Members of the Nuclear Regulatory Commission's Advisory Committee on Reactor Safeguards pressed officials Thursday to explain how they concluded that 50 miles was a safe distance from the crippled reactors. The Japanese government had set a 12-mile evacuation zone.
Randy Sullivan, who leads a protective measures team, says no data from the site was used to determine the distance. Instead, he says, it was calculated based on the potential conditions.
Sullivan told the committee that the calculation was based on "a big release" that they could not confirm was happening.
