U.S. NRC Blog

Transparent, Participate, and Collaborate

Monthly Archives: April 2016

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.

An Outage Twist: Degraded bolts at New York Nuclear Plant Warrant Attention

Neil Sheehan
Public Affairs Officer
Region I

When the Indian Point Unit 2 nuclear power plant entered a refueling and maintenance outage in early March, the to-do list included a task born of industry operating experience, both in the United States and overseas.

BaffleBoltsGraphic1_cleanbigfontSpecialists were geared up to check on the condition of bolts employed in the reactor vessel at the Buchanan, N.Y., facility. These are the kind of bolts you likely wouldn’t find at your local hardware store. Rather, they are made of a stainless-steel alloy capable of withstanding decades’ worth of neutron bombardment, as well as extraordinarily high temperatures and pressure.

Measuring about 2 inches in length and 5/8ths of an inch in diameter, the bolts hold in place a series of vertical metal plates. Known as baffle plates, they help direct water up through the nuclear fuel assemblies, where it is heated and subsequently used for power production.

The baffle plates are attached to eight levels of horizontal plates called baffle-former plates, which are in turn connected to the reactor core barrel.

As far back as the late 1980s, cracking was identified in baffle-former bolts – the bolts securing the baffle plates to the baffle-former plates — in pressurized-water reactors (PWRs) in France. (Both Indian Point Units 2 and 3 are PWRs.) The degradation is caused by what is known as irradiation-assisted stress corrosion cracking.

In response, the U.S nuclear industry began checking on these bolts in a small number of domestic PWRs on a sample basis.

The NRC staff also made use of a communications tool called an Information Notice to advise U.S. plant owners of what had been observed in Europe. A March 1998 notice let U.S. plant owners know that the baffle-former bolt cracking reported in foreign PWRs had occurred at the juncture of the bolt head and the shank, a location not accessible for visual examination.

Several U.S. plants subsequently evaluated their baffle-former bolts and in some cases replaced a sizable number.

Jumping ahead, the Electric Power Research Institute developed a standard industry program for the aging management of PWR reactor vessel internals and submitted it to the NRC in January 2009. The NRC staff approved the approach in an agency safety evaluation issued in December 2011 and then published in January 2012 as MRP-227-A. (MRP is short for Materials Reliability Program.)

Under this new standard, U.S. PWRs were to conduct an initial ultrasonic examination of all of their baffle-former bolts when the plant had between 25 and 35 effective full power years of service.

This is exactly what was being done at Indian Point Unit 2 during the current outage. It was adhering to the standards of MRP-227-A. In the course of this review, it was determined that 227 of 832 baffle-former bolts at the plant were degraded, which means any indication of cracking. What’s more, two bolt heads were missing.

The number of degraded baffle-former bolts was the largest seen to date at a U.S. reactor.

Entergy, Indian Point’s owner, is in the process of analyzing the condition and replacing the degraded bolts. It will also assess any implications for Indian Point Unit 3, though that reactor is believed to be less susceptible to the condition for several reasons, including fewer operational cycles.

As for the NRC, we will independently review the company’s analysis and bolt-replacement plans to ensure safety. The results of those reviews will be documented in an upcoming inspection report for the plant.

We have already had a metallurgical specialist on-site reviewing the company’s evaluations of the bolts and have agency experts reviewing the matter.

More information will be forthcoming on the issue. However, it’s important to note that the NRC staff will ensure the condition is fully understood and addressed prior to the plant returning to service. The NRC staff will also consider all available information in evaluating if changes are needed to the current inspection programs for these bolts across the industry.

 

Chernobyl – Thirty Years Ago Today

2015-6-4 Chornobyl (59)On April 26, 1986, a sudden surge of power during a reactor systems test destroyed Unit 4 of the nuclear power station at Chernobyl, Ukraine, in the former Soviet Union. The accident and the fire that followed released massive amounts of radioactive material into the environment.

So starts the NRC backgrounder on accident. Today, exactly three decades later, it’s still an event worth recalling.

Last year, NRC Commissioner William Ostendorff and several NRC staffers, (photo above right) visited the site and saw the progress for containment and decommissioning first hand.

Said Commissioner Ostendorff of his visit: “I was struck by the impact of this tragic accident in 1986, especially by the visit to the abandoned city of Pripyat. I saw first-hand the detailed work underway to more 2015-6-4 Chornobyl (35)permanently contain the damaged reactor for coming generations. I am grateful for the international support to fund the construction of the New Safe Confinement structure.”

The New Safe Confinement construction site can be seen in the photo to the left. The Commissioner’s visit included the construction site for the Dry Type Storage facility. The final completion date for this project is 2064.

As part of their tour, the Commissioner and NRC staff visited the abandoned city of Pripyat, home to an amusement park originally scheduled to open one week after the accident. (see photo below right)

After the accident, 2015-6-4 Prypiat (39)ferriswheelofficials closed off the area within 18 miles of the plant, except for those with official business at the plant and those people dealing with the consequences of the accident and operating the undamaged reactors. The Soviet (and later on, Russian) government evacuated about 115,000 people from the most heavily contaminated areas in 1986, and another 220,000 people in subsequent years.

For more information on the accident, check out this blog post or take a look at this video.

 

Preparing for Advanced Reactors

Deborah Jackson
Deputy Director
Division of Engineering Infrastructure and Advanced Reactors

Before a company gets down to the nuts and bolts of a reactor design, it has to consider the big picture of protecting the public. The NRC lays out this mandate through a combination of regulatory requirements and guidance. “General Design Criteria,” or GDC are a key part of the regulatory requirements. We’re at the point where public input will help us develop Advanced Reactor Design Criteria (ARDC) for tomorrow’s reactors.

The current criteria cover concepts such as protecting against severe natural events and putting multiple barriers between radioactive material and the environment. Designers and operators use that basis for designing, fabricating, building, testing, and operating a reactor’s safety-related equipment. Companies are now considering designs that depart from cooling reactors with water, so the NRC is moving towards properly adapting the GDC.

We’ve been working with the Department of Energy on this since 2013. Our initiative has examined where today’s GDC could apply to advanced designs, and where new or revised criteria make sense. A DOE report from late 2014 (parts one and two) laid out Advanced Reactor Design Criteria, which could fill the GDC role for non-light-water-cooled reactors.

The DOE set out both criteria independent of any specific technology, and specific criteria for reactors cooled by liquid sodium or an inert gas. These ARDC will not be binding requirements.

The NRC picked up the ball by considering existing information on advanced designs, and we’ve asked DOE additional questions while developing draft regulatory guidance on the ARDC. This is the first step in strategically preparing for the review of non-light-water reactor applications.

The preliminary draft of the ARDC will provide stakeholder insight into the NRC staff’s current views on how the GDC could be interpreted to address non-light-water reactor design features. Ultimately, a risk-informed, performance based advanced non-light water reactor regulatory framework is envisioned.

A specific question we’re looking at involves whether NRCs generic criteria are broad enough to cover the spectrum of designs being considered. We’re also asking whether the proposed criteria appropriately address some new concepts described in DOE’s documents.

Public comments, which can also be sent to AdvancedRxDCComments.Resource@nrc.gov, will be accepted through June 8. After we address these initial public comments, a draft regulatory guide will be developed and published in the Federal Register for public comment.

NRC Talks Research in Tennessee

Salman Haq
Reactor Engineer
Office of Nuclear Regulatory Research

We recently issued the draft report summarizing detailed research and analyses into what might happen during an accident at a nuclear power plant. Tomorrow, we’ll head to the third plant we analyzed, Sequoyah Nuclear Plant, to discuss the results with the surrounding communities. The plant is located in Soddy-Daisy, Tenn.

Cover of SOARCA Communications Brochure (NUREG BR-0359 Rev2)The project, called the State-of-the-Art Reactor Consequence Analyses, or SOARCA, looked at potential situations that could disable a reactor’s normal safety systems. The project used powerful computer programs to predict the plants’ behavior based on decades of real-world experiments into issues such as how reactor fuel responds during the extreme temperatures expected during these accidents.

SOARCA then plugged up-to-date information about the plants into the programs and examined how a potential accident might unfold.

We found that safety equipment the NRC required after the 9/11 attacks, or additional equipment that industry voluntarily added following the Fukushima event, if used according to plan, would help prevent or mitigate a reactor accident. Even for the most severe accidents the research came to three basic conclusions:

  • Accidents occur more slowly than we originally thought;
  • Accidents release less radioactive material than we originally thought; and
  • The emergency plans every U.S. reactor has in place can help keep people safe.

The project came to some more specific conclusions about accident effects around the three plants, Surry (southeast of Richmond, Va.), Peach Bottom (southeast of Lancaster, Pa.), and Sequoyah. For example, the slowly developing nature of the accidents and the existing emergency plans would help keep people safe, even during uncontrolled accidents.

Some of the NRC staff involved in SOARCA discussed the Sequoyah project on April 20, at the TVA Sequoyah Nuclear Training Building.

If you have comments on the draft report, you have until May 12, 2016 to send them in. The best way to comment is through regulations.gov, using Docket ID NRC-2016-0074. You can also mail comments (referencing the Docket ID) to Cindy Bladey, Office of Administration, Mail Stop: OWFN-12-H08, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.

If you submit comments in writing or in electronic form, they will be posted on the NRC website and on regulations.gov. The NRC will not edit or remove any identifying or contact information; please don’t include any information you wish to keep private.

We’ve also developed a public communications brochure to help explain the SOARCA project to a wider audience of stakeholders using plain language and more illustrations.

%d bloggers like this: