State-of-the-Art Reactor Consequence Analyses (SOARCA)

NRC initiated the State-of-the-Art Reactor Consequence Analyses (SOARCA) project to develop best estimates of the offsite radiological health consequences for potential severe reactor accidents. SOARCA analyzed the potential consequences of severe accidents at the Surry Power Station near Surry, Va. and the Peach Bottom Atomic Power Station near Delta, Pa. The project, which began in 2007, combined up-to-date information about the plants’ layout and operations with local population data and emergency preparedness plans. This information was then analyzed using state-of-the-art computer codes that incorporate decades of research into severe reactor accidents.

The Nuclear Regulatory Commission sought public comments on the SOARCA Draft Report (NUREG-1935) and held public meetings in February 2012 with residents near the two plants analyzed in the effort. The NRC staff published the final version of NUREG-1935 in November 2012. The final version contains appendices which address comments received from the public and the final letters from the independent external peer review committee.

SOARCA’s main findings fall into three basic areas: how a reactor accident progresses; how existing systems and emergency measures can affect an accident’s outcome; and how an accident would affect the public’s health.  The project’s preliminary findings include:

  • Existing resources and procedures can stop an accident, slow it down or reduce its impact before it can affect public health;
  • Even if accidents proceed uncontrolled, they take much longer to happen and release much less radioactive material than earlier analyses suggested; and
  • The analyzed accidents would cause essentially zero immediate deaths and only a very, very small increase in the risk of long-term cancer deaths.

Supporting technical information regarding the Peach Bottom analysis is available in NUREG/CR-7110, Volume 1, and supporting technical information regarding the Surry analysis is available in NUREG/CR-7110, Volume 2.  A brochure that describes the research for a general audience is available here: NUREG/BR-0359.