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Category Archives: Radioactive Waste

Updating Radioactive Materials Transportation Regulations

Emma Wong
Project Manager

10cfrIf you have ever wondered about the safety of packaging and transporting radioactive materials, now is the perfect opportunity to learn about it. The NRC is kicking off the process of updating our requirements in 10 CFR Part 71.

We do this periodically to reflect new information. Changes to international packaging and transportation standards published by the International Atomic Energy Agency, which serve as a standard for the U.S. and other nations, can also trigger revisions. Stringent safety requirements, as well as coordination among federal agencies, international regulators, and tribal, state and local officials, help to ensure radioactive materials shipments are made safely.

The U.S. Department of Transportation has primary responsibility for regulatory materials transport, while the NRC regulates packages for larger quantities. This structure provides many layers of safety.

When it is time to review our requirements, the NRC coordinates with DOT to ensure the two agencies have consistent regulatory standards. The process may take several years. We are also working to align our regulations with the IAEA’s.

To encourage public input, we are publishing an “issues paper” that outlines areas we have identified for possible revision. We’ll take comments on it for 60 days. We plan to use that input to develop a draft regulatory basis—a document that identifies a regulatory issue, and considers and recommends a solution. Once finalized, the draft regulatory basis will be made available for public comment. After taking comments on the draft, we can publish a final regulatory basis.

At that point, if our Commission agrees that revision to our requirements are needed, we would move into developing a proposed rule, then a final rule. Each step in the process takes about a year. Details on how to submit comments can be found in a Federal Register notice that will be published on November 21. This information and additional details about the rulemaking will be available on the federal rulemaking website.

We’re also planning a public meeting on Dec. 5-6 at NRC headquarters in Rockville, Md., to discuss the paper and answer questions. Details on participating, including by teleconference and webinar, can be found in our meeting notice.

img_0230While the regulations are being updated, the fact remains that radioactive materials are transported safely all the time. Millions of these shipments are made each year and arrive at their destination without incident. Occasionally, a carrier might be involved in a traffic accident. But in decades of experience, there has never been an accident that resulted in injury from exposure to the radioactive contents.

All shipments of radioactive material must also be made in compliance with DOT regulations. Smaller shipments pose extremely low risk. The larger the amount of radioactive materials, the more stringent DOT’s requirements are. DOT limits how much radioactivity can be transported in each package. That way, no transport accident involving these shipments would pose a significant health threat.

But what about larger amounts of radioactive materials? What about spent nuclear fuel?

In addition to meeting DOT requirements, larger shipments of radioactive cargo such as spent nuclear fuel and fissile material must meet NRC regulations for packaging and transport in Part 71. These regulations include very detailed requirements for shipping under normal conditions, as well as stringent tests to show the packages can withstand hypothetical severe accidents. These are the regulations we are updating now. If you would like to learn more about the transportation of spent fuel and radioactive materials, see our website.

Yucca Mountain Documents Now Publicly Available – In a New Online Library

David McIntyre
Public Affairs Officer

The NRC is flipping the switch today on its new LSN Library — making nearly 3.7 million documents related to the adjudicatory hearing on the proposed Yucca Mountain repository available to the public.

yuccatunnelThe library makes the discovery documents by various parties to the hearing public for the first time in five years, and with enhanced search capabilities. The new LSN Library is part of the NRC’s online documents database, known as ADAMS. Although the NRC staff’s discovery documents were already publicly available in ADAMS, those materials have been incorporated into the LSN Library to permit “one-stop” searching for Yucca-related technical information.

Here’s the genesis of the new library: The NRC created the Licensing Support Network, or LSN, back in 2001, years before the Department of Energy submitted its application in 2008 for construction authorization for a high-level waste repository at Yucca Mountain. The network was designed to allow easy access to the volumes of discovery documents that would support various aspects of the hearing.

The LSN was a database that required participants to house their documents on their own servers that were accessible for “crawling” by LSN software maintained by the NRC. This software created a document index. Participants and the public could search the index and generate a link to relevant documents on the participants’ home servers.

The LSN worked smoothly through the early stages of the hearing. But then the Department of Energy shut down the Yucca Mountain Project in 2010, and the NRC staff proceeded with an “orderly closure” of its review of DOE’s license application. As part of the orderly closure, an Atomic Safety and Licensing Board Panel’s Construction Authorization Board suspended the hearing in September 2011. The LSN was closed down the previous month, with the CAB directing the parties (other than the NRC staff, whose documents were already public in ADAMS) to provide all their LSN documents to the NRC’s Office of the Secretary.

Then in August 2013, the U.S. Court of Appeals for the District of Columbia Circuit ordered the NRC to resume its review of DOE’s Yucca Mountain application, using previously appropriated money from the Nuclear Waste Fund.

The Commission directed the staff to finish and publish its Safety Evaluation Report, the main technical review of the application. The staff published the final volumes in January 2015. Then the Commission directed the staff to prepare a supplement to DOE’s Environmental Impact Statement, covering certain groundwater issues that were not fully analyzed in the EIS. The staff issued the final supplement this past May.

Additionally, the Commission directed that if there was enough money remaining, the LSN documents should be made publicly available. As explained in a paper published August 12, that’s the work being completed now with activation of the LSN Library.

The library is significant for three reasons. First, it meets federal records requirements. Second, the library again provides public access to the previously-disclosed discovery materials should the Yucca Mountain adjudicatory hearing resume. Third, should the Yucca Mountain hearing not resume, the library will provide an important source of technical information for any future high-level waste repository licensing proceeding.

And of course, the library helps us meet the NRC’s goal of being an open and transparent regulator.

Taking a Look at an Independent Review of Spent Fuel Pool Safety and Security

Scott Burnell
Public Affairs Officer

 A recently published National Academy of Sciences report includes the academy’s latest thoughts on enhancing the safety and security of spent nuclear fuel storage. The NRC gave NAS the funding for the study at the direction of Congress. This report is Phase 2 of the NAS work; we’ll recap Phase 1 in a moment.

The agency sponsored the two-phase NAS study to identify lessons learned from the Fukushima accident and to follow up on previous NAS recommendations on spent fuel safety and security. The earlier NAS work looked at these same topics after the Sept. 11, 2001, terrorist attacks, and led to a 2004 report (our response to Congress about the 2004 report is on the agency’s website).

As the NAS gathered information for the latest report, they talked with NRC staff and received NRC documents related to relevant regulatory programs and requirements.

Our first look at the Phase 2 NAS report did not identify any safety or security issues that would require immediate action by the NRC. U.S. nuclear power plant security is extremely robust; the plants are some of the best protected facilities in the world. We have a long record of studying and analyzing the safety and security of spent fuel storage. Some of these studies have resulted in security enhancements. For example, after the 9/11 terrorist attacks, the NRC’s security assessments resulted in improvements to security at nuclear power plants, and strengthened the plants’ coordination with other federal and state agencies in responding to security threats.

Our post-Fukushima requirements for U.S. reactors have enhanced spent fuel pool safety. For example, we required plants to improve the ability of operators to monitor the water level in spent fuel pools. We also required plants to develop new strategies for adding water to these pools to keep them cool, even under the conditions that might exist following an extreme natural event, like a severe earthquake or flood.

Looking at all the available information, we remain confident U.S. spent fuel is safely and securely stored. The Phase 2 NAS report looks ahead to some areas that NAS believes warrant further study or action. We’ll evaluate the NAS report and its recommendations to see if we need to take any further action in the long run. The staff plans to provide the Commission with its assessment of the NAS Phase 2 report later this year.

We know the public has questions about safely and securely storing spent nuclear fuel, so the NRC website includes key points and frequently asked questions and answers. We expect to update this information once we’ve finished assessing the NAS report.

We looked at the NAS Phase 1 report in 2014. That report looked at the causes of the Fukushima accident and also identified lessons for improving nuclear power plant safety systems and operations. The staff provided the Commission an assessment of the Phase 1 report in SECY-15-0059. In our final assessment of the Phase 1 report, we determined that all of the NAS recommendations were being addressed by completed and ongoing NRC activities.

WCS Sends NRC Interim Storage Application

Mark Lombard
Director, Division of Spent Fuel Management

You may have heard that the NRC has received an application today for a centralized storage facility for spent nuclear fuel. We thought this would be a good time to talk about what that facility would do, and how we will review the application.

First some background. “Spent fuel” is the term we use for nuclear fuel that has been burned in a reactor. When spent fuel is removed from a reactor, it is very hot, so it is put immediately into an onsite pool of water for cooling. Initially, the plan in the ‘70s had been to send the spent fuel for “reprocessing” prior to final disposal, so usable elements could be removed and made into fresh fuel. But reprocessing fell out of favor in the United States in the ‘80s.

Officials from Waste Control Specialists deliver its application to construct and operate a consolidated interim storage facility to Joel Munday, Acting Deputy Director of the NRC’s Office of Nuclear Material Safety and Safeguards.

Officials from Waste Control Specialists deliver its application to construct and operate a consolidated interim storage facility to Joel Munday, Acting Deputy Director of the NRC’s Office of Nuclear Material Safety and Safeguards.

To manage their growing inventory, nuclear utilities turned to dry storage. The idea behind dry storage casks is to cool the fuel passively, without the need for water, pumps or fans. The first U.S. dry storage system was loaded in 1986. In the past 30 years, dry storage has proven to be safe and effective.

Against this backdrop, a Texas company, Waste Control Specialists (WCS), filed an application with us today for a dry cask storage facility to be located in Andrews County. WCS plans to store spent fuel from commercial reactors; initially, from reactors that have permanently shut down.

The application discusses utilizing dry storage casks that have previously been approved by the NRC. The spent fuel would arrive already sealed in canisters, so the handling would be limited to moving the canisters from transportation to storage casks.

Ever since Congress enacted the first law for managing spent nuclear fuel in 1982, federal policy has included some centralized site to store spent fuel before final disposal in a repository. Congress made DOE responsible for taking spent fuel from commercial reactors. It gave NRC the responsibility to review the technical aspects of storage facility designs to ensure they protect public health and safety and the environment.

We conduct two parallel reviews – one of the safety and security aspects, the other of potential environment impacts.

But before those reviews get underway, we will review the application to see if it contains enough information that is of high enough quality to allow us to do the detailed reviews. If it doesn’t, WCS will have a chance to supplement it. If we find the application is sufficient and accept it, we will publish a notice in the Federal Register. This notice will alert the public that we have accepted the application for technical review, and offer an opportunity to ask for a hearing.

Then we begin our reviews. At the beginning of our safety and security review, NRC staff will hold a public meeting near the site to answer questions about our process. We’ll also have public meetings with WCS as needed so the staff can ask questions about the application. We will document this review in a Safety Evaluation Report.

Once we get public and stakeholder input on the scope of our environmental review, we will conduct the review and document the results in a draft Environmental Impact Statement (EIS). We’ll ask the public and stakeholders to comment on the draft. After considering those comments, we’ll finalize it.

We expect the review process to take us about three years, assuming WCS provides us with good information in a timely way during our review.

If interested parties ask for a hearing, and their petition is granted by our Atomic Safety and Licensing Board, then the board will consider specific “contentions,” or challenges to our reviews of the safety, security or environmental aspects of the proposed facility. The board will hold a hearing on any contentions that cannot be resolved. We can’t predict how long this hearing process would take.

The Safety Evaluation Report, the EIS and the hearing need to be complete before the NRC staff can make a licensing decision. If the application meets our regulations, we’re legally bound to issue a license. We don’t consider whether there’s a need for the facility or whether we think it’s a good idea. Our reviews look at the regulatory requirements, which are carefully designed to ensure public health and safety will be protected, and at the potential environmental impacts and applicant’s plans for mitigating them.

Incidentally, we are expecting an application for a second centralized interim storage facility Nov. 30. This one, to be filed by Holtec International, will be for a site in New Mexico. We’ll follow the same process in reviewing that application.

Dry Casks 101: Managing Heat

CASK_101finalCaylee Johanson
Mechanical Engineer

In this series we’ve been talking about storing spent nuclear fuel in dry casks. One major function of these casks is to cool the fuel. Keeping the spent fuel from getting too hot is one way to ensure casks will be safe. As the fuel cools, heat is transferred from inside the cask to the outside.

Our experts look at how the cask will perform this function. We require the cask and fuel to remain within a certain temperature range. Our review looks at four main areas:

Spent fuel releases heat as a result of its radioactive decay. This is called decay heat. A key function of dry storage casks is to move the decay heat from the cask to the outside environment to ensure the fuel and cask components do not get too hot. Our experts look at how that heat will move through the cask and into the environment.

The method used to remove heat has to be reliable and provable. Heat must also be removed in a way that is passive—meaning no electrical power or mechanical device is needed. Casks use conduction, convection and radiation to transfer the heat to the outside.

Heat Radiation Transparent 2The graphic shows the three heat transfer methods. As you can see, conduction transfers heat from the burner through the pot to the handle. The process of heat rising (and cold falling) is known as convection. And the heat you feel coming off a radiator, or a hot stove, is known as radiant heat.

These methods work the same way in a storage cask. Where the canister or metal structure containing the fuel touches the fuel assemblies, heat is conducted toward the outside of the cask. Most casks have vents that allow outside air to flow naturally into the cask (but not into the canister) and cool the canister containing the fuel (convection). And most casks would be warm from radiant heat if you stood next to them. (The heat generated by a loaded spent fuel cask is typically less than is given off by a home-heating system.)

We limit how hot the cask components and fuel materials can get because we want to protect the cladding, or the metal tube that holds the fuel pellets. Limiting the heat is one important way we can ensure the cladding doesn’t degrade. The cask must  keep spent fuel cladding below 752 degrees Fahrenheit during normal storage conditions—a limit that, based on the material properties of the cladding, will prevent it from degrading. The fuel must also remain below 1058 degrees in off-normal or accident conditions (such as if a cask were dropped while it is being positioned on the storage pad, or if a flood or snow were to block the vents).

We also confirm the pressure inside is below the design limit to make sure the pressure won’t impact the structure or operations. Our experts review applications for new cask designs carefully to verify the fuel cladding and cask component temperatures and the internal pressure will remain below specified limits.

Each storage cask is designed to withstand the effects from a certain amount of heat. This amount is called the heat load. We look at whether the designer correctly considered how the heat load will affect cask component and fuel temperatures. We review how this heat load was calculated.

We also verify that the cask designer looked at all the environmental conditions that can be expected because these will also affect the cask component and fuel temperatures. These may include wind speed and direction, temperature extremes, and a site’s elevation (which can affect internal pressure). To make sure the right values are considered, we verify they match the historical records for a site or region.

We review all of the methods used to prove that the storage system can handle the specified heat loads. We also verify any computer codes used in the analysis and the values that were plugged in. For example, we look at the material properties for cask components used in the code. We look at calculations for temperatures and pressure. We make sure the computer codes are the latest versions.

And we only allow designers to use codes that have been endorsed by experts. We might run our own analysis using a different computer code to see if our results match the application.

The analysis and review allow us to see whether and how the dry cask will meet the temperature limits. Our review ensures the temperature is maintained and the cladding is protected. Finally, our review confirms the cask designer used acceptable methods to analyze or test the system and evaluate the thermal design. If we have any questions or concerns, we ask the designer for more information.

Only when we are satisfied that our requirements are met will we approve the thermal analysis in a cask application.

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