OMAHA, Neb. (AP) — A Nebraska environmental group wants federal regulators to keep the Fort Calhoun nuclear plant shut down because it would be inundated by floodwaters in the unlikely event of a dam failing upstream.
The Clean Nebraska group said Wednesday that the Nuclear Regulatory Commission's own assessment of the flood threat at the plant about 20 miles north of Omaha predicts all major equipment at Fort Calhoun would be flooded if the Oahe dam on the Missouri River failed.
The NRC said in its memo that this flooding issue at Fort Calhoun did not represent an immediate safety concern. Regulators said the problem could be addressed later as part of the agency's long-term effort to improve the safety of all nuclear plants in the wake of Japan's nuclear crisis last year.
The Clean Nebraska group argues that the flood threat is more pressing because the NRC estimates that dam failure could create floodwaters 46 feet higher than Fort Calhoun is prepared to handle.
"We now know that the flooding hazard at Fort Calhoun greatly exceeds the plant's flooding protection measures. It's not speculative; it's a real problem now," said David Lochbaum, nuclear safety director at the advocacy group Union of Concerned Scientists.
NRC spokesman Victor Dricks said this analysis of the flood threat at Fort Calhoun is preliminary and was designed to look at the consequences of a worst-case scenario. Dricks said the analysis doesn't suggest dam failure is likely.
"It's not an issue that needs to be addressed prior to any potential restart of the plant," Dricks said.
OPPD spokesman Jeff Hanson said the utility has conducted an extensive analysis of the flood threats at Fort Calhoun and developed a strategy that would protect the public in the unlikely event of dam failure.
"In such an event, the containment building would withstand the floodwaters and the fuel would be protected," Hanson said.
OPPD is in the midst of reanalyzing flood threats as part of the NRC's larger review of unlikely safety threats in the wake the nuclear meltdowns at Japan's Fukushima Dai-ichi plant, Hanson said.
Fort Calhoun initially shut down for routine maintenance in 2011, but last summer's flooding along the Missouri River and several regulatory violations have forced it to remain offline.
The recent violations that have kept Fort Calhoun offline include a small electrical fire in June 2011, the failure of a key electrical part during a 2010 test and deficiencies in flood planning that were discovered a year before last summer's extended flooding along the Missouri River.
The record flooding last summer reached as high as 1,006 feet above sea level at Fort Calhoun, but the Omaha Public Power District was able to protect the core of the plant because it has planned to handle flooding up to 1,014 feet above sea level.