Validation of ATHLET-CD with CORA-28 test /by Murat Tuter.
"Following the incidents at Chernobyl and Fukushima, severe accidents at nuclear power plants (NPP) have become a global concern. These accidents generally occur because of a failure in the reactor cooling system (RCS) and result in the melting of the reactor core and fission product release. This event is mostly caused by a LOCA, loss of flow accident, station blackout or loss of heat sink. During a severe accident, generation of hydrogen as a result of steam-zircaloy fuel cladding is a significant safety concern. To better understand and prevent the hydrogen generation issue, safety related experiments and safety related codes are being developed for NPPs in various countries. The goal of this article is to simulate and analyze the CORA-28 test at KIT (formerly KfKKernforschungszentrum Karlsruhe) to confirm the capabilities of one of the safety codes, ATHLET- CD (GRS). CORA experiments were conducted to examine hydrogen production and bundle degradation for BWR and PWR type fuel bundles under accident conditions, in order to better understand the attributes and behavior of a BWR or PWR bundle during a severe accident. The CORA-28 test differs from most other CORA tests in that it was performed with a pre-oxidized BWR bundle. It was seen that temperature evolutions, the hydrogen production rates and total amount of hydrogen production predicted by ATHLET-CD closely matched the CORA-28 experiment. If operators of nuclear power plants are able to predict hydrogen generation in the containment, that will help them in avoid hydrogen explosions and strengthen NPP safety measures"--Abstract, page iii.