There have been many flood-related concerns about the safety of nuclear power plants in the United States in the wake of the Fukushima Daiichi nuclear disaster, documents released through the Freedom of Information Act have shown that regulators have been concerned about the possibilities of floods overwhelming nuclear power stations for decades. The Nuclear Regulatory Commission has been instructing licensees to take another look at some of the risks posed to nuclear power plants by upstream dams among a host of other potential risks.
Currently, a seven and a half foot wall protects the Oconee nuclear plant, but previous estimates showed that between nine and sixteen feet of increased water could be generated by flooding and threaten Oconee’s backup control system. Last fall, two NRC risk analysis engineers Richard Perkins and Larry Criscione blasted the previous estimates and said that the NRC had been forced to heavily edit one flood report for fear of embarrassment over how long they have let the issue linger without resolution.
In response, Duke Energy commissioned a study which it submitted to the NRC earlier this month, which detailed its response to the Oconee Nuclear Power Station from the upstream Jocassee Dam. Duke Energy did not however release the flooding hazard study to the public, but while discussing details of the study on Monday with the Nuclear Regulatory Commission in Rockville, Maryland, some details became more clear. The reports given by Duke Energy representatives showed that, while the licensee admits that it is not impossible, they do not consider the failure of the massive 385 foot upstream dam a “credible risk”.
Arnie Gundersen, chief engineer for Fairewinds, laments the very verbage used by Duke officials commenting, “Not credible, is that not the same thing that TEPCO once said about risks from 50 foot tsunami waves?”
Source: Greenville Online