Advanced Nuclear Reactor

The U.S. Nuclear Regulatory Commission (NRC) recently released a staff paper-SECY-18-0096-seeking Commission approval of a new proposed methodology for establishing “functional containment” performance criteria for non-light water reactors (non-LWRs).  This methodology would step away from deterministic containment design parameters and embrace a concept of “‘functional containment’ as a barrier, or a set of barriers taken together, that effectively limits the physical transport of radioactive material to the environment.”  If approved, the proposed methodology would be a critical step in developing a framework for licensing non-LWR designs.

Many current NRC regulations and guidance documents are prescriptive in nature and focus on problems unique to LWR technology—that is, the regulations tell you squarely what you need to do, providing limited opportunity to meet the end objective of the regulation in a different way.  For example, NRC guidance in NUREG-800 Chapter 3 provides detailed requirements for the strength and thickness of barrier concrete.  As the NRC has started to grapple with non-LWR designs, it has shifted its focus to more risk-based and performance-based methodologies—that is, the NRC would define the objective, and an applicant would have more flexibility in showing the NRC how its design meets the objective.  Under the performance-based methodology proposed in the SECY paper, the requirements imposed on physical barriers would be determined based on the risk of migration of radioactive materials and the other safety measures being used for containment.

The new methodology proposed by the NRC staff, therefore, does not prescribe the traditional structures, systems, and components (SSCs) required for functional containment, but rather focuses on performance requirements.  This methodology will give non-LWR designers more flexibility and provide a more integrated approach for developing a regulatory framework for non-LWRs.

A key component of the methodology is the “identification and categorization of licensing-basis events.”  The NRC staff recommends using the set of event categories initially developed under the Next Generation Nuclear Plant Project and used in the Licensing Modernization Project as the baseline for developing performance criteria.  Based on these event categories, the performance criteria will be developed to meet fundamental safety requirements.  Once the performance criteria have been determined, it appears the developers of non-LWRs would consider the potential consequences associated with the identified events and assess the cost and benefits of potential SSC options to prevent or mitigate the migration of radioactive material.  The NRC staff is calling this approach the “Barrier Assessment” or “Bow Tie” method, as depicted in the figure below:

If approved, the prosed methodology for functional containment performance criteria will be incorporated into the draft guidance the NRC staff is currently compiling for non-LWR licensing.

If you would like more information please contact the authors.

On Sunday, the popular TV show Madam Secretary gave a starring role to the climate and security benefits of nuclear power. The episode, titled “Thin Ice,” which is still available on the CBS website, proffered a full-throated defense of the climate benefits of nuclear power, turned a grassroots activist organization into a supporter of nuclear energy, and showcased how a nuclear powered ice breaker protected the Arctic from a foreign incursion. It capped with Secretary McCord convincing the show’s President to revise the national nuclear policy. As Michael Shellenberger opined following the episode (he also walks through the episode in detail), this marks a turning point for Hollywood, and “represents a popular culture breakthrough for the pro-nuclear movement.”  We encourage everyone to watch the episode!

From there, the week has only gotten better for nuclear innovation. The U.S. Nuclear Regulatory Commission (NRC) completed “the first and most intensive phase of review for” NuScale’s Design Certification Application for its small modular reactor. The NuScale design review has six phases to its schedule; but the first review sets the tenor, as it establishes the NRC staff’s preliminary safety evaluation of the reactor and encompasses a large portion of the requests for additional information. NuScale performed admirably in both areas. Along with this significant milestone—which derisks the company’s regulatory path forward—NuScale also received US$40 million from U.S. Department of Energy to continue advancing its innovative new, passively safe reactor design. And even the issue of nuclear waste storage might see progress, as the Nuclear Waste Policy Amendments Act of 2018 will get a vote on the floor of the House soon. The bill will move forward interim storage of spent nuclear fuel, and seek resolution on the licensing of a final national repository.

And apart from advancements on earth, NASA successfully tested KRUSTY, or “Kilopower Reactor Using Stirling Technology,” a nuclear reactor for potential moon and Mars bases. NASA personnel stated after the successful Nevada trial that “[n]o matter what environment we expose it to, the reactor performs very well.” NASA, along with Hollywood and Congress it seems, has taken a renewed interest in the role nuclear power can play in space exploration.

If you wish to learn more about any of these encouraging events, please contact the authors.

NASA iTech and the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) are collaborating on a unique competition to identify transformational energy technologies that can address critical problems here on Earth that also hold great potential to solve critical technology challenges in future space exploration.  On that list: fission reactors.

NASA and ARPA-E are seeking to identify the nation’s top entrepreneurs and researchers to present their innovative technologies to address energy-specific challenges. A few examples of technology sub-themes that NASA believes have the potential to improve future space power systems include, but are not limited to:

  • Small Fission Power Systems
  • Fuel Cells and Regenerative Fuel Cells
  • High-energy Density Batteries and Supercapacitors
  • Solar Power Systems
  • Innovative Power Management and Distribution (including smart grids and wireless power transfer)
  • X-Factor Energy: innovations so compelling NASA and ARPA-E should know about them

Through April 29, 2018, inventors and entrepreneurs can submit a five-page white paper on their concept on the NASA iTech website.  A panel of subject matter experts from NASA and ARPA-E will review ideas submitted and select the top 10 finalists based on their relevance and potential impact to present at the upcoming 2018 iTech Energy Cycle.

The initial top 25 semi-finalists for this energy-focused cycle will be announced on May 10, 2018. The top 10 finalists will be announced on May 25, 2018. Those finalists will be invited to present their technologies and engage with NASA and ARPA-E subject matter experts, potential investors, and industry partners at the NASA iTech 2018 Energy Forum in New York City, June 11-14, 2018.

The ARPA-E at the U.S. Department of Energy provides R&D funding for transformational ideas to create America’s future energy technologies. ARPA-E focuses exclusively on early-stage technologies that could fundamentally change the way we generate, use, and store energy.

NASA iTech is an initiative sponsored by NASA’s Space Technology Mission Directorate and managed by the National Institute of Aerospace in Hampton, Virginia.  “NASA iTech has proven to be a successful public-private partnership model for stimulating the development of ground-breaking technologies, without the government being the early investor,” said Kira Blackwell, NASA iTech program executive in the Space Technology Mission Directorate at NASA Headquarters in Washington. “Previous entrants to NASA iTech have already raised more than $50 million in private investment funds.”  The NASA announcement is here.  For more information about the NASA iTech initiative, visit here.  For information about the Space Technology Mission Directorate, visit here.

Please contact one of the authors with any questions.

On April 4, the U.S. Nuclear Regulatory Commission (NRC) issued Regulatory Guide 1.232, Guidance for Developing Principal Design Criteria for Non-Light Water Reactors.  The regulatory guide’s generic set of Advanced Reactor Design Criteria cover most non-light-water technologies. The guide also includes technology-specific criteria for sodium-cooled fast reactors and high temperature gas-cooled reactors.

The regulatory guide describes how the general design criteria (GDC) set forth in Part 50 of the NRC’s regulations may be adapted for non-light-water reactor (non-LWR) designs. The guidance may be used by non-LWR reactor applicants to develop principal design criteria for any non-LWR designs, as required under the NRC nuclear power plant regulations. Notably, the guide can be used by advanced reactor designers to align their concepts with relevant NRC regulations for nuclear power plants, and will assist the NRC staff when reviewing future license applications.

We had previously written about the draft regulatory guide published by the NRC last year here.  As we noted then, this is an important document that deserves close attention by the advanced reactor community.  It provides one of the first detailed insights into how the NRC views advanced reactors, how far it is willing to step away from the GDC framework, and what it finds of importance from a safety perspective for advanced reactors.

For questions on the guidance, please contact one of the authors.

Nuclear power has had a busy year in 2017.  One of the most important trends for preserving the existing fleet of operating nuclear power plants has been the financial commitment  by US states to support nuclear power operating in their states and preserve their largest source of carbon-free power—and the thousands of jobs that go with it. This represents a significant reversal in state policy towards nuclear power, which traditionally has been left out of state programs promoting low or carbon free power—despite the fact that 60 percent of the carbon free power in the U.S. is generated by nuclear power. And the new state involvement has the potential to be a game-changer for next-generation reactors.

To highlight some of the key state activities from this year:

  • New York’s Clean Energy Standard and Illinois’s SB 2814, with their Zero-Emissions Credit (ZEC) programs, came into effect this year.  These programs represent among the first significant state efforts to  compensate nuclear power for its environmental benefits, and has helped keep a large number of nuclear power plants operational. Ohio has also introduced legislation to implement similar ZEC-type programs.
  • Federal district courts separately upheld both New York’s and Illinois’s ZEC programs against federal pre-emption and Constitutional challenges. Both decisions have been appealed, but nonetheless allow the state programs to continue in the interim.
  • Connecticut passed legislation that would allow nuclear power to compete directly against other zero-carbon resources in certain circumstances.
  • New Jersey introduced and advanced legislation to support nuclear power through “nuclear diversity certificates,” which would support the nuclear reactors for their environmental and fuel diversity attributes.

The core of many of these programs is valuing the benefits of nuclear power using the “social cost of carbon” framework. The social cost of carbon represents a potential measure of the harms caused by carbon emissions (and therefore, the value of carbon avoided by zero emissions generation). It was developed by a federal government interagency working group and has found itself increasingly referenced as part of state climate initiatives.

Although these programs directly benefit the current light water reactor fleet, it also signifies a larger trend by states to put nuclear power on an equal footing to other forms of low or zero-carbon generation sources.  This trend cannot be ignored by the advanced reactor industry. Just as renewable energy grew through state-level efforts to support the industry through renewable energy credit programs and portfolio standards, next generation reactor developers may want to look to states along with the federal government as potential sponsors for first-of-a-kind reactor projects.

These activities also explore the myriad different legal routes states can pursue to support the environmental and societal benefits of nuclear power. The U.S. energy grid is an ecosystem with many state, regional, and federal actors all working together to provide electricity at low cost and in accordance with legitimate policy goals. Disputes are likely to arise (and have arisen) as to where the borders between state and federal involvement. But that does not change the fact that states have always had a role in the in the promotion and regulation of nuclear power. An opportunity now exists to redefined that relationship, and for a new generation of state leaders to reengage with a new generation of reactor developers, for the benefit of all involved.

For more on state legislative activities affecting nuclear power, please contact the authors.

The U.S. Department of Energy’s (DOE’s) Gateway for Accelerated Innovation in Nuclear (GAIN) announced last week its second round of awards.  A number of these awards have gone directly to advanced reactor startups, and they hope to push forward a number of technologies related to advanced reactors or next-generation light-water reactors.

We wanted to take a little closer look at the awards in this post.  To explain, GAIN awards come in the form of “vouchers” which provide awardees “with access to the extensive nuclear research capabilities and expertise available across the U.S. DOE national laboratories complex.”  Some of the advanced reactor ventures that received vouchers include Elysium Industries, Kairos Power, Muons, Oklo, Terrestrial Energy, Transatomic Power, and others, covering a broad swatch of different reactor types.  One nuclear battery startup, named MicroNuclear, also received an award—nuclear battery technologies have been gaining traction, with the “U-Battery” consortium engaging with the Canadian Nuclear Safety Commission for pre-licensing review in March of this year.  In addition, a number of consulting and engineering companies also received awards, and the results from those projects could benefit a number of different reactor designs.

The most popular participating DOE laboratories are the Idaho, Argonne, and Oak Ridge National Laboratories, although Sandia and Pacific Northwest National Laboratories also will be partnering with certain awardees.  About half of the research projects touch on molten salt reactor technologies, focusing on topics such as different salt chemistries, thermal hydraulics, and waste reprocessing.  A number of awards focus on metal-cooled fast reactors (including regulatory support), and modeling and simulation issues.  Five projects also have a focus on light-water reactor technologies, exploring areas such as small modular reactor concepts and waste reprocessing.

For any questions related to next-generation nuclear reactors or the GAIN initiative, please contact the authors.

Wednesday, the NRC staff held a public meeting related to emergency planning for SMRs and other new reactor technologies. Slides from the meeting can be found here.

A few observations from the meeting—

  • Although early in the process, if executed correctly, the NRC’s Emergency Planning rulemaking could significantly reduce costs for new small modular reactors, advanced reactors, and even medical isotope reactors.
  • There was significant discussion during the meeting on a number of areas, but in particular—
    • Whether the rule would be “risk-informed.”
    • How site-specific features would be factored into the rulemaking.
    • How proposed industrial facilities near a nuclear power plant would affect emergency planning.

The NRC staff made clear during the meeting that the rulemaking would be risk-informed and consequence-oriented, and would work to incorporate the safety advances provided by new reactor designs.

  • The NRC staff emphasized that it welcomes written comments as it moves forward with this rulemaking, and will lean on them in developing a proposed rule.  Comments on the regulatory basis document are due by June 27, 2017.

For additional discussion on the meeting, please contact the authors.

Last week the U.S. Nuclear Regulatory Commission (NRC) and the U.S. Department of Energy held their third joint advanced reactor workshop.  The agenda focused on a variety of issues, including computer simulation of advanced reactors and updates from industry working groups.  Although a lot of insights were realized, four takeaways we wanted to discuss include:

  • The Need for a Test Reactor: Multiple panelists, including those designing simulation codes for advanced reactors, discussed a need for physical testing to validate new designs.  A new test reactor was suggested to be especially critical for validating new fuel designs.  We have recently discussed the importance for a test reactor for the advanced reactor community, as well as novel attempts to overcome the hurdles with building a new test reactor.
  •  NRC Acceptance of Vendor Codes: Panelists suggested at the conference that the NRC may be willing to use the same simulation codes as relied on by reactor designers for validation of new designs.  The viewpoint otherwise has been that the NRC would have to rely on or even create a totally separate simulation code to validate a particular design, which is both difficult and costly.
  • A Push for Consensus Standards: The importance of developing consensus standards, through organizations such as the American Society of Mechanical Engineers, was reemphasized at the workshop as a way for licensees to take the design of the regulatory framework into their own hands.  As one panelist noted, regulatory agencies in general are encouraged by statute and executive order to adopt consensus standards where possible.  It was also suggested that this approach could apply to simulation codes.
  • Licensing Technical Requirements Modernization: Southern Company is leading a team effort to identify aspects of the technical regulatory framework that need to be updated to support licensing of advanced reactors.  According to a description of the effort, in areas where gaps were identified the team would propose risk-informed and/or performance-based practices on a technology-inclusive basis.

At the conference it was explained that the result of this effort would be white papers that would eventually be turned into Nuclear Energy Institute-issued and NRC-approved guidance documents. The first such white paper will be on licensing basis events.

The speaker presentations can be found here.  If there are any questions on the above topics or other aspects of the regulatory framework for advanced reactors, please contact the authors.

On Friday, February 3, the U.S. Nuclear Regulatory Commission (NRC) published in the Federal Register draft “Guidance for Developing Principal Design Criteria for Non-Light Water Reactors.”  This draft new regulatory guide (identified as DG-1330) helps explain how the NRC’s “general design criteria” for traditional light-water nuclear power plants could be applied to non-light water (a.k.a. “advanced”) nuclear reactor design submissions, enabling applicants to develop principal design criteria as part of their regulatory filings.  Comments are due on the guidance by April 4, 2017.

The draft regulatory guide is a significant publication of over a 100 pages.  It provides a background of the NRC’s policy on advanced nuclear reactors, the role of general design criteria in reactor licensing, and joint NRC-U.S. Department of Energy (DOE) efforts to tailor the agency’s general design criteria to advanced reactors.  The general design criteria for traditional nuclear power plants are found at Appendix A to 10 C.F.R. Part 50, the chapter of the Code of Federal Regulations that contains the NRC’s primary regulations on nuclear power plant design.

But most interesting are the three appendices, which propose (A) technology-neutral design criteria for advanced reactors generally, (B) technology-specific design criteria for sodium-cooled fast reactors (SFRs), and (C) technology-specific design criteria for modular high temperature gas-cooled reactors (mHTGRs).  The appendices contain not only the design criteria, but the “NRC Rationale” explaining why/how they were adapted from the general design criteria.  In addition, pages 13 to 20 of the draft guide compare the three design criteria to the current set tailored to light-water reactors.

This is an important document that deserves close attention by the advanced reactor community.  It provides one of the first detailed insights into how the NRC views advanced reactors, how far it is willing to step away from the general design criteria framework, and what it finds of importance from a safety perspective for advanced reactors.

Notably, the basic approach taken by the NRC appears to mimic what the DOE suggested in its 2014 report, “Guidance for Developing Principal Design Criteria for Advanced (Non-Light Water) Reactors.”  There, the DOE likewise “proposed a set of advanced reactor design criteria” to serve in lieu of the general design criteria, but also proposed separate design criteria for SFRs and mHTGRs.  As explained by the NRC here, the DOE’s rationale was “that the safety objectives for some of the current [general design criteria] did not address design features specific to SFR and mHTGR technologies (e.g., sodium or helium coolant, passive heat removal systems, etc.).  Additional design criteria were developed to address unique features of those designs.”

It should be mentioned that this guide is just that—guidance.  As made clear in the draft guide, the proposed design criteria “are intended to provide stakeholders with insight into the staff’s views on how the [general design criteria] could be interpreted to address non-LWR design features,” but they are not binding.  It is still on the applicant to develop principal design criteria for her application, “considering public safety matters and fundamental concepts, such as defense in depth, in the design of their specific facility and for identifying and satisfying necessary safety requirements.”

Moreover, the regulatory framework for advanced reactors is still in flux.  As noted in a prior blog entry, this January legislation was introduced in Congress “to spur technology development related to advanced reactors.”  Recently, on January 23, separate legislation “to provide regulatory certainty for the development of advanced nuclear energy technologies” passed the House of Representatives.  This latter bill, entitled the “Advanced Nuclear Technology Development Act of 2017” is related to a prior bill that passed the House of Representatives in 2016, and was examined by our team here.

The advanced reactor industry is certainly picking up steam.  Terrestrial Energy earlier this month informed the NRC that it plans to file a license application for its molten salt reactor in 2019.  LeadCold around the same time announced a $200 million deal to develop its lead-cooled reactor.  We hope the NRC’s actions here evidence continued support for the advanced reactor community, and a willingness to recognize the unique safety and security benefits these new designs bring.

Please feel free to contact the authors with any questions.

January has already proven an eventful month for developers of small modular reactors (SMRs) and non-light water (i.e., advanced) reactors.

The U.S. Nuclear Regulatory Commission (NRC) is finally starting to see significant movement in regards to SMRs.  NuScale’s January 12 submission of its design certification application for a 50 MWe SMR design garnered significant news attention.  Also of note, on the same day the Tennessee Valley Authority’s (TVA’s) early site permit application for a SMR power plant at Clinch River, Tennessee was docketed by the NRC.

For advanced nuclear reactors, earlier this month the Nuclear Energy Innovation Capabilities Act was introduced in the House and Senate to spur technology development related to advanced reactors.  The companion bills, H.R.431 and S.97, were introduced by Representative Randy Weber and Senator Mike Crapo and have bipartisan support.  Although the text is not publicly available yet, in a press release from the House Committee on Science, Space, and Technology, Randy Weber stated that “[t]his legislation requires the Department of Energy to prioritize its R&D infrastructure on capabilities that will enable the private sector to develop advanced reactor technologies.”

Separate legislation geared towards improving the regulatory framework for advanced reactors progressed in Congress in 2016, but has since been dormant during the political transition (a detailed entry discussing this legislation is available here).  If one or both of these efforts is able to move forward this year, it could prove very helpful to the advanced reactor community.

For more on legislative developments related to SMRs and advanced nuclear reactors, please contact the authors.