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UNITED STATES OF AMERICA 

NUCLEAR REGULATORY COMMISSION 

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MEETING WITH ADVISORY COMMITTEE 

ON REACTOR SAFEGUARDS 

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THURSDAY, 

OCTOBER 6, 2016 

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ROCKVILLE, MARYLAND 

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The Commission met in the Commissioners= Conference Room at the 

Nuclear Regulatory Commission, One White Flint North, 11555 Rockville Pike, at 10:00 

a.m., Stephen G. Burns, Chairman, presiding. 

COMMISSION MEMBERS: 

STEPHEN G. BURNS, Chairman 

KRISTINE L. SVINICKI, Commissioner 

JEFF BARAN, Commissioner 
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ALSO PRESENT: 

DENNIS BLEY, ACRS Chairman 

MICHAEL L. CORRADINI, ACRS Vice Chairman 

RONALD G. BALLINGER, ACRS Member 

DANA A. POWERS, ACRS Member 

JOHN W. STETKAR, ACRS Member 

MARGARET CHU, ACRS Member 

JOSE A. MARCH-LEUBA, ACRS Member 

MATTHEW SUNSERI, ACRS Member 

ANNETTE VIETTI-COOK, Secretary of the Commission 

MARGARET DOANE, General Counsel 
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1 P R O C E E D I N G S 

2 CHAIRMAN BURNS: I want to welcome our new members, and now I 

3 think we'll join the other speakers and the Commissioners will join at the table and we'll 

4 begin our meeting. I'll call the meeting to order. I want to welcome members of the 

5 Advisory Committee on Reactor Safeguards, the NRC staff and members of the public 

6 who may be in the room or who may be watching us remotely. 

7 Today, this is one of our periodic meetings with the Advisory Committee. 

8 These meetings provide the Commission an opportunity to hear directly from the 

9 Committee about their work in general over the past six months, and in more detail about 

10 several key safety matters recently reviewed by the Committee. The presentations will 

11 be followed by a question and answer session with the Commission. Before we begin, 

12 would any of my colleagues like to have any opening comments? 

13 (No response.) 

14 CHAIRMAN BURNS: Okay, very good. I think we'll start with Mr. Bley 

15 and Dennis, would you begin the Committee's presentation? 

16 MEMBER BLEY: Thank you, Chairman. Are we going to have the 

17 slides? 

18 CHAIRMAN BURNS: That's good. There we go. 

19 MEMBER BLEY: Well, since our last meeting with the Commission in 

20 March of this year, we've issued 15 reports. The first four I'm going to go over we'll talk 

21 about more today. In fact, Dr. Powers will lead the discussion of our review of the Non22 Power Production or Utilization Facility License Renewal Rulemaking, so-called NPUF. 

23 Mr. Stetkar will lead us through the -- one of our last Fukushima reports, and this is the 
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1 one on Guidance for Flooding Hazard Reevaluation, Including Focused Evaluations and 

2 Integrated Assessments. 

3 Professor Corradini will talk us through our review of the risk significance 

4 determination process that was proposed by NuScale in a topical report, and Professor 

5 Ballinger will go over our review of the guidance and technical basis for that guidance for 

6 applying the alternative pressurized thermal shock rule. 

7 During this period, we looked at two COLAs. The first was Turkey Point 

8 Unit 6 and 7. The second is a little unusual. It's exceptions to the AP1000 certified 

9 design for the Levy plant. Levy was the lead plant for a number of exceptions that were 

10 found to be needed to implement the functions of the certified design. 

11 The first of those was a condensate return and passive residual heat 

12 removal issue, and then there were four others, main control room operator dose, main 

13 control room heat load, plant monitoring system, and hydrogen venting and containment. 

14 These were all quality issues in the design cert. Two of them were 

15 identified as errors in calculation. One is omissions and two of them were lost, so-called 

16 losses of design control. For example, on the main control room heat load, the 

17 calculations were done properly. But then over the years additional heat loads were 

18 added beyond what were expected. We also looked at license renewal applications. 

19 We had LaSalle County and Fermi 2. 

20 Next slide. We have two more Fukushima reports, one on the Tier 3 

21 recommendations for containment vents, hydrogen control, and advanced 

22 instrumentation, enhanced instrumentation, and the other on the natural hazards other 

23 than seismic and flooding. 
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1 We looked at several reports on -- that were guidance and bases, Reg. 

2 Guide 1.229 on risk-informed approach for addressing the effects of debris on post3 accident long term core cooling. This was that regulatory guide that was kind of left over 

4 from our 50.46(c) draft final rule evaluation of a few months back. Also, NUREG-1927, 

5 which is the standard review plan dealing with compliance for dry storage of spent nuclear 

6 fuel. 

7 Next one, please. We looked at the topical report, the so-called full 

8 spectrum LOCA, the Westinghouse calculations came for realistic loss of coolant accident 

9 evaluations over the whole spectrum of break sizes. We looked at the Diablo Canyon 

10 digital replacement of the process protection system, and in April we sent you our own 

11 biannual review of the NRC's Safety Research Program. 

12 Next slide. We had two visits that were important to us in this year. The 

13 first is one of our annual visits to the regions under the auspices of our Plant Operations 

14 and Fire Protection Subcommittee. We went to Region II, and while there we also visited 

15 the Vogtle site. We looked at the old existing units, primarily looking at the FLEX 

16 implementation there, and we got to see the AP1000 new site. 

17 I'll tell you there's been a tremendous amount of work done since the last 

18 time we were there, and it was a very useful trip for us. I also found out, just for 

19 information, if you go to their website, they have movies of this modular construction 

20 process, and you can see them moving these massive structures out onto the pads. 

21 We also sent our Metallurgy and Reactor Fuel Subcommittee to the 

22 AREVA fuel fabrication facility in Richland, Washington. 

23 Next one. Moving to our future work, we have two more Fukushima-
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1 related items. The first is a follow-on with respect to remaining issues dealing with 

2 natural hazards other than seismic and flooding, and the second is the mitigation of 

3 beyond design basis events rulemaking. For our Radiation Protection Subcommittee, 

4 we have a significant meeting coming up in two weeks on the 10 C.F.R. Part 51 

5 rulemaking. 

6 We've had many, many meetings with the staff and stakeholders over 

7 quite a few years in this area. New member Dr. Margaret Chu will be chairing that 

8 meeting, her first one. 

9 Next slide. We have one design certification. This is the continuing 

10 work on APR1400. The schedule is very intense on that and everyone's having a bit of 

11 trouble keeping up with it but it's moving forward. We have one COLA. We will have 

12 one COLA. That's the North Anna ESBWR. We have the NuScale safety focused 

13 review and we have to learn to understand what's meant by this, the safety-focused 

14 review. 

15 I thought they all were in a sense, but there's some new ideas being 

16 proposed, and we haven't seen those yet. In the license renewal area Grand Gulf, we're 

17 dealing with this week. We should finish that up, and we also will have South Texas. 

18 Next slide. GSI-191, the sump and debris issue. We have one 

19 technical report, the WCAP related to GSI-191 debris issues. We also have PWR 

20 Owners Group in vessel debris test results to review, and South Texas Project's risk21 informed amendment request that's continuing work. 

22 Next slide. In the digital I&C area, we will be reviewing a SECY paper 

23 on cybersecurity for fuel cycle facilities. This is kind of a fallout of the Commission's 2008 
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1 SRM in this area. Also before we start our review and comment of the digital I&C action 

2 plan, we're going to be briefed on how 50.59 can be used vis-a-vis digital I&C work. 

3 In the reliability and PRA area, we have two continuing projects to keep 

4 track of. The staff will be coming to talk with us on both Level 3 PRA and the 

5 development of human reliability analysis methods. 

6 Next slide, please. Our Metallurgy and Reactor Fuel Subcommittee has 

7 two issues coming up. One is continuation of the consequential steam generator tube 

8 rupture work and the second is the consolidation of dry cask and dry fuel storage standard 

9 review plans. 

10 This is kind of known as a management aging process in storage maps, 

11 which is kind of like a GALL for dry storage. 

12 The Thermohydraulic Subcommittee is looking at the AREVA extended 

13 flow window from Monticello, and the supplement to a topical report on the BISON code, 

14 which is the Westinghouse transient analysis code for BWRs. At this time, I'll turn it over 

15 to Dr. Dana Powers to talk about NPUF. 

16 MEMBER POWERS: I'll talk about NPUF. It's a new abbreviation. 

17 The agency, of course, needs new abbreviations. It encompasses the research and test 

18 reactors as well as our radionuclide facilities such as SHINE. I'm going to focus on the 

19 research and test reactors. These are the reactors that feel like they're the red-headed 

20 stepchildren of the licensed reactor world. 

21 We have about 31 of these facilities that are licensed and operating. 

22 Three of them are at government locations, three are in commercial locations, but the 

23 vast majority of them are located at universities. 
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1 Typically they have very low radionuclide inventory, they're operated at 

2 low pressure and low power, they're natural cooling, even air cooling is often sufficient for 

3 these facilities. 

4 On the other hand, they're located rather close to that population that we 

5 would consider "the public." When I say they're low power, the next slide shows some 

6 of the power spectra of these reactors. Four of them operate at less than one kilowatt, 

7 some as low as a small lightbulb. Five of them are over two megawatts, the rest arrayed 

8 in between most, between two and a quarter of a megawatt. 

9 They have relatively low usage. Four are used only a few hours per 

10 week. Sixteen of them are used a few hours per week, seven used maybe 20 hours, 40 

11 hours per week. Four have high levels of usage. They age slowly. 

12 That is, they're not operated at high pressures. They're not operated at 

13 high powers. They don't go through massive power changes. So there are not a lot of 

14 driving mechanisms for aging. Furthermore, they don't change in their design much. 

15 The trick for operating these facilities safely is to keep them well16 maintained and to operate them within the technical specifications with trained personnel. 

17 When the Atomic Energy Act was formulated, the research and test reactors carried a 

18 much higher level of accord. 

19 We knew at the time that we had a nifty new technology. We didn't know 

20 how to optimize it. We didn't know what all that could be done for it. We did know that 

21 before you could learn how to use this technology to its best, you had to have a generation 

22 of people that were trained to be familiar with the technology. 

23 Therefore, research and test reactors were accorded in the Atomic 
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1 Energy Commission a special status. They were accorded minimal regulations, 

2 consistent with the objective to protect the public health and safety. Somewhat 

3 arbitrarily, it was decided to license these facilities for 20 years. I think at the time no 

4 one actually thought any of the facilities would go through relicensing. 

5 At the time the Atomic Energy Act was written, new reactors were built, 

6 constructed, decommissioned and redesigned on about an 18 month cycle. But that has 

7 not been the case, and we have now reactors, some of which were originally licensed in 

8 the 1950's, some as recently as 2010, going through relicensing and it's been difficult. 

9 I think the Commission is acutely aware that there have been difficulties 

10 because of staff diversion onto things such as TMI, such as Fukushima to review the 

11 relicensing applications. At the same time, many of the facilities have small staffs. 

12 Some of them have staffs of two people. Some, of course, have larger staff. 

13 So it's been difficult for them to respond to the relicensing process with 

14 the alacrity that has been accorded to the power reactors. I think the Commission is 

15 aware of that and asks the staff to consider streamlining them. 

16 On the next point, the staff has taken what I think is a very novel 

17 approach. They have definitely thought out of the box for this one. What they propose 

18 is for the research reactors that they will be licensed with a non-expiring license. They 

19 will be required, however, to submit every five years an updated final safety analysis 

20 report and they will be subjected to the continuing program of inspection and monitoring. 

21 This is licensing under sufferance, rather than a periodic license. It's 

22 rather similar to the kind of licensing that's done in some European countries. ACRS 

23 examined this proposal from the staff for a non-expiring license. They concluded we 
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1 could identify no reason that this process would degrade safety. We could speculate 

2 that perhaps it would enhance safety because it would enhance familiarity with the 

3 technical specifications and the technical bases for those technical specifications, and 

4 that it would match more closely the cycle of personnel, especially at the university 

5 reactors. 

6 We drew similar conclusions on other aspects of the staff proposal, 

7 including changes in the dose criterion, the applicability of 10 C.F.R. 50.59 to 

8 decommissioning and timely submittals for license renewal applications, and basically 

9 concluded the staff had a good proposal and it should be approved. 

10 MEMBER STETKAR: This morning I'm going to briefly provide an 

11 overview of our review of the guidance for assessments performed for the reevaluated 

12 flooding hazards. 

13 Next slide. As a background, the staff developed guidance for these 

14 evaluations in COMSECY-15-0019. Basic elements of that guidance entailed focused 

15 evaluations to confirm that key safety functions are protected by existing barriers in the 

16 plant, or by committed plant modifications. 

17 If protection did not provide adequate margin against the reevaluated 

18 flooding hazard, then a so-called integrated assessment could be performed to evaluate 

19 the combined effects from plant-specific protection and flood damage mitigation 

20 strategies, and COMSECY-15-0019 in particular noted that revised integrated 

21 assessments of local intense precipitation would not be required. 

22 Next slide. In parallel to the staff's work on development of guidance for 

23 these integrated assessments, the industry itself was proceeding with the development 
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1 of guidance for implementation of FLEX. As part of that guidance, the industry noted 

2 that licensees could consider alternatives or so-called targeted mitigation strategies to 

3 compensate for possible limitations in site-specific FLEX strategies. 

4 The industry also developed guidance, in particular NEI 16-05 for the 

5 performance of assessments to be performed in response to the reevaluated flooding 

6 hazard, and the staff developed interim staff guidance JLD-ISG-2016-01, I hope they don't 

7 get any longer than that, to endorse the industry's guidance. 

8 Now the guidance and the staff's endorsement entails three so-called 

9 paths for these assessments, and we don't have time to go into details of the paths. But 

10 the salient information is that Paths 1 through 3 are deemed to be focused evaluations. 

11 Paths 4 and 5 are deemed to be integrated assessments. 

12 That distinction is important because the staff will review all of the 

13 integrated assessments in their Phase 2 regulatory evaluation process, to determine 

14 whether any regulatory requirements are required on a site-specific basis. So there's a 

15 distinction there. 

16 Next slide. I did provide you a brief overview of these paths. It's useful, 

17 shows the scope of each of the paths. It shows the progression from protection through 

18 mitigation with increasing attention as we go from Paths 1 to 5 to site-specific risk 

19 considerations. 

20 Next slide. We had several recommendations and conclusions during 

21 our review of this guidance. Our first conclusion was that this graded approach provides 

22 an appropriate evaluation framework. The focused evaluations first emphasize 

23 protection against flooding damage. 
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1 If that protection is not adequate, mitigation strategies are examined only 

2 if protection cannot be assured, and we concluded that that type of progressive evaluation 

3 appropriately considers the protection, mitigation, risk information and supports a defense 

4 in depth approach to external flooding. 

5 Next slide. With regard to the treatment of local intense precipitation, 

6 we recommended that if the mitigation strategies are needed for flooding caused by local 

7 intense precipitation, the staff should review those evaluations in the same manner as the 

8 integrated assessments that are performed for any other flooding mechanism. 

9 Next slide. We also had some comments and recommendations on 

10 assessment of the reliability of the mitigation strategies, and in particular the strategies 

11 that are developed for the so-called Path 5 assessments, and the higher frequency, I'm 

12 sorry, the Path 4 assessments and the higher frequency Path 5 assessments, or in effect 

13 the higher risk-significant scenarios. 

14 The assessments for those scenarios should demonstrate so-called 

15 effective mitigation, and by effective mitigation we mean mitigation that is both feasible 

16 and reliable. We noted that the guidance for equipment reliability and availability was 

17 actually quite good. However, in contrast, the guidance for evaluating personnel 

18 performance was relatively more weak. 

19 So we recommended that the staff should better specify expectations for 

20 assurance of reliable personnel performance in those higher risk scenarios. 

21 Next slide. We also had some comments and recommendations on the 

22 evaluation of seismically caused floods and in this topic in particular, I want to make sure 

23 that there's common understanding. We're talking here about seismic events that cause 
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1 damage at the site, and damage to nearby facilities that may then result in flooding. 

2 So an example would be a large earthquake that causes damage on the 

3 site and damage to a nearby dam. The dam failure would then cause flooding at the 

4 site. The concern is that licensees who develop strategies that are targeted to only a 

5 single hazard, for example targeted strategies for seismic or targeted strategies for 

6 flooding, those strategies could be compromised in the event of a compound scenario. 

7 So we recommended that the staff should develop guidance to ensure 

8 that the site-specific evaluations for sites that might be vulnerable to these types of 

9 scenarios explicitly consider them. 

10 Next slide. A draft version of the staff guidance recommended that an 

11 independent peer review be performed for every integrated assessment, and we 

12 observed that conducting those reviews could be quite challenging, both from a resource 

13 perspective and quite honestly from the ability to find available, independent technically 

14 qualified reviewers. 

15 In particular, probabilistic flooding hazard assessment is an evolving 

16 technology and the community just isn't all that large. The staff has revised the guidance. 

17 The final version of the guidance indeed has removed that requirement for independent 

18 peer reviews. So we think that's an improvement. 

19 Next slide. As Dr. Bley mentioned in his introduction, we are very 

20 actively involved in continuing engagement on all things Fukushima. In particular with 

21 regard to the flooding hazard assessments, our Fukushima Subcommittee was briefed 

22 on draft guidance for the Phase 2 regulatory evaluations in an August 17th subcommittee 

23 meeting. 
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1 The committee decided not to write a letter on that topic, excuse me, and 

2 we have requested future briefings on selected site-specific evaluations, in particular any 

3 Phase 3, I'm sorry, Path 3 evaluations that address mitigation of local intense 

4 precipitation, selected Path 4/Path 5 evaluations and an example of any targeted 

5 mitigation strategies that might compromise some of the safety functions. 

6 MEMBER CORRADINI: Sorry. I had it on and I turned it off. Sorry. 

7 So we'll talk about NuScale, in particular a topical report which is entitled "Risk 

8 Significance Determination." 

9 Next slide, please. So as you're well aware, NuScale's design 

10 certification application is expected to come in approximately in December, at the end of 

11 this year. In fact, as I understand it, the certification application is being reviewed now 

12 for acceptance. 

13 NuScale's integral pressurized water reactor is a particular design which 

14 really shows a lower risk profile than current light water reactors. In fact, the estimated 

15 CDF and LRF values, core damage frequency and large release frequencies, are much 

16 lower than current operating nuclear power plants. 

17 Next slide, please. So in terms of background, a component or a system 

18 is considered risk significant if its assumed failure causes a notable increase in the core 

19 damage frequency. Current risk significant criteria are embodied in Regulatory Guide 

20 1.200, and would overstate the importance of some structures, systems and components 

21 for a plant with such a low risk. 

22 I'd note that 1.200 has specific relative numerical criteria. So you look 

23 at a ratio. If the ratio is greater than X, you start classifying in a certain fashion. The 
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1 feeling is that these traditional criteria are insensitive to global safety improvements that 

2 you might see in such a design as NuScale. 

3 So for NuScale, this would result in the categorizing of a majority of the 

4 NuScale equipment modeled in the PRA as risk significant, and we just don't feel that's 

5 appropriate. 

6 Next slide, please. So NuScale's approach is a bit different. They take 

7 an alternative approach to Reg Guide 1.2 for identifying their SSCs as candidates for risk 

8 significance, and in fact what they do, NuScale follows a framework similar to Reg Guide 

9 1.174. 

10 What I mean there is they're basing it on larger increases of risk that may 

11 be acceptable if the CDF is smaller. So as I have a lower and lower estimated value for 

12 the CDF, I allow for more variability in the risk significance, and therefore classified in a 

13 different manner. 

14 NuScale's risk significance determination methodology is based on 

15 criteria for the candidate SSCs on a fixed contribution for the CDF and the LRF. I won't 

16 give you the numbers. I probably will get them wrong anyway, but a fixed value, and this 

17 NuScale-specific numerical value is different than what you see for AP1000 ESBWRs. 

18 So they're -- from a case by case basis, they're different. 

19 Next slide, please. So we looked at that in a Subcommittee meeting in 

20 March and then in a full Committee briefing and wrote a letter in May of '16. 

21 Next slide, please. So our conclusions and recommendations are that 

22 the criteria for determining risk significance in a case by case manner can lead to 

23 inconsistencies in regulatory positions. If you look at what is being done for NuScale, it 
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1 is different than AP1000, it is different than ESBWR on a case by case basis. 

2 We felt the staff should develop a consistent approach by adopting a 

3 continuous scale to determine quantitative risk significant criteria, with more margin 

4 allowed for plants with lower risk values. I note here that in principle, NuScale really is 

5 following this general procedure because of their lower risk profile, and it's actually based 

6 on some past ACRS recommendations, in particular a letter we wrote back in April 26th 

7 of '12 and July 16th of '14, discussing this concept of a flexible continuous scale. 

8 Next slide, please. From a case by case basis, we feel that the NuScale 

9 approach is reasonable provided that the current estimates of CDF and LRF remain 

10 approximately the same. And then finally we recommend that the staff is going to need 

11 to address the multi-module aspects of the NuScale design. You're probably all familiar 

12 with that this is a, for want of a better word, a six pack or a 12 pack idea, right. 

13 So therefore the way it's designed with a common pool, which has both 

14 radiological protection and ultimate heat sink abilities, there's going to be some 

15 interactions that have to be considered on a multi-module effect, and that could alter the 

16 CDF and LRF risk estimates and associated SSC classifications. 

17 Next slide, please. So we got back the staff's response to that, and I'll 

18 go over that briefly. The staff agrees that generic numerical criteria for determining risk 

19 significance would be advantageous rather than a case by case basis. Currently now as 

20 I had mentioned, they use a, what is called a risk achievement worth. 

21 For example, it's a rationing, and every one of those that I mentioned on 

22 the case by case basis are different. So the staff intends to pursue revisions of the 

23 quantitative risk significance criteria to make them consistent with a broad spectrum of 
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1 design and absolute levels of overall plant risk. In fact, the staff in its response noted 

2 that they will consider our suggestions from those two past letters I mentioned as a 

3 potential model to consider. 

4 Next slide, please. They also noted that numerical criteria will be 

5 scalable based on applicable base risk metrics, so that they'd be scaled based on whether 

6 those are for CDF, LRF or large early release frequencies, and numerical criteria will be 

7 anchored to thresholds for risk significance that conform with the acceptable risk increase 

8 guidelines that I mentioned in Reg Guide 1.174. 

9 They would also complement the existing criteria from Reg Guide 1.2, 

10 which would be in use for current operating plants. 

11 Next slide, please. So the staff actually noted that they will draft a single 

12 guidance document for using the PRA to rank these SSCs in their response. I'd also 

13 note that they said they'd begun this activity, which I'm quite happy with and we're looking 

14 forward to looking at it, and the staff will be revising these existing guidance documents 

15 as resources permit. 

16 Next slide. Finally, the staff agrees with the ACRS on the 

17 recommendation on multi-module aspects of the NuScale design. They're currently 

18 considering the impact of multi-module aspects of this design on the CDF and the LRF, 

19 and on the categorization of the SSCs, and that they will consider this as part of its review 

20 of the NuScale design certification, particularly through Section 17.4, Reliability 

21 Assurance Program. So with that, thank you, and you'll see more of NuScale. 

22 MEMBER BALLINGER: Good morning. 

23 CHAIRMAN BURNS: Good morning. 
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1 MEMBER BALLINGER: Over the past several years, we have been 

2 reviewing the guidance on the alternative pressurized thermal shock rule, which is 10 

3 C.F.R. 50.61(a). By way of background, the original rule, which was as near as I can 

4 recall promulgated in the 70's, along with an associated Reg Guide 1.99 that dealt with 

5 requirements to maintain sufficient ductility in the pressure vessel for a LOCA event, and 

6 the rules were very prescriptive because the database was limited, and so there was a 

7 lot of conservative built into it. 

8 The alternative rule, 61(a), was issued in 2010. So it's been an ongoing 

9 process and provides alternative limits that are based on much more sophisticated better 

10 analysis, fracture mechanics, probabilistic fracture mechanics analysis, which limits the 

vessel, frequency of vessel failure to 10-6 11 . So it's a new approach. 

12 NUREG-2163, which is the background document, and Reg Guide 1.230 

13 provide the guidance on use of the alternative rule. As I said, 61(a) is less restrictive on 

14 the reference temperature for embrittlement screening, and it should enable longer 

15 operations. That's particularly important for license renewal, license extension and 

16 things like that. But it comes at a cost to the licensee of responsibility to be sure that 

17 their vessel meets certain criteria. 

18 Those criteria primarily related to ensuring that the embrittlement 

19 behavior of their vessel is consistent with the database upon which the probabilistic 

20 fracture mechanics analysis was performed. 

21 So we want to make sure it's in the universe, and that means that there's 

22 an evaluation of plant-specific surveillance data that's required, and an evaluation of in23 service inspection data. The two are different. 
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1 The motivation again was that the original screening criteria resulted in 

2 an unnecessary burden without an improvement in overall safety. There was again a 

3 conservative bias on toughness that resulted in an artificial impediment to license 

4 renewal. Plant-specific analysis was an option if you couldn't meet the rule, but the -- 

5 nobody exercised that option because it was very onerous to do and it was found to be 

6 impractical. 

7 But there have been improvements in technical understanding. There's 

8 a few more of these, but these are the major ones, and that is the recognition that there's 

9 a spatial variation in fluence not so much through the wall, as we always recognize that, 

10 but around the vessel and through the welds and things like that. 

11 Most of the flaws in the vessel are now recognized as being subsurface 

12 not -- they're embedded rather than on the surface, and the previous rule had to assume 

13 that the vessels were surface-connected, which is where things would fail. That resulted 

14 in -- the spatial variation in fluence resulted in spatially dependent embrittlement 

15 properties. 

16 Next slide, please. So this is a short table which gives you the 

17 differences between the two with respect to this reference temperature screening criteria. 

18 The 61 was more restrictive. The 61(a) is voluntary by the way. The licensee can still 

19 use 61 if they desire to do that. 

20 You need -- they're better informed and less restrictive. The plant21 specific surveillance data required, we don't need to go through the required tests. But 

22 there are more tests that have to be passed in order for assurance that the vessel is within 

23 the database that was used for the new rule. So in the plant-specific flaw inspection the 
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1 same way. 

2 None was required before, before 61 that is, but for 61(a) you need to 

3 understand the flaw distribution in the vessel, again to make sure that that flaw distribution 

4 matches up with the flaw distribution that was used for the probabilistic fracture 

5 mechanics analysis. 

6 If there's a deviation from that, there's a path to account for that. But it's 

7 a little bit more -- requires more information. Again, so the plant-specific -- excuse me, 

8 next slide. 

9 The plant-specific surveillance checks ensures again that the plant 

10 surveillance data that's being assessed is well represented. With respect to the flaw 

11 inspections, the inspections again assure that we have the right distribution and they're 

12 consistent with ASME pressure boiler and pressure vessel code Section 11, and they 

13 have -- there has to be verification that the flaws of the clad metal interface do not open 

14 to the pressure vessel inside surface. So that's the surface-connected flaw issue. 

15 There's a requirement to assess NDE uncertainty, and again the flaws 

16 that are closer to the idea, which -- excuse me, ID, idea where the damage is the highest 

17 and therefore the susceptibility the highest, are assessed more stringently. 

18 And the recommendation that we made after review was that the guide 

19 and the NUREG should be issued. Thank you very much. 

20 MEMBER BLEY: That's it. 

21 CHAIRMAN BURNS: All right, that's it now. Thank you for the 

22 presentation and we'll begin the questions this morning with Commissioner Svinicki. 

23 COMMISSIONER SVINICKI: Chairman, is it Bley? Have I been saying 
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1 your name wrong for years and years? 

2 MEMBER BLEY: It is, thank you. 

3 COMMISSIONER SVINICKI: I thought I visited Pitcairn Island in 

4 January so Bley -- 

5 (Simultaneous speaking.) 

6 MEMBER BLEY: It's spelled a little differently. 

7 COMMISSIONER SVINICKI: It is spelled differently, but that's what I 

8 think of. Are you unrelated at all to Captain Bligh? 

9 MEMBER BLEY: That's B-L-I-G-H. I almost was a captain. 

10 COMMISSIONER SVINICKI: Well I know it is, but my name is spelled 

11 nothing like it was back in the Slovak region of Austro-Hungary. 

12 MEMBER BLEY: That's probably true. 

13 COMMISSIONER SVINICKI: Now we've seen some church records 

14 that had a Z and a Y and not as many I's. But in any event, it used to be that at Ellis 

15 Island they were able to take significant liberties. I think that my parents arrived and my 

16 father arrived, well his father, at a time of a wave of Polish immigration. 

17 So the name was made much more Polish. I've traveled to Poland and 

18 they say oh, you're Polish. I agree because I'll just affiliate with anyone who will have 

19 me. So if they think I'm Polish that's fine, but it's actually Slovak. 

20 MEMBER BLEY: It's German and Dutch maybe in it too. 

21 COMMISSIONER SVINICKI: Okay, but it is Bley. Okay, thank you. I 

22 just thought you were too nice to correct me for years and years and I wanted to get the 

23 record straight. So welcome to all members of the Committee, and a special welcome 
 22 

1 to the new members. Always appreciate. I know we regret when members don't renew 

2 with the Committee, but it's also very, very valuable to have new expertise and 

3 backgrounds represented. So I welcome the new members today. 

4 The Committee has been very prolific since our last meeting, so I did 

5 review -- I have the greatest intentions upon receiving the letter reports one by one, that 

6 I want to read them all so they go on a reading pile that many of us have. The preparation 

7 for this meeting always forces me. 

8 Now if we have a voting matter, of course, I pull that one out of the pile 

9 because I want, I give in all seriousness, although I'm not always in perfect alignment with 

10 the Committee's views, I give heavy, heavy weight to the Committee's input on any matter 

11 on which I'm voting. So I really have a respect for the work that you do. 

12 So you've teed up a number of issues, and I'm also going to close with 

13 some observations I make. When you read a body of a committee's work in one sitting, 

14 you get some discernible maybe trends for things. I'm always thinking about your 

15 engagement with the agency staff, your input to the Commission and how the general 

16 flow of all of those things appears to be working. 

17 So this meeting is also an opportunity for you to hear the Commission's 

18 feedback. So I want to provide that as well. I will interrupt Dr. Powers from the 

19 equations on which he's working right now and begin -- 

20 (Laughter.) 

21 MEMBER POWERS: He is not. He is recording your words as you're 

22 speaking. 

23 (Simultaneous speaking.) 
 23 

1 COMMISSIONER SVINICKI: Well, I was going to say and will still say 

2 that I'm beginning with Dr. Powers first of all as just evidence of my high regard for his 

3 work, and secondarily because he has introduced such a pleasing new acronym into 

4 today's discussion. It's just, it sounds like there's clouds and rainbows and unicorns 

5 around NPUF. 

6 So not all new acronyms are so melodious and pleasing to the ear, so I 

7 really do thank you for addressing this topic. 

8 MEMBER POWERS: And it is reflective of what it speaks to, rainbows 

9 and wonderful reactors. 

10 COMMISSIONER SVINICKI: No, I'm not certain. I'll have to do more -

11 - I'll have to do more thinking about that. But I was going to ask you about how the ACRS 

12 might have deliberated on the periodicity of five years for the updates. Now you went on 

13 to say in your oral remarks today what wasn't on the viewgraphs, that you feel it aligns 

14 with the turnover of maybe students, graduate students and personnel. 

15 But I guess what I was looking for is I know there's no perfect sweet spot, 

16 but did you talk about maybe it should be three years, maybe it should be seven years, 

17 you know. You were made comfortable with five? Is that, was that the high science of 

18 kind of round numbers or things you can divide ten by or -- 

19 MEMBER POWERS: I don't think you can divide five by ten evenly and 

20 not come up fractionally. But that's subject to analysis. You are correct. There is not 

21 going to be an engineering way to come up and say here is the optimal periodicity on this. 

22 We are aware that in the European system that they do typically five or ten years for a 

23 complete review of a power reactor, and that system -- 
 24 

1 COMMISSIONER SVINICKI: But I would also note though your Slide 

2 18 notes that there are very few design changes at these facilities. So how did you weigh 

3 that fact? 

4 MEMBER POWERS: The fact that the design changes are relatively 

5 rare was viewed more as an assurance that you're not going to have wholesale changes 

6 here, that the reports are going to look similar and the focus is going to be more on the 

7 technical specifications for the operation of the reactor as it is. 

8 And I was I think explicit in saying that it is with operation within the 

9 technical specifications that is a key to operating these reactors safely. Now the 

10 weighting that we would put, we had a general recognition that many of the people 

11 operating these reactors have like a four or five year tenure on this facility. 

12 You'll never be able to align it completely with their tenure, nor would you 

13 want to, I would think. You would want to have one experienced person moving out of 

14 the system but with an overlap sufficient to train the guy that was coming in as his 

15 replacement. 

16 To balance all of that and come up with some sort of an optimum was 

17 never undertaken by either the ACRS or the staff. 

18 COMMISSIONER SVINICKI: Was it more just that five years on 

19 balance seemed reasonable? 

20 MEMBER POWERS: It seemed reasonable. Ten years -- 

21 (Simultaneous speaking.) 

22 MEMBER POWERS: Twenty years was clearly too long, and a great 

23 deal of difficulty was encountered in reconstituting the licensing bases for these reactors 
 25 

1 for the license renewal. On the other hand, three years strikes us as that's all you would 

2 be doing because the staff -- many of these reactors are relatively small. As soon as 

3 you got one done, you would just be immediately starting on another one. 

4 So we wanted to some period, and that's about the level of thought on 

5 these things. 

6 COMMISSIONER SVINICKI: Okay, that's helpful. Was there also an 

7 element of that deliberation that looked at the way these reviews, as they're done now, 

8 tend to -- well, this isn't a scientific term -- tend to clump? You mentioned that the staff 

9 has -- some of these reviews have been prolonged because there have been intervening 

10 events like Fukushima or Three Mile Island. 

11 In a cursory look of mine, I felt like many of them had started operations 

12 around the same kind of Atoms for Peace in that time period. So they come up, their 20 

13 years not surprisingly then all tends to clump in a certain number of years, and every time 

14 the wave comes in NRC is a bit overwhelmed in adding that many wave of reviews to its 

15 current body of work because it's just kind of a surge. 

16 So was there any discussion or I don't know if the staff is looking at. 

17 Could they begin somehow to phase this in and then space them out so that they're not 

18 clumped? 

19 MEMBER POWERS: I think that's actually happening in here. 

20 COMMISSIONER SVINICKI: Okay. 

21 MEMBER POWERS: I think they're getting rid of the clumpiness of 

22 things. 

23 COMMISSIONER SVINICKI: Okay. 
 26 

1 MEMBER POWERS: And I'd just comment that you have a staff that's 

2 extremely familiar with these facilities and what not. So they kind of know all, they know 

3 where the skeletons are buried. 

4 COMMISSIONER SVINICKI: And although I'm sure that we do have 

5 employees with continuity on it, we also do rotate a lot of our technical staff around. So 

6 between the waves when the clump comes in, it does tend to be different people. We 

7 also, I think, like many government agencies, are perhaps facing another little mini-wave 

8 of retirements. 

9 So we might lose some of that continuity of knowledge. Well that's very 

10 thorough. Thank you again for your input on that. On the general topic of the flooding 

11 hazard reevaluation, there's discussion here about, you know, mitigation strategies are 

12 examined only if protection cannot be assured. 

13 Did the Committee engage the staff or deliberate amongst itself on its 

14 view of the staff's handling of saying, you know, what is the level of assurance that's 

15 necessary? I know this is a little bit of the soft science of the regulatory craft, as the 

16 Chairman calls it. But was there engagement on the staff's threshold determinations of 

17 what is the level of assurance that we're looking for? 

18 MEMBER STETKAR: I'm going to try to understand the question a little 

19 better. In terms of -- 

20 COMMISSIONER SVINICKI: Well, I mean, the events we're looking at 

21 as a body are generally, by definition, extremely low frequency. 

22 MEMBER STETKAR: Right. 

23 COMMISSIONER SVINICKI: So you've got to marry those two 
 27 

1 concepts. So, saying, you know, we're only going to do a certain type of examination or 

2 analysis that protection is assured, what does that mean? Because we can't divorce that 

3 from probability space. 

4 MEMBER STETKAR: Okay, good. I think that the approach -- and one 

5 of the reasons that we sort of requested seeing some examples of these evaluations -- 

6 is, I hate to be trite, but the devil is in the details, often. I think that the approach that's 

7 been taken is that the -- initially, the evaluation of the hazard itself is done -- the first 

8 evaluation is done very conservatively. So they assume -- a dam disappears. The 

9 wave of water comes down the valley or, you know, the cloud stays over you and dumps 

10 all of its water or whatever. 

11 They evaluate, first, what is the maximum flood depth from that extreme 

12 event? Without any consideration of its frequency or its probability. If the plant is 

13 adequately situated up on top of a hill, if they have adequate barriers, if they have 

14 adequate drainage to handle that event, that's it. That's the notion of protection. Might 

15 be too much in terms of frequency? That isn't addressed. So, the plants that look at 

16 protection in that sense, flooding protection, are, I believe, taking that approach, if they 

17 cannot demonstrate adequate margins. 

18 In other words, the maximum flood depth comes up to be a few 

19 centimeters below the top of their wall, if you will. They're then starting to invoke now 

20 more progressive evaluations of frequency, probability, consequences, more of a risk21 informed approach. 

22 So as you go into those Path 4 and Path 5 assessments, those are by 

23 design intended to evaluate both the frequency and the consequences on a site-specific 
 28 

1 basis and bring in more of those notions. 

2 COMMISSIONER SVINICKI: Well, I think that answer demonstrates the 

3 complexity of, first of all, the staff has had to confront in looking at these issues, but also 

4 then in the Committee's deliberations. 

5 I'm over my time, but I just wanted to offer a couple of observations on 

6 the NuScale topic. I just want to note that I'm in alignment with the Committee and that 

7 I think the staff's, you know, case-by-case approach ventures near to a kind of, you know, 

8 a relative risk notion. And I think that the Committee, I interpret, was a little bit disfavoring 

9 the fact that could lead to a bit of an ad hoc decision-making. 

10 Another outgrowth of that is it obscures the Commission's ability to have 

11 policy oversight into overall tolerance of risk and level of risk, which, you know, the 

12 Commission kind of disfavors taking an ad hoc approach to that, as is evidenced by 

13 having things like safety goals and other things that the Commission has wanted to have 

14 as a coherency to our overall approach to licensing things. 

15 I would say that the categorization of the SSCs, the issue that was 

16 explored by the Committee, feeds into some of the criticism that NRC gets that our 

17 processes are fundamentally not going to be amenable to new types of reactors. So I 

18 think by working with the staff to address something like this, it's a powerful demonstration 

19 of the fact that we can bring the expertise either through an advisory committee such as 

20 yours or the staff itself. There are mechanisms within this framework to make these 

21 kinds of adjustments if we just buckle down and do the work. 

22 The other thing that I appreciate -- and I know has been a challenge for 

23 the staff, for the Committee -- as we're in looking at some of the Tier 2 and Tier 3 things 
 29 

1 on Fukushima, the difficulty is that a lot of the paths and decisions have been made in 

2 the years since that accident through a number of different Commission SRMs. 

3 When I read the back and forth of the staff's response to some of the 

4 areas that the Committee would identify, the staff would say, "Listen, you know. We got 

5 a vote to close that out. We won't be doing further work in that area. And while we are 

6 always open to new learning, there does need to be, maybe even in a Project Aim 

7 environment, a mindset that says we have to have a basis for, you know, adding more 

8 decimal places to that analysis or fundamentally reopening something." 

9 We are, I think, getting to a point where there's a certain stability in the 

10 post-Fukushima regulatory approach and response. We're at some of the tail ends, 

11 through guidance and other things being developed, of really giving some sort of 

12 predictability and scrutability to that framework. 

13 So I do appreciate the Committee bringing its expertise to bear. The 

14 staff is now way down into the details where the devil resides. So I do appreciate that 

15 you're kind of engaged in a back and forth with them on that. 

16 And I'm way, way over my time. But I would just say, on the review that 

17 you do of the research program -- I've been meaning to give this feedback, I think, for a 

18 couple of years. It's intensely valuable what you do, but it is evident that it is intensely 

19 labor intensive for the Committee to do, and it results in a thick work product. I'm going 

20 to admit that, even as committed as I am, I read the staff's response because then I can 

21 kind of know what were the areas to be highlighted, and I always need to know what the 

22 agency staff is thinking since I'm a member of the Commission. 

23 So I, as an individual member of this Commission, would be open to 
 30 

1 hearing if there are ways to make that work product, you know, less of a kind of maybe 

2 the writing of it or the -- I don't know. Is the benefit in the engagement with the staff? 

3 And the staff sincerely values the input. 

4 I will say also that, in my nine-plus years here, the budget is the one time 

5 of year that I really look at the elements of the research program. In that venue, those 

6 research projects are competing with the entirety of the agency budget for my attention. 

7 So if you were to guess that they get kind of a superficial look, you'd be right. 

8 That's why I think your review is an all the more important thing. But that 

9 being said, I would be open. I think we've gotten a report in the same kind of format for 

10 a long time and it's extensive, it exceeded 80 pages this year. That's a real significant 

11 effort for the Committee. So I'm just open to things that would allow you to bring all the 

12 insights and maybe have some relief from the burden, it looks like. 

13 Is it Professor Corradini? I mean, you were introduced as Professor 

14 Corradini. Is that -- they've told me you're no longer teaching. 

15 MEMBER CORRADINI: They got rid of me. 

16 COMMISSIONER SVINICKI: Is the professor an honorific or is that -- 

17 because you're Dr. Corradini. 

18 MEMBER CORRADINI: They use the term "emeritus" when you're old 

19 and useless. 

20 COMMISSIONER SVINICKI: Okay. But you're still considered a 

21 professor. I know you're a doctor, but you're a professor even if you don't teach? 

22 MEMBER CORRADINI: Yes. 

23 COMMISSIONER SVINICKI: Okay. All right. Professor Corradini. I 
 31 

1 don't know. The Chairman's going to cut my mic off here in a second because I'm way 

2 over. 

3 CHAIRMAN BURNS: I'm a doctor, but only in Germany, is the law. 

4 MEMBER CORRADINI: Anyway, I will answer one -- I don't know what 

5 -- if I'm supposed to answer anything. But we have a new person in charge of the 

6 research report, and Dr. Rempe will solve the problem. 

7 COMMISSIONER SVINICKI: Oh, okay. Well, I'm not sure it's a 

8 problem because it's a very valuable report. But I think I'm doing, I guess, a mini Project 

9 Aim on you. If there's some way to make it a better use of the Committee's resources, 

10 I'll listen to it. I'm not speaking for anybody else. 

11 MEMBER BLEY: I would say, though, that Chapter 2 is a summary of 

12 everything. It's not very long. And we do divvy this thing up and each of us then -- 

13 COMMISSIONER SVINICKI: Oh, okay. I thought the lead, really -- 

14 because Dr. Apostolakis did have the lead for a while? Boy, did he complain about 

15 having to do that. 

16 (Simultaneous speaking.) 

17 MEMBER CORRADINI: Dr. Rempe, do you want to answer? 

18 MEMBER REMPE: I do, as Professor Emeritus Corradini said, I have 

19 just started doing this, and he finished the one that was issued last year. So I appreciate 

20 your comments, and I think it's a good topic that the Committee should discuss and find 

21 a way to, you know -- maybe it is time for a change. So thank you. 

22 COMMISSIONER SVINICKI: Thank you. Okay, I'm sorry, Mr. 

23 Chairman, and I should be. 
 32 

1 CHAIRMAN BURNS: Take whatever time you want, Commissioner. 

2 (Laughter.) 

3 COMMISSIONER SVINICKI: Wow. 

4 CHAIRMAN BURNS: I mean. one of the things with three members is 

5 that, in some ways, you don't -- I mean, you know, just sort of the -- I apologize, but the 

6 structure is -- 

7 COMMISSIONER SVINICKI: We're going to have to get so much more 

8 disciplined. 

9 CHAIRMAN BURNS: I will be more disciplined. 

10 COMMISSIONER SVINICKI: That's what happens. This happens on 

11 three-person commissions, and then it's a rude awakening when you get five again. 

12 CHAIRMAN BURNS: Yeah, exactly. So anyway, Commissioner 

13 Baran. 

14 COMMISSIONER BARAN: Great. Well, maybe the safest thing to do 

15 is use first names at this point rather than titles. But, well, thank you all for your work 

16 and for that of your colleagues. We really appreciate it. 

17 I wanted to follow up on the questions about the NPUF draft proposed 

18 rule, and there are a couple of -- well, there are several key elements. 

19 But, you know, a couple of the key elements that I think interact, it sounds like, in the 

20 analysis the Committee did of this, are the new requirement to have updated FSARs 

21 submitted every five years. And that's kind of paired, in a way, with unlimited terms for 

22 renewed licenses. 

23 So you explored that a little bit with Commissioner Svinicki on one side 
 33 

1 of it, which is what's the right periodicity on the submission of the FSARs? Let me ask 

2 about the term, or lack thereof, of a renewed license. 

3 Can you talk about -- you talked about several of the factors that affected 

4 the Committee's thinking on that. Can you talk a little bit more about why you think that 

5 strikes the right balance? Because if we're at 20 years now, it is novel to go all the way to 

6 unlimited. Did you look at is 30 years better, is 40 years better? You know, talk a little 

7 bit about -- 

8 MEMBER POWERS: Ordinarily we would not. 

9 COMMISSIONER BARAN: Okay. 

10 MEMBER POWERS: Our focus is going to be on the safety, and does 

11 this degrade the safety? We're not going to argue over the term. It's whether you have 

12 terms or unlimited licenses. And what we knew is that, certainly power reactors in this 

13 world, are licensed under sufferance. So it's not an unlimited license; it's a license that 

14 as long as you keep the reactor in good repair, operate within the technical specifications, 

15 then you can continue to operate. 

16 And that was the step that was being made here, and it struck us, that is 

17 not radical. It will work. It is coupled with a continuing inspection and monitoring 

18 program. What mechanism is there for degradation of safety here? None revealed 

19 itself. 

20 Will it reveal itself as time goes on? Perhaps. But we have an 

21 inspection and monitoring program to alert us if that happens. So that's the Committee's 

22 thinking. And the regulatory mechanics is not really our purview, and we're not going to 

23 tread into that. We're going to ask the question, does this degrade safety or not? 
 34 

1 COMMISSIONER BARAN: And so if there is a new requirement to 

2 submit the FSARs every five years, and therefore the licensee and the staff is focused on 

3 the licensing basis in a kind of updated way, is the Committee's view that there isn't -- if 

4 you have that, there isn't any additional safety benefit to going through a license renewal 

5 process? 

6 MEMBER POWERS: It was not really identifiable that there was one, 

7 that the FSAR and the familiarity with where your technical bases come about, why you 

8 do them, why are there limits on these reactors? 

9 I understand these are used for experiments, and so they're not 

10 necessarily repetitive operations of an identical nature going here -- some there are, but 

11 not necessarily. And so you have to know the technical specifications on your reactors 

12 not as rote, but rather what's the basis for it? And we saw that as much more important 

13 than any prescribed period of time. 

14 COMMISSIONER BARAN: Okay. Let me ask about another element 

15 of the draft proposed rule, and that relates to accident dose criteria for the research 

16 reactors. And so the proposal is to increase that from .1 rem to 1 rem. 1 rem lines up 

17 with EPA's protective action guidelines. But, you know, .1 rem lines up with the dose 

18 limits for individual members of the public, which is where the criterion is now. 

19 And as I read the draft Federal Register notice, I didn't come away really 

20 with a firm understanding of what the practical implications would be for a licensee of this 

21 change. Can you walk us through that? What effect is this going to have? 

22 MEMBER POWERS: I think it's going to be enormously small for the 

23 licensee. The inventories on typical facilities are sufficiently low they'd probably get .1 
 35 

1 for most of their accidents, but they have to look at their limiting accident. That may give 

2 them a little bit of relief there. For the typical one, probably not a lot. 

3 COMMISSIONER BARAN: Okay, because my understanding is the .1 

4 has been around, I guess, since '94. So that's a couple of decades. 

5 MEMBER POWERS: Yeah. 

6 COMMISSIONER BARAN: Has the staff talked about it? Are you 

7 aware of, have there been problems with the current .1 rem level? Is this in response to 

8 -- 

9 MEMBER POWERS: I think we did not pursue that in great depth. 

10 What we saw was that was consistent with the EPA protective action guidelines. We 

11 suffered from not having quantitative metrics on the incident frequency here. So, trying 

12 to align that with quantitative metrics on the consequences was kind of a pointless 

13 exercise. 

14 What attracted me in particular was, okay, you're getting alignment 

15 between the protective action guidelines and your accident analysis. That's a rare 

16 example of consistency in the regulatory process. Let's go with it. 

17 COMMISSIONER BARAN: Okay. Well, and so for the -- it sounds like 

18 relatively few research reactors for which this would really have an effect. What do you 

19 see as the likely effect in those cases? When it's time for license renewal, it's easier for 

20 them to perform the calculations, the accident scenario calculations? 

21 MEMBER POWERS: I don't think they're going to be impacted a lot 

22 anyway. 

23 COMMISSIONER BARAN: Okay. 
 36 

1 MEMBER POWERS: It gives them a number to compare against and 

2 say, "Yeah, I'm below the PAG here." It's consistent. The Health Physics Society tells 

3 us not to try to quantify consequences for less than 1 rem. Like I say, a rare example of 

4 consistency sounded very attractive. 

5 COMMISSIONER BARAN: And not to belabor this, so in terms of the 

6 consistency, it sounds like that's the main thing going for this proposal. So why, in your 

7 view, is it more important to be consistent with the EPA PAG than the Part 20 dose limit? 

8 It's consistent with the Part 20 dose limit now. 

9 MEMBER POWERS: Yes, but that's a public dose limit. You're talking 

10 about a rare event accident, limiting accident. The two shouldn't be the same if you're 

11 going to have a risk-informed regulation, even if it's qualitative risk. 

12 COMMISSIONER BARAN: Okay. John, let me ask about one of the 

13 Fukushima issues, which is the assessment of flooding hazard reevaluations. And as 

14 you talked about, ACRS recommended that an analysis similar to an integrated 

15 assessment be performed at the sites where mitigation strategies -- basically, the FLEX 

16 equipment -- are needed to compensate for the effects of local intense precipitation 

17 flooding. 

18 And in their response, the staff basically said -- this is a little bit of what 

19 Commissioner Svinicki was talking about -- "Well, the Commission already approved this. 

20 Thanks." And so which, you know, I guess is a fair response. When we voted on this, 

21 on the paper, you know, we didn't have the benefit of the ACRS' review at that time. 

22 And so I guess I should ask you a pretty frank question, which is: do you 

23 think we got this wrong? Is this something we should revisit? 
 37 

1 MEMBER STETKAR: I'm not going to answer that in a yes or no. I 

2 think that it's unfortunate that we didn't have an opportunity to give you feedback on the 

3 SECY paper in a timely manner. It just -- it didn't come before us. I wish we had. The 

4 staff's response does cite the SECY paper and the SRM on that SECY paper. 

5 However, the staff also said that they acknowledge our concerns and that 

6 they plan to use -- and I wrote this down so I wouldn't get it wrong -- engineering and 

7 operational judgment, in particular, when they look at those mitigating strategies for local 

8 intense precipitation. 

9 And in fact, it's one of the reasons we wrote a follow-up letter to the staff, 

10 just in our last meeting, and haven't heard back from them yet, but requesting that we see 

11 a few examples of how they're treating that. 

12 So they are sensitive to it, clearly. And we agreed with them in our letter 

13 that trying to revise the interim staff guidance at this point, introducing new discussions 

14 with the industry, new delays while people are under a pretty doggone tight time clock to 

15 produce these assessments, or worse, running the risk that people who are already in 

16 line to submit their assessments might use different principles than some of the later 

17 submittals, I think that this is a reasonable compromise. 

18 COMMISSIONER BARAN: Okay. Well, I think that answers my 

19 question. And sorry if I phrased it in a way that made you timid about answering it. 

20 MEMBER STETKAR: You get a chance to do that. 

21 COMMISSIONER BARAN: You know, I mean, obviously, it's optimal if, 

22 you know, you're able to review it in a timeframe when we're doing our decision-making. 

23 Sometimes that doesn't happen. If the Committee has real concerns about what was 
 38 

1 decided, I, at least, want to hear that. You know, and we should be thinking about 

2 whether in any of these cases we need to go back. 

3 It sounds like, in this case, the view is there are a lot of complexities to 

4 going back and the staff is looking at this still, and you all are still looking at it, so it's not 

5 really necessary here to go back. But, you know, from my point of view, at least, if there 

6 are times where you felt we should, I think we at least want to hear that. 

7 MEMBER BLEY: Thank you, and I think we do. Any time that we think 

8 there's really something that is a significant safety issue that somehow slips through, we 

9 do come back and raise it again. 

10 COMMISSIONER BARAN: I appreciate that. I'm a little bit over, but let 

11 me ask about one more topic since I have license to do unlimited questioning, I guess. 

12 (Laughter.) 

13 (Simultaneous speaking.) 

14 COMMISSIONER BARAN: I know, unlimited duration licenses, 

15 unlimited questioning. 

16 Let me ask Dennis about, in May, the Committee issued a letter on the 

17 staff's post-Fukushima evaluation of natural hazards other than seismic and flooding. 

18 And there were two items that the Committee identified that you all thought warranted 

19 additional staff attention. 

20 One was hazards that could impact the ultimate heat sink, specifically 

21 the effect of debris or the material on intake screens and heat exchangers. 

22 The other was hazards that could adversely affect air quality at a site for 

23 a prolonged period of time, a period that would go beyond Phase 1 of FLEX. 
 39 

1 Can you talk a little bit more about the Committee's concerns? 

2 MEMBER BLEY: Yeah. I think on this one, I'll pass it back to John, if 

3 that's okay, because he did most of the work on this. But yeah, I think we were worried 

4 about cases where assumptions of how things would work could get challenged by these 

5 situations. 

6 MEMBER STETKAR: And I think you've characterized it correctly, 

7 Dennis, also. We currently have a subcommittee meeting scheduled for the 19th of this 

8 month on the topic of the other external hazards. And it's going to be a busy 

9 subcommittee meeting. One item in that subcommittee meeting is to address the 

10 closeout of the high winds, snow and ice loading, which were passed on from the so11 called Task 2 evaluations to Task 3. 

12 However, we are going to go back and revisit those items that we raised 

13 in our letter with the staff. One of the items is quality of the ultimate heat sink water. 

14 One is air quality. And we mentioned a couple of others in our letter, in particular 

15 treatment of downstream dam failures and low water due to other conditions, such as a 

16 seiche. 

17 So we are continuing to follow up on those, and we will -- in the 

18 subcommittee meeting, I don't know whether the Committee will write a letter on that topic. 

19 If we do, it would be in our December meeting. 

20 COMMISSIONER BARAN: Okay. Well, if you end up writing the letter, 

21 if you have reactions to the revisions the staff has made to their assessment, I look 

22 forward to hearing it. Thank you. 

23 CHAIRMAN BURNS: Thank you. I'm going to throw a curveball here 
 40 

1 and ask the general counsel a question. This happened to me once when I was sitting 

2 there during an ACRS meeting. It was the most active meeting I had been in for some 

3 time. And I said, "Why? I'm coming to hear these guys talk technical issues." 

4 But my question is, just to refresh my recollection, the reason why we 

5 can look at, as the term goes, licenses at sufferance, for this set of reactors, because 

6 they're Section 104 licenses. And unlike 103, there is no term. 103 has the 40 years 

7 term, correct? Am I correct? 

8 MS. DOANE: Sorry, I'm not used to talking. 

9 CHAIRMAN BURNS: During this meeting. At this meeting. 

10 (Laughter.) 

11 MS. DOANE: At this meeting, right. Fair enough, right. So, that is 

12 right, and then also I think there was some look at whether the 40 year term was -- there 

13 was a technical basis for that 40 year term. That's another issue. And it wasn't. So 

14 there wasn't -- 

15 CHAIRMAN BURNS: No, no, because even in the 103 license, it's not 

16 a -- it's become a way of organizing the safety review, but it really had to do with antitrust 

17 and economic amortization, depreciation-type issues. 

18 MS. DOANE: Right. So those issues really didn't transcend either. 

19 CHAIRMAN BURNS: Yeah, and we won't go into -- like we still actually 

20 have commercial operating reactors that have 104 licenses, but we'll leave that one aside 

21 for today. 

22 The one thing, I think, you know, it's interesting that in the -- and I've got 

23 to read this, quite frankly, the staff's paper. My colleagues have spent a lot of time on 
 41 

1 this. 

2 I guess the one difference, perhaps, is between some of the models and 

3 I see in -- I think the Swiss is the one that comes to mind, is you have this license of 

4 sufferance, which I think is an interesting term, but you do have a periodic safety review. 

5 Now, I suppose that -- and I think maybe Dr. Powers, where the Committee's coming 

6 from, in effect the submission or the discipline of the five year review or the FSAR update 

7 in a sense gives that opportunity. It puts the burden on the staff, which probably is where 

8 it ought to be. But is that the comparison? 

9 MEMBER POWERS: That's right. We looked at the periodic safety 

10 review, and the submission of the FSAR is essentially identical requirements. The one 

11 differential you have between, say, the Swiss model is they require the power reactors to 

12 make changes to accommodate new understanding. We're probably not going to do that 

13 for these reactors, but that's the only difference. 

14 CHAIRMAN BURNS: Yeah, okay. 

15 MEMBER POWERS: So it seemed like it was a parallel kind of thing, 

16 maybe not identical but certainly parallel, and that gives you comfort that you're not going 

17 to degrade safety. 

18 CHAIRMAN BURNS: Yeah. I think the analogy is valuable, and you 

19 know, I think it helps in understanding. I think what it does, and I think that's one of the 

20 things I think looking at during your deliberation on the paper, on the proposal, is I do -- 

21 in some ways I can see that the burden on the staff -- and, again, I'm not saying that that's 

22 inappropriate -- but the burden on the staff in looking at perhaps at 50.59 changes or the 

23 FSAR updates is perhaps a little more exacting. But as you also commented, the relative 
 42 

1 change is, or changes, are relatively small, I think, for -- 

2 MEMBER POWERS: And they're going to be highlighted. 

3 CHAIRMAN BURNS: Yeah. 

4 MEMBER POWERS: They're going to stand out. They're not going to 

5 have to look for them and they're not going to, probably, not be radical. 

6 CHAIRMAN BURNS: Yeah, okay. All right. Let me turn to John here. 

7 One of the -- as you say, one of the recommendations from the review of the flooding 

8 hazard evaluation is not to do a peer review for each and every submission that came in, 

9 but there might be some focus. 

10 Had you all thought in terms of what criteria or considerations might go 

11 into whether determine whether to do, indeed, a peer review might be appropriate for a 

12 smaller subset or a particular evaluation that might trigger such an effort? 

13 MEMBER STETKAR: No. Quite honestly, we haven't. We reacted to 

14 the notion that was presented in the draft guidance that simply said that the staff wanted 

15 an independent peer review performed for any of the integrated assessments, which, if 

16 you're familiar with the difficulties that have transpired in having truly independent, truly 

17 peer reviews performed, for example the fire risk assessments to support a transition to 

18 NFPA 805, quite honestly, to have a similar pedigree of peer review for a probabilistic 

19 flooding hazard assessment, not necessarily the in-plant consequences but the flooding 

20 hazard assessment itself, it's not clear whether we could do one, because there just isn't 

21 that level of expertise in the industry. 

22 And that then leads to an awful lot of questions. There's then a learning 

23 curve. There's a learning curve by the staff, there's a learning curve by who would be 
 43 

1 the peer reviewers, who's qualified to perform the peer review, how much time does it 

2 take to perform the peer review? So our reaction initially was from that perspective. 

3 Now, I know the staff has not completely backed away from the notion of 

4 peer reviews in total. I believe their response to us said, well, we're not going -- they 

5 removed the appendix for peer reviews that was in the draft document. 

6 CHAIRMAN BURNS: Generic. 

7 MEMBER STETKAR: They were just generic. They told us that they 

8 may ask for peer reviews of selected elements of an analysis. I don't know what those 

9 would be. Again, that's part of our continuing dialogue with the staff on these topics. 

10 CHAIRMAN BURNS: Okay. And as they say, I think one of the things, 

11 I think -- and you touched on it, I think -- I learned during reviewing the various post12 Fukushima -- or the various requirements or various aspects of looking at natural hazards 

13 or external hazards is -- and I think you touch on it -- the sort of the state of the art 

14 knowledge. I think, for example, maybe I'll draw an analogy. It says we know in terms 

15 of seismology that so much work has been done in that area. So our understanding 

16 since when I walked in here in 1978, in terms of our understanding of a seismic review or 

17 our ability to do a seismic analysis, is much better than in the flooding area. And we're 

18 starting to get there, working on it. But I think part of what I understand is that's some of 

19 the issue. 

20 MEMBER STETKAR: That's exactly, I know, my own personal concern. 

21 I would feel much more comfortable with the notion of an independent peer review of the 

22 risk-informed seismic assessment, because people have been doing that. We have a 

23 body of experience. That being said, we've also developed a body of experience with 
 44 

1 evaluating fires, and we know the difficulties that the industry and the staff has faced with 

2 trying to get peer reviews of those assessments, despite the fact that we have, in principle, 

3 a current knowledge base on that technology. 

4 We do not have that knowledge base on probabilistic flooding analysis, 

5 and all elements of it. I don't care whether it's dam failure frequencies or probabilistic 

6 modeling of hydrology, or whether it's rainfall rates or any of the elements. 

7 We just don't have those. It's being developed, but it's slow. It's being 

8 developed. Also it's not being developed necessarily within the NRC. It's been 

9 developed in other agencies, and they're starting to be a lot more cooperation and 

10 understanding, but it's slow. 

11 And as Commissioner Svinicki said, if we want to bring closure to the 

12 Fukushima issues, we don't want to drag those -- we don't want to hold that closure 

13 subject to research-type reviews. 

14 CHAIRMAN BURNS: Okay, good. I'm going to touch on the PTS rule. 

15 Again, my understanding, I think what you said, Professor Ballinger, is that what we have 

16 is we have a rule from the late 70's or early 80's, and that this 50.61(a) is an alternative. 

17 Maybe just to help my understanding, how would you pick the 

18 alternative? What is it that the alternative does in terms of how do you pick which 

19 analyses you want to go with, or can you switch back and forth? 

20 I think part of it is, what you said is that the original rule, sort of like what 

21 we were just talking about, was based on a limited data set in terms of the ability to 

22 analyze PTS or the phenomenon. But I'm trying to understand a little bit better what the 

23 -- 
 45 

1 MEMBER BALLINGER: So your question is why would you choose one 

2 or the other? 

3 CHAIRMAN BURNS: Yeah. 

4 MEMBER BALLINGER: Well, first, any new reactor would never have 

5 to use -- would never have an issue with embrittlement because welding technology and 

6 things like that are -- so we won't even get close to the screening criteria over the life of 

7 those plants. So it's really for plants that are built now. And so why would you choose? 

8 If you have a plant for which you're about to exceed the screening criteria 

9 for 61, which would be 270 degrees Fahrenheit for a weld and 300 degrees for non-welds. 

10 And so if you were projecting ahead, say I wanted to go from 40 to 60 years or even 

11 further, if you project that you're going to exceed the screening criteria on 50.61, then 

12 assuming you're going to operate the reactor, then you would have no choice. 

13 CHAIRMAN BURNS: Yeah, you're really directed to. 

14 MEMBER BALLINGER: You'd have to do that, because when you do 

15 that analysis, I mean, because there's no guarantee that the analysis will come out better. 

16 But it mostly likely will, and so the screening criteria can get relaxed in some of these 

17 plants that are the older plants. 

18 When you look at how close they are to those screening limits, they're 

19 pretty close when you project, because you have to do the projection, and then you have 

20 to take action. 

21 If you get close to that screening criteria, you have to -- you can't wait 

22 until you get to the screening criteria. You have to do something now, and that likely 

23 includes some method to reduce the flux, the fluence to the vessel wall, which involves 
 46 

1 shuffling fuel and things around. And that's a huge economic issue. 

2 So it's not a wait until then and decide kind of thing. So that's how you 

3 would choose. 

4 CHAIRMAN BURNS: Okay, good. Actually, the one thing that reminds 

5 me, I wonder if we were back in 1990, '92, what this would have meant for Yankee Atomic, 

6 which was meant to be the first one in the license renewal. I don't know. It may be 

7 speculation, but kind of interesting. 

8 MEMBER BALLINGER: Member Bley knows a lot about that, I think. 

9 (Laughter.) 

10 CHAIRMAN BURNS: And I'm not -- I just speculate. But I just thought, 

11 because you know I was working on some of the rules following renewal, and, you know, 

12 Yankee Atomic was going to be the lead case, and as I recall, that was the issue. 

13 MEMBER BALLINGER: I might add that there's a table in, I forget 

14 which, I think the NUREG, or in several of the presentations, which identifies plants that 

15 are likely to have to use this. 

16 CHAIRMAN BURNS: Okay, okay. I haven't seen that. 

17 MEMBER BALLINGER: And that number is pretty small, pretty small. 

18 There's one that's already -- at least one, Palisades, which is using it. But the number is 

19 pretty, it's pretty small. 

20 CHAIRMAN BURNS: Pretty small, okay. 

21 MEMBER BLEY: What I can say about it is, at the time, Yankee had 

22 developed a plan for doing some testing and something akin to what's ended up in this 

23 rule to analyze in a probabilistic approach, but other things got in the way. 
 47 

1 CHAIRMAN BURNS: Yeah, yeah, okay, good. I'll close out. I think 

2 you answered a question -- or Commissioner Svinicki posed a question in terms of some 

3 what I think is potentially the longer term value of some of the work on the NuScale in 

4 terms of making more generic considerations. 

5 And it sounds like, to the extent that that approach can be translated into 

6 potential other, either Gen-IV type or thinking as we get to Gen-IV type reviews or other 

7 type reviews, it sounds like I think that's -- you all are looking sort of down that path, it 

8 sounded like to me. If so, I think that's a good idea. 

9 MEMBER CORRADINI: I think that's the case. I would emphasize one 

10 thing, though, that it's important to know enough about the design characteristics that one 

11 can make intelligent judgments about it. 

12 CHAIRMAN BURNS: Yeah, absolutely. Okay, thanks. 

13 Well, thank you all. Unless I've got any closing remarks from my 

14 colleagues, I want to again thank you for being here. Welcome to our new members, 

15 again. And again I think we all appreciate the work that the Committee does in its long 

16 tradition, both, as I said, of looking at sort of the bigger picture issues as well as focusing 

17 on particular applications and designs as we ask you to do and is expected under the 

18 statute. 

19 So thank you again for the presentations today, and we are adjourned. 

20 (Whereupon, the above-entitled matter went off the record.) 

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