Predictions of FLECHT bottom reflood experiments using RELAP5/MOD2

Conference · Wed Jan 01 00:00:00 EST 1986 · Trans. Am. Nucl. Soc.; (United States)

OSTI ID:6883189

Hassan, Y A

Several full-length emergency core heat transfer (FLECHT) bottom reflood tests were simulated using RELAP5/MOD2 code to assess its capabilities in predicting the reflood phenomena. The code provides a mechanistic approach in treating the quench propagation; it is based on fine axial resolution in the quench vicinity. The predictions of high flooding injection rate and steam cooling tests were in good agreement with the measurements. The low flooding injection rate tests showed a tendency to predict lower peak cladding temperatures than the data. The FLECHT experiments were performed with a cylindrical vessel 14.96 cm in diameter. The test rod bundle installed in the vessel was arranged in a 10 x 10 array simulating a quarter section of a 15 x 15 pressurized water reactor fuel assembly. The heated length of the 91 heater rods was 3.66 m with a cosine axial power distribution. The experiments were initiated with a bottom injection of cold water into the steam-filled, initially preheated rod bundle. The bundle exit pressure was maintained at a constant value during the transient. During the reflood phase, the water injection rate of the emergency core cooling system is one of the important factors that governs the reflooding behavior. In this study, the effects of various flooding rates were investigated using the RELAP5/MOD2 computer code. In addition, a comparison of the code predictions with the available experimental data was performed.

• Research Organization: Babcock and Wilcox, Lynchburg, VA
• OSTI ID: 6883189
• Report Number(s): CONF-860610-; TRN: 87-016357
• Journal Information: Trans. Am. Nucl. Soc.; (United States), Vol. 52; Conference: American Nuclear Society annual meeting, Reno, NV, USA, 15 Jun 1986
• Country of Publication: United States
• Language: English

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