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Category Archives: Operating Reactors

Lining Up New Protections with New Flood Info

Lauren K. Gibson
Project Manager
Japan Lessons Learned Division

Walkdowns (3)The NRC is moving forward on connecting two important lessons we learned from the Fukushima nuclear accident in Japan: protecting key safety functions and reevaluating flood hazards. The agency’s ongoing work would require U.S. nuclear power plants to ensure their protection strategies account for updated flood levels.

The Commission has approved the staff’s plan for completing the reevaluated flooding hazards review. The staff’s plan also covers how U.S. plants must account for the new hazards in their mitigation strategies for beyond-design-basis events. The plan requires U.S. plants to determine which flood hazard data could affect their strategies. We believe this approach is the quickest way to provide the most significant flood protection improvements.

The NRC assesses plants’ re-evaluated flood hazards to see whether the re-evaluated hazards were properly calculated. Plants need these assessments to evaluate their strategies against the re-evaluated hazard. We’re still reviewing some plants’ work; we’re issuing interim letters so those plants know how to follow the rest of the staff’s plan.

The plants examine whether their strategies work under the new hazard conditions and make any appropriate adjustments. For example, a strategy might require a pump in a location submerged by the new possible flood level. The plant would then consider options such as relocating the pump. These assessments and adjustments would be substantially complete by 2016.

The second part of completing the flooding hazard work involves either a focused evaluation or a broader integrated assessment of the plant’s protection capabilities. The specific work depends on:

  1. Which hazards, if any, cause flood levels higher than the plant’s original level.
  2. Whether the plant’s flood protections have available physical margin. (For example, if the new flood hazard level is six feet and a plant’s existing wall is seven feet tall, the wall has available physical margin to handle the new flood level.)
  3. Whether the higher flooding levels disable the plant’s ability to cool the reactor core or spent fuel pool, or protect containment.

If the local intense precipitation hazard is the only cause of a higher level, then the plant performs a focused evaluation. If other flooding hazards are involved, but the plant has available physical margin and can maintain safety functions, then the plant only needs a focused evaluation. The focused evaluation would identify any physical or procedure changes needed to address the new flood level. We would review and inspect these changes to ensure they resolve the issue.

The remaining plants would perform an integrated assessment, looking at all flooding hazards and identifying any changes needed to protect the plant from the new hazard. We’ll review these assessments and decide if voluntary plant actions would be effective or if the NRC must order plant changes.

You can find out more information about Recommendation 2.1—Flooding on the Japan Lessons Learned portion of the NRC website.

A Monday Quiz — A Blue Glow

The Advanced Test Reactor at Idaho National Laboratory uses plate type fuel in a clover leaf arrangement. The blue glow around the core is known as Cherenkov radiation. Courtesy of Idaho National Laboratory.

This Advanced Test Reactor runs tests that determine how fuels and materials react when bombarded by streams of neutrons and gamma rays under a variety of pressure and temperature conditions. Information that would normally require years to gather from normal reactor operations can be obtained in a matter of weeks or months. The primary “customer” of the reactor is the Naval Nuclear Propulsion Program.

The NRC licenses 31 research and test reactors in 21 states (as of 2014); eight research reactors are being decommissioned. We also license the operators and conduct some 50 inspections each year. DOE, however, regulates this particular test reactor.


Where is this test reactor located?
What scientist (and Nobel Prize winner) gave his name to the blue glow seen in this photo?


NRC — Ready for the 2015 Hurricane Season UPDATED

Update: Due to Hurricane Bill, the South Texas Project nuclear power plant, located near Bay City, Texas, has started tropical storm/hurricane procedures. Actions taken include performing a plant walkdown to secure and tie down anything that could be become a projectile missile or flying debris. The plant operator has implemented restrictions for employees to stay inside if winds get above 40 mph. Today, winds are projected to be sustained at 50 mph with gusts up to 60 mph. Both units are at full power unless winds reach speeds above 75 mph, but that is not expected at this time. They have additional staff onsite and supplies (cots, food, water). The resident inspectors are not evacuating and an additional group of NRC inspectors has been on site and will remain so to back up the residents if need be. (At this time the hurricane is not expected to affect River Bend or Waterford nuclear power plants, but the NRC’s Region IV will continue to monitor the projected path.)

Roger Hannah
Senior Public Affairs Officer
Region II

The hurricane season officially began June 1, but this year the Carolina coast experienced a tropical storm named Ana in early May. While Ana produced winds of more than 60 miles an hour near the Brunswick nuclear plant, there was no major damage. It did, however, serve as an early reminder of the NRC’s role in ensuring nuclear plants remain safe during damaging winds and storm surges.

A hurricane as seen by satellite. Be assured, it's not happening now.

A hurricane as seen by satellite. Be assured, it’s not a current photo and is NOT happening now.

The NRC has years of experience with hurricanes and other severe storms. Nuclear facilities were affected by Hurricane Andrew in Florida in 1992, by Katrina in Louisiana in 2005, by Sandy along the East Coast in 2012 and by many others. Although the National Oceanic and Atmospheric Administration predicts fewer storms this year than the historical average, any storm can be dangerous.

How does the NRC oversee the safety of nuclear plants and other facilities during these storms?

The NRC staff monitors tropical storms as they form, and if the projected path is towards the coast, the agency’s regional offices begin continuous tracking. If a storm’s path shows the possibility of it affecting a nuclear plant or other NRC-licensed facility, the NRC collects more information on the storm and NRC resident inspectors check the plant’s preparations. Depending on the projections, additional NRC inspectors may be dispatched to some nuclear plants.

Around 12 hours before predicted hurricane-force winds, nuclear facilities that may be in the path provide the NRC updates and NRC inspectors monitor the plant staff’s actions. Plant procedures require the plant operators to shut the reactor down if winds greater than a certain speed are expected on the plant site.

Nuclear plants are built to withstand all expected local meteorological events, including hurricanes, and actual storms have shown that plants can safely shut down and with little or no damage to important safety equipment.

The NRC stays in contact with plants and NRC inspectors on site as the storm passes over, and the agency has backup systems if regular communications channels are lost.

Once the storm is over, the NRC and FEMA assess damage and make sure local emergency response organizations can resume their normal roles. If the plant shut down, it will only be restarted after the NRC is satisfied there is no damage to safety equipment and emergency response capabilities have been restored.

Fortunately, most tropical storms and hurricanes do not adversely affect nuclear plants, but the NRC is ready in case one does.

A Focus on NRC Annual Assessment Meetings

Prema Chandrathil
Public Affairs Officer
Region III

formal meetingIt’s Spring – and annual assessment meetings are popping up all over. The NRC holds these important meetings every year for every nuclear power plant to provide information about how the plant performed in the previous year.

What happens at these meetings? If you attend, you can expect to hear about NRC inspection activities, how the plant performed from a safety perspective, and how it met NRC requirements, including if there were any violations and, if so, what actions were taken to correct those issues. You would also hear directly from NRC resident inspectors, who are at the plant on a daily basis and know the plant inside and out. They and other specialists inspect the plant to help ensure protection of the public health and safety.

We just posted a short YouTube Video on the subject today. “Three Minutes with an NRC Expert on the Annual Assessment Meetings” can be found here.
community outreachAs the video underscores, annual assessment meetings are not all the same. There are different types, including a formal meeting, an open house and community outreach event. The most common meeting is a formal meeting where the public is invited to observe the interactions between the NRC and plant staff. Open houses are informal and are designed to encourage one-on-one conversations. An example of a community outreach event is where the NRC would staff a booth at a local event in an effort to talk to more folks. The type of meeting will vary depending on the plant’s performance, community feedback and local interest.

No matter the format of the meeting, the public will have an opportunity to not only hear about the plant’s performance and NRC inspection efforts but also ask questions, make comments and talk to the NRC staff.

A common misconception is that these meetings are transcribed — they are not. The basis for the NRC’s discussion is the annual assessment letters issued by the NRC to individual plants. These letters are documented and publically available. You can find them on the NRC website.

3 minutes with AA_1The NRC continues to reach out in an effort to inform people about what the agency does, how we regulate and how a particular plant is doing in meeting NRC rules and regulations. We are committed to protecting public health and safety, and strive to be open and responsive in these annual assessment meetings.

If you are interested in any upcoming public meeting you can check out the public meeting schedule and review the meeting notice as well as the press release.

We hope you’ll check out the video to learn more.

NRC Inspectors Head to Indian Point 3’s Electrical Supply Room

Neil Sheehan
Public Affairs Officer
Region I

Dousing the fire that ensued after one of the Indian Point 3 nuclear power plant’s main transformers failed on the evening of May 9th required substantial amounts of water, as well as foam. The water was applied by the automatic fire-suppression system for the transformer and by the on-site fire brigade and firefighters from off-site who provided assistance.

indianpointOne of the follow-up concerns for the NRC is that during the event, some water was found on the floor of an enclosed room inside the plant housing electrical supply equipment. The power that flows through that equipment is used to operate plant safety systems and components.

The equipment was not affected by the water during the May 9th event, and the plant was safely shut down. The plant remains out of service while work to install a replacement transformer is carried out.

In order to better understand what occurred, the NRC is launching a Special Inspection at the plant today. The three-member team will evaluate, among other things, how the water – apparently totaling an inch or two on the room’s floor — ended up in the room; and the potential for a significantly larger volume of water to build up and adversely impact the electrical equipment.

The NRC applies risks insights and specific knowledge of plants when determining whether to perform a follow-up inspection and what type. In this case, the NRC decided it was appropriate to conduct a Special Inspection, the first level of “reactive” reviews performed in response to an event. The agency performs such inspections to independently evaluate and assess what occurred during an event, as well as any plans by the plant’s owner to fix related problems.

In addition to the Special Inspection, the NRC is continuing to review the transformer failure, operator and equipment response during the event, and other issues.

A report containing the findings of the Special Inspection will be issued within 45 days after the formal conclusion of the review.


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