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Title: Assessment of RELAP/MOD3 using BETHSY 6.2TC 6-inch cold leg side break comparative test

Technical Report ·
DOI:https://doi.org/10.2172/393373· OSTI ID:393373
; ; ;  [1]
  1. Korea Atomic Energy Research Institute, Yusung, Taejon (Korea, Republic of); and others

This report presents the results of the RELAP5/MOD3 Version 7j assessment on BETHSY 6.2TC. BETHSY 6.2TC test corresponding to a six inch cold leg break LOCA of the Pressurizer Water Reactor(PWR). The primary objective of the test was to provide reference data of two facilities of different scales (BETHSY and LSTF facility). On the other hand, the present calculation aims at analysis of RELAP5/N4OD3 capability on the small break LOCA simulation, The results of calculation have shown that the RELAP5/MOD3 reasonably predicts occurrences as well as trends of the major phenomena such as primary pressure, timing of loop seal clearing, liquid hold up, etc. However, some disagreements also have been found in the predictions of loop seal clearing, collapsed core water level after loop seal clearing, and accumulator injection behaviors. For better understanding of discrepancies in same predictions, several sensitivity calculations have been performed as well. These include the changes of two-phase discharge coefficient at the break junction and some corrections of the interphase drag term. As result, change of a single parameter has not improved the overall predictions and it has been found that the interphase drag model has still large uncertainties.

Research Organization:
US Nuclear Regulatory Commission (NRC), Washington, DC (United States). Office of Nuclear Regulatory Research; Korea Inst. of Nuclear Safety, Taejon (Korea, Republic of)
Sponsoring Organization:
Nuclear Regulatory Commission, Washington, DC (United States); Korea Inst. of Nuclear Safety, Taejon (Korea, Republic of)
OSTI ID:
393373
Report Number(s):
NUREG/IA-0131; ON: TI97000707; TRN: 96:029226
Resource Relation:
Other Information: PBD: Oct 1996
Country of Publication:
United States
Language:
English