NRC Completes Review of Oyster Creek's Ability to Handle 'Extreme Events'

The Oyster Creek Nuclear Generating Station should be able to handle extreme events like fires or floods, according to a recent review by the federal Nuclear Regulatory Commission.

 The NRC completed its inspection of Oyster Creek on April 28.

"The objective of this inspection was to promptly assess the capabilities of Oyster Creek to respond to extraordinary consequences similar to the Fukushima Daiichi Nuclear Station Fuel Damage Event," the NRC said in a letter to Michael J. Pacilio, President and Chief Nuclear Engineer for Exelon Nuclear.

The inspection was conducted by two resident inspectors, a region-based inspector and a region-based senior reactor analyst.

The NRC is billing the reviews as "temporary inspections" of all operating nuclear reactors in the United States.

The review assessed plants' capabilities to deal with large fires or explosions on site, internal and external flooding events, and equipment needed to mitigate fire and flood events.

"Like other plants, we identified some issues at Oyster Creek that either we’re going to have to remedy right away or we may have to look at a generic recommendation going forward that all the plants will have to address," NRC spokesman Neil A. Sheehan said. "This is really just our first cut and we just wanted to get a sense of
how these plants are positioned to deal with extreme events."

The review found no deficiencies in Oyster Creek's installed and portable equipment needed for any mitigation strategies.

But inspectors noted several other areas of concern. They included Oyster Creek's ability to respond to a station blackout in a timely manner,  emergency operating procedures to vent the primary containment drywell and torus air spaces and  depressurizing and injecting water into the reactor.

"The finding involved procedural deficiencies [that] challenged a strategy to depressurize and inject water into the reactor," according to the report. "The licensee entered these issues into their corrective action program. The licensee took immediate and corrective action to restore the mitigation strategy."

Inspectors also reviewed emergency operation procedures that would be used to vent the primary containment drywell and torus air spaces using the hardened vent system.

"The inspectors identified an apparent (beyond design and licensing basis) vulnerability, in that if AC power is not available, or if equipment failures occur, air flow in the ventilation systems may be lost and the use of the second vent path described above could result in hydrogen accumulation in the reactor building," the report states.

Oyster Creek should be able to handle a power blackout with current equipment. Exelon also has an agreement with Maxim Power Corporation to provide enough alternate power to deal with a blackout, the report states.

But inspectors said the tests demonstrated "very little margin" that an alternate power source could be started and aligned within a one-hour time requirement.

"Little margin exists (37 seconds) in demonstrating the capability to start and provide power from the alternate AC source within one hour," the report states.

Oyster Creek should be able to handle internal and external flooding events.

The inspectors verified the elevations of the reactor building, turbine building, emergency diesel generator building and other equipment needed for a safety shutdown were "above the probable maximum flood" levels, the report states.

The NRC also determined that training for plant operators and support staff to deal with mitigation strategies was "appropriate and consistent within industry guidelines."

Oyster Creek's agreement with the Forked River Volunteer Fire Company is intact and the department  has equipment to elevate monitor or spray nozzles to spray into the spent fuel pool and/or pumping capacity to charge the fire header or provide spray into the spent fuel pool, according to the report.

Out of 65 operating reactor sites, the NRC identified 12 that had issues with one more more requirements during the inspections.

"Three of the 12 sites have already resolved their issues and the remaining sites are actively working to resolve theirs," according to the NRC's website.

Oyster Creek is the oldest nuclear plant in the United States. It went online on Dec. 23, 1969.