U.S. NRC Blog

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Category Archives: Operating Reactors

Checking the Links in the Nuclear Supply Chain

Mary Anderson
Vendor Inspector
Office of New Reactors

 

The NRC’s focus on nuclear power plant safety doesn’t stop at the plants. Since the 1970s (at that time under the Atomic Energy Commission), NRC inspectors have kept a watch on the companies that provide safety-related components and services to U.S. plants.

 magnifyingglassThe agency believes plants and vendors have effective quality assurance programs in place to proactively prevent the use of counterfeit, fraudulent and suspect items. These programs include careful supplier selections, effective oversight of sub-suppliers, and the authority to challenge a part’s “pedigree” when necessary. 

The NRC oversees these quality activities by inspecting nuclear power plants and their vendors. Vendor inspection can include site visits to production facilities. We create and share information and guidance for the nuclear industry to improve detection of counterfeit and fraudulently marketed products. We also incorporate this information into our inspection programs. The NRC has yet to see any instance of these items in safety-related systems in U.S. plants, but constant vigilance by the licensees and the NRC is essential to make sure it stays that way.

 These days our Vendor Inspection Center of Expertise operates out of the Office of New Reactors to cover both operating reactors and those under construction. NRC staff experts inspect vendors, and observe when plants audit their suppliers, to determine if the plants are properly overseeing their supply chain. Importantly, the NRC also verifies that the plants and their vendors comply with our quality assurance criteria and our “Part 21” requirements for reporting defects and noncompliance, as well as applicable codes and standards.

 The center’s staff also inspect companies applying for design certificates, early site permits or combined licenses. We check on whether the applicants have effective quality assurance processes and procedures for activities related to their applications.

 Right now, we’re working on several vendor-related issues, including evaluating the industry’s process for safely upgrading commercial products that aren’t specifically made for nuclear applications to be used in some plant systems. Common items such as gaskets, nuts and bolts, and electrical relays could be acceptable for nuclear plant use, for example.

 We’re updating and simplifying Part 21, the NRC regulation that covers counterfeit, fraudulent and suspect items. We’re also confirming effective controls are in place to prevent such items from making their way into the U.S. safety-system supply chain. We’re clarifying the processes for evaluating and reporting defects, and the acceptance criteria for off-the-shelf commercial products. The Center is developing regulatory guides so plants and vendors better understand these processes.

 The NRC’s vendor workshop in Portland, Ore., gave us a forum to put this issue in the spotlight. Among a range of vendor topics, this year’s workshop included an industry perspective on counterfeit, fraudulent, and suspect items.

 The NRC has also been actively involved with our international partners to address the risk of counterfeit and fraudulent items. We’ve collaborated with the International Atomic Energy Agency and the Nuclear Energy Agency to share best practices and recommend options to strengthen inspection programs and increase information sharing.

The Latest Chapter in Diablo Canyon’s Seismic Saga

Lara Uselding
Public Affairs Officer, Region IV
 
Scott Burnell
Public Affairs Officer, HQ
 

Today, the NRC is looking over a 1,400-page report produced by the owners of the Diablo Canyon nuclear power plant for California state officials who had asked for new seismic information about the plant.

Specifically, Pacific Gas & Electric produced the report to meet part of a 2006 California law, California Assembly Bill 1632. PG&E shared the report with the NRC as they’re required to do as part of the plant’s existing long-term seismic research program.

diabloEarlier research examined the Shoreline fault, just offshore of Diablo Canyon. Both PG&E and the NRC had previously concluded, in 2009 and 2012, the fault could only generate a quake weaker than one from the Hosgri fault, which Diablo Canyon is designed to safely withstand.

For the new report, PG&E performed state-of-the-art surveys of faults near the plant, including the Shoreline fault. The new report’s more detailed information and updated analysis indicates the Shoreline fault is both longer than previously thought and able to produce a slightly stronger earthquake.

As part of its NRC requirements, PG&E must assess the report’s impact on plant operations. NRC Resident Inspectors and Region IV staff experts have already looked at PG&E’s assessment and so far the information provides confidence the plant can keep the public safe after a seismic event.

While PG&E’s new seismic information adds detail about the faults in the plant’s immediate vicinity, the company’s evaluation claims an earthquake generated by movement on the Shoreline fault would not be as energetic as previous studies say a Hosgri-generated earthquake would be.

Just as with the earlier Shoreline fault reports, the NRC will thoroughly review the new information through our existing oversight methods. The agency will take whatever action is appropriate if our review questions PG&E’s conclusions.

PG&E will also use this new information as it re-evaluates its overall seismic hazard as part of the NRC’s response to the 2011 Fukushima nuclear accident. PG&E’s re-evaluation is due to the NRC in March 2015. The NRC remains committed to integrating new information into our understanding of safety at all reactors.

Get NRC Correspondence on Operating Nuclear Power Plants by Email

Christine Steger
NRR Communications Analyst
 

refresh leafNo need to wait for the mailman anymore. You can quickly and easily receive documents about any operating nuclear power plant you wish electronically.

This distribution process makes it much easier for anyone—licensees, local and state government, members of the public — to quickly get the information they desire.

To sign up, go to the Operating Reactor Correspondence page on the NRC website. The webpage is arranged by region and includes maps that indicate where each plant is located, allowing you to easily find the reactors that are of interest to you. The site also allows you to subscribe and unsubscribe from plant distribution lists at any time.

By signing up, you will receive all outgoing operating reactor correspondence originating from Headquarters, Region I, III, and IV. (Region II is currently unavailable) Correspondence includes, but is not limited to, license amendments, relief requests, exemptions, requests for additional information and public meeting summaries.

Not only is the process faster and easier, but it saves resources, too. In 2010, about 15,000 subscribers received electronic information – avoiding the production of over 5.7 million printed pages.

Refresh is an occasional series where we re-run previous posts. This post originally ran on  April 26, 2011.

 

Natural Hazards Are Part of the Planning

Scott Burnell
Public Affairs Officer

 

Up to now the 2014 Atlantic hurricane season has been pretty calm, but the NRC always keeps an eye out for the strong weather-related events and other natural events the world can generate. We make sure both U.S. nuclear power plants and the agency are prepared for high winds, storm surge and a whole lot more.

Most recently, the seven reactors affected by 2012’s Superstorm Sandy remained safe. Other plants have safely withstood powerful storms, including Waterford 3 in Louisiana handling the effects of 2005’s Katrina and Turkey Point in Florida safely taking a direct hit from 1992’s Andrew.

Sandy may have left a mess in New York, but the nuclear reactors in its wake remained safe. Photo courtesy of FEMA

Sandy left a mess in New York, but the nuclear reactors in its wake remained safe. Photo courtesy of FEMA

Flooding can happen with or without storms, and U.S. plants are designed to and safely ride out significant events, such as when Fort Calhoun in Nebraska dealt with an overflowing Missouri River in 2011. Also in that year, Vermont Yankee remained safe as the Connecticut River valley suffered severe short-term floods from Hurricane Irene’s remnants.

Japan’s Fukushima Dai-ichi nuclear accident in March 2012 showed the world what flooding (in this case from a tsunami) can do to a reactor. The NRC’s learned several flooding-related lessons. from the accident. As a result of NRC direction, U.S. plants are using the latest software and technical know-how to re-analyze all flooding sources. This will help the NRC determine if the plants need to consider higher flooding water levels when establishing plans to stay safe. This effort has also examined existing flood protection and all plants have taken steps to confirm they can implement reliable flood safety plans. In the meantime, several plants have also chosen to enhance their flood protection.

An earthquake caused the tsunami that devastated Fukushima, and again U.S. plants are designed to stay safe in the face of quakes that affect their area. Virginia’s North Anna plant was hit by an August 2011 quake centered a short distance away. The earthquake was strong enough to be felt across the East Coast; it shook North Anna with a little more force than what the plant was originally designed to withstand. North Anna remained safe – multiple inspections showed the plant’s systems were undamaged. This was unsurprising, since plant systems are designed to withstand a combination of events that can exceed the forces generated by an earthquake alone.

As with flooding, the NRC has learned from Fukushima’s quake and other recent earthquakes, and we’re having every U.S. plant reanalyze earthquake hazards to see where enhancements might be needed. All the plants east of the Rockies have taken the first step in that process, and the other plants will do the same next March.

U.S. reactors are also designed for (and have safely survived) hazards such as tornadoes, droughts and other severe weather events. Even with all this preparation, Fukushima reminds us to prepare for the unexpected. The NRC’s approach here involves every U.S. reactor having additional portable systems to restore and maintain safety functions.

All of this work helps ensure the public stays safe when natural disasters strike that may impact U.S. nuclear power plants.

Looking For Better Ways to Determine Severe Weather Hazards

Thomas Nicholson
Senior Technical Advisor
Office of Nuclear Regulatory Research

 

The NRC staff evaluates flood hazards when we review applications for new nuclear facility sites. In addition, we re-examine flooding at operating nuclear power plants — a result of what we learned from the 2011 tsunami flooding at Fukushima Dai-ichi in Japan. These evaluations cover a range of flood events including extreme storms that produce intense local rainfall. The NRC works with other federal agencies to better understand events caused by severe weather as we develop ways to better evaluate possible flooding issues at these sites.

weatherBefore the Fukushima event, the NRC staff informed the Federal Subcommittee on Hydrology of the urgent need to update the National Weather Service’s reports for estimating extreme rainfall events. We use these reports as the basis for our flood design and protection studies. As a result, the subcommittee formed a task force and later the Extreme Storm Events Work Group. The work group is looking at the best practices being used to study extreme storms, and developing estimation procedures and guidance.

The Extreme Storm Events Work Group has an impressive membership. In addition to the NRC, it includes the National Weather Service, U.S. Army Corps of Engineers, U.S. Bureau of Reclamation, Federal Energy Regulatory Commission, Natural Resources Conservation Service, Tennessee Valley Authority, and the U.S. Geological Survey. The work group meets monthly to talk about ongoing activities and products federal agencies are developing to help monitor, model and publish rainfall estimates.

Based in large part on the group’s work, we held a three-day workshop last year on probabilistic flood hazard assessment. The workshop brought together more than 250 international experts and included presentations and panel discussions on extreme rainfall events, coastal storm surge flooding, river flooding, tidal waves, flood-induced dam and levee failures, and combined flood events.

More recently, the work group held a workshop at the National Weather Service to define needed extreme storm products for the nation. These products will greatly assist the federal agencies that are moving towards a risk-informed approach for assessing flooding hazards. NRC staff members are benefiting greatly by their interactions with their federal counterparts in the work group.

Nuclear power plants are built to withstand local extreme weather, but we are always learning how safety margins can be improved even more. By working with weather experts in other federal agencies, we can build on what they’re doing and our nuclear power plants will benefit from this collaboration. We can’t stop flooding from happening, but we can make sure the facilities we regulate are prepared to deal with it safely.

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