Verification of a decay heat model for power increase transients

In this paper, a decay heat model based on the 1979 ANS standard was tested for power increase transients. The model, used in the Westinghouse LOFTRAN code, was previously tested for the calculation of the decay heat following a reactor trip or shutdown. Tests for power increase transients using the same model indicated that the decay heat results of the LOFTRAN code were higher than the results obtained from the 1979 ANS standard. This overprediction is a result of using the five-group constants in the LOFTRAN model, which even though based on the 1979 ANS standard, were chosen to bound all cases. (Author)