NRC: Nukes Not Ready for Multiple Threats

Friday, May 20, 2011 @ 03:05 PM gHale

Complying with safety rules and regulations does not mean everything is safe and secure. That is one of the findings the Nuclear Regulatory Commission (NRC) found as it investigated nuclear plants in the U.S. after the Fukushima Daiichi nuclear plant disaster in Japan.

In late April the NRC inspected the Diablo Canyon nuclear power plant in southern California and its report did not find the owner, Pacific Gas & Electric Co. (PG&E), had any serious violation of the NRC’s safety rules.

That was the good news. The bad news was the NRC listed more than a half-dozen issues that could jeopardize the plant if it faced the chain reaction of unexpected and unplanned disasters the Fukushima nuclear plant faced.

NRC investigators reported:
• The plant had a single diesel-driven pump to provide emergency cooling water to a single reactor in case an earthquake cut off normal water flow. The pump could not service both of the plant’s reactors if they lost normal water supply simultaneously, the NRC staff said.
• Some doors at the plant required to protect against flooding of major safety equipment would not self-latch as required.
• The plant’s six emergency diesel generators were in the same plant area, and thus vulnerable to a “common mode” failure.
• An earthquake could cause a structural failure in the building where they stored the fire truck, and debris could block crews from using the truck.
• PG&E planned for a contractor to provide seawater for emergency cooling, but had no backup plan if an earthquake and tsunami blocked highways to the plant. PG&E was going to rely on the California National Guard to deliver diesel fuel for emergency generators if roads were impassable, but had no memorandum of understanding in place for the deliveries.
• Four 20-foot extension cables, used to operate fans that cool portable generators, were missing from their storage location.

This was a snapshot taken of the Diablo Canyon plant, but in the big picture just under 33 percent of the 104 U.S. reactors have some vulnerabilities in handling extreme emergencies, according to the NRC, which is preparing a summary of its post-Fukushima findings.

The NRC said operators have fixed all issues or they are on a schedule for correction, and the safety of the reactors was never in question.

PG&E spokesman Paul Flake said issues reported by the NRC were also a part of company’s own review after Fukushima, and an inspection by the Institute for Nuclear Power Operations, the industry’s confidential safety monitor.

“All of the issues identified in the [NRC] inspection report are being addressed,” he said. “We continue to work with the NRC to introduce safety improvements” required to protect the plant, he said.

When the plants started up decades ago and even up to the last few months, the government and plant operators lived in a world where they felt they had planned for the unthinkable. But in Japan, the unthinkable happened a few times over and now industry leaders are calling for a very rigorous and taught safety culture.

In most cases the plants were following the letter of intent of all requirements, but were they really ready for the unexpected?

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