MAAP [Modular Accident Analysis Program] steam generator modeling and benchmarking with Westinghouse MB-2 tests

A generalized theoretical model has been developed and numerically implemented to predict the thermal hydraulic response of a U-tube steam generator during various transients such as steam line break, steam generator tube rupture, loss of feed water, and primary side transients. A two region model is used with a simple and fast running code to calculate essential state variables. It can simulate all the transients from normal to the extreme conditions such as when the secondary side contains superheated steam with non-condensable gases and no water. Comparisons are made to the data of the Westinghouse Model Boiler No. 2 (MB-2) test1 for five types of transient: (1) 100% steam line break from hot standby condition, (2) 50% steam line break from hot standby condition. (3) 8% steam line break with steam generator tube rupture, (4) loss of feedwater from 100% power without reactor scram, and (5) loss of feed water from 100% power with reactor scram. Good agreement is observed between the model predictions and the test data. 9 refs., 16 figs