CET performance at ROSA/LSTF tests; Twelve tests with core heat-up

Suzuki, Mitsuhiro; Nakamura, Hideo  

This report summarizes performances of core exit thermocouples (CETs) observed in 12 ROSA/LSTF tests which include ten small-break loss-of-coolant accident (SBLOCA) tests and two abnormal transient tests as an additional report to the OECD/NEA ROSA Project Test 6-1 report. The contents of this report are prepared to a task group which was set up to review and consolidate background knowledge of CET application to PWR accident management (AM) measures in April 2008 in the Working Group of Analysis and Management of Accident (WGAMA) at OECD/NEA. These tests cover wide ranges of test conditions such as size and location of break, primary pressure, core power, reflux water fall-back and operator actions. CET performances relative to the core temperature history are studied in each test, and general performances of CET are summarized focusing on the time delay and slow and low temperature excursion.