Study on the prediction method of large break loss of coolant initial emergency condition

Method for prognosis of severe accident response progress initiated by large break loss of coolant (LBLOCA) was established, based on transient analysis for M310 reactor. The primary loop is rationally simplified based on characters of LBLOCA. The mass and energy conservation equations were solved approximately and the classical formula were used to prognose emergency condition progression. The active core area was divided into 4 radial rings and 10 axial levels, i.e. 40 cells. Experimental correlations were used to calculate heat transfer in the core and the cladding temperature was obtained. Then the core condition can be judged according to the cladding temperature. A code for prognosis of LBLOCA initiated emergency condition could be developed based on the method established in the paper. (authors)