The Rising River Puts Flood Preparations to the Test

Flood protection plans that the NRC requires for all nuclear power plants are now being put to the test by historic flooding along the Missouri River in Nebraska. Rising waters are lapping at three sides of the Cooper Nuclear Station in Brownville. Fort Calhoun, located 19 miles north of Omaha, looks like an island in aerial photos.

One question is on everyone’s mind: Will the flood preparations be good enough?

Cooper, which is operating at full power, sits two and a half feet above current river levels. It remains under the Unusual Event declared on June 19. (Unusual Event is the lowest of four emergency categories established by the NRC.)

Nebraska Public Power District officials have installed barriers required to protect buildings and structures from flooding. A three-foot earth and stone berm has been assembled around the plant’s electrical switchyard for additional protection. If all goes well, floodwaters will not impact vital plant equipment.

The NRC has augmented its inspection staff at Fort Calhoun where there is now two feet of water in many areas onsite. In addition to the two resident inspectors, three more inspectors and a branch chief are there to provide around the clock coverage of licensee activities.

The Ft. Calhoun plant remains under the Unusual Event declared on June 6. Omaha Public Power District (OPPD) officials have not restarted the plant, which has been in a refueling outage since early April. This way they can devote their full attention to dealing with the flood rather than adding the distraction of startup, which can take several days of preparation.

The plant has erected an Aquadam around the powerblock – vital areas including the containment and auxiliary buildings. The water-filled berm is eight feet tall and 16 feet wide at the base, and provides protection for up to six feet of water. The dam also protects several pieces of equipment that have been brought onsite, including an additional emergency diesel generator for supplying AC electrical power, water pumps, firefighting equipment and sandbagging supplies.

An earthern berm protects the electrical switchyard and a concrete barrier has been built around electrical transformers to protect them. Satellite phones have been distributed to key workers. Extra food and water has been stockpiled.

Existing diesel fuel tanks have been topped off and two additional fuel tanks have been brought onsite. Special gas-fired pumps are available in the event of station blackout. If there is a complete loss of power on site the pumps can circulate cooling water through the spent fuel pool and reactor core.

The NRC’s inspections in 2009 revealed deficiencies in OPPD’s flood response plan. The NRC increased its oversight of Fort Calhoun while the plant responded, and today the plant is well positioned to ride out the current extreme Missouri River flooding while keeping the public safe.

The NRC’s Region IV in Texas remains a hive of activity with communications ongoing between the technical staff, the resident inspectors at both sites, and licensee officials. Several times each day, managers discuss flood preparations with their licensee counterparts and receive briefings from the resident inspectors. Licensee plans are questioned, critiqued and where necessary augmented with input provided by NRC staff.

It’s all designed to stay one step ahead of the rising floodwaters.

Victor Dricks
Public Affairs

The NRC and the Write-in Campaign

The NRC has recently received thousands of nearly identical CitizenLetter© messages expressing concerns about U.S. nuclear power plants in light of Japan’s earthquake and tsunami, and the subsequent events at the Fukushima Daiichi Nuclear Power Station. The CitizenLetters mention the Pilgrim, Indian Point, Diablo Canyon and San Onofre plants, among others, asking for “immediate inspections” and making claims about the plants’ inability to withstand severe natural events.

The NRC makes sure that all U.S. nuclear power plants are built to withstand external events including earthquakes, flooding, and even tsunamis where they can occur. Each plant is designed to safely ride out the strongest earthquake appropriate for its location. The Diablo Canyon and San Onofre plants, for example, are designed to safely handle the highest levels of seismic activity expected at a U.S. site and both are also designed to withstand the largest tsunami that could affect the California coast.

The events that occurred in Japan are the result of seismic activity in a “subduction zone,” where one tectonic plate is pushed under another plate. The only place this kind of situation would occur in the U.S. is off the coast of northern California, Oregon and Washington. And the only nuclear plant anywhere near there is the Columbia Generating Station, which is some 225 miles inland.

It’s also important to understand that not only does the NRC devote thousands of hours a year to inspecting each nuclear power plant in this country, but that we have also conducted two inspections after the Japan incident specifically for issues related to emergency procedures and resources – just as the CitizenLetters mentioned. Both inspections showed U.S. plants are prepared to use those emergency measures to keep the public safe.

The first inspection covered “B5b” measures, which would help keep the reactors and spent fuel pools safe even after the sudden loss of significant areas of the plants. The second inspection examined the plants’ guidelines for reducing the severity of situations where a reactor core has been damaged. The NRC has also demanded more detailed information from every plant regarding its B5b measures.

A task force of senior NRC managers and staff has been working since early April to examine the lessons that can be learned from the situation in Japan. The task force’s systematic and methodical review will generate recommendations for any changes the NRC should make to its programs and regulations to ensure protection of public health and safety and the environment. This effort will also identify issues that warrant further study in the longer term. The task force is scheduled to provide its recommendations to the Commission in July.

So, while we thank everyone who sent a CitizenLetter, all the available information continues to show that U.S. nuclear power plants are designed and operated so they will protect the public and the environment, even after severe natural events.

Scott Burnell
Public Affairs
 
Note: Chairman Jaczko made some comments today about possible regulatory  improvements that may come out of the post-Japan review. They are posted here: http://www.nrc.gov/reading-rm/doc-collections/news/2011/11-113.pdf .
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