WorldWideScience

Sample records for chernobyl nuclear reactor

  1. Chernobyl and the safety of nuclear reactors in OECD countries

    International Nuclear Information System (INIS)

    This report assesses the possible bearing of the Chernobyl accident on the safety of nuclear reactors in OECD countries. It discusses analyses of the accident performed in several countries as well as improvements to the safety of RBMK reactors announced by the USSR. Several remaining questions are identified. The report compares RBMK safety features with those of commercial reactors in OECD countries and evaluates a number of issues raised by the Chernobyl accident

  2. Chernobyl reactor accident

    International Nuclear Information System (INIS)

    On April 26, 1986, an explosion occurred at the newest of four operating nuclear reactors at the Chernobyl site in the USSR. The accident initiated an international technical exchange of almost unprecedented magnitude; this exchange was climaxed with a meeting at the International Atomic Energy Agency in Vienna during the week of August 25, 1986. The meeting was attended by more than 540 official representatives from 51 countries and 20 international organizations. Information gleaned from that technical exchange is presented in this report. A description of the Chernobyl reactor, which differs significantly from commercial US reactors, is presented, the accident scenario advanced by the Russian delegation is discussed, and observations that have been made concerning fission product release are described

  3. Chernobyl reactor transient simulation study

    International Nuclear Information System (INIS)

    This paper deals with the Chernobyl nuclear power station transient simulation study. The Chernobyl (RBMK) reactor is a graphite moderated pressure tube type reactor. It is cooled by circulating light water that boils in the upper parts of vertical pressure tubes to produce steam. At equilibrium fuel irradiation, the RBMK reactor has a positive void reactivity coefficient. However, the fuel temperature coefficient is negative and the net effect of a power change depends upon the power level. Under normal operating conditions the net effect (power coefficient) is negative at full power and becomes positive under certain transient conditions. A series of dynamic performance transient analysis for RBMK reactor, pressurized water reactor (PWR) and fast breeder reactor (FBR) have been performed using digital simulator codes, the purpose of this transient study is to show that an accident of Chernobyl's severity does not occur in PWR or FBR nuclear power reactors. This appears from the study of the inherent, stability of RBMK, PWR and FBR under certain transient conditions. This inherent stability is related to the effect of the feed back reactivity. The power distribution stability in the graphite RBMK reactor is difficult to maintain throughout its entire life, so the reactor has an inherent instability. PWR has larger negative temperature coefficient of reactivity, therefore, the PWR by itself has a large amount of natural stability, so PWR is inherently safe. FBR has positive sodium expansion coefficient, therefore it has insufficient stability it has been concluded that PWR has safe operation than FBR and RBMK reactors

  4. The general public's attitude towards nuclear power after the reactor accident at Chernobyl

    International Nuclear Information System (INIS)

    The results of three public opinion polls made within two years after the Chernobyl reactor accident revealed a deep feeling of insecurity in the population which did not disappear or diminish in the time from the first to the third survey, but instead was stirred up again by the affairs in the nuclear industry. Other than former accidents in a nuclear facility, as the one at Harrisburg for example, the Chernobyl reactor accident - from the subjective point of view of many citizens - had effects of a dimension exceeding the political level, and reaching into the normal sphere of life of anybody. Torn between two contravening feelings, namely the wish to get rid of the nuclear energy risk as soon as possible, and the fear that this might mean farewell also to the amenities of a life as a free consumer, the population gave into the strategy of suppression, so that there is verbal protest against the hazards of nuclear energy, but no will to really give up the advantages of a comfortable life created by modern technologies. (orig./HP)

  5. The Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The documentation abstracted contains a complete survey of the broadcasts transmitted by the Russian wire service of the Deutsche Welle radio station between April 28 and Mai 15, 1986 on the occasion of the Chernobyl reactor accident. Access is given to extracts of the remarkable eastern and western echoes on the broadcasts of the Deutsche Welle. (HP)

  6. Medical lessons learned from chernobyl relative to nuclear detonations and failed nuclear reactors.

    Science.gov (United States)

    Dallas, Cham E

    2012-12-01

    The Chernobyl disaster in 1986 involved the largest airborne release of radioactivity in history, more than 100 times as much radioactivity as the Hiroshima and Nagasaki atomic bombs together. The resulting emergency response, administrative blunders, and subsequent patient outcomes from this large-scale radiological disaster provide a wealth of information and valuable lessons for those who may find themselves having to deal with the staggering consequences of nuclear war. Research findings, administrative strategies (successful and otherwise), and resulting clinical procedures from the Chernobyl experience are reviewed to determine a current utility in addressing the appropriate protocols for a medical response to nuclear war. As various myths are still widely associated with radiation exposure, attention is given to the realities of a mass casualty medical response as it would occur with a nuclear detonation. PMID:23241462

  7. The reactor accident of Chernobyl

    International Nuclear Information System (INIS)

    The contamination, caused by the radioactivity released during the reactor accident of Chernobyl was measured in samples taken in the environment of the Karlsruhe Nuclear Research Center. The radioactivity was determined in air, fodder, milk, vegetables, other plants, foodstuffs, soil, precipitations, drinking water, sludge and other samples. Results of measurements are reported which were received with considerably more than 1000 samples. The evaluation of the data will be presented in KfK 4140. (orig.)

  8. Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Following the accident at Chernobyl nuclear reactor, WHO organized on 6 May 1986 in Copenhagen a one day consultation of experts with knowledge in the fields of meteorology, radiation protection, biological effects, reactor technology, emergency procedures, public health and psychology in order to analyse the development of events and their consequences and to provide guidance as to the needs for immediate public health action. The present report provides detailed information on the transportation and dispersion of the radioactive material in the atmosphere, especially volatile elements, during the release period 26 April - 5 May. Presented are the calculated directions and locations of the radioactive plume over Europe in the first 5 days after the accident, submitted by the Swedish Meteorological and Hydrological Institute. The calculations have been made for two heights, 1500m and 750m and the plume directions are grouped into five periods, covering five European areas. The consequences of the accident inside the USSR and the radiological consequences outside the USSR are presented including the exposure routes and the biological effects, paying particular attention to iodine-131 effects. Summarized are the first reported measured exposure rates above background, iodine-131 deposition and concentrations in milk and the remedial actions taken in various European countries. Concerning the cesium-137 problem, based on the UNSCEAR assessment of the consequences of the nuclear fallout, one concludes that the cesium contamination outside the USSR is not likely to cause any serious problems. Finally, the conclusions and the recommendations of the meeting, taking into account both the short-term and longer term considerations are presented

  9. Chernobyl nuclear reactor accident fallout: Measurement and consequences. (Latest citations from the NTIS bibliographic database). Published Search

    International Nuclear Information System (INIS)

    The bibliography contains citations concerning the consequences of radioactive fallout from the Chernobyl nuclear reactor accident. Citations discuss radioactive monitoring, health hazards, and radiation dosimetry. Radiation contamination in the air, soil, vegetation, and food is examined. (Contains a minimum of 210 citations and includes a subject term index and title list.)

  10. Chernobyl nuclear reactor accident fallout: Measurement and consequences. (Latest citations from the NTIS Bibliographic database). Published Search

    International Nuclear Information System (INIS)

    The bibliography contains citations concerning the consequences of radioactive fallout from the Chernobyl nuclear reactor accident. Citations discuss radioactive monitoring, health hazards, and radiation dosimetry. Radiation contamination in the air, soil, vegetation, and food is examined. (Contains a minimum of 208 citations and includes a subject term index and title list.)

  11. Aspects of environmental monitoring by British Nuclear Fuels plc following the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The radioactive cloud from the Chernobyl reactor accident arrived in West Cumbria on 2 May 1986. The environmental monitoring facilities of the British Nuclear Fuels plc, Sellafield reprocessing plant were used to monitor radioactivity in air, deposition on grass and on soil and concentrations in milk. The distribution of deposition between sampled grass and soil was affected by heavy rainfall during the passage of the radioactive cloud. Measurements of radioactivity in milk at a lowland farm on the coastal plain resulted in a critical group effective dose of 0.64 mSv up to the end of July, but additional doses are expected to result from the use of silage during the winter. Comparisons are made between these doses from milk consumption and those predicted from the data available shortly after the deposition of the radioactivity on the pasture. (author)

  12. Nuclear energy after Chernobyl

    International Nuclear Information System (INIS)

    This paper on fundamental questions by a representative of the Federal German Government focuses on the following subjects: Nuclear energy as a part of the energy policy of the Federal German Government, the justifiability of nuclear energy, lessons from Chernobyl, nuclear phase-out, safety concepts for the future, supply of nuclear power plants, and nuclear waste disposal. (UA)

  13. Environmental and health consequences in Japan due to the accident at Chernobyl nuclear reactor plant

    International Nuclear Information System (INIS)

    A comprehensive review was made on the results of national monitoring program for environmental radioactivity in Japan resulting from the accident at the Chernobyl nuclear power plant in USSR. Period of monitoring efforts covered by the present review is from 30th of April 1986 to 31st of May 1987. A radioactive cloud released from the Chernobyl nuclear reactor initially arrived in Japan on 30th of April 1986 as indicated by the elevated level of 131I, 137Cs and 134Cs activity in the total deposition on 30th of April and also by the increased 137Cs body burden noted on 1st of May. Almost all the radioactive nuclides detected in the European countries were also identified in Japan. For example, the observed nuclides were: 95Zr, 95Nb, 99mTc, 103Ru, 106Ru, 110mAg, 111Ag, 125Sb, 127Sb, 129mTe, 131I, 132Te, 132I, 133I, 134Cs, 136Cs, 137Cs, 140Ba, 140La, 141Ce and 144Ce. Among the above radionuclides, the country average concentration was determined for 131I, 137Cs and 134Cs in various environmental materials such as air, fresh water, soil, milk, leafy and root vegetables, cereals, marine products and other foodstuffs. In contrast to the sharp decline of 131I which was negligible after a few months, 137Cs showed a tendency to maintain its activity in foodstuffs at an appreciable level one year later. Collective effective dose equivalent and dose equivalent to thyroid in Japanese population due to 137Cs, 134Cs and 131I were estimated to be around 590 man Sv and 4760 man Sv, respectively. Corresponding values for the per caput dose equivalent are 5 μSv for whole body and 40 μSv for thyroid, respectively. (author)

  14. Reactor accident at the Chernobyl nuclear power plant-Block 4. Effects, countermeasures and consequences

    International Nuclear Information System (INIS)

    The findings of the Summary Report on the Chernobyl accident issued by IAEA in September 1986 (International Nuclear Safety Advisory Group (INSAG): Summary Report on the Post-Accident Review Meeting on the Chernobyl Accident. Safety Series No. 78-INSAG-1 Vienna, International Atomic Energy Agency (IAEA). Sept. 1986) are updated, reviewing more recent publications providing more complete information on the events both within and outside the plant. The available information on the resulting radioactive pollution of agriculture and the food chain is discussed considering also the consequences for the future in comparison with the other sources of radioactivity in the environment. 21 refs.; 3 figs.; 3 tabs

  15. Assessment of status of main structures of unit 4 reactor at Chernobyl nuclear power station from results of visual and television examination 1988-1992

    International Nuclear Information System (INIS)

    This work deals with the assessment of status of main structures of unit 4 reactor at Chernobyl nuclear power station from results of visual and television examination 1988-1992. Descriptions of the examination of the reactor vault by a periscope and by boreholes drilled are given. (O.L.). 8 figs

  16. Nuclear-reactor accidents: Chernobyl, TMI, and Windscale. January 1974-September 1988 (Citations from Pollution Abstracts). Report for January 1974-September 1988

    International Nuclear Information System (INIS)

    This bibliography contains citations concerning studies and measurements of the radiological consequences of nuclear-reactor accidents. The citations cover specifically the Chernobyl reactor in the USSR, the Three Mile Island (TMI) reactor in the US, and the Windscale reactor in the UK. Included are detection and monitoring of the fallout, the resultant runoff into rivers, lakes, and the sea, the radiation effects on people, and the transfrontier radioactive contamination of the environment. (Contains 105 citations fully indexed and including a title list.)

  17. Radioactive contamination in the Netherlands caused by the nuclear reactor accident at Chernobyl

    International Nuclear Information System (INIS)

    In this report of the Dutch Coordination Commission for Measurements of Radioactivity and Xenobiotic matters (CCRX) a detailed survey is presented of the spread of radioactive material over Europe as a consequence of the reactor accident in Chernobyl and of measurements of the contamination of the physical environment, food and human people in the Netherlands. The radiation burden for the Dutch people and the effects upon public health are estimated and a measuring program is introduced for monitoring the effects of the reactor accident upon the Dutch people. Finally a number of requirements are discussed on the base of the acquired experiments, to which future watching programs should satisfy. 24 refs.; 32 figs.; 16 tabs

  18. Chernobyl reactor accident: medical management

    International Nuclear Information System (INIS)

    Chernobyl reactor accident on 26th April, 1986 is by far the worst radiation accident in the history of the nuclear industry. Nearly 500 plant personnel and rescue workers received doses varying from 1-16 Gy. Acute radiation syndrome (ARS) was seen only in the plant personnel. 499 individuals were screened for ARS symptoms like nausea, vomitting, diarrhoea and fever. Complete blood examination was done which showed initial granulocytosis followed by granulocytopenia and lymphocytopenia. Cytogenetic examinations were confirmatory in classifying the patients on the basis of the doses received. Two hundred and thirty seven cases of ARS were hospitalised in the first 24-36 hrs. No member of general public suffered from ARS. There were two immediate deaths and subsequently 28 died in hospital and one of the cases died due to myocardial infarction, making a total of 31 deaths. The majority of fatal cases had whole body doses of about 6 Gy, besides extensive skin burns. Two cases of radiation burns had thermal burns also. Treatment of ARS consisted of isolation, barrier nursing, replacement therapy with fluid electrolytes, platelets and RBC transfusions and antibiotic therapy for bacterial, fungal and viral infections. Bone marrow transplantations were given to 13 cases out of which 11 died due to various causes. Radiation burns due to beta, gamma radiations were seen in 56 cases and treated with dressings, surgical excision, skin grafting and amputation. Oropharangeal syndrome, producing extensive mucous in the oropharynx, was first seen in Chernobyl. The patients were treated with saline wash of the mouth. The patients who had radioactive contamination due to radioactive iodine were given stable iodine, following wash with soap, water and monitored. Fourteen survivors died subsequently due to other causes. Late health effects seen so far include excess of thyroid cancer in the children and psychological disorders due to stress. No excess leukemia has been reported so

  19. ASSESSMENT OF THE RADIONUCLIDE COMPOSITION OF "HOT PARTICLES" SAMPLED IN THE CHERNOBYL NUCLEAR POWER PLANT FOURTH REACTOR UNIT

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.; Jannik, T.; Marra, J.

    2011-10-01

    Fuel-containing materials sampled from within the Chernobyl Nuclear Power Plant (ChNPP) 4th Reactor Unit Confinement Shelter were spectroscopically studied for gamma and alpha content. Isotopic ratios for cesium, europium, plutonium, americium, and curium were identified and the fuel burnup in these samples was determined. A systematic deviation in the burnup values based on the cesium isotopes, in comparison with other radionuclides, was observed. The conducted studies were the first ever performed to demonstrate the presence of significant quantities of {sup 242}Cm and {sup 243}Cm. It was determined that there was a systematic underestimation of activities of transuranic radionuclides in fuel samples from inside of the ChNPP Confinement Shelter, starting from {sup 241}Am (and going higher), in comparison with the theoretical calculations.

  20. Nuclear reactor accidents: Chernobyl, TMI (Three Mile Island), and Windscale. January 1974-September 1989 (Citations from Pollution Abstracts). Report for January 1974-September 1989

    International Nuclear Information System (INIS)

    This bibliography contains citations concerning studies and measurements of the radiological consequences of nuclear reactor accidents. The citations cover specifically the Chernobyl reactor in the USSR, the Three Mile Island (TMI) reactor in the US, and the Windscale reactor in the UK. Included are detection and monitoring of the fallout, the resultant runoff into rivers, lakes, the sea, the radiation effects on people, and the transfrontier radio ative contamination of the environment. (This updated bibliography contains 164 citations, 59 of which are new entries to the previous edition.)

  1. Chernobyl

    International Nuclear Information System (INIS)

    The Chernobyl reactor accident provoked a wave of public discussion about the peaceful uses of nuclear energy, and particularly so in the Federal Republic of Germany. The article in hand discusses some consequences as can be assessed so far, although information on the causes and the course of the accident still is very incomplete. From the information available so far, the possible sequence of events is described. The safety engineering and design of Federal German reactor types is compared with the reactor type installed at Chernobyl, with the result that the Soviet type never would have been licensed in the FRG. The fallout, i.e. the resulting radiation exposure of the population, is expected to remain within the limits of the natural radioactivity; the political effects and possible consequences with regard to further commitments for the advancement of the fast breeder reactor line and the reprocessing of spent fuel are discussed. (orig./RB)

  2. Chernobyl lesson and the nuclear power prospects

    International Nuclear Information System (INIS)

    At sixteen years from the disaster which made the commercial power reactor nr. 4 of the Chernobyl NPP known worldwide, the radiation effects and the consequences are still vivid. A basic statement is to be underlined, namely, the Chernobyl event was not an accident in a nuclear power plant being in an industrial, commercial state of operation but an accident following an experiment done on the reactor. Lack of professionalism, of nuclear safety culture, the outrageous violation of basic rules and regulations, established for the unit operation, represent some of the causes originating the Chernobyl disaster. One of the most unfair consequences enhanced by an incorrect mass media information and political manipulation was the ensuing antinuclear media campaign. The paper quotes recent monographs and United Nations Documents showing how the facts were distorted to render arguments and support for various political, economical or humanistic goals. Thus, over more than 15 years due to the hard controversies and irrational campaigns on a global scale the nuclear power was discredited. Practically, all the nuclear power plant constructions were either delayed or cancelled. Moreover, some governments have sustained even closing the existing nuclear stations. The author asks himself rhetorically whether somebody has considered and quantified the immense losses produced by such unmotivated policy or else the additional damage and abuse caused to our home planet by the additional burning of fossil fuels to replace the nuclear fuel burning in nuclear power plants. The paper ends by mentioning the environmental advantages and economic efficiency of that clean energy source which is the nuclear power

  3. Radiological consequences of the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The reactor accident at unit 4 of the Chernobyl nuclear power plant in Ukraine has deeply affected the living conditions of millions of people. Especially the health consequences have been of public concern up to the present and also been the subject of sometimes absurd claims. The current knowledge on the radiological consequences of the accident is reviewed. Though an increased hazard for some risk groups with high radiation exposure, e.g., liquidators, still cannot be totally excluded for the future, the majority of the population shows no statistically significant indication of radiation-induced illnesses. The contribution of the Research Center Juelich to the assessment of the post-accidental situation and psychological relief of the population is reported. The population groups still requiring special attention include, in particular, children growing up in highly contaminated regions and the liquidators of the years 1986 and 1987 deployed immediately after the accident. (author)

  4. Western reactors: how they compare with Chernobyl

    International Nuclear Information System (INIS)

    The author explains why western light water reactors are intrinsically more dangerous than the RBMK, Chernobyl design. It is also argued that for the fast breeder reactors (such as the PFR at Dounreay and the Super Phenix at Creys Melville) are more dangerous and could actually explode like an atomic bomb. This is contrary to official assurances that the Western reactors are of a safer design and more safely operated than the Chernobyl reactor, and so a similar accident could not happen here. The PWRs and BWRs are compared with the RBMK as to pressure vessels/no pressure vessel, fuel rods, reactor containment and containment building. The superiority of Western engineering and reactor operation is also disputed, with the Three Mile Island accident used as evidence. (U.K.)

  5. The Chernobyl catastrophe is the most terrible civil nuclear incident

    International Nuclear Information System (INIS)

    Full text: The 4th nuclear reactor of the Chernobyl NPP exploded on 26 April 1986, 20 years ago. It's the most terrible nuclear civil accident of all times. The consequences of the Chernobyl accident led to contamination of 3,1 million ha of arable land, 1,5 million ha of natural pasture land, 3,5 million ha of forests and changed the lifestyle for millions of people in Belarus, Ukraine and Russia. It is well known that the mortality in the contaminated areas (infant mortality by cancer) drastically increased. The Chernobyl catastrophe is presented , such as a sad example for humanity, a complex political international, economical, social and, particular, ecological problem according to the traditional and new studies for the development of the nucleotide contaminated territories: 1. Financing of safety of stopped working 4th nuclear reactor (security of covering system) and of work another 3 blocks at the Chernobyl NPP. Detailed control of international financial support for guarantee the safety, security of the Chernobyl NPP and sustainable development for rehabilitation of the affected zones and people. 2. It should be marked increase in medical, demographic analysis and in social, economical protection of the people in the contaminated areas. 3. Analysis and synthesis, monitoring of the long-time data results due to environmental, ecological, social and political consequences of the Chernobyl disaster. 4. Protection from the possible terrorist (extra) actions and (inter) damage or incident function of the Chernobyl plant, such as an old generation nuclear power. 5. Planned budget for future studies in the affected territories and flexibility actually realization of budget (State and International). 6. Nuclear refuse and aria/water protection in the Ukraine, Belarus and Russia contaminated zones. 7. Risk evaluation of not good function of NPPs which are situated in Russia, Ukraine and in another places (always remembering that the Chernobyl catastrophe is the

  6. Health effects of low dose exposure to fission products from Chernobyl and the Fermi nuclear reactor in the population of the Detroit metropolitan area

    International Nuclear Information System (INIS)

    The present paper describes the results of the exposure of a very large population in the Detroit, Michigan, area to fallout from Chernobyl measured in 1986, followed by the reported releases from the start-up of the Fermi-II nuclear plant in 1988 located 20 miles from the city that receives its drinking water from Lake St. Clair downwind to the north-east of the plant. Due to the prior existence of a local cancer registry for a total population of about 4 million, and the availability of reliable public-heath statistics by age, race and sex, combined with the absence of an accident known to produce population movement and stress, highly significant rises and declines of the incidence of early childhood leukemia and other cancers could be related both geographically and temporally to the observed rises and declines of fission products in the milk as well as releases from the reactor. Furthermore, surprisingly rapid rises in the incidence of breast cancer also took place in Monroe County where the reactor is located and in Macomb County downwind on Lake St. Clair to the northeast, presumably due to weakening of the immune defenses by the mix of fission products not seen so rapidly after exposure in the case of external X-rays or gamma rays. For Michigan as a whole, for which incidence of thyroid cancer at all ages combined became available after 1985, rapid rises were observed after Chernobyl and the start of the Fermi plant, using as rapidly as in the case of Belarus and Connecticut. Additionally, highly significant synchronous rises in low birth weight, infant mortality, fetal deaths, asthma and infectious disease mortality were also observed consistent with the known action of bone-seeking fission products on the immune system, following reported nuclear tests, nuclear accidents and the start-up of the Fermi plant. (orig.)

  7. Radiological consequences of the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Fifty years of peaceful utilization of nuclear power were interrupted by the reactor accident in unit 4 of the Chernobyl nuclear power station in Ukraine in 1986, a disruptive event whose consequences profoundly affected the way of life of millions of people, and which has moved the public to this day. Releases of radioactive materials contaminated large areas of Belarus, the Russian Federation, and Ukraine. Early damage in the form of radiation syndrome was suffered by a group of rescue workers and members of the reactor operating crew, in some cases with fatal consequences, while the population does not, until now, show a statistically significant increase in the rate of late damage due to ionizing radiation expect for thyroid diseases in children. In particular, no increases in the rates of solid tumors, leukaemia, genetic defects, and congenital defects were detected. For some risk groups exposed to high radiation doses (such as liquidators) the hazard may still be greater, but the large majority of the population need not live in fear of serious impacts on health. Nevertheless, the accident shows major negative social and psychological consequences reinforced by the breakdown of the Soviet Union. This may be one reason for the observed higher incidence of other diseases whose association with the effects of radiation as a cause has not so far been proven. The measurement campaign conducted by the federal government in 1991-1993 addressed these very concerns of the public in an effort to provide unbiased information about exposures detected, on the one hand, in order to alleviate the fears of the public and reduce stress and, on the other hand, to contribute to the scientific evaluation of the radiological situation in the regions most highly exposed. The groups of the population requiring special attention in the future include especially children growing up in highly contaminated regions, and the liquidators of 1986 and 1987 employed in the period immediately

  8. Thyroid consequences of the Chernobyl nuclear accident.

    Science.gov (United States)

    Pacini, F; Vorontsova, T; Molinaro, E; Shavrova, E; Agate, L; Kuchinskaya, E; Elisei, R; Demidchik, E P; Pinchera, A

    1999-12-01

    It is well recognized that the use of external irradiation of the head and neck to treat patients with various non-thyroid disorders increases their risk of developing papillary thyroid carcinoma years after radiation exposure. An increased risk of thyroid cancer has also been reported in survivors of the atomic bombs in Japan, as well as in Marshall Island residents exposed to radiation during the testing of hydrogen bombs. More recently, exposure to radioactive fallout as a result of the Chernobyl nuclear reactor accident has clearly caused an enormous increase in the incidence of childhood thyroid carcinoma in Belarus, Ukraine, and, to a lesser extent, in the Russian Federation, starting in 1990. When clinical and epidemiological features of thyroid carcinomas diagnosed in Belarus after the Chernobyl accident are compared with those of naturally occurring thyroid carcinomas in patients of the same age group in Italy and France, it becomes apparent that the post-Chernobyl thyroid carcinomas were much less influenced by gender, virtually always papillary (solid and follicular variants), more aggressive at presentation and more frequently associated with thyroid autoimmunity. Gene mutations involving the RET proto-oncogene, and less frequently TRK, have been shown to be causative events specific for papillary cancer. RET activation was found in nearly 70% of the patients who developed papillary thyroid carcinomas following the Chernobyl accident. In addition to thyroid cancer, radiation-induced thyroid diseases include benign thyroid nodules, hypothyroidism and autoimmune thyroiditis, with or without thyroid insufficiency, as observed in populations after environmental exposure to radioisotopes of iodine and in the survivors of atomic bomb explosions. On this basis, the authors evaluated thyroid autoimmune phenomena in normal children exposed to radiation after the Chernobyl accident. The results demonstrated an increased prevalence of circulating thyroid

  9. The Chernobyl-4 Reactor and the possible causes of the accident

    International Nuclear Information System (INIS)

    A description and information about the Chernobyl nuclear reactor is given. Some comparison elements between the RBMK reactor type and GCR, CANDU, SGHWR and Hanford N reactor types are presented. A scenario of the possible causes of the accident is discussed. (A.F.)

  10. Lessons for Germany from the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Since the Chernobyl reactor accident, conclusions for Germany are being translated into action. They comprise the creation of the legal and administrative preconditions for a uniform assessment of exposure situations and concerted recommendations to exposed persons within the framework of precautionary radiation protection and nuclear disaster relief. Measuring to determine the levels of event-related and dose-relevant nuclides in environmental media is being extended. A communication infra-structure for real-time information of the population is to be established and international agreements on mutual information in the case of nuclear accidents are to be concluded. (DG)

  11. The Chernobyl Nuclear Power Plant accident: ecotoxicological update

    Science.gov (United States)

    Eisler, R.

    2003-01-01

    The accident at the Chernobyl, Ukraine, nuclear reactor on 26 April 1986 released large amounts of radiocesium and other radionuclides into the environment, contaminating much of the northern hemisphere, especially Europe. In the vicinity of Chernobyl, at least 30 people died, more than 115,000 others were evacuated, and consumption of milk and other foods was banned because of radiocontamination. At least 14,000 human cancer deaths are expected in Russia, Belarus, and the Ukraine as a direct result of Chernobyl. The most sensitive local ecosystems, as judged by survival, were the soil fauna, pine forest communities, and certain populations of rodents. Elsewhere, fallout from Chernobyl significantly contaminated freshwater and terrestrial ecosystems and flesh and milk of domestic livestock; in many cases, radionuclide concentrations in biological samples exceeded current radiation protection guidelines. Reindeer (Rangifer tarandus) in Scandinavia were among the most seriously afflicted by Chernobyl fallout, probably because their main food during winter (lichens) is an efficient absorber of airborne particles containing radiocesium. Some reindeer calves contaminated with 137Cs from Chernobyl showed 137Cs-dependent decreases in survival and increases in frequency of chromosomal aberrations. Although radiation levels in the biosphere are declining with time, latent effects of initial exposure--including an increased frequency of thyroid and other cancers--are now measurable. The full effect of the Chernobyl nuclear reactor accident on natural resources will probably not be known for at least several decades because of gaps in data on long-term genetic and reproductive effects and on radiocesium cycling and toxicokinetics.

  12. Collection, documentation and assessment of data measured in the Federal Republic of Germany after the reactor accident in the nuclear power plant at Chernobyl

    International Nuclear Information System (INIS)

    Representative for the Federal Republic of Germany, regions were selected that showed a lesser (Hesse) and higher (Bavaria) contamination. The contamination in individual environmental media (milk, i.a.) was demonstrated by values measured and assessed on a prognostic model and subsequently compared with each other. The intake was then evaluated on the basis of food basket and total body measurement data for determining the dose for various age groups and regions. Against those from food baskets, the doses derived from total body measurements were generally lower by 20-60%. This indicates change in consumption habits, adherence to recommendations and the effect of countermeasures, particularly in the higher contaminated southern region of the Federal Republic of Germany. The intake and dose assessments were compared to those measured during the time of contamination from fallout due to nuclear weapons tests. External radiation exposure and cumulative dose from fallout due to nuclear weapons tests and the Chernobyl accident were calculated. In 1986, the radiation exposure from external sources and from ingestion in consequence of the reactor accident had reached in the region of highest contamination (County of Berchtesgaden) 40%, in the lesser contaminated region (Hesse) about 5% of the average natural radiation exposure. (orig./HP)

  13. Considerations on nuclear safety in France, two years after Chernobyl

    International Nuclear Information System (INIS)

    In the first part of the paper, we shall briefly describe the three different categories of actions decided on in the wake of Chernobyl: 1. Research and development: physical phenomena and design features implicated in the accident 2. Measures concerning all nuclear installations 3. Measures specific to pressurized water reactors. In the second part, we shall give more detailed results of an initial re-assessment of PWR reactivity accidents

  14. The Chernobyl reactor accident source term: development of a consensus view

    International Nuclear Information System (INIS)

    Ten years after the reactor accident at Chernobyl, a great deal more data is available concerning the events, phenomena, and processes that took place. The purpose of this document is to examine what is known about the radioactive materials released during the accident, a task that is substantially more difficult than it might first appear to be. The Chernobyl station, like other nuclear power plants, was not instrumented to characterize a disastrous accident. The accident was peculiar in the sense that radioactive materials were released, at least initially, in an exceptionally energetic plume and were transported far from the reactor site. Release of radioactivity from the plant continued for several days. Characterization of the contamination caused by the releases of radioactivity has had a much lower priority than remediation of the contamination. Consequently, an assessment of the Chernobyl accident source term must rely to a significant extent on inferential evidence. The assessment presented here begins with an examination of the core inventories of radioactive materials. In subsequent sections of the report, the magnitude and timing of the releases of radioactivity are described. Then, the composition, chemical forms, and physical forms of the releases are discussed. A number of more recent publications and results from scientists in Russia and elsewhere have significantly improved the understanding of the Chernobyl source term. Because of the special features of the reactor design and the peculiarities of the Chernobyl accident, the source term for the Chernobyl accident is of limited applicability to the safety analysis of other types of reactors

  15. A preliminary assessment of individual doses in the environs of Berkeley, Gloucestershire, following the Chernobyl nuclear reactor accident

    International Nuclear Information System (INIS)

    A preliminary assessment has been made of the individual doses to critical group members of the public in the environs of Berkeley arising from fallout resulting from the Chernobyl accident. The assessment was based on measurements of airborne radionuclide concentrations, ground deposition and nuclide concentrations in rainwater, tapwater, grass, milk and green vegetables. The committed effective dose-equivalent was found to be as follows:- Adult - 200 μSv, 1 year old child - 500 μSv, the 10 year old child receiving a dose intermediate between these two values. The estimate accounts only for the nuclides measured and the specific exposure routes considered namely ingestion of milk and vegetables, inhalation and external exposure. However, it is believed that the inclusion of a range of other nuclides of potential significance, which may have been present but not measured, and potential intakes from additional routes is unlikely to increase the above estimates by more than a factor of 2. (author)

  16. Global impact of the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Radioactive material was deposited throughout the Northern Hemisphere as a result of the accident at the Chernobyl Nuclear Power Station on 26 April 1986. On the basis of a large amount of environmental data and new integrated dose assessment and risk models, the collective dose commitment to the approximately 3 billion inhabitants is calculated to be 930,000 person-gray, with 97% in the western Soviet Union and Europe. The best estimates for the lifetime expectation of fatal radiogenic cancer would increase the risk from 0 to 0.02% in Europe and 0 to 0.003% in the Northern Hemisphere. By means of an integration of the environmental data, it is estimated that approximately 100 petabecquerels of cesium-137 (1 PBq = 10(15) Bq) were released during and subsequent to the accident

  17. The Chernobyl reactor accident and how it changed the world

    International Nuclear Information System (INIS)

    After expressing his sympathy for the Chernobyl victims the author points out that in particular the Germans are tending to show emotions of a preponderantly negative character, that is emotions hampering a logical way of thinking and nourishing ideologies. He adds that the majority of the Western German population has not succeeded in seizing the real implications of radioactivity. Their ignorance results in a growing disbelief in the competent experts. Politicians therefore cannot but act as go-betweens between expert knowledge and the population. The reactor accident has made nuclear power a central topical subject of discussion in the election campaign. The author expresses his view on the need of giving a new direction to the safety debate by elucidating and illustrating the economic and ecological advantages as well as the safety of nuclear energy. (HSCH)

  18. The Chernobyl murder. The nuclear Goulag

    International Nuclear Information System (INIS)

    The authors of this book are the Chernobyl victims of the 26 April 1986 nuclear accident: millions of poor farmers, contaminated young mothers and children which eat every days radionuclides; ''Liquidators'', sacrificed to stop the fire of the power plants; invalids and also doctors and scientists which refuse the nuclear lobby. This book presents the two Byelorussian scientists which have risk their career and their health to help the contaminated populations. This book takes stock on the today nuclear policy and becomes alarm in seeing the development of the nuclear program in many countries. (A.L.B.)

  19. Radioactivity monitoring by the official monitoring stations in North-Rhine Westphalia and the Juelich Nuclear Research Centre after the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    This official report presents a governmental declaration of the prime minister of NRW, Mr. Rau, concerning the reactor accident at Chernobyl, and a joint declaration of ministers of NRW, concerning the impact of the accident on the Land NRW. These statements are completed by six official reports on radioactivity measurements carried out by the official monitoring stations of the Land and by the KFA Juelich. These reports inform about methods, scope, and results of the measuring campaigns accomplished by the Zentralstelle fuer Sicherheitstechnik (ZFS), the public materials testing office (MPA), the Chemisches Untersuchungsamt, the Landesamt fuer Wasser und Abfall, and the KFA Juelich. (DG)

  20. Measured transfer factors in milk and meat after the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    After the nuclear reactor accident at Chernobyl the radioactivity in the environment in Aachen was measured in detail at the Lehrgebiet Strahlenschutz in der Kerntechnik. The change of the different radionuclides in the eco-system made it possible to obtain radioecological parameters especially for iodine and caesium. The knowledge about the transport of iodine into cow's milk could be very much improved

  1. Radiation exposure: Cytogenetic tests. Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Forty test subjects who, either during or after the reactor accident of Chernobyl (26th April 1986), stayed at a building site at Shlobin 150 km away, were examined for spontaneously occurring as well as mitomycin C-induced Sister Chromatid Exchanges (SCE). The building site staff, who underwent a whole-body radionuclide count upon their return to Austria (June through September 1986), were used for the cytogenetic tests. The demonstration of the SCE was made from whole-blood cultures by the fluorescence/Giemse technique. At last 20 Metaphases of the 2nd mitotic cycle were evaluated per person. The radiation doses of the test subjects were calculated by adding the external exposure determined on the building site, the estimated thyroid dose through I-131, and the measured incorporation of Cs-134 and Cs-137. The subjects were divided into two groups for statistical analysis: One was a more exposed group (proven stay at Shlobin between 26th April and 31st May 1986, mostly working in the open air) and the other a less exposed group for comparison (staying at Shlobin from 1st Juni 1986 and working mainly indoors). (orig.)

  2. The Chernobyl reactor accident source term: Development of a consensus view

    International Nuclear Information System (INIS)

    In August 1986, scientists from the former Soviet Union provided the nuclear safety community with an impressively detailed account of what was then known about the Chernobyl accident. This included assessments of the magnitudes, rates, and compositions of radionuclide releases during the ten days following initiation of the accident. A summary report based on the Soviet report, the oral presentations, and the discussions with scientists from various countries was issued by the International Atomic Energy Agency shortly thereafter. Ten years have elapsed since the reactor accident at Chernobyl. A great deal more data is now available concerning the events, phenomena, and processes that took place. The purpose of this document is to examine what is known about the radioactive materials released during the accident. The accident was peculiar in the sense that radioactive materials were released, at least initially, in an exceptionally energetic plume and were transported far from the reactor site. Release of radioactivity from the plant continued for about ten days. A number of more recent publications and results from scientists in Russia and elsewhere have significantly improved our understanding of the Chernobyl source term. Because of the special features of the reactor design and the pecularities of the Chernobyl accident, the source term for the Chernobyl accident is of limited applicability of the safety analysis of other types of reactors

  3. Health consequences of Chernobyl. 25 years after the reactor catastrophy

    International Nuclear Information System (INIS)

    The report is an evaluation of studies indicating health effects as a consequence of the reactor catastrophe in Chernobyl. The most exposed population include the cleaning personnel (liquidators), the population evacuated from the 30 km zone, the populations in highly contaminated regions in Russia, Belarus and Ukraine, the European population in lass contaminated regions. The following issues are discussed: the liquidators, infant mortality, genetic and teratogenic damages, thyroid carcinoma and other thyroid diseases, carcinogenic diseases and leukemia, other diseases following the Chernobyl catastrophe.

  4. After the Chernobyl reactor accident: Just got away?

    International Nuclear Information System (INIS)

    The feeling of depression and insecurity experienced immediately after the Chernobyl reactor accident has gone by, and people go out for a walk again, and drink their milk. Are we happily aware we got away with it this time, or is it rather a feeling of resignation that makes us return to normal life? The Chernobyl disaster will only after some time be really assessed in its novel, global dimension. (orig.)

  5. Generalities about nuclear reactors

    International Nuclear Information System (INIS)

    From Zoe, the first nuclear reactor, till the current EPR, the French nuclear industry has always advanced by profiting from the feedback from dozens of years of experience and operations, in particular by drawing lessons from the most significant events in its history, such as the Fukushima accident. The new generations of reactors must improve safety and economic performance so that the industry maintain its legitimacy and its share in the production of electricity. This article draws the history of nuclear power in France, gives a brief description of the pressurized water reactor design, lists the technical features of the different versions of PWR that operate in France and compares them with other types of reactors. The feedback experience concerning safety, learnt from the major nuclear accidents Three Miles Island (1979), Chernobyl (1986) and Fukushima (2011) is also detailed. Today there are 26 third generation reactors being built in the world: 4 EPR (1 in Finland, 1 in France and 2 in China); 2 VVER-1200 in Russia, 8 AP-1000 (4 in China and 4 in the Usa), 8 APR-1400 (4 in Korea and 4 in UAE), and 4 ABWR (2 in Japan and 2 in Taiwan)

  6. NUCLEAR REACTOR

    Science.gov (United States)

    Anderson, C.R.

    1962-07-24

    A fluidized bed nuclear reactor and a method of operating such a reactor are described. In the design means are provided for flowing a liquid moderator upwardly through the center of a bed of pellets of a nentron-fissionable material at such a rate as to obtain particulate fluidization while constraining the lower pontion of the bed into a conical shape. A smooth circulation of particles rising in the center and falling at the outside of the bed is thereby established. (AEC)

  7. Thyroid carcinomas induced by Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    The Chernobyl nuclear station accident is the unprecedented catastrophic accident in human nuclear industry with a large of quantity of radioactive nucleons resulting in contamination in many countries of the northern Hemisphere. After almost 20 years studying, it is approved that Belarus is the most serious affected country by the accident. Especially thyroid carcinomas in the people exposed to radioactive fall-out is considered to be the only one late radiation effect. RET gene in the happening of thyroid carcinomas is being paid close attention at present

  8. The Chernobyl nuclear accident and its consequences

    International Nuclear Information System (INIS)

    An AAEC Task Group was set up shortly after the accident at the Chernobyl Nuclear Power Plant to monitor and evaluate initial reports and to assess the implications for Australia. The Task Group issued a preliminary report on 9 May 1986. On 25-29 August 1986, the USSR released details of the accident and its consequences and further information has become available from the Nuclear Energy Agency of OECD and the World Health Organisation. The Task Group now presents a revised report summarising this information and commenting on the consequences from the Australian viewpoint

  9. Evaluation of Radiation Impacts of Spent Nuclear Fuel Storage (SNFS-2) of Chernobyl NPP - 13495

    International Nuclear Information System (INIS)

    Radiation effects are estimated for the operation of a new dry storage facility for spent nuclear fuel (SNFS-2) of Chernobyl NPP RBMK reactors. It is shown that radiation exposure during normal operation, design and beyond design basis accidents are minor and meet the criteria for safe use of radiation and nuclear facilities in Ukraine. (authors)

  10. NUCLEAR REACTOR

    Science.gov (United States)

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  11. Nuclear reactors

    International Nuclear Information System (INIS)

    This draft chart contains graphical symbols from which the type of (nuclear) reactor can be seen. They will serve as illustrations for graphical sketches. Important features of the individual reactor types are marked out graphically. The user can combine these symbols to characterize a specific reactor type. The basic graphical symbol is a square with a point in the centre. Functional groups can be depicted for closer specification. If two functional groups are not clearly separated, this is symbolized by a dotted line or a channel. Supply and discharge lines for coolant, moderator and fuel are specified in accordance with DIN 2481 and can be further specified by additional symbols if necessary. The examples in the paper show several different reactor types. (orig./AK)

  12. Nuclear reactors

    International Nuclear Information System (INIS)

    A nuclear reactor has a large prompt negative temperature coefficient of reactivity. A reactor core assembly of a plurality of fluid-tight fuel elements is located within a water-filled tank. Each fuel element contains a solid homogeneous mixture of 50-79 w/o zirconium hydride, 20-50 w/o uranium and 0.5-1.5 W erbium. The uranium is not more than 20 percent enriched, and the ratio of hydrogen atoms to zirconium atoms is between 1.5:1 and 7:1. The core has a long lifetime, E.G., at least about 1200 days

  13. Nuclear reactors

    International Nuclear Information System (INIS)

    In a liquid cooled nuclear reactor, the combination is described for a single-walled vessel containing liquid coolant in which the reactor core is submerged, and a containment structure, primarily of material for shielding against radioactivity, surrounding at least the liquid-containing part of the vessel with clearance therebetween and having that surface thereof which faces the vessel make compatible with the liquid, thereby providing a leak jacket for the vessel. The structure is preferably a metal-lined concrete vault, and cooling means are provided for protecting the concrete against reaching a temperature at which damage would occur. (U.S.)

  14. Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hogerton, John

    1964-01-01

    This pamphlet describes how reactors work; discusses reactor design; describes research, teaching, and materials testing reactors; production reactors; reactors for electric power generation; reactors for supply heat; reactors for propulsion; reactors for space; reactor safety; and reactors of tomorrow. The appendix discusses characteristics of U.S. civilian power reactor concepts and lists some of the U.S. reactor power projects, with location, type, capacity, owner, and startup date.

  15. Analysis of the Chernobyl reactor accident. Pt. 2

    International Nuclear Information System (INIS)

    Of the six items of improvement measures including a future improvement measure announced by the USSR regarding the accident of Chernobyl nuclear power plant No. 4 reactor, the three items having exercised large influence over the plant behavior at the accident were analyzed by WIMS-ATR, EUREKA-2 and other calculational codes, and technically evaluated. As a result the following have been made clear: (1) If 80 manual control rods are inserted 1.2 m deep from the core upper end, any accident can be prevented by further inserting them at a 0.4 m/s speed, even under such power increase conditions as in this accident. (2) If the additional 80 manual control rods are inserted into the reactor, the coolant void reactivity coefficient can be improved from 2x10-4 Δk/k/% void to 1.4x10-4 Δk/k/% void. Further if the coefficient is less than 1.5x10-4 Δk/k/% void, the power increase speed will slow down much more and similar accidents can fully be prevented by means of the currently designed control rods of the shut-down system. (orig.)

  16. Documents, used for drawing up the CCRX-report 'Radioactive contamination in the Netherlands caused by the reactor accident at Chernobyl'. Part 1

    International Nuclear Information System (INIS)

    In these documents the results are summarized of a large number of measurements and calculations performed by various Dutch organizations in consequence of the nuclear reactor accident at Chernobyl. refs.; figs.; tabs

  17. Nuclear reactors

    International Nuclear Information System (INIS)

    Disclosed is a nuclear reactor cooled by a freezable liquid has a vessel for containing said liquid and comprising a structure shaped as a container, and cooling means in the region of the surface of said structure for effecting freezing of said liquid coolant at and for a finite distance from said surface for providing a layer of frozen coolant on and supported by said surface for containing said liquid coolant. In a specific example, where the reactor is sodium-cooled, the said structure is a metal-lined concrete vault, cooling is effected by closed cooling loops containing NaK, the loops extending over the lined surface of the concrete vault with outward and reverse pipe runs of each loop separated by thermal insulation, and air is flowed through cooling pipes embedded in the concrete behind the metal lining. 7 claims, 3 figures

  18. Chernobyl

    International Nuclear Information System (INIS)

    The reactor accident in Chernobyl also had a memorable 1986 Spring for the region of Lake Constance. Salad had to be ploughed up in the vegetable fields, the feeding of cows with fresh grass was forbidden, and becquerel values played a decisive role in food purchases. Along with the measurement of radioactivity in rainwater, the authors began to take food and soil samples; hundreds of samples were tested in the laboratories of the University of Constance. They provided, in cooperation with public authorities, for the protection of the population against radiation, and explained, in numerous lectures, the significance of this incident to everyday life. Besides, they recorded recent scientific findings about the behaviour of radioactive substances in the environment. The book gives a summary of the findings. It also includes, besides a description of the events of May 1986 at Lake Constance, a presentation of the results of scientific investigations into Chernobyl's radioactivity. This is thus the first detailed account of the diverse effects of the reactor accident with respect to one particular region which, though more than 1500 km away, was surprisingly seriously affected, and which, owing to its special features - Lake Constance is Europe's most important drinking water reservoir -, is particularly endangered, in case of radioactive release. (orig./HP) With 2 separate tabs

  19. Accident at the Chernobyl nuclear power plant and its consequences

    International Nuclear Information System (INIS)

    In the early morning of April 26, 1986, as the culmination of an almost incredible series of errors that began 24 hours earlier, Unit 4 of the Chernobyl nuclear complex, a so-called RBMK-1000 reactor, suffered the worst accident in the history of commercial nuclear power. There was an uncontrolled nuclear excursion, release of a large amount of energy, possibly comparable to hundreds of pounds of TNT, blowing the top off the reactor. There was no containment, in the traditional American sense, so the roof of the building was blown out, an unprecedented amount of radioactivity was released to the biosphere, and a graphite fire was ignited, which burned for days. The radiation that was released spread through Eastern Europe (the world first learned of it through Swedish observations), bringing with it both official and unofficial protests that the Soviet Union had made no announcement of the radiation release until they were, in effect, caught. In fact, after a few days, the Soviets seemed to recognize that nuclear safety is a matter of international concern, and became quite open in their search for cooperation. They invited officials of the International Atomic Energy Agency (IAEA) to visit the area and to fly over the plant, and agreed, in the end, to make a complete disclosure of the details of the accident at a special meeting of IAEA in Vienna, August 25 to 29, 1986. In preparation for that meeting they distributed a lengthy (400 pages) report on the event. This paper reviews this report

  20. Nuclear reactor

    International Nuclear Information System (INIS)

    A nuclear reactor is described in which the core components, including fuel-rod assemblies, control-rod assemblies, fertile rod-assemblies, and removable shielding assemblies, are supported by a plurality of separate inlet modular units. These units are referred to as inlet module units to distinguish them from the modules of the upper internals of the reactor. The modular units are supported, each removable independently of the others, in liners in the supporting structure for the lower internals of the reactor. The core assemblies are removably supported in integral receptacles or sockets of the modular units. The liners, units, sockets and assemblies have inlet openings for entry of the fluid. The modular units are each removably mounted in the liners with fluid seals interposed between the opening in the liner and inlet module into which the fluid enters in the upper and lower portion of the liner. Each assembly is similarly mounted in a corresponding receptacle with fluid seals interposed between the openings where the fluid enters in the lower portion of the receptacle or fitting closely in these regions. As fluid flows along each core assembly a pressure drop is produced along the fluid so that the fluid which emerges from each core assembly is at a lower pressure than the fluid which enters the core assembly. However because of the seals interposed in the mountings of the units and assemblies the pressures above and below the units and assemblies are balanced and the units are held in the liners and the assemblies are held in the receptacles by their weights as they have a higher specific gravity than the fluid. The low-pressure spaces between each module and its liner and between each core assembly and its module is vented to the low-pressure regions of the vessel to assure that fluid which leaks through the seals does not accumulate and destroy the hydraulic balance

  1. Fallout from Chernobyl and atmospheric nuclear weapons tests. Chernobyl in perspective

    International Nuclear Information System (INIS)

    Some results and experience gained so far in Sweden after the Chernobyl accident are discussed in the light of knowledge obtained from the studies of fallout from the atmospheric nuclear weapons tests. Cesium-137, which was an important radionuclide in the bomb fallout, was still more important after Chernobyl. For most Swedes the external irradiation from deposited Cs-137 was the dominating source of irradiation. Studies of Chernobyl fallout have given new information in the fate of contamination in the forest environment, lakes, urban areas, on shielding factors for houses etc. The releases from Chernobyl gave relatively lower dietary doses than expected form the same amount of Cs-137, released through nuclear weapons testing. However lake fish, moose and forest products have shown to be of greater importance than earlier realized. The main reason for the lower dietary doses from Chernobyl was the seasonal distribution of the fallout with deposition just before the start of the growing season. The various actions taken also reduced the intake of Cs-137 and Cs-134. Otherwise, there are no radical differences in the behaviour of cesium in the environment after the bombs and after Chernobyl. Differences may exist, primarily during the first year, due to different fallout conditions, where also the physical-chemical form of the fallout might have been of some importance. The average Swede will have an effective dose commitment of around 1 mSv from Chernobyl, which is about the same as from the bomb fallout. The highest doses due to Chernobyl area received by people living in high deposition areas (>80 kBq/m2 of CS-137) and consuming larger amounts of game animals, lake fish and reindeer. (66 refs.)

  2. The consequences of the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    After the decay of the iodine isotopes the measuring campaigns, in addition to the measuring of soil pollution and pollution of products, concentrated on the way of the cesium isotopes through the food chain, especially in crops, milk, meat and mother's milk. A special programme was developed for the analysis of foreign basic substances for teas, essences and tinctures. In connection with the incorporation measurements in the university hospital Eppendorf the measurement campaigns provided the data material in order to calculate with the aid of the computer program ECOSYS of the GSF the effective dose equivalent which the inhabitants of Hamburg additionally take up due to the accident of Chernobyl. Consequences with regard to measuring methods and social consequences are mentioned. (DG)

  3. 30 years life with Chernobyl, 5 years life with Fukushima. Health consequences of the nuclear catastrophes of Chernobyl and Fukushima

    International Nuclear Information System (INIS)

    The IPPNW report on health consequences of the nuclear catastrophes of Chernobyl and Fukushima covers the following issues: Part.: 30 years life with Chernobyl: Summarized consequences of Chernobyl, the accident progression, basic data of the catastrophe, estimation of health hazards as a consequence of the severe accident of Chernobyl, health consequences for the liquidators, health consequences for the contaminated population, mutagenic and teratogenic effects. Part B: 5 years life with Fukushima: The start of the nuclear catastrophe, emissions and contamination, consequences of the nuclear catastrophe on human health, thyroid surveys in the prefecture Fukushima, consequences of the nuclear catastrophe on the ecosystem, outlook.

  4. Chernobyl

    International Nuclear Information System (INIS)

    This book brings together a comprehensive history of the first 18 months of the accident at Chernobyl and the complete pictorial record of the disaster, including many photographs never seen in the West. It also gives a unique record of subsequent events in the USSR involving the evacuation and re-housing of a population of 135,000, the building of the 400,000 tonne concrete sarcophagus over the damaged reactor and the decontamination of the environment which may take years to complete. The human dimension of radiation injuries is recreated in the cast histories and hospital photographs of the firemen who brought the blaze under control. The problems of contamination of the food chain for various countries is included, and recommendations for safe levels of activity in milk are described

  5. Chernobyl and the problem of international obligations regarding nuclear accidents

    International Nuclear Information System (INIS)

    This paper analyses the way nuclear law was put to the test by the Chernobyl accident - in particular international nuclear law - so as to propose a train of thought which might contribute to adopting and revising the legal system presently in force or even new orientations. It deals only with that part of nuclear law which concerns accidents and their consequences (NEA)

  6. The accident at Chernobyl and its implications for the safety of CANDU reactors

    International Nuclear Information System (INIS)

    In August 1986, a delegation of Canadians, including two members of the staff of the AECB (Atomic Energy Control Board), attended a post-accident review meeting in Vienna, at which Soviet representatives described the accident and its causes and consequences. On the basis of the information presented at that meeting, AECB staff conducted a study of the accident to ascertain its implications for the safety of CANDU nuclear reactors and for the regulatory process in Canada. The conclusion of this review is that the accident at Chernobyl has not revealed any important new information which would have an effect on the safety requirements for CANDU reactors as presently applied by the AECB. All important aspects of the accident and its causes have been considered by the AECB in the licensing process for currently licensed reactors. However a number of recommendations are made with respect to aspects of reactor safety which should be re-examined in order to reinforce this conclusion

  7. Nuclear research reactors

    International Nuclear Information System (INIS)

    It's presented data about nuclear research reactors in the world, retrieved from the Sien (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: research reactors by countries; research reactors by type; research reactors by fuel and research reactors by purpose. (E.G.)

  8. 25 years since Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    Environmental and food radioactivity surveillance in Romania, begun since the early 60's, with 47 laboratories from National Environment Radioactivity Surveillance Network (NERSN) in the framework of Ministry of Environmental and the network of 21 Radiation Hygiene Laboratories (RHL) from centers and institutes of the Ministry of Public Health. The surveillance was conducted by global beta and alpha measurements, necessary to make some quick decisions as well as gamma spectrometry to detect high and low resolution profile accident. Thus the two networks together and some departmental labs recorded from the first moments (since April 30, 1986) the presence of the contaminated radioactive cloud originated from Ukraine, after the nuclear accident on 26 April 1986 at Chernobyl NPP, on the Romanian territory. NERSN followed up the radioactive contamination of air (gamma dose rate, atmospheric aerosols and total deposition), surface water, uncultivated soil, and spontaneous vegetation while the RHL monitored the drinking water and food. Early notification of this event allowed local and central authorities to take protective measures like: administration of stable iodine, advertisements in media on avoiding consumption of heavily contaminated food, prohibition of certain events that took place outdoors, interdiction of drinking milk and eating milk products for one month long. Most radionuclides, fission and activation products (22 radionuclides), released during the accident, have been determined in the environmental factors. A special attention was paid to radionuclides like Sr-90, I-131, Cs-134 and Cs-137, especially in aerosol samples, where the maximum values were recorded on Toaca Peak (Ceahlau Mountain) on May, the first, 1986: 103 Bq/m3, I-131, 63 Bq/m3, Cs-137. The highest value of I-131 in drinking water, 21 Bq/l, was achieved on May, the third, 1986 in Bucharest and in cow milk exceeded the value of 3000 Bq/l. For sheep milk some sporadic values exceeding 10

  9. Nuclear reactor

    International Nuclear Information System (INIS)

    In order to reduce neutron embrittlement of the pressue vessel of an LWR, blanked off elements are fitted at the edge of the reactor core, with the same dimensions as the fuel elements. They are parallel to each other, and to the edge of the reactor taking the place of fuel rods, and are plates of neutron-absorbing material (stainless steel, boron steel, borated Al). (HP)

  10. Transgenic plants are sensitive bioindicators of nuclear pollution caused by the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Kovalchuk, I.; Kovalchuk, O. [Ivano-Frankivsk State Medical Academy (Ukraine)]|[Friedrich Miescher Inst., Basel (Switzerland); Arkhipov, A. [Chernobyl Scientific and Technical Center of International Research (Ukraine); Hohn, B. [Friedrich Miescher Inst., Basel (Switzerland)

    1998-11-01

    To evaluate the genetic consequences of radioactive contamination originating from the Nuclear reactor accident of Chernobyl on indigenous populations of plants and animals, it is essential to determine the rates of accumulating genetic changes in chronically irradiated populations. An increase in germline mutation rates in humans living close to the Chernobyl Nuclear Power Plant site, and a two- to tenfold increase in germline mutations in barn swallows breeding in Chernobyl have been reported. Little is known, however, about the effects of chronic irradiation on plant genomes. Ionizing radiation causes double-strand breaks in DNA, which are repaired via illegitimate or homologous recombination. The authors make use of Arabidopsis thaliana plants carrying a {beta}-glucuronidase marker gene as a recombination substrate to monitor genetic alterations in plant populations, which are caused by nuclear pollution of the environment around Chernobyl. A significant increase in somatic intrachromosomal recombination frequencies was observed at nuclear pollution levels from 0.1--900 Ci/km{sup 2}, consistent with an increase in chromosomal aberrations. This bioindicator may serve as a convenient and ethically acceptable alternative to animal systems.

  11. Transgenic plants are sensitive bioindicators of nuclear pollution caused by the Chernobyl accident

    International Nuclear Information System (INIS)

    To evaluate the genetic consequences of radioactive contamination originating from the Nuclear reactor accident of Chernobyl on indigenous populations of plants and animals, it is essential to determine the rates of accumulating genetic changes in chronically irradiated populations. An increase in germline mutation rates in humans living close to the Chernobyl Nuclear Power Plant site, and a two- to tenfold increase in germline mutations in barn swallows breeding in Chernobyl have been reported. Little is known, however, about the effects of chronic irradiation on plant genomes. Ionizing radiation causes double-strand breaks in DNA, which are repaired via illegitimate or homologous recombination. The authors make use of Arabidopsis thaliana plants carrying a β-glucuronidase marker gene as a recombination substrate to monitor genetic alterations in plant populations, which are caused by nuclear pollution of the environment around Chernobyl. A significant increase in somatic intrachromosomal recombination frequencies was observed at nuclear pollution levels from 0.1--900 Ci/km2, consistent with an increase in chromosomal aberrations. This bioindicator may serve as a convenient and ethically acceptable alternative to animal systems

  12. Types of Nuclear Reactors

    International Nuclear Information System (INIS)

    The presentation is based on the following areas: Types of Nuclear Reactors, coolant, moderator, neutron spectrum, fuel type, pressurized water reactor (PWR), boiling water reactor (BWR) reactor pressurized heavy water (PHWR), gas-cooled reactor, RBMK , Nuclear Electricity Generation,Challenges in Nuclear Technology Deployment,EPR, APR1400, A P 1000, A PWR, ATMEA 1, VVER-1000, A PWR, VVER 1200, Boiling Water Reactor, A BWR, A BWR -II, ESBUR, Ke ren, AREVA, Heavy Water Reactor, Candu 6, Acr-1000, HWR, Bw, Iris, CAREM NuCcale, Smart, KLT-HOS, Westinghouse small modular Reactor, Gas Cooled Reactors, PBMR.

  13. Development of the nuclear safety regime and support programs for Chernobyl

    International Nuclear Information System (INIS)

    The reactor accident of Chernobyl and its consequences continue to be among the most important topics of international politics even now, 25 years after the event. The international community, often with Germany in the lead, takes the concerns caused by the accident seriously and responds realistically to the questions raised by the accident. A comprehensive action program has been initiated. The reactor catastrophe of Chernobyl has shown very clearly that protection from the hazards of the peaceful uses of nuclear power, as defined as a main goal in national atomic energy laws, depends not only on the safety of nuclear power plants operated in the respective country but also on the safety of such plants run in other countries. Decommissioning the nuclear power plants in one's country therefore is not going to remove the risk of potentially becoming a victim of accidents elsewhere. The decision for or against using nuclear power, however, continues to be taken nationally. The risk can be further reduced only by ensuring worldwide the highest possible level of safety of nuclear power plants. The Chernobyl incident de facto initiated the establishment of a comprehensive international safety regime as well as extensive measures strengthening international cooperation in nuclear safety and radiation protection. A whole system of international conventions has since been established. Many multilateral support programs as well as bilateral or trilateral projects with active German participation have helped Ukraine to overcome the consequences of the Chernobyl accident on the part of industry and also establish and strengthen, in technical terms, an independent licensing and supervisory authority under nuclear law. (orig.)

  14. Nuclear reactor

    International Nuclear Information System (INIS)

    In an improved reactor core for a high conversion BWR reactor, Pu-breeding type BWR type reactor, Pu-breeding type BWR type rector, FEBR type reactor, etc., two types of fuel assemblies are loaded such that fuel assemblies using a channel box of a smaller irradiation deformation ratio are loaded in a high conversion region, while other fuel assemblies are loaded in a burner region. This enables to suppress the irradiation deformation within an allowable limit in the high conversion region where the fast neutron flux is high and the load weight from the inside of the channel box due to the pressure loss is large. At the same time, the irradiation deformation can be restricted within an allowable limit without deteriorating the neutron economy in the burner region in which fast neutron flux is low and the load weight from the inside of the channel box is small since a channel box with smaller neutron absorption cross section or reduced wall thickness is charged. As a result, it is possible to prevent structural deformations such as swelling of the channel box, bending of the entire assemblies, bending of fuel rods, etc. (K.M.)

  15. The Chernobyl reactor accident - provisional results and consequences

    International Nuclear Information System (INIS)

    Those involved at present in the analysis and estimation of consequences of the Chernobyl reactor accident are in a dilemma: While a worried and uncertain Western German public is calling for information the Soviet Union was practicing a rigorously restrictive information policy. Both the severity of the reactor accident and the complexity of events do urgently require the acquisition and evaluation of facts which will provide the basis for an objective factual discussion of issues and possible measures. The paper abstracted is trying to assess the alleged causes of the accident and estimate possible consequences. However, all attempts of that kind are based but on incomplete and dubious information as of May 21st, 1986. (orig.)

  16. Nuclear reactor

    International Nuclear Information System (INIS)

    The liquid metal (sodium) cooled fast breeder reactor has got fuel subassemblies which are bundled and enclosed by a common can. In order to reduce bending of the sides of the can because of the load caused by the coolant pressure the can has got a dodecagon-shaped crosssection. The surfaces of the can may be of equal width. One out of two surfaces may also be convex towards the center. (RW)

  17. Nuclear reactor

    International Nuclear Information System (INIS)

    A detector having high sensitivity to fast neutrons and having low sensitivity to thermal neutrons is disposed for reducing influences of neutron detector signals on detection values of neutron fluxes when the upper end of control rod pass in the vicinity of the neutron flux detector. Namely, the change of the neutron fluxes is greater in the thermal neutron energy region while it is smaller in the fast neutron energy region. This is because the neutron absorbing cross section of B-10 used as neutron absorbers of control rods is greater in the thermal neutron region and it is smaller in the fast neutron region. As a result, increase of the neutron detection signals along with the local neutron flux change can be reduced, and detection signals corresponding to the reactor power can be obtained. Even when gang withdrawal of operating a plurality of control rods at the same time is performed, the reactor operation cycle can be measured accurately, thereby enabling to shorten the reactor startup time. (N.H.)

  18. Nuclear reactor

    International Nuclear Information System (INIS)

    Cover gas spaces for primary coolant vessel, such as a reactor container, a pump vessel and an intermediate heat exchanger vessel are in communication with each other by an inverted U-shaped pressure conduit. A transmitter and a receiver are disposed to the pressure conduit at appropriate positions. If vibration frequencies (pressure vibration) from low frequency to high frequency are generated continuously from the transmitter to the inside of the communication pipe, a resonance phenomenon (air-column resonance oscillation) is caused by the inherent frequency or the like of the communication pipe. The frequency of the air-column resonance oscillation is changed by the inner diameter and the clogged state of the pipelines. Accordingly, by detecting the change of the air-column oscillation characteristics by the receiver, the clogged state of the flow channels in the pipelines can be detected even during the reactor operation. With such procedures, steams of coolants flowing entrained by the cover gases can be prevented from condensation and coagulation at a low temperature portion of the pipelines, otherwise it would lead clogging in the pipelines. (I.N.)

  19. Chernobyl nuclear accident: Effects on food. (Latest citations from the Food Science and Technology Abstracts database). Published Search

    International Nuclear Information System (INIS)

    The bibliography contains citations concerning studies and measurements of the radioactive contamination by the Chernobyl nuclear reactor accident of food and the food chain. The studies cover meat and dairy products, vegetables, fish, food chains, and radioactive contamination of agricultural farms and lands. (Contains 250 citations and includes a subject term index and title list.)

  20. Introduction of Nuclear Reactor Engineering

    International Nuclear Information System (INIS)

    This book introduces development, status, supply and demand and resource of nuclear reactor. It deals with basic knowledge of nuclear reactor, which are reactor system, heat recovery in reactor core, structural feature in reactor, materials of structure in reactor, shielding of gamma ray, shielding of reactor, safety and environmental problem of nuclear power plant, nuclear fuel and economical efficiency of nuclear energy.

  1. Initiative for decommissioning of Chernobyl Nuclear Plant

    International Nuclear Information System (INIS)

    Construction of the New Safety Confinement (NSC) for the Chernobyl unit 4 started 2010, after about 25 years of Chernobyl accident and will complete summer of 2015. This project is being conducted by assistance of EU, USA and other countries including Japan. NSC can cover the whole facility of unit 4, and is installed various components or tools including big bridge crane for decommissioning unit 4 and has durability over 100 years. In addition to construction of NSC, various activities for preparing the decommissioning including developing the technology of monitoring the inside of destructive building and remote access technologies. The spent fuel storage facility and waste proposal facilities are also constructed.. These activities include many valuable information about how to smoothly conduct the decommissioning and it would be important to learn the above activities in conducting the post-processing activities on the Fukushima-Daiichi accident successfully. (author)

  2. Chernobyl coverage: how the US media treated the nuclear industry

    International Nuclear Information System (INIS)

    This study attempted to uncover whether enough background information about nuclear power and the nuclear industries in the USA, USSR and Eastern and Western Europe had been included during the first two weeks of US coverage of the Chernobyl accident so that Americans would not be misled in their understanding of and attitudes toward nuclear power in general. It also sought to determine if reporters took advantage of the Chernobyl accident to attack nuclear technology or the nuclear industry in general. Coverage was analysed in five US newspapers and on the evening newscasts of the three major US television networks. Despite heavy coverage of the accident, no more than 25% of the coverage was devoted to information on safety records, history of accidents and current status of nuclear industries. Not enough information was provided to help the public's level of understanding of nuclear power or to put the Chernobyl accident in context. However, articles and newscasts generally balanced use of pro- and anti-nuclear statements, and did not include excessive amounts of fear-inducing and negative information. (author)

  3. Cancer following the Chernobyl nuclear accident: what we have learned

    International Nuclear Information System (INIS)

    Full text: Twenty years later, the accident at the Chernobyl nuclear plant in Ukraine remains the largest of its kind. Ukraine and Belarus in particular were heavily contaminated, principally with radioiodine which concentrate in the thyroid gland. Before Chernobyl, little was known about, the risk of thyroid cancer in those exposed to radioiodine as children, although there were some reports based on exposed adults. A number of epidemiologic studies have since been conducted to evaluate populations in Chernobyl-exposed areas. These have provided valuable information about the risks of Iodine-131 to children. I will summarize these studies and the lessons the international scientific and medical community have learned from this research on Chernobyl. Finally, I will describe progress with a seminal project: the Belarus-American Study of Thyroid Cancer and Other Thyroid Diseases following the Chernobyl Accident. This collaborative effort has involved screening a cohort of approximately 12,000 individuals exposed as young persons at two year intervals for three consecutive cycles. This is the first study, cohort in design, to be based on individual, measured doses and thus can provide the best quantitative estimate of the dose-response relationship between Iodine-131 and risk of thyroid cancer

  4. Chernobyl today. Impressions and informations from a visit to the nuclear power plant in July 1995

    International Nuclear Information System (INIS)

    A visit to Chernobyl by Western experts was organized within the 1995 Nuclear Technology Conference. The region, which had been evacuated after the reactor accident in the Chernobyl-4 nuclear generating unit on April 26, 1986, now again offers employment to some 15,000 people. 120 scientific organizations are conducting studies in the protected zone. No indications of any consequences of the accident can be seen in the natural environment. As the manager of the power plant put it: 'This is a good region to live in.' In order to maintain this standard of living, the agencies responsible in Ukraine plan to repair unit 2, which has been down because of a fire in the turbine building since 1991, resynchronize it with the power grid, and run it up until 2002. Unit 1 is to be decommissioned in 1998; unit 3, in 2001. The biggest problem on site is the stability of the sarcophagus around unit 4. (orig./UA)

  5. Nuclear reactor physics

    CERN Document Server

    Stacey, Weston M

    2010-01-01

    Nuclear reactor physics is the core discipline of nuclear engineering. Nuclear reactors now account for a significant portion of the electrical power generated worldwide, and new power reactors with improved fuel cycles are being developed. At the same time, the past few decades have seen an ever-increasing number of industrial, medical, military, and research applications for nuclear reactors. The second edition of this successful comprehensive textbook and reference on basic and advanced nuclear reactor physics has been completely updated, revised and enlarged to include the latest developme

  6. Immediate medical consequences of nuclear accidents: lessons from Chernobyl

    International Nuclear Information System (INIS)

    The immediate medical response to the nuclear accident at the Chernobyl nuclear power station involved containment of the radioactivity and evacuation of the nearby population. The next step consisted of assessment of the radiation dose received by individuals, based on biological dosimetry, and treatment of those exposed. Medical care involved treatment of skin burns; measures to support bone marrow failure, gastrointestinal tract injury, and other organ damage (i.e., infection prophylaxis and transfusions) for those with lower radiation dose exposure; and bone marrow transplantation for those exposed to a high dose of radiation. At Chernobyl, two victims died immediately and 29 died of radiation or thermal injuries in the next three months. The remaining victims of the accident are currently well. A nuclear accident anywhere is a nuclear accident everywhere. Prevention and cooperation in response to these accidents are essential goals

  7. Dose estimates in Japan following the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Estimates have been made of the maximum individual doses and the collective doses in Japan following the Chernobyl reactor accident. Based on the measured data of ground deposition and radionuclide concentrations in air, raw milk, milk on sale and leafy vegetables, the doses from some significant radionuclides were calculated for 5 typical exposure pathways; cloudshine, groundshine, inhalation, ingestion of milk and leafy vegetables. The maximum effective dose equivalents for hypothetical individuals were calculated to be 1.8 mrem for adults, 3.7 mrem for children and 6.0 mrem for infants. The collective effective dose equivalent in Japan was estimated to be 5.8 x 104 man · rem; 0.50 mrem of the average dose per capita. (author)

  8. Consequences of the nuclear power plant accident at Chernobyl.

    OpenAIRE

    Ginzburg, H M; Reis, E.

    1991-01-01

    The Chernobyl Nuclear Power Plant accident, in the Ukrainian Soviet Socialist Republic (SSR), on April 26, 1986, was the first major nuclear power plant accident that resulted in a large-scale fire and subsequent explosions, immediate and delayed deaths of plant operators and emergency service workers, and the radioactive contamination of a significant land area. The release of radioactive material, over a 10-day period, resulted in millions of Soviets, and other Europeans, being exposed to m...

  9. Lessons of the Chernobyl Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    Insensitivity of radiation without measuring apparatus and health outcome observed in the atomic bomb survivors of Hiroshima and Nagasaki are major sources that make people fear the possible late effects of radiation exposure attributable to nuclear power plant accident. However, the health conditions of people in the last 20 years around Chernobyl indicated the necessity to review the risk assessment suggesting that effects of radiation exposure may considerably be different between the atomic bombing and nuclear power plant accident. (author)

  10. What did change in the FRG after the Chernobyl reactor accident? On the situation in churches

    International Nuclear Information System (INIS)

    The author discusses in detail the implications of the reactor desaster of Chernobyl both in terms of social ethics and theology and demonstrates processes within the churches and official church statements. (DG)

  11. The accident at the Chernobyl' nuclear power plant and its consequences

    International Nuclear Information System (INIS)

    The material is taken from the conclusions of the Government Commission on the causes of the accident at the fourth unit of the Chernobyl' nuclear power plant and was prepared by a team of experts appointed by the USSR State Committee on the Utilization of Atomic Energy. It contains general material describing the accident, its causes, the action taken to contain the accident and to alleviate its consequences, the radioactive contamination and health of the population and some recommendations for improving nuclear power safety. 7 annexes are devoted to the following topics: water-graphite channel reactors and operating experience with RBMK reactors, design of the reactor plant, elimination of the consequences of the accident and decontamination, estimate of the amount, composition and dynamics of the discharge of radioactive substances from the damaged reactor, atmospheric transport and radioactive contamination of the atmosphere and of the ground, expert evaluation and prediction of the radioecological state of the environment in the area of the radiation plume from the Chernobyl' nuclear power station, medical-biological problems. A separate abstract was prepared for each of these annexes. The slides presented at the post-accident review meeting are grouped in two separate volumes

  12. International nuclear law in the 25 years between Chernobyl and Fukushima and beyond

    International Nuclear Information System (INIS)

    This paper is dedicated both to legal developments since the accident at the Chernobyl nuclear power plant 25 years ago and possible legal implications of the accidents at Fukushima Daiichi which occurred after Japan was struck by a devastating earthquake on 11 March 2011. Following the accident at Three Mile Island in 1979 and at Chernobyl in 1986, Fukushima will be remembered as the third major accident in the history of civilian nuclear power reactors. Yet Chernobyl was and remains the worst trauma in this history as a result of which nuclear developments slowed down significantly. Eventually, the industry emerged as a safer and stronger technology, particularly because the 25 years between Chernobyl and Fukushima were marked by an exceptional national and international commitment to nuclear safety and emergency preparedness so as to prevent accidents and minimise potential damages, if such occur. From a legal point of view it is safe to say that the nuclear industry is one of the most strictly regulated. However, it is equally safe to say that there is no zero risk technology and that accidents can happen. For several weeks after the tragic events in Japan the world's focus turned - justifiably so - to the Fukushima Daiichi nuclear power units. It was nevertheless astonishing to observe that the real tragedy, the terrible loss of lives, swept away villages, and the chaos following the breakdown of all kinds of infrastructure were treated as a sideshow compared with the dramatic images of explosions at the Fukushima Daiichi units and helicopters trying to drop seawater into the spent fuel pools. The live broadcasting of accidents might present one of the first lessons to be learnt in our Internet and 24-hour news channel era which did not exist at the time of Chernobyl. The international legal community will also face challenges as the accident has put 25 years of international co-operation and international nuclear law-making to its first serious test. The

  13. Nuclear Reactor Physics

    Science.gov (United States)

    Stacey, Weston M.

    2001-02-01

    An authoritative textbook and up-to-date professional's guide to basic and advanced principles and practices Nuclear reactors now account for a significant portion of the electrical power generated worldwide. At the same time, the past few decades have seen an ever-increasing number of industrial, medical, military, and research applications for nuclear reactors. Nuclear reactor physics is the core discipline of nuclear engineering, and as the first comprehensive textbook and reference on basic and advanced nuclear reactor physics to appear in a quarter century, this book fills a large gap in the professional literature. Nuclear Reactor Physics is a textbook for students new to the subject, for others who need a basic understanding of how nuclear reactors work, as well as for those who are, or wish to become, specialists in nuclear reactor physics and reactor physics computations. It is also a valuable resource for engineers responsible for the operation of nuclear reactors. Dr. Weston Stacey begins with clear presentations of the basic physical principles, nuclear data, and computational methodology needed to understand both the static and dynamic behaviors of nuclear reactors. This is followed by in-depth discussions of advanced concepts, including extensive treatment of neutron transport computational methods. As an aid to comprehension and quick mastery of computational skills, he provides numerous examples illustrating step-by-step procedures for performing the calculations described and chapter-end problems. Nuclear Reactor Physics is a useful textbook and working reference. It is an excellent self-teaching guide for research scientists, engineers, and technicians involved in industrial, research, and military applications of nuclear reactors, as well as government regulators who wish to increase their understanding of nuclear reactors.

  14. Report on the accident at the Chernobyl Nuclear Power Station

    International Nuclear Information System (INIS)

    This report presents the compilation of information obtained by various organizations regarding the accident (and the consequences of the accident) that occurred at Unit 4 of the nuclear power station at Chernobyl in the USSR on April 26, 1986. The various authors are identified in a footnote to each chapter. An overview of the report is provided. Very briefly the other chapters cover: the design of the Chernobyl nuclear station Unit 4; safety analyses for Unit 4; the accident scenario; the role of the operator; an assessment of the radioactive release, dispersion, and transport; the activities associated with emergency actions; and information on the health and environmental consequences from the accident. These subjects cover the major aspects of the accident that have the potential to present new information and lessons for the nuclear industry in general

  15. Chernobyl

    International Nuclear Information System (INIS)

    Due to southeasterly wind and rainfall during the critical days after the Chernobyl accident, Norway got a substantial part of the cesium isotopes released. The radioactive fallout followed closely the rainfall and was mainly concentrated to some thin populated areas in the central parts of the country. This report summerize the results from a post-Chernobyl research program on aquatic and terrestrial ecosystems in contaminated areas. Pathways, processes and factors determining the Cs-137 concentration in soil, plant, water, fish and wild animal were investigated. 84 refs., 40 figs., 20 tabs

  16. Compendium of the Environmental Measurements Laboratory's research projects related to the Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    Following the accident at the Chernobyl nuclear reactor power station in the USSR on April 26, 1986, the Environmental Measurements Laboratory (EML) initiated a number of research projects as follows: (1) selected sites in both the Deposition and Surface Air networks were alerted and their sampling protocols adjusted to accommodate the anticipated arrival times and activity concentrations of the Chernobyl debris; (2) a number of cooperative programs involving field work, sampling, analysis and data interpretation were set up with institutions and scientists in other countries; (3) EML's Regional Baseline Station at Chester, NJ, as well as the roof of the Laboratory in New York City, provided bases for sampling and measurements to study the radionuclide concentrations, radiation levels, physical characteristics and potential biological implications of the Chernobyl fallout on the northeastern United States; and (4) the resulting fallout from the Chernobyl accident provided an 'experiment of opportunity' in that it enabled us to study fresh fission product deposition using collection systems resurrected from the 1950's and 1960's for comparison with current state-of-the-art methodology. The 13 reports of this volume have been entered separately into the data base

  17. Compendium of the Environmental Measurements Laboratory's research projects related to the Chernobyl nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Volchok, H L; Chieco, N [comps.

    1986-10-01

    Following the accident at the Chernobyl nuclear reactor power station in the USSR on April 26, 1986, the Environmental Measurements Laboratory (EML) initiated a number of research projects as follows: (1) selected sites in both the Deposition and Surface Air networks were alerted and their sampling protocols adjusted to accommodate the anticipated arrival times and activity concentrations of the Chernobyl debris; (2) a number of cooperative programs involving field work, sampling, analysis and data interpretation were set up with institutions and scientists in other countries; (3) EML's Regional Baseline Station at Chester, NJ, as well as the roof of the Laboratory in New York City, provided bases for sampling and measurements to study the radionuclide concentrations, radiation levels, physical characteristics and potential biological implications of the Chernobyl fallout on the northeastern United States; and (4) the resulting fallout from the Chernobyl accident provided an 'experiment of opportunity' in that it enabled us to study fresh fission product deposition using collection systems resurrected from the 1950's and 1960's for comparison with current state-of-the-art methodology. The 13 reports of this volume have been entered separately into the data base.

  18. Chernobyl and the media

    International Nuclear Information System (INIS)

    The way the media reported the Chernobyl nuclear reactor accident was discussed at a day seminar in Birmingham in July. Contributors were from the Forsmark nuclear power station in Sweden where the disaster was first noticed, the International Atomic Energy Agency, the Russian film industry, French TV and SCRAM. Personal experiences and opinions of Chernobyl and the media were discussed. The approach in West Germany, France, Finland and the United Kingdom is compared. (UK)

  19. Requirements of coolants in nuclear reactors

    International Nuclear Information System (INIS)

    This study discussed the purposes and types of coolants in nuclear reactors to generate electricity. The major systems and components associated with nuclear reactors are cooling system. There are two major cooling systems utilized to convert the heat generated in the fuel into electrical power. The primary system transfers the heat from the fuel to the steam generator, where the secondary system begins. The steam formed in the steam generator is transferred by the secondary system to the main turbine generator, where it s converted into electricity after passing through the low pressure turbine. There are various coolants used in nuclear reactors-light water, heavy water and liquid metal. The two major types of water-cooled reactors are pressurized water reactors (PWR) and boiling water reactors (BWR) but pressurized water reactors are more in the world. Also discusses this study the reactors and impact of the major nuclear accidents, in the April 1986 disaster at the Chernobyl nuclear power plant in Ukraine was the product operators, and in the March 2011 at the Fukushima nuclear power plant in Japan was the product of earthquake of magnitude 9.0, the accidents caused the largest uncontrolled radioactive release into the environment.(Author)

  20. Chernobyl

    International Nuclear Information System (INIS)

    This report relates the Chernobylsk accident, why following a succession of technical malfunctions and human errors, reactor no. 4 of the Chernobylsk nuclear power plant explodes on April 26. 1986. Radioactive dust, aerosols and gases (including caesium and iodine) are ejected into atmosphere. The regions worst hit are in the immediate vicinity of the plant, but deposits are very uneven, producing a leopard spot type of pattern. Propelled by easterly winds, the radioactive cloud disperses increasingly, scattering deposits over the whole of Europe. At the beginning of May, the cloud arrives in France. the eastern portion of the country is most strongly affected. Ground, water and agriculture are contaminated by caesium deposits in Belarus, Ukraine and Russian Federation. About the contamination in France, ground contamination is slight, fourteen years later, however, it is still detectable. Relative to the impact on health in the vicinity of Chernobylsk plant, it is hard to assess this impact. Among children in Southern Belarus, the number of thyroid cancers has risen one hundred-fold. In France, the doses delivered represents generally less than 1% of the average annual dose from radioactivity of natural origin. But some of the doses received were higher. Today, the protective sarcophagus covering the damaged reactor is fragile. Reactor no.3, still in operation, continues to pose a risk but the shutdown is provided for december 2000. (N.C.)

  1. 15 years after Chernobyl. Nuclear power and climate change?

    International Nuclear Information System (INIS)

    Fifteen years after two massive explosions and a subsequent fire released a giant radioactive cloud into the atmosphere over the Chernobyl nuclear power plant located in what used to be the USSR, 388 farms with 230,000 sheep in Wales, England and Scotland are still subject to restriction orders. The contamination levels stand at several hundred Becquerels of cesium per kilogram of meat, too much to be consumed by human beings. The sheep have to be moved for some time to low or non-contaminated pastures in order to allow the bodies to loose some of their radioactivity before they can be slaughtered. For many countries the 1986 Chernobyl catastrophe came a public turning point for the future of nuclear energy. (author)

  2. 15 years after Chernobyl. Nuclear power and climate change?

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M

    2001-04-01

    Fifteen years after two massive explosions and a subsequent fire released a giant radioactive cloud into the atmosphere over the Chernobyl nuclear power plant located in what used to be the USSR, 388 farms with 230,000 sheep in Wales, England and Scotland are still subject to restriction orders. The contamination levels stand at several hundred Becquerels of cesium per kilogram of meat, too much to be consumed by human beings. The sheep have to be moved for some time to low or non-contaminated pastures in order to allow the bodies to loose some of their radioactivity before they can be slaughtered. For many countries the 1986 Chernobyl catastrophe came a public turning point for the future of nuclear energy. (author)

  3. Impacts of the Chernobyl reactor accident on the territories of the former German Democratic Republic in 1989

    International Nuclear Information System (INIS)

    Several reports by SAAS (the Nuclear Safety and Radiation Protection Board of the German Democratic Republic) have been discussing the effects of the Chernobyl reactor accident through 1989. Only a summary had been published for 1989 in the environmental radioactivity annual report. Institut fuer Umweltschutz had been in charge of the publication of a more detailed account as part of the 'environmental report' but the project was abandoned since the institute was wound up as of October 1990. The report under review concludes the separate German Demoncratic Republic reporting by publishing the part of the manuscript on environmental contamination caused by artificial radionuclides which gives the 1989 situation on the basis of the previous results on the effects of the Chernobyl reactor accident. The appendix lists the SAAS reports published in the past. (orig./BBR)

  4. The consequences of the Chernobyl nuclear accident in Greece

    International Nuclear Information System (INIS)

    In this report the radioactive fallout on Greece from the Chernobyl nuclear accident is described. The flow pattern to Greece of the radioactive materials released, the measurements performed on environmental samples and samples of the food chain, as well as some estimations of the population doses and of the expected consequences of the accident are presented. The analysis has shown that the radiological impact of the accident in Greece can be considered minor. (J.K.)

  5. Soviet medical response to the Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    The nuclear accident at Chernobyl was the worst in the history of nuclear power. It tested the organized medical response to mass radiation casualties. This article reviews the Soviet response as reported at the 1986 postaccident review meeting in Vienna and as determined from interviews. The Soviets used three levels of care: rescue and first aid at the plant site; emergency treatment at regional hospitals; and definitive evaluation and treatment in Moscow. Diagnosis, triage, patient disposition, attendant exposure, and preventive actions are detailed. The United States would be well advised to organize its resources definitively to cope with future nonmilitary nuclear accidents

  6. Nuclear reactor theory

    International Nuclear Information System (INIS)

    This textbook is composed of two parts. Part 1 'Elements of Nuclear Reactor Theory' is composed of only elements but the main resource for the lecture of nuclear reactor theory, and should be studied as common knowledge. Much space is therefore devoted to the history of nuclear energy production and to nuclear physics, and the material focuses on the principles of energy production in nuclear reactors. However, considering the heavy workload of students, these subjects are presented concisely, allowing students to read quickly through this textbook. (J.P.N.)

  7. The nuclear safety account and the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    In 1993, the G-7 officially proposed that the European Bank for Reconstruction and Development set up the Nuclear Safety Account (NSA) and act as the Account's secretariat. The Bank's Board of Directors approved this proposal and the Rules of the NSA on 22 March 1993 and the NSA became effective on 14 April 1993. The NSA finances, through grants, operational and near-term technical safety improvements for Soviet-designed nuclear reactors in the countries of the former Soviet Union, central and eastern Europe. Priority is given to those reactors which present the highest level of risk that can be significantly reduced by short-term and cost-effective safety improvements, and which are necessary to ensure the continuing electricity supply in the region. Efforts are therefore focused on WWER 440/230 and RBMK types of reactors and on the purchase of equipment as opposed to studies, which a number of donors already fund. Finance from the NSA is not used to extend the operating lifetime of unsafe reactors

  8. Fossil nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Maurette, M.

    1976-01-01

    The discussion of fossil nuclear reactors (the Oklo phenomenon) covers the earth science background, neutron-induced isotopes and reactor operating conditions, radiation-damage studies, and reactor modeling. In conclusion possible future studies are suggested and the significance of the data obtained in past studies is summarized. (JSR)

  9. Research Nuclear Reactors

    International Nuclear Information System (INIS)

    Published in English and in French, this large report first proposes an overview of the use and history of research nuclear reactors. It discusses their definition, and presents the various types of research reactors which can be either related to nuclear power (critical mock-ups, material test reactors, safety test reactors, training reactors, prototypes), or to research (basic research, industry, health), or to specific particle physics phenomena (neutron diffraction, isotope production, neutron activation, neutron radiography, semiconductor doping). It reports the history of the French research reactors by distinguishing the first atomic pile (ZOE), and the activities and achievements during the fifties, the sixties and the seventies. It also addresses the development of instrumentation for research reactors (neutron, thermal, mechanical and fission gas release measurements). The other parts of the report concern the validation of neutronics calculations for different reactors (the EOLE water critical mock-up, the MASURCA air critical mock-up dedicated to fast neutron reactor study, the MINERVE water critical mock-up, the CALIBAN pulsed research reactor), the testing of materials under irradiation (OSIRIS reactor, laboratories associated with research reactors, the Jules Horowitz reactor and its experimental programs and related devices, irradiation of materials with ion beams), the investigation of accident situations (on the CABRI, Phebus, Silene and Jules Horowitz reactors). The last part proposes a worldwide overview of research reactors

  10. Research nuclear reactors

    International Nuclear Information System (INIS)

    Since the divergence of the first nuclear reactor in 1942, about 600 research or test reactors have been built throughout the world. Today 255 research reactors are operating in 57 countries and about 70% are over 25 years old. Whereas there are very few reactor types for power plants because of rationalization and standardisation, there is a great diversity of research reactors. We can divide them into 2 groups: heavy water cooled reactors and light water moderated reactors. Heavy water cooled reactors are dedicated to the production of high flux of thermal neutrons which are extracted from the core by means of neutronic channels. Light water moderated reactors involved pool reactors and slightly pressurized closed reactors, they are polyvalent but their main purposes are material testing, technological irradiations, radionuclide production and neutron radiography. At the moment 8 research reactors are being built in Canada, Germany, Iran, Japan, Kazakhstan, Morocco, Russia and Slovakia and 8 others are planned in 7 countries (France, Indonesia, Nigeria, Russia, Slovakia, Thailand and Tunisia. Different research reactors are described: Phebus, Masurca, Phenix and Petten HFR. The general principles of nuclear safety applied to test reactors are presented. (A.C.)

  11. Analysis of fluid-structure interaction and structural response of Chernobyl-4 reactor

    International Nuclear Information System (INIS)

    On April 26, 1986, an accident occurred at the Chernobyl-4 Nuclear Power Plant in the Soviet Union. A post accident meeting was held in Vienna during the week of August 25, 1986. In mid-July 1986, the DOE formed a team to analyze the accident, including experts from the national laboratories such as Argonne National Laboratory, Brookhaven National Laboratory, Oak Ridge National Laboratory, and Pacific Northwest Laboratory. The goal was to assess the information's plausibility, provided analytical support to the US delegation during the post-accident review meeting and obtain a technical understanding of the accident. Detailed analyses of the team work are given in Ref. 1 (DOE, 1986). The accident at Chernobyl-4 occurred during the running of a test to determine a turbogenerator's ability to provide in-house emergency power after shutting off its steam supply. The accident was the result of a large, destructive power excursion. The major design related factor in the accident was the large positive void coefficient of reactivity. This feature, not present in the US reactors, means that an increase in power is likely to lead to an increase in reactivity which will further increase power, and finally result in the destructive accident. 5 refs., 11 figs

  12. Radioactivity measurements in Krakow surroundings in the aftermath of Chernobyl reactor accident

    International Nuclear Information System (INIS)

    A team from different laboratories of the Institute of Nuclear Physics was formed to set a crash program of measurement of water and food contamination after the Chernobyl reactor accident. The main contaminants in the first days were 131I and 132Te which were superseded later on by 104Ru, 137Cs and 134Cs. The highest value of contamination of surface waters by 131I was attained in the Vistula river on the 2-nd of May with 530 Bq/dm3. Also measurements of food contamination by 131I,134Cs, 137Cs and 137Te were carried out. The additional effective dose equivalent related to Chernobyl accident received by the population of Krakow region in May 1986 was estimated at 0.45 mSV (45 rem). Another rise of 134Cs + 137Cs content up to 46 Bq/dm3 in cows milk was observed during March and April 1987 and was probably explicable by the use of hay harvested in June 1986. (author)

  13. Radioactive Waste Management In The Chernobyl Exclusion Zone - 25 Years Since The Chernobyl Nuclear Power Plant Accident

    International Nuclear Information System (INIS)

    Radioactive waste management is an important component of the Chernobyl Nuclear Power Plant accident mitigation and remediation activities of the so-called Chernobyl Exclusion Zone. This article describes the localization and characteristics of the radioactive waste present in the Chernobyl Exclusion Zone and summarizes the pathways and strategy for handling the radioactive waste related problems in Ukraine and the Chernobyl Exclusion Zone, and in particular, the pathways and strategies stipulated by the National Radioactive Waste Management Program. The brief overview of the radioactive waste issues in the ChEZ presented in this article demonstrates that management of radioactive waste resulting from a beyond-designbasis accident at a nuclear power plant becomes the most challenging and the costliest effort during the mitigation and remediation activities. The costs of these activities are so high that the provision of radioactive waste final disposal facilities compliant with existing radiation safety requirements becomes an intolerable burden for the current generation of a single country, Ukraine. The nuclear accident at the Fukushima-1 NPP strongly indicates that accidents at nuclear sites may occur in any, even in a most technologically advanced country, and the Chernobyl experience shows that the scope of the radioactive waste management activities associated with the mitigation of such accidents may exceed the capabilities of a single country. Development of a special international program for broad international cooperation in accident related radioactive waste management activities is required to handle these issues. It would also be reasonable to consider establishment of a dedicated international fund for mitigation of accidents at nuclear sites, specifically, for handling radioactive waste problems in the ChEZ. The experience of handling Chernobyl radioactive waste management issues, including large volumes of radioactive soils and complex structures

  14. RADIOACTIVE WASTE MANAGEMENT IN THE CHERNOBYL EXCLUSION ZONE - 25 YEARS SINCE THE CHERNOBYL NUCLEAR POWER PLANT ACCIDENT

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.; Jannik, T.

    2011-10-01

    Radioactive waste management is an important component of the Chernobyl Nuclear Power Plant accident mitigation and remediation activities of the so-called Chernobyl Exclusion Zone. This article describes the localization and characteristics of the radioactive waste present in the Chernobyl Exclusion Zone and summarizes the pathways and strategy for handling the radioactive waste related problems in Ukraine and the Chernobyl Exclusion Zone, and in particular, the pathways and strategies stipulated by the National Radioactive Waste Management Program. The brief overview of the radioactive waste issues in the ChEZ presented in this article demonstrates that management of radioactive waste resulting from a beyond-designbasis accident at a nuclear power plant becomes the most challenging and the costliest effort during the mitigation and remediation activities. The costs of these activities are so high that the provision of radioactive waste final disposal facilities compliant with existing radiation safety requirements becomes an intolerable burden for the current generation of a single country, Ukraine. The nuclear accident at the Fukushima-1 NPP strongly indicates that accidents at nuclear sites may occur in any, even in a most technologically advanced country, and the Chernobyl experience shows that the scope of the radioactive waste management activities associated with the mitigation of such accidents may exceed the capabilities of a single country. Development of a special international program for broad international cooperation in accident related radioactive waste management activities is required to handle these issues. It would also be reasonable to consider establishment of a dedicated international fund for mitigation of accidents at nuclear sites, specifically, for handling radioactive waste problems in the ChEZ. The experience of handling Chernobyl radioactive waste management issues, including large volumes of radioactive soils and complex structures

  15. Analysis of nuclear fuel reliability based on Chernobyl NPP operation for validation of fuel element service life extension

    International Nuclear Information System (INIS)

    Results of failure intensity of fuel assemblies at Chernobyl-1 and Chernobyl-3 NPP during 10 years are given. Fuel assembly reliability is connected with seal failure reactor operation. Preliminary results are discussed

  16. Summary report on the environmental monitoring around Tokai area following the accident at Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    An accident took place at the Chernobyl nuclear power plant in USSR in the early hours of 26 April 1986. The plant caught fire and some degree of reactor inventry was released to the environment. Following the accident, debris of the radioactivity from Chernobyl was detected in all the European countries and countermeasures were taken in some countries. In Japan, many kinds of radionuclides were detected in rain, airbone dust and other environmental samples from 3 May and ''Headquaters for Radioactivity Countermeasure'' was organized in the Japanese Government. Health and Safety Division at the Tokai Works, PNC, performed the environmental monitoring for the Chernobyl accident in addition to the statutory monitoring program. This report presents results of the environmental monitoring performed at Tokai Works. Furthermore, study on the environmental transfer parameters and preliminary estimation of the committed dose equivalent to the public around Tokai area are discussed. (author)

  17. Nuclear reactor internals arrangement

    International Nuclear Information System (INIS)

    A nuclear reactor internals arrangement is disclosed which facilitates reactor refueling. A reactor vessel and a nuclear core is utilized in conjunction with an upper core support arrangement having means for storing withdrawn control rods therein. The upper core support is mounted to the underside of the reactor vessel closure head so that upon withdrawal of the control rods into the upper core support, the closure head, the upper core support and the control rods are removed as a single unit thereby directly exposing the core for purposes of refueling

  18. Reactors. Nuclear propulsion ships

    International Nuclear Information System (INIS)

    This article has for object the development of nuclear-powered ships and the conception of the nuclear-powered ship. The technology of the naval propulsion P.W.R. type reactor is described in the article B.N.3 141 'Nuclear Boilers ships'. (N.C.)

  19. Global risk of radioactive fallout after major nuclear reactor accidents

    OpenAIRE

    Lelieveld, J.; KUNKEL, D.; M. G. Lawrence

    2012-01-01

    Major reactor accidents of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the cumulative, global risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents (the most severe ones on the International Nuclear Event Scale, INES 7), using particulate 137Cs and gaseous ...

  20. Chernobyl: Endless horror. Late effects of the reactor catastrophe

    International Nuclear Information System (INIS)

    Ten years after the accident, the people of Chernobyl are trying to live a normal life, but the problems resulting from the catastrophe have not been solved. Some of them are just starting to emerge. (orig.)

  1. Nuclear reactor repairing device

    International Nuclear Information System (INIS)

    Purpose: To enable free repairing of an arbitrary position in an LMFBR reactor. Constitution: A laser light emitted from a laser oscillator installed out of a nuclear reactor is guided into a portion to be repaired in the reactor by using a reflecting mirror, thereby welding or cutting it. The guidance of the laser out of the reactor into the reactor is performed by an extension tube depending into a through hole of a rotary plug, and the guidance of the laser light into a portion to be repaired is performed by the transmitting and condensing action of the reflecting mirror. (Kamimura, M.)

  2. Nuclear reactor physics course for reactor operators

    International Nuclear Information System (INIS)

    The education and training of nuclear reactor operators is important to guarantee the safe operation of present and future nuclear reactors. Therefore, a course on basic 'Nuclear reactor physics' in the initial and continuous training of reactor operators has proven to be indispensable. In most countries, such training also results from the direct request from the safety authorities to assure the high level of competence of the staff in nuclear reactors. The aim of the basic course on 'Nuclear Reactor Physics for reactor operators' is to provide the reactor operators with a basic understanding of the main concepts relevant to nuclear reactors. Seen the education level of the participants, mathematical derivations are simplified and reduced to a minimum, but not completely eliminated

  3. 10 years after the Chernobyl reactor accident. Thyroid cancer and consequences of public health in the CIS

    International Nuclear Information System (INIS)

    Ten years after the accident at the Chernobyl nuclear reactor, governmental and international organisations have identified considerable effects on the health of the various affected groups. A dramatic - over 100-fold - increase in thyroid cancers among children in Belarus has been caused by papillary thyroid carcinomas that are marked by aggressive growth with early metastatic spread. As early as 1995, the number of new cases of thyroid cancer among adults was four times the mean figure in the period before 1986. In Oblast Gomel, the number of children with diabetes mellitus doubled between 1986 and the end of 1995. The number of recorded cases of thyroid cancer, particularly among children, by far exceeds the prognoses made on the basis of established radiation risk estimates, and points to a considerable underestimation of the consequences of the Chernobyl accident. (orig.)

  4. Special lecture on nuclear reactor

    International Nuclear Information System (INIS)

    This book gives a special lecture on nuclear reactor, which is divided into two parts. The first part has explanation on nuclear design of nuclear reactor and analysis of core with theories of integral transports, diffusion Nodal, transports Nodal and Monte Carlo skill parallel computer and nuclear calculation and speciality of transmutation reactor. The second part deals with speciality of nuclear reactor and control with nonlinear stabilization of nuclear reactor, nonlinear control of nuclear reactor, neural network and control of nuclear reactor, control theory of observer and analysis method of Adomian.

  5. Reactor core of nuclear reactor

    International Nuclear Information System (INIS)

    In a BWR type nuclear reactor, the number of first fuel assemblies (uranium) loaded in a reactor core is smaller than that of second fuel assemblies (mixed oxide), the average burnup degree upon take-out of the first fuel assemblies is reduced to less than that of the second fuel assemblies, and the number of the kinds of the fuel rods constituting the first fuel assemblies is made smaller than that of the fuel rods constituting the second fuel assemblies. As a result, the variety of the plutonium enrichment degree is reduced to make the distribution of the axial enrichment degree uniform, thereby enabling to simplify the distribution of the enrichment degree. Then the number of molding fabrication steps for MOX fuel assemblies can be reduced, thereby enabling to reduce the cost for molding and fabrication. (N.H.)

  6. Health hazards from radiocaesium following the Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    The WHO Regional Office for Europe has organized a series of meetings to assess the health impact of the Chernobyl nuclear accident. Considering the long-term importance of radiocaesium a decision was made to examine carefully the following aspects of this radionuclide in Europe: rate of deposition; environmental pathways through soil, flora and fauna to humans; absorption, distribution, metabolism, and excretion in humans; estimated doses resulting from these exposures; and some consideration of the possible adverse health effects. This is a report from a working group studying the health implications of radiocaesium. Refs, figs and tabs

  7. The nuclear soliton reactor

    International Nuclear Information System (INIS)

    The basic reactor physics of a completely novel nuclear fission reactor design - the soliton-reactor - is presented on the basis of a simple model. In such a reactor, the neutrons in the critical region convert either fertile material in the adjacent layers into fissile material or reduce the poisoning of fissile material in such a manner that successively new critical regions emerge. The result is an autocatalytically driven burn-up wave which propagates throughout the reactor. Thereby, the relevant characteristic spatial distributions (neutron flux, specific power density and the associated particle densities) are solitons - wave phenomena resulting from non-linear partial differential equations which do not change their shape during propagation. A qualitativley new kind of harnessing nuclear fission energy may become possible with fuel residence times comparable with the useful lifetime of the reactor system. In the long run, fast breeder systems which exploit the natural uranium and thorium resources, without any reprocessing capacity are imaginable. (orig.)

  8. Radiological consequence of Chernobyl nuclear power accident in Japan

    International Nuclear Information System (INIS)

    Two years have elapsed since the accident in Chernobyl nuclear power station shocked those concerned with nuclear power generation. The effect that this accident exerted on human environment has still continued directly and indirectly, and the reports on the effect have been made in various countries and by international organizations. In Japan, about the exposure dose of Japanese people due to this accident, the Nuclear Safety Commission and Japan Atomic Energy Research Institute issued the reports. In this report, the available data concerning the envrionmental radioactivity level in Japan due to the Chernobyl accident are collected, and the evaluation of exposure dose which seems most appropriate from the present day scientific viewpoint was attempted by the detailed analysis in the National Institute of Radiological Sciences. The enormous number of the data observed in various parts of Japan were different in sampling, locality, time and measuring method, so difficulty arose frequently. The maximum concentration of I-131 in floating dust was 2.5 Bq/m3 observed in Fukui, and the same kinds of radioactive nuclides as those in Europe were detected. (Kako, I.)

  9. Report on the accident at the Chernobyl Nuclear Power Station

    International Nuclear Information System (INIS)

    This report presents the compilation of information obtained by various organizations regarding the accident (and the consequences of the accident) that occurred at Unit 4 of the nuclear power station at Chernobyl in the USSR on April 26, 1986. Each organization has independently accepted responsibility for one or more chapters. The specific responsibility of each organization is indicated. The various authors are identified in a footnote to each chapter. Very briefly the other chapters cover: the design of the Chernobyl nuclear station Unit 4; safety analyses for Unit 4; the accident scenario; the role of the operator; an assessment of the radioactive release, dispersion, and transport; the activities associated with emergency actions; and information on the health and environmental consequences from the accident. These subjects cover the major aspects of the accident that have the potential to present new information and lessons for the nuclear industry in general. The task of evaluating the information obtained in these various areas and the assessment of the potential implications has been left to each organization to pursue according to the relevance of the subject to their organization. Those findings will be issued separately by the cognizant organizations. The basic purpose of this report is to provide the information upon which such assessments can be made

  10. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    An improved nuclear power reactor fuel element is described which consists of fuel rods, rod guide tubes and an end plate. The system allows direct access to an end of each fuel rod for inspection purposes. (U.K.)

  11. Nuclear reactor simulator

    International Nuclear Information System (INIS)

    The Nuclear Reactor Simulator was projected to help the basic training in the formation of the Nuclear Power Plants operators. It gives the trainee the opportunity to see the nuclear reactor dynamics. It's specially indicated to be used as the support tool to NPPT (Nuclear Power Preparatory Training) from NUS Corporation. The software was developed to Intel platform (80 x 86, Pentium and compatible ones) working under the Windows operational system from Microsoft. The program language used in development was Object Pascal and the compiler used was Delphi from Borland. During the development, computer algorithms were used, based in numeric methods, to the resolution of the differential equations involved in the process. (author)

  12. Prophylaxis of radiation-induced thyroid cancers in children after the reactor catastrophe of Chernobyl

    International Nuclear Information System (INIS)

    The incidence of thyroid cancer in children living in heavily contaminated regions some 100 km away from the Chernobyl nuclear power plant has increased significantly between 1989 and 1993. On the basis of this observation, preparations for iodine blockage of the thyroid in cases of reactor accidents should be made not only near but also far from nuclear power plants. The WHO recommendations on age-related dosage should be followed; the total iodide dose ranging between 15 and 150 mg daily may be split into several portions. In addition, prophylaxis of iodine-deficient goiters with 50-200 μg of iodide daily leads to a significant reduction of the risk of radiation-induced cancers. Consequent elimination of alimentary iodine deficiency should therefore be considered as the basis of precautions against health affects of reactor accidents. Thyroid hormones are indicated only in cases of thyroid enlargement, provided that lesions suspicious for malignancy have been definitely excluded. In the case of thyroid nodules in childhood, the indication for surgery and histological verification of the lesion has to be taken generously. (orig.)

  13. Physics of nuclear reactors

    International Nuclear Information System (INIS)

    This manual covers all the aspects of the science of neutron transport in nuclear reactors and can be used with great advantage by students, engineers or even reactor experts. It is composed of 18 chapters: 1) basis of nuclear physics, 2) the interactions of neutrons with matter, 3) the interactions of electromagnetic radiations and charged-particles with matter, 4) neutron slowing-down, 5) resonant absorption, 6) Doppler effect, 7) neutron thermalization, 8) Boltzmann equation, 9) calculation methods in neutron transport theory, 10) neutron scattering, 11) reactor reactivity, 12) theory of the critical homogenous pile, 13) the neutron reflector, 14) the heterogeneous reactor, 15) the equations of the fuel cycle, 16) neutron counter-reactions, 17) reactor kinetics, and 18) calculation methods in neutron scattering

  14. Consequences of the nuclear power plant accident at Chernobyl

    International Nuclear Information System (INIS)

    The Chernobyl Nuclear Power Plant accident, in the Ukrainian Soviet Socialist Republic (SSR), on April 26, 1986, was the first major nuclear power plant accident that resulted in a large-scale fire and subsequent explosions, immediate and delayed deaths of plant operators and emergency service workers, and the radioactive contamination of a significant land area. The release of radioactive material, over a 10-day period, resulted in millions of Soviets, and other Europeans, being exposed to measurable levels of radioactive fallout. Because of the effects of wind and rain, the radioactive nuclide fallout distribution patterns are not well defined, though they appear to be focused in three contiguous Soviet Republics: the Ukrainian SSR, the Byelorussian SSR, and the Russian Soviet Federated Socialist Republic. Further, because of the many radioactive nuclides (krypton, xenon, cesium, iodine, strontium, plutonium) released by the prolonged fires at Chernobyl, the long-term medical, psychological, social, and economic effects will require careful and prolonged study. Specifically, studies on the medical (leukemia, cancers, thyroid disease) and psychological (reactive depressions, post-traumatic stress disorders, family disorganization) consequences of continued low dose radiation exposure in the affected villages and towns need to be conducted so that a coherent, comprehensive, community-oriented plan may evolve that will not cause those already affected any additional harm and confusion

  15. Consequences of the nuclear power plant accident at Chernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Ginzburg, H.M.; Reis, E. (Health Resources and Services Administration, Rockville, MD (USA))

    1991-01-01

    The Chernobyl Nuclear Power Plant accident, in the Ukrainian Soviet Socialist Republic (SSR), on April 26, 1986, was the first major nuclear power plant accident that resulted in a large-scale fire and subsequent explosions, immediate and delayed deaths of plant operators and emergency service workers, and the radioactive contamination of a significant land area. The release of radioactive material, over a 10-day period, resulted in millions of Soviets, and other Europeans, being exposed to measurable levels of radioactive fallout. Because of the effects of wind and rain, the radioactive nuclide fallout distribution patterns are not well defined, though they appear to be focused in three contiguous Soviet Republics: the Ukrainian SSR, the Byelorussian SSR, and the Russian Soviet Federated Socialist Republic. Further, because of the many radioactive nuclides (krypton, xenon, cesium, iodine, strontium, plutonium) released by the prolonged fires at Chernobyl, the long-term medical, psychological, social, and economic effects will require careful and prolonged study. Specifically, studies on the medical (leukemia, cancers, thyroid disease) and psychological (reactive depressions, post-traumatic stress disorders, family disorganization) consequences of continued low dose radiation exposure in the affected villages and towns need to be conducted so that a coherent, comprehensive, community-oriented plan may evolve that will not cause those already affected any additional harm and confusion.

  16. SNAP Nuclear Space Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Corliss, William R

    1966-01-01

    This booklet describes the principles of nuclear-reactor space power plants and shows how they will contribute to the exploration and use of space. It compares them with chemical fuels, solar cells, and systems using energy from radioisotopes. The SNAP (Systems for Nuclear Auxiliary Power) Program, begun in 1955, is described.

  17. [Dynamics of tritium content in flood-lands reservoirs of the Pripyat river and cooling pond of the Chernobyl nuclear plant].

    Science.gov (United States)

    Gudkov, D I

    1999-01-01

    Tritium content in water from natural and artificial reservoirs within 30-km exclusion zone of the Chernobyl NPP has been determined. The increase of Tritium activity in the involved water reserwous has been registered in May 1994 and April 1995. As supposed the source of the increase, nuclear power plants, equipped with WWER reactors and located in catchment area of Pripyat river. PMID:10689425

  18. Proceedings of the 6rd Radiobiological conference with international participation dedicated to 20th anniversary of nuclear accident in Chernobyl, 2006

    International Nuclear Information System (INIS)

    Scientific conference deals with problems in radiobiology, photobiology and radio-environmental sciences. Some papers deal with the historical aspects development of reactor accidents (Chernobyl NPP and NPP A-1 Jaslovske Bohunice) as well as history of nuclear sciences in former Czechoslovakia. Proceedings contain forty-seven papers

  19. Chernobyl nuclear accident: Effects on food. April 1986-November 1989 (Citations from the Food Science and Technology Abstracts data base). Report for April 1986-November 1989

    International Nuclear Information System (INIS)

    This bibliography contains citations concerning studies and measurements of the radioactive contamination by the Chernobyl nuclear reactor accident of food and the food chain. The studies cover meat and dairy products, vegetables, fish, food chains, and radioactive contamination of agricultural farms and lands. (This updated bibliography contains 108 citations, 43 of which are new entries to the previous edition.)

  20. Chernobyl nuclear accident: effects on foods. April 1986-October 1988 (Citations from the Food Science and Technology Abstracts data base). Report for April 1986-October 1988

    International Nuclear Information System (INIS)

    This bibliography contains citations concerning studies and measurements of the radioactive contamination of the Chernobyl nuclear reactor accident of food and food chains. The studies cover meat and dairy products, vegetables, fish, food chains, and radioactive contamination of agricultural farms and lands. (Contains 65 citations fully indexed and including a title list.)

  1. Global risk of radioactive fallout after nuclear reactor accidents

    OpenAIRE

    Lelieveld, J.; KUNKEL, D.; M. G. Lawrence

    2011-01-01

    Reactor core meltdowns of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents, using particulate 137Cs and gaseous 131I as proxies for the fallout. It appears that previously the occurrence of ma...

  2. Chernobyl nuclear power plant accident and thyroid cancer in children

    International Nuclear Information System (INIS)

    Since August 1991, six surveys have been made on thyroid cancer in children in Ukraine and Belorussia. The results were compared with those for Hiroshima A-bomb survivors. Children with thyroid cancer were characterized as having the following: (1) frequent occurrence of thyroid cancer; (2) extremely short latency period; (3) poorly differentiated papillary adenocarcinoma; (4) frequent occurrence within the thyroid gland; (5) the association of fibrosis, lymphocyte infiltration, and proliferation of follicular epithelial cells; (6) frequent occurrence of sclerosing variant of papillary cancer associated with fibrosis and lymphocyte infiltration, especially in heavily exposed areas. These findings were supposed to be attributable to Chernobyl nuclear power plant accident. No data has been available on infantile thyroid cancer in Hiroshima A-bomb survivors because of the following reasons: (1) acute death from acute radiation injury, leukemia and cancer other than thyroid cancer; (2) few survey on thyroid cancer during the first 10 years after exposure; (3) the lack of surgical data on thyroid cancer. In the case of Chernobyl survivors, there were few acute death cases; I-131 seemed to have damaged specifically the thyroid gland; heavily exposed areas corresponded to areas with low iodine intake; pediatric thyroid gland is sensitive to I-131, leading to the possibility that infantile thyroid cancer may have been induced by I-131. (N.K.)

  3. Preliminary report about nuclear accident of Chernobylsk reactor

    International Nuclear Information System (INIS)

    The preliminary report of nuclear accident at Chernobyl, in URSS is presented. The Chernobyl site is located geographically and the RBMK type reactors - initials of russian words which mean high power pressure tube reactors are described. The conditions of reactor operation in beginning of accident, the events which lead to reactor destruction, the means to finish the fire, the measurements adopted by Russian in the accident location, the estimative of radioactive wastes, the meteorological conditions during the accident, the victims and medical assistence, the sanitary aspects and consequences for population, the evaluation of radiation doses received at small and medium distance and the estimative of reffered doses by population attained are presented. The official communication of Russian Minister Council and the declaration of IAEA general manager during a collective interview in Moscou are annexed. (M.C.K.)

  4. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    A nuclear reactor fuel element comprising a column of vibration compacted fuel which is retained in consolidated condition by a thimble shaped plug. The plug is wedged into gripping engagement with the wall of the sheath by a wedge. The wedge material has a lower coefficient of expansion than the sheath material so that at reactor operating temperature the retainer can relax sufficient to accommodate thermal expansion of the column of fuel. (author)

  5. Water cooled nuclear reactor

    International Nuclear Information System (INIS)

    The description is given of a water cooled nuclear reactor comprising a core, cooling water that rises through the core, vertical guide tubes located inside the core and control rods vertically mobile in the guide tubes. In this reactor the cooling water is divided into a first part introduced at the bottom end of the core and rising through it and a second part introduced at the top end of the guide tubes so as to drop in them

  6. Nuclear reactor design

    CERN Document Server

    2014-01-01

    This book focuses on core design and methods for design and analysis. It is based on advances made in nuclear power utilization and computational methods over the past 40 years, covering core design of boiling water reactors and pressurized water reactors, as well as fast reactors and high-temperature gas-cooled reactors. The objectives of this book are to help graduate and advanced undergraduate students to understand core design and analysis, and to serve as a background reference for engineers actively working in light water reactors. Methodologies for core design and analysis, together with physical descriptions, are emphasized. The book also covers coupled thermal hydraulic core calculations, plant dynamics, and safety analysis, allowing readers to understand core design in relation to plant control and safety.

  7. Comparison of the Chernobyl and Fukushima nuclear accidents: A review of the environmental impacts

    Energy Technology Data Exchange (ETDEWEB)

    Steinhauser, Georg, E-mail: georg.steinhauser@colostate.edu; Brandl, Alexander; Johnson, Thomas E.

    2014-02-01

    The environmental impacts of the nuclear accidents of Chernobyl and Fukushima are compared. In almost every respect, the consequences of the Chernobyl accident clearly exceeded those of the Fukushima accident. In both accidents, most of the radioactivity released was due to volatile radionuclides (noble gases, iodine, cesium, tellurium). However, the amount of refractory elements (including actinides) emitted in the course of the Chernobyl accident was approximately four orders of magnitude higher than during the Fukushima accident. For Chernobyl, a total release of 5300 PBq (excluding noble gases) has been established as the most cited source term. For Fukushima, we estimated a total source term of 520 (340–800) PBq. In the course of the Fukushima accident, the majority of the radionuclides (more than 80%) was transported offshore and deposited in the Pacific Ocean. Monitoring campaigns after both accidents reveal that the environmental impact of the Chernobyl accident was much greater than of the Fukushima accident. Both the highly contaminated areas and the evacuated areas are smaller around Fukushima and the projected health effects in Japan are significantly lower than after the Chernobyl accident. This is mainly due to the fact that food safety campaigns and evacuations worked quickly and efficiently after the Fukushima accident. In contrast to Chernobyl, no fatalities due to acute radiation effects occurred in Fukushima. - Highlights: • The environmental effects of Chernobyl and Fukushima are compared. • Releases of radionuclides from Chernobyl exceeded Fukushima by an order of magnitude. • Chernobyl caused more severe radiation-related health effects. • Overall, Chernobyl was a much more severe nuclear accident than Fukushima. • Psychological effects are neglected but important consequences of nuclear accidents.

  8. Integral nuclear reactor

    International Nuclear Information System (INIS)

    The invention deals with an inprovement of the design of an integral pressurized water nuclear reactor. A typical embodyment of the invention includes a generally cylindrical pressure vessel that is assembled from three segments which are bolted together at transverse joints to form a pressure tight unit that encloses the steam generator and the reactor. The new construction permits primary to secondary coolant heat exchange and improved control rod drive mecanisms which can be exposed for full service access during reactor core refueling, maintenance and inspection

  9. Analysis of radioactive contaminations and radiological hazard in Poland after the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    It is a report on radiological impact in Poland following the Chernobyl reactor accident prepared in the Central Laboratory for Radiological Protection. The results of measurement and its analysis are presented. Isotopic composition of the contamined air and the concentration of radionuclides are determined. The trajectories of the airborne radioactive material movement from Chernobyl to Poland at the last days of April 1986 are presented. Assessment of the radiological risk of the population is done. 38 refs., 20 figs., 11 tabs. (M.F.W.)

  10. Chernobyl and status of nuclear power development in the USSR

    International Nuclear Information System (INIS)

    The Chernobyl accident has seriously affected development of the USSR nuclear power program. But it has not eliminated the basic prerequisites for nuclear power development in the USSR which are: - resources and consumption territorial disproportions; - large share of oil and gas in electricity generation; - negative ecological aspects of coal plants; - high power industry development rate. At the same time it has aggravated the old problems and has given rise to some new-ones of which the most important are: - increased safety requirements; rise in costs; longer construction schedules; public opinion. On the whole for further safe development of nuclear power a detailed analysis of the Chernobyl accident is required, including studies of long-term accident consequences and measures of their mitigation and elimination. A necessary condition for NPP operation to be continued would also be development and rapid implementation of technical approaches which would permit to eliminate the design shortcomings in the RBMK NPPs both operating and those under construction. At the same time we have to ensure their competitiveness with other energy sources and possibility of expansion of their applications. The problem of public opinion should be emphasised. After the Chernobyl accident we have faced a social phenomenon which is quite new in this country. There is almost no site where the population was not opposed to NPP construction. For us these problems are especially difficult as we have had no experience of this kind of interactions with the public. We are planning and begin to realize a program basing on the current world experience. This program includes primarily a wide series of publications on the problems of nuclear energy its ecologic and economic advantages as compared with conventional and alternative energy sources,, using all cur-rent media. Centers of public information discussion clubs, exhibitions etc are being organized. In particular, our Institute has

  11. Fright from Chernobyl; Skremselet fra Tsjernobyl

    Energy Technology Data Exchange (ETDEWEB)

    2011-07-01

    Research on nuclear power be defined through catastrophes, said Norwegian experts. The worst of them throwing after 25 years still an equally long and dark shadow. 25 years since the Chernobyl accident. The article has fact boxes on the three major reactor accidents, Chernobyl with RBMK reactor; Three Mile Island with PWR and BWR reactor at Fukushima. Points out the danger by untrained personnel deal with risky situations. (AG)

  12. The Chernobyl reactor accident and the aquatic environment of the UK: a fisheries viewpoint

    International Nuclear Information System (INIS)

    The monitoring programme undertaken by the Directorate throughout the UK following the Chernobyl reactor accident is described. The results of sampling and analysis of fish, shellfish, seaweed and other materials are discussed. Chernobyl fallout was readily detected in all sectors of the aquatic environment, particularly during May when the highest concentrations were observed. An assessment of the radiological impact of the fallout shows that freshwater fish were the most important source of individual (critical group) exposure though, based on cautious assumptions, the effective dose equivalent is around 1 mSv in a year. The collective effective dose equivalent commitment from Chernobyl due to aquatic ingestion pathways, predominantly marine fish, is estimated to be 30 man Sv. (author)

  13. Nuclear Reactors and Technology

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Hicks, S.C. [eds.

    1992-01-01

    This publication Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency`s Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on the Energy Science and Technology Database and Nuclear Science Abstracts (NSA) database. Current information, added daily to the Energy Science and Technology Database, is available to DOE and its contractors through the DOE Integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user`s needs.

  14. Materials for nuclear reactors

    International Nuclear Information System (INIS)

    The improved performance of present generation nuclear reactors and the realization of advanced reactor concepts, both, require development of better materials. Physical metallurgy/materials science principles which have been exploited in meeting the exacting requirements of nuclear reactor materials (fuels and structural materials), are outlined citing a few specific examples. While the incentive for improvement of traditional fuels (e.g., UO2 fuel) is primarily for increasing the average core burn up, the development of advanced fuels (e.g., MOX, mixed carbide, nitride, silicide and dispersion fuels) are directed towards better utilization of fissile and fertile inventories through adaptation of innovative fuel cycles. As the burn up of UO2 fuel reaches higher levels, a more detailed and quantitative understanding of the phenomena such as fission gas release, fuel restructuring induced by radiation and thermal gradients and pellet-clad interaction is being achieved. Development of zirconium based alloys for both cladding and pressure tube applications is discussed with reference to their physical metallurgy, fabrication techniques and in-reactor degradation mechanisms. The issue of radiation embrittlement of reactor pressure vessels (RPVs) is covered drawing a comparison between the western and eastern specifications of RPV steels. The search for new materials which can stand higher rates of atomic displacement due to radiation has led to the development of swelling resistant austenitic and ferritic stainless steels for fast reactor applications as exemplified by the development of the D-9 steel for Indian fast breeder reactor. The presentation will conclude by listing various materials related phenomena, which have a strong bearing on the successful development of future nuclear energy systems. (author)

  15. International nuclear third party liability law: The response to Chernobyl

    International Nuclear Information System (INIS)

    In terms of liability and compensation issues, the response of the international community to the accident at Chernobyl has been comprehensive, aimed at modernising two outdated international regimes, linking them together and adopting a brand, new global one - all this in the hope of bettering the situation of victims of a nuclear accident, wherever they may be found. That improvement will be brought about in a number of ways once all of the relevant international instruments have entered into force. Much more money will be available to compensate victims of a nuclear accident and that money will be more readily and easily accessible. More victims will be entitled to compensation, both in terms of the type of damage that they have suffered and where those victims were physically located at the time they suffered it; in some cases, such as under the Supplementary Compensation Convention, victims in states other than that of the liable operator will be in a privileged position as regards a portion of the available compensation. In addition, the period in which claims for compensation can be made in respect of personal injury and loss of life has been extended, in recognition of the fact that some such injuries may not manifest themselves for many years after the accident has occurred. Yet despite the lessons learned from Chernobyl, despite the attempts to make these new or amended instruments as attractive as possible to encourage the broadest possible adherence, their acceptance by individual states has not been overwhelming. This is particularly true in the case of the VC Protocol and the CSC where the required liability amounts and financial security limits were intentionally established at levels deemed to be acceptable to the vast majority of potential parties. It is equally discouraging to see that Ukraine has not ratified either the VC Protocol or the CSC, even though it signed both shortly after their adoption in 1997. Similarly, the Russian Federation has

  16. Nuclear reactor power monitor

    International Nuclear Information System (INIS)

    The device of the present invention monitors phenomena occurred in a nuclear reactor more accurately than usual case. that is, the device monitors a reactor power by signals sent from a great number of neutron monitors disposed in the reactor. The device has a means for estimating a phenomenon occurred in the reactor based on the relationship of a difference of signals between each of the great number of neutron monitors to the positions of the neutron monitors disposed in the reactor. The estimation of the phenomena is conducted by, for example, conversion of signals sent from the neutron monitors to a code train. Then, a phenomenon is estimated rapidly by matching the code train described above with a code train contained in a data base. Further. signals sent from the neutron monitors are processed statistically to estimate long term and periodical phenomena. As a result, phenomena occurred in the reactor are monitored more accurately than usual case, thereby enabling to improve reactor safety and operationability. (I.S.)

  17. Papers submitted to the international forum ''one decade after Chernobyl: nuclear safety aspects''. Working material

    International Nuclear Information System (INIS)

    The objective of the forum is to review the remedial measures taken since the Chernobyl accident for improving the safety of RBMK reactors and the Chernobyl containment structure (sarcophagus). The forum will also serve to exchange information on national, bilateral and multilateral efforts for the enhancement of RBMK safety. The conclusions and recommendations will serve as a basis for a background paper to be prepared for presentation, by the forum chairman, at the International Conference ''One decade after Chernobyl'' to held in Vienna from 8-12 April 1996. Refs, figs, tabs

  18. CANDU nuclear reactor technology

    International Nuclear Information System (INIS)

    AECL has over 40 years of experience in the nuclear field. Over the past 20 years, this unique Canadian nuclear technology has made a worldwide presence, In addition to 22 CANDU reactors in Canada, there are also two in India, one in Pakistan, one in Argentina, four in Korea and five in Romania. CANDU advancements are based on evolutionary plant improvements. They consist of system performance improvements, design technology improvements and research and development in support of advanced nuclear power. Given the good performance of CANOU plants, it is important that this CANDU operating experience be incorporated into new and repeat designs

  19. The accident at the Chernobyl' nuclear power plant and its consequences. Pt. 1. General material

    International Nuclear Information System (INIS)

    The report contains a presentation of the Chernobyl' nuclear power station and of the RBMK-1000 reactor, including its principal physical characteristics, the safety systems and a description of the site and of the surrounding region. After a chronological account of the events which led to the accident and an analysis of the accident using a mathematical model it is concluded that the prime cause of the accident was an extremely improbable combination of violations of instructions and operating rules committed by the staff of the unit. Technical and organizational measures for improving the safety of nuclear power plants with RBMK reactors have been taken. A detailed description of the actions taken to contain the accident and to alleviate its consequences is given and includes the fire fighting at the nuclear power station, the evaluation of the state of the fuel after the accident, the actions taken to limit the consequences of the accident in the core, the measures taken at units 1, 2 and 3 of the nuclear power station, the monitoring and diagnosis of the state of the damaged unit, the decontamination of the site and of the 30 km zone and the long-term entombment of the damaged unit. The measures taken for environmental radioactive contamination monitoring, starting by the assessment of the quantity, composition and dynamics of fission products release from the damaged reactor are described, including the main characteristics of the radioactive contamination of the atmosphere and of the ground, the possible ecological consequences and data on the exposure of plant and emergency service personnel and of the population in the 30 km zone around the plant. The last part of the report presents some recommendations for improving nuclear power safety, including scientific, technical and organizational aspects and international measures. Finally, an overview of the development of nuclear power in the USSR is given

  20. The cooling pond of the Chernobyl Nuclear Power Plant: A groundwater remediation case history

    Science.gov (United States)

    Bugai, Dmitri A.; Waters, Robert D.; Dzhepo, Sergei P.; Skalsk'ij, Alexander S.

    1997-04-01

    The cooling pond of the Chernobyl nuclear power plant was heavily contaminated as a result of the reactor accident in April 1986. From 1989 to 1993 the cooling pond represented one of the major sources of 90Sr migration from the Chernobyl site to the Dnieper River. Several attempts have been made to contain radioactive contamination within the pond. Overestimation of releases via groundwater pathway and design mistakes led to unsuccessful remedial actions in 1986 and in later periods. In addition, remediation criteria based solely on comparison of contaminant concentrations in groundwater with drinking water standards were not effective from the health risk perspective, because the public was not directly exposed to contaminated groundwater; the exclusion zone surrounding the site acted as an institutional control to prevent public access. In light of recent estimates of low risks due to radionuclide transport outside the exclusion zone, a "no action" approach may represent the most reasonable strategy for the near-term management of the cooling pond.

  1. 15 years after Chernobyl. Nuclear plus greenhouse effect?

    International Nuclear Information System (INIS)

    Today, the argument in favour of nuclear energy is not an economical one nor linked to energy resources but is at the level of climatic change. Nuclear energy is seen as the only energy source without carbon dioxide emissions. A more detailed analysis of greenhouse gases on the life cycle shows that nuclear energy gives as greenhouse gases as big hydroelectric power plants or wind power plants, these emissions are more important than for biogas installations with cogeneration. The strategy of energy efficiency is certainly more competitive than the new reactors in other terms it is more efficiency to reduce the consumption than to increase the nuclear production. (N.C.)

  2. Nuclear reactor constructions

    International Nuclear Information System (INIS)

    A nuclear reactor construction comprising a reactor core submerged in a pool of liquid metal coolant in a primary vessel which is suspended from the roof structure of a containment vault. Control rods supported from the roof structure are insertable in the core which is carried on a support structure from the wall of the primary vessel. To prevent excessive relaxation of the support structure whereby the control rods would be displaced relative to the core, the support structure incorporates a normally inactive secondary structure designed to become effective in bracing the primary structure against further relaxation beyond a predetermined limit. (author)

  3. Nuclear safety cooperation for Soviet designed reactors

    International Nuclear Information System (INIS)

    The nuclear accident at the Chernobyl nuclear power plant in 1986 first alerted the West to the significant safety risks of Soviet designed reactors. Five years later, this concern was reaffirmed when the IAEA, as a result of a review by an international team of nuclear safety experts, announced that it did not believe the Kozloduy nuclear power plants in Bulgaria could be operated safely. To address these safety concerns, the G-7 summit in Munich in July 1992 outlined a five point program to address the safety problems of Soviet Designed Reactors: operational safety improvement; near-term technical improvements to plants based on safety assessment; enhancing regulatory regimes; examination of the scope for replacing less safe plants by the development of alternative energy sources and the more efficient use of energy; and upgrading of the plants of more recent design. As of early 1994, over 20 countries and international organizations have pledged hundreds of millions of dollars in financial assistance to improve safety. This paper summarizes these assistance efforts for Soviet designed reactors, draws lessons learned from these activities, and offers some options for better addressing these concerns

  4. Chernobyl, 13 years after

    International Nuclear Information System (INIS)

    This is an annual report, regularly issued by IPSN, that presents the ecological and health consequences of the Chernobyl Nuclear Accident. The present status of the Chernobyl Nuclear Plant, which Ukraine engaged to stop definitively in year 2000, is summarized. The only reactor unit now in operation is Chernobylsk-3 Reactor which poses two safety questions: evolution of cracks in part of the tubing and behaviour of the pressure tubes. Although, some improvements in the RBMK reactor types were introduced, problems remain that make IPSN to stress the requirement of stopping this NPP completely. In the contaminated territories surrounding Chernobyl incidence rate of infant thyroid cancers continues to grow, reaching values 10 to 100 times higher than the natural rate. In France the IPSN analyzed 60,000 records carried out in 17 sites during May 1986 and April 1989. It was estimated that the individual dose received during 60 years (1986-2046) by the inhabitants of the most affected zone (eastern France) is lower than 1.5 mSv, a value lower than 1% of the natural cosmic and telluric radioactivity exposure for the same period. For the persons assumed to live in the most attacked forests (from eastern France) and nourishing daily with venison and mushrooms the highest estimate is 1 mSv a year. Concerning the 'hot spots', identified in mountains by IPSN and CRIIRAD, the doses received by excursionists are around 0.015 mSv. For an average inhabitant of the country the dose piled up in the thyroid due to iodine-131 fallout is estimated to 0.5-2 mSv for an adult and 6.5-16 mSv for an infant. These doses are 100 to 1000 times lower than the ones to which the infants living in the neighbourhood of Chernobyl are exposed to. The contents of the report is displayed in the following six chapters: 1. Chernobyl in some figures; 2. The 'sarcophagus' and the reactors of the Chernobyl NPP; 3. Health consequences of the Chernobyl accident;. 4. The impact of Chernobyl fallout in France

  5. Nuclear Rocket Engine Reactor

    CERN Document Server

    Lanin, Anatoly

    2013-01-01

    The development of a nuclear rocket engine reactor (NRER ) is presented in this book. The working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, high energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K is displayed. Design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials like carbide and uranium carbide compounds in the temperatures interval 300 - 3000 K are presented. Technological aspects of strength and thermal strength resistance of materials are considered. The design procedure of possible emergency processes in the NRER is developed and risks for their origination are evaluated. Prospects of the NRER development for pilotless space devices and piloted interplanetary ships are viewed.

  6. Nuclear power reactor physics

    International Nuclear Information System (INIS)

    The purpose of this book is to explain the physical working conditions of nuclear reactors for the benefit of non-specialized engineers and engineering students. One of the leading ideas of this course is to distinguish between two fundamentally different concepts: - a science which could be called neutrodynamics (as distinct from neutron physics which covers the knowledge of the neutron considered as an elementary particle and the study of its interactions with nuclei); the aim of this science is to study the interaction of the neutron gas with real material media; the introduction will however be restricted to its simplified expression, the theory and equation of diffusion; - a special application: reactor physics, which is introduced when the diffusing and absorbing material medium is also multiplying. For this reason the chapter on fission is used to introduce this section. In practice the section on reactor physics is much longer than that devoted to neutrodynamics and it is developed in what seemed to be the most relevant direction: nuclear power reactors. Every effort was made to meet the following three requirements: to define the physical bases of neutron interaction with different materials, to give a correct mathematical treatment within the limit of necessary simplifying hypotheses clearly explained; to propose, whenever possible, numerical applications in order to fix orders of magnitude

  7. Nuclear reactor constructions

    International Nuclear Information System (INIS)

    An improvement in the construction of liquid metal cooled nuclear reactors of the kind in which the fuel assembly is submerged in a pool of coolant contained by a primary vessel housed in a concrete vault, is described. In this modification the roof of the vault carries heat exchangers immersed in the pool of coolant, the lower ends of which are hydraulically damped against oscillation caused by seismic disturbances. (U.K.)

  8. Nuclear research reactors in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Cota, Anna Paula Leite; Mesquita, Amir Zacarias, E-mail: aplc@cdtn.b, E-mail: amir@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    The rising concerns about global warming and energy security have spurred a revival of interest in nuclear energy, giving birth to a 'nuclear power renaissance' in several countries in the world. Particularly in Brazil, in the recent years, the nuclear power renaissance can be seen in the actions that comprise its nuclear program, summarily the increase of the investments in nuclear research institutes and the government target to design and build the Brazilian Multipurpose research Reactor (BMR). In the last 50 years, Brazilian research reactors have been used for training, for producing radioisotopes to meet demands in industry and nuclear medicine, for miscellaneous irradiation services and for academic research. Moreover, the research reactors are used as laboratories to develop technologies in power reactors, which are evaluated today at around 450 worldwide. In this application, those reactors become more viable in relation to power reactors by the lowest cost, by the operation at low temperatures and, furthermore, by lower demand for nuclear fuel. In Brazil, four research reactors were installed: the IEA-R1 and the MB-01 reactors, both at the Instituto de Pesquisas Energeticas Nucleares (IPEN, Sao Paulo); the Argonauta, at the Instituto de Engenharia Nuclear (IEN, Rio de Janeiro) and the IPR-R1 TRIGA reactor, at the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN, Belo Horizonte). The present paper intends to enumerate the characteristics of these reactors, their utilization and current academic research. Therefore, through this paper, we intend to collaborate on the BMR project. (author)

  9. Environmental problems associated with decommissioning the Chernobyl Nuclear Power Plant Cooling Pond.

    Science.gov (United States)

    Oskolkov, B Ya; Bondarkov, M D; Gaschak, S P; Maksymenko, A M; Maksymenko, V M; Martynenko, V I; Farfán, E B; Jannik, G T; Marra, J C

    2010-11-01

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities associated with residual radioactive contamination of their territories is an imperative issue. Significant problems may result from decommissioning of cooling ponds with residual radioactive contamination. The Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond is one of the largest self-contained water reservoirs in the Chernobyl region and Ukrainian and Belorussian Polesye region. The 1986 ChNPP Reactor Unit Number Four significantly contaminated the ChNPP Cooling Pond. The total radionuclide inventory in the ChNPP Cooling Pond bottom deposits are as follows: ¹³⁷Cs: 16.28 ± 2.59 TBq; ⁹⁰Sr: 2.4 ± 0.48 TBq; and ²³⁹+²⁴⁰Pu: 0.00518 ± 0.00148 TBq. The ChNPP Cooling Pond is inhabited by over 500 algae species and subspecies, over 200 invertebrate species, and 36 fish species. The total mass of the living organisms in the ChNPP Cooling Pond is estimated to range from about 60,000 to 100,000 tons. The territory adjacent to the ChNPP Cooling Pond attracts many birds and mammals (178 bird species and 47 mammal species were recorded in the Chernobyl Exclusion Zone). This article describes several options for the ChNPP Cooling Pond decommissioning and environmental problems associated with its decommissioning. The article also provides assessments of the existing and potential exposure doses for the shoreline biota. For the 2008 conditions, the estimated total dose rate values were 11.4 40 μGy h⁻¹ for amphibians, 6.3 μGy h⁻¹ for birds, 15.1 μGy h⁻¹ for mammals, and 10.3 μGy h⁻¹ for reptiles, with the recommended maximum dose rate being equal to 40 μGy h⁻¹. However, drying the ChNPP Cooling Pond may increase the exposure doses to 94.5 μGy h⁻¹ for amphibians, 95.2 μGy h⁻¹ for birds, 284.0 μGy h⁻¹ for mammals, and 847.0 μGy h⁻¹ for reptiles. All of these anticipated dose rates exceed the recommended values. PMID:20938234

  10. Bone marrow transplantation after the Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    On April 26, 1986, an accident at the Chernobyl nuclear power station in the Soviet Union exposed about 200 people to large doses of total-body radiation. Thirteen persons exposed to estimated total-body doses of 5.6 to 13.4 Gy received bone marrow transplants. Two transplant recipients, who received estimated doses of radiation of 5.6 and 8.7 Gy, are alive more than three years after the accident. The others died of various causes, including burns (the cause of death in five), interstitial pneumonitis (three), graft-versus-host disease (two), and acute renal failure and adult respiratory distress syndrome (one). There was hematopoietic (granulocytic) recovery in nine transplant recipients who could be evaluated, six of whom had transient partial engraftment before the recovery of their own marrow. Graft-versus-host disease was diagnosed clinically in four persons and suspected in two others. Although the recovery of endogenous hematopoiesis may occur after exposure to radiation doses of 5.6 to 13.4 Gy, we do not know whether it is more likely after the transient engraftment of transplanted stem cells. Because large doses of radiation affect multiple systems, bone marrow recovery does not necessarily ensure survival. Furthermore, the risk of graft-versus-host disease must be considered when the benefits of this treatment are being weighed

  11. Measures taken to improve the safety of nuclear power plants in the USSR after the Chernobyl accident

    International Nuclear Information System (INIS)

    The Soviet delegation to the IAEA experts' meeting (August 25-29, 1986) presented information on the Chernobyl Nuclear Power Plant accident and its consequences. Using data obtained through August 1, 1986, this information contained the results of an investigation into the causes of the accident as well as a description and preliminary analysis of the effectiveness of the immediate steps taken to limit and eliminate its consequences. Subsequent efforts were channeled in the following directions: (1) Continuing operations to eliminate the accident's consequences including: (a) completing the design and construction of a protective cover (sarcophagus) to reliably protect the environment from radioactivity and the introduction of radioactive matter from the destroyed unit; (b) further decontamination of the Chernobyl Nuclear Power Plant site and inhabited areas within the affected zone; and (c) carrying out required sanitary and medical measures to ensure the safety of the population and to protect their health. (2) Development and implementation of longitudinal studies of the long-term consequences of the accident. (3) Development of introduction of measures to increase the safety of working nuclear power stations. (4) Examination of plans for the future development of the nuclear power industry and prospects for increasing its safety level, including: conceptual development of a new generation of nuclear reactors; and expansion of scientific investigation into all aspects of safety assessment and safety assurance in the nuclear power industry. The present report examines the progress of studies along these lines and the conclusions which have been drawn

  12. Towards nuclear fusion reactors

    International Nuclear Information System (INIS)

    In the middle of 21st century, the population on the earth is expected to double, and the energy that mankind consumes to triple. The nuclear fusion which is said the ultimate energy source for mankind is expected to solve this energy problem. As for fusion reactors, fuel materials exist inexhaustibly, distributing evenly, they have high safety in principle, the product of burning is harmless nonradioactive substance that does not require the treatment and disposal, and the attenuation of induced radioactivity due to neutrons is quick and the effect to global environment is little. The basic plan of second stage nuclear fusion research and development was decided in 1975, aiming at attaining the critical plasma condition. JT-60 has attained it in 1987. The project of international thermonuclear fusion experimental reactor (ITER) was started, and the conceptual design was carried out. Under such background, the third stage basic plan was decided in 1992, and its objective is self ignition condition, long time burning and the basis of the reactor engineering technology. The engineering design of the ITER is investigated. (K.I.)

  13. Chernobyl, 14 years later

    International Nuclear Information System (INIS)

    This report draws an account of the consequences of Chernobyl accident 14 years after the disaster. It is made up of 8 chapters whose titles are: 1) Some figures about Chernobyl accident, 2) Chernobyl nuclear power plant, 3)Sanitary consequences of Chernobyl accident, 4) The management of contaminated lands, 5) The impact in France of Chernobyl fallout, 6) International cooperation, 7) More information about Chernobyl and 8) Glossary

  14. Nuclear reactor building

    Science.gov (United States)

    Gou, Perng-Fei; Townsend, Harold E.; Barbanti, Giancarlo

    1994-01-01

    A reactor building for enclosing a nuclear reactor includes a containment vessel having a wetwell disposed therein. The wetwell includes inner and outer walls, a floor, and a roof defining a wetwell pool and a suppression chamber disposed thereabove. The wetwell and containment vessel define a drywell surrounding the reactor. A plurality of vents are disposed in the wetwell pool in flow communication with the drywell for channeling into the wetwell pool steam released in the drywell from the reactor during a LOCA for example, for condensing the steam. A shell is disposed inside the wetwell and extends into the wetwell pool to define a dry gap devoid of wetwell water and disposed in flow communication with the suppression chamber. In a preferred embodiment, the wetwell roof is in the form of a slab disposed on spaced apart support beams which define therebetween an auxiliary chamber. The dry gap, and additionally the auxiliary chamber, provide increased volume to the suppression chamber for improving pressure margin.

  15. Some geochemical and environmental aspects of the Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    Radionuclide fallout on Byelorussia in the first days after the accident was mainly dependent on the mass movement of air and rain. In cities, fallout was confined to regions with intensive industrial dust emissions, as well as to river valleys, where degassing of deep-seated zones through faults occurred side by side with evaporation. Radionuclide washout from upland territories can be related to secondary processes. After 5 a, radioactivity near the surface of the Earth had decreased due to the decay of shortlived isotopes and penetration of radionuclides deeper into the soil, although the major part still occurs at a depth of 1-5 cm. Bogs, peat-bog soils, aquifers with fluctuating groundwater levels, variable pH-Eh conditions and a high-biological activity all contribute to radionuclide migration. A part of the radionuclides is gradually removed from eluvial landscapes and accumulated in subareal landscapes (e.g. lakes, oxbow-lakes, water-storage basins). The Chernobyl debris is represented by the following: ''hot'' particles, pseudocolloids, aerosols and gaseous compounds. Two zones can be distinguished around the reactor differing in the ratio of ''hot'' particles and condensate fallout. A very important role is assigned to biological processes and organic matter, which cause the destruction of ''hot'' particles, the formation or organometallic complexes, and water migration of nuclides. After 300 and more years, the distribution of radionuclides in the landscape will have been determined by weathering, erosion and sedimentation which strongly depend on climatic conditions. Side by side with a gradual decay of Cs and Sr, an appreciable accumulation of 241Am, which is very mobile in landscapes, should be expected due to decaying 241Pu. (Author)

  16. Reflections on Chernobyl

    International Nuclear Information System (INIS)

    The Chernobyl and Three Mile Island reactor accidents are revealing some of the social costs of such failures, widespread opposition to nuclear power. As far as mortality and morbidity go, Chernobyl was probably a smaller incident than the chemical disaster at Bhopal. But nuclear people must accept the idea that a nuclear hazard is perceived as somehow different. Since nuclear energy will be needed to replace oil eventually, and the environmental impacts of properly operating nuclear power plants are far less than those of fossil fuelled power plants, this appears to be an appropriate time for the United States and other interested countries to start developing inherently safe nuclear power plants which will be acceptable to the public

  17. Measurement in nuclear reactors

    International Nuclear Information System (INIS)

    A nuclear reactor construction has a flux detector comprising a bundle of fibre optics each having a bead incorporating a substance which scintillates on being struck by neutrons or gamma radiations. The other ends of the fibre optics terminate at an image intensifier. The optical fibres may be of glass made from a mixture of silica, alkaline earth metal oxide, cerous oxide and alkali metal oxide. The beads may be incorporated in a disc forming a detector head, which is in a protective guide tube, through which an inert gas may be passed. (author)

  18. Health status and follow-up of the Chernobyl Nuclear Power Plant accident liquidators in Latvia

    International Nuclear Information System (INIS)

    The accident at the Nuclear Power Plant in Chernobyl create a new problem for health professionals in Latvia due to the fact that 6475 inhabitants (mainly healthy and men of reproductive age) of Latvia took part in clear-up works in Chernobyl within the period 1986-1991. Chernobyl clear-up workers were exposed γ-radiation and they also incorporated radionuclides. The doses documented for the clear-up workers are variable; they are estimated to be between 0.01-0.5 Gy although the specialists working on the precision of received doses think that they could be even 2 or 3 times higher. The aim of this work is to evaluate the health status of liquidators investigating them on a long-term basis: to create the correct system of health status evaluation of Chernobyl clear-up workers, to improve the register of Chernobyl clear-up workers and of their children, to analyze the data about the incidence of different diseases and mortality gained from follow-ups, to evaluate health status and clinical picture within the period of time, to work out and use adequate methods of treatment. Chernobyl clear-up workers more often than the control group suffer from diseases of the nervous, the endocrine and the metabolic and immune system. They also have higher rate of incidence for diseases of digestive and respiratory system and for diseases of bones, muscles and connective tissue higher rates of accidents and suicides. Now, ten years after the accident there are Chernobyl clear-up workers who are chronically ill and their health status is expected to be worse in the next few years. Regular follow-up and medical examination of Chernobyl clear-up workers and their children should be carried out every year. Regular rehabilitation of Chernobyl clear-up workers should be provided by the government

  19. A neutron monitoring system for evaluating nuclear safety at the Chernobyl Unit 4 fuel debris

    International Nuclear Information System (INIS)

    The remains of the nuclear fuel that was severely damaged in the 1986 Chernobyl unit 4 accident lie in large masses in the premises under the reactor. The fuel debris exists in the form of dusts, chunks, and lavas, and the quantities are substantial--some rooms contain several tons of fuel. Since there is a possibility of water entering these rooms, there is an obvious concern over criticality safety. Incidents of increased neutron count rates have been noted in the vicinity of nuclear fuel debris. Pacific Northwest National Laboratory (PNNL), under a program funded by the US Department of Energy, responded to this safety concern by assembling a new monitoring system to characterize the radiation environment in the vicinity of major fuel deposits. The new monitoring system will measure the gamma and neutron radiation fields in several locations. The measurement data can be tracked over time to determine the characteristics of the radiation fields and better understand the nuclear safety conditions in the vicinity of the fuel. The monitoring system was designed to provide information that will allow a better interpretation of any future events

  20. Health consequences of Chernobyl. 25 years after the reactor catastrophy; Gesundheitliche Folgen von Tschernobyl. 25 Jahre nach der Reaktorkatastrophe

    Energy Technology Data Exchange (ETDEWEB)

    Pflugbeil, Sebastian; Schmitz-Feuerhake, Inge [Gesellschaft fuer Strahlenschutz e.V., Berlin (Germany); Paulitz, Henrik; Claussen, Angelika [Internationale Aerzte fuer die Verhuetung des Atomkrieges, Aerzte in sozialer Verantwortung e.V. (IPPNW), Berlin (Germany). Deutsche Sektion

    2011-04-15

    The report is an evaluation of studies indicating health effects as a consequence of the reactor catastrophe in Chernobyl. The most exposed population include the cleaning personnel (liquidators), the population evacuated from the 30 km zone, the populations in highly contaminated regions in Russia, Belarus and Ukraine, the European population in lass contaminated regions. The following issues are discussed: the liquidators, infant mortality, genetic and teratogenic damages, thyroid carcinoma and other thyroid diseases, carcinogenic diseases and leukemia, other diseases following the Chernobyl catastrophe.

  1. Follow-up to the accident at Chernobyl and its implications for the safety of CANDU reactors

    International Nuclear Information System (INIS)

    This report updates the status of the nine recommendations arising from the AECB staff review of the Chernobyl accident (INFO--0234). Six of the nine recommendations have been satisfactorily responded to by the Canadian nuclear utilities and are considered to be closed. Any follow-up actions arising from the responses to the recommendations will be addressed as part of the continuing licensing process. Of the remaining three, one concerns the effectiveness of the reactor shutdown systems under unusual circumstances. Satisfactory progress is being made. The other two outstanding items concern reviews of emergency and fire fighting practices. Again, satisfactory progress is being made but the response to the recommendations is not yet complete. Each recommendation is discussed separately in the body of this report

  2. The Chernobyl reactor accident and its consequences. Informative report prepared on behalf of the IAEA meeting, Vienna, August 25-29, 1986. Pt. 1

    International Nuclear Information System (INIS)

    GRS has revised the German translation of part 1 of the report on the Chernobyl reactor accident. The translation is technically clear and intelligible and contains the current technical terms. The report comprises a description of RBMK-1000, a chronological description of the accident, the analysis of the accident, the causes of the accident, measures preventing the further development of the accident as well as measures controlling the radioactive contamination of the environment and the population. The report discusses immediate emergency measures improving the safety of RBMK-type nuclear power plants and deals with recommendations for nuclear safety engineering. (DG)

  3. Chernobyl - Could it happen here? [videorecording

    International Nuclear Information System (INIS)

    Following the accident at the Soviet nuclear power station at Chernobyl in April 1986, the CEGB produced this video which has now been updated in the light of the information provided by the Soviets at the International Atomic Energy Agency Conference in Vienna. At this conference it was made clear that the Chernobyl accident would have been impossible in any nuclear reactor operational outside the USSR. This video explains why. It examines the main reasons for the failure of the reactor at Chernobyl and the two fundamental design flaws which resulted in the sequence of events leading up to the accident. It shows how British reactors have built-in protection to compensate for failure in any part of the system, and how the reactors are tolerant to operator error. The programme also explains the safety standards and regulations which are enforced in CEGB nuclear power stations and the rigorous training that reactor operators have to undergo

  4. Water Cooled FBNR Nuclear Reactor

    International Nuclear Information System (INIS)

    A new era of nuclear energy is emerging through innovative nuclear reactors that are to satisfy the new philosophies and criteria that are developed by the INPRO program of the International Atomic Energy Agency (IAEA). The IAEA is establishing a new paradigm in relation to nuclear energy. The future reactors should meet the new standards in respect to safety, economy, non-proliferation, nuclear waste, and environmental impact. The Fixed Bed Nuclear Reactor (FBNR) is a small (70 MWe) nuclear reactor that meets all the established requirements. It is an inherently safe and passively cooled reactor that is fool proof against nuclear proliferation. It is simple in design and economic. It can serve as a dual purpose plant to produce simultaneously both electricity and desalinated water thus making it especially suitable to the needs of most of developing countries. FBNR is developed with the support of the IAEA under its program of Small Reactors Without On-Site Refuelling (SRWOSR). The FBNR reactor uses the pressurized water reactor (PWR) technology. It fulfills the objectives of design simplicity, inherent and passive safety, economy, standardization, shop fabrication, easy transportability and high availability. The inherent safety characteristic of the reactor dispenses with the need for containment; however, a simple underground containment is envisaged for the reactor in order to reduce any adverse visual impact. (author)

  5. Radiation monitoring during construction of the encapsulation for unit 4 of the Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    The accident at the Chernobyl nuclear power plant caused high levels of surface contamination by radionuclides and gamma radiation exposure dose levels in excess of 400 R/h. Moreover, the radiation fields were uneven and inhomogeneous. This is due to the fact that, in addition to dispersed fuel, fragments of the reactor core were also ejected into the buildings and the area surrounding the Chernobyl nuclear power plant. The dosimetric monitoring section monitored the radiation situation. Both traditional and specially developed methods were used to monitor the radiation situation, enabling the measurement of radiation risk factors, the determination of space-angular distribution of gamma radiation, and the detection of local contamination sources. Radiation situation monitoring results show that 75-80% of the gamma radiation was coming from nuclear fuel in the plant compound and not 'streamings' from the wreck of the Unit 4 reactor. The area has been covered with a protective layer thus reducing the gamma radiation levels by 7-20 times. After the encapsulation had been erected, gamma radiation levels in the vicinity of Unit 4 decreased by a factor of approximately 100. The concentration of radioactive aerosols at the work sites while the encapsulation was under construction was, at most, ten times the permitted concentration (PCA), and only when certain operations were being performed which raised a lot of dust did it reach 100-300 PCA. Owing to the high levels of gamma radiation, the danger of external irradiation of personnel was significantly greater than the danger from internal irradiation. Therefore staff were monitored individually for gamma radiation. A permissible dose level of 25 R for the whole period of work (1-2 months) was implemented for the purpose of individual dosimetric monitoring, and a control level of 1 R per shift. The mean exposure dose received by personnel directly involved in the construction of the encapsulation was 8.6 R, and 50.6% of

  6. Virtual nuclear reactor for education of nuclear reactor physics

    International Nuclear Information System (INIS)

    As one of projects that were programmed in the cultivation program for human resources in nuclear engineering sponsored by the Ministry of Economy, Trade and Industry, the development of a virtual reactor for education of nuclear reactor physics started in 2007. The purpose of the virtual nuclear reactor is to make nuclear reactor physics easily understood with aid of visualization. In the first year of this project, the neutron slowing down process was visualized. The data needed for visualization are provided by Monte Carlo calculations; The flights of the respective neutrons generated by nuclear fissions are traced through a reactor core until they disappear by neutron absorption or slow down to a thermal energy. With this visualization and an attached supplement textbook, it is expected that the learners can learn more clearly the physical implication of neutron slowing process that is mathematically described by the Boltzmann neutron transport equation. (author)

  7. Nuclear reactor with control rods

    International Nuclear Information System (INIS)

    The invention relates to liquid cooled nuclear reactors. In particular, it concerns reactors with mobile control rods in a straight line and guide tubes to guide these control rods through the internal upper components of the reactor vessel and in the aligned fuel assemblies of the core

  8. Preliminary nuclear power reactor technology qualitative assessment for Malaysia

    International Nuclear Information System (INIS)

    Since the worlds first nuclear reactor major breakthrough in December 02, 1942, the nuclear power industry has undergone tremendous development and evolution for more than half a century. After surpassing moratorium of nuclear power plant construction caused by catastrophic accidents at Three-mile island (1979) and Chernobyl (1986), today, nuclear energy is back on the policy agendas of many countries, both developed and developing, signaling nuclear revival or nuclear renaissance. Selection of suitable nuclear power technology has thus been subjected to primary attention. This short paper attempts to draw preliminary technology assessment for the first nuclear power reactor technology for Malaysia. Methodology employed is qualitative analysis collating recent finding of tnb-kepco preliminary feasibility study for nuclear power program in peninsular malaysia and other published presentations and/or papers by multiple experts. The results suggested that pressurized water reactor (PWR) is the prevailing technology in terms of numbers and plant performances, and while the commercialization of generation IV reactors is remote (e.g. Not until 2030), generation III/ III+ NPP models are commercially available on the market today. Five (5) major steps involved in reactor technology selection were introduced with a focus on introducing important aspects of selection criteria. Three (3) categories for the of reactor technology selection were used for the cursory evaluation. The outcome of these analyses shall lead to deeper and full analyses of the recommended reactor technologies for a comprehensive feasibility study in the near future. Recommendations for reactor technology option were also provided for both strategic and technical recommendations. The paper shall also implore the best way to select systematically the first civilian nuclear power reactor. (Author)

  9. Nuclear reaction data and nuclear reactors

    International Nuclear Information System (INIS)

    These two volumes contain the lecture notes of the workshop 'Nuclear Reaction Data and Nuclear Reactors: Physics, Design and Safety', which was held at the Abdus Salam ICTP in the Spring of 2000. The workshop consisted of five weeks of lecture courses followed by practical computer exercises on nuclear data treatment and design of nuclear power systems. The spectrum of topics is wide enough to timely cover the state-of-the-art and the perspectives of this broad field. The first two weeks were devoted to nuclear reaction models and nuclear data evaluation. Nuclear data processing for applications to reactor calculations was the subject of the third week. On the last two weeks reactor physics and on-going projects in nuclear power generation, waste disposal and safety were presented

  10. The health status of Chernobyl nuclear power plant accident liquidators in Latvia

    International Nuclear Information System (INIS)

    The accident at the Chernobyl Nuclear Power Plant (NPP) in 1986 is so far the largest nuclear accident, and has created a new problem for nuclear medicine. This accident has also become a problem for Latvia due to the more than 6000 residents who participated in the clean-up works at Chernobyl. The aim of our study was to assess the health status of Chernobyl NPP accident liquidators, in comparison with a male control group in Latvia. We have examined the health of 2512 Chernobyl clean-up workers (males between age of 35-55 with documented and biologically estimated doses of received ionising radiation). For comparison of morbidity, we used a control group consisting of 3887 employees of the Ministry of Internal Affairs (males of the same age groups). The morbidity of Chernobyl NPP accident clean-up workers was generally higher than of control group. The highest contribution to morbidity in each age group of liquidators was from digestive, musculosceletal, nervous system and circulatory system diseases, as well as from mental disorders. (author)

  11. Return to Chernobyl

    International Nuclear Information System (INIS)

    Despite the catastrophic accident at the Chernobylsk 4 reactor in 1986, the Ukraine is currently expanding its nuclear industry. The government is committed to increasing the share of nuclear output to 40% of the country's electric power and the Chernobyl plant is included in this plan. All the Chernobyl reactors were closed down at the time of the accident, but units 1, 2 and 3 had all been restarted after safety modifications by December 1987. A fire in the turbine hall of unit 2 in 1991 resulted in the closure of that reactor and precipitated a political decision to close the entire plant by 1993. The economic consequences of such action and the safe operation of the remaining two reactors led, however, to the reversal of that decision. Work is now far advanced on unit 2 for a restart in 1996 and the management wants to upgrade all three reactors according to IAEA guidelines. Nevertheless, the question of closure of the Chernobyl plant remains in the air. A conditional acceptance of closure by 2000 has been made by the Ukraine provided the shortfall in power is taken up by a new gas-fired station. International finance is being sought for decommissioning, for urgent action on the decaying sarcophagus of unit 4, and for the gas-fired plant. Closure of the plant, given the social upheaval of the accident and recent political events, could contribute to the health of the Ukrainian national psyche. (UK)

  12. Safety and economics of new generations of nuclear reactors

    International Nuclear Information System (INIS)

    In the framework of the so-called ENGINE program (ENergy Generation In the Natural Environment) of ECN, safety and economic aspects of nuclear reactor generations have been reviewed. After the Chernobyl accident in 1986 much has been done to enhance the safety of nuclear reactors. One promising development is the so-called passively safe light water reactor, which can be considered as the next generation of light water reactors. It has a rated power of 600 MWe or less, and safety is primarily based on passive systems. In accident conditions there is no need for operator action to keep the core cooled and covered with water for at least 72 hours. Passively safe water reactors need no demonstration stage and could be commercial around 1995. Two nuclear reactors of current design (1st generation, APWR and ABWR) and 3 pas-sively safe reactors (2nd generation, AP600, SBWR and SIR) are reviewed. Besides the 2nd generation reactors, other reactor types come into con-sideration, which are characterized by the most consequent utilisation of passive safety. A core melt accident with such a reactor is either highly unlikely or virtually impossible. Because of their advanced design demonstration is inevitable. Two reactor types of this 3rd generation are reviewed. Commercial introduction is expected after 2005. The economics of nuclear reactors are compared to those of ad-vanced coal fired power plants for the period 2000-2045. The Integrated Coal Gasification Combined Cycle (IGCC) plant is used as a reference, and economically acceptable nuclear investment costs are calculated, based on annualised costs and a 30 year economic life. These economi-cally acceptable investment costs are compared to published investment costs of current reactors. (author). 113 refs.; 7 figs.; 22 tabs

  13. Establishment of nuclear safety regulatory regime in Ukraine. Lessons of Chernobyl

    International Nuclear Information System (INIS)

    The issue of safety of Ukraine's Nuclear Power Plants attracts a particular attention world-wide, and the reasons for that are clearly understood: the memories of the Chernobyl tragedy happened in 1986 will possess the minds of people of the world for years. The international community is aware that the political changes and transient economy crisis the former Soviet Union States are facing today, make the resolution of nuclear facilities safety problems less possible. Nevertheless, the understanding and perception of safety policy in Ukraine underwent drastic changes after the Chernobyl accident, and the policy pursued by the Ukraine's safety authority contributes to turning the changes into good practices

  14. Migration and biological effect of radionuclides in forest biogeocenozes of the Chernobyl Nuclear Power Station region

    International Nuclear Information System (INIS)

    The results are presented of radioecological and radiobiological investigations in forest biogeocenozes of the 30 kilometer zone of failure in the Chernobyl Nuclear Power Station. The authors present the quantitative evaluation of the distribution of radionuclei in the main component of the soil-plant layer in landscape areas linked in the drainage flow. The morphophysiological special features and hidden variations of the seeds of certain representatives of woody and herbaceous plants of the 30 kilometer zone of the Chernobyl Nuclear Power Station are determined. 12 refs., 5 figs., 3 tabs

  15. Optimal control of nuclear reactors

    International Nuclear Information System (INIS)

    The modern control theory is applied to the design of control systems for experimental nuclear reactors that do not belong to power reactors, the component forms of optimal control systems for nuclear reactors are demonstrated. The adoption of output quadratic integral criterion and incomplete state feedback technique can make these systems both efficient and economical. Moreover, approximate handling methods are given so as to simplify the calculations in design. In addition, the adoptable reference values of parameters are given in the illustration

  16. Uptake in the human body resulting from the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    During the reactor accident at Chernobyl, radioactive material was released to the atmosphere and was carried with the winds to many parts of Europe. Specifically some quantities of I-131, Cs-134 and Cs-137 in air have reached the European countries and exposed the population to internal radiation via inhalation. As a result of the fallout, these radionuclides were also taken by people via the food chain, this soon became the most significant exposure pathway. To determine the level of internal contamination, people were monitored for I-131, Cs-134 and Cs-137. Personal monitoring was performed on citizens (or visitors) of the European countries outside the Soviet Union or those who happened to visit the Soviet Union during or immediately after the Chernobyl accident. This paper gives a summary of the personal monitoring reported mainly by Canada, Finland, France, Switzerland and the United Kingdom. The paper also gives a summary of the techniques used today to assess internal contamination and in particular, it elaborates on the two methods which were used to measure uptake in the human body resulting from the Chernobyl accident. For these two methods (whole body or thyroid direct count and activity in urine) the paper summarizes the main physical, metabolic and radiological parameters for I-131, Cs-134 and Cs-137. These parameters help to put the two methods of personal monitoring into perspective and to convert the reported data on personal monitoring into internal radiation doses

  17. Impressions of Chernobyl

    International Nuclear Information System (INIS)

    Three years on from the nuclear power plant accident, an inaugural meeting of the Wano (World Association of Nuclear Operators) discusses impressions of the Chernobyl incident on a technical tour through the Chernobyl exclusion zone. (author)

  18. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    The description is given of a nuclear reactor fuel assembly comprising fuel elements arranged in a supporting frame composed of two end pieces, one at the top and the other at the bottom, on which are secured the ends of a number of vertical tubes, each end piece comprising a plane bottom on which two series of holes are made for holding the tubes and for the passage of the coolant. According to the invention, the bottom of each end piece is fixed to an internal plate fitted with the same series of holes for holding the tubes and for the fluid to pass through. These holes are of oblong section and are fitted with fixing elements cooperating with corresponding elements for securing these tubes by transversal movement of the inside plate

  19. Nuclear reactor inspection device

    International Nuclear Information System (INIS)

    A typical embodiment of the invention combines a novel cellular end fitting for a nuclear reactor fuel assembly with a new design for a fuel rod end cap and a radiation sensing device probe to provide a means for swiftly and accurately distinguishing sound fuel rods from those rods that have developed leaks. For example, a somewhat thinner than usual fuel rod end cap is accessible through the open cellular structure of the end fitting to permit a hollow metal probe to contact the fuel rod end cap. This direct contact excludes most of the water, metal and other shielding materials from the volume between the interior of the fuel rod and the radiation detector, thereby improving the quality of the fuel rod examination. A bridge and trolley structure for accurately positioning the probe also is described

  20. Nuclear reactor spacer assembly

    International Nuclear Information System (INIS)

    A fuel assembly for a nuclear reactor is disclosed wherein the fuel element receiving and supporting grid is comprised of a first metal, the guide tubes which pass through the grid assembly are comprised of a second metal and the grid is supported on the guide tubes by means of expanded sleeves located intermediate the grid and guide tubes. The fuel assembly is fabricated by inserting the sleeves, of initial outer diameter commensurate with the guide tube outer diameters, through the holes in the grid assembly provided for the guide tubes and thereafter expanding the sleeves radially outwardly along their entire length such that the guide tubes can subsequently be passed through the sleeves. The step of radial expansion, as a result of windows provided in the sleeves having dimensions commensurate with the geometry of the grid, mechanically captures the grid and simultaneously preloads the sleeve against the grid whereby relative motion between the grid and guide tube will be precluded

  1. Nuclear reactor measurement system

    International Nuclear Information System (INIS)

    An instrument to detect the temperature and flow-rate of the liquid metal current of a coolant fluid sample from adjacent sub-assemblies of a liquid metal-cooled nuclear reactor is described. It includes three thermocouple hot junctions mounted in series, each intended for exposure to a sample-current from a single sub-assembly, electromagnetic coils being mounted around an induction core which detects variations in the liquid metal flow-rate by deformation of the lines of flux. The instrument may also include a thermocouple to detect the mean temperature of the sample-current of coolant fluid from several sources, the result being that the temperature of the coolant fluid current in a sub-assembly may be inferred from the three temperature readings associated with this sub-assembly

  2. Chernobyl: four years later: attitudes, risk management and communication

    OpenAIRE

    Pligt, van der, J.; Midden, C.H.J.

    1990-01-01

    Discusses the impact that the nuclear reactor accident at Chernobyl has had on risk management and risk communication in relation to risk perception; decisions and coping with uncertainty; and public opinion, personal attitudes, and public policy.

  3. Chernobyl, 17 after

    International Nuclear Information System (INIS)

    This information document takes stock on the Chernobyl accident effects, 17 years after the reactor accident. The domains concerned are: the Chernobyl power plant, the sanitary consequences of the accident in the most exposed countries, the Chernobyl environment and the polluted regions management, the Chernobyl accident consequences in France; Some data and technical sheets on the RBMK reactors and the international cooperation are also provided. (A.L.B.)

  4. Sodium-cooled nuclear reactors

    International Nuclear Information System (INIS)

    This book first explains the choice of sodium-cooled reactors by outlining the reasons of the choice of fast neutron reactors (fast neutrons instead of thermal neutrons, recycling opportunity for plutonium, full use of natural uranium, nuclear waste optimization, flexibility of fast neutron reactors in nuclear material management, fast neutron reactors as complements of water-cooled reactors), and by outlining the reasons for the choice of sodium as heat-transfer material. Physical, chemical, and neutron properties of sodium are presented. The second part of the book first presents the main design principles for sodium-cooled fast neutron reactors and their core. The third part proposes an historical overview and an assessment of previously operated sodium-cooled fast neutron reactors (French reactors from Rapsodie to Superphenix, other reactors in the world), and an assessment of the main incidents which occurred in these reactors. It also reports the experience and lessons learned from the dismantling of various sodium-cooled fast breeder reactors in the world. The next chapter addresses safety issues (technical and safety aspects related to the use of sodium) and environmental issues (dosimetry, gaseous and liquid releases, solid wastes, and cooling water). Then, various technological aspects of these reactors are addressed: the energy conversion system, main components, sodium chemistry, sodium-related technology, advances in in-service inspection, materials used in reactors and their behaviour, and fuel system. The next chapter addresses the fuel cycle in these reactors: its integrated specific character, report of the French experience in fast neutron reactor fuel processing, description of the transmutation of minor actinides in these reactors. The last chapter proposes an overview of reactors currently projected or under construction in the world, presents the Astrid project, and gives an assessment of the economy of these reactors. A glossary and an index

  5. Fast reactors and nuclear nonproliferation

    International Nuclear Information System (INIS)

    Problems are discussed with regard to nuclear fuel cycle resistance in fast reactors to nuclear proliferation risk due to the potential for use in military programs of the knowledge, technologies and materials gained from peaceful nuclear power applications. Advantages are addressed for fast reactors in the creation of a more reliable mode of nonproliferation in the closed nuclear fuel cycle in comparison with the existing fully open and partially closed fuel cycles of thermal reactors. Advantages and shortcomings are also discussed from the point of view of nonproliferation from the start with fast reactors using plutonium of thermal reactor spent fuel and enriched uranium fuel to the gradual transition using their own plutonium as fuel. (author)

  6. The Chernobyl effect

    International Nuclear Information System (INIS)

    In what way and to what extent does an event like the Chernobyl reactor accident influence the citizen's attitudes and political commitment. This book evolves a number of theses on these questions dealing above all with the determinants of political protest. Two investigations are presented in order to verify those theses: in 1982 and 1987 (some nine months after the Chernobyl reactor accident), the same persons were interviewed. In addition, representative surveys in the Federal Republic of Germany are analysed, in order to assess in general the impact of Chernobyl. From the contents: explanation model for political protest; Chernobyl effect: effect of critical events on the mobilization of political protest; discontent with nuclear energy use, political alienation and protest; internal incentives for protest: norms, readiness for aggression, and entertainment quality of protest; resources as determinants of political protest; sanctions and protest; social nets and political protest; verification of a central model of political protest, and problems encountered by research. Appendix: investigation plan and random sampling of the panel of nuclear power opponents. (orig./HP)

  7. Accounting, control and physical protection of nuclear material at the Chernobyl Shelter

    International Nuclear Information System (INIS)

    The existing assessments of nuclear material amounts present within the post-accident Chernobyl unit 4 are provided. The system for accounting for and control of Shelter nuclear material is considered. The common nature of the tasks for nuclear material accounting, control and physical protection is demonstrated. The configuration and characteristics of the Shelter physical protection system are described and factors that may adversely affect its effectiveness are identified

  8. 30 years life with Chernobyl, 5 years life with Fukushima. Health consequences of the nuclear catastrophes of Chernobyl and Fukushima; 30 Jahre Leben mit Tschernobyl, 5 Jahre Leben mit Fukushima. Gesundheitliche Folgen der Atomkatastrophen von Tschernobyl und Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Claussen, Angelika; Rosen, Alex

    2016-02-15

    The IPPNW report on health consequences of the nuclear catastrophes of Chernobyl and Fukushima covers the following issues: Part.: 30 years life with Chernobyl: Summarized consequences of Chernobyl, the accident progression, basic data of the catastrophe, estimation of health hazards as a consequence of the severe accident of Chernobyl, health consequences for the liquidators, health consequences for the contaminated population, mutagenic and teratogenic effects. Part B: 5 years life with Fukushima: The start of the nuclear catastrophe, emissions and contamination, consequences of the nuclear catastrophe on human health, thyroid surveys in the prefecture Fukushima, consequences of the nuclear catastrophe on the ecosystem, outlook.

  9. Safety of light water reactors. Risks of nuclear technology

    International Nuclear Information System (INIS)

    The book on the safety of light-water reactors includes the following chapters: Part I: Physical and technical safety concept of actual German and future European light-water reactors: (1) Worldwide operated nuclear power plants in 2011, (2) Some reactor physical fundamentals. (3) Nuclear power plants in Germany. (4) Radioactive exposure due to nuclear power plants. (5) Safety concept of light-water reactors. (6) Probabilistic analyses and risk studies. (7) Design of light-water reactors against external incidents. (8) Risk comparison of nuclear power plants and other energy systems. (9) Evaluation of risk studies using the improved (new) safety concept for LWR. (19) The severe reactor accidents of Three Mile Island, Chernobyl and Fukushima. Part II: Safety of German LWR in case of a postulated aircraft impact. (11) Literature. (12) Review of requirements and actual design. (13) Incident scenarios. (14) Load approach for aircraft impact. (15) Demonstration of the structural behavior in case of aircraft impact. (16) Special considerations. (17) Evaluation of the safety state of German and foreign nuclear power plants. Part III: ROSOS as example for a computer-based decision making support system for the severe accident management. (19) Literature. (20) Radiological fundamentals, accident management, modeling of the radiological situation. (21) The decision making support system RODOS. (22) RODOS and the Fukushima accident. (23) Recent developments in the radiological emergency management in the European frame.

  10. The Chernobyl accident

    International Nuclear Information System (INIS)

    In connection with the Chernobyl accident the report gives a description of the technical features of importance to the accident, the course of events, and the estimated health hazards in the local environment. Dissimilarities in western and Sovjet reactor safety philosophy are dealt with, as well as conceivable concequences in relation to technology and research in western nuclear power programmes. Results of activity level measurements of air and foodstuff, made in Norway by Institute for Energy Technology, are given

  11. Improving nuclear safety at international research reactors: The Integrated Research Reactor Safety Enhancement Program (IRRSEP)

    International Nuclear Information System (INIS)

    Nuclear energy continues to play a major role in the world's energy economy. Research and test reactors are an important component of a nation's nuclear power infrastructure as they provide training, experiments and operating experience vital to developing and sustaining the industry. Indeed, nations with aspirations for nuclear power development usually begin their programs with a research reactor program. Research reactors also are vital to international science and technology development. It is important to keep them safe from both accident and sabotage, not only because of our obligation to prevent human and environmental consequence but also to prevent corresponding damage to science and industry. For example, an incident at a research reactor could cause a political and public backlash that would do irreparable harm to national nuclear programs. Following the accidents at Three Mile Island and Chernobyl, considerable efforts and resources were committed to improving the safety posture of the world's nuclear power plants. Unsafe operation of research reactors will have an amplifying effect throughout a country or region's entire nuclear programs due to political, economic and nuclear infrastructure consequences. (author)

  12. Nuclear reactor building

    International Nuclear Information System (INIS)

    Purpose: To prevent seismic vibrations of external buildings from transmitting to the side walls of a reactor container in a tank type FBR reactor building. Constitution: The reactor building is structured such that the base mat for a reactor container chamber and a reactor container is separated from the base mat for the walls of building, and gas-tight material such as silicon rubber is filled in the gap therebetween. With such a constitution, even if the crane-supporting wall vibrates violently upon occurrence of earthqualkes, the seismic vibrations do not transmit toward the reactor container chamber. (Horiuchi, T.)

  13. Chernobyl, 12 years later

    International Nuclear Information System (INIS)

    This report draws an account of the consequences of Chernobyl accident 12 years after the disaster. It is made up of 7 chapters whose titles are: 1) Some figures about Chernobyl accident, 2) The Chernobyl nuclear power plant, 3)Sanitary consequences of Chernobyl accident, 4) The management of contaminated lands, 5) The impact in France of Chernobyl fallout, 6) The Franco-German cooperation, and 7) Glossary

  14. Chernobyl nuclear accident revealed from the 7010 m Muztagata ice core record

    Institute of Scientific and Technical Information of China (English)

    TIAN LiDe; YAO TanDong; WU GuangJian; LI Zhen; XU BaiQing; LI YueFang

    2007-01-01

    The total activity variation with depth from a 41.6 m Muztagata ice core drilled at 7010 m,recorded not only the 1963 radioactive layer due to the thermonuclear test,but also clearly the radioactive peak released by the Chernobyl accident in 1986.This finding indicates that the Chernobyl nuclear accident was clearly recorded in alpine glaciers in the Pamirs of west China,and the layer can be potentially used for ice core dating in other high alpine glaciers in the surrounding regions.

  15. Consequences of the Chernobyl reactor accident with respect to the feeding of infants

    International Nuclear Information System (INIS)

    In view of the persisting and understandable fear of parents with regard to radioactivity in the food of their babies as a consequence of the Chernobyl reactor accident, the Commission on Nutrition of the Deutsche Gesellschaft fuer Kinderheilkunde (German Society of Pediatrics) and the Strahlenschutzkommission have published a statement. According to this statement, the maximum permissible level of radioactivity in commercial baby food has been fixed by the EC to be 370 Bq/kg. The dietetic food industry itself has fixed a maximum for its products which is only a tenth of the radioactivity level permitted by the EC directive. The milk powders for infants tested since the reactor accident contained no measurable radioactivity or only very low amounts of Cs 134 or Cs 137, correspondung to a maximum of 25 Bq/kg in the product. Late damage to health is not to be expected. (orig./ECB)

  16. Scientific recommendations for the reconstruction of radiation doses due to the reactor accident at Chernobyl

    International Nuclear Information System (INIS)

    In the years after the Chernobyl reactor accident, many studies of the radiation exposure levels and resulting health effects in the countries of the CIS have been conducted. The increasing incidence of childhood thyroid cancers in Belarus and Ukraine has stimulated worldwide multi- and bilateral cooperations with those countries and Russia in order to optimize benefits for those directly affected, but also to enlarge current knowledge of the consequences of reactor accidents. An international workshop on dose reconstruction was held in Bad Honnef, June 6 to 9, 1994, to address the problems which arise in dose reconstruction. The main objectives of this workshop were to bring together the best professional expertise and scientific knowledge and to achieve a better, multi-disciplinary harmonisation of the different scientific approaches. After intensive discussions the participants of this workshop formulated the following scientific recommendations for radiation dose reconstruction. (orig.)

  17. Chernobyl 2015

    International Nuclear Information System (INIS)

    After having recalled the Chernobyl accident process and consequences for the power station buildings, and also the emergency interventions to cover the reactor and avoid that the molten core reaches underground waters, the author proposes a brief overview of the consequences at the international level in the field of nuclear safety with the emergence of a culture of safety which has been applied in other industrial sectors, with the improvement of the quality of transmitted information, and with the lessons learned about the efficiency of early ingestion of iodine pills. The author evokes the construction of a containment arch to dismantle the whole installation, comments the various results published on health consequences and gives some explanations about their discrepancy

  18. Teaching About Nature's Nuclear Reactors

    CERN Document Server

    Herndon, J M

    2005-01-01

    Naturally occurring nuclear reactors existed in uranium deposits on Earth long before Enrico Fermi built the first man-made nuclear reactor beneath Staggs Field in 1942. In the story of their discovery, there are important lessons to be learned about scientific inquiry and scientific discovery. Now, there is evidence to suggest that the Earth's magnetic field and Jupiter's atmospheric turbulence are driven by planetary-scale nuclear reactors. The subject of planetocentric nuclear fission reactors can be a jumping off point for stimulating classroom discussions about the nature and implications of planetary energy sources and about the geomagnetic field. But more importantly, the subject can help to bring into focus the importance of discussing, debating, and challenging current thinking in a variety of areas.

  19. Safety device for nuclear reactor

    International Nuclear Information System (INIS)

    This invention relates to a safety device for a nuclear reactor, particularly a liquid metal (generally sodium) cooled fast reactor. This safety device includes an absorbing element with a support head connected by a disconnectable connector formed by the armature of an electromagnet at the end of an axially mobile vertical control rod. This connection is so designed that in the event of it becoming disconnected, the absorbing element gravity slides in a passage through the reactor core into an open container

  20. Control rod drive of nuclear reactor

    International Nuclear Information System (INIS)

    This invention relates to nuclear reactors and, more particularly, to a drive of a control rod of a nuclear reactor and allows power control, excess reactivity compensation, and emergency shut-down of a reactor. (author)

  1. Disaster policy and nuclear liability: insights from post-Chernobyl agriculture in the United Kingdom

    International Nuclear Information System (INIS)

    The recent events at Chernobyl have again brought the issues of nuclear safety to the forefront of the nuclear power debate. Fortunately, our experience with such incidents has been very limited, but it is important to learn as much as possible from such events so as to minimize the cost and effect of any other nuclear incidents, be they small or large. Much of the discussion about the possible effects of nuclear incidents has centered around the human cost in terms of health. While this is undoubtedly of paramount concern, the effect of the release of radiation from Chernobyl on the agricultural resource base in Europe can provide valuable insights on how to reduce the costs associated with the contamination of agricultural areas. This article outlines some of the lessons that can be learned using the livestock-raising industry in northern Wales as an example

  2. R[ionuclide transport after the Chernobyl reactor accident and derivation of r[ioecological parameters

    International Nuclear Information System (INIS)

    Since due to the nuclear reactor accident in Chernobyl r[ionuclides arrived in the vicinity of Aachen, the enhancement of the local dose rate, the deposition of the different r[ionuclides on ground and vegetation and the transport of the r[ionuclides into the environment were measured. Partly the measurements were continued until today. Very informative time sequences of the specific activity in grass, food, cow's milk, beef, in the different plants, trees, ploughed soil and undisturbed soil, mushrooms, game, in humans etc. resulted. During different private and official journeys in the old Laender of the Federal Republic of Germany surface covering measurements of the 134Cs and 137Cs activity deposited on grass land at different places were carried out. These data were implemented into a map on ground contamination in 1986 in Germany, published in 1991 by the Institute for Water, Soil and Air Hygiene of the Federal Public Health Department in Berlin. Transfer factors soil-grass were measured in the whole Federal Republic of Germany analyzing grass samples which were partly taken at the same time. A large amount of r[ioecological parameters could be derived from the different time sequences. These are in particular: The deposition velocity for iodine and particle bound r[ioanuclides on grass and in forests, the rainout coefficient in dependence of the precipitation intensity, the retention factors on grass, the biological half-life time on grass, the transfer factor soil-grass in dependence of time, the transfer factor food-milk during the pasture period and during stable stay, the transfer factor food-beef, the transfer factors in eatable mushrooms, the translocation factor of cesium in cereals etc. A multi-compartment model was developed to calculate the specific Cs activity in cow's milk and beef. The specific activity in milk can be calculated sufficiently exact using a simple single compartment model. The correlation of the specific Cs activity in spruce

  3. Application of natural adsorbents as decontamination agents for the elimination of the consequences of the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The scientific foundations of using natural adsorbents as ion exchangers,filtering media and adagulants for water purification ase presented. The results showing the efficiency of practical application of natural adsorbents for the decontamination of water, clothes, machinery, construction materials, etc. during the elimination of the consequences of the Chernobyl reactor accident in 1986-1987 are presented

  4. Nuclear Reactor RA Safety Report, Vol. 11, Reactor operation

    International Nuclear Information System (INIS)

    This volume includes the following chapters describing: Organisation of reactor operation (including operational safety, fuel management, and regulatory rules for RA reactor operation); Control and maintenance of reactor components (reactor core, nuclear fuel, heavy water and cover gas systems, mechanical structures, electric power supply system, reactor instrumentation); Quality assurance and Training of the reactor personnel

  5. Nuclear reactors and fuel cycle

    International Nuclear Information System (INIS)

    The Center for Nuclear Engineering has shown expertise in the field of nuclear and energy systems ad correlated areas. Due to the experience obtained over decades in research and technological development at Brazilian Nuclear Program personnel has been trained and started to actively participate in the design of the main system that will compose the Brazilian Multipurpose Reactor (RMB) which will make Brazil self-sufficient in the production of radiopharmaceuticals. The institution has participated in the monitoring and technical support concerning the safety, licensing and modernization of the research reactors IPEN/MB-01 and IEA-R1. The Nuclear Fuel Center is responsible for the production of the nuclear fuel necessary for the continuous operation of the IEA-R1 research reactor. Development of new fuel technologies is also a permanent concern

  6. Implications of the accident at Chernobyl for safety regulation of commercial nuclear power plants in the United States: Volume 1, Main report: Final report

    International Nuclear Information System (INIS)

    This report was prepared by the Nuclear Regulatory Commission (NRC) staff to assess the implications of the accident at the Chernobyl nuclear power plant as they relate to reactor safety regulation for commercial nuclear power plants in the United States. The facts used in this assessment have been drawn from the US fact-finding report (NUREG-1250) and its sources. The general conclusions of the document are that there are generic lessons to be learned but that no changes in regulations are needed due to the substantial differences in the design, safety features and operation of US plants as compared to those in the USSR. Given these general conclusions, further consideration of certain specific areas is recommended by the report. These include: administrative controls over reactor regulation, reactivity accidents, accidents at low or zero power, multi-unit protection, fires, containment, emergency planning, severe accident phenomena, and graphite-moderated reactors

  7. Implications of the accident at Chernobyl for safety regulation of commercial nuclear power plants in the United Sates: Volume 2, Appendix - Public comments and their disposition: Final report

    International Nuclear Information System (INIS)

    This report was prepared by the Nuclear Regulatory Commission (NRC) staff to assess the implications of the accident at the Chernobyl nuclear power plant as they relate to reactor safety regulation for commercial nuclear power plants in the United States. The facts used in this assessment have been drawn from the US fact-finding report(NUREG-1250) and its sources. The general conclusions of the document are that there are generic lessons to be learned but that no changes in regulations are needed due to the substantial differences in the design, safety features and operation of US plants as compared to those in the USSR. Given these general conclusions, further consideration of certain specific areas is recommended by the report. These include: administrative controls over reactor regulation, reactivity accidents, accidents at low or zero power, multi-unit protection, fires, containment, emergency planning, severe accident phenomena, and graphite-moderated reactors

  8. Random processes in nuclear reactors

    CERN Document Server

    Williams, M M R

    1974-01-01

    Random Processes in Nuclear Reactors describes the problems that a nuclear engineer may meet which involve random fluctuations and sets out in detail how they may be interpreted in terms of various models of the reactor system. Chapters set out to discuss topics on the origins of random processes and sources; the general technique to zero-power problems and bring out the basic effect of fission, and fluctuations in the lifetime of neutrons, on the measured response; the interpretation of power reactor noise; and associated problems connected with mechanical, hydraulic and thermal noise sources

  9. Liability problems arising from nuclear reactor accidents

    International Nuclear Information System (INIS)

    In case of damage to health or property, it has always been approved legal tradition in all highly developed legal systems to perform compensation for damage in money. This principle also applies to damage caused by nuclear accidents. In the F.R.G., care has been taken at a very early stage to provide for appropriate liability provisions to afford financial security to the extent required by the special hazards involved in the peaceful use of atomic energy. Recent events have shown that the legal provisions available are appropriate and practicable. Citizens affected will receive fair compensation for damage. The Federal Administrative Office so far counted 30.392 applications for compensation in compliance with section 38, sub-sec. (2) Atomic Energy Act. Up to June 16, 1986, payments for compensation of losses amounted to DM 38.7 millions. By accepting the claims for compensation the State provides protection for German nationals and persons of equal rank. A limitation to DM one billion for compensation for damage caused by nuclear energy seems to be appropriate also in the light of the Chernobyl reactor accident. (orig./HP)

  10. The future of nuclear reactors

    International Nuclear Information System (INIS)

    The Atomic Energy Commission Advisory Committee on Reactor Safeguards began work in early 1948 with the firm and unanimous conviction that nuclear power could not survive a significant damaging accident. They as a committee felt that their job was to make reactors so safe that no such event would ever occur. However, ambitious reactor planners did not like all the buts and cautions that the committee was raising. They seemed to delay unduly their setting sail into the brave new world of clean, cheap, safe nuclear energy. The committee was soon nicknamed the Committee on Reactor Prevention. Reactors, of course, represented a tremendous step into the future. To an unprecedented extent, they were based on theory. But the committee did not have the luxury of putting a preliminary model into operation and waiting for difficulties to show up. In assessing new designs and developments, they had to anticipate future difficulties. Their proposals in good part were accepted, but their deep emphasis on safety did not become a part of the program. Today, forty years later, the author still believes both in the need for nuclear reactors and in the need of a thorough-going, pervasive emphasis on their safety. Real, understandable safety can be achieved, and that achievement is the key to our nuclear future. The details he gives are only examples. The need for reactors that are not only safe but obviously safe can be ignored only at our peril

  11. Studies on nuclear reactor design

    International Nuclear Information System (INIS)

    this thesis presents two studies for safety aspects in nuclear reactor design. the fission process that occurs in the reactor core is the most important process for the harmful effect of produced radiation especially neutrons with different energies and gamma radiations for their strong penetrability . so studying the criticality of the fissile materials in the reactor is one of the most important safety aspects for the reactor design, the attenuation of the neutrons and gammas using suitable shielding materials with suitable thicknesses is the second study that is discussed in this thesis

  12. Gas-cooled nuclear reactor

    International Nuclear Information System (INIS)

    The invention aims at simplying gas-cooled nuclear reactors. For the cooling gas, the reactor is provided with a main circulation system comprising one or several energy conversion main groups such as gas turbines, and an auxiliary circulation system comprising at least one steam-generating boiler heated by the gas after its passage through the reactor core and adapted to feed a steam turbine with motive steam. The invention can be applied to reactors the main groups of which are direct-cycle gas turbines

  13. After Chernobyl. Psychological factors affecting health after a nuclear disaster

    Energy Technology Data Exchange (ETDEWEB)

    Havenaar, J.M.

    1996-04-23

    During his stay in Belarus, Ukraine and Russia the author learned much about the medical and psychological consequences of the Chernobyl accident, and about the rapidly changing societies of the former Soviet Union. The chapters of this dissertation may be regarded as being stations along the way in this learning process. Chapter 1 describes his first impressions and the accounts he heard about the events that followed the catastrophe. It summarizes the current knowledge about the radiological consequences of the disaster. Chapter 2 presents a review of the literature about the psychological impact of disasters, such as Chernobyl, Bhopal and Three Mile Island, events that are characterized by the release of potentially harmful quantities of toxic substances into the environment. Chapters 3 and 4 describe the painstaking process of obtaining the necessary reliable research instruments, which were totally lacking in the Russian language. Without such instruments no valid epidemiological research is possible. Furthermore, these research instruments were to provide a tool to assist the Byelorussian physicians in their daily practice, helping them to assess the presence of psychosocial and psychiatric problems in their patients in a more reliable fashion. Chapter 5 describes the mental health situation in the region and analyses the presence of high-risk groups towards whom special intervention programmes. Chapter 6 investigates the question to what extent the high levels of psychopathology in Gomel can be attributed to the impact of the Chernobyl disaster, even more than six years after the event. In chapter 7 the perspective is widened. The field of mental health is left behind and the domain of public health is addressed. This chapter describes the relationship between subjective health and illness behaviour in relation to objective clinical parameters of physical and mental health. Finally, in chapter 8, the findings from these studies are critically reviewed and

  14. After Chernobyl. Psychological factors affecting health after a nuclear disaster

    International Nuclear Information System (INIS)

    During his stay in Belarus, Ukraine and Russia the author learned much about the medical and psychological consequences of the Chernobyl accident, and about the rapidly changing societies of the former Soviet Union. The chapters of this dissertation may be regarded as being stations along the way in this learning process. Chapter 1 describes his first impressions and the accounts he heard about the events that followed the catastrophe. It summarizes the current knowledge about the radiological consequences of the disaster. Chapter 2 presents a review of the literature about the psychological impact of disasters, such as Chernobyl, Bhopal and Three Mile Island, events that are characterized by the release of potentially harmful quantities of toxic substances into the environment. Chapters 3 and 4 describe the painstaking process of obtaining the necessary reliable research instruments, which were totally lacking in the Russian language. Without such instruments no valid epidemiological research is possible. Furthermore, these research instruments were to provide a tool to assist the Byelorussian physicians in their daily practice, helping them to assess the presence of psychosocial and psychiatric problems in their patients in a more reliable fashion. Chapter 5 describes the mental health situation in the region and analyses the presence of high-risk groups towards whom special intervention programmes. Chapter 6 investigates the question to what extent the high levels of psychopathology in Gomel can be attributed to the impact of the Chernobyl disaster, even more than six years after the event. In chapter 7 the perspective is widened. The field of mental health is left behind and the domain of public health is addressed. This chapter describes the relationship between subjective health and illness behaviour in relation to objective clinical parameters of physical and mental health. Finally, in chapter 8, the findings from these studies are critically reviewed and

  15. Technique of nuclear reactors controls

    International Nuclear Information System (INIS)

    This report deal about 'Techniques of control of the nuclear reactors' in the goal to achieve the control of natural uranium reactors and especially the one of Saclay. This work is mainly about the measurement into nuclear parameters and go further in the measurement of thermodynamic variables,etc... putting in relief the new features required on behalf of the detectors because of their use in the thermal neutrons flux. In the domain of nuclear measurement, we indicate the realizations and the results obtained with thermal neutron detectors and for the measurement of ionizations currents. We also treat the technical problem of the start-up of a reactor and of the reactivity measurement. We give the necessary details for the comprehension of all essential diagrams and plans put on, in particular, for the reactor of Saclay. (author)

  16. Low-power nuclear reactors

    International Nuclear Information System (INIS)

    A brief development history of low-power nuclear reactors is presented in this paper. Nowadays, some countries have plans to build a series of small nuclear power plants (also floating ones) for use in remote regions. Present constructions of such NPP are presented in this paper. (author)

  17. Nuclear reactors and fuel cycle

    International Nuclear Information System (INIS)

    The Nuclear Fuel Center (CCN) of IPEN produces nuclear fuel for the continuous operation of the IEA-R1 research reactor of IPEN. The serial production started in 1988, when the first nuclear fuel element was delivered for IEA-R1. In 2011, CCN proudly presents the 100th nuclear fuel element produced. Besides routine production, development of new technologies is also a permanent concern at CCN. In 2005, U3O8 were replaced by U3Si2-based fuels, and the research of U Mo is currently under investigation. Additionally, the Brazilian Multipurpose Research Reactor (RMB), whose project will rely on the CCN for supplying fuel and uranium targets. Evolving from an annual production from 10 to 70 nuclear fuel elements, plus a thousand uranium targets, is a huge and challenging task. To accomplish it, a new and modern Nuclear Fuel Factory is being concluded, and it will provide not only structure for scaling up, but also a safer and greener production. The Nuclear Engineering Center has shown, along several years, expertise in the field of nuclear, energy systems and correlated areas. Due to the experience obtained during decades in research and technological development at Brazilian Nuclear Program, personnel has been trained and started to actively participate in design of the main system that will compose the Brazilian Multipurpose Reactor (RMB) which will make Brazil self-sufficient in production of radiopharmaceuticals. The institution has participated in the monitoring and technical support concerning the safety, licensing and modernization of the research reactors IPEN/MB-01 and IEA-R1. Along the last two decades, numerous specialized services of engineering for the Brazilian nuclear power plants Angra 1 and Angra 2 have been carried out. The contribution in service, research, training, and teaching in addition to the development of many related technologies applied to nuclear engineering and correlated areas enable the institution to fulfill its mission that is to

  18. Fundamentals of Nuclear Reactor Physics

    CERN Document Server

    Lewis, E E

    2008-01-01

    This new streamlined text offers a one-semester treatment of the essentials of how the fission nuclear reactor works, the various approaches to the design of reactors, and their safe and efficient operation. The book includes numerous worked-out examples and end-of-chapter questions to help reinforce the knowledge presented. This textbook offers an engineering-oriented introduction to nuclear physics, with a particular focus on how those physics are put to work in the service of generating nuclear-based power, particularly the importance of neutron reactions and neutron behavior. Engin

  19. Characteristics of Chernobyl-derived radionuclides in particulate form in surface waters in the exclusion zone around the Chernobyl Nuclear Power Plant

    Science.gov (United States)

    Matsunaga, Takeshi; Ueno, Takashi; Amano, Hikaru; Tkatchenko, Y.; Kovalyov, A.; Watanabe, Miki; Onuma, Yoshikazu

    1998-12-01

    The distribution of Chernobyl-derived radionuclides in river and lake water bodies at 6-40 km from the Chernobyl Nuclear Power Plant was studied. Current levels of radionuclides (Cesium-137, Strontium-90, Plutonium, Americium and Curium isotopes) in water bodies and their relation to the ground contamination are presented. The investigation of the radionuclide composition of aqueous and ground contamination revealed that radionuclides on suspended solids (particulate form) originate mainly from the erosion of the contaminated surface soil layer in the zone. Apparent distribution ratios between particulate and dissolved forms are compared to known distribution coefficients.

  20. nuclear reactor design calculations

    International Nuclear Information System (INIS)

    In this work , the sensitivity of different reactor calculation methods, and the effect of different assumptions and/or approximation are evaluated . A new concept named error map is developed to determine the relative importance of different factors affecting the accuracy of calculations. To achieve this goal a generalized, multigroup, multi dimension code UAR-DEPLETION is developed to calculate the spatial distribution of neutron flux, effective multiplication factor and the spatial composition of a reactor core for a period of time and for specified reactor operating conditions. The code also investigates the fuel management strategies and policies for the entire fuel cycle to meet the constraints of material and operating limitations

  1. Nuclear reactor internal structures

    International Nuclear Information System (INIS)

    The upper internal structures of the reactor are connected to the closing head so as to be readily removed with the latter and a skirt connected to the lower portion of said upper structures so as to surround the latter, extends under the control rods when they are removed from the reactor core. Through such an arrangement the skirt protects the control rods and supports the vessel closing-head and the core upper structures, whenever the head is severed from the vessel and put beside the latter in order to discharge the reactor

  2. The Chernobyl murder. The nuclear Goulag; Le crime de Tchernobyl. Le goulag nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Tchertkoff, W

    2006-07-01

    The authors of this book are the Chernobyl victims of the 26 April 1986 nuclear accident: millions of poor farmers, contaminated young mothers and children which eat every days radionuclides; ''Liquidators'', sacrificed to stop the fire of the power plants; invalids and also doctors and scientists which refuse the nuclear lobby. This book presents the two Byelorussian scientists which have risk their career and their health to help the contaminated populations. This book takes stock on the today nuclear policy and becomes alarm in seeing the development of the nuclear program in many countries. (A.L.B.)

  3. GE's advanced nuclear reactor designs

    International Nuclear Information System (INIS)

    The excess of US electrical generating capacity which has existed for the past 15 years is coming to an end as we enter the 1990s. Environmental and energy security issues associated with fossil fuels are kindling renewed interest in the nuclear option. The importance of these issues are underscored by the National Energy Strategy (NES) which calls for actions which open-quotes are designed to ensure that the nuclear power option is available to utilities.close quotes Utilities, utility associations, and nuclear suppliers, under the leadership of the Nuclear Power Oversight Committee (NPOC), have jointly developed a 14-point strategic plan aimed at establishing a predictable regulatory environment, standardized and pre-licensed Advanced Light Water Reactor (ALWR) nuclear plants, resolving the long-term waste management issue, and other open-quotes enabling conditions.close quotes GE is participating in this national effort and GE's family of advanced nuclear power plants feature two reactor designs, developed on a common technology base, aimed at providing a new generation of nuclear plants to provide safe, clean, economical electricity to the world's utilities in the 1990s and beyond. Together, the large-size (1300 MWe) Advanced Boiling Water Reactor (ABWR) and the small-size (600 MWe) Simplified Boiling Water Reactor (SBWR) are innovative, near-term candidates for expanding electrical generating capacity in the US and worldwide. Both possess the features necessary to do so safety, reliably, and economically

  4. The accident of Chernobyl

    International Nuclear Information System (INIS)

    RBMK reactors (reactor control, protection systems, containment) and the nuclear power plant of Chernobyl are first presented. The scenario of the accident is given with a detailed chronology. The actions and consequences on the site are reviewed. This report then give the results of the source term estimation (fision product release, core inventory, trajectories, meteorological data...), the radioactivity measurements obtained in France. Health consequences for the French population are evoked. The medical consequences for the population who have received a high level of doses are reviewed

  5. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    A fuel assembly construction for liquid metal cooled fast breeder reactors is described in which the sub-assemblies carry a smaller proportion of parasitic material than do conventional sub-assemblies. (U.K.)

  6. Nuclear reactor (1960)

    International Nuclear Information System (INIS)

    The first French plutonium-making reactors G1, G2 and G3 built at Marcoule research center are linked to a power plant. The G1 electrical output does not offset the energy needed for operating this reactor. On the contrary, reactors G2 and G3 will each generate a net power of 25 to 30 MW, which will go into the EDF grid. This power is relatively small, but the information obtained from operation is great and will be helpful for starting up the power reactor EDF1, EDF2 and EDF3. The paper describes how, previous to any starting-up operation, the tests performed, especially those concerned with the power plant and the pressure vessel, have helped to bring the commissioning date closer. (author)

  7. BWR type nuclear reactor

    International Nuclear Information System (INIS)

    Purpose: To simplify the structure of an emergency core cooling system while suppressing the flow out of coolants upon rapture accidents in a coolant recycling device of BWR type reactors. Constitution: Recirculation pumps are located at a position higher than the reactor core in a pressure vessel, and the lower plenum is bisected vertically by a partition plate. Further, a gas-liquid separator is surrounded with a wall and the water level at the outer side of the wall is made higher than the water level in the inside of the wall. In this structure, coolants are introduced from the upper chamber in the lower plenum into the reactor core, and the steams generated in the reactor core are separated in the gas-liquid separator, whereby the separated liquid is introduced as coolants by way of the inner chamber into the lower chamber of the lower plenum and further sent by way of the outer chamber into the reactor core. Consequently, idle rotation of the recycling pumps due to the flow-in of saturated water is prevented and loss of coolants in the reactor core can also be prevented upon raptures in the pipeway and the driving section of the pump connected to the pressure vessel and in the bottom of the pressure vessel. (Horiuchi, T.)

  8. 131I content in canine thyroids in the Warsaw urban area after the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The levels of 131I were determined in the thyroids of 20 dogs from Warsaw submitted to euthanasia between May and September 1986. The animals were living with humans and were in similar way exposed to contamination after the Chernobyl reactor accident. After calculation of the radioactivity for May 10th the contamination was found to range from 142.9 to 1372.9 Bq. These values corresponded to the contamination of human thyroids as reported by Central Laboratory for Radiation Protection in Warsaw. From the begining of May to the end of November the number of operations performed in dogs for pathological thyroid hyperplasia was six times higher than in the preceding time period. 5 refs., 2 tabs. (author)

  9. Report of the Land Berlin: The Chernobyl reactor accident and its effects on Berlin

    International Nuclear Information System (INIS)

    This report presents in detail the activities of the Berlin Senate administrations for the protection of the population after the reactor accident and outlines the consequences that have already resulted or are still to be expected for the people and the environment in Berlin. The radiation control guidelines and the provided instruments enabled the Berlin Senate to encounter the sudden accident with a fast and unbureaucratic crisis management. The special geopolitical situation of Berlin made it possible to set up a comprehensive control and measuring program for imported food. This report shows that all the measures required in connection with Chernobyl were taken by the Berlin Senate and that there is an effective precautionary program. (orig./HSCH)

  10. Debris from the Chernobyl nuclear disaster: how it came to the UK, and its consequences to agriculture

    International Nuclear Information System (INIS)

    Part of the debris from the Chernobyl reactor explosion crossed Britain a week after it had been emitted. Heavy thunderstorms and a northward-moving cold front washed out much of the radioactive iodine and caesium - especially on to the upland areas of North Wales, northern England, SW Scotland and northern Ireland. Several lessons have been learnt, including information on the dry and wet removal rates. Some of these lessons are being incorporated into a new transport and deposition model being developed by the Meteorological Office, with help from other UK centres of expertise, for use in the event of another serious nuclear or chemical accident in Europe. In lowland areas rich in clay minerals, the deposition of Chernobyl debris was of only transient importance to agriculture: in the two weeks following the passage of debris over the country the levels of iodine-131 in milk were readily detected, even though they were well below Government limits, and fell to insignificance thereafter. In upland sheep-rearing areas, by contrast, the caesium has remained mobile in the acidic soils; in many places the levels in sheep have exceeded Government limits, and since 1986 have been falling only slowly. (author)

  11. Surface activity distribution measurements and establishment of a dose rate map inside the destroyed Chernobyl reactor

    International Nuclear Information System (INIS)

    A Gamma Locator designed for contamination survey inside the reactor hall of the 4th unit of Chernobyl NNP has been developed. The device consists of a detector head and a remote control computer connected by a 150 m long cable. The detector head (dimensions: 500 mm by 500 mm by 400 mm; weight: about 40 kg) is a collimated scintillation gamma detector (the collimation angle is 10 deg.). It is installed on a scanning unit and was placed inside the reactor hall. The Gamma Locator scans all surfaces of the reactor hall with angular steps (≤ 1 deg. vertically as well as horizontally) and the particle fluence from the corresponding direction is recorded. The distance between the device head and the measured surface is instantaneously registered by a laser distance gauge. Inside the collimator there is a small CCD camera which makes it possible to obtain a visible image of the measured surface. The effective surface activity levels are presented in colour on the screen of the control computer. The gamma detector essentially consists of a CsI(TI) scintillator crystal (φ 8 mm in diameter, 2.5 mm in thickness) and a Si photodiode. The detector energy resolution is about 8% for radiation from 137Cs. The exposure dose rate distribution in the reactor hall is estimated from the measured effective surface activities /137Cs is the main gamma emitting isotope inside the reactor hall). The results of dose rate calculations are presented in colour superposed on a drawing of the reactor hall. (au)

  12. Surface activity distribution measurements and establishment of a dose rate map inside the destroyed Chernobyl reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chesnokov, A.V.; Fedin, V.I.; Gulyaev, A.A. [RECOM Ltd., Moscow (Russian Federation)] [and others

    1999-02-01

    A Gamma Locator designed for contamination survey inside the reactor hall of the 4th unit of Chernobyl NNP has been developed. The device consists of a detector head and a remote control computer connected by a 150 m long cable. The detector head (dimensions: 500 mm by 500 mm by 400 mm; weight: about 40 kg) is a collimated scintillation gamma detector (the collimation angle is 10 deg.). It is installed on a scanning unit and was placed inside the reactor hall. The Gamma Locator scans all surfaces of the reactor hall with angular steps ({<=} 1 deg. vertically as well as horizontally) and the particle fluence from the corresponding direction is recorded. The distance between the device head and the measured surface is instantaneously registered by a laser distance gauge. Inside the collimator there is a small CCD camera which makes it possible to obtain a visible image of the measured surface. The effective surface activity levels are presented in colour on the screen of the control computer. The gamma detector essentially consists of a CsI(TI) scintillator crystal ({phi} 8 mm in diameter, 2.5 mm in thickness) and a Si photodiode. The detector energy resolution is about 8% for radiation from {sup 137}Cs. The exposure dose rate distribution in the reactor hall is estimated from the measured effective surface activities ({sup 137}Cs is the main gamma emitting isotope inside the reactor hall). The results of dose rate calculations are presented in colour superposed on a drawing of the reactor hall. (au) 1 tab., 28 ills., 16 refs.

  13. Long-term assessment of contaminated articles from the Chernobyl reactor

    International Nuclear Information System (INIS)

    The Chernobyl accident caused a release of radioactive materials from the reactor into the environment. This event contaminated people, their surroundings and their personal property, especially in the zone around the reactor. Among the affected individuals were British students who were studying in Minsk and Kiev at the time of the Chernobyl accident. These students were exposed to external and internal radiation, and the individuals' articles of clothing were contaminated. The primary objective of this study was to analyze a sample of this contaminated clothing 20 years after the accident using three different detectors, namely, a BP4/4C scintillation detector, a Min-Con Geiger-Müller tube detector and a high-purity germanium (HPGe) detector. The clothing articles were initially assessed and found not to be significantly contaminated. However, there were several hot spots of contamination in various regions of the articles. The net count rates for these hot spots were in the range of 10.00 ± 3.16 c/s to 41.00 ± 6.40 c/s when the BP4/4C scintillation detector was used. The HPGe detector was used to identify the radionuclides present in the clothing, and the results indicated that the only active radionuclide was 137Cs because of this isotope's long half-life. - Highlights: • The study highlights the effect of radionuclide half-life on the uncertainty of the pollution measurement. • Most of the observed radionuclides 20 years ago have now disappeared due the decay effect. • The study shows improvements in radiation detectors by detecting very low activities of isotopes not measured 20 years ago

  14. Fixed bed nuclear reactor concept

    International Nuclear Information System (INIS)

    Full text: The fixed bed nuclear reactor (FBNR) is essentially a pressurized light water reactor (PWR) having spherical fuel elements constituting a suspended reactor core at its lowest bed porosity. The core is movable thus under any adverse condition, the fuel elements can leave the reactor core naturally through the force of gravity and fall into the passively cooled fuel chamber or leave the reactor all together entering the spent fuel pool. It is a small and modular reactor being simple in design. Its spent fuel is in such a convenient form and size that may be utilized directly as the source for irradiation and applications in agriculture and industry. This feature results in a positive impact on waste management and environmental protection. The principle features of the proposed reactor are that the concept is polyvalent, simple in design, may operate either as fixed or fluidized bed, have the core suspended contributing to inherent safety, passive cooling features of the reactor. The reactor is modular and has integrated primary system utilizing either water, supercritical steam or helium gas as its coolant. Some of the advantages of the proposed reactor are being modular, low environmental impact, exclusion of severe accidents, short construction period, flexible adaptation to demand, excellent load following characteristics, and competitive economics. The characteristics of the Fluidized Bed Nuclear Reactor (FBNR) concept may be analyzed under the light of the requirements set for the IV generation nuclear reactors. It is shown that FBNR meet the goals of (1) Providing sustainable energy generation that meets clean air objectives and promotes long-term availability of systems and effective fuel utilization for worldwide energy production, (2) Minimize and manage their nuclear waste and notably reduce the long term stewardship burden in the future, thereby improving protection for the public health and the environment, (3) Excel in safety and reliability

  15. Innovative designs of nuclear reactors

    International Nuclear Information System (INIS)

    The world development scenarios predict at least a 2.5 time increase in the global consumption of primary energy in the first half of the twenty-first century. Much of this growth can be provided by the nuclear power which possesses important advantages over other energy technologies. However, the large deployment of nuclear sources may take place only when the new generation of reactors appears on the market and will be free of the shortcomings found in the existing nuclear power installations. The public will be more inclined to accept nuclear plants that have better economics; higher safety; more efficient management of the radioactive waste; lower risk of nuclear weapons proliferation, and provided that the focus is made on the energy option free of ∇e2 generation. Currently, the future of nuclear power is trusted to the technology based on fast reactors and closed fuel cycle. The latter implies reprocessing of the spent nuclear fuel of the nuclear plants and re-use of plutonium produced in power reactors

  16. The results of the research and studies concerning the information about the Chernobyl nuclear disaster

    International Nuclear Information System (INIS)

    The studies conducted by the National Board of Psychological Defence after the Chernobyl nuclear accident concern questions of great importance about crisis information. The Chernobyl fallout created problems for the mass media and the authorities. Both lacked individual preparedness. The knowledge necessary to face strong demands for information from the public was lacking. A sign of this lack of knowledge and experience was shown when individual journalists - contrary to their usual behaviour - uncritically accepted the sometimes ambiguous information coming from the central authorities. For the authorities it was very much the same. The expert authority, the National Institute for Radiation Protection, had quite a lot of know-how, but no resources for such extensive information as the situation required. Significant problems must be solved concerning the cooperation between central and regional authorities. Direct contacts must be established so that both types of authorities do not learn through mass media what has been decided. The wordings of the messages conveyed in such critical situations must be a matter of more concern. Facts known by the authorities must be presented in a way comprehensible to the public. Technical terms and units must be used with great care. Negative information must of course be presented but measures should be taken to countermand the negative effect. A special responsibility should rest with the school system. The difficulties of informing the public after the Chernobyl disaster were still more emphasized by the study of how the brochure After Chernobyl was received

  17. Neutrino physics with nuclear reactors

    International Nuclear Information System (INIS)

    This is a lecture given at the Gif Summer School held in 1992 in Montpellier. It contains three chapters. These are devoted to neutrino oscillations, to the nuclear reactors used as neutrino sources, and to the experiments performed with neutrinos from nuclear reactors, respectively. The first chapter offers a theoretical frame, the second discusses the investigation capabilities of nuclear reactors as neutrino sources while the last one describes the experimental aspects. These aspects are related to the neutrino flux measurement and the flavor oscillation, the search for neutrino oscillation, the neutrino scattering on electrons, the neutrino decay, the coherent neutrino scattering on nuclei and the electron neutrino-electron antineutrino oscillations implied by the Majorana nature of neutrinos. In concluding the author points to the possible ways of refining these extremely subtle experiments, which will be approached in the near future. 117 refs., 9 figs., 11 tabs

  18. AREVA's nuclear reactors portfolio

    International Nuclear Information System (INIS)

    A reasonable assumption for the estimated new build market for the next 25 years is over 340 GWe net. The number of prospect countries is growing almost each day. To address this new build market, AREVA is developing a comprehensive portfolio of reactors intended to meet a wide range of power requirements and of technology choices. The EPR reactor is the flagship of the fleet. Intended for large power requirements, the four first EPRs are being built in Finland, France and China. Other countries and customers are in view, citing just two examples: the Usa where the U.S. EPR has been selected as the technology of choice by several U.S utilities; and the United Kingdom where the Generic Design Acceptance process of the EPR design submitted by AREVA and EDF is well under way, and where there is a strong will to have a plant on line in 2017. For medium power ranges, the AREVA portfolio includes a boiling water reactor and a pressurized water reactor which both offer all of the advantages of an advanced plant design, with excellent safety performance and competitive power generation cost: -) KERENA (1250+ MWe), developed in collaboration with several European utilities, and in particular with Eon; -) ATMEA 1 (1100+ MWe), a 3-loop evolutionary PWR which is being developed by AREVA and Mitsubishi. AREVA is also preparing the future and is deeply involved into Gen IV concepts. It has developed the ANTARES modular HTR reactor (pre-conceptual design completed) and is building upon its vast Sodium Fast Reactor experience to take part into the development of the next prototype. (author)

  19. Radiation safety during construction of the encapsulation at the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    A review is given of the main radiation safety problems which were solved during design and construction of the encapsulation for Unit 4 of the Chernobyl nuclear power plant which was destroyed in the accident of 26 April 1986. Information is given on the conditions under which large scale restoration work was performed, and on the design stipulations laid down for construction of the encapsulation for the destroyed unit. The paper discusses the technical, organizational and health measures which were used to ensure that radiation safety regulations and standards were observed during construction. The problems of organizing a radiation safety service inside the construction and assembly organization which built the encapsulation are discussed. Finally, conclusions are drawn with regard to the experience which has been gained in the area of radiation safety implementation during large scale post-accident restoration work under problematic radiation conditions such as those at the Chernobyl nuclear power plant site. (author). 7 refs, 6 figs, 1 tab

  20. Chernobyl after five years and over

    International Nuclear Information System (INIS)

    On April 26th 1986 the catastrophe occurred at the nuclear electric power generation system. The first inkling of the accident was known through the Swedish monitoring station about the radioactive fallout. It was also in 1986 that the USSR gave an idea of an earlier accident which happened in 1957. The Chernobyl reactor has pressure tubes and is a pressure vessel reactor. Graphite is used as an industrial material. In western reactors in USA with the increase in heat, power generation comes down. The international AEC discussed the Chernobyl comprehensively and came out with conclusion of deficiency in design which was accepted by the Soviet side without any demur. In 1970, in UK an accident has been reported with pressurized reactor. In 1987, Chernobyl was discussed under the chair of Eugene Volkov by USSR. In 1989, another conference was arranged at Sicily. The first annual nuclear safety met at Minsk in 1990 (June); USSR/USA meet on Chernobyl was also held at Solchin in 1989. A future meeting on Chernobyl was held at Paris in July 1991. In all these meetings, it is emphasized that more training and safety culture establishment was necessary by the international nuclear safety advisory group on safety. (author). 2 refs., 1 tab

  1. Chernobyl: exclusive investigation. How the French nuclear lobby buries the truth in contaminated areas. The After-Chernobyl or 'Living happy' in contaminated area

    International Nuclear Information System (INIS)

    According to the results of this inquiry, the CEPN (study centre on assessment of protection in the nuclear sector) has been created by the main actors of the nuclear industrial sector (EFG, Cogema, CEA and IRSN) and is at the origin of the ETHOS and CORE projects. Moreover, these projects have been financed by public funds. It also shows that the FNSEA (farmer trade union) has been allied to the French nuclear lobby for the distribution probably contaminated and radioactive foodstuff. It evokes the case of Belarus researcher who denounced such contamination and the misappropriation of international funds, and who was sent to jail. It comments the collaboration between the French nuclear sector and the Belarus regime, denounces how the truth about Chernobyl has been hidden, the cynical results of the ETOS program which would imply the consumption of contaminated foodstuff in France in case of nuclear accident. Some proposals are made: to dismantle the CEPN, to stop the participation of French organisations to the CORE and FARMING programs, creation of an independent commission on the consequences of the Chernobyl accident, and so on. For the authors, phasing out nuclear is the only solution o avoid a new Chernobyl

  2. Nuclear reactor downcomer flow deflector

    Science.gov (United States)

    Gilmore, Charles B.; Altman, David A.; Singleton, Norman R.

    2011-02-15

    A nuclear reactor having a coolant flow deflector secured to a reactor core barrel in line with a coolant inlet nozzle. The flow deflector redirects incoming coolant down an annulus between the core barrel and the reactor vessel. The deflector has a main body with a front side facing the fluid inlet nozzle and a rear side facing the core barrel. The rear side of the main body has at least one protrusion secured to the core barrel so that a gap exists between the rear side of the main body adjacent the protrusion and the core barrel. Preferably, the protrusion is a relief that circumscribes the rear side of the main body.

  3. Lessons learned from the TMI-2 accident and Chernobyl nuclear disaster for nuclear safety innovation

    International Nuclear Information System (INIS)

    The 2011 off the Pacific coast of Tohoku Pacific Earthquake and the Tsunami gave the serious damage to the Fukushima-Daiichi Nuclear Power Plants (NPPs). The accidents occurred in Unit 1, 2, 3 and 4. It is said that the height of tsunami attacked Fukushima NPP was more than 14m. After 50 minutes from the automatic shut-down, tsunami attacked the NPPs in Fukushima Daiichi NPPs. For example, the Unit 1 lost A/C power caused the loss of water injection function; it made the core meltdown and unusual increase of PCV pressure in the midnight to March 11th to 12th morning. Though the Unit one has the Isolation Condenser Core Cooling system, it was stopped by the operator to keep the cooling rate of 55degC/h. Finally, the isolation signal was transmitted from the control room to the motor driven isolation valves when the control room's battery discharged. It was the initiation of the core meltdown. The lessons from the TMI-2 accident, human error and instrumentation and control system trouble cased the core damage. Though the NPPs in European counties have filtered venting system after the Chernobyl Nuclear disaster, there are not filtered venting system connected the containment vessel in Japanese NPPs. If the Fukushima Daiichi NPPs have filtered venting system, the venting could be much earlier and no nuclear disaster would be occurred. (author)

  4. Nuclear reactor PBMR and cogeneration; Reactor nuclear PBMR y cogeneracion

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J. R.; Alonso V, G., E-mail: ramon.ramirez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    In recent years the nuclear reactor designs for the electricity generation have increased their costs, so that at the moment costs are managed of around the 5000 US D for installed kw, reason for which a big nuclear plant requires of investments of the order of billions of dollars, the designed reactors as modular of low power seek to lighten the initial investment of a big reactor dividing the power in parts and dividing in modules the components to lower the production costs, this way it can begin to build a module and finished this to build other, differing the long term investment, getting less risk therefore in the investment. On the other hand the reactors of low power can be very useful in regions where is difficult to have access to the electric net being able to take advantage of the thermal energy of the reactor to feed other processes like the water desalination or the vapor generation for the processes industry like the petrochemical, or even more the possible hydrogen production to be used as fuel. In this work the possibility to generate vapor of high quality for the petrochemical industry is described using a spheres bed reactor of high temperature. (Author)

  5. Radiation management and health management at the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    This paper describes the measures taken by the Chernobyl nuclear power plant since the accident in April 1986 to date, compares them with the situation of the current Fukushima nuclear accident, and introduces the contents of the authors' visit and coverage in October 2013, including the report of radiation damage. At the Chernobyl site, a new sarcophagus is under construction since 2012. The health care of the workers working at the new and old sarcophaguses of the Chernobyl nuclear power plant is carried out at a national level of Ukraine, which is an important management for decommissioning work. Health diagnosis is also applied to the workers in the new sarcophagus, and radiation-related disease is not reported at present. The number of the persons who died from acute radiation exposure diseases after the accident was 28. It was reported that chronic lymphocytic leukemia (CLL) appeared significantly when the radiation exceeded 100 mSv. The workers who wish to work at the Chernobyl nuclear power plant must pass the test and obtain national qualifications, and then they are able to work for the first time. In the check-in medical control, about half of applicants were rejected. Workers who work at the new sarcophagus are subject to comprehensive health management under the Ukrainian law. There were 58 people who reached annual exposure dose limit of 20 mSv or more among 7,529 people, the cause of which may be the work at the areas of high radiation dose. Even in Fukushima, it is important to perform high quality management based on centralized medical examination, and to further analyze the effects of low-dose exposure to radiation. (A.O.)

  6. Distribution and migration of long lived radionuclides in the environment around the Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    Characteristics of the distribution and migration of long lived radionuclides in the environment around the Chernobyl Nuclear Power Plant (30 km exclusion zone) has been investigated. Research items are, (i) Distribution of long lived radionuclides in the surface environment, (ii) Speciation of long lived radionuclides in the surface environment, (iii) Characteristics of the migration in the surface environment, (iv) Characteristics of the uptake into the vegetables, (v) Prediction of future radioecological situation in the environment, respectively. (author)

  7. The consequences of the Chernobyl nuclear accident in Greece - Report No. 2

    International Nuclear Information System (INIS)

    In this report a realistic estimate of the radioactive fallout on Greece from the Chernobyl nuclear accident is described. The measurements performed on environmental samples and samples of the food chain, as well as some realistic estimations for the population doses and the expected consequences of the accident are presented. The analysis has shown that the radiological impact of the accident in Greece can be considered minor. (J.K.)

  8. Cesium-137 urinary excretion by northeastern (Pordenone) Italian people following the Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    To estimate the radiological consequences in humans due to the Chernobyl nuclear accident (5 May 1986), we have determined both the 137Cs concentration in food and the 137Cs daily urinary excretion on 198 residents of the Pordenone area. The resulting experimental data have been compared with those estimated from the International Commission on Radiological Protection Publication 10A model (ICRP 1971) using a suitable dietary intake, and they were found to be in reasonable agreement

  9. Nuclear reactor container

    International Nuclear Information System (INIS)

    In a container of a BWR type reactor, spray water is stored in a pedestal cavity. A perforated hole is formed on the side wall of the pedestal, and a stirrer is disposed in the pedestal cavity to stir the stored spray water. During reactor operation, the door on the side wall of the pedestal is closed to prevent discharge of fission products to the dry well when a severe accident should occur. During periodical inspection for the plant, the door is opened to enable an operator to access to the inside of the pedestal. When a molten reactor core should drop to the pedestal cavity, fission products generated from the failed reactor core left in a pressure vessel pass through the spray water in the pedestal cavity. Then, most of the fission products are held in the spray water by a scrubbing effect when they pass through the spray water. In addition, the stored spray water is stirred by the stirrer to enhance the scrubbing effect thereby enabling to further decrease the amount of the fission products discharged to the dry well. (N.H.)

  10. Nuclear reactor constructions

    International Nuclear Information System (INIS)

    A method of constructing a radiation shielding plug for use in the roof of the coolant containment vault of liquid metal cooled fast breeder reactors is described. The construction allows relative movement of that part of service cables and pipes which are carried by the fixed roof and that part which is carried by the rotatable plug. (U.K.)

  11. Global risk of radioactive fallout after nuclear reactor accidents

    Directory of Open Access Journals (Sweden)

    J. Lelieveld

    2011-11-01

    Full Text Available Reactor core meltdowns of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents, using particulate 137Cs and gaseous 131I as proxies for the fallout. It appears that previously the occurrence of major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a core melt of any nuclear power plant worldwide, more than 90% of emitted 137Cs would be transported beyond 50km and about 50% beyond 1000 km distance. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of 137Cs and 131I are quite different, the radioactive contamination patterns over land and the human deposition exposure are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in southern Asia where a core melt can subject 55 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  12. Chernobyl - a Canadian technical perspective

    International Nuclear Information System (INIS)

    On April 26, 1986, the Number 4 reactor at the Chernobyl Nuclear Power Station in the Soviet Union suffered a severe accident which destroyed the reactor core and led to a loss of life. The four reactors at this station are of the RBMK-1000 type - boiling-light-water cooled, graphite moderated, vertical pressure-tube reactors, each generating 1000 MW of electricity through two turbines. AECL has carefully studied the accident, and the design of Chernobyl, to see if anything has been overlooked in the CANDU design. This report reviews the results of that study, in particular the relevant features of the Chernobyl design which exacerbated the accident, and compares them to the CANDU 600 design. A number of issues (the sign of the void coefficent and the pressure-tube design) have also been given some international prominence in the post-Chernobyl analysis; these are discussed in this report and shown to be irrelevant to the CANDU design. Finally this report describes the subjects identified for further design follow-up in Canada

  13. Estimation Of 137Cs Using Atmospheric Dispersion Models After A Nuclear Reactor Accident

    Science.gov (United States)

    Simsek, V.; Kindap, T.; Unal, A.; Pozzoli, L.; Karaca, M.

    2012-04-01

    Nuclear energy will continue to have an important role in the production of electricity in the world as the need of energy grows up. But the safety of power plants will always be a question mark for people because of the accidents happened in the past. Chernobyl nuclear reactor accident which happened in 26 April 1986 was the biggest nuclear accident ever. Because of explosion and fire large quantities of radioactive material was released to the atmosphere. The release of the radioactive particles because of accident affected not only its region but the entire Northern hemisphere. But much of the radioactive material was spread over west USSR and Europe. There are many studies about distribution of radioactive particles and the deposition of radionuclides all over Europe. But this was not true for Turkey especially for the deposition of radionuclides released after Chernobyl nuclear reactor accident and the radiation doses received by people. The aim of this study is to determine the radiation doses received by people living in Turkish territory after Chernobyl nuclear reactor accident and use this method in case of an emergency. For this purpose The Weather Research and Forecasting (WRF) Model was used to simulate meteorological conditions after the accident. The results of WRF which were for the 12 days after accident were used as input data for the HYSPLIT model. NOAA-ARL's (National Oceanic and Atmospheric Administration Air Resources Laboratory) dispersion model HYSPLIT was used to simulate the 137Cs distrubition. The deposition values of 137Cs in our domain after Chernobyl Nuclear Reactor Accident were between 1.2E-37 Bq/m2 and 3.5E+08 Bq/m2. The results showed that Turkey was affected because of the accident especially the Black Sea Region. And the doses were calculated by using GENII-LIN which is multipurpose health physics code.

  14. Nuclear reactors and disarmament

    International Nuclear Information System (INIS)

    From a brief analysis of the perspectives of nuclear weapons arsenals reduction, a rational use of the energetic potential of the ogives and the authentic destruction of its warlike power is proposed. The fissionable material conversion contained in the nuclear fuel ogives for peaceful uses should be part of the disarmament agreements. This paper pretends to give an approximate idea on the resources re assignation implicancies. (Author)

  15. Nuclear reactor container

    International Nuclear Information System (INIS)

    Upon reactor accident, hydrogen and oxygen are generated by water-zirconium reaction and radiolysis of water, which are accumulated in the reactor. If the concentration of hydrogen and oxygen exceeds a burning limit, there is a possibility of hydrogen burning to cause a danger of deteriorating the integrity of the reactor container and the equipments therein. The limit for the occurrence of the detonation is determined by a relationship between the scale of a detonation cell and the size of the container, and if the scale is greater than the container, the detonation does not occur. The scale of the cell is determined by a gas combustion rate and, if the combustion reaction is suppressed, detonation does not occur even in a large container. Then, an appropriate diluent is added to increase heat capacity of a gas mixture to thereby suppress the temperature elevation of the gas. Incombustible gases having a great heat capacity are preferred for the diluent, and CO2 is used. As the concentration of the CO2 gas to be added is increased, the detonation cell is made greater. Thus, occurrence of detonation due to combustion of the accumulated hydrogen can be prevented. (N.H.)

  16. Action level for imported food in Japan after the reactor accident at Chernobyl

    International Nuclear Information System (INIS)

    The nuclear accident at Chernobyl in Apr. 1986 caused a widespread release of radionuclides to environment. As a result of food movement in international trade, it was necessary to decide action level of radionuclides for food imported in Japan. The action level was derived from the following basic principle: Dose equivalent should be less than one third of 0.5 rem/year for whole body exposure. Assuming that the composition of representative radionuclides (90Sr, 134Cs and 137Cs) in imported food are equal to those of fallout in Japan and consumption of internal food products reduces total intake of radionuclides to 35 %, action level indicated by sum of 134Cs and 137Cs concentrations was estimated to be 370 Bq/kg. From Nov. 1986 to Sep. 1987, it was observed that twenty samples in imported food contained radioactivity exceeding the action level. (author)

  17. Light-water nuclear reactors

    International Nuclear Information System (INIS)

    This work gives basic information on light-water reactors which is advanced enough for the reader to become familiar with the essential objectives and aspects of their design, their operation and their insertion in the industrial, economic and human environment. In view of the capital role of electric energy in the modern economy a significant place is given to electron-nuclear power stations, particularly those of the type adopted for the French programme. The work includes sixteen chapters. The first chapter relates the history and presents the various applications of light water reactors. The second refers to the general elementary knowledge of reactor physics. The third chapter deals with the high power light-water nuclear power station and thereby introduces the ensuing chapters which, up to and including chapter 13, are devoted to the components and the various aspects of the operation of power stations, in particular safety and the relationship with the environment. Chapter 14 provides information on the reactors adapted to applications other than the generation of electricity on an industrial scale. Chapter 15 shows the extent of the industrial effort devoted to light-water reactors and chapter 16 indicates the paths along which the present work is preparing the future of these reactors. The various chapters have been written to allow for separate consultation. An index of the main technical terms and a bibliography complete the work

  18. Nuclear reactor PBMR and cogeneration

    International Nuclear Information System (INIS)

    In recent years the nuclear reactor designs for the electricity generation have increased their costs, so that at the moment costs are managed of around the 5000 US D for installed kw, reason for which a big nuclear plant requires of investments of the order of billions of dollars, the designed reactors as modular of low power seek to lighten the initial investment of a big reactor dividing the power in parts and dividing in modules the components to lower the production costs, this way it can begin to build a module and finished this to build other, differing the long term investment, getting less risk therefore in the investment. On the other hand the reactors of low power can be very useful in regions where is difficult to have access to the electric net being able to take advantage of the thermal energy of the reactor to feed other processes like the water desalination or the vapor generation for the processes industry like the petrochemical, or even more the possible hydrogen production to be used as fuel. In this work the possibility to generate vapor of high quality for the petrochemical industry is described using a spheres bed reactor of high temperature. (Author)

  19. Chernobyl fantasy

    International Nuclear Information System (INIS)

    Several versions of technical reasons of Chernobyl accident, which have received a wide resonance in mass-media, and are seemed as reasonable for most public without any special education in reactor's physics, are discussed. Probable reasons of its origination are analysed, and its scientific groundlessness is shown

  20. Health requirements for nuclear reactor operators

    International Nuclear Information System (INIS)

    The health prerequisites established for the qualification of nuclear reactor operators according to CNEN-NE-1.01 Guidelines Licensing of nuclear reactor operators, CNEN-12/79 Resolution, are described. (M.A.)

  1. Gaseous fuel nuclear reactor research

    Science.gov (United States)

    Schwenk, F. C.; Thom, K.

    1975-01-01

    Gaseous-fuel nuclear reactors are described; their distinguishing feature is the use of fissile fuels in a gaseous or plasma state, thereby breaking the barrier of temperature imposed by solid-fuel elements. This property creates a reactor heat source that may be able to heat the propellant of a rocket engine to 10,000 or 20,000 K. At this temperature level, gas-core reactors would provide the breakthrough in propulsion needed to open the entire solar system to manned and unmanned spacecraft. The possibility of fuel recycling makes possible efficiencies of up to 65% and nuclear safety at reduced cost, as well as high-thrust propulsion capabilities with specific impulse up to 5000 sec.

  2. Instrumentation for nuclear reactor control

    International Nuclear Information System (INIS)

    This lecture is concerned with engineers and technicians not specialized in nuclear reactor control. The different methods of measurement used are briefly reviewed: current or pulse measurement, and Campbell system; the electronic networks are described and a part is devoted to the cables connecting detectors and electronic assemblies

  3. Nuclear Reactors and Technology; (USA)

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Hicks, S.C. (eds.)

    1991-01-01

    Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database (EDB) during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency's Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on EDB and Nuclear Science Abstracts (NSA) database. Current information, added daily to EDB, is available to DOE and its contractors through the DOE integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user's needs.

  4. Ensuring radiation safety during construction of the facility ''Ukrytie'' and restoration of unit 3 of the Chernobyl nuclear power station

    International Nuclear Information System (INIS)

    On April 26, 1986, an accident at the fourth power unit of the Chernobyl NPS (ChNPS) destroyed the reactor core and part of the power unit building, whereby sizeable amounts of radioactive materials, stored in reactor at operation, were released into the environment, and there were also highly active fragments of fuel elements and pieces of graphite from reactor spread on ChNPS site near to safety block. Information on the accident at ChNPS, including its cause and consequences, was considered at special meeting, conducted by IAEA on August 25-29, 1986, in Vienna. In final report of International Advisory Group for Nuclear Safety (IAGNS), prepared by results of meeting activities, the main stages of the accident effects elimination (AEE) immediately on the station site according to the data, received before August 1, 1986, were discussed. In 1987-1990 the published materials on the later period of AEE, completed by building ''Ukrytie'' installation at the fourth power unit of ChNPS

  5. Study of a cohort of Latvian workers having participated to the decontamination of the nuclear site of Chernobyl

    International Nuclear Information System (INIS)

    In the consequences attributable to the accident at the Chernobyl nuclear power plant, it is debated whether post-disaster psycho-pathology is related to the perception of the level of contamination or the level of contamination itself. To address this issue, the authors have assessed the association of various exposure mental and psychosomatic distress, on a sample of 1,1412 Latvian liquidators drawn from the State Latvian Chernobyl clean-up workers registry. The outcome considered was a mixed mental/psychosomatic disorder occurring during the time period 1986-1995. Comparisons between subgroups of the cohort, classified according to exposure type or level, were based on the proportional hazards model. Length of work (≥ 28 days) in a 10 km radius from the reactor (relative risk (RR) = 1.39, 95 percent confidence interval (CI) 1.14-1.70), work (> 1 time) on the damaged reactor roof (RR 1.46, 95 percent CI 1.02-2.09), forest work (RR 1.41,95 percent CI 1.19-1.68), and fresh fruits consumption (≥ 1 time/day) (RR 1.72,95 percent CI 1.12-2.65) are risk factors for mixed mental/ psychosomatic disorder. Construction of the sarcophagus (RR 1.82, 95 percent CI 0.89-3.72), is also associated with this outcome, although non significantly. These findings confirm that some exposure variables represent risk factors for mental disorders and suggest some radiation-induced consequences although surely overweight by stress-related effects. (author)

  6. Change of attitude and behaviour of the West-German population after the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    As a result of the Chernobyl reactor accident, the West-German population has shown to be much more aware of the hazards emanating from environmental pollution and chemical or radioactive contamination of food. It could be observed that, on the whole, consumption of important basic food has been reduced, so that the population's supply with various, significant nutrients is expected to deteriorate. The nutrients to be mentioned in this context are primarily calcium, riboflavin, folic acid, and ascorbic acid. Investigations over the period May to July 1986 show that the reactor accident's impact on the food consumption behaviour subsides only slowly, and it remains to be seen to what extent changes and fluctuations in the population's nutritional behaviour will have to be taken as 'normal'. Hence some sort of nutritional deficiency can be expected among certain groups of the population, either temporarily or over a prolonged period. A National Survey of Food Consumption currently in preparation will yield more detailed insight into the whole process. (orig./MG)

  7. Micro-analytical uranium isotope and chemical investigations of zircon crystals from the Chernobyl “lava” and their nuclear fuel inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Pöml, P., E-mail: Philipp.POEML@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Burakov, B. [Laboratory of Applied Mineralogy and Radiogeochemistry, V.G. Khlopin Radium Institute, 28, 2-nd Murinskiy Ave., St. Petersburg 194021 (Russian Federation); Geisler, T. [Steinmann Institut für Geologie, Mineralogie und Paläontologie, University of Bonn, Poppelsdorfer Schloss, 53115 Bonn (Germany); Walker, C.T. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Grange, M.L.; Nemchin, A.A. [Department of Applied Geology, Western Australian School of Mines, Curtin University, GPO Box U1987, Western Australia 6845 (Australia); Berndt, J. [Institut für Mineralogie, Westfälische Wilhelms-Universität, Corrensstraße 24, 48149 Münster (Germany); Fonseca, R.O.C. [Steinmann Institut für Geologie, Mineralogie und Paläontologie, University of Bonn, Poppelsdorfer Schloss, 53115 Bonn (Germany); Bottomley, P.D.W.; Hasnaoui, R. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany)

    2013-08-15

    U isotope data measured on real fragments of the Chernobyl nuclear fuel included in zircon crystals crystallised from the Chernobyl “lava” are presented for the first time. The U isotope data show no anomalies and lie within the expected burnup values for the Chernobyl nuclear fuel. However, the U concentration, the U isotopic composition, and the Ti concentration in the host zircon vary significantly within single crystals as well as between single crystals. Our results indicate that during the time of melt activity temperature and melt composition likely varied considerably. New melt was formed progressively (and solidified) during the accident that reacted and mixed with pre-existing melt that never fully equilibrated. In such an environment zircon crystals crystallised at temperatures below 1250 °C, as estimated from thermodynamic considerations along with the observation that the centre of the investigated zircon crystal contains monoclinic ZrO{sub 2} inclusions. Since the zircon crystals crystallised before the silicate melt spread out into the reactor block basement, the flow of the melt into the basement must also have occurred at temperatures below 1250 °C.

  8. Micro-analytical uranium isotope and chemical investigations of zircon crystals from the Chernobyl “lava” and their nuclear fuel inclusions

    International Nuclear Information System (INIS)

    U isotope data measured on real fragments of the Chernobyl nuclear fuel included in zircon crystals crystallised from the Chernobyl “lava” are presented for the first time. The U isotope data show no anomalies and lie within the expected burnup values for the Chernobyl nuclear fuel. However, the U concentration, the U isotopic composition, and the Ti concentration in the host zircon vary significantly within single crystals as well as between single crystals. Our results indicate that during the time of melt activity temperature and melt composition likely varied considerably. New melt was formed progressively (and solidified) during the accident that reacted and mixed with pre-existing melt that never fully equilibrated. In such an environment zircon crystals crystallised at temperatures below 1250 °C, as estimated from thermodynamic considerations along with the observation that the centre of the investigated zircon crystal contains monoclinic ZrO2 inclusions. Since the zircon crystals crystallised before the silicate melt spread out into the reactor block basement, the flow of the melt into the basement must also have occurred at temperatures below 1250 °C

  9. Nuclear reactor effluent monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Minns, J.L.; Essig, T.H. [Nuclear Regulatory Commission, Washington, DC (United States)

    1993-12-31

    Radiological environmental monitoring and effluent monitoring at nuclear power plants is important both for normal operations, as well as in the event of an accident. During normal operations, environmental monitoring verifies the effectiveness of in-plant measures for controlling the release of radioactive materials in the plant. Following an accident, it would be an additional mechanism for estimating doses to members of the general public. This paper identifies the U.S. Nuclear Regulatory Commission (NRC) regulatory basis for requiring radiological environmental and effluent monitoring, licensee conditions for effluent and environmental monitoring, NRC independent oversight activities, and NRC`s program results.

  10. Water cooled nuclear reactor

    International Nuclear Information System (INIS)

    In the reactor operating with supercritical pressure and temperature part of the water flowing through the moderator tubes is deflected at the outlet and mixed with a residual partial flow of the coolant fed into the core as well as passed along the fuel rods in opposite direction. By special guiding of the flow downward through the guide tubes of the control rods insertion of the control rods is simplified because of reduced frictional forces. By this means it is also achieved to design less critical the control rod cooling with respect to flow rate control and operating behavior in case of a scram. (orig.)

  11. Nuclear reactor plant

    International Nuclear Information System (INIS)

    The plant consists mainly of a steam-raising unit and a steam turbine with high pressure and low pressure stages. There is at least one superheater or intermediate superheater between the steam-raising unit and the low pressure stage. In order to improve the plant efficiency, a high temperature reactor is provided as a source of heat for the superheater or intermediate superheater, which supplies the superheater heat with an energy efficiency of over 60%. This increases the overall net efficiency from 33% to over 36%. (orig.)

  12. Decommissioning of Salaspils nuclear reactor

    International Nuclear Information System (INIS)

    In May 1995, the Latvian Government decided to shut down the Research Reactor Salaspils (SRR) and to dispense with nuclear energy in future. The reactor has been out of operation since July 1998. A conceptual study for the decommissioning of SRR has been carried out by Noell-KRC-Energie- und Umwelttechnik GmbH from 1998-1999. he Latvian Government decided on 26 October 1999 to start the direct dismantling to 'green field' in 2001. The results of decommissioning and dismantling performed in 1999-2001 are presented and discussed. The main efforts were devoted to collecting and conditioning 'historical' radioactive waste from different storages outside and inside the reactor hall. All radioactive material more than 20 tons were conditioned in concrete containers for disposal in the radioactive waste depository 'Radons' in the Baldone site. Personal protective and radiation measurement equipment was upgraded significantly. All non-radioactive equipment and material outside the reactor buildings were free-released and dismantled for reuse or conventional disposal. Weakly contaminated material from the reactor hall was collected and removed for free-release measurements. The technology of dismantling of the reactor's systems, i.e. second cooling circuit, zero power reactors and equipment, is discussed in the paper. (author)

  13. Fifteen years after the accident at the Chernobyl nuclear power plant. Lessons learned

    International Nuclear Information System (INIS)

    Fifteen years has passed on this year since accident at the Chernobyl Nuclear Power Plant had formed on April 26, 1986. From before or after the accident, the world experienced a number of changes. On August, 1986, USSR carried out a report on the accident at an international conference on the accident at Chernobyl held at Wien. Outlines of the report are described in a report of IAEA INSAG (INSAG-1). After then, various facts hidden in the USSR report at this time have appeared. Then, INSAG revised previous INSAG-1 and published INSAG-7 re-evaluated on technical meanings of the accident on 1992, which became so-called finished issue on technical analysis and evaluation on causes and progresses of the accident. To correctly understand lessons on the accident, it must be begun from correct understanding of its real facts. It is widely recognized that its actual and fundamental reason was slight or neglect on safety found at whole of nuclear development and applications in USSR and shorts of safety culture such as emptiness of technology and regulation brought by them, relaxation of working rule, and so on, which were only the largest lesson on the Chernobyl accident. (G.K.)

  14. Global risk of radioactive fallout after major nuclear reactor accidents

    Directory of Open Access Journals (Sweden)

    J. Lelieveld

    2012-05-01

    Full Text Available Major reactor accidents of nuclear power plants are rare, yet the consequences are catastrophic. But what is meant by "rare"? And what can be learned from the Chernobyl and Fukushima incidents? Here we assess the cumulative, global risk of exposure to radioactivity due to atmospheric dispersion of gases and particles following severe nuclear accidents (the most severe ones on the International Nuclear Event Scale, INES 7, using particulate 137Cs and gaseous 131I as proxies for the fallout. Our results indicate that previously the occurrence of INES 7 major accidents and the risks of radioactive contamination have been underestimated. Using a global model of the atmosphere we compute that on average, in the event of a major reactor accident of any nuclear power plant worldwide, more than 90% of emitted 137Cs would be transported beyond 50 km and about 50% beyond 1000 km distance before being deposited. This corroborates that such accidents have large-scale and trans-boundary impacts. Although the emission strengths and atmospheric removal processes of 137Cs and 131I are quite different, the radioactive contamination patterns over land and the human exposure due to deposition are computed to be similar. High human exposure risks occur around reactors in densely populated regions, notably in West Europe and South Asia, where a major reactor accident can subject around 30 million people to radioactive contamination. The recent decision by Germany to phase out its nuclear reactors will reduce the national risk, though a large risk will still remain from the reactors in neighbouring countries.

  15. NUCLEAR REACTOR FUEL ELEMENT

    Science.gov (United States)

    Wheelock, C.W.; Baumeister, E.B.

    1961-09-01

    A reactor fuel element utilizing fissionable fuel materials in plate form is described. This fuel element consists of bundles of fuel-bearing plates. The bundles are stacked inside of a tube which forms the shell of the fuel element. The plates each have longitudinal fins running parallel to the direction of coolant flow, and interspersed among and parallel to the fins are ribs which position the plates relative to each other and to the fuel element shell. The plate bundles are held together by thin bands or wires. The ex tended surface increases the heat transfer capabilities of a fuel element by a factor of 3 or more over those of a simple flat plate.

  16. Utilization of nuclear research reactors

    International Nuclear Information System (INIS)

    Full text: Report on an IAEA interregional training course, Budapest, Hungary, 5-30 November 1979. The course was attended by 19 participants from 16 Member States. Among the 28 training courses which the International Atomic Energy Agency organized within its 1979 programme of technical assistance was the Interregional Training Course on the Utilization of Nuclear Research Reactors. This course was held at the Nuclear Training Reactor (a low-power pool-type reactor) of the Technical University, Budapest, Hungary, from 5 to 30 November 1979 and it was complemented by a one-week Study Tour to the Nuclear Research Centre in Rossendorf near Dresden, German Democratic Republic. The training course was very successful, with 19 participants attending from 16 Member States - Bangladesh, Bolivia, Czechoslovakia, Ecuador, Egypt, India, Iraq, Korean Democratic People's Republic, Morocco, Peru, Philippines, Spain, Thailand, Turkey, Vietnam and Yugoslavia. Selected invited lecturers were recruited from the USA and Finland, as well as local scientists from Hungarian institutions. During the past two decades or so, many research reactors have been put into operation around the world, and the demand for well qualified personnel to run and fully utilize these facilities has increased accordingly. Several developing countries have already acquired small- and medium-size research reactors mainly for isotope production, research in various fields, and training, while others are presently at different stages of planning and installation. Through different sources of information, such as requests to the IAEA for fellowship awards and experts, it became apparent that many research reactors and their associated facilities are not being utilized to their full potential in many of the developing countries. One reason for this is the lack of a sufficient number of trained professionals who are well acquainted with all the capabilities that a research reactor can offer, both in research and

  17. Economic analysis of nuclear reactors

    International Nuclear Information System (INIS)

    The report presents several methods for estimating the power costs of nuclear reactors. When based on a consistent set of economic assumptions, total power costs may be useful in comparing reactor alternatives. The principal items contributing to the total power costs of a nuclear power plant are: (1) capital costs, (2) fuel cycle costs, (3) operation and maintenance costs, and (4) income taxes and fixed charges. There is a large variation in capital costs and fuel expenses among different reactor types. For example, the standard once-through LWR has relatively low capital costs; however, the fuel costs may be very high if U3O8 is expensive. In contrast, the FBR has relatively high capital costs but low fuel expenses. Thus, the distribution of expenses varies significantly between these two reactors. In order to compare power costs, expenses and revenues associated with each reactor may be spread over the lifetime of the plant. A single annual cost, often called a levelized cost, may be obtained by the methods described. Levelized power costs may then be used as a basis for economic comparisons. The paper discusses each of the power cost components. An exact expression for total levelized power costs is derived. Approximate techniques of estimating power costs will be presented

  18. Nuclear reactor fuelling machine

    International Nuclear Information System (INIS)

    The refuelling machine described comprises a rotatable support structure having a guide tube attached to it by a parellel linkage mechanism, whereby the guide tube can be displaced sideways from the support structure. A gripper unit is housed within the guide tube for gripping the end of a fuel assembly or other reactor component and has means for maintenance in the engaging condition during travel of the unit along the guide tube, except for a small portion of the travel at one end of the guide tube, where the inner surface of the guide tube is shaped so as to maintain the gripper unit in a disengaging condition. The gripper unit has a rotatable head, means for moving it linearly within the guide tube so that a component carried by the unit can be housed in the guide tube, and means for rotating the head of the unit through 1800 relative to its body, to effect rotation of a component carried by the unit. The means for rotating the head of the gripper unit comprises ring and pinion gearing, operable through a series of rotatable shafts interconnected by universal couplings. The reason for provision for 1800 rotation is that due to the variation in the neutron flux across the reactor core the side of a fuel assembly towards the outside of the core will be subjected to a lower neutron flux and therefore will grow less than the side of the fuel assembly towards the inside of the core. This can lead to bowing and possible jamming of the fuel assemblies. Full constructional details are given. See also BP 1112384. (U.K.)

  19. Liquid-cooled nuclear reactor

    International Nuclear Information System (INIS)

    Hydrogen can be added to nuclear reactors with a liquid hydrogen-containing coolant on the suction side of a high pressure pump in the purification system. According to the invention this is performed by means of a liquid jet condenser which uses the coolant as liquid and which is preferably charged from the pressure side of the high pressure pump and conveys the liquid to a mixer connected in series with the high pressure pump. The invention is to be used especially in pressurized water reactors. (orig./PW)

  20. Liquid-cooled nuclear reactor

    International Nuclear Information System (INIS)

    Hydrogen can be added to nuclear reactors with a liquid hydrogen-containing coolant on the suction side of a high pressure pump in the purification system. According to the invention this is performed by means of a liquid jet condenser which uses the coolant as liquid and which is preferably charged from the pressure side of the high pressure pump and conveys the liquid to a mixer connected in series with the high pressure pump. The invention is to be used especially in pressurized water reactors. (orig.)

  1. Behaviour of Chernobyl fallout radionuclides deposited on peat and urban surfaces in Finland

    International Nuclear Information System (INIS)

    In the thesis the impact of the Chernobyl nuclear reactor accident on Finland was studied in three aspects: (1) the areal distribution of Chernobyl fallout in Finland was determined by measuring peat samples, (2) the behaviour of fallout radionuclides was investigated in the combustion of peat in power plants, and (3) the removal rates of fallout radionuclides on urban surfaces were resolved

  2. Medical preparedness: Chernobyl as a model for southeastern Michigan

    International Nuclear Information System (INIS)

    The Detroit Chapter of Physicians for Social Responsibility developed a project to evaluate the potential response of the local medical community to a small nuclear disaster involving radiation injuries. The model was patterned after the Chernobyl nuclear power plant disaster of April 26, 1986. They surveyed the potential response to a hypothetical disaster at the Enrico Fermi II nuclear reactor located south of Detroit

  3. Recycling device of nuclear reactor

    International Nuclear Information System (INIS)

    In a recycling device of a nuclear reactor, a coolant recycling system is disposed by using an outer loop, while a branched connection pipe is connected to a feed water jet pump driving system. Further, the coolant recycling system is constituted with a remaining-heat removing system having a heat exchanger. The connection pipe branched from the downstream of the heat exchanger is connected to the suction side of the jet pump driving pump. Even when feedwater is not returned or returned only insufficiently from a condensate/feedwater system, such as in a case of reactor start up, since sufficient jet pump driving water can be ensured, reactor power can be controlled by controlling the reactor core flow rate by the driving water, to improve the operationability. Further, the burden on control rods can be decreased to improve reliability compared with the case of controlling the power only by the operation of the control rods. Further, since the recycling flow rate of coolants in the reactor core can be ensured sufficiently, occurrence of temperature difference between the upper and the lower portions of a pressure vessel can be prevented effectively, to improve reactor integrity. (N.H.)

  4. Retrospection of Chernobyl nuclear accident for decision analysis concerning remedial actions in Ukraine

    International Nuclear Information System (INIS)

    It is considered the efficacy of decisions concerning remedial actions when of-site radiological monitoring in the early and (or) in the intermediate phases was absent or was not informative. There are examples of such situations in the former Soviet Union where many people have been exposed: releases of radioactive materials from 'Krasnoyarsk-26' into Enisey River, releases of radioactive materials from 'Chelabinsk-65' (the Kishtim accident), nuclear tests at the Semipalatinsk Test Site, the Chernobyl nuclear accident etc. If monitoring in the early and (or) in the intermediate phases is absent the decisions concerning remedial actions are usually developed on the base of permanent monitoring. However decisions of this kind may be essentially erroneous. For these cases it is proposed to make retrospection of radiological data of the early and intermediate phases of nuclear accident and to project decisions concerning remedial actions on the base of both retrospective data and permanent monitoring data. In this Report the indicated problem is considered by the example of the Chernobyl accident for Ukraine. Their of-site radiological monitoring in the early and intermediate phases was unsatisfactory. In particular, the pasture-cow-milk monitoring had not been made. All official decisions concerning dose estimations had been made on the base of measurements of 137Cs in body (40 measurements in 135 days and 55 measurements in 229 days after the Chernobyl accident). For the retrospection of radiological data of the Chernobyl accident dynamic model has been developed. This model has structure similar to the structure of Pathway model and Farmland model. Parameters of the developed model have been identified for agricultural conditions of Russia and Ukraine. By means of this model dynamics of 20 radionuclides in pathways and dynamics of doses have been estimated for the early, intermediate and late phases of the Chernobyl accident. The main results are following

  5. Nuclear reactor safety

    International Nuclear Information System (INIS)

    Dr. Buhl feels that nuclear-energy issues are too complex to be understood as single topics, and can only be understood in relationship to broader issues. In fact, goals and risks associated with all energy options must be seen as interrelated with other broad issues, and it should be understood that there are presently no clearcut criteria to ensure that the best decisions are made. The technical community is responsible for helping the public to understand the basic incompatibility of hard and soft technologies and that there is no risk-free energy source. Four principles are outlined for assessing the risks of various energy technologies: (1) take a holistic view; (2) compare the risk with the unit energy output; (3) compare the risk with those of everyday activities; and (4) identify unusual risks associated with a particular option. Dr. Buhl refers to the study conducted by Dr. Inhaber of Canada who used this approach and concluded that nuclear power and natural gas have the lowest overall risk

  6. Liquid cooled nuclear reactors

    International Nuclear Information System (INIS)

    A construction is described for a liquid metal cooled fast reactor, in which the core is supported in a pool of liquid coolant, wherein a catchment tray is provided for any debris falling from the core. The tray comprises a complex of open top collecting vessels with central support struts, the vessels being spaced apart and arranged in layers in a lattice pitch. The lattice pitches of the vessels in each layer are off-set to the lattice pitches of the vessels in the other layers, so that upper vessels partially overlap lower vessels, and the support struts extend through interspaces defined by the vessels in off-set pitch to a common supporting sub-structure. The complex of vessels offers a complete catchment area for falling debris, whilst being pervious to liquid coolant circulating upwardly by convection. The collecting vessels preferably comprise conical dishes and are arranged in triangular lattice pitch in each layer, and the complex of vessels comprises three layers. Alternatively the collecting vessels may be rectilinear and arranged on a square lattice. The catchment tray may comprise two or more such complexes in stacked array. (U.K.)

  7. Nuclear reactor container

    International Nuclear Information System (INIS)

    A gas containing vessel has a water pool which is in communication with a dry well containing a reactor pressure vessel by way of a communication pipe is disposed. A capacity of a gas phase portion of the gas containing chamber, a capacity of the dry well, a water depth of a bent tube communicating the dry well with a pressure suppression pool of a pressure suppression chamber and a water depth of the communication pipe are determined so as to satisfy specific conditions. Since the water depth of the communication pipe is less than the water depth of the bent tube, incondensible gases and steams in the dry well flow into the water pool of the gas containing chamber at the initial stage of loss of coolant accident. Subsequently, steams in the dry well flow into the pressure suppression pool of the pressure suppression chamber by way of the bent tube. Accordingly, since the incondensible gases in the dry well do not flow into the pressure suppression chamber, pool swelling phenomenon in the pressure suppression chamber is not caused even if the water depth of the bent tube which leads to the pressure suppression chamber is great. Further, pressure increase due to transfer of the incondensible gases is decreased. (I.N.)

  8. Water cooled FBNR nuclear reactor

    International Nuclear Information System (INIS)

    Full text: The world with its increasing population and the desire for a more equitable and higher standard of living, is in the search for energy that is abundant and does not contribute to the problem of global warming. The answer to this is a new paradigm in nuclear energy; i.e., through the innovative nuclear reactors that meet the IAEA's INPRO philosophies and criteria that will guarantee the generation of safe and clean energy. The emerging countries to nuclear energy that are not in hurry for energy and look into the future are looking into the participation in the development of such innovative nuclear reactors. They can start developing the non-nuclear components of such reactors in parallel with creating the nuclear infra-structures according to the guidelines of the IAEA suggested in its milestones document. In this way, they can benefit from numerous advantages that the development of a high technology can bring to their countries be it scientific, technological, economic or political. A solution to the present world economic crisis is investing in such projects that contribute to the real economy rather than speculative economy. This will help both local and world economy. One such innovative nuclear reactor is the FBNR that is being developed with the support of the IAEA in its program of Small Reactors Without On-site Refuelling. It is a small (70 MWe) reactor with simple design based on the proven PWR technology (www.sefidvash.net/fbnr). The simplicity in design and the world wide existence of water reactor technology, makes it a near term project compared to other future reactors. Small reactors are most adequate for both the developing and developed countries. They require low capital investment, and can be deployed gradually as energy demand calls for. The generation of energy at the local of consumption avoids high cost of energy transmission. The paradigm of economy of scale does not apply to the FBNR as it is a small reactor by its nature. The

  9. Three dimensional diffusion calculations of nuclear reactors

    International Nuclear Information System (INIS)

    This work deals with the three dimensional calculation of nuclear reactors using the code TRITON. The purposes of the work were to perform three-dimensional computations of the core of the Soreq nuclear reactor and of the power reactor ZION and to validate the TRITON code. Possible applications of the TRITON code in Soreq reactor calculations and in power reactor research are suggested. (H.K.)

  10. Administration of stable iodine to the population around the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    Potassium iodide was reportedly given to nearly five and a half million persons after the Chernobyl accident. During the International Chernobyl Project, investigators asked the general population in both highly contaminated and control settlements about thyroid prophylaxis. Only 25% of persons currently living in the most contaminated regions reported taking potassium iodide. Sixty-six percent indicated that they did not take potassium iodide and 9% were uncertain. Of those who took stable iodine prophylactically, 44% indicated that it was in solution, 44% that it was in tablets and 12% did not remember. Only about one third of persons were able to indicate the duration of time that they took such medication. The average was 6.2 days. It appears that iodine prophylaxis will not have a major impact on estimated collective thyroid doses to the general population living around the Chernobyl nuclear power plant. The impact that distribution of KI had upon the plant and emergency accident workers remains unknown to us. (author)

  11. Production of radionuclides in nuclear reactor

    International Nuclear Information System (INIS)

    Given is a short review on the production of radionuclides which was performed in the Vinca Institute of Nuclear Sciences by using the nuclear reactor RA. Regarding the considerations of the possible re-starting of this reactor its use for the production of medical radionuclides should be taken into account. Listed are some of the important medical radionuclides routinely produced in nuclear reactors in the world and discussed the conditions for their obtaining in the reactor RA. (author)

  12. Actinide transmutation in nuclear reactors

    International Nuclear Information System (INIS)

    This report has also been published as a PhD thesis. It discusses the reduction of the transuranics part of nuclear waste. Requirements and criteria for efficient burning of transuranics are developed. It is found that a large reduction of transuranics produced per unit of energy is possible when the losses in reprocessing are small and when special transuranics burner reactors are used at the end of the nuclear era to reduce the transuranics inventory. Two special burner reactors have been studied in this thesis. In chapter 3, the Advanced Liquid Metal Reactor is discussed. A method has been developed to optimize the burning capability while complying to constraints imposed on the design for safety, reliability, and economics. An oxide fueled and metallic fueled ALMR have been compared for safety and transuranics burning. Concluded is that the burning capability is the same, but that the higher thermal conductivity of the metallic fuel has a positive effect on safety. In search for a more effective waste transmuter, a modified Molten Salt Reactor was designed for this study. The continuous refueling capability and the molten salt fuel make a safe design possible without uranium as fuel. A four times faster reduction of the transuranics is possible with this reactor type. The amount of transuranics can be halved every 10 years. The most important conclusion of this work is that it is of utmost importance in the study of waste transmutation that a high burning is obtained with a safe design. In future work, safety should be the highest priority in the design process of burner reactors. (orig.)

  13. Reactors for nuclear electric propulsion

    International Nuclear Information System (INIS)

    Propulsion is the key to space exploitation and power is the key to propulsion. This paper examines the role of nuclear fission reactors as the primary power source for high specific impulse electric propulsion systems for space missions of the 1980s and 1990s. Particular mission applications include transfer to and a reusable orbital transfer vehicle from low-Earth orbit to geosynchronous orbit, outer planet exploration and reconnaissance missions, and as a versatile space tug supporting lunar resource development. Nuclear electric propulsion is examined as an indispensable component in space activities of the next two decades

  14. Nuclear reactors in remote earth

    International Nuclear Information System (INIS)

    Same basic geological principles along with other facts, have allowed us to establish the existence in the remote past (Between 2.5 and 4 x 10''9 years ago) of the uranium deposits and/or uranium mineralized volumes, which be-have as nuclear reactors. A simplified neutronic diffusion model have allowed us to describe the main characteristics of such systems. The obtained results indicate that this phenomenon was a rather frequent fact. (Author) 7 refs

  15. Gas-cooled nuclear reactor

    International Nuclear Information System (INIS)

    The gas temperature of a hot gas loop in gas-cooled nuclear reactor plants shall be able to be modified without influencing the gas temperature of the other loops. If necessary, it should be possible to stop the loop. This is possible by means of a mixer which is places below the heat absorbing component in the hot channel and which is connected to a cold gas line. (orig.)

  16. Radioactive contamination of Bavarian game as a result of the Chernobyl reactor accident. Pt. 1

    International Nuclear Information System (INIS)

    The Cs-137 contamination of the soil in South Germany, especially around Schwabmuenchen, after the reactor accident in Chernobyl at the end of April 1986 amounted up to 20000 Bq/2. At certain places, maximum loads of even 40000 Bq/2 were measured. In the other South Bavarian regions and the southern parts of East Bavaria Cs-137 loads of between 5000-10000 Bq/2 were recorded which gradually declined to the North and to the West and reached values of <5000 Bq/2 in Lower Franconia. The regional distribution of the radiocaesium contamination in Bavarian game, especially deer, showed in the time from May to June for the area south of the Danube a 3.4 times higher contamination with Cs-137 and Cs-134 as compared to the North-Bavarian regions. By the end of July, the activities in South Bavaria were reduced to 756 Bq Cs-137/kg venison as compared to 2020 Bq/kg in May and June. In North Bavaria the values amounted to 239 Bq as compared to 591 Bq Cs-137/kg venison. From September onwards, the rise in Cs-137 activities in venison could be attributed to the feeding plants. (ECB)

  17. Health hazards to the population of Hamburg, due to the Chernobyl reactor accident. Part 2

    International Nuclear Information System (INIS)

    Estimations of cancer incidence within a time period of 50 years are stated and in brackets for comparison the cancer deaths within a time period of 50 years based on the Hamburg cancer register for 1985: 1) Pulmonary cancer 0-2 (47 100) 2) Thyroid (thyroida. 3) Hepatic cancer 1-69 (5 700) 4) Leucaemia 3-609 (8 850) 5) All cancer diseases 3-609 (259 000). Presuming that all cancer diseases caused by the Chernobyl accident lead to death and taking into consideration the total cancer risk of the next 50 years, the number of cancer deaths increases at maximum by a little more than one five hundredth (0.23%) As concerns the genetic risk, it is to be noticed that the estimated numbers of 1 to up to 55 cases per generation above all refer to the minor modifications of hereditary factor. With regard to severe hereditary diseases within the next two generations the health authority estimates that in comparison to the single case of clinical importance caused by the reactor accident there are 1760 spontaneous hereditary diseases. (orig./HP)

  18. Estimate of the radiation exposure of the Austrian population due to the reactor accident Chernobyl

    International Nuclear Information System (INIS)

    One year after the reactor accident at Chernobyl an estimate as objective as possible of the average exposure of the Austrian population in the first year after the accident is attempted. Besides the exposure path of external radiation from the cloud and ground and the exposure due to inhalation the most important path, that caused by ingestion of radionuclides via contaminated food is described in detail. The contribution of various food stuffs to the ingestion dose is described. The effective equivalent dose estimated from the average activity concentration and the average consumption per year of the respective food stuffs amounts to 0.46 mSv for the adult and 0.40 mSv for the one year old infant in the first year. In addition to the dose due to external radiation and inhalation this results in a total dose of 0.53 mSv for the adult and 0.47 mSv for the infant. The ingestion dose estimated in this way poses possibly a substantial overestimation since the whole body activity content measured in numerous whole body counter measurements results in only one third of the dose estimated from food activity concentrations. 18 refs., 11 figs. (Author)

  19. What shall we do with the broken reactor? Darmstadt-based consulting firm is a major participant in the international project for building a lasting containment around the severely damaged reactor at Chernobyl

    International Nuclear Information System (INIS)

    Environmental engineering know-how and international experience recommended the firm ARCADIS Trischler and Partners as a member of project staff when in 1996 the European Commission (EC) was soliciting competent partners for the project in compliance with the TACIS programme and in cooperation with the Ukrainian government and the G7 Working group for nuclear safety. The project was intended to establish the plans and procedures for erecting a containment around the severely damaged and hazardous reactor 4 at Chernobyl that was to guarantee short-term and long-term structural and radiological safety of the reactor and its isolation from the atmosphere. The Darmstadt-based consulting firm was entrusted with the planning task by the EC and the G7 member states and on behalf of the European Bank for Reconstruction and Development (EBRD) contributed an essential part to the activities for successful implementation of the project. (orig./CB)

  20. Total nuclear phaseout. 30 years after Chernobyl. What still has to be done; Alle aussteigen. 30 Jahre nach Tschernobyl. Was noch zu tun ist

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-03-15

    The brochure of the German Federal Environment Ministry on the necessity of total nuclear phaseout 30 years after Chernobyl discusses the following issues that still have to be done: Search for a final repository in deep rocks, building of a steel dome for Chernobyl and the roadmap for nuclear phaseout.

  1. Evaluation investigation 'Chernobyl'

    International Nuclear Information System (INIS)

    This report is an evaluation of the attitude of the Dutch government in response to the Chernobyl accident. It deals with measures taken by the government in order to minimize the (possible) effects, apparent shortcomings and how one has dealt with them, measures which can be taken at least by the Netherlands in case of a reactor accident given the presence of dozens of nuclear power plants in Europe. Good and less good aspects of the temporary organization are noted and some general recommendations are given. (Auth.)

  2. After Chernobyl. Possibilities of phasing out nuclear power in Sweden

    International Nuclear Information System (INIS)

    According to the currently applicable Parliamentary decision, the phasing out of nuclear power in Sweden must be completed by the year 2010. The National Energy Administration has analyzed the following questions. If it were to become evident that operating several or all of the Swedish nuclear power plants entailed serious risks, what possibilities would there be of phasing them out in the short term or over a longer period. And what would the consequences be with regard to the national economy and the environment? First we report the consequences of a rapid phase-out. Here, it is assumed that several or all nuclear plants would be taken out of operation within a period of two years. Available compensatory resources would be limited to more intensive utilization of existing hydropower, back-pressure plants, combined power and heating plants and oil-fired plants. The second alternative is a phase-out in ten years. Moreover, a case is discussed in which phase-out is planned and implemented from 1987 to 2005. Such a plan would provide industry more time to adjust, while a number of alternative techniques and fuels could be used to replace nuclear power. The consequences of the different phase-out alternatives can be described only within a framework of certain assumptions regarding the worldwide development. Important factors here include fuel prices and economic trends. Environmental restrictions comprise another important prerequisite

  3. The Chernobyl case: its repercussions on the International System on Civil Liability for Nuclear Damages

    International Nuclear Information System (INIS)

    With the discovery of the Nuclear Energy the world has been development her life the present investigation is based in the accident of the one of the most important Nuclear Power Plant in the world, situated in the Union of Socialist Sovietic Republics. The Nuclear Power Plant of Chernobyl. Us found in the investigation what not exist one legislation agree with the needs of development of the actual world in matter of the liability civil in case of the nuclear accidents. Found only the Convention of the Vienna. the Convention of the Brussels the which only cover the transportation the Nuclear substances in ships and others transportation medios. The complementary a the convention of the Paris and actually The Communication in case of the nuclear accidents and radiological accidents. In the present work think what the Community International haven the needs of created one legislation with character international what can help a the many countries what have Nuclear Power Plants, on all for protection of the her habitants. The International Atomic Energy Agency together with the International Justice Court and the United Nations Organization (U.N.O.) aplicated the law in matter of the nuclear accidents derivates of the liability responsibility in the use of the Nuclear Plants for elaboration the Electrical Energy or for Investigation in matter the nuclear energy both with identical responsibility civil in case the nuclear accident. (Author)

  4. Assessment of the impact of the Chernobyl Reactor accident on the Biota of Swedeish Streams and Lakes

    International Nuclear Information System (INIS)

    The Chernobyl reactor accident resulted in elevated levels of radionuclides in the air space above Sweden, which were then washed into Swedish lakes and streams. Before suspended particles stripped the water column, the concentration of /sp137/Cs in small Swedish lakes was in the order of 10-40 Bq/l. This level of radioactivity should result in a negligible increase in the external exposure rate. However, by August 1986 increased levels of radioactivity were found at all trophic levels of freshwater ecosystems from algae to top carnivore, and from the available data the levels of radioactivity are still increasing. The calculated dose rate for the aquatic biota caused by the two cesium isotopes, /sp134/Cs and /sp137/Cs, is about 25 times higher than natural levels. While acute effectrs of the Chernobyl fallout on freshwater biota are unlikely, the long term ecological effects bear watching

  5. The evaluation of the Chernobyl reactor accident by the help of the Hungarian Surveillance of Germinal Mutations

    International Nuclear Information System (INIS)

    The germinal mutagenic consequences or radioactive fall-out deposition from the Chernobyl accident in Hungary was evaluated in the ongoing program on the population-based Hungarian Surveillance of Germinal Mutations. The surveillance is based on three groups of indicator conditions: 15 sentinel anomalies (indicators of germinal dominant gene mutations), Down syndrome (an indicator of germinal numerical and structural chromosomal mutations) and unidentified multiple congenital abnormalities (indicators of germinal dominant gene and chromosomal mutations). Cases with indicator conditions were selected from the material of the Hungarian Congenital Abnormality Registry. After the diagnostic accuracies were checked, familial and sporadic cases were separated and only the latter group was evaluated for evidence of new mutations. The analysis did not reveal any measurable germinal mutagenic effects of the Chernobyl reactor accident in Hungary. (author)

  6. Radioactive contamination of rivers as a result of the accident at the Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    The formation of radioactive contamination of the Belarussian rivers after the accident at the Chernobyl Nuclear Power Plant is discussed in this manuscript. On the basis of data monitored, the authors analyzed the runoff and transport of cesium-137 and strontium-90 in the Dnieper-Sozh river system. They present the details of the Iput' river monitoring. They have drawn certain conclusions concerning the transport and fate of radionuclides based upon their analysis of the data on the transport of radioactive contamination in these rivers

  7. Research nuclear reactor operation management

    International Nuclear Information System (INIS)

    Some aspects of reactor operation management are highlighted. The main mission of the operational staff at a testing reactor is to operate it safely and efficiently, to ensure proper conditions for different research programs implying the use of the reactor. For reaching this aim, there were settled down operating plans for every objective, and procedure and working instructions for staff training were established, both for the start-up and for the safe operation of the reactor. Damages during operation or special situations which can arise, at stop, start-up, maintenance procedures were thoroughly considered. While the technical skill is considered to be the most important quality of the staff, the organising capacity is a must in the operation of any nuclear facility. Staff training aims at gaining both theoretical and practical experience based on standards about staff quality at each work level. 'Plow' sheet has to be carefully done, setting clear the decision responsibility for each person so that everyone's own technical level to be coupled to the problems which implies his responsibility. Possible events which may arise in operation, e.g., criticality, irradiation, contamination, and which do not arise in other fields, have to be carefully studied. One stresses that the management based on technical and scientific arguments have to cover through technical, economical and nuclear safety requirements a series of interlinked subprograms. Every such subprograms is subject to some peculiar demands by the help of which the entire activity field is coordinated. Hence for any subprogram there are established the objectives to be achieved, the applicable regulations, well-defined responsibilities, training of the personnel involved, the material and documentation basis required and activity planning. The following up of positive or negative responses generated by experiments and the information synthesis close the management scope. Important management aspects

  8. Accelerator Driven Subcritical Reactors and their Function in the Future of Nuclear Power

    International Nuclear Information System (INIS)

    The Development of nuclear power reactors has slowed dozen considerably following the Three Mile Island accident in the US, and came to a standstill in most countries after the Chernobyl accident in Russia. This, in spite of the otherwise excellent safety and economic record of nuclear power plants in the west. The major reason is the public concern about safety of these plants and the disposal of the nuclear waste, which is considered by the public to be the most dangerous, produced by any industrial enterprise. The introduction of accelerators, or rather accelerator driven systems, the ADS, is intended to provide a partial response to the above concerns

  9. After Chernobyl

    International Nuclear Information System (INIS)

    The Chernobyl accident mobilized profound anxieties in many people, which subsequently were repressed again and played down with the aid of the known psychological mechanisms. The authors trace the anxiety, and the resistance against it, and pose the question of whether we are at all capable of learning to think along new lines. From the contents: 10 theses on Chernobyl 1986 (Anders, G.); Anxiety, apathy and new thinking (Richter, H.-E.); On the Germans' particular way of dealing with existential threats (Wirth, H.-J.); Appeasement and delusion - small and big flights from powerlessness (Leithaeuser, T.); Socio-psychological theses on the consequences of nuclear energy (Clemenz, M.); Psychological arguments in the discussion about Chernobyl (Kettner, M.); Relationship between fear and technology (Brede, K.); Inhumanity of technology (Spangenberg, N.); Psychology of nuclear addiction (Bauriedl, T.); Nature or technology - search of the wizard's apprentice for lost salvation (Bastian, T./Hilger, M.); Living under a nuclear threat - significance of existential fear experienced during childhood (Boehnke, K., et al.); Survey of, and psychoanalytical reflections on, poisoned childhood (Petri, H.); On knowing, feeling, and experience after Chernobyl (Thiel, W.); Sociopsychological aspects of the staging of politics as a state spectacle fit for the media (Fuechner, H.). (orig./HP)

  10. The reactor accident at Chernobyl: A possibility to test colloid-controlled transport of radionuclides

    International Nuclear Information System (INIS)

    Radioactive fall-out from the damaged nuclear power plant at Chernobyl (USSR) has been measured between May 2 and May 20, 1986 in the River Glatt (Zurich, Switzerland) and in a shallow groundwater stream which is hydraulically connected to the river. Water infiltrating from the river into the groundwater was sampled at different distances and depths by means of a system of piezometer tubes which are part of an experimental installation for the investigation of groundwater quality and migration processes. The aquifer is a quarternary glaciofluvial deposit consisting of stones, gravel, sand, silt and clays. It is typical for large parts of alpine and peri-alpine regions and contains in Switzerlamd about 80% of the drinking water supplies. The radionuclides Tc-99m, Ru-103, I-131, Te-132, Cs-134 and Cs-137 were measured several times in the river water and in the groundwater using calibrated Ge(Li) gamma-ray spectrometers. Based on the present state of data evaluation the authors conclude that anionic species like iodides, ruthenates or tellurates are not or only slightly sorbed, whereas cesium is completely retained during infiltration from the river into the groundwater. Colloid (>0.05 μm) controlled migration of radionuclides in this heterogeneous glaciofluvial deposits is a transport mechanism of minor importance. However, with the present data it cannot be excluded completely

  11. Nuclear reactors Monitoring using neutrinos detectors1

    International Nuclear Information System (INIS)

    We study the feasibility to use antineutrinos detectors for monitoring of nuclear reactors. Using a simple model of fission shower with two components, we illustrate how the numbers of antineutrinos detected at a distance L from the reactor depend on the composition of the nuclear combustible and how it could be used for nuclear safeguards policy.

  12. Exporting apocalypse: CANDU reactors and nuclear proliferation

    International Nuclear Information System (INIS)

    The author believes that the peaceful use of nuclear technology leads inevitably to the production of nuclear weapons, and that CANDU reactors are being bought by countries that are likely to build bombs. He states that exports of reactors and nuclear materials cannot be defended and must be stopped

  13. Worldwide advanced nuclear power reactors with passive and inherent safety: What, why, how, and who

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Reich, W.J.

    1991-09-01

    The political controversy over nuclear power, the accidents at Three Mile Island (TMI) and Chernobyl, international competition, concerns about the carbon dioxide greenhouse effect and technical breakthroughs have resulted in a segment of the nuclear industry examining power reactor concepts with PRIME safety characteristics. PRIME is an acronym for Passive safety, Resilience, Inherent safety, Malevolence resistance, and Extended time after initiation of an accident for external help. The basic ideal of PRIME is to develop power reactors in which operator error, internal sabotage, or external assault do not cause a significant release of radioactivity to the environment. Several PRIME reactor concepts are being considered. In each case, an existing, proven power reactor technology is combined with radical innovations in selected plant components and in the safety philosophy. The Process Inherent Ultimate Safety (PIUS) reactor is a modified pressurized-water reactor, the Modular High Temperature Gas-Cooled Reactor (MHTGR) is a modified gas-cooled reactor, and the Advanced CANDU Project is a modified heavy-water reactor. In addition to the reactor concepts, there is parallel work on super containments. The objective is the development of a passive box'' that can contain radioactivity in the event of any type of accident. This report briefly examines: why a segment of the nuclear power community is taking this new direction, how it differs from earlier directions, and what technical options are being considered. A more detailed description of which countries and reactor vendors have undertaken activities follows. 41 refs.

  14. Worldwide advanced nuclear power reactors with passive and inherent safety: What, why, how, and who

    International Nuclear Information System (INIS)

    The political controversy over nuclear power, the accidents at Three Mile Island (TMI) and Chernobyl, international competition, concerns about the carbon dioxide greenhouse effect and technical breakthroughs have resulted in a segment of the nuclear industry examining power reactor concepts with PRIME safety characteristics. PRIME is an acronym for Passive safety, Resilience, Inherent safety, Malevolence resistance, and Extended time after initiation of an accident for external help. The basic ideal of PRIME is to develop power reactors in which operator error, internal sabotage, or external assault do not cause a significant release of radioactivity to the environment. Several PRIME reactor concepts are being considered. In each case, an existing, proven power reactor technology is combined with radical innovations in selected plant components and in the safety philosophy. The Process Inherent Ultimate Safety (PIUS) reactor is a modified pressurized-water reactor, the Modular High Temperature Gas-Cooled Reactor (MHTGR) is a modified gas-cooled reactor, and the Advanced CANDU Project is a modified heavy-water reactor. In addition to the reactor concepts, there is parallel work on super containments. The objective is the development of a passive ''box'' that can contain radioactivity in the event of any type of accident. This report briefly examines: why a segment of the nuclear power community is taking this new direction, how it differs from earlier directions, and what technical options are being considered. A more detailed description of which countries and reactor vendors have undertaken activities follows. 41 refs

  15. Nuclear reactors appointment book Uruguay at the moment

    International Nuclear Information System (INIS)

    This essay have included among its chapters Energy and development, fuels, Nuclear Energy, types of Nuclear Reactors, main objections against Power Nuclear Reactors, other Reactors proposals, legal framework and Nuclear safety in Uruguay

  16. Seismic Design of Nuclear Reactor

    International Nuclear Information System (INIS)

    In case the requirement of design is against natural phenomena, it is important to grasp the detailed characteristics of the natural phenomena for the proper design, and as the grasp is more strict and accurate, the design of high adaptability or durability to the requirement can be done. The aseismatic design of nuclear reactors is similar to it, and the decision of the magnitude of supposed earthquakes is important. The aseismatic design of nuclear power stations in Japan has been carried out in conformity with the national guideline for examining the aseismatic design. The aseismatic design of nuclear reactors is carried out in the order of the survey of geological features, ground and earthquakes, the determination of the input magnitude and characteristics of earthquakes, the formation of simulated earthquake waves, the analysis of the response of buildings and structures to earthquakes, and structural analysis. The decision of input earthquakes is done by the detailed historical earthquake data based on local features and the survey of geological features and ground. The determination of earthquake input, the analysis of earthquake response and structural analysis, and the other features of the aseismatic design are explained. (K.I.)

  17. Comments on nuclear reactor safety in Ontario

    International Nuclear Information System (INIS)

    The Chalk River Technicians and Technologists Union representing 500 technical employees at the Chalk River Nuclear Laboratories of AECL submit comments on nuclear reactor safety to the Ontario Nuclear Safety Review. Issues identified by the Review Commissioner are addressed from the perspective of both a labour organization and experience in the nuclear R and D field. In general, Local 1568 believes Ontario's CANDU nuclear reactors are not only safe but also essential to the continued economic prosperity of the province

  18. Standby after the Chernobyl accident

    International Nuclear Information System (INIS)

    The report is an investigation concerning strandby and actions by SKI (Swedish Nuclear Power Inspectorate) and SSI (National Institute of Radiation Protection) due to the Chernobyl reactor accident. It consists of a final report and two appendices. The final report is divided into two parts: 'I: Facts' and 'II: Analyzes'. 'Facts': The Swedish model for information: radio, press. Basic knowledge about ionizing radiation in the society. Resources for information. Need for information. Message forms for information. Announcements from the authorities in TV, radio, press, meeting, advertisements. Statements concerning the reactor accident and its consequences in Swedish mass media. How did the public recieve the information? 'Analyzis': Information responsibilities and policies. SSI information activities concerning radiologic accidents, conditions, methods and resources. Ditto for SKI, Swedish National Food Administration and the National Board of Agriculture. Appendix I: Information from authorities in the press three weeks after the Chernobyl accident: The material and the methods. The acute phase, the adoptation phase, the extension of the persective. What is said about the authorities in connection with Chernobyl? Appendix II: The fallout from Chernobyl, the authorities and the media coverage: The nationwide, regional and local coverage from radio and television. Ditto from the press. Topic and problem areas in reporting. Instructions from the authorities in media. Contribution in the media from people representing the authorities. Fallout in a chronologic perspective. (L.F.)

  19. Artificial intelligence in nuclear reactor operation

    International Nuclear Information System (INIS)

    Assessment of four real fuzzy control applications at the MIT research reactor in the US, the FUGEN heavy water reactor in Japan, the BR1 research reactor in Belgium, and a TRIGA Mark III reactor in Mexico will be examined through a SWOT analysis (strengths, weakness, opportunities, and threats). Special attention will be paid to the current cooperation between the Belgian Nuclear Research Centre (SCK·CEN) and the Mexican Nuclear Centre (ININ) on AI-based intelligent control for nuclear reactor operation under the partial support of the National Council for Science and Technology of Mexico (CONACYT). (authors)

  20. 15 years after Chernobyl, nuclear power plant safety improved world-wide, but regional strains on health, economy and environment remain

    International Nuclear Information System (INIS)

    Fifteen years after the Chernobyl accident, exhaustive studies by the IAEA and others provide a solid understanding of the causes and consequences of the accident, which stemmed from design deficiencies in the reactor compounded by violation of operating procedures. These deficiencies and the lack of an international notification mechanism led to the speedy adoption of early Notification and Assistance Conventions as well as later establishment of the landmark Convention on Nuclear Safety. Lessons learned from the accident were also a significant driving force behind a decade of IAEA assistance to the countries of Central and eastern Europe and the Former Soviet Union. Much of this work was focused on identifying the weaknesses in and improving the design safety of WWER and RBMK reactors

  1. Molten salts in nuclear reactors

    International Nuclear Information System (INIS)

    Collection of references dealing with the physicochemical studies of fused salts, in particular the alkali and alkali earth halides. Numerous binary, ternary and quaternary systems of these halides with those of uranium and thorium are examined, and the physical properties, density, viscosity, vapour pressure etc... going from the halides to the mixtures are also considered. References relating to the corrosion of materials by these salts are included and the treatment of the salts with a view to recuperation after irradiation in a nuclear reactor is discussed. (author)

  2. Internal structure for nuclear reactor

    International Nuclear Information System (INIS)

    The description is given of an internal structure for a nuclear reactor of the type having inside a presssure vessel a core composed of a number of fuel assemblies and a number of mobile control components. It includes a bottom grid integral with the vessel on which are secured the fuel assemblies, an intermediate grid located above the assemblies and also integral with the vessel, an upper grid located at the upper part of the vessel and integral with it and multiple vertical maintenance devices, extending between the upper and intermediate grids

  3. An observation report on the late effects of the disaster of the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    As part of international medical cooperation for the Chernobyl nuclear power plant accident, the authors participated in four fact-finding surveys for the aftermath in May 1990, and May, June, and July 1991. This report gives an outline of the surveys, with the purpose of providing the basic information for the future countermeasures. The focus of this paper is on medical surveys for hematopoietic disease (mainly leukemia), infantile thyroid abnormality, and congenital abnormality. In 8 children undergoing hematopoietic examination, accumulated exposure doses were all one rad or less. Infantile leukemia is discussed in terms of exposure doses, radioactivity, radiation-related leukemic types, and the future management. The results of thyroid examination performed in 40 persons at a hospital in the Ukraine are presented: 17 persons were noted to have sclerosing struma associated with atrophy. Incidence of thyroid cancer, presented from two facilities of the Ukraine and four facilities of the Belorussia, is reported. Thyroid abnormality is discussed in terms of radioiodine, I-131 treatment in Basedow's disease, Bikini nuclear exlosion, Hiroshima and Nagasaki A-bomb survivors, and Chernobyl pediatric survivors. The final topic, congenital abnormality, covers the information on fetal and neonatal death and the occurrence of anomaly obtained from reliable physicians in the Belorussia, and is discussed in terms of exposure doses. Finally, problems encountered in surveys for the aftermath are also mentioned. (N.K.)

  4. distribution of Release Fission Products Through the Nuclear Reactor Site

    International Nuclear Information System (INIS)

    Through the operation of nuclear reactors, radioactive fission products could be release to the environment as a result of severe accidents e.g. Chernobyl accident. Estimation of the atmospheric dispersion, distribution and transport of the radioactive fission products is essential to assessment of the risk to the public from such accidents. In this work, the polluted plume is treated as a matrix of isolated particles.These particles are the fission product isotopes, which compose the radioactive plume.The fission products were classified depending on its half live into three category, long-lived, medium lived and small half-life.The normalized concentrations of the fission product isotopes in the radioactive plume were calculated.The travel time (the time elapsed from the released instant till the deposited time) of each fission products was calculated. The area around the nuclear reactor stack was divided into different zones, started from the reactor stack position until 5 km.The deposited radioactive fission products in each zone was estimated.The calculations were done using the spherical Gaussian plume model

  5. Feasibility of studies on health effects in western Europe due to the reactor accident at Chernobyl and Recommendations for research

    International Nuclear Information System (INIS)

    The report considers whether studies of health effects related to the radioactive contamination of western Europe caused by the releases from the Chernobyl reactor accident would be useful. The report evaluates the exposure patterns and the dose levels within the European Community, the different health effects that might be induced by such doses, and the likelihood that epidemiological studies could produce scientifically useful information. The report concludes that at the exposure levels experienced in the European Community the study of post-Chernobyl cancer rates in adults and the study of heritable genetic effects in the offspring of those exposed would be unproductive. It also concludes that even a study of childhood cancer following in utero exposure would be unlikely to demonstrate any attributable increase in risk. However, the report recommends that a small epidemiologic survey of childhood cancer be conducted within areas where selected cancer registration was in existence at the time of the Chernobyl accident to check the ability to predict risks from doses of the order received, to contribute to the understanding of the occurrence of childhood leukemia and to allay public anxiety

  6. Thyroid gland state in persons of Kiev region after Chernobyl accident at the Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    After Chernobyl accident, the growth of thyroid pathology, particularly the children's thyroid cancer, has been noted in Kiev Region. Reconstruction of exposure doses on thyroid gland is one of the major problems on liquidation of medical effects of the Chernobyl accident. While accessing the dose load it is necessary to take into account not only iodine-131 contribution to the radiation load, but also that of other iodine short-living radionuclides as well as radionuclides of other chemical elements inhalated or swallowed into the organism. Analysis of pathological involvement of the thyroid gland is to be performed with regard for the state of other organs and systems, i.e. on the entire organism level, thyroid gland playing the leading role in its functioning

  7. Autonomous Control of Space Nuclear Reactors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Nuclear reactors to support future robotic and manned missions impose new and innovative technological requirements for their control and protection...

  8. The application problems of nuclear reactors

    International Nuclear Information System (INIS)

    Latvia is surrounded by closely located nuclear reactors. In a distance of 1000 km from Latvia there are 62 working and 12 suspended high power nuclear reactors. Near the borders of Latvia, in the 3 km range four countries are exploiting 12 nuclear reactors, whose reliability and safe operation is always arousing profound interest in our community. On estimating the prospects of Latvian energetics we can conclude that at the beginning of the next century it will be extremely complicated task to supply our country with electricity and heat without nuclear reactors. This is due to lack of the domestic energy resources and to the necessity of reducing harmful pollutions of TECs. (authors)

  9. Nuclear reactor built, being built, or planned

    International Nuclear Information System (INIS)

    This document contains unclassified information about facilities built, being built, or planned in the United States for domestic use or export as of December 31, 1990. The Office of Scientific and Technical Information, US Department of Energy, gathers this information annually from Washington headquarters and field offices of DOE, from the US Nuclear Regulatory Commission, from the US reactor manufacturers who are the principal nuclear contractors for foreign reactor locations, from US and foreign embassies, and from foreign governmental nuclear departments. The book is divided into three major sections: Section 1 consists of a reactor locator map and reactor tables; Section 2 includes nuclear reactors that are operating, being built, or planned; and Section 3 includes reactors that have been shut down permanently or dismantled. Sections 2 and 3 contain the following classification of reactors: Civilian, Production, Military, Export, and Critical Assembly

  10. Liquid metal cooled nuclear reactors

    International Nuclear Information System (INIS)

    Reference is made to liquid metal cooled nuclear reactors of the 'pool' type. In such reactors the core, the heat exchangers, and the coolant circulating pumps are submerged in a pool of liquid metal. In operation of the reactor it is necessary to be able to locate and identify components submerged in the pool, and before moving rotating shields in the roof of the pool-containing vault it is necessary to ensure that all the normally suspended absorber rods have been inserted in the core and released from their suspensions. Television cameras are unsuitable for use in the opaque liquid metal but ultrasound in the megahertz range has been used to give a television screen kind of display. There is some difficulty, however, in transmitting ultrasound signals from a transducer into the pool of coolant because the transducer must be protected from the high temperature environment of the coolant. This difficulty has been partially overcome, however, by transmitting the signals by way of a wave guide extending from the transducer into the coolant pool. Such a wave guide may comprise a column of liquid metal within a dip tube. The column of liquid coolant is uninterrupted by a supporting diaphragm. Such a system is here described. (U.K.)

  11. Decommissioning of nuclear reactor systems

    International Nuclear Information System (INIS)

    The decision-making process involving the decommissioning of the British graphite-moderated, gas-cooled Magnox power stations is complex. There are timing, engineering, waste disposal, cost and lost generation capacity factors and the ultimate uptake of radiation dose to consider and, bearing on all of these, the overall decision of when and how to proceed with decommissioning may be heavily weighed by political and public tolerance dimensions. These factors and dimensions are briefly reviewed with reference to the ageing Magnox nuclear power stations, of which Berkeley and Hunterston A are now closed down and undergoing the first stages of decommissioning and Trawsfynydd, although still considered as available capacity, has had both reactors closed down since February 1991 and is awaiting substantiation and acceptance of a revised reactor pressure vessel safety case. Although the other first-generation Magnox power station at Hinkley Point, Bradwell, Dungeness and Sizewell are operational, it is most doubtful that these stations will be able to eke out a generating function for much longer. It is concluded that the British nuclear industry has adopted a policy of deferred decommissioning, that is delaying the process of complete dismantlement of the radioactive components and assemblies for at least one hundred years following close-down of the plant. (Author)

  12. Effects of the Chernobyl accident on public perceptions of nuclear plant accident risks

    International Nuclear Information System (INIS)

    Assessments of public perceptions of the characteristics of a nuclear power plant accident and affective responses to its likelihood were conducted 5 months before and 1 month after the Chernobyl accident. Analyses of data from 69 residents of southwestern Washington showed significant test-retest correlations for only 10 of 18 variables--accident likelihood, three measures of impact characteristics, three measures of affective reactions, and hazard knowledge by governmental sources. Of these variables, only two had significant changes in mean ratings; frequency of thought and frequency of discussion about a nearby nuclear power plant both increased. While there were significant changes only for two personal consequences (expectations of cancer and genetic effects), both of these decreased. The results of this study indicate that more attention should be given to assessing the stability of risk perceptions over time. Moreover, the data demonstrate that experience with a major accident can actually decrease rather than increase perceptions of threat

  13. Licensed reactor nuclear safety criteria applicable to DOE reactors

    International Nuclear Information System (INIS)

    The Department of Energy (DOE) Order DOE 5480.6, Safety of Department of Energy-Owned Nuclear Reactors, establishes reactor safety requirements to assure that reactors are sited, designed, constructed, modified, operated, maintained, and decommissioned in a manner that adequately protects health and safety and is in accordance with uniform standards, guides, and codes which are consistent with those applied to comparable licensed reactors. This document identifies nuclear safety criteria applied to NRC [Nuclear Regulatory Commission] licensed reactors. The titles of the chapters and sections of USNRC Regulatory Guide 1.70, Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants, Rev. 3, are used as the format for compiling the NRC criteria applied to the various areas of nuclear safety addressed in a safety analysis report for a nuclear reactor. In each section the criteria are compiled in four groups: (1) Code of Federal Regulations, (2) US NRC Regulatory Guides, SRP Branch Technical Positions and Appendices, (3) Codes and Standards, and (4) Supplemental Information. The degree of application of these criteria to a DOE-owned reactor, consistent with their application to comparable licensed reactors, must be determined by the DOE and DOE contractor

  14. After Chernobyl

    International Nuclear Information System (INIS)

    This report discusses a number of effects of the Chernobyl-accident on public opinion about nuclear power. The analysis is based on a comparison of a survey conducted shortly after Chernobyl and a number of measurements in the Netherlands between 1982 and 1986. The conclusions can be summarized as follows: Attitudes towards nuclear power and especially towards building new stations have become much more negative after the disaster in Chernobyl. Although a majority of the population now wants to close existing nuclear power stations, there appears strong support for continuation of nuclear research. The structure of the nuclear debate has not changed fundamentally. Supporters and opponents have kept the same demographic characteristics. The arguments which distinguish them have not changed, except that the expectation of a serious accident has an increased impact on attitudes. A majority of the population felt the information after the accident not sufficient. Since 1982 attitudes towards coal also have become more negative, mainly as a consequence of the higher visibility of effects of acid rain. (Auth.)

  15. Tracking the cloud from Chernobyl

    International Nuclear Information System (INIS)

    In the aftermath of the accident at Chernobul nuclear power station, many scientists are studying how the radionuclides from the reactor's core dispersed across Europe and became deposited on the ground. A group in the Department of Mechanical Engineering at Imperial College have developed a computer model, MESOS, specifically to study the transport of pollutants in the atmosphere over very large distances. In the past, this model has been used to study the potential consequences of hypothetical accidents at nuclear power plants in neighbouring countries. Now it has been used to estimate where the radioactivity from Chernobyl went. The Chernobyl model is explained and some estimates from the MESOS model are presented. By comparing the model estimates with observations a full assessment of the environmental consequences of the accident will be possible. It should be possible to find out the way in which pollutants travel long distances, how they are deposited on the ground and their transport through food chains. (U.K.)

  16. Morbidity of Chernobyl Nuclear Power Plant Accident Clean - up Workers with Oncological Diseases from 1990 to 2004

    International Nuclear Information System (INIS)

    The world's largest ever radiation accident involving a nuclear reactor occurred on 26 April 1986 at the Chernobyl nuclear power plant (CNPP). More than 6 000 Latvian inhabitants worked to clean-up CNPP accident in 1986-1991. The duration of accident clean-up workers exposure was from few weeks to 6 months, including external as well as internal radiation. The estimated external radiation doses were 0,01-0,5 Gy. Latvian CNPP accident clean-up workers State register was created on the basis of the Center of Occupational and Radiological medicine of P. Stradins Clinical University hospital in 1994 but examination of clean-up workers was started in 1986. Our aim was to analyse oncological morbidity in clean-up workers in comparison with oncological morbidity in Latvian men population. Materials and methods. For analysis of oncological morbidity in NPP accident clean-up workers, the data of Latvian CNPP accident clean-up workers State Register were used. The group for investigation includes 4053 males what were examined regularly (in average 1600 persons every year) from 1998 to 2004. From these groups of clean-up workers we have revealed 177 persons with oncological diseases over the observation period. Among them only two women but others were men. We have used for the comparison of oncological morbidity data of Latvian Cancer registry and Central bureau of statistics. Summary morbidity with oncological diseases and morbidity with oncological diseases of prostata, stomach, lungs and thyroid for men who have taken part in clean-up works were analysed. Oncological morbidity in age group 35-69 years over the observation period 1998-2004 were compared With age-matched non-exposed population morbidity. Results and discussion. In the structure of oncological morbidity of the Chernobyl accident clean-up workers over the period 1990-2004 in the first place was lung cancer, in the second place -stomach cancer, in the third place -prostate cancer. CNPP clean-up worker's common

  17. Licensed reactor nuclear safety criteria applicable to DOE reactors

    International Nuclear Information System (INIS)

    This document is a compilation and source list of nuclear safety criteria that the Nuclear Regulatory Commission (NRC) applies to licensed reactors; it can be used by DOE and DOE contractors to identify NRC criteria to be evaluated for application to the DOE reactors under their cognizance. The criteria listed are those that are applied to the areas of nuclear safety addressed in the safety analysis report of a licensed reactor. They are derived from federal regulations, USNRC regulatory guides, Standard Review Plan (SRP) branch technical positions and appendices, and industry codes and standards

  18. Migration studies of 137Cs from nuclear weapons fallout and the Chernobyl accident

    International Nuclear Information System (INIS)

    The vertical migration of 137Cs originating from nuclear weapons fallout (NWF) and the Chernobyl accident has been studied at 27 reference sites in western Sweden. An attempt to describe the present depth distribution with an alternative solution of the Convection-Dispersion Equation (CDE) with a pulse-like fallout as initial condition was made. The actual depth profiles in the soil samples were fit to a sum of the CDE for both NWF and Chernobyl debris. The magnitudes of the fallouts were estimated from precipitation calculations and GIS-mapping, leaving two free parameters (convection velocity and effective dispersion constant) for performing the fit of the depth profiles. In some cases using only two parameters is not sufficient to achieve an accurate representation for the depth profile, indicating an over- or underestimate of the magnitude of the fallout. In these cases the magnitude of the fallout is also varied. The fitted depth profiles were used to correct in situ measurements from the same locations for the actual depth distribution, showing good agreement with the accumulated activities in soil samples

  19. Proliferation Resistant Nuclear Reactor Fuel

    International Nuclear Information System (INIS)

    Global appetite for fission power is projected to grow dramatically this century, and for good reason. Despite considerable research to identify new sources of energy, fission remains the most plentiful and practical alternative to fossil fuels. The environmental challenges of fossil fuel have made the fission power option increasingly attractive, particularly as we are forced to rely on reserves in ecologically fragile or politically unstable corners of the globe. Caught between a globally eroding fossil fuel reserve as well as the uncertainty and considerable costs in the development of fusion power, most of the world will most likely come to rely on fission power for at least the remainder of the 21st century. Despite inevitable growth, fission power faces enduring challenges in sustainability and security. One of fission power's greatest hurdles to universal acceptance is the risk of potential misuse for nefarious purposes of fissionable byproducts in spent fuel, such as plutonium. With this issue in mind, we have discussed intrinsic concepts in this report that are motivated by the premise that the utility, desirability, and applicability of nuclear materials can be reduced. In a general sense, the intrinsic solutions aim to reduce or eliminate the quantity of existing weapons usable material; avoid production of new weapons-usable material through enrichment, breeding, extraction; or employ engineering solutions to make the fuel cycle less useful or more difficult for producing weapons-usable material. By their nature, these schemes require modifications to existing fuel cycles. As such, the concomitants of these modifications require engagement from the nuclear reactor and fuel-design community to fully assess their effects. Unfortunately, active pursuit of any scheme that could further complicate the spread of domestic nuclear power will probably be understandably unpopular. Nevertheless, the nonproliferation and counterterrorism issues are paramount, and

  20. Flow visualization techniques in nuclear reactors, (1)

    International Nuclear Information System (INIS)

    Heat energy generated in nuclear reactors is transferred by coolants to utilizing systems such as electric power and process industries etc. Therefore, heat removal characteristics of nuclear reactors depends on flow conditions of coolants in a reactor core and in cooling systems. In order to make clear flow patterns of these coolants, the flow visualization method is often applied prior to actual measurements of pressure, velocity and so on. This paper describes basic techniques for flow visualization especially in nuclear reactor, and gives applied examples of this technique. (author)

  1. Problems of nuclear reactor safety. Vol. 1

    International Nuclear Information System (INIS)

    Proceedings of the 9. Topical Meeting 'Problems of nuclear reactor safety' are presented. Papers include results of studies and developments associated with methods of calculation and complex computerized simulation for stationary and transient processes in nuclear power plants. Main problems of reactor safety are discussed as well as rector accidents on operating NPP's are analyzed

  2. Nuclear reactor simulator for a teaching laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kosilov, A.N. (Moscow Engineering Physics Inst. (USSR))

    A nuclear reactor simulator is described which has been developed by the Department of Automatics and Telemechanics of the Moscow Engineering Physics Institute to provide students with an insight into, and familiarity with the characteristics of a nuclear reactor and its systems through evaluation, manipulation and experimentation.

  3. A Comparison of the Effects of the Chernobyl and Three Mile Island Nuclear Accidents on the U.S. Electric Utility Industry

    OpenAIRE

    AKTAR, İsmail

    2005-01-01

    We examined the stock market reaction to two nuclear accidents, the Three Mile Island incident and the Chernobyl disaster. We were interested in determining whether the negative stock market reaction following these events was consistently related to the level of nuclear exposure by each firm and whether the negative reaction was reasonably linked to human safety concerns. Prior research has shown that following TMI, but anomalously not Chernobyl, firms with the more nuclear capacity experien...

  4. Chernobyl: getting to the heart of the matter

    International Nuclear Information System (INIS)

    In the second of two linked articles on the aftermath of the Chernobyl nuclear reactor accident of 1986, the author explores the effects on local agriculture and the health of populations affected by the contamination from the fall-out, especially children. Agriculture around Chernobyl has resumed, with workers moving back from the cities to areas where radiation doses are similar to parts of Cornwall. Concern continues about the safety of milk from cows grazing contaminated grass and eating local mushrooms. The largest risk to children's health is not birth deformaties, but leukaemia, possibly in part due to iodine deficiency in their diet prior to contamination. Concern also continues about keeping power supplies going in areas heavily dependent on nuclear power. Reactor safety issues remaining operational RBMK reactors and the sarcophagus around Chernobyl-4 itself have yet to be resolved. (UK)

  5. Summary of Chernobyl followup research activities

    International Nuclear Information System (INIS)

    In NUREG-1251, ''Implications of the Accident at Chernobyl for Safety Regulation of Commercial Nuclear Power Plants in the United States,'' April 1989, the NRC staff concluded that no immediate changes in NRC's regulations regarding design or operation of US commercial reactors were needed; however, it recommended that certain issues be considered further. NRC's Chernobyl followup research program consisted of the research tasks undertaken in response to the recommendations in NUREG-1251. It included 23 tasks that addressed potential lessons to be learned from the Chernobyl accident. This report presents summaries of NRC's Chernobyl followup research tasks. For each task, the Chernobyl-related issues are indicated, the work is described, and the staff's findings and conclusions are presented. More detailed reports concerning the work are referenced where applicable. This report closes out NRC's Chernobyl followup research program as such, but additional research will be conducted on some issues as needed. The report includes remarks concerning significant further activity with respect to the issues addressed

  6. Radiation contamination after the Chernobyl nuclear accident and the effective dose received by the population of Croatia

    International Nuclear Information System (INIS)

    Because of the Chernobyl nuclear accident which led to enhanced deposition of all fission products, contamination of the human environment in the Republic of Croatia was much higher than in the previous two decades. The paper deals with the investigation of deposition and contamination by fission product radionuclides (137Cs and 90Sr, in particular), especially within the human food chain. Its aim was to determine differences in contamination levels resulting from the Chernobyl accident and from large-scale atmospheric nuclear weapon tests. For the year following the Chernobyl accident, the radiation doses received from external and internal exposures were estimated for 1-year old infants, children at the age of 10-years and adults. The corresponding annual effective doses were 1·49, 0·93 and 0·83 mSv, respectively. The paper also gives data on the yearly intakes of 137Cs and 90Sr in foods and the corresponding effective doses received by the population of Croatia over many years from the global fallout following nuclear weapons testing and the Chernobyl accident. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Chernobyl health effects

    International Nuclear Information System (INIS)

    On 26 April 1986, a few short minutes were not enough to destroy one of the four nuclear reactors at Chernobyl and cause, over the next few weeks, the deaths of 31 people from among the staff, rescuers and firefighters who had dealt with the accident and prevented the spread of the catastrophe to the other three reactors on the site. The experts and the authorities soon recognized that the consequences of this event for the environment and for the surrounding populations would last several decades. Forecast estimates from very diverse sources of the nature and extent of these consequences came thick and fast, particularly in the years 1986 and 1987. Unfortunately, they differed so greatly in both time and space that they lacked all credibility. As the news spread through the public, it could only worsen a social climate which was already seriously upset by the effects of the catastrophe itself. 55 refs

  8. Origin of a signal detected with the LSD detector after the accident at the chernobyl nuclear power plant

    Science.gov (United States)

    Agafonova, N. Yu.; Malgin, A. S.; Fulgione, W.

    2013-08-01

    A rare signal was detected at 23:53 Moscow time on April 27, 1986 with the LSD low-background scintillation detector located under Mont Blanc at a distance of 1820 km from Chernobyl. To reveal the origin of this signal, we discuss the results obtained with other instruments operating within a similar program, as well as analyze the characteristics of the pulses of the signal and facts referring to the explosion of the Chernobyl reactor. A hypothesis based on detection with the LSD of gamma-quanta from β decays of 135I nuclei ejected into atmosphere by the reactor explosion and carried in the underground detector camera with air of positive ventilation is considered. The explosion origin of the LSD signal indicates a new technogenic source of the background in the search for neutrino bursts from cores of collapsing stars.

  9. Origin of a signal detected with the LSD detector after the accident at the chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    A rare signal was detected at 23:53 Moscow time on April 27, 1986 with the LSD low-background scintillation detector located under Mont Blanc at a distance of 1820 km from Chernobyl. To reveal the origin of this signal, we discuss the results obtained with other instruments operating within a similar program, as well as analyze the characteristics of the pulses of the signal and facts referring to the explosion of the Chernobyl reactor. A hypothesis based on detection with the LSD of gamma-quanta from β decays of 135I nuclei ejected into atmosphere by the reactor explosion and carried in the underground detector camera with air of positive ventilation is considered. The explosion origin of the LSD signal indicates a new technogenic source of the background in the search for neutrino bursts from cores of collapsing stars

  10. Origin of a signal detected with the LSD detector after the accident at the chernobyl nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Agafonova, N. Yu., E-mail: natagafonova@gmail.com; Malgin, A. S., E-mail: malgin@lngs.infn.it [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Fulgione, W. [Istituto Nazionale di Fisica Nucleare, and Osservatorio Astrofisico di Torino, Istituto di Fisica dello Spazio Interplanetario (Italy)

    2013-08-15

    A rare signal was detected at 23:53 Moscow time on April 27, 1986 with the LSD low-background scintillation detector located under Mont Blanc at a distance of 1820 km from Chernobyl. To reveal the origin of this signal, we discuss the results obtained with other instruments operating within a similar program, as well as analyze the characteristics of the pulses of the signal and facts referring to the explosion of the Chernobyl reactor. A hypothesis based on detection with the LSD of gamma-quanta from {beta} decays of {sup 135}I nuclei ejected into atmosphere by the reactor explosion and carried in the underground detector camera with air of positive ventilation is considered. The explosion origin of the LSD signal indicates a new technogenic source of the background in the search for neutrino bursts from cores of collapsing stars.

  11. Nuclear reactor fuel rod spacer

    International Nuclear Information System (INIS)

    A spacer for positioning at least the four corner fuel rods in a tubular flow channel of a nuclear reactor is disclosed. The spacer comprises a support member having four side bands interconnected by four corner bands to form a unitary structure. Each of the side bands has a L-shaped lobe adjacent to each of its ends with one leg of each lobe extending to the adjacent end of its side band. Each of the corner bands is narrower than the side bands and is offset so as to be spaced from the lobe. One leg of each lobe is positioned to engage the tubular flow channel to maintain proper spacing between the flow channel and the adjacent corner fuel rod and to improve the thermal-hydraulic performance of the spacer

  12. Nuclear reactor internals alignment configuration

    Science.gov (United States)

    Gilmore, Charles B.; Singleton, Norman R.

    2009-11-10

    An alignment system that employs jacking block assemblies and alignment posts around the periphery of the top plate of a nuclear reactor lower internals core shroud to align an upper core plate with the lower internals and the core shroud with the core barrel. The distal ends of the alignment posts are chamfered and are closely received within notches machined in the upper core plate at spaced locations around the outer circumference of the upper core plate. The jacking block assemblies are used to center the core shroud in the core barrel and the alignment posts assure the proper orientation of the upper core plate. The alignment posts may alternately be formed in the upper core plate and the notches may be formed in top plate.

  13. Emergency cooling system for nuclear reactors

    International Nuclear Information System (INIS)

    Upon loss of coolant in a nuclear reactor as when a coolant supply or return line breaks, or both lines break, borated liquid coolant from an emergency source is supplied in an amount to absorb heat being generated in the reactor even after the control rods have been inserted. The liquid coolant flows from pressurized storage vessels outside the reactor to an internal manifold from which it is distributed to unused control rod guide thimbles in the reactor fuel assemblies. (author)

  14. Noise thermometry in nuclear reactors

    International Nuclear Information System (INIS)

    Since in nuclear reactors the measuring sensor cannot be easily replaced, the value of the sensor resistance, as well as the selection of transmission lines with respect to good transmission characteristics of the whole arrangement and minimizing the correlative error terms, must already be optimized when designing a noise thermometer arrangement. The TRARAU computer program was developed for this purpose enabling the influences of the lines to be computed by taking into consideration all the effects occurring through the lines, such as transmission errors and correlative error terms. In order to check the accuracy of the TRARAU computer program a series of laboratory measurements were implemented enabling both the pure transmission behaviour of the line arrangement with respect to the measuring signal to be detected, as well as the overall line error. In all cases this resulted in a very good agreement of the measured values with the computed values. The transmission behaviour of noise thermometer arrangements occuring in practice were studied with the example of two reactor experiments. In both cases it was possible to demonstrate successfully the potential of the computer program TRARAU. As the parametric studies have shown, optimum matching over unlimited band widths is not feasible in principle. By reducing the upper band limit, however, the line error can practically always be kept sufficiently small. With good matching larger band widths can also be used. (orig./HP)

  15. Chernobyl, 16 years later

    International Nuclear Information System (INIS)

    This document on the Chernobyl site evolution is constituted around four main questions. What about the future of the Chernobyl site, the damaged reactor and the ''sarcophagus'' constructed around the reactor? What about the sanitary consequences of the accident on the liquidators asked to blot out the radiation and the around people exposed to radiation? What about the contaminated land around the power plant and their management? Concerning the France, what were the ''radioactive cloud'' sanitary consequences? (A.L.B.)

  16. An ill wind from Chernobyl

    International Nuclear Information System (INIS)

    This article discusses the effects that the poisonous dust emanating from the Chernobyl nuclear reactor explosion of 1986 had on human, animal and plant population in the Soviet Union and across Europe. One of the chief criticisms raised is of governments, inside and outside the Soviet Block restricting information about danger to people or, in some cases, denying any consequences. This has led to widespread public opinion against nuclear programmes for power generation, and calls for adequate and appropriate compensation for victims of the accident. (UK)

  17. Nuclear reactor safety research in Kazakhstan

    International Nuclear Information System (INIS)

    Full text : The paper summarizes activities being implemented by the National Nuclear Center of the Republic of Kazakhstan in support of safe operation of nuclear reactors; shows its crucial efforts and further road map in this line. As is known, the world community considers nuclear reactor safety as one of the urgent research areas. Kazakhstan has been pursuing studies in support of nuclear energy safety since early 80s. The findings allow to coordinate available computational methods and design new ones while validating new NPP Projects and making analysis for reactor installations available

  18. Observations on the geology and geohydrology of the Chernobyl' nuclear accident site, Ukraine

    Science.gov (United States)

    Matzko, J.R.; Percious, D.J.; Rachlin, J.; Marples, D.R.

    1994-01-01

    The most highly contaminated surface areas from cesium-137 fallout from the April 1986 accident at the Chernobyl' nuclear power station in Ukraine occur within the 30-km radius evacuation zone set up around the station, and an 80-km lobe extending to the west-southwest. Lower levels of contamination extend 300 km to the west of the power station. The geology, the presence of surface water, a shallow water table, and leaky aquifers at depth make this an unfavorable environment for the long-term containment and storage of the radioactive debris. An understanding of the general geology and hydrology of the area is important to assess the environmental impact of this unintended waste storage site, and to evaluate the potential for radionuclide migration through the soil and rock and into subsurface aquifers and nearby rivers. -from Authors

  19. Behavior of long lived radionuclides in surface environment around the Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    A large part of long lived radionuclides in surface soils sampled in the exclusion zone (30 km zone) around the Chernobyl Nuclear Power Plant are distributed at a depth of few centimeter, but some elements are penetrating into the deep ground. The penetration was different with the kinds of nucleus and soil. More than half of Sr-90 moved easily. Nuclide except Sr-90 are included in humin and insoluble fraction, especially Cs-137 is remarkable. Pu isotopes are included in amorphous iron oxide, fulvic acid and manganese oxide. Cs-137 are kept in hot particles, clay minerals and humin, Am-241 in fulvic acid and clay minerals. DOC is consisted of less than ten thousand of molecular weight. However, most part of transuranic elements have more than ten thousand of molecular weight and they are bonding with fulvic acid, fumic substance, and dissolved. (S.Y.)

  20. Cytogenetic features of leukaemias diagnosed in residents of areas contaminated after the Chernobyl nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Domracheva, E.V. E-mail: dom@blood.ru; Aseeva, E.A.; Obukhova, T.N.; Kobzev, Y.N.; Olshanskaya, Y.V.; D' achenko, L.V.; Udovichenko, A.I.; Zakharova, A.V.; Milyutina, G.I.; Nechai, V.V.; Vorobiov, A.I

    2000-05-15

    A comparison of chromosomal abnormalities in bone marrow leukaemic cells and of stable and unstable aberrations in lymphocytes of patients with hematological malignancies who live in areas with or without contamination by the Chernobyl nuclear accident has been made using FISH and G-banding. Healthy residents of these areas comprised the control group. No systematic cytogenetic differences of leukaemic cells between patients from contaminated and uncontaminated areas were observed. Lymphocyte aberrations, however, were generally higher in all subjects from contaminated areas. Comparison has been made with specific cytogenetic features of leukaemic cells and a high level of stable aberrations in lymphocytes of patients with secondary leukaemias that had developed after chemo- and/or radio-therapy.

  1. ''Hot'' particles as products of accident at the Chernobyl nuclear power plant and their oncogenic danger

    International Nuclear Information System (INIS)

    The basic groups of ''hot'' particles, products of accident at the Chernobyl Nuclear Power Plant which greatly have determined the radioactive contamination of the environment are considered for their properties. The inhalation way of penetration of these particles into the human lungs is noted to be radiation-dangerous. The relation of risks connected with possible yield of oncotransformed cells of the pulmonary tissue due to its irradiation with ionizing radiation from ''hot'' particles or activity - and composition equal set of radionuclides has been estimated. It is shown in the suggested qualitative model that estimation of maximum permissible content of radionuclide in lungs in the approximation of their diffusive distribution is the most conservative one

  2. Industrial Complex for Solid Radwaste Management at Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    In the framework of the preparation for the decommissioning of the Chernobyl Nuclear Power Plant (ChNPP) an Industrial Complex for Solid Radwaste Management (ICSRM) will be built under the EC TACIS Program in the vicinity of ChNPP. The paper will present the proposed concepts and their integration into existing buildings and installations. Further, the paper will consider the safety cases, as well as the integration of Western and Ukrainian Organizations into a cohesive project team and the requirement to guarantee the fulfillment of both Western standards and Ukrainian regulations and licensing requirements. The paper will provide information on the status of the interim design and the effects of value engineering on the output of basic design phase. The paper therefor summarizes the design results of the involved design engineers of the Design and Process Providers BNFL (LOT 1), RWE NUKEM GmbH (LOT 2 and General) and INITEC (LOT 3)

  3. Transgenerational genomic instability in children of irradiated parents as a result of the Chernobyl Nuclear Accident

    International Nuclear Information System (INIS)

    The study of families irradiated as a result of the accident at the Chernobyl Nuclear Power Plant revealed significantly increased aberrant genomes frequencies (AGFs) not only in irradiated parents (n = 106, p 137Cs) of peripheral blood samples from the children and their parents at doses of 0.1, 0.2 and 0.3 Gy. The spectrum and frequency of chromosome aberrations were studied in the 1st and 2nd cell generations. The average AGF was significantly increased at all doses (except 0.1 Gy) in children of irradiated parents, as compared to children born from non-irradiated parents. Amplification of cells with single-break chromosome aberrations in mitosis 2, as compared to mitosis 1, suggests the replication mechanism of realization of potential damage in DNA and the occurrence of genomic instability in succeeding cell generations.

  4. Daddy, What's a Nuclear Reactor?

    International Nuclear Information System (INIS)

    No matter what we think of the nuclear industry, it is part of mankind's heritage. The decommissioning process is slowly making facilities associated with this industry disappear and not enough is being done to preserve the information for future generations. This paper provides some food for thought and provides a possible way forward. Industrial archaeology is an ever expanding branch of archaeology that is dedicated to preserving, interpreting and documenting our industrial past and heritage. Normally it begins with analyzing an old building or ruins and trying to determine what was done, how it was done and what changes might have occurred during its operation. We have a unique opportunity to document all of these issues and provide them before the nuclear facility disappears. Entombment is an acceptable decommissioning strategy; however we would have to change our concept of entombment. It is proposed that a number of nuclear facilities be entombed or preserved for future generations to appreciate. This would include a number of different types of facilities such as different types of nuclear power and research reactors, a reprocessing plant, part of an enrichment plant and a fuel manufacturing plant. One of the main issues that would require resolution would be that of maintaining information of the location of the buried facility and the information about its operation and structure, and passing this information on to future generations. This can be done, but a system would have to be established prior to burial of the facility so that no information would be lost. In general, our current set of requirements and laws may need to be re-examined and modified to take into account these new situations. As an alternative, and to compliment the above proposal, it is recommended that a study and documentation of the nuclear industry be considered as part of twentieth century industrial archaeology. This study should not only include the power and fuel cycle

  5. Chernobyl bibliography

    International Nuclear Information System (INIS)

    The purpose of the DOE/OHER Chernobyl Database project is to create and maintain an information system to provide usable information for research studies related to the nuclear accident. The system is the official United States repository for information about the Chernobyl accident and its consequences, and currently includes an extensive bibliography and diverse radiological measurements with supporting information. PNL has established two resources: original (not summarized) measurement data, currently about 80,000 measurements, with ancillary information; and about 2,200 bibliographic citations, some including abstracts. Major organizations that have contributed radiological measurement data include the Washington State Department of Social and Health Services; United States Environmental Protection Agency (domestic and foreign data); United States Nuclear Regulatory Commission; Stone ampersand Webster; Brookhaven National Laboratory; Commissariat A L'energie Atomique in France; Ministry of Agriculture, Fisheries, and Food in the United Kingdom; Japan National Institute of Radiological Sciences; and the Finnish Centre For Radiation and Nuclear Safety (STUK). Scientists in Australia, Austria, Belgium, Canada, China, Denmark, England, Federal Republic of Germany, Finland, France, Ireland, Italy, Japan, the Netherlands, Romania, Scotland, Spain, Sweden, Switzerland, United States, Wales, and Yugoslavia have made contributions. Bibliographic materials have been obtained from scientists in the above countries that have replied to requests. In addition, literature searches have been conducted, including a search of the DOE Energy Database. The last search was conducted in January, 1989. This document lists the bibliographic information in the DOE/OHER Chernobyl Database at the current time

  6. Chernobyl bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Carr, F. Jr.; Mahaffey, J.A.

    1989-09-01

    The purpose of the DOE/OHER Chernobyl Database project is to create and maintain an information system to provide usable information for research studies related to the nuclear accident. The system is the official United States repository for information about the Chernobyl accident and its consequences, and currently includes an extensive bibliography and diverse radiological measurements with supporting information. PNL has established two resources: original (not summarized) measurement data, currently about 80,000 measurements, with ancillary information; and about 2,200 bibliographic citations, some including abstracts. Major organizations that have contributed radiological measurement data include the Washington State Department of Social and Health Services; United States Environmental Protection Agency (domestic and foreign data); United States Nuclear Regulatory Commission; Stone Webster; Brookhaven National Laboratory; Commissariat A L'energie Atomique in France; Ministry of Agriculture, Fisheries, and Food in the United Kingdom; Japan National Institute of Radiological Sciences; and the Finnish Centre For Radiation and Nuclear Safety (STUK). Scientists in Australia, Austria, Belgium, Canada, China, Denmark, England, Federal Republic of Germany, Finland, France, Ireland, Italy, Japan, the Netherlands, Romania, Scotland, Spain, Sweden, Switzerland, United States, Wales, and Yugoslavia have made contributions. Bibliographic materials have been obtained from scientists in the above countries that have replied to requests. In addition, literature searches have been conducted, including a search of the DOE Energy Database. The last search was conducted in January, 1989. This document lists the bibliographic information in the DOE/OHER Chernobyl Database at the current time.

  7. Nuclear reactor philosophy and criteria

    International Nuclear Information System (INIS)

    Nuclear power plant safety criteria and principles developed in Canada are directed towards minimizing the chance of failure of the fuel and preventing or reducing to an acceptably low level the escape of fission products should fuel failure occur. Safety criteria and practices are set forth in the Reactor Siting Guide, which is based upon the concept of defence in depth. The Guide specifies that design and construction shall follow the best applicable code, standard or practice; the total of all serious process system failures shall not exceed one in three years; special safety systems are to be physically and functionally separate from process systems and each other; and safety systems shall be testable, with unavailability less than 10-3. Doses to the most exposed member of the public due to normal operation, serious process failures, and dual failures are specified. Licensees are also required to consider the effects of extreme conditions due to airplane crashes, explosions, turbine disintegration, pipe burst, and natural disasters. Safety requirements are changing as nuclear power plant designs evolve and in response to social and economic pressures

  8. Soil contamination in Northern Austria as aftermath of the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The soil contamination caused by the accident at Chernobyl was very uneven distributed in Austria. In late autumn 1986 soil samples from northern Austria were analysed in order to get to know the actual contamination in terms of figures. The extreme values for Cs-137 found were 962 and 73630 Bq/m2 respectively. 3 refs., 2 figs. (Author)

  9. Classification of hot particles from the Chernobyl accident and nuclear weapons detonations by non-destructive methods

    International Nuclear Information System (INIS)

    Both after the Chernobyl accident and nuclear weapon detonations, agglomerates of radioactive material, so-called hot particles, were released or formed which show a behaviour in the environment quite different from the activity released in gaseous or aerosol form. The differences in their characteristic properties, in the radionuclide composition and the uranium and actinide contents are described in detail for these particles. While nuclear bomb hot particles (both from fission and fusion bombs) incorporate well detectable trace amounts of 60Co and 152Eu, these radionuclides are absent in Chernobyl hot particles. In contrast, Chernobyl hot particles contain 125Sb and 144Ce which are absent in atomic bomb HPs. Obvious differences are also observable between fusion and fission bombs' hot particles (significant differences in 152Eu/155Eu, 154Eu/155Eu and 238Pu/239Pu ratios) which facilitate the identification of HPs of unknown provensence. The ratio of 239Pu/240Pu in Chernobyl hot particles could be determined by a non-destructive method at 1:1.5. A non-destructive method to determine the content of non-radioactive elements by Kα-emission measurements was developed by which inactive Zr, Nb, Fe and Ni could be verified in the particles

  10. Generation III reactors - the nuclear renaissance

    International Nuclear Information System (INIS)

    The European Pressurized Reactor - GEN III+, the PWR type reactor, remains the world's first and currently being built power reactor everywhere. ATMEA1, a new 1,100 MWe pressurized water reactor combines state-of-the art- technology from AREVA and Mitsubishi Heavy Industries to meet the challenges of the nuclear renaissance. Thus, the next evolutionary design of Generation III reactors will be deployed over many decades and will represent a large part of the worldwide fleet throughout the 21st century. Generation III reactors will equip the future NPPs ensuring improved safety and reliability, with passive safety systems and a very low probability for core melt. The Generation III Reactors as 'The Nuclear Renaissance' is presented in the paper. (author)

  11. Proliferation Resistant Nuclear Reactor Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gray, L W; Moody, K J; Bradley, K S; Lorenzana, H E

    2011-02-18

    Global appetite for fission power is projected to grow dramatically this century, and for good reason. Despite considerable research to identify new sources of energy, fission remains the most plentiful and practical alternative to fossil fuels. The environmental challenges of fossil fuel have made the fission power option increasingly attractive, particularly as we are forced to rely on reserves in ecologically fragile or politically unstable corners of the globe. Caught between a globally eroding fossil fuel reserve as well as the uncertainty and considerable costs in the development of fusion power, most of the world will most likely come to rely on fission power for at least the remainder of the 21st century. Despite inevitable growth, fission power faces enduring challenges in sustainability and security. One of fission power's greatest hurdles to universal acceptance is the risk of potential misuse for nefarious purposes of fissionable byproducts in spent fuel, such as plutonium. With this issue in mind, we have discussed intrinsic concepts in this report that are motivated by the premise that the utility, desirability, and applicability of nuclear materials can be reduced. In a general sense, the intrinsic solutions aim to reduce or eliminate the quantity of existing weapons usable material; avoid production of new weapons-usable material through enrichment, breeding, extraction; or employ engineering solutions to make the fuel cycle less useful or more difficult for producing weapons-usable material. By their nature, these schemes require modifications to existing fuel cycles. As such, the concomitants of these modifications require engagement from the nuclear reactor and fuel-design community to fully assess their effects. Unfortunately, active pursuit of any scheme that could further complicate the spread of domestic nuclear power will probably be understandably unpopular. Nevertheless, the nonproliferation and counterterrorism issues are paramount

  12. Nuclear waste management, reactor decommisioning, nuclear liability and public attitudes

    International Nuclear Information System (INIS)

    This paper deals with several issues that are frequently raised by the public in any discussion of nuclear energy, and explores some aspects of public attitudes towards nuclear-related activities. The characteristics of the three types of waste associated with the nuclear fuel cycle, i.e. mine/mill tailings, reactor wastes and nuclear fuel wastes, are defined, and the methods currently being proposed for their safe handling and disposal are outlined. The activities associated with reactor decommissioning are also described, as well as the Canadian approach to nuclear liability. The costs associated with nuclear waste management, reactor decommissioning and nuclear liability are also discussed. Finally, the issue of public attitudes towards nuclear energy is addressed. It is concluded that a simple and comprehensive information program is needed to overcome many of the misconceptions that exist about nuclear energy and to provide the public with a more balanced information base on which to make decisions

  13. The Italian debate on nuclear energy in the post Chernobyl age

    International Nuclear Information System (INIS)

    Full text of publication follows: Italy entered with enthusiasm into the production of nuclear energy for civil use at the end of 50. By 1966 - with an overall output of 3.9 billions kWh - Italy had become the fourth world producer of electricity generated by nuclear reactions, the second one in Europe after Great Britain. Chernobyl's 1986 disaster, which so much shook public opinion all over Europe, had particularly important economic and political consequences in Italy. In a controversial referendum, held in November 1987, Italian citizens voted for the repeal of three laws which promoted the installation of nuclear power plants on the Italian soil and the participation of ENEL (National Institution for the Electrical Energy) to plant constructions abroad. The 1987 referendum was interpreted by the Italian government as an opposition to nuclear power generation - the following year, the four Italian plants (Garigliano, Latina, Trino Vercellese, Caorso) ceased their activity and plans to build new plants were abandoned. This decision marked the ruin of Italian research on nuclear energy, that in the 30 had known a glorious era thanks to Enrico Fermi works. As the 20. Anniversary of Chernobyl's accident is drawing near, the University of Milan and ICS-research group (Innovations in Communication of Science) at SISSA, Trieste, have decided to analyse jointly the reasons which brought Italy to give up its nuclear energy production. In the present scenario of controversies concerning the development of science and technology, in which European countries exchange experiences of best practice to involve the public in decision making processes, Italy reaction to Chernobyl accident can indeed be considered paradigmatic in that it anticipated crucial risks governance issues in today relationship between science and society. The research project draws on methodologies used in media studies and on socio linguistic analysis, as developed by risk perception and risk

  14. Nuclear reactor kinetics and plant control

    CERN Document Server

    Oka, Yoshiaki

    2013-01-01

    Understanding time-dependent behaviors of nuclear reactors and the methods of their control is essential to the operation and safety of nuclear power plants. This book provides graduate students, researchers, and engineers in nuclear engineering comprehensive information on both the fundamental theory of nuclear reactor kinetics and control and the state-of-the-art practice in actual plants, as well as the idea of how to bridge the two. The first part focuses on understanding fundamental nuclear kinetics. It introduces delayed neutrons, fission chain reactions, point kinetics theory, reactivit

  15. Nuclear reactor steam depressurization valve

    International Nuclear Information System (INIS)

    This patent describes improvement in a nuclear reactor plant, an improved steam depressurization valve positioned intermediate along a steam discharge pipe for controlling the venting of steam pressure from the reactor through the pipe. The improvement comprises: a housing including a domed cover forming a chamber and having a partition plate dividing the chamber into a fluid pressure activation compartment and a steam flow control compartment, the valve housing being provided with an inlet connection and an outlet connection in the steam flow control compartment, and a fluid duct in communication with a source of fluid pressure for operating the valve; a valve set mounted within the fluid flow control compartment comprising a cylindrical section surrounding the inlet connection with one end adjoining the connection and having a radially projecting flange at the other end with a contoured extended valve sealing flange provided with an annular valve sealing member, and a valve cylinder traversing the partition plate and reciprocally movable within an opening in the partition plate with one terminal and extending into the fluid pressure activation compartment and the other terminal end extending into the steam flow control compartment coaxially aligned with the valve seat surrounding the inlet connection, the valve cylinder being surrounded by two bellow fluid seals and provided with guides to inhibit lateral movement, an end of the valve cylinder extending into the fluid flow control compartment having a radially projecting flange substantially conterminous with the valve seat flange and having a contoured surface facing and complimentary to the contoured valve seating surface whereby the two contoured valve surfaces can meet in matching relationship, thus providing a pressure actuated reciprocatable valve member for making closing contact with the valve seat and withdrawing therefrom for opening fluid flow through the valve

  16. Radiation exposure and breast cancer: lessons from Chernobyl.

    Science.gov (United States)

    Ogrodnik, Aleksandra; Hudon, Tyler W; Nadkarni, Prakash M; Chandawarkar, Rajiv Y

    2013-04-01

    The lessons learned from the Chernobyl disaster have become increasingly important after the second anniversary of the Fukushima, Japan nuclear accident. Historically, data from the Chernobyl reactor accident 27 years ago demonstrated a strong correlation with thyroid cancer, but data on the radiation effects of Chernobyl on breast cancer incidence have remained inconclusive. We reviewed the published literature on the effects of the Chernobyl disaster on breast cancer incidence, using Medline and Scopus from the time of the accident to December of 2010. Our findings indicate limited data and statistical flaws. Other confounding factors, such as discrepancies in data collection, make interpretation of the results from the published literature difficult. Re-analyzing the data reveals that the incidence of breast cancer in Chernobyl-disaster-exposed women could be higher than previously thought. We have learned little of the consequences of radiation exposure at Chernobyl except for its effects on thyroid cancer incidence. Marking the 27th year after the Chernobyl event, this report sheds light on a specific, crucial and understudied aspect of the results of radiation from a gruesome nuclear power plant disaster. PMID:23691737

  17. Proliferation resistance features in nuclear reactor designs

    International Nuclear Information System (INIS)

    Full text: The presentation gives an overview of the fundamental principles of non-proliferation of nuclear materials and technologies in the process of designing the nuclear reactors. The nuclear power engineering includes the activities involving the risk of proliferation of nuclear weapons (such as separation of uranium isotopes (enrichment), long-term storage of irradiated fuel, reprocessing of irradiated fuel by means of separation of plutonium and/or uranium wherefrom, storage of separated fissile materials). Proliferation resistance can be defined as the characteristic of a given nuclear power system which would prevent change-over or unauthorized production and use of the nuclear materials or technologies intended to possession of nuclear weapons or other nuclear explosives. The basic principles of non-proliferation as formulated in the frame of IAEA-sponsored international project INPRO have been analyzed for their relevance in designing the innovative nuclear power systems based on lead-cooled fast reactors. (author)

  18. Proliferation resistance features in nuclear reactor designs

    International Nuclear Information System (INIS)

    The paper presents a review of the main principles for technologies and materials protection from unauthorized proliferation and application to be considered in nuclear reactors designing. Nuclear power features certain operations sensitive to nuclear weapons proliferation (such as separation of uranium isotopes (enrichment), long storage of spent fuel, processing of spent fuel, plutonium and/or uranium recovery from spent fuel, storage of recovered fissile materials). Proliferation resistance is defined as a nuclear energy system characteristic that impedes the diversion or undeclared production of nuclear material, or misuse of technology with the purpose of acquiring nuclear weapons or other nuclear explosive devices. The basic principles of non-proliferation established in the INPRO international project sponsored by IAEA have been discussed as implemented for designing of the innovative nuclear energy systems based on fast lead-cooled nuclear reactors

  19. Accident on the Chernobyl nuclear power plant. Getting over the consequences and lessons learned

    International Nuclear Information System (INIS)

    The book is devoted to the 20 anniversary of the accident on the 4th Power Unit of the Chernobyl NPP. The power plant construction history, accident reasons, its consequences, the measures on its liquidation are represented. The current state of activity on the Chernobyl power unit decommission, the 'Shelter' object conversion into the ecologically safe system is described. The future of the Chernobyl NPP site and disposal zone is discussed

  20. ENVIRONMENTAL PROBLEMS ASSOCIATED WITH DECOMMISSIONING THE CHERNOBYL NUCLEAR POWER PLANT COOLING POND

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.

    2009-09-30

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. In addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.

  1. Environmental Problems Associated With Decommissioning The Chernobyl Nuclear Power Plant Cooling Pond

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E. B.; Jannik, G. T.; Marra, J. C.; Oskolkov, B. Ya.; Bondarkov, M. D.; Gaschak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.

    2009-11-09

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. In addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.

  2. Environmental Problems Associated With Decommissioning The Chernobyl Nuclear Power Plant Cooling Pond

    International Nuclear Information System (INIS)

    Decommissioning of nuclear power plants and other nuclear fuel cycle facilities has been an imperative issue lately. There exist significant experience and generally accepted recommendations on remediation of lands with residual radioactive contamination; however, there are hardly any such recommendations on remediation of cooling ponds that, in most cases, are fairly large water reservoirs. The literature only describes remediation of minor reservoirs containing radioactive silt (a complete closure followed by preservation) or small water reservoirs resulting in reestablishing natural water flows. Problems associated with remediation of river reservoirs resulting in flooding of vast agricultural areas also have been described. In addition, the severity of environmental and economic problems related to the remedial activities is shown to exceed any potential benefits of these activities. One of the large, highly contaminated water reservoirs that require either remediation or closure is Karachay Lake near the MAYAK Production Association in the Chelyabinsk Region of Russia where liquid radioactive waste had been deep well injected for a long period of time. Backfilling of Karachay Lake is currently in progress. It should be noted that secondary environmental problems associated with its closure are considered to be of less importance since sustaining Karachay Lake would have presented a much higher radiological risk. Another well-known highly contaminated water reservoir is the Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond, decommissioning of which is planned for the near future. This study summarizes the environmental problems associated with the ChNPP Cooling Pond decommissioning.

  3. Perinatal mortality after Chernobyl. - Excess perinatal deaths, stillborns and malformations in Germany, Europe and highly exposed regions of Germany and Europe after the Chernobyl reactor accident of April 1986

    International Nuclear Information System (INIS)

    In 1987, the year following the Chernobyl accident, perinatal mortality was significantly increased in Germany as well as in Poland. The numbers of excess perinatal deaths were 317 and 320, respectively. Monthly data from Germany, Poland and the region of Zhitomir, Ukraine, exhibit a significant association between perinatal mortality and the delayed caesium concentration in pregnant women with a time-lag of seven months. In addition to an increase in 1987, perinatal mortality in the most contaminated areas of Ukraine and Belarus show a second rise beginning in 1989 which can be related to the action of strontium. The cumulative effect from strontium outweighs the effect of caesium in 1987 by more than a factor of 10. Monthly data of malformation rates in newborn were only available for the State of Bavaria, Germany. No increase is observed in 1987 in the Bavarian average. But at the end of 1987, seven month after the highest caesium concentration in pregnant women in April and May 1987, a highly significant dependency of malformation rates on caesium soil contamination is found. There is a growing awareness of many lasting detrimental health consequences of the Chernobyl nuclear reactor eruption in large parts of central, eastern and northern Europe. A flexible synoptic spatial-temporal method based on logistic regression is suggested for the analysis of official national as well as district by district reproductive failure data. The main idea is to model a spatial-temporal annual or monthly data set by adjusting for country or region specific trend functions and either to test for local or global temporal jumps or broken sticks (change-points) associated with the years 1986 or 1987 or, alternatively, to test for a spatial effect of regionally stratified exposure or dosimetry data on reproductive outcome. In numerous official data sets of central, eastern, and northern European countries or regions absolute or relative increases of stillbirth proportions after

  4. Calculation models for a nuclear reactor

    International Nuclear Information System (INIS)

    Determination of different parameters of nuclear reactors requires neutron transport calculations. Due to complicity of geometry and material composition of the reactor core, neutron calculations were performed for simplified models of the real arrangement. In frame of the present work two models were used for calculations. First, an elementary cell model was used to prepare cross section data set for a homogenized-core reactor model. The homogenized-core reactor model was then used to perform neutron transport calculation. The nuclear reactor is a tank-shaped thermal reactor. The semi-cylindrical core arrangement consists of aluminum made fuel bundles immersed in water which acts as a moderator as well as a coolant. Each fuel bundle consists of aluminum cladded fuel rods arranged in square lattices. (author)

  5. Management of Spent Nuclear Fuel from Nuclear Power Plant Reactor

    International Nuclear Information System (INIS)

    Management of spent nuclear fuel from Nuclear Power Plant (NPP) reactor had been studied to anticipate program of NPP operation in Indonesia. In this paper the quantity of generated spent nuclear fuel (SNF) is predicted based on the national electrical demand, power grade and type of reactor. Data was estimated using Pressurized Water Reactor (PWR) NPP type 1.000 MWe and the SNF management overview base on the experiences of some countries that have NPP. There are four strategy nuclear fuel cycle which can be developed i.e: direct disposal, reprocessing, DUPlC (Direct Use of Spent PWR Fuel In Candu) and wait and see. There are four alternative for SNF management i.e : storage at the reactor building (AR), away from reactor (AFR) using wet centralized storage, dry centralized storage AFR and prepare for reprocessing facility. For the Indonesian case, centralized facility of the wet type is recommended for PWR or BWR spent fuel. (author)

  6. The radioactive contamination of milk and milk products due to the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The situation in the area around the town of Kiel in a given period of time is taken as the example to explain the radioactive contamination of milk and milk products due to the Chernobyl fallout. The measured data reported refer to the nuclides I-131 and Cs-137 in milk, and are compared with data on the I-131 and Cs-137 activity measured in raw milk collected in southern Bavaria, and in other Lands of the F.R.G. (DG)

  7. Nuclear data needs for fusion reactors

    International Nuclear Information System (INIS)

    The nuclear design of fusion reactor components (e.g., first wall, blanket, shield, magnet, limiter, divertor, etc.) requires an accurate prediction of the radiation field, the radiation damage parameters, and the activation analysis. The fusion nucleonics for these tasks are reviewed with special attention to point out nuclear data needs and deficiencies which effect the design process. The main areas included in this review are tritium breeding analyses, nuclear heating calculations, radiation damage in reactor components, shield designs, and results of uncertainty analyses as applied to fusion reactor studies. Design choices and reactor parameters that impact the neutronics performance of the blanket are discussed with emphasis on the tritium breeding ratio. Nuclear data required for kerma factors, shielding analysis, and radiation damage are discussed. Improvements in the evaluated data libraries are described to overcome the existing problems

  8. Autonomous Control of Space Nuclear Reactors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Nuclear reactors to support future lunar and Mars robotic and manned missions impose new and innovative technological requirements for their control and protection...

  9. A swivelling transfer device for nuclear reactors

    International Nuclear Information System (INIS)

    The invention relates to a swivelling transfer device for fuel-assemblies. According to the invention, the device comprises, within a protective enclosure, a swivelling system comprising two sets of rails rotatable about an axis and so arranged that the lower and thereof penetrates into the extensions of the extremities of ramps dipped into the reactor and into a storage enclosure. This can apply to the transfer of nuclear reactor fuel assemblies, in particular for reactors of the molten sodium fast neutron type

  10. Nuclear data requirements for fusion reactor shielding

    International Nuclear Information System (INIS)

    The nuclear data requirements for experimental, demonstration and commercial fusion reactors are reviewed. Particular emphasis is given to the shield as well as major reactor components of concern to the nuclear performance. The nuclear data requirements are defined as a result of analyzing four key areas. These are the most likely candidate materials, energy range, types of needed nuclear data, and the required accuracy in the data. Deducing the latter from the target goals for the accuracy in prediction is also discussed. A specific proposal of measurements is recommended. Priorities for acquisition of data are also assigned. (author)

  11. Migration behavior of released radionuclides in the river system in the exclusion zone of the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    This work has been carried out for assessment of secondary migration of the Chernobyl-derived radionuclides through a river system in terms of their amount and forms of the mobile component. It would contribute: a) to clarify controlling factors which cause remobilization/immobilization of the released radionuclides for the river system in the vicinity of the Chernobyl Nuclear Power Plant; and also, b) to find effective countermeasures to prevent secondary contamination in a river system after a nuclear accident. With the objectives described above, migration behavior of the radionuclides in the river system in the exclusion zone was investigated for suspended solid, bottom sediment and river water. In this paper: i) the result of radiochemical analyses for dissolved radionuclides; and, ii) physical form of 137Cs in river waters are described and discussed

  12. Nuclear data requirements for fusion reactor nucleonics

    International Nuclear Information System (INIS)

    Nuclear data requirements for fusion reactor nucleonics are reviewed and the present status of data are assessed. The discussion is divided into broad categories dealing with data for Fusion Materials Irradiation Test Facility (FMIT), D-T Fusion Reactors, Alternate Fuel Cycles and the Evaluated Data Files that are available or would be available in the near future

  13. Nuclear reactor vessels with sealable rotatable covers

    International Nuclear Information System (INIS)

    Liquid metal cooled nuclear reactor installations have a rotating cover with an annular blade or skirt which clips into an annular trough of mercury and forms a gas seal. The design is such that abnormal pressure occurring in the reactor vessel is balanced by an increase in level of the mercury. Also applicable to irradiated fuel storage. (U.K.)

  14. Reactor Physics and the Nuclear Fuel Cycle

    Directory of Open Access Journals (Sweden)

    Md Minhaj Ahmed

    2013-11-01

    Full Text Available Questions regarding the feasibility of fusion power are examined, taking into account fuel cycles and breeding reactions, energy balance and reactor conditions, approaches to fusion, magnetic confinement, magneto hydro dynamic instabilities, micro instabilities, and the main technological problems which have to be solved. Basic processes and balances in fusion reactors are considered along with some aspects of the neutronics in fusion reactors, the physics of neutral beam heating, plasma heating by relativistic electrons, radiofrequency heating of fusion plasmas, adiabatic compression and ignition of fusion reactors, dynamics and control of fusion reactors, and aspects of thermal efficiency and waste heat. Attention is also given to fission-fusion hybrid systems, inertial-confinement fusion systems, the radiological aspects of fusion reactors, design considerations of fusion reactors, and a comparative study of the approaches to fusion power. The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. It consists of steps in the front end, which are the preparation of the fuel, steps in the service period in which the fuel is used during reactor operation, and steps in the back end, which are necessary to safely manage, contain, and either reprocess or dispose of spent nuclear fuel. If spent fuel is not reprocessed, the fuel cycle is referred to as an open fuel cycle (or a once-through fuel cycle; if the spent fuel is reprocessed, it is referred to as a closed fuel cycle..

  15. Problems of nuclear reactor safety. Vol. 2

    International Nuclear Information System (INIS)

    Theses of proceedings of the 9 Topical Meeting on problems of nuclear power plant safety are presented. Reports include results of neutron-physical experiments carried out for reactor safety justification. Concepts of advanced reactors with improved safety are considered. Results of researches on fuel cycles are given too

  16. Nuclear reactor fuel elements charging tool

    International Nuclear Information System (INIS)

    To assist the loading of nuclear reactor fuel elements in a reactor core, positioning blocks with a pyramidal upper face charged to guide the fuel element leg are placed on the lower core plate. A carrier equipped with means of controlled displacement permits movement of the blocks over the lower core plate

  17. The Chernobyl accident and the Spanish nuclear power plants. Technical report

    International Nuclear Information System (INIS)

    On the morning of April 26, 1986, Unit 4 of the Chernobyl Nuclear Power Plant (Ukraine, USSR) suffered an accident of the greatest magnitude among those which have taken place in nuclear energy installations employed for peaceful uses. The accident reached a degree of severity unknown up to now in nuclear energy generating plants, both with respect to the loss of human lives and the effects caused to the neighboring population (as well as to other nations within a wide radius of radioactivity dispersal), and also with respect to the damage caused in the nuclear plant itself. In the light of the anxiety created internationally, the USSR State Committee for the Utilization of Atomic Energy prepared a report (1), based on the conclusions of the Governmental Commission entrusted to study the causes of the accident, which was presented at the international meeting of experts held at the International Atomic Energy Agency (IAEA) headquarters in Vienna from August 25 to 29, 1986. The present technical report has been prepared by the Spanish nuclear power plants within the framework of UNIDAD ELECTRICA, S.A. (UNESA) - the Association of Spanish electric utilities - in collaboration with EMPRESARIOS AGRUPADOS, S.A. The report reflects the utilities' analyses of the causes and consequences of the accident and, based on similarities and differences with Spanish plants under construction and in operation, intends to: a. Evaluate the possibility of an accident with similar consequences occurring in a Spanish plant b. Identify possible design and operation modifications indicated by the lessons learned from this accident

  18. Forensic Reconstructions of Radioactive Particulate Releases at the Chernobyl and the Al Tuwaitha Nuclear Facilities

    International Nuclear Information System (INIS)

    Evaluating dispersion of nuclear materials released by accidental, operational, or clandestine means is important to the international community. Our research team has performed forensic reconstructions of radionuclide releases at the Chernobyl Nuclear Power Plant (ChNPP) in Ukraine and the Al Tuwaitha Nuclear Facility (ATNF) near Baghdad, Iraq. Our objectives at ChNPP were to determine the influences of extant atmospheric conditions on particle size distributions and their depositions in the near-field (less than 12 km) regions surrounding the complex. We derived mathematical models of particulate fluid-flow in varying velocity and turbulence fields to fit with 3000 geographically-referenced measurements. Conformity of predicted and empirical fallout patterns was excellent, enabling accurate reconstructions of the particle size contributions, weather conditions, and release energies from the accident. The objectives at ATNF were to evaluate means of dispersion and characterization of nuclear materials within and outside of the compound. Normal facility operations, military actions, and looting of the facility could have contributed to the release of radioactivity, but would yield quite different geographic and radionuclide profiles. Detailed gamma, alpha, and beta radiation profiles were examined for 400 geographically-referenced soil samples collected from ATNF and the villages of Ishtar and Al Ryhad. Natural uranium clusters were identified in several locations clearly showing that looting of yellowcake was the primary means of dispersion. No dispersion of nuclear materials was shown to result from military operations at the site. Our programs demonstrate the precision of geographic-based forensic reconstructions and show that forecast models are robust.(author)

  19. Large Scale Weather Control Using Nuclear Reactors

    CERN Document Server

    Singh-Modgil, M

    2002-01-01

    It is pointed out that controlled release of thermal energy from fission type nuclear reactors can be used to alter weather patterns over significantly large geographical regions. (1) Nuclear heat creates a low pressure region, which can be used to draw moist air from oceans, onto deserts. (2) Creation of low pressure zones over oceans using Nuclear heat can lead to Controlled Cyclone Creation (CCC).(3) Nuclear heat can also be used to melt glaciers and control water flow in rivers.

  20. Optical techniques for nuclear reactor inspection

    International Nuclear Information System (INIS)

    Optical inspection techniques available and relevant to the various stages of the life cycle of a nuclear reactor are briefly reviewed. Experience in the three main types of nuclear reactor of interest to the CEGB, Magnox, AGR and PWR, is discussed. Conventional optical systems and stereoscopic viewing systems are described together with specialized and novel techniques, mainly Marchwood Engineering Laboratory's developments, which have proved valuable in tackling a variety of inspection problems. (U.K.)

  1. Psychological consequences of exposure to ionizing radiation. Lessons of Chernobyl

    International Nuclear Information System (INIS)

    From the results of a survey among the population in areas of the former Soviet Union (Gomel region) which were affected by the nuclear reactor accident of Chernobyl it appears that fear for radiation can have a negative impact on the public health. The results of the survey can help governments to deal with the psychological effects of disasters. 3 refs

  2. RA Research nuclear reactor - Annual report 1987

    International Nuclear Information System (INIS)

    Annual report concerning the project 'RA research nuclear reactor' for 1987, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities

  3. Nuclear reactor vessel fuel thermal insulating barrier

    Science.gov (United States)

    Keegan, C. Patrick; Scobel, James H.; Wright, Richard F.

    2013-03-19

    The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel that has a hemispherical lower section that increases in volume from the center line of the reactor to the outer extent of the diameter of the thermal insulating barrier and smoothly transitions up the side walls of the vessel. The space between the thermal insulating harrier and the reactor vessel forms a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive inlet valve for the cooling water includes a buoyant door that is normally maintained sealed under its own weight and floats open when the cavity is Hooded. Passively opening steam vents are also provided.

  4. Materials for generation-IV nuclear reactors

    International Nuclear Information System (INIS)

    Materials science and materials development are key issues for the implementation of innovative reactor systems such as those defined in the framework of the Generation IV. Six systems have been selected for Generation IV consideration: gas-cooled fast reactor, lead-cooled fast reactor, molten salt-cooled reactor, sodium-cooled fast reactor, supercritical water-cooled reactor, and very high temperature reactor. The structural materials need to resist much higher temperatures, higher neutron doses and extremely corrosive environment, which are beyond the experience of the current nuclear power plants. For this reason, the first consideration in the development of Generation-IV concepts is selection and deployment of materials that operate successfully in the aggressive operating environments expected in the Gen-IV concepts. This paper summarizes the Gen-IV operating environments and describes the various candidate materials under consideration for use in different structural applications. (author)

  5. Fixed bed suspended core nuclear reactor concept

    International Nuclear Information System (INIS)

    The fixed bed nuclear reactor (FBNR) is essentially a pressurized light water reactor having spherical fuel elements constituting a suspended reactor core at its lowest bed porosity. The principle features of the proposed reactor are that the concept is polyvalent, simple in design, may operate either as fixed or fluidized bed, have the core suspended contributing to inherent safety, passive cooling features of the reactor. The reactor is modular and has an integrated primary system utilizing either water, supercritical steam or helium gas as its coolant. Some of the advantages of the proposed reactor are being modular, low environmental impact, exclusion of severe accidents, short construction period, flexible adaptation to demand, excellent load following characteristics, and competitive economics. (orig.)

  6. Research nuclear reactor RA - Annual Report 1989

    International Nuclear Information System (INIS)

    Annual report concerning the project 'RA research nuclear reactor' for 1989, financed by the Serbian ministry of science is divided into two parts. First part is concerned with RA reactor operation and maintenance, which is the task of the Division for reactor engineering of the Institute for multidisciplinary studies and RA reactor engineering. Second part deals with radiation protection activities at the RA reactor which is the responsibility of the Institute for radiation protection. Scientific council of the Institute for multidisciplinary studies and RA reactor engineering has stated that this report describes adequately the activity and tasks fulfilled at the RA reactor in 1989. The scope and the quality of the work done were considered successful both concerning the maintenance and reconstruction, as well as radiation protection activities

  7. Scientometric analysis of the means of scientific communication of the problem of medical consequences of Chernobyl Nuclear accident

    International Nuclear Information System (INIS)

    In this paper evaluation of the structure and trends in the development of the Ukrainian scientific communication tools on the medical consequences of the Chernobyl nuclear accident using bibliometric methods has been given. The main developers of methodical documents are allocated, the dynamics of the distribution of methodical references, information letters and innovations is estimated. The importance of scientific communications tools in dissemination and use of new medical knowledge is demonstrated

  8. Nuclear data needs for fast reactors

    International Nuclear Information System (INIS)

    The nuclear data, i.e., the numerical information about every nuclide - especially those representing the probabilities of various nuclear interactions and of radioactivity - of interest in a nuclear fission reactor are among the most essential inputs to be known a priori, to the best possible accuracy, for the design of nuclear reactor. The nuclides of interest cover not just (1) the fuel nuclides, the containers, the coolant, the moderator (if any), etc., that are initially inserted, but also (2) the actinides, the fission products, etc. that would be produced from the moment the reactor goes into operation and (3) the decay products that are produced even while the reactor is shutdown. The nuclide-list is known to cover a few hundreds. The neutron-nuclear interaction cross-section data, required for a few tens of reactions, very sensitively depend on the nuclide species and the neutron energy. Hence the data requirement significantly varies between thermal and fast reactors. The present talk is intended to touch upon the kinds and forms of nuclear data needed in the design and analysis of fast reactors. The recent variants available in the databases and some inter-comparison results will also be presented. (author)

  9. Fast-acting nuclear reactor control device

    International Nuclear Information System (INIS)

    A fast-acting nuclear reactor control device is described for controlling a safety control rod within the core of a nuclear reactor, the reactor controlled by a reactor control system, the device comprising: a safety control rod drive shaft and an electromagnetic clutch co-axial with the drive shaft operatively connected to the safety control rod for driving and positioning the safety control rod within or without the reactor core during reactor operation, the safety rod being oriented in a substantially vertical position to allow the rod to fall into the reactor core under the influence of gravity during shutdown of the reactor; the safety control rod drive shaft further operatively connected to a hydraulic pump such that operation of the drive shaft simultaneously drives and positions the safety control rod and operates the hydraulic pump such that a hydraulic fluid is forced into an accumulator, filling the accumulator with oil for the storage and supply of primary potential energy for safety control rod insertion such that the release of potential energy in the accumulator causes hydraulic fluid to flow through the hydraulic pump, converting the hydraulic pump to a hydraulic motor having speed and power capable of full length insertion and high speed driving of the safety control rod into the reactor core; a solenoid valve interposed between the hydraulic pump and the accumulator, said solenoid valve being a normally open valve, actuated to close when the safety control rod is out of the reactor during reactor operation; and further wherein said solenoid opens in response to a signal from the reactor control system calling for shutdown of the reactor and rapid insertion of the safety control rod into the reactor core, such that the opening of the solenoid releases the potential energy in the accumulator to place the safety control rod in a safe shutdown position

  10. Thermal-hydraulic analysis of nuclear reactors

    CERN Document Server

    Zohuri, Bahman

    2015-01-01

    This text covers the fundamentals of thermodynamics required to understand electrical power generation systems and the application of these principles to nuclear reactor power plant systems. It is not a traditional general thermodynamics text, per se, but a practical thermodynamics volume intended to explain the fundamentals and apply them to the challenges facing actual nuclear power plants systems, where thermal hydraulics comes to play.  Written in a lucid, straight-forward style while retaining scientific rigor, the content is accessible to upper division undergraduate students and aimed at practicing engineers in nuclear power facilities and engineering scientists and technicians in industry, academic research groups, and national laboratories. The book is also a valuable resource for students and faculty in various engineering programs concerned with nuclear reactors. This book also: Provides extensive coverage of thermal hydraulics with thermodynamics in nuclear reactors, beginning with fundamental ...

  11. Computerized reactor monitor and control for nuclear reactors

    International Nuclear Information System (INIS)

    The analysis of a computerized process control system developed by Transelektro-KFKI-Videoton (Hangary) for a twenty-year-old research reactor in Budapest and or a new one in Tajura (Libya) is given. The paper describes the computer hardware (R-10) and the implemented software (PROCESS-24K) as well as their applications at nuclear reactors. The computer program provides for man-machine communication, data acquisition and processing, trend and alarm analysis, the control of the reactor power, reactor physical calculations and additional operational functions. The reliability and the possible further development of the computerized systems which are suitable for application at reactors of different design are also discussed. (Sz.J.)

  12. Distance to realization of nuclear fusion reactors

    International Nuclear Information System (INIS)

    Recently the research and development of nuclear fusion have progressed conspicuously, and reached the point of attaining the critical condition. In this paper, it is attempted to forecast how long does it take to realize a final nuclear fusion power reactor (a demonstration reactor). The research and development of nuclear fusion have two important meanings. One is it is a promising means for ensuring an energy source for the future in Japan. Another is it has been brought up to the present status as the large scale project research maintaining the creativity and originality without requiring the introduction of technology from foreign countries. Hereafter, it is necessary to bring it up large as the Japanese basic technology. The research and development of nuclear fusion has advanced steadily, producing many physical knowledges and technical development. The principle and present status of nuclear fusion are explained. Now, an experimental fusion reactor is investigated as the next step. A large helical system project was started as 7-year project from 1990. The start of the operation of a prototype nuclear fusion power reactor is assumed in 2026, and that of a demonstration reactor is assumed in 2040. The investment for nuclear fusion and the extending effect are discussed. (K.I.)

  13. Nuclear data usage for research reactors

    International Nuclear Information System (INIS)

    In the department of research reactor, many neutronics calculations have been performed to construct, to operate and to modify research reactors of JAERI with several kinds of nuclear data libraries. This paper presents latest two neutronic analyses on research reactors. First one is design work of a low enriched uranium (LEU) fuel for JRR-4 (Japan Research Reactor No.4). The other is design of a uranium silicon dispersion type (silicide) fuel of JRR-3M (Japan Research Reactor No.3 Modified). Before starting the design work, to estimate the accuracy of computer code and calculation method, experimental data are calculated with several nuclear data libraries. From both cases of calculations, it is confirmed that JENDL-3.2 gives about 1 %Δk/k higher excess reactivity than JENDL-3.1. (author)

  14. The risks of nuclear energy technology. Safety concepts of light water reactors

    International Nuclear Information System (INIS)

    Analyses the risks of nuclear power stations. Discusses the security concept of reactors. Analyzes possible crash of air planes on a reactor containment. Presents measures against the spread of radioactivity after a severe accident. Written in engaging style for professionals and policy makers. The book analyses the risks of nuclear power stations. The security concept of reactors is explained. Measures against the spread of radioactivity after a severe accident, accidents of core melting and a possible crash of an air plane on a reactor containment are discussed. The book covers three scientific subjects of the safety concepts of Light Water Reactors: - A first part describes the basic safety design concepts of operating German Pressurized Water Reactors and Boiling Water Reactors including accident management measures introduced after the reactor accidents of Three Mile Island and Chernobyl. These safety concepts are also compared with the experiences of the Fukushima accidents. In addition, the safety design concepts of the future modern European Pressurized Water Reactor (EPR) and of the future modern Boiling Water Reactor SWR-1000 (KERENA) are presented. These are based on new safety research results of the past decades. - In a second, part the possible crash of military or heavy commercial air planes on a reactor containment is analyzed. It is shown that reactor containments can be designed to resist to such an airplane crash. - In a third part, an online decision system is presented. It allows to analyze the distribution of radioactivity in the atmosphere and to the environment after a severe reactor accident. It provides data for decisions to be taken by authorities for the minimization of radiobiological effects to the population. This book appeals to readers who have an interest in save living conditions and some understanding for physics or engineering.

  15. The risks of nuclear energy technology. Safety concepts of light water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Raskob, Wolfgang; Landman, Claudia; Paesler-Sauer, Juergen [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Kern- und Energietechnk (IKET); Kessler, Guenter; Veser, Anke; Schlueter, Franz-Hermann

    2014-11-01

    Analyses the risks of nuclear power stations. Discusses the security concept of reactors. Analyzes possible crash of air planes on a reactor containment. Presents measures against the spread of radioactivity after a severe accident. Written in engaging style for professionals and policy makers. The book analyses the risks of nuclear power stations. The security concept of reactors is explained. Measures against the spread of radioactivity after a severe accident, accidents of core melting and a possible crash of an air plane on a reactor containment are discussed. The book covers three scientific subjects of the safety concepts of Light Water Reactors: - A first part describes the basic safety design concepts of operating German Pressurized Water Reactors and Boiling Water Reactors including accident management measures introduced after the reactor accidents of Three Mile Island and Chernobyl. These safety concepts are also compared with the experiences of the Fukushima accidents. In addition, the safety design concepts of the future modern European Pressurized Water Reactor (EPR) and of the future modern Boiling Water Reactor SWR-1000 (KERENA) are presented. These are based on new safety research results of the past decades. - In a second, part the possible crash of military or heavy commercial air planes on a reactor containment is analyzed. It is shown that reactor containments can be designed to resist to such an airplane crash. - In a third part, an online decision system is presented. It allows to analyze the distribution of radioactivity in the atmosphere and to the environment after a severe reactor accident. It provides data for decisions to be taken by authorities for the minimization of radiobiological effects to the population. This book appeals to readers who have an interest in save living conditions and some understanding for physics or engineering.

  16. Small reactors and the 'second nuclear era'

    International Nuclear Information System (INIS)

    Predictions of the nuclear industry's demise are premature and distort both history and politics. The industry is reemerging in a form commensurate with the priorities of those people and nations controlling the global forces of production. The current lull in plant orders is due primarily to the world recession and to factors related specifically to reactor size. Traditional economies of scale for nuclear plants have been greatly exaggerated. Reactor vendors and governments in Great Britain, France, West Germany, Japan, the United States, Sweden, Canada, and the Soviet Union are developing small reactors for both domestic applications and export to the Third World. The prefabricated, factory-assembled plants under 500 MWe may alleviate many of the existing socioeconomic constraints on nuclear manufacturing, construction, and operation. In the industrialized world, small reactors could furnish a qualitatively new energy option for utilities. But developing nations hold the largest potential market for small reactors due to the modest size of their electrical systems. These units could double or triple the market potential for nuclear power in this century. Small reactors will both qualitatively and quantitatively change the nature of nuclear technology transfers, offering unique advantages and problems vis-a-vis conventional arrangements. (author)

  17. Nuclear Power from Fission Reactors. An Introduction.

    Science.gov (United States)

    Department of Energy, Washington, DC. Technical Information Center.

    The purpose of this booklet is to provide a basic understanding of nuclear fission energy and different fission reaction concepts. Topics discussed are: energy use and production, current uses of fuels, oil and gas consumption, alternative energy sources, fossil fuel plants, nuclear plants, boiling water and pressurized water reactors, the light…

  18. U.S. Nuclear Power Reactor Plant Status

    Data.gov (United States)

    Nuclear Regulatory Commission — Demographic data on U.S. commercial nuclear power reactors, including: plant name/unit number, docket number, location, licensee, reactor/containment type, nuclear...

  19. Safety review, assessment and inspection on research reactors, experimental reactors, nuclear heating reactors and critical facilities

    International Nuclear Information System (INIS)

    In 1998, the NNSA organized to complete the nuclear safety review on the test loop in-reactor operation of the High-flux Engineering Experimental Reactor (HFEER) and the re-operation of the China Pulsed Reactor and the Uranium-water Criticality Facility. The NNSA conducted the nuclear safety review on the CP application of the China Experimental Fast Reactor (CEFR) and the siting of China Advanced Research Reactor (CARR), and carried out the construction supervision on HTR-10, and dealt with the event about the technological tube breakage of HWRR and other events

  20. Learning the hard way: Did the lessons taught by the Chernobyl nuclear accident contribute to improving nuclear law?

    International Nuclear Information System (INIS)

    The overview of main international nuclear law features presented in this article provides the proof that the international community is capable of reacting in an effective and adequate way to a disaster of the Chernobyl accident type. States and international organisations joined their legal and political forces to tackle the legal aspects connected with the accident. The efforts were focused on two goals: prevention of possible future nuclear accidents and mitigation of the consequences of an accident should it occur. The legal instruments to achieve these objectives are binding international agreements and conventions, non-binding international recommendations, such as technical codes and standards, and, last but not least, national legislative and regulatory measures. Since public international law is an imperfect and sometimes weak legal regime which has to be accepted by states and which in particular needs the national implementation of its obligations, national law, without prejudice to its far reaching 'internationalisation', still plays the crucial role in obtaining a sound legal nuclear energy and ionising radiation

  1. Teratological evaluation of pregnancy outcomes in Hungary after the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The monthly distribution of pregnancy outcomes such as induced abortions, spontaneous abortions, stillbirths, newborns with birth weight under 2500 g, isolated congenital anomalies, identified multiple congenital anomaly syndromes including fetal radiation syndrome, and unidentified multiple congenital anomalies was evaluated in Hungary after the Chernobyl accident until Apr 1987. Only a somewhat higher rate of newborns with birth weight under 2500 g in May and June, 1986 was detected. It may have been due to premature labour caused by anxiety. (author) 15 refs.; 2 tabs

  2. Seiberdorf scientists give answers to questions in connection with the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    This is a collection of 8 largely non-technical papers written by experts in radiation protection, biology and agriculture from the Austrian Research Centre Seibersdorf, on the consequences for Austria of the Chernobyl fallout and washout. 5 papers are also published (partly under different titles) in the journals Pflanzenarzt 7-8, 1986, Agrozucker 4, 1986 und Blick ins Land, 1986. From the rest, one paper is treated separately for INIS while two papers are elemtary general introductions to radioactivity, radiation, units and doses. (G.Q.)

  3. Cold nuclear fusion reactor and nuclear fusion rocket

    OpenAIRE

    Huang Zhenqiang

    2013-01-01

    "Nuclear restraint inertial guidance directly hit the cold nuclear fusion reactor and ion speed dc transformer" [1], referred to as "cold fusion reactor" invention patents, Chinese Patent Application No. CN: 200910129632.7 [2]. The invention is characterized in that: at room temperature under vacuum conditions, specific combinations of the installation space of the electromagnetic field, based on light nuclei intrinsic magnetic moment and the electric field, the first two strings of the nucle...

  4. Dispersion modelling after Chernobyl

    International Nuclear Information System (INIS)

    At the time of the Chernobyl accident, little was known about the magnitude and time pattern of the release from the damaged reactor. This paper describes the detective work done in the weeks following the accident to assess the release and its dispersal across Europe; also new calculations done since the USSR presentations in Vienna at the end of August 1986 and some estimates of longer term collective dose commitment are given. The MESOS computer model developed at Imperial College to simulate the dispersal of hypothetical accidental releases of important radionuclides, out to distances of several hundred kilometers, and estimate levels of contamination in the air and deposited on the ground, was adapted for real time use. Combined with meteorological data and measurements of radionuclides collected from miscellaneous sources across Europe, it was possible to estimate how much had been released. To conclude, some general remarks are made about the implications of the Chernobyl accident for technical support in emergency procedures for any future nuclear accident. (UK)

  5. News on the natural nuclear reactor

    International Nuclear Information System (INIS)

    Data characterizing conditions of occurrence and the status of a natural nuclear reactor the remnants of which are discovered in the ore open pit of the Oklo deposit (Gabon) are presented. Transport of alkali earth elements (Rb, Sr, Cs and Ba) as well as Pd, Ag, Cd and Te isotopes near the reactor was investigated. Reactor criticality arose, probably, during or soon after U deposition. The reactor has ceased after 500000 years of operation; the energy of about 15 GW x year was generated. Approximately 80 t of uranium (12 tons of sup(235)U) were utilized during reactor operation. Approximately 10 tons of fission products and 4 tons of sup(239)Pu were formed. Reactor operation was periodical, multiply repeated. Water migrating over sandstone pores was not only a moderator but a self-regulator as well

  6. Post-accident balance of nuclear fuel in Chernobylsk-4 reactor

    International Nuclear Information System (INIS)

    Review of published materials on the amount and state of nuclear fuel at the Chernobyl NPP unit-4 facilities. There were 190287.3 kg of uranium or 215006.4 rg of uranium dioxide in the reactor core at the moment of the accident and 103-172 kg of fuel assemblies fuel in the cooling pond. The cooling pond was dehydrated, however all fuel assemblies are therein. The reactor core duel was identified in several dozens of fuel assemblies out of 1659 located in the reactor at the moment of the accident in form of their dispersed fragments (approximately 15 tons) in avalanche-like heat-containing masses. 13 refs.; 2 figs.; 3 tabs

  7. Desalination of seawater with nuclear reactors

    International Nuclear Information System (INIS)

    About 40 % of the world population is concerned with water scarcity. This article reviews the different techniques of desalination: distillation (MED and MSF), reverse osmosis (RO), and electrodialysis (ED). The use of nuclear energy rests on several arguments: 1) it is economically efficient compared to fossil energy. 2) nuclear reactors provide heat covering a broad range of temperature, which allows the implementation of all the desalination techniques. 3) the heat normally lost at the heat sink could be used for desalination. And 4) nuclear is respectful of the environment. The feedback experience concerning nuclear desalination is estimated to about 100 reactor-years, it is sufficient to allow the understanding of all the physical and technological processes involved. In Japan, 8 PWR-type reactors are coupled to MED, MSF, and RO desalination techniques, the water produced is used locally mainly for feeding steam generators. (A.C.)

  8. Desalination of seawater with nuclear reactors

    International Nuclear Information System (INIS)

    About 40 % of the world population is concerned with water scarcity. This article reviews the different techniques of desalination: distillation (MED and MSF), reverse osmosis (RO), and electrodialysis (ED). The use of nuclear energy rests on several arguments: 1) it is economically efficient compared to fossil energy; 2) nuclear reactors provide heat covering a broad range of temperature, which allows the implementation of all the desalination techniques; 3) the heat normally lost at the heat sink could be used for desalination; and 4) nuclear is respectful of the environment. The feedback experience concerning nuclear desalination is estimated to about 100 reactor-years, it is sufficient to allow the understanding of all the physical and technological processes involved. In Japan, 8 PWR-type reactors are coupled to MED, MSF, and RO desalination techniques, the water produced is used locally mainly for feeding steam generators. (A.C.)

  9. Nuclear data needs for fusion reactors

    International Nuclear Information System (INIS)

    The nuclear design of fusion components (e.g., first wall, blanket, shield, magnet, limiter, divertor, etc.) requires an accurate prediction of the radiation field, the radiation damage parameters, and the activation analysis. The fusion nucleonics for these tasks are reviewed with special attention to point out nuclear data needs and deficiencies which effect the design process. The main areas included in this review are tritium breeding analyses, nuclear heating calculations, radiation damage in reactor components, shield designs, and results of uncertainty analyses as applied to fusion reactor studies. Design choices and reactor parameters that impact the neutronics performance of the blanket are discussed with emphasis on the tritium breeding ratio. Nuclear data required for kerma factors, shielding analysis, and radiation damage are discussed. Improvements in the evaluated data libraries are described to overcome the existing problems. 84 refs., 11 figs., 9 tabs

  10. HYSPLIT's Capability for Radiological Aerial Monitoring in Nuclear Emergencies: Model Validation and Assessment on the Chernobyl Accident

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Gunhyo; Kim, Juyoul [Seoul National University, Seoul (Korea, Republic of); Shin, Hyeongki [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2007-10-15

    The Chernobyl accident took place on 25 April 1986 in Ukraine. Consequently large amount of radionuclides were released into the atmosphere. The release was a widespread distribution of radioactivity throughout the northern hemisphere, mainly across Europe. A total of 31 persons died as a consequence of the accident, and about 140 persons suffered various degrees of radiation sickness and health impairment in the acute health impact. The possible increase of cancer incidence has been a real and significant increase of carcinomas of the thyroid among the children living in the contaminated regions as the late health effects. Recently, a variety of atmospheric dispersion models have been developed and used around the world. Among them, HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) model developed by NOAA (National Oceanic and Atmospheric Administration)/ARL (Air Resources Laboratory) is being widely used. To verify the HYSPLIT model for radiological aerial monitoring in nuclear emergencies, a case study on the Chernobyl accident is performed.

  11. Mortality studies in children affected by the Chernobyl nuclear accident in the district of Gomel, Belarus

    International Nuclear Information System (INIS)

    As a result of the Chernobyl nuclear accident in 1986, the district of Gomel in Belarus has become the most contaminated area within the former USSR. A comparative pilot study conducted by the authros to establish the mortality in that district during the 1984-1992 period has not yet revealed any elevated mortality among children aged 0 to <15 years for the period after the accident. Diseases of the respiratory system and congential anomalies were found to be the principal causes of death in this age group (ICD9: classes VIII and XIV). Owing to the low number of children born during the study period and the concomitant small number of deaths from neoplasms, a clear analysis of changes in the structure of mortality from neoplasma (ICD9: class II) has not yet been possible. The birth rate in the Gomel district where the highest radiation exposure was experienced has dropped: There was an obvious decrease suring 1987, i.e. during the year which immediately followed that of the accident, to rise again in 1992 to levels comparable to those of other study areas. (orig.)

  12. Contamination and radiation exposure in Germany following the accident at the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    The radioactive substances released following the accident at the Chernobyl nuclear power plant were distributed by atmospheric transport over large parts of Europe. Due to dry and wet deposition processes, soil and Plants were contaminated. The ''radioactive cloud'' was first monitored on the 29th of April by near surface measurement stations; by the 30th of April the whole of southern Germany was affected. The contaminated air then spread out in both westerly and northerly directions, resulting in increased airborne radioactivity over the entire country within the following days. Airborne radionuclides were deposited on soil and plants in dry form as well as by precipitation. Locally varying deposits resulted from different activity concentrations in aerosols and very large differences in the intensity of precipitation during the passage of contaminated air masses. Rain fails were particularly heavy in Germany during the time the cloud was passing, especially south of the Danube where on average 2,000 to 50,000 Bq of Cs-137 was deposited per square meter on soil, and in some cases even as much as 100,000 Bq per square meter

  13. Measurement of the whole-body 137Cs in residents around the Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    To understand the current situation of internal radiation exposure in the population around the Chernobyl Nuclear Power Plant (CNPP), we examined the 137Cs body burden in six residents of Belarus, Ukraine and Russia in 2002 and 2004 using the whole-body counter (WBC) at Nagasaki Univ. (Japan). The data were compared with those of our previous study performed in 1993-1994 using the same method. In 2002 and 2004, peaks of 137Cs were detected in two residents from Gomel, which was heavily contaminated by the CNPP accident, one from Minsk (Belarus) and one from Kiev (Ukraine), but another resident from Minsk showed no 137Cs peaks. The results of the present study suggests that residents around the CNPP are still exposed to chronic 137Cs internal irradiation, probably due to the daily consumption of contaminated domestic foods, but the risk of any disease by the irradiation is quite low. Long-term follow-up of WBC around the CNPP is useful and may contribute to radiation safety regulation together with a reduction of unnecessary radio-phobia for the residents. (authors)

  14. Short lived radionuclides in food and feed after the nuclear accident in Chernobyl

    International Nuclear Information System (INIS)

    The results of identification and short lived radionuclides (I-131, I(Te)-132, Cs-136, Ce-141, 144, Ru-103, 106, Ba(La)-140, Zr-95, Mo-99, Nb-95, Sb-125) mass activities evaluation in food (milk and dairies, meat, honey, fruits, vegetables) and feeds (oilseed rupe, alfalfa, fresh green mass) after the nuclear accident at Chernobyl, in 1986, are presented. The results indicate that in the first month after the accident and afterwards, in the first half of the year, the contribution of the short lived radionuclides in the total activity of the samples ranged from 2-64%, varying with food and feed, locality and time of sampling. Compared to the activity of I-131, the short lived radionuclides contributed from 1.3 to 470%, while compared to the activities of the long term radionuclides Cs-134 and Cs-137, the activity of the short lived radionuclides in the first half of the year after the accident ranged from 12% to more than 300%. The traces of Ag-110m were found in the majority of the samples, too. (1 tab.)

  15. Radioecological estimation of the condition of wild fauna in the zone of Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    As the result of long time of wildlife radioecological monitoring in the zone of Chernobyl nuclear accident the main trends in radioactive contamination of the animals of different taxones, the condition of fauna biodiversity have been shown. After a noticeable decrease of the radionuclide contents observed in the period immediately following the accident which was mainly caused by decay of short-living isotopes, in recent years a tendency of stabilising the radionuclide accumulation was found in the majority of the animal groups. The dynamics and state of the fauna depends more on the secondary effects of human evacuation than on direct radioecological impact. Natural ecological succession may have accelerated due to the post-evacuation removal of human pressure on contaminated habitats. Cessation of economic activity had the greatest effect on the structure and number of ornithocomplexes and populations of commercial game mammals. Changes in aquatic animals are expressed to a smaller extent and follow the laws of natural development to a greater extent. These dynamics processes of transformation of wildlife communities offer a unique opportunity to study the development and conservation of wild animal biodiversity within the context of specific land use and landscape ecological changes. (authors)

  16. Features of a subcritical nuclear reactor

    International Nuclear Information System (INIS)

    Highlights: • The keff was calculated using six factor formula and MCNP code. • Both methods agree when the reactor is loaded from 800 to 1900 kg. • With the MCNP5 code the neutron spectra and doses were estimated. • The Ambient dose was measured outside the subcritical assembly. - Abstract: A subcritical nuclear reactor is a device where the nuclear-fission chain reaction is initiated and maintained using an external neutron source. It is a valuable educational and research tool where in a safe way many reactor parameters can be measured. Here, we have used the six-factor formula to calculate the effective multiplication factor of a subcritical nuclear reactor Nuclear Chicago model 9000. Using the MCNP5 code, a three-dimensional model of the subcritical reactor was developed to estimate the effective multiplication factor, the neutron spectra, and the total and thermal neutron fluences along the radial and axial axis. The MCNP5 results of the effective multiplication factor were compared with those obtained from the six-factor formula. The effective dose and the Ambient dose equivalent, at three sites outside the reactor, were estimated; the Ambient dose equivalent was also measured and compared with the calculated values

  17. Experimental verification of dynamic radioecological models after the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    The comparitive analysis uses model data and data derived from field experiments. The translocation factors for Cs-134 and Cs-137 in edible plants have been determined after spraying of fields with Chernobyl fallout rainwater, considering the time of irrigation in relation to plant growth, and are shown to be the following: 0.002 - 0.13 in winter wheat, 0.003 - 0.09 in spring wheat, 0.002 - 0.27 in winter rye, 0.002 - 0.04 in barley, 0.05 - 0.35 in potatoes, 0.02 - 0.07 in carrots, 0.04 - 0.3 in bush beans, 0.1 - 0.5 in cabbage. The weathering half-life in lettuce is 10 days. The transfer factors for Cs-137 uptake by the roots have been determined to be 0.002 on the avarage for grain, 0.002 for potatoes, 0.004 for white cabbage, 0.003 for bush beans and carrots, and 0.007 for lettuce. The measured data agree well with the radioecological concentration data predicted by the ECOSYS model for post-Chernobyl radionuclide distribution. Some results of the verification study could be used to improve the results of the ECOSYS model by modification of certain parameters. (orig./HP)

  18. The modern Saamish reindeer husbandry in Sweden after the reactor accident of Chernobyl

    International Nuclear Information System (INIS)

    Large parts of the reindeer herding area in Sweden were contaminated with radioactive caesium from the Chernobyl fallout deposited mainly between 62 and 66 n.lat. by heavy rain-and snowfalls between April 28-30, the fjell and boreal forest regions of north-western Jaemtland and south-western Vaesterbotten being the home of 500 reindeer Saamis, organized in 19 Saamebys, and being the winter- and summer reindeer grazing areas for about 100000 reindeer worst contaminated, with a maximum soil contamination of 60000 Bq/m2 Cs137 along a line Gaevle-Gaeddede. The socio-economic effects and consequences of Chernobyl have on the hand changed the daily and yearly work routine patterns by applying early slaughter and feeding programs. On the other hand it has shown the vulnerability of reindeer husbandry in particular and of Saami culture and livelihood in general. It has also pointed out the influence of the state compensation payments have helped the mostly hit Saamebys to survive economically and the Saami herders to preserve their ethic identity and specific way of life. The measure of introducing a strict radioactivity limit should be fixed internationally. In reindeer meat where the average annual consumption is as low as 200 g per person a limit as low as 300 pr 1500 Bq/kg is in fact ineffective in reducing cancer risks but it has proved disastrous for the reindeer meat market

  19. Workshop on short-term health effects of reactor accidents: Chernobyl

    International Nuclear Information System (INIS)

    The high-dose early-effects research that has been continued has been done in the context of infrequent accidents with large radiation sources and the use of bone marrow transfusions for treating malignancies, especially leukemia. It thus seemed appropriate to bring together those who have done research on and have had experience with massive whole-body radiation. The objectives were to review what is known about the acute effects of whole-body irradiation, to review the current knowledge of therapy, and particularly of the diagnostic and immunologic problems encountered in bone marrow therapy, and to compare this knowledge with observations made to date on the Chernobyl accident radiation casualties. Dr. Robert Gale, who had helped to care for these casualties, was present at the Workshop. It was hoped that such a review would help those making continuing clinical and pathological observations on the Chernobyl casualties, and that these observations would provide a basis for recommendations for additional research that might result in improved ability to manage successfully this type of severe injury

  20. Workshop on short-term health effects of reactor accidents: Chernobyl

    Energy Technology Data Exchange (ETDEWEB)

    1986-08-08

    The high-dose early-effects research that has been continued has been done in the context of infrequent accidents with large radiation sources and the use of bone marrow transfusions for treating malignancies, especially leukemia. It thus seemed appropriate to bring together those who have done research on and have had experience with massive whole-body radiation. The objectives were to review what is known about the acute effects of whole-body irradiation, to review the current knowledge of therapy, and particularly of the diagnostic and immunologic problems encountered in bone marrow therapy, and to compare this knowledge with observations made to date on the Chernobyl accident radiation casualties. Dr. Robert Gale, who had helped to care for these casualties, was present at the Workshop. It was hoped that such a review would help those making continuing clinical and pathological observations on the Chernobyl casualties, and that these observations would provide a basis for recommendations for additional research that might result in improved ability to manage successfully this type of severe injury.

  1. Inhalation of radionuclides during agricultural work in areas contaminated as a result of the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Radionuclide concentrations have been determined inside and outside the cabs of tractors operated on soils that are typical of the 30 km exclusion zone around the Chernobyl nuclear power plant. It was found that when the total plutonium deposit exceeded 3.7 kBq m-2 and the 137Cs deposit exceeded 7.4 MBq m-2, the levels of these radionuclides in the operator's cabin could exceed the maximum permissible air concentrations. However, due to the seasonal nature of work, the quantities of these radionuclides inhaled would not exceed the annual limit on intake. Dose to the lungs caused by the inhalation of hot particles has been addressed by either including or neglecting spatial dose distribution. The levels of risk of carcinogenic changes in cells of lung tissue calculated according to each of the two approaches have been shown to be of the same order of magnitude. (author)

  2. Feedback of reactor operating data to nuclear methods development

    International Nuclear Information System (INIS)

    The problems in obtaining power reactor data for reliable nuclear methods development and the major sources of power reactor data for this purpose are reviewed. Specific examples of the use of power reactor data in nuclear methods development are discussed. The paper concludes with recommendations on the key elements of an effective program to use power reactor data in nuclear methods development

  3. Chernobyl: 30 years after - Proceedings of the technical meeting of the French Society of Radiation Protection

    International Nuclear Information System (INIS)

    The French Society of Radiation Protection (SFRP) organized a technical meeting on the present day situation of the Chernobyl site, 30 years after the accident of the nuclear power plant. The review deals with the situation of the facility and of its safety works, the environment, the management of wastes, the workers and populations exposure, and the health monitoring of the exposed populations. This document brings together the abstracts and the presentations (slides) of the different talks given at the meeting: 1 - The main highlights 30 years after the Chernobyl accident (Didier CHAMPION, SFRP); 2 - Circumstances, progress and consequences of the Chernobyl accident - Lessons and experience feedback for the other RBMK reactors (Michel CHOUHA, IRSN); 3 - Chernobyl, a confinement arch for 100 years (Patrick CHABRIER, Thomas CHAUVEAU - BOUYGUES); 4 - The reactor wastes management and the dismantling operations (Guy DAMETTE - IRSN); 5 - Environment contamination in the vicinity of the site (Yves THIRY - ANDRA); 6 - Impact of the accident on agriculture (Vanessa DURAND - IRSN); 7 - The fate of remediation wastes (Francois BESNUS - IRSN); 8 - Chernobyl fallouts in France (Philippe RENAUD - IRSN); 9 - The ecological consequences of the Chernobyl accident (Christelle ADAM-GUILLERMIN - IRSN); 10 - Results of liquidators and populations exposure (Florence MENETRIER - CEA); 11 - Thyroid cancers monitoring in the Chernobyl area and the role of modifying genetic factors (Fabienne LESUEUR - Institut Curie); 12 - Results of the Chernobyl accident health impact studies (Dominique LAURIER - IRSN); 13 - Impact on populations living condition (Thierry SCHNEIDER - CEPN); 14 - Molecular signature of radiation induced thyroid tumors (Sylvie CHEVILLARD - CEA)

  4. Chernobyl, 13 years after; Tchernobyl, 13 ans apres

    Energy Technology Data Exchange (ETDEWEB)

    Regniault-Lacharme, Mireille; Metivier, Henri [Inst. de Protection et de Surete Nucleaire, CEA Centre d' Etudes de Fontenay-aux-Roses, 92 (France)

    1999-04-01

    This is an annual report, regularly issued by IPSN, that presents the ecological and health consequences of the Chernobyl Nuclear Accident. The present status of the Chernobyl Nuclear Plant, which Ukraine engaged to stop definitively in year 2000, is summarized. The only reactor unit now in operation is Chernobylsk-3 Reactor which poses two safety questions: evolution of cracks in part of the tubing and behaviour of the pressure tubes. Although, some improvements in the RBMK reactor types were introduced, problems remain that make IPSN to stress the requirement of stopping this NPP completely. In the contaminated territories surrounding Chernobyl incidence rate of infant thyroid cancers continues to grow, reaching values 10 to 100 times higher than the natural rate. In France the IPSN analyzed 60,000 records carried out in 17 sites during May 1986 and April 1989. It was estimated that the individual dose received during 60 years (1986-2046) by the inhabitants of the most affected zone (eastern France) is lower than 1.5 mSv, a value lower than 1% of the natural cosmic and telluric radioactivity exposure for the same period. For the persons assumed to live in the most attacked forests (from eastern France) and nourishing daily with venison and mushrooms the highest estimate is 1 mSv a year. Concerning the 'hot spots', identified in mountains by IPSN and CRIIRAD, the doses received by excursionists are around 0.015 mSv. For an average inhabitant of the country the dose piled up in the thyroid due to iodine-131 fallout is estimated to 0.5-2 mSv for an adult and 6.5-16 mSv for an infant. These doses are 100 to 1000 times lower than the ones to which the infants living in the neighbourhood of Chernobyl are exposed to. The contents of the report is displayed in the following six chapters: 1. Chernobyl in some figures; 2. The 'sarcophagus' and the reactors of the Chernobyl NPP; 3. Health consequences of the Chernobyl accident;. 4. The impact of

  5. Artificial radioactivity in the vicinity of St. Marianna University School of Medicine after the Chernobyl reactor accident

    International Nuclear Information System (INIS)

    Following the Chernobyl reactor accident on April 26, 1986, rain water and atomospheric dust were monitored for their possible contamination by artificial radionuclides on the roof of the building of our medical school from April 30 through June 8, 1986. Radiological monitoring was also performed on cabbages obtained from a nearby field, city water, cow's milk produced in Kanagawa Prefecture and human milk obtained from a volunteer living in Kawasaki. Our campus and the nearby area were exposed to 131I from May 2 through 22 by rainfall and from May 1 through 15 by atomospheric dust. In particular, rain water on May 4 and May 5 contained 7600 pCi (282 Bq)/l and 6000 pCi (222 Bq)/l, respectively. The cabbage specimen obtained on May 7 was contaminated by 131I with 808 pCi/kg wet weight, but another specimen obtained on June 6 was not contaminated by any detectable amounts of 131I. No radioactivity was detected in city water during the period monitored. Cow's milk and human milk contained, as a total of β-radioactivity, 1412 pCi (52 Bq)/l and 915 pCi (34 Bq)/l, respectively. However, parallel determinations on their potassium concentrations revealed that these radioactivities were due entirely to natural 40K. The degree of radiological contamination in and around our campus following the Chernobyl accident was mostly below the action levels above which the governments of several countries involving Japan would take preventive measures against possible radiation damages. Although 131I radioactivities contained in the rain water of the first week of May, 1986 significantly exceeded the action level for this radionuclide, their effects on human health were considered negligible and undetectable in the vicinity of our school. (author)

  6. Chernobyl nuclear accident hydrologic analysis and emergency evaluation of radionuclide distributions in the Dnieper River, Ukraine, during the 1993 summer flood

    Energy Technology Data Exchange (ETDEWEB)

    Voitsekhovitch, O.V. [Ukrainian Hydrometeorological Inst., Kiev (Ukraine); Zheleznyak, M.J. [Ukrainian Academy of Sciences, Kiev (Ukraine). Cybernetics Center; Onishi, Y. [Pacific Northwest Lab., Richland, WA (United States)

    1994-06-01

    This report describes joint activities of Program 7.1.F, ``Radionuclide Transport in Water and Soil Systems,`` of the USA/Commonwealth of Independent States (CIS) Joint Coordinating Committee of Civilian Nuclear Reactor Safety to study the hydrogeochemical behavior of radionuclides released to the Pripyat and Dnieper rivers from the Chernobyl Nuclear Power Plant in Ukraine. These joint activities included rapid evaluation of radionuclide distributions in the Pripyat and Dnieper river system and field data evaluation and modeling for the 1993 summer flood to assist the Ukrainian government in their emergency response during the flood. In July-August 1993, heavy rainfall over the Pripyat River Catchment in Belarus and Ukraine caused severe flooding, significantly raising {sup 90}Sr concentrations in the river. Near the Chernobyl area, the maximum {sup 90}Sr concentration in the Pripyat River reached 20--25 PCi/L in early August; near the Pripyat River mouth, the concentration rose to 35 pCi/L. The peak {sup 90}Sr concentration in the Kiev Reservoir (a major source of drinking water for Kiev) was 12 pCi/L. Based on these measured radionuclide levels, additional modeling results and the assumption of water purification in a water treatment station, {sup 90}Sr concentrations in Kiev`s drinking water were estimated to be less than 8 pCi/L. Unlike {sup 90}Sr, {sup 137}Cs concentrations in the Pripyat River during the flood did not rise significantly to the pre-flood levels. Estimated {sup 137}Cs concentrations for the Kiev drinking water were two orders of magnitude lower than the drinking water standard of 500 pCi/L for {sup 137}Cs.

  7. Chernobyl nuclear accident hydrologic analysis and emergency evaluation of radionuclide distributions in the Dnieper River, Ukraine, during the 1993 summer flood

    International Nuclear Information System (INIS)

    This report describes joint activities of Program 7.1.F, ''Radionuclide Transport in Water and Soil Systems,'' of the USA/Commonwealth of Independent States (CIS) Joint Coordinating Committee of Civilian Nuclear Reactor Safety to study the hydrogeochemical behavior of radionuclides released to the Pripyat and Dnieper rivers from the Chernobyl Nuclear Power Plant in Ukraine. These joint activities included rapid evaluation of radionuclide distributions in the Pripyat and Dnieper river system and field data evaluation and modeling for the 1993 summer flood to assist the Ukrainian government in their emergency response during the flood. In July-August 1993, heavy rainfall over the Pripyat River Catchment in Belarus and Ukraine caused severe flooding, significantly raising 90Sr concentrations in the river. Near the Chernobyl area, the maximum 90Sr concentration in the Pripyat River reached 20--25 PCi/L in early August; near the Pripyat River mouth, the concentration rose to 35 pCi/L. The peak 90Sr concentration in the Kiev Reservoir (a major source of drinking water for Kiev) was 12 pCi/L. Based on these measured radionuclide levels, additional modeling results and the assumption of water purification in a water treatment station, 90Sr concentrations in Kiev's drinking water were estimated to be less than 8 pCi/L. Unlike 90Sr, 137Cs concentrations in the Pripyat River during the flood did not rise significantly to the pre-flood levels. Estimated 137Cs concentrations for the Kiev drinking water were two orders of magnitude lower than the drinking water standard of 500 pCi/L for 137Cs

  8. Optimally moderated nuclear fission reactor and fuel source therefor

    Science.gov (United States)

    Ougouag, Abderrafi M.; Terry, William K.; Gougar, Hans D.

    2008-07-22

    An improved nuclear fission reactor of the continuous fueling type involves determining an asymptotic equilibrium state for the nuclear fission reactor and providing the reactor with a moderator-to-fuel ratio that is optimally moderated for the asymptotic equilibrium state of the nuclear fission reactor; the fuel-to-moderator ratio allowing the nuclear fission reactor to be substantially continuously operated in an optimally moderated state.

  9. A compendium of the measurements related to the Chernobyl nuclear accident

    International Nuclear Information System (INIS)

    Results of radiation measurements performed in Belgium after the Chernobyl accident are presented. Contamination of air, soil, milk, grass, fruit, vegetables and water is studied. The committed effective dose equivalents for the population are estimated. (MCB)

  10. Reconstruction of the doses to the population evacuated from the 30 km-zone around the Chernobyl reactor

    International Nuclear Information System (INIS)

    As a consequence of the Chernobyl accident, large areas around the reactor were severely contaminated. As a consequence, the 30 km zone around the reactor was evacuated. The evacuation started with the city of Pripyat with a population of approximately 50000. For early evacuees, the exposure was mainly due to external exposure and inhalation, since the time was too short to induce relevant ingestion doses (Goulko et al., 1998). In contrast to Pripyat, for most of the other evacuees from the 30 km zone the time period was long enough to receive also relevant exposures via the ingestion pathway. Various assessments performed for contaminated areas have underlined the importance of ingestion and inhalation for the exposure of the evacuated population. For the population living in the contaminated area, external exposure was one of the most relevant pathways. Short-lived radionuclides and early migration processes of the radionuclides influenced these exposures. Before the present project these contributions and processes were only implicitly taken into account in areas where a sufficient number of early gamma dose rate measurements was performed. A general model on early external exposures of the population in contaminated areas was missing. Also, for later periods there was no general model for the uncertainties of estimates of external exposures. (orig.)

  11. Design of a nuclear reactor cooperative controller

    International Nuclear Information System (INIS)

    This paper describes the development of a fuzzy logic controller software package and explores the feasibility of its use in nuclear reactor operation. The controller complements reactor operator actions, and the operators can override the controller decisions. Techniques of providing learning capability to the controller are also being investigated to improve the reasoning and control skill of the controller. The fuzzy logic controller is implemented in C language and its overall structure is shown. The heart of the systems consists of a fuzzifier, a rule interpreter, and a defuzzifier. The controller is designed as a stand-alone package that can be interfaced to a simulated model of a nuclear reactor. Since no model is an accurate representation of the actual process being modeled, some tuning must be performed to use the controller in an actual reactor. This is accomplished using the learning feature of the controller

  12. Prevalence of bronchopulmonary pathology in the participants of Chernobyl Nuclear Power Plant accident response

    International Nuclear Information System (INIS)

    Epidemiologic examination of the participants of the Chernobyl accident response is performed. Fact of acute effect of the Chernobyl aerosol inhalation on respiratory organs is found. Prevalence of bronchopulmonary diseases in participants of accident response is almost 2 times higher than that in reference group. Further program of investigations includes the hospital stage and the preventive measures at prehospital stage under ambulatory conditions. Assessments of the efficiency of performed treatment - prophylactic measures and their economic benefit are made

  13. Water shielding nuclear reactor container

    International Nuclear Information System (INIS)

    The reactor container of the present invention contains a reactor pressure vessel, and has double steel plate walls endurable to elevated inner pressure and keeping airtightness, and shielding water is filled inside from a water injection port. It is endurable to a great inner pressure satisfactorily and keep airtightness by the two spaced relatively thin steel plates. It exhibits radiation shielding effect by filling water substantially the same as that of a conventional reactor container made of iron reinforced concretes. Then, it is no more necessary to use concretes for the construction of the reactor container, which shortens the term of the construction, and saves the construction cost. In addition, a cooling effect for the reactor container is provided. Syphons are disposed contiguously to a water injection port and the top end of the syphon is immersed in an equipment temporarily storage pool, and further, pipelines are connected to the double steel plate walls or the syphons for supplying shielding water to enhance the cooling effect. (N.H.)

  14. Nuclear reactor power control device

    International Nuclear Information System (INIS)

    When occurrence of earthquakes is judged in a BWR type reactor, the power is decreased by inserting a portion of control rods, reducing a speed of recycling pumps, stopping recycling pumps, increasing the opening degree of a main steam control valve and opening a main steam relief valve. The reactor scram can be avoided by bypassing neutron flux high signal, settling a filter to neutron flux signals and setting a reactor scram set value by neutron flux signals, for example, to 120%. There is constituted an interlock for performing reactor scram when both of a neutron flux high signal and a signal outputted if a surface heat flux corresponding signal formed by applying calculation to the neutron flux high signal exceeds a set value are valid, to avoid unnecessary reactor scram. As a measuring means, not only an acceleration meter in the power plant, but also acceleration meters at remote places, acceleration meters or displacement meters for various kinds of equipments in the power plant are used, and when signals from them exceed set values, earthquake judgement is conducted. (N.H.)

  15. Introduction to the neutron kinetics of nuclear power reactors

    CERN Document Server

    Tyror, J G; Grant, P J

    2013-01-01

    An Introduction to the Neutron Kinetics of Nuclear Power Reactors introduces the reader to the neutron kinetics of nuclear power reactors. Topics covered include the neutron physics of reactor kinetics, feedback effects, water-moderated reactors, fast reactors, and methods of plant control. The reactor transients following faults are also discussed, along with the use of computers in the study of power reactor kinetics. This book is comprised of eight chapters and begins with an overview of the reactor physics characteristics of a nuclear power reactor and their influence on system design and

  16. Nuclear reactor fissile isotopes antineutrino spectra

    OpenAIRE

    Sinev, V.

    2012-01-01

    Positron spectrum from inverse beta decay reaction on proton was measured in 1988-1990 as a result of neutrino exploration experiment. The measured spectrum has the largest statistics and lowest energy threshold between other neutrino experiments made that time at nuclear reactors. On base of the positron spectrum the standard antineutrino spectrum for typical reactor fuel composition was restored. In presented analysis the partial spectra forming this standard spectrum were extracted using s...

  17. The safety of Ontario's nuclear reactors

    International Nuclear Information System (INIS)

    A Select Committee of the Legislature of Ontario was established to examine the affairs of Ontario Hydro, the provincial electrical utility. Extensive public hearings were held on several topics including the safety of nuclear power reactors operating in Ontario. The Committee found that these reactors are acceptably safe. Many of the 24 recommendations in this report deal with the licensing process and public access to information. (O.T.)

  18. Nuclear Research Center IRT reactor dynamics calculation

    International Nuclear Information System (INIS)

    The main features of the code DIRT, for dynamical calculations are described in the paper. With the results obtained by the program, an analysis of the dynamic behaviour of the Research Reactor IRT of the Nuclear Research Center (CIN) is performed. Different transitories were considered such as variation of the system reactivity, coolant inlet temperature variation and also variations of the coolant velocity through the reactor core. 3 refs

  19. Liquid metal cooled nuclear reactor constructions

    International Nuclear Information System (INIS)

    A liquid metal cooled nuclear reactor construction is described comprising a reactor core submerged in a pool of liquid metal coolant contained in a vessel which is housed in a concrete containment vault, the roof structure of the vault having thermal insulation comprising a series of super-imposed spaced plates, with baffles disposed so as to restrict convectional flow of metal vapour through the interspaces of the plates and between the uppermost plate or plates and the vault roof structure. (author)

  20. Advanced nuclear reactor types and technologies

    Energy Technology Data Exchange (ETDEWEB)

    Ignatiev, V. [ed.; Feinberg, O.; Morozov, A. [Russian Research Centre `Kurchatov Institute`, Moscow (Russian Federation); Devell, L. [Studsvik Eco and Safety AB, Nykoeping (Sweden)

    1995-07-01

    The document is a comprehensive world-wide catalogue of concepts and designs of advanced fission reactor types and fuel cycle technologies. Two parts have been prepared: Part 1 Reactors for Power Production and Part 2 Heating and Other Reactor Applications. Part 3, which will cover advanced waste management technology, reprocessing and disposal for different nuclear fission options is planned for compilation during 1995. The catalogue was prepared according to a special format which briefly presents the project title, technical approach, development status, application of the technology, reactor type, power output, and organization which developed these designs. Part 1 and 2 cover water cooled reactors, liquid metal fast reactors, gas-cooled reactors and molten salt reactors. Subcritical accelerator-driven systems are also considered. Various reactor applications as power production, heat generation, ship propulsion, space power sources and transmutation of such waste are included. Each project is described within a few pages with the main features of an actual design using a table with main technical data and figure as well as references for additional information. Each chapter starts with an introduction which briefly describes main trends and approaches in this field. Explanations of terms and abbreviations are provided in a glossary.

  1. Advanced nuclear reactor types and technologies

    International Nuclear Information System (INIS)

    The document is a comprehensive world-wide catalogue of concepts and designs of advanced fission reactor types and fuel cycle technologies. Two parts have been prepared: Part 1 Reactors for Power Production and Part 2 Heating and Other Reactor Applications. Part 3, which will cover advanced waste management technology, reprocessing and disposal for different nuclear fission options is planned for compilation during 1995. The catalogue was prepared according to a special format which briefly presents the project title, technical approach, development status, application of the technology, reactor type, power output, and organization which developed these designs. Part 1 and 2 cover water cooled reactors, liquid metal fast reactors, gas-cooled reactors and molten salt reactors. Subcritical accelerator-driven systems are also considered. Various reactor applications as power production, heat generation, ship propulsion, space power sources and transmutation of such waste are included. Each project is described within a few pages with the main features of an actual design using a table with main technical data and figure as well as references for additional information. Each chapter starts with an introduction which briefly describes main trends and approaches in this field. Explanations of terms and abbreviations are provided in a glossary

  2. Equipments for use in nuclear reactors

    International Nuclear Information System (INIS)

    Purpose: To prevent nickel from leaching into nuclear reactor coolants thereby suppress the generation of cobalt 58 due to activation. Constitution: Equipments for use in nuclear reactor cores such as control rod covering tubes, control rod sheaths, feedwater heater tubes, etc. are constituted with ferrite type stainless steels not containing nickel and containing more than 10 wt% chromium incorporated as the basic element with nitrogen at a level higher than the impurity content. While the ferrite type materials have been used for the pressure vessel, there has been a problem in view of the embrittlement under irradiation when used as the equipments in nuclear reactor cores. However, it has been found that the embrittlement under irradiation can be improved by the incorporation of nitrogen in excess of the impurity level. Accordingly, the material of the present invention can suppress the generation of cobalt 58, provide corrosion resistance and avoid embrittlement under irradiation. (Takahashi, M.)

  3. Nuclear reactor safety in the USA

    International Nuclear Information System (INIS)

    Nuclear reactor safety in the USA has emphasized a defense-in-depth approach to protecting the public from reactor accidents. This approach was severely tested by the Three Mile Island accident and was found to be effective in safeguarding the public health and safety. However, the economic impact of the TMI accident was very large. Consequently, more attention is now being given to plant protection as well as public-health protection in reactor-safety studies. Sophisticated computer simulations at Los Alamos are making major contributions in this area. In terms of public risk, nuclear power plants compare favorably with other large-scale alternatives to electricity generation. Unfortunately, there is a large gulf between the real risks of nuclear power and the present public perception of these risks

  4. Device for nuclear reactor control

    International Nuclear Information System (INIS)

    The device for power height distribution control in channel-type uranium-graphite reactor cores is described. The device is a water filled vertical channel positioned in the reactor core. The device consists of a controlling rod, displacer in a form of a throttle and gas cavity and discharge throttle. The rod is fixed in upper position with an electromagnet. By shifting a displacer and changing flow rate established are the required height and position of a controlling liquid column. In the emergency protection, a drive shifts the displacer under core space or the displacer drops under the action of its own weight at electromagnet clutch doenergyzation whereas the channel is filled by liquid. The application of the suggested device permits to improve economic and operating characteristics of reactors

  5. Nuclear reactor fuel element splitter

    International Nuclear Information System (INIS)

    A method and apparatus are disclosed for removing nuclear fuel from a clad fuel element. The fuel element is power driven past laser beams which simultaneously cut the cladding lengthwise into at least two longitudinal pieces. The axially cut lengths of cladding are then separated, causing the nuclear fuel contained therein to drop into a receptacle for later disposition. The cut lengths of cladding comprise nuclear waste which is disposed of in a suitable manner. 6 claims, 10 drawing figures

  6. 78 FR 64028 - Decommissioning of Nuclear Power Reactors

    Science.gov (United States)

    2013-10-25

    ... COMMISSION Decommissioning of Nuclear Power Reactors AGENCY: Nuclear Regulatory Commission. ACTION... regulatory guide (RG) 1.184 ``Decommissioning of Nuclear Power Reactors.'' This guide describes a method NRC... decommissioning process for nuclear power reactors. The revision takes advantage of the 13 years...

  7. Nuclear reactors with auxiliary boiler circuit

    International Nuclear Information System (INIS)

    A gas-cooled nuclear reactor has a main circulatory system for the gaseous coolant incorporating one or more main energy converting units, such as gas turbines, and an auxiliary circulatory system for the gaseous coolant incorporating at least one steam generating boiler arranged to be heated by the coolant after its passage through the reactor core to provide steam for driving an auxiliary steam turbine, such an arrangement providing a simplified start-up procedure also providing emergency duties associated with long term heat removal on reactor shut down

  8. IAEA role in nuclear reactor safety standardization

    International Nuclear Information System (INIS)

    In 1981 the electricity generation by nuclear power plants all over the world reached 8% of total production. It can be expected that at the turn of century up to 25% of electric power will be provided by means of nuclear fuel burning. In connection with NPP total number growth, their attraction to large population centres, widening of the atomic energy application areas, the importance of nuclearreactor safety problems can only increase. The safety measures have usually the structure of sequential barriers: for accident preventing, for protection from accidents, for accident localization. NPP safety is a complex problem having scientific, engineering, juridical, social and political aspects. Since these problems have an international importance, IAEA should actively work on their solving. Practically all the topics of nuclear power development and nuclear reactor s;fety lie within the activity area of the Department of nuclear power and safety, its sections: of nuclear safety, nuclear power, nuclear fuel cycle. In 1974 a decision was made in IAEA about initiation of work on development of an international nuclear safety standards system (NUSS Programme). These activities are divided into five major branches: a government organization for nuclear safety regulations; site selection for NPP; NPP desing; operation, start of operation and decommissioning; quality provision for NPP. The report presents a list of documents, comprising the NUSS Programme. The complection of all the works within the scope of the Programme is planned for 1985. After 1985 the start of development of fast neutron reactor and fuel cycle enterprise safety standards is planned

  9. Evolution of nuclear reactor containments in India: Addressing the present day challenges

    International Nuclear Information System (INIS)

    Indigenously developed Pressurized Heavy Water Reactors (PHWRs) that form the backbone of current stage of nuclear power development in India have seen continuous evolution of their containment systems. This evolution that has taken place over implementation of 18 PHWRs (200/220/540 MWe) has encompassed all aspects of containment design, viz. the structural system, energy management system, radio-activity management and hydrogen management system. As a part of ongoing efforts toward strengthening of safety performance, India is also ready with the design of Advance Heavy Water Reactor (AHWR), which represents a technology demonstrator for advanced reactor systems and for thorium utilization. This reactor has a number of improved passive safety features and it is capable of meeting the demanding safety challenges that future reactor system would be expected to meet as a result of emerging expectations in the background of accidents over the past three decades viz. those at Three Mile Island (1979), Chernobyl (1986) and most recently at Fukushima (2011). In this lecture I shall focus on the evolution of nuclear reactor containments in India and highlight the design, associated structural and thermal hydraulics safety assessment made over the years for the improvement of containment performance

  10. Local AREA networks in advanced nuclear reactors

    International Nuclear Information System (INIS)

    The report assesses Local Area Network Communications with a view to their application in advanced nuclear reactor control and protection systems. Attention is focussed on commercially available techniques and systems for achieving the high reliability and availability required. A basis for evaluating network characteristics in terms of broadband or baseband type, medium, topology, node structure and access method is established. The reliability and availability of networks is then discussed. Several commercial networks are briefly assessed and a distinction made between general purpose networks and those suitable for process control. The communications requirements of nuclear reactor control and protection systems are compared with the facilities provided by current technology

  11. Methods in nuclear reactors calculations

    International Nuclear Information System (INIS)

    Studies are made of the neutron transport equation corresponding to the the real and virtual reactors, as well as the starting hypotheses. Methods are developed to solve the transport equation in slab geometry, and Pl; Bl; Ml; Sn and discrete ordinates approximations. (Author)

  12. Technical characteristics of new generation of nuclear power plants; Charakterystyka techniczna elektrowni jadrowych nowej generacji

    Energy Technology Data Exchange (ETDEWEB)

    Janczak, R.; Mikulski, A.; Staron, E. [Instytut Energii Atomowej, Swierk-Otwock (Poland)

    1997-12-31

    The concept of Advanced Light Water Reactors (ALWR) as a new generation of nuclear reactors for energetics have been presented. The influence of reactor accidents (TMI and Chernobyl) on technical and scientific development of nuclear reactors has been discussed from the view point of safety assurance and requirements being defined by American and European Nuclear Regulatory commission. 12 refs, 14 figs.

  13. Nuclear safety. Concerns about the nuclear power reactors in Cuba

    International Nuclear Information System (INIS)

    In 1976, the Soviet Union and Cuba concluded an agreement to construct two 440-megawatt nuclear power reactors near Cienfuegos on the south central coast of Cuba, about 180 miles south of Key West, Florida. The construction of these reactors, which began around 1983, was a high priority for Cuba because of its heavy dependence on imported oil. Cuba is estimated to need an electrical generation capacity of 3,000 megawatts by the end of the decade. When completed, the first reactor unit would provide a significant percentage (estimated at over 15 percent) of Cuba's need for electricity. It is uncertain when Cuba's nuclear power reactors will become operational. On September 5, 1992, Fidel Castro announced the suspension of construction at both of Cuba's reactors because Cuba could not meet the financial terms set by the Russian government to complete the reactors. Cuban officials had initially planned to start up the first of the two nuclear reactors by the end of 1993. However, before the September 5 announcement, it was estimated that this reactor would not be operational until late 1995 or early 1996. The civil construction (such as floors and walls) of the first reactor is currently estimated to be about 90 percent to 97 percent complete, but only about 37 percent of the reactor equipment (such as pipes, pumps, and motors) has been installed. The civil construction of the second reactor is about 20 percent to 30 percent complete. No information was available about the status of equipment for the second reactor. According to former Cuban nuclear power and electrical engineers and a technician, all of whom worked at the reactor site and have recently emigrated from Cuba, Cuba's nuclear power program suffers from poor construction practices and inadequate training for future reactor operators. One former official has alleged, for example, that the first reactor containment structure, which is designed to prevent the accidental release of radioactive material into

  14. Chernobyl: a documentary story

    International Nuclear Information System (INIS)

    This account of the Chernobyl disaster of April 1986 is based on interviews with many of the participants. Realising that the Chernobyl accident was to have a massive impact on the USSR and the world, the author felt impelled to travel to the designated danger zone around the reactor, to live there and to interview firemen, first-aid workers, party and government officials and local media representatives. The result is a variety of vivid eyewitness accounts that are unprecedented in their detail and frankness. These accounts show why the author considers the Chernobyl accident to be the most important event in the Soviet Union since World War II. The book, itself a product of glasnost, reveals how the Chernobyl accident was viewed from inside the Soviet Union. (author)

  15. Advanced nuclear reactor systems - an Indian perspective

    International Nuclear Information System (INIS)

    The Indian nuclear power programme envisages use of closed nuclear fuel cycle and thorium utilisation as its mainstay for its sustainable growth. The current levels of deployment of nuclear energy in India need to be multiplied nearly hundred fold to reach levels of electricity generation that would facilitate the country to achieve energy independence as well as a developed status. The Indian thorium based nuclear energy systems are being developed to achieve sustainability in respect of fuel resource along with enhanced safety and reduced waste generation. Advanced Heavy Water Reactor and its variants have been designed to meet these objectives. The Indian High Temperature Reactor programme also envisages use of thorium-based fuel with advanced levels of passive safety features. (author)

  16. Reference Neutron Radiographs of Nuclear Reactor Fuel

    OpenAIRE

    Domanus, Joseph Czeslaw

    1986-01-01

    Reference neutron radiographs of nuclear reactor fuel were produced by the Euraton Neutron Radiography Working Group and published in 1984 by the Reidel Publishing Company. In this collection a classification is given of the various neutron radiographic findings, that can occur in different parts of pelletized, annular and vibro-conpacted nuclear fuel pins. Those parts of the pins are shown where changes of appearance differ from those for the parts as fabricated. Also radiographs of those as...

  17. Nuclear data for fusion reactor technology

    International Nuclear Information System (INIS)

    The meeting was organized in four sessions and four working groups devoted to the following topics: Requirements of nuclear data for fusion reactor technology (6 papers); Status of experimental and theoretical investigations of microscopic nuclear data (10 papers); Status of existing libraries for fusion neutronic calculations (5 papers); and Status of integral experiments and benchmark tests (6 papers). A separate abstract was prepared for each of these papers

  18. Radiation shield for nuclear reactors

    International Nuclear Information System (INIS)

    A reusable radiation shield for use in a reactor installation comprises a thin-walled, flexible and resilient container, made of plastic or elastomeric material, containing a hydrogenous fluid with boron compounds in solution. The container can be filled and drained in position and the fluid can be recirculated if required. When not in use the container can be folded and stored in a small space. The invention relates to a shield to span the top of the annular space between a reactor vessel and the primary shield. For this purpose a continuous toroidal container or a series of discrete segments is used. Other forms can be employed for different purposes, e.g. mattress- or blanket-like forms can be draped over potential sources of radiation or suspended from a mobile carrier and placed between a worker and a radiation source. (author)

  19. Nuclear reactor alignment plate configuration

    Science.gov (United States)

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R

    2014-01-28

    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  20. Chernobyl, 14 years later; Tchernobyl, 14 ans apres

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This report draws an account of the consequences of Chernobyl accident 14 years after the disaster. It is made up of 8 chapters whose titles are: (1) Some figures about Chernobyl accident, (2) Chernobyl nuclear power plant, (3)Sanitary consequences of Chernobyl accident, (4) The management of contaminated lands, (5) The impact in France of Chernobyl fallout, (6) International cooperation, (7) More information about Chernobyl and (8) Glossary.