River Levels on the Rise – The NRC At The Ready

Lara Uselding
Public Affairs Officer
Region IV
 

NEW UPDATE: Currently, river levels are at 1000 feet 6 inches with levels not expected to increase more than a few inches over the next 24 hours. OPPD is returning the plant to full power. NRC inspectors provided around the clock coverage through last weekend and the agency will continue closely monitoring plant operations and river conditions.

UPDATE: Fort Calhoun began decreasing power at midnight, and is currently holding at a reduced power level. The river level is now predicted to crest at 1,002.4 feet on Saturday, which is lower than previously predicted. For comparison, the 2011 flood peaked at about 1,007 feet. Three people from Region IV will begin around the clock coverage today in support of the resident inspectors.

Three years ago this month marks the anniversary of the record Missouri river floods. Now, due to heavy rains, the NRC is once again watching rising Missouri River levels impacting Nebraska’s Fort Calhoun nuclear power plant,  north of Omaha.

Cooper Nuclear Station in Brownville is not anticipating a major impact this weekend.

Fort Calhoun’s procedure requires them to declare a Notice of Unusual Event and be shut down by the time river levels at the site reach 1,004 feet mean sea level. Thursday afternoon, river levels were at 998 and rising. Normally, river levels at the site range from 980 to 990 feet mean sea level.

Over the past week, NRC’s Region IV in Arlington, Texas, has been engaged in routine calls with the United States Army Corps of Engineers, National Weather Service, Federal Emergency Management Agency, National Oceanic and Atmospheric Administration, states, and local response organizations to understand changes in the predicted river levels and assess potential impacts on the plants. 

Simultaneously, the NRC has been overseeing actions that Omaha Public Power District (Fort Calhoun) and Nebraska Public Power District (Cooper) are taking to protect the plant against impending flood waters. At this time, river levels at Cooper are not projected to be high enough to require a plant shutdown.

OPPD’s actions involve the use of sand bags, flood doors, and readying mobile pumps as river levels are projected to rise. They have also ordered equipment to protect certain buildings on site. NRC resident inspectors, who live in the area and work at the plant, have been monitoring the flood preparations.

The NRC is sending more staff to the plant to support the resident inspectors and provide around the clock coverage. During the 2011 flood, river levels at Fort Calhoun reached about 1007 feet and the plant remained in a safe shutdown condition. The plant restarted late last year only after extensive flooding improvements and other safety upgrades mandated by the NRC. Fort Calhoun remains under increased NRC regulatory oversight.

Region IV will continue monitoring the situation for both plants over the weekend.

 

 

NRC Grants Ft. Calhoun License Amendment Request

Lara Uselding
Public Affairs Officer
Region IV
 

When someone sees the words Fort Calhoun and flooding in the same document, it gets attention. So we thought we’d provide some insight into a document — issued this week — with that very word combination.

Ft. Calhoun Senior Resident Inspector John Kirkland provides "boots on the ground" oversight at the plant.
Ft. Calhoun Senior Resident Inspector John Kirkland provides “boots on the ground” oversight at the plant.

The Fort Calhoun Station, located north of Omaha, Neb., and operated by the Omaha Public Power District (OPPD), recently restarted after a long hiatus. But months before that happened, in April 2012, OPPD asked permission to implement a license change involving actions to protect the plant at high and low river levels.

On Jan. 28, 2014, the NRC granted the request and issued a license amendment officially changing when the plant should be powered down during a flood scenario. Simply put, the change involves powering down at 1004 feet mean sea level versus the previously set level of 1009 feet. In addition to setting the river rising to a lower level, the NRC document also specifies that the plant must shutdown within six hours of river levels dropping below 976 feet 9 inches mean sea level.

This all started back in 2010 when NRC inspectors identified concerns with the plant’s flood protection strategy. So this is not a newly identified item and it does not change the plant’s design basis flood. It is an official change to the plant’s license during flood conditions and provides a more conservative level of action.

It is important to note that prior to restart, the licensee made modifications to the plant and had plans in place to protect the plant from rising river levels.

There is still ongoing and important work being done by OPPD, NRC and the U.S. Army Corps of Engineers to evaluate flood risks at the site in accordance with the post-Fukushima actions. The current target date for OPPD providing this information to the NRC is March 12, 2014. In the meantime, the plant is safe and has measures in place to respond to flooding events.

Fort Calhoun: Heat-Up, But Not Start Up

Lara Uselding
Public Affairs Officer
Region IV
 

Following a two-and-a-half year shutdown, Omaha Public Power District (OPPD) is ready to heat up Fort Calhoun’s reactor coolant system to inspect for any leaks. Heat-up is not the same as restarting the plant. The plant has been shut down since April 2011 for a refueling outage. The outage was extended due to historic Missouri River flooding followed by an electrical fire and other restart complications.

Fort Calhoun Station is heating up the reactor coolant system to ensure that the pipes carrying high pressure water or steam do not have leaks. Rather than heating up the reactor using the fission process, OPPD will use the reactor coolant pumps to heat up water and get steam flowing through the system. NRC inspectors are on site to observe licensee activities as well as perform independent inspections to ensure there are no leaks.

In early October, OPPD submitted a license amendment request seeking NRC permission to use a different methodology to evaluate high-pressure pipe breaks. OPPD has to demonstrate that if a high pressure pipe ruptures, that it would not negatively impact nearby equipment.

On Oct. 25, after reviewing public comments and additional information provided by the licensee, NRC approved this license amendment. OPPD did plant modifications and has performed calculations that show a potential pipe rupture will not affect nearby equipment. NRC inspectors are independently verifying the licensee’s analysis and modifications.

In addition, the staff has finalized its review of OPPD’s request to be exempt from the NRC’s fatigue rule which sets work hour limits in support of plant heat-up activities. The NRC’s fatigue rule puts limits on certain workers’ weekly hours to protect against fatigue. For example, during a refueling outage, a worker is allowed to work up to 72 hours every week versus an average of 54 hours over six weeks.

Before the NRC issued the exemption, the staff ensured that workers will have sufficient time to rest prior to working additional hours in support of the heat-up activities.

In addition, the NRC is continuing independent review of the remaining restart checklist items.

Next steps include preparations for the next public meeting whereby staff will update the public on NRC’s oversight status. No decision about restart will be made at that meeting.

Keeping Fort Calhoun’s Tornado Analysis Up To Date

Scott Burnell
Public Affairs Officer
 

When someone mentions the Fort Calhoun plant in Nebraska, flooding issues are probably what comes to mind these days. But the tornadoplant has to withstand everything that Mother Nature can throw at it and tornadoes, obviously, are in the mix.

Fort Calhoun’s been doing some work recently that has the plant operator asking the NRC for permission to revise how its license specifies how to determine tornado effects. Fort Calhoun’s request fits into its ongoing efforts to resolve the issues that have kept the plant shut down since early 2011. The plant, about 19 miles north of Omaha, Neb., has already reinforced several areas of the site against potential tornado damage based on analysis with an NRC-approved method.

That method uses more realistic criteria related to the impact of flying debris in a tornado. While that tornado analysis method is approved, Fort Calhoun’s license still reflects older information, so the plant needs to formally bring the license into line with the analysis method’s criteria.

Fort Calhoun’s owner, the Omaha Public Power District, believes their proposed license change won’t affect the plant’s overall risk of an accident, and the company’s asked the NRC to review the request using a faster process. If we agree a quicker review is appropriate, we could come to a decision on the license change within a couple of days and then offer an opportunity for a public hearing after the change.

More information on Fort Calhoun’s request is available on the NRC’s website, and we have a notice in the local paper as well. Our public meeting in Omaha tonight will discuss our inspection activities and the overall progress Fort Calhoun has made in addressing agency concerns, as well as this most recent request.

Fort Calhoun: A Status Update

Lara Uselding
Public Affairs Officer, Region IV
 

fcsThe NRC held a public meeting with Omaha Public Power District (OPPD) on March 27 to discuss the status of the Fort Calhoun nuclear plant. The plant, just north of Omaha, Neb., has been shut down since April 9, 2011, for a refueling outage. The outage was extended due to historic flooding along the Missouri River followed by an electrical fire that led to an “Alert” declaration and further restart complications.

At the March meeting, NRC oversight panel members shared that a 15-member inspection team had been on site conducting a very thorough inspection and independent verification of the plant’s current status.

Based on the results of the team inspection activities, the NRC has found there are a number of potential issues that appear to need licensing actions. The NRC has scheduled a meeting with OPPD officials on April 22 to discuss four changes the licensee made to the plant that may have required prior NRC approval.

The first involves a change made to the plant’s water intake structure, which was discussed in a recently issued report. Secondly, OPPD used a method to evaluate systems, structures and components for seismic conditions that was not part of their licensing basis. Thirdly, they changed the method for analyzing the suitability of piping systems without approval. Lastly, some plant equipment may not be adequately protected from tornado-driven projectiles.

The meeting to discuss these issues is open to the public and details about the meeting can be found here. The public is encouraged to contact the project managers to obtain meeting materials prior to the meeting and to ensure they plan for the appropriate number of bridge lines.

A second meeting also is scheduled between NRC and OPPD on April 22. That meeting, to discuss the ongoing review of flood mitigation activities, is closed to the public due to sensitive security information being discussed.