Analysis of semiscale test S-LH-2 using RELAP5/MOD2

Technical Report · Tue Mar 31 23:00:00 EST 1992

OSTI ID:5281630

Brodie, P; Hall, P C ^[1]

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1. National Power Nuclear, Barnwood (United Kingdom)

The RELAP5/MOD2 code is being used by National Power Nuclear Technology Division for calculating Small Break Loss of Coolant Accidents (SBLOCA) and pressurized transient sequences for the Sizewell B'' PWR. To assist in validating RELAP5/MOD2 for the above application, the code is being used to model a number of small LOCA and pressurized fault simulation experiments carried out in integral test facilities. The present report describes a RELAP5/MOD2 analysis of the small LOCA test S-LH-2 which was performed on the Semiscale Mod-2C Facility. S-LH-2 simulated a SBLOCA caused by a break in the cold leg pipework of an area equal to 5% of the cold leg flow area. RELAP5/MOD2 gave reasonably accurate predictions of system thermal hydraulic behavior but failed to calculate the core dryout which occurred due to coolant boil-off prior to accumulator injection. The error is believed due to combinations of errors in calculating the liquid inventory in the core and steam generators, and incorrect modelling of the void fraction gradient within the core.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (United States). Office of Nuclear Regulatory Research; National Power Nuclear, Barnwood (United Kingdom)
• Sponsoring Organization: NRC; Nuclear Regulatory Commission, Washington, DC (United States)
• OSTI ID: 5281630
• Report Number(s): NUREG/IA-0065; GD/PE-N--745; PWR/HTWG/P--(89)708; ON: TI92014254
• Country of Publication: United States
• Language: English

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