CRAC-II

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CRAC-II is both the computer code and the 1982 report of the simulation results (entitled Calculation of Reactor Accident Consequences) performed by Sandia National Laboratories for the Nuclear Regulatory Commission.

The simulations calculated the possible consequences of a worst-case accident under worst-case conditions (a so-called "class-9 accident") for a number of different U.S. nuclear power plants. In this study the Indian Point Energy Center was calculated to have the largest possible consequences, with estimated maximum possible casualty numbers of around 50,000 deaths, 150,000 injuries, and property damage of $274 Billion to $314 Billion (those numbers may have increased since 1982 due to higher population density and increased property values).

The study's results were replaced by the more rigorous 1991 NUREG-1150 calculations.

[edit] NRC disclaimer to CRAC-II and NUREG-1150

"The U.S. Nuclear Regulatory Commission has devoted considerable research resources, both in the past and currently, to evaluating accidents and the possible public consequences of severe reactor accidents. The NRC's most recent studies have confirmed that early research into the topic led to extremely conservative consequence analyses that generate invalid results for attempting to quantify the possible effects of very unlikely severe accidents. In particular, these previous studies did not reflect current plant design, operation, accident management strategies or security enhancements. They often used unnecessarily conservative estimates or assumptions concerning possible damage to the reactor core, the possible radioactive contamination that could be released, and possible failures of the reactor vessel and containment buildings. These previous studies also failed to realistically model the effect of emergency preparedness. The NRC staff is currently pursuing a new, state-of-the-art assessment of possible severe accidents and their consequences."