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Published: 2014-09-30
Abstract Views: 52
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DOI: https://doi.org/10.53747/jnst.v4i3.230
Issue
Vol. 4 No. 3 (2014)
Section
Articles
How to Cite
Le , D. D., Bui , T. H., & Vo , T. H. (2014). Application of MELCOR to Westinghouse 4-loop PWR severe accident and evaluation of RPV lower head performance. Nuclear Science and Technology, 4(3), 1-6. https://doi.org/10.53747/jnst.v4i3.230

Application of MELCOR to Westinghouse 4-loop PWR severe accident and evaluation of RPV lower head performance

Le Dai Dien1, Bui Thi Hoa1, Vo Thi Huong2
1 Nuclear Safety Center, INST-VINATOM
2 University of Science and Technology (UST), Korea

Main Article Content

Abstract

In this study, MELCOR computer code is used to simulate the progression of a severe accident initiated from station blackout (SBO) accident for a Westinghouse 4-loop PWR. The hydraulic system is modeled using control volumes and flow paths. The reactor pressure vessel and internals, the primary loops with a pressurizer, steam generators, containment and accumulators are simulated for steady state in a good agreement with reference data.


The two scenarios concerning SBO are investigated. The first scenario simulates RCP seal leakage during SBO and the other is SBLOCA to highlight an effectiveness of accumulators as well as to compare with the first simulation. All active safety systems which depend on AC power are assumed to be unavailable in this analysis.


The main result of the study is an evaluation of RPV lower head integrity during severe accidents. This is preliminary work and expected to give the experience for further studies in the severe accident in nuclear power plants.

Article Details

Keywords

Severe Accident, Station Blackout (SBO), Core melt, RCP Seal leakage, RPV Lower head, Loss of coolant Accident, Accumulator

References

1. Larry Humphries et al, 7th MELCOR Users Workshop, Albuquerque NM, (September 2005).
2. MELCOR Computer Code Manuals, Ver. 1.8.6. Rev.3 of NUREG/CR-6119, SAND2005-5713, Sandia National Laboratories, (2005)
3. C.D.Fletcher et al, SCDAP/RELAP5 Thermal-Hydraulic Evaluations of the Potential for Containment Bypass During Extended Station Blackout Severe Accident Sequences in a Westinghouse Four-Loop PWR, NUREG/CR-6995. (March 2010).
4. Jacopo Buongiorno. PWR Description: Engi-neering of Nuclear System, MIT.
5. Westinghouse Technology Manual. Reactor Coolant System, USNRC Technical Training Center, RV0598
6. S.G. Ashbaugh et al., “Simulation of Mixed Oxide (MOX) Versus Low Enrichment Uranium (LEU) Fuel Severe Accident Response Using MELCOR, Sand2005-4361c.
7. Resolution of Generic Safety Issues: Issue 23: Reactor Coolant Pump Seal Failures (Rev. 1) (NUREG-0933, Main Report with Supplements 1–34).