Research on Estimating Methods and Application of Fuel Rods Defect

2017 ◽  
Author(s):  
Huaibin Li ◽  
Yaru Fu ◽  
Lanfang Mao ◽  
Qiliang Mei
Keyword(s):  
Radiation Dose ◽  
Nuclear Power Station ◽  
Nuclear Power ◽  
Evaluation Method ◽  
Fission Products ◽  
Fuel Management ◽  
Power Station ◽  
Fuel Rods ◽  
Reactor Coolant ◽  
The World

When fuel rods have defects, the fission products in the fuel rods will come out and enter the reactor coolant through the defects. The release of the fission products will result in the increase of radiation dose, the indeterminacy of the fuel management and will influence the economics and safety of the nuclear power station. Based on the analysis of the typical nuclides activities in reactor coolant, the evaluation of the defect fuel rods can be realized. This paper studied the related analysis around the world and determined the methods to evaluate the number, the defect type (open or tight) and the burn-up of the defect fuel rods. The evaluation method of this paper can be used to evaluate the defects of fuel rods, and can provide valuable information for the fuel management and dose analysis, and also can be a useful technical support to the operation of nuclear power station.

scholarly journals Contamination of Fukushima Daiichi Nuclear Power Station with actinide elements

2019 ◽  
Vol 107 (9-11) ◽  
pp. 965-977
Author(s):  
Yoshikazu Koma ◽  
Erina Murakami
Keyword(s):  
Nuclear Power Station ◽  
Nuclear Power ◽  
Analytical Data ◽  
Fission Products ◽  
Great Earthquake ◽  
Contaminated Water ◽  
Power Station ◽  
Containment Vessel ◽  
Fukushima Daiichi ◽  
Actinide Elements

Abstract The Fukushima Daiichi Nuclear Power Station, which is owned by the Tokyo Electric Power Company, was damaged by the great earthquake and tsunami on March 11, 2011, and serious contamination due to radioactive nuclides occurred. To investigate the waste management methodologies, contaminated materials were radiochemically analyzed. This paper reviews the analytical data concerning actinide elements. Contaminated water has accumulated in the basement of the reactor and other buildings, and actinide nuclides have been detected in this water. Actinides first get dissolved into the water inside the primary containment vessel, and then their concentration in the water decreases to a certain level with further flow. The contaminated water is chemically decontaminated; however, the actinide concentration does not decrease with time. This suggests that the actinides are continuously being supplied by the damaged fuel via slow dissolution. The dissolved transuranic (TRU) nuclides are recovered in the precipitate via a chemical treatment and are mostly removed from the water. Pu, Am, and Cm were detected in the topsoil at the site and appear to originate from the damaged fuel, whereas the detected U originates from natural sources. TRU nuclides slowly move in soil to deeper layers. The contamination of the rubble is nonuniform, and actinides are detected as well as fission products. Inside the reactor building of unit #2, the TRU nuclide concentration is comparatively higher near the boundary of the primary containment vessel, which experienced a fault during the accident. As for the vegetation, TRU nuclides were only found in fallen leaves near the reactor buildings.

Research about the Hydrogen Removal Verification Method through Porous Medium of Silver Zeolite in Nuclear Power Station

2020 ◽  
Vol 999 ◽  
pp. 31-38
Author(s):  
Qing Bo Bao ◽  
Jian Hu ◽  
Shao Fei Zhou
Keyword(s):  
Nuclear Power Station ◽  
Nuclear Power ◽  
Evaluation Method ◽  
Natural Circulation ◽  
Catalyst Layer ◽  
Severe Accident ◽  
Test Device ◽  
Power Station ◽  
Verification Method ◽  
Silver Zeolite

After severe accident in the nuclear power station, it is necessary to remove the hydrogen timely for the purpose of preventing the containment integrity from breach. This report has investigated and studied the role of silver zeolite in the reaction of hydrogen and oxygen. According to the catalyst role, the principle test device for hydrogen removal with silver zeolite is provided. The force of natural circulation for principle test device is created by the Chimney Effect, which is the result of different density between the internal and external of the device. Also, this report suggests the flowing capability calculation method of up-thrust about the mixture gas passing through the catalyst layer of silver zeolite. The evaluation method of hydrogen removal efficiency with silver zeolite is described. Finally, this report gives the method of CFX numeric analog and the specific simulating steps for the layer of silver zeolite using for catalytic role.

Gas-phase composition in the fuel rods at Novyi Voronezh nuclear power station

1976 ◽  
Vol 40 (3) ◽  
pp. 243-246 ◽  
Author(s):  
A. T. Ageenkov ◽  
A. A. Buravtsov ◽  
E. M. Valuev ◽  
L. I. Golubev ◽  
Z. V. Ershova ◽  
...  
Keyword(s):  
Phase Composition ◽  
Gas Phase ◽  
Nuclear Power Station ◽  
Nuclear Power ◽  
Power Station ◽  
Fuel Rods

Incorporation of the Radioactive Interinfluence in Multi-Unit Seismic PRA

2018 ◽  
Author(s):  
Shuhei Matsunaka ◽  
Chikahiro Sato ◽  
Manabu Watanabe
Keyword(s):  
Nuclear Power Station ◽  
Nuclear Power ◽  
Power Plants ◽  
Evaluation Method ◽  
Common Factor ◽  
Radioactive Material ◽  
Power Station ◽  
Core Damage ◽  
Accident Management ◽  
Multiple Units

Kashiwazaki-Kariwa nuclear power station of TEPCO is the largest nuclear power station in the world, and it has seven nuclear power plants. As the experience at Fukushima Daiichi nuclear power station accident in March 2011 involving concurrent core damage at multiple units, it is considered that the risk derived from hazards of Earthquakes and Tsunamis is relatively significant in Japan, and these events have a high likelihood of damaging multiple units simultaneously. Therefore, it is very important to grasp the multi-unit specific risk. Although there are some unique accident scenarios of Multi-Unit PRA, this paper focuses on the influence of radioactive materials released outside the containment vessel on the accident management of the adjacent unit. The events including core damage and loss of containment function should be considered as the causes of the release of radioactive substances, and operator’s operation or the like should be considered as objects to be adversely affected by them. It is necessary to incorporate that into PRA to confirm the effect on risk. It is very difficult in terms of the maturity of evaluation method and the calculation load to accurately incorporate consequences derived from time series of various events and complicated interaction into PRA model. Therefore, as the first step in evaluating the risk of influence of radioactive material release on the accident management, some streamlining efforts are implemented according to the purpose. For example, Kashiwazaki-Kariwa unit 6 and unit 7 were set as the target units for model simplification. We also assume the earthquake as the initiating event due to the strong common factor for multi units. Whether or not to be operable in the adjacent plant is set conservatively based on deterministic evaluation. PRA taking into consideration the radiation influence by multi-unit accident is compared with normal PRA. Some kind of Core Damage Frequency (CDF) such as CDF1 (Core Damage Frequency at which the damage of one or the other of two unit occur), CDF2 (CDF at which the damage of both of units occur) and CDFTOTAL (CDF at which the damage of one or more units occur: CDF1 + CDF2) are quantified, and the degree of this issue is provided. Although the change of CDFTOTAL was insignificant, the necessity of further study was shown from the viewpoint of the amount and timing of radioactive substance released due to an approximately 1.5-fold increase in CDF2.

scholarly journals A METHOD FOR EVALUATING THE MAXIMUM TSUNAMI LOADINGS ON SEAWALLS

2018 ◽  
pp. 91
Author(s):  
Takuya Toriyama ◽  
Kisaburo Azuma ◽  
Hiroshi Moritani ◽  
Nobuo Ishida
Keyword(s):  
Froude Number ◽  
Nuclear Power Station ◽  
Nuclear Power ◽  
Evaluation Method ◽  
Power Station ◽  
Wave Pressure ◽  
Flume Tests ◽  
Proper Design

A seawall in a nuclear power station is one of the important structures to protect from tsunami. Estimation of tsunami loadings on structures is an important part of the proper design of seawalls. In this study, hydraulic flume tests was conducted to investigate the characteristics of tsunami loadings. Correlations between the loading on a seawall and the Froude number as characteristics of the tsunami flow were investigated. Finally, we proposed a new evaluation method to evaluate the design wave pressure on a seawall. A new evaluation method can predict the design wave pressure on a seawall with taking the characteristics of the tsunami flow into consideration.

`The star called Wormwood': the cause and effect of the Chernobyl catastrophe

1992 ◽  
Vol 1 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Helene Knorre
Keyword(s):  
Nuclear Power Station ◽  
Nuclear Power ◽  
Communist Regime ◽  
Technical Failure ◽  
Power Station ◽  
Cause And Effect ◽  
The World ◽  
Chernobyl Nuclear Power Station ◽  
Political Failure

The explosion at the Chernobyl nuclear power station in 1986 astounded the world. It was shocking not just because of the technical failure—unfortunately such things happen from time to time—but as a social and political failure. The Chernobyl catastrophe undermined and exposed the false, vicious and inhumane Soviet totalitarian system. The Chernobyl explosion initiated the disintegration of the corrupt Communist regime—a regime which had been deemed unshakeable in the USSR.

Phenomena Identification Ranking Table (PIRT) for the MAAP Enhancement Project

2013 ◽  
Author(s):  
Norio Sakai ◽  
Hideki Horie ◽  
Hiromasa Yanagisawa ◽  
Tadashi Fujii ◽  
Shinya Mizokami ◽  
...  
Keyword(s):  
Nuclear Power Station ◽  
Nuclear Power ◽  
Reactor Vessel ◽  
Atomic Energy ◽  
Power Station ◽  
Fuel Rods ◽  
Plant System ◽  
Accident Scenario ◽  
Fuel Rod ◽  
Analysis Models

A phenomena identification ranking table (PIRT) was constructed to identify important phenomena that should be considered in simulating the accident progression for the Fukushima Dai-ichi nuclear power station and predicting the molten core and debris distribution in the reactor system with the MAAP code. The accident scenario, starting from reactor scram to PCV failure, was divided into four time phases in which fuel rod degradation, molten core relocation, and reactor vessel failure were selected as the phase-changing events. Phenomena that would have occurred in the accident were identified in the plant system including the reactor vessel and the containment that consist of 16 sub-components, consistent with the MAAP nodalization for the BWR system. The importance of the identified phenomena was evaluated for each time phase in cooperation with the experts in the Atomic Energy Society of Japan. Eventually total of 1047 phenomena were identified, of which 386 were ranked as ‘highly’ important for the analysis code to evaluate the behavior of molten fuel rods and reactor internal materials. These important phenomena are compared with those considered in the current MAAP analysis models to make sure what should be enhanced to improve the analysis capability for the accident progression.

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