According to a Web site, SOARCA is a research effort that seeks to "realistically estimate" the outcomes of the leak of a nuclear power plant's radioactive material.

A core component of SOARCA's tests is a software tool from Sandia National Laboratories called . The NRC describes MELCOR as software that can be used to model the "progression of severe accidents in light-water reactor nuclear power plants."

The NRC also uses a separate software tool called MACCS2 to study the potential health implications of an accident involving radiation leaks.

"MELCOR is designed specifically for the purpose of predicting the response of nuclear power plants to severe accidents that might be initiated by low frequency events involving multiple safety system failures," said Randall Gauntt, the manager of Sandia's severe accident and consequence assessment department.

One of the scenario's the software is designed to model is a so-called Station Blackout scenario initiated by seismic damage, similar to what is happening in Japan right now, he said.