Federal regulators said Tuesday they will closely watch the Fort Calhoun nuclear-power plant in Nebraska following problems with flood protection and automatic shut-down operations found at the plant.
Power-plant owner Omaha Public Power District shut down the plant in April to refuel the reactor, but suspended those activities in June as rising Missouri River water levels threatened the plant. Flood barriers have protected the plant, but some of those protections weren't in place a year ago, according to the Nuclear Regulatory Commission.
While NRC inspectors plan to continue monitoring the plant as long as water levels remain high, the agency's stepped-up scrutiny is unrelated to the flooding, said NRC spokesman Victor Dricks.
"They are receiving heightened oversight because of inadequate procedures to protect their intake structure and auxiliary building from a flood…and other past performance issues," Mr. Dricks said.
The NRC's move comes as the agency and the 104 nuclear-power plants it oversees face heightened public concern about safety following the March earthquake and tsunami that triggered a disaster at a nuclear-power complex in Japan. The NRC has been considering proposals issued last week by a staff task force that looked at how prepared U.S. nuclear-power plants are for similar natural disasters.
On Tuesday, the NRC cited Omaha Public Power with a safety violation after inspectors found last year that one of four key electrical systems used to automatically shut down the reactor in an emergency wasn't working.
In October, the NRC cited the utility for violating rules that require it to be able to protect an auxiliary building with important reactor controls and other parts of the plant from flooding. NRC inspectors found that the utility did not have adequate procedures in place to protect key facilities from a flood up to 1,014 feet and that it would not be able to complete a so-called cold shutdown under normal operations.
Omaha Public Power has fixed the problems, but because of the citations, the plant has been placed in a category of facilities that require greater NRC attention, Mr. Dricks said.
"At no time was there any risk to the health and safety of the public and we will continue to work with the NRC," said Mike Jones, a spokesman for the utility.
Staff at the plant, which is still offline, have managed to keep all critical areas dry, despite floodwaters that have enveloped a parking lot and other areas of the facility that aren't critical, Mr. Jones said.
He added that while Missouri River water levels have not risen over the past week, they remain above 1,004 feet, the level at which the Fort Calhoun plant must cease operations, under government rules.
The utility does not know when it will be able to restart the plant, Mr. Jones said.
