values, 2) exposure pathways which are considered in models, 3) assumptions of assessor such as contamination surfaces which might affect to an exposure receptor and their sizes, 4) parameter values which are related with remediation measures applied through literature survey. It was identified that a Korean urban contamination model METRO-K is a useful tool for decision-making support through the participation of EMRAS program

An investigation of awareness on the Fukushima nuclear accident and Radioactive contamination

Energy Technology Data Exchange (ETDEWEB)

Ha, Jeong Chul; Song, Young Ju [Dept. of Consumer Safety, Korea Consumer Agency, Eumseong (Korea, Republic of)

2016-05-15

The objective of this study was to investigate Korean people's awareness about impact of the Fukushima nuclear power plant accident in Japan and radioactive contamination caused by it. The respondents of the survey were 600 adults who resided in the Seoul metropolitan area. The survey results show that the majority of respondents were concerned about impact of radiation leakage that might have an effect on our environment. They were worried about radioactive contamination of foodstuffs, particularly fishery products and preferred to acquire information through TV(49.8%) or the Internet(31.3%). Meanwhile, respondents mentioned that the information on the Fukushima nuclear accident and radioactive contamination had not been sufficient and they didn't know well about the follow-up measures of the government on the accident. Most respondents answered that information on radioactive contamination levels and safety of foods and environment was most needed. The results of this study could be useful to enhance awareness on radioactivity and improve risk communication on nuclear power plant accidents.

Design and development of food radioactivity contamination monitoring system

International Nuclear Information System (INIS)

Narayan, Pradeep; Vaijapurkar, S.G.; Bohra, Dinesh

2014-01-01

Radioactivity has been part and parcel of living being since the existence of the earth. It is available everywhere in our environment and being responsible for evolution of life on earth at some extent. However, the radioactivity in excess of the natural radioactive can have harmful effects on living being. The radiation exposure can be of external or internal origin or of both. The main route of internal radiation exposure is through the contaminated food chains. The concentration of natural radioactivity in food varies in range of 40-600 Bq/kg. 40 K being the single major radionuclide of food with typical radioactivity; 50 Bq/kg in milk, 420 Bq/kg in milk powder, 165 Bq/kg in potatoes, and 125 Bq/kg in beef is also the main contributor of natural radiation doses to human being. Measurement of radioactivity in food items and drinks is thus very important in controlling the internal exposure to human being especially in case of nuclear disaster. Though, the methods and techniques for food radioactivity measurement already existing, the need of portable instrument is warranted to measure the radioactivity in food items in raw form. Measurement of radioactivity may help in quick and mass screening of food items in case of nuclear emergencies. Any enhanced level of radioactivity in food items especially in case of nuclear emergency need to be evaluated for controlling its spread and restriction of consumption by the public. This way, it may help in managing internal radioactivity contamination to human being

Radioactive contamination incidents involving protective clothing

International Nuclear Information System (INIS)

Reichelt, R.A.; Clay, M.E.; Eichorst, A.J.

1998-01-01

The study focuses on incidents at Department of Energy facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work, (2) working conditions, (3) type of anti-contamination material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-contamination clothing most often identified was cotton or water-resistant disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled. 1 ref., 6 figs., 1 tab

Chernobyl three years later: radiobiologic evaluation of a radioactive contamination

International Nuclear Information System (INIS)

Behar, A.; Cohen-Boulakia, F.; Othmani, S.

1990-01-01

On April 26, 1986, after partial fusion and confining loss by explosion of a nuclear reactor, 5 x 10(7) Ci of radionuclides escaped from Chernobyl. Three years later, maps show contamination by radioactive isotopes (formed during that period) of 21,000 km2 of Soviet soil, mainly in Byelorussia and part of the Ukraine. Decontamination measures have not been effective to date and 135,000 persons are being followed medically, taking into account the radioactive doses they received. An initial excess of morbidity from solid tumors has been noted much sooner than in the case of Hiroshima and Nagasaki, but its significance is in dispute. Three years later, only the extent of the ecologic disaster caused by the radioactive contamination can be confirmed. It is too early to draw conclusions about radiation-induced carcinogenesis for the contaminated population

Total effective dose equivalent associated with fixed uranium surface contamination

International Nuclear Information System (INIS)

Bogard, J.S.; Hamm, R.N.; Ashley, J.C.; Turner, J.E.; England, C.A.; Swenson, D.E.; Brown, K.S.

1997-04-01

This report provides the technical basis for establishing a uranium fixed-contamination action level, a fixed uranium surface contamination level exceeding the total radioactivity values of Appendix D of Title 10, Code of Federal Regulations, part 835 (10CFR835), but below which the monitoring, posting, and control requirements for Radiological Areas are not required for the area of the contamination. An area of fixed uranium contamination between 1,000 dpm/100 cm 2 and that level corresponding to an annual total effective dose equivalent (TEDE) of 100 mrem requires only routine monitoring, posting to alert personnel of the contamination, and administrative control. The more extensive requirements for monitoring, posting, and control designated by 10CFR835 for Radiological Areas do not have to be applied for these intermediate fixed-contamination levels

Early-Stage Bioassay for Monitoring Radioactive Contamination in Living Livestock

OpenAIRE

Yamaguchi, Toshiro; Sawano, Kaita; Kishimoto, Miori; Furuhama, Kazuhisa; Yamada, Kazutaka

2012-01-01

Soil samples from the ground surface and feces and blood from a mixed-breed male pig were collected on April 10, 2011 at a farm within 20 km of the Fukushima Daiichi nuclear power plant. The radioactivity of each sample was measured using a Ge semiconductor detector. Despite the fact that the pig had been fed non-contaminated imported feed, 131I, 134Cs and 137Cs were detected in the feces, and 134Cs and 137Cs were detected in the blood clots. Because it is considerably difficult to measure ra...

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

International Nuclear Information System (INIS)

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

2003-01-01

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

Radioactive contamination characteristics in China following Chernobyl accident

International Nuclear Information System (INIS)

Wang Zuoyuan

1987-01-01

In the aftermath of Chernobyl nuclear reactor accident, the Environmental Radiation Surveillance Network of Ministry of Public Health of China has done monitoring on environmental samples to determine the contamination levels of radioactivity. Radionuclides, such as I-131, I-132, Cs-137, Cs-134 and Te-132, were found on surface of airplanes, which flew in domestic airlines between May 1-3, that means the radionuclides from Chernobyl accident already reached high altitude atmosphere over China, but the concentration was much lower than that in Europe. During the period of May 2-15, in most stations, radionuclides were found in different environmental samples, such as air, milk, vegetables, rain water, river and lake water, and sheep thyroid. Radioactivity levels of samples were higher in north part of China than in south. The amounts of radionuclides in all samples were well below the derived air concentrations and derived intake concentrations specified in the National Basic Health Standards for Radiological Protection. Thus, the public need not to take any precautions for the purpose of radiation protection

Radioactive contamination, what actions for the polluted sites; Contamination radioactive, quelles actions pour les sites pollues

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

The nuclear safety authority and the direction of prevention of pollutions and risks have organised the first edition of the national colloquium: radioactive contamination: what actions for polluted sites. Four axes can be taken to follow this colloquium: prevention, outstanding tools to evaluate risks and rehabilitation, a better responsibility of operators and memory keeping. (N.C.)

Contamination and decontamination of vehicles when driven in radioactive areas

International Nuclear Information System (INIS)

Ulvsand, T.; Nygren, U.

1999-10-01

There is reason to ask whether it is beneficial to decontaminate vehicles, in view of the great effort applied. If the level of contamination is low before the decontamination process, then the cost is not motivated, even if the decontamination is shown to be effective in relative terms. The report describes two trials at the National NBC Defence School in Umeaa and one trial at the French test site in Bourges. The aim is to investigate how vehicles are contaminated and at which ground deposition levels troublesome levels of contamination will arise. In the trials, a non-radioactive agent substituting real radioactivity was used. The trials in Sweden so far have used the oversnow vehicle BV 206, during both winter and summer conditions. The vehicles were driven a specific distance along a road on which a known amount of the test substance had been dispersed. Samples were taken on pre-determined areas on one side of the vehicles to measure the amount of test substance. Later, the vehicles continued along a 'clean' road where additional samples were taken, but on the other side of the vehicles. The largest amount of test substance was collected on the tracks and on the back of the vehicle. The tracks and mud-flaps were effectively decontaminated when the vehicles were driven along a clean road, while most of the contamination remained on the backside. The purpose of the trials in France was to compare the results from our non-radioactive and their radioactive method, based on the radioactive La-140. Due to ground conditions, the level of contamination on the vehicles was much less than in the trials in Umeaa, but the effect decontamination could be measured after all

Radioactive contamination incidents involving protective clothing

Energy Technology Data Exchange (ETDEWEB)

Reichelt, R.; Clay, M.; Eichorst, J.

1996-10-01

The study focuses on incidents at Department of Energy (DOE) facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work; (2) working conditions; (3) type of anti-contamination (anti-C) material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning (D&D) projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-C clothing most often identified was cotton or water-resistant, disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled.

Radioactive contamination incidents involving protective clothing

International Nuclear Information System (INIS)

Reichelt, R.; Clay, M.; Eichorst, J.

1996-10-01

The study focuses on incidents at Department of Energy (DOE) facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work; (2) working conditions; (3) type of anti-contamination (anti-C) material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning (D ampersand D) projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-C clothing most often identified was cotton or water-resistant, disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled

Treatment techniques for the removal of radioactive contaminants from drinking water

International Nuclear Information System (INIS)

Logsdon, Gary S.

1978-01-01

Maximum contaminant levels have been set for radioactive contaminants, as required by the Safe Drinking Water Act (PL 93-523). Treatment techniques are available for removing radium and beta-gamma emitters. Presently-used methods of removing radium-226 are precipitative lime softening (80-90% removal) ion exchange softening (95% removal) and reverse osmosis (95% removal). The 5 p Ci/l limit for radium can be met with conventional technology for raw waters in the 5-100 p Ci/l concentration range. Treatment for removal of beta or gamma emitters must be based upon chemical rather than radioactive characteristics of the contaminant. Reverse osmosis can remove a broad spectrum of ions and molecules from water, so it is the process most likely to be used. The maximum contaminant level for beta and gamma radioactivity is an annual dose equivalent to the total body or any organ not to exceed 4 m rem/year. The fate of radionuclides after removal from drinking water should be considered. Presently radium is disposed with other process wastes at softening plants removing radium. Confinement and disposal as a radioactive waste would be very expensive. (author)

Radon-induced surface contaminations in neutrinoless double beta decay and dark matter experiments

International Nuclear Information System (INIS)

Pattavina, L.

2011-01-01

In experiments looking for rare events, like neutrinoless double beta decay (DBD0ν) and dark matter search (DM), one of the main issues is to increase the experimental sensitivity through the material selection and production. The background contribution coming from the materials used for the detector realization has to be minimized. Moreover the net reduction of the background produced by the bulk part of the apparatus has raised concerns about the background contribution coming from the surfaces. Many procedures and techniques were developed during the last years in order to remove and to minimize the presence of possible contaminants on detector surfaces. To succeed in this strategy a big effort was put in defining all possible mechanisms that lead to surface contaminations, as well as specific cleaning procedures, which are able to reduce and control the surface radioactivity. The presence in air and gases of possible radioactive elements that can stick on the detector surfaces can lead to a recontamination process that will vanish all the applied cleaning procedures. Here is presented and analyzed the contribution to the background of rare events experiments like CUORE experiment (DBD0ν) and EDELWEISS experiment (DM) produced by an exposure of their detector components to a big activity of 222 Rn, radioactive daughter isotope from the 238 U chain. (author)

Development of plastic scintillator based food radioactivity contamination monitoring system

International Nuclear Information System (INIS)

Parihar, A.; Sahani, R.M.; Mahala, V.K.; Vaijapurkar, S.G.

2016-01-01

Radioactivity is naturally present in soil, water and food stuffs. Food can be contaminated after discharge of radioactivity into the environment from industries that concentrate natural radionuclide and from civil or military nuclear operations. The contamination can be in three ways; by direct deposition, through the food chain and induced radioactivity due to exposure of high neutron flux. The health effects on human depend on the type of radionuclide and the length of time people are exposed to it. The studies of fission product behaviour in the food chain have revealed radionuclide Strontium-90, Caesium 137 and Iodine-131 are of major concern. Plastic scintillator is already developed indigenously at Defence Laboratory, Jodhpur. Efforts has been made to develop a portable field instrument using plastic scintillator for assessment of beta ( 90 Sr) and gamma ( 137 Cs and 131 I) radioactivity in food

DOE`s radioactively - contaminated metal recycling: The policy and its implementation

Energy Technology Data Exchange (ETDEWEB)

Warren, S.; Rizkalla, E.

1997-02-01

In 1994, the Department of Energy`s Office of Environmental Restoration initiated development of a recycling policy to minimize the amount of radioactively-contaminated metal being disposed of as waste. During the following two years, stakeholders (including DOE and contractor personnel, regulators, members of the public, and representatives of labor and industry) were invited to identify key issues of concern, and to provide input on the final policy. As a result of this process, a demonstration policy for recycling radioactively-contaminated carbon steel resulting from decommissioning activities within the Environmental Management program was signed on September 20, 1996. It specifically recognizes that the Office of Environmental Management has a tremendous opportunity to minimize the disposal of metals as waste by the use of disposal containers fabricated from contaminated steel. The policy further recognizes the program`s demand for disposal containers, and it`s role as the major generator of radioactively-contaminated steel.

Radioactive Mapping Contaminant of Alpha on The Air in Space of Repair of Hot Cell and Medium Radioactivity Laboratory in Radio metallurgy Installation

International Nuclear Information System (INIS)

Yusuf-Nampira; Endang-Sukesi; S-Wahyuningsih; R-Budi-Santoso

2007-01-01

Hot cell and space of acid laboratory medium activity in Radio metallurgy Installation are used for the examination preparation of fuel nuclear post irradiation. The sample examined is dangerous radioactive material representing which can disseminate passing air stream. The dangerous material spreading can be pursued by arranging air stream from laboratory space to examination space. To know the performance the air stream arrangement is hence conducted by radioactive mapping contaminant of alpha in laboratory / space of activity place, for example, medium activity laboratory and repair space. This mapping radioactivity contaminant is executed with the measurement level of the radioactivity from sample air taken at various height with the distance of 1 m, various distance and from potential source as contaminant spreading access. The mapping result indicate that a little spreading of radioactive material happened from acid cupboard locker to laboratory activity up to distance of 3 m from acid cupboard locker and spreading of radioactive contaminant from goods access door of the hot cell 104 to repair space reach the distance of 2 m from goods door access. Level of the radioactive contamination in the space was far under maximum limitation allowed (20 Bq / m 3 ). (author)

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.

Environmental remediation. Strategies and techniques for cleaning radioactively contaminated sites

International Nuclear Information System (INIS)

Falck, W. Eberhard

2001-01-01

Actions for a cleaner and safety environment have risen on social and political agendas in recent years. They include efforts to remediate contaminated sites posing a radiological risk to humans and the surrounding environment. Radiological risks can result from a variety of nuclear and non-nuclear activities. They include: nuclear or radiological accidents; nuclear weapons production and testing; poor radioactive waste management and disposal practices; industrial manufacturing involving radioactive materials; conventional mining and milling of ores and other production processes, e.g. oil and gas production, resulting in enhanced concentrations of naturally occurring radioactive materials (NORMs). The IAEA has developed a comprehensive programme directed at the remediation of radioactively contaminated sites. The programme collates and distributes knowledge about contaminated sites; appropriate methods for their characterization; assessment of their potential environmental and radiological impact; and applicable methods for their clean-up, following internationally recommended safety criteria. The overall resources, and which are technologically less advanced, to focus their efforts and chose appropriate strategies for the abatement or removal of exposure to radiation. An important aspect is the intention to 'close the loop' in the nuclear fuel cycle in the interests of sustainable energy development including nuclear power

Rapid Evaluation of Radioactive Contamination in Rare Earth Mine Mining

Science.gov (United States)

Wang, N.

2017-12-01

In order to estimate the current levels of environmental radioactivity in Bayan Obo rare earth mine and to study the rapid evaluation methods of radioactivity contamination in the rare earth mine, the surveys of the in-situ gamma-ray spectrometry and gamma dose rate measurement were carried out around the mining area and living area. The in-situ gamma-ray spectrometer was composed of a scintillation detector of NaI(Tl) (Φ75mm×75mm) and a multichannel analyzer. Our survey results in Bayan Obo Mine display: (1) Thorium-232 is the radioactive contamination source of this region, and uranium-238 and potassium - 40 is at the background level. (2) The average content of thorium-232 in the slag of the tailings dam in Bayan Obo is as high as 276 mg/kg, which is 37 times as the global average value of thorium content. (3) We found that the thorium-232 content in the soil in the living area near the mining is higher than that in the local soil in Guyang County. The average thorium-232 concentrations in the mining areas of the Bayan Obo Mine and the living areas of the Bayan Obo Town were 18.7±7.5 and 26.2±9.1 mg/kg, respectively. (4) It was observed that thorium-232 was abnormal distributed in the contaminated area near the tailings dam. Our preliminary research results show that the in-situ gamma-ray spectrometry is an effective approach of fast evaluating rare earths radioactive pollution, not only can the scene to determine the types of radioactive contamination source, but also to measure the radioactivity concentration of thorium and uranium in soil. The environmental radioactive evaluation of rare earth ore and tailings dam in open-pit mining is also needed. The research was supported by National Natural Science Foundation of China (No. 41674111).

Study of surface potential contamination in radioisotope and radiopharmaceutical production facilities and alternative solutions

International Nuclear Information System (INIS)

Suhaedi Muhammad; Rimin Sumantri; Farida Tusafariah; Djarwanti Rahayu Pipin Soedjarwo

2013-01-01

Radioisotope and radiopharmaceutical production facilities that exist in their operations around the world in the form of radiological impacts of radiation exposure, contamination of surface and air contamination. Given the number of existing open source in radioisotope and radiopharmaceutical production facility, then the possibility of surface contamination in the work area is quite high. For that to protect the safety and health of both workers, the public and the environment, then the licensee must conduct an inventory of some of the potential that could result in contamination of surfaces in radioisotope and radiopharmaceutical production facilities. Several potential to cause surface contamination in radioisotope and radiopharmaceutical production facilities consist of loss of resources, the VAC system disorders, impaired production facilities, limited resources and lack of work discipline and radioactive waste handling activities. From the study of some potential, there are several alternative solutions that can be implemented by the licensee to address the contamination of the surface so as not to cause adverse radiological impacts for both radiation workers, the public or the environment. (author)

Development of floor smear sampler (floor radioactive contamination measuring instrument) for nuclear facilities

International Nuclear Information System (INIS)

Miyagawa, Minoru; Ito, Haruo; Nozawa, Katsuro; Shinohara, Yotaro; Hashimoto, Hiroshi.

1980-01-01

The control of the floor contamination with radioactive substances in nuclear facilities is strictly carried out by smear method, in which the contaminants on floor surfaces are wiped off with filter papers or cloths, and the contamination density on the floor surfaces is measured through their intensity of radioactivity. This wiping work is laborious since it is carried out in leaning-over posture when many samples must be taken in wide floor area. Therefore, to achieve labor saving in this work, an automatic sampler was developed. In the floor smear sampler developed, samples are taken on long band type wiping cloths only by handle operation, and the sample numbers are printed. When many samples are taken in wide floor area, this is especially effective, and the labor saving by 1/3 to 1/2 can be achieved. At present, this sampler is put in practical use in Hamaoka Nuclear Power Station. At the time of trial manufacture, the method of wiping, the mechanisms of wiping, cloth feeding and running, the contact pressure and the number of times of wiping affecting wiping efficiency and the required torque of a motor were examined. The developed sampler is that of constant contact pressure, vibration wiping type, and the rate of sampling is 10 sec per one sample. 100 samples can be taken on one roll of wiping cloth. The results of performance test are reported. (Kako, I.)

Inductively coupled plasma mass spectrometer installation modifications in a radioactive contaminated laboratory for the analysis of DOE radioactive waste streams

International Nuclear Information System (INIS)

Giaquinto, J.M.; Keller, J.M.; Meeks, A.M.

1998-01-01

The operation and maintenance of a complex analytical instrument such as an inductively coupled plasma mass spectrometer in a radioactive contaminated environment presents unique problems and challenges that have to be considered in the purchasing and installation process. Considerations such as vendor experience, typical radiation levels, sample matrices encountered during sample analysis, instrument accessibility for maintenance, and upkeep must be incorporated into the decision process. The Radioactive Materials Analytical Laboratory (RMAL) at Oak Ridge National Laboratory (ORNL) recently purchased and installed an inductively coupled plasma mass spectrometer for the analysis of Department of Energy (DOE) radioactive waste streams. This presentation will outline the purchasing decision, installation of the instrument, and how the modifications needed to operate in a radioactive contaminated laboratory do not significantly impact the daily operation and maintenance requirements of the instrument. Also, a contamination survey of the system will be presented which demonstrates the contamination levels in the instrument from the sample introduction system to the detector. (author)

Inductively coupled plasma mass spectrometer installation modifications in a radioactive contaminated laboratory for the analysis of DOE radioactive waste streams

International Nuclear Information System (INIS)

Giaquinto, J.M.; Keller, J.M.; Meeks, A.M.

1997-04-01

The operation and maintenance of a complex analytical instrument such as an inductively coupled plasma mass spectrometer in a radioactive contaminated environment presents unique problems and challenges that have to be considered in the purchasing and installation process. Considerations such as vendor experience, typical radiation levels, sample matrices encountered during sample analysis, instrument accessibility for maintenance, and upkeep must be incorporated into the decision process. The Radioactive Materials Analytical Laboratory (RMAL) at Oak Ridge National Laboratory (ORNL) recently purchased and installed an inductively coupled plasma mass spectrometer for the analysis of Department of Energy (DOE) radioactive waste streams. This presentation will outline the purchasing decision, installation of the instrument, and how the modifications needed to operate in a radioactive contaminated laboratory do not significantly impact the daily operation and maintenance requirements of the instrument. Also, a contamination survey of the system will be presented which demonstrates the contamination levels in the instrument from the sample introduction system to the detector

In-situ vitrification of radioactively contaminated soils: summary paper

International Nuclear Information System (INIS)

Buelt, J.L.; Fitzpatrick, V.F.

1987-01-01

The in-situ vitrification (ISV) process is a new technology that has been developed from its conceptual phase through selected field-scale application tests during the last six years. In situ vitrification converts contaminated soils and waste inclusions into a durable glass and crystalline waste form by in-place melting. Electrodes are inserted into the soil to be treated and an electrical current is passed through the soil to be treated and an electrical current is passed through the soil to melt it. After cooling, the process fixes (TRU) and fission product radionuclides making them relatively nonleachable, resistant to intrusion, and nondispersible when intentionally disturbed. Another application considered for isolation of radioactively contaminated soils, but not yet developed, is the generation of impermeable barrier walls to prevent ground water seepage into a site. The barrier technique could also be used over the surface of an existing disposal site to deter plant and animal intrusion. The development units have been extensively tested with many types of soils and waste inclusions such as concrete, buried metals, sealed containers, organic chemicals with high boiling points such as polychlorinated biphenyls, and inorganic chemicals, including toxic heavy metals, nitrates, and sulfates. Nitrates and organics are destroyed, while heavy metals and fluorides are retained to a high percentage within the molten soil during processing. At $200 to $300/m 3 for radioactive waste, the process is economically competitive with many alternative remediation processes. The ISV process has been developed to the point where it is ready for large-scale field testing at an actual TRU-contaminated soil site. 5 references, 2 figures, 2 tables

Sites in the United States contaminated with radioactivity

International Nuclear Information System (INIS)

Wolbarst, A.B.; Blom, P.F.; Chan, D.

1999-01-01

Over the century that radioactive materials have been mined, processed, produced, and utilized, many sites across the US have become contaminated. Such sites include bases and installations of the Department of Defense, weapons production and research facilities of the Department of Energy, properties under the authority of other Federal agencies, privately-owned and governmental facilities that are licensed by the Nuclear Regulatory Commission and its Agreement States, and sites licensed by or the responsibility of states. This review reports on aspects of work by the Environmental Protection Agency, the Department of Defense, the Department of Energy, the Nuclear Regulatory Commission, and others to identify sites contaminated with radioactive materials. It also describes the principal programs that have been instituted to deal with them

Environmental safety of the disposal system for radioactive substance-contaminated wastes

International Nuclear Information System (INIS)

Oosako, Masahiro

2012-01-01

In accordance with the full-scale enforcement of 'The Act on Special Measures concerning the Handling of Radioactive Pollution' in 2012, the collective efforts of entire Japan for dealing with radioactive pollutants began. The most important item for dealing with radioactive pollution is to control radioactive substances that polluted the global environment and establish a contaminated waste treatment system for risk reduction. On the incineration system and landfill disposal system of radioactive waste, this paper arranges the scientific information up to now, and discusses the safety of the treatment / disposal systems of contaminated waste. As for 'The Act on Special Measures concerning the Handling of Radioactive Pollution,' this paper discusses the points of the Act and basic policy, roadmap for the installation of interim storage facilities, and enforcement regulations (Ordinance of the Ministry of the Environment). About the safety of waste treatment system, it discusses the safety level of technical standards at waste treatment facilities, safety of incineration facilities, and safety of landfill disposal sites. (O.A.)

Verification of radioactive contamination surveys for practical use in biological research centres

International Nuclear Information System (INIS)

Macias, M.T.; Requejo, C.; Ruiz, M.; Pina, R.

2006-01-01

Unsealed sources are commonly used in science research laboratories. Their manipulation may imply a radioactive contamination hazard. Therefore, adequate and sensitive survey meters must be available, and must have an effective and accurate response to intensity and type of radiation emitted by the used radionuclides to identify and quantify the possible contamination and then be able to avoid any associated or unwanted consequences that may arise. Periodic surveys are performed to show control, any time, any place radioactive contamination is suspected, and to ensure radioisotopes are being used safely. The immediate work areas must be often checked with portable survey monitors, including the entire lab and particularly bench tops, personnel protective equipment or solely designated equipment for isotope use (micro-fuges, water baths, incubators). These are carried out with portable survey instruments like Geiger-Muller tubes, proportional counters and scintillation detectors that provide direct or indirect measurements capabilities. The Radiation Safety Office (R.S.O.) as well as the radioactive compounds working laboratories at the Instituto de Inv. Biomedicas 'A. Sols' (Madrid-Spain) are provided with an adequate radiation measurement instrument. But, before a portable survey instrument is used, several quality checks should be made (batteries, calibration sticker), and the instrument response should be tested with a check source. This paper aims at determining, with a R.S.O. procedure, these surveys working parameters -detection efficiency, calibration factors and minimum detectable activities-, using reference checking sources ( 14 C, 36 Cl, and 90 Sr/ 90 Y) with known radioactivity covering the energy range of beta emitting isotopes used in biological research. No gamma portable monitors have been tested for the R.S.O. has no gamma checking sources. Therefore, 58 beta monitors were tested, obtaining t he efficiency values, the calibration factors (Bq cm-2 s

Issues facing the management of radioactively contaminated lead within the DOE system

International Nuclear Information System (INIS)

Gilmore, M.C.; Kent, S.H.

1993-01-01

The purpose of this paper is to discuss and evaluate the issues that managing and operating contractors in the US DOE system should consider that are associated with management of radioactively contaminated elemental lead. There are many instances where DOE contaminated lead fall within Resource Conservation and Recovery Act (RCRA) regulation. In light of the Federal Facilities Compliance Act (FFCA), it is becoming increasingly important for additional regulatory options to be explored in order to facilitate proper treatment, storage and disposal of RCRA regulated lead. Various DOE facilities have initiated processes to reuse or recycle contaminated lead. Technologies such as melt-refining, surface blasting, and electromigration are being explored. One or more of these technologies may be the key to reducing contaminated lead inventories in the DOE system. Many DOE facilities are finding that these efforts need to have stringent regulatory evaluation since some alternatives have proven to be environmentally desirable but not economically feasible

Airborne radioactive contamination following aerosol ventilation studies

International Nuclear Information System (INIS)

Mackie, A.; Hart, G.C.; Ibbett, D.A.; Whitehead, R.J.S.

1994-01-01

Lung aerosol ventilation studies may be accompanied by airborne contamination, with subsequent surface contamination. Airborne contamination has been measured prior to, during and following 59 consecutive 99 Tc m -diethylenetriamine pentaacetate (DTPA) aerosol studies using a personal air sampler. Airborne contamination ranging between 0 and 20 330 kBq m -3 has been measured. Airborne contamination increases with degree of patient breathing difficulty. The effective dose equivalent (EDE) to staff from ingested activity has been calculated to be 0.3 μSv per study. This figure is supported by data from gamma camera images of a contaminated staff member. However, surface contamination measurements reveal that 60% of studies exceed maximum permissible contamination limits for the hands; 16% of studies exceed limits for controlled area surfaces. (author)

Radioactive contamination of natural and artificial materials

International Nuclear Information System (INIS)

Kovalchuk, E.L.; Pomansky, A.A.; Smolnikov, A.A.; Temmoev, A.H.

1980-01-01

The gamma radiation of different materials was measured in an underground low-background chamber with extraordinary background characteristics. The excellent background conditions of the measurements enabled investigators to see the alpha-particle peaks of the internal radioactive contamination of NaI(Tl) detectors, which were especially made for these measurements. The sensitivity limit of the installation was determined by the internal contamination of the NaI(Tl) detectors alone. Any radiation background, except for three substances, tungsten, copper, and brass, could be registered

The supposed radioactive contamination of the Puelche aquifer

International Nuclear Information System (INIS)

Martini, Leopoldo E.

2005-01-01

The paper attempts to clarify the supposed radioactive contamination of the Puelche Aquifer in the Ezeiza Atomic Center Area, Ezeiza, province of Buenos Aires (Argentina). Reports are listed that show categorically that no anthropogenic uranium contamination is present. As far as the nitrates contamination is concerned, it is not generated by the Ezeiza Atomic Center, because the Center is downward from the contaminated zone. It is possible that the contamination is produced by houses in the area without suitable sewage. In the present case the best contribution to the environmental right, besides the adaptation and the systematization of the different legal instruments, is to found the analysis of the facts on the scientific and technical knowledge. (author) [es

Method of melting and decontaminating radioactive contaminated aluminum material

International Nuclear Information System (INIS)

Uda, Tatsuhiko; Miura, Noboru; Kawasaki, Katsuo; Iba, Hajime.

1986-01-01

Purpose: To improve the decontaminating efficiency upon melting decontamination of radioactive-contaminated aluminum materials. Method: This invention concerns an improvement for the method of melting decontamination by adding slug agent composed of organic compound to contaminated aluminum material and extracting the radioactive materials into the slug thereby decontaminating the aluminum material. Specifically metals effective for reducing the active amount of aluminum are added such that the content is greater than a predetermined value in the heat melting process. The metal comprises Mg, Cu or a mixture thereof and the content is more than 4 % including those previously contained in the aluminum material. (Ikeda, J.)

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.)

Proposal of traceability chain for direct measurements of radioactive contamination in Cuba

International Nuclear Information System (INIS)

Walwyn Salas, Gonzalo; Tamayo Garcia, Jose A.; Cornejo Diaz, Nestor

2008-01-01

The measurements of the radioactive surface contamination are common used to demonstrate the compliance with safety regulations at national level. It is mandatory that those measurements are traceable to national standards through the suitable calibration of the monitors used for survey. In Cuba, there is not a harmonized methodology for evaluation of contamination from direct measurements and no standardized calibration service for portable monitors is routinely provided to users. The Secondary Standard Dosimetry Laboratory of Cuba has recently established the calibration service of contamination monitors in terms of instrument efficiency using the reference sources of known emission rate per unit area in accordance with international normative ISO 8769. In the present paper, is proposed a traceable scheme of direct measurements of contamination that involve the calibration at the laboratory level using multi-source method and the evaluation of contaminations at user level in terms of activity per unit area. Some improvements from the previous single-source method of calibration are explained in order to support the advantages that offer the new chain for those measurements in the country. (author)

Implementation of GIS-DSS PRANA within sustainable rehabilitation of radioactive contaminated territories

International Nuclear Information System (INIS)

Yatsalo, B.

2003-01-01

Full text: Analysis of the current situation in contaminated farms and settlements of Bryansk region is based on the monitoring data and model estimates. Model assessments of agricultural produce contamination, doses to the local population, radiological risk and results of countermeasure (CM) implementation have been carried out with the use of PRANA GIS-DSS. Applied Geographic Information System (GIS) PRANA is a Decision Support System (DSS) for implementation within the rehabilitation of radioactive contaminated territories. PRANA has been introduced for practical use in Bryansk as a GIS-DSS system for monitoring networking support and countermeasure analysis. The main blocks of the PRANA DSS are: libraries of electronic maps, including different layers of vector maps of landuse for all contaminated districts of Bryansk region: Novozybkov, Klintsy, Gordeevsky, Krasnogorsky, Zlynkovsky and Klimovsky (more than 30000 polygons of vector electronic maps); databases (radioecological, ecological, economic, demographic and other monitoring data and model parameters, including attributive information of vector electronic maps); model blocks for assessing: contamination of agricultural production, external and internal doses to the local population, radiological risks and corresponding results of CMs implementation; evaluation of CMs effectiveness and decision-making support an protection of the population and rehabilitation of radioactive contaminated territories both on local and regional/district levels (from separate settlement/field up to group of settlements/farms and region as a whole). The following 'risk indices' are considered within decision-making an Risk Based Land Management (RBLM) with the use of PRANA DSS: surface density contamination of territory with radionuclides ( 137 Cs, 90 Sr); contamination of agricultural production (plant growing and animal husbandry, including farm and private production); external and internal doses to the local population

Radioactive contamination of the biosphere and consequences for food supply

International Nuclear Information System (INIS)

Wiechen, A.

1989-01-01

The paper deals with all aspects of radioactive contamination of the biosphere and corresponding consequences for food supply. In particular, releases of radioactivity by nuclear weapon tests in the early 60's and nuclear accidents in recent years are discussed. Contamination of food in the Federal Republic of Germany by these events and corresponding ingestion dose are demonstrated using examples. Furthermore diffusion of radionuclides and their transfer through the food chains to man are described. Suitable methods of decontamination at different production steps and their viability are discussed. (orig.) [de

Experiences in monitoring airborne radioactive contamination in JAERI

International Nuclear Information System (INIS)

Ikezawa, Y.; Okamoto, T.; Yabe, A.

1980-01-01

The following results were obtained at the Japan Atomic Energy Research Institute (JAERI) from experience in air monitoring at the hot cells for handling highly radioactive materials, the glove box containing plutonium and the cell for producing 99 Mo. (1) The ratios of activities of airborne dust to those of whole dust were of the order of 10 -2 for the semi-volatile form of 125 Sb, and 10 -3 to 10 -4 for the particulate form of 137 Cs, 144 Ce and 144 Pr, when irradiated fuels were cut in the hot cells. (2) The activity median aerodynamic diameter (AMAD) of airborne particle size distributions varied from O.4 to 15 μm with changing geometric standard deviation (sigmasub(g)) 1.7 to 7, depending on types of metallurgical treatment of fuels and on kinds of work in the cells. (3) A resuspension factor (the ratio of the concentration of airborne contamination to the surface contamination) was found to be 4x10 -8 to approximately 2x10 -7 cm -1 for plutonium oxide deposited on the floor surface. (4) The collection efficiency of the charcoal-loaded filter paper for airborne radioiodine, consisting of 60% inorganic and 40% organic iodide, was over 95% under conditions of relative humidity 40 to approximately 80% and face velocity 50 cm/sec, during the production of 99 Mo. (H.K.)

Mesoscale modelling of radioactive contamination formation in Ukraine caused by the Chernobyl accident

International Nuclear Information System (INIS)

Talerko, Nikolai

2005-01-01

This work is devoted to the reconstruction of time-dependent radioactive contamination fields in the territory of Ukraine in the initial period of the Chernobyl accident using the model of atmospheric transport LEDI (Lagrangian-Eulerian DIffusion model). The modelling results were compared with available 137 Cs air and ground contamination measurement data. The 137 Cs atmospheric transport over the territory of Ukraine was simulated during the first 12 days after the accident (from 26 April to 7 May 1986) using real aerological information and rain measurement network data. The detailed scenario of the release from the accidental unit of the Chernobyl nuclear plant has been built (including time-dependent radioactivity release intensity and time-varied height of the release). The calculations have enabled to explain the main features of spatial and temporal variations of radioactive contamination fields over the territory of Ukraine on the regional scale, including the formation of the major large-scale spots of radioactive contamination caused by dry and wet deposition

Radiation contamination monitors

International Nuclear Information System (INIS)

Kato, Tsutomu; Iba, Hiroshi; Sato, Hiroshi

1999-01-01

To make sure of no contamination on people, used articles and working uniforms coming out of the radiation controlled area, nuclear power plants are equipped with radioactive contamination monitors. This paper outlines the basic specifications and advantages of our personnel surface contamination monitors to inspect whole-body surface contamination of people coming out, article surface contamination monitors to inspect the surface and inside contamination of used articles brought out, laundry monitors to inspect surface contamination of working uniforms used in the area before and after a wash, and whole-body counters to inspect and measure the internal contamination of a person out of the area. (author)

Survey of radioactive contamination of foodstuffs

International Nuclear Information System (INIS)

Lee, W. R.; Lee, C. W.; Choi, G. S.; Cho, Y. H.; Kang, M. J.; Cheong, K. H.; Kim, H. R.; Kwak, J. Y.

2005-11-01

The purpose of this study is to survey and assess radioactive contamination of foodstuffs in order to reduce the probability of intake of contaminated foodstuffs. Based on survey and assessment, final goal is to improve the public health by radiation protection. Sampled foodstuffs items are collected from the markets : one group are imported foodstuffs and the other group are domestic foodstuffs producted around nuclear facilities. After pretreatments such as drying, ashing, and homogenization, all samples were analyzed by gamma spectrometer system. The 137 Cs radionuclide was only measured among the regulation radionuclides ( 137 Cs, 134 Cs, 131 I) of food code. All radionuclides of the domestic foodstuffs collected around nuclear facilities were below Minimum Detectable Activity (MDA). But the activity concentrations of Inonotus obliquus (Chaga mushooms) from Russia ranged up to 171.27 (average value : 36.65) Bq/kg-fresh. In the case of blueberry jam, the radioactivity of 137 Cs is higher than expected value. Other samples are below MDA except some spices. Based on the previous and present results, it should be strengthen to survey for Inontus obliquus (Chaga mushooms), of which the radioactivity shows the range from MDA up to 800.01 Bq/kg-fresh. It should assess the public radiation exposure via food chain because it has the excess provability of the maximum permitted level of food code, which is regulation of KFDA. The development method based on international standard would be used at radioactive analysis as well as education of practical workers and it could be applied as the basis data for amending the analysis method of food code. Our country only surveys gamma emitting radionuclides till now but international organization or foreign countries for example EU survey alpha and beta emitting radionuclides as well as gamma emitting radionuclides. So our country should also research necessity of survey for alpha and beta emitting radionuclides

Radioactive contamination in the environs of the Hanford Works for the period October, November, December 1949

Energy Technology Data Exchange (ETDEWEB)

Paas, H.J.; Singlevich, W.

1950-03-02

This report summarizes the measurements made for radioactive contamination in the environs of the Hanford Works. The principal sources of the radioactivity originating as a result of operations at Hanford which affect the environment in this area are the two waste stacks in the separations area and the cooling water from the four pile areas. Measurements are also made on samples taken from the Hanford waste systems which are primarily confined within the project proper. Although monthly summaries of these data are reported in Health Instrument Divisions Environs reports, a somewhat more detailed discussion of these data is covered in the quarterly report. In this manner, a better evaluation of possible trends can be detected as a result of the increased number of measurements made available by combining the data for a three month period. The following areas are discussed: meteorology, radioactive contamination of vegetation, airborne contamination and air radiation levels, radioactive contamination in Hanford wastes, radioactive contamination in the Columbia and Yakima rivers; beta activity in rain and snow, and radioactive contamination in drinking water and test wells.

Remediation Of Radioactive Contaminated Soil in Oil Fields

International Nuclear Information System (INIS)

Taha, A.A.; Hassib, G.M.; Ibrahim, Z.A.

2011-01-01

Radioactive contamination by naturally occurring radioactive materials (NORM) in evaporation pond has been evaluated. At several onshore oil field locations, the produced water is discharged to form artificial lagoons or ponds. Subsequently, the released waters drain to the ground leaving radioactive deposits associated with the soil that eventually require remedial action in accordance with radiation protection principles. The present study aims to investigate the remediation of contaminated soil in some oil fields and in this concern, two scenarios were proposed. The first scenario is studying the feasibility of using soil washing technique (a physical-chemical separation process) for removing radium-226 from the contaminated soil samples collected from an evaporating pond. The size/activity distribution analyses were carried out. The data obtained showed that almost 68 % of the investigated soil was coarse sand (≥ 300 μm), 28 % was medium and fine sand (≤300 μm and (≥75 μm) and only small fraction of 4 % was silt and clay (≤75 μm). A series of mild acids such as HCl and mild NaCl/HCl (chloride washing) were used for washing the investigated soil fractions. The obtained data showed that the coarse fraction ≥ 300 μm can be re mediated below a regulatory level of 1Bq/g. and the radium from this coarse fraction could be easily removed by screening and chloride washing. For the remediation of (≤ 300 μm and (≥ 75 μm soil fractions, a series of mild chloride washing experiments also showed that the chloride base (NaCl/HCl) was found to be potentially useful. However, there was a difficulty in achieving a low radium value in the fine (≥ 75 μm size fractions using chloride washing. The second scenario is to get rid of all contaminated soil and store it in a concrete basin through the program of radiological protection of personnel and environment. Preliminary gamma survey of contaminated soil showed that the significant area of the investigated

SUDOQU, a new dose-assessment methodology for radiological surface contamination.

Science.gov (United States)

van Dillen, Teun; van Dijk, Arjan

2018-06-12

A new methodology has been developed for the assessment of the annual effective dose resulting from removable and fixed radiological surface contamination. It is entitled SUDOQU (SUrface DOse QUantification) and it can for instance be used to derive criteria for surface contamination related to the import of non-food consumer goods, containers and conveyances, e.g., limiting values and operational screening levels. SUDOQU imposes mass (activity)-balance equations based on radioactive decay, removal and deposition processes in indoor and outdoor environments. This leads to time-dependent contamination levels that may be of particular importance in exposure scenarios dealing with one or a few contaminated items only (usually public exposure scenarios, therefore referred to as the 'consumer' model). Exposure scenarios with a continuous flow of freshly contaminated goods also fall within the scope of the methodology (typically occupational exposure scenarios, thus referred to as the 'worker model'). In this paper we describe SUDOQU, its applications, and its current limitations. First, we delineate the contamination issue, present the assumptions and explain the concepts. We describe the relevant removal, transfer, and deposition processes, and derive equations for the time evolution of the radiological surface-, air- and skin-contamination levels. These are then input for the subsequent evaluation of the annual effective dose with possible contributions from external gamma radiation, inhalation, secondary ingestion (indirect, from hand to mouth), skin contamination, direct ingestion and skin-contact exposure. The limiting effective surface dose is introduced for issues involving the conservatism of dose calculations. SUDOQU can be used by radiation-protection scientists/experts and policy makers in the field of e.g. emergency preparedness, trade and transport, exemption and clearance, waste management, and nuclear facilities. Several practical examples are worked

The role of bioindicators in assessing radioactive contamination

International Nuclear Information System (INIS)

Marovicj, G.

1990-01-01

The paper is a survey of investigations into radioactive contamination of selected plant and animal species (bioindicators) which have the capacitr for multiple accumulation of fission products. Literature data on the contamination of bioindicators are compared with special reference to the accumulation of 131 I, 137 Cs and 90 Sr as a result of atmospheric nuclear experiments and the nuclear accident at Chernobyl. (author) 52 refs.; 3 figs [sh

Radioactivity decontamination of materials commonly used as surfaces in general-purpose radioisotope laboratories.

Science.gov (United States)

Leonardi, Natalia M; Tesán, Fiorella C; Zubillaga, Marcela B; Salgueiro, María J

2014-12-01

In accord with as-low-as-reasonably-achievable and good-manufacturing-practice concepts, the present study evaluated the efficiency of radioactivity decontamination of materials commonly used in laboratory surfaces and whether solvent spills on these materials affect the findings. Four materials were evaluated: stainless steel, a surface comprising one-third acrylic resin and two-thirds natural minerals, an epoxy cover, and vinyl-based multipurpose flooring. Radioactive material was eluted from a (99)Mo/(99m)Tc generator, and samples of the surfaces were control-contaminated with 37 MBq (100 μL) of this eluate. The same procedure was repeated with samples of surfaces previously treated with 4 solvents: methanol, methyl ethyl ketone, acetone, and ethanol. The wet radioactive contamination was allowed to dry and then was removed with cotton swabs soaked in soapy water. The effectiveness of decontamination was defined as the percentage of activity removed per cotton swab, and the efficacy of decontamination was defined as the total percentage of activity removed, which was obtained by summing the percentages of activity in all the swabs required to complete the decontamination. Decontamination using our protocol was most effective and most efficacious for stainless steel and multipurpose flooring. Moreover, treatment with common organic solvents seemed not to affect the decontamination of these surfaces. Decontamination of the other two materials was less efficient and was interfered with by the organic solvents; there was also great variability in the overall results obtained for these other two materials. In expanding our laboratory, it is possible for us to select those surface materials on which our decontamination protocol works best. © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Management of Radioactive Wastes

International Nuclear Information System (INIS)

Tchokosa, P.

2010-01-01

Management of Radioactive Wastes is to protect workers and the public from the radiological risk associated with radioactive waste for the present and future. It application of the principles to the management of waste generated in a radioisotope uses in the industry. Any material that contains or is contaminated with radionuclides at concentrations or radioactivity levels greater than ‘exempt quantities’ established by the competent regulatory authorities and for which no further use is foreseen or intended. Origin of the Radioactive Waste includes Uranium and Thorium mining and milling, nuclear fuel cycle operations, Operation of Nuclear power station, Decontamination and decommissioning of nuclear facilities and Institutional uses of isotopes. There are types of radioactive waste: Low-level Waste (LLW) and High-level Waste. The Management Options for Radioactive Waste Depends on Form, Activity, Concentration and half-lives of the radioactive waste, Storage and disposal methods will vary according to the following; the radionuclides present, and their concentration, and radio toxicity. The contamination results basically from: Contact between radioactive materials and any surface especially during handling. And it may occur in the solid, liquid or gas state. Decontamination is any process that will either reduce or completely remove the amount of radionuclides from a contaminated surface

A Study on the Method to Discriminate Between the Internal and External Radioactive Contamination Using Whole Body Counter

International Nuclear Information System (INIS)

Kong, T. Y.; Kim, H. G.; Yang, H. Y.; Kang, D. W.; Lim, S. N.; Kim, H. J.; Jin, H. H.; Lee, S. G.; Park, S. C.

2006-01-01

Whole Body Counter (WBC) is used to identify and measure the radioactivity in the body of human beings in a nuclear power plants (NPPs). In domestic NPPs, it is prescribed that all workers should take a whole body counting after radiation works if the possibilities of radioactive contamination exist or the radioactivity is detected by a portal monitoring. It is, however, found that the external skin contamination is occasionally estimated as the internal radioactive contamination. In this case, the worker assumed to be detected is recommended to take showers for the decontamination of skin and take a whole body counting again. Although the detected radioactivity is reduced remarkably after several decontaminations, confirmed as the external skin contamination, it is determined finally as an internal exposure if the radioactivity is still detected in the body of worker. The amount of detected radioactivity can be much higher than that of the expected for this mistaken contamination since the radioisotopes attached to skin come to be close to the detectors of WBC. Finally, this makes the misjudgment of the external skin contamination as well as the excessively conservative estimation of radioactive contamination. In this study, several experiments were carried out to discriminate between the internal and external radioactive contamination using the humanoid phantom and WBC. Preliminary experimental results indicated that the use of front and backside counts could be applied to the discrimination of the external skin contamination and the difference of detected radioactivities between front and backside counts was less than about factor 2 for the internal contamination

Development of the Discrimination Programs between the Internal and External Radioactive Contamination of Workers Using a Whole Body Counter

International Nuclear Information System (INIS)

Kong, T. Y.; Kim, H. G.; Lim, S. N.; Kim, H. J.; Jin, H. H.; Lee, S. G.; Park, S. C.

2006-01-01

A whole body counter (WBC) is used to identify and measure the radioactivity in the body of human beings in a nuclear power plant (NPP). In domestic NPPs, several whole body counters are in operation to monitor the internal radioactive contamination of workers. All workers take a whole body counting after radiation works if there is high possibility of radioactive contamination or the radioactivity is detected by portal monitoring. It is, however, found that the external contamination is occasionally estimated as the internal radioactive contamination. In this case, the worker is recommended to take showers for the decontamination of skin and take a whole body counting again. Although the detected radioactivity is reduced remarkably after several decontaminations, confirmed as the external contamination, it is determined finally as an internal contamination if the radioactivity is still detected in the body of worker. The amount of detected radioactivity can be much higher than that of the expected for this mistaken contamination since the radioisotopes attached to skin come to be close to the detectors of WBC. Finally, this makes not only the misjudgment of the external contamination as the internal contamination, but also the excessively conservative estimation of radioactive contamination. In this study, several experiments were carried out to set up the discrimination program between the internal and external radioactive contamination using the humanoid phantom and a whole body counter. After the analysis of experimental results, we found that the use of front and backside counts could be applied to the discrimination of the external contamination and the ratio of detected radioactivities between front and backside counts was more than about factor 2 for the external contamination

Contamination of stainless steel process piping with radioactive cobalt colloids and methods for decontamination

International Nuclear Information System (INIS)

Adeleye, S.A.; White, D.A.

1992-01-01

Significant deposits of activity can occur on the internal surface of pipework carrying aqueous radioactive liquid. This paper describes experimental work to contaminate stainless steel piping with colloidal particles of Co 60 and considers decontamination methods. The effects on steel contamination of varying cobalt concentration and aqueous liquor pH were investigated. Deposition increased with increasing cobalt concentration and the ''plate-out'' increased markedly with increasing liquid pH. Low deposition occurred at pH ∼ 2 increasing by orders of magnitude at pH ∼ 10. Steel type had an effect on activity picked up. It was shown that liquid turbulence, on the surface, reduced activity deposition. Since the extent of contamination to be removed depends on deposition or ''plate-out'' kinetics, the factors affecting the rate of activity deposition are considered. Specimens of steel piping were treated by contacting with acid, electroetching or abrasion with emery cloth. Surface treatment was shown to delay deposition, in certain instances, but did not have much effect on overall equilibrium level of surface activity. The surface activity could be reduced by treatment with dilute nitric acid: however significant activity remained. Most of the remaining activity could be removed by treatment with nitric acid in an ultrasonic bath. (Author)

Studies on the radioactive contamination due to nuclear detonations II. Preliminary findings on the radioactive fallout due to nuclear detonations

Energy Technology Data Exchange (ETDEWEB)

Nishiwaki, Yasushi [Nuclear Reactor Laboratory, Tokyo Institute of Technology, Tokyo (Japan); Nuclear Reactor Laboratoroy, Kinki University, Fuse City, Osaka Precture (Japan)

1961-11-25

Since we have detected a considerable amount of artificial radioactivity in the rain in spring 1954, it has become one of the most important items, from the health physics point of view, to continue measurements of radioactivity in the rain and in the atmosphere. To watch out the radioactive contamination of our environment due to repeated nuclear weapons testings in other countries was also considered to be important from the nuclear engineering point of view, in the sense that the permissible allowances of the radioactivity for the peaceful uses of atomic energy might be lowered if the degree of radioactive contamination due to nuclear testings should continue to increase gradually and indefinitely. If the permissible level were lowered, the cost for radiation protection may be expected to increase at the peaceful uses of atomic energy and should the radioactive contamination increase seriously in the future, it was anticipated that we may have to face a very difficult situation in designing the atomic energy facilities for peaceful purposes in our country. From these points of views, we have been continuing measurements of the radioactivity in the rain in Osaka, Japan since the spring of 1954. Some of the preliminary findings are introduced in this paper.

Studies on the radioactive contamination due to nuclear detonations II. Preliminary findings on the radioactive fallout due to nuclear detonations

International Nuclear Information System (INIS)

Nishiwaki, Yasushi

1961-01-01

Since we have detected a considerable amount of artificial radioactivity in the rain in spring 1954, it has become one of the most important items, from the health physics point of view, to continue measurements of radioactivity in the rain and in the atmosphere. To watch out the radioactive contamination of our environment due to repeated nuclear weapons testings in other countries was also considered to be important from the nuclear engineering point of view, in the sense that the permissible allowances of the radioactivity for the peaceful uses of atomic energy might be lowered if the degree of radioactive contamination due to nuclear testings should continue to increase gradually and indefinitely. If the permissible level were lowered, the cost for radiation protection may be expected to increase at the peaceful uses of atomic energy and should the radioactive contamination increase seriously in the future, it was anticipated that we may have to face a very difficult situation in designing the atomic energy facilities for peaceful purposes in our country. From these points of views, we have been continuing measurements of the radioactivity in the rain in Osaka, Japan since the spring of 1954. Some of the preliminary findings are introduced in this paper

Status of foreign practices for the management of alpha-contaminated radioactive wastes

International Nuclear Information System (INIS)

Lakey, L.T.

1982-08-01

Alpha-contaminated radioactive wastes, a product of mixed-oxide fuel fabrication, fuel reprocessing, weapons production and decommissioning programs, are being generated in at least ten countries. There is general agreement worldwide that these wastes should be treated differently than the beta-gamma or low-level waste. There is no consensus, however, on a quantitative definition of alpha-contaminated wastes. Reported definitions vary from > 0.035 nCi/g to > 100 nCi/g. Incineration is the most common treatment, with cement and bitumen the most common fixation agents. The only disposal means in use today are the sea dumping practice by Belgium and the United Kingdom and the surface disposal and deep-well discharge by the USSR. Sea dumping, however, is restricted to low levels of alpha activity, while the USSR appears to be favoring geologic disposal. All countries appear to be moving toward deep geologic repositories as the favored means of disposing of alpha-contaminated radioactive wastes. West Germany has actually disposed of such wastes in the Asse Salt Mine but has discontinued that operation for political reasons. Repository projects are actively under way in Belgium, West Germany, India, Sweden, and the Unted States, with many other countries planning repository programs. One US project, the Waste Isolation Pilot Plant, will, according to present schedules, be the first repository operational since Asse. 6 tables

Radioactive contamination of aquatic media and organisms

International Nuclear Information System (INIS)

Fontaine, Y.

1960-01-01

After a brief account of the radioactive wastes produced by peaceful or military uses of Atomic Industry, the author first describes a series of observations carried out 'in the field' on the extent of contamination in aquatic organisms with respect to that of the medium. The experimental studies are then analysed, with reference both to the radioisotope metabolism and to the factors and types of contamination of aquatic organisms by wastes from atomic industry. A precise experimental project is presented at the end of the paper, including almost 300 references. (author) [fr

Multiple containment for LSA [low specific activity] and SCO [surface contaminated objects] wastes

International Nuclear Information System (INIS)

Burgess, M.H.

1993-09-01

Radioactive wastes are generally transported in the form of Low Specific Activity (LSA) materials or Surface Contaminated Objects (SCO). This report proposes that a method of acknowledging the beneficial effects of multiple containment for such wastes should be written into the 1996 Edition of the IAEA Transport Regulations. Experience used to assess risks from on-site movements of radioactive material in the UK can be applied to develop safety arguments justifying the alleviation of off-site transport risks. (UK)

Radioactive contamination of sewage sludge. Preliminary data

Energy Technology Data Exchange (ETDEWEB)

Soeder, C J; Zanders, E; Raphael, T

1986-01-01

Because of the radioactivity released through the explosion of the nuclear reactor near Chernobyl radionuclides have been accumulated to a significant extent in sewage sludge in the Federal Republic of Germany. This is demonstrated for samples from four activated sludge plants according to a recent recommendation of the German Commission for Radiation Protection, there is until now no reason to deviate from the common practices of sludge disposal or incineration. The degree of radioactive contamination of plant materials produced on farm lands on which sewage sludge is being spread cannot be estimated with sufficient certainty yet. Additional information is required.

Decontamination of radioactive metal surfaces by plasma arc gouging

International Nuclear Information System (INIS)

Osamu, K.; Makoto, K.; Takao, K.

1983-01-01

Experiments have been carried out to develop a new decontamination method that applies plasma arc gouging for removal of a thin surface layer from radioactively contaminated metallic wastes. Plasma arc gouging has been carried out on stainless steel and carbon steel pipes. The torch nozzle and gouging angle have been optimized to increase the decontamination rate. A water film is formed on the pipe surface to reduce both dust concentration in the off-gas and prevent slag particles, which are splashed up by the plasma gas, from adhering to the gouged surface. Using chromium-electroplated carbon steel pipes as samples, a decontamination factor of >10 3 is obtained after gouging to a depth of about0.5 mm in combination with ultrasonic cleaning

Process for affixing radioactive contamination on contaminated materials or wastes. Its application

International Nuclear Information System (INIS)

Aubouin, Guy; Aude, Georges; Tassigny, Christian de.

1982-01-01

The invention concerns a process for affixing radioactive contamination on materials or waste matter in order to ensure that the materials are transferred in complete safety or to package them when their activity is low. Under this process at least one coat of a resin polymerizable at ambient temperature, for example an epoxy resin, a polyester resin, a vinyl resin or a mixture of thermohardening resin and thermoplastic resin, is sprayed on to the contaminated material part by means of an electrostatic gun [fr

Method and device of decontaminating radioactive solid wastes

International Nuclear Information System (INIS)

Hasegawa, Hiroshi; Tamada, Masami.

1983-01-01

Purpose: To surely enable grinding for the inner surface of hollow radioactive solid wastes such as pipeways or valves, as well as enable to decontaminate these solid wastes to such a level as being capable of processing in the same manner for the ordinary wastes. Method: A grinding piece abutting resiliently against the inner surface of a hollow radioactive solid wastes to be contaminated is attached at the top end of a flexible shaft, and the inner surface of the radioactive solid wastes is ground while rotating and slightly reciprocating, as well as axially moving the flexible shaft. Consequently, since the grinding piece is always abutted against the inner surface of the radioactive solid wastes just following after the profile of the inner surface, and the flexible shaft is resiliently flexed corresponding to the profile of the inner surface of the radioactive solid wastes, even an inner surface of radioactive solid wastes with a complicated configuration can surely be ground entirely. This surely enables to remove radioactive claddings and contaminated layers deposited on the surface. (Yoshihara, H.)

49 CFR 176.715 - Contamination control.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Contamination control. 176.715 Section 176.715... Requirements for Radioactive Materials § 176.715 Contamination control. Each hold, compartment, or deck area... the removable (non-fixed) radioactive surface contamination is not greater than the limits prescribed...

49 CFR 173.443 - Contamination control.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Contamination control. 173.443 Section 173.443... SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials § 173.443 Contamination control. (a) The level of non-fixed (removable) radioactive contamination on the external surfaces of each package offered for...

Current Measures on Radioactive Contamination in Japan: A Policy Situation Analysis.

Science.gov (United States)

Gilmour, Stuart; Miyagawa, Shoji; Kasuga, Fumiko; Shibuya, Kenji

2016-01-01

The Great East Japan Earthquake on 11th March 2011 and the subsequent Fukushima Dai-ichi nuclear power plant disaster caused radioactive contamination in the surrounding environment. In the immediate aftermath of the accident the Government of Japan placed strict measures on radio-contamination of food, and enhanced radio-contamination monitoring activities. Japan is a pilot country in the WHO Foodborne Disease Burden Epidemiology Reference Group (FERG), and through this initiative has an opportunity to report on policy affecting chemicals and toxins in the food distribution network. Nuclear accidents are extremely rare, and a policy situation analysis of the Japanese government's response to the Fukushima Dai-ichi nuclear accident is a responsibility of Japanese scientists. This study aims to assess Japan government policies to reduce radio-contamination risk and to identify strategies to strengthen food policies to ensure the best possible response to possible future radiation accidents. We conducted a hand search of all publicly available policy documents issued by the Cabinet Office, the Food Safety Commission, the Ministry of Health, Labor and Welfare (MHLW), the Ministry of Agriculture, Forestry and Fishery (MAFF) and prefectural governments concerning food safety standards and changes to radiation and contamination standards since March 11th, 2011. We extracted information on food shipment and sales restrictions, allowable radio-contamination limits, monitoring activities and monitoring results. The standard for allowable radioactive cesium (Cs-134 and Cs-137) of 100 Bq/Kg in general food, 50 Bq/Kg in infant formula and all milk products, and 10 Bq/Kg in drinking water was enforced from April 2012 under the Food Sanitation Law, although a provisional standard on radio-contamination had been applied since the nuclear accident. Restrictions on the commercial sale and distribution of specific meat, vegetable and fish products were released for areas at risk of

Radiation safety for incineration of radioactive waste contaminated by cesium

International Nuclear Information System (INIS)

Veryuzhs'kij, Yu.V.; Gryin'ko, O.M.; Tokarevs'kij, V.V.

2016-01-01

Problems in the treatment of radioactive waste contaminated by cesium nuclides are considered in the paper. Chornobyl experience in the management of contaminated soil and contaminated forests is analyzed in relation to the accident at Fukushima-1. The minimization of release of cesium aerosols into atmosphere is very important. Radiation influence of inhaling atmosphere aerosols polluted by cesium has damage effect for humans. The research focuses on the treatment of forests contaminated by big volumes of cesium. One of the most important technologies is a pyro-gasification incineration with chemical reactions of cesium paying attention to gas purification problems. Requirements for process, physical and chemical properties of treatment of radioactive waste based on the dry pyro-gasification incineration facilities are considered in the paper together with the discussion of details related to incineration facilities. General similarities and discrepancies in the environmental pollution caused by the accidents at Chornobyl NPP and Fukushima-1 NPP in Japan are analyzed

Treatment of Gravel Contaminated with Naturally Occurring Radioactive Element

International Nuclear Information System (INIS)

Sohsah, M. A.; Kamal, S. M.; Mamoon, A.

2004-01-01

Environmental protection primarily means controlling the releases of radioactive and non-radioactive wastes to the environment and involves treatment, storage, cleanup and disposal of these wastes. The present study concerns the cleanup of gravel that has been contaminated with 2 26 R a. Aqueous solutions of different compositions including water and various concentrations of calcium chloride and barium chloride were used to leach the contaminated gravel. The leaching experiments were carried out in glass column. In some leaching experiments, samples of sandy soil were placed below the gravel to test the sorption of the leached 2 26 R a by the soil. The relative efficiencies of the leachant and the extent of sorption of the leached radionuclide were determined both by the liquid scintillation counting and by the thermoluminescent chips. The TLD chips record the dose before and after decontamination of the gravel and before and after contamination of the soil samples when used. The results obtained indicated that acidified barium chloride was relatively the most effective leachant of 2 26 R a contamination. It reduced the dose from the contaminated gravel to almost half. The soil sample used adsorbs the leached radionuclides efficiently, increasing the soil naturally low dose to about six folds

Treatment of Radioactive Contaminated Soil and Concrete Wastes Using the Regulatory Clearance

Energy Technology Data Exchange (ETDEWEB)

Kang, Il Sik; Ryu, W. S.; Kim, T. K.; Shon, J. S.; Ahn, S. J.; Lee, Y. H.; Bae, S. M.; Hong, D. S.; Ji, Y. Y.; Lee, B. C

2008-11-15

In the radioactive waste storage facilities at the Korea Atomic Energy Research Institute (KAERI) in Daejoen, there are thousands drums of radioactive contaminated soil and concrete wastes. The soil and concrete wastes were generated in 1988 during the decommissioning process of the research reactor and the attached radioactive waste treatment facility which were located in Seoul. The wastes were transported to Daejeon and have been stored since then. At the generation time, the radioactive contamination of the wastes was very low, and the radionuclides in the wastes was Co-60 and Cs-137. As the wastes have been stored for more than 20 years, the radioactivity concentration of the wastes has been decayed to become very extremely low. The wastes are needed to be treated because they take up large spaces at the storage facility. Also by treating the wastes, final disposal cost can be saved. So, the regulatory clearance was considered as a treatment method for the soil and concrete wastes with extremely low radioactivity concentration.

Radioactive contamination of the Dutch soil in consequence of the nuclear reactor accident at Chernobyl

International Nuclear Information System (INIS)

Koester, H.W.; Mattern, F.C.M.; Pennders, R.M.J.

1987-01-01

As a consequence of the reactor accident in Chernobyl air, contaminated with radioactive materials, spread over the Netherlands. From 2nd May to 6th May, with dry and to a greater extent with wet deposits, important quantities of radionuclides came upon the earth surface. In this period the weather circumstances within the Netherlands differed strongly resulting in distinct variations in deposit. In this document a preliminary picture is given of the contamination of the Dutch bottom on the basis of soil samplings made in the first few months after the accident. No attention is paid to geographic differences in bottom contamination. The contamination of the bottom is expressed in Bq/kg dry soil as well as in Bq/m 2 soil. 5 refs.; 6 tabs. (H.W.)

A prospect of the administration against problems of environmental contamination caused by radioactive nuclides

International Nuclear Information System (INIS)

Osako, Masahiro

2012-01-01

At first, focusing on the problem of radioactive contaminated wastes caused by Fukushima Daiichi Nuclear Accident, the Author described an outline of the waste management policy based on the law on special measures against the environmental contamination by radioactive nuclides. Next, the Author discussed a prospect of the environmental administration against the radioactive contamination problem. The most important mission of the environmental administration for the future must be to establish a social basis for the sustainable development, in other words the building-up of a newly social value added, through the measures against this unprecedented disaster. (author)

Control of radioactive contamination of food in the country Somogy

International Nuclear Information System (INIS)

Varga, E.; Viragh, I.

1980-01-01

The radioactive contamination of spinach, sorrel, lettuce, animal bones, milk and fish was determined in the period 1961-1978. Peak values were measured in 1963 and 1976. The contamination of plants reached higher levels, however, it did not exceed 25 pCi per g dry weight. (L.E.)

Lichens as indicators of radioactive contamination

International Nuclear Information System (INIS)

Biarzov, L.

1993-01-01

Samples of lichens were investigated, collected in 1987 in the Eastern Urals and in 1988 in the vicinity of Chernobyl. Data are given on the size of thalli of epiphytic lichens from trunks of pine in the Chernobyl area, and on the beta activity in epiphytic lichens in the birch forests of the Urals 30 years after the Kyshtym accident, as well as concentrations of 40 K, 106 Ru, 134 Cs, 137 Cs, and 144 Ce in lichen thalli and the bark of pine tree, taken at 5 locations in the vicinity of Chernobyl 1000 days after the accident. Also given are cross-ratios of radioactivity of 106 Ru, 134 Cs, 137 Cs, and 144 Ce in lichen thalli and in the bark of pine trees. The results indicate that the activity of radionuclides in lichen thalli make a fairly reliable indicator of relative differences between the investigated areas in terms of the level of surface contamination and qualitative composition of the involved radionuclides. (J.B.) 4 tabs., 15 refs

Development of Radioactive Substance Contamination Diffusion Preventive Equipment for a Hot cell

International Nuclear Information System (INIS)

Choo, Yong Sun; Kim, Do Sik; Baik, Seung Je; Yoo, Byung Ok; Kim, Ki Ha; Lee, Eun Pyo; Ahn, Sang Bok; Ryu, Woo Seok

2009-01-01

The hot cell of irradiated materials examination facility (IMEF), which has been operating since 1996, is generally contaminated by the radioactive nuclides of irradiated nuclear fuels and structural steels like Cs-137, Co-60, Co-134 and Ru-106. Especially Cs-137 is a main contaminated radioactive isotope which is easily moved here and there due to air flow in the hot cell, water-soluble, extremely toxic, and has a half-life of 30.23 years. To repair or fix the abnormal function of test apparatus installed in the hot cell, the maintenance door, so called a rear door and located at an intervention area, is opened to enter the hot cell inside. In a moment of opening the maintenance door, dirty air diffusion from the hot cell to an intervention area could be occurred in spite of increasing the rpm of exhaust fan to maintain much low under pressure, but an adjacent area to a maintenance door, i.e. intervention area, is very severely contaminated due to the unpredictable air flow. In this paper, the development of the radioactive substance contamination diffusion preventive equipment for a hot cell is studied to prevent dirty and toxic gaseous radioactive nuclides diffusion from a hot cell and installed at an intervention area of IMEF

Radioactive contamination of aquatic media and organisms; La contamination radioactive des milieux et des organismes aquatiques

Energy Technology Data Exchange (ETDEWEB)

Fontaine, Y [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

After a brief account of the radioactive wastes produced by peaceful or military uses of Atomic Industry, the author first describes a series of observations carried out 'in the field' on the extent of contamination in aquatic organisms with respect to that of the medium. The experimental studies are then analysed, with reference both to the radioisotope metabolism and to the factors and types of contamination of aquatic organisms by wastes from atomic industry. A precise experimental project is presented at the end of the paper, including almost 300 references. (author) [French] Apres une courte etude des dechets radioactifs produits par les utilisations pacifiques ou militaires de l'Industrie Atomique, l'auteur fait etat d'abord des observations effectuees 'sur le terrain' concernant l'extension de la contamination des organismes aquatiques en rapport avec celle du milieu. L'auteur analyse ensuite les etudes experimentales se rapportant aussi bien au metabolisme des radioisotopes qu'aux facteurs et aux modalites de la contamination des organismes aquatiques par les dechets de l'industrie atomique. Un projet de travail experimental precis est presente a la fin de cette revue qui comporte pres de 300 references bibliographiques. (auteur)

Cleanup procedures at the Nevada Test Site and at other radioactively contaminated sites including representative costs of cleanup and treatment of contaminated areas

International Nuclear Information System (INIS)

Talmage, S.S.; Chilton, B.D.

1987-09-01

This review summarizes available information on cleanup procedures at the Nevada Test Site and at other radioactively contaminated sites. Radionuclide distribution and inventory, size of the contaminated areas, equipment, and cleanup procedures and results are included. Information about the cost of cleanup and treatment for contaminated land is presented. Selected measures that could be useful in estimating the costs of cleaning up radioactively contaminated areas are described. 76 refs., 16 tabs

Analysis of Radioactivity Contamination Level of Kartini Reactor Efluen Gas to the Environment

International Nuclear Information System (INIS)

Suratman; Purwanto; Aminjoyo, S

1996-01-01

The analysis of radioactivity contamination level of Kartini reactor efluen gas to the environment has been done from 13-10-'95 until 8-2-'96. The aim of this research is to determine the radioactivity contamination level on the environment resulted from the release of Kartini reactor efluen gas and other facilities at Yogyakarta Nuclear Research Centre through stack. The analysis methods is the student t-test, the first count factor test and the gamma spectrometry. The gas sampling were carried out in the stack reactor, reactor room, environment and in other room for comparison. Efluen gas was sucked through a filter by a high volume vacuum pump. The filter was counted for beta, gamma and alpha activities. The radioactivity contamination level of the efluen gas passing through the stack to the environment was measured between 0.57 - 1.34 Bq/m3, which was equal to the airborne radioactivity in environment between 0.69 - 1.12 Bq/m3. This radioactivity comes from radon daughter, decay products result from the natural uranium and thorium series of the materials of the building

Measures against radioactive contamination due to Fukushima First Nuclear Power Plant accidents. Part 3. Removing and decontamination of contaminated soil

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)

Characterization of radioactively contaminated sites for remediation purposes

International Nuclear Information System (INIS)

1998-05-01

Characterization of the contaminated site is essential before embarking on a programme for its remediation and ultimate restoration. Reliable and suitable data must be obtained regarding the distribution and physical, chemical and nuclear properties of all radioactive contaminants. Characterization data is necessary for assessing the associated radiation risks and is used in support of the required engineering design and project planning for the environmental restoration. In addition, continuing characterization can provide information regarding efficiency of the cleanup methods and influence possible redirection of work efforts. Similarly, at the end of the remediation phase, characterization and ongoing monitoring can be used to demonstrate completion and success of the cleanup process. The suggested methodology represents a contribution attempting to solve the issue of preremediation characterization in a general manner. However, a number of difficulties might make this methodology unsuitable for general application across the diverse social, environmental and political systems in the IAEA Member States. This TECDOC covers the methodologies used to characterize radioactively contaminated sites for the purpose of remediating the potential sources of radiation exposure and assessing the hazards to human health and the environment

Survey of radioactive contamination distribution in the Naka-Dori area, Tohoku, Japan

International Nuclear Information System (INIS)

Hohara, Sin-ya; Inagaki, Masayo; Yamanishi, Hirokuni; Wakabayashi, Genichiro; Sugiyama, Wataru; Itoh, Tetsuo

2013-01-01

The Kinki University Atomic Energy Research Institute investigated radioactive contamination due to the Fukushima Daiichi Nuclear Power Plant accident in urban areas of the Fukushima Naka-Dori Area in the TOHOKU region, Japan. A specific activity measurement of the surface soil and a survey of the dose rate distribution in urban areas were performed. From the results of this research, a decrease in dose rate in paved areas became clear, and differences due to the “wash out effect” in paved areas for different paving materials was measured and verified. (author)

Characterization of naturally occurring radioactive materials and Cobald-60 contaminated ferrous scraps from steel industries

International Nuclear Information System (INIS)

Chao, H.E.; Chiu, H.S.; Hunga, J.Y.; His, H.W.; Chen, Y.B.

2002-01-01

Since the occurrence of radioactively contaminated rebar incident in 1992, steel industries in Taiwan were encouraged by Atomic Energy Council (AEC) to install portal monitor to detect the abnormal radiation in shipments of metal scrap feed. From 1994 through 1999, there were 53 discoveries of radioactivity in ferrous scraps by steel companies. These include 15 orphan radioactive sources, 16 cobalt-60 contaminated rebars, 20 Naturally Occurring Radioactive Material (NORM) contaminated scraps, and two unknowns. Most NORM-contaminated scraps were from abroad. The NORM and cobalt-60 contaminated scraps were taken from the steel mills and analyzed in laboratory. The analytical results of scales and sludge sampled from NORM-contaminated scraps combining with the circumstantial evidences indicate that five possible industrial processes may be involved. They are oil production and treatment, heavy mineral sand benefication and rare earth processing, copper mining and processing, recovery of ammonium chloride by lime adsorption in Ammonium-soda process, and tailing of uranium enrichment process. The cobalt-60 activity and trace elements concentrations of contaminated rebars confirm that all of them were produced domestically in the period from Oct. 1982 to Jan. 1983, when the cobalt-60 sources were lost and entered the electric arc furnace to produce the contaminated rebars. (author)

Survey of radioactive contamination of foodstuffs

Energy Technology Data Exchange (ETDEWEB)

Lee, W. R.; Lee, C. W.; Choi, G. S.; Cho, Y. H.; Kang, M. J.; Cheong, K. H.; Kim, H. R.; Kwak, J. Y

2005-11-15

The purpose of this study is to survey and assess radioactive contamination of foodstuffs in order to reduce the probability of intake of contaminated foodstuffs. Based on survey and assessment, final goal is to improve the public health by radiation protection. Sampled foodstuffs items are collected from the markets : one group are imported foodstuffs and the other group are domestic foodstuffs producted around nuclear facilities. After pretreatments such as drying, ashing, and homogenization, all samples were analyzed by gamma spectrometer system. The {sup 137}Cs radionuclide was only measured among the regulation radionuclides ({sup 137}Cs, {sup 134}Cs, {sup 131}I) of food code. All radionuclides of the domestic foodstuffs collected around nuclear facilities were below Minimum Detectable Activity (MDA). But the activity concentrations of Inonotus obliquus (Chaga mushooms) from Russia ranged up to 171.27 (average value : 36.65) Bq/kg-fresh. In the case of blueberry jam, the radioactivity of {sup 137}Cs is higher than expected value. Other samples are below MDA except some spices. Based on the previous and present results, it should be strengthen to survey for Inontus obliquus (Chaga mushooms), of which the radioactivity shows the range from MDA up to 800.01 Bq/kg-fresh. It should assess the public radiation exposure via food chain because it has the excess provability of the maximum permitted level of food code, which is regulation of KFDA. The development method based on international standard would be used at radioactive analysis as well as education of practical workers and it could be applied as the basis data for amending the analysis method of food code. Our country only surveys gamma emitting radionuclides till now but international organization or foreign countries for example EU survey alpha and beta emitting radionuclides as well as gamma emitting radionuclides. So our country should also research necessity of survey for alpha and beta emitting

Sources to environmental radioactive contamination from nuclear activities in the former USSR

International Nuclear Information System (INIS)

Polikarpov, G.G.; Aarkrog, A.

1993-01-01

There is three major sites of radioactive environmental contamination in the former USSR: the Cheliabinsk region in the Urals, Chernobyl NPP in Ukraine and Novaya Zemlya in the Arctic Ocean. The first mentioned is the most important with regard to local (potential) contamination, the last one dominates the global contamination. A number of sites and sources are less well known with regard to environmental contamination. This is thus the case for the plutonium production factories at Tomsk and Dodonovo. More information on nuclear reactors in lost or dumped submarines is also needed. From a global point of view reliable assessment of the radioactive run-off from land and deposits of nuclear waste in the Arctic Ocean are in particular pertinent

Biological cycles of radioactive contaminants

International Nuclear Information System (INIS)

Michon, M.-G.

1959-01-01

Artificial radio-elements (synthesized for scientific or industrial purposes)having been released, may be absorbed by plants or animals, and may eventually involve a catenation of organisms as some feed on the others. All organisms living in a polluted river become more radioactive than the water, which was to be expected, in as much as organisms are hypertonic in respect to sweet water. Conversely, soil brings into play physico-chemical phenomena (absorption) such that plants can get only a small portion of contaminating radio-elements, land animal feeding on such plants are relatively less exposed to contamination, and carnivorous animals feeding on herbivorous are still less exposed. Man, notably is fairly well protected, whereas lower organisms, notably unicellular organisms may suffer (mutations..). Reprint of a paper published in 'Revue de Pathologie Generale et de Physiologie Clinique', n. 707, April 1959, p. 505-514 [fr

Radioactive contamination from Chernobyl accident over Alexandria city

International Nuclear Information System (INIS)

Ammar, E.A.; El-Khatib, A.M.; Wahba, A.G.; Elraey, M.

1987-01-01

The concentration of radioactive contamination in air resulting from the Chernobyl accident has been followed up. A sudden and sharp increase was detected seven days after the start of the accident. This increase amounted to about 650 times the normal air-borne activity. (author)

Survey and decontamination trial of boat wastes contaminated with radioactive cesium

International Nuclear Information System (INIS)

Takigami, Hidetaka; Yamamoto, Takashi; Suzuki, Go; Takeuchi, Yukio; Tanosaki, Takao; Takata, Mitsuyasu; Okubo, Takuro

2013-01-01

Field survey was conducted to investigate radioactive cesium contamination status of the fiber reinforced plastic (FRP) boats which were damaged by the Great East Japan Earthquake and resulting tsunami, and further affected by nuclear fallout from the accident at the Fukushima No. 1 nuclear power plant. Radiation dose rate was measured targeted at some selected boats and the surrounding environment by using radiation survey meters (i.e., NaI (Tl) scintillation counter and GM counter) and a radiation-sensing camera in order to visualize a dose rate distribution within the area. In addition, FRP parts, sediment deposits and stagnant waters in the boats were sampled and their "1"3"4Cs and "1"3"7Cs radioactivity were measured by gamma-ray spectrometry using NaI (Tl) scintillation or Ge detector. From the monitoring results, materials or sediments in the boats enhanced the radiation levels, however, which can be significantly reduced by decontamination operations such as removal and wash-out of the materials or sediments (i.e., countermeasures for surface-deposited radioactivity). Consequently, the conducted survey and decontamination approaches became a good model and promoted a prompt dismantlement, removal and further disposal/recycle by the local authorities concerned. (author)

Test and evaluation of radioactively contaminated transducers and transmitters

International Nuclear Information System (INIS)

Strahm, R.C.

1983-01-01

People in the nuclear industries face some unique problems when handling, testing, or examining transducers and transmitters that have been radioactively contaminated. Although many people and organizations, including EG and G Idaho, have performed such work for many years, there are no set, structured approaches or procedures. This paper discusses a disciplined laboratory approach to contaminated transducer testing and evaluation, utilizing equipment and facilities developed specifically for this type of work

Dry decontamination technology development for high radioactive contaminant application - Development of residual radiation assessment methodology for high radioactive facility decontamination

Energy Technology Data Exchange (ETDEWEB)

Lee, G. J.; Hong, D. S.; Jeong, H. Y. [Korea Advanced Institute of Science and Technology, Taejon (Korea)

2000-04-01

Humidity around the concrete structure can make the moisture distribution within the concrete. Moisture content of the structure will change due to the diffusion process with time. Radioactive material on the surface of concrete will eventually diffuse into the porous concrete and contaminates the internal region of the concrete. In this study, we have assumed two different diffusion processes depending on the different moisture content. One is for slow diffusion process near the surface and the other is for fast diffusion process in deep region. We have developed the mathematical diffusion model for the two different diffusion regions and the corresponding analytic solutions for the two regions are obtained. 19 refs., 15 figs., 9 tabs. (Author)

Current Measures on Radioactive Contamination in Japan: A Policy Situation Analysis.

Directory of Open Access Journals (Sweden)

Stuart Gilmour

Full Text Available The Great East Japan Earthquake on 11th March 2011 and the subsequent Fukushima Dai-ichi nuclear power plant disaster caused radioactive contamination in the surrounding environment. In the immediate aftermath of the accident the Government of Japan placed strict measures on radio-contamination of food, and enhanced radio-contamination monitoring activities. Japan is a pilot country in the WHO Foodborne Disease Burden Epidemiology Reference Group (FERG, and through this initiative has an opportunity to report on policy affecting chemicals and toxins in the food distribution network. Nuclear accidents are extremely rare, and a policy situation analysis of the Japanese government's response to the Fukushima Dai-ichi nuclear accident is a responsibility of Japanese scientists. This study aims to assess Japan government policies to reduce radio-contamination risk and to identify strategies to strengthen food policies to ensure the best possible response to possible future radiation accidents.We conducted a hand search of all publicly available policy documents issued by the Cabinet Office, the Food Safety Commission, the Ministry of Health, Labor and Welfare (MHLW, the Ministry of Agriculture, Forestry and Fishery (MAFF and prefectural governments concerning food safety standards and changes to radiation and contamination standards since March 11th, 2011. We extracted information on food shipment and sales restrictions, allowable radio-contamination limits, monitoring activities and monitoring results. The standard for allowable radioactive cesium (Cs-134 and Cs-137 of 100 Bq/Kg in general food, 50 Bq/Kg in infant formula and all milk products, and 10 Bq/Kg in drinking water was enforced from April 2012 under the Food Sanitation Law, although a provisional standard on radio-contamination had been applied since the nuclear accident. Restrictions on the commercial sale and distribution of specific meat, vegetable and fish products were released for

Protection against radioactive contamination of food and agricultural products

International Nuclear Information System (INIS)

Szabo, A.; Kovacs, Z.

1977-01-01

Due to contaminating effects from nuclear explosions and nuclear power plants, the systematic investigation of environmental radioactive contamination is absolutely necessary. In order to reduce the artificial radiation dose to which the human body is exposed, isotope content of foods and agricultural products should be known. The authors evaluate the decontamination possibilities of food produced from vegetable and animal products, starting from the contamination of some products. For vegetable product decontamination the use of suitable fertilizers, thorough scrubbing in excess water and, for cereals, milling is proposed. As the most effective preventive measure of radiation contamination of food products of animal origin, appropriate packing is proposed. The storage and preservation problems are emphasized for short half-life radiation contamination. (P.J.)

Radioactive contamination of aquatic media and organisms; La contamination radioactive des milieux et des organismes aquatiques

Energy Technology Data Exchange (ETDEWEB)

Fontaine, Y. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

After a brief account of the radioactive wastes produced by peaceful or military uses of Atomic Industry, the author first describes a series of observations carried out 'in the field' on the extent of contamination in aquatic organisms with respect to that of the medium. The experimental studies are then analysed, with reference both to the radioisotope metabolism and to the factors and types of contamination of aquatic organisms by wastes from atomic industry. A precise experimental project is presented at the end of the paper, including almost 300 references. (author) [French] Apres une courte etude des dechets radioactifs produits par les utilisations pacifiques ou militaires de l'Industrie Atomique, l'auteur fait etat d'abord des observations effectuees 'sur le terrain' concernant l'extension de la contamination des organismes aquatiques en rapport avec celle du milieu. L'auteur analyse ensuite les etudes experimentales se rapportant aussi bien au metabolisme des radioisotopes qu'aux facteurs et aux modalites de la contamination des organismes aquatiques par les dechets de l'industrie atomique. Un projet de travail experimental precis est presente a la fin de cette revue qui comporte pres de 300 references bibliographiques. (auteur)

Imaging plant leaves to determine changes in radioactive contamination status in Fukushima, Japan.

Science.gov (United States)

Nakajima, Hiroo; Fujiwara, Mamoru; Tanihata, Isao; Saito, Tadashi; Matsuda, Norihiro; Todo, Takeshi

2014-05-01

The chemical composition of plant leaves often reflects environmental contamination. The authors analyzed images of plant leaves to investigate the regional radioactivity ecology resulting from the 2011 accident at the Fukushima No. 1 nuclear power plant, Japan. The present study is not an evaluation of the macro radiation dose per weight, which has been performed previously, but rather an image analysis of the radioactive dose per leaf, allowing the capture of various gradual changes in radioactive contamination as a function of elapsed time. In addition, the leaf analysis method has potential applications in the decontamination of food plants or other materials.

Methodology for determining acceptable residual radioactive contamination levels at decommissioned nuclear facilities/sites

International Nuclear Information System (INIS)

Watson, E.C.; Kennedy, W.E. Jr.; Hoenes, G.R.; Waite, D.A.

1979-01-01

The ultimate disposition of decommissioned nuclear facilities and their surrrounding sites depends upon the degree and type of residual contamination. Examination of existing guidelines and regulations has led to the conclusion that there is a need for a general method to derive residual radioactive contamination levels that are acceptable for public use of any decommissioned nuclear facility or site. This paper describes a methodology for determining acceptable residual radioactive contamination levels based on the concept of limiting the annual dose to members of the public. It is not the purpose of this paper to recommend or even propose dose limits for the exposure of the public to residual radioactive contamination left at decommissioned nuclear facilities or sites. Unrestricted release of facilities and/or land is based on the premise that the potential annual dose to any member of the public using this property from all possible exposure pathways will not exceed appropriate limits as may be defined by Federal regulatory agencies. For decommissioned land areas, consideration should be given to people living directly on previously contaminated areas, growing crops, grazing food animals and using well water. Mixtures of radionuclides in the residual contamination representative of fuel reprocessing plants, light water reactors and their respective sites are presented. These mixtures are then used to demonstrate the methodology. Example acceptable residual radioactive contamination levels, based on an assumed maximum annual dose of one millirem, are calculated for several selected times following shutdown of a facility. It is concluded that the methodology presented in this paper results in defensible acceptable residual contamination levels that are directly relatable to risk assessment with the proviso that an acceptable limit to the maximum annual dose will be established. (author)

Radioactive contamination of the Dnepr-Sozh river basin in Belarus after the accident at the Chernobyl NPP

International Nuclear Information System (INIS)

Zhukova, O.M.; Matveenko, I.I.; Pokumejko, Yu.M.; Shagalova, E.D.

1998-01-01

Systematic control over the radioactive contamination of surface waters is carried out at five main rivers of Belarus: Dnepr, Sozh, Pripyat, Iput, Besed. The experimental watershed of Iput river (Dnepr-Sozh basin) have been chosen for revealing the general rules of radioactive contamination of the rivers of Belarus on the basis of generalization of the monitoring data and field investigations. It has been found that transport of radionuclides on suspended solids is one of the main forms of migration of radionuclides in the river (caesium-137 in particular). Thus, the analysis of contamination of the rivers of Belarus has shown that the most intensive runoff of radionuclides from the territories of the watershed occurs in the head of the Dnepr basin, namely by its tributaries, Iput and Sozh. The annual runoff of radionuclides in soluble form by the rivers of Belarus in 1987-1996 has decreased significantly. Transport of radioisotopes with suspended and drawn wash loads significantly affects their migration and its contribution to the total runoff of radionuclides has increased with time. The runoff of radionuclides with transported wash loads varied within 20-80% from the total runoff of radionuclides. Sedimentation of river suspended load carrying radionuclides in the sites with slow river flow creates local movable ecologically dangerous centres of accumulation of radionuclides in bottom sediments particularly in front of the diverting dams. Existence of such centres of radioactive contamination requires their monitoring, assessment of their possible effects, and, if necessary, their decontamination

Residual radioactive contamination at Maralinga and Emu, 1985

International Nuclear Information System (INIS)

Lokan, K.H.

1985-04-01

An account is provided of residual contamination at Maralinga and Emu, in South Australia, where the United Kingdom Atomic Weapons Research Establishment conducted nuclear weapons development trials between 1953 and 1963. Detailed information is presented about contamination levels at sites on the range where radioactive materials were dispersed. Some of these were associated with trials involving natural uranium or short-lived isotopes which are no longer present. There are four sites where plutonium-239 was dispersed in substantial quantities from minor trials and information is presented about its distribution. Much of this material has been diluted by mixing with local soil, but there is a significant quantity of material present in the form of contaminated fragments, particularly at Taranaki. A considerable quantity of uranium-235 is also present at Taranaki. An assessment is made of the radiological significance of the dispersed plutonium and it is concluded that the material represents a potential long term hazard while it remains in its present form. Residual radioactivity associated with all but one of the seven major trial sites involving nuclear explosions continues to decay in a predictable way and will in the worst case, fall below levels considered safe for continuous occupancy within about fifty years. One site, Tadje, contains significant concentrations of plutonium over a small area and onsidered to be an additional plutonium-contaminated locality. Measurements of beryllium concentrations in soil are presented

Environmental and human exposure as a result of radioactive discharges

International Nuclear Information System (INIS)

2010-02-01

Nuclear accidents can lead to the discharge of radioactive particulates, gases, and liquid effluents into the environment. Effluents are characterized by their composition, duration and by other characteristics which can influence the dispersion of radioactivity in the environment. Populations can be exposed directly or through the contamination of the terrestrial and aquatic environments. Therefore, it is necessary to take into consideration both the environmental contamination pathways and the human contamination pathways through the environment. This document summarizes these different pathways: contamination by atmospheric discharge (surface contamination, surface waters, terrestrial fauna and flora); contamination by liquid discharge; spreading of contaminated areas; human contamination pathways (external irradiation, internal contamination, skin contamination). (J.S.)

Influence of radioactive contamination to agricultural products by rainfall during a nuclear accident

International Nuclear Information System (INIS)

Hwang, W. T.; Han, M. H.; Choi, Y. H.; Lee, H. S.; Lee, C. W.

2001-01-01

For the consideration of the effects on radioactive contamination of agricultural products by rainfall during a nuclear accident, the wet interception coefficients for the plants were derived, and the previous dynamic food chain model was also modified. From the results, radioactive contamination of agricultural products was greatly decreased by rainfall, and it decreased dramatically according to increase of rainfall amount. It means that the predictive contamination in agricultural products using the previous dynamic food chain model, in which dry interception to the plants is only considered, can be overestimated. Influence of rainfall on the contamination of agricultural products was the most sensitive for 131 I, and the least sensitive for 90 Sr

Transfer of radioactive contamination from milk to commercial dairy products

International Nuclear Information System (INIS)

Wilson, L.G.; Sutton, P.M.

1988-01-01

The fate of radioactive contamination resulting from fallout from the Chernobyl accident was studied during milk processing. A range of commercial dairy products was produced on a pilot-laboratory scale and the radiocaesium contents were measured by high-resolution gamma spectrometry. The results show that the radiocaesium partitioned with the water phase and therefore butter, cream and cheese had relatively low levels of radioactivity. Ion exchange demineralization was effective in removing radiocaesium from whey. Ultrafiltration of whey resulted in a reduction of radioactivity relative to retentate solids. (author)

Responses of the soil decomposer community to the radioactive contamination

International Nuclear Information System (INIS)

Svetlana, Maksimova

2004-01-01

The knowledge about biodiversity and about reasons and laws of dynamics of decomposer invertebrates has exclusively important (rather applied, or theoretical) significance for soil science. Earthworms and millipedes are probably the most important members of the soil biota and major contributors to total zoo-mass. Their activities are such that they are extremely important in maintaining soil fertility in a variety of ways. They play an important part in the redistribution of radionuclides accumulated in the natural biogeocenoses and accumulation of radionuclides in their bodies depends on their concentration in the habitat. Since radionuclides can limit biological activity, studies to estimate the tolerance of decomposer community to potentially toxic radiators are needed. The effect of radioactive contamination on the soil invertebrates and decomposition processes in the different biogeocenoses we intensively studied during 17 years after Chernobyl accident. The soil invertebrates were collected according to generally accepted method by M. Ghilyarov. Soil samples were 0,25 m 2 and animals were extracted from samples by hand sorting. Usually decomposition was affected by the presence of decomposer fauna. Considerable differences were found in the species number. The species composition of sites differed clearly. The study showed that the fauna was poorer under increasing levels of radioactive contamination. The higher radionuclide content was found to result in suppression of decomposer community. The results showed a vertical migration of earthworms to deeper soil layers with increasing of radioactive contamination. With the absence of decomposer fauna due to migration to the deeper layer and mortality, the layer of litter increased. The results show that the earthworms were of small size. Cocoon production decreased. Radioactive contamination altered the process of reproduction and age structure of decomposer fauna. The invertebrates collected from the

Responses of the soil decomposer community to the radioactive contamination

Energy Technology Data Exchange (ETDEWEB)

Svetlana, Maksimova [Institute of Zoology of National Academy of Sciences of Belarus, Minsk (Belarus)

2004-07-01

The knowledge about biodiversity and about reasons and laws of dynamics of decomposer invertebrates has exclusively important (rather applied, or theoretical) significance for soil science. Earthworms and millipedes are probably the most important members of the soil biota and major contributors to total zoo-mass. Their activities are such that they are extremely important in maintaining soil fertility in a variety of ways. They play an important part in the redistribution of radionuclides accumulated in the natural biogeocenoses and accumulation of radionuclides in their bodies depends on their concentration in the habitat. Since radionuclides can limit biological activity, studies to estimate the tolerance of decomposer community to potentially toxic radiators are needed. The effect of radioactive contamination on the soil invertebrates and decomposition processes in the different biogeocenoses we intensively studied during 17 years after Chernobyl accident. The soil invertebrates were collected according to generally accepted method by M. Ghilyarov. Soil samples were 0,25 m{sup 2} and animals were extracted from samples by hand sorting. Usually decomposition was affected by the presence of decomposer fauna. Considerable differences were found in the species number. The species composition of sites differed clearly. The study showed that the fauna was poorer under increasing levels of radioactive contamination. The higher radionuclide content was found to result in suppression of decomposer community. The results showed a vertical migration of earthworms to deeper soil layers with increasing of radioactive contamination. With the absence of decomposer fauna due to migration to the deeper layer and mortality, the layer of litter increased. The results show that the earthworms were of small size. Cocoon production decreased. Radioactive contamination altered the process of reproduction and age structure of decomposer fauna. The invertebrates collected from the

Experimental study of contamination by inhalation of radioactive iodine aerosols. Biological balance

International Nuclear Information System (INIS)

Marble, G.

1968-01-01

Several articles have been published concerning research into contamination produced by inhalation of radioactive iodine aerosols in monkeys. Results dealing with the biological balance of this contamination are presented and discussed in this report. (author) [fr

The Norwegian Radiation Protection Authority leads international cooperation on radioactive contamination in the Arctic

International Nuclear Information System (INIS)

1995-01-01

In cooperation with Russia, Norway is responsible for the part of Arctic Monitoring and Assessment Programme (AMAP) concerning radioactivity. An assessment of the consequences of radioactive contamination for the environment in northern areas will be an important part of AMAP's report to the Ministers of the Environment in the eight participating countries in 1996. The report will contain an overview of the sources of the contamination and the level of radioactivity in the environment, in addition to an evaluation of the consequences for humans and the environment

Disposal sheet for preventing scattering of radioactive contaminated material

International Nuclear Information System (INIS)

Miyasaka, Shun-ichi; Kurioka, Hitoshi; Nakamura, Kenjiro.

1990-01-01

Upon disposal of vinyl sheets at the final stage of dismantling operation for nuclear buildings, etc., radioactive contaminated materials caused by cutting concretes, etc. remain on the sheets. In view of the above, members capable of restoring original shape due to the temperature difference are attached to the sheet main body so that the sheet main body may be folded into a bag-like shape. Since the members as described above are bent upon temperature elevation in the sheets, the sheet main body is pulled by the members and then spontaneously folded into a bag-like shape. As a result, the radioactive contaminated materials remaining on the sheets are wrapped into the sheet main body free from touch to operator's hands or without scattering to the surrounding. This can prevent operator's external and internal exposure. (T.M.)

[Decorporation agents for internal radioactive contamination].

Science.gov (United States)

Ohmachi, Yasushi

2015-01-01

When radionuclides are accidentally ingested or inhaled, blood circulation or tissue/organ deposition of the radionuclides causes systemic or local radiation effects. In such cases, decorporation therapy is used to reduce the health risks due to their intake. Decorporation therapy includes reduction and/or inhibition of absorption from the gastrointestinal tract, isotopic dilution, and the use of diuretics, adsorbents, and chelating agents. For example, penicillamine is recommended as a chelating agent for copper contamination, and diethylene triamine pentaacetic acid is approved for the treatment of internal contamination with plutonium. During chelation therapy, the removal effect of the drugs should be monitored using a whole-body counter and/or bioassay. Some authorities, such as the National Council on Radiation Protection and Measurements and International Atomic Energy Agency, have reported recommended decorporation agents for each radionuclide. However, few drugs are approved by the US Food and Drug Administration, and many are off-label-use agents. Because many decontamination agents are drugs that have been available for a long time and have limited efficacy, the development of new, higher-efficacy drugs has been carried out mainly in the USA and France. In this article, in addition to an outline of decorporation agents for internal radioactive contamination, an outline of our research on decorporation agents for actinide (uranium and plutonium) contamination and for radio-cesium contamination is also presented.

Investigation of some regularities of the contamination of the surface snow in the ChAPP region in January-February 1987

International Nuclear Information System (INIS)

Glazunov, V.O.; Amosov, M.M.; Eldashev, V.V.; Draj, O.N.; Pashevich, V.I.

1989-01-01

The data on the surface snow radioactivity inspection obtained in winter 1987 are analyzed. A share of individual radionuclides in the general pollution of surface snow is considered. Changes in general and individual nuclide contamination dependent of the azimuth and distance are presented. A disperse content of contaminants in the surface snow is analyzed. The sampling techniques and snow sample preparation for γ-spectrometry are reported. 5 refs., 8 figs., 7 tabs

Decontamination method of contaminated metals

International Nuclear Information System (INIS)

Kawamura, Fumio; Ueda, Yoshihiro; Sato, Chikara; Komori, Itaru.

1980-01-01

Purpose: To effectively separate radioactive materials from molten metals in dry-processing method by heating metals contaminated with radioactive materials at a temperature below melting point to oxidize the surface thereof, then heating them to melt and include the radioactive materials into the oxides. Method: Metals contaminated with radioactive materials are heated at a temperature below the melting point thereof in an oxidizing atmosphere to oxidize the surface. Thereafter they are heated to melt at temperature above the melting point of the metals, and the molten metals are separated with the radioactive materials included in the oxides. For instance, radiation-contaminated aluminum pipe placed on the bed of an electrical heating furnace, and heated at 500 0 C which is lower than the melting point 660 0 C of aluminum for 1 - 2 hours while supplying air from an air pipe into the furnace, and an oxide film is formed on the surface of the aluminum pipe. Then, the furnace temperature is increased to 750 0 C wherein molten aluminum is flown down to a container and the oxide film is separated by floating it as the slug on the molten aluminum. (Horiuchi, T.)

The reality of radioactive contamination in construction of Taiwan and the treatment concerned

International Nuclear Information System (INIS)

Huang Chin-Wang

2005-01-01

It has been more than 50 years since Taiwan started the research on the peace application of radioactivity. During the first 20-30 years, it was found that the radioactive contaminated waste steel from atomic power plants was recycled together with general waste steel and was used to make other products including reinforcing bars. It was because the radiation resources ware not carefully controlled and managed. Since 1982, the radioactive contaminated reinforcing bars and buildings were gradually found, as the radiation dose rates were 5 μSv/h and 0.5 μSv/h, respectively. The radioactive nuclide was all Co-60. By August 2003, 1,626 households, 7,824 people's houses were founded to be radioactive contaminated. Furthermore, radiation dose rates higher than 5 μSv/h were measured from 264 of those householders. The government has started to ameliorate this situation and 94.7% of the cases have become normal. The cancer death rate of these people is found to be 0.49% (89 patients in 7,824 people, 39 was dead), and it is 4 times higher than that for general people. In order to solute this pollution problem, the government has made the law to check the radioactivity of all reinforcing bars and to control and manage those radiation resources more carefully. Additionally, there are tax exemption, subsidy, and expropriation with compensation for the polluted buildings. (author)

Characterization and remediation of highly radioactive contaminated soil at Hanford

International Nuclear Information System (INIS)

Buckmaster, M.A.; Erickson, J.K.

1993-09-01

The Hanford Site, Richland, Washington, contains over 1,500 identified waste sites and numerous groundwater plumes that will be characterized and remediated over the next 30 years. As a result of the Hanford Federal Facility Agreement and Consent Order, the US Department of Energy (DOE) has initiated a remedial investigation/feasibility study (RI/FS) at the 200-BP-1 operable unit. The 200-BP-1 RI/FS is the first Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) investigation on the Hanford Site that involves highly radioactive and chemically contaminated soils. The initial phase of site characterization was designed to assess the nature and extent of contamination associated with the source waste sites within the 200-BP-1 operable unit. Characterization activities consisted of drilling and sampling, chemical and physical analysis of samples, and development of a conceptual vadose zone model. These data were then used. to develop remedial alternatives during the FS evaluation. The preferred alternative resulting from the RI/FS process for the 200-BP-1 operable unit is to construct a surface isolation barrier. The multi-layered earthen barrier will be designed to prevent migration of contaminants resulting from water infiltration, biointrusion, and wind and water erosion

Fluorescence Imaging Reveals Surface Contamination

Science.gov (United States)

Schirato, Richard; Polichar, Raulf

1992-01-01

In technique to detect surface contamination, object inspected illuminated by ultraviolet light to make contaminants fluoresce; low-light-level video camera views fluorescence. Image-processing techniques quantify distribution of contaminants. If fluorescence of material expected to contaminate surface is not intense, tagged with low concentration of dye.

Method of decontaminating radioactive metal wastes

International Nuclear Information System (INIS)

Miyaji, Nobuyoshi.

1985-01-01

Purpose: To completely prevent the surface contamination of an equipment and decrease the amount of radioactive wastes to be resulted. Method: The surfaces of vessels, pipeways or the likes of nuclear reactor facilities to be contaminated with radioactive materials are appended with thin plates of metals identical or different from the constituents of the surfaces so as to be releasable after use. The material and the thickness of the plates and the method of appending then are determined depending on the state of use of the appended portions. Since only the stripped plates have to be processed as radioactive wastes, the amount of wastes can be decreased and, since the scrap materials can be reused, it is advantageous in view of the resource-saving. (Sekiya, K.)

Measures to be taken in cases of radioactive contamination of the skin

International Nuclear Information System (INIS)

Anon.

1991-01-01

This recommendation refers to those technical, medical and scientific facilities in which unsealed radioactive substances are handled. These facilities include, among other things: nuclear power plants, facilities of the fuel cycle, scientific and industrial laboratories, doctors' practices, hospitals and medical laboratories. Any unnecessary contamination of individuals shall be avoided. If contamination does occur, the resulting radiation exposure shall be kept as low as possible, even below the dose limits of the Radiological Protection Ordinance, taking into consideration the state of the art and also taking into account all circumstances pertaining to each individual case. Preventive measures to avoid or limit contamination represent the most effective form of protection. Preventive measures therefore include regular checks on the condition of the skin and constant personal skin care. Specific decontamination instructions must be provided for each individual plant and also, where applicable, for each individual workplace. Contaminated items of clothing must be removed before decontamination is commenced. Low levels of contamination can usually be eleminated in one step by washing with water. There is no need to carry out further decontamination steps where the decontamination effect is less than 10% and the remaining surface-related activity is less than 10 Bq/cm 2 (averaged over 100 cm 2 where the contamination is largely distributed over the entire area). (orig.) [de

Radioactive sources and contaminated materials in scrap: monitoring, detection and remedial actions

International Nuclear Information System (INIS)

Gallini, R.; Berna, V.; Bonora, A.; Santini, M.

1999-01-01

The scrap recycling in steel and other metal mills represents one of the most relevant activities in the Province of Brescia (Lombardy, Italy). In our Province more than 20 million tonnes of metal scrap are recycled every year by a melting process. Since 1990, many accidents which took place were caused by the unwanted melting of radioactive sources, that were probably hidden in metal scrap. In 1993, the Italian Government stated directives to monitor metal scrap imported from non-EC countries because of the suspicion of the illegal traffic of radioactive materials. In 1996, a law imposed the control of all metal scrap, regardless of their origins. Since 1993, our staff have controlled thousands of railway wagons and trucks. Approximately a hundred steel mills and foundries of aluminium, cooper, brass, etc. have also been controlled and many samples have been collected (flue dust, slag, finished products). During these controls, contaminated areas have been brought to light in two warehouses (Cs 137), in 6 companies (Cs 137 and Am 241), in two landfills of industrial waste (Cs 137) and in a quarry (Cs 137). Up to now the contaminated areas have been cleaned, except for the last one. About 150 radioactive sources on contaminated materials have been found in metal scrap. We found radioactive sources of Co 60, Ra 226, Ir 192, Kr 85, Am 241, while the contamination of metals was mainly due to Ra 226. The situation described above justifies an accurate control of the amount of scrap to reduce the risk of contamination of the workers in the working areas, in the environment and in the general public. (author)

The changes in the ecology and physiology of soil invertebrates under influences of radioactive contamination

International Nuclear Information System (INIS)

Maksimova, S.

2006-01-01

The soil biota is important in building and maintaining soil structure and fertility. Invertebrates are ideal as potential bio indicators of the environmental impact of radioactive contamination: they are widely distributed, often abundant and generally thought of as having low dispersive capacity. They can use as test organisms to detect the side-effects of radioactive contamination. The long-term analysis of ecological and physiological after-effects and biodiversity changes had been studied in the zone of radioactive contamination. Material was collected in the Gomel Region (Belarus), 30 km away from the CNPP in 1986-2004 applying usual pedobiological techniques (soil samples and Barber's pitfall traps) at reference points subjected to radioactive contamination. Soil samples were collected at 0 to 25 cm depth. Samples were taken in locations, which had received considerable radionuclide contaminations. These sites differed in contamination by the composition of fall-out, the forms of radionuclide content in soils, their intake into trophic chains and accumulation in animal and plant organisms. The impacts have been investigated at the: 1) organism and population levels , in terms of individual life histories (birth rate, growth, mortality) or species selection; 2) at the community level: to species diversity and to effects on trophic structure. The invertebrates were determined to species or genera, including juvenile stages. Radioactive contamination caused a distinct decrease in species number; the dominance structure of the community changed. The saprophagous are especially sensitive to environmental disturbances. An initial sharp reduction of animal biodiversity and simplification of the community structure of soil fauna were observed, followed by a long-term process of returning to the initial parameters. Changes in hemolymph, necroses of epithelium and cell structure in connective tissue were registered. The most drastic after-effects were manifested in

Radiological risk assessment of a radioactively contaminated site

International Nuclear Information System (INIS)

Devgun, J.S.

1990-01-01

A limited-scope preliminary assessment of radiological risk has been conducted at a radioactively contaminated site under current site use conditions and based on the available preliminary radiological characterization data for the site. The assessment provides useful input to the remedial action planning for the site. 8 refs., 1 fig., 2 tabs

Aquatic ecosystems within the Chernobyl NPP exclusion zone: radioactive contamination, doses and effects

International Nuclear Information System (INIS)

Gudkov, D.I.; Kuzmenko, M.I.; Krot, Y.G.; Kipnis, L.S.; Mardarevich, M.G.; Ponomaryov, A.V.; Derevets, V.V.; Nazarov, A.B.

2003-01-01

For past 17 years after accident the character of radioactive contamination of water objects within the Chernobyl NPP exclusion zone has undergone essential changes. First of all it connected with realisation on a wide area of deactivation works, and also with transformation of radioactive substances in water-soil systems. Besides, during 1991-95 the complex of hydraulic engineering structures as protection dams, interfering washing away of radioactive substances from soils of the left-bank catchment basin and changed a hydrological regime of these territories during a high water, was constructed. The levels of radionuclide contamination of water objects within the Chernobyl NPP exclusion zone was rather stabilised. Due to high water change rate the river bottom sediments have undergone decontamination processes (especially during floods and periods of high water) and over the years have ceased to play the essential role as a secondary source of water contamination. On the other hand, the closed reservoirs have considerably higher levels of radioactive contamination caused by limited water change and by relatively high concentration of radionuclides deposited in the bottom sediments. Therefore, for the majority of standing reservoirs the level of radionuclide content is determined mainly by the rates of mobile radionuclide forms exchange between bottom sediment and water, as well as by the external washout from the catchment basin. In this paper will be considered: (1) the latest data on radionuclide content (Sr-90, Cs-137, Pu-238, Pu-239+240 and Am-241) and dynamics in water, seston, bottom sediments and hydrobionts of different trophic levels and ecological groups; (2) the peculiarities of formation of vegetative communities from lakes within embankment territory of Pripyat River flood-lands and its impact on radionuclide redistribution in aquatic ecosystems; (3) the major hydrochemical factors, which determine the behaviour of radionuclides in the aquatic

Radioactive contamination of honey and other bee-keeping products

International Nuclear Information System (INIS)

Frantsevich, L.I.; Komissar, A.D.; Levchenko, I.A.

1990-01-01

Great amount of dust is collected in propolis under emergency atmospheric fallouts. Specific coefficient of the product migration amounts to several m 2 per 1 kg. Propolis is a good biological indicator of radioactive fallouts. The propolis collection is inadmissible after radioactive fallouts. Cocoon residuals obtained during bees-wax separation contain many radionuclides and should be disposed in special places. Nuclides are absent in bees-wax. Nuclides accumulated absent in a bee organism migrate into honey and queen milk, the honey is contaminated mainly via biogenic path

Development of automatic smear testing sampler for radioactive contamination of floor in nuclear power plant

International Nuclear Information System (INIS)

Nozawa, Katsuro; Hashimoto, Hiroshi; Shinohara, Yohtaro; Iwaki, Kiyotaka

1980-01-01

The floor contamination with radioactive substances in the controlled area of nuclear power stations is strictly controlled, and it is tested by the smear method, wiping the contaminants on floors with filter papers or cloths and measuring the radioactive intensity to obtain contamination density. The works are very laborious, therefore the automatic smear sampler was developed. Simple operation, shortening of time required for wiping, constant and high efficiency of wiping, and easy numbering of samples were the aims in the development. The method of wiping, the mechanisms of wiping, cloth feeding and running, the surface pressure at the time of wiping, the number of times of wiping and required motor torque were studied. The outline of the developed sampler is explained. The performance of the sampler was compared with manual wiping. The efficiency of wiping with the sampler was 92%, assuming manual wiping as 100. Difference was not observed between careful manual wiping and the wiping with the sampler, therefore it was confirmed that this automatic floor smear sampler can be put in practical use. By conventional manual sampling, the maximum limit was about 400 samples/man-day, but when this sampler is used, about 1000 samples/sampler-day is possible. At present, this sampler is operated in Hamaoka Nuclear Power Station. (Kako, I.)

Protection against radioactive contamination of foods and agricultural products

International Nuclear Information System (INIS)

Szabo, A.; Kovacs, Z.

1977-01-01

Methods suitable for diminishing radioactive contamination of foods and agricultural products and reducing at the same time the irradiation hazards for the human organism are dealt with. The possibilities for the decontamination of foods vegetal and of animal origin are discussed separately. (author)

Studies on the remediation of environment contaminated with radioactive pollutants using the chemical separation technique

Energy Technology Data Exchange (ETDEWEB)

Kurotaki, Katsumi; Yonehara, Hidenori; Sahoo, S.K. [National Inst. of Radiological Sciences, Chiba (Japan); Ishii, Toshiaki [National Inst. of Radiological Sciences, Hitachinaka, Ibaraki (Japan). Lab. for Radioecology

2001-12-01

Remediation of soil and drinking water contaminated with radioactive nuclides is important for the mitigation of radiation exposure. Then we attempted to construct the remediation system including the dose estimation system using the chemical separation technique to remove pollutants from the environment. The information on air dose rate is important for assessment of risk from the radiation exposure. Then we measured the air dose rate and analysed the relationship between air dose rate and the contamination of soil at the area in Russia (Bryansk district) contaminated by Chernobyl Nuclear Power Plant accident. Moreover, we analysed the soil of Bryansk district on the concentration of rare earth elements, thorium and uranium and on the isotope ratio of strontium. On the other hand, we tried to develop the rapid measurement method of radioactivity of Sr-90 which is one of the dangerous radionuclides, because the method of radioactivity measurement in the literature is too time-consuming. It was reported recently that the molecules containing SH group form the covalent bond with gold atoms at the surface of gold plate and that crown ether compounds have strong affinity to strontium. Then we attempted to synthesize the crown ether containing SH group. In addition, we search the inorganic elements accumulated to special organisms of fishes and other animals in sea in order to find out new reagent for trace elements. Transition metal such as Co, Fe, Ni, Ti, V and Zn were detected from the intracellular granules in the bronchial heart of octopus. (author)

The consequences of radioactive contamination of forest ecosystems due to Chernobyl accident

International Nuclear Information System (INIS)

Tikhomirov, F.A.; Shcheglova, A.I.

1997-01-01

The effect of forests on the radionuclide primary distribution in different components of the contaminated ecosystems is considered by the example of Chernobyl accident. A basic mathematical model is developed describing 137 Cs biogeochemical cycling under conditions of quasi-steady state radionuclide redistribution in the ecosystem. Forest ecosystems are proved to diminish radionuclide migration in the environment, and forest should be regarded as an important sanitary factor. The contribution of contaminated forests and forest products to the total irradiation dose to local population is estimated. Special countermeasures are elaborated in order to diminish unfavorable consequences of forest radioactive contamination. A long-term dynamics of radioactive situation in the forest ecosystems in forecasted and further studies on the subject are drafted

PROCESS OF DECONTAMINATING MATERIAL CONTAMINATED WITH RADIOACTIVITY

Science.gov (United States)

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

1958-09-16

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

Beta Autoradiography. An analytical technique to investigate radionuclides contamination on surface

International Nuclear Information System (INIS)

Ficher, P.; Goutelard, F.; Siitari-Kauppi, M.

2012-01-01

In decommissioning of old buildings and after disposal of nuclear facilities (materials, glove boxes,...), the inventory of the radioactive contamination of various building materials needs to be obtained in order to fix the working condition for dismantling. The challenge of this study was to classify different building materials of a whole research laboratory that was dedicated to research on organic molecules labeled with H-3 and C-14. The problem of waste classification is essential for safety treatment of waste and also for its cost. The analytical technique of beta autoradiography particularly well known for biological researches has been tested to investigate radionuclides contamination on surface. This technique is mainly interesting for beta and alpha emitters but also sensitive to gamma radiation. The first step of this technique is the deposit of a film on the surface of material to be analyzed. Films can be deposited on the ground or also fixed on the walls or even on the ceiling. The film is a plastic sheet covered with an emulsion containing photostimulable crystals and Eu that is activated when the film is exposed on radioactive source. The exposed films are then scanned with the Cyclone Plus equipment to get a digitized image. This image represents the radioactivity of the surface studied. The possibility to re-use the films is very important to investigate a large area. This autoradiography technique has retained our attention for its sensitivity and moreover the possibility of 2-dimensional investigation has been found as a real advantage. However it remains now as a qualitative technique and new studies must be launched to prove its quantitative potentialities. The high spatial resolution was not as important as in biological observation, and the mm resolution is totally sufficient

Measures to detect and control radioactive contaminated metallurgical scrap at border checkpoints in Poland

International Nuclear Information System (INIS)

Smagala, G.

1999-01-01

The issue of radioactive contaminated metallurgical scrap has never received a high priority in Poland and in the international community. Since the dissolution of the former Soviet Union a higher attention has been given to the problem. Poland which is located between the West and East Europe has the obligation to develop and implement an effective prevention and detection system. The reasons to increase national control and detection system at the border checkpoints in Poland are to avoid the following risks: post Chernobyl contamination transports of commodities; transport of contaminated metal scrap; transfer of radioactive waste for their disposal or utilization; high risk of becoming a transit country of illicit trafficking of nuclear materials and radioactive sources. In order to avoid the above-mentioned risks, Poland initiated in 1990, a deployment of the portable radiation devices at the border checkpoints and, as of 1998, the number of installed instruments exceeded a hundred. This paper presents Poland's activities to detect contaminated scrap at its border checkpoints. (author)

Method of burning ion-exchange resin contaminated with radioactivity

International Nuclear Information System (INIS)

Suzuki, Shigenori.

1986-01-01

Purpose: To process spent ion exchange resins to reduce their volume, without increasing the load on a off-gas system and in a stable state and at the same time not leaving any uncombusted portions. Method: The water slurries of the ion exchange resins contaminated with radioactive materials is dehydrated or dry combusted to reduce the water content. A binder is then added to solidify the ion exchange resin. The solidified ion exchange resins are then combusted in a furnace. This prevents the ion exchange resin from being dispersed by air and combustion gases. Furthermore, the solidified ion exchange resins in the form of small pellets burn from the surface inwards. Moreover the binder is carbonized by the combustion heat and promotes combustion to convert the ion exchange resins into a solid mass, making sure that no uncombusted portion is left. (Takahashi, M.)

Radioactive food and environment contamination

International Nuclear Information System (INIS)

Yousif, A.M.

2001-01-01

The Food and Environment Control Centre of Abu Dhabi Municipality with the help of IAEA has established facilities for regular monitoring of food and environmental samples for radioactive contamination. The Centre is now capable of measuring gamma, beta as well as alpha activity in different types of samples. The main activities in the area of food monitoring are as follows: General monitoring of food gamma radionuclides in foodstuffs by high resolution gamma spectrometry; Determination of specific gamma radionuclides in foodstuffs by high resolution gamma spectrometry; Radiochemical determination of Sr-90 using liquid scintillation analyzer or by gas flow proportional counter; Measurement of gross alpha activity in drinking water

Radioactive contamination, what actions for the polluted sites

International Nuclear Information System (INIS)

2004-01-01

The nuclear safety authority and the direction of prevention of pollutions and risks have organised the first edition of the national colloquium: radioactive contamination: what actions for polluted sites. Four axes can be taken to follow this colloquium: prevention, outstanding tools to evaluate risks and rehabilitation, a better responsibility of operators and memory keeping. (N.C.)

Assessment of sites concerning radioactive contamination during preparation of a Contamination Site Register; Bewertung der radiologischen Altlastenrelevanz von gewerblichen und industriellen Standorten

Energy Technology Data Exchange (ETDEWEB)

Gellermann, Rainer [Nuclear Control and Consulting GmbH, Braunschweig (Germany); Flesch, Klaus [Saechsisches Landesamt fuer Umwelt, Landwirtschaft und Geologie (LfULG), Dresden (Germany)

2014-07-01

Experience gained since 1990 in the new, but also old German Federal States has shown that there are radioactive contaminated sites beside the legacies of uranium mining in Germany which caused exposures exceeding the radiation protection limits for members of the public. The reason for this situation is that radioactivity has been excluded in the compilation of the register for potentially hazardous sites that are prepared routinely in the context of soil protection assessments. Moreover, the information contained in these registers is not yet evaluated regarding aspects of radioactivity. In many cases, the information existing at the soil protection authorities needs only to be additionally filtered in order to identify potentially hazardous sites for radioactive contamination. For that reason, the working group ''Natural radioactivity'' (AKNAT) of the German-Swiss Radiation Protection Association developed a specific catalogue of business branches that provides indications for radioactive legacies.

Vitrification of radioactive contaminated soil by means of microwave energy

Science.gov (United States)

Yuan, Xun; Qing, Qi; Zhang, Shuai; Lu, Xirui

2017-03-01

Simulated radioactive contaminated soil was successfully vitrified by microwave sintering technology and the solidified body were systematically studied by Raman, XRD and SEM-EDX. The Raman results show that the solidified body transformed to amorphous structure better at higher temperature (1200 °C). The XRD results show that the metamictization has been significantly enhanced by the prolonged holding time at 1200 °C by microwave sintering, while by conventional sintering technology other crystal diffraction peaks, besides of silica at 2θ = 27.830°, still exist after being treated at 1200 °C for much longer time. The SEM-EDX discloses the micro-morphology of the sample and the uniform distribution of Nd element. All the results show that microwave technology performs vitrification better than the conventional sintering method in solidifying radioactive contaminated soil.

Dating of oilfield contamination by Natural Occurring Radioactive Materials (NORM) using isotopic ratios

International Nuclear Information System (INIS)

Al-Masri, M. S.; Othman, I.; Aba, A.

2008-05-01

In the present work, the possibility of using radium isotope ratios (226, 224, 228) for dating of NORM contaminated sites in the oilfields due to uncontrolled disposal of produced water into the environmental NORM contaminated soil sample were collected from different locations in Syrian Oilfields and radioactivity analysed. In addition, production water samples were collected and analysed to determine the isotopes ratios of the naturally occurring radioactive materials. The results have shown that the 228 Ra/ 226 Ra can be successfully used to date contaminated soil provided that this ratio is determined in production water. Moreover, the 210 Pb/ 226 Ra activity ratios was used for the first time for dating of contaminated soil where all factors affecting the method application have been evaluated. Furthermore, the obtained results for dating using the three methods were compared with the actual contamination dates provided by the oil companies. (Authors)

Secondary radioactive contamination of the Black Sea after Chernobyl accident: recent levels, pathways and trends

International Nuclear Information System (INIS)

Gulin, S.B.; Mirzoyeva, N.Yu.; Egorov, V.N.; Polikarpov, G.G.; Sidorov, I.G.; Proskurnin, V.Yu.

2013-01-01

The recent radionuclide measurements have showed that concentrations of the Chernobyl-derived 137 Cs and 90 Sr in the surface Black Sea waters are still relatively high, reaching 56 and 32 Bq m −3 , respectively. This is comparable or even exceeds the pre-Chernobyl levels (∼16 Bq 137 Cs and 22 Bq 90 Sr per m 3 as the basin-wide average values). The measurements have revealed that the Black Sea continues to receive Chernobyl radionuclides, particularly 90 Sr, by the runoff from the Dnieper River. An additional source of 90 Sr and 137 Cs was found in the area adjacent to the Kerch Strait that connects the Black Sea and the Sea of Azov. This may be caused by the inflow of the contaminated Dnieper waters, which come to this area through the North-Crimean Canal. The long-term monitoring of 137 Cs and 90 Sr concentration in the Black Sea surface waters and in the benthic brown seaweed Cystoseira sp., in comparison with the earlier published sediment records of the radionuclides, have showed signs of a secondary radioactive contamination, which has started to increase since the late 1990's. This may be the result of the combined effect of a higher input of radionuclides from the rivers in 1995–1999 due to an increased runoff; and a slow transport of the particulate bound radionuclides from the watersheds followed by their desorption in seawater from the riverine suspended matter and remobilization from the sediments adjacent to the river mouths. -- Highlights: • Concentration of 137 Cs and 90 Sr in the Black Sea water is still relatively high. • The Black Sea continues to receive considerable radionuclide amount from the rivers. • The North-Crimean Canal is significant source of the Black Sea radioactivity. • Secondary radioactive contamination of the Black Sea increased in the late 1990's. • Radionuclide remobilization from sediments leads to a further Black Sea pollution

Dispersal of radioactivity by wildlife from contaminated sites in a forested landscape

Energy Technology Data Exchange (ETDEWEB)

Garten, C.T. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

1995-12-31

Oak Ridge National Laboratory (ORNL) is located within the Valley and Ridge Physiographic Province of eastern Tennessee (USA). Wildlife populations have access to some radioactively contaminated sites at ORNL. Contaminated animals or animal nests within the Laboratory`s boundaries have been found to contain {sup 90}Sr or {sup 137}Cs on the order of 10{sup -2}-10{sup 4} Bq g{sup -1} and trace amounts of other radionuclides (including transuranic elements). Animals that are capable of flight and animals with behaviour patterns or developmental life stages involving contact with sediments in radioactive ponds, like benthic invertebrates, present the greatest potential for dispersal of radioactivity. The emigration of frogs and turtles from waste ponds also presents a potential for dispersal of radioactivity but over distances < 5 km. Mud-dauber wasps (Hymenoptera) and swallows (Hirundinidae) may transport radioactive mud for nest building, but also over relatively short distances (0.2-1 km). Movement by small mammals is limited by several factors, including physical barriers and smaller home ranges. Larger animals, like white-tailed deer (Odocoileus virginianus) are potential vectors of radioactivity due to their greater body size, longer life expectancy, and larger home range. Larger animals contain greater amounts of total radioactivity than smaller animals, but tissue concentrations of {sup 137}Cs generally decline with body size. (author).

Phytoremediation options for radioactively contaminated sites evaluated

International Nuclear Information System (INIS)

Vandenhove, Hildegarde

2013-01-01

Highlights: ► We present an overview of the most important site and environmental radioactive contamination problems encountered. ► The potential role of different phytomanagement options is discussed and illustrated with examples. ► The phytomanagement options considered are: soil phytoextraction, rhizofiltration, wetlands and alternative land use. - Abstract: The application of nuclear energy and the use of radionuclides for industrial, medical and research purposes have caused significant contamination of certain sites and their environment, which could result in health problems for several centuries if nothing is undertaken to remedy these situations. Except for the immediate environment of the facility, where decontamination activities may be feasible and affordable, the contamination often extents over a vast area and decontamination would be costly and could result in vast amounts of waste. Therefore, more realistic yet efficient remediation options should be searched for of which phytomanagement is among the potential options. A number of phytomanagement approaches will be discussed

Comparative study between radioactive contamination in milk powder by chernobyl accident [137Cs] and natural radioactivity [40K

International Nuclear Information System (INIS)

Navarrete, J.M.; Martinez, T.; Cabrera, L.

2005-01-01

After the Chernobyl accident in 1986, Mexico imported from an European country 28,000 Tons of contaminated milk powder with the fission product 137 CS. When the contamination was detected, the alarm among the authorities and population spread out very quick and of course the product was retired at once from the foodstuff market. Nevertheless, the public panic grew up in such a manner, that even the way to manage and to dispose safely this material, considered highly dangerous, was largely discussed. Now, about two decades ago from this event, a study has been performed to compare the level of radioactivity due to both radioisotopes present in one saved sample: the artificial contaminant 137 CS, beside the natural, all around present 40 K, in order to evaluate in a more realistic way how risky was the management, possible consumption, and final disposition of this nourishment. This paper considers results obtained within an uncertainty degree equal to ±5%, and set up conclusions by comparing artificial and natural radioactivity present in that contaminated milk powder.

On-site radioactive soil contamination at the Andreeva Bay shore technical base, Northwest Russia

NARCIS (Netherlands)

Reistad, O.; Dowdall, M.; Selnaes, O. G.; Standring, W. J. F.; Hustveit, S.; Steenhuisen, F.; Sorlie, A.

The radioactive waste (RAW) storage site at Andreeva Bay in the Russian Northwest has experienced radioactive contamination both as a result of activities carried out at the site and due to incidents that have occurred there in the past such as accidental releases of radioactive materials. The site

Dispersal of radioactivity by wildlife from contaminated sites in a forested landscape

International Nuclear Information System (INIS)

Garten, C.T. Jr.

1992-01-01

Oak Ridge National Laboratory (ORNL) is located within the Ridge and Valley physiographic province of eastern Tennessee (USA). This area is characterized by deciduous forests dominated by hardwood and mixed mesophytic tree species. Wildlife populations have access to some radioactively contaminated sites at ORNL, and contaminated animals or animal nests within the Laboratory's boundaries have been found to contain on the order of 10 -12 to 10 -6 Ci/g of 90 Sr or 137 Cs, and trace amounts of other radionuclides (including transuranic elements). Theoretical calculations indicate that nanocurie levels of 90 Sr in bone can arise from relatively small amounts (1%) of contaminated browse vegetation in a deer's diet. Measures that have been undertaken at ORNL to curtail the dispersal of radioactivity by animals are briefly reviewed

Methods for the calculation of derived working limits for surface contamination by low-toxicity radionuclides

International Nuclear Information System (INIS)

Gibson, J.A.B.; Wrixon, A.D.

1979-01-01

Surface contamination is often measured as an indication of the general spread of radioactive contamination in a particular place. Derived working limits, (DWLs) for surface contamination provide figures against which to assess the significance of measurements. Derived working limits for surface contamination were first established for use in the nuclear energy industry. They were designed to cope with a wide range of unspecified radionuclides and were therefore based on the assumption that the contamination was due to the presence of the most hazardous radionuclides, e.g. 90 Sr, 210 Pb, 226 Ra and 239 Pu. While this assumption may still be appropriate when the radionuclide mixture is unknown, there are now many specialized uses of particular low-toxicity radionuclides in universities, hospitals and general industry. If it is known that only a particular radionuclide is present, the general DWL can be replaced by a more specific value. The methods for calculating DWLs for some of the more commonly employed low-toxicity radionuclides are described. The exposure pathways considered are (a) external radiation of the skin and inhalation of airborne material from contaminated surfaces in active areas; (b) external irradiation of the skin and ingestion from contaminated skin. Some consideration is given to the effect of the revised dose equivalent limits in the most recent recommendations of ICRP. (author)

Radioactive substance solidifying device

International Nuclear Information System (INIS)

Sakoda, Kotaro.

1979-01-01

Purpose: To easily solidify radioactive substances adhering to the surfaces of solid wastes without scattering in the circumference by paints, and further to reduce surface contamination concentrations. Constitution: Solid wastes are placed on a hanging plate, and dipped in paints within a paint dipping treatment tank installed at the lower part of a treatment tank by means of a monorail hoist, and the surfaces of said solid wastes are coated with paints, thereby to solidify the radioactivity on the surfaces of the solid wastes. After dipping, the solid wastes are suspended up to a paint spraying tank to dry the paints. After drying, non-contaminated paints are atomized to apply through an atomizing tube onto the solid wastes. After drying the atomized paints, the solid wastes are carried outside the treatment tank by means of the monorail hoist. (Yoshino, Y.)

Microwave/vacuum drying treatment of radioactively contaminated animal carcasses

International Nuclear Information System (INIS)

Chen Zongming; Zhang Yinsheng; Teng Hongdi; Zhu Chongde; Ge Lixin; Wang Jinliang

1994-01-01

The paper describes a microwave/vacuum drying process for the treatment of radioactively contaminated animal carcasses. The experiment demonstrated the feasibility of the process. The treatment process could completely remove the water from carcasses and effectively extend the preservation period. No radiological impact was found on workplace and environment

Radioactive contamination status of an elementary school in southern Miyagi Prefecture, Japan, four years after decontamination

International Nuclear Information System (INIS)

Yamaguchi, Toshiro; Sato, Mitsuyoshi; Nagakubo, Kazuyoshi

2017-01-01

We investigated the radioactive contamination status of an elementary school in southern Miyagi Prefecture, Japan, four years after decontamination. The radioactive dose rate was measured in the playground (n = 36), back yard (n = 1), parking lot (n = 3), and gutters (n = 30) with a thallium-activated sodium iodide scintillation detector. In addition, topsoil from the playground and gutters sediment were measured with a high-purity germanium semiconductor detector, and sand from the parking lot and sediment from gutters was imaged following an autoradiography method. The mean radioactive dose rate in the playground was almost 0.08 μSv/h. The dose rate was higher at sites facing the mountains, near the main gate, and by the front entrance of the school building. Meanwhile, the radioactive cesium (Cs) concentration of sediment imaged using autoradiography was > 8,000 Bq/kg. These results indicated that the radioactive dose rates in the decontaminated school were below the threshold for being a health hazard. However, the topsoil in the playground had been re-contaminated with radioactive Cs, which had likely been transported via dirt attached to children's shoes and car tires. In addition, the radioactive sediment in the gutters had likely been contaminated by rainwater, suggesting that radioactive protection is necessary when handling gutter sediment. (author)

Internal radioactive contamination in selected groups of CRNL employees

International Nuclear Information System (INIS)

Evans, D.W.S.

1975-10-01

This report details the development and execution of a 30 month program designed to characterize the magnitude and distribution of internal radioactive contaminaton amongst selected groups of employees at Chalk River Nuclear Laboratories, using a shadow shield whole-body counter. The results show that the levels of contamination in these employees are very low, and no contaminant was present in amounts exceeding 10% of the maximum permissible body burden, with the exception of a medically administered radionuclide (selenium-75). Details of the time course of some of the body burdens are also furnished. (author)

Mathematical Modeling of Non-Fickian Diffusional Mass Exchange of Radioactive Contaminants in Geological Disposal Formations

Directory of Open Access Journals (Sweden)

Anna Suzuki

2018-01-01

Full Text Available Deep geological repositories for nuclear wastes consist of both engineered and natural geologic barriers to isolate the radioactive material from the human environment. Inappropriate repositories of nuclear waste would cause severe contamination to nearby aquifers. In this complex environment, mass transport of radioactive contaminants displays anomalous behaviors and often produces power-law tails in breakthrough curves due to spatial heterogeneities in fractured rocks, velocity dispersion, adsorption, and decay of contaminants, which requires more sophisticated models beyond the typical advection-dispersion equation. In this paper, accounting for the mass exchange between a fracture and a porous matrix of complex geometry, the universal equation of mass transport within a fracture is derived. This equation represents the generalization of the previously used models and accounts for anomalous mass exchange between a fracture and porous blocks through the introduction of the integral term of convolution type and fractional derivatives. This equation can be applied for the variety of processes taking place in the complex fractured porous medium, including the transport of radioactive elements. The Laplace transform method was used to obtain the solution of the fractional diffusion equation with a time-dependent source of radioactive contaminant.

Methodological guide: management of industrial sites potentially contaminated by radioactive substances; Guide methodologique: gestion des sites industriels potentiellement contamines par des substances radioactives

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

At the request of the Ministries of Health and the Environment, IPSN is preparing and publishing the first version of the methodological guide devoted to managing industrial sites potentially contaminated by radioactive substances. This guide describes a procedure for defining and choosing strategies for rehabilitating such industrial sites. (author)

Radioactive Waste Management and Environmental Contamination Issues at the Chernobyl Site

International Nuclear Information System (INIS)

Napier, Bruce A.; Schmieman, Eric A.; Voitsekhovitch, Oleg V.

2007-01-01

The destruction of the Unit 4 reactor at the Chernobyl Nuclear Power Plant resulted in the generation of radioactive contamination and radioactive waste at the site and in the surrounding area (referred to as the Exclusion Zone). In the course of remediation activities, large volumes of radioactive waste were generated and placed in temporary near surface waste-storage and disposal facilities. Trench and landfill type facilities were created from 1986 to 1987 in the Chernobyl Exclusion Zone at distances 0.5 to 15 km from the NPP site. This large number of facilities was established without proper design documentation, engineered barriers, or hydrogeological investigations and they do not meet contemporary waste-safety requirements. Immediately following the accident, a Shelter was constructed over the destroyed reactor; in addition to uncertainties in stability at the time of its construction, structural elements of the Shelter have degraded as a result of corrosion. The main potential hazard of the Shelter is a possible collapse of its top structures and release of radioactive dust into the environment. A New Safe Confinement (NSC) with a 100-years service life is planned to be built as a cover over the existing Shelter as a longer-term solution. The construction of the NSC will enable the dismantlement of the current Shelter, removal of highly radioactive, fuel-containing materials from Unit 4, and eventual decommissioning of the damaged reactor. More radioactive waste will be generated during NSC construction, possible Shelter dismantling, removal of fuel containing materials, and decommissioning of Unit 4. The future development of the Exclusion Zone depends on the future strategy for converting Unit 4 into an ecologically safe system, i.e., the development of the NSC, the dismantlement of the current Shelter, removal of fuel containing material, and eventual decommissioning of the accident site. To date, a broadly accepted strategy for radioactive waste

Radioactive waste management and environmental contamination issues at the Chernobyl site.

Science.gov (United States)

Napier, B A; Schmieman, E A; Voitsekovitch, O

2007-11-01

The destruction of the Unit 4 reactor at the Chernobyl Nuclear Power Plant resulted in the generation of radioactive contamination and radioactive waste at the site and in the surrounding area (referred to as the Exclusion Zone). In the course of remediation activities, large volumes of radioactive waste were generated and placed in temporary near-surface waste storage and disposal facilities. Trench and landfill type facilities were created from 1986-1987 in the Chernobyl Exclusion Zone at distances 0.5-15 km from the nuclear power plant site. This large number of facilities was established without proper design documentation, engineered barriers, or hydrogeological investigations and they do not meet contemporary waste-safety requirements. Immediately following the accident, a Shelter was constructed over the destroyed reactor; in addition to uncertainties in stability at the time of its construction, structural elements of the Shelter have degraded as a result of corrosion. The main potential hazard of the Shelter is a possible collapse of its top structures and release of radioactive dust into the environment. A New Safe Confinement (NSC) with a 100 y service life is planned to be built as a cover over the existing Shelter as a longer-term solution. The construction of the NSC will enable the dismantlement of the current Shelter, removal of highly radioactive, fuel-containing materials from Unit 4, and eventual decommissioning of the damaged reactor. More radioactive waste will be generated during NSC construction, possible Shelter dismantling, removal of fuel-containing materials, and decommissioning of Unit 4. The future development of the Exclusion Zone depends on the future strategy for converting Unit 4 into an ecologically safe system, i.e., the development of the NSC, the dismantlement of the current Shelter, removal of fuel-containing material, and eventual decommissioning of the accident site. To date, a broadly accepted strategy for radioactive waste

Radioactive waste and contamination in the former Soviet Union

International Nuclear Information System (INIS)

Suokko, K.; Reicher, D.

1993-01-01

Decades of disregard for the hazards of radioactive waste have created contamination problems throughout the former Soviet Union rivaled only by the Chernobyl disaster. Although many civilian activities have contributed to radioactive waste problems, the nuclear weapons program has been by far the greatest culprit. For decades, three major weapons production facilities located east of the Ural Mountains operated in complete secrecy and outside of environmental controls. Referred to until recently only by their postal abbreviations, the cities of Chelyabinsk-65, Tomsk-7, and Krasnoyarsk-26 were open only to people who worked in them. The mismanagement of waste at these sites has led to catastrophic accidents and serious releases of radioactive materials. Lack of public disclosure, meanwhile, has often prevented proper medical treatment and caused delays in cleanup and containment. 5 refs

Strategies for the management of radioactively contaminated sites

International Nuclear Information System (INIS)

Butter, K. R.; Fellingham, L. R.; Holdroyd, S. D.; Smith-Briggs, J. L.

1997-01-01

The rehabilitation of radioactively contaminated land is a small but growing field of activity. Worldwide the activity has been dominated by the rehabilitation of uranium mining and milling sites and areas affected by major nuclear accidents, such as Chernobyl and Khystym. To date most of the sites in or associated with the UK have been small in scale and have generally involved natural radionuclides. However, with the decommissioning of large areas of many old nuclear industry sites and those associated with the development and production of nuclear weapons and the operations of nuclear submarines, the scale of these operations is set to rise very significantly. This paper addresses key considerations in managing the rehabilitation of radioactively contaminated sites. It illustrates their significance through examples ranging in scale from a few hectares to tens of thousands of square kilometres. The first example deals with a former waste storage and processing area at Harwell Laboratory. The second covers a risk reduction rehabilitation programme at the former British nuclear weapons test site at Maralinga in Australia. The third assesses the potential for cost-effective countermeasures to reduce aggregate doses received outside the 30 km exclusion zone around the Chernobyl nuclear reactor site

Behavior of radioactive cesium during incineration of radioactively contaminated wastes from decontamination activities in Fukushima.

Science.gov (United States)

Fujiwara, Hiroshi; Kuramochi, Hidetoshi; Nomura, Kazutaka; Maeseto, Tomoharu; Osako, Masahiro

2017-11-01

Large volumes of decontamination wastes (DW) generated by off-site decontamination activities in Fukushima Prefecture have been incinerated since 2015. The behavior of radioactive cesium during incineration of DW was investigated at a working incineration plant. The incineration discharged bottom ash (BA) and fly ash (FA) with similar levels of radiocesium, and the leachability of the radiocesium from both types of ash was very low (incineration of contaminated municipal solid waste (CMSW) reported in earlier studies. The source of radiocesium in DW-FA is chiefly small particles derived from DW and DW-BA blown into the flue gas, not the deposition of gaseous synthesized radiocesium compounds on the surfaces of ash particles in the flue gas as observed in CMSW incineration. This source difference causes the behavior of radiocesium during waste incineration to differ between DW and CMSW. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of apparatus for surveying uranium surface contamination quantity

International Nuclear Information System (INIS)

Wang Qingheng; Han Jingquan

1994-11-01

An apparatus for measuring uranium contamination of the surface of reactor plate component is described. The searching unit of the apparatus is a large surface multi-wire proportional counter. The cathode of the counter is made of stainless steel with low radioactive background, the window is made of film which is plated with aluminum about 6 μm; and the anode is mad by gild tungsten wire of 0.025 mm diameter. The sensitive area of the counter is 1113 mm x 100 mm. It has been shown that the intrinsic radioactive background of the apparatus is 0.002 cpm/cm 2 (2 count/min). The detecting efficiency is 67% for enriched uranium source (2π solid angle). The stability is 0.84% within 24 hour (including detector, high voltage power supply, amplifier, discriminator, computer, type and display system). The lower detection limit of the apparatus is 4.6 x 10 -10 g/cm 2 (for 20% 235 U, 0.13% 234 U, 79.64% 238 U). The apparatus can present timing by a computer controlling, and it also has the following functions: displaying, automatic alarming, classifying and typing the results. (2 tabs., 7 figs.)

Understanding Contamination; Twenty Years of Simulating Radiological Contamination

Energy Technology Data Exchange (ETDEWEB)

Emily Snyder; John Drake; Ryan James

2012-02-01

A wide variety of simulated contamination methods have been developed by researchers to reproducibly test radiological decontamination methods. Some twenty years ago a method of non-radioactive contamination simulation was proposed at the Idaho National Laboratory (INL) that mimicked the character of radioactive cesium and zirconium contamination on stainless steel. It involved baking the contamination into the surface of the stainless steel in order to 'fix' it into a tenacious, tightly bound oxide layer. This type of contamination was particularly applicable to nuclear processing facilities (and nuclear reactors) where oxide growth and exchange of radioactive materials within the oxide layer became the predominant model for material/contaminant interaction. Additional simulation methods and their empirically derived basis (from a nuclear fuel reprocessing facility) are discussed. In the last ten years the INL, working with the Defense Advanced Research Projects Agency (DARPA) and the National Homeland Security Research Center (NHSRC), has continued to develop contamination simulation methodologies. The most notable of these newer methodologies was developed to compare the efficacy of different decontamination technologies against radiological dispersal device (RDD, 'dirty bomb') type of contamination. There are many different scenarios for how RDD contamination may be spread, but the most commonly used one at the INL involves the dispersal of an aqueous solution containing radioactive Cs-137. This method was chosen during the DARPA projects and has continued through the NHSRC series of decontamination trials and also gives a tenacious 'fixed' contamination. Much has been learned about the interaction of cesium contamination with building materials, particularly concrete, throughout these tests. The effects of porosity, cation-exchange capacity of the material and the amount of dirt and debris on the surface are very important factors

Radioactive waste disposal implications of extending Part IIA of the Environmental Protection Act to cover radioactively contaminated land.

Science.gov (United States)

Nancarrow, D J; White, M M

2004-03-01

A short study has been carried out of the potential radioactive waste disposal issues associated with the proposed extension of Part IIA of the Environmental Protection Act 1990 to include radioactively contaminated land, where there is no other suitable existing legislation. It was found that there is likely to be an availability problem with respect to disposal at landfills of the radioactive wastes arising from remediation. This is expected to be principally wastes of high volume and low activity (categorised as low level waste (LLW) and very low level waste (VLLW)). The availability problem results from a lack of applications by landfill operators for authorisation to accept LLW wastes for disposal. This is apparently due to perceived adverse publicity associated with the consultation process for authorisation coupled with uncertainty over future liabilities. Disposal of waste as VLLW is limited both by questions over volumes that may be acceptable and, more fundamentally, by the likely alpha activity of wastes (originating from radium and thorium operations). Authorised on-site disposal has had little attention in policy and guidance in recent years, but may have a part to play, especially if considered commercially attractive. Disposal at BNFL's near surface disposal facility for LLW at Drigg is limited to wastes for which there are no practical alternative disposal options (and preference has been given to operational type wastes). Therefore, wastes from the radioactively contaminated land (RCL) regime are not obviously attractive for disposal to Drigg. Illustrative calculations have been performed based on possible volumes and activities of RCL arisings (and assuming Drigg's future volumetric disposal capacity is 950,000 m3). These suggest that wastes arising from implementing the RCL regime, if all disposed to Drigg, would not represent a significant fraction of the volumetric capacity of Drigg, but could have a significant impact on the radiological

Radioactive waste disposal implications of extending Part IIA of the Environmental Protection Act to cover radioactively contaminated land

International Nuclear Information System (INIS)

Nancarrow, D J; White, M M

2004-01-01

A short study has been carried out of the potential radioactive waste disposal issues associated with the proposed extension of Part IIA of the Environmental Protection Act 1990 to include radioactively contaminated land, where there is no other suitable existing legislation. It was found that there is likely to be an availability problem with respect to disposal at landfills of the radioactive wastes arising from remediation. This is expected to be principally wastes of high volume and low activity (categorised as low level waste (LLW) and very low level waste (VLLW)). The availability problem results from a lack of applications by landfill operators for authorisation to accept LLW wastes for disposal. This is apparently due to perceived adverse publicity associated with the consultation process for authorisation coupled with uncertainty over future liabilities. Disposal of waste as VLLW is limited both by questions over volumes that may be acceptable and, more fundamentally, by the likely alpha activity of wastes (originating from radium and thorium operations). Authorised on-site disposal has had little attention in policy and guidance in recent years, but may have a part to play, especially if considered commercially attractive. Disposal at BNFL's near surface disposal facility for LLW at Drigg is limited to wastes for which there are no practical alternative disposal options (and preference has been given to operational type wastes). Therefore, wastes from the radioactively contaminated land (RCL) regime are not obviously attractive for disposal to Drigg. Illustrative calculations have been performed based on possible volumes and activities of RCL arisings (and assuming Drigg's future volumetric disposal capacity is 950 000 m 3 ). These suggest that wastes arising from implementing the RCL regime, if all disposed to Drigg, would not represent a significant fraction of the volumetric capacity of Drigg, but could have a significant impact on the radiological

Contamination analysis unit

International Nuclear Information System (INIS)

Gregg, H.R.; Meltzer, M.P.

1996-01-01

The portable Contamination Analysis Unit (CAU) measures trace quantities of surface contamination in real time. The detector head of the portable contamination analysis unit has an opening with an O-ring seal, one or more vacuum valves and a small mass spectrometer. With the valve closed, the mass spectrometer is evacuated with one or more pumps. The O-ring seal is placed against a surface to be tested and the vacuum valve is opened. Data is collected from the mass spectrometer and a portable computer provides contamination analysis. The CAU can be used to decontaminate and decommission hazardous and radioactive surfaces by measuring residual hazardous surface contamination, such as tritium and trace organics. It provides surface contamination data for research and development applications as well as real-time process control feedback for industrial cleaning operations and can be used to determine the readiness of a surface to accept bonding or coatings. 1 fig

Assessment of radioecological situation of a site contaminated by technologically enhanced natural radioactivity in Croatia

International Nuclear Information System (INIS)

Marovic, G.; Sencar, J.

1999-01-01

Radioactivity contamination originating from the coal fired power plant and its waste dumps located in a bay of the Adriatic which is due to geographical characteristics sensitive to any kind of pollution including radioactivity is discussed. Investigations of coal used in regular plant operation and of solid incombustile ash and slag showed increased concentrations of natural radioactivity which may cause general environmental contamination of the bay as well as contamination of the marine environment of this part of Croatian Adriatic. There are two coal slag and ash piles, one of them was closed and covered by soil and the other is a still operating pile. The location of both piles presents a considerable environmental problem: situated close to the seaside, slag and ash are accumulating in the littoral zone and, in the case of operating pile, are being filled up directly into the sea. The aim of this study was to determine the radioactivity level at the ash and slag deposits and to assess the risk of increased radioactivity for the inhabitants of the nearby urban area, for the plant workers and general environment of the bay including the marine environment of this part of the Croatian Adriatic. (author)

On development of systematical recommendations for the appropriate decision-making during relief works of radioactive contaminated areas

International Nuclear Information System (INIS)

Bobrov, A.F.; Grachev, M.I.; Andrianov, K.N.; Grinev, M.P.; Savkin, M.N.

1994-01-01

The basic principle and decision-making structure on the relief of radioactive contaminated areas on the basic of the cost-benefit analysis are presented. Dose criteria and classification of radioactive contaminated areas are discussed. The examples of multifactorial analysis and hierarchy analysis method are given. 2 tabs

Radioactive contamination: atlas France and Europe. French soils contamination by Chernobyl accident fallouts - The lie evidences

International Nuclear Information System (INIS)

Paris, Andre; Castanier, Corinne

2002-01-01

This document deals with the Chernobyl nuclear accident impacts and the authorities transparency. The first part is a reference document constituted by the CRIIRAD and showing how the authorities strove for minimizing the real contamination of French soils by the Chernobyl fallouts. In the second part, an atlas provides the detailed maps of the radioactive contamination of soils based on more than 3000 measurements carried out by a geologist, Andre Paris, assisted by the CRIIRAD laboratory

Possibility of using radioactivity control measurements for determining contamination paths in nutritional vectors

International Nuclear Information System (INIS)

Garnier, A.

1966-01-01

The object of the report is to study the possibility of using results of radioactivity controls for determining the paths followed by contamination in nutritional vectors; these are necessary for calculating protection norms. Radioactive contamination of a nutritional vector is expressed in terms of parameters which suggest that a certain number of criteria may be used for choosing the results which are to be exploited. An actual example of a 'vertical' study based on results of measurements made purely for control purposes shows the difficulties which may be encountered. A list of the results obtained by the control networks set up in the Community Countries, either for the atmosphere, for milk, or for other foodstuffs, shows that these networks are not at the present organised in such a way as to make such a study possible. It appears desirable that a large part of the work carried out by the control Services be oriented in such a way as to yield the complementary information required for experimental studies of radioactive contamination transfers. (author) [fr

Packaging and transportation of radioactively contaminated lead

International Nuclear Information System (INIS)

Gleason, Eugene; Holden, Gerard

2007-01-01

Under the management of the Nuclear Decommissioning Authority (NDA) the government of the United Kingdom has launched an ambitious program to remediate the nation's nuclear waste legacy. Over a twenty-five year period NDA plans to decommission several first generation nuclear power plants and other radioactive facilities. The use innovative, safe 'fit for purpose' technologies will be a major part of this complex program. This paper will present a case study of a recently completed project undertaken in support of the nuclear decommissioning activities at the Sellafield site in the United Kingdom. The focus is on an innovative application of new packaging technology developed for the safe transportation of radioactively contaminated lead objects. Several companies collaborated on the project and contributed to its safe and successful conclusion. These companies include British Nuclear Group, Gravatom Engineering, W. F. Bowker Transport, Atlantic Container Lines, MHF Logistical Solutions and Energy Solutions. New containers and a new innovative inter-modal packaging system to transport the radioactive lead were developed and demonstrated during the project. The project also demonstrated the potential contribution of international nuclear recycling activities as a safe, economic and feasible technical option for nuclear decommissioning in the United Kingdom. (authors)

The accumulation of radioactive contaminants in drinking water distribution systems.

Science.gov (United States)

Lytle, Darren A; Sorg, Thomas; Wang, Lili; Chen, Abe

2014-03-01

The accumulation of trace contaminants in drinking water distribution system sediment and scales has been documented, raising concerns that the subsequent release of the contaminants back to the water is a potential human exposure pathway. Radioactive contaminants are of concern because of their known health effects and because of their persistence within associated distribution system materials. The objective of this work was to measure the amount of a number of radioactive contaminants (radium, thorium, and uranium isotopes, and gross alpha and beta activity) in distribution solids collected from water systems in four states (Wisconsin, Illinois, Minnesota, and Texas). The water utilities chosen had measurable levels of radium in their source waters. In addition, 19 other elements in the solids were quantified. Water systems provided solids primarily collected during routine fire hydrant flushing. Iron was the dominant element in nearly all of the solids and was followed by calcium, phosphorus, magnesium, manganese, silicon, aluminum and barium in descending order. Gross alpha and beta radiation averaged 255 and 181 pCi/g, and were as high as 1602 and 1169 pCi/g, respectively. Total radium, thorium and uranium averaged 143, 40 and 6.4 pCi/g, respectively. Radium-226 and -228 averaged 74 and 69 pCi/g, and were as high as 250 and 351 pCi/g, respectively. Published by Elsevier Ltd.

Inventory and systematization of data on radiation-chemical contamination of rivers running along Bryansk-Belarusian 'cesium spot'

International Nuclear Information System (INIS)

Germenchuk, M.G.; Zhukova, O.M.; Bakarykava, Zh.; Popova, E.; Gorbatova, G.

2005-01-01

Inventory and systematization of the data on radioactive-chemical contamination of rivers are made. Systematization of the data on chemical and radiation contamination component of rivers was made with using the index of integrated radiation-chemical surface waters contamination (IRCCI=WCI+RCI). Chemical contamination of surface water has been estimated using water contamination index (WCI). It constitutes an integrated magnitude considering ratios of six more significant pollutants to their maximum concentration limits. In dependence on WCI surface water can be attributed to one of seven classes: from 'clean' (with WCI≤1) to 'extremely dirty' (with WCI>10). At present for estimation of radioactive contamination of surface water only comparison with Republican permissible levels are used. But it is not enough for complex estimation of water quality because it does not enable to estimate the extent of radionuclide exceeding over their permissible levels. Therefore for estimation of radioactive pollution level, water radioactive contamination index (RCI) was applied. It is a sum of ratios of main radionuclide concentrations to their permissible levels. Application of RCI enabled to compare radioactive contamination before and after the Chernobyl accident. Application of the index of integrated radiation-chemical surface water contamination enabled to obtain the most complete and impartial estimate of surface water quality of some rivers. Retrospective estimation of the water quality shows that in 1990 surface waters of some rivers should be considered as belonging to more contaminated category of quality if radiation component would have been considered. (authors)

Radioactive Contamination of Agricultural Products in Poland

International Nuclear Information System (INIS)

Muszynski, W.; Grabowski, D.; Rubel, B.; Kurowski, W.; Swietochowska, J.; Smagala, G.

2003-01-01

Radiological contamination of the environment is caused by nuclear activities on the globe: nuclear weapon tests and the Chernobyl accident. The transfer of radionuclides to the organism via ingestion is one of the sources of doses obtained by people. To assess the doses received by humans the intake of isotopes with daily diet was defined. The concentration of radionuclides in foodstuffs was determined. The network of Service for Measurement of Radioactive Contamination systematically controls all kinds of important agricultural products such as milk, meat, vegetables, fruit, cereals and forest products: mushrooms, blueberries etc. Measurement stations involved in food monitoring act within Sanitary-Epidemiological Stations, Veterinary Hygiene Units and Chemical-Agricultural Stations. All activities are co-ordinated by the Central Laboratory for Radiological Protection. The level of activity of caesium isotopes has regularly been monitored in collected samples originating from different administrative districts of Poland. Since 1994 the 134 Cs concentration has been below the detection limit. The activity of 137 Cs has been measured to determine long-term effect of the accident on the contamination of milk, meat and other foodstuffs. (orig.)

Optimization of fodder rations for intensive development of cattle-breeding in an radioactive contaminated zone

International Nuclear Information System (INIS)

Stolyarov, G.V.

1999-01-01

It has been calculated some variants of the optimal structure of milk cow herd's fodder rations in a radioactive contaminated zone in dependence of the contamination density. Rations were balanced in primary nutritive including digestible protein. It has been determined their costs and specific radioactivity of cesium-137. These fodder rations can be recommended to the farms of the Gomel Region suffered from the Chernobyl nuclear power station explosion

Multiple methods for assessing the dose to skin exposed to radioactive contamination

International Nuclear Information System (INIS)

Dubeau, J.; Heinmiller, B.E.; Corrigan, M.

2017-01-01

There is the possibility for a worker at a nuclear installation, such as a nuclear power reactor, a fuel production facility or a medical facility, to come in contact with radioactive contaminants. When such an event occurs, the first order of business is to care for the worker by promptly initiating a decontamination process. Usually, the radiation protection personnel performs a G-M pancake probe measurement of the contamination in situ and collects part or all of the radioactive contamination for further laboratory analysis. The health physicist on duty must then perform, using the available information, a skin dose assessment that will go into the worker's permanent dose record. The contamination situations are often complex and the dose assessment can be laborious. This article compares five dose assessment methods that involve analysis, new technologies and new software. The five methods are applied to 13 actual contamination incidents consisting of direct skin contact, contamination on clothing and contamination on clothing in the presence of an air gap between the clothing and the skin. This work shows that, for the cases studied, the methods provided dose estimates that were usually within 12% (1σ) of each other, for those cases where absolute activity information for every radionuclide was available. One method, which relies simply on a G-M pancake probe measurement, appeared to be particularly useful in situations where a contamination sample could not be recovered for laboratory analysis. (authors)

Redispersion of indoor surface contamination: a review

International Nuclear Information System (INIS)

Sansone, E.B.; Slein, M.W.

1978-01-01

The importance of surface contamination as a potential source of exposure to hazardous materials is discussed. Data from the literature concerning the resuspension of indoor surface contamination are presented. Reported procedures for quantitating surface contamination are compared. It is suggested that, despite its limitations, surface contamination monitoring may be useful in estimating potential risks from hazardous materials. (Auth.)

Radioecological conditions in the towns, where the status of radioactive contamination zones will change

International Nuclear Information System (INIS)

Ageeva, T.N.; Shapsheeva, T.P.; Zajtsev, A.A.; Makarevich, I.A.

2015-01-01

The article presents data of changes in the density of soil contamination in settlements where in 2015 change of the status of contaminated areas is possible. Article contains analysis of monitoring of radioactive contamination of food from private farms, the results of radio ecological inspection conducted in 2013-2014. (authors)

Sources of radioactive contamination inside houses

International Nuclear Information System (INIS)

Sajet, A.S.

2010-01-01

People may be exposed at home to multiple sources of nuclear radiation such as gamma, beta and alpha rays emitters. House atmosphere is polluted with nuclear radiation from water pollutants and rocks used in the construction. Radon is the only radioactive non-metallic element. Environmental organizations estimated that all houses contain varying concentrations of radon gas, and the residents are exposed to levels of radon over the years. The source of radon in houses is uranium, which may be found in rocks of the house, soil of the garden, water of the deep artesian wells and building materials, especially granite rocks. Breathing air that contains high levels of radon causes lung cancer. Radon is the second cause of lung disease after smoking. There are many means to reduce house pollution including: utilisation of air filters to remove contaminated dust particles, keep residential areas away from the establishments that use nuclear technology or embedded by nuclear waste, avoid using materials made from asbestos in construction works and proper use and disposal of chemicals and medicines containing radioactive isotopes. (author)

Industrial-Scale Processes For Stabilizing Radioactively Contaminated Mercury Wastes

International Nuclear Information System (INIS)

Broderick, T. E.; Grondin, R.

2003-01-01

This paper describes two industrial-scaled processes now being used to treat two problematic mercury waste categories: elemental mercury contaminated with radionuclides and radioactive solid wastes containing greater than 260-ppm mercury. The stabilization processes were developed by ADA Technologies, Inc., an environmental control and process development company in Littleton, Colorado. Perma-Fix Environmental Services has licensed the liquid elemental mercury stabilization process to treat radioactive mercury from Los Alamos National Laboratory and other DOE sites. ADA and Perma-Fix also cooperated to apply the >260-ppm mercury treatment technology to a storm sewer sediment waste collected from the Y-12 complex in Oak Ridge, TN

Study of the correlation between radioactive contamination of milk and forage with strontium 90

Energy Technology Data Exchange (ETDEWEB)

Sabo, A; Mezei, I [Joint Inst. for Nuclear Research, Dubna (USSR). Lab. of Neutron Physics

1978-08-01

Significant correlation between radioactive contamination of milk and forage is established on the basis of the data mathematic treatment. Contamination of cow milk by /sup 90/Sr is approximately one order less than forage contamination, which testifies to high discrimination ability of cows in biological chain soil-plant-animal-man. Animals have this ability only in relation to /sup 90/Sr. For other radioactive isotopes discirmination factor can differ significantly from the one characteristic of /sup 90/Sr. It is stressed that as a result of high discrimination ability of cows /sup 90/Sr quantity, penetrating into human body from vegetable products is much more, than the one penetrating from milk and milk products.

Contamination of the air and other environmental samples of the Ulm region by radioactive fission products after the accident of the Chernobyl reactor

International Nuclear Information System (INIS)

Krivan, V.; Egger, K.P.; Hausbeck, R.; Schmid, W.

1986-01-01

Since April 30, 1986, the radioactivity of the fission products released by the accident of the Chernobyl reactor has been measured in the air of the city of Ulm. The airborne dust samples were collected with flow calibrated samplers on cellulose acetate membrane filters and counted with a high resolution gamma ray spectrometer. Later on, the radioactivity measurements were expanded to other relevant environmental samples contaminated by radioactive atmospheric precipitates including grass, spruce needles, mosses, lichens, various kinds of food, drinking water, asphalt and concrete surface layers, municipal sewage sludge and sewage sludge ash. This paper reports the obtained results. (orig.) [de

The contamination on farm products from 125I

International Nuclear Information System (INIS)

Zhao Wenhu; Xu Shiming; Hou Lanxin

1990-02-01

The 125 I contamination on 15 farm products have been investigated. The effects of 12 farm crops (wheat, bean, eggplants and other vegetables) contaminated by 125 I during the growing stage on their fruits and seeds have been studied. The results show that the 125 I radioactive substance is mainly concentrated on the fruit surface, and the radioactivity rapidly decreased towards its kernel. The fruits and seeds would not be contaminated when plants were contaminated in the seedling stage

Wipe sampling for characterization of noncompactable radioactive waste

International Nuclear Information System (INIS)

Barbieri, Aline E.O.; Ferreira, Robson J.; Vicente, Roberto

2009-01-01

Wipe sampling is a method of monitoring radioactive surface contamination on working area and on radioactive, non-compactable wastes, constituted of large pieces of replaced parts of equipment in nuclear and radioactive installations. In this method, sampling is executed by rubbing a disc of filter paper on the contaminated surface in such a way as to collect entirely or partially the deposited material. The target radioisotopes are subsequently measured directly on the wipe or extracted by appropriate radio analytical methods and then qualitatively and quantitatively determined. The collection factor, or the efficiency with which the material is removed from the surface and deposited on the smear, is the main source of error in quantitative measurements. The determination of the collection efficiency is the object of this communication. (author)

Long term survey on food pollution and contamination by radioactive fallout in Fukuoka, Japan (1961 - 1976)

International Nuclear Information System (INIS)

Morishige, Toshiko; Ishinishi, Noburu; Cho, Tetsuji.

1977-01-01

The contamination and the pollution of foodstuffs by radioactive fallout have been investigated since 1961 in Fukuoka city and its suburban area. The results obtained were as follows. 1) Recently, the degree of the contamination of greens by radioactive fallout which fell on the leaves decreased to one thousandth in the early stage of the investigation (1961 - 1962). In the period of the investigation, the remarkable increase of the radioactivity of fallout was observed within a week after the Chinese nuclear bomb explosion in the atmosphere (1st, 2nd, 5th, 12th, 13th, and 15th). The radioactivity was 2 to 300 times higher than the usual level. 2) The radioactivity was not remarkable in vegetables which were washed with soap, but it decreased gradually year by year. The increase of the radioactivity was also observed a few days after the atmospheric nuclear explosion. 3) In milk, there were no remarkable yearly decreases of the radioactivity from the beginning of the investigation, but the seasonal variations of the radioactivity, such as higher in April and May, were observed. 4) The radioactivity in diets based on the standard food production in Japan was the highest in 1967. It decreased gradually from 1967 to 1971 and after that the remarkable variation of the activity was not observed. 5) 137 Cs contamination of foodstuffs has been observed quantitatively by the method of gamma spectrometry, while sometimes 95 Zr- 95 Nb, 103 Ru, and 131 I were also detected from the specimens obtained immediately after the nuclear explosions. (auth.)

Evaluation of Radioactive Contamination in Hamadan Nuclear Medicine Centers Using Wipe Technique

Directory of Open Access Journals (Sweden)

N. Rostampour

2014-02-01

.Conclusion: In centers 1 and 2, most of the radioactive contamination occurred under the hood due to labeling of radiopharmaceuticals activity. Also, in center 3, the highest contamination rate belonged to patients’ corridor that could be due to frequent the area. According to this subject, necessary measures in this regard should be considered by the department responsible for health physics.

Status of radiation dose and radioactive contamination due to the Fukushima accident

International Nuclear Information System (INIS)

Baba, Mamoru

2016-01-01

The accident at Fukushima Daiichi Nuclear Power Plant (NPP), March 2011, caused serious radioactive contamination over wide area in east Japan. Therefore, it is important to know the effect of the accident and the status of NPP. This paper provides a review on the status of radiation dose and radioactive contamination caused by the accident on the basis of publicized information. Monitoring of radiation dose and exposure dose of residents has been conducted extensively by the governments and various organizations. The effective dose of general residents due to the accident proved to be less than a mSv both for external and internal dose. The equivalent committed dose of thyroid was evaluated to be a few mSv in mean value and less than 50 mSv even for children. Monitoring of radioactivity concentration has been carried out on food ingredients, milk and tap water, and actual meal. These studies indicated the percentage of foods above the regulation standard was over 10% in 2011 but decreasing steadily with time. The internal dose due to foods proved to be tens of μSv and much less than that due to natural 40 K even in the Fukushima area and decreasing steadily, although high level concentration is still observed in wild plants, wild mushrooms, animals and some kind of fishes. According to extensive studies, not only the effect of the accident but also the pathway and countermeasures against radioactive contamination have been revealed, and they are applied very effectively for restoration of environment and reconstruction of the area

Status of radiation dose and radioactive contamination due to the Fukushima accident

Energy Technology Data Exchange (ETDEWEB)

Baba, Mamoru [Tohoku Univeristy, Sendai (Japan)

2016-06-15

The accident at Fukushima Daiichi Nuclear Power Plant (NPP), March 2011, caused serious radioactive contamination over wide area in east Japan. Therefore, it is important to know the effect of the accident and the status of NPP. This paper provides a review on the status of radiation dose and radioactive contamination caused by the accident on the basis of publicized information. Monitoring of radiation dose and exposure dose of residents has been conducted extensively by the governments and various organizations. The effective dose of general residents due to the accident proved to be less than a mSv both for external and internal dose. The equivalent committed dose of thyroid was evaluated to be a few mSv in mean value and less than 50 mSv even for children. Monitoring of radioactivity concentration has been carried out on food ingredients, milk and tap water, and actual meal. These studies indicated the percentage of foods above the regulation standard was over 10% in 2011 but decreasing steadily with time. The internal dose due to foods proved to be tens of μSv and much less than that due to natural {sup 40}K even in the Fukushima area and decreasing steadily, although high level concentration is still observed in wild plants, wild mushrooms, animals and some kind of fishes. According to extensive studies, not only the effect of the accident but also the pathway and countermeasures against radioactive contamination have been revealed, and they are applied very effectively for restoration of environment and reconstruction of the area.

Comparative evaluations of surface contamination detectors calibration with radioactive sources - used in the Goiania accident, and standard sources

International Nuclear Information System (INIS)

Becker, P.H.B.; Marecha, M.H.H.

1997-01-01

The construction of Cs-137 standard flat sources for calibration of surface contamination detectors, used in the Goiania accident in 1987, is described and the procedures adopted are reported. At that time, standard sources were not available. Nowadays the Instituto de Radioprotecao e Dosimetria has standard sources acquired from Amersham which are used as calibration standards for surface contamination detectors. Comparative evaluations between the standard flat sources constructed for the accident and the calibrated ones are presented

Radioactive contamination of ingredients used in sweets industry

International Nuclear Information System (INIS)

Bodnar, Jozsef

1988-01-01

On the basis of samples tested in 1983-1987, the activity concentrations relative to unit dry matter are 2,5-3,5-times higher in cocoa shell than in cocoa beans, but the samples have only a small overall radioactive contamination within the total β activity, the 40 K activity ratio in cocoa beans is 72%, in cocoa shells 79%. The respective ratio of 87 Rb can be 20% in the two samples. The activity concentration contribution of 90 Sr and 137 Cs contamination in cocoa beans and cocoa shells is together 2%. The data of the samples from different locations do not show any significant differences. In samples from 1986-1987 the increase of cesium activity concentration can be observed. (author)

GWSCREEN: A semi-analytical model for assessment of the groundwater pathway from surface or buried contamination: Theory and user's manual

International Nuclear Information System (INIS)

Rood, A.S.

1992-03-01

GWSCREEN was developed for assessment of the groundwater pathway from leaching of radioactive and non radioactive substances from surface or buried sources. The code was designed for implementation in the Track 1 and Track 2 assessment of Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) sites identified as low probability hazard at the Idaho National Engineering Laboratory (DOE, 1991). The code calculates the limiting soil concentration such that regulatory contaminant levels in groundwater are not exceeded. The code uses a mass conservation approach to model three processes: Contaminant release from a source volume, contaminant transport in the unsaturated zone, and contaminant transport in the saturated zone. The source model considers the sorptive properties and solubility of the contaminant. Transport in the unsaturated zone is described by a plug flow model. Transport in the saturated zone is calculated with a semi-analytical solution to the advection dispersion equation for transient mass flux input

Transport of contaminants by Arctic sea ice and surface ocean currents

International Nuclear Information System (INIS)

Pfirman, S.

1995-01-01

Sea ice and ocean currents transport contaminants in the Arctic from source areas on the shelves, to biologically active regions often more than a thousand kilometers away. Coastal regions along the Siberian margin are polluted by discharges of agricultural, industrial and military wastes in river runoff, from atmospheric deposition and ocean dumping. The Kara Sea is of particular concern because of deliberate dumping of radioactive waste, as well as the large input of polluted river water. Contaminants are incorporated in ice during suspension freezing on the shelves, and by atmospheric deposition during drift. Ice releases its contaminant load through brine drainage, surface runoff of snow and meltwater, and when the floe disintegrates. The marginal ice zone, a region of intense biological activity, may also be the site of major contaminant release. Potentially contaminated ice from the Kara Sea is likely to influence the marginal ice zones of the Barents and Greenland seas. From studies conducted to date it appears that sea ice from the Kara Sea does not typically enter the Beaufort Gyre, and thus is unlikely to affect the northern Canadian and Alaskan margins

Risk evaluation of radioactive contamination in some species of edible mushrooms

International Nuclear Information System (INIS)

Droujinina, I.; Schinner, F.; Dromp, W.

1998-01-01

Full text of publication follows: edible mushrooms play an important role even in modern society - far beyond their value as food supply. The search for and gathering of edible mushrooms is one of the last possibilities of urbanized man to satisfy his drive as a hunter and collector in nature and thus an important part of the cultural heritage. Deprivation of this recreational activity due to radioactive contamination is considered simply a certain loss of quality of life and thus may have a strong emotional and sociological impact. The accident at the Chernobyl reactor on 26 April 1986 led to considerable amounts of radioactive material being distributed over a large area of Europe with Austria as one of the highest contaminated western countries. 13 years after the accident at Chernobyl, the long-lived isotopes such as cesium 137 (physical half-life of 30.2 years) and others are still of concern. Several publications suggest that the consumption of wild growing mushrooms has to be regarded as risky. The aim of our study is to provide some new investigations on the process of accumulation of radioactive Cs in ecosystems with the focus of attention on fungi, Therefore factors and processes limiting isotope accumulation of edible mushrooms are being determined, using standard microbiological and physical methods. Through a series of experiments and evaluations some factors limiting the accumulation of radionuclides in mycelia and in fruit bodies of selected mushrooms with a main emphasis placed on taxonomic position of each species and type of metabolism are being defined. On this basis careful extrapolation to the industrially cultivated species and to the most popular objects amongst mushroom-collectors is to be achieved. Our approach of assessing the risk of radioactive contamination of edible mushrooms, which is applicable for any assumed scenario, will be discussed. (authors)

Evaluation of radioactive inventory of nuclear ship MUTSU

International Nuclear Information System (INIS)

Adachi, M.

1995-01-01

The operation of the Nuclear Ship MUTSU was terminated in January 1992. Radioactivities and dose rates on the surfaces of reactor components were measured in order to estimate the residual radioactive inventory in the MUTSU. The predicted radioactive inventory due to neutron activation was calculated by using a computer code systems. The results show good correlation between predicted and measured values radioactivities in the core baffle plate. The radioactive inventory was estimated to be 8.4 x 10 14 Bq as of 1.5 years from the final shutdown of reactor operation. The contamination in reactor components was estimated from the contamination level measured in the Japan Power Demonstration Reactor (JPDR), from which the dose rates in the reactor room were calculated. The radioactive inventory due to contamination was estimated at 3.4 x 10 10 Bq. Some difference was found between these calculations and measurements. (Author)

Radioactive contamination in the environs of the Hanford Works for the period April - May - June, 1948

Energy Technology Data Exchange (ETDEWEB)

Singlevich, W.

1948-10-15

This report summarizes the radioactive contamination measured at the Hanford Works and immediate plant areas for the quarter April, May, and June, 1948. Topics discussed are: Meteorology; airborne contamination; contamination in the Columbia and Yakima Rivers; and contamination in rain, drinking water, vegetation, and in Hanford Wastes.

Restoration of water environment contaminated by radioactive cesium released from Fukushima Daiichi NPP

Energy Technology Data Exchange (ETDEWEB)

Takeshita, K.; Takahashi, H. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 157-8550 (Japan); Jinbo, Y. [CDM Cosulting Co.Ltd., 1-13-13 Tsukiji Chuo-ku Tokyo 104-0045 (Japan); Ishido, A. [Radwaste and Decommissioning Center, 1-7-6 Toranomon, Minato-ku, Tokyo 105-0001 (Japan)

2013-07-01

In the Fukushima Daiichi NPP Accident, large amounts of volatile radioactive nuclides, such as {sup 131}I, {sup 134}Cs and {sup 137}Cs, were released to the atmosphere and huge areas surrounding the nuclear site were contaminated by the radioactive fallout. In this study, a combined process with a hydrothermal process and a coagulation settling process was proposed for the separation of radioactive Cs from contaminated soil and sewage sludge. The coagulation settling operation uses Prussian Blue (Ferric ferrocyanide) and an inorganic coagulant. The recovery of Cs from sewage sludge sampled at Fukushima city (100.000 Bq/kg) and soil at a nearby village (55.000 Bq/kg), was tested. About 96% of Cs in the sewage sludge was removed successfully by combining simple hydrothermal decomposition and coagulation settling. However, Cs in the soil was not removed sufficiently by the combined process (Cs removal is only 56%). The hydrothermal decomposition with blasting was carried out. The Cs removal from the soil was increased to 85%. When these operations were repeated twice, the Cs recovery was over 90%. The combined process with hydrothermal blasting and coagulation settling is applicable to the removal of Cs from highly contaminated soil.

Characterization of radioactive contaminants and water treatment trials for the Taiwan Research Reactor's spent fuel pool

International Nuclear Information System (INIS)

Huang, Chun-Ping; Lin, Tzung-Yi; Chiao, Ling-Huan; Chen, Hong-Bin

2012-01-01

Highlights: ► Deal with a practical radioactive contamination in Taiwan Research Reactor spent fuel pool water. ► Identify the properties of radioactive contaminants and performance test for water treatment materials. ► The radioactive solids were primary attributed by ruptured spent fuels, spent resins, and metal debris. ► The radioactive ions were major composed by uranium and fission products. ► Diatomite-based ceramic depth filter can simultaneously removal radioactive solids and ions. - Abstract: There were approximately 926 m 3 of water contaminated by fission products and actinides in the Taiwan Research Reactor's spent fuel pool (TRR SFP). The solid and ionic contaminants were thoroughly characterized using radiochemical analyses, scanning electron microscopy equipped with an energy dispersive spectrometer (SEM-EDS), and inductively coupled plasma optical emission spectrometry (ICP-OES) in this study. The sludge was made up of agglomerates contaminated by spent fuel particles. Suspended solids from spent ion-exchange resins interfered with the clarity of the water. In addition, the ionic radionuclides such as 137 Cs, 90 Sr, U, and α-emitters, present in the water were measured. Various filters and cation-exchange resins were employed for water treatment trials, and the results indicated that the solid and ionic contaminants could be effectively removed through the use of <0.9 μm filters and cation exchange resins, respectively. Interestingly, the removal of U was obviously efficient by cation exchange resin, and the ceramic depth filter composed of diatomite exhibited the properties of both filtration and adsorption. It was found that the ceramic depth filter could adsorb β-emitters, α-emitters, and uranium ions. The diatomite-based ceramic depth filter was able to simultaneously eliminate particles and adsorb ionic radionuclides from water.

Radioactivity of the Bega sediment-case study of a contaminated canal

International Nuclear Information System (INIS)

Bikit, I.; Varga, E.; Conkic, Lj.; Slivka, J.; Mrda, D.; Curcic, S.; Zikic-Todorovic, N.; Veskovic, M.

2005-01-01

The Bega canal is one among many heavily polluted canals in Vojvodina (the northern province of Serbia and Montenegro). In the framework of the revitalization of this canal, the radionuclide content of the sediment was investigated in order to support the safe deposition after excavation. It was found that, in comparison with the Danube sediment and Vojvodina soil, the Bega sediment is contaminated with 238 U and 137 Cs. The origin of this contamination is discussed. No traces of contamination by nuclear power plants in the region were found, while the presence of technologically enhanced, natural occurring radioactive materials (TENORM) was proved

Some thoughts concerning the radioactive contamination of foodstuffs 10 years after the Chernobyl disaster

International Nuclear Information System (INIS)

Szabo, S.A.

1997-01-01

Although the Chernobyl disaster happened 10 years ago (26 Apr. 1986), investigation of the radioactive contamination of the environmental is still in the focus of interest. However it can be established that the pollution level in Hungary- like other, from the place of accident rather far located countries - decreased significantly in the food chain in comparison with measured data in May-June, 1986. Practically the present contamination level (e.q. 137 Cs, 90 Sr) since 1989 is the same as it was in the years before the disaster. Since the level of artificial contamination is much less than the natural radioactivity (e.q. 40 K, 226 Ra) of the foodstuffs, the radiation burden caused by the consumed foodstuffs is negligible. (author)

Protection of atmospheric air against radioactive gas and aerosol contaminants

International Nuclear Information System (INIS)

Zykova, A.S.

1984-01-01

Measures for contamination protection of atmospheric air subdivided into active and passive ones, are considered. The active measures envisage: development and application of waste-free flowsheets, use of flowsheets which restrict formation of gaseous-aerosol discharges; application of highly efficient treatment facilities torage. Dispersion of radioactive substances, released with discharges to the atmosphere, using high stacks; development of the corresponding site-selection solutions and arrangement of sanitary protective zones belong to passive measures. Measures for protection of atmospheric air also include waste and air contamination monitoring. The measures described are considered as applied to NPPs

Prevention and mitigation of groundwater contamination from radioactive releases

International Nuclear Information System (INIS)

1988-10-01

This document gives basic information on potential pathways and mechanisms, by which radioactive materials from releases can reach man, and on modelling considerations to predict the behaviour of radioactive materials in the ground. The main objective is to present an overview of existing techniques for preventing the offsite releases of contaminants into the groundwater systems and techniques for mitigation of effects of such releases should they occur. The recommended techniques are fully applicable to any hazardous materials, such as organic liquids, and toxic materials or otherwise dangerous materials, the presence of which in the accessible biosphere can represent health risks as well as economic losses to the general public. 11 refs, 2 figs, 8 tabs

The Calculation of Self-Disposal Date by Analyzing the Radioactive Contamination of Air Filters Disused in Radioisotope Production Facility

International Nuclear Information System (INIS)

Kim, Sung Ho; Lee, Bu Hyung; Kwon, Soo Il

2016-01-01

The aim of the study is to decrease the diffusion of air contamination which occurred in radiation work places handle radioisotope under the permissible level. Accordingly, we replaced used air filter with a new one at the appropriate time , and computed disposal dates for disposing used air filters by calculate radioactive contamination. Air filter contaminated by radioactivity is possible to be self-disposed on condition that all detected nuclides is below permissible level according to Nuclear Safety and Security Commission (NSSC) notification No. 2014-003. Radioisotope, produced by 30, 50 MeV cyclotron and carried from other institutions, is used to treat patients, diagnose diseases, and research technology in Korea Institute of Radiological and Medical Sciences (KIRAMS). With unsealed sources generate radioactive contamination in air, it is important to use fume hood or hot cell. The accurate date needs to be calculated by the equation for calculation of self disposal date. If disposal date is in 1000 days, disposal for external institution is required. With increasing the number of medical institute which was related to use the radioisotopes, the importance of radioactive safety management was increased. As disposing radioactive waste, in particular, is the procedure of inspecting for releasing radioactive waste to outside, appropriate action and continuous research are required at a radioactive safety management.

Investigation of radiation safety management at nuclear medicine facilities in Japan. Contamination of radioactivity in the draining-water system

International Nuclear Information System (INIS)

Endo, Keigo; Koizumi, Mitsuru; Kinoshita, Fujimi; Nakazawa, Keiji

1999-01-01

Radiation-safety management condition in Japanese nuclear medicine facilities were investigated by the questionnaire method. The first questionnaire was asked in all Japanese 1,401 Nuclear Medicine facilities. Answers from 624 institutes (44.5%) were received and analyzed. The radiation-safety management in nuclear medicine institutes was considered to be very well performed everyday. Opinion for the present legal control of nuclear medicine institutes was that the regulation in Japan was too strict for the clinical use of radionuclides. The current regulation is based on the assumption that 1% of all radioactivity used in nuclear medicine institutes contaminates into the draining-water system. The second questionnaire detailing the contamination of radioactivity in the draining-water system was sent to 128 institutes, and 64 answers were received. Of them, 42 institutes were considered to be enough to evaluate the contamination of radioactivity in the draining-water system. There was no difference between 624 institutes answered to the first questionnaire and 42 institutes, where the radioactivity in the draining-water system measured, in the distribution of the institute size, draining-water system equipment and the radioactivity measuring method, and these 42 institutes seemed to be representative of Japanese nuclear medicine institutes. Contamination rate of radioactivity into the draining system was calculated by the value of radioactivity in the collecting tank divided by the amount of radionuclides used daily in each institute. The institutes were divided into two categories on the basis of nuclear medicine practice pattern; type A: in-vivo use only and type B: both in-vivo and in-vitro use. The contamination rate in 27 type A institutes did not exceed 0.01%, whereas in 15 type B institutes the contamination rate distributed widely from undetectable to above 1%. These results indicated that the present regulation for the draining-water system, which assumed

Facilities for treatment of radioactive contaminated water in nuclear power plants

International Nuclear Information System (INIS)

1981-02-01

The standard applies to processes applied in facilities for treatment of radioactive contaminated water in nuclear power plants with LWR- and HTR-type reactors. It does not apply to the treatment of concentrates obtained in the decontamination of water. (orig.) [de

Method and apparatus for treating liquid contaminated with radioactive particulate solids

International Nuclear Information System (INIS)

Hirs, G.

1976-01-01

A method and apparatus reduces the amount of radioactive solids resulting from the filtration of particulate contaminants from liquid in a nuclear reactor plant. A filtration system includes a pre-filter comprising a sheet filter medium through which the reactor liquid passes to remove relatively large particulate contaminants for storage or disposal. The reactor liquid is then passed through a bed of granular filter medium to accumulate substantially all the previously non-filtered contaminants and thereby provide a clarified liquid suitable for reuse in the reactor. Backwash liquid is flowed through the granular filter bed to remove and entrain the accumulated contaminants into a slurry which is received by a reservoir where the slurry is maintained quiescently to settle the contaminants. Removal of liquid from the reservoir concentrates the contaminants for storage or further processing, without the necessity of large quantities of filter aids that would increase the quantity of storage-requiring contaminated solids

Assessment of the environmental radioactive contamination levels by depleted uranium after NATO aggression on FR Yugoslavia

International Nuclear Information System (INIS)

Pavlovic, S.; Pavlovic, R.; Markovic, S; Plecas, I.

2001-01-01

During NATO aggression on FR Yugoslavia various ammunition have been used, some of them for the first time. Among others, 30 mm bullets with depleted uranium (DU) penetrators have been used. Radioactivity contamination surveys have started during the war due to indications that DU is used in cruise missiles. Besides that, there were a lot of radioactivity analysis of food, drinking water etc. Some of the obtained results are presented in this paper. Depleted uranium ammunition can permanently contaminate environment and so produce effects on population. Relation of the international radiation and environmental protection standards and contamination levels are discussed as well. (author)

Ethanol production from rice on radioactively contaminated field toward sustainable rice farming

International Nuclear Information System (INIS)

Yokoyama, Shinya; Izumi, Bintaro; Oki, Kazuo

2011-01-01

Radioactive species such as 137 Cs were discharged from Fukushima Daiichi Nuclear Power Plant which was severely damaged by the enormous earthquake and tsunami. Cropland has been radioactively contaminated by 137 Cs etc. and it seems impossible to plant rice due to the non-suitability for food. According to the reports, 137 Cs transferred into the rice from soil is less than 1% on the average. Therefore, it is expected that the concentration of 137 Cs in bioethanol will be well below the tentative restriction value even if bioethanol could be produced from the rice. It is proposed that the rice field should be filled with water to avoid the flow of runoff contaminated by radioactive cesium compounds because they are insoluble in aqueous phase and that bioethanol should be produced from the rice in order to maintain the multifunction of rice field and to continue the agriculture. If rice farming is halted and neglected, agricultural function of rice field as well as local community will be permanently destroyed. (author)

Applicability of monitored natural attenuation at radioactively contaminated sites

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-01-15

The IAEA attaches great importance to the dissemination of information that can assist Member States with the development, implementation, maintenance and continuous improvement of systems, programmes and activities that support a sustainable nuclear fuel cycle and nuclear applications, including managing the legacy of past practices and accidents. Hence, the IAEA has initiated a comprehensive programme of work covering all aspects of environmental remediation including: - Technical and non-technical factors influencing decision making in environmental remediation; - Site characterization techniques and strategies; - Assessment of remediation technologies; - Assessment of technical options for cleanup of contaminated media; - Post-restoration compliance monitoring; - Assessment of the costs of remediation measures. It has been observed that many measures to remove or contain contamination are inefficient below certain concentrations, in general costly, and of a limited lifetime compared with the half-lives of the radionuclides concerned. Dispersed low level contamination poses a particular challenge to those charged with its remediation. Economic considerations in many Member States also result in constraints being placed on resources available to deal with such contamination. Experience has also shown that many techniques are not efficient below certain concentration thresholds or may entail impacts on certain environmental compartments in addition to those due to the contamination itself. This includes doses received by workers on the remediation project. As a result, the concept of relying on geological media to retain contaminants and/or to 'flatten out' concentration/dose peaks is increasingly being discussed in a remediation context. Technical Reports Series No. 424 (Remediation of Sites with Dispersed Radioactive Contamination) examined a variety of technological options for remediating dispersed contamination and concluded that the approaches can be broadly

Applicability of monitored natural attenuation at radioactively contaminated sites

International Nuclear Information System (INIS)

2006-01-01

The IAEA attaches great importance to the dissemination of information that can assist Member States with the development, implementation, maintenance and continuous improvement of systems, programmes and activities that support a sustainable nuclear fuel cycle and nuclear applications, including managing the legacy of past practices and accidents. Hence, the IAEA has initiated a comprehensive programme of work covering all aspects of environmental remediation including: - Technical and non-technical factors influencing decision making in environmental remediation; - Site characterization techniques and strategies; - Assessment of remediation technologies; - Assessment of technical options for cleanup of contaminated media; - Post-restoration compliance monitoring; - Assessment of the costs of remediation measures. It has been observed that many measures to remove or contain contamination are inefficient below certain concentrations, in general costly, and of a limited lifetime compared with the half-lives of the radionuclides concerned. Dispersed low level contamination poses a particular challenge to those charged with its remediation. Economic considerations in many Member States also result in constraints being placed on resources available to deal with such contamination. Experience has also shown that many techniques are not efficient below certain concentration thresholds or may entail impacts on certain environmental compartments in addition to those due to the contamination itself. This includes doses received by workers on the remediation project. As a result, the concept of relying on geological media to retain contaminants and/or to 'flatten out' concentration/dose peaks is increasingly being discussed in a remediation context. Technical Reports Series No. 424 (Remediation of Sites with Dispersed Radioactive Contamination) examined a variety of technological options for remediating dispersed contamination and concluded that the approaches can be broadly

Design criteria for a worldwide directory of radioactively contaminated sites (DRCS)

International Nuclear Information System (INIS)

2001-11-01

The publication attempts to fulfil two main objectives: (a) to describe the activities and underlying considerations and concepts for the development by the IAEA of a worldwide Directory of Radioactively Contaminated Sites; (b) to give some recommendations for the development of such directories at the Member States level. In addition to a discussion of the conceptual considerations on the design of an IAEA-level directory, the results of previous efforts on data collation are presented. The DRCS also intends to collate technical information on remedial actions taken or proposed, thus giving examples for consultation in similar cases. Hence, the information available in such a Directory is intended to provide decision makers with a useful reference frame for their own actions. In this the IAEA attempts to assume the role of a clearing-house of information pertinent to characterization of radioactively contaminated sites and their remediation and restoration

Design criteria for a worldwide directory of radioactively contaminated sites (DRCS)

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-11-01

The publication attempts to fulfil two main objectives: (a) to describe the activities and underlying considerations and concepts for the development by the IAEA of a worldwide Directory of Radioactively Contaminated Sites; (b) to give some recommendations for the development of such directories at the Member States level. In addition to a discussion of the conceptual considerations on the design of an IAEA-level directory, the results of previous efforts on data collation are presented. The DRCS also intends to collate technical information on remedial actions taken or proposed, thus giving examples for consultation in similar cases. Hence, the information available in such a Directory is intended to provide decision makers with a useful reference frame for their own actions. In this the IAEA attempts to assume the role of a clearing-house of information pertinent to characterization of radioactively contaminated sites and their remediation and restoration.

The radioactive fall-out harm of nuclear burst to crops and its protection

International Nuclear Information System (INIS)

Zhao Wenhu; Xu Xinyu; Zhu Yongyi; Qiu Tongcai

1990-10-01

The radioactive contamination in the ground burst center is severe and the contaminated area is often large, as well as the effect of radioactive contamination is long. With different kinds of crops, the effects of external contamination caused by the fall-out are different. The contamination can easily be reduced by wind or rain. On the leaf surface it can be washed off and reduced to 10%. A small amount of fission product can be absorbed through plant roots. It is mainly distributed in leaves and stems. The radioactive contamination of fall-out would damage the crops and reduce the production. After an atmospheric test, the fall-out of 90 Sr and 137 Cs plays an important role in the biological effects. The absorption and distribution of radioactive contaminants in crops, their chemical states in soil and the measures to reduce the absorbed radioactivity are respectively studied

GWSCREEN: A semi-analytical model for assessment of the groundwater pathway from surface or buried contamination: Theory and user`s manual

Energy Technology Data Exchange (ETDEWEB)

Rood, A.S.

1992-03-01

GWSCREEN was developed for assessment of the groundwater pathway from leaching of radioactive and non radioactive substances from surface or buried sources. The code was designed for implementation in the Track 1 and Track 2 assessment of Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) sites identified as low probability hazard at the Idaho National Engineering Laboratory (DOE, 1991). The code calculates the limiting soil concentration such that regulatory contaminant levels in groundwater are not exceeded. The code uses a mass conservation approach to model three processes: Contaminant release from a source volume, contaminant transport in the unsaturated zone, and contaminant transport in the saturated zone. The source model considers the sorptive properties and solubility of the contaminant. Transport in the unsaturated zone is described by a plug flow model. Transport in the saturated zone is calculated with a semi-analytical solution to the advection dispersion equation for transient mass flux input.

Possibilities of a metal surface radioactive decontamination using a pulsed CO2 laser

Science.gov (United States)

Milijanic, Scepan S.; Stjepanovic, Natasa N.; Trtica, Milan S.

2000-01-01

There is a growing interest in the laser radioactive decontamination of metal surfaces. It offers advantages over conventional methods: improved safety, reduction of secondary waste, reduced waste volume, acceptable cost. A main mechanism of cleaning in by lasers is ablation. In this work a pulsed TEA CO2 laser was used for surface cleaning, primarily in order to demonstrate that the ablation from metal surfaces with this laser is possible even with relatively low pulse energies, and secondary, that it could be competitive with other lasers because of much higher energy efficiencies. The laser pulse contains two parts, one strong and shot peak at the beginning, followed with a tail. The beam was focused onto a contaminated surface with a KBr lens. The surface was contaminated with 137Cs. Three different metals were used: stainless steel, copper and aluminum. The evaporated material was pumped out in air atmosphere and transferred to a filter. Presence of the activity on the filter was proved by a germanium detector-multichannel analyzer. Activity levels were measured by a GM counter. Calculated decontamination factors as well as collection factors have shown that ablation takes place with relatively high efficiency of decontamination. This investigation suggests that decontamination using the CO2 laser should be seriously considered.

Radiobiological significance of radioactive contamination - summary assessment based on great number of measurements

International Nuclear Information System (INIS)

Angelov, V.; Bonchev, Ts.; Mavrodiev, V.; Kyrdzhilov, N.

1995-01-01

In order to facilitate quantitative and qualitative characterisation of radioactive contamination the authors introduce a relative estimate of radionuclide activity by setting as a reference the most abundant element -Co-60 in the case of the Kozloduy NPP. The ratio η i of the mean annual permissible concentration in air for each radionuclide (RPC-92) to that of Co-60 is calculated. It is found that η i has the same or close values for groups of radionuclides, e.g. η i = 2.10 -4 for 238 Pu, 239 Pu, 240 Pu, 241 Am, 244 Cm; η i = 5 for 89 Sr, 91 Y; 93 Nb, 134 Cs, 137 Cs; η i = 50 for 55 Fe, 63 Ni, 95 Zr, 95 Nb, 140 Ba, 140 La. Then it is compared to the experimentally measured values of the same quantity η iexp , derived from surface contamination data. The ratio η iexp /η i is plotted against log η i . The resulting nomograms give graphic representation of the radiobiological significance of various radionuclide groups. Data from different locations at the Kozloduy NPP are presented. It is found that the alpha emitter contamination has highest values in the Unit 1 (WWER-440) control rooms after repair. The Unit 5 (WWER-1000) has lower alpha contamination compared to WWER-440 units. 1 ref., 5 figs., 1 tab

Radioactive contamination in monitors received for calibration; Contaminacao em monitores de radiacao recebidos para calibracao

Energy Technology Data Exchange (ETDEWEB)

Dias, Paulo S.; Santos, Gilvan C. dos; Brunelo, Maria Antonieta G.; Paula, Tiago C. de; Pires, Marina A.; Borges, Jose C. [MRA Comercio de Instrumentos Eletronicos Ltda., Jardinopolis, SP (Brazil). Centro de Ensaios e Pesquisas em Metrologia (METROBRAS)

2013-10-01

The Calibration Laboratory - LABCAL, from the Research Center for Metrology and Testing - METROBRAS, MRA Comercio de Instrumentos Eletronicos Ltda., began activities in October 2008 and, in August 2009, decided to establish a procedure for monitoring tests, external and internal, of all packages received from customers, containing instruments for calibration. The aim was to investigate possible contamination radioactive on these instruments. On July 2011, this procedure was extended to packagings of personal thermoluminescent dosemeters - TLD, received by the newly created Laboratory Laboratorio de Dosimetria Pessoal - LDP . In the monitoring procedure were used monitors with external probe, type pancake, MRA brand, models GP - 500 and MIR 7028. During the 37 months in which this investigation was conducted, were detected 42 cases of radioactive contamination, with the following characteristics: 1) just one case was personal dosimeter, TLD type; 2) just one case was not from a packing from nuclear medicine service - was from a mining company; 3) contamination occurred on packs and instruments, located and/or widespread; 4) contamination values ranged from slightly above the level of background radiation to about a thousand fold. Although METROBRAS has facilities for decontamination, in most cases, especially those of higher contamination, the procedure followed was to store the contaminated material in a room used for storage of radioactive sources. Periodically, each package and/or instrument was monitored, being released when the radiation level matched the background radiation. Every contamination detected, the client and/or owner of the instrument was informed. The Brazilian National Energy Commission - CNEN, was informed, during your public consultation for reviewing the standard for nuclear medicine services, held in mid-2012, having received from METROBRAS the statistical data available at the time. The high frequency of contamination detected and the high

Building classification trees to explain the radioactive contamination levels of the plants; Construction d'arbres de discrimination pour expliquer les niveaux de contamination radioactive des vegetaux

Energy Technology Data Exchange (ETDEWEB)

Briand, B

2008-04-15

The objective of this thesis is the development of a method allowing the identification of factors leading to various radioactive contamination levels of the plants. The methodology suggested is based on the use of a radioecological transfer model of the radionuclides through the environment (A.S.T.R.A.L. computer code) and a classification-tree method. Particularly, to avoid the instability problems of classification trees and to preserve the tree structure, a node level stabilizing technique is used. Empirical comparisons are carried out between classification trees built by this method (called R.E.N. method) and those obtained by the C.A.R.T. method. A similarity measure is defined to compare the structure of two classification trees. This measure is used to study the stabilizing performance of the R.E.N. method. The methodology suggested is applied to a simplified contamination scenario. By the results obtained, we can identify the main variables responsible of the various radioactive contamination levels of four leafy-vegetables (lettuce, cabbage, spinach and leek). Some extracted rules from these classification trees can be usable in a post-accidental context. (author)

EP toxicity testing of lead to resolve disposition of radioactively contaminated lead