scholarly journals Analysis of Severe Accidents in Spent Fuel Pool of Fukushima Daiichi NPP Using MELCOR 1.8.6 Computer Code

2016 ◽  
pp. 13-20
Author(s):  
O. Kotsuba ◽  
Yu. Vorobyov ◽  
O. Zhabin ◽  
D. Gumenyk
Keyword(s):  
Computer Analysis ◽  
Computer Code ◽  
Computer Models ◽  
Reliable Data ◽  
Severe Accident ◽  
Spent Fuel ◽  
Severe Accidents ◽  
Spent Fuel Pool ◽  
Fukushima Daiichi ◽  
To Receive

The paper presents specific approaches to modeling the spent fuel pool (SFP) of Fukushima Daiichi NPP and results of thermohydraulic calculations of severe accidents in SFP using MELCOR 1.8.6 computer code. The dynamics of main processes accompanying severe accident progression in SFP of such a type was defined based on computer analysis. Obtained results may be used to improve available SFP computer models to receive more reliable data on the progression of emergency processes in NPP SFPs.

Research and Development of Validation and Drill System for Full Scope of Severe Accident Management Guideline

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
Zhifei Yang ◽  
Yali Chen ◽  
Hu Luo
Keyword(s):  
Research And Development ◽  
Computer Code ◽  
Severe Accident ◽  
Accident Analysis ◽  
Spent Fuel ◽  
Accident Management ◽  
Analysis Computer ◽  
Spent Fuel Pool ◽  
Accident Scenarios ◽  
Drill System

To respond to the urgent needs of verification, training, and drill for full scope severe accident management guidelines (FSSAMG) among nuclear regulators, utilities, and research institutes, the FSSAMG verification and drill system is developed. The FSSAMG includes comprehensive scenarios under power condition, shutdown condition, spent fuel pool (SFP) condition, and refueling conditions. This article summarized the research and development of validation and drill system for FSSAMG by using the severe accident analysis computer code modular accident analysis program 5 (MAAP5). Realistic accident scenarios can be verified and exercised in the developed system to support FSSAMG training, drill, examination, and verification.

scholarly journals EVALUATION METRICS APPLIED TO ACCIDENT TOLERANT FUEL CLADDING CONCEPTS FOR VVER REACTORS

2016 ◽  
Vol 4 ◽  
pp. 89 ◽  
Author(s):  
Martin Sevecek ◽  
Mojmir Valach
Keyword(s):  
Severe Accident ◽  
Evaluation Metrics ◽  
Development Phase ◽  
Fuel System ◽  
Fuel Cladding ◽  
High Interest ◽  
Severe Accidents ◽  
Time Period ◽  
Fukushima Daiichi ◽  
Reactor Types

Enhancing the accident tolerance of LWRs became a topic of high interest in many countries after the accidents at Fukushima-Daiichi. Fuel systems that can tolerate a severe accident for a longer time period are referred as Accident Tolerant Fuels (ATF). Development of a new ATF fuel system requires evaluation, characterization and prioritization since many concepts have been investigated during the first development phase. For that reason, evaluation metrics have to be defined, constraints and attributes of each ATF concept have to be studied and finally rating of concepts presented. This paper summarizes evaluation metrics for ATF cladding with a focus on VVER reactor types. Fundamental attributes and evaluation baseline was defined together with illustrative scenarios of severe accidents for modeling purposes and differences between PWR design and VVER design.

FUELPOOL: A Computer Program to Model CANDU Spent Fuel Pool Severe Accident Progression and Consequences

2020 ◽  
Author(s):  
Yong Mann Song ◽  
Jong Yeob Jung ◽  
Sunil Nijhawan
Keyword(s):  
Water Layer ◽  
Daily Basis ◽  
Severe Accident ◽  
Mitigation Measures ◽  
Fluid Loss ◽  
Spent Fuel ◽  
On Line ◽  
Additional Water ◽  
Spent Fuel Pool ◽  
Tennis Court

Abstract CANDU PHWR spent fuel pools (SFPs), smaller than a tennis court, contain up to 38,000 or more (49,000 in Wolsong)fuel bundles in geometries not replicated in any other power reactor. Therefore, the phenomenological issues, accident progression pathways and effectiveness of mitigative actions are somewhat different. This requires a dedicated approach in progression and consequence assessments of potential accidents and development of mitigation measures. The SFPs house densely packed fuel bundles stacked in about a hundred vertical stainless steel tray towers, each containing 24 spent fuel bundles in each of the 16 or more (19 in Wolsong) horizontal fish basket style steel trays. Some of theupto 10 year worth of the on-line refuelled bundles in the SFP are at relatively high decay powers as fuel trays are prepped for the towers in near daily basis. In addition, there is a provision (see Figure 1) that a full core of bundles 20 days after being at full power can be transferred to the spent fuel bay at any time. About 4.5m of additional water layer on top of the tray towers provide radiation protection and a healthy margin to small rate of fluid loss.

Probabilistic Assessment of Countermeasures for Loss of Ultimate Heat Sink to Spent Fuel Pool

2017 ◽  
Author(s):  
Bumpei Fujioka ◽  
Naoki Hirokawa ◽  
Daisuke Taniguchi
Keyword(s):  
Heat Sink ◽  
Nuclear Power ◽  
Water System ◽  
Cooling Water ◽  
Severe Accident ◽  
Probabilistic Assessment ◽  
Spent Fuel ◽  
The Past ◽  
Plant Safety ◽  
Spent Fuel Pool

In the Fukushima Dai-ichi nuclear power station, Loss of Ultimate Heat Sink (LUHS) was caused by the great east japan earthquake and the subsequent tsunami [1]. It resulted in severe accident in three units. In that time, fuel damage in Spent Fuel Pool (SFP) were prevented by the various countermeasures such as makeup by pump truck and recovery of injection systems /cooling water system. In the past, Probabilistic Safety Assessment (PSA) has been developed with a focus on the reactor. After the accident, it has been acknowledged that SFP PSA is important to enhance the plant safety. In this study, probabilistic assessment is performed to suggest countermeasures for LUHS to SFP.

Study on Hydrogen Risk of Spent Fuel Compartment Induced by Containment Venting

2017 ◽  
Author(s):  
Yabing Li ◽  
Xuewu Cao
Keyword(s):  
Control System ◽  
Heat Removal ◽  
Compartment Model ◽  
Severe Accident ◽  
Spent Fuel ◽  
Fukushima Accident ◽  
Spent Fuel Pool ◽  
Heat Removal System ◽  
And Control ◽  
Removal System

Hydrogen risk in the spent fuel compartment becomes a matter of concern after the Fukushima accident. However, researches are mainly focused on the hydrogen generated by spent fuels due to lack of cooling. As a severe accident management strategy, one of the containment venting paths is to vent the containment through the normal residual heat removal system (RNS) to the spent fuel compartment, which will cause hydrogen build up in it. Therefore, the hydrogen risk induced by containment venting for the spent fuel compartment is studied for advanced passive PWR in this paper. The spent fuel pool compartment model is built and analyzed with integral accident analysis code couple with the containment analysis. Hydrogen risk in the spent fuel pool compartment is evaluated combining with containment venting. Since the containment venting is mainly implemented in two different strategies, containment depressurization and control hydrogen flammability, these two strategies are analyzed in this paper to evaluated the hydrogen risk in the spent fuel compartment. Result shows that there will not be significate hydrogen built up with the hydrogen control system available in the containment. However, if the hydrogen control system is not available, venting into the spent fuel pool compartment will cause a certain level of hydrogen risk there. Besides, suggestions are made for containment venting strategy considering hydrogen risk in spent fuel pool compartment.

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