CABRI-RAFT TP2 and TP-A1 tests simulating the unprotected loss-of-flow accident in sodium-cooled fast reactors

小野田 雄一; 深野 義隆; 佐藤 一憲; Marquie, C.*; Duc, B.*

Proceedings of 13th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-13) (CD-ROM), 15 Pages, 2009/09

TP2 and TP-A1 tests were conducted in the framework of the CABRI-RAFT program to study post-failure material-relocation during the Unprotected Loss-of-Flow (ULOF) accident in sodium-cooled fast reactors. In these tests, a three-pin-cluster geometry was adopted to supply complementary information to the existing CABRI-single-pin tests. Two different levels of energy injection into the fuel pins were realized to clarify the effect of fuel enthalpy on axial fuel relocation. Starting from a steady-state condition, Loss of Flow (LOF) was applied and then Transient Over Power (TOP) was triggered 13.4 s and 9.1 s after the coolant boiling in the TP2 and TP-A1 tests, respectively. Through a close look at these test results, it is concluded that the fuel relocation is dominated by accumulated fuel enthalpy and is not depending on three-pin-cluster or single pin conditions.