Sodium Boiling Dryout Correlation for LMFBR Fuel Assemblies

摘要

Under certain postulated accident conditions for a Liquid Metal Fast Breeder Reactor (LMFBR), such as the failure of the shutdown heat removal system (SHRS), sodium boiling and clad dryout might occur in the fuel assemblies. It is important to predict the time from boiling inception to dryout, since sustained clad dryout will result in core damage. In this paper a dryout correlation is presented. This correlation is based on 21 boiling tests which resulted in dryout from the THORS BUNDLE 6A, a 19-pin full-length simulated LMFBR fuel assembly and from the THORS Bundle 9, a 61-pin full-length simulated LMFBR fuel assembly. All these tests were performed as follows: for each specified bundle power, an initial steady-state high sodium flow was established, for which sodium boiling did not occur in the bundle. The temperature at the outlet of the test section was approx. 700 exp 0 C. Then, using a programmable pump control system, the flow was reduced to a low value and boiling occurred. (ERA citation 09:037663)