Tag: Fukushima

Scott Burnell

Public Affairs Officer

 

The NRC has already ordered numerous upgrades to nuclear power plant safety based on what we’ve learned about the Fukushima nuclear incident in 2011. Now, the NRC’s Commission is doing more. They have just approved a two-track approach for additional improvements to systems at 31 U.S. reactors that would vent pressure during accidents.

The Commission’s decision is outlined in a Staff Requirements Memorandum. It provides details about the decision, but this is the bottom line: the NRC will issue an Order requiring stronger venting systems and will use the agency’s rulemaking process to consider the best approach by which these 31 reactors can keep radioactive material from the environment during a severe accident.

Some background: Some of the U.S. reactors that are similar to the Fukushima Dai-ichi plant have vents that reduce pressure during an accident and keep water flowing to the reactor to cool the fuel. The venting systems at Fukushima played a role in their nuclear crisis, and the NRC, last March, issued an Order to the 31 plants with similar designs to take action. The plants either had to install vents or improve their existing venting system. The goal was to make sure the vents can operate during the early phases of an accident, even if the plant lost all power for an extended time.

In their latest decision, the NRC Commission votes to further strengthen these vents. The NRC staff has 60 days to finalize an Order for these enhancements. Generally speaking, these additional requirements mean the vents could handle the pressures, temperatures and radiation levels from a damaged reactor, and that plant personnel could operate the vents under these conditions.

As part of the same decision, the Commissioners directed the staff to begin a formal rulemaking on filtering methods that would prevent radioactive material from escaping containment in an accident, either through new filter systems or a combination of existing systems. The staff will develop the technical analysis, a proposed rule and then a final rule. Throughout this process, the public and various stakeholders will have opportunities to submit comments and attend meetings to ask questions. And there will be many future posts about the progress!

David Skeen

Director, Japan Lessons-Learned Directorate

 

Today is the second anniversary of the terrible earthquake, related tsunami and the resulting nuclear accident in Japan. Two years ago, the world watched in horror as the tragedy unfolded. Almost from those very first days, the NRC began to focus on learning from the incident to enhance our reactor safety – and to make sure such an incident would never happen here at home.

For example, U.S. nuclear power plants are using existing programs to address issues identified during last year’s walkdowns, which examined each plant’s earthquake and flooding protection features. Our resident inspectors are watching over that work using our Reactor Oversight Process, and we expect to audit approximately 20 plants (10 for earthquake walkdowns and 10 for flooding) in the spring and early summer to ensure the plants remain protected from such hazards.

We also continue to work with the plants on their re-analysis of flooding and earthquake hazards. We prioritized the flooding re-evaluations last year, examining several factors to give plants one, two or three years to submit their work. The first set of plants should have their responses in by tomorrow, and we’ll review the re-evaluated hazards before issuing a safety assessment for each site. The first set of earthquake hazard re-evaluations, for plants in the central and eastern United States, will be due in September. We’ll give those documents a similar review and resulting safety assessment for each plant.

The plants have also obtained additional equipment that can help keep the reactor and spent fuel pools cool if normal power sources are lost for extended periods of time, as was the case at Fukushima. This work responds to one of three Orders we issued to U.S. nuclear power plants in March 2012. Every plant provided a status report on complying with those Orders in October 2012, and we’ve found that all plants appear to be on track to meet the Orders’ requirements by the required deadlines.

The plants have also recently submitted their integrated approaches to comply with the Orders, and we’re reviewing those plans. By the end of April we’re also expecting the plants to provide the their assessments of how many staff a plant needs to have on hand to respond to a loss of power involving every reactor at a given site

The staff’s latest update to the Commissioners on Fukushima-related activities provides a more detailed look at how each of the NRC Near-Term Task Force’s recommendations is being implemented. While all of the Fukushima-related items are important, we’ve made sure U.S. reactors are paying proper attention to maintaining plant safety, any ongoing work of greater safety benefit or other existing high-priority actions protective of safety.