U.S. NRC Blog

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Ten Things You May Not Know — About Nuclear Power and the NRC

Stephanie West
Public Affairs Specialist

It’s summer and you might be reading this blog while relaxing in the sun or otherwise taking it easy. So, just for fun, we’ve listed 10 nuclear-related facts you might find interesting, albeit light, reading:

1. Nothing lasts forever. Every year or two, reactor operators spend about a month, removing and replacing about one-third of a reactor’s fuel and performing various maintenance activities during plant outages to make sure reactors perform efficiently. Source: NRC Information Digest

youtube22. No bowling leagues. In order to preserve their objectivity, NRC resident inspectors are discouraged from attending social events where nuclear plant employees are involved. They also may not serve at any nuclear plant longer than seven years.

3. Who at the NRC must train to escape a sinking helicopter? Health physicists in NRC’s Region IV office of course. A handful of them must fly to inspect offshore oil rigs in federal waters. They must be prepared not only to escape a helicopter, but to survive a fire on an oil platform by jumping into the sea and fighting off sharks by kicking them in the snout.

4. Quick question: Where is the largest research reactor in the U.S.? Check below for the answer. But you should know that Research and Test Reactors operating at levels of 2 megawatts thermal (MWt) or greater receive a full NRC inspection every year. The largest U.S. research reactor, which produces 20 MWt, is 75 times smaller than the smallest U.S. commercial power reactor.

5. Once the explosive ingredient in Soviet nuclear warheads, highly enriched uranium was diluted to become the stuff that powered our homes and businesses in the U.S. The Megatons to Megawatts program was born from a 1993 agreement between the U.S. and Russia to reduce the stockpile of Soviet-era highly enriched uranium.

6. Everyone loves this story. MB900371234The most all-time viewed post on this NRC blog is “Putting the Axe to the Scram Myth” with more than 18,000 views since it was originally posted in 2011.

7. It’s just not easy being a spent nuclear fuel transportation cask. Each must be designed to survive a 30-foot drop onto an unyielding surface, a puncture test, a fully engulfing fire at 1,425 degrees Fahrenheit for 30 minutes and immersion under water.

8. The Watts Bar nuclear plant makes its mark both on this century and the last. Unit 1 was the last U.S. reactor to come online in the 20th century and Unit 2 is expected to be the first to come online in the 21st. Read more about the history of the Watts Bar Nuclear Plant in our blog post: Watts Bar – Making History In Yet Another Century.

9. Months of planning, thorough inspections, dozens of law enforcement officials, a specially equipped truck – and a S.W.A.T. team. It sounds like a checklist for an action movie. Instead it was used to move a mini refrigerator-sized irradiator in Anchorage about 2.5 miles. These small irradiators are used to sterilize medical equipment and products, and contain a sealed source of radioactive material. They are protected to keep the public and environment safe from exposure, but also to keep it out of the hands of terrorists.

reportcard10. It’s no “easy A.” In addition to years of related experience, NRC-licensed nuclear plant operators must receive extensive classroom, simulator and on-the-job training. But they also must be certified as physically and mentally fit to be an operator. Source: NRC Information Digest

Answer: National Institute of Standards & Technology, Gaithersburg, Md.

 

Dry Casks 101: What Do Robots Have to do With Dry Cask Storage?

Darrell Dunn
Materials Engineer

CASK_101finalCutting-edge robot technology is making it easier to inspect inside spent fuel dry cask storage systems.

You may remember from past blog posts that most spent fuel dry cask storage systems, or casks, consist of stainless steel canisters that are welded shut to safely contain the radioactive contents. The canisters are in turn placed inside thick storage overpacks to shield plant workers and the public from radiation. As these casks remain in use for longer time frames, the ability to inspect canister surfaces and welds will become an important aspect of the NRC’s confidence in their safety.

To be clear: techniques for inspecting canister surfaces and welds have been used for decades. These techniques are collectively known as nondestructive examination (NDE) and include a variety of methods, such as visual, ultrasonic, eddy current and guided wave examinations.

img2 (002)Where do robots come in? They are a delivery system. Robots are being developed to apply these NDE techniques inside casks. Not just any robot will do. These robots need to fit into small spaces and withstand the heat and radiation inside the cask. The state-of-the-art is evolving quickly.

To date, the Electric Power Research Institute and cask manufacturers have successfully demonstrated robotic inspection techniques to NRC staff three times: at the Palo Verde plant in Arizona (Sept. 2-3, 2015), at the McGuire plant in North Carolina (May 16-19, 2016), and just last month, at Maine Yankee (July 12-13, 2016).

At Palo Verde, the robot was used to deliver eddy current testing instrumentation inside a cask. Eddy current testing detects variations in electromagnetically induced currents in metals. Because it is sensitive to surface defects, eddy current testing is a preferred method for detecting cracks. The inspection robot was used to examine part of the mockup canister fabrication weld. An EPRI report provides a detailed description of the Palo Verde test. Future reports are expected on the McGuire and Maine Yankee demonstrations. These demonstrations are helping to refine the robots’ designs.

Cutaway Cask Mockup with Robot (002)The Maine Yankee demo was conducted in July 2016 on a cask loaded in 2002. The demo involved a robot maneuvering a camera with a fiber optic probe, which meets the industry code for visual examinations, inside the cask. The probe was able to access the entire height of the canister, allowing the camera to capture images of the fabrication and closure welds. The welds showed no signs of degradation. The canister was intact and in good condition.

The robot was also able to obtain samples from surfaces of the cask and canister. These samples are being analyzed for atmospheric deposits that could cause corrosion.

Ultimately, if degradation is identified, cask users would select their preferred mitigation and repair option.  They would have to meet the NRC’s safety requirements before implementing it.

Cask inspections are important to ensure continued safe storage of spent nuclear fuel and robots will continue to be a helpful tool in this important activity.

When Plans Change — Discontinuing Some Rulemaking

Leslie Terry
Team Leader
Office of Administration

NRC does its job with regulations contained in the Chapter I of Title 10 of the Code of Federal Regulations. These regulations cover everything from commercial 10cfrreactors to nuclear materials used in a variety of settings, to storing and disposing of nuclear waste.

A year ago we explained how we keep our rules up to date and unveiled a web page to provide periodic updates on our rulemaking activities. To recap, we identify the rules already under development and any new rules that need to be written. We then rank by priority every rule, regardless of the regulatory area. This way we ensure we’re focusing our resources on the high priority rules that most contribute to the NRC’s key strategic goals of safety and security. We also monitor the progress of our rulemaking activities and develop budget estimates for preparing new rules.

Sometimes our rulemaking plans change. Our Commissioners voted recently to approve a staff recommendation to discontinue eight rulemaking activities that were in the early stages of development.

During our most recent review, the staff identified several rulemakings that were in the early stages of development, but staff believes are no longer needed to meet the NRC’s key strategic goals of safety and security. The staff wrote a paper requesting Commission approval to discontinue nine activities, and discussed a 10th rulemaking the Commission had already decided to discontinue. The Commission agreed to discontinue seven of the nine rulemakings the staff proposed.

The discontinued rulemakings covered a variety of topics, and the basis to discontinue is different for each rulemaking. For example, we have a rulemaking underway to better define the requirements for reactors that have permanently shut down and are decommissioning. We felt that rulemaking was an appropriate place to address decommissioning options, including entombment for power reactors, so we are discontinuing a separate rulemaking on entombment.

We also feel the current case-by-case framework is sufficient for reviewing the limited number of requests we’ve received for alternate disposal pathways for waste with very low activity. So we’re discontinuing a rulemaking to set generic requirements, which had already been on hold for a number of years. Instead, we’ll take another look at the issue as part of an assessment of low level radioactive waste disposal, and if we decide that a rulemaking is necessary, we’ll ask the Commission to revisit the issue.

We encourage you to read more about the Commission’s vote and the staff’s proposal on our web site. You can also check our prioritization web page for future updates on our rulemaking activities.

REFRESH: The Power of Power Uprates

Since this blog post first ran in December 2011, the NRC staff has approved 16 additional power uprates, increasing the nuclear fleet’s output by an additional 1300 megawatts electric. An additional three are under review (for the three reactors at Browns Ferry), and the staff expects to receive an additional 10 uprate applications through the end of September 2017.  David McIntyre

Neil Sheehan
Public Affairs Officer
Region
I

refresh leafMuch news space has been devoted over the years to the prospects for new reactors in the U.S. However, new reactors are not the only way the nation’s share of nuclear-generated electricity can be increased — and it doesn’t involve earth-movers, the construction of new buildings or other changes visible to the casual observer.

Another option available to nuclear power plant owners is to pursue a power uprate, which essentially means an increase in the maximum amount of power a reactor can generate. But before a power uprate can be implemented, it must first undergo a thorough review by the NRC.

Take for example, the NRC’s approval of a 15 percent power uprate for the Nine Mile Point 2 nuclear power plant in upstate New York. That approval was the culmination of an NRC review that began with the submittal of the application on May 27, 2009.

During the course of the agency’s evaluation of the proposal, NRC staff scrutinized data regarding the proposal and posed dozens of technical questions to the plant’s owner, Constellation. They included queries about the effects of greater stresses on piping and the plant’s steam dryer, a component at the top of the reactor vessel, as a result of operations at higher power levels.

Power_Uprates_past-current-future (002)The NRC does not proceed to a final decision until all such questions are answered to our full satisfaction.

Uprates are not a new development. In fact, the NRC approved the first uprate back in 1977 and has to date approved 140 such applications. All told, the uprates have led to an increase in power output nationwide of about 6,000 megawatts electric.

There are three different kinds of power uprates: “measurement uncertainty recapture” uprates, “stretch” uprates and “extended” uprates. Here’s a brief description of each:

Measurement uncertainty recapture uprates – They involve an increase of less than 2 percent and are achieved by implementing enhanced techniques for calculating reactor power levels. State-of-the-art devices are used to more precisely measure feedwater flow, which is used to calculate reactor power.

Stretch uprates – The increases are typically between 2 and 7 percent and usually involve changes to instrumentation settings but do not require major plant modifications.

Extended uprates – Power boosts of this type have been approved for increases of up to 20 percent. They usually involve significant modifications to major pieces of non-nuclear equipment, such as high-pressure turbines, condensate pumps and motors, main generators and/or transformers. The Nine Mile Point 2 uprate would fall into this category.

For more information on power uprates, visit the NRC web site.

Incorporating Enhanced Fines Into the NRC’s Enforcement Policy

Russell Arrighi
Senior Enforcement Specialist

Starting next month, the NRC’s tools for enforcing our regulations will get a boost through increased fines, referred to as “civil penalties” in the NRC’s regulations and policies. The agency’s enforcement staff is working these changes into the process for assigning penalties when a person or company breaks our rules.

budgetThe NRC has always had the authority, under the Atomic Energy Act, to levy fines. We just issued an interim final rule that increases the maximum civil monetary penalty for violations of the Act to $280,469 per violation, per day. That’s double the previous maximum fine.

This change stems from the Federal Civil Penalties Inflation Adjustment Act Improvements Act of 2015, which helps keep fines high enough to deter violations. The law required federal agencies to make an initial “catch-up” adjustment by July 1, 2016, effective by August 1. The NRC and other agencies must also make annual adjustments for inflation beginning in 2017.

The NRC is making changes to its Enforcement Policy to keep the policy’s dollar amounts in line with the new maximum fine. For instance, we’re doubling the base civil penalty that applies to nuclear plants and other large licensees for the most severe violations.

We’re also increasing the policy’s lesser penalties for other licensee types, such as material users, to maintain the proportional relationship between penalties. An exception to these changes involves fines for the loss, abandonment, or improper transfer or disposal of regulated material. The NRC can adjust these fines relative to the estimated or actual cost of authorized disposal.

You can find more information on these changes through a set of Questions and Answers we’ve posted on the Office of Enforcement’s section of the NRC website.

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