USNRC and EPRI Announce New Seismic Source Characterization Model for NPPs

The US Nuclear Regulatory Commission (USNRC), together with the Electric Power Research Institute(EPRI) and the US Department of Energy (USDOE) today released details of a new model for calculating the seismic risk for Nuclear Power Plants (NPPs) in the Central & Eastern United States (C & E US). This replaces the EPRI Report NP-4276 Seismic Hazard Methodology for the Central and Eastern United States of July 1986; and the Lawrence Livermore National Laboratory Model, Seismic Hazard Characterization of 69 Nuclear Plant Sites East of the Rocky Mountains, (Bernreuter, D.L., et al., 1989, NUREG/CR-5250, Volumes 1–8), and is the result of a 4-year long joint EPRI-USNRC project to revise the ground motion estimates that can be expected at a given NPP location in the C&E US.

Speaking broadly, the new model results in a greater ground motion for a given NPP location, and the greatest increases in ground motion estimates have been obtained for nuclear power plants in the vicinity of the New Madrid (TN) and Charleston (SC) fault systems, based on a 7-plant sample selected for detailed study by the USNRC. The new, higher ground motion estimates do not by themselves translate to a higher nuclear safety risk for NPPs at those locations - each NPP must re- calculate its safety risk based on details of its own design and plant layout, relative to the enhanced ground motion risk it faces.

The USNRC is asking the NPPs it regulates to re-evaluate their seismic risk based on this new model, and the model will also be used in assessing the seismic risk for new nuclear plants in the region during the new licensing process. While the new seismic and ground motion risk estimates have been in development for the last several years, the Commission direction in this regard is also part of regulatory initiatives in response to the events at the Fukushima nuclear power plant following the Tohoku earthquake and tsunami-following, on 11 March 2011.

USDOE Issues Funding Opportunity Announcement for SMRs

The US Department of Energy (USDOE) issued a draft Funding Opportunity Announcement (FOA) this week, intended to support activities related to the design and licensing of Small Modular Reactors (SMRs), defined as reactors with an electric output of 300MWe or less; which can be manufactured remotely, transported to point of construction, with on-site assembly largely limited to system integration of components for operation.

Importantly, the USDOE is interested in designs with passive safety (e.g., against consequences of a nuclear accident) as well as inherent safety (e.g., against natural catastrophes such as earthquakes, windstorms or floods), in addition to designs with long inter-refueling periods, low capital cost outlays, low maintenance and operating costs, and high proliferation resistance. The stated intention is to support up to 2 reactor designs through the USNRC design and licensing process, with the ability to be deployed ‘expeditiously’ being an important merit criterion. 2022, a decade from now, is the target year for commercial operation.

Proponents may choose to pursue licensing from the USNRC under either 10 CFR 50 or 10 CFR 52. Stakeholders are encouraged to form consortia, and proponents are encouraged to form design-centered working groups (DCWGs) across the supply and value chains e.g., SMR manufacturers, power utilities, local bodies; and the activities funded by USDOE are required to draw at least 50% of their total resources required, from internal sources. The total amount of funding available from USDOE is estimated to be $452 M, subject to Congressional appropriations. The current draft FOA will be issued in final form after feedback from, and consultation with, stakeholders.

NRC Seeks Prompt Action on Fukushima Near-Term Task Force Recommendations

The US Nuclear Regulatory Commission today directed its staff to complete several actions over the next 45 days in response to the 12 recommendations of its Near-Term Task Force on the Fukushima Nuclear Accident, which submitted its report on July 12.

The Commission has asked the staff to produce a paper by September 9, outlining which of the recommendations 2-12 (recommendation 1 was that the entire regulatory framework be holistically reviewed) should be implemented immediately, including a public dialogue on the process, the schedule for which will be announced soon. It has also asked the staff to produce, by October 3, another paper prioritizing recommendations 2-12, explaining the rationale, and also engaging both the public and other stakeholders. Over the next 18 months, the staff will consider recommendation 1, to review the entire regulatory framework, balancing risk -informed regulation, and defence-in-depth considerations.

NRC Briefing: Severe Accidents and Level 3 PRA

The staff of the US Nuclear Regulatory Commission today held a briefing for the Commissioners on Severe Accidents, and Options for proceeding with Probabilistic Risk Asessment - Level 3 (PRA Level 3).

Traditionally, PRA/PSA Level 3 has not been a strong regulatory requirement because the results of Level 1 (usually the core damage frequency, CDF) and the results of Level 2 (large early release fraction/frequency, LERF) can be used as surrogate proxies for the types of Risk Metrics that a Level 3 PSA/PRA might generate, which could include the following: the number of early fatalities; the number of early injuries, the number of latent cancer fatalities, or the total population dose at different locations; as well as the individual early and latent fatality risk, and the economic cost of mitigation actions taken following a severe accident. The CDF, for example, can proxy for the latent cancer risk, while the LERF could proxy for the prompt fatality risk.

However, a number of potential benefits are foreseen for a full PRA Level 3 analysis, including feedback into risk-informed regulatory guidance for new reactors and use of risk insights in forthcoming SMR design reviews. In addition, capabilities such as modeling of radionuclide aqueous dispersion modes, and multi-unit risk assessment could also be addressed. The modeling of radionuclide dispersal in the event of a severe accident which is initiated by an external event such as an earthquake, tsunami or hurricane also calls for additional modeling efforts, since meteorological variables such as windspeed & direction, ambient precipitation and humidity may not correspond to what is normally expected for that site at that time of year (for example).

NRC Staff plan to use an existing SPAR (Standardized Plant Assessment Risk) model as the basis for proceeding to PSA Level 3. The SPAR model is essentially a plant-specific PSA/PRA Level 1 designed to incorporate both external and internal initiating events, recent modifications of which include capabilities to yield LERFs. Since external hazards are site-specific, much greater value can be expected to be derived if the SPAR model selected for development to PRA Level 3 is for a NPP site that is either representative of the entire population of NPPs, or, has a larger than average number and type of external hazards.

NRC Releases Near-term Report of Fukushima Task Force

The United States Nuclear Regulatory Commission has released the Near-Term Task Force Review of Insights from the Fukushima Da-ichi Accident: Recommendations for Enhancing Reactor Safety in the 21st Century.

The report has 12 recommendations, which I cite here in full, verbatim.

Clarifying the Regulatory Framework
1. The Task Force recommends establishing a logical, systematic, and coherent regulatory framework for adequate protection that appropriately balances defense-in-depth and risk considerations.
Ensuring Protection
2. The Task Force recommends that the NRC require licensees to reevaluate and upgrade as necessary the design-basis seismic and flooding protection of structures, systems, and components for each operating reactor.
3. The Task Force recommends, as part of the longer term review, that the NRC evaluate potential enhancements to the capability to prevent or mitigate seismically induced fires and floods.
Enhancing Mitigation
4. The Task Force recommends that the NRC strengthen station blackout mitigation capability at all operating and new reactors for design-basis and beyond-design-basis external events.
5. The Task Force recommends requiring reliable hardened vent designs in boiling water reactor facilities with Mark I and Mark II containments. (Section 4.2.2)
6. The Task Force recommends, as part of the longer term review, that the NRC identify insights about hydrogen control and mitigation inside containment or in other buildings as additional information is revealed through further study of the Fukushima Dai-ichi accident.
7. The Task Force recommends enhancing spent fuel pool makeup capability and instrumentation for the spent fuel pool.
8. The Task Force recommends strengthening and integrating onsite emergency response capabilities such as emergency operating procedures, severe accident management guidelines, and extensive damage mitigation guidelines .
Strengthening Emergency Preparedness
9. The Task Force recommends that the NRC require that facility emergency plans address prolonged station blackout and multiunit events.
10. The Task Force recommends, as part of the longer term review, that the NRC pursue additional emergency preparedness topics related to multiunit events and prolonged station blackout.
11. The Task Force recommends, as part of the longer term review, that the NRC should pursue emergency preparedness topics related to decisionmaking, radiation monitoring, and public education.
Improving the Efficiency of NRC Programs
12. The Task Force recommends that the NRC strengthen regulatory oversight of licensee safety performance (i.e., the Reactor Oversight Process) by focusing more attention on defense-in-depth requirements consistent with the recommended defense-in-depth framework.

CNSC Presentations at NRC-RIC 2010

Two senior officials of the Canadian Nuclear Safety Commission (CNSC) made presentations at the US Nuclear Regulatory Commission Regulatory Information Conference 2010 (NRC-RIC 2010) last week. The President of the CNSC, Dr. Michael Binder, spoke at NRC-RIC-2010 on A Canadian Regulator's Perspective on International Cooperation. He noted that there were now 48 CANDU-type power reactors in 7 different countries (plus 3 reactors under construction - 1 in Argentina and 2 in India). Emphasizing that national regulators have responsibilities toward customer countries, which he considered an international extension of Canada's safety mandate, he outlined the three phases of Canada's current engagement with the regulatory mechanism in a customer country: (i) With the national regulating agency in the buyer country (ii) On-site, at the end-use location of Canadian-origin technology (e.g. at the site of a CANDU reactor). (iii) Training of regulators as well as interactions at the university level. As the Nuclear Renaissance unfolds, he also indicated that the pattern of Canadian inernational regulatory engagement might move beyond bilateral engagements and evolve to encompass more multilateral mechanisms such as the Multinational Design Evaluation Program (MDEP), with greater harmonization of codes and standards and perhaps including a code of conduct for vendors of nuclear technology.

The Vice President of the CNSC's Technical Services Branch, Terry Jamieson took the theme of International Cooperation in Nuclear Regulation forward, speaking on the MDEP's Role in Converging Codes and Standards. He outlined the efforts of the Codes and Standards Working Group (CSWG) of the MDEP, and indicated that the present focus of the group was on the pressure boundary components. Although different countries had their own codes and standards regarding pressure boundary components, the American Society of Mechanical Engineers (ASME) codes were used as a basis for comparison, focusing first on Class I Pressure Vessels. The objective was to eventually evolve a harmonized set of standards (since full convergence was not found feasible). Next steps will focus on codes for Class I piping, pumps and valves, and later on codes for components beyond those at the pressure boundary.

Nuclear Regulatory Commission Regulatory Information Conference NRC-RIC-2010

The US Nuclear Regulatory Commission (NRC) will be holding its annual Regulatory Information Conference (NRC-RIC) from March 9 to March 11, 2010. The conference will bring together a variety of stakeholders in the nuclear sector with regulators and technical specialists, both from the NRC and from US national laboratories. While most attendees will be from within the US, there will also be a large number of attendees from other countries, including Canada, who will share their own experiences and provide their own insights into nuclear regulatory affairs.

Apart from plenary sessions addressed by NRC Chairman and Commissioners, there will also be technical sessions on a number of cutting-edge issues at the interface of regulation and technology. These include a session on Materials Degradation at the Containment and Reactor Coolant System Pressure Boundary [Audio], which will discuss probabilistic analysis tools for carrying out the assessment of materials degradation at the pressure boundary, incorporating insights from investigations of the Pressurized Thermal Shock phenomenon. This is expected to contribute, for example, to better understanding of the probability of leak before rupture of piping systems. There are also at least two technical sessions on international issues: one on International Coordination between countries pursuing New Nuclear Power, another on International Cooperation on New Reactors [including the activities of the Multinational Design Evaluation Program (MDEP)]. Another session is devoted to discussing regulatory applications of International Experience in Operating Nuclear Reactors.

A technical session on Regulatory and Policy Issues for Small Modular Reactors should prove particularly interesting - since there is now great interest in the possibility of constructing small and modular reactors (including for isotope production; research; and local, off-grid power or heat applications). [Audio of event].

A separate session discussing the interest in Small and Modular Reactors will also be held [Audio].There will also be a session devoted to new developments in Probabilistic Risk Analysis (PRA) for nuclear power plants, including a talk on peer review of the US NRC's SPAR (Standardized Plant Analysis Risk) model. [Audio]

There is also a session on technical, policy and R&D issues related to the licensing of the Next Generation Nuclear Plant (NGNP), a gas-cooled reactor currently under development. [Session; Audio]. This includes a talk on the US NRC's efforts to develop an evaluation model(EM) for the NGNP. Other sessions of interest include a poster session on Central and Eastern US Seismic Source Characterization (SSC) model development, which may have implications for characterizing seismic sources in Canada as well.

Overall, the conferences promises to be quite interesting indeed.

Update: The US NRC published a Commission Paper (SECY-10-0034) on Potential Policy, Licensing, and Key Technical Issues for Small Modular Nuclear Reactor Designs on 3-28-2010.

Canada: Nuclear Renaissance or Nuclear Vita Nova?

The Nuclear Renaissance has been a much-awaited thing in Canada, for at least the last four years, if not longer. Renaissance, of course, suggests the idea of 'rebirth', a beginning anew of a life once lived; with the subtext that things in this rebirthed life will be much the same as before, only newer.

Over the last several decades, the Canadian nuclear industry evolved to encompass three main sectors: Uranium Mining, Reactors for Power Production, and Radioisotopes for Medical Uses. Of these three, the reactor segment has had the greatest visibility, while, on a worldwide basis, it was actually the uranium mining and medical radioisotope segments which had the greatest relative market share. A 'renaissance' in the Canadian nuclear sector therefore came to be understood primarily in terms of new reactors, and new reactors essentially of the same CANDU pressure-tube configuration that Canada pioneered and which now are operating in many other countries as well.

But in his speech at the US Nuclear Regulatory Commission's Annual Regulatory Information Conference in March 2009, NRC-RIC-2009, the Deputy Director General of the International Atomic Energy Agency (IAEA), Mr. Tomohiro Taniguchi of Japan, speaking at the session on Global Perspectives on the Nuclear Renaissance, introduced a new phrase that he hoped would refocus the emphasis on new ways of doing things in the new nuclear age: Nuclear Vita Nova:

I, on the other hand, view this reality as a Vita Nova, or new life, because the nuclear community needs new ideas and innovative thinking to address new challenges, rather than a simple revival of the "good old days."

At the current juncture, when Nuclear New Build - which seemed imminent just a few months ago - has been indefinitely postponed in the main Canadian province; when the main Canadian reactor builder faces an uncertain future; and when the main private reactor operator in Canada has withdrawn its license applications for new nuclear reactors - it is certainly worth pondering what is in store for the Canadian nuclear sector - a Renaissance, or a Vita Nova? And if it is to be the latter, might the relative (and perceived) importance of the three main sectors change from what it was in the past? At the moment the answer is not clear, but the singular salience of the question must certainly be recognized.

(Dr. Taniguchi took care to mention at the end of his talk, for the benefit of those who might have missed the allusion, which, given his audience, was probably everybody - that his neologism 'Vita Nova' was actually the Latin form of the Italian La Vita Nuova, the title of a collection of verse that Dante Alighieri wrote in 1295, being an expression of the medieval genre of courtly love. Incidentally, the incoming Director General of the IAEA, beginning 01 December 2009, is also from Japan - Yukiya Amano. He will be taking over from Dr. Mohamed El-Baradei of Egypt, who has been named Director General Emeritus, an honor he shares with Dr. Hans Blix. Dr. Amano's appointment to the Director-Generalship of the IAEA will be ratified during the 53rd General Conference of the IAEA in Vienna, 14-18 September 2009. Like Dr. El-Baradei and Dr. Blix, Dr. Amano is also a lawyer. By coincidence, the current Director-General of ITER, Mr. Kaname Ikeda, and the current Executive Director of the International Energy Agency (IEA), Mr. Nobuo Tanaka, are also Japanese.)


Update: After I wrote this post, I discovered that on the TV Ontario program The Agenda, the season-opening episode on 8th September had been on Canada's Nuclear Future. I am pleased to embed the video, featuring an extremely spirited discussion (in which, as Steve Paikin, the host, quipped, they ran out of time but clearly not energy. The astute physicist reader of this blog will immediately see Steve Paikin's probably unintended pun here - since energy and time are classically canonically conjugate variables, they are related through a quantum uncertainty principle - the more precisely you bound one of them [in this case, time], the more uncertain the other will be!):