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REFRESH — Who Sets National Nuclear Energy Policy?


refresh leafWho decides if the U.S. is going to use nuclear energy to meet this country’s electric needs? It’s a question we get here at the NRC not infrequently. The short answer: Congress and the President. Together they make the nation’s laws and policies directing civilian nuclear activity – for both nuclear energy and nuclear materials used in science, academia, and industry.

Federal laws, like the Atomic Energy Act, set out our national nuclear policy. For example, in the Atomic Energy Act, Congress provided that the nation will “encourage widespread participation in the development and utilization of atomic energy for peaceful purposes.” Other federal laws, like the Energy Policy Act of 2005, call for the federal government to provide support of, research into, and development of nuclear technologies and nuclear energy. The President, as the head of the executive branch, is responsible for implementing these policies.

But sometimes, things get confusing as to who does what when it comes to putting these laws into practice! Although the NRC is a federal government agency with the word “nuclear” in its name, the NRC plays no role in making national nuclear policy. Instead, the NRC’s sole mission is to regulate civilian use of nuclear materials, ensuring that the public health, safety, and the environment are adequately protected.

The NRC’s absence from nuclear policymaking is no oversight, but a deliberate choice. Before there was an NRC, the U.S. Atomic Energy Commission (AEC) was responsible for both developing and regulating nuclear activities. In 1974, Congress disbanded the AEC, and assigned all of the AEC’s responsibilities for developing and supporting nuclear activities to what is now the U.S. Department of Energy (DOE). At the same time, Congress created the NRC as an independent regulatory agency, isolating it from executive branch direction and giving it just one task – regulating the safety of civilian nuclear activities.

Today, the DOE, under the direction of the President, supports federal research and development of nuclear technologies and nuclear energy in accordance with federal laws and policy goals. At the DOE, the Office of Nuclear Energy takes the lead on these programs.

Since its creation  four decades ago, the NRC’s only mission has been to regulate the safe civilian use of nuclear material. For that reason, the most important word here in the NRC’s name is not “Nuclear,” but “Regulatory.” Because the NRC has no stake in nuclear policymaking, the NRC can focus on its task of protecting public health and safety from radioactive hazards through regulation and enforcement.

REFRESH is an occasional series where we revisit previous posts. This originally ran in August 2012.


Dry Cask 101 – Criticality Safety

Drew Barto
Senior Nuclear Engineer

CASK_101finalIn earlier Science 101 posts, we told you about how nuclear chain reactions are used to generate electricity in reactors. In a process known as fission, uranium atoms in the fuel break apart, or disintegrate, into smaller atoms. These atoms cause other atoms to split, and so on. This “chain reaction” releases large amounts of heat and power. Another word for this process is “criticality.”

The potential for criticality is an important thing to consider about reactor fuel throughout its life. Fuel is most likely to go critical when it is fresh. It is removed from the reactor after several years (typically four to six) because it will no longer easily support a self-sustaining chain reaction. This “spent fuel” is placed into a storage pool. After cooling for some time in a pool, the fuel may be put into dry storage casks.

Here, a spent fuel assembly is loaded into a dry storage cask.

Here, a spent fuel assembly is loaded into a dry storage cask.

When fuel is removed from the reactor, we require licensees to ensure it will never again be critical. This state is referred to as “subcriticality.” Preventing an inadvertent criticality event is one safety goal of our regulations. Subcriticality is required whether the fuel is stored in a pool or a dry cask. We require it for both normal operating conditions and any accident that could occur at any time.

There are many methods that help to control criticality. The way spent fuel assemblies are positioned is an important one. How close they are to each other and the burnup of (or amount of energy extracted from) nearby assemblies all have an impact. This method of control is referred to as fuel geometry.

Certain chemicals, such as boron, can also slow down a chain reaction. Known as a “neutron absorber,” boron captures neutrons released during fission, and keeps them from striking uranium atoms. Fuel burnup is another factor. As we said above, after some time in the reactor it is harder for fuel to sustain a chain reaction. The longer the fuel is in the reactor, the less likely it is to go critical. However, high burnup fuel generates greater heat loads and radiation, which must be taken into account.

Spent fuel storage cask designs often rely on design features to make sure the fuel remains subcritical. When we review a cask design, this is one of the key elements the NRC looks at in detail.

Casks have strong “baskets” to maintain fuel geometry. They also have solid neutron absorbers, typically made of aluminum and boron, between fuel assemblies. The applications that we review must include an analysis of all the elements that contribute to criticality safety. Part of the analysis is a 3-D model that shows how the fuel will act in normal and accident conditions.

A dry storage canister is loaded into a horizontal storage module.

A dry storage canister is loaded into a horizontal storage module.

Our technical experts review this analysis to make sure the factors that could affect criticality have been identified. We check to see that the models address each of these factors in a realistic way. In cases where the models require assumptions, we make sure they are conservative. That means they result in more challenging conditions than we would actually expect. We also create our own computer models to confirm that the design meets our regulatory requirements. We will only approve a storage cask design if, in addition to meeting other safety requirements, our criticality experts are satisfied that our subcriticality safety requirements have been met.

Our reviewers look at several other technical areas in depth any time we receive an application for a spent fuel storage cask. We will talk about some of the others—materials, thermal, and shielding—in future posts.

The Open Forum is Open for Business

Holly Harrington
Blog Moderator

communicationwordcloudWe created the Open Forum section of the NRC blog more than four years ago. It was not part of our original plan, but our blog comment guidelines stipulated that comments needed to be related to the topic of the post to which they are submitted. We quickly realized there were a number of comments being submitted that didn’t adhere to this guideline and would have therefore not been posted, but otherwise met the comment criteria. And we wanted to be able to post them. So we decided we needed a place where anyone could bring up any topic they wish (related to the NRC).

And so the Open Forum section was created.

Since its creation there have been more than 300 submitted comments on a wide range of topics including climate change, nuclear power’s future and solar storms.

Comments on the Open Forum (as with the rest of the blog) are moderated and must adhere to the Comment Guidelines. Otherwise, the platform is open for any NRC-related topic you’d like to bring up or to comment on. It’s important to note that blog comments are not considered formal communication with the NRC. Questions and concerns can always be submitted in a variety of formal ways. Safety or security allegations should not be submitted via the blog, and will not be posted if submitted. For more information, go here.

You can easily find the Open Forum section listed on left side of every page of the blog. You can also sign up to receive notice of new comments to the section by clicking on “Reply” at the bottom of the comments and then clicking the “Notify me of new comments via email” box.

Spent Fuel Casks 101 — What We Regulate and Why

Mark Lombard
Director, Division of Spent Fuel Management

CASK_101finalWe talked back in March about dry casks for storing spent nuclear fuel and how they work. Today we want to introduce you to the different things the NRC looks at each time we review a cask application.

To recap: spent fuel is placed into cooling pools at reactor sites when it can no longer efficiently sustain a nuclear reaction. Dry casks give utilities an alternate way to store their spent fuel, freeing up space in the pools. They were first developed back in the 1980s because space in the pools – designed for temporary storage – was growing short.

Our requirements for dry cask storage can be found in 10 CFR Part 72. All structures, systems and components important to safety must meet quality standards for design, fabrication and testing. And they must be structurally able to withstand wind, rain, snow and ice, temperature extremes, hurricanes and tornadoes, earthquakes, and fires and explosions.

Fuel pellets, rods, and casks_r9Part 72 and related NRC guidance on casks and storage facilities also detail specific engineering requirements. Casks must be designed to keep water out so the fuel can’t have a chain reaction, as it would in a reactor. The casks must also shield workers and the public from radiation. They must safely remove the heat remaining in the spent fuel. And the materials used in dry casks and their physical properties must be well-understood and analyzed.

The NRC has dozens of experts in different scientific and engineering disciplines whose job is to review cask applications (which can be hundreds of pages long) and the detailed technical designs they contain. We will explain in more detail in later blog posts what our experts look for and how they go about approving a cask design.

Penn State University’s Breazeale Reactor Celebrates 60 Years

Thomas Wellock

pennstateLast month, Pennsylvania State University’s Breazeale Research Reactor celebrated its 60th anniversary as the nation’s oldest licensed reactor. The Breazeale reactor has been invaluable in research, training, and in establishing Penn State’s well-regarded nuclear engineering program. As part of the Atoms for Peace program, it trained foreign engineers as reactor operators and tested fuel integrity for reactors exported to other nations.

It is a historic marker of early reactor development.

In the early 1950s, universities raced to build research reactors. North Carolina State College jumped ahead when it contracted with the Atomic Energy Commission (AEC) to build a reactor that started up in 1953. By 1955, 14 schools had applied to the AEC for the license required of new reactors under the Atomic Energy Act of 1954.

Penn State had two important assets in this race: money and William Breazeale. Penn State’s board of trustees committed ample funds for construction and operation. To win AEC approval, Penn State followed NC State’s successful strategy of raiding the AEC for faculty talent and a reactor design.

An electrical engineer by training, Breazeale had worked for several years at Oak Ridge National Laboratory supporting the design of thorium and uranium-fueled reactors. His signal accomplishment was in leading the design team for the Bulk Shielding Reactor, the prototype of the “swimming pool” research reactors built at Penn State and facilities around the world. Penn State hired Breazeale to serve as its first-ever professor of nuclear engineering.

The swimming pool reactor was safe, inexpensive, and startlingly simple. Engineers just placed the reactor fuel at the bottom of a tank 30 feet deep so that the water served as a source of cooling and radiation shielding. Faculty and students could stand on a platform directly over the reactor to operate and view it.

Nevertheless, the AEC’s Advisory Committee for Reactor Safeguards (ACRS) made the path to licensing approval so challenging that a frustrated Breazeale once suggested the Committee did not “view the [reactor] hazard problem in its proper perspective.” It wasn’t the last time that ACRS safety concerns were challenged by applicants and vendors.

Earlier this month, NRC Chairman Stephen Burns (right) visited Penn State and toured the reactor. He's standing here with Kenan Unlu, Ph.D., Professor of Nuclear Engineering.

Earlier this month, NRC Chairman Stephen Burns (right) visited Penn State and toured the reactor. He’s standing here with Kenan Unlu, Ph.D., Professor of Nuclear Engineering.

The ACRS fretted over the potential for theft of the fuel, power excursions, and the proximity of the reactor to college housing. The reactor’s 3.6 kilograms of highly enriched fuel posed a safeguards risk, and the Committee demanded a combination of security guards and radiation monitors to protect it. Penn State had to carry out fuel test program and moved the reactor further away than planned from faculty housing. The ACRS also required an emergency plan for notifying local authorities, public evacuation, and cleanup.  Ironing out these issues delayed licensing. When President Dwight Eisenhower gave the college’s commencement address in June 1955, he could only look down into an empty tank with no fuel.

But persistence led to success. On the morning of August 15, Breazeale and doctoral student Robert Cochran started the reactor for the first time. Both veteran Oak-Ridge operators, their approach to criticality was careful but confident enough that they paused so that Cochran could run to the registrar’s office. At 11:30 a.m., the reactor went critical. Then Breazeale and Cochran shut down the reactor and stored the fuel in a vault for two weeks. It was, after all, summer vacation.

The Breazeale reactor reminds us how much reactor safety has changed while staying the same. Its 1955 license was just two pages of conditions. When Penn State renewed it in 2009, the license had grown to 60 pages. Safety regulation is more complex today, but the inherent safety of Breazeale’s reactor remains as important today as it was in 1955.


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