November 1999 Highlight

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Hungary

VEIKI completes hydrogen mixing analysis

The Institute for Electric Power Research (VEIKI) in Hungary completed an analysis of multi-compartment hydrogen mixing in the Paks VVER-440/213 reactor for a loss-of-coolant accident (LOCA) associated with a 100-mm pipe break. The VEIKI researchers used the state-of-the-art GASFLOWII 3-D CFD computer code to evaluate the time history of hydrogen concentration on a compartment-by-compartment basis. Hydrogen safety is one of the key issues in addressing beyond-design-basis accidents in nuclear power plants. Support for running the GASFLOW code was provided by Argonne National Laboratory. One of the objectives was to compare the hydrogen distribution results obtained using GASFLOW with results using a lumped-parameter code CONTAIN. Results have indicated very significant differences, with GASFLOW providing the more conservative results. (Walter Pasedag, DOE, 301-903-3628; Bruce Spencer, ANL, 630-252-6564)