The accidents during shutdown conditions Temelin NPP

International Nuclear Information System (INIS)

Sykora, M.; Mlady, O.

1996-01-01

Two parallel activities oriented for the accidents during shutdown conditions are performed at Temelin NPP: Development of symptom based emergency operating procedures (EOPs) applicable for the accidents which could occur during operational modes 1 through 4; independent evaluation of plant safety as part of the Temelin Shutdown probabilistic assessment to define the accidents which could occur during mode 5 and 6 for which the EOPs must be extended. Both these activities are in progress now because Temelin plant is still in the construction phase

Robot dispatching Scenario for Accident Condition Monitoring of NPP

International Nuclear Information System (INIS)

Kim, Jongseog

2013-01-01

In March of 2011, unanticipated big size of tsunami attacks Fukushima NPP, this accident results in explosion of containment building. Tokyo electric power of Japan couldn't dispatch a robot for monitoring of containment inside. USA Packbot robot used for desert war in Iraq was supplied to Fukushima NPP for monitoring of high radiation area. Packbot also couldn't reach deep inside of Fukushima NPP due to short length of power cable. Japanese robot 'Queens' also failed to complete a mission due to communication problem between robot and operator. I think major reason of these robot failures is absence of robot dispatching scenario. If there was a scenario and a rehearsal for monitoring during or after accident, these unanticipated obstacles could be overcome. Robot dispatching scenario studied for accident of nuclear power plant was described herein. Study on scenario of robot dispatching is performed. Flying robot is regarded as good choice for accident monitoring. Walking robot with arm equipped is good for emergency valve close. Short time work and shift work by several robots can be a solution for high radiation area. Thin and soft cable with rolling reel can be a good solution for long time work and good communication

Aspects of accident management in Cernavoda NPP

International Nuclear Information System (INIS)

Dascalu, N.

1999-01-01

As a general conclusion, the accident management system as implemented at Cerna voda NPP is expected to be appropriate for handling a severe accident, should it occur, in such a way that the environmental radiological consequences would be insignificant and radiation exposure of the personnel be within recommendations. It is recognized, however, that continued development and verification of the system as well as effective personnel training programs are essential to maintain the safety level achieved. (author)

Morbidity pattern of non-cancer endocrine disease in ChNPP accident emergency workers (1992-2013 Clinical/ Epidemiological Registry data)

International Nuclear Information System (INIS)

Kamyins'kij, O.V.; Pronyin, O.V.; Afanas'jev, D.Je.

2014-01-01

Effects of ionizing radiation and other hazardous factors on endocrine system in the ChNPP AEW appeared upon 15-25 years. There was a significant (2-10-fold) and reliable (p < 0.01) increase of the incidence of the nodular goiter, autoimmune thyroiditis, obesity, type 2 diabetes mellitus. And there is a trend to further increase

The post-accidents exploitation of Chernobyl NPP

International Nuclear Information System (INIS)

Nosovskij, A.V.

1996-01-01

Problems facing the Chernobyl NPP personnel since its commissioning and during its post-accident operation are considered. The accomplished measures on improving the power units safety, normalization of the radiation situation as well as the impact of psychological factor at the safety culture level are discussed

Some results of liquidation of accident effects at the Chernobyl' NPP

International Nuclear Information System (INIS)

Ignatenko, E.I.; Komarov, V.I.; Zverkov, V.V.; Proskuryakov, A.G.

1989-01-01

The results of works dealing with liquidation of accident effects at the Chernobyl' NPP are generalized. Some measures realized are estimated. Suggestions directed to efficiency increase when eliminating such accident effects are formulated

Sensitivity Analysis of Evacuation Speed in Hypothetical NPP Accident by Earthquake

Energy Technology Data Exchange (ETDEWEB)

Kim, Sung-yeop; Lim, Ho-Gon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Effective emergency response in emergency situation of nuclear power plant (NPP) can make consequences be different therefore it is regarded important when establishing an emergency response plan and assessing the risk of hypothetical NPP accident. Situation of emergency response can be totally changed when NPP accident caused by earthquake or tsunami is considered due to the failure of roads and buildings by the disaster. In this study evacuation speed has been focused among above various factors and reasonable evacuation speed in earthquake scenario has been investigated. Finally, sensitivity analysis of evacuation speed in hypothetical NPP accident by earthquake has been performed in this study. Evacuation scenario can be entirely different in the situation of seismic hazard and the sensitivity analysis of evacuation speed in hypothetical NPP accident by earthquake has been performed in this study. Various references were investigated and earthquake evacuation model has been developed considering that evacuees may convert their evacuation method from using a vehicle to walking when they face the difficulty of using a vehicle due to intense traffic jam, failure of buildings and roads, and etc. The population dose within 5 km / 30 km have been found to be increased in earthquake situation due to decreased evacuation speed and become 1.5 - 2 times in the severest earthquake evacuation scenario set up in this study. It is not agreed that using same emergency response model which is used for normal evacuation situations when performing level 3 probabilistic safety assessment for earthquake and tsunami event. Investigation of data and sensitivity analysis for constructing differentiated emergency response model in the event of seismic hazard has been carried out in this study.

Sensitivity Analysis of Evacuation Speed in Hypothetical NPP Accident by Earthquake

International Nuclear Information System (INIS)

Kim, Sung-yeop; Lim, Ho-Gon

2016-01-01

Effective emergency response in emergency situation of nuclear power plant (NPP) can make consequences be different therefore it is regarded important when establishing an emergency response plan and assessing the risk of hypothetical NPP accident. Situation of emergency response can be totally changed when NPP accident caused by earthquake or tsunami is considered due to the failure of roads and buildings by the disaster. In this study evacuation speed has been focused among above various factors and reasonable evacuation speed in earthquake scenario has been investigated. Finally, sensitivity analysis of evacuation speed in hypothetical NPP accident by earthquake has been performed in this study. Evacuation scenario can be entirely different in the situation of seismic hazard and the sensitivity analysis of evacuation speed in hypothetical NPP accident by earthquake has been performed in this study. Various references were investigated and earthquake evacuation model has been developed considering that evacuees may convert their evacuation method from using a vehicle to walking when they face the difficulty of using a vehicle due to intense traffic jam, failure of buildings and roads, and etc. The population dose within 5 km / 30 km have been found to be increased in earthquake situation due to decreased evacuation speed and become 1.5 - 2 times in the severest earthquake evacuation scenario set up in this study. It is not agreed that using same emergency response model which is used for normal evacuation situations when performing level 3 probabilistic safety assessment for earthquake and tsunami event. Investigation of data and sensitivity analysis for constructing differentiated emergency response model in the event of seismic hazard has been carried out in this study

Chernobyl NPP accident: a year later

International Nuclear Information System (INIS)

Asmolov, V.G.; Borovoj, A.A.; Demin, V.F.

1988-01-01

Consideration is being given to measures on liquidation of Chernobyl accident aftereffects, conducted since August, 1986. One of the most important measures lay in construction of the ''shelter'', which must provide long-term conservation of accidental unit. Works on decontamination of reactor area and contaminated populated regions were continued. Measures on providing safety of population and its health protection were performed. An attention was paid to long-term investigations on studying delayed aftereffects of the accident, monitoring of invironment, development and introduction of measures on improving NPP safety. Prospects of further development of nuclear power engeneering and possibilities of improving its safety are considered

Fission product source from Ignalina NPP in case of loss-of-coolant accidents

International Nuclear Information System (INIS)

Ubonavicius, E.; Rimkevicius, S.

2001-01-01

The release of radioactive materials to the environment is of special importance in the case of any accident at Nuclear Power Plants (NPP). The integrated analysis of thermal-hydraulic parameters behavior and radioactive fission products (FP) transport and deposition in the compartments play an important role in the evaluation of FP release to the environment and determines the irradiation dozes of personnel and public. In this report the transport and the deposition of radioactive material in the Ignalina NPP unit 1 compartments as well as the FP source term to the environment in the case of design basis loss-of-coolant accidents are discussed. The calculation models for the evaluation of FP transport and deposition as well as the results of performed calculations of several accidents at Ignalina NPP are presented. (author)

NPP Krsko containment environmental conditions during postulated accident

International Nuclear Information System (INIS)

Kozaric, M.; Cavlina, N.; Spalj, S.

1989-01-01

This paper presents NPP Krsko containment pressure and temperature increase during Loss of Coolant Accident (LOCA) and Main Steam Line Break (MSLB). Containment environmental condition calculation was performed by CONTEMPT4/MOD4 computer code. Design accident calculations were performed by RELAP4/MOD6 and RELAP5/MOD1 computer codes. Calculational abilities and application methodology of these codes are presented. The CONTEMPT code is described in more detail. The containment pressure and temperature time distribution are presented as well. (author)

Estimation and forecasting of the state of conifer forests in the area of the ChNPP accident

International Nuclear Information System (INIS)

Kozubov, G.M.; Taskaev, A.I.; Abaturov, Yu.D.

1989-01-01

Radiation monitoring of conifer forests was performed over the area of 15-20 hectare for all directions from the ChNPP. Biometric growth indices of pinetrees and sprucetrees during the period 1986-1988 were studied. The specific features of vegetative morphological changes in the mentioned trees were estimated for different absorbed dose rates. The quality factors of seeds were shown to be bioindicators of the absorbed doses in the case of highly chronic radiation injuries. In conclusion it was recommended to arrange a permanent radiation monitoring of radiation environment and to provide radiation protection of forests. figs. 2; tabs. 7

Analysis of heavy radiological accidents in NPP and gamma-irradiators

Energy Technology Data Exchange (ETDEWEB)

Angelov, V [Civil Defence Administration, Sofia (Bulgaria); Semova, T; Bonchev, Ts [Sofia Univ. (Bulgaria). Fizicheski Fakultet

1996-12-31

A review of several heavy radiological accidents, their cause, character, radioactivity emission, victims and economical impact is presented in the form of uniform tables. Eleven cases of incidents in power plants and 4 cases of accidents involving powerful gamma irradiators are considered. Radiological accidents in Bulgaria, not connected with the Kozloduy NPP, are listed. The human factor has been identified as the main cause for most of the accidents. It is stressed that the probability of heavy accident increases at the time of reactor refuelling, repair or testing. Technical failures could be eliminated by improved check and diagnostics procedures. 2 tabs., 12 refs.

Analysis of heavy radiological accidents in NPP and gamma-irradiators

International Nuclear Information System (INIS)

Angelov, V.; Semova, T.; Bonchev, Ts.

1995-01-01

A review of several heavy radiological accidents, their cause, character, radioactivity emission, victims and economical impact is presented in the form of uniform tables. Eleven cases of incidents in power plants and 4 cases of accidents involving powerful gamma irradiators are considered. Radiological accidents in Bulgaria, not connected with the Kozloduy NPP, are listed. The human factor has been identified as the main cause for most of the accidents. It is stressed that the probability of heavy accident increases at the time of reactor refuelling, repair or testing. Technical failures could be eliminated by improved check and diagnostics procedures. 2 tabs., 12 refs

Some problems connected with the Chernobyl NPP Unit 4 Accident

International Nuclear Information System (INIS)

Bar'yakhtar, V.G.

1994-01-01

The description of the eruption of radionuclides caused by the Chernobyl NPP Unit 4 Accident, including the effective time of the accident, quality and quantity of radio waste, is presented. A particular attention is given to the spotty structure of Chernobyl's contamination. The assumption that the spots distribution may be a consequence of the turbulent processes in the atmosphere is made

Radioactive waste management after NPP accident: Post-Chernobyl experience

International Nuclear Information System (INIS)

Mikhalevich, A.; Grebenkov, A.

2000-01-01

As a result of the Chernobyl NPP accident a very large amount of so-called 'Chernobyl waste' were generated in the territory of Belarus, which was contaminated much more than all other countries. These wastes relate mainly to two following categories: low-level waste (LLW) and new one 'Conventionally Radioactive Waste' (CRW). Neither regulations nor technology and equipment were sufficiently developed for such an amount and kind of waste before the accident. It required proper decisions in respect of regulations, treatment, transportation, disposal of waste, etc. (author)

RADIATION CONDITIONS IN KALUGA REGION 30 YEARS AFTER CHERNOBYL NPP ACCIDENT

Directory of Open Access Journals (Sweden)

A. G. Ashitko

2016-01-01

Full Text Available The article describes radiation conditions in the Kaluga region 30 years after the Chernobyl NPP accident. The Chernobyl NPP accident caused radioactive contamination of nine Kaluga region territories: Duminichsky, Zhizdrinsky, Kuibyshevsky, Kirovsky, Kozelsky, Ludinovsky, Meshchovsky, Ulyanovsky and Hvastovichsky districts. Radioactive fallout was the strongest in three southern districts: Zhizdrinsky, Ulyanovsky and Hvastovichsky, over there cesium-137 contamination density is from 1 to 15Ci/km. According to the Russian Federation Government Order in 2015 there are 300 settlements (S in the radioactive contamination zone, including 14 settlements with caesium-137 soil contamination density from 5 to 15 Ci/ km2 and 286 settlements with the contamination density ranging from 1 to 5 Ci/km2. In the first years after the Chernobyl NPP accident in Kaluga region territories, contaminated with caesium-137, there were introduced restrictive land usage, were carried out agrochemical activities (ploughing, mineral fertilizer dressing, there was toughened laboratory radiation control over the main doze-forming foodstuff. All these measures facilitated considerable decrease of caesium-137 content in local agricultural produce. Proceeding from the achieved result, in 2002 there took place the transition to more tough requirements SanPiN 2.3.2.1078-01. Analysis of investigated samples from Zhizdrinsky, Ulyanovsky and Hvastovichsky districts demonstrated that since 2005 meat samples didn’t exceed the standard values, same for milk samples since 2007. Till the present time, the use of wild-growing mushrooms, berries and wild animals meat involves radiation issues. It was demonstrated that average specific activity of caesium-137 in milk samples keeps decreasing year after year. Long after the Chernobyl NPP accident, the main products forming internal irradiation doses in population are the wild-growing mushrooms and berries. Population average annual

NPP Krsko Severe Accident Management Guidelines Implementation

International Nuclear Information System (INIS)

Basic, I.; Krajnc, B.; Bilic-Zabric, T.; Spiler, J.

2002-01-01

Severe Accident Management is a framework to identify and implement the Emergency Response Capabilities that can be used to prevent or mitigate severe accidents and their consequences. The USA NRC has indicated that the development of a licensee plant specific accident management program will be required in order to close out the severe accident regulatory issue (Ref. SECY-88-147). Generic Letter 88-20 ties the Accident management Program to IPE for each plant. The SECY-89-012 defines those actions taken during the course of an accident by the plant operating and technical staff to: 1) prevent core damage, 2) terminate the progress of core damage if it begins and retain the core within the reactor vessel, 3) maintain containment integrity as long as possible, and 4) minimize offsite releases. The subject of this paper is to document the severe accident management activities, which resulted in a plant specific Severe Accident Management Guidelines implementation. They have been developed based on the Krsko IPE (Individual Plant Examination) insights, Generic WOG SAMGs (Westinghouse Owners Group Severe Accident Management Guidances) and plant specific documents developed within this effort. Among the required plant specific actions the following are the most important ones: Identification and documentation of those Krsko plant specific severe accident management features (which also resulted from the IPE investigations). The development of the Krsko plant specific background documents (Severe Accident Plant Specific Strategies and SAMG Setpoint Calculation). Also, paper discusses effort done in the areas of NPP Krsko SAMG review (internal and external ), validation on Krsko Full Scope Simulator (Severe Accident sequences are simulated by MAAP4 in real time) and world 1st IAEA Review of Accident Management Programmes (RAMP). (author)

Diversity of microflora at the fourth destroyed unit of the ChNPP

International Nuclear Information System (INIS)

Parenyuk, O.Yu.; Shavanova, K.Je.; Yilljenko, V.V.; Gudkov, Yi.M.; Nanba, K.; Takasi, T.; Syimutyin, Yi.O.; Samofalova, D.O.; Ribalka, V.B.

2017-01-01

DNA of the substrate, sampled from six points in the destroyed 4-th power unit of ChNPP, where the dose rate on the microorganisms ranges from 0.008 to 0.12 Gy/h, was analyzed by New Generation Sequencing technology. It was found that the most diverse and stable microbiome occurs in sample, located outside of the ''Ukryttya'' object on the industrial site (conditional control). There are no dominants in it, which means that it is the most balanced and approximate to the general state of the soil microbiome of ecosystems surrounding the ChNPP. As for the sample, taken from the spot, where the dose rate was the highest, total number of species represented appeared eight times smaller, but dominance index was the highest, which indicates the formation of distinct microbiome dominants.

Generalization of Nuclear Safety and Course of Accident Events Research in the Ignalina NPP

International Nuclear Information System (INIS)

Kaliatka, A.; Uspuras, E.

2001-01-01

The safety analysis shown that after implementation of SAR recommendations Ignalina NPP is adequately protected against accidents which required fast initiation of automatic protections. In case of accidents with long-term loss of core cooling additional operator actions are required. Accident management in case long-term core cooling are analyzed in this paper. (author)

Development of filter module for passive filtration and accident gas release confinement system for NPP

International Nuclear Information System (INIS)

Yelizarov, P.G.; Efanov, A.D.; Martynov, P.N.; Masalov, D.P.; Osipov, V.P.; Yagodkin, I.V.

2005-01-01

Full text of publication follows: One of the urgent problems of the safe NPP operation is air cleaning from radioactive aerosols and volatile iodine compounds under the accident operation conditions of NPP. A principally new passive accident gas release confinement system is used as the basis of the designs of new generation reactor power blocks under the-beyond-design-basis accident conditions with total loss of current. The basic structural component of the passive filtration system (PFS) is the filter-sorber being heated up to 300 deg. C. The filter-sorber represents a design consisting of 150 connected in parallel two-step filtering modules. The first step is intended to clean air from radioactive aerosols, the second one - to clean air from radioactive iodine and its volatile compounds. The filter-sorber is located in the upper point of the exterior protection shell. Due to natural convection, it provides confinement of r/a impurities and controlled steam-gas release from the inter-shell space into atmosphere. The basic specific design feature is the two-section design of the PFS filter module consisting of a coarse-cleaning section and a fine-cleaning section. A combination of layer-by-layer put filtering materials on the basis of glass fiber and metal fiber. The pilot PFS filter module specimen tests run in conditions modeling accident situation indicated that at a filtration rate of 0,3 cm/s the aerodynamic resistance of the module does not exceed 12 Pa, the filtration effectiveness equals 99,99 % in terms of aerosol, no less than 99,9% in terms of radioactive 131 I and no less than 99,0% in terms of organic compounds of iodine (CH 3 131 I); the dust capacity amounts to a value above 50 g/m 2 . The obtained results of tests comply with the design requirements imposed on the PFS filter-sorber module. (authors)

Social aspects in evaluation of health status of subjects who participated in liquidation of radiation accident consequences

International Nuclear Information System (INIS)

Tukov, A.R.; Kleev, N.A.; Shafranskij, I.L.

2000-01-01

The morbidity rate of the Russian atomic industry workers, the liquidators of ChNPP accident consequences and their future life span shorting with an account of their social status are evaluated. Tentative and standard morbidity values were calculated with an account of various social groups of the liquidators. Intensive values of the man-year losses were used in the methodology for evaluating the vital potential losses. The study results indicated considerable morbidity difference in certain diseases by the persons of various social groups, who took part in liquidation of the ChNPP accident consequences [ru

NPP physical protection and information security as necessary conditions for reducing nuclear and radiation accident risks

International Nuclear Information System (INIS)

Pogosov, O.Yu.; Derevyanko, O.V.

2017-01-01

The paper focuses on the fact that nuclear failures and incidents can lead to radioactive contamination of NPP premises. Nuclear and radiation hazard may be caused by malefactors in technological processes when applying computers or inadequate control in case of insufficient level of information security.The researchers performed analysis of factors for reducing risks of nuclear and radiation accidents at NPPs considering specific conditions related to information security of NPP physical protection systems. The paper considers connection of heterogeneous factors that may increase the risk of NPP accidents, possibilities and ways to improve adequate modelling of security of information with limited access directly related to the functioning of automated set of engineering and technical means for NPP physical protection. Within the overall Hutchinson formalization, it is proposed to include additional functional dependencies on indicators specific for NPPs into analysis algorithms.

Integral thermal model of severe accident dynamics of NPP with containment

International Nuclear Information System (INIS)

Arutyunyan, R.V.; Bol'shov, L.A.; Vasil'ev, A.D.; Kamennov, G.P.

1991-01-01

An analytical model of the interaction of reactor core remains with concrete during severe accidents at nuclear power plants is considered. Time dependences of side and radial concrete melting are plotted. Time dependences of containment atmosphere temperature and pressure during a severe accident at nuclear power plants are investigated analytically and numerically. The sensitivity of the results to the coefficient values in the problem is studied within the range of their concertainty. The Kaverna-1 is described. The results of modelling a severe NPP accident which have been obtained using the Kaverna-1 package are presented

Environmental Impact Assessment following a Nuclear Accident to a Candu NPP

International Nuclear Information System (INIS)

Margeanu, C.A.; Margeanu, S.; Olteanu, Gh.

2009-01-01

The paper presents calculations of nuclear accident consequences to public and environment, for a Candu NPP using advanced fuel in two hypothetical accident scenarios: (1) large LOCA followed by partial core melting with early containment failure; (2) late core disassembly and containment bypass through ECCS. During both accidents a release occurs, radioactive contaminants being dispersed into atmosphere. As reference, estimations for Candu standard UO 2 fuel were used. The radioactive core inventory was obtained by using ORIGEN-S computer code included in ORNL,SCALE 5 programs package. Radiological consequences assessment to public and environment was performed by means of PC COSYMA computer code

Information on the Chernobyl NPP accident and its consequencies prepared for IAEA

Energy Technology Data Exchange (ETDEWEB)

1986-11-01

The information on the accident at the 4th power unit of the Chernobyl NPP and its consequences prepared for IAEA on the basis of the conclusions made by the Government commission constituted for investigating the accident causes and implementing the necessary emergency and reconstruction measures is given. The accident with reactor core disruption and partial destruction of the building Lappened on 26.04.86 at 1 hour and 23 minutes. The accident occurred before reactor shut-down for planned repairs during the testing of one of turbogenerators. The design features of the RBMK-1000 reactor plant, its main physical characteristics and parameters of the NPP safety system are considered. The chronology of the accident development and the results of analysis carried out using a mathematical model are given. The causes of the accident are analyzed. The measures for preventing the accident development and lessening its consequences as well as those for the environment radioactive contamination control and sanitary provisions are described in detail. The conclusion is made that the original cause of the accident is highly improbable combination of disorder and errors in operational conditions made by the personnel of the power unit. It is emphasized that development of the world nuclear engineering, besides advantages in the field of power supply and natural resources conservation, incurs also damages of international character. Among these are transboundary radioactivity transport, in particular, during serious radiation accidents and the danger of international terrorism and specific radiation hazard of nuclear objects under war conditions. All this defines the key necessity of deep international cooperation in the field of nuclear power engineering and its safeguarding.

Development of a dose assessment computer code for the NPP severe accident

International Nuclear Information System (INIS)

Cheong, Jae Hak

1993-02-01

A real-time emergency dose assessment computer code called KEDA (KAIST NPP Emergency Dose Assessment) has been developed for the NPP severe accident. A new mathematical model which can calculate cloud shine has been developed and implemented in the code. KEDA considers the specific Korean situations(complex topography, orientals' thyroid metabolism, continuous washout, etc.), and provides functions of dose-monitoring and automatic decision-making. To verify the code results, KEDA has been compared with an NRC officially certified code, RASCAL, for eight hypertical accident scenarios. Through the comparison, KEDA has been proved to provide reasonable results. Qualitative sensitivity analysis also the been performed for potentially important six input parameters, and the trends of the dose v.s. down-wind distance curve have been analyzed comparing with the physical phenomena occurred in the real atmosphere. The source term and meteorological conditions are turned out to be the most important input parameters. KEDA also has been applied to simulate Kori site and a hyperthetical accident with semi-real meteorological data has been simulated and analyzed

Comparison of HRA methods based on WWER-1000 NPP real and simulated accident scenarios

International Nuclear Information System (INIS)

Petkov, Gueorgui

2010-01-01

Full text: Adequate treatment of human interactions in probabilistic safety analysis (PSA) studies is a key to the understanding of accident sequences and their relative importance in overall risk. Human interactions with machines have long been recognized as important contributors to the safe operation of nuclear power plants (NPP). Human interactions affect the ordering of dominant accident sequences and hence have a significant effect on the risk of NPP. By virtue of the ability to combine the treatment of both human and hardware reliability in real accidents, NPP fullscope, multifunctional and computer-based simulators provide a unique way of developing an understanding of the importance of specific human actions for overall plant safety. Context dependent human reliability assessment (HRA) models, such as the holistic decision tree (HDT) and performance evaluation of teamwork (PET) methods, are the so-called second generation HRA techniques. The HDT model has been used for a number of PSA studies. The PET method reflects promising prospects for dealing with dynamic aspects of human performance. The paper presents a comparison of the two HRA techniques for calculation of post-accident human error probability in the PSA. The real and simulated event training scenario 'turbine's stop after loss of feedwater' based on standard PSA model assumptions is designed for WWER-1000 computer simulator and their detailed boundary conditions are described and analyzed. The error probability of post-accident individual actions will be calculated by means of each investigated technique based on student's computer simulator training archives

Investigation and evaluation for environmental impact at Fukushima Daiichi NPP accident

International Nuclear Information System (INIS)

2012-01-01

In 2012, JNES investigated the weather data and the environmental monitoring data and constructed the method to specify contribution of the environmental impact from each plant based on the dose analysis result at Unit 1-3 of Fukushima Daiichi NPP accident. JNES calculated the dose rate in an accident early stage based on analysis of a monitoring data. Moreover, JNES evaluated the dose by additional release of the radioactive material in case of assuming the loss of coolant injection to a nuclear reactor by the request of NISA. (author)

NPP accident scenario. Which emergency measures are planned in Switzerland?

International Nuclear Information System (INIS)

Flury, Christoph

2016-01-01

As a consequence of the reactor accident in Fukushima the Swiss government has ordered an extensive analysis of emergency planning in case of a NPP accident Switzerland. A special working group has analyzed the possible improvements of Swiss emergency planning based on the experiences in Japan. Under the special direction of the Bundesamt fuer Bevoelkerungsschutz (BABS) the agreed improvements were integrated into the emergency concept. The reference scenarios have been re-assessed and the zone concept adapted. The emergency measures include shelter-type rooms (basement or window-less rooms), the preventive distribution of iodine pills, measures concerning agriculture, aquatic systems, preventive evacuation, traffic regulations, and delayed evacuation.

Health of the population having suffered after the Chernobyl NPP accident

International Nuclear Information System (INIS)

Stozharov, A.N.; Zubovich, V.K.; Lazyuk, G.I.; Stel'makh, V.A.

1997-01-01

Are given the results of researches carried out in Belarus in 1996 on the following directions: study of influence of radiological consequences of the Chernobyl accident on health of the people; development of methods and means of diagnostics, treatment and preventive maintenance of diseases at various categories of victims; development and introduction in practice of effective methods of preventive maintenance and treatment of diseases of both mother and child in conditions of influence of the Chernobyl accident consequences; study of genetic consequences caused by the Chernobyl NPP accident and development of effectual measures of their prevention; creation of effective preventive means and food additives for treatment and rehabilitation of the persons having suffered after the Chernobyl accident; optimization of system of measures for health saving of the having suffered population and development of ways of increase of its efficiency

Evaluation of postpone Ch NPP accident consequences. Health state of children born in families of cleaners taking part in the Chernobyl accident consequences

International Nuclear Information System (INIS)

Koretskaya, L.S.; Kornesku, A.V.; Koretskaya, L.I.; Moldovanu, M.; Samotyya, E.E.; Etsko, L.A.

2009-01-01

The analysis of the results of the medical investigation during 1996-2008 years of the health of the about 200 children (107 girls, 115 boys 5-17 years old), which parents took part in liquidation of C NPP accident have been performed. Clinical, immunological disturbance and increased chromosome mutagenesis intensity in somatic cells of the investigated children gave reason to classify them among those with the increased risk of probability of the pathology with genetic component. This may be considerate as a well founded conclusion for elaboration of separated registry of the children born in families of liquidators. The immunological disturbance of children probably reflects the disturbance of the differential processes and maturity of cells of thymus and can be the consequences of the factors influence related with the clinic pathologies. The results permitted to select the group for feature cytogenesis and clinic investigations (authors)

Advances in safety countermeasures at the Tomari NPP of Hokkaido Electric Power on the basis of Fukushima Daiichi NPP accident. Fire protection and other advances

International Nuclear Information System (INIS)

Shibata, Taku; Dasai, Katsumi

2014-01-01

Fire protections for the nuclear power plants have been based on the fire laws and the conventional guide. After Fukushima Daiichi NPP accident, many safety countermeasures - also about Fire Protection - have been discussed in the Japanese authorities. This paper shows our present activities in the Tomari NPP about the fire protections from the view points of Fire Prevention, Fire Detection/Suppression Systems and Fire Protection, and other advances. (author)

Developing Off-site Emergency Preparedness and Response Model (OEPRM) for Severe Accident of NPP in a Densely Populated Country Using System Dynamics Approach

Energy Technology Data Exchange (ETDEWEB)

Hossena, Muhammed Mufazzal; Kang, Kyoung Ho; Song, Jin Ho [KAERI, Deajeon (Korea, Republic of)

2016-05-15

The main objectives of this study are to find the influencing factors of systems and sub-systems of OEPRM, to find the interdependency among the influencing factors, and to develop a conceptual qualitative OEPRM for densely populated NPP country in case of SA using system dynamics (SD). NPP accidents are classified as nuclear accidents and incidents depending on the severity. Severe accident (SA) is certain low probability accident that are beyond design basis accident which may arise due to multiple failures of safety systems leading to significant core degradation and jeopardize the integrity of many or all of the barriers to the release of radioactive material. The weakness to the off-site emergency response in the time of Fukushima accident was observed. So, it is crucial to develop an off-site emergency preparedness and responses model (OEPRM) for radiological emergency in densely populated country from the Fukushima emergency response lesson. In this study, an OEPRM is developed for densely populated NPP country to mitigate radiological effects in case of SA using SD approach. Besides, this study focuses the weakness of emergency response in Fukushima accident and proposed solution approach. The development of OEPRM in case of SA of NPP is very complex because of the involvement of various organization and it requires highly specialized agencies and technical experts. Moreover, if the country is agriculture based, it will make completely sophisticated.

Developing Off-site Emergency Preparedness and Response Model (OEPRM) for Severe Accident of NPP in a Densely Populated Country Using System Dynamics Approach

International Nuclear Information System (INIS)

Hossena, Muhammed Mufazzal; Kang, Kyoung Ho; Song, Jin Ho

2016-01-01

The main objectives of this study are to find the influencing factors of systems and sub-systems of OEPRM, to find the interdependency among the influencing factors, and to develop a conceptual qualitative OEPRM for densely populated NPP country in case of SA using system dynamics (SD). NPP accidents are classified as nuclear accidents and incidents depending on the severity. Severe accident (SA) is certain low probability accident that are beyond design basis accident which may arise due to multiple failures of safety systems leading to significant core degradation and jeopardize the integrity of many or all of the barriers to the release of radioactive material. The weakness to the off-site emergency response in the time of Fukushima accident was observed. So, it is crucial to develop an off-site emergency preparedness and responses model (OEPRM) for radiological emergency in densely populated country from the Fukushima emergency response lesson. In this study, an OEPRM is developed for densely populated NPP country to mitigate radiological effects in case of SA using SD approach. Besides, this study focuses the weakness of emergency response in Fukushima accident and proposed solution approach. The development of OEPRM in case of SA of NPP is very complex because of the involvement of various organization and it requires highly specialized agencies and technical experts. Moreover, if the country is agriculture based, it will make completely sophisticated

External Reactor Vessel Cooling Evaluation for Severe Accident Mitigation in NPP Krsko

International Nuclear Information System (INIS)

Mihalina, M.; Spalj, S.; Glaser, B.

2016-01-01

The In-Vessel corium Retention (IVR) through the External Reactor Vessel Cooling (ERVC) is mean for maintaining the reactor vessel integrity during a severe accident, by cooling and retaining the molten material inside the reactor vessel. By doing this, significant portion of severe accident negative phenomena connected with reactor vessel failure could be avoided. In this paper, analysis of NPP Krsko applicability for IVR strategy was performed. It includes overview of performed plant related analysis with emphasis on wet cavity modification, plant's site specific walk downs, new applicable probabilistic and deterministic analysis, evaluation of new possibilities for ERVC strategy implementation regarding plant's post-Fukushima improvements and adequacy with plant's procedures for severe accident mitigation. Conclusion is that NPP Krsko could perform in-vessel core retention by applying external reactor vessel cooling strategy with reasonable confidence in success. Per probabilistic and deterministic analysis, time window for successful ERVC strategy performance for most dominating plant damage state scenarios is 2.5 hours, when onset of core damage is observed. This action should be performed early after transition to Severe Accident Management Guidance's (SAMG). For loss of all AC power scenario, containment flooding could be initiated before onset of core damage within related emergency procedure. To perform external reactor vessel cooling, reactor water storage tank gravity drain with addition of alternate water is needed to be injected into the containment. ERVC strategy will positively interfere with other severe accident strategies. There are no negative effects due to ERVC performance. New flooding level will not threaten equipment and instrumentation needed for long term SAMGs performance and eventually diluted containment sump borated water inventory will not cause return to criticality during eventual recirculation phase due to the

Real-time management (RTM) by cloud computing system dynamics (CCSD) for risk analysis of Fukushima nuclear power plant (NPP) accident

Energy Technology Data Exchange (ETDEWEB)

Cho, Hyo Sung [Yonsei Univ., Wonju Gangwon-do (Korea, Republic of). Dept. of Radiation Convergence Engineering; Woo, Tae Ho [Yonsei Univ., Wonju Gangwon-do (Korea, Republic of). Dept. of Radiation Convergence Engineering; The Cyber Univ. of Korea, Seoul (Korea, Republic of). Dept. of Mechanical and Control Engineering

2017-03-15

The earthquake and tsunami induced accident of nuclear power plant (NPP) in Fukushima disaster is investigated by the real-time management (RTM) method. This non-linear logic of the safety management is applied to enhance the methodological confidence in the NPP reliability. The case study of the earthquake is modeled for the fast reaction characteristics of the RTM. The system dynamics (SD) modeling simulations and cloud computing are applied for the RTM method where the real time simulation has the fast and effective communication for the accident remediation and prevention. Current tablet computing system can improve the safety standard of the NPP. Finally, the procedure of the cloud computing system dynamics (CCSD) modeling is constructed.

Real-time management (RTM) by cloud computing system dynamics (CCSD) for risk analysis of Fukushima nuclear power plant (NPP) accident

International Nuclear Information System (INIS)

Cho, Hyo Sung; Woo, Tae Ho; The Cyber Univ. of Korea, Seoul

2017-01-01

The earthquake and tsunami induced accident of nuclear power plant (NPP) in Fukushima disaster is investigated by the real-time management (RTM) method. This non-linear logic of the safety management is applied to enhance the methodological confidence in the NPP reliability. The case study of the earthquake is modeled for the fast reaction characteristics of the RTM. The system dynamics (SD) modeling simulations and cloud computing are applied for the RTM method where the real time simulation has the fast and effective communication for the accident remediation and prevention. Current tablet computing system can improve the safety standard of the NPP. Finally, the procedure of the cloud computing system dynamics (CCSD) modeling is constructed.

Use of nonstatistical techniques for pattern recognition to detect risk groups among liquidators of the Chernobyl NPP accident aftereffects

International Nuclear Information System (INIS)

Blinov, N.N.; Guslistyj, V.P.; Misyurev, A.V.; Novitskaya, N.N.; Snigireva, G.P.

1993-01-01

Attempt of using of the nonstatistical techniques for pattern recognition to detect the risk groups among liquidators of the Chernobyl NPP accident aftereffects was described. 14 hematologic, biochemical and biophysical blood serum parameters of the group of liquidators of the Chernobyl NPP accident impact as well as the group of donors free of any radiation dose (controlled group) were taken as the diagnostic parameters. Modification of the nonstatistical techniques for pattern recognition based on the assessment calculations were used. The patients were divided into risk group at the truth ∼ 80%

Selection of optimal treatment procedures for non-standard radioactive waste arising from decommissioning of NPP after accident

Energy Technology Data Exchange (ETDEWEB)

Strážovec, Roman, E-mail: strazovec.roman@javys.sk [Institute of Nuclear and Physical Engineering, Slovak University of Technology in Bratislava, Ilkovičova 3, 812 19 Bratislava (Slovakia); JAVYS, a.s., Tomášikova 22, 821 02 Bratislava (Slovakia); Hrnčíř, Tomáš [DECOM, a.s., Sibírska 1, 917 01 Trnava (Slovakia); Lištjak, Martin [Institute of Nuclear and Physical Engineering, Slovak University of Technology in Bratislava, Ilkovičova 3, 812 19 Bratislava (Slovakia); VUJE, a.s., Okružná 5, 918 64 Trnava (Slovakia); Nečas, Vladimír [Institute of Nuclear and Physical Engineering, Slovak University of Technology in Bratislava, Ilkovičova 3, 812 19 Bratislava (Slovakia)

2016-05-15

The decommissioning of nuclear power plants is becoming a standard industrial activity where the optimization processes of partial activities are inevitable mainly for technical and economic reasons. In Slovakia, the decommissioning of A1 NPP is very specific case because A1 NPP is rare type of NPP (prototype) and furthermore its operation was affected by the accident. A large number of specific non-standard radioactive waste, such as long-time storage cases (hereinafter LSC), that is not usually present within the decommissioning projects of NPP with a regular termination of operation, represent one of the significant consequences of the accident and issues arisen from follow-up activities. The presented article describes the proposal of processing and conditioning of non-standard radioactive waste (such as LSC), together with description of methodology applied in the proposal for update of waste acceptance criteria for the processing and conditioning of radioactive waste (hereinafter RAW) within Bohunice Radioactive waste Treatment and Conditioning Centre (hereinafter RWTC). The results of performed detailed analysis are summarized into new waste acceptance criteria for technological lines keeping in mind safety principles and requirements for protection of operating personnel, the public and the environment.

Personal dosimetry at the radiation accidents

International Nuclear Information System (INIS)

Perevoznikov, O.N.; Klyuchnikov, A.A.; Kanchenko, V.A.

2007-01-01

The radiation accidents of different types and the methods of the dosimetry used at the consequences liquidation are considered. The long-term experience of the population personal instrumental dosimetric control carrying out at the ChNPP accident consequences liquidation is widely covered in details. The concepts are stated out and the results are presented on the functioning of the created system for personal dose monitoring of the population of Ukraine irradiation. The use of the person radiation counters at the internal irradiation population and personal dose assessment is considered in details

Age peculiarities of reproductive morbidity in female participants of the ChNPP accident consequences clean-up (according to the figures from SRU, 1988-2012 survey period)

International Nuclear Information System (INIS)

Majevs'ka, Yo.O.; Buzunov, V.O.

2015-01-01

Data on the Chernobyl disaster survivors received from the State Registry of Ukraine are out line in the paper. Review of the level and pattern of genital system morbidity was carried out for the 17,237 female participants of the ChNPP accident cleanup works in 1986-1987 depending on time under risk upon radiation expo sure and reproductive age at exposure. Survey period lasted since 1988 till 2012. Assessment of morbidity level, confidential intervals, and statistical significance was carried out using the trial version of OpenEpiversion 2.3.1. software. Statistical significance was also rated using the z-score and t- criterion. The results of this cohort epidemiological study showed that there are some peculiarities of natural course of the female genital system disease depending on reproductive age at exposure and time under risk upon radiation impact. Comparative statistical review of the level and pattern of genital system morbidity at different times within a survey period. Exposure to ionizing radiation in the childbearing age (18-45 years old) can be a risk factor of elevated incidence of uterine leiomyoma, benign mammary dysplasia (i.e. benign breast disease), and salpingooophoritis. It is far to assume that uterine and mammary tissues are more sensitive to impact of ionizing radiation in females of the childbearing age vs. in persons exposed in premenopause or menopause

Sensitivity and uncertainty analysis for Ignalina NPP confinement in case of loss of coolant accident

International Nuclear Information System (INIS)

Urbonavicius, E.; Babilas, E.; Rimkevicius, S.

2003-01-01

At present the best-estimate approach in the safety analysis of nuclear power plants is widely used around the world. The application of such approach requires to estimate the uncertainty of the calculated results. Various methodologies are applied in order to determine the uncertainty with the required accuracy. One of them is the statistical methodology developed at GRS mbH in Germany and integrated into the SUSA tool, which was applied for the sensitivity and uncertainty analysis of the thermal-hydraulic parameters inside the confinement (Accident Localisation System) of Ignalina NPP with RBMK-1500 reactor in case of Maximum Design Basis Accident (break of 900 mm diameter pipe). Several parameters that could potentially influence the calculated results were selected for the analysis. A set of input data with different initial values of the selected parameters was generated. In order to receive the results with 95 % probability and 95 % accuracy, 100 runs were performed with COCOSYS code developed at GRS mbH. The calculated results were processed with SUSA tool. The performed analysis showed a rather low dispersion of the results and only in the initial period of the accident. Besides, the analysis showed that there is no threat to the building structures of Ignalina NPP confinement in case of the considered accident scenario. (author)

Radiation state of environment in the 30-km zone of Chernobyl NPP, water objects

International Nuclear Information System (INIS)

Sukhoruchkin, A.K.

1994-01-01

The level of radioactivity in the zone of Chernobyl NPP before the accident is shown. The extremely high level of radioactive contamination produced by the release from the ChNPP at the accident declined as short-lived nuclides decayed. The aerial γ surveys of the 5 km zone of the ChNPP in October, 1986 and September, 1987 are shown. The radiation hygienic parameters of long-lived nuclides at the moment of release are presented. The main contribution to the dose in inhalation is expected from transuranium nuclides, and in ingestion, 90 Sr. The radiation situation in the 30 km zone is at present determined by 137 Cs, 90 Sr and transuranium nuclides, and such nuclide mixture is very unfavorable from the radiobiological point of view. The dosimetric monitoring of them is discussed. The soil contamination density in the 5 km zone is shown. The circumstances of the rich water resources in the region are explained, and the state of contamination is shown. The observation of radioactive contamination of the surface water of Pripyat River is described, and the results are shown. Much concern in the 30 km zone was aroused by the radiation state of groundwater at the places of the forced temporary burial of solid radioactive waste. The state of the cooling water pond in relation to Pripyat River is reported. (K.I.)

The contents of Cs 137 in ichthyofauna of cooling pond after removing of ChNPP from operation

International Nuclear Information System (INIS)

Zarubin, O.L.

2002-01-01

As a result of removing of ChNPP from operation, temperature and hydrological parameters of its cooling pond considerably have changed, that, in turn, has affected the earlier usual characteristic by this ecosystem and Cs 137 content in some its components

RADIATION HYGIENIC CONSEQUENCES OF THE ACCIDENT AT THE CHERNOBYL NPP AND THE TASKS OF THEIR MINIMIZATION

Directory of Open Access Journals (Sweden)

G. G. Onischenko

2009-01-01

Full Text Available The paper presents data on the role and results of activities of Rospotrebnadzor bodies and institutions in the field of ensuring population radiation protection during various periods since accident at the Chernobyl NPP. Radiation hygienic characterization of territories affected by radioactive contamination from the accident, population exposure dose range, issues of ensuring radiological well-being of population and ways of their solution are being presented in the paper.

Analysis of the behaviour of the Kozloduy NPP Unit 3 under severe accident conditions

International Nuclear Information System (INIS)

Velev, V.; Saraeva, V.

2004-01-01

The objective of the analysis is to study the behaviour of the Kozloduy NPP Unit 3 under severe accident conditions. The analysis is performed using computer code MELCOR 1.8.4. This report includes a brief description of Unit 3 active core as well as description and comparison of the key events

Dynamics of Sr-90 content in environmental objects of Ukrainian-Byelorussian Poles'e after the Chernobyl' NPP accident

International Nuclear Information System (INIS)

Likhtarev, I.A.; Kajro, I.A.; Shandala, N.K.; Los', I.N.; Repin, V.S.; Gul'ko, G.M.; Chepurnoj, N.I.; Berkovskij, V.B.; Tsygankov, N.Ya.; Pozhivalova, S.B.

1990-01-01

Ecological, dosemetric and radiation-sanitary aspects of the problem of Sr-90 contamination of environmental objects and food in Ukrainian-Byelorussian Poles'e in three-year period after the Chernobyl' NPP accident are discussed. Analysis of the materials collected shows that efficient equivalent radiation doses from Sr-90 being intaken into the region of Urkainian-Byelorussian Poles'e after the Chernobyl' NPP accident expected to be gained during 70 years of critical population group life are not exceed 1 mSv; this value is by the factor of 10-100 smaller than the dose values connected with radioactive cesium. The problem of environment contamination with Sr-90 transforms from hot radiation-sanitary situation into more quiet radioecological one

Accident localization system with jet condensers for VVER 440-V 230 NPP at Jaslovske Bohunice

International Nuclear Information System (INIS)

Murani, J.

1995-01-01

The operational safety of the V1 nuclear power plant (NPP) is unsatisfactory and does not correspond to present requirements as to nuclear safety. Further NPP operation after 1995 is conditional on nuclear safety enhancement to a level comparable with that in West European countries. This aim should be achieved by a principal reconstruction involving in addition to others also backfitting the V1 NPP with technical facilities aimed at coping with a design basis accident (DBA).To cope with such an accident the Power Equipment Research Institute (VUEZ) designed an accident localization system with jet condensers. This system consists of (a) an air trap (one for each unit, mutually interconnected) with an expansion bell enclosed within, placed on a plate with 200 pipes of jet condensers passing through, and (b) a connecting duct between the hermetic zone and the air trap. The vertical jet condenser is an essential element of the system designed for steam condensation. Apart from condensation it serves as a water seal separating units 1 and 2.Demonstration tests of the jet condenser (model 1:1) condensing function were carried out at the testing unit of the All-Union Research Institute for NPP Operation (VNIIAES), Moscow in Kashir, 11-22 September 1992. These experiments proved the jet condenser ability to ensure complete condensation of the steam produced. Experimental verification of the sealing function (model 1:1) was carried out at the testing unit of the VUEZ Tlmace. These experiments concerning the dynamics and overpressure in the free space above the pool were close to the conditions in the air trap during DBA. The jet condenser height was proved to be sufficient to ensure the sealing function. Design and experimental work has been implemented in close cooperation with Russian experts Mr. V.N. Bulynin from the VNIIAES, Moscow, and Mr. M.V. Kuznecov from the Scientific and Engineering Center for Nuclear and Radiological Safety, Moscow. (orig.)

Measurement of long-lived radionuclides in surface soil around F1NPP accident site by Accelerator Mass Spectrometry

Science.gov (United States)

Miyake, Yasuto; Matsuzaki, Hiroyuki; Sasa, Kimikazu; Takahashi, Tsutomu

2015-10-01

In March 2011, vast amounts of radionuclides were released into the environment due to the Fukushima Daiichi Nuclear Power Plant (F1NPP) accident. However, very little work has been done concerning accident-derived long-lived nuclides such as 129I (T1/2 = 1.57 × 107 year) and 36Cl (T1/2 = 3.01 × 105 year). 129I and 131I are both produced by 235U fission in nuclear reactors. Being isotopes of iodine, these nuclides are expected to behave similarly in the environment. This makes 129I useful for retrospective reconstruction of 131I distribution during the initial stages of the accident. On the other hand, 36Cl is generated during reactor operation via neutron capture reaction of 35Cl, an impurity in the coolant or reactor component. Resulting 36Cl/Cl ratio within the reactor is thus much higher compared to that in environment. Similar to 129I, 36Cl is expected to have leaked out during the accident and it is important to evaluate its effects. In this study, 129I concentrations were determined in several surface soil samples collected around F1NPP. Average 129I/131I ratio was estimated to be 26.1 ± 5.8 as of March 11, 2011, consistent with calculations using ORIGEN2 code and other published data. 36Cl/Cl ratios in some of the soil samples were likewise measured and ranged from 1.1 × 10-12 to 2.6 × 10-11. These are higher compared to ratios measured around F1NPP before the accident. A positive correlation between 36Cl and 129I concentration was observed.

A brief overview of Ignalina NPP safety issues

International Nuclear Information System (INIS)

Almenas, K.; Ushpuras, E.

1998-01-01

A description of the safety of Ignalina NPP in a very popular form is presented. Answers to the most frequently recurring questions concerning the Ignalina NPP are provided based on recently completed international studies. Questions are like these: can a similar accident to the one that occurred in Chernobyl take place at Ignalina NPP, does the Ignalina NPP have a containment, what are the probabilities and potential consequences of accidents, etc. The brochure contains a short description of Ignalina NPP safety improvement programs

New methods for rapid data acquisition of contaminated land cover after NPP accident

International Nuclear Information System (INIS)

Hulka, J.; Cespirova, I.

2009-01-01

Aim of the research project is the analysis of the modem and rapid reliable data acquisition methods for agricultural countermeasures, feed-stuff restrictions and clean-up of large contaminated areas after NPP accident. Acquiring agricultural reliable data especially based on satellite technology and analysis of landscape contamination (based on computer code vs. in situ measurements, airborne and/or terrestrial mapping of contamination) are discussed. (authors)

New methods for rapid data acquisition of contaminated land cover after NPP accident

International Nuclear Information System (INIS)

Hulka, J.; Cespirova, I.

2008-01-01

Aim of the research project is the analysis of the modem and rapid reliable data acquisition methods for agricultural countermeasures, feed-stuff restrictions and clean-up of large contaminated areas after NPP accident. Acquiring agricultural reliable data especially based on satellite technology and analysis of landscape contamination (based on computer code vs. in situ measurements, airborne and/or terrestrial mapping of contamination) are discussed. (authors)

Safety assessment and improvement of Ignalina NPP against downcomer ruptures outside Accident Localisation System

International Nuclear Information System (INIS)

Rimkevicius, S.; Urbonavicius, E.

2002-01-01

Accident Localisation System (ALS) of Ignalina NPP is a pressure suppression type confinement, designed to prevent the release of contaminated steam-water mixture to the environment in case of Loss-of-Coolant Accident (LOCA). One of the peculiarities of Ignalina NPP with RBMK-1500 reactors is that not all of the reactor coolant circuit is enclosed within ALS. Some part of downcomers, that connect Drum Separator (DS) and suction header of main circulation pump is located outside ALS. In case of downcomer rupture in DS compartment the discharge is not confined, but flows to the environment through the safety panels installed in the ceiling of DS compartments. Numerous safety analyses were performed to assess the safety of Ignalina NPP against downcomer break outside ALS, and results were used for different applications in order to improve the safety of the plant. This paper presents the overview of the performed analyses, recommendations raised and safety improvements made to enhance the safety level of NPP. One of the applications is to present the recommendations for safety improvement if maximal allowable pressure limits are exceeded. The calculations results demonstrate that in the case of two downcomers rupture in drum separators compartment the maximum permissible pressure in the reactor hall could be exceeded. The knock-out panels from the reactor hall to the environment were recommended and installed for reactor hall overpressure protection. The evaluation of the drainage system efficiency from DS compartments was performed. In this case the especial attention was paid to analyse the water collection and drainage system behaviour in long term after postulated breaks. The analysis results showed that the modernization of the drainage system prevents the accumulation of the released water in the compartments even in the case of two downcomer pipes ruptures, and decreases the release of radioactive fission products (FP) to the environment.(author)

Training center of Rovenskaya NPP. The experience of creation

International Nuclear Information System (INIS)

Fedorov, O.M.; Aristov, B.N.

1991-01-01

Experience in creation of a teaching-training centre at the Rovno NPP, which uses means available at unified NPPs, at most is discussed. The centre hardware complex functions include the event filing and providing for user-friendly interface with NPP technical personnel under training. The system of personnel training at the Rovno NPP teaching-training centre gives an opportunity to analyze accidents and emergency conditions more completely and carefully. The taching analysis of failures and accidents by a NPP operators using the complex of the teaching-training centre hardware sufficiently improves knowledge of particular accidents

Peculiarities of hormonal regulation of physical development and bone tissue in children born after accident at Chernobyl nuclear power plant

International Nuclear Information System (INIS)

Antipkin, Y.G.; Arabskaya, L.P.

2003-01-01

Investigation of three groups of children being from 5 to 12 years old born after ChNPP accident was conducted. The 1 group consisted of 128 children lived in radionuclide contaminated territories. The 2 group consisted from 128 children born in families of the Chernobyl accident consequences liquidators (ACL). The 3 group consisted of 96 children lived in 'relatively clean' territories. Revealed age and gender differences in height growth activation periods, i.e. the second and third 'spurts' of height rise kids from the radiation study groups occur later than in children from 'conditionally clean' territories. Body height growth in children of both gender residing in radiation-contaminated territories occurs within the same age periods. Body height growth in kids born in families of the ChNPP accident liquidators occurred more fluently with neither pre-pubertal, nor pubertal 'spurt' of height in boys and no pubertal one - in girls, that is stipulated by low basal GH level (and low testosterone in boys)

Rupture of DN 500 - design basic accident at units 3 and 4 of Kozloduy NPP

International Nuclear Information System (INIS)

Uruchev, V.; Vassilev, P.; Ivanova, A.; Sartmadjiev, A.

2005-01-01

The original design of Kozloduy NPP Units 3 and 4 assumes as Design Basis Accident (DBA) the rupture of DN 32 mm primary pipeline, while an initial event of double-sided guillotine break of primary pipeline with maximal diameter is not considered. In the course of units modernization it have been demonstrated once and again that both the emergency core cooling systems and the localization systems can cope with larger and larger primary circuit leaks. After the installation of a Jet-Vortex Condenser (JVC) at Units 3 and 4 it was substantiated that, the integrity of the hermetic rooms is ensured even in case of double-sided guillotine break of a primary circuit pipeline with maximal diameter (DEGB). The technical justification of the jet-vortex condenser, elaborated by VNIAEC, contains calculations determining both the source term and the doses obtained outside the NPP site after LOCA DN 500. LOCA DN 500 is considered in these analyses as a beyond design basis accident and it is so included in the SAR and approved by the Nuclear Regulatory Agency (NRA). The thermo-hydraulic calculations performed later on show that the emergency core cooling systems can cope with this initial event at conservative assumptions. In order to classify this initiating event as a design basis accident it is necessary to demonstrate that the core cooling criteria are fulfilled and the internal and external doses outside the NPP site are within the permissible limits fixed for design basis accident by the Bulgarian regulatory body (NRA), when using conservative assumptions. For this purpose two consecutive studies were performed - evaluation of the DEGB probability and categorization of the initial event according to the contemporary regulations acting in Republic of Bulgaria. The presented report summarizes the results of the performed conservative analyses of double-sided guillotine break accident of main circulation line taking into account the probability of rupture of large diameter

Measurement of long-lived radionuclides in surface soil around F1NPP accident site by Accelerator Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Miyake, Yasuto; Matsuzaki, Hiroyuki [Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo (Japan); Sasa, Kimikazu; Takahashi, Tsutomu [AMS Group, Tandem Accelerator Complex, Research Facility Center for Science and Technology, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan)

2015-10-15

In March 2011, vast amounts of radionuclides were released into the environment due to the Fukushima Daiichi Nuclear Power Plant (F1NPP) accident. However, very little work has been done concerning accident-derived long-lived nuclides such as {sup 129}I (T{sub 1/2} = 1.57 × 10{sup 7} year) and {sup 36}Cl (T{sub 1/2} = 3.01 × 10{sup 5} year). {sup 129}I and {sup 131}I are both produced by {sup 235}U fission in nuclear reactors. Being isotopes of iodine, these nuclides are expected to behave similarly in the environment. This makes {sup 129}I useful for retrospective reconstruction of {sup 131}I distribution during the initial stages of the accident. On the other hand, {sup 36}Cl is generated during reactor operation via neutron capture reaction of {sup 35}Cl, an impurity in the coolant or reactor component. Resulting {sup 36}Cl/Cl ratio within the reactor is thus much higher compared to that in environment. Similar to {sup 129}I, {sup 36}Cl is expected to have leaked out during the accident and it is important to evaluate its effects. In this study, {sup 129}I concentrations were determined in several surface soil samples collected around F1NPP. Average {sup 129}I/{sup 131}I ratio was estimated to be 26.1 ± 5.8 as of March 11, 2011, consistent with calculations using ORIGEN2 code and other published data. {sup 36}Cl/Cl ratios in some of the soil samples were likewise measured and ranged from 1.1 × 10{sup −12} to 2.6 × 10{sup −11}. These are higher compared to ratios measured around F1NPP before the accident. A positive correlation between {sup 36}Cl and {sup 129}I concentration was observed.

Experience in reconstruction of psychological reality for persons engaged in elimination of the Chernobyl' NPP accident effects

International Nuclear Information System (INIS)

Salamatov, V.A.; Nyagu, A.T.

1990-01-01

The results of psichosemantic studies of adaptation process are discussed, i.e. the consciousness contents for personnel (120 persons) engaged in works connected with the Chernobyl' NPP accident effect elimination and reconstruction of the subjective image of the Chernobyl' NPP 30-km zone on this basis are described. The mental tension for the zone personnel is estimated. The results obtained testify to the presence of chronic stress and exceeding the level of psychoemotional tension. Increases in the uneasiness level and emotional instability for the personnel are revealed

Radioecological monitoring of the Black Sea basin following the Chernobyl NPP accident

International Nuclear Information System (INIS)

Kulebakina, L.G.; Polikarpov, G.G.

1991-01-01

A monitoring programme was drawn up to study the radioecological situation of the Black Sea basin following the Chernobyl NPP accident, with studies being carried out from May 1986 onwards to determine the levels of radioactive contamination in various parts of the Black Sea, the Sea of Azov and the Aegean Sea, including the estuaries of major rivers (Dnieper, Danube, Dniester and Don) and shelf areas of the Black Sea and the Sea of Azov. The work focused on long-lived radionuclides ( 90 Sr and 137 Cs), with the migration dynamics of these radionuclides in the aquatic environment, bed sediments and aquatic biota (including plants, molluscs, crustacea and fish) being studied. We compared the behaviour of radionuclides in the aquatic environment of the Dnieper reservoirs following the Chernobyl accident (our data) with the behaviour of radionuclides in lakes in the Urals following the Kyshtym accident (published data). As in the case of the lakes in the Urals, the Dnieper waters contain substantial concentrations of 90 Sr as a result of the Chernobyl accident, and 90 Sr therefore enters the Black Sea with the Dnieper waters. The paper compares the contribution of the Chernobyl accident to radioactive contamination of the Black Sea with that of global fallout. (author)

Environmental and agricultural impacts of the Chernobyl NPP accident on the countries of the northern hemisphere

International Nuclear Information System (INIS)

Yang Xuexian

1990-12-01

The accident at the Chernobyl Nuclear Power Plant (NPP) on April 26, 1986 resulted in large quantities of radioactive materials being released into the atmosphere. The environmental contaminations and agricultural impacts of the accident on the countries of the northern hemisphere were reviewed. Radiological consequences of the accident were briefly assessed. The data were presented on the results of radioactivity monitoring for air, ground and water, average individual effective dose commitment for each county, and levels of contamination on plant cover, milk, meat in live animals, food, aquatic, and other agricultural products etc. The transfer coefficients of radionuclides in grass-(cow)-milk were listed. Finally, problems on radioecology were discussed

Carrying out and planning measures for improvement of radiation situation in alienation zone after accident at Chernobyl NPP

International Nuclear Information System (INIS)

Kazakov, S.V.

1994-01-01

Technogenic radionuclides that were released into environment as the result of the Chernobyl accident joined the energy and mass transfer processes, which to a great extent are determined by the specificity of natural and climatic conditions of Ukrainian woodlands. The state of the spread of radioactive materials, and the data furnished by the Dosimetric Monitoring Board of the NPO 'Pripyat' over the zone territory are reported. After the primary radioactive contamination of the terrain, with meteorfactors superimposed on the physical and chemical conditions of radioactivity release and topographic factors, a new type of vegetation has developed, as well as a pattern of the economic exploitation of the territory. The process of radioactivity redistribution by water, wind and technogenic transport must be carefully investigated. The studies on radionuclide migration and the results are discussed. The estimation of dynamic capacitance in soil in the nearby zone of the ChNPP, the studies of hydrogeological condition in the 10 km zone, the analysis of groundwater condition, the studies on the wind-lift transport and fallout of radionuclides in 30 km zone and others are reported. Decontamination measures, one of the most large scale and labor-intensive operations in the elimination of the accident effects, and the burial of radioactive waste are described. The requirements for executing the project are summarized. (K.I.)

Carrying out and planning measures for improvement of radiation situation in alienation zone after accident at Chernobyl NPP

Energy Technology Data Exchange (ETDEWEB)

Kazakov, S.V. [Nauchno-Proizvodstvennoe Ob``edinenie Pripyat`, Chernobyl` (Ukraine)

1994-11-01

Technogenic radionuclides that were released into environment as the result of the Chernobyl accident joined the energy and mass transfer processes, which to a great extent are determined by the specificity of natural and climatic conditions of Ukrainian woodlands. The state of the spread of radioactive materials, and the data furnished by the Dosimetric Monitoring Board of the NPO `Pripyat` over the zone territory are reported. After the primary radioactive contamination of the terrain, with meteorfactors superimposed on the physical and chemical conditions of radioactivity release and topographic factors, a new type of vegetation has developed, as well as a pattern of the economic exploitation of the territory. The process of radioactivity redistribution by water, wind and technogenic transport must be carefully investigated. The studies on radionuclide migration and the results are discussed. The estimation of dynamic capacitance in soil in the nearby zone of the ChNPP, the studies of hydrogeological condition in the 10 km zone, the analysis of groundwater condition, the studies on the wind-lift transport and fallout of radionuclides in 30 km zone and others are reported. Decontamination measures, one of the most large scale and labor-intensive operations in the elimination of the accident effects, and the burial of radioactive waste are described. The requirements for executing the project are summarized. (K.I.).

ESTE EMO and ESTE EBO - emergency response system for NPP Mochovce and NPP Bohunice V-2

International Nuclear Information System (INIS)

Caeny, P.; Chyly, M.; Suchon, D.; Smejkalova, E.; Fabova, V.; Mancikova, M.; Muller, P.

2009-01-01

Programs ESTE EMO and ESTE EBO are emergency response systems that help the crisis staff of the NPP in assessing the source term (predicted possible release of radionuclides to the atmosphere ), in assessing the urgent protective measures and sectors under threat, in assessing real release (symptoms of release really detected and observed), in calculating radiological impacts of real release, averted or avertable doses, potential doses and doses during transport or evacuation on specified routes. Both systems serve as instruments in case of severe accident (DBA or BDBA) at NPP Mochovce or NPP Bohunice, accidents with threat of release of radioactivity to the atmosphere. Systems are implemented at emergency centre of Mochovce NPP and Bohunice NPP and connected online to the sources of technological and radiological data from the reactor, primary circuit, confinement, secondary circuit, ventilation stack, from the area of NPP (TDS 1) and from the emergency planning zone (TDS 11). Systems are connected online to the sources of meteorological data, too. (authors)

ESTE EMO and ESTE EBO - emergency response system for NPP Mochovce and NPP Bohunice V-2

International Nuclear Information System (INIS)

Caeny, P.; Chyly, M.; Suchon, D.; Smejkalova, E.; Fabova, V.; Mancikova, M.; Muller, P.

2008-01-01

Programs ESTE EMO and ESTE EBO are emergency response systems that help the crisis staff of the NPP in assessing the source term (predicted possible release of radionuclides to the atmosphere ), in assessing the urgent protective measures and sectors under threat, in assessing real release (symptoms of release really detected and observed), in calculating radiological impacts of real release, averted or avertable doses, potential doses and doses during transport or evacuation on specified routes. Both systems serve as instruments in case of severe accident (DBA or BDBA) at NPP Mochovce or NPP Bohunice, accidents with threat of release of radioactivity to the atmosphere. Systems are implemented at emergency centre of Mochovce NPP and Bohunice NPP and connected online to the sources of technological and radiological data from the reactor, primary circuit, confinement, secondary circuit, ventilation stack, from the area of NPP (TDS 1) and from the emergency planning zone (TDS 11). Systems are connected online to the sources of meteorological data, too. (authors)

Lessons learned from the decommissioning process affected by an accident during operation. The case of A1 NPP in Slovakia

International Nuclear Information System (INIS)

Daniska, Vladimir; Timulak, Jan; Pekar, Anton; Niznansky, Vojtech; Konecny, Ladislav

2007-01-01

Decommissioning of NPP's with standard shutdown is currently well known process. The A1 NPP in Slovakia was shutdown in 1977 after the accident in the core which caused the damage of the fuel and contamination of systems. Long period from 1977 to 2008 was needed to manage issues resulting from affecting the systems and structures of A1 NPP and the environment by the accident. Management of the damaged spent fuel, decontamination of the primary circuit and other processes generated large amounts of alpha bearing waste, mostly liquid, having sludge phases with specific physical-chemical and radiological properties. Up to 1994, the approach for eliminating the consequences of the accident was based on safety priorities. The systematic approach, which includes also the rehabilitation of the affected environment, was implemented in the period 1994-2008. The process includes also establishing of the decommissioning infrastructure, legislative and funding system with the aim to implement the standard decommissioning procedures after 2008. However, the specific aspects, especially the level and radio-nuclide composition of contamination of systems and structures will remain. For final decommissioning 2008-2033, the approach was selected which foresees four licensed phases. This approach enables proper planning and performing of individual decommissioning phases. (authors)

137Cs and 90Sr in the water of the ChNPP cooling pond

Directory of Open Access Journals (Sweden)

V. V. Kanivets

2014-12-01

Full Text Available Results of long-term observations on 137Cs and 90Sr concentration in water mass of the ChNPP Cooling Pond are presented. Drastic transformation of the intrinsic trend in changes with time of averaged radionuclides con-tent in water is clearly demonstrated alongside with the spatial heterogeneity of radioactive contamination of water body. The cycling character of seasonal changes of 137Cs activity concentration in water is being linked to hydrochemical, temperature and oxygen regimes of the Cooling Pond.

Beyond designed functional margins in CANDU type NPP. Radioactive nuclei assessment in an LOCA type accident

Directory of Open Access Journals (Sweden)

Budu Andrei Razvan

2015-01-01

Full Text Available European Union's energy roadmap up to year 2050 states that in order to have an efficient and sustainable economy, with minimum or decreasing greenhouse gas emissions, along with use of renewable resources, each constituent state has the option for nuclear energy production as one desirable option. Every scenario considered for tackling climate change issues, along with security of supply positions the nuclear energy as a recommended option, an option that is highly competitive with respect to others. Nuclear energy, along with other renewable power sources are considered to be the main pillars in the energy sector for greenhouse gas emission mitigation at European level. European Union considers that nuclear energy must be treated as a highly recommended option since it can contribute to security of energy supply. Romania showed excellent track-records in operating in a safe and economically sound manner of Cernavoda NPP Units 1&2. Both Units are in top 10 worldwide in terms of capacity factor. Due to Romania's need to ensure the security of electricity supply, to meet the environmental targets and to move to low carbon generation technologies, Cernavoda Units 3&4 Project appears as a must. This Project was started in 2010 and it is expected to have the Units running by 2025. Cost effective and safety operation of a Nuclear Power Plant is made taking into consideration functional limits of its equipment. As common practice, every nuclear reactor type (technology used is tested according to the worse credible accident or equipment failure that can occur. For CANDU type reactor, this is a Loss of Cooling Accident (LOCA. In a LOCA type accident in a CANDU NPP, using RELAP/SCDAP code for fuel bundle damage assessment the radioactive nuclei are to be quantified. Recently, CANDU type NPP accidents are studied using the RELAP/SCDAP code only. The code formerly developed for PWR type reactors was adapted for the CANDU geometry and can assess the

Generalization of Nuclear Safety and Course of Accident Events Research in the Ignalina NPP; Branduolines saugos ir avariju eigos Ignalinos AE tyrimu apibendrinimas

Energy Technology Data Exchange (ETDEWEB)

Kaliatka, A; Uspuras, E [Lithuanian Energy Institute, Kaunas (Lithuania)

2001-07-01

The safety analysis shown that after implementation of SAR recommendations Ignalina NPP is adequately protected against accidents which required fast initiation of automatic protections. In case of accidents with long-term loss of core cooling additional operator actions are required. Accident management in case long-term core cooling are analyzed in this paper. (author)

Checking of seismic and tsunami hazard for coastal NPP of Chinese continent after Fukushima nuclear accident

Institute of Scientific and Technical Information of China (English)

Chang Xiangdong; Zhou Bengang; Zhao Lianda

2013-01-01

A checking on seismic and tsunami hazard for coastal nuclear power plant (NPP) of Chinese continent has been made after Japanese Fukushima nuclear accident caused by earthquake tsunami.The results of the checking are introduced briefly in this paper,including the evaluations of seismic and tsunami hazard in NPP siting period,checking results on seismic and tsunami hazard.Because Chinese coastal area belongs to the continental shelf and far from the boundary of plate collision,the tsunami hazard is not significant for coastal area of Chinese continent.However,the effect from tsunami still can' t be excluded absolutely since calculated result of Manila trench tsunami source although the tsunami wave is lower than water level from storm surge.The research about earthquake tsunami will continue in future.The tsunami warning system and emergency program of NPP will be established based on principle of defense in depth in China.

Calculation of an accident with delayed scram at NPP Greifswald using the coupled code DYN3D/ATHLET

Energy Technology Data Exchange (ETDEWEB)

Kliem, S

1998-10-01

Complex computer codes modeling the whole reactor system including 3D neutron kinetics in combination with advanced thermohydraulic plant models become more and more important for the safety assessment of nuclear reactors. Transients or experiments with both neutron kinetic and thermalhydraulic data are needed for the validation of such coupled codes like DYN3D/ATHLET. First of all measured results from nuclear power plant (NPP) transients should be used, because the experimental thermalhydraulic facilities do not offer the possibility to model space-dependent neutron kinetic effects and research reactors with reliably measured 3D neutron kinetic data do not allow to study thermalhydraulic feedback effects. In this paper, an accident with delayed scram which occurred in 1989 at the NPP Greifswald is analyzed. Calculations of this accident were carried out with the goal to validate the coupled code DYN3D/ATHLET. (orig.)

Calculation of an accident with delayed scram at NPP Greifswald using the coupled code DYN3D/ATHLET

International Nuclear Information System (INIS)

Kliem, S.

1998-01-01

Complex computer codes modeling the whole reactor system including 3D neutron kinetics in combination with advanced thermohydraulic plant models become more and more important for the safety assessment of nuclear reactors. Transients or experiments with both neutron kinetic and thermalhydraulic data are needed for the validation of such coupled codes like DYN3D/ATHLET. First of all measured results from nuclear power plant (NPP) transients should be used, because the experimental thermalhydraulic facilities do not offer the possibility to model space-dependent neutron kinetic effects and research reactors with reliably measured 3D neutron kinetic data do not allow to study thermalhydraulic feedback effects. In this paper, an accident with delayed scram which occurred in 1989 at the NPP Greifswald is analyzed. Calculations of this accident were carried out with the goal to validate the coupled code DYN3D/ATHLET. (orig.)

Issues on safe radioactive waste management at ChNPP site in International Shelter Implementation Plan

International Nuclear Information System (INIS)

Bykov, V.; Kilochytska, T.; Gromyko, S.; Kadkin, Y.; Kondratiev, S.; Pavlenko, A.; Bogorinski, P.

2003-01-01

The International Shelter Implementation Plan (SIP) [1], is aimed to convert the ChNPP unit 4, destroyed by a beyond-design accident in 1986, into an environmentally safe facility by means of large-scale projects such as stabilization of the existing Sarcophagus (Shelter), construction of a New Safe Confinement (NSC), and installation of engineering and monitoring systems. This report presents some important safety issues concerning radioactive waste (RAW) management at the Shelter. One of the main problems of RAW management is to dispose of large volumes of RAW generated during ground preparation work. It is necessary that RAW be sorted carefully to separate low-active radioactive waste (LLW), which will be the majority, from high-level waste. Considering the fact that the Shelter is in the exclusion zone, the interim storage of LLW in this zone is possible, but a set of safety measures is required, e.g. prevention of dust generation or spreading of radioactivity with water. Another problem is high level RAW management. Highly radioactive fragments of the core, including fuel were ejected during the accident and are now buried under the man-made layer around the Shelter. Unanticipated disclosure of such fragments may happen during any ground preparation work as well as during clearing of premises inside the damaged buildings. Therefore, permanent radiation monitoring is required to prevent any intolerable exposure of workers. Unanticipated disclosure of high-active radioactive waste (HLW) could lead to considerable delay of any work. Since it is particularly difficult to remove HLW from those locations, which can not be easily accessed with removal equipment, such waste needs to be confined and properly shielded at in situ. Due to absence of a permanent HLW storage, an interim storage needs to be provided for in the territory of the Sarcophagus. (author)

Emergency preparedness at Ignalina NPP

International Nuclear Information System (INIS)

Kairys, A.

1998-01-01

Brief review of Ignalina NPP safety upgrading and personnel preparedness to act in cases of accidents is presented. Though great activities are performed in enhancing the plant operation safety, the Ignalina NPP management pays a lot of attention to preparedness for emergency elimination and take measures to stop emergency spreading. A new Ignalina NPP emergency preparedness plan was drawn up and became operational. It is the main document to carry out organizational, technical, medical, evacuation and other activities to protect plant personnel, population, the plant and the environment from accident consequences. Great assistance was rendered by Swedish experts in drawing this new emergency preparedness plan. The plan consists of 3 parts: general part, operative part and appendixes. The plan is applied to the Ignalina NPP personnel, Special and Fire Brigade and also to other contractor organizations personnel carrying out works at Ignalina NPP. There are set the following emergency classes: incident, emergency situation, alert, local emergency, general emergency. Separate intervention level corresponds to each emergency class. Overview of personnel training to act in case of an emergency is also presented

Characteristics of border nervous-mental disorders for victims connected with the Chernobyl' NPP accident

International Nuclear Information System (INIS)

Sapsaj, S.A.

1992-01-01

It is revealed that border nervouse-mental disorders for victims connected with the Chernobyl' NPP accident are the most widely spread diseases. Their specific features are the following: prevalence of the disorders from asthenic and psycho-organic circles; relatively small positive dynamics in the cause of treatment; uniformity in symptoms, which do not depend on psychological characteristics of a person. Particular efforts should be concentrated on developing psychosocial programs for rendering the victims help. 3 refs

The EC TACIS project 'Social impact of closing Chornobyl NPP' objectives, tasks and intended outcomes

International Nuclear Information System (INIS)

Schoen, A.

2001-01-01

Being part of the common activities of Slavutich and ChNPP, our EC TACIS project representatives already actively participated in the elaboration of the state programme aimed to ensure the social security of the ChNPP personnel and the population of Slavutich in the result of the final shut down of ChNPP

Radiation safety of the helicopter air crow-liquidators of the Chernobyl NPP accident

International Nuclear Information System (INIS)

Davydov, B.I.; Ponomarenko, V.A.; Ushakov, I.B.

1992-01-01

Three aspects of the radiation safety of the helicopter air crew who took part in the elimination of the Chernobyl NPP accident after-effects during the period from the 27-th of April to July 1986 were considered: dosimetry, physical protection and radioprotector use. 1125 subjects from the flight and engineer personnel were irradiated: 6%-2.5 mSv and more, 32%-2.1-2.5 mSv and about 60% - up to 2.0 mSv. It is stated that the use of physical protection (local screening of a pilot seat and use of special antiradiation belts) makes irradiation doe 2-3 times less. In the intense conditions of flight activity the pilots preferred the radioprotector adrenaline to cystamin. Alimentary aids in the earlier and later periods after the accident influenced favourably somatic and psychic states. 16 refs.; 1 tab

An experience of information support of the Russian federal programs of the overcoming of consequences of the accident at the Chernobyl NPP

International Nuclear Information System (INIS)

Linge, I.I.; Ossipiants, I.A.; Ilushkin, I.I.; Melihova, E.I.; Blinov, B.K.; Marchenko, T.A.

2002-01-01

Since 1992, by a number of paragraphs of the federal programs on overcoming consequences of accident on Chernobyl NPP, the measures on informational-analytic support of the federal programs were provided. Within the framework of this activity for the solution of various aspects of Chernobyl's problem central bank of generalized data and numerous information systems were created. In the report the brief description of some of them is presented. In particular the databank on radioactive situation includes the information on 12 thousand settlements of Russia which have been exposed to radioactive contamination as a result of the accident.The medico-demographic section of a databank includes information on death rate for the reasons for all subjects of Russian Federation since 1982 till the present time. The developed information systems are available to all participants of work on overcoming of consequences of the accident. There are given the examples of integral estimates in short- and long-term forecasts of development of a situation in territories suffered by the accident at the Chernobyl NPP. (author)

Lessons learned and implications of the Fukushima NPP accidents

International Nuclear Information System (INIS)

Tokuhiro, A.

2014-01-01

The global nuclear 'enterprise' is now 3-1/2 years (March 11, 2011) beyond the historic Tohoku earthquake (M9.0), subsequent tsunami (~14-15m waves), and unfortunately, the continuing consequences of the 'Fukushima nuclear power plant (NPP) accident. We now live in the post-Fukushima nuclear era. First let us pay our respects to this tragic loss-of-life (~16,000 fatalities) as a result of the earthquake and tsunami; also 10-years earlier in 2004, centered further south in the Indian Ocean (230,000+ fatalities). The movie, 'The Impossible', was a reminder that indeed, energy provides sustenance and socio-economic development for humankind. Energy will determine the state of AsiaPacific (AP) in years to come. Over the past 15-years, AP has clearly had increasing means to lead global economic growth, relative to stagnating economies of scale in Europe and U.S. AP also has both existing and emerging larger-scale industrial ambitions and capital to construct new nuclear power plants (NPPs). China has some 25-28 units under construction at 11 sites; the near-term goal is to establish 40GW of generating capacity by 2020 and to reach some 70-75GW approximately 10 years later. Although some investments are also being made in renewable energy, the demand for capacity clearly dictates further growth in nuclear power. However, unless high expectations for safety, safety culture are concurrently encouraged, we may face the next nuclear accident again in Asia. This work looks at the technical and non-technical lessons learned from the Fukushima Daiichi accident and the implications that we cannot afford to ignore. (author)

Lessons learned and implications of the Fukushima NPP accidents

Energy Technology Data Exchange (ETDEWEB)

Tokuhiro, A., E-mail: tokuhio@uidaho.edu [Univ. of Idaho, Idaho Falls, ID (United States)

2014-07-01

The global nuclear 'enterprise' is now 3-1/2 years (March 11, 2011) beyond the historic Tohoku earthquake (M9.0), subsequent tsunami (~14-15m waves), and unfortunately, the continuing consequences of the 'Fukushima nuclear power plant (NPP) accident. We now live in the post-Fukushima nuclear era. First let us pay our respects to this tragic loss-of-life (~16,000 fatalities) as a result of the earthquake and tsunami; also 10-years earlier in 2004, centered further south in the Indian Ocean (230,000+ fatalities). The movie, 'The Impossible', was a reminder that indeed, energy provides sustenance and socio-economic development for humankind. Energy will determine the state of AsiaPacific (AP) in years to come. Over the past 15-years, AP has clearly had increasing means to lead global economic growth, relative to stagnating economies of scale in Europe and U.S. AP also has both existing and emerging larger-scale industrial ambitions and capital to construct new nuclear power plants (NPPs). China has some 25-28 units under construction at 11 sites; the near-term goal is to establish 40GW of generating capacity by 2020 and to reach some 70-75GW approximately 10 years later. Although some investments are also being made in renewable energy, the demand for capacity clearly dictates further growth in nuclear power. However, unless high expectations for safety, safety culture are concurrently encouraged, we may face the next nuclear accident again in Asia. This work looks at the technical and non-technical lessons learned from the Fukushima Daiichi accident and the implications that we cannot afford to ignore. (author)

Assessment of effectiveness of anti-seismic measures in stabilization project of ChNPP shelter object

International Nuclear Information System (INIS)

Kondrat'ev, S.N.; Kritskij, V.B.; Ryzhov, D.I.; Shugajlo, A.P.; Shugajlo, Al.P.; Prabkhakara, M.

2004-01-01

The major factors, which may lead to the collapse of the Shelter object (SO) civil structures, are extreme natural phenomena and among them earthquake. In order to raise the resistance of the SO civil structure to seismic and other significant loads and to reduce the risk of their collapse ChNPP requested KSK Consortium to develop the SO Detailed Design for stabilization. At the present work the results of assessment of anti-seismic measures are given based on results of a technical review of the Detailed Design

Ignalina NPP Safety Analysis: Models and Results

International Nuclear Information System (INIS)

Uspuras, E.

1999-01-01

Research directions, linked to safety assessment of the Ignalina NPP, of the scientific safety analysis group are presented: Thermal-hydraulic analysis of accidents and operational transients; Thermal-hydraulic assessment of Ignalina NPP Accident Localization System and other compartments; Structural analysis of plant components, piping and other parts of Main Circulation Circuit; Assessment of RBMK-1500 reactor core and other. Models and main works carried out last year are described. (author)

Development of Highly Survivable Power and Communication System for NPP Instruments under Severe Accident

Energy Technology Data Exchange (ETDEWEB)

Yoo, Seung J.; Gu, Beom W.; Nguyen, Duy T.; Choi, Bo H.; Rim, Chun T. [KAIST, Daejeon (Korea, Republic of); Lee, So I. [KHNP CRI, Daejeon (Korea, Republic of)

2014-10-15

According to the detail report from the Fukushima nuclear accident, the failure of conventional instruments is mainly due to the following reasons. 1) Insufficient backup battery capacity after the station black out (SBO) 2) The malfunction or damage of instruments due to the extremely harsh ambient condition after the severe accident 3) The cut-off of power and communication cable due to the physical shocks of hydrogen explosion after the severe accident Since the current equipment qualification (EQ) for the NPP instruments is based on the design basis accident such as loss of coolant accident (LOCA), conventional instruments, which are examined under EQ condition, cannot guarantee their normal operation during the severe accident. A 7m-long-distance wireless power transfer and a radio frequency (RF) communication were introduced with conventional wired system to increase a redundancy. A heat isolation box and a harness are adopted to provide a protection from the expected physical shocks such as missiles and drastic increase of ambient temperature and pressure. A detail design principle of the highly survivable power and communication system, which has 4 sub-systems of a DCRS wireless power transfer, a Zigbee wireless communication, a GFRP harness, and a passive type router with a fly back regulator, has been presented in this paper. Each sub-system has been designed to have a robust operation characteristic regardless of the estimated physical shocks after the severe accident.

Development of Highly Survivable Power and Communication System for NPP Instruments under Severe Accident

International Nuclear Information System (INIS)

Yoo, Seung J.; Gu, Beom W.; Nguyen, Duy T.; Choi, Bo H.; Rim, Chun T.; Lee, So I.

2014-01-01

According to the detail report from the Fukushima nuclear accident, the failure of conventional instruments is mainly due to the following reasons. 1) Insufficient backup battery capacity after the station black out (SBO) 2) The malfunction or damage of instruments due to the extremely harsh ambient condition after the severe accident 3) The cut-off of power and communication cable due to the physical shocks of hydrogen explosion after the severe accident Since the current equipment qualification (EQ) for the NPP instruments is based on the design basis accident such as loss of coolant accident (LOCA), conventional instruments, which are examined under EQ condition, cannot guarantee their normal operation during the severe accident. A 7m-long-distance wireless power transfer and a radio frequency (RF) communication were introduced with conventional wired system to increase a redundancy. A heat isolation box and a harness are adopted to provide a protection from the expected physical shocks such as missiles and drastic increase of ambient temperature and pressure. A detail design principle of the highly survivable power and communication system, which has 4 sub-systems of a DCRS wireless power transfer, a Zigbee wireless communication, a GFRP harness, and a passive type router with a fly back regulator, has been presented in this paper. Each sub-system has been designed to have a robust operation characteristic regardless of the estimated physical shocks after the severe accident

Chernobyl'-90. Reports of the 1. International conference on biological and radioecological aspects of the Chernobyl' NPP accident effects. V. 2, part 2. Radiation sanitary. Radiobiology. Agricultural radioecology

International Nuclear Information System (INIS)

Senin, E.V.

1990-01-01

The results of works done in 1988-1990 within the ecology part of the complex program dealing with elimination of the Chernobyl' NPP accident effect in regions of Ukraine, Belarus and Russia, as well as the data of foreign specialists on the Chernobyl' radioactive fallout effects in many countries are analyzed. Comparative analysis of the methods, means and results of acitivities dealing with accident effect eliminations on South Urals and at the Chernobyl' NPP is given

Chernobyl'-90. Reports of the 1. International conference on biological and radioecological aspects of the Chernobyl' NPP accident effects. V. 2, part 1. Radiation sanitary. Radiobiology. Agricultural radioecology

International Nuclear Information System (INIS)

Senin, E.V.

1990-01-01

The results of works done in 1988-1990 within the ecology part of the complex program dealing with elimination of the Chernobyl' NPP accident effects in regions of Ukraine, Belarus and Russia, as well as the data of foreign specialists on the Chernobyl' radioactive fallout effects in many countries are analyzed. Comparative analysis of the methods, means and results of activities dealing with accident effect eliminations on South Urals and at the Chernobyl' NPP is given

Japan Catastrophic Earthquake and Tsunami in Fukushima Daiichi NPP; Is it Beyond Design Basis Accident or a Design Deficiency and Operator Unawareness?

International Nuclear Information System (INIS)

Gaafar, M.A.; Refeat, R.M.; EL-Kady, A.A.

2012-01-01

On March 11, 2011 a catastrophic earthquake and tsunami struck the north east coast of Japan. This catastrophe damaged fully or partially the six units of the Fukushima Daiichi Nuclear Power Plant.Questions were raised following the aftermath, whether it is beyond design basis accident caused by severe natural event or a failure by the Japanese authorities to plan to deal with such accident. There are many indications that the Utility of Fukushima Daiichi NPP, Tokyo Electric Power Company (TEPCO), did not pay enough attention to numerous facts about the incompatibility of the site and several design defects in the plant units. In fact there are three other NPP sites nearby Fukushima Daiichi Plant (about 30 to 60 Km far from Fukushima Daiichi NPP), with different site characteristics, which survived the same catastrophic earthquake and tsunami, but they were automatically turned into a safe shutdown state. These plants sites are Fukushima Daini Plant (4 units), Onagawa Plant (3 units) and Tokai Daini (II) Plant (one unit). In this paper, the aftermath Fukushima Daiichi plant integrity is pointed out. Some facts about the site and design concerns which could have implications on the accident are discussed. The response of Japan Authority is outlined and some remarks about their actions are underlined. The impacts of this disaster on the Nuclear Power Program worldwide are also discussed.

Status of antiviral immunity in patients with non-alcoholic liver fatty disease, who were Chornobyl NPP accident liquidators

Directory of Open Access Journals (Sweden)

A.A. Chumak

2017-11-01

Full Text Available 34 men were examined, who after participating in the liquidation of the Chornobyl NPP accident developed non-alcoholic fatty liver disease. The state of antiviral defense was evaluated by the levels of immunoglobulin (Ig G and IgM antibodies in the blood serum. In most patients with non-alcoholic steatohepatitis, who were Chornobyl NPP accident liquidators, antibodies of the IgG, but not IgM class to the persistent mixed infection with herpes simplex virus types 1 and 2, cytomegaly and Epstein-Barr were found. A positive correlation was established between the antibody titers to the herpes simplex virus types 1 and 2 (anti-HSV-1/2 IgG and cytomegalovirus (anti-CMV IgG (rs = 0.383, p = 0.040, as well as between the antibodies titers to the nuclear antigen of Epstein-Barr virus (anti-EBV NA IgG and antibodies to core antigen of Epstein-Barr (anti-EBV VCA IgG (rs = 0.584, p = 0.002 in patients with persistent mixed infection of these herpesviruses.

Transuranium elements intake during works connected with the Chernobyl' NPP accident effect elimination

International Nuclear Information System (INIS)

Popov, V.I.; Kukhta, B.A.; Kononykhina, N.N.

1992-01-01

The materials of studies realized in 1989, 1990, 1991 and dealing with internal irradiation control caused by intake of transuranium elements (TUE) for the Chernobyl' NPP personnel and persons engaged in the accident effect elimination are generalized. the leading part of TUE inhalation intake in formation of internal irradiation doses is revealed. Evaluation of TUE inhalation intake hazards is made according to the results of measuring TUE activity in urine samples for the personnel examined (271 persons). The results of surveillance shows the effect of organism internal irradiation connected with TUE intake through respiratory organs. 23 refs.; 1 tab

Radioactive wastes management of NPP

International Nuclear Information System (INIS)

Klyuchnikov, A.A.; Pazukhin, Eh.M.; Shigera, Yu. M.; Shigera, V.Yu.

2005-01-01

Modern knowledge in the field of radiation waste management on example of the most serious man-made accident at Chernobyl NPP are illuminated. This nuclear power plant that after accident in 1986 became in definite aspect an experimental scientific ground, includes all variety of problems which have to be solved by NPP personnel and specialists from scientific organizations. This book is aimed for large sphere of readers. It will be useful for students, engineers, specialists and those working in the field of nuclear power, ionizing source and radiation technology use for acquiring modern experience in nuclear material management

Radionuclides contamination of fungi after accident on the Chernobyl NPP

Energy Technology Data Exchange (ETDEWEB)

Zarubina, Nataliia E.; Zarubin, Oleg L. [Institute for Nuclear Research of National Academy of Sciense, 03680, pr-t Nauki, 47, Kiev (Ukraine)

2014-07-01

Accumulation of radionuclides by the higher fungi (macromycetes) after the accident on the Chernobyl atomic power plant in 1986 has been studied. Researches were spent in territory of the Chernobyl alienation zone and the Kiev region. Our research has shown that macromycetes accumulate almost all types of radionuclides originating from the accident ({sup 131}I, {sup 140}Ba /{sup 140}La, {sup 103}Ru, {sup 106}Ru, {sup 141}Ce, {sup 144}Ce, {sup 95}Nb, {sup 95}Zr, {sup 137}Cs and {sup 134}Cs). They accumulate the long-living {sup 90}Sr in much smaller (to 3 - 4 orders) quantities than {sup 137}Cs. We have established existence of two stages in accumulation of {sup 137}Cs by higher fungi after the accident on the Chernobyl NPP: the first stage resides in the growth of the concentration, the second - in gradual decrease of levels of specific activity of this radionuclide. Despite reduction of {sup 137}Cs specific activity level, the content of this radionuclide at testing areas of the 5-km zone around the Chernobyl NPP reaches 1,100,000 Bq/kg of fresh weight in 2013. We investigated dynamics of accumulation of Cs-137 in higher fungi of different ecological groups. One of the major factors that influence levels of accumulation of {sup 137}Cs by fungi is their nutritional type (ecological group). Fungi that belong to ecological groups of saprotrophes and xylotrophes accumulate this radionuclide in much smaller quantities than symbio-trophic fungi. As a result of the conducted research it has been established that symbio-trophic fungi store more {sup 137}Cs than any other biological objects in forest ecosystems. Among the symbio-trophic fungi species, species showing the highest level of {sup 137}Cs contamination vary in different periods of time after the deposition. It is connected with variability of quantities of these radio nuclides accessible for absorption at the depth of localization of the main part of mycelium of each species in a soil profile. Soil contamination

ACCIDENT AT «FUKUSHIMA-»I NPP: FIRST RESULTS OF EMERGENCY RESPONSE REPORT 2: ACTIVITIES OF THE ROSPOTREBNADZOR AUTHORITIES FOR THE RADIATION PROTECTION OF THE RUSSIAN FEDERATION POPULATION ON THE EARLY STAGE OF ACCIDENT

Directory of Open Access Journals (Sweden)

G. G. Onischenko

2011-01-01

Full Text Available Basic measures of the Rospotrebnadzor emergency response during the early stage of the «Fukushima-I» NPP radiation accident are being analyzed in the article. Radiation monitoring of the environmental objects of the territories of the Russian Federation Far East Federal District, radiation control of arriving from Japan vehicles, freights and passengers as well as imported from Japan food products were promptly organized. This allowed to get reliable evaluations of the levels of radioactive contamination at the Russian Federation territory and population exposure doses due to the «Fukushima-I» NPP accident, timely exclude the possibility of import to the Russian territory for the freights, vehicles, food products having contamination exceeding established in the Russian Federation standards.

Modelling of melting and solidification transport phenomena during hypothetical NPP severe accidents

International Nuclear Information System (INIS)

Sarler, B.

1992-01-01

A physical and mathematical framework to deal with the transport phenomena occuring during melting and solidification of the hypothetical NPP severe accidents is presented. It concentrates on the transient temperature, velocity, and species concentration distributions during such events. The framework is based on the Mixture Continuum Formulation of the components and phases, cast in the boundary-domain integral shape structured by the fundamental solution of the Laplace equation. The formulation could cope with various solid-liquid sub-systems through the inclusion of the specific closure relations. The deduced system of boundary-domain integral equations for conservation of mass, energy, momentum, and species could be solved by the boundary element discrete approximative method. (author) [sl

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Basic parameters of the Cs 137 contents in some components of trophic chains of Kanevskoe reservoir after accident on Chernobyl NPP

International Nuclear Information System (INIS)

Zarubin, O.L.; Pan'kov, I.V.; Volkova, E.N.; Belyaev, V.V.

2002-01-01

The analysis of parameters of radioactive pollution of water and biota of Kanevskoe reservoir has shown, what even in 15 years after accident on Chernobyl NPP, the distribution of Cs 137 on the basic components by this ecosystem has not achieved an equilibrium condition

Conference: Nuclear Safety at the Ignalina NPP - Achievements and Challenges

International Nuclear Information System (INIS)

1999-01-01

Brief description of conference which took place in Vilnius on 8-9 April 1999 is presented. The aim of the international conference is to review the work carried out, to evaluate its influence on the nuclear safety, to get acquainted with the safety system of the Ignalina NPP. On December 31, the Ignalina NPP celebrated its 15 year anniversary. During that period the Ignalina NPP has produced more than 182 billion kWh of electricity. Nuclear power is not only immense economic benefit but also a syndrome of fear of an atomic bomb and the Chernobyl accident that has formed over the years. Numerous comprehensive international studies have been performed at the Ignalina NPP. After the Chernobyl accident many steps have been taken to improve the safety of the Ignalina NPP. The introduced changes guaranteed that the void coefficient remained negative in all possible circumstances. The Ignalina NPP is intensively preparing for licensing of unit 1

Integrated framework for the external cost assessment of nuclear power plant accident considering risk aversion: The Korean case

International Nuclear Information System (INIS)

Lee, Sang Hun; Kang, Hyun Gook

2016-01-01

Recently, the estimation of accident costs within the social costs of nuclear power plants (NPPs) has garnered substantial interest. In particular, the risk aversion behavior of the public toward an NPP accident is considered an important factor when integrating risk aversion into NPP accident cost. In this study, an integrated framework for the external cost assessment of NPP accident that measures the value of statistical life (VSL) and the relative risk aversion (RRA) coefficient for NPP accident based on an individual-level survey is proposed. To derive the willingness to pay and the RRA coefficient for NPP accident risks, a survey was conducted on a sample of 1550 individuals in Korea. The estimation obtained a mean VSL of USD 2.78 million and an RRA coefficient of 1.315. Based on the estimation results in which various cost factors were considered, a multiplication factor of 5.16 and an external cost of NPP accidents of 4.39E−03 USD-cents/kW h were estimated. This study is expected to provide insight to energy policy decision-makers on analyzing the economic validity of NPP compared to other energy sources by reflecting the estimated external cost of NPP accident into the unit electricity generation cost of NPP. - Highlights: •External cost assessment framework for NPP is proposed considering risk aversion. •VSL was derived from WTP for mortality risk reduction from hypothetical NPP accident. •RRA was derived to integrate public risk aversion into external cost of NPP accident. •Individual-level survey was conducted to derive WTP and RRA for NPP accident risk. •The external cost was estimated considering the direct cost factors of NPP accident.

NPP Krsko Containment Response Following Main Steam Line Break

International Nuclear Information System (INIS)

Spalj, S.; Grgic, D.; Cavlina, N.

2000-01-01

This paper presents the calculation of thermohydraulic environmental parameters (pressure and temperature) inside containment of Krsko NPP after postulated Main Steam Line Break (MSLB) accident. This analysis was done as a part of the ambient parameters specification in the frame of the NPP Krsko Equipment Qualification (EQ) project. The RELAP5/mod2 computer code was used for the determination of MSLB mass and energy release and computer code GOTHIC was used to calculate pressure and temperature profiles inside NPP Krsko containment. The analysis was performed for spectrum of break sizes to account for possible steam superheating during accidents with smaller break sizes. (author)

Qinshan NPP large break LOCA safety analysis

International Nuclear Information System (INIS)

Shi Guobao; Tang Jiahuan; Zhou Quanfu; Wang Yangding

1997-01-01

Qinshan NPP is the first nuclear power plant in the mainland of China, a 300 MW(e) two-loop PWR. Large break LOCA is the design-basis accident of Qinshan NPP. Based on available computer codes, the own analysis method which complies with Appendix k of 10 CFR 50 has been established. The RELAP4/MOD7 code is employed for the calculations of blowdown, refill and reflood phase of the RCS respectively. The CONTEMPT-LT/028 code is used for the containment pressure and temperature analysis. The temperature transient in the hot rod is calculated using the FRAP-6T code. Conservative initial and functional assumptions were adopted during Qinshan NPP large break LOCA analysis. The results of the analysis show the applicable acceptance criteria for the loss-of-coolant accident are met

Chernobyl'-88. Reports of the 1. All-Union scientific and technical meeting on results of accident effect elimination at the Chernobyl' NPP. V. 7. Part 1. Localization of accident consequences at the 4th power unit, operating site of the Chernobyl NPP and adjoining territories

International Nuclear Information System (INIS)

Ignatenko, E.I.

1989-01-01

The next data on the accident consequence elimination are presented: temperature monitoring results, gamma radiation exposure dose rates, neutron and gamma fields, aerosol disperse composition. The information system for scientific researches FINISH and automatic subsystems for radiation control and the Ukrytie object diagnostics are described. Decontamination of the Chernobyl' NPP territory, equipment and rooms is described too

Chernobyl'-88. Reports of the 1. All-Union scientific and technical meeting on results of accident effect elimination at the Chernobyl' NPP. V. 7. Part 2. Localization of accident consequences at the 4th power unit, operating site of the Chernobyl' NPP and adjoining territories

International Nuclear Information System (INIS)

Ignatenko, E.I.

1989-01-01

The next data on the accident consequence elimination are presented: temperature monitoring results, gamma radiation exposure dose rates, neutron and gamma fields, aerosol disperse composition. The information system for scientific researches FINISH and automatic subsystems for radiation control and the Ukrytie object diagnostics are described. Decontamination of the Chernobyl' NPP territory, equipment and rooms is described too

Safety reassessment of the Paks NPP (the AGNES project)

Energy Technology Data Exchange (ETDEWEB)

Gado, J [Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics; Bajsz, J; Cserhati, A; Elter, J [Paksi Atomeroemue Vallalat, Paks (Hungary); Hollo, E [Energiagazdalkodasi Intezet, Budapest (Hungary); Kovacs, K [EROTERV Engineering and Contractor Co (Hungary); Maroti, L [Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics; Miko, S [Paksi Atomeroemue Vallalat, Paks (Hungary); Techy, Z [Energiagazdalkodasi Intezet, Budapest (Hungary); Vidovszky, I [Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics

1996-12-31

The reassessment of the Paks NPP safety according to internationally recognized criteria of the Advanced General and New Evaluation of Safety (AGNES) project is outlined. The Paks NPP consists of four WWER-440/V-213 units. The following groups of analysis have been performed: system analysis and description; analysis of design basis accidents; severe accidents analysis; level 1 probabilistic safety analysis. Postulated accidents (PA) and Anticipated Operational Occurrences (AOO) are estimated in detail for the following initiating events: increase/decrease in secondary heat removal; decrease in primary coolant inventory; increase/decrease of reactor coolant inventory; reactivity and power distribution anomalies; analysis of transients with the failure of reactor scram (ATWS); pressurized thermal shock analyses. Severe accident analysis was made for the accidents on in-vessel phase and containment phase, for radioactive release and for accident management.

Safety reassessment of the Paks NPP (the AGNES project)

International Nuclear Information System (INIS)

Gado, J.; Hollo, E.; Kovacs, K.; Maroti, L.; Techy, Z.; Vidovszky, I.

1995-01-01

The reassessment of the Paks NPP safety according to internationally recognized criteria of the Advanced General and New Evaluation of Safety (AGNES) project is outlined. The Paks NPP consists of four WWER-440/V-213 units. The following groups of analysis have been performed: system analysis and description; analysis of design basis accidents; severe accidents analysis; level 1 probabilistic safety analysis. Postulated accidents (PA) and Anticipated Operational Occurrences (AOO) are estimated in detail for the following initiating events: increase/decrease in secondary heat removal; decrease in primary coolant inventory; increase/decrease of reactor coolant inventory; reactivity and power distribution anomalies; analysis of transients with the failure of reactor scram (ATWS); pressurized thermal shock analyses. Severe accident analysis was made for the accidents on in-vessel phase and containment phase, for radioactive release and for accident management

NPP Krsko small break LOCA analysis

International Nuclear Information System (INIS)

Mavko, B.; Petelin, S.; Peterlin, G.

1987-01-01

Parametric analysis of small break loss of coolant accident for the Krsko NPP was calculated by using RELAP5/MOD1 computer code. The model that was used in our calculations has been improved over several years and was previously tested in simulation (s) of start-up tests and known NPP Krsko transients. In our calculations we modelled automatic actions initiated by control, safety and protection systems. We also modelled the required operator actions as specified in emergency operating instructions. In small-break LOCA calculations, we varied break sizes in the cold leg. The influence of steam generator tube plugging on small break LOCA accidents was also analysed. (author)

Safety requirement of the nuclear power plants, after TMI-2 accident and their possible implementation on Bushehr NPP

International Nuclear Information System (INIS)

Mirhabibi, N.; Tochai, M.T.M.; Ashrafi, A.; Farnoudi, E.

1985-01-01

Based on the lessons learned from the TMI-2 accident and other research and developments, many improvements have been required for the design, manufacturing and operation of nuclear power plants in recent years. These requirements have already been implemented to the plants in operation and considered as new safety requirements for new plants. In the present paper these requirements and their possible implementation on Bushehr NPP are discussed. (Author)

Application of the ALARA principle to minimize the collective dose in NPP accident management within the containment

International Nuclear Information System (INIS)

Bogorad, V.; Slepchenko, O.; Kyrylenko, Y.

2016-01-01

The paper focuses on application of the ALARA principle to minimize the collective doses (both for NPP personnel and the public) related to admission of personnel to the containment for accident management activities and depending on operation of ventilation systems. Results from assessment of radiation consequences are applied to a small - break LOCA with failure of LPIS at VVER - 1000 reactors. The public doses are evaluated using up - to - date RODOS, MACCS and HotSpot software for assessment of radiation consequences. The personnel doses are evaluated with MicroShield and InterRAS codes. The time function and optimal value of the collective dose are defined. The developed approach can be applied for minimization of the collective dose for optimization of accident management strategies at NPPs

Response of neutrophils in peripheral blood of participants in the liquidation of Chernobyl NPP accident consequences to an additional radiation exposure in vitro

International Nuclear Information System (INIS)

Timoshevskij, A.A.; Grebenyuk, A.N.; Kalinina, N.A.

2001-01-01

Specific effect of radiation exposure in vitro on morphobiochemical characteristics of leukocytes in peripheral blood of the participants in the liquidation of Chernobyl NPP consequences are investigated. Samples of peripheral blood taken from 49 participants in the liquidation of Chernobyl NPP consequences were irradiated in vitro in doses 0.25, 0.50 and 1.0 Gy. Cytochemical analysis of neutrophils was used for estimating the contents of lipids and cationic proteins, and also the activity of alkaline phosphatase and myeloperoxidase. The irradiation of samples of peripheral blood taken from the participants in the liquidation of Chernobyl NPP consequences has the same effects on functional and metabolic somatic status but with no history of exposure to the complex of radiation accident factors [ru

Distribution and migration of ⁹⁰Sr in components of the Dnieper River basin and the Black Sea ecosystems after the Chernobyl NPP accident.

Science.gov (United States)

Mirzoyeva, N Yu; Egorov, V N; Polikarpov, G G

2013-11-01

The change in (90)Sr concentrations in hydrobionts, water and bottom sediments of the Chernobyl NPP pond-cooler, the Kievskoe and Kakhovskoe reservoirs, the Northern-Crimean canal and the Black Sea after the Chernobyl NPP accident was studied. The environmental half-times for the decrease of (90)Sr concentrations were determined: in water - 4.1-24.3 years; algae and flowering water plants - 3.6-7.7 years, in molluscs - 2.4-6.7 years, and in fish - 7.8-12.9 years. The time for (90)Sr concentrations to decrease to pre-accident levels were estimated: in freshwater reservoirs and the northwest part of the Black Sea this was 32-44 years, and in freshwater hydrobionts this was 25-73 years. The contribution of dose from (90)Sr to the hydrobionts, sampled from the Kakhovskoe reservoir, the Northern-Crimean canal and the Black Sea, has not reached values which could impact them during the entire post-accident period. This complex of comparative studies was carried out for the first time. Copyright © 2013 Elsevier Ltd. All rights reserved.

Chernobyl'-90. Reports of the 1. International conference on biological and radioecological aspects of the Chernobyl' NPP accident effects. V. 1, part 1. Radioecology of plants. Radioecology of terrestrial animals. Radioecology of hydrobionts

International Nuclear Information System (INIS)

Senin, E.V.

1990-01-01

The results of works done in 1988-1990 within the ecology part of the complex program dealing with elimination of the Chernobyl NPP accident effects in regions of Ukraine, Belarus and Rissua, as well as the data of foreign specialists on the Chernobyl radioactive fallout effects in many countries are analyzed. Comparative analysis of the methods, means and results of activities dealing with accident effect eliminations on South Urals and at the Chernobyl NPP is given

Chernobyl'-90. Reports of the 1. International conference on biological and radioecological aspects of the Chernobyl' NPP accident effects. V. 1, part 2. Radioecology of plants. Radioecology of terrestrial animals. Radioecology of hydrobionts

International Nuclear Information System (INIS)

Senin, E.V.

1990-01-01

The results of works done in 1988-1990 within the ecology part of the complex program dealing with elimination of the Chernobyl' NPP accident effects in regions of Urkaine, Belarus and Russia, as well as the data of foreign specialists on the Chernobyl' radioactive fallout effects in many countries are analyzed. Comparative analysis of the methods, means and results of activities dealing with accident effect eliminations on South Urals and at the Chernobyl' NPP is given

Conceptual Design of Portable Filtered Air Suction Systems For Prevention of Released Radioactive Gas under Severe Accidents of NPP

Energy Technology Data Exchange (ETDEWEB)

Gu, Beom W.; Choi, Su Y.; Yim, Man S.; Rim, Chun T. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2014-05-15

It becomes evident that severe accidents may occur by unexpected disasters such as tsunami, heavy flood, or terror. Once radioactive material is released from NPP through severe accidents, there are no ways to prevent the released radioactive gas spreading in the air. As a remedy for this problem, the idea on the portable filtered air suction system (PoFASS) for the prevention of released radioactive gas under severe accidents was proposed. In this paper, the conceptual design of a PoFASS focusing on the number of robot fingers and robot arm rods are proposed. In order to design a flexible robot suction nozzle, mathematical models for the gaps which represent the lifted heights of extensible covers for given convex shapes of pipes and for the covered areas are developed. In addition, the system requirements for the design of the robot arms of PoFASS are proposed, which determine the accessible range of leakage points of released radioactive gas. In this paper, the conceptual designs of the flexible robot suction nozzle and robot arm have been conducted. As a result, the minimum number of robot fingers and robot arm rods are defined to be four and three, respectively. For further works, extensible cover designs on the flexible robot suction nozzle and the application of the PoFASS to the inside of NPP should be studied because the radioactive gas may be released from connection pipes between the containment building and auxiliary buildings.

Radiation accidents and defence of population

International Nuclear Information System (INIS)

Memmedov, A.M.

2002-01-01

Full text: Development of nuclear physics, the fundamental and the applied researches in the field of radioactive insured wide possibility for application of radionuclides and ionizing radiation source in the different fields of national economy. Application of radionuclides in chemical, metallurgical, food industry, in agriculture and etc. Fields provide a large economic profit. It's hard to apprise significance of ionizing radiation source using in medicine for diagnostics and treatment of different disease. Nuclear power engineering and nuclear industry are developing intensively. At same time nuclear power, ionizing radiation sources incur potential treat for surroundings and health of population. As even that stage of protective measure development: there is no possibility of that happening of radiation accidents. A radiation accident qualifies as loss of ionizing radiation sources direction, which provoked by disrepair equipment, natural calamity or other causes which could bring to unplanned irradiation of population or radioactive pollution of surroundings. At present some following typical cases connected with radiation accident have been chosen: Contentious using or keeping of ionizing radiation source with breach of established requires; Loss, theft of ionizing radiation sources or radiation plants, instruments; Leaving the sources of ionizing radiation in the holes; Refusal radiation technic exploited in industry, medicine, SRI and etc; Disrepair in nuclear transport means of conveyance; Crashes and accidents at NPP and at other enterprises of nuclear industry. The radiation accidents according to character, degree and scales have been divided into two groups: Radiation accidents not connected with NPP; Accidents in the nuclear engineering and industry; The radiation accidents not connected with NPP according their consequence divide into 5 groups; accidents which do not come to irradiation of personal, persons from population (more PN-permissible norm

Safety analysis of accident localization system

International Nuclear Information System (INIS)

1999-01-01

A complex safety analysis of accident localization system of Ignalina NPP was performed. Calculation results obtained, results of non-destruct ing testing and experimental data of reinforced concrete testing of buildings does not revealed deficiencies of buildings of accident localization system at unit 1 of Ignalina NPP. Calculations were performed using codes NEPTUNE, ALGOR, CONTAIN

Modelling of Cs-137 availability in soils subjected to contamination after the accident at the Chernobyl NPP

International Nuclear Information System (INIS)

Fesenko, S.V.; Spiridonov, S.I.; Sanzharova, N.I.; Aleksakhin, R.M.

1996-01-01

Results of the application of the model describing behaviour of the radionuclide in meadow ecosystems for the analysis of the factors governing of the radionuclide availability in soils are presented. The estimation of characteristics of fuel particles in near zone of the Chernobyl NPP is given. It is shown that in the first period after the accident the main factors determining Cs-137 availability in soil are property of soil and mat as well as fallout characteristics. Refs. 6, figs. 5

Chernobyl NPP accident consequences cleaning up participants in Ukraine -health status epidemiologic study main results

International Nuclear Information System (INIS)

Buzunov, V.; Omelyanetz, N.; Strapko, N.; Ledoschuck, B.; Krasnikova, L.; Kartushin, G.

1996-01-01

The Epidemiologic Studies System for Chernobyl NPP Accident consequences cleaning up participants (CNPP ACCP) health status was worked out and than improving in Ukraine after the CNPP Accident. The State Register of Ukraine both with several other Registers are the organizational, methodological and informational basis here. The ACCP health status worsening ,-was registered in dynamics through the post-accidental period i.e. the nervous system, digestive system, blood circulation system, respiratory system, bone-muscular system, endocrine and genitourinary systems chronic non-tumoral pathology both with mental disorders amount increase. In cohort study the differences of morbidity formation were fixed among emergency workers with different radiation exposure doses. The dependence of leukemia morbidity on presence in 30-km zone duration was noticed, it's access manifested 5 years after the participance in ACC. The ACCP disablement increase with main reason of general somatic diseases, and annual mortality growth are registered. But that doesn't exceed the mortality rate among population of working age in Ukraine

Psychology of NPP operation safety

International Nuclear Information System (INIS)

Tret'yakov, V.P.

1993-01-01

The book is devoted to psychologic investigations into different aspects of NPP operative personnel activities. The whole set of conditions on which successful and accident-free personnel operation depends, is analysed. Based on original engineering and socio-psychologic investigations complex psychologic support for NPP personnel and a system of training and upkeep of operative personnel skills are developed. The methods proposed have undergone a practical examination and proved their efficiency. 154 refs., 12 figs., 9 tabs

Severe accident management at the Loviisa NPP - Application of integrated ROAAM and PSA level 2

International Nuclear Information System (INIS)

Siltanen, S.; Routamo, T.; Tuomisto, H.; Lundstrom, P.

2007-01-01

The Risk Oriented Accident Analysis Methodology (ROAAM) was developed for assessment and management of rare, high consequence hazards. The purpose of most ROAAM applications has been to solve major, isolated severe accident issues related to early containment failure such as Mark-I Liner Attack and Direct Containment Heating. In addition to ROAAM in the issue resolution context, the so called Integrated ROAAM approach can be used to provide an overall frame of safety evaluation that allows determination of whether an adequate level of safety has been achieved for a plant. Integrated ROAAM approach brings together quantifications of probabilistic elements based on statistical inference and treatment of deterministic elements based on identification of dominant physics, for severe accident phenomenology, in a well defined and clearly structured way. Fortum, as an owner of the Loviisa NPP, used the Integrated ROAAM approach when developing and implementing a comprehensive severe accident management (SAM) strategy for the Loviisa NPP. The SAM strategy is based on unique features of this VVER-440 plant with ice condenser containment and it includes hardware modifications at the plant, substantial new I and C qualified for severe accident conditions, new SAM guidelines, a SAM Handbook, revision of emergency preparedness organization, and versatile training approaches. It could be argued that the resolution of individual severe accident issues is not sufficient for assessing the overall safety of a nuclear power plant, and thus the ROAAM (in an issue resolution context) is not performing the same function as a PSA study (level 2 included). Actually the Integrated ROAAM approach takes on even a more ambitious task than the PSA, since it determines how a balance can be achieved between accident prevention and mitigation of containment-threatening physical phenomena. Thus it provides a tool for implementing a sound diverse defence-in-depth strategy at a plant. Integrated

Problems of Chernobyl Exclusion Zone

International Nuclear Information System (INIS)

Kholosha, V.Yi.

2014-01-01

The collection comprises the results of researches and design activity in the ChNPP exclusion zone, aimed at the development of technologies, equipment and devices for radioactive waste management and ChNPP accident clean-up, at studying the composition and structure of the Exclusion zone soil activity solid bearers, form transformation of the fission products of fuel fallout radionuclide composition in the ChNPP near zone, the spatial distribution of radionuclides and other radioecological issues.. Much attention is paid to medical and biological aspects of the accident influence on the flora, fauna and people's health, labour conditions and incidence of the workers of the Exclusion zone

NPP accident scenario. Which emergency measures are planned in Switzerland?; Szenario KKW-Unfall. Welche Notfallschutzmassnahmen sind in der Schweiz geplant?

Energy Technology Data Exchange (ETDEWEB)

Flury, Christoph [Bundesamt fuer Bevoelkerungsschutz (BABS), Bern (Switzerland). Eidgenoessisches Departement fuer Verteidigung Bevoelkerungsschutz und Sport (VBS)

2016-07-01

As a consequence of the reactor accident in Fukushima the Swiss government has ordered an extensive analysis of emergency planning in case of a NPP accident Switzerland. A special working group has analyzed the possible improvements of Swiss emergency planning based on the experiences in Japan. Under the special direction of the Bundesamt fuer Bevoelkerungsschutz (BABS) the agreed improvements were integrated into the emergency concept. The reference scenarios have been re-assessed and the zone concept adapted. The emergency measures include shelter-type rooms (basement or window-less rooms), the preventive distribution of iodine pills, measures concerning agriculture, aquatic systems, preventive evacuation, traffic regulations, and delayed evacuation.

Selection of NPP for Kazakhstan

International Nuclear Information System (INIS)

Zhotabaev, Zh.R.

2003-01-01

Commercial NPP for Kazakhstan should to meet to several main requirements: 1). Safety operation (accident probability not more than 10 -6 1/p. year). 2). High efficiency > 40 %. 3). Possibility of use for high-temperature chemistry and hydrogen production. 4). Possibility for manufacturing of considerable part of equipment in Kazakhstan. 5). Possibility for fuel production and reprocessing in Kazakhstan. 6). Independence from existence of large water-supply sources. Comparative analysis of several NPP with different reactors (WWR-1000, Candu, BREST, VG-400; graphite molten salt reactor) shows that NPP with the graphite molten salt reactor meets to all above requirements, but hydrogen production it is possible by more complete 4-stage technology, since coolant temperature is 800 Deg. C. The principle advantage is possibility of manufacturing of main equipment and fuel in Kazakhstan that reduce the cost of NPP construction and operation

Report on Fukushima Daiichi NPP precursor events

International Nuclear Information System (INIS)

2014-01-01

The main questions to be answered by this report were: The Fukushima Daiichi NPP accident, could it have been prevented? If there is a next severe accident, may it be prevented? To answer the first question, the report addressed several aspects. First, the report investigated whether precursors to the Fukushima Daiichi NPP accident existed in the operating experience; second, the reasons why these precursors did not evolve into a severe accident. Third, whether lessons learned from these precursor events were adequately considered by member countries; and finally, if the operating experience feedback system needs to be improved, based on the previous analysis. To address the second question which is much more challenging, the report considered precursor events identified through a search and analysis of the IRS database and also precursors events based on risk significance. Both methods can point out areas where further work may be needed, even if it depends heavily on design and site-specific factors. From the operating experience side, more efforts are needed to ensure timely and full implementation of lessons learnt from precursor events. Concerning risk considerations, a combined use of risk precursors and operating experience may drive to effective changes to plants to reduce risk. The report also contains a short description and evaluation of selected precursors that are related to the course of the Fukushima Daiichi NPP accident. The report addresses the question whether operating experience feedback can be effectively used to identify plant vulnerabilities and minimize potential for severe core damage accidents. Based on several of the precursor events national or international in-depth evaluations were started. The vulnerability of NPPs due to external and internal flooding has clearly been addressed. In addition to the IRS based investigation, the WGRISK was asked to identify important precursor events based on risk significance. These precursors have

The IAEA Accident Management Programme

Energy Technology Data Exchange (ETDEWEB)

Kabanov, L.; Jankowski, M.; Mauersberger, H. (International Atomic Energy Agency, Vienna (Austria))

1993-02-01

Accident prevention and mitigation programmes and the Emergency Response System (ERS) are important elements of the Agency's activities in the area of nuclear power plant (NPP) safety. Safety Codes and Guides on siting, design, quality assurance and the operation of NPPs have been produced and are used by NPP operating organizations. Nuclear safety evaluation services are provided by the IAEA. The Emergency Response System and the International Nuclear Event Scale (INES) have been developed. The framework for the development of an accident management programme has been set up. The main goal is to develop an Accident Management Manual to provide a systematic, structured approach to the development and implementation of an accident management programme at NPPs. An outline of the Manual has been distributed and the first draft is available. The component parts are: Co-ordinated research programmes (CRPs) on severe accident management and containment behaviour; the use of vulnerability analysis; mitigation of the effects of hydrogen, and generic symptom oriented emergency operating procedures. The IAEA provides guidance by the dissemination of information on methods for accident management; collates information on approaches in this field in different organizations and countries; and arranges exchange of experience and the promulgation of knowledge through the training of NPP managers and senior technical staff. (orig.).

The IAEA Accident Management Programme

International Nuclear Information System (INIS)

Kabanov, L.; Jankowski, M.; Mauersberger, H.

1993-01-01

Accident prevention and mitigation programmes and the Emergency Response System (ERS) are important elements of the Agency's activities in the area of nuclear power plant (NPP) safety. Safety Codes and Guides on siting, design, quality assurance and the operation of NPPs have been produced and are used by NPP operating organizations. Nuclear safety evaluation services are provided by the IAEA. The Emergency Response System and the International Nuclear Event Scale (INES) have been developed. The framework for the development of an accident management programme has been set up. The main goal is to develop an Accident Management Manual to provide a systematic, structured approach to the development and implementation of an accident management programme at NPPs. An outline of the Manual has been distributed and the first draft is available. The component parts are: Co-ordinated research programmes (CRPs) on severe accident management and containment behaviour; the use of vulnerability analysis; mitigation of the effects of hydrogen, and generic symptom oriented emergency operating procedures. The IAEA provides guidance by the dissemination of information on methods for accident management; collates information on approaches in this field in different organizations and countries; and arranges exchange of experience and the promulgation of knowledge through the training of NPP managers and senior technical staff. (orig.)

Psychosomatic and somatopsychic aspects of the development of mental disturbances in liquidators of the Chernobyl NPP accident

International Nuclear Information System (INIS)

Rumyantseva, G.M.

2003-01-01

For mathematic-statistical analysis of factors, probably influencing the formation of mental disorders in participants of the liquidation of Chernobyl NPP accident the database containing 165 variables was made. By factor and dispersion analysis variables, influencing mental disorders formation rate, and share of influence and correlation dependencies were discriminated and calculated. The mental disturbances, emerging after an ecological radiation catastrophe, form not only due to direct and indirect action of physical factors, but as a consequence of inclusion of somatopsychic and psychosomatic mechanisms, associated directly with catastrophe effect

The application of the assessment of nuclear accident status in emergency decision-making during nuclear accident

International Nuclear Information System (INIS)

Yang Ling

2011-01-01

Nuclear accident assessment is one of the bases for emergency decision-making in the situation of nuclear accident in NPP. Usually, the assessment includes accident status and consequence assessment. It is accident status assessment, and its application in emergency decision-making is introduced here. (author)

Measuring Risk Aversion for Nuclear Power Plant Accident: Results of Contingent Valuation Survey in Korea

International Nuclear Information System (INIS)

Lee, Sang Hun; Kang, Hyun Gook

2015-01-01

Within the evaluation of the external cost of nuclear energy, the estimation of the external cost of nuclear power plant (NPP) severe accident is one of the major topics to be addressed. For the evaluation of the external cost of NPP severe accident, the effect of public risk averse behavior against the group accidents, such as NPP accident, dam failure, must be addressed. Although the equivalent fatalities from a single group accident are not common and its risk is very small compared to other accidents, people perceive the group accident more seriously. In other words, people are more concerned about low probability/high consequence events than about high probability/low consequence events having the same mean damage. One of the representative method to integrate the risk aversion in the external costs of severe nuclear reactor accidents was developed by Eeckoudt et al., and he used the risk aversion coefficient, mainly based on the analysis of financial risks in the stock markets to evaluate the external cost of nuclear severe accident. However, the use of financial risk aversion coefficient to nuclear severe accidents is not appropriate, because financial risk and nuclear severe accident risk are entirely different. In this paper, the individual-level survey was conducted to measure the risk aversion coefficient and estimate the multiplication factor to integrate the risk aversion in the external costs of NPP severe accident. This study propose an integrated framework on estimation of the external cost associated with severe accidents of NPP considering public risk aversion behavior. The theoretical framework to estimate the risk aversion coefficient/multiplication factor and to assess economic damages from a hypothetical NPP accident was constructed. Based on the theoretical framework, the risk aversion coefficient can be analyzed by conducting public survey with a carefully designed lottery questions. Compared to the previous studies on estimation of the

Measuring Risk Aversion for Nuclear Power Plant Accident: Results of Contingent Valuation Survey in Korea

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Hun; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of)

2015-05-15

Within the evaluation of the external cost of nuclear energy, the estimation of the external cost of nuclear power plant (NPP) severe accident is one of the major topics to be addressed. For the evaluation of the external cost of NPP severe accident, the effect of public risk averse behavior against the group accidents, such as NPP accident, dam failure, must be addressed. Although the equivalent fatalities from a single group accident are not common and its risk is very small compared to other accidents, people perceive the group accident more seriously. In other words, people are more concerned about low probability/high consequence events than about high probability/low consequence events having the same mean damage. One of the representative method to integrate the risk aversion in the external costs of severe nuclear reactor accidents was developed by Eeckoudt et al., and he used the risk aversion coefficient, mainly based on the analysis of financial risks in the stock markets to evaluate the external cost of nuclear severe accident. However, the use of financial risk aversion coefficient to nuclear severe accidents is not appropriate, because financial risk and nuclear severe accident risk are entirely different. In this paper, the individual-level survey was conducted to measure the risk aversion coefficient and estimate the multiplication factor to integrate the risk aversion in the external costs of NPP severe accident. This study propose an integrated framework on estimation of the external cost associated with severe accidents of NPP considering public risk aversion behavior. The theoretical framework to estimate the risk aversion coefficient/multiplication factor and to assess economic damages from a hypothetical NPP accident was constructed. Based on the theoretical framework, the risk aversion coefficient can be analyzed by conducting public survey with a carefully designed lottery questions. Compared to the previous studies on estimation of the

Expert software for accident identification

International Nuclear Information System (INIS)

Dobnikar, M.; Nemec, T.; Muehleisen, A.

2003-01-01

Each type of an accident in a Nuclear Power Plant (NPP) causes immediately after the start of the accident variations of physical parameters that are typical for that type of the accident thus enabling its identification. Examples of these parameter are: decrease of reactor coolant system pressure, increase of radiation level in the containment, increase of pressure in the containment. An expert software enabling a fast preliminary identification of the type of the accident in Krsko NPP has been developed. As input data selected typical parameters from Emergency Response Data System (ERDS) of the Krsko NPP are used. Based on these parameters the expert software identifies the type of the accident and also provides the user with appropriate references (past analyses and other documentation of such an accident). The expert software is to be used as a support tool by an expert team that forms in case of an emergency at Slovenian Nuclear Safety Administration (SNSA) with the task to determine the cause of the accident, its most probable scenario and the source term. The expert software should provide initial identification of the event, while the final one is still to be made after appropriate assessment of the event by the expert group considering possibility of non-typical events, multiple causes, initial conditions, influences of operators' actions etc. The expert software can be also used as an educational/training tool and even as a simple database of available accident analyses. (author)

The main results of fulfilment in 1996 of the scientific part of the State programme of the Republic of Belarus for minimization and overcoming of the Chernobyl NPP accident consequences (1996-2000)

International Nuclear Information System (INIS)

Konoplya, E.F.

1997-01-01

In the publication are summarized the basic results of the researches executed in 1996 in the framework of the 'Scientific maintenance of the decision of problems of the Chernobyl NPP accident consequences' of the State program of Republic of Belarus for minimization and overcoming of the Chernobyl NPP accident consequences on 1996-2000 on the following directions: dose monitoring of the population, estimation and forecast of both collective irradiation dozes and risks of radiation induced diseases; development and optimization of a complex of measures for effective land use and decrease of radioactive contamination of agricultural production in order to reduce irradiation dozes of the population; development of complex technologies and means of decontamination, processing and burial of radioactive wastes; development of the measures for increase of radiation protection of the population of Belarus during of the reducing period after the Chernobyl accident; development of complex system of an estimation and decision-making on problems of radiation protection of the population living on contaminated territories; study of influence of radiological consequences of the Chernobyl accident on health of people, development of methods and means of diagnostics, treatment and preventive maintenance of diseases for various categories of the victims; development of effective methods of preventive maintenance and treatment of diseases of both mother and child in conditions of influence of the Chernobyl NPP accident consequences; study of genetic consequences caused by the Chernobyl accident and development of effectual measures of their prevention; creation of the effective both prophylactic means and food additives for treatment and rehabilitation of the persons having suffered after the Chernobyl accident; study of the radioisotopes behaviour dynamics in environment (air, water, ground), ecosystems and populated areas; optimization of the system of radiation ecological

Accident management on french PWRS

International Nuclear Information System (INIS)

Queniart, D.

1990-06-01

After a brief recall of French safety rationale, the reactor operation and severe accident management is given. The research and development aimed at developing accident management procedures and emergency organization in France for the case of a NPP accident are also given

Assessment of forms finding of Chernobyl radionuclides in bottom sediments of cooling pond of the ChNPP

Directory of Open Access Journals (Sweden)

V. P. Protsak

2014-09-01

Full Text Available Assessment of forms finding of radionuclides 90Sr, 137Cs, 238Pu, 239,240Pu, 241Am and dispersal composition of fuel particles in bottom sediments of cooling pond of the ChNPP is carried out. According to the results of re-search in the year of 2012 more than 98 % of radionuclides in bottom sediments were in non-exchange (ex-changeable state, while in the composition of the fuel particles can be contained about 70% 90Sr and more than 80 % 241Am and of the plutonium isotopes. Obtained results indicate the selective leaching of radionuclides from the matrix of fuel particles.

A program package connected with a communication network for accident statistics of NPP, TPP, HPP and the power lines

International Nuclear Information System (INIS)

Madjarova, A.

1993-01-01

The package is designed for registration and analysis of accidents according to users' needs. A possibility is also provided for easy data transfer and access to data on implemented decisions. Special programmes are developed for NPP, TPP, HPP, electricity supply branch, regional distribution management and the National Electric Company. The system is open for local network connection and file exchange between the workstations. The dialogue features are user-friendly. The emergency situations are classified according to the requirements of the enacted in Bulgaria 'Regulations for Investigation, Classification and Recording of Accidents in Electric and Thermal Stations and Networks, 1993'. The unified data input provides a possibility for insertion of additional texts (remarks), correcting and updating. Data security tools are also envisaged. (author)

Current status of Chernobyl NPP decommissioning

International Nuclear Information System (INIS)

2009-01-01

Strategy of Chernobyl NPP decommissioning with the decommissioning license 2002-2064 is presented. The main activities at the stage of ChNPP units shutdown (2002 - 2012) are: units maintenance in safe state; decommissioning infrastructure construction; unloading of SNF – main activity determining the stage duration; systems and elements final shutdown; decommissioning life-support systems reconstruction; Comprehensive engineering and radiation survey (CERS); dismantling of the reactor facilities external equipment; removal of RAW from units; decommissioning documentation development. The decommissioning activities main results are presented

Observation of radioactive aerosol particle sizes in 30-km zone of the ChNPP in 1986-1987 years

International Nuclear Information System (INIS)

Skitovich, V.I.; Budyka, A.K.; Ogorodnikov, B.I.

1989-01-01

Investigation into disperse composition of radioactive aerosols was conducted in the ChNPP spaces, over ruins of 4 block, on job site and separate points of the 30-km zone by multilayer filters from ultrathin fibers. In probes taken from the job site radioactive isotopes were grouped on the particles with more than 2,5 μcm diameter. Particle sizes in the room were less than near terrestrial layer of atmosphere on job site. It is shown that the aerosol sizes containing alpha active nuclides are idential with gamma radiating isotopes of refractory elements. 4 refs., 1 fig., 2 tabs

Radiation doses estimation for hypothetical NPP Krsko accidents without and with PCFV using RASCAL software

International Nuclear Information System (INIS)

Vukovic, Josip; Konjarek, Damir; Grgic, Davor

2014-01-01

Calculation is done using Source Term to Dose module of RASCAL (Radiological Assessment System Consequence Analysis) software to estimate projected radiation doses from a radioactive plume to the environment. Utilizing this module, it is possible to do preliminary assessment of consequences to the environment in case of adverse reactor conditions or releases from other objects containing radioactive materials before the emergency situation has happened or in the early phase. RASCAL is simple, easy to use, fast-running tool able to provide initial estimate of radiological consequences of nuclear accidents. Upon entering rather limited amount of input parameters for the Krsko NPP, mostly key plant parameters, time dependent source term calculation is executed to determine radioactive inventory release rates for different plant conditions, release paths and availability of protective measures. These rates given for each radionuclide as a function of time are used as an input to atmospheric dispersion and transport model. Together with release rates, meteorological conditions dataset serve as input to determine the behavior of the radioactive releases that is plume in the atmosphere. So as an output, RASCAL produces a 'dispersion envelope' of radionuclide concentrations in the atmosphere. These concentrations of radionuclides in the atmosphere are further used for estimating the doses to the environment and the public downwind the release point. Throughout this paper, dose assessment is performed for two distances, close-in distance and distance out to 40 km from the source, for hypothetical NPP Krsko accidents without and with Passive Containment Filtered Vent (PCFV) system used. Obvious difference is related to released radioactivity of Iodine isotopes. Results of radioactive effluents deposition in the environment are displayed via various doze parameters, radionuclide concentrations and materials exposure rates in this particular case. (authors)

Clinical and encephalographic study of the dynamics of asthenic syndrome in persons involved in the liquidation of Chernobyl NPP accident consequences

International Nuclear Information System (INIS)

Sukharskaya, Marta; Tsurkanu, Lukretsiya; Kirka, Luchiya; Boshnyaga, Emiliya; Godorozha, Mikhai; Toma, Viktoriya; Postovan, Alla; Andronik, Zinaida; Mornyala, Elena; Popovich, Lyudmila

2011-01-01

The article is devoted to the analysis of dynamics of asthenic syndrome and electro encephalography indicators during the 25 years after the Chernobyl NPP accident. Four stages of syndrome development were segregated. The clear correlation between the course of mental disorder and electro encephalography indicators was discovered. This made it possible to determine the intensity and weight of pathological processes and conduct the effective timely treatment. (authors)

Ideal scaling of BETHSY 9.1.B test results to NPP

International Nuclear Information System (INIS)

Petelin, S.; Guntel, I.

1995-01-01

The transient scenario standard problem 27 (ISP-27) was implemented in the RELAP5 analysis of small break loss of coolant accident for Krsko nuclear power plant (Krsko NPP). The objective was to evaluate the effectiveness of ISP-27 proposed accident management procedure for real NPP and to compare the physical phenomena known from experimental background with the phenomena predicted by RELAP5 simulation of real plant transient. The analyses showed that, if relevant break, power scaling criteria, primary and secondary pressure are fulfilled the RELAP5 model of Krsko NPP cannot completely ensure the simulation of typical thermal-hydraulic phenomena observed in BETHSY facility during ISP-27. Much better satisfaction is observed on ideal scaled up model. (author)

Radionuclide localization at the Chernobyl' NPP territory

International Nuclear Information System (INIS)

Mamaev, L.A.; Galkin, G.A.; Khrabrov, S.L.; Polyakov, A.S.; Mikhejkin, S.V.

1989-01-01

Experience is generalized of using different dust suppression (DS) compounds during Chernobyl' accident consequence elimination. Polymer DS compounds were used at the NPP operating site; the compounds kept dust-like radioactive contaminations during 1-2 months. DS at the country was realized by means of the compound on base of latex. The conclusion is made that the DS measures improved radiation situation in the NPP zone. 7 refs

Intelligent system for accident identification in NPP

International Nuclear Information System (INIS)

Hernandez, J.L.

1998-01-01

Accidental situations in NPP are great concern for operators, the facility, regulatory bodies and the environmental. This work proposes a design of intelligent system aimed to assist the operator in the process of decision making initiator events with higher relative contribution to the reactor core damage occur. The intelligent System uses the results of the pre-operational Probabilistic safety Assessment and the Thermal hydraulic Safety Analysis of the NPP Juragua as source for building its knowledge base. The nucleus of the system is presented as a design of an intelligent hybrid from the combination of the artificial intelligence techniques fuzzy logic and artificial neural networks. The system works with variables from the process of the first circuit, second circuit and the containment and it is presented as a model for the integration of safety analyses in the process of decision making by the operator when tackling with accidental situations

Meeting up-to-date safety requirements in the Russian NPP projects

International Nuclear Information System (INIS)

Tepkyan, G. O.; Yashkin, A. V.

2014-01-01

Safety features in Russian NPP designs are implemented by the combination of active and passive safety systems • Russian NPP designs are in compliance with up-to-date international and European safety requirements and refer to Generation III+ • Russian state-of-the-art designs have already implemented some design solutions, which take into account “post-Fukushima” requirements. Russian NPP design principles have been approved during the European discussions in spring 2012, including the IAEA extraordinary session addressed to Fukushima NPP accident

Technical innovations at NPP Dukovany - for safe and efficient operation

International Nuclear Information System (INIS)

Sabata, M.; Vasa, I.

2000-01-01

Inherent features of the NPP Dukovany design provide a significant confidence in its nuclear safety assurance; among these features should be emphasised the reactor core stability and its control and protection system capability to hold the reactor in safe state following scram or accident conditions. Nevertheless, NPP Dukovany was designed in the early seventies, and current requirements for nuclear safety assurance are more strict and/or specific as a result of the technical development and lessons learned from nuclear accidents. The paper compares the safety design base established at the time of NPP Dukovany project implementation and the current reference design base. The paper also presents procedures applied to implement technical and operational measures which are introduced to fulfil the current basic safety criteria. The scope of such measures applied at NPP Dukovany is compared with that of EU countries introduced for the same reason - to meet the updated safety related requirements. Examples of some innovations already implemented or under implementation give an idea how NPP Dukovany proceeds in reaching the goal of harmonising its safety with the requirements to be met before the Czech Republic becomes a member country of the European Union. (author)

Design safety improvements of Kozloduy NPP

International Nuclear Information System (INIS)

Hinovski, I.

1999-01-01

Design safety improvements of Kozloduy NPP, discussed in detail, are concerned with: primary circuit integrity; reactor pressure vessel integrity; primary coolant piping integrity; primary coolant overpressure protection; leak before break status; design basis accidents and transients; severe accident analysis; improvements of safety and support systems; containment/confinement leak tightness and strength; seismic safety improvements; WWER-1000 control rod insertion; upgrading and modernization of Units 5 and 6; Year 2000 problem

Thirtieth anniversary of reactor accident in A-1 Nuclear Power Plant Jaslovske Bohunice

International Nuclear Information System (INIS)

Kuruc, J.; Matel, L.

2007-01-01

The facts about reactor accidents in A-1 Nuclear Power Plant Jaslovske Bohunice, Slovakia are presented. There was the reactor KS150 (HWGCR) cooled with carbon dioxide and moderated with heavy water. A-1 NPP was commissioned on December 25, 1972. The first reactor accident happened on January 5, 1976 during fuel loading. This accident has not been evaluated according to the INES scale up to the present time. The second serious accident in A-1 NPP occurred on February 22, 1977 also during fuel loading. This INES level 4 of reactor accident resulted in damaged fuel integrity with extensive corrosion damage of fuel cladding and release of radioactivity into the plant area. The A-1 NPP was consecutively shut down and is being decommissioned in the present time. Both reactor accidents are described briefly. Some radioecological and radiobiological consequences of accidents and contamination of area of A-1 NPP as well as of Manivier Canal and Dudvah River as result of flooding during the decommissioning are presented (authors)

An accident diagnosis algorithm using long short-term memory

Directory of Open Access Journals (Sweden)

Jaemin Yang

2018-05-01

Full Text Available Accident diagnosis is one of the complex tasks for nuclear power plant (NPP operators. In abnormal or emergency situations, the diagnostic activity of the NPP states is burdensome though necessary. Numerous computer-based methods and operator support systems have been suggested to address this problem. Among them, the recurrent neural network (RNN has performed well at analyzing time series data. This study proposes an algorithm for accident diagnosis using long short-term memory (LSTM, which is a kind of RNN, which improves the limitation for time reflection. The algorithm consists of preprocessing, the LSTM network, and postprocessing. In the LSTM-based algorithm, preprocessed input variables are calculated to output the accident diagnosis results. The outputs are also postprocessed using softmax to determine the ranking of accident diagnosis results with probabilities. This algorithm was trained using a compact nuclear simulator for several accidents: a loss of coolant accident, a steam generator tube rupture, and a main steam line break. The trained algorithm was also tested to demonstrate the feasibility of diagnosing NPP accidents. Keywords: Accident Diagnosis, Long Short-term Memory, Recurrent Neural Network, Softmax

External Cost Assessment of Nuclear Power Plant Accident considering Public Risk Aversion Behavior: the Korean Case

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Hun; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of)

2016-05-15

The conventional approach for monetary valuation of NPP accident consequence consists of calculating the expected value of various accident scenarios. However, the main criticism of the conventional approach is that there is a discrepancy between the social acceptability of the risk and the estimated expected value of NPP accident. Therefore, an integrated framework for the estimation of the external cost associated with an NPP accident considering the public risk aversion behavior was proposed in this study based on the constructed theoretical framework for estimating both the value of statistical life (VSL) and the risk aversion coefficient associated with an NPP accident to take account of the accident cost into the unit electricity generation cost of NPP. To estimate both parameters, an individual-level survey was conducted on a sample of 1,364 participants in Korea. Based on the collected survey responses, both parameters were estimated based on the proposed framework and the external cost of NPP accident was estimated based on the consequence analysis and considering the direct cost factors for NPP accident. Internalization of external costs into the comprehensive energy production cost has been considered as a potentially efficient policy instrument for a more sustainable energy supply and use. However, the internalization of externalities, such as public health damage, have raised a number of generic policy issues in a nuclear energy sector, with specific challenges resulting from the distinct characteristics of external cost estimation. Especially, the major challenge remained to address the public safety concerns regarding a nuclear accident, which can be specified as low-probability high-consequence accident, driven by the aspects of public risk aversion.

External Cost Assessment of Nuclear Power Plant Accident considering Public Risk Aversion Behavior: the Korean Case

International Nuclear Information System (INIS)

Lee, Sang Hun; Kang, Hyun Gook

2016-01-01

The conventional approach for monetary valuation of NPP accident consequence consists of calculating the expected value of various accident scenarios. However, the main criticism of the conventional approach is that there is a discrepancy between the social acceptability of the risk and the estimated expected value of NPP accident. Therefore, an integrated framework for the estimation of the external cost associated with an NPP accident considering the public risk aversion behavior was proposed in this study based on the constructed theoretical framework for estimating both the value of statistical life (VSL) and the risk aversion coefficient associated with an NPP accident to take account of the accident cost into the unit electricity generation cost of NPP. To estimate both parameters, an individual-level survey was conducted on a sample of 1,364 participants in Korea. Based on the collected survey responses, both parameters were estimated based on the proposed framework and the external cost of NPP accident was estimated based on the consequence analysis and considering the direct cost factors for NPP accident. Internalization of external costs into the comprehensive energy production cost has been considered as a potentially efficient policy instrument for a more sustainable energy supply and use. However, the internalization of externalities, such as public health damage, have raised a number of generic policy issues in a nuclear energy sector, with specific challenges resulting from the distinct characteristics of external cost estimation. Especially, the major challenge remained to address the public safety concerns regarding a nuclear accident, which can be specified as low-probability high-consequence accident, driven by the aspects of public risk aversion

Fukushima nuclear accident and the social responsibility of science

International Nuclear Information System (INIS)

Yoshioka, Hitoshi

2011-01-01

Five months had passed since Fukushima Daiichi Nuclear Power Plant (NPP) accident occurred but still there was no knowing when the accident ended. Released radioactivity seemed to be greater than one million terra Bq and if there occurred an explosive rupture of containment vessel due to the failure of containment vent or occurrence of steam explosion, the amount of released radioactivity might amount to be at least equivalent to or surpass that of Chernobyl NPP accident. There existed still a risk that overheating and meltdown of nuclear fuels might reoccur with loss of cooling due to a possible giant aftershock. This article described total views on significant disaster that the accident brought about on many neighboring residents or wide range of people. After a general discussion about what was social responsibility of scientists, social responsibility of scientists for Fukushima Daiichi NPP accident was discussed. Responsibility of omission was also argued. (T. Tanaka)

Comparative modeling analyses of Cs-137 fate in the rivers impacted by Chernobyl and Fukushima accidents

Energy Technology Data Exchange (ETDEWEB)

Zheleznyak, M.; Kivva, S. [Institute of Environmental Radioactivity, Fukushima University (Japan)

2014-07-01

The consequences of two largest nuclear accidents of the last decades - at Chernobyl Nuclear Power Plant (ChNPP) (1986) and at Fukushima Daiichi NPP (FDNPP) (2011) clearly demonstrated that radioactive contamination of water bodies in vicinity of NPP and on the waterways from it, e.g., river- reservoir water after Chernobyl accident and rivers and coastal marine waters after Fukushima accident, in the both cases have been one of the main sources of the public concerns on the accident consequences. The higher weight of water contamination in public perception of the accidents consequences in comparison with the real fraction of doses via aquatic pathways in comparison with other dose components is a specificity of public perception of environmental contamination. This psychological phenomenon that was confirmed after these accidents provides supplementary arguments that the reliable simulation and prediction of the radionuclide dynamics in water and sediments is important part of the post-accidental radioecological research. The purpose of the research is to use the experience of the modeling activities f conducted for the past more than 25 years within the Chernobyl affected Pripyat River and Dnieper River watershed as also data of the new monitoring studies in Japan of Abukuma River (largest in the region - the watershed area is 5400 km{sup 2}), Kuchibuto River, Uta River, Niita River, Natsui River, Same River, as also of the studies on the specific of the 'water-sediment' {sup 137}Cs exchanges in this area to refine the 1-D model RIVTOX and 2-D model COASTOX for the increasing of the predictive power of the modeling technologies. The results of the modeling studies are applied for more accurate prediction of water/sediment radionuclide contamination of rivers and reservoirs in the Fukushima Prefecture and for the comparative analyses of the efficiency of the of the post -accidental measures to diminish the contamination of the water bodies. Document

Consideration on application of RAP to G-II NPP

International Nuclear Information System (INIS)

Shen Shen

2010-01-01

The design (D-RAP) for nuclear power plant has been adopted internationally in new-build advanced nuclear power plant design, which increases the ability of the risk-significant SSCs to carry out its functions during the accident circumstances especially in the severe accident situation, and reduces the risk of a nuclear power plant. The concept of reliability assurance program for advanced nuclear power plant can also be applied to nuclear power plants which second-generation NPP technology is used. Through analysis and research, the risk-significant SSCs in actual NPP can also be screened, and these SSCs can be managed appropriately, so that can improve the overall plant ability to against the severe accident, reduce the risk, and improve their safety and economy. Also such technology used does not exist any insurmountable technical difficulties and a lot of money input. (authors)

Peculiarities of forming and dissemination of radioactive contamination in Iput' river after the Chernobyl NPP accident

International Nuclear Information System (INIS)

Zhukova, O.M.; Shiryaeva, N.M.; Myshkina, N.K.; Shagalova, Eh.D.; Denisova, V.V.; Skurat, V.V.

2001-01-01

The process of radiation contamination forming of the river systems by Cs 137 and Sr 90 after the Chernobyl NPP accident was analyzed. It was shown that before 1990-1994 the river system contamination was formed by the initial falling out of radionuclides on the aquatic surface. After 2000 the contamination will form by means of entrance of radionuclides with surface flowing off from columbines. It was determined that the transboundary transport of radionuclides from the Russia territories influences essentially on contamination of Iput' river on the territory of Belarus. On the authors estimations such input was 30% for Cs 137 and 96% for Sr 90 in 1986, 86% for Cs 137 and 65% for Sr 90 at present

The role of the international Chornobyl Center in coordinating and conducting the work related to Chornobyl NPP closure and creation the new employment opportunities in Slavutych

International Nuclear Information System (INIS)

Nosovskij, A.V.

2001-01-01

The Slavutych division of the international Chornobyl Center (ICC) actively conducts its work in Slavutych from 1997. The following work was conducted during the last years: Documentation on the ChNPP 1-st Unit and 2-nd Unit decommissioning was developed. Comprehensive engineering and radiation survey of the 1-st Unit was conducted. Decommissioning database was created. On demand of Chornobyl NPP, the work on development the following documents was conducted: The 3-rd Unit shutdown program. Comprehensive program on ChNPP decommissioning. ChNPP personnel and Slavutych residents social protection program

Approach to accident management in RBMK-1500

International Nuclear Information System (INIS)

Kaliatka, A.; Urbonavicius, E.; Uspuras, E.

2008-01-01

In order to ensure the safe operation of the nuclear power plants accident management programs are being developed around the world. These accident management programs cover the whole spectrum of accidents, including severe accidents. A lot of work is done to investigate the severe accident phenomena and implement severe accident management in NPPs with vessel-type reactors, while less attention is paid to channel-type reactors CANDU and RBMK. Ignalina NPP with RBMK-1500 reactor has implemented symptom based emergency operation procedures, which cover management of accidents until the core damage and do not extend to core damage region. In order to ensure coverage of the whole spectrum of accidents and meet the requirements of IAEA the severe accident management guidelines have to be developed. This paper presents the basic principles and approach to management of beyond design basis accidents at Ignalina NPP. In general, this approach could be applied to NPPs with RBMK-1000 reactors that are available in Russia, but the design differences should be taken into account

Experiments on The Retention of The Fission Product Iodine in Nuclear Reactor Accidents

International Nuclear Information System (INIS)

Bruchertseifer, H.; Cripps, R.; Guentay, S.; Jaeckel, B.

2004-01-01

The paper reports PSI participation in the ICHEMM Project (Iodine Chemistry and Mitigation Mechanisms) of the EU 5th Framework Programme, which has the objective of identifying new possible mitigation processes, or accident management measures, favouring the conversion of volatile iodine species, especially organic iodine released during a severe accident at a Nuclear Power Plant (NPP), into nonvolatile forms. Significant effort has been expended, firstly to develop analytical methods for determining concentrations of the common iodine species (iodide, iodate, molecular iodine and methyl iodide), and secondly to provide missing and important information on decomposition phenomena and involved reactions. Experiments have been conducted at PSI to obtain data on thermal (hydrolysis) and radiolytic decomposition of CH 3 I in aqueous solution under conditions as close as possible to those in an anticipated accident. Radioactive-labelled methyl iodide was used to monitor and quantify the decomposition and to determine the overall mass balance. Results have shown that CH 3 I hydrolysis at 90 o C will dominate over radiolysis at the dose rates (max. 0.4 Gy.s -1 ) employed in the experiments. Much increased decomposition rates of CH 3 I have been achieved with chemical reagents (additives), such as sodium thiosulphate or ammonium sulphide. After completion of the ICHEMM Project, further advances have been made from experiments carried out on additives (especially in combination with Aliquat 336) in terms of a fast and complete retention of iodine. The data from these experiments are of direct relevance to severe accident management for both PWR and BWR systems. The impact of the results on possible strategies for management of radioactive waste has also been investigated. (author)

Experiments on The Retention of The Fission Product Iodine in Nuclear Reactor Accidents

Energy Technology Data Exchange (ETDEWEB)

Bruchertseifer, H.; Cripps, R.; Guentay, S.; Jaeckel, B

2004-03-01

The paper reports PSI participation in the ICHEMM Project (Iodine Chemistry and Mitigation Mechanisms) of the EU 5th Framework Programme, which has the objective of identifying new possible mitigation processes, or accident management measures, favouring the conversion of volatile iodine species, especially organic iodine released during a severe accident at a Nuclear Power Plant (NPP), into nonvolatile forms. Significant effort has been expended, firstly to develop analytical methods for determining concentrations of the common iodine species (iodide, iodate, molecular iodine and methyl iodide), and secondly to provide missing and important information on decomposition phenomena and involved reactions. Experiments have been conducted at PSI to obtain data on thermal (hydrolysis) and radiolytic decomposition of CH{sub 3}I in aqueous solution under conditions as close as possible to those in an anticipated accident. Radioactive-labelled methyl iodide was used to monitor and quantify the decomposition and to determine the overall mass balance. Results have shown that CH{sub 3}I hydrolysis at 90{sup o}C will dominate over radiolysis at the dose rates (max. 0.4 Gy.s{sup -1}) employed in the experiments. Much increased decomposition rates of CH{sub 3}I have been achieved with chemical reagents (additives), such as sodium thiosulphate or ammonium sulphide. After completion of the ICHEMM Project, further advances have been made from experiments carried out on additives (especially in combination with Aliquat 336) in terms of a fast and complete retention of iodine. The data from these experiments are of direct relevance to severe accident management for both PWR and BWR systems. The impact of the results on possible strategies for management of radioactive waste has also been investigated. (author)

Use of MAAP code for identification of key plant vulnerabilities for the beyond design accidents and their mitigation at NPP Krsko

International Nuclear Information System (INIS)

Krajnc, B.

1995-01-01

NPP Krsko performed according to GL 88-20, Supplement 1-4 and RUJV requirement the Individual Plant Examination analyses. For the required deterministic analyses the MAAP 3.0B code was used. It was proven that such severe accident analysis can be used for evaluation of the overall level of safety improvement that can be gained with the different modifications and alternate design. In this paper one such important outcomes from these analyses will be presented. (author)

Chernobylsk NPP accident and its medical effects

International Nuclear Information System (INIS)

Gus'kova, A.K.

2000-01-01

Medical effects of the Chernobyl accident for various groups of people engaged in liquidation of the accident aftereffects and residents of the regions affected are assessed. Specific medical and social recommendations for each of the five groups of patients are made. Special attention is paid to the health of children who were exposed to external radiation in combination with intake of iodine isotopes. Extremely unfavourable influence of the mass media on the health of people involved in the Chernobyl accident is painted out. The necessity of adequate rehabilitation measures for various categories of patients involved in a large-scale accident is emphasized [ru

Dutch National Plan combat nuclear accidents

International Nuclear Information System (INIS)

1988-01-01

This document presents the Dutch National Plan combat nuclear accidents (NPK). Ch. 2 discusses some important starting points which are determining for the framework and the performance of the NPK, in particular the accident typology which underlies the plan. Also the new accident-classification system for the Dutch nuclear power plants, the standardization for the measures to be taken and the staging around nuclear power plants are pursued. In ch. 3 the legal framework of the combat nuclear accidents is described. In particular the Nuclear-power law, the Accident law and the Municipality law are pursued. Also the role of province and municipality are described. Ch. 4 deals with the role of the owner/licensee of the object where the accident occurs, in the combat of accident. In ch. 5 the structure of the nuclear-accident combat at national level is outlined, subdivided in alarm phase, combat phase and the winding-up phase. In ch.'s 6-12 these phases are elaborated more in detail. In ch.'s 10-13 the measures to be taken in nuclear accidents, are described. These measures are distinguished with regard to: protection of the population and medical aspects, water economy, drinking-water supply, agriculture and food supply. Ch. 14 describes the responsibility of the burgomaster. Ch.'s 15 and 16 present an overview of the personnel, material, procedural and juridical modifications and supplements of existing structures which are necessary with regard to the new and modified parts of the structure. Ch. 17 indicates how by means of the appropriate education and exercise it can be achieved that all personnel, services and institutes concerned possess the knowledge and experience necessary for the activities from the NKP to be executed as has been described. Ch. 18 contains a survey of activities to be performed and a proposal how these can be realized. (H.W.). figs.; tabs

Study of lymphocyte sensitization to protein S-100 in the patients with cerebrovascular diseases, suffered due to Chernobyl NPP accident

International Nuclear Information System (INIS)

Khomenko, V.Yi.

2004-01-01

Among the persons with cerebrovascular diseases, suffered due to Chernobyl NPP accident two groups of patients were revealed: with DNA coloration coefficients in response to protein S-100 stimulation below and above 1. Patients with DNA coloration coefficients <1 were older, they had statistically significant lower monocytes and T-activated lymphocytes absolute counts as well as increased content of cholesterol-2 and circulating immune complexes. Charges found there suggested possible existence of different pathways of immune response to antigenic stimulation by S-100 protein

Chernobyl NPP: Completion of LRW Treatment Plant and LRW Management on Site - 12568

Energy Technology Data Exchange (ETDEWEB)

Fedorov, Denis; Adamovich, Dmitry [SIA ' RADON' , Moscow (Russian Federation); Klimenko, I.; Taranenko, L. [IVL Engineering, Kiev (Ukraine)

2012-07-01

Since a beginning of ChNPP operation, and after a tragedy in 1986, a few thousands m3 of LRW have been collected in a storage tanks. In 2004 ChNPP started the new project on creation of LRW treatment plant (LRWTP) financed from EBRD fund. But it was stopped in 2008 because of financial and contract problems. In 2010 SIA RADON jointly with Ukrainian partners has won a tender on completion of LRWTP, in particular I and C system. The purpose of LRTP is to process liquid rad-wastes from SSE 'Chernobyl NPP' site and those liquids stored in the LRWS and SLRWS tanks as well as the would-be wastes after ChNPP Power Units 1, 2 and 3 decommissioning. The LRTP design lifetime - 20 years. Currently, the LRTP is getting ready to perform the following activities: 1. retrieval of waste from tanks stored at ChNPP LWS using waste retrieval system with existing equipment involved; 2. transfer of retrieved waste into LRTP reception tanks with partial use of existing transfer pipelines; 3. laboratory chemical and radiochemical analysis of reception tanks contest to define the full spectrum of characteristics before processing, to acknowledge the necessity of preliminary processing and to select end product recipe; 4. preliminary processing of the waste to meet the requirements for further stages of the process; 5. shrinkage (concentrating) of preliminary processed waste; 6. solidification of preliminary processed waste with concrete to make a solid-state (end product) and load of concrete compound into 200-l drums; 7. curing of end product drums in LRTP curing hall; 8. radiologic monitoring of end product drums and their loading into special overpacks; 9. overpack radiological monitoring; 10. send for disposal (ICSRM Lot 3); The current technical decisions allow to control and return to ChNPP of process media and supporting systems outputs until they satisfy the following quality norms: salt content: < 100 g/l; pH: 1 - 11; anionic surface-active agent: < 25 mg/l; oil

Surveillance of Strontium-90 in Foods after the Fukushima Daiichi Nuclear Power Plant Accident.

Science.gov (United States)

Nabeshi, Hiromi; Tsutsumi, Tomoaki; Uekusa, Yoshinori; Hachisuka, Akiko; Matsuda, Rieko; Teshima, Reiko

2015-01-01

As a result of the Fukushima Daiichi nuclear power plant (NPP) accident, various radionuclides were released into the environment. In this study, we surveyed strontium-90 ((90)Sr) concentrations in several foodstuffs. Strontium-90 is thought to be the third most important residual radionuclide in food collected after the Fukushima Daiichi, NPP accident after following cesium-137 ((137)Cs) and cesium-134 ((134)Cs). Results of (90)Sr analyses indicated that (90)Sr was detect in 25 of the 40 radioactive cesium (r-Cs) positive samples collected in areas around the Fukushima Daiichi NPP, ranging in distance from 50 to 250 km. R-Cs positive samples were defined as containing both (134)Cs and (137)Cs which are considered to be indicators of the after-effects of the Fukushima Daiichi NPP accident. We also detected (90)Sr in 8 of 13 r-Cs negative samples, in which (134)Cs was not detected. Strontium-90 concentrations in the r-Cs positive samples did not significantly exceed the (90)Sr concentrations in r-Cs negative samples or the (90)Sr concentration ranges in comparable food groups found in previous surveys before the Fukushima Daiichi NPP accident. Thus, (90)Sr concentrations in r-Cs positive samples were indistinguishable from the background (90)Sr concentrations arising from global fallout prior to the Fukushima accident, suggesting that no marked increase of (90)Sr concentrations has occurred in r-Cs positive samples as a result of the Fukushima Daiichi NPP accident.

AGNES - safety reassessment of Paks NPP

International Nuclear Information System (INIS)

Gado, J.

1995-01-01

The main goal of the AGNES (Advanced General and New Evaluation of Safety) project for the reassessment of the safety of Paks Nuclear Power Plant, Hungary, was to improve the safety culture of the technology at Paks. A report was prepared on the reassessment of the Paks NPP safety. The analysis was divided into four groups: systems analysis, analysis of design basis accidents, severe accident analysis, and level 1 probabilistic safety analysis. Proposed safety enhancement measures are discussed. (N.T.)

NPP Krsko Severe Accident Management Guidelines Upgrade

International Nuclear Information System (INIS)

Mihalina, Mario; Spalj, Srdjan; Glaser, Bruno; Jalovec, Robi; Jankovic, Gordan

2014-01-01

Nuclear Power Plant Krsko (NEK) has decided to take steps for upgrade of safety measures to prevent severe accidents, and to improve the means to successfully mitigate their consequences. The content of the program for the NEK Safety Upgrade is consistent with the nuclear industry response to Fukushima accident, which revealed many new insights into severe accidents. Therefore, new strategies and usage of new systems and components should be integrated into current NEK Severe Accident Management Guidelines (SAMG's). SAMG's are developed to arrest the progression of a core damage accident and to limit the extent of resulting releases of fission products. NEK new SAMG's revision major changes are made due to: replacement of Electrical Recombiners by Passive Autocatalytic Recombiners (PARs) and the installation of Passive Containment Filtered Vent System (PCFV); to handle a fuel damage situation in Spent Fuel Pool (SFP) and to assess risk of core damage situation during shutdown operation. (authors)

Development of a dose assessment computer code for the NPP severe accident at intermediate level - Korean case

International Nuclear Information System (INIS)

Cheong, J.H.; Lee, K.J.; Cho, H.Y.; Lim, J.H.

1993-01-01

A real-time dose assessment computer code named RADCON (RADiological CONsequence analysis) has been developed. An approximation method describing the distribution of radionuclides in a puff was proposed and implemented in the code. This method is expected to reduce the time required to calculate the cloud shine (external dose from radioactive plumes). RADCON can simulate an NPP emergency situation by considering complex topography and continuous washout phenomena and provide a function of effective emergency planning. To verify the code results, RADCON has been compared with RASCAL, which was developed for the U.S. NRC by ORNL, for eight hypothetical accident scenarios. Sensitivity analysis was also performed for the important input parameters. (2 tabs., 3 figs.)

The intelligent system for accident identification in NPP

International Nuclear Information System (INIS)

Hernandez, Jorge Luis.

1998-01-01

Accidental situations in NPP are of greet concern for operators, the facility, regulatory bodies and the environment. This work proposes a design of intelligent system aimed to assist the operator in the process of decision making when initiator events with higher relative contribution to the reactor core damage occur. The intelligent System uses the results of the pre operational Probabilistic Safety Assessment and the Thermal hydraulic Safety Analyses of the NPP Juragua as source for building its knowledge base. The nucleus of the system is presented as a design of an intelligent hybrid system from the combination of the artificial intelligence techniques: fussy logic and artificial neural networks. The system works with variables from the process of the firsts circuit, second circuit and the containment and it is presented as a model for the integration of safety analyses in the process of decision making by the operator when tackling with accidental situations

Chernobyl'-88. Reports of the 1. All-Union scientific and technical meeting on results of accident effect elimination at the Chernobyl' NPP. V. 4. Organization of accident effect elimination and prospects of the 30-km zone use

International Nuclear Information System (INIS)

Ignatenko, E.I.

1989-01-01

Some results of liquidation of the Chernobyl' NPP accident effects and main principles of the zone development are discussed. The problems of management for the zone territory and natural objects and the ways for wood industry development are considered. The state estimation and forecasting for conifers in the zone, wood ecosystem radioactive contamination effects, analysis of conifer genetic effects are made. The results of physical-mathematical simulation of formation of the Chernobyl' NPP near zone territory contamination with long-living radionuclides are given. The protection ability of the aeration zone soil-grounds within the boundaries of radiogeochemical effects of radioactive effluents from internal surfaces of air conduit and ventilation duct during ventilation system operation is estimated

Problems of Chernobyl exclusion zone

International Nuclear Information System (INIS)

1996-01-01

The collection comprises the results of researches and design activity in the ChNPP exclusion zone with the aim to develop technology, equipment and instruments for RAW management and accident clean-up, studying of the composition and structure of the activity solid bearers in the soil of the exclusion zone and transformation of the radionuclides in the nearest zone of ChNPP. Much attention is paid to medical and biological problems of the accident influence on the flora, fauna and people's health labour conditions and incidence of the people involved

Problems of Chornobyl Exclusion Zone

International Nuclear Information System (INIS)

Kashparov, V.A.

2009-01-01

The collection comprises the results of researches and design activity in the ChNPP exclusion zone with the aim to develop technology, equipment and instruments for RAW management and accident clean-up, studying of the composition and structure of the activity solid bearers in the soil of the exclusion zone and transformation of the radionuclides in the nearest zone of ChNPP. Much attention is paid to medical and biological problems of the accident influence on the flora, fauna and people's health, labour conditions and incidence of the people involved.

Chernobyl NPP decommissioning efforts - Past, Present and Future. Decommissioning Efforts on Chernobyl NPP site - Past, Present

International Nuclear Information System (INIS)

Kuchinskiy, V.

2017-01-01

Two unique large-scale projects are underway at the moment within the Chernobyl - Exclusion zone - Shelter object transformation into ecologically safe system and the decommissioning of 3 Chernobyl NPP Units. As a result of beyond design accident in 1986 the entire territory of the industrial site and facilities located on it was heavily contaminated. Priority measures were carried out at the damaged Unit under very difficult conditions to reduce the accident consequences and works to ensure nuclear and radiation safety are continuous, and the Unit four in 1986 was transformed into the Shelter object. Currently, works at the Shelter object are in progress. Under assistance of the International Community new protective construction was built above the existing Shelter object - New Safe Confinement, which will ensure the SO Safety for the long term - within up to 100 years. The second major project is the simultaneous decommissioning of Chernobyl NPP Units 1, 2 and 3. Currently existing Chernobyl NPP decommissioning Strategy has been continuously improved starting from the Concept of 1992. Over the years the following was analyzed and taken into account: the results of numerous research and development works, international experience in decommissioning, IAEA recommendations, comments and suggestions from the governmental and regulatory bodies in the fields of nuclear energy use and radioactive waste management. In 2008 the final decommissioning strategy option for Chernobyl NPP was approved, that was deferred gradual dismantling (SAFSTOR). In accordance with this strategy, decommissioning will be carried out in 3 stages (Final Shutdown and Preservation, Safe Enclosure, Dismantling). The SAFSTOR strategy stipulates: -) the preservation of the reactor, the primary circuit and the reactor compartment equipment; -) the dismantling of the equipment external in relation to the reactor; -) the safe enclosure (under the supervision); -) the gradual dismantling of the primary

Accident management approach in Armenia

International Nuclear Information System (INIS)

Ghazaryan, K.

1999-01-01

In this lecture the accident management approach in Armenian NPP (ANPP) Unit 2 is described. List of BDBAs had been developed by OKB Gydropress in 1994. 13 accident sequences were included in this list. The relevant analyses had been performed in VNIIAES and the 'Guidelines on operator actions for beyond design basis accident (BDBA) management at ANPP Unit 2' had been prepared. These instructions are discussed

Radiation conditions in the Oryol region territory impacted by radioactive contamination caused by the Chernobyl NPP accident

Directory of Open Access Journals (Sweden)

G. L. Zakharchenko

2016-01-01

Full Text Available Research objective is retrospective analysis of radiation conditions in the Oryol region during 1986- 2015 and assessment of efficacy of the carried out sanitary and preventive activities for population protection against radiation contamination caused by the Chernobyl NPP accident.Article materials were own memoirs of events participants, analysis of federal state statistic surveillance forms 3-DOZ across the Oryol region, f-35 “Data on patients with malignant neoplasms, f-12 “Report on MPI activities”. Risk assessment of oncological diseases occurrence is carried out on the basis of AAED for 1986- 2014 using the method of population exposure risk assessment due to long uniform man-made irradiation in small doses. Results of medical and sociological research of genetic, environmental, professional and lifestyle factors were obtained using the method of cancer patients’ anonymous survey. Data on "risk" factors were obtained from 467 patients hospitalized at the Budgetary Health Care Institution of the Oryol region “Oryol oncology clinic”; a specially developed questionnaire with 60 questions was filled out.The article employs the method of retrospective analysis of laboratory and tool research and calculation of dose loads on the Oryol region population, executed throughout the whole period after the accident.This article provides results of the carried out laboratory research of foodstuff, environment objects describing the radiation conditions in the Oryol region since the first days after the Chernobyl NPP accident in 1986 till 2015.We presented a number of activities aimed at liquidation of man-caused radiation accident consequences which were developed and executed by the experts of the Oryol region sanitary and epidemiology service in 1986-2015. On the basis of the above-stated one may draw the conclusions listed below. Due to interdepartmental interaction and active work of executive authorities in the Oryol region, the

Vertical transfer of radionuclides in soils of different genesis after Chernobyl NPP accident

International Nuclear Information System (INIS)

Bakarykava, Zh.; Shagalova, E.; Zhukova, O.

2003-01-01

In this paper a vertical transfer of radionuclides in soils of different genesis after Chernobyl NPP accident was studied. Analysis of obtained data revealed that the main content of cesium-137 is located in 0-5 cm layer of turf-podsolic, sandy-loam and loamy soil provided the lack of their humidification, and of light un-bogged (automorphous) soil as well. Cesium-137 penetration into light un-bogged soils with that sings of surplus humidification is approximately 10 cm deep. Strontium-90 as global birth so Chernobyl origin migrates more rapidly than cesium-137 because of less strong bond with soil absorbing complex. Cesium-137 migration coefficients amounted (0.03-0.46)·10 -7 cm 2 /s for a slow component, and for the fast one (0.39-0.67)·10 -7 cm 2 /s. Strontium-90 migration coefficients in the experimented sites, amounted (0.07-0.58)·10 -7 cm 2 /s for a slow component, and for the fast one (0.64-1.28)·10 -7 cm 2 /s. (authors)

Reconstruction of the Chernobyl emergency and accident management

International Nuclear Information System (INIS)

Schinner, F.; Andreev, I.; Andreeva, I.; Fritsche, F.; Hofer, P.; Lettner, E.; Seidelberger, E.; Kromp-Kolb, H.; Kromp, W.

1998-01-01

Full text of publication follows: on April 26, 1986 the most serious civil technological accident in the history of mankind occurred of the Chernobyl Nuclear Power Plant (ChNPP) in the former Soviet Union. As a direct result of the accident, the reactor was severely destroyed and large quantities of radionuclides were released. Some 800000 persons, also called 'liquidators' - including plant operators, fire-fighters, scientists, technicians, construction workers, emergency managers, volunteers, as well as medical and military personnel - were part of emergency measurements and accident management efforts. Activities included measures to prevent the escalation of the accident, mitigation actions, help for victims as well as activities in order to provide a basic infrastructure for this unprecedented and overwhelming task. The overall goal of the 'Project Chernobyl' of the Institute of Risk Research of the University of Vienna was to preserve for mankind the experience and knowledge of the experts among the 'liquidators' before it is lost forever. One method used to reconstruct the emergency measures of Chernobyl was the direct cooperation with liquidators. Simple questionnaires were distributed among liquidators and a database of leading accident managers, engineers, medical experts etc. was established. During an initial struggle with a number of difficulties, the response was sparse. However, after an official permit had been issued, the questionnaires delivered a wealth of data. Furthermore a documentary archive was established, which provided additional information. The multidimensional problem in connection with the severe accident of Chernobyl, the clarification of the causes of the accident, as well as failures and successes and lessons to be learned from the Chernobyl emergency measures and accident management are discussed. (authors)

Brief review of 1995 events at Ukraine's NPPs. Report on the ChNPP unit 1 of November 27.1995 ''strict regime area premises contamination after reactor refuelling''

International Nuclear Information System (INIS)

Lomakin, V.

1996-01-01

In 1995 number of events at NPP had considerably decreased as compared with that for previous 1992-94, amounted in 87. In particular, as compared with 1994, events number had decreased by 36%. It characterizes a total improvement of current NPPs safety level during 1995. The most events number as recalculated per single unit was at the South Ukraine NPP - 8. The least - at the ChNPP - 4 in total, and 1,3 per unit. Decreasing of a total events number for 1995 did also accordingly reduce other quantitative system indices which reflect state of NPPs safety level. Among event root causes, as it was before, ''administrative management deficiencies'' and ''staff training deficiencies'' are still dominanting. ''Human factor'' issues are still pending for NPPs safety, despite of considerable efforts applied to improved efficiency of correcting measures aimed at their solution. Of sufficient importance for events system development in 1995 was the work implemented at the SSTC NRS/NRA as regards preparation of modern edition of the ''Regulation on order of NPP events investigation and account''. The IAEA/Nuclear Safety Division rendered a sufficient assistance for this work to be done through arrangement of advisory help to Ukrainian specialists from international experts. 2 figs, 8 diagrams

Fukushima-Daiichi after the severe accident (estimation)

International Nuclear Information System (INIS)

Otcenasek, Petr

2011-01-01

All facts about the Fukushima-Daiichi NPP and about the accident known at the time of publication are summarized and expected remedial actions and consequences of the accidents are deduced. The paper is structured as follows: (1) Accident initiation is known; (2) Logically inferred results; (3) Framework identification; (4) Survey; and (5) Economic and strategic impacts of the accident. Worldwide solidarity is mentioned in conclusion. (P.A.)

NIRS external dose estimation system for Fukushima residents after the Fukushima Dai-ichi NPP accident

Science.gov (United States)

Akahane, Keiichi; Yonai, Shunsuke; Fukuda, Shigekazu; Miyahara, Nobuyuki; Yasuda, Hiroshi; Iwaoka, Kazuki; Matsumoto, Masaki; Fukumura, Akifumi; Akashi, Makoto

2013-04-01

The great east Japan earthquake and subsequent tsunamis caused Fukushima Dai-ichi Nuclear Power Plant (NPP) accident. National Institute of Radiological Sciences (NIRS) developed the external dose estimation system for Fukushima residents. The system is being used in the Fukushima health management survey. The doses can be obtained by superimposing the behavior data of the residents on the dose rate maps. For grasping the doses, 18 evacuation patterns of the residents were assumed by considering the actual evacuation information before using the survey data. The doses of the residents from the deliberate evacuation area were relatively higher than those from the area within 20 km radius. The estimated doses varied from around 1 to 6 mSv for the residents evacuated from the representative places in the deliberate evacuation area. The maximum dose in 18 evacuation patterns was estimated to be 19 mSv.

Development of Krsko Severe Accident Management Database (SAMD)

International Nuclear Information System (INIS)

Basic, I.; Kocnar, R.

1996-01-01

Severe Accident Management is a framework to identify and implement the Emergency Response Capabilities that can be used to prevent or mitigate severe accidents and their consequences. Krsko Severe Accident Management Database documents the severe accident management activities which are developed in the NPP Krsko, based on the Krsko IPE (Individual Plant Examination) insights and Generic WOG SAMGs (Westinghouse Owners Group Severe Accident Management Guidance). (author)

Dissemination of Knowledge about NPP Instrumentation and Control Systems

International Nuclear Information System (INIS)

Yastrebenetsky, M.

2016-01-01

Full text: Instrumentation and control (I&C) systems are the most variable part in the nuclear power plants (NPP) comparatively with any other NPP systems. This statement is connected with the wide use of computers, rapid changes in information technologies, with the appearance of new computer complex electronic components, e.g., field programmable gate arrays (FPGA) and with appropriate point of their insertion into NPP I&C life cycle. The changes in NPP I&C systems require the dissemination of the knowledge about these systems. Lessons after Fukushima accident increase necessity of these actions. The elaboration and following dissemination of this knowledge took place in different directions: • Writing and issue of three new books about NPP I&C systems for specialists and for students which were issued in Ukrainian and USA public houses (the last book was issued in 2014); • Organization of five international scientific technical conferences, devoted to NPP I&C safety problems; • Elaboration of national (Ukrainian) standards and regulations pertaining to safety important NPP I&C systems (the last standard was issued in 2015) and participation in elaboration of international standards; • Lecturing for university students, NPP specialists and I&C designers. These actions in all directions are added to IAEA activity in the area NPP I&C systems (e.g., IAEA NP-T-3.12 “Core Knowledge on I&C systems in NPP”). (author

Crisis communication at NPP-Fukushima 1 accident

International Nuclear Information System (INIS)

Tsuchida, S.

2012-01-01

The crisis communication at the TEPCO Fukushima Daiichi Nuclear Power Plant accident in the disaster 3.11 was examined. I discussed the nature of crisis communication which is information exchange between the persons responsible to the accident and the public. And Myth of Panic and Elite Panic were also discussed. (author)

Prediction of hydrogen concentration in nuclear power plant containment under severe accidents using cascaded fuzzy neural networks

Energy Technology Data Exchange (ETDEWEB)

Choi, Geon Pil; Kim, Dong Yeong; Yoo, Kwae Hwan; Na, Man Gyun, E-mail: magyna@chosun.ac.kr

2016-04-15

Highlights: • We present a hydrogen-concentration prediction method in an NPP containment. • The cascaded fuzzy neural network (CFNN) is used in this prediction model. • The CFNN model is much better than the existing FNN model. • This prediction can help prevent severe accidents in NPP due to hydrogen explosion. - Abstract: Recently, severe accidents in nuclear power plants (NPPs) have attracted worldwide interest since the Fukushima accident. If the hydrogen concentration in an NPP containment is increased above 4% in atmospheric pressure, hydrogen combustion will likely occur. Therefore, the hydrogen concentration must be kept below 4%. This study presents the prediction of hydrogen concentration using cascaded fuzzy neural network (CFNN). The CFNN model repeatedly applies FNN modules that are serially connected. The CFNN model was developed using data on severe accidents in NPPs. The data were obtained by numerically simulating the accident scenarios using the MAAP4 code for optimized power reactor 1000 (OPR1000) because real severe accident data cannot be obtained from actual NPP accidents. The root-mean-square error level predicted by the CFNN model is below approximately 5%. It was confirmed that the CFNN model could accurately predict the hydrogen concentration in the containment. If NPP operators can predict the hydrogen concentration in the containment using the CFNN model, this prediction can assist them in preventing a hydrogen explosion.

90Sr content in the Black Sea bottom sediments after the Chernobyl NPP accident and its use as a radiotracer for an assessment of bottom settlement rate

International Nuclear Information System (INIS)

Mirzoyeva, N. Y.; Egorov, V. N.; Polikarpov, G. G.

2006-01-01

The increase of 9 0Sr concentrations in the Black Sea bottom sediments along to western coast of the Black Sea and south part of Crimea was observed in 1987-1988 years. To our opinion, it was connected with hydrological processes (for example, currents), occurring in the given sea parts. The most polluted by post-Chernobyl 9 0Sr areas were bottom sediments of Dnieper, Dniester and Danube River deltas, territory of an arrangement of a main channel of the North-Crimea Channel - region of a peninsula Tarkhankut, southeast part of Crimea (Feodosiya area). The similar situation in confined of the greatest contents 9 0Sr to the specified areas not only is kept with time (till 2000), but the process of increase of 9 0Sr concentration in bottom sediments of the investigated regions is observed. So average concentration of 9 0Sr in Dnieper River delta bottom sediments in 1987 was 28,5 Bq kg - 1 , in 2000 - 148,2 28,5 Bq kg - 1 of Dry Weight. Such character of 9 0Sr redistribution shows, that both in first years after Chernobyl NPP accident, and in the following time, the entry of 9 0Sr in the Black Sea basin occurs, basically, with water flow of the large rivers in a northwest part of the Black Sea, discharge waters of the North-Crimean Channel. These sources of 9 0Sr input to the Black Sea ecosystem considerably prevailed above direct atmospheric pollution by given radionuclide in April-May 1986 at once after the Chernobyl NPP accident. On the base of monitoring researches results the maps of 9 0Sr dynamics redistribution in the Black Sea bottom sediments (0-5 cm) since 1986 (Chernobyl NPP accident) up to 2000 were sketched out. The distribution of 9 0Sr radionuclide in the bottom sediments columns, which were selected from the Corukh river mouth region and from the Dnieper-Bug estuary area, is investigated. The peaks of 9 0Sr increased contents were founded in the profile of its vertical distribution in the bottom sediments. These peaks correspond to the periods of 9 0Sr

Investigation of Chernobyl NPP and recovery of environment and medical service in Ukraine

International Nuclear Information System (INIS)

Narabayashi, Tadashi; Hamamoto, Kazuko; Mizumachi, Wataru; Okamoto, Koji

2013-01-01

Fukushima Daiichi NPP accident will be terminated, if sufficient care of recovery for heart of people, economy and environment leads to happy Fukushima. It might be taken more than 20 years or more. The overseas NPP investigation group in the study committee for safety regulatory of NPP in PES division in JSME visited Chernobyl NPP, Ministry of Emergencies, National Institute for Strategic Studies under the President of Ukraine, Chernobyl Center, Slavutych, Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine, National University of Life and Environmental Science of Ukraine, Institute for Safety Problems of Nuclear Power Plants and Chernobyl Museum. The investigation of bases of their new technology for deep LRW cleaning of Fukushima genesis from the whole range of radionuclides, including uranium and transuranic elements, organic impurities and simultaneous concentration of radioactive components in a small volume. The recovery of environment and care of heart of people were good in Ukraine. The lessons derived from the accident, we can decide what we should do. (author)

Chernobyl'-88. Reports of the 1. All-Union scientific and technical meeting on results of accident effect elimination at the Chernobyl' NPP. V. 3. Part 2. Predictions of the variation in environmental radioactivity and radiation doses at the accidental zone

International Nuclear Information System (INIS)

Ignatenko, E.I.

1989-01-01

Experimental and radiation-sanitary data on radiation situation in the 30-km accident zone at the Chernobyl' NPP are discussed. Doses of soil, vegetation and animals contamination in this region are estimated. Long-term predictions of radiation situation in the accident zone are made

Severe accident training simulator APROS SA

International Nuclear Information System (INIS)

Raiko, Eerikki; Salminen, Kai; Lundstroem, Petra; Harti, Mika; Routamo, Tomi

2003-01-01

APROS SA is a severe accident training simulator based on the APROS simulation environment. APROS SA has been developed in Fortum Nuclear Services Ltd to serve as a training tool for the personnel of the Loviisa NPP. Training with APROS SA gives the personnel a deeper understanding of the severe accident phenomena and thus it is an important part of the implementation of the severe accident management strategy. APROS SA consists of two parts, a comprehensive Loviisa plant model and an external severe accident model. The external model is an extension to the Loviisa plant model, which allows the simulation to proceed into the severe accident phase. The severe accident model has three submodels: the core melting and relocation model, corium pool model and fission product model. In addition to these, a new thermal-hydraulic solver is introduced to the core region of the Loviisa plant model to replace the more limited APROS thermal-hydraulic solver. The full APROS SA training simulator has a graphical user interface with visualizations of both severe accident management panels at the operator room and the important physical phenomena during the accident. This paper describes the background of the APROS SA training simulator, the severe accident submodels and the graphical user interface. A short description how APROS SA will be used as a training tool at the Loviisa NPP is also given

The application of the health effects models to the severe accident consequence analysis of nuclear power plants

International Nuclear Information System (INIS)

Yang Ling; Yeung, M.R.

1998-01-01

Health Effect Model (HEM) is an important model used in the analysis of severe accidents consequence of the Nuclear Power Plants (NPP). The accuracy of HEM affects the reliability of the assessment for the accidents consequences, and furthermore, the effectiveness of the emergency countermeasures taken for the health protection of the public around the NPPs. Based on the NUREG/CR4214 series reports, the paper sets appropriate parameters for HEM by studying both early and late HEMs used for domestic NPP accident consequence analysis. In the study, the Guangdong Daya Bay NPP is chosen as an example study to calculate the health risk of the Hong Kong population caused by Daya Bay NPP

Instrumentation and equipment for monitoring and controlling NPP post-accident situations. Working material. Proceedings of a specialists' meeting held in Dimitrovgrad, Russian Federation, 12-15 September 1995

International Nuclear Information System (INIS)

1995-01-01

The objectives of the Specialist's Meeting were: To provide an international forum for presentation and discussion on experience with instrumentation and equipment for monitoring and controlling NPP post-accident situations; to share experience on the design and improvements in the subject area; to identify and describe advanced features for safety and post-accident management improvements. In order to facilitate a structure discussion and not to omit important problem areas, papers on the following subjects were considered to be within the scope of the Specialist's Meeting: Analysis of existing post-accident instrumentation (in terms of range, qualification and redundancy) to support post-accident management. Requirements for post accident instrumentation and equipment - operating experience, regulations, standards; experience in upgrading of the existing instrumentation; instrumentation and equipment for emergency management systems (emergency rooms and national centers); post-accident computerized aids to assist operators; post-accident operating procedures; R and D in post-accident instrumentation, future trends. The present volume contains: (1) the papers presented by national delegates; (2) programme of the meeting; (3) description of the RIAR research facilities; and (4) list of participants. Refs, figs and tabs

Dukovany NPP operation

International Nuclear Information System (INIS)

Vlcek, Jaroslav

2010-01-01

The topics discussed include: Dukovany NPP among CEZ Group power plants; International missions at the plant; Plant operation results; and Strategic goals and challenges. Historical data are presented in the graphical form, such as the unit capacity factor, unplanned capability loss factor, unplanned automatic scrams, fuel reliability, industrial safety accident rate, collective radiation exposure, WANO index, power generation data, and maximum achievable power by the end of year. Also discussed were the company culture and human resources, maintenance, power uprate, and related phenomena. (P.A.)

Safety enhancement concept for NPP of new generation with VVER reactors

International Nuclear Information System (INIS)

Bezlepkin, V.; Kukhtevich, I.; Semashko, S.; Svetlov, S.; Solodovnikov, A.

2004-01-01

With the present day conditions, in order to successfully promote new NPP designs in the electric power markets, it is necessary to ensure enhanced technical/economic performances provided that international safety requirements are properly adhered to. When compared with high-powered nuclear power plants, NPP VVER-640 design (medium powered) possesses a number of advantages for the regions with undeveloped energy systems. Reduced specific energy intensity of the core adopted in this type of reactor allows to ensure the emergency cooldown of the reactor plant by passive means and to minimize the 'human factor' risk and external effects and provide sound substantiations as to how to retain corium inside RPV in case of severe accidents. At the same time, high-powered NPPs seem to be promising for regions with developed energy systems. Among such designs, NPP VVER-1000 and VVER-1500 designs are the most desirable. Configuration of new generation NPP with VVER-1500 is to be selected based on the gained experience in designing NPPs of previous generations considering the latest safety requirements and situation in the domestic and global energy markets for the time being and in the short run. Recent IAEA publications and latest EUR requirements insist that the following key safety indices should be established for new NPP designs: - aggregated frequency of core melting is 10 -6 (1/year); - frequency of maximum accident release is 10 -7 (1/year). To meet the aforementioned criteria, it is necessary to implement some safety assurance principles recommended by IAEA (in-depth defence, single failure, redundancy, diversity, etc.), application of deterministic and probabilistic methods for selection of safety assurance activities and means and use of reasonable combination of active and passive systems. Application of VVER-640 concept to high-powered NPPs seems to be a formidable task due to a number of reasons, namely, it is quite difficult to carry out cooldown process

Dose limit for emergency workers. Application of Fukushima-Daiichi NPP accident and problems for the future

International Nuclear Information System (INIS)

Sugai, Kenji

2012-01-01

Described are details of management for workers' personal exposure dose, of problems raised and of their solutions taken under various complicated conditions of Fukushima Daiichi Nuclear Power Plant (NPP) Accident (Mar. 2011). As the entrance/exit (en/ex) for the NPP site with regular control were impossible due to the hydrogen explosion which expanded the control area to 20 km distance from the site, Japan Football Village (J-Village) localizing at the border and Important Anti-seismic Building in the site were defined to be the bases of en/ex and of their control, respectively. Flooded 5,000 alarm pocket dosimeters (APD) by tsunami were not usable and only 320 APD remained available. At the quite early stage of working at the site, one representative worker in a group had only one APD. Management of internal exposure was also difficult essentially because the power source of the whole body counter was unavailable. At an early emergent stage alone, workers with higher dose than the limit (100 mSv for emergency) were observed, but >90% of workers were exposed to <50 mSv (the limit for the radiation worker). Six male Tokyo Electric Power Company (TEPCO) personnel were exposed to 250 mSv (specially defined dose limit) or more with the maximum 678.80 mSv, in whom the internal exposure due to radioiodine largely attributed. They were examined for their health by the expert doctors in National Institute of Radiological Sciences, were found free of abnormality and were to be followed up thereafter. Out of 19 female TEPCO personnel, two had exceeded the dose limit 5 mSv/3 mo and other 2, the annual limit 1 mSv. They received the examination by the industrial doctor, were found free of abnormality, but were decided not to work at the site. Recently, about 5,000 APD have been purchased for personal usage and dose management is conducted by bar-coding of individual workers, and internal exposure is managed with 11 whole body counters by once a month measurement in J

MDEP Design-Specific Common Position CP-APR1400WG-01. Common position addressing Fukushima Daiichi nuclear power plant accident

International Nuclear Information System (INIS)

2016-05-01

The MDEP APR1400 Working Group (APR1400WG) members consist of members from Republic of Korea, United Arab Emirates, and the United States. A main objectives of MDEP is to encourage convergence of code, standard and safety goals with exploring the opportunities for harmonization of regulatory practice and cooperation on safety review of APR-1400 specific designs. This common position addressing is aimed at sharing knowledge, information and experience on safety improvement related to lessons learned from the Fukushima Daiichi NPP Accident or Fukushima Daiichi NPP Accident-related issues amongst APR-1400 WG member states to achieve the MEDP goal. Because not all of these Regulators have completed the regulatory review of their APR1400 applications yet, this paper identifies common preliminary approaches to address potential safety improvements for APR1400 plants, as well as common general expectations for new nuclear power plants, as related to lessons learned from the Fukushima Daiichi NPP Accident or Fukushima Daiichi NPP Accident-related issues. While some asymmetry exists among those of three Regulators in terms of design, regulatory practice and licensing milestone sharing information and common understanding on post-Fukushima Daiichi NPP Accident enhancement would be promote resilient design for countering beyond design extreme external event like Fukushima Daiichi NPP nuclear disaster. This common position paper aims at identifying characteristics of post-Fukushima Daiichi NPP Accident enhancements putting in place by each country and setting common position to achieve balanced and harmonized APR-1400 design. After the safety reviews of the APR1400 design applications that are currently in review are completed, the regulators will update this paper to reflect their safety conclusions regarding the APR1400 design and how the design could be enhanced to address Fukushima Daiichi NPP Accident-related issues. The common preliminary approaches are organised into

Analysis of transients for NPP with VVER-440 using the code SiTAP

International Nuclear Information System (INIS)

Kalinenko, V.

1994-06-01

The report contains analysis of transients ''Loop connection'' and ''Steam generator tube rupture'' for nuclear power plants (NPP) with VVER-440. To obtain more detailed information about NPP's dynamic characteristics, various variants of initial and boundary conditions are considerd. Calculation of these transients was performed using the SiTAP code developed at the Nuclear Safety Institute of the Russian Research Centre ''Kurchatov Institute''. SiTAP code is a multifunctional computer tool for fast analysis of transient and accidental processes of VVER type reactors for engineers working in the field of NPP dynamics. SiTAP can be used form comparative analysis of several variants of accident scenarios to find out the conditions leading to most serious consequences from a safety point of view. In such cases, additional analyses using best-estimate codes should be carried out. The results of SiTAP for a faulty loop connection leading to a boron dilution accident are intended to be used as boundary conditions for a more detailed anlaysis with the aid of the three-dimensional reactor core model DYN3D, developed in the Research Centre Rossendorf for the simulation of reactivity initiated accidents. (orig.)

Criterion for adoption of urgent decision on population protection measures in case of NPP accident

International Nuclear Information System (INIS)

Konstantinov, Yu.O.

1985-01-01

The main table of a criterion for making decision about population protection measures in case of NPP accident is reconsidered. In comparison with the previous data the table doesn't contain contact irradiation and food-stuff contamination with 90 Sr and 137 Cs because of their insignificance relatively to external irradiation as a result of inert radioactive gaseous and halogen release and internal irradiation by iodine radioisotopes. Defining more exactly the criterion one should pay more attention to the discussion of numerical values of internal irradiation dose of thyroid gland. The choice of hazard-levels giving the foundation for making decision concerning protection measures should be determined both by biological radiation risk and scale of hazard relative protection urgebcy the degree of accuracy of potential irradiation or contamination evaluation by possibilities of measures carried out in time, difficulties, unfavourable psychologic effect and risk for population health. The criterion should permit flexibility in decision making according to concrete conditions

Modelling of melting and solidification transport phenomena during hypothetical NPP severe accidents

Energy Technology Data Exchange (ETDEWEB)

Sarler, B [Inst. Jozef Stefan, Ljubljana (Slovenia)

1992-07-01

A physical and mathematical framework to deal with the transport phenomena occuring during melting and solidification of the hypothetical NPP severe accidents is presented. It concentrates on the transient temperature, velocity, and species concentration distributions during such events. The framework is based on the Mixture Continuum Formulation of the components and phases, cast in the boundary-domain integral shape structured by the fundamental solution of the Laplace equation. The formulation could cope with various solid-liquid sub-systems through the inclusion of the specific closure relations. The deduced system of boundary-domain integral equations for conservation of mass, energy, momentum, and species could be solved by the boundary element discrete approximative method. (author) [Slovenian] Predstavljeno je fizikalno in matematicno ogrodje za obravnavo prenosnih pojavov taljenja in strjevanja med hipoteticnimi tezkimi nezgodami v jedrskih elektrarnah. Osredotoceno je na popis neustaljene porazdelitve temperatur, hitrosti in koncentracij sestavin med taksnimi dogodki. Ogrodje temelji na formulaciji kontinuuma mesanice komponent in faz, v obliki robno obmocnih integralskih enacb, ki so sestavljena na podlagi fundamentalne resitve Laplace-ove enacbe. Formulacija lahko popisuje stevilne trdno-tekoce pod-sisteme na podlagi specificnih sklopitvenih relacij. Izpeljan sistem robno-obmocnih integralskih enacb za popis ohranitve mase, energije, gibalne kolicine in sestavin lahko resimo na podlagi diskretne aproksimativne metode robnih elementov. (author)

Spent fuel pool risk analysis for the Dukovany NPP

Energy Technology Data Exchange (ETDEWEB)

Hust' ak, S.; Jaros, M.; Kubicek, J. [UJV Rez, a.s., Husinec-Rez (Czech Republic)

2013-07-01

UJV Rez, a.s. maintains a Living Probabilistic Safety Assessment (Living PSA) program for Dukovany Nuclear Power Plant (NPP) in the Czech Republic. This project has been established as a framework for activities related to risk assessment and to support for risk-informed decision making at this plant. The most extensively used PSA application at Dukovany NPP is risk monitoring of instantaneous (point-in-time) risk during plant operation, especially for the purpose of configuration risk management during plant scheduled outages to avoid risk significant configurations. The scope of PSA for Dukovany NPP includes also determination of a risk contribution from spent fuel pool (SFP) operation to provide recommendations for the prevention and mitigation of SFP accidents and to be applicable for configuration risk management. This paper describes the analysis of internal initiating events (IEs) in PSA for Dukovany NPP, which can contribute to the risk from SFP operation. The analysis of those IEs was done more thoroughly in the PSA for Dukovany NPP in order to be used in instantaneous risk monitoring. (orig.)

Cytogenetic examination of persons working in the area of radiation accident at the Fukushima-1 NPP in Japan

Directory of Open Access Journals (Sweden)

Nugis V.Yu.

2014-12-01

Full Text Available Purpose: biological dose indication of employees of the Ministry of Emergency Situations of Russia who took part in the work in Japan in connection with the accident at Fukushima-1 NPP and several journalists covering this event. Material and methods. The analysis of chromosomal aberrations in peripheral blood lymphocyte cultures of 46 people was performed. Results. The frequency of chromosomal damages exceeded background levels in only 3 people, and aberration character testified irradiation in previous situations. Conclusion. The significant overexposure of these workers during they stayed in Japan is absent, however it is necessary to perform a preliminary analysis of chromosome aberrations if you intend to exercise of biological dose indication after returning of people from areas of potential exposure.

NPP life management program - status report for Slovenia

International Nuclear Information System (INIS)

Glumac, B.

1998-01-01

Status report on NPP life management in Slovenia is dealing with possible life extension of NPP Krsko which comprises: replacement of steam generator; power upgrade; exchange of plant process computer; snubber reduction program, additional forced ventilation cooling system. Fuel improvements are predicted as well as the problems of storing spent fuel, low and intermediate waste if the plant is to operate through 2023 and possibly beyond that date. Related research activities are concerned with radiation damage, modelling of reactor core parameters by Monte Carlo calculations and PSA and severe accidents studies. Most of the activities are performed in cooperation with foreign organisations

Atomic physics and atomic industry in Ukraine. Outline of history and present

International Nuclear Information System (INIS)

Tykhyy, Volodymyr

2013-01-01

After the accident of 26 April 1986 at no.4 of Chernobyl NPP (ChNPP), units no.1 and no.2 were restarted in October, 1986. Unit no.3 was restarted in December, 1987. After the accident of 1986, there was a permanent pressure from Western governments which insisted that ChNPP did not meet nuclear safety requirement and shut down. Eventually an agreement between the Government of Ukraine and donor countries was reached to close down ChNPP. The last reactor no.3 was shut down on 2000. After this, ChNPP is legally in the state of decommissioning. There are the following descriptions; National nuclear energy generating company 'Energoatm', Service and education for nuclear power plants, nuclear fuel and nuclear fuel cycle, and Uranium zirconium production sector. In Ukraine, the share of nuclear energy in total electricity generation is very high, but the industry is heavily dependent on the supply of equipment and fuel expertise from Russia. The only improvement that is planned is in-country production of fuel assemblies, but the dependence on enriched uranium will remain. Ukrainian share in production of equipment for nuclear industry in the former Soviet Block countries is quite high, but the success of this sector depends on efforts of Russia to remain an important player on the nuclear industry market in the world. (N.T.)

The psychological background about human error and safety in NPP

International Nuclear Information System (INIS)

Zhang Li

1992-01-01

A human error is one of the factors which cause an accident in NPP. The in-situ psychological background plays an important role in inducing it. The author analyzes the structure of one's psychological background when one is at work, and gives a few examples of typical psychological background resulting in human errors. Finally it points out that the fundamental way to eliminate the unfavourable psychological background of safety production is to establish the safety culture in NPP along with its characteristics

Results from modernization of the containment localization systems of the Kozloduy NPP units 3 and 4

International Nuclear Information System (INIS)

Sabinov, S.

2005-01-01

The improvements of the Accident Localization System (SLA) of units 3 and 4 systematically implemented by Kozloduy NPP shows an important direction for increasing the safety of NPP with WWER-440/V-230 containments. During the years Kozloduy NPP implemented a large scope of activities aimed in full resolution of all generic shortcomings identified in the original design of these containments. These activities allowed already in 2002 to justify that integrity of the containment is assured for all postulated events and the radiological consequences for all DBAs and BDBAs without core degradation are within the regulatory limits. The last phase of this modernization was oriented toward achieving the same goals in case of severe accidents by installation of systems for avoiding long term pressurization of the SG compartments and by installation of a system for keeping of negative pressure (slight vacuum) during the late phases of development of the accidents thus minimizing significantly the uncontrolled radioactive releases from the containment and assured controlled purified release of radioactivity to environment, and for elimination of conditions for H2 deflagration within the localization system. This paper summarizes the results of the whole modernization process with an emphasis of the implementation of the latest phase successfully completed by Kozloduy NPP in first quarter of 2005 which allowed the plant to demonstrate remarkable mitigation capability for a comprehensive set of very low probability severe accidents scenarios in line with the approach now being promoted for the modern design NPPs

Safety investigation of team performance in accidents

International Nuclear Information System (INIS)

Petkov, G.; Todorov, V.; Takov, T.; Petrov, V.; Stoychev, K.; Vladimirov, V.; Chukov, I.

2004-01-01

The paper presents the capacities of the performance evaluation of teamwork (PET) method. Its practicability and efficiency are illustrated by retrospective human reliability analyse of the famous nuclear and maritime accidents. A quantitative assessment of operators' performance on the base of thermo-hydraulic (T/H) calculations and full-scope simulator data for set of NPP design basic accidents with WWER is demonstrated. The last data are obtained on the 'WWER-1000' full-scope simulator of Kozloduy NPP during the regular practical training of the operators' teams. An outlook on the 'evaluation system of main control room (MCR) operators' reliability' project, based on simulator data of operators' training is given

Scheme of higher-density storage of spent nuclear fuel in Chernobyl NPP interim storage facility no. 1

International Nuclear Information System (INIS)

Britan, P.M.

2008-01-01

On 29. March 2000 the Cabinet of Ministers of Ukraine issued a decree prescribing that the last operating unit of Chernobyl NPP be shut down before its design lifetime expiry. In accordance with the Contract concluded on 14 June 1999 between the National Energy-generating Company 'Energoatom' and the Consortium of Framatome, Campenon Bernard-SGE and Bouygues, in order to store the spent ChNPP fuel a new interim dry storage facility (ISF-2) for spent ChNPP fuel would be built. Currently the spent nuclear fuel (spent fuel assemblies - SFAs) is stored in reactor cooling pools and in the reactors on Units 1, 2, 3, as well as in the wet Interim Storage Facility (ISF-1). Taking into account the expected delay with the commissioning of ISF-2, and in connection with the scheduled activities to build the New Safe Confinement (including the taking-down of the existing ventilation stack of ChNPP Units 3 and 4) and the expiry of the design operation life of Units 1 and 2, it is expedient to remove the nuclear fuel from Units 1, 2 and 3. This is essential to improve nuclear safety and ensure that the schedule of construction of the New Safe Confinement is met. The design capacity of ISF-1 (17 800 SFAs) is insufficient to store all SFAs (21 284) currently on ChNPP. A technically feasible option that has been applied on other RBMK plants is denser storage of spent nuclear fuel in the cooling ponds of the existing ISF-1. The purpose of the proposed modifications is to introduce changes to the ISF-1 design supported by necessary justifications required by the Ukrainian codes with the objective of enabling the storage of additional SFAs in the existing storage space (cooling pools). The need for the modification is caused by the requirement to remove nuclear fuel from the ChNPP units as soon as possible, before the work begins to decommission these units, as well as to create safe conditions for the construction of the New Safe Confinement over the existing Shelter Unit. (author)

Annual activity report of Ignalina NPP Safety Analysis Group for 1995 year

International Nuclear Information System (INIS)

Ushpuras, E.; Augutis, J.; Bubelis, E.

1995-01-01

The main results of Ignalina NPP Safety Analysis Group (ISAG) investigations for 1995 are presented. ISAG is concentrating its research activities into four areas: the neutrons dynamics modelling, simulation of transient processes during loss of coolant accident, the reactor cooling systems modelling and the probabilistic safety assessment of accident confinement system. 18 refs., 9 tabs., 110 figs

Annual activity report of Ignalina NPP Safety Analysis Group for 1994 year

International Nuclear Information System (INIS)

Ushpuras, E.; Kaliatka, A.; Chesna, B.; Dundulis, G.

1995-01-01

The main results of Ignalina NPP Safety Analysis Group (ISAG) investigations for 1994 are presented. ISAG is concentrated its research activities into 3 areas: the neutrons dynamics modeling, simulation of transient processes during loss of coolant accident and calculation of reactor building structure's streses and other mechanical properties in the case of accident. 6 refs., 13 tabs., 69 figs

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

International Nuclear Information System (INIS)

Farfan, E.; Jannik, T.

2011-01-01

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

Annual activity report of Ignalina NPP Safety Analysis Group for the year 1997

International Nuclear Information System (INIS)

Ushpuras, E.; Augutis, J.; Bubelis, E.; Kaliatka, A

1998-01-01

The main results of Ignalina NPP Safety Analysis Group (ISAG) investigations for the year 1997 are presented. ISAG is concentrating its research activities into four areas: the neutrons dynamics modelling, simulation of transient processes during loss of coolant accident, the reactor cooling systems modelling and the probabilistic safety assessment of accident confinement system

IPEEE Review of other external events of the NPP Asco

International Nuclear Information System (INIS)

Canadell, F.; Aleman, A.; Beltran, F.; Pifarre, D.; Hernandez, H.; Gasca, C.

2011-01-01

Within the process of maintaining and updating the risk analysis of the NPP Asco, results from the review of the vulnerability study of the plant against severe accidents caused by external success (Individual Plant Examination of External Events, IPEEE).

Effect of natural circulation on RCS depressurization strategy in PWR NPP

International Nuclear Information System (INIS)

Zhang Kun; Tong Lili; Cao Xuewu

2009-01-01

The natural circulation model of Chinese Qinshan Nuclear Power Plant (NPP) Unit 2 is built using SCDAP/RELAP5 code. Selecting TMLB' accident as the base sequence, this paper analyzes the natural circulation phenomena in high-pressure core melt severe accident. In order to study the effect of natural circulation on RCS depressurization strategy, the accident progressions of RCS depressurization with and without natural circulation are simulated, respectively. According to the results, the natural circulation can delay the initiation of RCS depressurization and the whole accident progression, but it does not evidently influence the results of RCS depressurization. (authors)

Accidents during shutdown conditions for NPP with WWER-1000/428

International Nuclear Information System (INIS)

Antropov, H.A.

1996-01-01

This paper considers the effect of such internal initiating events upon safety of the NPP with WWER-1000/428 as boron dilution and loss of residual heat removal at the reduced coolant inventory in the primary circuit. 2 refs

Analysis of flooding possibilities of premises of Ignalina NPP

International Nuclear Information System (INIS)

1999-01-01

Analysis of flooding possibilities of premises with safety related equipment of Ignalina NPP was performed. In calculations codes SQUIRT and RELAP5 was used. In most cases it was found that it would be enough time to take corrective measure in the case of flooding accident

[The results of a cytogenetic examination of children who were victims of the accident at the Chernobyl Atomic Electric Power Station and who reside in an ecologically unfavorable region].

Science.gov (United States)

Frolov, V M; Baryliak, I R; Peresadin, M O; Khrypko, S V; Kuziuberdina, K M

1994-01-01

It has been detected that children evacuated from the zone with the elevated radioactivity level have the increased number of chromosomal and chromatid aberrations. The frequency of chromatid aberrations is 2.1-fold lower in country-side children than in children from industrial towns. Cytogenetic disturbances in immunocompetent cells correlate with the level of immune imbalance. Children born in families of liquidators of the ChNPP accident in the first year after their return from the accident zone have substantial cytogenetic and immune disturbances. Children living near sources of atmospheric pollution are characterized by the 3-4-fold increase in frequencies of chromatid anomalies and by the development of a pronounced immunodeficiency.

Reconstruction of the size of nuclear fuel particle aerosol by the investigation of a radionuclide behaviour in body of the Chernobyl accident witnesses

International Nuclear Information System (INIS)

Kutkov, V.A.

1996-01-01

As a result of the Chernobyl NPP (ChNPP) accident aerosol particles of dispersed nuclear fuel were released to the atmosphere. Inhalation of those aerosol became the source of internal exposure for witnesses of the Chernobyl accident. To assess correctly internal doses from a mixture of radionuclides present in air in the form of aerosol particles one mast assign each radionuclide to a certain inhalation class by its chemical speciation in aerosol and define the airborne characteristics (the activity median aerodynamic diameter, AMAD and the standard geometric deviation, fig) of that particular aerosol. Moreover, information on any particular radionuclide is useless for other components since, in such a mixture, the radionuclides are generally independent and may belong to different particles. On the contrary, all nuclear fuel particle (NFP) radionuclides belong to the same particle, being matrix-bound. The collective behaviour of the matrix-bound radionuclides in the environment and in the human barrier organs makes it possible to spread to the aerosol of NFP any estimates of AMAD and β g obtained for any particular NFP radionuclide. This is principal feature of NFP aerosol as distinguished from a mere mixture of aerosol particles carry different radionuclides. (author)

Accident at TEPCo’s Fukushima-Daiichi NPP - LL for Operator/Industry

International Nuclear Information System (INIS)

Omoto, Akira

2011-01-01

Lessons Learned - Emergency Management: • Loss of communication tool and plant information (SPDS) at NPP; • Dissemination of information: - Damage to social infrastructure by earthquake hampered dissemination of information to local government and residents: - Lack of Information sharing with local residents on dispersion of FP (SPEEDI) and risk of radiation with neighboring countries on release of slightly-contaminated water: - “Data but not information”; •Who is in charge?: - Ambiguity in delineation of responsibility; - Recognized role by Joint (Government and TEPCO) ERC and local resources center 20—30km away from NPP; • Offsite center: function was lost by loss of electricity and radiation; • Effective channeling of emergency supports: - Systematize domestic/foreign helping hands for logistics/experts

A model for severe accidents management of WWER 440 at Kozloduy NPP

International Nuclear Information System (INIS)

Genovski, I.; Bonev, B.; Velev, V.; Grigorov, A.; Filipov, L.

2006-01-01

In order to reduce the residual risk associated with hypothetical severe nuclear accidents, systems and components for filtered containment venting and H2 reduction were implemented in the Kozloduy NPP units 3 and 4. The system technologies developed have to fulfill the following main tasks: 1) Creating a new pressure barrier system to confine the activity inventory by maintaining a slight containment sub-atmospheric pressure thereby preventing any relevant unfiltered activity releases. 2) Retaining a great extend of the airborne activity in the liquid phase of the venturi scrubber unit and return these activity back into the containment. 3) Controlling the containment atmosphere H2 gas mixture to prevent fast deflagration that may jeopardize the containment integrity. To meet above mentioned requirement a system was developed, consisting of a venturi scrubber unit which comprises a high speed long venturi section, a metal fibre filter section and molecular sieve. The system is operated by a turbo blower unit supplied with electrical power from the unaffected unit. The system keeps a slight sub-atmospheric pressure (approx. 5 - 10 mbar) in the containment with the purpose to minimize the uncontrolled radioactive release from the containment to the environment. The final analysis showed that the containment performance in combination with above mentioned countermeasures could be increased significantly and the impact to the environment is minimized

Application of Robotic System for Emergency Response in NPP

International Nuclear Information System (INIS)

Jeong, Kyung Min; Seo, Yong Chil; Shin, Ho Chul; Lee, Sung Uk; Cho, Jae Wan; Choi, Young Soo; Kim, Chang Hoi; Kim, Seung Ho

2010-01-01

Increasing energy demand and concerns over climate change make increasing use of nuclear power plant in worldwide. Even though the probability of accident is greatly reduced, safety is the highest priority issue in the nuclear energy industry. Applying highly reliable and conservative 'defense in depth' concepts with the design and construction of NPP, there are very little possibilities with which accidents are occur and radioactive materials are released to environments in NPP. But NPP have prepared with the emergency response procedures and conduct exercises for post-accident circumstance according to the procedures. The application of robots for emergency response task for post-accident in nuclear facilities is not a new concept. Robots have been sent to recover the damaged reactor at Chernobyl where human workers could receive a lifetime dose of radiation in minutes. Based on NRC's TMI-2 Cleanup Program, several robots were built in the 1980s to help gather information and remove debris from a reactor at the Three Mile Island nuclear power plant that partially melted down in 1979. The first robot was lowered into the basement through a hatch and human operators monitoring in a control room drove it through mud, water and debris, capturing the initial post-accident images of the reactor's basement. It was used for several years equipped with various tools allowing it to scour surfaces, scoop samples and vacuum sludge. A second version carried a core sampler to determine the intensity and depth of the radiation that had permeated into the walls. To perform cleanup tasks, they built Workhorse that featured system redundancy and had a boom extendable to reach high places, but it was never used because it had too many complexities and to clean and fix. While remote robotics technology has proven to remove the human from the radioactive environment, it is also difficult to make it useful because it may requires skill about remote control and obtaining remote

Application of Robotic System for Emergency Response in NPP

Energy Technology Data Exchange (ETDEWEB)

Jeong, Kyung Min; Seo, Yong Chil; Shin, Ho Chul; Lee, Sung Uk; Cho, Jae Wan; Choi, Young Soo; Kim, Chang Hoi; Kim, Seung Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-10-15

Increasing energy demand and concerns over climate change make increasing use of nuclear power plant in worldwide. Even though the probability of accident is greatly reduced, safety is the highest priority issue in the nuclear energy industry. Applying highly reliable and conservative 'defense in depth' concepts with the design and construction of NPP, there are very little possibilities with which accidents are occur and radioactive materials are released to environments in NPP. But NPP have prepared with the emergency response procedures and conduct exercises for post-accident circumstance according to the procedures. The application of robots for emergency response task for post-accident in nuclear facilities is not a new concept. Robots have been sent to recover the damaged reactor at Chernobyl where human workers could receive a lifetime dose of radiation in minutes. Based on NRC's TMI-2 Cleanup Program, several robots were built in the 1980s to help gather information and remove debris from a reactor at the Three Mile Island nuclear power plant that partially melted down in 1979. The first robot was lowered into the basement through a hatch and human operators monitoring in a control room drove it through mud, water and debris, capturing the initial post-accident images of the reactor's basement. It was used for several years equipped with various tools allowing it to scour surfaces, scoop samples and vacuum sludge. A second version carried a core sampler to determine the intensity and depth of the radiation that had permeated into the walls. To perform cleanup tasks, they built Workhorse that featured system redundancy and had a boom extendable to reach high places, but it was never used because it had too many complexities and to clean and fix. While remote robotics technology has proven to remove the human from the radioactive environment, it is also difficult to make it useful because it may requires skill about remote control and

Radioactive source management in Daya Bay NPP

International Nuclear Information System (INIS)

Mao Chun Yang

2000-01-01

'Small sources causes big accidents' had occurred worldwide many times. Radioactive source management in Nuclear Power Plant in very important for its safety record. This paper introduces the way and experience of radioactive source management in Daya Bay NPP from aspects of clarifying the responsibilities, centralizing the management of high radioactivity sources, work process management and experience feedback etc. (author)

Research on sever accident emergency simulation system for CPR1000

International Nuclear Information System (INIS)

Yang Zhifei; Liao Yehong; Liang Manchun; Li Ke; Yang Jie; Chen Yali

2015-01-01

The enhanced capability to nuclear power plant (NPP) severe accident management and emergency response depends heavily on exercises. Since the exercise scene is usually monotonous and not realistic, and conduct of exercise has a high cost, the effect of enhancing the capability is limited. Thus, the development of a Sever Accident Emergency Simulation System (SAESS) is necessary. SAESS is able to connect NPP simulator, and simulates the process of severe accident management, personnel evacuation, the dispersion of radioactive plume, and emergency response of emergency organizations. The system helps to design several of exercise scenes and optimize the disposal strategy in different severe accidents. In addition, the system reduces the cost of emergency exercise by computer simulation, benefits the research of exercise, increases the efficiency of exercise and enhances the emergency decision-making capability. This paper introduces the design and application of SAESS. (author)

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

International Nuclear Information System (INIS)

Nosovskij, A.V.; Vasil'chenko, V.N.; Klyuchnikov, A.A.; Prister, B.S.

2006-01-01

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

Improvement of Severe Accident Analysis Computer Code and Development of Accident Management Guidance for Heavy Water Reactor

International Nuclear Information System (INIS)

Park, Soo Yong; Kim, Ko Ryu; Kim, Dong Ha; Kim, See Darl; Song, Yong Mann; Choi, Young; Jin, Young Ho

2005-03-01

The objective of the project is to develop a generic severe accident management guidance(SAMG) applicable to Korean PHWR and the objective of this 3 year continued phase is to construct a base of the generic SAMG. Another objective is to improve a domestic computer code, ISAAC (Integrated Severe Accident Analysis code for CANDU), which still has many deficiencies to be improved in order to apply for the SAMG development. The scope and contents performed in this Phase-2 are as follows: The characteristics of major design and operation for the domestic Wolsong NPP are analyzed from the severe accident aspects. On the basis, preliminary strategies for SAM of PHWR are selected. The information needed for SAM and the methods to get that information are analyzed. Both the individual strategies applicable for accident mitigation under PHWR severe accident conditions and the technical background for those strategies are developed. A new version of ISAAC 2.0 has been developed after analyzing and modifying the existing models of ISAAC 1.0. The general SAMG applicable for PHWRs confirms severe accident management techniques for emergencies, provides the base technique to develop the plant specific SAMG by utility company and finally contributes to the public safety enhancement as a NPP safety assuring step. The ISAAC code will be used inevitably for the PSA, living PSA, severe accident analysis, SAM program development and operator training in PHWR

Improvement of Severe Accident Analysis Computer Code and Development of Accident Management Guidance for Heavy Water Reactor

Energy Technology Data Exchange (ETDEWEB)

Park, Soo Yong; Kim, Ko Ryu; Kim, Dong Ha; Kim, See Darl; Song, Yong Mann; Choi, Young; Jin, Young Ho

2005-03-15

The objective of the project is to develop a generic severe accident management guidance(SAMG) applicable to Korean PHWR and the objective of this 3 year continued phase is to construct a base of the generic SAMG. Another objective is to improve a domestic computer code, ISAAC (Integrated Severe Accident Analysis code for CANDU), which still has many deficiencies to be improved in order to apply for the SAMG development. The scope and contents performed in this Phase-2 are as follows: The characteristics of major design and operation for the domestic Wolsong NPP are analyzed from the severe accident aspects. On the basis, preliminary strategies for SAM of PHWR are selected. The information needed for SAM and the methods to get that information are analyzed. Both the individual strategies applicable for accident mitigation under PHWR severe accident conditions and the technical background for those strategies are developed. A new version of ISAAC 2.0 has been developed after analyzing and modifying the existing models of ISAAC 1.0. The general SAMG applicable for PHWRs confirms severe accident management techniques for emergencies, provides the base technique to develop the plant specific SAMG by utility company and finally contributes to the public safety enhancement as a NPP safety assuring step. The ISAAC code will be used inevitably for the PSA, living PSA, severe accident analysis, SAM program development and operator training in PHWR.

Analysis of the first stage in the reactor accident development at the Chernobyl NPP fourth unit

International Nuclear Information System (INIS)

Adamov, E.O.; Vasilevskij, V.P.; Ionov, A.I.

1988-01-01

Results of analyzing possible development of the first stage of the accident at the Chernobyl NPP fourth unit from the moment of pressing the Az-5 push button are presented. Calculations were conducted using the TRIADA three-dimensional dynamic program both for conditions without pump switching off and with their switching off. Distribution of neutron field over the core volume was determined according to actual readings of in-core detectors immediately before turbogenerator switching off. It is shown that sufficient reconstruction of neutron field begins immediately after pressing the Az-5 push button. Prohibitive decrease of operative reactivity margin which was admitted by personnel in the accident resulted in the growth of neutron power in reactor lower part within 1.5 s, predominating over power decrease in the upper part. Thus, the average integral power grows achieving the maximum during 7.5 s, after which its sharp decrease begins. Conditions with switching off of 4 circulating pumps lead to intesive growth of power and reactor runaway, initiated in the lower part of the core, which safety rods have not managed to reach. Fuel element temperature at that exceeds fuel melting point in the most power-intensive regions. This causes extremely intensive process of steam generation and overheating, pressure growth in the circuit, short-time decrease of the rate of operating pumps, destruction of fuel channels and the whole reactor. Primary measures assuring RBMK ractor safety were formulated on the basis of conducted investigation

SAT for NPP personnel training in USA

International Nuclear Information System (INIS)

Spinney, R.

1995-01-01

This discussion addressed the experience with the application of SAT at USA NPPs. In particular, the transition of NPP training processes, staff composition, and reporting structure from the TMI accident to present. As well, oversight and guidance activities of the INPO and more intensive inspection by the NRC began during this period. The average NPP training staff grew to 30-40 per unit, along with a change in reporting line from plant to corporate management. With the reduction of resources occurring in the late 1980s, overall training staff size decreased, the composition changed, and reporting line reverted to plant management. The overall lessons-learned for application of the SAT consisted of the need for simplification, management involvement, and exploitation of the technology

Automations influence on nuclear power plants: a look at three accidents and how automation played a role.

Science.gov (United States)

Schmitt, Kara

2012-01-01

Nuclear power is one of the ways that we can design an efficient sustainable future. Automation is the primary system used to assist operators in the task of monitoring and controlling nuclear power plants (NPP). Automation performs tasks such as assessing the status of the plant's operations as well as making real time life critical situational specific decisions. While the advantages and disadvantages of automation are well studied in variety of domains, accidents remind us that there is still vulnerability to unknown variables. This paper will look at the effects of automation within three NPP accidents and incidents and will consider why automation failed in preventing these accidents from occurring. It will also review the accidents at the Three Mile Island, Chernobyl, and Fukushima Daiichi NPP's in order to determine where better use of automation could have resulted in a more desirable outcome.

Problems of Chernobyl exclusion zone

International Nuclear Information System (INIS)

1996-01-01

The collection comprises the results of researches and design activity in the ChNPP exclusion zone with the aim to develop technology, equipment and instruments for RAW management and accident clean-up, studying of the composition and structure of the activity solid bearers in the soil of the exclusion zone and transformation of the radionuclides in the nearest zone of ChNPP. Much attention is paid to medical and biological problems of the accident influence on the flora, fauna and people's health, labour conditions and incidence of the people involved. The collection comprises the information for scientists, experts, postgraduates and students in gaged in ecology, radioecology, nuclear engineering, radiology, radiochemistry and radiobiology

A case study of economic incentives and local citizens' attitudes toward hosting a nuclear power plant in Japan: Impacts of the Fukushima accident

International Nuclear Information System (INIS)

Kato, Takaaki; Takahara, Shogo; Nishikawa, Masashi; Homma, Toshimitsu

2013-01-01

The attitude of local communities near a nuclear power plant (NPP) is a key factor in nuclear policy decision making in Japan. This case study compared local citizens' attitudes in 2010 and 2011 toward the benefits and drawbacks of hosting Kashiwazaki–Kariwa NPP. The Fukushima accident occurred in this period. After the accident, benefit recognition of utility bill refunds clearly declined, while that of public facilities did not, suggesting the influence of a bribery effect. The negative shift of attitudes about hosting the NPP after the accident was more modest in Kariwa Village, which saw a large expansion of social welfare programs, than in the other two areas, which lacked such a budget expansion. Policy implications of these results regarding the provision of economic incentives in NPP host areas after the Fukushima accident were discussed. - Highlights: • The Fukushima accident shocked Japan's nuclear policy. • Citizens' attitudes toward incentives of hosting a nuclear power plant surveyed. • More citizens thought negatively about incentives after the Fukushima accident. • The bribery effect, mode and amount of incentives affected citizens' attitudes

ORSEC technological risks, Blayais NPP

International Nuclear Information System (INIS)

2016-01-01

The Particular intervention plan (PPI in French) is an emergency plan which foresees the measures and means to be implemented to address the potential risks of the presence and operation of a nuclear facility. This plan is implemented and developed by the Prefect in case of nuclear accident (or incident leading to a potential accident), the impact of which extending beyond the facility perimeter. It represents a special section of the organisation plan for civil protection response (ORSEC plan). The PPI foresees the necessary measures and means for crisis management during the first hours following the accident and is triggered by the Department Prefect according to the information provided by the facility operator. Its aim is to protect the populations leaving within 10 km of the facility against a potential radiological hazard. The PPI describes: the facility, the intervention area, the protection measures for the population, the conditions of emergency plan triggering, the crisis organisation, the action forms of the different services, and the post-accident stage. This document is the public version of the Particular intervention plan of the Blayais NPP (Gironde, France)

Abstracts of papers of international scientific conference 'Fundamental and applied aspects of radiobiology: Biological effects of low doses and radioactive contamination of environment (Radioecological and medical biological consequences of the Chernobyl NPP accident)'

International Nuclear Information System (INIS)

Konoplya, E.F.; Astakhov, A.I.; Bogdevich, I.M.; Borisevich, N.Ya.; Zubovich, V.K.; Knat'ko, V.A.; Lobanok, L.M.; Matsko, V.P.; Mrochek, A.G.

1998-05-01

The results of research works executed in Belarus, as well as in Ukraine and Russia, on various aspects of the Chernobyl problematic are given: radiation medicine and risks, radiobiological effects and their forecasting, radioecology and agricultural radiology, decontamination and radioactive wastes management, socio economic and psychological problems caused by the Chernobyl NPP accident

About choosing the power unit of NPP

International Nuclear Information System (INIS)

Alekseev, P.N.; Mordashev, V.M.; Proshkin, A.A.; Stukalov, V.A.; Subbotin, S.A.; Tsibul'skij, V.F.; Chernilin, Yu.F.

2008-01-01

The present-day domestic nuclear power industry faces the necessity to make both process and economy related decisions. The mentioned decisions should cover all the aspects of the nuclear power complex. In particular, as of now, no substantiation of the present-day and the future requirements for the power unit of the WWER and fast reactor NPPs is available. The choice of the unit power of an NPP should involve consideration of all factors and should not be boiled down to the efforts to ensure the minimization of the investment and the operation constituents of the electric power generation costs. The aim of the present paper was to ensure elaboration of the recommendations to substantiate the optimal unit power of NPP power units based on the analysis of various factors to design, to construct and to operate an NPP (investment, time of construction, the unscheduled shutdown losses, the unification, the fabrication quality, the accident damage, etc.), and the electrical network potentialities and the regional electric power demands [ru

Annual activity report of Ignalina NPP Safety Analysis Group for 1996 year

International Nuclear Information System (INIS)

Ushpuras, E.; Augutis, J.; Bubelis, E.

1997-03-01

The main results of Ignalina NPP Safety Analysis Group (ISAG) investigations for 1996 are presented. ISAG is concentrating its research activities into four areas: the neutrons dynamics modelling, simulation of transient processes during loss of coolant accident, the reactor cooling systems modelling and the probabilistic safety assessment of accident confinement system. Ignalina Safety Analysis Report was prepared on the basis of these results. 37 refs., 9 tabs., 96 figs

Lessons of the accident at Three Mile Island nuclear power plant

International Nuclear Information System (INIS)

Veksler, L.M.

1983-01-01

Measures taken in the USA for improving safety of NPPs after the accident at ''Three Mile Island'' nuclear power plant are considered. Activities, related to elimination of accident consequences are analyzed. Perspectives of resuming the NPP operation are discussed

Calculation of behaviour of the Juragua NPP containment with code TRACOV/MOD1

International Nuclear Information System (INIS)

Castillo Alvarez, J.; Valle Cepero, R.; Luis, J.; San Roman, J.C.; Pomier, L.

1996-01-01

The containment of Juragua NPP has some unique features, which differ from the rest of the PWR reactors design. Those features impose additional requirements for its numerical simulation. In this paper is analyzed the behaviour of the Juragua NPP containment during accident situation with double ended break of the primary pipelines with flow in both direction using the code TRACOV/MOD1. The results are compared with obtained by the designer. The main restrictions of the code are identified

Analysis of Fukushima Daiichi Accident Using HFACS

International Nuclear Information System (INIS)

Mohamed, Saeed Almheiri

2013-01-01

The shadow of Fukushima Daiichi nuclear power plant (NPP) accident is still too big and will last long. On the other hand, it could still teach us lots of lessons to better design and operate nuclear power plants. In this paper, we will be focusing on the Fukushima Daiichi accident, especially on human organizational factors. We will analyze the accident using Human Factors Analysis and Classification System (HFACS) in order to better understand the organizational climate of TEPCO 1 and NISA 2 that led to Fukushima Daiichi Accident. HFACS was developed for the U. S. aviation industry and has been used at many industries like the rail and mining industries. We found that the HFACS to be greatly beneficial in investigating the latent and organizational causes for the accident. The application results show that the causes of Fukushima Daiichi accident were spread out from sharp end (i.e. Unsafe Act) to blunt end (i. e. Organizational Influences). This means that the corresponding countermeasures should cover from front line staff to management. Thus, we managed to develop a better understanding on how to prevent similar errors or violations. The incident and near-miss have a lot of helpful information because it may show the actual and latent deficiencies of complex systems. We applied the HFACS into Fukushima Daiichi accident to better locate the causes related to both sharp and blunt ends of operation of NPP. In order to derive useful lessons from the accident analysis, the analyst should try to find the similarities not differences from the incident. It is imperative that whatever accident/incident analysis systems we use, we should fully utilize the disastrous Fukushima accident

Analysis of Fukushima Daiichi Accident Using HFACS

Energy Technology Data Exchange (ETDEWEB)

Mohamed, Saeed Almheiri [Korea Advanced Institue of Science and Technology, Daejeon (Korea, Republic of)

2013-10-15

The shadow of Fukushima Daiichi nuclear power plant (NPP) accident is still too big and will last long. On the other hand, it could still teach us lots of lessons to better design and operate nuclear power plants. In this paper, we will be focusing on the Fukushima Daiichi accident, especially on human organizational factors. We will analyze the accident using Human Factors Analysis and Classification System (HFACS) in order to better understand the organizational climate of TEPCO{sup 1} and NISA{sup 2} that led to Fukushima Daiichi Accident. HFACS was developed for the U. S. aviation industry and has been used at many industries like the rail and mining industries. We found that the HFACS to be greatly beneficial in investigating the latent and organizational causes for the accident. The application results show that the causes of Fukushima Daiichi accident were spread out from sharp end (i.e. Unsafe Act) to blunt end (i. e. Organizational Influences). This means that the corresponding countermeasures should cover from front line staff to management. Thus, we managed to develop a better understanding on how to prevent similar errors or violations. The incident and near-miss have a lot of helpful information because it may show the actual and latent deficiencies of complex systems. We applied the HFACS into Fukushima Daiichi accident to better locate the causes related to both sharp and blunt ends of operation of NPP. In order to derive useful lessons from the accident analysis, the analyst should try to find the similarities not differences from the incident. It is imperative that whatever accident/incident analysis systems we use, we should fully utilize the disastrous Fukushima accident.

Assessment of the event at Rovno NPP owing to the unexpected opening and obstruction of the safety valve lock mechanism of the pressure compensator

International Nuclear Information System (INIS)

Alonso, C.

1993-01-01

The main objective of this analysis is to be able to identify the sequence of the accident and evaluate the real frequency observed in similar nuclear power plants, according to the experience registered in the data bases of the NPP accident information system (ISI-AES) as well as the quality assurance information system (ISKO). This work describes how the analysis of events in a VVER-440 reactor NPP was performed

Beyond Design Basis Severe Accident Management as an Element of DiD Concept Strengthening

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, M., E-mail: kuznetsov_mv@vosafety.ru [FSUE VO “Safety”, Moscow (Russian Federation)

2014-10-15

The 4{sup th} Level of DiD is ensured by management of beyond design basis accidents which is achieved by implementation of the Beyond Design Basis Accidents Management Guidance (BDBAMG) and, if necessary, by additional technical devices and organizational measures at NPP Unit. BDBAMG is located between Levels 3 and 5 in DiD and is related to them. It is connected with Level 3 by means of conditions generated at this Level and according to which BDBAM should be initiated (Level 4). It is associated with Level 5 by conditions which necessitate implementation of Emergency planning. Both types of conditions should be identified in BDBAMG. BDBAs including the phase of severe damage of fuel and protective barriers (severe accidents) in accordance with Russian regulatory framework are a subset of all BDBAs set. In this connection, such accident scenarios meet the representativeness criterion for further analysis and development of Guidance for their management. BDBAMG availability, as it provides robustness of DiD as a whole, is an obligatory condition for obtaining a NPP operational license. In the process of BDBAMG development and implementation a feedback with technical and organizational measures, comprising Level 1 and, to a less extent, Level 2, comes up. BDBAMG verification is an important final stage of its development. Addressing severe accidents, it is a challenging issue for a full scope simulator and may require its software modernization to make it responsive to severe accident phenomena. The existing BDBAMGs should be updated due to NPP Unit modernizations and in conjunction with the latest knowledge on severe accident phenomenology and lessons learnt from known events (e.g. NPP Fukushima). Thus, improvements incorporated in BDBAMG, enhance the strength of DiD. (author)

Accident transient processes at NPPs with the WWER type reactors

International Nuclear Information System (INIS)

Bukrinskij, A.M.

1982-01-01

Thermal-physical and nuclear-physical transient processes at NPPs with the WWER type reactors during accidents with the main technological equipment failures and the accidents with loss of coolant in the primary and secondary coolant circuits are considered. Mathematical methods used for these processes modelling is described. Examples of concrete calculations for accidents with different failures are given. Comparative analysis of the results of dynamic tests at the Novo-Voronezh-3 reactor is presented. It is concluded that the modern NPP design is impossible without application of mathematical modelling methods. The mathematical modelling of transients is also necessary for proper and safe NPP operation. Mathematical modelling of accidents at NPPs is a comparatively new method of investigation. Its success and development are completely based on the progress in modern computer development. With their improvement the mathematical models will become more complicate and adequacy of real physical process representation by their means will increase

Applications of probabilistic accident consequence evaluation in Cuba

International Nuclear Information System (INIS)

Rodriguez, J.M.

1996-01-01

Are presented the approaches and results of the application of Accident Consequence Evaluation methodologies in on emergency in the Juragua Nuclear Power Plant site and a population evaluation of a planned NPP site in the east of the country Findings on population sector weighing and assessment of effectiveness of primary countermeasures in the event of sever accidents (SST1 and PWR4 source terms) in Juragua NPP site are discussed Results on comparative risk-based evaluation of the population predicted evolution (in 3 temporal horizons: base year, 2005 year and 2050 year) for the planned site are described. Evaluation also included sector risk weighing, risk importance of small towns in the nearby of the effects on risk of population freezing and relocation of these villages

Post-processing activities after Chernobyl accident in Ukraine and lesson learned to the response Fukushima Dai-ichi accident

International Nuclear Information System (INIS)

Fujii, Yuzo

2012-01-01

After the accident of Chernobyl NPP no.4 1986, various activities including the construction of the shelter, prevention of the release of radioactive dust and liquid from the shelter, monitoring the condition of the damaged core, and disposal of radioactive waste have been implemented in the Chernobyl site for mitigating the nuclear and radioactive risks of damaged nuclear facilities, and the reducing radiation dose of working personnel. The construction of new shelter started for the decommissioning of the damaged unit no.4. facility. For reducing the radiation dose to the inhabitants from the contaminated land and feedstuff, the countermeasures including the set of the exclusive zone and permissible level of radionuclide in the foodstuff have been conducted for the countrywide. These activities include many valuable information about how to recover the condition of the site and maintain the social activities after the severe accident of NPP, and it would be important to learn the above activities in conducting the post-processing activities on the Fukushima-Daiichi accident successfully. (author)

Assistance to the Fukushima Daiichi NPP accident

International Nuclear Information System (INIS)

Sakuma, Minoru

2012-01-01

Immediately after the reactor accident of Fukushima Daiichi Nuclear Power Plant occurring on March 11, 2011, JAEA started and continues to work with its every possible effort for remediation and has established the head quarter for countermeasure in Fukushima prefecture. The present paper includes main activities of assisting Fukushima area such as environmental monitoring and decontamination, technical advises to Japanese and local government, and others. Some are in cooperation with universities and others with Tokyo Electric Power Company. Towards closing the reactor accident, JAEA is joining the integrated activities for cooling the damaged reactor core and management of storing and disposal of radioactive wastes produced and large amount of remaining contaminated water to find out an adequate method for decontamination and preparing the manual for it. (S. Ohno)

A quantitative assessment method for the NPP operators' diagnosis of accidents

International Nuclear Information System (INIS)

Kim, M. C.; Seong, P. H.

2003-01-01

In this research, we developed a quantitative model for the operators' diagnosis of the accident situation when an accident occurs in a nuclear power plant. After identifying the occurrence probabilities of accidents, the unavailabilities of various information sources, and the causal relationship between accidents and information sources, Bayesian network is used for the analysis of the change in the occurrence probabilities of accidents as the operators receive the information related to the status of the plant. The developed method is applied to a simple example case and it turned out that the developed method is a systematic quantitative analysis method which can cope with complex relationship between the accidents and information sources and various variables such accident occurrence probabilities and unavailabilities of various information sources

The Chernobyl NPP decommissioning: Current status and alternatives

International Nuclear Information System (INIS)

Mikolaitchouk, H.; Steinberg, N.

1996-01-01

After the Chernobyl accident of April 26, 1986, many contradictory decisions were taken concerning the Chernobyl nuclear power plant (NPP) future. The principal source of contradictions was a deadline for a final shutdown of the Chernobyl NPP units. Alterations in a political and socioeconomic environment resulted in the latest decision of the Ukrainian Authorities about 2000 as a deadline for a beginning of the Chernobyl NPP decommissioning. The date seems a sound compromise among the parties concerned. However, in order to meet the data a lot of work should be done. First of all, a decommissioning strategy has to be established. The problem is complicated due to both site-specific aspects and an absence of proven solutions for the RBMK-type reactor decommissioning. In the paper the problem of decommissioning option selection is considered taking into account an influence of the following factors: relevant legislative and regulatory requirements; resources required to carry out decommissioning (man-power, equipment, technologies, waste management infrastructure, etc.); radiological and physical status of the plant, including structural integrity and predictable age and weather effects; impact of planned activities at the destroyed unit 4 and within the 30-km exclusion zone of the Chernobyl NPP; planed use of the site; socio-economic considerations

Development of the international Chornobyl center in Slavutych its role in nuclear facilities decommissioning

International Nuclear Information System (INIS)

Nosovskij, A.

2002-01-01

ChNPP site should be actively used for development and realizing the efforts on RBMK reactors decommissioning technologies, as well as Unit 'Shelter' transformation into ecologically safe system. Those technologies and methods will be required in future both in Ukraine and abroad. So, it is wise to employ another direction of ChNPP site utilization as a polygon for development and implementing new technologies associated with decommissioning. Besides, it could be used for exercising the methods and technologies of large-scale man-caused accidents elimination

A Radiological Survey Approach to Use Prior to Decommissioning: Results from a Technology Scanning and Assessment Project Focused on the Chornobyl NPP

Energy Technology Data Exchange (ETDEWEB)

Milchikov, A.; Hund, G.; Davidko, M.

1999-10-20

The primary objectives of this project are to learn how to plan and execute the Technology Scanning and Assessment (TSA) approach by conducting a project and to be able to provide the approach as a capability to the Chernobyl Nuclear Power Plant (ChNPP) and potentially elsewhere. A secondary objective is to learn specifics about decommissioning and in particular about radiological surveying to be performed prior to decommissioning to help ChNPP decision makers. TSA is a multi-faceted capability that monitors and analyzes scientific, technical, regulatory, and business factors and trends for decision makers and company leaders. It is a management tool where information is systematically gathered, analyzed, and used in business planning and decision making. It helps managers by organizing the flow of critical information and provides managers with information they can act upon. The focus of this TSA project is on radiological surveying with the target being ChNPP's Unit 1. This reactor was stopped on November 30, 1996. At this time, Ukraine failed to have a regulatory basis to provide guidelines for nuclear site decommissioning. This situation has not changed as of today. A number of documents have been prepared to become a basis for a combined study of the ChNPP Unit 1 from the engineering and radiological perspectives. The results of such a study are expected to be used when a detailed decommissioning plan is created.

A Radiological Survey Approach to Use Prior to Decommissioning: Results from a Technology Scanning and Assessment Project Focused on the Chernobyl NPP

International Nuclear Information System (INIS)

Milchikov, A.; Hund, G.; Davidko, M.

1999-01-01

The primary objectives of this project are to learn how to plan and execute the Technology Scanning and Assessment (TSA) approach by conducting a project and to be able to provide the approach as a capability to the Chernobyl Nuclear Power Plant (ChNPP) and potentially elsewhere. A secondary objective is to learn specifics about decommissioning and in particular about radiological surveying to be performed prior to decommissioning to help ChNPP decision makers. TSA is a multi-faceted capability that monitors and analyzes scientific, technical, regulatory, and business factors and trends for decision makers and company leaders. It is a management tool where information is systematically gathered, analyzed, and used in business planning and decision making. It helps managers by organizing the flow of critical information and provides managers with information they can act upon. The focus of this TSA project is on radiological surveying with the target being ChNPP's Unit 1. This reactor was stopped on November 30, 1996. At this time, Ukraine failed to have a regulatory basis to provide guidelines for nuclear site decommissioning. This situation has not changed as of today. A number of documents have been prepared to become a basis for a combined study of the ChNPP Unit 1 from the engineering and radiological perspectives. The results of such a study are expected to be used when a detailed decommissioning plan is created

Thermal Hydraulic design parameters study for severe accidents using neural networks

Energy Technology Data Exchange (ETDEWEB)

Roh, Chang Hyun; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Chang, Keun Sun [Sunmoon University, Asan (Korea, Republic of)

1998-12-31

To provide the information on severe accident progression is very important for advanced or new type of nuclear power plant (NPP) design. A parametric study, therefore, was performed to investigate the effect of thermal hydraulic design parameters on severe accident progression of pressurized water reactors (PWRs). Nine parameters, which are considered important in NPP design or severe accident progression, were selected among the various thermal hydraulic design parameters. The backpropagation neural network (BPN) was used to determine parameters, which might more strongly affect the severe accident progression, among nine parameters. For training, different input patterns were generated by the latin hypercube sampling (LHS) technique and then different target patterns that contain core uncovery time and vessel failure time were obtained for Young Gwang Nuclear (YGN) Units 3 and 4 using modular accident analysis program (MAAP) 3.0B code. Three different severe accident scenarios, such as two loss of coolant accidents (LOCAs) and station blackout (SBO), were considered in this analysis. Results indicated that design parameters related to refueling water storage tank (RWST), accumulator and steam generator (S/G) have more dominant effects on the progression of severe accidents investigated, compared to the other six parameters. 9 refs., 5 tabs. (Author)

Thermal Hydraulic design parameters study for severe accidents using neural networks

Energy Technology Data Exchange (ETDEWEB)

Roh, Chang Hyun; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Chang, Keun Sun [Sunmoon University, Asan (Korea, Republic of)

1997-12-31

To provide the information on severe accident progression is very important for advanced or new type of nuclear power plant (NPP) design. A parametric study, therefore, was performed to investigate the effect of thermal hydraulic design parameters on severe accident progression of pressurized water reactors (PWRs). Nine parameters, which are considered important in NPP design or severe accident progression, were selected among the various thermal hydraulic design parameters. The backpropagation neural network (BPN) was used to determine parameters, which might more strongly affect the severe accident progression, among nine parameters. For training, different input patterns were generated by the latin hypercube sampling (LHS) technique and then different target patterns that contain core uncovery time and vessel failure time were obtained for Young Gwang Nuclear (YGN) Units 3 and 4 using modular accident analysis program (MAAP) 3.0B code. Three different severe accident scenarios, such as two loss of coolant accidents (LOCAs) and station blackout (SBO), were considered in this analysis. Results indicated that design parameters related to refueling water storage tank (RWST), accumulator and steam generator (S/G) have more dominant effects on the progression of severe accidents investigated, compared to the other six parameters. 9 refs., 5 tabs. (Author)

The Fukushima accident

International Nuclear Information System (INIS)

Maqua, M.; Stueck, R.

2012-01-01

On 11 March 2011, the Tohoku earthquake and the subsequent tsunami hit the Japanese east coast, causing more than 15,000 fatalities. To this date, 3,000 people are still missing. The Fukushima Dai-ichi NPP was the nuclear installation that was most affected by the tsunami. The earthquake cut off the NPP from the national grid. About 45 minutes later, the tsunami flooded units 1-4 and led to core meltdown events with large releases for units 1, 2 and 3. Unit 4 had been in refuelling outage at that time and lost the cooling of the spent fuel pool for several days. Considerable hydrogen explosions occurred in units 1, 3 and 4. Shortly after the accident, TEPCO started to mitigate the consequences of the accident by providing external cooling to the reactors and by removing the radioactive debris from the site. Great emphasis was laid on effective radiation protection measures for the clean-up workers. Thus, up to now there has been no fatality due to the radiation caused by the Fukushima accident. The main steps of the accident sequences are described, taking into account the latest findings of investigations performed by TEPCO or on behalf of the regulatory body. The presentation focuses on the description of the status of the Fukushima Dai-ichi nuclear power plant and the future steps for cleaning-up the site. In the presentation, the major phases of the roadmap that TEPCO has developed for the clean-up are highlighted. The risks associated with the current plant status and the clean-up phases are described. Abstract the content of the manuscript in a few lines.

Investigation of evaluation method for marine radiological impact during an accident

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-08-15

In 2012, JNES carried out to investigate the measurement information of radionuclide released to the ocean at Fukushima Daiichi NPP accident, the foreign regulation for marine radiological impact, and the evaluation method for release and diffusion to the ocean at the accident inside and outside Japan. (author)

Radiation accident at the South Urals in 1957

International Nuclear Information System (INIS)

Nikipelov, B.V.; Romanov, G.N.; Buldakov, L.A.; Babaev, N.S.; Kholina, Yu.B.; Mikerin, E.I.

1989-01-01

Radiation accidents with release of radioactive substances into environment which took place in the South Ural in 1957 is evaluated. Scientific researches conducted since 1957 are described. Scientific data of unique fundamental and applied value were obtaibed. Recommendations for the organization and content of radiation sanctuary are developed. Scientific researches permitted to make reliable long-turm prediction of radiation situation developed owing to the Chernobyl NPP accident and to work out practical recommendations so as to reduce adverse aftereffects of the accident

Sisifo-gas a computerised system to support severe accident training and management

International Nuclear Information System (INIS)

Castro, A.; Buedo, J.L.; Borondo, L.; Lopez, N.

2001-01-01

Nuclear Power Plants (NPP) will have to be prepared to face the management of severe accidents, through the development of Severe Accident Guides and sophisticated systems of calculation, as a supporting to the decision-making. SISIFO-GAS is a flexible computerized tool, both for the supporting to accident management and for education and training in severe accident. It is an interactive system, a visual and an easily handle one, and needs no specific knowledge in MAAP code to make complicate simulations in conditions of severe accident. The system is configured and adjusted to work in a BWR/6 technology plant with Mark III Containment, as it is Cofrentes NPP. But it is easily portable to every other kind of reactor, having the level 2 PSA (probabilistic safety analysis) of the plant to be able to establish the categories of the source term and the most important sequences in the progression of the accident. The graphic interface allows following in a very intuitive and formative way the evolution and the most relevant events in the accident, in the both system's way of work, training and management. (authors)

Development of the model MAAP5-DOSE for dose analysis in Cofrentes NPP

International Nuclear Information System (INIS)

Gonzalez, C.; Diaz, P.; Ibanez, L.; Lamela, B.; Serrano, C.

2013-01-01

Iberdrola Ingenieria y Construccion has developed a model of Cofrentes NPP with code MAAP5-DOSE in order to be able to assess in realistic conditions the the expected dose in points and radiological consequences of severe accident of local action.

Bioindication of total toxicity and teratogenicity of bottom deposits and soils from regions with different degree of the influence of the Chernobyl NPP accident using the developing embryos of grey sea urchins

International Nuclear Information System (INIS)

Grishchenko, O.M.; Chumak, V.K.; Grishchenko, S.O.; Rachins'kij, V.N.; Grishchenko, N.O.

1992-01-01

The changes (for 1983-90) in total toxicity and teratogenicity of bottom deposits in the Dnieper cascade and soil from some regions of the Ukraine with unequal degree of the influence of the Chernobyl NPP accident have been comparatively studied using developing embryos and larvae of grey sea urchins which are very sensitive to the unfavourable effect of radionuclides, many chemical technogenic factors. (author)

Operating and mathematical representation of resonances between flow parameters oscillations and structure vibrations of NPP

Energy Technology Data Exchange (ETDEWEB)

Proskuryakov, K.N.; Yang Shan Afshar, E.; Polyakov, N.I. [Nuclear Power Plant Department of Moscow Power Engineering Institute Technical Univ., Moscow (Russian Federation)

2007-07-01

The experimental data that have been obtained from the measurements of noise signals in primary circuit of NPP with reactor of WWER-1000 are presented. The causes of resonant interaction between Eigen-Frequencies of Oscillations of the Coolant Pressure (EFOCP) and structure vibrations are discussed. An application-oriented approach to the problem of identification of abnormal phenomena of thermal-hydraulic parameters is proposed. Logarithmic Decrement {delta} is determined. The bigger damping ratio {zeta} provides bigger {delta} and correspondingly smaller values of Q-factor and amplitude X(t)max. All experimental units intended for NPP severe accident investigation must satisfy to the NPP Q-factor criterion of similarity. (authors)

Operating and mathematical representation of resonances between flow parameters oscillations and structure vibrations of NPP

International Nuclear Information System (INIS)

Proskuryakov, K.N.; Yang Shan Afshar, E.; Polyakov, N.I.

2007-01-01

The experimental data that have been obtained from the measurements of noise signals in primary circuit of NPP with reactor of WWER-1000 are presented. The causes of resonant interaction between Eigen-Frequencies of Oscillations of the Coolant Pressure (EFOCP) and structure vibrations are discussed. An application-oriented approach to the problem of identification of abnormal phenomena of thermal-hydraulic parameters is proposed. Logarithmic Decrement δ is determined. The bigger damping ratio ζ provides bigger δ and correspondingly smaller values of Q-factor and amplitude X(t)max. All experimental units intended for NPP severe accident investigation must satisfy to the NPP Q-factor criterion of similarity. (authors)

Environmental radiological consequences of a loss of coolant accident

International Nuclear Information System (INIS)

Guimaraes, A.C.F.

1981-01-01

The elaboration of a calculation model to determine safety areas, named Exclusion Zone and Low Population Zone for nuclear power plants, is dealt with. These areas are determined from a radioactive doses calculation for the population living around the NPP after occurence of a postulated ' Maximum Credible Accident' (MCA). The MCA is defined as an accident with complete loss of primary coolant and consequent fusion of a substantial portion of the reactor core. In the calculations carried out, data from NPP Angra I were used and the assumptions made were conservative, to be compatible with licensing requirements. Under the most pessimistic assumption (no filters) the values of 410m and 1000m were obtained for the Exclusion Zone and Low Population Zone radii, respectivily. (Author) [pt

MDEP Common Position CP-STC-02. Common Position Addressing Fukushima Daiichi Nuclear Power Accident

International Nuclear Information System (INIS)

2016-09-01

Following the nuclear accident in Japan as a consequence of the earthquake and tsunami, the MDEP Members provide the following information, based on initial information available, to ensure adequate safety of new reactor design activities being undertaken pursuant to the MDEP program of work. Due to the extensive nature of the magnitude and duration of the Fukushima Daiichi NPP accident, it is important to consider lessons learnt at an early stage of the design. In this context, the extensive work done by the IAEA, the International Atomic Energy Agency, is also acknowledged. Vendors, licensees and applicants involved in New Design activities should examine the implications of the Fukushima Daiichi NPP accident and identify relevant issues to be taken into account to strengthen defense in depth. Those lessons learnt should include, but not be limited to, plans to assess the following: - Provisions taken in the design basis concerning flooding, earthquake, other extreme natural phenomena and combinations of external event hazards appropriate to each country, - The robustness of the plant to maintain its safety functions beyond the design basis hazards, - The capability of the plant to withstand extended loss of all electrical power supplies as well as prolonged loss of ultimate heat sink and other essential supplies, and - The capability of the plant to cope with such extreme situations, including provisions to manage severe accidents (such as combustible gas management). In assessing these areas, the effect of multiple units and nuclear fuel storages should be considered. The MDEP regulators will strive to harmonize approaches to incorporate lessons learnt in their ongoing national safety reviews of new reactors. Based on the design-specific common positions, this paper identifies the approaches to address potential safety improvements for several designs as related to lessons learned from the Fukushima Daiichi NPP accident or related issues. Designs being

Integrated assessment of radio-ecological situation using Gis-technology and spatial data bank of environment of NPP 30-km area

International Nuclear Information System (INIS)

Lev, T.D.; Tishchenko, O.G.; Piskun, V.N.

2011-01-01

In accordance with the requirements of IAEA on providing information-analytical and cartographic materials for NPP emergency systems Institute for safety problems of NPP is creating the spatial data bank taking into account geographical features, socio-economic indexes and information of monitoring of NPP environment. Based on analysis of connection between ecological parameters and geographical features of locality the specific of radio-ecological conditions of territories of NPP 30-m area is exposed by the example of Rivne and Khmel'nickiy NPP. Determination on critical territories maximally influencing on forming of the radiation dose for a population will allow to develop in good time preventive and protective measures for a population at the different scenarios of accident situation.

Unmanned aerial complexes as a way of NPP and environment radiation monitoring

International Nuclear Information System (INIS)

Babak, V.P.; Kanchenko, V.A.; Klyuchnikov, A.A.; Krasnov, V.A.; Chepur, N.L.

2012-01-01

As a example of the using of unmanned aircraft for video monitoring and radiation background measurement in the accident area at the NPP Fukushima -1 are shown the efficiency of its use. The analyse of possible environmental monitoring remotely piloted ultralight unmanned aerial vehicle are carried out

The influence of biotic and abiotic factors on (137)Cs accumulation in higher fungi after the accident at Chernobyl NPP.

Science.gov (United States)

Zarubina, N

2016-09-01

Levels of soil contamination with (137)Cs, the belonging of fungi to a certain ecological group, the localization depth of the main part of mycelium in soil are the primary factors influencing the value of (137)Cs specific activity in higher fungi after the accident at Chernobyl NPP. It has been found that the value of (137)Cs specific activity in fungi of one species could vary by more than 10 times during a vegetation period. A correlation between the changes of (137)Cs content in fungi during the vegetation period and the amount of precipitates during various periods preceding the collection of samples has not been determined. An assumption has been proposed stating dependence between peculiarities of mycelium growth during the vegetation period and the changes of (137)Cs specific activity in fungi. Copyright © 2015 Elsevier Ltd. All rights reserved.

Scientific and technical aspects of Chernobyl

International Nuclear Information System (INIS)

Gligalo, V.M.; Nosovs'kij, A.V.

2002-01-01

The collection contains the presentations and scientific articles prepared for and discussed during the Conference titled '2001: International Cooperation For Chernobyl'. The materials outline the outcomes achieved while implementing Chernobyl site scientific-technical researches and projects, as well as activities aimed at enhancing the ChNPP safety, decommissioning and radwaste management. It also highlights the issues related to transforming the Unit Shelter into an ecologically safe system, represents the results of ecological researches in the Exclusion Zone, medical effects of the 1986 accident at Chernobyl NPP, together with social and economic problems the city of Slavutich faces now due to the early ChNPP Units decommissioning, and Slavutich business development opportunities under the circumstances of Special Economic Zone 'Slavutich'

Scientific and technical aspects of Chernobyl; Naukovyi ta tekhnyichnyi aspekti Chornobilya

Energy Technology Data Exchange (ETDEWEB)

Gligalo, V M; Nosovs' kij, A V [eds.

2002-07-01

The collection contains the presentations and scientific articles prepared for and discussed during the Conference titled '2001: International Cooperation For Chernobyl'. The materials outline the outcomes achieved while implementing Chernobyl site scientific-technical researches and projects, as well as activities aimed at enhancing the ChNPP safety, decommissioning and radwaste management. It also highlights the issues related to transforming the Unit Shelter into an ecologically safe system, represents the results of ecological researches in the Exclusion Zone, medical effects of the 1986 accident at Chernobyl NPP, together with social and economic problems the city of Slavutich faces now due to the early ChNPP Units decommissioning, and Slavutich business development opportunities under the circumstances of Special Economic Zone 'Slavutich'.

Scientific and technical aspects of international cooperation in Chernobyl; Naukovyi ta tekhnyichnyi aspekti myizhnarodnogo spyivrobyitnitstva v Chornobilyi

Energy Technology Data Exchange (ETDEWEB)

Gligalo, V M; Nosovs' kij, A V [eds.

2001-07-01

The collection contains the presentations and scientific articles prepared for and discussed during the Conference titled '2000: International Cooperation For Chernobyl'. The materials outline the outcomes achieved while implementing Chernobyl site scientific-technical researches and projects, as well as activities aimed at enhancing the ChNPP safety, decommissioning and radwaste management. It also highlights the issues related to transforming the Unit Shelter into an ecologically safe system, represents the results of ecological researches in the Exclusion Zone, medical effects of the 1986 accident at Chernobyl NPP, together with social and economic problems the city of Slavutich faces now due to the early ChNPP Units decommissioning, and Slavutich business development opportunities under the circumstances of Special Economic Zone 'Slavutich'.

Scientific and technical aspects of international cooperation in Chernobyl

International Nuclear Information System (INIS)

Gligalo, V.M.; Nosovs'kij, A.V.

2001-01-01

The collection contains the presentations and scientific articles prepared for and discussed during the Conference titled '2000: International Cooperation For Chernobyl'. The materials outline the outcomes achieved while implementing Chernobyl site scientific-technical researches and projects, as well as activities aimed at enhancing the ChNPP safety, decommissioning and radwaste management. It also highlights the issues related to transforming the Unit Shelter into an ecologically safe system, represents the results of ecological researches in the Exclusion Zone, medical effects of the 1986 accident at Chernobyl NPP, together with social and economic problems the city of Slavutich faces now due to the early ChNPP Units decommissioning, and Slavutich business development opportunities under the circumstances of Special Economic Zone 'Slavutich'

Development of Draft Regulatory Guide on Accident Analysis for Nuclear Power Plants with New Safety Design Features

Energy Technology Data Exchange (ETDEWEB)

Bang, Young Seok; Woo, Sweng Woong; Hwang, Tae Suk [KINS, Daejeon (Korea, Republic of); Sim, Suk K; Hwang, Min Jeong [Environment and Energy Technology, Daejeon (Korea, Republic of)

2016-05-15

The present paper discusses the development process of the draft version of regulatory guide (DRG) on accident analysis of the NPP having the NSFD and its result. Based on the consideration on the lesson learned from the previous licensing review, a draft regulatory guide (DRG) on accident analysis for NPP with new safety design features (NSDF) was developed. New safety design features (NSDF) have been introduced to the new constructing nuclear power plants (NPP) since the early 2000 and the issuance of construction permit of SKN Units 3 and 4. Typical examples of the new safety features includes Fluidic Device (FD) within Safety Injection Tanks (SIT), Passive Auxiliary Feedwater System (PAFS), ECCS Core Barrel Duct (ECBD) which were adopted in APR1400 design and/or APR+ design to improve the safety margin of the plants for the postulated accidents of interest. Also several studies of new concept of the safety system such as Hybrid ECCS design have been reported. General and/or specific guideline of accident analysis considering the NSDF has been requested. Realistic evaluation of the impact of NSDF on accident with uncertainty and separated accident analysis accounting the NSDF impact were specified in the DRG. Per the developmental process, identification of key issues, demonstration of the DRG with specific accident with specific NSDF, and improvement of DGR for the key issues and their resolution will be conducted.

'Kozloduy' NPP geological environment as a barrier against radionuclide migration

International Nuclear Information System (INIS)

Antonov, D.

2000-01-01

The aim of this report is to present an analysis of the geological settings along Kozloduy NPP area from the viewpoint of a natural, protective barrier against unacceptable radionuclides migration in the environment. Possible sources of such migration could be an eventual accident in an active nuclear plant; radioactive releases from decommissioned Power Units or from temporary or permanent radioactive waste repositories. The report is directed mainly to the last case, and especially to the site selection for near surface short lived low and intermediate level (LILW) radioactive repository. The main conclusion of the geological settings assessment and of the many years monitoring is that the Kozloduy NPP area offers good possibilities for site selection of LILW repository. (author)

Concept of space NPP radiation safety and its realization in the Kosmos-1900 satellite

International Nuclear Information System (INIS)

Gryaznov, G.M.; Nikolaev, V.S.; Serbin, V.I.; Tyugin, V.M.

1989-01-01

A standard NPP for a space vehicle, radioactivity composition and radiation safety systems are considered. Plausible accidents on board the space vehicle and requirements to system operation reliability are discussed. The main reactor characteristics situation on board the Kosmos-1900 satellite and completion of its flight are described. The experience in providing radiation safety of space NPP has shown that it is sufficient to use two independent systems: a drift system and a reactor dispersion system based on separation of its structure by active means

Failure Mode Estimation of Wolsong Unit 1 Containment Building with respect to Severe Accident Condition

International Nuclear Information System (INIS)

Hahm, Dae Gi; Choi, In Kil

2009-01-01

The containment buildings in a nuclear power plant (NPP) are final barriers against the exposure of harmful radiation materials at severe accident condition. Since the accident at Three Mile Island nuclear plant in 1979, it has become necessary to evaluate the internal pressure capacity of the containment buildings for the assessment of the safety of nuclear power plants. According to this necessity, many researchers including Yonezawa et al. and Hu and Lin analyzed the ultimate capacity of prestressed concrete containments subjected to internal pressure which can be occurred at sever accident condition. Especially in Wolsong nuclear power plant, the Unit 1 containment structures were constructed in the late 1970 to early 1980, so that the end of its service life will be reached in near future. Since that the complete decommission and reconstruction of the NPP may cause a huge expenses, an extension of the service time can be a cost-effective alternative. To extend the service time of NPP, an overall safety evaluation of the containment building under severe accident condition should be performed. In this study, we assessed the pressure capacity of Wolsong Unit 1 containment building under severe accident, and estimated the responses at all of the probable critical areas. Based on those results, we found the significant failure modes of Wolsong Unit 1 containment building with respect to the severe accident condition. On the other hand, for the aged NPP, the degradation of their structural performance must also be explained in the procedure of the internal pressure capacity evaluation. Therefore, in this study, we performed a parametric study on the degradation effects and evaluated the internal pressure capacity of Wolsong Unit 1 containment building with considering aging and degradation effects

Level of health of cleaners taking part in the Chernobyl accident consequences

International Nuclear Information System (INIS)

Margine, L.; Vicol, C.

2009-01-01

During the period of 1986-1988 about 3,000 Moldova citizens took part in Chernobyl NPP accident consequences elimination. In this article the level of morbidity, disability and mortality among Chernobyl accident consequences liquidation participants is analyzed. As a result of analysis of medical documentation and statistical data was revealed that the sickness rate among disaster fighters 2,3 times higher than general sickness rate of the population in Moldova. Disability in this category is at average of 73 per cent as opposed to the overall index for the population of Moldova - 4,4%, this means it is 17 times higher. Mortality among the participants of the accident at Chernobyl NPP is 6 times higher of general data. The participants of the breakdown elimination of Chernobyl accident consequences are equal in their right with the participants and invalids of war and with the disabled workers. Medical and social security of this group is regulated by the legislation of the Republic of Moldova

Analysis of ASTEC code adaptability to severe accident simulation for CANDU type reactors

International Nuclear Information System (INIS)

Constantin, Marin; Rizoiu, Andrei

2008-01-01

In order to prepare the adaptation of the ASTEC code to CANDU NPP severe accident analysis two kinds of activities were performed: - analyses of the ASTEC modules from the point of view of models and options, followed by CANDU exploratory calculation for the appropriate modules/models; - preparing the specifications for ASTEC adaptation for CANDU NPP. The paper is structured in three parts: - a comparison of PWR and CANDU concepts (from the point of view of severe accident phenomena); - exploratory calculations with some ASTEC modules- SOPHAEROS, CPA, IODE, CESAR, DIVA - for CANDU type reactors specific problems; - development needs analysis - algorithms, methods, modules. (authors)

The Effect of NPP's Stack Height to Radiation Dose

International Nuclear Information System (INIS)

Pandi, Liliana Yetta; Rohman, Budi

2003-01-01

The purpose of dose calculation for accidents is to analyze the capability of NPP to maintain the safety of public and workers in case an accident occurs on the Plant in a site. This paper calculates the Loss of Coolant Accident in PWR plant. The calculation results shows that no risks of serious radiation exposure are given to the neighboring public even if such a large accident occurred, and the effect of stack height can be predicted by analysis of the calculation results. The whole dose is calculated for some location (100 m, 300 m, 500 m, 700 m, 900 m, 1500 m, and 2000 m) with three difference stack height i.e. 0 m, 40 m and 100 m. The result of the whole dose calculation is under permitted criteria for whole dose : 0.25 Sv and thyroid dose : 3.0 Sv. The calculation of radiation dose in this paper use EEDCDQ code

Psychosocial state of the adult evacuees and risk factors of negative change.

Science.gov (United States)

Buzunov, V O; Loganovsky, K M; Krasnikova, L I; Bomko, M O; Belyayev, Yu M; Yaroshenko, Zh S; Domashevska, T E

2017-12-01

Numerous scientific studies have been carried out since the ChNPP accident indicating that the last one has caused a severe psychosocial stress in survivors. Population of radioactively contaminated territories, people migrated from the areas of strict radiation control, and accident consequences clean up participants in 1986 1987 were covered by the conducted research projects. Nature of the stress herewith is polygenic and includes factors directly related to the Chernobyl catastrophe, and factors being a result of social and economic circumstances. This report is devot ed to the results of research on psychosocial state of population evacuated from the 30 km zone of the ChNPP. Study and evaluation of psychosocial state of population evacuated from the 30 km ChNPP zone at the age of 18 years and older; identification of potential psychosocial risk factors for the health loss. The sampling epidemiological study of psychosocial state of population aged 18-50 years evacuated from the 30 km zone of ChNPP was conducted at the NRCRM Radiation Registry Outpatient Clinic and Radiation Psychoneurology Department. The study subjects (n=258) were mostly (98%) females. Study was con ducted from October 2013 till May 2015. All the sample members were registered since 1992 in the system of life long health monitoring, i.e. the NRCRM Clinical and Epidemiological Registry. Study subjects were interviewed through the method using an original «Questioning Inventory». Mathematical processing of study results was held using the Epi Info 7 software package. According to the study results, a nuclear accident at the Chornobyl NPP has become a powerful psychoso cial stress for evacuated people. Psychosocial state of the evacuees, formed during the post accident period, with full reason can be defined as a state of stable, chronic psychosocial stress. Nature of factors that caused the stress development is polygenic. Block of stressors directly related to the accident was determined

Key developments in the advanced NPP with WWER-640/V-407 reactor plant design

International Nuclear Information System (INIS)

Dragunov, Yu.G.; Mokhov, V.A.; Nikitenko, M.P.; Afrov, A.M.

1999-01-01

The report covers the main design features of advanced NPP equipped with WWER-640 reactor, that take into account the up-to-date approaches in the process of forming safety concepts. An approach to accident management has been analysed, beyond design-basis accidents included. A description of principal safety systems has been presented as well as the interrelation of their operation. The principal features of the systems design have been shown. (author)

Electrical Grid Conditioning For First NPP Integration, a Systems Engineering Approach Incorporating Quality Function Deployment

Energy Technology Data Exchange (ETDEWEB)

Pwani, Henry; James, J. [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2013-10-15

Nuclear power plant has a high potential to cause serious harm to environment as evidenced by effects of Fukushima and Chernobyl accidents. A reliable electrical power is required for a NPP to facilitate cooling after a shutdown. Failure of electrical power supply during shutdown increases core damage probability. Research shows that a total of 39% of LOOP related events in US are electrical grid centered. In Korea, 38% and 29% of all events that led to NPP shutdown at Hanul units 3-6 and at Hanbit units 3-6 respectively were electrical related. Electric grids for both operating and new NPPs must therefore be examined and upgraded for reliability improvement in order to enhance NPP safety.

Dynamics of health status of residents in the Lugyny district after the accident at the ChNPS

International Nuclear Information System (INIS)

Godlevsky, I.; Nasvit, O.

1998-01-01

The Lugyny district lies in the northern part of the Zhytomyr region of Ukraine within 110-150 km from the Chernobyl nuclear power station (ChNPS). Its territory is crossed by the southern and south-western tracks that were formed by the Chernobyl accident in April 1986. The total territory of the district constitutes approximately 900 km 2 , the territory of agricultural land - more than 300 km 2 , and about 190 km 2 of them arable land. Practically all agricultural land in the district have the 137 Cs contamination density higher than 1 Ci/km 2 . Prior to the Chernobyl accident about 30 thousand residents were living in the Lugyny district. By the present moment the population of the district has dropped to approximately 22 thousand people due to resettlement from the most contaminated territories and the decrease in the birth-rate. (J.P.N.)

Experimental Studies for the VVER-440/213 Bubble Condenser System for Kola NPP at the Integral Test Facility BC V-213

International Nuclear Information System (INIS)

Blinkov, V.N.; Melikhov, O.I.; Melikhov, V.I.; Davydov, M.V.; Wolff, H.; Arndt, S.

2012-01-01

In the frame of Tacis Project R2.01/99, which was running from 2003 to 2005, the bubble condenser system of Kola NPP (unit 3) was qualified at the integral test facility BC V-213. Three LB LOCA tests, two MSLB tests, and one SB LOCA test were performed. The appropriate test scenarios for BC V-213 test facility, modeling accidents in the Kola NPP unit 3, were determined with pretest calculations. Analysis of test results has shown that calculated initial conditions and test scenarios were properly reproduced in the tests. The detailed posttest analysis of the tests performed at BC V-213 test facility was aimed to validate the COCOSYS code for the calculation of thermohydraulic processes in the hermetic compartments and bubble condenser. After that the validated COCOSYS code was applied to NPP calculations for Kola NPP (unit 3). Results of Tacis R2.01/99 Project confirmed the bubble condenser functionality during large and small break LOCAs and MSLB accidents. Maximum loads were reached in the LB LOCA case. No condensation oscillations were observed.

Trends of Training Courses Conducted in the Human Resources Development Center of the National Institute for Quantum and Radiological Science and Technology After the Fukushima Dai-Ichi Nuclear Power Plant Accident.

Science.gov (United States)

Shimizu, Yuko; Iida, Haruzo; Nenoi, Mitsuru

2017-07-01

Environmental contamination with radioactive materials caused by the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident in 2011 raised a serious health concern among residents in Japan, and the demand for radiation experts who can handle the radiation-associated problems has increased. The Human Resources Development Center (HRDC) of the National Institute of for Quantum and Radiological Science and Technology in Japan has offered a variety of training programs covering a wide range of technologies associated with radiation since 1959. In this study, the time-course change in the number and age of the applicants for training programs regularly scheduled at HRDC were analyzed to characterize the demand after the NPP accident. The results suggested that the demand for the training of industrial radiation experts elevated sharply after the NPP accident followed by a prompt decrease, and that young people were likely stimulated to learn the basics of radiation. The demand for the training of medical radiation experts was kept high regardless of the NPP accident. The demand for the training of radiation emergency experts fluctuated apparently with three components: a terminating demand after the criticality accident that occurred in 1999, an urgent demand for handling of the NPP accident, and a sustained demand from local governments that undertook reinforcement of their nuclear disaster prevention program. The demand for the training of school students appeared to be increasing after the NPP accident. It could be foreseen that the demand for training programs targeting young people and medical radiation experts would be elevated in future.

Main directions of works on radioactive waste management at 30-km zone near the Chernobyl' NPP

International Nuclear Information System (INIS)

Grushinskij, B.Ya.; Komarov, V.I.; Proskuryakov, A.N.; Kham'yanov, L.N.; Khubizov, S.B.; Ignatenko, E.I.; Ryzhkova, V.N.; Luppov, V.A.; Matskevich, G.V.; Frolov, V.N.

1989-01-01

Main points and stages of creating an specialized enterprise for centralized reprocessing and radioactive waste disposal are considered. The enterprise is intended for collection conditioning and burial of all types of radioactive wastes, formed during liquidation of accident effect at the Chernobyl' NPP as well as forming in operation of NPP. The enterprise is also used to decontaminate equipment and constructions, for reprocessing of secondary radioactive wastes forming during decontamination process of equipment constructions, transport and work clothes

Positive and negative aspects of the Kozloduy NPP; AEhS Kozloduy - plyusy i minusy

Energy Technology Data Exchange (ETDEWEB)

Kouzmanov, K [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1996-12-31

This opening address delivered by the Kozloduy NPP General Director summarizes the benefits and drawbacks of the Kozloduy NPP. It is emphasized that the plant supplies 40% of the national electricity demand and has been running without any accidents or environmental contamination. The production cost of the electricity produced is between two and three times less than the one from thermal stations. Among the disadvantages are: great initial investments; the need to handle and store properly the radioactive waste; the need for modernization and reconstruction in order to improve safety.

Core-melting accidents in Chernobyl and Harrisburg

International Nuclear Information System (INIS)

Loon, A.J. van; Vonderen, A.C.M. van

1987-01-01

This publication deals with the essences of the reactor accident in Chernobylsk and the conclusions to be drawn from these with regard to reactor safety. Therein the technical differences between the reactor types in the West and the East play an important role. Also attention is spent to the now generally accepted philosophy that by simplification and making use of proven technologies, a further deminishing of the risks can be achieved step by step. In ch.'s 2 and 4 the origin and course of the accidents in respectively Chernobylsk and Harrisburg are analyzed; in the analysis of the Chernobylsk accident also date have been used which were provided by the Sovjet-Union, supplied with results of studies of the U.S. Department of Energy (DOE). In ch. 3 this information is compared with the insights which have grown at KEMA about these on the base of reactor physical and thermohydraulic considerations and of computer calculations reproducing the course of the accident. An important question is if, and if so: to which extent, an accident such as the one in Chernobylsk also can take place in the West. In order to answer that question as accurate as possible the consequences of core meltings accidents and the risk for such an accident taking place are pursued. In ch. 6 the legal frameworks are indicated by which the risk may be limited and by which eventually yet occurring damage may be arranged. Ch. 7 finally deals with the lessons which the accidents in Chernobylsk and Harrisburg have learnt us and with the possible consequences of these for the further application of nuclear power in the Netherlands. (H.W.). 105 refs.; 42 figs.; 17 refs

Operational behaviour of WWER nuclear power units after Chernobyl accident

International Nuclear Information System (INIS)

Milivojevic, S.; Spasojevic, D.

2000-01-01

The indicators of effectiveness of WWER operation, in 1987-1998 were analyzed. For three groups of nuclear units (WWER, NPP Kozloduy, NPP Paks), the trends of Indicators flow were established. The comparative analysis of forced outage rate, and load factor of WWERs and nuclear units all in the world was carried out; it gives the general picture of accident influence on the states and the relations of these indicators in considered period (author)

Radiobiological effects in organisms of plants and animals exposed to ionizing irradiation in the Chernobyl NPP zone

International Nuclear Information System (INIS)

Panchenko, N.A.; Arkhipov, N.P.; Alesina, M.Y.; Kuchma, V.I.; Gaschak, S.P.; Burov, N.I.

1997-01-01

Influence of ionizing radiation on forest ecosystems most clearly revealed itself near the Chernobyl NPP (ChNPP), were magnitudes of absorbed doses reached 'lethal' values, as applied to conifers. Main contribution to absorbed dose was due to beta-radiation of short-living radionuclides. To largest extent the radiobiological effects appeared at injured plantations of pines and firs. Nevertheless, during the first year maximum absorbed doses influenced also on leaf-bearing trees (birch, alder, asp) which then rehabilitated themselves completely

Scientific provision and control in plant - breeding on contaminated territory of Ukraine

International Nuclear Information System (INIS)

Bondar, P.F.; Ivanov, Yu.A.; Prister, B.S.; Perepelyatnikov, G.P.

1996-01-01

Complex of tasks and methods of its solution during the assessment of radiological situation, as well as some ways of its improvement on farmlands, subjected to radioactive contamination after the accident on ChNPP, are demonstrated

Analysing The Thermalhydraulic Parameters Of VVER-1000 Reactor For The Accident Of Steam Generator Tube Rupture

International Nuclear Information System (INIS)

Luu Nam Hai; Truong Cong Thang

2011-01-01

To ensure the safety operation of nuclear power plant (NPP), a lot of postulated accident scenarios were considered and analysed. This research chose and analysed the accident of steam generator tube rupture (SGTR) under the actual plant conditions by using the simulation program PCTRAN. The SGTR accident is happen when the NPP is under operation with the steady state condition (power of 3000 MWth, primary pressure of 157 bar and secondary pressure of 63 bar). The accident is initiated by creating a break with equivalent diameter of 100 mm in the area of lower row heat exchanging tubes. The result of analysis is compared with the calculation of the Shariz University, Iran using the thermal hydraulics code RELAP5/mod3.2 and the report in the PSAR data of VVER-1000. This comparison shows that it is possible for using PCTRAN to analyse accidents of VVER-1000 reactor. (author)

Time changes in radiocesium wash-off from various land uses after the Fukushima Daiichi NPP accident

Science.gov (United States)

Onda, Yuichi; Kato, Hiroaki; Yoshimura, Kazuya; Tsujimura, Maki; Wakiyama, Yoshifumi; Taniguchi, Keisuke; Sakaguchi, Aya; Yamamoto, Masayoshi

2014-05-01

A number of studies have been conducted to monitor and model the time series change of radiocesium transfer through aquatic systems after significant fallout, especially from the Chernobyl disaster. However, no data is available for the temporal changes of radiocesium concentration in environmental materials such as soil and water after the Fukushima Daiichi nuclear power plant accident. Our research team has been monitoring the environmental consequences of radioactive contamination just after the Fukushima Daiichi NPP accident in Yamakiya-district, Kawamata town, Fukushima prefecture. Research items are listed below. 1. Radiocesium wash-off from the runoff-erosion plot under different land use. 2. Measurement of radiocesium transfer in forest environment, in association with hydrological pathways such as throughfall and overlandflow on hillslope. 3. Monitoring on radiocesium concentration in soil water, ground water, and spring water. 4. Monitoring of dissolved and particulate radiocesium concentration in river water, and stream water from the forested catchment. 5.Measurement of radiocesium content in drain water and suspended sediment from paddy field. Our monitoring result demonstrated that the Cs-137 concentration in eroded sediment from the runoff-erosion plot has been almost constant for the past 3 years, however the Cs-137 concentration of suspended sediment from the forested catchment showed slight decrease through time. On the other hand, the suspended sediment from paddy field and those in river water from large catchments exhibited rapid decrease in Cs-137 concentration with time. The decreasing trend of Cs-137 concentration were fitted by the two-component exponential model, differences in decreasing rate of the model were compared and discussed among various land uses and catchment scales. Such analysis can provide important insights into the future prediction of the radiocesium wash-off from catchments with different land uses.

Comparative radiation impact on biota and man in the area affected by the accident at the Chernobyl nuclear power plant

International Nuclear Information System (INIS)

Fesenko, S.V.; Alexakhin, R.M.; Geras'kin, S.A.; Sanzharova, N.I.; Spirin, Ye.V.; Spiridonov, S.I.; Gontarenko, I.A.; Strand, P.

2005-01-01

A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) - ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human species were not observed after the Chernobyl accident, were employed. For the study area within the 30 km ChNPP zone dose burdens to 10 reference biota groups and the population (with and without evacuation) and the corresponding RIFs were calculated. It has been found that in 1986 (early period after the accident) the emergency radiation standards for man do not guarantee adequate protection of the environment, some species of which could be affected more than man. In 1991 RIFs for man were considerably (by factor of 20.0-1.1 x 10 5 ) higher compared with those for selected non-human species. Thus, for the long term after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well

Comparative radiation impact on biota and man in the area affected by the accident at the Chernobyl nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Fesenko, S.V. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation) and International Atomic Energy Agency, Agency' s Laboratories, Seibersdorf A-2444 (Austria)]. E-mail: s.fesenko@iaea.org; Alexakhin, R.M. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Geras' kin, S.A. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Sanzharova, N.I. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Spirin, Ye.V. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Spiridonov, S.I. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Gontarenko, I.A. [Russian Institute of Agricultural Radiology and Agroecology, Kievskoe shosse, Kaluga region, Obninsk 249020 (Russian Federation); Strand, P. [Norwegian Radiation Protection Authority, Oesteras (Norway)

2005-07-01

A methodological approach for a comparative assessment of ionising radiation effects on man and non-human species, based on the use of Radiation Impact Factor (RIF) - ratios of actual exposure doses to biota species and man to critical dose is described. As such doses, radiation safety standards limiting radiation exposure of man and doses at which radiobiological effects in non-human species were not observed after the Chernobyl accident, were employed. For the study area within the 30 km ChNPP zone dose burdens to 10 reference biota groups and the population (with and without evacuation) and the corresponding RIFs were calculated. It has been found that in 1986 (early period after the accident) the emergency radiation standards for man do not guarantee adequate protection of the environment, some species of which could be affected more than man. In 1991 RIFs for man were considerably (by factor of 20.0-1.1 x 10{sup 5}) higher compared with those for selected non-human species. Thus, for the long term after the accident radiation safety standards for man are shown to ensure radiation safety for biota as well.

Development of Krsko Severe Accident Management Guidance (SAMG)

International Nuclear Information System (INIS)

Cizel, F.

1999-01-01

In this lecture development of severe accident management guidances for Krsko NPP are described. Author deals with the history of severe accident management and implementation of issues (validation, review of E-plan and other aspects SAMG implementation guidance). Methods of Westinghouse owners group, of Combustion Engineering owners group, of Babcock and Wilcox owners group, of the BWR owners group, as well as application of US SAMG methodology in Europe and elsewhere are reviewed

Reasons for the RBMK reactor accident at the Chernobyl NPP

International Nuclear Information System (INIS)

Novikov, I.I.; Kruzhilin, G.N.; Anan'ev, E.P.

1995-01-01

This analysis of the reasons for the Chernobyl Reactor accident in 1986 places the blame firmly with the reactor operators, who, it is argued, made a number of dramatic mistakes while controlling the reactor. The report also included an additional analysis of the causes of the accident. (UK)

Test research and analysis for ultimate capacity of Qinshan NPP PCCV

International Nuclear Information System (INIS)

Zufeng, X.

1994-01-01

This paper introduces design and research for containment of Qinshan NPP which is the first PWR in CHINA designed and constructed by ourselves. The PCCV design is basically in conformity to ASME code. To verify the structural integrity capacity of Qinshan NPP containment, we fulfilled SIT and ILRT successfully in June, 1991. The special attention of the paper is focused on the ultimate capacity of the PCCV under severe accidents and earthquake. A study comprised of five different independent parts has been performed for the development of containment model test and corresponding nonlinear analysis. There are two prestressed concrete containment models with equipment hatch. One is 1/15 scale with steel liner tested on shake table and then moved out loaded with atmospheric pressure. The other is 1/10 scale without steel liner loaded with water pressure until destruction. From different methods including model test and nonlinear analysis, all obtained unanimous conclusion. The capacity under internal pressure and earthquake is reliable. The safety margin is enough. Consequently, in the second phase of Qinshan NPP and other PWR NPP under design, PCCV should be a better selection in China since it's more economic, rational and safe. (author)

Social problems and territorial experiences from closing down Tihange NPP

International Nuclear Information System (INIS)

Lizin, A.M.

2000-01-01

The town of Huy, better known by the name of the NPP Tihange, which is the nearby village, accounts to 50,000 inhabitants including the surrounding region. An Advisory Committee at a community level was set up concerned with the emergency services and the NPP related problems. One of the outstanding problems is the planned interim storage for radioactive waste. The unsolved question of long term storage in Belgium resulted in the fact that general situation is not promising for launching the debate on the future of nuclear energy. The mission of the delegation from Huy visited Tokaimura with the aim to measure the scale of real responsibilities and the concern against nuclear power that the accident created in the population

Containment integrity analysis under accidents

International Nuclear Information System (INIS)

Lin Chengge; Zhao Ruichang; Liu Zhitao

2010-01-01

Containment integrity analyses for current nuclear power plants (NPPs) mainly focus on the internal pressure caused by design basis accidents (DBAs). In addition to the analyses of containment pressure response caused by DBAs, the behavior of containment during severe accidents (SAs) are also evaluated for AP1000 NPP. Since the conservatism remains in the assumptions,boundary conditions and codes, margin of the results of containment integrity analyses may be overestimated. Along with the improvements of the knowledge to the phenomena and process of relevant accidents, the margin overrated can be appropriately reduced by using the best estimate codes combined with the uncertainty methods, which could be beneficial to the containment design and construction of large passive plants (LPP) in China. (authors)

Analytical support for SAMG development as a part of accident management

International Nuclear Information System (INIS)

Honcarenko, R.

1999-01-01

The decision to built up and implement a comprehensive Accident Management Program applying best world-wide knowledge made during last year at Temelin. A small group of engineers dedicated to Accident Management was formed at Temelin NPP as a part of the plant organisation scheme. A short summary of these activities performed by this group is presented. (author)

Accident sequence precursor analysis level 2/3 model development

International Nuclear Information System (INIS)

Lui, C.H.; Galyean, W.J.; Brownson, D.A.

1997-01-01

The US Nuclear Regulatory Commission's Accident Sequence Precursor (ASP) program currently uses simple Level 1 models to assess the conditional core damage probability for operational events occurring in commercial nuclear power plants (NPP). Since not all accident sequences leading to core damage will result in the same radiological consequences, it is necessary to develop simple Level 2/3 models that can be used to analyze the response of the NPP containment structure in the context of a core damage accident, estimate the magnitude of the resulting radioactive releases to the environment, and calculate the consequences associated with these releases. The simple Level 2/3 model development work was initiated in 1995, and several prototype models have been completed. Once developed, these simple Level 2/3 models are linked to the simple Level 1 models to provide risk perspectives for operational events. This paper describes the methods implemented for the development of these simple Level 2/3 ASP models, and the linkage process to the existing Level 1 models

Environmental monitoring of the Kozloduy NPP: 20 year experience

Energy Technology Data Exchange (ETDEWEB)

Aleksiev, A; Tsochev, S; Dimitrov, M; Avramov, V [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1996-12-31

The radiation monitoring system of the Kozloduy NPP is described and the assessment of the environmental impact of the power plant is presented. Measurements are carried out in 36 control points distributed in 3 areas: radiation protected area (3 km diameter), radiation controlled area (12 km) and surveillance area (100 km). Comparison of radiation monitoring data for 1993 with data recorded in the pre-operational period (1972-74) show that no significant changes can be detected in the activity of {sup 90} Sr and gross beta activity. An increase in Cs-137 activity (38 Bq/kg d.w. versus 7 Bq/kg d.w.) is found in the soil and bottom sediments in the Danube river, which is attributed to Chernobyl accident. The Kozloduy NPP operation is continuously monitored for release of artificial radionuclides by gaseous and liquid effluents. It is reported that the average population exposure in the 30 km area due to liquid effluents is 3-4.10{sup -4} man Sv/a. A system for automated continuous radiation monitoring in 10 control stations is available in case of radiation accidents. It is supplemented by a mobile laboratory. Meteorological measurements are carried out by automatic station MC-10 and a second station is under construction. 21 refs., 2 figs., 6 tabs.

Environmental monitoring of the Kozloduy NPP: 20 year experience

International Nuclear Information System (INIS)

Aleksiev, A.; Tsochev, S.; Dimitrov, M.; Avramov, V.

1995-01-01

The radiation monitoring system of the Kozloduy NPP is described and the assessment of the environmental impact of the power plant is presented. Measurements are carried out in 36 control points distributed in 3 areas: radiation protected area (3 km diameter), radiation controlled area (12 km) and surveillance area (100 km). Comparison of radiation monitoring data for 1993 with data recorded in the pre-operational period (1972-74) show that no significant changes can be detected in the activity of 90 Sr and gross beta activity. An increase in Cs-137 activity (38 Bq/kg d.w. versus 7 Bq/kg d.w.) is found in the soil and bottom sediments in the Danube river, which is attributed to Chernobyl accident. The Kozloduy NPP operation is continuously monitored for release of artificial radionuclides by gaseous and liquid effluents. It is reported that the average population exposure in the 30 km area due to liquid effluents is 3-4.10 -4 man Sv/a. A system for automated continuous radiation monitoring in 10 control stations is available in case of radiation accidents. It is supplemented by a mobile laboratory. Meteorological measurements are carried out by automatic station MC-10 and a second station is under construction. 21 refs., 2 figs., 6 tabs

Overview of the cooperation between the Chernobyl Center's International Radioecology Laboratory in Slavutych, Ukraine, and U.S. research centers between 2000 and 2010.

Science.gov (United States)

Bondarkov, Mikhail D; Gaschak, Sergey P; Oskolkov, Boris Ya; Maksimenko, Andrey M; Farfán, Eduardo B; Jannik, G Timothy; Labone, Elizabeth D

2011-10-01

The International Radioecology Laboratory (IRL) located in Slavutych, Ukraine, was created in 1999 under the initiative of the United States Government and the Government of Ukraine in the framework of international cooperation on evaluation and minimization of consequences of the Chernobyl nuclear power plant (ChNPP) accident. Since the time the IRL was founded, it has participated in a large number of projects, including the following: 1) study of radionuclide accumulation, distribution, and migration in components of various ecological systems of the Chernobyl Exclusion Zone (ChEZ); 2) radiation dose assessments; 3) study of the effects of radiation influence on biological systems; 4) expert analysis of isotopic and quantitative composition of radioactive contaminants; 5) development of new methods and technologies intended for radioecological research; 6) evaluation of future developments and pathways for potential remediation of the ChEZ areas; 7) assistance in provision of physical protection systems for ionizing irradiation sources at Ukrainian enterprises; 8) reviews of open Russian language publications on issues associated with consequences of the ChNPP accident, radioactive waste management, radioecological monitoring, and ChNPP decommissioning; 9) conduct of training courses on problems of radioecology, radiation safety, radioecological characterization of test sites and environmental media, and research methods; 10) conduct of on-site scientific conferences and workshops on the ChEZ and radioecology problems; participation in off-site scientific conferences and meetings; and 11) preparation of scientific and popular science publications and interactions with mass media representatives. This article provides a brief overview of the major achievements resulting from this cooperation between the IRL and U.S. research centers.

Feature extraction and sensor selection for NPP initiating event identification

International Nuclear Information System (INIS)

Lin, Ting-Han; Wu, Shun-Chi; Chen, Kuang-You; Chou, Hwai-Pwu

2017-01-01

Highlights: • A two-stage feature extraction scheme for NPP initiating event identification. • With stBP, interrelations among the sensors can be retained for identification. • With dSFS, sensors that are crucial for identification can be efficiently selected. • Efficacy of the scheme is illustrated with data from the Maanshan NPP simulator. - Abstract: Initiating event identification is essential in managing nuclear power plant (NPP) severe accidents. In this paper, a novel two-stage feature extraction scheme that incorporates the proposed sensor type-wise block projection (stBP) and deflatable sequential forward selection (dSFS) is used to elicit the discriminant information in the data obtained from various NPP sensors to facilitate event identification. With the stBP, the primal features can be extracted without eliminating the interrelations among the sensors of the same type. The extracted features are then subjected to a further dimensionality reduction by selecting the sensors that are most relevant to the events under consideration. This selection is not easy, and a combinatorial optimization technique is normally required. With the dSFS, an optimal sensor set can be found with less computational load. Moreover, its sensor deflation stage allows sensors in the preselected set to be iteratively refined to avoid being trapped into a local optimum. Results from detailed experiments containing data of 12 event categories and a total of 112 events generated with a Taiwan’s Maanshan NPP simulator are presented to illustrate the efficacy of the proposed scheme.

The ASSET service. Will another accident occur in the nuclear industry? In which country? When?

Energy Technology Data Exchange (ETDEWEB)

Thomas, B [International Atomic Energy Agency, Vienna (Austria)

1997-10-01

The presentation discusses the following issues: prevention of accidents at nuclear power plants(NPP); promotion of self assessment of NPP safety; guidance of self assessment; the ASSET methodology; plant defence in depth; safety culture; operating experience feedback;guidance for ASSET peer-review; ASSET missions conducted at the request of the IAEA member states.

The ASSET service. Will another accident occur in the nuclear industry? In which country? When?

International Nuclear Information System (INIS)

Thomas, B.

1997-01-01

The presentation discusses the following issues: prevention of accidents at nuclear power plants(NPP); promotion of self assessment of NPP safety; guidance of self assessment; the ASSET methodology; plant defence in depth; safety culture; operating experience feedback;guidance for ASSET peer-review; ASSET missions conducted at the request of the IAEA member states

Radiation protection in Bohunice NPP. Description of present status

International Nuclear Information System (INIS)

Dobis, L.

2001-01-01

Radiation protection (RP) at Bohunice NPP has reached the high international standard. The fact was approved by several independent international missions (OSART , WANO, WENRA, ...). A lot of modifications have been done in order to improve the standard of radiation protection. All the BSS requirements have been implemented into the plant regulations before the State Law No 290/1996 and 470/2000 came into the force. Internal audits are regularly performed at NPP in order to reveal potential deficiencies. In 2001 there were 4 such audits focused on quality assurance, software operation, LBB concept and limits and condition of safe operation. State Health Institute, the regulatory body in the radiation protection, performs the inspection at least ones a month. Good relationship with the inspectors of State Health Institute also contributes to the safe operation of the NPP. There were not any radiation accident. All anomalies or radiation events are investigated at a plant level. The results of root cause analysis and proposal of corrective actions are provided to IAEA and WANO databases for the distribution. The Radiation protection department of Bohunice NPP cooperates with the other Czech and Slovak NPPs. Regular meetings on radiation protection and lately also on emergency preparedness are organized. The cooperation is excellent. Occupational exposure is reviewed also with respect of ISOE data. Bohunice NPP (even with high dose burden caused by reconstruction of V1 NPP) can be found in the first half of world PWR speaking about the collective exposure per reactor. V2 NPP itself reaches the lowest collective exposure in the world. All doses are below the limits and kept ALARA. ALARA system has been established already in 1997 at Bohunice NPP and its results are obvious for example looking at dose results during the reconstruction works at V1 NPP. The operation of Bohunice NPP has negligible influence to its surroundings. The values of gas and liquid effluents move

Some ecological aspects of the using nucleus explosions in peace purpose

International Nuclear Information System (INIS)

Kalinovskij, A.K.; Krasnov, V.A.; Pazukhin, Eh.M.

2010-01-01

This paper presents a brief review of published data about radioactive contamination of environment after carried out underground nuclear explosions for peaceful purposes with reason to use the accumulated experience at liquidation consequences after accident on ChNPP.

First days of the Chernobyl accident. Private experience

International Nuclear Information System (INIS)

Karpan, Nikolay

2013-01-01

Ex-deputy chief engineer of Chernobyl NPP described the time-series personal experience of the fourth unit accident on 26 April, 1986. He was informed the accident at home at 4 o'clock. He came to the plant at 7 o'clock. He and other newcomers were no informed about what happened at the plant and about details of the accident from top manager of the plant. He gathered important information about the accident from people that were eyewitness of the accident and recorded their evidences. He reported to head engineer and his deputy that solution of boron acid could be brought into reactor for suppression of the chain reaction. Director of NPP asked authorities to bring boron acid to the plant, but the boron acid was not received before the chain reaction. The critical state began approximately 20 in the evening. After 4 hours of the critical state exposition dose rate of gamma radiation was ten times from 20 R/h in the morning and middle of day to 200 R/h. He consider as the first fault of the Governmental Commission was the absence of efforts for bringing boron to gorges of fuel and to shaft of reactor. The second fault was that protective countermeasures for city population protection were not undertaken. The authorities of Chernobyl began to wait for decisions of higher authorities. This means that responsibility was moved to them. (N.T)

Distribution of 137Cs, 90Sr, 239+240Pu, 241Am and 230,232Th on the fractions of natural organic species soils of ChNPP alienation zone

International Nuclear Information System (INIS)

Odintsov, A.A.; Sazhenyuk, A.D.

2003-01-01

The experimental data determination of distribution 137 Cs, 90 Sr, 239+240 Pu, 241 Am 'Chernobyl' releases and 230 , 232 Th on the fraction of humic and fulvic acids sandy- podsolic, meadow and peaty soils taken in the exclusive zone ChNPP are presents. Soils organic matter was isolated by conventional alkali extraction (Turin's method). It was shown that, with depending of soils types 15-45 % 241 Am associate with fulvic acids. In all investigated types of soils 30 - 40 % 239+240 Pu connects with humic acids, as strong complexes. The distribution of environmental 230 , 232 Th and artificial 239+240 Pu on the fraction natural organic species is the same

Environmental Radiation Monitoring In The Chernobyl Exclusion Zone - History And Results 25 Years After

International Nuclear Information System (INIS)

Farfan, E.; Jannik, T.

2011-01-01

This article describes results of the radiation environmental monitoring performed in the Chernobyl Exclusion Zone (ChEZ) during the period following the 1986 Chernobyl Nuclear Power Plant accident. This article presents a brief overview of five comprehensive reports generated under Contract No. DE-AC09-96SR18500 (Washington Savannah River Company LLC, Subcontract No. AC55559N, SOW No. ON8778) and summarizes characteristics of the ChEZ and its post-accident status and the history of development of the radiation monitoring research in the ChEZ is described. This article addresses characteristics of the radiation monitoring in the ChEZ, its major goals and objectives, and changes of these goals and objectives in the course of time, depending on the tasks associated with the phase of mitigation of the ChNPP accident consequences. The results of the radiation monitoring in the ChEZ during the last 25 years are also provided.

ENVIRONMENTAL RADIATION MONITORING IN THE CHERNOBYL EXCLUSION ZONE - HISTORY AND RESULTS 25 YEARS AFTER

Energy Technology Data Exchange (ETDEWEB)

Farfan, E.; Jannik, T.

2011-10-01

This article describes results of the radiation environmental monitoring performed in the Chernobyl Exclusion Zone (ChEZ) during the period following the 1986 Chernobyl Nuclear Power Plant accident. This article presents a brief overview of five comprehensive reports generated under Contract No. DE-AC09-96SR18500 (Washington Savannah River Company LLC, Subcontract No. AC55559N, SOW No. ON8778) and summarizes characteristics of the ChEZ and its post-accident status and the history of development of the radiation monitoring research in the ChEZ is described. This article addresses characteristics of the radiation monitoring in the ChEZ, its major goals and objectives, and changes of these goals and objectives in the course of time, depending on the tasks associated with the phase of mitigation of the ChNPP accident consequences. The results of the radiation monitoring in the ChEZ during the last 25 years are also provided.

Safety analysis of Ignalina NPP during shutdown conditions

International Nuclear Information System (INIS)

Kaliatka, A.; Uspuras, E.

2000-01-01

The accident analysis for the Ignalina NPP with RBMK-1500 reactors at normal operating conditions and at minimum controlled power level (during startup of the reactor) has been performed in the frame of the project I n-Depth Safety Assessment of the Ignalina NPP , which was completed in 1996. However, the plant conditions during the reactor shutdown differ from conditions during reactor operation at full power (equipment status in protection systems, set points for actuation of safety and protection systems, etc.). Results of RELAP5 simulation of two worst initiating events during reactor shutdown - Pressure Header rupture in case of steam reactor cooldown as well as Pressure Header rupture in case of water reactor cooldown are discussed in the paper. Results of analysis shown that reactor are reliably cooled in both cases. Further analysis for all range of initial events during reactor shutdown and at shutdown conditions is recommended. (author)

The Clearing House on Operating Experience Feedback (CH-OEF)

International Nuclear Information System (INIS)

Tanarro Colodron, J.

2016-01-01

Full text: The Clearing House on Operating Experience Feedback (CH-OEF) is an online information system that contains three technical databases available only to registered users: 1) Operating Experience Feedback (OEF) records, containing information about events occurred at Nuclear Power Plants; 2) Nuclear Power Plant (NPP) records, containing technical details about NPPs; 3) Documents about operating experience, such as the Topical Operating Experience Reports (TOERs) and the quarterly reports on nuclear power plant events. The main objective of the information system is to develop communication, cooperation and sharing of operating experience amongst the national nuclear regulatory authorities participating in EU Clearinghouse network. The CH-OEF is essential for the preparation and dissemination of the quarterly reports on NPP events. These reports are published every three months and are intended to be complementary to other international reporting systems, containing mainly recent information publicly available. Only events that are considered to be likely to have lessons applicable to EU NPPs or with a real or potential impact on nuclear safety are addressed in the reports. The CH-OEF is a fundamental tool for their preparation, providing specific features for a more efficient sharing of information as well as for facilitating the related discussion and decision making. (author

Radioactive dispersion analysis for hypothetical nuclear power plant (NPP) candidate site in Perak state, Malaysia

Science.gov (United States)

Shamsuddin, Shazmeen Daniar; Basri, Nor Afifah; Omar, Nurlyana; Koh, Meng-Hock; Ramli, Ahmad Termizi; Saridan Wan Hassan, Wan Muhamad

2017-10-01

Malaysia is planning to build a nuclear power plant (NPP) by 2030 to diversify the national electricity supply and resources. Selection of an NPP site must consider various factors, especially nuclear safety consideration to fulfil the nuclear safety objectives. Environmental Risk Assessment Analysis is a part of safety requirements by the International Atomic Energy Agency (IAEA) prior to the NPP commissioning process. Risk Assessments Analysis (RIA) is compulsory for the NPP site evaluation. One of RIA methods are Radioactive Dispersion Analysis using probabilistic risk analysis software. It is also important to perform studies to estimate the impact to the neighbouring population in the case of a nuclear accident at the power plant. In the present work, aimed to study the impact of a hypothetical nuclear accident by simulating the dispersion pattern of radionuclides originated from a candidate site at Manjung, Perak. The work has been performed using the HotSpot Health Physics codes. Two types of radionuclides have been considered namely 137Cs and 131I. In calculations, the initial concentration of radioactive materials of Fukushima Daiichi accident data are used which are 2.06 x 1016 Bq and 1.68 x 1017 Bq respectively for the two radionuclides. The result shows that the dispersion distance obtained from both software are not the same. It shows that 137Cs and 131I can be dispersed as far as 16 km and 80 km away from the site during radiological accident respectively, reaching major towns in Perak. Using HOTSPOT, the estimated total effective dose equivalent (TEDE) for 137Cs and 131I at major towns in Perak such as Lumut and Sitiawan are 1.2 mSv and 9.9 mSv. As for Taiping, Ipoh, Kampar, and Teluk Intan the estimated TEDE is around 0.2 mSv and 1.6 mSv respectively. In conclusion, the dispersion can reach as far as 80 km from the site. However, estimated annual effective dose is not more than 1 mSv limit, which is considered acceptable in the point of view of

Radioactive dispersion analysis for hypothetical nuclear power plant (NPP candidate site in Perak state, Malaysia

Directory of Open Access Journals (Sweden)

Shamsuddin Shazmeen Daniar

2017-01-01

Full Text Available Malaysia is planning to build a nuclear power plant (NPP by 2030 to diversify the national electricity supply and resources. Selection of an NPP site must consider various factors, especially nuclear safety consideration to fulfil the nuclear safety objectives. Environmental Risk Assessment Analysis is a part of safety requirements by the International Atomic Energy Agency (IAEA prior to the NPP commissioning process. Risk Assessments Analysis (RIA is compulsory for the NPP site evaluation. One of RIA methods are Radioactive Dispersion Analysis using probabilistic risk analysis software. It is also important to perform studies to estimate the impact to the neighbouring population in the case of a nuclear accident at the power plant. In the present work, aimed to study the impact of a hypothetical nuclear accident by simulating the dispersion pattern of radionuclides originated from a candidate site at Manjung, Perak. The work has been performed using the HotSpot Health Physics codes. Two types of radionuclides have been considered namely 137Cs and 131I. In calculations, the initial concentration of radioactive materials of Fukushima Daiichi accident data are used which are 2.06 x 1016 Bq and 1.68 x 1017 Bq respectively for the two radionuclides. The result shows that the dispersion distance obtained from both software are not the same. It shows that 137Cs and 131I can be dispersed as far as 16 km and 80 km away from the site during radiological accident respectively, reaching major towns in Perak. Using HOTSPOT, the estimated total effective dose equivalent (TEDE for 137Cs and 131I at major towns in Perak such as Lumut and Sitiawan are 1.2 mSv and 9.9 mSv. As for Taiping, Ipoh, Kampar, and Teluk Intan the estimated TEDE is around 0.2 mSv and 1.6 mSv respectively. In conclusion, the dispersion can reach as far as 80 km from the site. However, estimated annual effective dose is not more than 1 mSv limit, which is considered acceptable in the point

Graphic console for analysis of severe accidents visualization of OEs, NAEs and calculation of the source term for the NPP-LV (CoGrAAS)

International Nuclear Information System (INIS)

Sandoval V, S.; Mendoza E, P. R.; Gonzalez C, J. M.; Cecenas F, M.; Tijerina S, F.

2016-09-01

In response to the Fukushima Daiichi nuclear power plant accident, the NRC conducted an analysis and issued recommendations to improve the safety of the nuclear reactors. These include strengthening and integrating emergency response capabilities and emphasizing periodic staff training, the performance of simulation exercises. As a tool to observe these recommendations, the Graphic Console was developed for Analysis of Severe Accidents, Visualization of OEs, NAEs and calculation of the source term for nuclear power plant of Laguna Verde (NPP-LV ; CoGrAAS). The CoGrAAS is a computer system that displays in an integrated, graphic and dynamic way the information of a catalog of previously simulated accident scenarios. Has core mimics, vessel, primary containment and safety systems, trend graph of thermodynamic and radiological variables and the emergency procedures (OEs), chronological list of events, windows with detailed information for the dry-well, among others. The use of CoGrAAS allows that staff to understand and become familiar with the thermo-hydraulic progression of actual scenarios that exceed the design basis including those with core damage as severe accidents. The system enables personnel to develop an integral vision of the scenarios during the exercises and drills by observing and analyzing the evolution of the main reactor, core and primary containment variables, the response of emergency systems and the influence of that progression on OEs and the emergency action levels (NAEs). The CoGrAAS allows o observe the radiological variables and obtain the source term, to make the projection of doses, at any time within the scenario evolution. Thus, not only can the phenomenology of severe accidents be analyzed and understood, it is also possible to exercise, verify and evaluate the performance of critical tasks in the application of procedures, guidelines and emergency management plans. (Author)

Study on integrated design and analysis platform of NPP

International Nuclear Information System (INIS)

Lu Dongsen; Gao Zuying; Zhou Zhiwei

2001-01-01

Many calculation software have been developed to nuclear system's design and safety analysis, such as structure design software, fuel design and manage software, thermal hydraulic analysis software, severe accident simulation software, etc. This study integrates those software to a platform, develops visual modeling tool for Retran, NGFM90. And in this platform, a distribution calculation method is also provided for couple calculation between different software. The study will improve the design and analysis of NPP

Accident for natural gas well with hydrogen sulfide in relation to nuclear power plant siting

International Nuclear Information System (INIS)

Tan Chengjun; Shangguang Zhihong; Sha Xiangdong

2010-01-01

In order to make assessment to the potential impact from accident of natural gas wells with hydrogen sulfide on the habitability of main control room of nuclear power plant (NPP), several assumptions such as source terms of maximum credible accident, conservative atmospheric conditions and release characteristics were proposed in the paper, and the impact on the habitability of main control room was evaluated using toxicity thresholds recommended by foreign authority. Case results indicate that the method can provide the reference for the preliminary assessment to external human-induced events during the siting phrase of NPP. (authors)

Chernobyl'-92. Reports of the 3. All-Union scientific and technical meeting on results of accident effect elimination at the Chernobyl' NPP. V. 1. Radiation monitoring. Migration of radionuclides in environment. Part 2

International Nuclear Information System (INIS)

Senin, E.V.

1992-01-01

Section Radiation monitoring comprises: atlas of area radioactive contamination as a result of the Chernobyl' NPP accident, state of automated radiation monitoring control system, hydrological monitoring, radiation situation in different areas, problems of radiation monitoring and protection of water objects, methods for determining radionuclidescontents, radiochemical mechanisms of radionuclide migration mobility in the Chernobyl' effluents, the results of investigations into migration of radionuclides in soils, landscapes, bottom depositions, in the soil-plant chain

Probability estimation of potential harm to human health and life caused by a hypothetical nuclear accident at the nuclear power plant

International Nuclear Information System (INIS)

Soloviov, Vladyslav; Pysmenniy, Yevgen

2015-01-01

This paper describes some general methodological aspects of the assessment of the damage to human life and health caused by a hypothetical nuclear accident at the nuclear power plant (NPP). Probability estimation of death (due to cancer and non-cancer effects of radiation injury), disability and incapacity of individuals were made by taking into account the regulations of Ukraine. According to the assessment, the probability of death due to cancer and non-cancer effects of radiation damage to individuals who received radiation dose of 1 Sv is equal to 0.09. Probability of disability of 1, 2 or 3 group regardless of the radiation dose is 0.009, 0.0054, 0.027, respectively. Probability of temporary disability of the individual who received dose equal to 33 mSv (the level of potential exposure in a hypothetical nuclear accident at the NPP) is equal 0.16. This probability estimation of potential harm to human health and life caused by a hypothetical nuclear accident can be used for NPP in different countries using requirements of regulations in these countries. And also to estimate the amount of insurance payments due to the nuclear damage in the event of a nuclear accident at the NPP or other nuclear industry enterprise. (author)

Peculiarities of viruses Herpesviridae family persistence in patients with non-alcoholic fatty liver disease who had been exposed to the factors of Chornobyl NPP accident

International Nuclear Information System (INIS)

Chumak, A.A.; Nosach, O.V.; Ovsyannyikova, L.M.; And Others

2014-01-01

According to the presence of class IgG antiviral antibodies, NAFLD patients regardless of radiation influence in anamnesis have high prevalence of Herpesviridae family viral infection: herpes simplex 1/2 types, cytomegalovirus and Epstein-Barr virus. In the group of patients who had been exposed to the factors of Chornobyl NPP accident greater part of seropositive results and higher mean values of the probed antibodies titres were registered than in the groups of comparison. The mix infection by the viruses of herpes simplex 1/2 types and cytomegaly was registered in most patients with existence of direct correlation between the levels of anti-HSV-1/2 IgG and anti-CMV IgG

Simulation and dose analysis of a hypothetical accident in Sanmen nuclear power plant

International Nuclear Information System (INIS)

Zhu, Yangmo; Guo, Jianghua; Nie, Chu; Zhou, Youhua

2014-01-01

Highlights: • Atmospheric dispersion following a hypothetical accident in Sanmen NPP is simulated. • Japan, North Korea and Russia are slightly influenced in this accident. • In Taiwan and South Korea, population on 100% and 35% of the land should be given information about reducing dose. • In mainland China, about 284 thousand people are likely to get cancer. - Abstract: In November 2013, an AP1000 nuclear power plant (NPP) will be put into commercial operation. An atmospheric dispersion of radionuclides during a severe hypothetical accident in Sanmen NPP, Zhejiang province, China, is simulated with a Lagrangian particle dispersion model FLEXPART. The accident assumes that a station blackout (SBO) accident occurred on August 25, 2011, 55% core was damaged and 49 radionuclides were released into the atmosphere. Our simulation indicates that, during this dispersion, the radioactive plume will cover the mainland China, Taiwan, Japan, North Korea, South Korea and Russia. The radiation dose levels in Japan, North Korea and Russia are the lightest, usually less than 1 mSv. The influenced areas in these countries are 9901 km 2 , 31,736 km 2 and 2,97,524 km 2 , respectively; dose levels in Taiwan and South Korea are moderate, no more than 20 mSv. Information about reducing dose should be given to the public. Total influenced areas in these two countries are 3621 km 2 and 42,370 km 2 , which take up 100% of the land in Taiwan and 35% of the land in South Korea; the worst situation happens in mainland China. The total influenced area is 3 × 106 km 2 and 1,40,000 km 2 in this area has a dose level higher than 20 mSv. Measurement must be taken to reduce the dose. More than 284 thousand residents will face the risk of developing cancer. Furthermore, 96% of this population is mainly concentrated in Zhejiang province, where Sanmen NPP locates

On the results of nuclear fuel temperature dynamics restoration at the Chornobyl NPP unit 4 during active phase of the accident

Directory of Open Access Journals (Sweden)

O. V. Mikhailov

2016-02-01

Full Text Available Fuel temperature dynamics was reconstructed for active phase of the accident at the Chernobyl NPP Unit 4. Method of effective temperature calculation for uranium oxide is based on implementation of the CORSOR type mathematical codes and the model of lava-like fuel containing materials (LFCM formation from fragments of the former core (FFC in the room 305/2. Calculations were carried out according to release rate of 131I and 137Cs radionuclides during the period from April 26 until May 6, 1986. The rate of temperature drop during the FCM stage cooling bath silicate melt was estimated. It is shown that the main streams of LFCM could be formed at more moderate values of temperatures than it was performed previously. The results of the work are used to verify the “blast furnace” version of LFCM formation and formation of FCM with high uranium concentration.

About the causes and circumstances of the Chernobyl NPP accident

International Nuclear Information System (INIS)

Shteynberg, N.

1992-01-01

The Chernobyl accident is the product of unsatisfactory solutions to scientific-technical, socio-economic and human problems. The documentarily recorded power excursion of the reactor and its rise velocity as well as the quick pressure rise in the separator drum admit the conclusion that the cause of the accident was the rapid power excursion of the reactor and not some external influence. (DG) [de

Portable Filtered Air Suction System for Released Radioactive Gases Prevention under a Severe Accident of NPPs

International Nuclear Information System (INIS)

Gu, Beom W.; Choi, Su Y.; Rim, Chun T.

2013-01-01

In this paper, the portable filtered air suction system (PoFASS) for released radioactive gases prevention under a severe accident of NPP is proposed. This technology can prevent the release of the radioactive gases to the atmosphere and it can be more economical than FVCS because PoFASS can cover many NPPs with its high mobility. The conceptual design of PoFASS, which has the highest cost effectiveness and robustness to the environment condition such as wind velocity and precipitation, is suggested and the related previous research is introduced in this paper. The portable filtered air suction system (PoFASS) for released radioactive gases prevention can play a key role to mitigate the severe accident of NPP with its high cost effectiveness and robustness to the environment conditions. As further works, the detail design of PoFASS to fabricate a prototype for a demonstration will be proceeded. When released radioactive gases from the broken containment building in the severe accident of nuclear power plants (NPPs) such as the Chernobyl and Fukushima accidents occur, there are no ways to prevent the released radioactive gases spreading in the air. In order to solve this problem, several European NPPs have adopted the filtered vented containment system (FVCS), which can avoid the containment failure through a pressure relief capability to protect the containment building against overpressure. However, the installation cost of FVCS for a NPP is more than $10 million and this system has not been widely welcomed by NPP operating companies due to its high cost

The tsunami probabilistic risk assessment (PRA). Example of accident sequence analysis of tsunami PRA according to the standard for procedure of tsunami PRA for nuclear power plants

International Nuclear Information System (INIS)

Ohara, Norihiro; Hasegawa, Keiko; Kuroiwa, Katsuya

2013-01-01

After the Fukushima Daiichi nuclear power plant (NPP) accident, standard for procedure of tsunami PRA for NPP had been established by the Standardization Committee of AESJ. Industry group had been conducting analysis of Tsunami PRA for PWR based on the standard under the cooperation with electric utilities. This article introduced overview of the standard and examples of accident sequence analysis of Tsunami PRA studied by the industry group according to the standard. The standard consisted of (1) investigation of NPP's composition, characteristics and site information, (2) selection of relevant components for Tsunami PRA and initiating events and identification of accident sequence, (3) evaluation of Tsunami hazards, (4) fragility evaluation of building and components and (5) evaluation of accident sequence. Based on the evaluation, countermeasures for further improvement of safety against Tsunami could be identified by the sensitivity analysis. (T. Tanaka)

Fukushima. The accident sequence and important causes. Pt. 2/3; Fukushima. Unfallablauf und wesentliche Ursachen. T. 2/3

Energy Technology Data Exchange (ETDEWEB)

Pistner, Christoph [Oeko-Institut e.V., Darmstadt (Germany). Bereich Nukleartechnik und Anlagensicherheit

2013-07-01

In this part on the accident sequence in the NPP Fukushima Daiichi on March 11, 2011 the important safety systems of a nuclear power plant are described, including the design of a nuclear boiling water reactor with Mark-II type containment, the high-pressure injection system and the systems for afterheat removal. The chronology of the accident progress in the NPP units 1-3 is described. The units 4-6 were shutdown due to revision work. Due to the earthquake an electric power transformation station close to the NPP site and the power poles were destroyed, the redundant power supply of the neighboring electricity supplier Tohoku did not work. All emergency diesel generators were flooded and destroyed resulting in the so-called station blackout. Firefighting trucks and materials for radiation protection and the infrastructure at the NPP site were destroyed. The release of radioactivity induced a severe contamination of the reactor site.

Study of risc factors affecting the number of mental disorders and nervous system diseases for people who participated in liquidation of consequences of ChNPP accident

International Nuclear Information System (INIS)

Ivanov, V.K.; Chekin, S.Yu.; Mikhal'skij, A.I.; Petrovskij, A.M.

1992-01-01

Interrelation of disease incidence for liquidators and factors affecting it has been studied. The diseases (mental disorders and nervous system diseases) have been taken into account provided more than 10% of people have suffered of the above diseases. Date of getting into the accident zone; duration of work within the zone; the radiation dose accumulated were considered to be risc factors. Getting into the accident zone and duration of work within the zone of accident have been though to be the main risc factors. 3 figs.; 2 tabs

Fuel design and operational experience in Loviisa NPP, future trends in fuel issues

International Nuclear Information System (INIS)

Terasvirta, R.

2001-01-01

This paper summarizes the past operational experience of nuclear fuel with reference to most significant design changes during the years. In general, the fuel behaviour in Loviisa NPP in terms of leaking fuel assemblies has been good. The major improvements by fuel design changes in Lovissa NPP, including rod elongation margin, change in the pellet design and manufacturing process, upper grid modifications, change of material in the spacer grids and reduction of the shroud tube thickness are discussed and related to the number of failed fuel assemblies. The detailed investigation of fuel failure rates as function of different fuel and operation characteristics allows to classify the leaking fuel assemblies according to the cause of failure. In a brief discussion concerning new changes in the safety guide for nuclear design limits, re-issued by the Finnish Safety Authority (STUK), the frequencies for class 1 and class 2 accidents are determined. Another change in this guide is the introduction of design limits for the number of fuel rods experiencing DNB in class 1 accidents and number of failed rods in class 2 accidents. It is concluded that as far as normal operation is concerned, there seems to be sufficiently large margin between present operational limits in Loviisa and the design limits. The real limits do not come from fuel behaviour in the normal operation or operational occurrences but from the accident behaviour. At the moment, fuel assembly burnup extension beyond 45 MWd/kgU is clearly out of the question before further information and positive results are obtained on high burnup fuel behaviour in accident conditions

Development of Accident Scenario for Interim Spent Fuel Storage Facility Based on Fukushima Accident

Energy Technology Data Exchange (ETDEWEB)

Lee, Dongjin; Choi, Kwangsoon; Yoon, Hyungjoon; Park, Jungsu [KEPCO-E and C, Yongin (Korea, Republic of)

2014-05-15

700 MTU of spent nuclear fuel is discharged from nuclear fleet every year and spent fuel storage is currently 70.9% full. The on-site wet type spent fuel storage pool of each NPP(nuclear power plants) in Korea will shortly exceed its storage limit. Backdrop, the Korean government has rolled out a plan to construct an interim spent fuel storage facility by 2024. However, the type of interim spent fuel storage facility has not been decided yet in detail. The Fukushima accident has resulted in more stringent requirements for nuclear facilities in case of beyond design basis accidents. Therefore, there has been growing demand for developing scenario on interim storage facility to prepare for beyond design basis accidents and conducting dose assessment based on the scenario to verify the safety of each type of storage.

Design considerations for post accident monitoring system of a research reactor

International Nuclear Information System (INIS)

Jang, Gwi Sook; Park, Je Yun; Kim, Young Ki

2012-01-01

The Post Accident Monitoring System (PAMS) provides primary information for operators to assess the plant conditions and perform their role in bringing the plant to a safe condition during an accident. The PAMS of NPP (Nuclear Power Plant) in KOREA provides the continuous display of the PAM category 1 parameters specified in R.G 1.97, Rev. 03. Recently the PAMS of NPP has been designed according to R.G 1.97, Rev. 04. There is no PAMS at the HANARO in KOREA, but recently RRs (Research Reactors) around the world are going to have PAMS for various multi purposes. We should determine the design considerations for PAMS in a Korean RR based on the design state analysis. Thus, this paper proposes strategies on the design considerations for the PAMS of a Korean RR

Revisiting Ulchin 4 SGTR Accident - Analysis for EOP Improvement

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun-Hye; Lee, Wook-Jo; Jerng, Dong-Wook [Chung-Ang University, Seoul (Korea, Republic of)

2016-10-15

The Steam Generator Tube Ruputure (SGTR) is an accident that U-tube inside the SG is defected so that the reactor coolant releases through broken U-tube and this is one of design basis accidents. Operating the Nuclear Power Plants (NPP), maintaing the integrity of core and preventing radiation release are most important things. Because of risks, many researchers have studied scenarios, impacts and the ways to mitigate SGTR accidents. The study to provide an experimental database of aerosol particle retention and to develop models to support accident management interventions during SGTR was performed. The scaled-down models of NPP were used for experiments, also, MELCOR and SCDAP/RELAP5 were used to simulate a design basis SGTR accident. This study had a major role to resolve uncertainties of various physical models for aerosol mechanical resuspension. The other study which analyzed SGTR accident for System-integrated Modular Advanced Reactor (SMART) was performed. In this analysis, the amount of break flow was focused and TASS/SMRS code was used. It assumed that maximum leak was generated, and found that high RCS pressure, low core inlet coolant temperature, and low break location of the SG cassette contributed to leakage. Although the leakage was large, there was no direct release to atmosphere because the pressure of secondary loop was maintained below the safety relief valve set point. In this analysis, comparison of mitigating procedure when SGTR occurs between shutdown condition and full power condition was performed. In shutdown condition, the core uncovery would not take place in 16 hours whether the cooling procedures are performed or not. Therefore, the integrated amount of break flow should be considered only. In this point of view, cooling through intact SG only, case 3, is the best way to minimize the amount of break flow. In full power condition, the core water level is changed due to high reactor power. The important thing to protect NPP is to keep

Neutronic calculations for Angra-1 steam line break accident

International Nuclear Information System (INIS)

Ponzoni Filho, Pedro; Sato, Sadakatu

2000-01-01

The reduction of boron concentration in the Boron Injection Tank (BIT), to the room temperature solubility level, makes necessary a reanalysis of the steam line break accident of Angra 1 NPP. This paper describes the neutronic calculation related to this reanalysis. The main steps of the work were: review of reactivity parameters used in the accident simulation; search of xenon profiles that cause the most severe core power distribution; calculation of hot channel factors and other neutronic parameters necessary for DNBR determination. The final conclusion, related to the steam line break accident, states the BIT concentration may be reduced to 2000 ppm. (author)

Long term effects of Minks of the radiation factors from the Chernobyl accident

International Nuclear Information System (INIS)

Bondar, A.Y.; Zamostian, V.P.; Riasenko, V.I.

1997-01-01

The study of small radiation dose influence on human and animal reproductive functions becomes more and more topical after Chernobyl Nuclear Power Plant (ChNPP) accident. In the number of cases, animals that reside in continues internal, as well as external exposure zone, have pregnancy interruption in its early stages (up to 30 days). This, without any doubts testifies for reproductive process disorder as a whole (hypophysis-ovary-uterus system) and also, as its separate links. The important thing is that a break in any one of those links leads to pregnancy interruption. Hence, in order to determine any disorders in reproductive system functional state, profound and detailed morphofunctional study of the system links (accounting for radiation exposure factors) needs to be done. Because research in this field has just started, we were unable to find any material on this topic. There are, however, some references for morphofunctional changes of endocrine glands, hypophysis in particular and sex glands, refereed to small radiation doses

Environmental radioactivity of the Danube basin in the vicinity of the Kozloduy NPP (July 1994)

Energy Technology Data Exchange (ETDEWEB)

Badulin, V; Zlatanova, R; Botsova, L; Mireva, Z [National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

1996-12-31

Analytical results from radiation monitoring carried out at the Kozloduy NPP area are reported. Sampling of water, sediment, soil and grass for beta and gamma activity has been done in 13 points at distances ranging from 6 to 90 km from the plant. The comparison of data with the values for the previous year does not show any significant variations in radioactivity. The values of {sup 90}Sr activity in river water are less than 10 mBq/l, in river bottom sediment - less than 2 Bq/kg, in soil - less than 4 Bq/kg and in grass -below 8 Bq/kg. Activity of Cs-137 is highest in river bottom sediment - 6-43 Bq/kg which is attributed to the Chernobyl accident. It is concluded that the radioactive effluents and atmospheric releases from the Kozloduy NPP do not produce any noticeable changes in environmental radioactivity caused by the global fallout and the Chernobyl accident. 9 figs., 1 tab.

Regulation Plans on Severe Accidents developed by KINS Severe Accident Regulation Preparation TFT

International Nuclear Information System (INIS)

Kim, Kyun Tae; Chung, Ku Young; Na, Han Bee

2016-01-01

Some nuclear power plants in Fukushima Daiichi site had lost their emergency reactor cooling function for long-time so the fuels inside the reactors were molten, and the integrity of containment was damaged. Therefore, large amount of radioactive material was released to environment. Because the social and economic effects of severe accidents are enormous, Korean Government already issued 'Severe Accident Policy' in 2001 which requires nuclear power plant operators to set up 'Quantitative Safety Goal', to do 'Probabilistic Safety Analysis', to install 'Severe Accident Countermeasures' and to make 'Severe Accident Management Plan'. After the Fukushima disaster, a Special Safety Inspection was performed for all operating nuclear power plants of Korea. The inspection team from industry, academia, and research institutes assessed Korean NPPs capabilities to cope with or respond to severe accidents and emergency situation caused by natural disasters such as a large earthquake or tsunami. As a result of the special inspection, about 50 action items were identified to increase the capability to cope with natural disaster and severe accidents. Nuclear Safety Act has been amended to require NPP operators to submit Accident Management Plant as part of operating license application. The KINS Severe Accident Regulation Preparation TFT had first investigated oversea severe accident regulation trend before and after the Fukushima accident. Then, the TFT has developed regulation draft for severe accidents such as Severe accident Management Plans, the required design features for new NPPs to prevent severe accident against multiple failures and beyond-design external events, countermeasures to mitigate severe accident and to keep the integrity of containment, and assessment methodology on safety assessment plan and probabilistic safety assessment

The Impact of Severe Nuclear Accidents on National Decision for Nuclear Decommissioning

International Nuclear Information System (INIS)

Suh, Young A; Hornibrook, Carol; Yim, Man Sung

2016-01-01

Many researchers have tried to identify the impact of severe nuclear accidents on a country's or international nuclear energy policy [2-3]. However, there is little research on the influence of nuclear accidents and historical events on a country's decision to permanently shutdown an NPP versus international nuclear decommissioning trends. To demonstrate the correlation between a nuclear severe accident and the impact on world nuclear decommissioning, this research reviewed case studies of individual historical events, such as the St. Lucens, TMI, Chernobyl, Fukushima accidents and the series of events leading up to the collapse of the Soviet Union. For validation of the results of these case studies, a statistical analysis was conducted using the R code. This will be useful in explaining how international and national decommissioning strategies are affected by shutdown reasons, i.e. world historical events. The number of permanently shutdown NPPs was selected as an indicator because any relationship between the number of permanently In conclusion, nuclear severe accidents and historical events have an impact on the number of international NPPs that shutdown permanently and cancelled NPP construction. This directly impacts international nuclear decommissioning policy and nuclear energy policy trends. The number of permanently shutdown NPPs was selected as an indicator because any relationship between the number of permanently

A recommended epidemiological study design for examining the adverse health effects among emergency workers who experienced the TEPCO fukushima daiichi NPP accident in 2011.

Science.gov (United States)

Yasui, Shojiro

2016-01-01

Results from medical examinations conducted in 2012 of workers who were engaged in radiation work in 2012 as a result of the 2011 Fukushima Daiichi Nuclear Power Plant (NPP) accident showed that the prevalence of abnormal findings was 4.21%, 3.23 points higher than the 0.98% that was found prior to the accident in the jurisdiction area of the labor inspection office which holds jurisdiction over the NPP. The Ministry of Health, Labour and Welfare (MHLW) concluded that the 2010 and 2012 data cannot be easily compared because 70% of the enterprises within the jurisdiction of the office that reported the 2012 results were different from those that did so in 2010. In addition, although the radiation workers' estimated average dose weighted by number of workers was 3.66 times higher than decontamination workers' dose, the prevalence among radiation workers was only 1.14 times higher than that among decontamination workers. Based on the results of the medical examinations, however, the MHLW decided to implement an epidemiological study on the health effects of radiation exposure on all emergency workers. This article explains key issues of the basic design of the study recommended by the expert meeting established in the MHLW and also identifies challenges that could not be resolved and thus required further consideration by the study researchers. The major issues included: (a) study methods and target group; (b) evaluation of cumulative doses; (c) health effects (end points); (d) control of confounding factors; and (e) study implementation framework. Identified key challenges that required further deliberation were: (a) preventing arbitrary partisan analysis; (b) ensuring a high participation rate; (c) inquiry about the medical radiation doses; and (d) the preparedness of new analytical technology. The study team formulated and implemented the pilot study in 2014 and started the full-scale study in April 2015 with funding from a research grant from the MHLW.

OVERVIEW OF THE COOPERATION BETWEEN THE CHERNOBYL CENTER'S INTERNATIONAL RADIOECOLOGY LABORATORY IN SLAVUTYCH, UKRAINE AND U.S. RESEARCH CENTERS BETWEEN 2000-2010

Energy Technology Data Exchange (ETDEWEB)

Farfan, E.; Jannik, T.

2011-10-01

The International Radioecology Laboratory (IRL) located in Slavutych, Ukraine was created in 1999 under the initiative of the United States Government and the Government of Ukraine in the framework of international cooperation on evaluation and minimization of consequences of the Chernobyl nuclear power plant (ChNPP) accident. Since the time the IRL was founded, it has participated in a large number of projects, including the following: (1) study of radionuclide accumulation, distribution, and migration in components of various ecological systems of the Chernobyl Exclusion Zone (ChEZ); (2) radiation dose assessments; (3) study of the effects of radiation influence on biological systems; (4) expert analysis of isotopic and quantitative composition of radioactive contaminants; (5) development of new methods and technologies intended for radioecological research; (6) evaluation of future developments and pathways for potential remediation of the ChEZ areas; (7) assistance in provision of physical protection systems for ionizing irradiation sources at Ukrainian enterprises; (8) reviews of open Russian language publications on issues associated with consequences of the ChNPP accident, radioactive waste management, radioecological monitoring, and ChNPP decommissioning; (9) conduct of training courses on problems of radioecology, radiation safety, radioecological characterization of test sites and environmental media, and on research methods; (10) conduct of on-site scientific conferences and workshops on the ChEZ and radioecology problems; participation in off-site scientific conferences and meetings; and (11) preparation of scientific and popular science publications, and interactions with mass media representatives. This article provides a brief overview of the major achievements resulting from this cooperation between the IRL and U.S. research centers.

Overview Of The Cooperation Between The Chernobyl Center's International Radioecology Laboratory In Slavutych, Ukraine And U.S. Research Centers Between 2000-2010

International Nuclear Information System (INIS)

Farfan, E.; Jannik, T.

2011-01-01

The International Radioecology Laboratory (IRL) located in Slavutych, Ukraine was created in 1999 under the initiative of the United States Government and the Government of Ukraine in the framework of international cooperation on evaluation and minimization of consequences of the Chernobyl nuclear power plant (ChNPP) accident. Since the time the IRL was founded, it has participated in a large number of projects, including the following: (1) study of radionuclide accumulation, distribution, and migration in components of various ecological systems of the Chernobyl Exclusion Zone (ChEZ); (2) radiation dose assessments; (3) study of the effects of radiation influence on biological systems; (4) expert analysis of isotopic and quantitative composition of radioactive contaminants; (5) development of new methods and technologies intended for radioecological research; (6) evaluation of future developments and pathways for potential remediation of the ChEZ areas; (7) assistance in provision of physical protection systems for ionizing irradiation sources at Ukrainian enterprises; (8) reviews of open Russian language publications on issues associated with consequences of the ChNPP accident, radioactive waste management, radioecological monitoring, and ChNPP decommissioning; (9) conduct of training courses on problems of radioecology, radiation safety, radioecological characterization of test sites and environmental media, and on research methods; (10) conduct of on-site scientific conferences and workshops on the ChEZ and radioecology problems; participation in off-site scientific conferences and meetings; and (11) preparation of scientific and popular science publications, and interactions with mass media representatives. This article provides a brief overview of the major achievements resulting from this cooperation between the IRL and U.S. research centers.

Modelling of distribution of emissions from point source on the territory of the Belarusian NPP

International Nuclear Information System (INIS)

Cherkasova, V.V.; Smirnova, T.V.

2016-01-01

The work is devoted to the numerical assessment of the possible spread of emissions on the territory of the Belarusian NPP considering the wind pattern of the area in question. The results will help to develop draft guidelines for the operator to response to nuclear radiation accident. (authors)

Principles and criteria for environmental restoration of the contaminated banks near NPP Bohunice

International Nuclear Information System (INIS)

Slavik, O.; Moravek, J.

1995-01-01

The 18 km long banks of the Bohunice NPP waste water recipient are contaminated by 137 Cs as a result of two accidents on the CO 2 cooled NPP-A1 unit in 1976 and 1977. Contamination acceptance limits 6 or 8 Bq 137 Cslg of soil, depending on contaminated area size, were derived on the basis of developed principles, and approved by the authorities. Removing and safe burial of 1,100 m 3 of contaminated soil from steep area and 15 cm thick clean soil covering on about 1ha of flat area of the contaminated banks is planned in frame of the re-considered restoration project implementation in 1995/96. (author)

Emergency operating procedures improvement based on the lesson learned from the Fukushima Daiichi accident

Energy Technology Data Exchange (ETDEWEB)

Wu, Wen-Hsiung, E-mail: whwu1127@aec.gov.tw [Atomic Energy Council, 2F., No. 80, Sec.1, Chenggong Rd., Yonghe Dist., New Taipei City 234, Taiwan (China); Institute of Nuclear Engineering and Science, National Tsing Hua University, No. 101, Sec. 2, Guangfu Rd., Hsinchu City 300, Taiwan (China); Liao, Lih-Yih, E-mail: lyliao@iner.gov.tw [Institute of Nuclear Energy Research, Atomic Energy Council, No. 1000, Wenhua Rd., Jiaan Village, Longtan Township, Taoyuan County 325, Taiwan (China)

2016-12-01

Highlights: • Discuss the problem of EOPs at the time of Fukushima accident to deal with the prolonged SBO. • Elaborate the potential risk accompanied with the emergency depressurization in the SBO. • Describe a special guideline to cope with Fukushima-like accidents and provide its technical basis. • Point out that Fukushima accident might have been prevented if improved EOPs had been used. • Propose key points and suggestions for improving the EOPs. - Abstract: One of the lessons learned from the Fukushima Daiichi accident is the emergency operating procedures (EOPs) have to be improved. The BWR Owners’ Group revised the emergency procedure guidelines and addressed the lesson learned from the Fukushima Daiichi accident in revision 3 in order to avoid loss of turbine-driven makeup water systems during reactor depressurization. However, the improvement deserves much more attention. The existing EOPs at the time of the accident may not be adequate enough for the prolonged station blackout condition, because resources required for performing the EOPs are vastly unavailable or gradually exhausted. The improved EOPs must not only permit early reactor pressure vessel depressurization, but also address the risk accompanied with the emergency depressurization. For this reason, Taiwan Power Company proposed the Ultimate Response Guideline (URG) to cope with Fukushima-like accidents. The main content of the URG is a two-stage depressurization strategy, namely the controlled depressurization and the emergency depressurization. The technical basis of the two-stage depressurization strategy was discussed in this paper. The effectiveness of the URG was verified by using TRAC/RELAP Advanced Computational Engine (TRACE). Besides, the emergency responses performed by Fukushima Daini nuclear power plant (Fukushima Daini NPP) were found to be very similar to the URG. The consequences of Fukushima Daini NPP somehow demonstrate that the URG is effective for Fukushima

Emergency operating procedures improvement based on the lesson learned from the Fukushima Daiichi accident

International Nuclear Information System (INIS)

Wu, Wen-Hsiung; Liao, Lih-Yih

2016-01-01

Highlights: • Discuss the problem of EOPs at the time of Fukushima accident to deal with the prolonged SBO. • Elaborate the potential risk accompanied with the emergency depressurization in the SBO. • Describe a special guideline to cope with Fukushima-like accidents and provide its technical basis. • Point out that Fukushima accident might have been prevented if improved EOPs had been used. • Propose key points and suggestions for improving the EOPs. - Abstract: One of the lessons learned from the Fukushima Daiichi accident is the emergency operating procedures (EOPs) have to be improved. The BWR Owners’ Group revised the emergency procedure guidelines and addressed the lesson learned from the Fukushima Daiichi accident in revision 3 in order to avoid loss of turbine-driven makeup water systems during reactor depressurization. However, the improvement deserves much more attention. The existing EOPs at the time of the accident may not be adequate enough for the prolonged station blackout condition, because resources required for performing the EOPs are vastly unavailable or gradually exhausted. The improved EOPs must not only permit early reactor pressure vessel depressurization, but also address the risk accompanied with the emergency depressurization. For this reason, Taiwan Power Company proposed the Ultimate Response Guideline (URG) to cope with Fukushima-like accidents. The main content of the URG is a two-stage depressurization strategy, namely the controlled depressurization and the emergency depressurization. The technical basis of the two-stage depressurization strategy was discussed in this paper. The effectiveness of the URG was verified by using TRAC/RELAP Advanced Computational Engine (TRACE). Besides, the emergency responses performed by Fukushima Daini nuclear power plant (Fukushima Daini NPP) were found to be very similar to the URG. The consequences of Fukushima Daini NPP somehow demonstrate that the URG is effective for Fukushima

International Conference 'Twenty Years after Chernobyl Accident. Future Outlook'. Abstracts proceeding

International Nuclear Information System (INIS)

Anon

2006-01-01

This conference concludes a series of events dedicated to the 20 anniversary of the Chernobyl accident and promote an effective implementation of the accumulated international experience in the following areas: Radiation protection of the population and emergency workers, and the environmental consequences of Chernobyl accident; Medical and public health response to radiation emergencies; Strengthening radiological emergency management of radiation accidents; Economic and legal aspects of radioactive waste management and nuclear power plants decommissioning; Radioactive waste management: Chernobyl experience; Nuclear power plant decommissioning: Chernobyl NPP; Transformation of the Chernobyl Sarcophagus into an ecologically safe system

20 years after Chernobyl Accident. Future outlook. National Report of Ukraine

Energy Technology Data Exchange (ETDEWEB)

Baloga, V I [ed.

2006-07-01

The scale of the Chernobyl catastrophe - the most severe man made nuclear accident in the history of mankind - is well known to both scientists and politicians worldwide. The basic causes of the catastrophe were as follows: Conduction an incompletely and incorrectly prepared electrical experiment; The low professional level of operators, and of the NPP management and the officials of the Ministry of Electrification as a whole in the area of NPP safety; Insufficient safety level of the graphite-uranium reactor RBMK-1000; Constructive faults RBMK-1000; Personnel mistakes. The report describes and reviews the actions of the governments of the USSR, Ukraine, and the Verkhovna Rada of Ukraine; the activities of scientists in elimination of the accident consequences; and elimination of the additional experience gained over the past years. Mistakes made during these activities are highlighted.

20 years after Chernobyl Accident. Future outlook. National Report of Ukraine

International Nuclear Information System (INIS)

Baloga, V.I.

2006-01-01

The scale of the Chernobyl catastrophe - the most severe man made nuclear accident in the history of mankind - is well known to both scientists and politicians worldwide. The basic causes of the catastrophe were as follows: Conduction an incompletely and incorrectly prepared electrical experiment; The low professional level of operators, and of the NPP management and the officials of the Ministry of Electrification as a whole in the area of NPP safety; Insufficient safety level of the graphite-uranium reactor RBMK-1000; Constructive faults RBMK-1000; Personnel mistakes. The report describes and reviews the actions of the governments of the USSR, Ukraine, and the Verkhovna Rada of Ukraine; the activities of scientists in elimination of the accident consequences; and elimination of the additional experience gained over the past years. Mistakes made during these activities are highlighted

MDEP AP1000WG Design-Specific Common Position CP-AP1000WG-02. Common position addressing Fukushima Daiichi NPP accident-related issues

International Nuclear Information System (INIS)

2016-09-01

A severe accident involving several units took place in Japan at Fukushima Daiichi nuclear power plant (NPP) in March 2011. The immediate cause of the accident was an earthquake followed by a tsunami coupled with inadequate provisions against the consequences of such events in the design. Opportunities to improve protection against a realistic design basis tsunami had not been taken. As a consequence of the tsunami, safety equipment and the related safety functions were lost at the plant, leading to core damage in three units and subsequently to large radioactive release. Several studies have already been performed to better understand the accident progression and detailed technical studies are still in progress in Japan and elsewhere. In the meantime, on-going studies on the behaviour of nuclear power plants in very severe situations, similar to Fukushima Daiichi, seek to identify potential vulnerabilities in plant design and operation; to suggest reasonably practicable upgrades; or to recommend enhanced regulatory requirements and guidance to address such situations. Likewise, agencies around the world that are responsible for regulating the design, construction and operation of AP1000 R plants are engaged in similar activities. The MDEP AP1000 R Working Group (AP1000 WG) members consist of members from Canada, China, the United Kingdom and the United States. Since the regulatory review of their AP1000 R applications have not been completed by all of these Countries yet, this paper identifies common preliminary approaches to address potential safety improvements for AP1000 R plants as related to lessons learned from the Fukushima Daiichi accident or Fukushima Daiichi-related issues. In seeking common position, regulators will provide input to this paper to reflect their safety conclusions regarding the AP1000 R design and how the design could be enhanced to address Fukushima Daiichi issues. The common preliminary approaches are organized into five sections

Tracing nuclear elements released by Fukushima Nuclear Power Plant accident

Science.gov (United States)

Tsujimura, M.; Onda, Y.; Abe, Y.; Hada, M.; Pun, I.

2011-12-01

Radioactive contamination has been detected in Fukushima and the neighboring regions due to the nuclear accident at Fukushima Daiichi Nuclear Power Plant (NPP) following the earthquake and tsunami occurred on 11th March 2011. The small experimental catchments have been established in Yamakiya district, Kawamata Town, Fukushima Prefecture, located approximately 35 km west from the Fukushima NPP. The tritium (3H) concentration and stable isotopic compositions of deuterium and oxygen-18 have been determined on the water samples of precipitation, soil water at the depths of 10 to 30 cm, groundwater at the depths of 5 m to 50 m, spring water and stream water taken at the watersheds in the recharge and discharge zones from the view point of the groundwater flow system. The tritium concentration of the rain water fell just a few days after the earthquake showed a value of approximately 17 Tritium Unit (T.U.), whereas the average concentration of the tritium in the precipitation was less than 5 T.U. before the Fukushima accident. The spring water in the recharge zone showed a relatively high tritium concentration of approximately 12 T.U., whereas that of the discharge zone showed less than 5 T.U. Thus, the artificial tritium was apparently injected in the groundwater flow system due to the Fukushima NPP accident, whereas that has not reached at the discharge zone yet. The monitoring of the nuclear elements is now on going from the view points of the hydrological cycles and the drinking water security.

Regulation Plans on Severe Accidents developed by KINS Severe Accident Regulation Preparation TFT

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyun Tae; Chung, Ku Young; Na, Han Bee [KINS, Daejeon (Korea, Republic of)

2016-05-15

Some nuclear power plants in Fukushima Daiichi site had lost their emergency reactor cooling function for long-time so the fuels inside the reactors were molten, and the integrity of containment was damaged. Therefore, large amount of radioactive material was released to environment. Because the social and economic effects of severe accidents are enormous, Korean Government already issued 'Severe Accident Policy' in 2001 which requires nuclear power plant operators to set up 'Quantitative Safety Goal', to do 'Probabilistic Safety Analysis', to install 'Severe Accident Countermeasures' and to make 'Severe Accident Management Plan'. After the Fukushima disaster, a Special Safety Inspection was performed for all operating nuclear power plants of Korea. The inspection team from industry, academia, and research institutes assessed Korean NPPs capabilities to cope with or respond to severe accidents and emergency situation caused by natural disasters such as a large earthquake or tsunami. As a result of the special inspection, about 50 action items were identified to increase the capability to cope with natural disaster and severe accidents. Nuclear Safety Act has been amended to require NPP operators to submit Accident Management Plant as part of operating license application. The KINS Severe Accident Regulation Preparation TFT had first investigated oversea severe accident regulation trend before and after the Fukushima accident. Then, the TFT has developed regulation draft for severe accidents such as Severe accident Management Plans, the required design features for new NPPs to prevent severe accident against multiple failures and beyond-design external events, countermeasures to mitigate severe accident and to keep the integrity of containment, and assessment methodology on safety assessment plan and probabilistic safety assessment.

Radiological environment within an NPP after a severe nuclear accident

Science.gov (United States)

Andgren, Karin; Fritioff, Karin; Buhr, Anna Maria Blixt; Huutoniemi, Tommi

2017-09-01

The radiological environment following a severe nuclear accident can be visualised on building layouts. The direct radiation in an area (or room) can be visualized on the layout by a colouring scheme depending on the dose rate level (for example orange for high gamma dose rate level and purple for an intermediate gamma dose rate level). Following the Fukushima accident, a need for update of these layouts has been identified at the Swedish nuclear power plant of Forsmark. Shielding calculations for areas where access is desired for severe accident management have been performed. Many different sources of radiation together with different types of shielding material contribute to the dose that would be received by a person entering the area. External radiation from radioactivity within e.g. pipes and components is considered and also external radiation from radioactivity in the air (originating from diffuse leakage of the containment atmosphere). Results are presented as dose rates for relevant dose points together with a method for estimating the dose rate levels for each of the rooms of the reactor building.

Radiological environment within an NPP after a severe nuclear accident

Directory of Open Access Journals (Sweden)

Andgren Karin

2017-01-01

Full Text Available The radiological environment following a severe nuclear accident can be visualised on building layouts. The direct radiation in an area (or room can be visualized on the layout by a colouring scheme depending on the dose rate level (for example orange for high gamma dose rate level and purple for an intermediate gamma dose rate level. Following the Fukushima accident, a need for update of these layouts has been identified at the Swedish nuclear power plant of Forsmark. Shielding calculations for areas where access is desired for severe accident management have been performed. Many different sources of radiation together with different types of shielding material contribute to the dose that would be received by a person entering the area. External radiation from radioactivity within e.g. pipes and components is considered and also external radiation from radioactivity in the air (originating from diffuse leakage of the containment atmosphere. Results are presented as dose rates for relevant dose points together with a method for estimating the dose rate levels for each of the rooms of the reactor building.

Safety analysis methodology for Chinshan nuclear power plant spent fuel pool under Fukushima-like accident condition

Energy Technology Data Exchange (ETDEWEB)

Lin, Hao-Tzu [Institute of Nuclear Energy Research, Taoyuan, Taiwan (China). Research Atomic Energy Council; Li, Wan-Yun; Wang, Jong-Rong; Tseng, Yung-Shin; Chen, Hsiung-Chih; Shih, Chunkuan; Chen, Shao-Wen [National Tsing Hua Univ., HsinChu, Taiwan (China). Inst. of Nuclear Engineering and Science

2017-03-15

Chinshan nuclear power plant (NPP), a BWR/4 plant, is the first NPP in Taiwan. After Fukushima NPP disaster occurred, there is more concern for the safety of NPPs in Taiwan. Therefore, in order to estimate the safety of Chinshan NPP spent fuel pool (SFP), by using TRACE, MELCOR, CFD, and FRAPTRAN codes, INER (Institute of Nuclear Energy Research, Atomic Energy Council, R.O.C.) performed the safety analysis of Chinshan NPP SFP. There were two main steps in this research. The first step was the establishment of Chinshan NPP SFP models. And the transient analysis under the SFP cooling system failure condition (Fukushima-like accident) was performed. In addition, the sensitive study of the time point for water spray was also performed. The next step was the fuel rod performance analysis by using FRAPTRAN and TRACE's results. Finally, the animation model of Chinshan NPP SFP was presented by using the animation function of SNAP with MELCOR analysis results.

Analysis of the radioactive aerosols sampled with Lepestok respirators during work in the Chernobyl' NPP region

International Nuclear Information System (INIS)

Borisova, L.I.; Polevov, V.N.; Borisov, N.B.; Basmanov, P.I.

1989-01-01

Aerosols sampled with Lepestok type respirators in the Chernobyl' NPP region following the accident were analysed by gamma-spectroscopic and optical-radiographic methods and nuclide ratio of the aerosol sediment after respirators usage were determined. Parameters of the sampled gamma-active aerosol particles were obtained. ref. 1; tabs. 3

Improving Research Reactor Accident Response Capability at the Hungarian Nuclear Safety Authority

International Nuclear Information System (INIS)

Vegh, J.; Gajdos, F.; Horvath, Cs.; Matisz, A.; Nyisztor, D.

2013-06-01

The paper describes the design and implementation of an on-line operation monitoring and accident response support system to be used at the CERTA emergency response centre of Hungarian Atomic Energy Authority (HAEA). The monitored facility is the Budapest Research Reactor (BRR), which is a tank-type thermal reactor having 10 MW thermal power. The basic reason for the development of the on-line safety information system is to extend the emergency response capability of the CERTA crisis centre to include emergencies related to BRR, as well. CERTA is operated by HAEA at its Budapest headquarters and the centre already has an on-line system for monitoring the state of the four units of Paks NPP, Hungary. The system is called CERTA VITA and it is able to monitor the four VVER-440/V213 units during their normal operation, and during emergencies (including severe accidents). Ensuring appropriate emergency response capabilities, as well as improving the presently available systems and tools was one of the important recommendations resulting from the analyses following the severe accident at Fukushima. This task is valid not only for the operators of the nuclear facilities but also for the nuclear safety authorities, therefore HAEA decided to launch a project - together with the Centre for Energy Research, the operator of BRR - to establish an on-line information system similar to the CERTA VITA used for monitoring the four units of the Paks NPP. It is believed that by the introduction of this new on-line system the accident response capabilities of HAEA will be further enhanced and the BRR emergencies will be handled at the same professional level as potential emergencies at Paks NPP. (authors)

Radiation monitoring in the NPP environment, control of radioactivity in NPP-environment system

International Nuclear Information System (INIS)

Egorov, Yu.A.

1987-01-01

Problems of radiation monitoring and control of the NPP-environment system (NPPES) are considered. Radiation control system at the NPP and in the environment provides for the control of the NPP, considered as the source of radioactive releases in the environment and for the environmental radiation climate control. It is shown, that the radiation control of the NPP-environment system must be based on the ecological normalization principles of the NPP environmental impacts. Ecological normalization should be individual for the NPP region of each ecosystem. The necessity to organize and conduct radiation ecological monitoring in the NPP regions is pointed out. Radiation ecological monitoring will provide for both environmental current radiation control and information for mathematical models, used in the NPPES radiation control

[Comparative analysis of the radionuclide composition in fallout after the Chernobyl and the Fukushima accidents].

Science.gov (United States)

Kotenko, K V; Shinkarev, S M; Abramov, Iu V; Granovskaia, E O; Iatsenko, V N; Gavrilin, Iu I; Margulis, U Ia; Garetskaia, O S; Imanaka, T; Khoshi, M

2012-01-01

The nuclear accident occurred at Fukushima Dai-ichi Nuclear Power Plant (NPP) (March 11, 2011) similarly to the accident at the Chernobyl NPP (April 26, 1986) is related to the level 7 of the INES. It is of interest to make an analysis of the radionuclide composition of the fallout following the both accidents. The results of the spectrometric measurements were used in that comparative analysis. Two areas following the Chernobyl accident were considered: (1) the near zone of the fallout - the Belarusian part of the central spot extended up to 60 km around the Chernobyl NPS and (2) the far zone of the fallout--the "Gomel-Mogilev" spot centered 200 km to the north-northeast of the damaged reactor. In the case of Fukushima accident the near zone up to about 60 km considered. The comparative analysis has been done with respect to refractory radionuclides (95Zr, 95Nb, 141Ce, 144Ce), as well as to the intermediate and volatile radionuclides 103Ru, 106Ru, 131I, 134Cs, 137Cs, 140La, 140Ba and the results of such a comparison have been discussed. With respect to exposure to the public the most important radionuclides are 131I and 137Cs. For the both accidents the ratios of 131I/137Cs in the considered soil samples are in the similar ranges: (3-50) for the Chernobyl samples and (5-70) for the Fukushima samples. Similarly to the Chernobyl accident a clear tendency that the ratio of 131I/137Cs in the fallout decreases with the increase of the ground deposition density of 137Cs within the trace related to a radioactive cloud has been identified for the Fukushima accident. It looks like this is a universal tendency for the ratio of 131I/137Cs versus the 137Cs ground deposition density in the fallout along the trace of a radioactive cloud as a result of a heavy accident at the NPP with radionuclides releases into the environment. This tendency is important for an objective reconstruction of 131I fallout based on the results of 137Cs measurements of soil samples carried out at

The RELAP5-Based NPA of the VVER Type Paks NPP

International Nuclear Information System (INIS)

Guba, A.; Toth, I.; Mandy, C.; Stubbe, E.

1999-01-01

NPA is a data driven interactive graphical tool for visualisation of different plant conditions. Data generated by the analysis code RELAP5/MOD3.2 are processed and displayed on a computer monitor. The NPA model of Paks NPP Unit 3 was developed with the aim to demonstrate the phenomena occurring in different transient/accident scenarios. This VVER-specific NPA development is a result of a cooperation between BELGATOM and KFKI-AEKI. (author)

Cleanup of large areas contaminated as a result of a nuclear accident

International Nuclear Information System (INIS)

1989-01-01

The purposes of the report are to provide an overview of the methodology and technology available to clean up contaminated areas and to give preliminary guidance on matters related to the planning, implementation and management of such cleanups. This report provides an integrated overview of important aspects related to the cleanup of very large areas contaminated as a result of a serious nuclear accident, including information on methods and equipment available to: characterize the affected area and the radioactive fallout; stabilize or isolate the contamination; and clean up contaminated urban, rural and forested areas. The report also includes brief sections on planning and management considerations and the transport and disposal of the large volumes of wastes arising from such cleanups. For the purposes of this report, nuclear accidents which could result in the deposition of decontamination over large areas if the outer containment fails badly include: 1) An accident with a nuclear weapon involving detonation of the chemical high explosive but little, if any, nuclear fission. 2) A major loss of medium/high level liquid waste (HLLW) due to an explosion/fire at a storage site for such waste. 3) An accident at a nuclear power plant (NPP), for example a loss of coolant accident, which results in some core disruption and fuel melting. 4) An accident at an NPP involving an uncontrolled reactivity excursion resulting in the violent ejection of a reactor core material and rupture of the containment building. 117 refs, 32 figs, 12 tabs

Six Decades of Nuclear Accidents, Nuclear Compensation, and Issues of Radioactive Waste Management

International Nuclear Information System (INIS)

Boonsuwan, P.; Songjakkeaw, A.

2011-11-01

Thailand has made a serious aim to employ nuclear power by adopting five 1,000 MWt in the 2010 national Power Development Plan (PDP 2010) with the first NPP coming online in 2020. However, after the Fukushima nuclear disaster in March 2011, the National Energy Policy Committee had made the resolution to postpone the plan by 3 years. The post-Fukushima atmosphere does not bode well for the public sentiment towards the proposed programme, especially with regards to safety of an NPP. Nonetheless, during the six decades that NPPs have been in operation in 32 countries worldwide, there are only 19 serious accidents involving fatalities and/or damage to properties in excess of 100 million USD. Out of the three significant accidents - Fukushima nuclear accident (2011), Chernobyl nuclear accident (1986), and Three Miles Island nuclear accident (1979) - only the accident at Three Miles Island occurs during normal operation. Such can be implied that the operation of NPPs does maintain a high level of safety. The current technology on nuclear safety has been advancing greatly to the point that the new NPP design claims to render the possibility of a severe accident resulting in core melting insignificant. Along with the technical improvements, laws and regulations have also be progressing in parallel to adequately compensate and limit the liability of operators in case of a nuclear accident. The international agreements such as the Vienna Convention on Civil Liability for Nuclear Damage and the Convention of the Third Party Liability in the Field of Nuclear Energy had also been established and also the national laws of countries such as the United States and Japan have been implemented to address such issues to the point that victims of a nuclear accidents are adequately and justly compensated. In addition to the issues of nuclear accident, the dilemma in nuclear waste management, especially with regards to the High Level Waste which is highly radioactive while having very

The Impact of Severe Nuclear Accidents on National Decision for Nuclear Decommissioning

Energy Technology Data Exchange (ETDEWEB)

Suh, Young A; Hornibrook, Carol; Yim, Man Sung [KAIST, Daejeon (Korea, Republic of)

2016-05-15

Many researchers have tried to identify the impact of severe nuclear accidents on a country's or international nuclear energy policy [2-3]. However, there is little research on the influence of nuclear accidents and historical events on a country's decision to permanently shutdown an NPP versus international nuclear decommissioning trends. To demonstrate the correlation between a nuclear severe accident and the impact on world nuclear decommissioning, this research reviewed case studies of individual historical events, such as the St. Lucens, TMI, Chernobyl, Fukushima accidents and the series of events leading up to the collapse of the Soviet Union. For validation of the results of these case studies, a statistical analysis was conducted using the R code. This will be useful in explaining how international and national decommissioning strategies are affected by shutdown reasons, i.e. world historical events. The number of permanently shutdown NPPs was selected as an indicator because any relationship between the number of permanently In conclusion, nuclear severe accidents and historical events have an impact on the number of international NPPs that shutdown permanently and cancelled NPP construction. This directly impacts international nuclear decommissioning policy and nuclear energy policy trends. The number of permanently shutdown NPPs was selected as an indicator because any relationship between the number of permanently.

A Preliminary Study on the Containment Integrity following BIT Removal for Kori NPP Unit 3,4

Energy Technology Data Exchange (ETDEWEB)

Song, Dong Soo; Byun, Choong Sup [KEPRI, Nuclear Power Generation Laboratory, Daejeon (Korea, Republic of); Jo, Jong Young [ENERGEO Inc., Sungnam (Korea, Republic of)

2008-05-15

The Boron Injection Tank (BIT) is to provide high concentrated boric acid to the reactor in order to mitigate the consequences of postulated Main Steam Line Break accidents (MSLB). Although BIT plays an important role in mitigating the accident, high concentration of 20,000ppm causes valve leakage, pipe clog, precipitation and continuous heat tracing have to be provided. This paper is for the feasibility study of containment integrity using CONTEMPT code for BIT removal of Kori Nuclear Power Plant (NPP) Unit 3, 4.

A Preliminary Study on the Containment Integrity following BIT Removal for Kori NPP Unit 3,4

International Nuclear Information System (INIS)

Song, Dong Soo; Byun, Choong Sup; Jo, Jong Young

2008-01-01

The Boron Injection Tank (BIT) is to provide high concentrated boric acid to the reactor in order to mitigate the consequences of postulated Main Steam Line Break accidents (MSLB). Although BIT plays an important role in mitigating the accident, high concentration of 20,000ppm causes valve leakage, pipe clog, precipitation and continuous heat tracing have to be provided. This paper is for the feasibility study of containment integrity using CONTEMPT code for BIT removal of Kori Nuclear Power Plant (NPP) Unit 3, 4

Study on the offsite emergency planning against an accident in NPP

International Nuclear Information System (INIS)

Khang, Byung Oui; Lee, Goan Yup; Wu, Jong Sup; Kim, Joo Hag; Lee, Jong Tai; Lee, Jae Eun; Ahn, Chul Hyun; Ahn, Jae Hyun; Park, Dae Woo

2009-12-01

- Proposing effective local nuclear emergency preparedness system against nuclear/radiological accidents. - Proposing improved preparation/operation scheme on emergency response facilities, installations and equipment. - Establishing protection scheme on the general public against nuclear/radiological accidents. - Proposing effective preparation/operation scheme on local radioactive monitoring system. - Establishing effective training/drill scheme on the nuclear emergency preparedness. - Proposing effective technical administrative system of the local government (Busan metropolitan city)

Technology for NPP decantate treatment realized at Kola NPP

International Nuclear Information System (INIS)

Stakhiv, Michael; Avezniyazov, Slava; Savkin, Alexander; Fedorov, Denis; Dmitriev, Sergei; Kornev, Vladimir

2007-01-01

At Moscow SIA 'Radon' jointly with JSC 'Alliance Gamma', the technology for NPP Decantate Treatment was developed, tested and realized at Kola NPP. This technology consists of dissolving the salt residue and subsequent treatment by ozonization, separation of the deposits formed from ozonization and selective cleaning by ferro-cyanide sorbents. The nonactive salt solution goes to an industrial waste disposal site or a repository specially developed at NPP sites for 'exempt waste' products by IAEA classification. This technology was realized at Kola NPP in December 2006 year. At this time more than 1000 m 3 of decantates log time stored are treated. It allows solving very old problem to empty decantates' tanks at NPPs in environmentally safe manner and with high volume reduction factor. (authors)

Chernobyl'-88. Reports of the 1. All-Union scientific and technical meeting on results of accident effect elimination at the Chernobyl' NPP. V. 3. Part 1. Predictions of the variation in environmental radioactivity and radiation doses at the accidental zone

International Nuclear Information System (INIS)

Ignatenko, E.I.

1989-01-01

Information on the prediction of environmental radioactivity in case of general accident at NPP, at reactor site and external zone was presented. Attention was also paid to the prediction of subterranean and ground water contamination, to the modelling and prediction of environmental radioactivity in the Pripyat river water reservoirs, to the population cytogenetic examination, to the prediction of forest state. Data on the realization of radiation monitoring were presented. Features of the modern forms of realization of prevention and correction of neurotic and psychosomatic disorders, rapid methods for the diagnosis of personnel psychophysical state, problems of the prediction of radiation doses to personnel of main Chernobyl' NPP shops and to population in case of its rerelocation in 30-km zone

Assessing the consequences in a nuclear accident scenario at Cernavoda NPP

International Nuclear Information System (INIS)

Margeanu, Sorin; Angelescu, Tatiana

2004-01-01

Having in view a possible nuclear incident, considerable planning is necessary to reduce at manageable levels the types of decisions leading to effective responses concerning the public protection. One of the most important parts of an emergency response plan is the computerized system which allows to predict the radiological impact of the accident and to provide information in a manageable and effective form for evaluating alternative countermeasure strategies in the various stages of the accident. In this paper the PC-COSYMA results for early containment failure of a CANDU reactor are presented. The deterministic health effects arising in nuclear accident situation are also presented. As source term we have used the core inventory obtained with ORIGEN computer code. The essential input parameters for PC-COSYMA computer code are also done. (authors)

The enhancement of Ignalina NPP in design and operational safety

International Nuclear Information System (INIS)

Negrivoda, G.

1999-01-01

Enhancement of Ignalina NPP design include: core design improvements; fuel channel integrity (multiple pressure tube rupture); improvements of shutdown systems; improvements of instrumentation and control devices; containment strength and tightness; design basis accident analysis; improvements of safety and support systems; seismic safety enhancement; Year 2000 project; cracks in pipes. Enhancement of operational safety includes: quality assurance; configuration management; safety management and safety culture; emergency operating procedures; training and full scope simulator; in-service inspection; fire protection and ageing monitoring and management

Pre feasibility assesment of smart off shore NPP (ONPP) of gravity based-structure type for Indonesia

International Nuclear Information System (INIS)

Sahala M Lumbanraja; Dharu Dewi

2017-01-01

The SMART ONPP GBS-type is a small power (100 MWe) pressurized water reactor, and located at offshore site. This technology was developed based on existing SMART nuclear technology & offshore drilling technology with a gravity-based type of structure. This is a response to the post-Fukushima accident, Japan (2011), to improve the safety system, overcome the land limitations, and minimize the public resistance to NPP cases in the inland. The purpose of this paper is to assess the pre-feasibility of the implementation of GBS NPP in Indonesia both in terms of technological feasibility and regulation. The method used is literature review and continued with descriptive analysis. The result shows that SMART ONPP are worth considering because they offer improved aspects of safety, offshore tread availability, and better public acceptance. So far, this NPP can not be implemented in Indonesia because it is hampered by Government Regulation No. 2 year 2014 regarding Licensing of Nuclear Installation Safety and Security which stipulates that site is an inland location and NPP built in Indonesia should be proven. (author)

Fukushima. The accident sequence and important causes. Pt. 1/3

International Nuclear Information System (INIS)

Pistner, Christoph

2013-01-01

On March 11, 2011 a strong earthquake at the east coast of Japan and a subsequent tsunami caused severe damage at the NPP site of Fukushima Daiichi. The article covers the fundamental safety aspects of the accident progress according to the state of knowledge. The principles of nuclear technology and reactor safety are summarized in order to allow the understanding of the accidental sequence. Even two years after the disaster many questions on the sequence of accident events are still open.

Crisis, criticism, change: Regulatory reform in the wake of nuclear accidents

International Nuclear Information System (INIS)

Sexton, Kimberly A.; )

2015-01-01

Accidents are a forcing function for change in the nuclear industry. While these events can shed light on needed technical safety reforms, they can also shine a light on needed regulatory system reforms. The TEPCO Fukushima Daiichi nuclear power plant (NPP) accident in Japan is the most recent example of this phenomenon, but it is not the only one. In the wake of the three major accidents that have occurred in the nuclear power industry - Three Mile Island (TMI) in the United States; Chernobyl in Ukraine, in the former Soviet Union; and the Fukushima Daiichi NPP accident in Japan - a commission or committee of experts issued a report (or reports) with harsh criticism of the countries' regulatory system. And each of these accidents prompted changes in the respective regulatory systems. In looking at these responses, however, one must ask if this crisis, criticism, change approach is working and whether regulatory bodies around the world should instead undertake their own systematic reviews, un-prompted by crisis, to better ensure safety. This article will attempt to analyse the issue of regulatory reform in the wake of nuclear accidents by first providing a background in nuclear regulatory systems, looking to international and national legal frameworks. Next, the article will detail a cross-section of current regulatory systems around the world. Following that, the article will analyse the before and after of the regulatory systems in the United States, the Soviet Union and Japan in relation to the TMI, Chernobyl and Fukushima accidents. Finally, taking all this together, the article will address some of the international and national efforts to define exactly what makes a good regulator and provide conclusions on regulatory reform in the wake of nuclear accidents. (author)

Development of the methodology and approaches to validate safety and accident management

International Nuclear Information System (INIS)

Asmolov, V.G.

1997-01-01

The article compares the development of the methodology and approaches to validate the nuclear power plant safety and accident management in Russia and advanced industrial countries. It demonstrates that the development of methods of safety validation is dialectically related to the accumulation of the knowledge base on processes and events during NPP normal operation, transients and emergencies, including severe accidents. The article describes the Russian severe accident research program (1987-1996), the implementation of which allowed Russia to reach the world level of the safety validation efforts, presents future high-priority study areas. Problems related to possible approaches to the methodological accident management development are discussed. (orig.)

The international cooperation using the example of the reactor accident in Chernobyl

International Nuclear Information System (INIS)

Molitor, Norbert

2017-01-01

The explosion of the reactor unit 4 of the NPP Chernobyl and the subsequent fire was up to now the most severe accident in the civil nuclear industry. The consequences of the accident far outside the Ukraine and the former Soviet Union demonstrated that nuclear safety is a trans-border challenge. The mitigation of the accident consequences and the recovery of safety for the public, the workers and the environment required outstanding efforts and the international cooperation was of significant importance. The contribution discusses experiences and practical aspects of the international cooperation and implications for future cooperation options for the long-term removal of accident consequences.

2. International conference. Radiobiological consequences of nuclear accidents; Russian-Norwegian Satellite Symposium on nuclear accidents, radioecology and health. Abstracts. Part 2

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

Materials on radiobiological effect of ionizing radiation under emergency situations are presented. The radiation contamination of environmental media after the Chernobyl NPP accident (ground, earth and water ecological systems), effect of external and internal irradiation on the inhabitants of the region are estimated. Time characteristic of radiation risk of originating tumors and genetic injuries is given.

2. International conference. Radiobiological consequences of nuclear accidents; Russian-Norwegian Satellite Symposium on nuclear accidents, radioecology and health. Abstracts. Part 2

International Nuclear Information System (INIS)

1994-01-01

Materials on radiobiological effect of ionizing radiation under emergency situations are presented. The radiation contamination of environmental media after the Chernobyl NPP accident (ground, earth and water ecological systems), effect of external and internal irradiation on the inhabitants of the region are estimated. Time characteristic of radiation risk of originating tumors and genetic injuries is given

Characteristics of Hydrogen Monitoring Systems for Severe Accident Management at a Nuclear Power Plant

Science.gov (United States)

Petrosyan, V. G.; Yeghoyan, E. A.; Grigoryan, A. D.; Petrosyan, A. P.; Movsisyan, M. R.

2018-02-01

One of the main objectives of severe accident management at a nuclear power plant is to protect the integrity of the containment, for which the most serious threat is possible ignition of the generated hydrogen. There should be a monitoring system providing information support of NPP personnel, ensuring data on the current state of a containment gaseous environment and trends in its composition changes. Monitoring systems' requisite characteristics definition issues are considered by the example of a particular power unit. Major characteristics important for proper information support are discussed. Some features of progression of severe accident scenarios at considered power unit are described and a possible influence of the hydrogen concentration monitoring system performance on the information support reliability in a severe accident is analyzed. The analysis results show that the following technical characteristics of the combustible gas monitoring systems are important for the proper information support of NPP personnel in the event of a severe accident at a nuclear power plant: measured parameters, measuring ranges and errors, update rate, minimum detectable concentration of combustible gas, monitoring reference points, environmental qualification parameters of the system components. For NPP power units with WWER-440/270 (230) type reactors, which have a relatively small containment volume, the update period for measurement results is a critical characteristic of the containment combustible gas monitoring system, and the choice of monitoring reference points should be focused not so much on the definition of places of possible hydrogen pockets but rather on the definition of places of a possible combustible mixture formation. It may be necessary for the above-mentioned power units to include in the emergency operating procedures measures aimed at a timely heat removal reduction from the containment environment if there are signs of a severe accident phase

CFD analysis of the temperature field in emergency pump room in Loviisa NPP

Energy Technology Data Exchange (ETDEWEB)

Rämä, Tommi, E-mail: tommi.rama@fortum.com [Fortum Power and Heat, P.O.B. 100, FI-00048 Fortum (Finland); Toppila, Timo, E-mail: timo.toppila@fortum.com [Fortum Power and Heat, P.O.B. 100, FI-00048 Fortum (Finland); Kelavirta, Teemu, E-mail: teemu.kelavirta@fortum.com [Fortum Power and Heat, Loviisa Power Plant, P.O.B. 23, FI-07901 Loviisa (Finland); Martin, Pasi, E-mail: pasi.martin@fortum.com [Fortum Power and Heat, Loviisa Power Plant, P.O.B. 23, FI-07901 Loviisa (Finland)

2014-11-15

Highlights: • Laser scanned room geometry from Loviisa NPP was utilized for CFD simulation. • Uncertainty of CFD simulation was estimated using the Grid Convergence Index. • Measured temperature field of pump room was reproduced with CFD simulation. - Abstract: In the Loviisa Nuclear Power Plant (NPP) six emergency pumps belonging to the same redundancy are located in the same room. During a postulated accident the cooling of the room is needed as the engines of the emergency pumps generate heat. Cooling is performed with fans blowing air to the upper part of the room. Temperature limits have been given to the operating conditions of the main components in order to ensure their reliable operation. Therefore the temperature field of the room is important to know. Temperature measurements were made close to the most important components of the pump room to get a better understanding of the temperature field. For these measurements emergency pumps and cooling fan units were activated. To simulate conditions during a postulated accident additional warm-air heaters were used. Computational fluid dynamic (CFD) simulations were made to support plant measurements. For the CFD study one of the pump rooms of Loviisa NPP was scanned with a laser and this data converted to detailed 3-D geometry. Tetrahedral computation grid was created inside the geometry. Grid sensitivity studies were made, and the model was then validated against the power plant tests. With CFD the detailed temperature and flow fields of the whole room were produced. The used CFD model was able to reproduce the temperature field of the measurements. Two postulated accident cases were simulated. In the cases the operating cooling units were varied. The temperature profile of the room changes significantly depending on which units are cooling and which only circulating the air. The room average temperature stays approximately the same. The simulation results were used to ensure the acceptable operating

The Fukushima Daiichi Accident. Technical Volume 4/5. Radiological Consequences

International Nuclear Information System (INIS)

2015-08-01

This technical volume describes the consequences associated with radioactivity and radiation from the accident at the Fukushima Daiichi nuclear power plant (NPP) for people and the environment. A number of international organizations have already issued reports on the potential health and environmental consequences of the accident, notably the World Health Organization (WHO) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The intention of the assessments presented in this volume is to build on their work, using more recent data where available. Quantitative information arising from both personal and environmental monitoring has been provided by the Government of Japan. Section 4.1 provides the best estimates of the magnitude and form of radioactive releases during the accident to the atmosphere and directly into the surrounding sea. It also explains the movement of the discharged radionuclides through air and water and the eventual deposition of the atmospheric activity on land in Japan and other countries worldwide, as well as on the open oceans. The goal is to provide a consolidated repository of information on releases to, and levels of radionuclides in, the environment. Some of this information is used in the analyses in subsequent sections of this volume. Section 4.2 gives an overview of exposures to the main groups of emergency workers at the Fukushima Daiichi NPP, to groups of off-site workers and to members of the public. Where sufficient data are available, average effective dose and thyroid equivalent doses derived from personal measurements are compared with the results of previous assessments for specific locations, population groups and time periods. Section 4.3 summarizes relevant aspects of the system of radiation protection in place at the time of the accident. It includes an overview of the legislation and guidance used to implement the radiation protection framework in Japan. This section also provides a

Accidents with nuclear power plants, ch. 11

International Nuclear Information System (INIS)

Anon.

1976-01-01

A recalculation of the consequences of nuclear power plant accidents is presented taking into account different parameters or different quantities than those usually accepted. A case study of a nuclear power plant planned for the Eems-river estuary in the Netherlands is presented

Methods and means for improving the man-machine systems for NPP control

International Nuclear Information System (INIS)

Konstantinov, L.V.; Rakitin, I.D.

1984-01-01

Consideration is being given to the role of ''human factors'' and the ways of improving the man-machine interaction in NPP control and safety systems (CSS). Simulators and tAaining equipment on the basis of dynamic power unit models used for training and improving skill of NPP operatoAs, as well as for mastering collective actions of personnel under accidental conditions are considered in detail. The most perfect program complexes for fast NPP diagnostics and theiA pealization in the Federal Republic of Germany, Japan, Canada, the USA and other countries are described. A special attention is paid to the means and methods of videoterminal dialogue operator interaction with an object both in normal and extreme situations. It is noted that the problems of the man-machine interaction have become the subject of study only in the end of 70s after analyzing the causes of the Three-Mile-Island accident (USA). Publications dealing with the development of perspective control rooms for NPP were analyzed. It was concluded that radical changes both in equipment and principles of organizing the personnel activity will take place in the nearest future. They will be based on the progress in creating dialogue means and computers of the fourth and fifth generations as well as on engineering and psychological and technical aspects of designing

IPEEE Review of other external events of the NPP Asco; Revision del IPEEE de sucesos externos de C.N. Asco

Energy Technology Data Exchange (ETDEWEB)

Canadell, F.; Aleman, A.; Beltran, F.; Pifarre, D.; Hernandez, H.; Gasca, C.

2011-07-01

Within the process of maintaining and updating the risk analysis of the NPP Asco, results from the review of the vulnerability study of the plant against severe accidents caused by external success (Individual Plant Examination of External Events, IPEEE).

Comparison of Severe Accident Results Among SCDAP/RELAP5, MAAP, and MELCOR Codes

International Nuclear Information System (INIS)

Wang, T.-C.; Wang, S.-J.; Teng, J.-T.

2005-01-01

This paper demonstrates a large-break loss-of-coolant accident (LOCA) sequence of the Kuosheng nuclear power plant (NPP) and station blackout sequence of the Maanshan NPP with the SCDAP/RELAP5 (SR5), Modular Accident Analysis Program (MAAP), and MELCOR codes. The large-break sequence initiated with double-ended rupture of a recirculation loop. The main steam isolation valves (MSIVs) closed, the feedwater pump tripped, the reactor scrammed, and the assumed high-pressure and low-pressure spray systems of the emergency core cooling system (ECCS) were not functional. Therefore, all coolant systems to quench the core were lost. MAAP predicts a longer vessel failure time, and MELCOR predicts a shorter vessel failure time for the large-break LOCA sequence. The station blackout sequence initiated with a loss of all alternating-current (ac) power. The MSIVs closed, the feedwater pump tripped, and the reactor scrammed. The motor-driven auxiliary feedwater system and the high-pressure and low-pressure injection systems of the ECCS were lost because of the loss of all ac power. It was also assumed that the turbine-driven auxiliary feedwater pump was not functional. Therefore, the coolant system to quench the core was also lost. MAAP predicts a longer time of steam generator dryout, time interval between top of active fuel and bottom of active fuel, and vessel failure time than those of the SR5 and MELCOR predictions for the station blackout sequence. The three codes give similar results for important phenomena during the accidents, including SG dryout, core uncovery, cladding oxidation, cladding failure, molten pool formulation, debris relocation to the lower plenum, and vessel head failure. This paper successfully demonstrates the large-break LOCA sequence of the Kuosheng NPP and the station blackout sequence of the Maanshan NPP

Feed water distribution pipe replacement at Loviisa NPP

Energy Technology Data Exchange (ETDEWEB)

Savolainen, S.; Elsing, B. [Imatran Voima Loviisa NPP (Finland)

1995-12-31

Imatran Voima Oy operates two WWER-440 reactors. Unit 1 has been operating since 1977 and unit 2 since 1981. First damages of feed water distribution (FWD) pipe were observed in 1989. The FWD-pipe T-connection had suffered from severe erosion corrosion damages. Similar damages have been been found also in other WWER-440 type NPPs. In 1989 the nozzles of the steam generator YB11 were inspected. No signs of the damages or signs of erosion were detected. The first damaged nozzles were found in 1992 in steam generators of both units. In 1992 it was started studying different possibilities to either repair or replace the damaged FWD-pipes. Due to the difficult conditions for repairing the damaged nozzles it was decided to study different FWD-pipe constructions. In 1991 two new feedwater distributors had been implemented at Dukovany NPP designed by Vitckovice company. Additionally OKB Gidropress had presented their design for new collector. In spring 1994 all the six steam generators of Rovno NPP unit 1 were replaced with FWD-pipes designed by OKB Gidropress. After the implementation an experimental program with the new systems was carried out. Due to the successful experiments at Rovno NPP Unit 1 it was decided to implement `Gidropress solution` during 1994 refueling outage into the steam generator YB52 at Loviisa 2. The object of this paper is to discuss the new FWD-pipe and its effects on the plant safety during normal and accident conditions. (orig.).

Feed water distribution pipe replacement at Loviisa NPP

Energy Technology Data Exchange (ETDEWEB)

Savolainen, S; Elsing, B [Imatran Voima Loviisa NPP (Finland)

1996-12-31

Imatran Voima Oy operates two WWER-440 reactors. Unit 1 has been operating since 1977 and unit 2 since 1981. First damages of feed water distribution (FWD) pipe were observed in 1989. The FWD-pipe T-connection had suffered from severe erosion corrosion damages. Similar damages have been been found also in other WWER-440 type NPPs. In 1989 the nozzles of the steam generator YB11 were inspected. No signs of the damages or signs of erosion were detected. The first damaged nozzles were found in 1992 in steam generators of both units. In 1992 it was started studying different possibilities to either repair or replace the damaged FWD-pipes. Due to the difficult conditions for repairing the damaged nozzles it was decided to study different FWD-pipe constructions. In 1991 two new feedwater distributors had been implemented at Dukovany NPP designed by Vitckovice company. Additionally OKB Gidropress had presented their design for new collector. In spring 1994 all the six steam generators of Rovno NPP unit 1 were replaced with FWD-pipes designed by OKB Gidropress. After the implementation an experimental program with the new systems was carried out. Due to the successful experiments at Rovno NPP Unit 1 it was decided to implement `Gidropress solution` during 1994 refueling outage into the steam generator YB52 at Loviisa 2. The object of this paper is to discuss the new FWD-pipe and its effects on the plant safety during normal and accident conditions. (orig.).

Safety regulation - twenty years after Chernobyl accident

International Nuclear Information System (INIS)

Aleksashin, P.P.; Bukrinskij, A.M.; Gordon, B.G.

2006-01-01

Main stages of development, successes, achievements and shortcomings of activity of supervision body after the Chernobyl NPP accident are analysed. The estimation of the realized variations of the functions of the state supervision department is carried out. Results of the twenty year period of improvement of the supervision body are summed up. The measures for increasing the efficiency of the supervision body operation are outlined [ru

Decommissioning of Brennilis NPP

International Nuclear Information System (INIS)

Baize, Jean-Marc

1998-01-01

This EDF press communique give information related to the decommissioning of the Brennilis NPP. The following five items are developed in this report: 1. the level-2 decommissioning operations at the Brennilis NPP; 2. the Brennilis NPP, a pilot operation from the commissioning up to the decommissioning; 3. history of the Brennilis NPP decommissioning; 4. the types of radioactive wastes generated by the Brennilis NPP decommissioning; 5. the Brennilis NPP - a yard management as a function of the wastes. The document contains also seven appendices addressing the following subjects: 1. the share of decommissioning assigned to EDF and the decommissioning steps; 2. the EDF installations in course of decommissioning; 3. the CEA decommissioned installations or in course of decommissioning; 4. regulations; 5. costs; 6. waste management - principles; 7. data on the decommissioning yard

Pre-operational Study on Impact of Temelin NPP on Hydrosphere

International Nuclear Information System (INIS)

Hanslik, E.J.

1999-01-01

Beginning of the construction of Temelin Nuclear Power Plant (NPP) in south Bohemia (CR) dates back to 1986. It is planned that the first water-cooled reactor could be put into operation in 2000. A research project, funded from the national budget and carried out under supervision of the Czech Ministry of Environment, has been aimed at examining pre-operational environmental conditions (a reference level) in terms of concentrations of radioactive and non-radioactive polluting substances in components of the environment, particularly in hydrosphere, and at predicting possible impacts of future operation of Temelin NPP. Special attention paid to the hydrosphere is associated with requirements for protection of water quality in the Vltava River, which serves as water resource for Prague capital. The paper summarises selected interim results of the project, particularly those concerning per-operational environmental conditions and impacts predicted for standard operation of the plant. More detailed description of the results including possible impacts of the so called maximum project accident is presented in (1)

Reliability research based experience with systems and events at the Kozloduy NPP units 1-4

Energy Technology Data Exchange (ETDEWEB)

Khristova, R; Kaltchev, B; Dimitrov, B [Energoproekt, Sofia (Bulgaria); Nedyalkova, D; Sonev, A [Kombinat Atomna Energetika, Kozloduj (Bulgaria)

1996-12-31

An overview of equipment reliability based on operational data of selected safety systems at the Kozloduy NPP is presented. Conclusions are drawn on reliability of the service water system, feed water system, emergency power supply - category 2, emergency high pressure ejection system and spray system. For the units 1-4 all recorded accident protocols in the period 1974-1993 have been processed and the main initiators identified. A list with 39 most frequent initiators of accidents/incidents is compiled. The human-caused errors account for 27% of all events. The reliability characteristics and frequencies have been calculated for all initiating events. It is concluded that there have not been any accidents with consequences for fuel integrity or radioactive release. 14 refs.

Reliability research based experience with systems and events at the Kozloduy NPP units 1-4

International Nuclear Information System (INIS)

Khristova, R.; Kaltchev, B.; Dimitrov, B.; Nedyalkova, D.; Sonev, A.

1995-01-01

An overview of equipment reliability based on operational data of selected safety systems at the Kozloduy NPP is presented. Conclusions are drawn on reliability of the service water system, feed water system, emergency power supply - category 2, emergency high pressure ejection system and spray system. For the units 1-4 all recorded accident protocols in the period 1974-1993 have been processed and the main initiators identified. A list with 39 most frequent initiators of accidents/incidents is compiled. The human-caused errors account for 27% of all events. The reliability characteristics and frequencies have been calculated for all initiating events. It is concluded that there have not been any accidents with consequences for fuel integrity or radioactive release. 14 refs

Modeling of coherent heat and mass-exchange phenomena for a specter of primary circuit leaks in a NPP with WWER-1000 type reactor

International Nuclear Information System (INIS)

Stanev, I.; Mladenova, S.; Hadjiev, V.

2004-01-01

Subject of study are the inter-relations between the primary leak parameters, the containment pressure and the functioning of the WWER-1000/V320 plant systems. The model includes systems for normal operation and safety systems, which are actuated in the initial stage of the accident. The studied specter of primary leaks includes diameters from 10 to 60 mm. The model is based on the design features of unit 5 in NPP Kozloduy. This paper presents a fragment of the work, performed jointly by Atoma Consult Ltd and NPP Kozloduy Plc on the validation of the symptom oriented emergency operation procedures for units 5 and 6 in NPP Kozloduy. (authors)

Consequences of the Chernobyl accident in Lithuania

International Nuclear Information System (INIS)

Mastauskas, A.; Nedvecktaite, T.; Filistovic, V.

1997-01-01

After the Chernobyl accident of 26 April, 1986, population dose assessment favours the view that the radiation risk of population effected by the early fallout would be different from that in regions contaminated later. Taking into account the short half-time of the most important radioactive iodine isotopes, thyroid disorders would be expected mainly to follow the early fallout distribution. At the time of accident at Unite 4 of the Chernobyl NPP, surface winds were from the Southeast. The initial explosions and heat carried volatile radioactive materials to the 1,5 km height, from where they were transported over the Western part of Belarus, Southern and Western part of Lithuania toward Scandinavian countries. Thus the volatile radioiodine and some other radionuclides were detected in Lithuania on the very first days after the accident. The main task of the work - to conduct short Half-time radioiodine and long half-time radiocesium dose assessment of Lithuanian inhabitants a result of the early Chernobyl accident fallout

Decommissioning of NPP A-1

International Nuclear Information System (INIS)

Anon

2009-01-01

In this presentation the Operation history of A1 NPP, Project 'Decommissioning of A1 NPP' - I stage, Project 'Decommissioning of A1 NPP ' - II stage and Next stages of Project 'Decommissioning of A1 NPP ' are discussed.

Cohort formation for epidemiological study of medical consequences of the Chernobyl accident

International Nuclear Information System (INIS)

Rozhko, A.V.; Masyakin, V.B.; Vlasova, N.G.

2008-01-01

Belarus State Registry of the Chernobyl-affected population contains information about 276 000 residents of the Republic of Belarus exposed due to the Chernobyl NPP accident. Evidently, the population who lived in the evacuation zone was exposed mostly to radiation and also people participating in the liquidation of the Chernobyl accident consequences (emergency workers) within this zone in early post accident period of the catastrophe. Taking into account this criterion, we singled out the group out of all data files including all people who stayed in the evacuation zone not later than on May 31, 1986. The total number of the group made up 39 548 people including 4251 people who were under 18 at the moment of the accident. By preliminary estimation the number of person-years taking into account the deceased and left out of observation made up at the beginning of 2007- 735 600. During the period since 1986 there was detected 2671 cases of malignant tumors in the cohort and among people who were children and adolescents in 1986 there was registered 106 cases of malignant tumors (82% -thyroid cancer). Among 7483 of the deceased, malignant tumors is the cause of death at 1260 people. At present the real number of alive and remained subjects under observation makes up 25359 people including 2321 people who were under 18 at the moment of the accident. This group will form the base for further prospective research aiming at assessment of medical consequences of the Chernobyl NPP accident. (author)

Environmental Problems Associated with Decommissioning of Chernobyl Power Plant Cooling Pond

Science.gov (United States)

Foley, T. Q.; Oskolkov, B. Y.; Bondarkov, M. D.; Gashchak, S. P.; Maksymenko, A. M.; Maksymenko, V. M.; Martynenko, V. I.; Jannik, G. T.; Farfan, E. B.; Marra, J. C.

2009-12-01

Decommissioning of nuclear power plants and other nuclear fuel cycle facilities associated with residual radioactive contamination is a fairly pressing issue. Significant problems may result from decommissioning of cooling ponds. The Chernobyl Nuclear Power Plant (ChNPP) Cooling Pond is one of the largest self-contained bodies of water in the Chernobyl Region and Ukrainian Polesye with a water surface area of 22.9 km2. The major hydrological feature of the ChNPP Cooling Pond is that its water level is 6-7 m higher than the water level in the Pripyat River and water losses due to seepage and evaporation are replenished by pumping water from the Pripyat River. In 1986, the accident at the ChNPP #4 Reactor Unit significantly contaminated the ChNPP Cooling Pond. According to the 2001 data, the total radionuclide inventory in the ChNPP Cooling Pond bottom deposits was as follows: 16.28 ± 2.59 TBq for 137Cs; 2.4 ± 0.48 TBq for 90Sr, and 0.00518 ± 0.00148 TBq for 239+240Pu. Since ChNPP is being decommissioned, the ChNPP Cooling Pond of such a large size will no longer be needed and cost effective to maintain. However, shutdown of the water feed to the Pond would expose the contaminated bottom deposits and change the hydrological features of the area, destabilizing the radiological and environmental situation in the entire region in 2007 - 2008, in order to assess potential consequences of draining the ChNPP Cooling Pond, the authors conducted preliminary radio-ecological studies of its shoreline ecosystems. The radioactive contamination of the ChNPP Cooling Pond shoreline is fairly variable and ranges from 75 to 7,500 kBq/m2. Three areas with different contamination levels were selected to sample soils, vegetation, small mammals, birds, amphibians, and reptilians in order to measure their 137Cs and 90Sr content. Using the ERICA software, their dose exposures were estimated. For the 2008 conditions, the estimated dose rates were found to be as follows: amphibians - 11

Fracture mechanics analysis and evaluation for the RPV of the Chinese Qinshan 300 MW NPP and PTS

International Nuclear Information System (INIS)

He Yinbiao; Isozaki, Toshikuni

2000-03-01

One of the most severe accident conditions of a reactor pressure vessel (RPV) in service is the loss of coolant accident (LOCA). Cold safety injection water is pumped into the downcomer of the RPV through inlet nozzles, while the internal pressure may remain at high level. Such an accident is called pressurized thermal shock (PTS) transient according to 10 CFR 50.61 definition. This paper illustrates the fracture mechanics analysis for the existing RPV of the Chinese Qinshan 300 MW nuclear power plant (NPP) under the postulated PTS transients that include SB-LOCA, LB-LOCA of Qinshan NPP and Rancho Seco transients. 3-D models with the flaw depth range a/w=0.05∼0.9 (a: flaw depth; w: wall thickness) were used to probe what kind of flaw and what kind of transient are most dangerous for the RPV in the end of life (EOF). Both the elastic and elastic-plastic material models were used in the stress analysis and fracture mechanics analysis. The different types of flaw and the influence of the stainless steel cladding on the fracture analysis were investigated for different PTS transients. comparing with the material initiation crack toughness K IC , the fracture evaluation for the RPV in question under PTS transients are performed in this paper. (author)

Transfer of fallout radionuclides by Fukushima NPP accident from tree crown to forest ecosystem

Science.gov (United States)

Onda, Y.; Kato, H.; Wakahara, T.; Kawamori, A.; Tsujimura, M.

2011-12-01

Radioactive contamination has been detected in Fukushima and the neighboring prefectures due to the nuclear accident at Fukushima Daiichi Nuclear Power Plant (NPP) following the earthquake and tsunami on 11 March 2011. The total deposition of radioactive materials in fallout samples for 137Cs ranged from 0.02to >10 M Bq/m2 for Cs-137. Experimental catchments have been established in Yamakiya district, Kawamata Town, Fukushima prefecture, located about 35 km from Fukushima power plant, and designated as the evacuated zone. Approximate Cs-137 fallout in this area is 200-600k Bq/m2. We established 3 forest sites: broad leaf tree forest and two Japanese cedar forest plantation (young and mature). In each site we installed towers of 8-12 meters. Using these towers, we sampled tree leaves, and measure Cs-137 and Cs-134 in the laboratory, and also we have measure Cs-137, Cs-134 content at various height in each forest using a portable High Purity Germanium (HPGe) detector (Ortech; Detective-EX). We also measured the throughfall, stem flow and litter fall inside of the forest. In each site, we establish the 20 m x 20 m plot to monitor the changes of fallout radionuclides through time with the portable HPGe detector. The monitoring is now ongoing but we found significant amount of Cs-134 and Cs-137 has been trapped by cedar forest plantations especially young trees, but not so much in broad leaf trees. The trapped Cs-137 and Cs-134 is then washed by rainfall and found into throughfall. Therefore, in forest ecosystems, the fallout has been still ongoing, and and effective remediation method in forested area (especially cedar plantation) can be removing the trees.

Psychic pathology of anthropogenic accidents at risk enterprises

International Nuclear Information System (INIS)

Pukhovskij, N.N.

1993-01-01

The literary data on the clinic and pathogenesis distinctions of traumatic and posttraumatic stress following the accidents are analyzed. The inner contradictory character of the Chernobyl NPP operators reaction to psychodraumatic situation is revealed. A number of concepts liable to discussion is given: inner contradiction of the reactions to traumatic stress on account of accidents at risk cuterprises puts forward the way for psychology evolution in process, besides, posttraumatic stress may be considered as one of the stages of such evolution; the misuse of spirits by the persons with traumatic stress appeared on account of accidents at risk enterprises puts forward the way for the subsequent evolution towards psychic degeneration; the prevailing effect of the reality denial among the personnel of the risk enterprises may form a muthcreative attitude to technical sphere and play a certain role in the emergence of anthropogenic accidents at these enterprises. 22 refs

Realistic analysis of steam generator tube rupture accident in Angra-1 reactor

International Nuclear Information System (INIS)

Fontes, S.W.F.

1989-01-01

This paper presents the analysis of different scenarios for a Steam Generator Tube Rupture accident (SGTR) in Angra-1 NPP. The results and conclusions will be used as support in the preparation of the emergency situation programs for the plant. For the analysis a SGTR simulation was performed with RETRAN-02 code. The results indicated that the core integrity and the plant itself will not affect by small ruptures in SG tubes. For large ruptures the analysis demonstrated that the accident may have harmful consequences if the operator do not actuate effectively since the initial moments of the accidents. (author) [pt

RBMK-1500 accident management for loss of long-term core cooling

International Nuclear Information System (INIS)

Uspuras, E.; Kaliatka, A.

2001-01-01

Results of the Level 1 probabilistic safety assessment of the Ignalina NPP has shown that in topography of the risk, transients dominate above the accidents with LOCAs and failure of the core long-term cooling are the main factors to frequency of the core damage. Previous analyses have shown, that after initial event, as a rule, the reactivity control, as well as short-term and intermediate cooling are provided. However, the acceptance criteria of the long-term cooling are not always carried out. It means that from this point of view the most dangerous accident scenarios are the scenarios related to loss of the core long-term cooling. On the other hand, the transition to the core condition due to loss of the long-term cooling specifies potential opportunities for the management of the accident consequences. Hence, accident management for the mitigation of the accident consequences should be considered and developed. The most likely initiating event, which probably leads to the loss of long term cooling accident, is station blackout. The station blackout is the loss of normal electrical power supply for local needs with an additional failure on start-up of all diesel generators. In the case of loss of electrical power supply MCPs, the circulating pumps of the service water system and MFWPs are switched-off. At the same time, TCV of both turbines are closed. Failure of diesel generators leads to the non-operability of the ECCS long-term cooling subsystem. It means the impossibility to feed MCC by water. The analysis of the station blackout for Ignalina NPP was performed using RELAP5 code. (author)

Contamination dynamics in fallouts, pasturable vegetation and milk in Leningrad distrist after Chernobyl accident

International Nuclear Information System (INIS)

Nedbaevskaya, N.A.; Sanzharova, N.I.; Blinova, L.D.; Kryshev, I.I.; Aleksakhin, R.M.

1991-01-01

Radiation monitoring of individual elements of agroecosystem in the area of the Leningrad NPP is carried out with the purpose of studying the concentration dynamics of radioisotopes in the atmosphere resulting from the accident at the Chernobyl NPP. The γ-radiation dose rate on the terrain, content and radionuclide composition of atmospheric fallout, content of γ-emitting isotopes in the soil and plants at pastures is monitored from April up to September 1986; radioisotope content in cow milk by pasturing is determined

Preparedness and planning for nuclear accidents at national level

International Nuclear Information System (INIS)

Shiukshta, A.

1998-01-01

National plan for the protection of population in the case in nuclear accident at Ignalina NPP is presented. The plan was elaborated and approved in 1995, tested in a number of training and practical operations and positively evaluated by experts. The plan provides for measures of protection, their scope, schedule, executive officers and organizations and procedure of implementation

Knowledge Management Learned from Decommissioning and Environmental Remediation after an Unexpected Radiological Contamination Occurred at Fukushima Dai-ichi NPP Accident

International Nuclear Information System (INIS)

Inoue, T.

2016-01-01

Full text: The Fukushima Dai-ichi Nuclear Power Plant (NPP) Accident resulted in severe damage of cores in units 1 to 3, and subsequently entailed not only contamination of facility but also widely-spread radiological contamination in environment due to the release of radioactive nuclides. Decommissioning activities will require at least 30–40 years with various stages of operation, such as contaminated water treatment, decontamination of reactor buildings, retrieval of spent fuel (SF) from SF pools, inspection of primary containment vessel (PCV) and reactor pressure vessel (RPV), and retrieval and further management of damaged fuel and melted debris. Especially, a water injection for core cooling is a pressing issue to stabilize the melted debris, which leads to produce a large amount of contaminated water. Environmental remediation is a crucial issue to return a normal life for local residents. On-site cleaning and off-site remediation produce various kinds and enormous amount of contaminated material with low to high radioactivity. Knowledge management of on-site and off-site issues over generation are critical to achieve the cleaning and remediation requiring a couple of decades. In addition, knowledge obtained through a long term-operation should be shared globally. (author

Post-accident monitoring systems in Prototype Fast Breeder Reactor

International Nuclear Information System (INIS)

Suriya Murthy, N.; Sivasailanathan, Vidhya; Ananth, Allu; Roy, Kallol

2018-01-01

PFBR is a 500 MW(e) MOX fueled and sodium cooled fast reactor (SFR) under advanced stage of commissioning at Kalpakkam. Currently, the main vessel is preheated and sodium has been charged into two secondary loops that are operated in recirculation mode. In order to characterize the radiation field and contamination, the workplace monitoring is undertaken using installed monitors that are commissioned and made operational. This helps to ensure radiological protection during normal operating conditions. On the other hand, radiological monitoring in emergency conditions is quite different. For undertaking the mitigative accident management, a set of specialized nuclear instruments called post-accident monitoring systems (PAMS) which include radiation monitors are stipulated. The Fukushima Daiichi accident emphasized the importance and need for reliable accident monitoring instrumentation to indicate the safety functions during the progression and aftermath of accident in NPP. In PFBR, the PAMS are integrated with other monitoring systems in design stage itself to manage the measurements and indicating the safety functions for implementing EOP and SAMG

Interrogations to Learn from the Fukushima Accident

International Nuclear Information System (INIS)

Gisquet, E.; Jeffroy, F.

2016-01-01

On March 11, 2011, an earthquake in eastern Japan caused the reactors in operation at the Fukushima Daiichi nuclear power plant (NPP) to trip. The emergency generators started and then suddenly failed following the tsunami. The cooling water injection system no longer worked. Suddenly plunged into total darkness, the operators had to manage the accident. Starting from the official reports and testimonies on the Fukushima accident, IRSN has conducted a survey “Human and Organizational Factors Perspective on the Fukushima Nuclear Accident.” Four years after the accident, however, as more witness accounts become available, IRSN feels it useful to return to the human and organizational response to the accident inside the NPP itself. To what extent can the participants act and coordinate their actions when faced with such a dramatic situation? To what degree did their actions contribute to the disaster? Rather than looking at the causes of the accident, this study examines the unfolding of the crisis, particularly in the most urgent early stages, and draws lessons for safety culture from the decisions and actions of key actors. The main results would be presented in three key areas: 1. How to make sense of the situation? People had to make sense of what happened and create new indicators. Since instruments and controls, as well as many communication technologies, were knocked out by the tsunami, all the standard means of determining the status of the reactors were impossible. Although they were under normal circumstances almost completely dependent on these indicators, and although (or because) their lives were most directly at risk, the operators managed this uncertainty through various means that will be successively presented. 2. What are the challenges for the emergency structure? The Emergency Response Center (ERC) operations team was responsible for being in contact with the operators in the control rooms and providing them technical support as needed. The ERC

Numerical Analysis of Loss of Residual Heal Removal System (RHRS) during Mid-Loop Operation for Hanul NPP Units 1 and 2

Energy Technology Data Exchange (ETDEWEB)

Kim, Sook Kwan; Park, Seong Gyu; Han, Sang Koo [ACT Co., Daejeon (Korea, Republic of)

2016-10-15

As a part of supporting LPSD (Low Power and Shutdown) PSA (Probabilistic Safety Assessment) of Hanul NPP units 1 and 2, numerical analysis for a loss of RHRS (Residual Heat Removal system) during midloop operation was performed using RELAP5/MOD3.3 code. The one of main purpose of thermal hydraulic analysis for PSA work is to estimate times allowable for operation actions in each accident. A loss of RHRS during mid-loop operation may cause more significant results than during RCS full condition due to reduced RCS inventory. In order to perform this kind of analysis, it is particularly important to establish a steady state of mid-loop operational initial condition. Mid-loop operation corresponds to POS(Plant Operational State) 5 and 11 in the category of LPSD PSA at Hanul NPP units 1 and 2. RELAP5/MOD3.3 code was used to predict behaviors of RCS and fuels for the case of loss of RHRS during mid-loop operation at Hanul NPP units 1 and 2. The initial state of mid-loop operational condition was established by proper control of charging and letdown flow. Considering existing similar analysis results for this kind of accident, it can be concluded that RELAP5 code well predicts reasonably the behavior of RCS for loss of RHRS during mid-loop operation in Hanul NPP units 1 and 2. Thus the method developed in the analysis can be applied reasonably to support LPSD PSA.

Structure of comorbid diseases inpatients with non-alcoholic fatty liver disease, exposed to ionizing radiation as a result of the Chornobyl NPP accident

International Nuclear Information System (INIS)

Gasanova, O.V.; Sarkyisova, E.O.; Ovsyannyikova, L.M.; And Others

2014-01-01

A significant amount of co-morbid pathology was found in all studied groups but III CG: at the average from 4.1 ± 0.4 diseases in II CG to 5.2 ± 0.2 in the main group of patients (p < 0.05), among which in 6.6-7.1 % of cases more than 10 diseases were established. The most common disorders were cardiovascular and cerebrovascular and endocrine diseases. Structure of comorbid pathology in NAFLD in the main study group differed from this in II CG by a significantly greater frequency of detection of cerebrovascular diseases (73.5 and 56 %, p < 0.05). As for features of the metabolic syndrome in Chornobyl accident sufferers essential hypertension (71.3 % ), discirculatory encephalopathy (48.5 %) and thyroid diseases (47.1 %) were more frequent than in II GC: correspondingly 58 % (p < 0.001), 28 %, (p < 0.01), and 30 %, (p < 0.05). Essential hypertension in only 35.7 % patients without NAFLD (I CG) was detected (71.3 % in the study group, p < 0.01), and chronic cerebrovascular insufficiency in 71.4 % (39.7 % in the study group, p < 0.01). Structure of comorbid pathology in NAFLD patients sufferers of the Chornobyl NPP accident was different both in a large number of identified diseases and nosological structure. The most common disorders were cardiovascular, cerebrovascular, and endocrine diseases. Significantly higher incidence of essential hypertension, vascular encephalopathy, and thyroid disease was determined

Mochovce NPP simulator

International Nuclear Information System (INIS)

Ziakova, M.

1998-01-01

Mochovce NPP simulator basic features and detailed description of its characteristics are presented with its performance, certification and application for training of NPP operators as well as the training scenario

Dosimetry problems when evaluating radiation effects on the personnel, restoration work participants, and human population due to the Chernobyl accident

International Nuclear Information System (INIS)

Abramov, Yu.V.; Osanov, D.P.; Gimadova, T.I.; Gus'kov, V.M.; Kruchkov, V.P.; Pavlov, D.A.; Shaks, A.I.

1993-01-01

System of radiation monitoring operations of the Chernobyl NPP personnel is described for the period from the date of accident up to present time as well as of persons worked in the Chernobyl NPP 30 km zone, servicemen, and human population. Unsatisfactory organization of radiation on monitoring is marked and causes of this fact are considered. 8 refs.; 3 figs

Two managerial grids in NPP

International Nuclear Information System (INIS)

Zhao Hui

2012-01-01

Today, the nuclear power corporation (NPC) enjoys the profit of LCEP (the low carbon economic policy). at the same time, they also enduring more and more pressure. For example, the partner competition or the NPP potential occupational risk . The efficient counterplot of risk is the self-ability cultivation. It is essential to research the NPP managerial flow. The nuclear power plant (NPP) unit is a carrier of the NPC enterprise management system, and has taken on a new look 'pull one portion then the whole moving'. The NPP has three systematical characters, the security responsibility center, the man-machine system and the input-output system. The manufacturing system and the enterprise management system are the great constituents of the NPP managerial flows. Means of systems analysis, we can find out the truth of the NPP running interface. In CHINA, there are many operating experiences near 20 years. It indicates that the NPP manufacturing system and the enterprise system are the roots of the nuclear power corporation, the core of the all NPP systems must be based on it. So the ability cultivation is the work core to NPP. It is reliably to ensure the NPP to be up against problems, for instance, the security duty, the costing control and the man-machine system running harmoniously. This paper introduces the NPP managerial flow and the present state of QNPC, also come up with a proposal to refer for the NPC development actions of collective measure, specialization, standardization, fine. (author)

Evaluation of containment peak pressure and structural response for a large-break loss-of-coolant accident in a VVER-440/213 NPP

Energy Technology Data Exchange (ETDEWEB)

Spencer, B.W.; Sienicki, J.J.; Kulak, R.F.; Pfeiffer, P.A. [Argonne National Lab., IL (United States); Voeroess, L.; Techy, Z. [VEIKI Inst. for Electric Power Research, Budapest (Hungary); Katona, T. [Paks Nuclear Power Plant (Hungary)

1998-07-01

A collaborative effort between US and Hungarian specialists was undertaken to investigate the response of a VVER-440/213-type NPP to a maximum design-basis accident, defined as a guillotine rupture with double-ended flow from the largest pipe (500 mm) in the reactor coolant system. Analyses were performed to evaluate the magnitude of the peak containment pressure and temperature for this event; additional analyses were performed to evaluate the ultimate strength capability of the containment. Separate cases were evaluated assuming 100% effectiveness of the bubbler-condenser pressure suppression system as well as zero effectiveness. The pipe break energy release conditions were evaluated from three sources: (1) FSAR release rate based on Soviet safety calculations, (2) RETRAN-03 analysis and (3) ATHLET analysis. The findings indicated that for 100% bubbler-condenser effectiveness the peak containment pressures were less than the containment design pressure of 0.25 MPa. For the BDBA case of zero effectiveness of the bubbler-condenser system, the peak pressures were less than the calculated containment failure pressure of 0.40 MPa absolute.

Optimization of chronic obstructive pulmonary disease treatment in clean-up workers of the Chornobyl NPP accident in the remote period after irradiation

International Nuclear Information System (INIS)

Sushko, V.O.; Shvajko, L.Yi.; Bazika, K.D.; Ryazhs'ka, A.S.

2015-01-01

Studied 60 chronic obstructive pulmonary disease (COPD) patients before treatment and 1 year after from the beginning, who were randomly assigned to two groups: the first group of patients (32 persons) additionally was appointed long reception (6 months) combination Ambroxol (30 mg x 3 times per day) and Essenciale (600 mg x 3 times per day), in the second group (28 people) patients received only basic therapy. The doses of radiation exposure were 25-500 mSv. Were studied clinical, functional characteristics, the number of exacerbations. Low response to the basic COPD therapy were shown by clean-up workers of the Chornobyl NPP accident, which is defined by the absence of significant changes in lung function tests. Additional appointments to the basic treatment of COPD combination of Ambroxol (30 mg x 3 times per day) and Essenciale (600 mg x 3 times per day) within 6 months of the liquidators of the Chernobyl made it possible to reduce the frequency of exacerbations in 46.9% patients without significant improvement in lung function tests

Integrated risk assessment for multi-unit NPP sites—A comparison

International Nuclear Information System (INIS)

Kumar, C. Senthil; Hassija, Varun; Velusamy, K.; Balasubramaniyan, V.

2015-01-01

Highlights: • Framework for integrated risk assessment for multi-unit NPP sites. • Categorization of external and internal events. • Modelling of key issues: mission time, cliff-edge, common cause failures, etc. • Safety goals for multi-unit NPP sites. • Comparison of site core damage frequency in one, two, three and four unit sites. - Abstract: Most of the nuclear power producing sites in the world houses multiple units. Such sites are faced with hazards generated from external events: earthquake, tsunami, flood, etc. and can threaten the safety of nuclear power plants. Further, risk from a multiple unit site and its impact on the public and environment was evident during the Fukushima nuclear disaster in March 2011. It is therefore important to evolve a methodology to systematically assess the risk from multi-unit site. For a single unit site, probabilistic risk assessment technique identifies the potential accident scenarios, their consequences, and estimates the core damage frequency that arise due to internal and external hazards. This challenging task becomes even more complex for a multiple unit site, especially when the external hazards that has the potential to generate one or more correlated hazards or a combination of non-correlated hazards are to be modelled. This paper presents an approach to evaluate risk for multiple NPP sites and also compare the risk for sites housing single, double and multiple nuclear plants.

Integrated risk assessment for multi-unit NPP sites—A comparison

Energy Technology Data Exchange (ETDEWEB)

Kumar, C. Senthil, E-mail: cskumar@igcar.gov.in [AERB-Safety Research Institute, Kalpakkam (India); Hassija, Varun; Velusamy, K. [Reactor Design Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India); Balasubramaniyan, V. [AERB-Safety Research Institute, Kalpakkam (India)

2015-11-15

Highlights: • Framework for integrated risk assessment for multi-unit NPP sites. • Categorization of external and internal events. • Modelling of key issues: mission time, cliff-edge, common cause failures, etc. • Safety goals for multi-unit NPP sites. • Comparison of site core damage frequency in one, two, three and four unit sites. - Abstract: Most of the nuclear power producing sites in the world houses multiple units. Such sites are faced with hazards generated from external events: earthquake, tsunami, flood, etc. and can threaten the safety of nuclear power plants. Further, risk from a multiple unit site and its impact on the public and environment was evident during the Fukushima nuclear disaster in March 2011. It is therefore important to evolve a methodology to systematically assess the risk from multi-unit site. For a single unit site, probabilistic risk assessment technique identifies the potential accident scenarios, their consequences, and estimates the core damage frequency that arise due to internal and external hazards. This challenging task becomes even more complex for a multiple unit site, especially when the external hazards that has the potential to generate one or more correlated hazards or a combination of non-correlated hazards are to be modelled. This paper presents an approach to evaluate risk for multiple NPP sites and also compare the risk for sites housing single, double and multiple nuclear plants.

Expedition surveys of the sea water and atmospheric air radioactive contamination in the Russian Far Eastern coastal areas and in the North- Western Pacific in connection with accident at the 'Fukushima-1' NPP

Energy Technology Data Exchange (ETDEWEB)

Nikitin, Aleksandr; Shershakov, Viacheslav; Artemev, Georgii [Research and Production Association ' Typhoon' (RPA ' Typhoon' ), Obninsk, Kaluga Region (Russian Federation); Ramzaev, Valery [Ramzaev Saint-Petersburg Research Institute of Radiation Hygiene, Saint-Petersburg (Russian Federation); Osokin, Vladimir [V.G.Khlopin Radium institute, Saint-Petersburg (Russian Federation); Sevastianov, Aleksandr [Far Eastern Regional Hydrometeorological Research Institute, Vladivostok (Russian Federation)

2014-07-01

In accordance with decision of the Russian Federation Federal Service on Hydro-meteorology and Environmental Monitoring (Roshydromet) on assessment of the sea water and atmospheric air radioactive contamination in the Russian coastal areas of the Far East in connection with accident at the 'Fukushima-1' NPP in Japan, two radioecological expedition surveys were conducted onboard of research vessels of the Far Eastern Regional Hydro-meteorological Research Institute (FERHRI) of Roshydromet in the Sea of Japan and in the North-Western Pacific (in the area adjacent to Kurile Islands and in the Kuroshio current selected area (coordinates 36 deg. 00'- 39 deg. 33' n., 146 deg. 33'- 150 deg. 00' e.): first survey in April-May 2011, onboard R/V 'Pavel Gordienko', second survey in August-September 2012, onboard R/V 'Akademik Shokalsky'. Both surveys were conducted under the Russian Geographical Society patronage. The leading Russian institutions dealing with ensuring of population radiation safety and protection of environment from radioactive contamination were enlisted to investigations. The following main observations were performed during the surveys: constant measurement of gamma-radiation dose rate above the sea surface; twenty-four hour sampling of atmospheric aerosols, sea water sampling from the surface and deep water horizons with preliminary concentrating of radionuclides for onboard gamma-spectrometry and for subsequent transportation to the shore laboratories for further analysis. During the expeditions, a real-time data were received onboard of research vessels which characterize impact of input of radioactive products of the 'Fukushima-1' NPP accident on radioactive contamination of environment existed on that period (these are onboard estimates of {sup 137}Cs and {sup 134}Cs concentrations in the sea water samples and {sup 131}I, {sup 137}Cs, {sup 134}Cs content in atmospheric aerosol samples, data

Spatio-temporal variability of the deposited radioactive materials in forest environments after the Fukushima Daiichi NPP accident

Science.gov (United States)

Kato, H.; Onda, Y.; Komatsu, Y.; Yoda, H.

2012-12-01

Soil, vegetation and other ecological compartments are expected to be highly contaminated by the deposited radionuclides after the Fukushima Daiichi nuclear power plant (NPP) accident triggered by a magnitude 9.1 earthquake and the resulting tsunami on Marchi 11, 2011. Study site have been established in Yamakiya district, Kawamata Town, Fukushima prefecture, located about 35 km from Fukushima power plant, and designated as the evacuated zone. The total deposition of radioactive materials at the study site ranged from 0.02to >10 M Bq/m2 for Cs-137. The mature cedar, young cedar, and broad-leaf stands were selected as experimental site for the monitoring of spatio-temporal variability of the deposited radionuclides after the accidental release of radioactive materials. In order to measure the vertical distribution of radioactivity in forest, a tower with the same height of tree have been established at each experimental site. The measurement of radioactivity by using a portable Ge gamma-ray detector (Detective-DX-100, Ortec) and radionuclide analysis of leaf samples at different height revealed that a large proportion of radionuclides which deposited on forest were trapped by canopies of the cedar forests. In contrast, in the broad-leaf forest highest radioactivity was found at the forest floor. Furthermore, spatio-temporal variability of radioactivity at the forest floor indicated that huge amount of caesium still remains on the canopy of coniferous forest, and subsequently transfers to forest floor in association with throughfall, stemflow, and litter fall.

An application of A.I. to organizational learning in an operating NPP

International Nuclear Information System (INIS)

Poumadere, M.

1990-01-01

An A.I. type approach is developed in order to rapidly and systematically integrate the various elements of human and structural learning (e.g. cognitive representations, feedback and interactions within an operating NPP. The objective followed is to develop throughout a functioning plant and over a relatively brief period (6 weeks), a measurement and diagnostic program involving all plant personnel. Measurements are positioned within a three-dimensional polarized factor space and feedback to participants with the transfer of analytic tools. This program has been applied in a French nuclear power plant. The gain in organizational knowledge is tested. One year after first-wave measures, measurement is repeated with the same population and the same objects. Interim evolutions along NPP criteria (e.g. lost-time accident rate) are observed. The parallel evolutions between participant diagnostic data and operating criteria seem to indicate an improved level of organizational learning

Cardiovascular diseases and systolic function of left ventricle in clean up workers of Chernobyl accident (based on 30 years follow up).

Science.gov (United States)

Bazyka, O D; Belyi, D O

2017-12-01

To study the dynamics of circulatory system diseases during the 30 year period after irradiation, changes in the status of systolic function of heart left ventricle (LV) and the features of its remodeling in clean up workers (CW) of the accident at the Chernobyl nuclear power plant (ChNPP). It was examined 144 CW at ChNPP, including 52 patients, who survived acute radiation sick ness (ARS) grade of severity 1-3, and 105 non irradiated persons (control group - CG). CW have been divided into two subgroups: without signs of ARS (ARS0) and those who suffered from ARS. CW and CG patients were male who had no signs of cardiovascular, nervous, pulmonary or endocrine pathology prior to the Chernobyl accident. Their average age at the beginning of the accident was 33.9-37.7 years. The study program included clinical examina tion, echocardiography, retrospective and statistical analysis. Hypertensive heart disease (HHD) has developed in the CW, including the ARS convalescents, by 12 years, and ischemic heart disease (CHD) at 9-11 years is believed to be earlier than in comparable non irradiated patients. In the post accident period, there was an increased mean value of LV posterior wall (PW) thickness, interventricular septum (IVS), myocardium mass and myocardium mass normalized by body surface area. These indices grew with the increase of HHD duration. Over the 30 year follow up period, between CW and CG from 14.3 to 28.6 % of patients with LV increased volumes it was found a decreased ejection fraction (EF), what indicated the development of sys tolic LV dysfunction with the phenomena of left ventricular heart failure (HF). Reduction of EF correlated with increase of end systolic volume (ESV) having the highest statistical strength. In CW and persons of CG there was from 77.3 to 84.8 % of patients had clinical signs of HF with preserved EF. From this number, 56-63.6 % of patients had concentric and 18.8-26.7 % had eccentric LV hypertrophy (LVH), and in 6.1 to 15.6% of

NPP post-accident monitoring system based on unmanned aircraft vehicle:concept, design principles

International Nuclear Information System (INIS)

Sachenko, A.A.; Kochan, V.V.; Kharchenko, V.S.; Yanovskij, M.Eh.; Yastrebenetskij, M.A.; Fesenko, G.V.

2016-01-01

The paper presents a concept of designing the post-accident system for monitoring the equipment and territory of nuclear power plant after a severe accident based on unmanned aircraft vehicle (UAVs). Wired power and communications networks are found out as the most vulnerable ones during the accident monitoring, and informativity, reliability and veracity are recognized as system basic parameters. It is proposed to equip measurement and control modules with backup wireless communication channels and deploy the repeaters network based on UAVs to ensure the informativity. Modules possess the backup power battery, and repeaters appear in the appropriate places after the accident to provide the survivability. Moreover, an optimization of UAVs' location is proposed according to the minimum energy consumption criterion. To ensure the veracity, it is expected to design the noise-immune protocol for message exchange and archiving and self-diagnostics of all system components

The Roll of Canopy on Interception and Redistribution of Anthropogenic Radionuclides Derived from Fukushima Daiichi Nuclear Power Plant Accident in Coniferous Forest Plantations

Science.gov (United States)

Kato, H.; Onda, Y.; Kawaguchi, S.; Gomi, T.

2011-12-01

Soil, vegetation and other ecological compartments are expected to be highly contaminated by the deposited radionuclides after the Fukushima Daiichi nuclear power plant (NPP) accident triggered by a magnitude 9.1 earthquake and the resulting tsunami on Marchi 11, 2011. A large proportion of radionuclides which deposited on forest area are trapped by canopies, throughfall and stemflow are the most important pathways for the input of radionuclides into the soil of forest floor. In this study, to investigate the roll of forest canopy on interception and redistribution of the deposited radionuclides, a series of field monitoring experiment of throughfall and stemflow were conducted in coniferous forest plantations in Tochigi prefecture, 170 km southwest from the NPP. A set of 20 throughfall collectors with latticelike distribution and 5 stemflow collectors were located in the 10m × 10m interception plot, and the activities of caesium (137Cs, 134Cs) and radioiodine (131I) in throughfall and stemflow were quantified by using a high purity n-type germanium coaxial gamma ray detectors. Rainfall, throughfall, and stemflow samples were collected from 10 rainfall events, which includes first rainfall event after the NPP accident. The cumulative fallout of radionuclides in the study site was 3400 Bq m-2 for 137Cs, 3300 Bq m-2 for 134Cs, and 26000 Bq m-2 for 131I, respectively. The 137Cs in rainfall decreased exponentially with time since the NPP accident. For the rainfall event of 28 March, which is first rainfall event after the NPP accident, both the amount and concentration of caesium clearly increased with throughfall, whereas the concentration of radioiodine decreased with throughfall. For the subsequent rainfall events, the concentration of caesium decreased with throughfall, whereas radioiodine was not detected as a result of decay due to short half-life. At the end of May, approximately 30% and 60% of total caesium deposited after the NPP accident remained on the

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

International Nuclear Information System (INIS)

Baba, Mamoru

2016-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Baba, Mamoru [Tohoku Univeristy, Sendai (Japan)

2016-06-15

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

Nuclear Accidents: Consequences for Human, Society and Energy Sector

Directory of Open Access Journals (Sweden)

L. A. Bolshov

2016-01-01

Full Text Available The article examines radiation and hygienic regulations with regard to the elimination of consequences of the Chernobyl NPP accident in the context of relationships with other aspects, primarily socio-economic and political factors. This experience is reasonable to take into account when defining criteria in other regulatory fields, for example, in radioactive waste classification and remediation of areas. The article presents an analysis of joint features and peculiarities of nuclear accidents in the industry and energy sectors. It is noted that the scale of global consequences of the Chernobyl NPP accident is defined by the large-scale release of radioactivity into the environment, as well as an affiliation of the nuclear installation with the energy sector. Large-scale radiation accidents affect the most diverse spheres of human activities, what, in its turn, evokes the reverse reaction from the society and its institutions, including involvement of political means of settlement. If the latter is seeing for criteria that are scientifically justified and feasible, then the preconditions for minimizing socio-economic impacts are created. In other cases, political decisions, such as nuclear units’ shutdown and phasing out of nuclear energy, appear to be an economic price which society, as a whole and a single industry sector, pay to compensate the negative public response. The article describes fundamental changes in approaches to ensure nuclear and radiation safety that occurred after the Chernobyl NPP accident. Multiple and negative consequences of the Chernobyl accident for human and society are balanced to some extent by a higher level of operational safety, emergency preparedness, and life-cycle safety. The article indicates that harmonization and ensuring consistency of regulations that involve different aspects of nuclear and radiation safety are important to implement practical solutions to the nuclear legacy problems. The

Vegetation fires, smoke emissions, and dispersion of radionuclides in the chernobyl exclusion zone

Science.gov (United States)

Wei Min Hao; Oleg O. Bondarenko; Sergiy Zibtsev; Diane Hutton

2009-01-01

The accident of the Chernobyl nuclear power plant (ChNPP) in 1986 was probably the worst environmental disaster in the past 30 years. The fallout and accumulation of radionuclides in the soil and vegetation could have long-term impacts on the environment. Radionuclides released during large, catastrophic vegetation fires could spread to continental Europe, Scandinavia...

Overview of Fukushima accident and regulatory issues for FCFS after the accident

International Nuclear Information System (INIS)

Ueda, Y.

2013-01-01

In the first part of his presentation Yoshinori Ueda (JNES, Japan) gave an overview of the Fukushima accident and an outline of the emergency safety measures and response at the NPP site. The second part was focused on the regulatory issues for FCFs after the accident. The first issue was the emergency safety measures in case of total loss of AC power (loss capabilities of decay heat removal and hydrogen accumulation prevention) and tsunami in the reprocessing facilities and associated spent fuel storages at Tokai and Rokkasho plants. The second issue was the directions to the licensees of these facilities to secure the work environment in the main control rooms in case of complete loss of AC power, to secure communication within the facility in case of such emergency, and to secure material and equipment for radiation protection, and to deploy heavy tools for rubble removal. No paper has been made available for this presentation

Simulation of the WWER-440/213 maximum credible accident at the EhNITs stand

International Nuclear Information System (INIS)

Blinkov, V.N.; Melikhov, O.I.; Melikhov, V.I.; Davydov, M.V.; Sokolin, A.V.; Shchepetil'nikov, Eh.Yu.

2000-01-01

The calculations of thermohydraulic processes through the ATHLET code for determining optimal conditions for modeling the coolant leakage at the EhNITs stand by the maximum credible accident at the NPP with WWER-440/213 reactor are presented. The diameters of the nozzle at the stand, whereby the local criterion of coincidence with the data on the NPP (by the maximum flow) and integral criterion of coincidence (by the mass and energy of the coolant, effluent during 10 s) are determined in the process of parametric calculations [ru

Changing NPP consumption patterns in the Holocene: from Megafauna "liberated" NPP to "ecological bankruptcy"

Science.gov (United States)

Doughty, C.

2015-12-01

There have been vast changes in how net primary production (NPP) is consumed by humans and animals during the Holocene beginning with a potential increase in availability following the Pleistocene megafauna extinctions. This was followed by the development of agriculture which began to gradually restrict availability of NPP for wild animals. Finally, humans entered the industrial era using non-plant based energies to power societies. Here I ask the following questions about these three energy transitions: 1. How much NPP energy may have become available following the megafauna extinctions? 2. When did humans, through agriculture and domestic animals, consume more NPP than wild mammals in each country? 3. When did humans and wild mammals use more energy than was available in total NPP in each country? To answer this last question I calculate NPP consumed by wild animals, crops, livestock, and energy use (all converted to units of MJ) and compare this with the total potential NPP (also in MJ) for each country. We develop the term "ecological bankruptcy" to refer to the level of consumption where not all energy needs can be met by the country's NPP. Currently, 82 countries and a net population of 5.4 billion are in the state of ecologically bankruptcy, crossing this threshold at various times over the past 40 years. By contrast, only 52 countries with a net population of 1.2 billion remain ecologically solvent. Overall, the Holocene has seen remarkable changes in consumption patterns of NPP, passing through three distinct phases. Humans began in a world where there was 1.6-4.1% unclaimed NPP to consume. From 1700-1850, humans began to consume more than wild animals (globally averaged). At present, >82% of people live in countries where not even all available plant matter could satisfy our energy demands.

Estimation of the loss of Offsite power frequency for the probabilistic safety assessment of the Juragua NPP

International Nuclear Information System (INIS)

Vilaragut Llanes, J.J.; Valhuerdi Debesa, C.

1996-01-01

The loss offsite power is defined as the interruption of the preferred power supply to the essential and non essential switchgear buses necessitating or resulting in the use of emergency AC power supply. Because many safety system required for reactor core decay heat removal and containment heat removal depend on AC power, a loss of offsite power, if emergency power supply (diesel generators) fails, could be severe accidents The purpose of this work was to determine, for the Probabilistic Safety Assessment of the Juragua NPP, the causes, frequency and duration relationships of the loss of offsite power. A description is presented of the different factor that determine the occurrence of this event and the characteristics for the Juragua NPP

Accident analysis of Fukushima Daiichi Nuclear Power Station unit 1

International Nuclear Information System (INIS)

Kobayashi, Masahide; Narabayashi, Tadashi; Tsuji, Masashi; Chiba, Go; Nagata, Yasunori; Shimoe, Tomohiro

2015-01-01

As a result of the Great East Japan Earthquake that occurred on 11 March 2011, all AC and DC power at the Fukushima Daiichi NPP units 1 to 3 were lost soon after the tsunami. The core cooling function was lost, and the cores of units 1 to 3 were damaged. The purpose of this work is to clarify the progress of the accident in unit 1, which was damaged the earliest among the 3 units. Therefore, an original severe accident analysis code was developed, and the progress of the accident was evaluated from the analysis results and the actual data. As a result, the leakage path from a pressure vessel was clarified, and some lessons and knowledge were gained. (author)

Investigation on Conversion of I-Graphite from Decommissioning of Chernobyl NPP into a Stable Waste Form Acceptable for Long Term Storage and Disposal

International Nuclear Information System (INIS)

Zlobenko, Borys; Fedorenko, Yriy; Yatzenko, Victor; Shabalin, Borys; Skripkin, Vadim

2016-01-01

For Ukraine, the main radiocarbon ( 14 C) source is irradiated graphite from Chernobyl Nuclear Power Plant. The ChNPP is a decommissioned nuclear power station about 14 km northwest of the city of Chernobyl, and 110 km north of Kyiv. The ChNPP had four RBMK reactor units. The commissioning of the first reactor in 1977 was followed by reactor No. 2 (1978), No. 3 (1981), and No.4 (1983). Reactors No.3 and 4 were second generation units, whereas Nos.1 and 2 were first-generation units. RBMK is an acronym for ''High Power Channel-type Reactor'' of a class of graphite-moderated nuclear power reactor with individual fuel channels that uses ordinary water as its coolant and graphite as its moderator. The combination of graphite moderator and water coolant is found in no other type of nuclear reactor

Economic damage and state policy on the overcoming of the Chernobyl NPP catastrophe consequences. Chapter 2

International Nuclear Information System (INIS)

Konoplya, E.F.; Rolevich, I.V.

1998-01-01

The economic consequences of the Chernobyl NPP accident for the Republic of Belarus are given. The damage, taking into account the 30-years period needed for its overcoming, is estimated to be 235 billion US$ that is equal to 32 annual budgets of the republic of 1985. The losses connected with the deterioration of population health, damage incurred in industry and social sphere, agriculture, building complex, transport and communication, housing, with contamination of raw, mineral, land, water, forest and other resources are shown. The main directions of the state and legislative bodies activity on overcoming of the Chernobyl NPP accident consequences are directed on realization of complex of measures on maximum decreasing the radiation exposure dose; providing safety of people's health at the expense of medical preventive measures, improvement of their health, social insurance and resettlement from the zones where the safe living criteria are not observed; providing safe living conditions in regions subjected to radioactive contamination; rise of population life quality in these regions; scientific research of the problems connected with radiation influence on ecosystem, etc. The medical care and social protection systems of the affected population are describe

Hygienic training of population being victims of the Chernobyl accident

International Nuclear Information System (INIS)

Terman, A.V.; Mozgovaya, A.V.; Polesskij, V.A.

1995-01-01

Study results on the role of social factors in formation of attitude to own health and its self-evaluation by the population of the regions, subjected to impact of the Chernobyl NPP accident. An extremely important component block is determined in the programs on hygienic training of the population being victims of the accident, namely, adequate information of the public on dose-effect dependencies, on radionuclide behaviour in the environmental objects, on possible measures for reduction of undesirable effects. Necessity is noted of transfer from universal programs of hygienic training to differential ones up to individual training

The comparative analysis of safety and economic competitiveness of the advanced high-power reactor projects of NPP

International Nuclear Information System (INIS)

Batyrbekov, G.A.; Makhanov, U.M.; Philimonova, R.A.; Kichutkina, E.G.

2002-01-01

The comparative analysis results of the safety and economic competitiveness of the seven advanced large sized reactors projects (900 MW and more) are submitted in that report: EPR, Frameatome France, Siemens Germany; EP-1000 Westinghouse, USA and Genesi Italy; Candu 9, Atomic Energy of Canada Ltd; System 80 +, ABB, USA; KNGR, group NSSS Engineering and Development, Korea Power Engineering Company, Inc; APWR, Electric Power company, Japan Atomic Power Company, Mitsubishi Heavy Industries, Westinghouse Electric; and WWER-1000 (V-392), Atomenergoproject/Gidropress Russian Federation. According to the economic competitiveness of listed compared power reactors the 14 criteria of safety have been accepted. These criteria: 1. Features of the barrier system of 'defence-in-depth'. 2. The self-security of a reactor under increase of power and reactivity of a reactor, decrease of the expense and phase transformations of the reactor core coolant (presence of negative feedbacks). 3. Presence of the reactor shutdown systems responding principles of a variety, independence and reservation. Presence of the passive means of initiation and operation of the emergency protection. 4. The emergency cooling of the core of reactor. A presence of the passive means of cooling. Presence of the water reservation for the water supply of the different safety systems. 5. The emergency electrical supply, its reliability and degree of reservation. 6. The prevention measures of the heavy accident with the melt core. The decrease of the heavy accident probability. 7. The account of the heavy accident under development of the levels of protection. 8. The protection levels of NPP, the technological criteria of efficiency of the each safety barriers and the limiting radiation criteria for the each level of protection , in particular for the design-basis and beyond-design-basis accidents. 9. The measures for reduction of the heavy accident consequences. The management by the beyond

Noble gas control room accident filtration system for severe accident conditions (N-CRAFT)

International Nuclear Information System (INIS)

Hill, Axel; Stiepani, Cristoph; Drechsler, Michael

2015-01-01

Severe accidents might cause the release of airborne radioactive substances to the environment of the NPP either due to containment leakages or due to intentional filtered containment venting. In the latter case aerosols and iodine are retained, however noble gases are not retainable by the FCVS or by conventional air filtration systems like HEPA filters and iodine absorbers. Radioactive noble gases nevertheless dominate the activity release depending on the venting procedure and the weather conditions. To prevent unacceptable contamination of the control room atmosphere by noble gases, AREVA GmbH has developed a noble gas control room accident filtration system (CRAFT) which can supply purified fresh air to the control room without time limitation. The retention process is based on dynamic adsorption of noble gases on activated carbon. The system consists of delay lines (carbon columns) which are operated by a continuous and simultaneous adsorption and desorption process. CRAFT allows minimization of the dose rate inside the control room and ensures low radiation exposure to the staff by maintaining the control room environment suitable for prolonged occupancy throughout the duration of the accident. CRAFT consists of a proven modular design either transportable or permanently installed. (author)

The NEA benchmark study of the accident at the Fukushima Daiichi NPP

International Nuclear Information System (INIS)

Koganeya, Toshiyuki

2015-01-01

In November 2012, the NEA, under the aegis of the Committee on the Safety of Nuclear Installations (CSNI), initiated a joint research project called the Benchmark Study of the Accident at the Fukushima Daiichi Nuclear Power Station (BSAF). Objectives of this project include supporting Fukushima Daiichi decommissioning by analysing accident progression and the current status of the reactors, such as fuel debris distribution in the reactor pressure vessels and primary containment vessels in preparation for fuel debris removal. A second objective of the project is to improve SA (severe analysis) codes through comparisons with data from the Fukushima reactors. So as to enhance communication between analysts and those involved in decommissioning activities, participants in the project have been discussing the remaining uncertainties in relation to understanding the accident and the data needs from the viewpoint of the analysts. Since the accident sequences at the Fukushima Daiichi site include a wide range of phenomena, a phased approach is being applied in this benchmark exercise while awaiting more detailed information on debris examination and other factors. This article provides an overview of the project (scope, input data and boundary conditions, participants (from eight countries), analytical approach - common case and best estimate case) as well as an outline of the project's next phase (BASF phase 2) that begins in June 2015

Study on spraying water soluble resin to reduce pollution for Fukushima daiichi NPP accident

International Nuclear Information System (INIS)

Zhang Qiong; Guo Ruiping; Zhang Chunming; Han Fujuan; Hua Jie; Zhang Jiankui

2012-01-01

After Fukushima nuclear accident, Tokyo electric power company used the method of spraying water soluble resin synthesis at the scene of the accident, to restrain and control the spread of the radioactive dust, by forming consolidation layer in pollution area surface. This paper briefly introduced the accident, motivation of spraying water soluble resin, spraying range and implementation process. According to the relevant report on Fukushima nuclear accident, the effect of spraying water soluble resin for reducing pollution was analyzed. The mechanism of reducing pollution for water soluble resin and the application prospect were discussed. Spraying water soluble resin for fixing radioactive dust has reasonable reducing pollution effect. It is worth to use as reference and study in China. (authors)

NPOESS Preparatory Project (NPP) Science Overview

Science.gov (United States)

Butler, James J.

2011-01-01

NPP Instruments are: (1) well understood thanks to instrument comprehensive test, characterization and calibration programs. (2) Government team ready for October 25 launch followed by instrument activation and Intensive Calibration/Validation (ICV). NPP Data Products preliminary work includes: (1) JPSS Center for Satellite Applications and Research (STAR) team ready to support NPP ICV and operational data products. (2) NASA NPP science team ready to support NPP ICV and EOS data continuity.

Scenarios catalog for the graphical console for analysis of severe accidents visualization of OEs, NAEs and calculation of source term of the NPP-LV

International Nuclear Information System (INIS)

Sandoval V, S.; Mendoza R, M. E.; Tijerina S, F.; Garcia C, T.

2016-09-01

A nuclear power plant is operated at all times within the design criteria of structures, systems and components, and according to the operation technical specifications. For different areas of work of a nuclear power plant is necessary to carry out practices in which is useful to have the prediction of the thermo-hydraulic and radiological progression of scenarios that imply exceeding that design bases, even reaching the damage of the fuel in different degree. During the exercises and drills of the External Plan of Emergency Response, the projection of doses is done to exercise the different tasks of the plan. To make the projection of doses is required to have the radiological source term of the scenario on which is practiced. Because of this, was identified the convenience of having a catalog of scenarios for which the radiological source term was calculated. In 2004, a first version of the catalog was produced for a power of 2027 MW, and in 2011 the catalog was updated for extended power conditions, 2317 MW. Both versions were made using the severe accident simulator MAAP-3B. That catalog consists of a form and an optical storage device. The form contains tables and figures in which the characteristics of the scenario to be practiced are searched and the electronic files of the corresponding radiological source term are located in the storage device. Due to the recent development of the graphical console for analysis of severe accidents, visualization of OEs, NAEs and calculation of the source term for the nuclear power plant of Laguna Verde (NPP-LV) CoGrAAS, the catalog printed was replaced by an electronic catalog for the CoGrAAS. The new catalog retains the philosophy of the previous catalog, constituted by a wide collection of scenarios that involve different circumstances and phenomena, that can be used to practice different tasks during training exercises or simulacrums, and combined with the following advantages: the scenario selection is made from an

Oxidation behavior analysis of cladding during severe accidents with combined codes for Qinshan Phase II Nuclear Power Plant

International Nuclear Information System (INIS)

Shi, Xingwei; Cao, Xinrong; Liu, Zhengzhi

2013-01-01

Highlights: • A new verified oxidation model of cladding has been added in Severe Accident Program (SAP). • A coupled analysis method utilizing RELAP5 and SAP codes has been developed and applied to analyze a SA caused by LBLOCA. • Analysis of cladding oxidation under a SA for Qinshan Phase II Nuclear Power Plant (QSP-II NPP) has been performed by SAP. • Estimation of the production of hydrogen has been achieved by coupled codes. - Abstract: Core behavior at a high temperature is extremely complicated during transition from Design Basic Accident (DBA) to the severe accident (SA) in Light Water Reactors (LWRs). The progression of core damage is strongly affected by the behavior of fuel cladding (oxidation, embrittlement and burst). A Severe Accident Program (SAP) is developed to simulate the process of fuel cladding oxidation, rupture and relocation of core debris based on the oxidation models of cladding, candling of melted material and mechanical slumping of core components. Relying on the thermal–hydraulic boundary parameters calculated by RELAP5 code, analysis of a SA caused by the large break loss-of-coolant accident (LBLOCA) without mitigating measures for Qinshan Phase II Nuclear Power Plant (QSP-II NPP) was performed by SAP for finding the key sequences of accidents, estimating the amount of hydrogen generation and oxidation behavior of the cladding

Conceptual Design of Hybrid Safety Features for NPP by Utilizing Solar Updraft Tower

Energy Technology Data Exchange (ETDEWEB)

Song, Sub Lee [Handong Global University, Pohang (Korea, Republic of); Choi, Young Jae; Kim, Yong Jin [KAIST, Daejeon (Korea, Republic of); Park, Hyo Chan; Park, Youn Won [BEES, Daejeon (Korea, Republic of)

2016-05-15

In this study, hybrid safety features for NPP with solar updraft tower (SUT) is conceptually suggested to cope with loss of ultimate heat sink accident. The hybrid safety features utilizing SUT target NPPs in seashore of Arabian Gulf. Usually NPPs are constructed near seashore to utilize sea water as an ultimate heat sink. Residual heat or decay heat of nuclear reactor will diffuse into the ocean through the condenser. NPPs in Middle East are expected to be placed in seashore of Arabian Gulf. The NPP site of Barakah is an actual example. For NPPs in seashore of Arabian Gulf, an additional safety concern should be considered. Arabian Gulf is the largest oil transporting route in the world. The oil spill risk in Arabian Gulf will be the largest simultaneously. Unfortunately, not like other oceans, Arabian Gulf is a kind of closed ocean which does not have strong ocean currents connected to out of the gulf. If once oil spill is occurred, its influence can be propagated more than our expectation. The spilled oil also can affect to NPPs in seashore by covering surfaces of condenser. It will directly cause loss of ultimate heat sink. The hybrid safety features of SUT system are expected to aid normal operation of safety system and mitigate consequence of severe accident. Detail analysis and technology development is ongoing now.

Conceptual Design of Hybrid Safety Features for NPP by Utilizing Solar Updraft Tower

International Nuclear Information System (INIS)

Song, Sub Lee; Choi, Young Jae; Kim, Yong Jin; Park, Hyo Chan; Park, Youn Won

2016-01-01

In this study, hybrid safety features for NPP with solar updraft tower (SUT) is conceptually suggested to cope with loss of ultimate heat sink accident. The hybrid safety features utilizing SUT target NPPs in seashore of Arabian Gulf. Usually NPPs are constructed near seashore to utilize sea water as an ultimate heat sink. Residual heat or decay heat of nuclear reactor will diffuse into the ocean through the condenser. NPPs in Middle East are expected to be placed in seashore of Arabian Gulf. The NPP site of Barakah is an actual example. For NPPs in seashore of Arabian Gulf, an additional safety concern should be considered. Arabian Gulf is the largest oil transporting route in the world. The oil spill risk in Arabian Gulf will be the largest simultaneously. Unfortunately, not like other oceans, Arabian Gulf is a kind of closed ocean which does not have strong ocean currents connected to out of the gulf. If once oil spill is occurred, its influence can be propagated more than our expectation. The spilled oil also can affect to NPPs in seashore by covering surfaces of condenser. It will directly cause loss of ultimate heat sink. The hybrid safety features of SUT system are expected to aid normal operation of safety system and mitigate consequence of severe accident. Detail analysis and technology development is ongoing now

NPP life management (abstracts)

International Nuclear Information System (INIS)

Litvinskij, L.L.; Barbashev, S.V.

2002-01-01

Abstracts of the papers presented at the International conference of the Ukrainian Nuclear Society 'NPP Life Management'. The following problems are considered: modernization of the NPP; NPP life management; waste and spent nuclear fuel management; decommissioning issues; control systems (including radiation and ecological control systems); information and control systems; legal and regulatory framework. State nuclear regulatory control; PR in nuclear power; training of personnel; economics of nuclear power engineering

Plutonium emission from the Fukushima accident

International Nuclear Information System (INIS)

Bossew, P.

2013-01-01

A strong earthquake and subsequent tsunami on 11 th March 2011 initiated a severe accident in units 1 to 4 of Fukushima Dai-ichi nuclear power plant, resulting in substantial releases of radionuclides. While much has since been published 00 environmental contamination and exposure to radio--iodine and radio-caesium, little is known about releases of plutonium and other non-volatile elements. Although the total activities of released 131 I, 134 Cs and 137 Cs are of the same order of magnitude as of the Chernobyl accident in 1986, the contribution of little volatile elements, including Pu, is much smaller in Fukushima fallout. The reason is the different physical nature of the accident sequence which led to a release of some 10 - 5% of the core inventories only (to be compared with 3.5% from Chernobyl). In this contribution the available data on Pu in Fukushima fallout will be reviewed. Data sources are mainly reports and press releases by Japanese authorities and a few scientific articles. The mean ratio 239+240 Pu: 137 Cs in the near field around the NPP (mainly part of Fukushima prefecture and districts of adjacent prefectures) can be assumed about 3 x 10 - 7 , to be compared to nearly 0.01 in the vicinity of Chernobyl, down to about 3 x 10 -6 in Central Europe. Isotopic ratios 238 Pu: 239+240 Pu are about 2.2 (0.46 and 0.035 in Chemobyl and global fallout, respectively). Activity concentrations of Fukushima- 239+240 Pu in surface soil were found up to above 0.1 Bq/kg d.m. in the immediate vicinity of the Fukushima NPP and about one order of magnitude less in Fukushima city, about 60 km away. The 239+240 Pu activity released into the atmosphere is roughly estimated some 10 9 Bq (Chemobyl : almost 10 14 Bq). (author)

First retrieval of hourly atmospheric radionuclides just after the Fukushima accident by analyzing filter-tapes of operational air pollution monitoring stations.

Science.gov (United States)

Tsuruta, Haruo; Oura, Yasuji; Ebihara, Mitsuru; Ohara, Toshimasa; Nakajima, Teruyuki

2014-10-22

No observed data have been found in the Fukushima Prefecture (FP) for the time-series of atmospheric radionuclides concentrations just after the Fukushima Daiichi Nuclear Power Plant (FD1NPP) accident. Accordingly, current estimates of internal radiation doses from inhalation, and atmospheric radionuclide concentrations by atmospheric transport models are highly uncertain. Here, we present a new method for retrieving the hourly atmospheric (137)Cs concentrations by measuring the radioactivity of suspended particulate matter (SPM) collected on filter tapes in SPM monitors which were operated even after the accident. This new dataset focused on the period of March 12-23, 2011 just after the accident, when massive radioactive materials were released from the FD1NPP to the atmosphere. Overall, 40 sites of the more than 400 sites in the air quality monitoring stations in eastern Japan were studied. For the first time, we show the spatio-temporal variation of atmospheric (137)Cs concentrations in the FP and the Tokyo Metropolitan Area (TMA) located more than 170 km southwest of the FD1NPP. The comprehensive dataset revealed how the polluted air masses were transported to the FP and TMA, and can be used to re-evaluate internal exposure, time-series radionuclides release rates, and atmospheric transport models.

First retrieval of hourly atmospheric radionuclides just after the Fukushima accident by analyzing filter-tapes of operational air pollution monitoring stations

Science.gov (United States)

Tsuruta, Haruo; Oura, Yasuji; Ebihara, Mitsuru; Ohara, Toshimasa; Nakajima, Teruyuki

2014-01-01

No observed data have been found in the Fukushima Prefecture (FP) for the time-series of atmospheric radionuclides concentrations just after the Fukushima Daiichi Nuclear Power Plant (FD1NPP) accident. Accordingly, current estimates of internal radiation doses from inhalation, and atmospheric radionuclide concentrations by atmospheric transport models are highly uncertain. Here, we present a new method for retrieving the hourly atmospheric 137Cs concentrations by measuring the radioactivity of suspended particulate matter (SPM) collected on filter tapes in SPM monitors which were operated even after the accident. This new dataset focused on the period of March 12–23, 2011 just after the accident, when massive radioactive materials were released from the FD1NPP to the atmosphere. Overall, 40 sites of the more than 400 sites in the air quality monitoring stations in eastern Japan were studied. For the first time, we show the spatio-temporal variation of atmospheric 137Cs concentrations in the FP and the Tokyo Metropolitan Area (TMA) located more than 170 km southwest of the FD1NPP. The comprehensive dataset revealed how the polluted air masses were transported to the FP and TMA, and can be used to re-evaluate internal exposure, time-series radionuclides release rates, and atmospheric transport models. PMID:25335435