ML20307A524
| ML20307A524 | |
| Person / Time | |
|---|---|
| Issue date: | 09/22/2020 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| Widmayer, D, ACRS | |
| References | |
| NRC-1104 | |
| Download: ML20307A524 (117) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Future Plant Designs Subcommittee Docket Number: (n/a)
Location: teleconference Date: Tuesday, September 22, 2020 Work Order No.: NRC-1104 Pages 1-81 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1323 Rhode Island Avenue, N.W.
Washington, D.C. 20005 (202) 234-4433
1 1
2 3
4 DISCLAIMER 5
6 7 UNITED STATES NUCLEAR REGULATORY COMMISSIONS 8 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 9
10 11 The contents of this transcript of the 12 proceeding of the United States Nuclear Regulatory 13 Commission Advisory Committee on Reactor Safeguards, 14 as reported herein, is a record of the discussions 15 recorded at the meeting.
16 17 This transcript has not been reviewed, 18 corrected, and edited, and it may contain 19 inaccuracies.
20 21 22 23 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 www.nealrgross.com
1 1 UNITED STATES OF AMERICA 2 NUCLEAR REGULATORY COMMISSION 3 + + + + +
4 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 5 (ACRS) 6 + + + + +
7 FUTURE PLANT DESIGNS SUBCOMMITTEE 8 + + + + +
9 TUESDAY 10 SEPTEMBER 22, 2020 11 + + + + +
12 The Subcommittee met via Video-13 Teleconference, at 9:30 a.m. EDT, Joy Rempe, Chair, 14 presiding.
15 COMMITTEE MEMBERS:
16 JOY L. REMPE, Chairman 17 WALTER L. KIRCHNER, Member-at-large 18 RONALD G. BALLINGER, Member 19 CHARLES H. BROWN, JR. Member 20 VESNA B. DIMITRIJEVIC, Member 21 JOSE MARCH-LEUBA, Member 22 DAVID A. PETTI, Member 23 MATTHEW W. SUNSERI, Member 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
2 1 ACRS CONSULTANT:
2 MICHAEL CORRADINI 3 DESIGNATED FEDERAL OFFICIAL:
4 DEREK A. WIDMAYER 5 ALSO PRESENT:
6 TAMARA BLOOMER, RES 7 JOHN TOMON, RES 8 KIM WEBBER, RES 9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
3 1 AGENDA 2 Opening Remarks . . . . . . . . . . . . . . . . . 4 3 Staff Introduction and Overview 4 Radiation Protection Code Modernization . . 7 5 Non-LWR Code Development, Volume 4, 6 "Licensing and Siting Dose Assessment Codes" 7 Discussion of Licensing and Siting Dose 8 Assessment Codes 9 Discussion of Volume 4 Tasks 10 Leveraging Other Non-LWR Code Readiness Work 11 Other non-NRC Dose Assessment Codes for 12 Non-LWR Readiness & Other Considerations . 20 13 Discussion . . . . . . . . . . . . . . . . . . . 73 14 Adjourn . . . . . . . . . . . . . . . . . . . . 81 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
4 1 P R O C E E D I N G S 2 9:30 a.m.
3 MEMBER REMPE: Good morning. This meeting 4 will now come to order. This is the meeting of the 5 Advisory Committee on Reactor Safeguards, Subcommittee 6 on Future Plant Designs.
7 I'm Joy Rempe and I'm chairing the Future 8 Plant Designs Subcommittee today. ACRS members in 9 attendance include Charlie Brown, Walt Kirchner, David 10 Petti, Jose March-Leuba, Ron Ballinger, Vesna 11 Dimitrijevic, Matt Sunseri, and we expect to be joined 12 by Pete Ricardella later in the meeting.
13 We also have our consultant, Mike 14 Corradini, in attendance. Derek Widmayer, of the ACRS 15 staff, is the designated federal official for this 16 meeting.
17 The purpose of today's meeting is to 18 review the draft report, NRC non-LWR Vision and 19 Strategy, Volume 4 -- help me out with -- the 20 Licensing and Siting Dose Assessment Codes.
21 The Subcommittee will gather information, 22 analyze relevant issues and facts, and formulate 23 proposed decisions and actions as appropriate.
24 This matter, along with a draft Volumes 1 25 through 3 in this report series, is scheduled to be NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
5 1 addressed at the October full Committee meeting.
2 The ACRS was established by statute and is 3 governed by the Federal Advisory Committee Act, FACA.
4 The NRC implements FACA in accordance with its 5 regulations, found in Title 10 of the Code of Federal 6 Regulations, Part 7.
7 The Committee can only speak through its 8 published reports. We hold meetings to gather 9 information and perform preparatory work that will 10 support our deliberations at a full Committee meeting.
11 The rules for participating in all ACRS 12 meetings, including today's, were announced in the 13 Federal Register.
14 The ACRS section of the U.S. NRC public 15 website provides our charter, bylaws, agenda, letter 16 reports, and full transcripts of all full and 17 subcommittee meetings, including slides presented 18 therein. The meeting notice and agenda for this 19 meeting were posted there.
20 As stated in the Federal Register, notice 21 and the public meeting notice is posted on this 22 website, members of the public who desire to provide 23 written or oral input to the Subcommittee may do so, 24 and should contact the designated federal official 25 five days prior to the meeting, as practicable.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
6 1 Today's meeting is open to public 2 attendance and we've received no written statements, 3 or requests to make an oral statement.
4 We've also set aside ten minutes in the 5 agenda for spontaneous comments from members of the 6 public attending or listening to our meetings.
7 Today's meeting is being held with a 8 telephone bridge line, allowing participation of the 9 public over the phone, and a transcript of today's 10 meeting is being kept. Therefore, we request that 11 meeting participants on the bridge line will identify 12 themselves when they speak, and to speak with 13 sufficient clarity and volume so they can be readily 14 heard.
15 Participants in the meeting room should 16 use the microphones -- excuse me. That's left over 17 from an old write-up and I forgot to cross that out.
18 But at this time, I do ask that all meeting 19 participants place themselves on mute, unless talking, 20 so that their cell phones or other devices that make 21 noise in the homes, such as clock bells, won't disrupt 22 this meeting.
23 And I will now proceed with the meeting 24 and call on Kim Webber, Deputy Director of the 25 Division of Systems Analysis, of the Office of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
7 1 Research, to make introductory remarks. Kim?
2 MS. WEBBER: Yes, thank you, Joy. And 3 good morning to you and the other members.
4 Thank you for taking the time to review 5 our latest volume of the Code Development Activities, 6 Volume 4, Licensing and Siting Dose Assessment Codes.
7 I'm going to skip to the next slide, since you 8 introduced me already.
9 By way of an agenda, I have with me today 10 John Tomon. He's the Chief of the Radiation 11 Protection Branch in my division. And he and his 12 staff have been working very hard with staff in NRR 13 and NMSS over the last several months to develop a 14 strategy that we believe is the most resource-15 effective approach for the codes covered by Volume 4, 16 and will ensure the safety as we conduct our licensing 17 review of non-light water reactors.
18 I'll provide high-level overview of the 19 status of the whole non-light water reactor code 20 development project, and a short introduction to 21 Volume 4. Then I'll turn the presentation over to 22 John, who's going to discuss the details of Volume 4, 23 including the topics shown on this slide and in the 24 agenda.
25 With non-light water advanced reactor NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
8 1 applications on our doorstep, including the March 2 submission of the Oklo application, our Office of 3 Research mission, now more than ever, is to enable the 4 regulatory offices to be ready to conduct their 5 licensing activities.
6 With our be-ready attitude, we are doing 7 research differently, by embarking on more be-ready 8 strategies, and transforming to become a more modern 9 risk-informed regulator.
10 To improve mission value, we are working 11 hard to deliver the tools, expertise, and information, 12 in a cost-effective and efficient manner, so that 13 licensing can be completed on time and within the 14 allotted resources.
15 A key element of this strategy is 16 developing the codes and analytical tools, like the 17 ones you see here, and having them ready to go for use 18 and safety analysis.
19 Through our code development activities 20 and collaborations with many organizations you see on 21 this slide, our staff has been acquiring a lot of new 22 knowledge about advanced reactor designs and phenomena 23 important to safety, thus growing staff expertise and 24 analytical capabilities, in addition to capturing 25 knowledge not only in the codes, but also in code NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
9 1 documentation.
2 To facilitate the agency's readiness, the 3 NRC's near-term implementation action plan was 4 developed in the summer of 2017. The IAP is the 5 vehicle to execute the NRC's vision to safely achieve 6 effective and efficient non-light water reactor 7 mission readiness.
8 As you know, the IAP includes six 9 strategies, which are shown here, and Strategy 2 10 focuses on computer codes and knowledge to perform 11 regulatory reviews. On the next slide I'll discuss 12 high-level progress made for Strategy 2.
13 As you know, earlier this year we 14 completed the Introduction, and Volumes 1 through 3.
15 We thank you for conducting an in-depth and thorough 16 review of our plans. Your views and perspectives 17 resulted in changes in those plans in support of the 18 realization of IAP Strategy 2.
19 Each report identifies the computer codes 20 that we may use for our independent safety analysis, 21 gaps in code development capabilities and data, 22 verification and validation needs, along with specific 23 code development tasks.
24 Volumes 1 through 3 focus on systems 25 analysis, fuel performance, neutronics, source term, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
10 1 severe accident progression, and accident consequence 2 codes.
3 If you'd like to follow the status of our 4 code development activities, you can go to the NRC's 5 advance reactor public webpage, which is shown on the 6 slide.
7 If you scroll down the page, and then 8 click on the summary of integrated schedule and 9 regulatory activities image, you'll see the status of 10 the near-term code development tasks for each volume.
11 Although not the subject for this meeting, 12 the status of code development activities for 13 Volumes 1 through 3 is provided for your reference in 14 the background slides, as Slide 34. At a later 15 meeting, we'll provide more information on these 16 activities.
17 As you know, we're developing two 18 additional volumes, Volume 4, which is the subject of 19 this meeting, and Volume 5, which focuses on code 20 development activities related to criticality and 21 shielding considerations for the front and back end of 22 the fuel cycle.
23 We had a meeting scheduled with the 24 Subcommittee on December 1st to talk with you about 25 Volume 5. We value your feedback and recommendations.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
11 1 As we requested a letter from you on Volumes 1 2 through 3, we are also requesting a letter from you on 3 Volumes 4 and 5. I believe a full Committee meeting 4 with a summary of Volumes 4 and 5 is being scheduled 5 for February.
6 Volume 4 provides an overview of the 7 radiation protection related to technical areas that 8 warrant code development modifications in our 9 literature reviews.
10 The codes that John will describe shortly 11 provide radiation dose assessment capabilities that 12 encompass nuclear power plant licensing, including 13 reactor siting, design basis accidents, and normal 14 effluent release analysis.
15 The codes also support dose assessment for 16 emergency response and severe accidents, and 17 atmosphere transport dispersion and site 18 decommissioning regulatory actions.
19 MEMBER REMPE: So --
20 MS. WEBBER: Depending on the --
21 MEMBER REMPE: Oh, I'm sorry. I thought 22 you were done. Go ahead, please finish your slide, 23 and then I have a question.
24 MS. WEBBER: Yes. Depending on the 25 analytical needs identified for these areas, the suite NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
12 1 of 10 codes, they needed to be modified for each 2 combination of fuel and advance reactor type, of which 3 there are many combinations.
4 To modify each of the codes for each fuel 5 reactor combination could be resource-intensive. And 6 that's a more resource-efficient approach is to 7 consolidate, while also modernizing, the codes. Going 8 forward, we would maintain the consolidated set of 9 codes.
10 As you know, code consolidation and 11 modernization also make sense since these codes have 12 been inconsistently maintained over the years based on 13 organizational needs, and there are overlaps in 14 models, dose coefficients, functionality, and use 15 cases.
16 Code consolidation and modernization are 17 natural progression steps in the lifecycle of computer 18 codes, and have been demonstrated successfully by the 19 NRC in the past.
20 For example, our trace thermal hydraulics 21 codes, MELCOR source term and severe accident code, 22 and our fast fuel performance code, have all undergone 23 consolidation and modernization efforts. And now, we 24 can go to your question, before I turn it over to 25 John.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
13 1 MEMBER REMPE: So, I have a couple of 2 questions. First off, with the earlier volumes, the 3 ongoing work with MELCOR and MACCS, because of later 4 questions I'm going to be bringing up, I know that 5 you're going to be giving us an update in a closed 6 session later on today, but can you say something 7 about the progress that's being made with applying 8 MELCOR in the open section?
9 Because I know there have been public 10 meetings about ongoing efforts with trying to apply 11 MELCOR for the various non-LWR technologies.
12 MS. WEBBER: Yeah. So, this is an image 13 from the public website. And what you can see is, in 14 the regulatory activity column, this is a list of all 15 of our code development activities for each of those 16 volumes.
17 So, here on this line you see Code 18 Assessment Report, Volume 1; Code Assessment Report, 19 Volume 2; Code Assessment Report, Volume 3. And you 20 see sub-level milestones under each of those.
21 And so, for Volume 3, which is focused on 22 MELCOR scale and MACCS, you can see a number of 23 different activities. And then over to the right, 24 whether those activities have been completed, or what 25 the target schedule is to complete those activities.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
14 1 And so what you'll see here is that for 2 Volumes 1 and 3, a lot of work has gone to develop 3 reference plant models for the different types of 4 reactors. And those reference plant models are 5 descriptions of different advanced reactor designs 6 based on publicly available information for the 7 different types of reactors.
8 And so you can see that for Volumes 1 9 and 2, many of those reference plant models have been 10 completed.
11 Additionally, for MELCOR and SCALE, 12 they're working on completing reference plant models 13 for several different advanced reactor designs. For 14 MACCS, there are plans to do some radium nuclide 15 screening analysis, and then the near field 16 atmospheric transport and dispersion model assessment 17 has been done.
18 So, I hope that this answers the question.
19 And we'll talk a little bit more about that in the 20 later session.
21 MEMBER REMPE: So, I appreciate this.
22 Again, because of upcoming letters or discussions, I 23 want to make sure what is it Camby said in the open 24 session. So, that's why I'm asking these questions 25 for you now.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
15 1 MS. WEBBER: Sure.
2 MEMBER REMPE: Now, the source term for 3 each technology -- although there may be gaps, which 4 I assume are identified in these ongoing efforts with 5 MELCOR -- but there is a base source term that could 6 be used as input for all these other Volume 4 codes.
7 MS. WEBBER: Yes.
8 MEMBER REMPE: Because you do depend on 9 MELCOR and MACCS to do the Volume 4 work.
10 MS. WEBBER: That's right.
11 (Simultaneous speaking.)
12 MEMBER REMPE: Right?
13 MS. WEBBER: Yes.
14 MEMBER REMPE: Okay. So, that helps a 15 lot. And then I draw your attention -- but you can 16 bounce this question to John Tomon -- but I guess I'm 17 one of the ACRS members that has the common 18 misconception mentioned in Volume 4, because actually, 19 we even discussed this at our prior meetings, about 20 why not have a simpler version of MACCS that can read 21 in those source terms from MELCOR, although other work 22 you're doing with Volume 3 codes, and really 23 consolidate things.
24 I mean, read in the local weather and have 25 something that is fast running with MACCS, instead of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
16 1 trying to consolidate the numerous codes we're going 2 to be hearing about with Volume 4.
3 To me -- and we discussed this before --
4 and I thought the prior transcript from the prior 5 meeting when I reviewed it, the staff said yeah, 6 that's a long-term goal, but we kind of wanted to do 7 this earlier mid-term consolidation.
8 And knowing -- I think even Volume 4 said 9 we're not going to plan up and running for five years, 10 where you have to worry about an emergency. It sounds 11 like you have a bit of time.
12 So, when I reviewed Volume 4, I really had 13 that question in my mind, and I wasn't convinced by 14 what I read that it was really necessary to go through 15 this intermediate step.
16 MS. WEBBER: So, because we recall that 17 that was a question you had raised, I think John 18 specifically is going to address that in his 19 presentation.
20 MEMBER REMPE: Good. Thank you.
21 MS. WEBBER: You're welcome. Any more 22 questions from the Committee?
23 MEMBER BROWN: Yeah, Charlie Brown.
24 MS. WEBBER: Hi, Charlie.
25 MEMBER BROWN: I'm not an expert in this NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
17 1 stuff, I'm the I&C guy. But I'm reading your approach 2 part and you talked about modernized dose assessment.
3 Now, we've been doing dose assessments and 4 stuff for over 60 years now for plants. And so I'm 5 just kind of curious what modernize means.
6 MS. WEBBER: I think in this context --
7 and John can correct me if I'm wrong -- modernization 8 means to go towards a code language that results in 9 faster speeds of codes and is able to be more 10 interoperable with multiple codes. I don't know, 11 John, if you want to nuance that answer.
12 MR. TOMON: Yes. Exactly what Kim was 13 saying is that many of the codes right now were built 14 kind of in silos and by themselves. And so 15 transferring input and output from one code to another 16 code usually involves many intermediate steps.
17 So, we kind of viewed this as modernizing 18 the codes so that they all work together. They use a 19 common language both in the inputs and the outputs, so 20 that the information can be transferred back and forth 21 fluidly between what we're calling -- and I'm going to 22 get to in a little bit -- the calculational engines 23 that actually do the actual calculations for the code.
24 MEMBER BROWN: Are the codes that NRC 25 uses? Or are you talking about the industry codes NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
18 1 that are developed by various, I guess, other bodies?
2 MR. TOMON: These are NRC codes. These 3 are our NRC codes that we've developed.
4 MEMBER BROWN: Okay, I understand that 5 then. Thank you.
6 MR. TOMON: Yes.
7 MEMBER REMPE: Out of curiosity, are the 8 codes in FORTRAN? And are you using just a new 9 version of FORTRAN, or are you going to a different 10 language?
11 MR. TOMON: Well, some of the codes are in 12 an older version of FORTRAN, some are in the newer 13 version, some are in Java. But it's really the output 14 files themselves in the data. They're not in a common 15 language, so usually you have to do some manipulation 16 by the operator and the user, and intermediate steps, 17 to either take a source term, or take an atmospheric 18 transport values, and then put them into the dose 19 assessment codes.
20 So, what we wanted to do was build a 21 construct -- as I'll get to -- that does this all, and 22 then it's one code that the user operates, and then 23 the information is passed fluidly from the input to 24 the output, and also guide the user, to ask the user, 25 what kind of outputs are you looking for, so that the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
19 1 user can really drive what he wants to see in the 2 output files.
3 MEMBER BALLINGER: This is Ron Ballinger.
4 Can't you just do this with scripts?
5 MR. TOMON: Well, for some of the codes we 6 could, but for most of the users it would be more, I 7 don't know, user-friendly just to have it all in one 8 area in the codes.
9 And there are some issues with the codes 10 right now that combining them together, there's some 11 duplication that has to be done because some of them 12 use the same atmospheric transport models in the 13 codes, but yet I have to maintain them in three 14 different codes, whereas if I put them all together in 15 one atmospheric transport engine, as it were, then I 16 would only have to make changes to that one engine, 17 and then that data could be passed for, say a mid-18 field calculation, a near-field calculation, or a far-19 field calculation.
20 MEMBER BALLINGER: Yeah, but the sort of 21 workload to do this is definitely not linear. Once 22 you get out of scripts, it's non-linear and it becomes 23 an enormous task for which there are unknown unknowns, 24 so to speak.
25 MS. WEBBER: So, I'm wondering if we NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
20 1 should transition to John's presentation, because I 2 think he's going to talk about some of these things.
3 Would you like me to stop sharing my screen, and at 4 least we'll transition to John's presentation?
5 MEMBER REMPE: That sounds like a good 6 idea, Kim.
7 MS. WEBBER: Okay.
8 And then if you want to continue with 9 questions, we can do that.
10 MEMBER REMPE: Do any members have any 11 other questions while we're in transition mode here?
12 PARTICIPANT: No, Joy. Thanks for 13 asking.
14 MEMBER REMPE: Thank you.
15 MR. TOMON: So, does everybody see my 16 screen now?
17 (Chorus of aye.)
18 MR. TOMON: Okay, thanks. So, good 19 morning. As Kim said, my name is John Tomon and I'm 20 the Chief of the Radiation Protection Branch of the 21 Office of Research. And this morning I'm going to 22 discuss Volume 4, the Licensing and Siting Dose 23 Assessment Code Plan, that my staff developed in 24 collaboration with the program offices and several of 25 our code contractors and developers.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
21 1 Volume 4, Licensing and Siting Dose 2 Assessment Codes, this report describes the vision and 3 strategy to achieve readiness for non-light water 4 reactor designs for the Licensing and Siting Dose 5 Assessment Codes, and is a living document.
6 It provides an overview of the technical 7 issues related to the different non-light water 8 reactor design technologies that warrant code 9 development, modifications, and/or literature reviews.
10 The report is generally oriented towards 11 generic activities that benefit all non-light water 12 reactor designs, while ensuring that the codes 13 continue applicability for the current light water 14 reactor fleet.
15 MEMBER BROWN: Can I ask a question? This 16 is Charlie Brown again.
17 MR. TOMON: Sure.
18 MEMBER BROWN: I had just backtracked to 19 the -- you can keep this slide up -- back to the 20 earlier one where you're talking about -- let me 21 think, did I get this straight -- with the non-light 22 water reactors, I'm trying to get a handle between 23 light water reactor and non-light water reactor when 24 we talk about atmospheric transport dispersion, all 25 that other type of good stuff you all want to develop.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
22 1 Are the characteristics of the non-light 2 water reactors, in terms of their particulate or their 3 fuel constituency or appearance, that change what 4 we've done in the light water reactor world?
5 MR. TOMON: Well, in some -- as we're 6 going to talk to later -- in some of the slides, some 7 of the non-light water reactor designs are saying that 8 if there are radionuclides that are induced into 9 environmental source term, they could be of a 10 different particulate size typically different than we 11 currently use in the 1-to-10 micron range for the 12 current atmospheric transport and dispersion codes.
13 They could be down in the nanometers, 14 which could have a different result on doses. So, 15 there is that aspect.
16 And then there's the other aspect, that 17 some of the non-light water reactor water reactor 18 designs are using different -- not as far exclusionary 19 of boundaries and emergency planning zones as the 20 current light water reactor fleet -- and so in that 21 regard some of our atmospheric transfer codes, because 22 they were built kind of rigidly for specific purposes 23 of the near-field, the mid-field, and the far-field, 24 there are certain attributes and correction factors in 25 some codes that would be applicable and would want to NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
23 1 be used by the non-light water reactor designers and 2 reviewers for the near-field, that maybe isn't a 3 function of the mid-field characteristics.
4 So, to that end, that is another reason 5 why we kind of wanted to combine at least all of these 6 codes, and specifically into engines and in the 7 atmospheric transport phase, so that you could choose 8 from, and maybe have available, those correction 9 factors that are available in one code right now in 10 the specific code design available to all the codes to 11 do all the calculations.
12 MEMBER BALLINGER: This is Ron again. I 13 think we're dealing with that with NuScale right now.
14 No?
15 MR. TOMON: Yes, sir. Yeah, typically 16 using, for the exclusion area boundary and the low-17 population zone, the PAVAN Code, it doesn't take into 18 account building wake effects and corrections like 19 that.
20 And so, they wanted to use -- with the 21 ARCON Code, which is for control room habitability, 22 they wanted to use corrections that were used in that, 23 but that's not built in to the PAVAN Code.
24 So, as a result, they have to do 25 additional work, or code work, to make these NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
24 1 corrections work. So, that's where we felt combining 2 the codes would be beneficial for all, both the 3 licensees and the reviewers.
4 MEMBER REMPE: But now, we saw from Kim's 5 slide that the near-field equations have now been put 6 into MACCS. Right, John?
7 MR. TOMON: I know they evaluated it. I'm 8 not sure. We've been working with our counterparts in 9 the other branches, and I'm not sure if and how 10 they've been completely implemented into MACCS.
11 But we are going to continue to work with 12 them in that, so that when we combine these, any 13 lessons learned they learn from that. We're not going 14 to try to reproduce the wheel in that regard, but use 15 what they've already done into our codes, in and of 16 itself, for the reviewers that need it for this 17 purpose.
18 MEMBER REMPE: Okay. I thought that they 19 had the box that it was completed. Maybe I misread 20 the chart for -- or I didn't remember correctly.
21 MS. BLOOMER: Can I answer that? Hi, this 22 is Tammy Bloomer.
23 MEMBER REMPE: Yes, please do.
24 MS. BLOOMER: So, I'm the Branch Chief for 25 the Accident Analysis Branch. We work through the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
25 1 MACCS code with Sandia.
2 And the chart that you're referring to, we 3 did an assessment of the applicability of MACCS for 4 near-field ATD modeling, and that is what was 5 completed.
6 The incorporation of the calculations into 7 MACCS is not yet completed, and we will have those 8 calculations identified and the models prepared by the 9 March time frame, 2021, and incorporated into MACCS 10 shortly thereafter.
11 MEMBER REMPE: Great. Thank you for the 12 update.
13 MR. TOMON: Any additional questions, or 14 shall I go on?
15 MEMBER BROWN: Yeah. This is Charlie 16 Brown again. Just trying to get a better handle on --
17 you keep talking about consolidating codes, making 18 them easier to use and all that type of stuff.
19 MR. TOMON: Yes, sir.
20 MEMBER BROWN: Again, in the light water 21 world, as well as the non-light water world, 22 fissionable material is fissionable material. They're 23 the same, kind of. So, you know what those are.
24 But irradiated materials that could get 25 dispersed in an accident condition are going to be NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
26 1 different in many circumstances for the non-light 2 water reactors.
3 I haven't heard you talk about how you 4 come up with characterizing these materials, that we 5 don't even know what they all are yet for the non-6 light water reactors, and how your codes will be 7 amenable to incorporating those.
8 MR. TOMON: And as we're going to let to 9 later on when I talk about some of the tasks in 10 Volume 4 and some of the codes, that is one of the 11 things we're working on.
12 For example, right now we have, for light 13 water reactors to those fission products and those 14 activation products as you were talking about, we have 15 a code that similarly does this for, and is released 16 for what we consider normal effluent source terms for 17 light water reactors for both pressurized and boiling 18 water reactors, the GALE code.
19 It takes into account the activation 20 products, corrosion products, and we then use that as 21 our source term input to the NRC dose code, combined 22 with the LADTAP code, to do dose assessment. That is 23 one of the issues that we have.
24 And we're working with our partners, our 25 radiation protection code assessment contractor, PNNL, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
27 1 and their work with source terms with the National 2 Reactor Innovation Center, to come up with what would 3 be a good source term, or what's the best way to 4 develop a source term to encompass all these 5 activation products that we might see from these 6 various non-light water reactor designs. And again, 7 we don't have a firm direction on whether that's going 8 to be just some generic module that just allows the 9 user to import this, or we're going to actually -- but 10 we are looking at operational data where we can find 11 it, to see if we can actually hard wire maybe some of 12 these values into the codes to begin with, so that the 13 user can select, versus having to use user-defined 14 inputs.
15 MEMBER BROWN: Okay, so if I hear you 16 right, what you're saying, you're trying to roll all 17 this stuff up in the source term parts of these codes.
18 MR. TOMON: Yes, sir. Yes, sir.
19 MEMBER BROWN: Okay. Thank you.
20 MEMBER REMPE: And say that again, because 21 in my mind I would assume you'd take something from 22 the MELCOR evaluations of each technology, as a base 23 that would be put into your codes, as are the MACCS, 24 if -- with what I'm kind of suggesting.
25 And then the user would say, okay, it's NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
28 1 only at 25 percent power when it had the release, and 2 they would do whatever they wanted to do. And now, 3 you're thinking you're going to get it from someplace 4 other than MELCOR?
5 MR. TOMON: No. I mean, there's going to 6 be multiple sources that we envision getting this data 7 from. MELCOR and working with the staff over at the 8 Accident Analysis Branch and the Severe Accident 9 Branch, we envision getting MELCOR data typically 10 similar to what we use right now in the RASCAL code, 11 where that data from MELCOR is hard-wired into RASCAL, 12 and the user does not have to select specific 13 pressures or temperatures.
14 They're asked a series of questions, to 15 come up with a rapid dose assessment characteristic 16 based upon some other inputs that they put in.
17 So, again, we envision that the source 18 term module would include inputs from both MELCOR, 19 inputs from operational data, if there is any 20 available, specifically because when you look at a 21 normal effluent source term from GALE -- like the GALE 22 code puts out for pressurized and boiling water 23 reactors -- that's mostly operational data that it 24 includes for the reactor cooling source term.
25 So, we envision multiple sources going NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
29 1 into developing the source term module. But we 2 already have that in for P's and VWRs, but we have 3 them in separate places for different things, for 4 different codes.
5 So, where we envision is to combine them 6 all together into one source term engine, that would 7 then be used with the other engines in the code, to 8 get the outputs that the user desired.
9 MEMBER REMPE: Okay, so you might say for 10 the other operational data, you might have a 11 circulating activity, or something that's been fine-12 tuned, or something like that. But from the core, 13 basically -- of course, how old the core is and things 14 like that, that would come from other analysis results 15 from --
16 MR. TOMON: Yep.
17 MEMBER REMPE: -- within the NRC complex.
18 Got it.
19 MR. TOMON: Yes, ma'am. Okay. Anything 20 else, or shall I continue?
21 MEMBER REMPE: Please go on.
22 MR. TOMON: Okay. So, in the next slide, 23 when the staff on the Radiation Protection Branch and 24 our code developers and contractors started the 25 process to think about making our codes ready for non-NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
30 1 light water reactor technologies, we sought out 2 various sources of information, including the other 3 three volumes that Kim discuss earlier for Strategy 2, 4 to identify the various non-light water designs that 5 the dose assessment codes would need to be prepared 6 for.
7 As we looked further into the non-light 8 water designs, we further categorized them into 9 further generic classes of non-light water reactor 10 designs for Volume 4, to include molten salt reactors, 11 high-temperature gas cool reactors, liquid metals, 12 cool fast reactors, and several stationary and 13 transportable micro-reactor designs.
14 MEMBER REMPE: So, could you stay on that 15 price? Like -- when is the soonest that you, the NRC, 16 would estimate you'd have a plan up and running, where 17 you might be concerned about the need to use these 18 codes for emergency response guidance?
19 MR. TOMON: Well, the emergency response 20 guidance I would assume -- I know we have the Oklo 21 application in-house, which came in in March, so I 22 would need somebody to back me up on that. I would 23 think we're looking at three to five years to actually 24 have some sort of source term analysis that we could 25 put into our source term module for accident NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
31 1 scenarios.
2 But by the same token, we would also need 3 from the dose assessment and licensing siting space, 4 we would also need to look at the normal reactor 5 effluent releases that are going to happen during 6 normal operation.
7 And as far as I know right now, we've been 8 in contact with our counterparts over in NRR, and from 9 the initial application from Oklo, there's not a 10 really good environmental source term they have from 11 both an accident scenario, or from a normal source 12 term scenario, included in their application.
13 So, right now I don't know a firm date 14 that I could give you, but I would say probably three 15 to five years.
16 MEMBER REMPE: So, on Page 36 out of 53 of 17 your report, you have here, and I quote, non-LWR 18 plants are not expected to be operational within five 19 years at the earliest. Now, today you've said three 20 to five years. And so, is that just an updated 21 response since you wrote the report?
22 And then, I'd note that yes, you're right 23 about the circulating activity is important for siting 24 and licensing, but in some of these advanced reactors, 25 but the gas reactor, the circulating activity may be NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
32 1 important for a lot of things, because it takes a lot 2 to get the core up to where you have accident 3 releases.
4 So, I would think this is something that 5 would be used again for other evaluations that would 6 require like MELCOR, not just your codes.
7 MS. WEBBER: Joy? On the timing piece, so 8 we're constantly adjusting our priorities, given what 9 we know of applicants potentially making submittals.
10 And so, the fact that the report might say three to 11 five years and John is telling you five years, is 12 symptomatic of that dynamic environment.
13 And so, I think we're trying to do the 14 best that we can to be ready. And so that's where we 15 are right now.
16 MEMBER REMPE: It's just interesting how 17 fast it's moving up.
18 MS. WEBBER: Oh, I know. It's a very 19 dynamic fast-paced environment that we're all feeling.
20 MEMBER PETTI: So, I have a question.
21 John, is it fair to say that the biggest concern 22 technically with all these codes, besides the 23 modernization and the consolidation, is the ability to 24 accurately calculate low EPZ results, for instance, 25 where the site boundary is really tight, and making NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
33 1 sure that the tool can calculate that accurately, 2 given how so many of them are hard-wired for large 3 light water reactor-type sites.
4 MR. TOMON: Yes, that's correct.
5 MEMBER PETTI: Is this the biggest thing?
6 MR. TOMON: Yes, that's one of the biggest 7 things. I mean, some of the codes -- and I was going 8 to speak to this a little later -- some of the codes, 9 as written right now, are semi-flexible, in that while 10 they're written for the large light water reactors, 11 they will allow you to use user-defined 12 characteristics.
13 For example, the SNAP/RADTRAD code, it's 14 more labor-intensive for both the applicant and the 15 user to come up with the source term at the release 16 fractions and timing sequences for their reactor, than 17 doing a typical -- what's hard-wired into the code 18 right now, a dropdown selection of a pressurized water 19 reactor or boiling water reactor inventory, and the 20 release fraction and timing sequences.
21 So, some of the codes are that way and 22 they're going to be used in that specific code; the 23 SNAP/RADTRAD code is written in Java and the transfer 24 of information is very much along the lines of what we 25 talked about being from input and output in our code NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
34 1 modernizations strategy. So, yes.
2 So, it will be more labor-intensive. Some 3 of the codes can do it right now, but that is a big 4 issue and concern in getting these codes ready so that 5 both the applicants or, in our case, just the 6 reviewers, have the tools available. They don't have 7 to go to five different places. It's all available at 8 one place that they can do it. And if possible, hard-9 wired in, and if not, at least at the minimum, be 10 something that they could import and bring into the 11 code as a user-defined spectrum. But the goal would 12 ultimately be to have these as hard-wired inputs into 13 the code, that they can select from in multiple 14 choices, or multiple selection options.
15 MEMBER PETTI: All right.
16 MR. TOMON: Yes. Okay, so the regulatory 17 needs for dose assessment codes. So, with the 18 assistance of the program offices, we then identified 19 specific dose assessment computer codes or tools that 20 the NRC staff uses to perform independent assessments 21 and confirmatory calculations, with respect to the 22 various regulations in the Code of Federal 23 Regulations, and NRC Regulatory Guides.
24 In Volume 4, we grouped these dose 25 assessment codes based upon two areas. First was NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
35 1 based upon the source terms -- severe accident, design 2 basis accident, the normal or routine effluent 3 releases and decommissioning -- and also based upon 4 the types of reviews that are done for them, whether 5 it's dose consequences, siting and environmental 6 reviews, and decommissioning reviews.
7 The staff also determined that these dose 8 assessment codes would have to be updated for the 9 various non-light water reactor designs and phases, 10 based upon the availability of the resources and the 11 time frame for the various non-light water reactor 12 applications.
13 Case in point, as was already brought up, 14 we've already been in discussions with NRR about the 15 Oklo application and trying to stay in tune to what 16 needs to be done now ahead of time, prior to doing any 17 other of our phase approaches.
18 That application is at hand right now.
19 But as of right now, as I said, there's no 20 environmental source term that they have in their 21 application.
22 Our phase approach. We are considering in 23 the near-term, now through the next five years, an 24 intermediate phase, five to ten years, and a longer-25 term phase greater than ten years, with the ultimate NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
36 1 long-term goal of reducing the current ten-plus 2 license and siting dose assessment codes down to one 3 or two codes that accomplish the same regulatory 4 functions as all the existing ten codes currently do 5 now.
6 MEMBER REMPE: John, could we stay on that 7 prior slide? In the report I really like that you 8 finally describe what the different tools do, and 9 there was clearly a lot of overlap.
10 What I wasn't sure of after reading the 11 report was how many other agencies use these various 12 different tools.
13 MR. TOMON: Meaning federal agencies, or 14 federal and state agencies?
15 MEMBER REMPE: What I'm really looking 16 for, is there any -- like we know that MACCS, and even 17 MELCOR actually, have a users group that helped 18 contribute to activities related to co-development and 19 maintenance.
20 Are there any codes here that have other 21 organizations that are helping to support NRC in 22 maintaining and developing these codes?
23 MR. TOMON: Well all of these codes, in 24 one form or another, are codes under the Radiation 25 Protection Code Analysis and Maintenance Program NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
37 1 (RAMP). So there are user groups for all of these 2 codes, and RAMP not only includes these NRC dose 3 codes -- there's about 10 listed here -- but there's 4 also another five to six codes that are included under 5 RAMP.
6 So the user group has a wide breadth of 7 both international and state and local agencies, other 8 federal agencies, and the codes like the RASCAL code, 9 their user group includes the state and local 10 officials who are decision-makers for protection of 11 action guidelines.
12 Licensees are also included in the RAMP 13 user group. And we do get contributions from them.
14 We do solicit at our two RAMP meetings, input and 15 feedback from the users groups. We do it not only at 16 those meetings, but we also try to do it throughout 17 the year.
18 For all these codes, we routinely have 19 email help lines that they can ask questions and make 20 recommendations and inputs for improvements to the 21 code. So the RAMP is really the mechanism by which we 22 do our outreach for most of these codes and get input 23 and feedback on these codes.
24 MEMBER REMPE: So again, I'm still 25 struggling with my question that I raised with Kim NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
38 1 earlier, about why not just go to MACCS and have a 2 simplified option? And I'm still not sure I've got a 3 good answer to that question.
4 Aren't the answers that some of these 5 other agencies are really pushing no, keep these 6 codes? I'm still struggling with why we can't --
7 because at the earlier meeting we discussed this, it 8 was not just ruled out that you just can't do it, 9 which is what this report tends to imply.
10 MR. TOMON: Well some of the codes, like 11 specifically the RASCAL code, as we said before in the 12 past, and I know it's not the only answer, but the 13 RASCAL user group is a unique group. They are 14 typically local and state officials that are 15 protective action decision makers, that are trying to 16 make decisions based on real-time accidents, or real-17 time events in the plant, using real-time meteorology, 18 both observational and forecast dated, to make their 19 protective action decisions based upon the pre-20 existing emergency plans they have.
21 Usually, in most of the cases, most of 22 these first responders are not very technically savvy 23 in some cases in the reactor physics world and the 24 nuclear plant world. They are really just looking at 25 what is the environmental source term, what is that NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
39 1 term that's leaving containment that can be 2 transported downwind, and what do I have to do to 3 protect my people?
4 Most of our state and local officials 5 don't particularly want to just go with what the 6 licensee says, even though the licensee is -- we do 7 confirmatory analysis at the operations center and the 8 incident response center, to verify what the 9 protective action recommendations are and the 10 decisions are.
11 Typically the state and local officials, 12 those decision-makers, sit there, want to make some 13 sort of back-up calculation, confirmatory calculation, 14 to what they're getting from the licensees in their 15 locality. So they will run RASCAL.
16 But again, RASCAL, they don't have that 17 technical background and savvy to know what this plant 18 pressure or this plant temperature, or this 19 containment pressure means. They don't know that.
20 But what RASCAL does, it asks them very 21 simple questions based on hard-wired MELCOR data 22 that's already in, and scale data for the core 23 inventories, that we ask them some specific questions, 24 they make some very minor inputs, weather is 25 automatically downloaded for them, and that they can NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
40 1 run a relatively quick, scientifically defensible, 2 calculation, that they can then look at what the 3 licensee is telling them, and confirm it one way or 4 another, same way as the NRC is doing that, and the 5 same response.
6 MEMBER REMPE: So again, I'm still puzzled 7 why you can't take MACCS, put a simplified option with 8 the hard-wired data and the questions required, since 9 it's coming from other codes, and do something like 10 that.
11 Because the report says it's a common 12 misconception. Well it seems to me still that it's an 13 attitude of whether I want to do it this way or the 14 other way. And I'm not seeing that it's impossible to 15 do.
16 MR. TOMON: I guess I'm not saying it's 17 impossible. But the paradigm for the user communities 18 are totally different. And building off inputs from 19 the MACCS code, I mean we intend as a staff to 20 leverage work done, because resources, as everybody 21 always knows, resources are always tight all the way 22 around.
23 We don't plan to do things in a vacuum, 24 not working with what work on MELCOR is being done, 25 what work in scale is being done, and what work in NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
41 1 MACCS is being done.
2 But the user community typically -- I know 3 they came up with a MACCS-lite, as it were, many years 4 ago, a fast-running MACCS, but for whatever reason --
5 and one of the reasons I think I remember hearing but 6 don't quote me on it -- was that the user community, 7 meaning the state and local officials, found it way 8 too difficult to use, as compared to codes like the 9 RASCAL code, that asked very simple questions to do 10 it.
11 Ultimately, I guess if you look at it --
12 to get to your statement, Joy -- they basically do the 13 same things. They have the same inputs from MELCOR, 14 the weather runs are much less because they do real-15 time data in RASCAL.
16 But the way the format that's used in 17 RASCAL, is something that the user community kind of 18 expects, is kind of used to, and it's not difficult 19 for them to make the decisions and recommendations, 20 based upon the outputs of the RASCAL code.
21 (Simultaneous speaking.)
22 MEMBER REMPE: I just think we're getting 23 back to what we heard at the prior meeting then, that 24 if you look at it in the long-term -- and again, you 25 need to be very careful about the customer and what NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
42 1 they want -- but you could have another MACCS-lite 2 that would download the data very rapidly.
3 And it might be a more efficient use of 4 resources if you looked at the long-term, which is 5 kind of where we got to at the prior meeting. And 6 none of that discussion actually shows up in this 7 report.
8 And that's where I was confused, because 9 I just can't see a reason that it couldn't be done.
10 I mean the report's pretty strong. It says this is a 11 common misconception. Well it's not a misconception.
12 It's just an approach that you've selected. Right?
13 MR. TOMON: Yes. And I guess getting to 14 your point, that is something we could look to in the 15 long-term, maybe 10-plus years. Because originally 16 when we talked about it -- in the later slides when I 17 go on -- this approach for code consolidation and 18 modernization trying to get them in, as I said 19 earlier, we're trying to get down to one or two codes.
20 And ultimately, the goal would be to get 21 down to one. And there's always been some discussion 22 in a group with our contractors right now, that 23 loading something like RASCAL into this one code that 24 did everything that these 10 codes does, but just have 25 it so that the RASCAL code would be something that NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
43 1 just the emergency response the immediate responders 2 would use, that might not be something we can do up 3 front, and it might be something we can do later on 4 down the line, to get it into one code, as it were.
5 So I mean we're not -- I guess the answer 6 is I'm not saying that we are completely ruling out 7 something like that. But for now, we see as keeping 8 RASCAL and kind of MACCS, making them feed off each 9 other from what they do, and even in the point, even 10 if we get to a point later on, maybe 10 years down the 11 road, that there's some way to combine, that's not out 12 of the realm of possibility. But right now that's not 13 currently in our plan.
14 MS. WEBBER: Yeah, can I just add 15 something quickly? I think John characterized it 16 pretty well. But so Joy, it's not impossible to do.
17 We could do it. We have chosen to take this route, or 18 the route that's represented in Volume 4.
19 Part of it is that we have an internal-to-20 the-NRC community that use these different codes at 21 different times. And so to provide codes that the 22 individual communities who use all these codes at the 23 bottom, different people use them at different times, 24 I think that's a service that we need to provide.
25 And so to introduce potentially a new code NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
44 1 with a different set of dynamics plus additional 2 costs, is something that maybe we could do in the long 3 run, but it may not support our near-term activities 4 with applicants coming through the door in the next 5 few years.
6 MEMBER REMPE: So I get what you're doing.
7 But I mean if you looked at the long-term and the cost 8 of maintaining all of these different codes, or even 9 what you end up with the consolidated version versus 10 going to the long-term goal of having MACCS, 11 downloading stuff from MELCOR and immediate data 12 coming from the site, the long-term cost to the agency 13 might be lower.
14 But again, how you get funding allocated 15 from Congress on an annual basis or users, that kind 16 of thing has to be considered. But I think the 17 report's not accurately reflecting that this was an 18 approach selected because of whatever. Because it 19 implies it's a misconception, you can't do it. And I 20 think that needs to be corrected.
21 MS. WEBBER: Okay. Thanks for the 22 comment. I wonder if we should move on to the next 23 slide.
24 MEMBER REMPE: Please do. I'll quit 25 whining about it. But thank you for also being a NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
45 1 little bit more forthright about it than what I saw in 2 the report.
3 MS. WEBBER: Okay, thanks.
4 MR. TOMON: So continuing on, as shown in 5 the bottom of the previous slide and in this figure 6 from Volume 4, we are looking towards the possibility 7 of having to make ready 10 licensing siting dose 8 assessment codes for the various non-LWR applications.
9 Included in these codes are the 10 radionuclide transport removal and dose estimation 11 code (RADTRAD), the control room habitability code 12 (HABIT), the atmospheric relative concentrations and 13 support of control room habitability (ARCON), the 14 ground level air concentrations for accidental release 15 codes (PAVAN), the gaseous and liquid ethylene code 16 (GALE), the normal effluent dose assessment and siting 17 code (NRCDose), the normal relative air concentrations 18 and relative disposition factors code (XOQDOQ), the 19 radioactive material transport dose assessment code 20 (RADTRAN), the radiological system for consequence 21 analysis code (RASCAL), the decommissioning and 22 decontamination code (DandD), and the residual 23 radioactivity code (RESRAD).
24 In Volume 4, we also included discussions 25 on other codes that either non-light water reactor NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
46 1 designers are considered using in their applications, 2 such as the Generation 2 code, or the GEN2 code, or 3 codes which have inputs to the codes on this slide, 4 such as the dose coefficient package code (DCFPAK),
5 the SCALE code, the MELCOR code.
6 In the next few slides, I'll briefly 7 discuss the purpose of each of these codes for 8 licensing and siting purposes.
9 MEMBER BROWN: Can I ask another question 10 that just popped up as you read through all that?
11 MR. TOMON: Mm-hmm. Yes, sir.
12 MEMBER BROWN: Part of your -- if you go 13 back to that earlier slide, you talked about 14 consolidation and modernization. So you must have 15 listed a dozen codes or so.
16 MR. TOMON: 10, sir. Yes.
17 MEMBER BROWN: 10, okay, I was off a 18 little bit.
19 MR. TOMON: No problem.
20 MEMBER BROWN: So I presume when you talk 21 about consolidating, you want to bring these 22 together --
23 MR. TOMON: Yes, sir.
24 MEMBER BROWN: -- in their operations.
25 Isn't there a danger in that? I mean it's nice many NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
47 1 times to have a lot of eggs, as opposed to having one 2 big basket. If something has to be worked on or done 3 in an overall consolidating code, it takes out of 4 service all of them.
5 So I've just been thinking about that 6 after I looked at your introduction stuff and 7 everything else. Have you taken that into 8 consideration?
9 I understand the idea of trying to not 10 have to go piecemeal, but consolidation could also add 11 complexity and reduce usability, if something goes 12 wrong and you've got to go correct something in one of 13 the modules or sub-modules or whatever. The whole 14 code is out of service.
15 MR. TOMON: Well the goal was -- and one 16 of our phases in our goal was to do the atmospheric 17 transport consolidation, the ARCON, PAVAN and the 18 XOQDOQ codes.
19 And in that, one of our goals -- and 20 you're right, and we wanted to do it as a proof of 21 concept to see if we developed that one engine, 22 because they all use straight-line Gaussian plume 23 models, that we still met the existing requirements 24 for the different regulatory guides and the different 25 needs of those codes, but that they were consolidated NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
48 1 into one module, so that -- because currently right 2 now, codes like ARCON just got updated.
3 But some of the codes have not been 4 updated in years. And to do changes, or to do stuff 5 to them, is more labor-intensive. So what we figured 6 is if we did this proof of concept with this one 7 engine -- we called it the atmospheric transport 8 engine -- that would be our first to see -- and it's 9 a natural kind of evolution of the codes, because they 10 all use the same models underneath for calculational 11 purposes, with different varying correction factors in 12 there.
13 So we're going with the assumption that 14 that will be our first proof of concept, and we'll 15 learn from that as we move further on with the other 16 codes. But we don't foresee it -- I mean I guess we 17 didn't foresee it as a big stumbling point in taking 18 down all the other codes and taking us out of work in 19 that particular point in time. Because we -- go 20 ahead.
21 MS. WEBBER: I was just going to say, plus 22 you wouldn't take those old codes out of service until 23 you got a working new version of the consolidated 24 models.
25 MR. TOMON: That's correct. We would make NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
49 1 sure that the proof of concept works and meets the 2 needs of the program offices and before we would 3 sunset those codes, as Kim is saying.
4 MEMBER BROWN: Yeah, but once you have a 5 working model that's been blessed, you're inevitably 6 going to want to make changes to it. And when it's 7 taken out of service to make changes, that takes out 8 of service everything.
9 MS. WEBBER: I think with code 10 development, as I understand it from a limited 11 perspective, they don't take out a service -- the 12 code -- while they're working on the next version.
13 So as I understand it, there's a working 14 version, regardless of what's in that code and the 15 models and phenomena modeled in those codes. And then 16 as they're building new functionality or making 17 changes to the code based on bugs that have been 18 identified, they'll redo the validation for the code 19 before they release it, so that it ends up being a 20 working code.
21 MEMBER BROWN: Okay. Thank you, Kim.
22 MS. WEBBER: Yeah, sure.
23 MR. TOMON: So my next slide depicts the 24 safety and environmental review codes that are used 25 for siting purposes for design basis accidents.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
50 1 The RADTRAD code is used by the NRC staff 2 and applicants to calculate doses to demonstrate 3 compliance with the nuclear plant siting criteria at 4 the exclusion area boundary in the low-population 5 zone. It is also used to calculate occupational 6 radiation doses within the control room and/or other 7 offsite emergency facilities.
8 The code is joined together at the front 9 end, with the symbolic nuclear analysis package, is 10 commonly referred to as SNAP/RADTRAD.
11 The PAVAN code is used to estimate 12 relative ground-level, short-term air concentrations 13 resulting from releases of design basis accident at 14 the exclusion area boundary and the outer boundary of 15 the population zone.
16 PAVAN uses a straight line Gaussian plume 17 model that assumes a release rate is constant for the 18 entire period of the release.
19 The ARCON code is used to calculate short-20 term accident air concentrations in support of control 21 room habitability assessments, as described in Reg 22 Guide 1.194. The code uses a straight-line Gaussian 23 model that assumes constant release rate.
24 ARCON also implements building wake, low 25 wind speed dispersion algorithms, and ground level and NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
51 1 elevated source release modes.
2 The next code I will briefly discuss is 3 the HABIT code, which is used to examine control room 4 habitability following a postulated release of toxic 5 chemicals, based on regulations in Reg Guide 1.78.
6 The code consists of four FORTRAN codes 7 connected through a common graphical user interface.
8 These codes include the external transport computer 9 code EXTRAN, which is a Gaussian puff dispersion 10 model, the control room chemical code CHEM, the 11 Environmental Protection Agency's dense gas dispersion 12 code (DEGADIS), and the Department of Energy's denser-13 than-air release computer code SLAB.
14 This slide shows the relationship of dose 15 assessment codes which are used for normal effluent 16 releases and transportation reviews. The GALE code, 17 as I spoke to before, which is used to estimate annual 18 routine releases of radioactive gases and liquid 19 effluence from pressurized and boiling water reactors, 20 based upon the regulations in Reg Guide 1.112, the 21 NRCDose code, which is a software suite that contains 22 a common graphical user interface that runs three 23 FORTRAN codes -- GASPAR, LADTAP and XOQDOQ code --
24 working together, these codes are used to estimate 25 offsite doses from liquid and gaseous radioactive NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
52 1 releases from routine nuclear power plant operations, 2 and implement those low-as-reasonably-achievable 3 requirements of Appendix I of 10 CFR Part 50.
4 The LADTAP code, which implements the 5 liquid pathway models in Reg Guide 1.113, and when 6 combined with the normal liquid effluent from the GALE 7 code, will calculate the annual doses from routine 8 releases of reactor coolant effluence per Reg 9 Guide 1.109.
10 The XOQDOQ and GASPAR codes implement the 11 atmospheric pathway models in Reg Guide 1.111, and 12 when combined with normal gaseous effluent source term 13 from the GALE code, GASPAR will calculate the annual 14 doses from routine releases of gaseous effluence per 15 Reg Guide 1.109.
16 Finally, the RADTRAN code is used to 17 estimate doses from routine and accident scenarios 18 involving the transportation of radioactive material, 19 including spent nuclear fuel.
20 The code is used for environmental impact 21 statements pursuant to the requirements of the 22 National Environmental Policy Act and NRC and 23 Department of Transportation regulations.
24 Dose consequence codes. The RASCAL code 25 is an emergency response code, as we've already talked NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
53 1 about, used to perform independent dose consequence 2 projections during the initial plume phase of 3 radiological incidence and emergency, including severe 4 accidents.
5 As I spoke to before, it was designed to 6 provide scientifically defensible dose projection, 7 within 15 minutes of the occurrence of an event to 8 support protective action decision-makers at the state 9 and local level, as well as the NRC staff.
10 While very similar to the MACCS code, each 11 of these codes serves a different user community, with 12 different expectations.
13 For example, as I spoke to earlier, the 14 RASCAL users typically are first responders, state and 15 local personnel, running many different what-if 16 scenarios during the plume phase of an event.
17 RASCAL uses automatically downloaded, 18 real-time observational and forecast meteorological 19 data from the National Weather Service, combined with 20 a limited number of user supplied plant inputs, to 21 provide dose projections to compare to the EPA's 22 protective action guidelines.
23 MACCS users are typically emergency 24 planners and dose-consequence analysts who use the 25 code for facility siting purposes. Additionally, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
54 1 MACCS codes require a significant number of weather 2 trials and plant inputs, and can require several hours 3 to days to set up and run calculations. MACCS 4 calculations also extend to the intermediate and long-5 term phases of an event.
6 Decommissioning codes. The staff decided 7 to, before thinking when developing Volume 4, to 8 include decommissioning codes as part of our phased 9 approach for our non-light water reactor code 10 readiness strategy.
11 Codes such as decontamination and 12 decommissioning (DandD) and the RESRAD family of 13 codes, are used by licensees and the staff in license 14 termination surveys. They are briefly discussed in 15 this volume to bring attention to the entire lifecycle 16 of non-light water reactors, not just siting, 17 licensing and operations.
18 Their need to be evaluated may become more 19 apparent in the longer term implementation plan, i.e.,
20 greater than 10 years.
21 Research and other codes. Finally, the 22 staff also looked at several other dose assessment 23 codes that are either similar in function to many of 24 the licensing and siting codes already discussed in 25 the previous slides, or are codes which are used as NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
55 1 inputs to the licensing and siting codes.
2 Such codes at the ones that are similar to 3 the ones we've already talked about was the 4 Generation 2 computer code, or the GEN2 computer code, 5 which models atmospheric releases of radioactive 6 materials to the environment, and had a similar dose 7 assessment and points with several of the licensing 8 and siting codes previously discussed.
9 MEMBER REMPE: John, I meant to ask you 10 earlier, but what would you use for assessing release 11 from a reactor that's being transported either by rail 12 or by airplane?
13 MR. TOMON: Well that's where the RADTRAN 14 code on the couple of slides back would come into 15 effect. And right now that scenario is not in there, 16 because we would have to add that source term to the 17 RADTRAN code. But it would be the RADTRAN code.
18 That's the purpose of the RADTRAN code.
19 MEMBER REMPE: Okay. Yeah, and that's 20 what I thought when I read the report. I guess I 21 couldn't hear it during this session. I might have 22 missed it. Thank you.
23 MR. TOMON: Yes. The Dose Coefficient 24 Package File, or DCFPAK, includes nuclear decay data 25 and dose and risk coefficients for exposure for each NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
56 1 of the 1,252 radionuclides addressed in ICRP 2 Publication 107. Parts of DCFPAK are currently used 3 in the RASCAL code, NRCDose, and the SNAP/RADTRAD 4 codes.
5 Finally, the staff also included a 6 discussion of the scale and MELCOR codes in Volume 4, 7 because these outputs from both are currently hard-8 wired into codes such as RASCAL and SNAP/RADTRAD.
9 The staff plans to leverage work done on 10 these codes for non-light water reactor technologies 11 in our licensing and siting codes, where applicable.
12 Volume 4 Code Readiness Test. Working 13 with our individual dose assessment code developers 14 and the radiation protection computer code analysis 15 maintenance program (RAMP contractor, Pacific 16 Northwest National Laboratory), the staff developed 17 the five tests listed on this slide to prepare the 18 license and siting dose assessment codes for non-light 19 water reactor readiness.
20 These tests included looking at Code 21 Consolidation and Modernization, Task 1, code source 22 terms, atmospheric transport and dispersion models, 23 dose coefficients used, and environmental pathway 24 models used in some of the codes.
25 Code Consolidation and Modernization, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
57 1 Task 1. One of the first tasks that the staff came 2 upon was the number of license and siting dose 3 assessment codes, 10, and the number of different non-4 light water reactor designs.
5 The staff decided that code consolidation, 6 where possible, was an efficient means of maintaining 7 and writing the codes with the resources available.
8 Code consolidation and modernization was viewed at a 9 means to help reduce functional redundancy between 10 codes, outdated science and technology associated with 11 the design and development of the codes, limited 12 ability of the current codes to assess advanced 13 reactor designs, agency resources associated with 14 undue analysis and co-distribution efforts, and the 15 inefficiency of having to maintain multiple codes.
16 With this thought in mind, we came up with 17 a code consolidation approach with the assistance of 18 our RAMP contractor, Pacific Northwest National 19 Laboratory.
20 We developed a three-pillar approach to 21 code consolidation, including first create 22 consolidated engines. This is a set of functional 23 modules for engines that would be developed to form 24 the regulatory calculations as those performed by the 25 current suite of licensing and siting dose assessment NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
58 1 codes.
2 The functional engine approach improves 3 development flexibility by allowing future 4 modifications and efficient data transfer.
5 Furthermore, separating these capabilities 6 as standalone engines eliminates the code redundancy 7 and inefficiencies that currently exist.
8 Second, develop a standardized data 9 transfer schema. Using standardized data transfer 10 schema, such as extensive markup language, or XML, for 11 encoding data for each engine, would make data input 12 universal and adaptable, while making it easy to pass 13 output data between the different functional engines.
14 By using the extensive markup language as 15 a data management system within the consolidated code 16 framework, the entire system would be more robust 17 relative to the advancements in the nuclear industry, 18 and any improvements in data entry, such as 19 downloading meteorological data inputs.
20 Finally, the last pillar is to build a 21 single user interface. A single user interface would 22 be developed separate from the functional engines that 23 would interact with users and communicate with the 24 functional engines to execute user-defined commands.
25 The user interface would be designed to NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
59 1 effortlessly guide users to the relevant code engine 2 input screens, primarily through a series of questions 3 about desired outputs.
4 The conceptual model for a consolidated 5 code. The figure on this slide is a conceptual 6 diagram of the proposed consolidated code paradigm 7 showing how the models from the existing siting and 8 licensing codes could be integrated into a new 9 consolidated code.
10 The modules within the consolidated code 11 would be grouped or characterized within this general 12 dose assessment approach. In addition, the modules 13 would be further broken down into scientific 14 disciplines, to account for the unique differences of 15 these fields.
16 The proposed consolidated code would have 17 several modules or components of each, which will 18 contain phenomenological models from the existing 19 light water reactor codes.
20 The eight modules of the consolidating 21 code include a source term including core inventories; 22 release fractions and timing sequences; an atmospheric 23 transport and dispersion modeling, to include near-,
24 mid- and far-field models; aquatic pathway modeling, 25 including ocean, river and lake dispersion; NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
60 1 environmental accumulation; human biota consequence 2 modeling; non-human biota consequence modeling; dose 3 efficients and health risk factors; and an integrated 4 dose module.
5 The second task of Volume 4 was to 6 identify the source term inputs, such as the 7 radionuclide fuel inventories, reactor coolant 8 inventories, plant design and operational data, for 9 each of the non-light water reactor designs.
10 Source terms are one of the higher 11 priority modules, because it's the first data needed 12 in the dose assessment process.
13 For normal operations, the radionuclides 14 of interest in the source term include fission 15 products, capture products, activation products 16 produced during normal operations, and the reactor 17 cooling system.
18 For accident conditions, both severe 19 accidents and design basis accidents, the primary 20 source term information will be from the work on the 21 SCALE and MELCOR codes described in Volume 3.
22 And finally the transportation source 23 term, the various non-light water reactor fuel types, 24 vary significantly from the current light water fuel 25 configurations.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
61 1 In addition, some of the non-light water 2 reactor designs may adopt a battery-type approach 3 where it's likely that the entire core containing the 4 spent fuel will be transported as a single shipment.
5 Therefore, the transportation source term and module 6 will need to take these issues into account and 7 consideration.
8 Some other source term considerations, the 9 radiation protection branch staff plans to work with 10 the program offices and the other co-development 11 branches and research to leverage activities from 12 Volumes 1, 2 and 3.
13 We are also working with your RAMP 14 contractor, Pacific Northwest National Laboratory, to 15 leverage their source term work and activities with 16 the National Reactor Innovation Center. And 17 specifically we will look to leverage the work done 18 with SCALE and MELCOR codes, to estimate the 19 inventories and these fractions and timing sequences, 20 and reduction mechanisms, for the various non-light 21 water reactor designs.
22 Finally, some of our current licensing and 23 siting assessment codes, as I spoke to earlier, are 24 flexible in their current configuration, to accept 25 source terms outside of the current light water NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
62 1 reactor designs.
2 For example, as currently constructed, the 3 SNAP/RADTRAD code will allow users to enter user-4 defined source terms, release fractions, and timing 5 sequence. However, this is a more involved thought 6 process than selecting from current hard-wired 7 pressurized and boiling water reactor options already 8 in the code.
9 Additionally, NRCDose can allow for import 10 of user-defined source terms. However, there is 11 currently no code that will perform normal effluent 12 reactor source term calculations for non-light water 13 reactor technology, like the GALE code does for light 14 water reactor technology.
15 MEMBER KIRCHNER: John?
16 MR. TOMON: Yes.
17 MEMBER KIRCHNER: This is Walt Kirchner.
18 MR. TOMON: Yes.
19 MEMBER KIRCHNER: Some of these designs 20 will produce significant amounts of tritium. How does 21 that fit into the overall scheme that you envision?
22 MR. TOMON: In some of the later tasks we 23 do talk about that. We will have to consider both the 24 amount for the high-temperature gas cool reactor, and 25 the molten salt reactor, the tritium that is being NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
63 1 produced, both with the environmental pathways and the 2 dose coefficients that we use in the code.
3 So we are looking towards that. We are 4 also looking to try to get some of the operational 5 data from the molten salt reactor, to see what the 6 tritium concentrations were and what they were seeing 7 for maybe their normal tritium concentrations in the 8 plant, so that we can take that into consideration as 9 we move on and develop a source term for those codes.
10 MEMBER KIRCHNER: I'm sorry. To follow 11 on, how do you deal with -- tritium production is not 12 such an issue with our current fleet. It's a bigger 13 issue, for example, for the CANDU reactors. How do we 14 take care of it currently with the existing suite of 15 codes that you use?
16 MR. TOMON: I would have to defer to --
17 I'm not really 100 percent sure how the exact 18 mechanism we use in our codes -- I mean I know 19 typically, that typical code that you would see that 20 in the source term, or it would be included in the 21 source term would be when performing calculations 22 within the NRCDose code.
23 However, I'm not really 100 percent sure 24 of how we take that into account for the current P and 25 PWR, BWR fleet.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
64 1 MEMBER KIRCHNER: Yeah, it just becomes --
2 the reason I raise it, it becomes a much larger 3 concern with some of these advanced designs than we've 4 had to deal with in the past. Okay, thank you.
5 MEMBER PETTI: So Walt, there is 6 international work done through the IAEA on what's the 7 state of the art tritium transport code. Because of 8 other technologies that use tritium. And so the 9 fusion program has spent a lot of time internationally 10 on the code called UFOTRI, which I think is now in the 11 IAEA database.
12 So there is a community that has looked 13 into that. They've done release experiments to make 14 sure they understand the transport and the uptake.
15 And there's a lot of data out there.
16 MEMBER KIRCHNER: Yeah. Dave, I almost 17 imagine that it would be an overlay of the existing 18 framework that John has been sharing with us, almost 19 like a side -- I hate to say a side calculation, but 20 it probably would be an overlay and you would deal 21 with it perhaps independently with other codes that 22 have been developed, as you point to in the fusion 23 community.
24 MEMBER REMPE: Could we ask for you as a 25 follow-on to maybe send us a note through Derek, John, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
65 1 about what is done with tritium for the current fleet?
2 MR. TOMON: Sure. I can look into that.
3 Sure, no problem.
4 MEMBER REMPE: Thank you.
5 MR. TOMON: The third module or third task 6 we have in the report involves the atmospheric 7 transport and dispersion model.
8 Most of the licensing and siting dose 9 assessments use or have atmospheric transport and 10 dispersion models, which are typically Gaussian plume 11 models. For example, ARCON, PAVAN and the XOQDOQ 12 codes use straight-line Gaussian models with different 13 correction factors, such as building wake effects, 14 wind direction, wind speed, atmospheric stability 15 cost, location of the release point, stacked downwash 16 and plume rise to adjust for the codes used.
17 As a proof of concept for code 18 consolidation, the staff is looking to consolidate 19 ARCON, PAVAN and the XOQDOQ into a single atmospheric 20 engine and a phased approach.
21 Phase 1 would be an integrated atmospheric 22 engine that would have the capability of performing 23 near-field, mid-field, and far-field calculations, 24 thereby the user could perform regulatory calculations 25 relevant to any of these three distances.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
66 1 Phase 2 would involve adding capabilities 2 to the consolidated atmospheric to support non-light 3 water reactor technology sitings, such as siting in 4 remote areas with differing atmospheric stability, 5 diffusion and dispersion characteristics.
6 MEMBER KIRCHNER: John?
7 MR. TOMON: Yes?
8 MEMBER KIRCHNER: That last statement 9 doesn't kind of ring true. We have that same problem 10 with the current fleet. What would be different? It 11 might be Alaska where you haven't sited before or 12 something like that, but I would think from a 13 methodology standpoint, that's just a factor of 14 importing the local meteorological conditions, right?
15 MR. TOMON: Well, what they're -- I guess 16 what we're looking at here, and that's why it's a 17 phase 2 part of the approach, is that we're looking at 18 most of the Pasquill-Gifford calculations for 19 dispersion and diffusion were done in the middle of 20 the United States with relatively flat terrain and 21 topography back in the '60s.
22 So, I know there have been and we have 23 been in discussion with our meteorologists that we 24 work with on the PAVAN code and the ARCON code in 25 Pacific Northwest National Laboratory, that there have NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
67 1 been other studies that have been done in some remote 2 areas where there are those, where those dispersion 3 and diffusion characteristics might not be, the 4 Pasquill-Gifford ones might not be true to what is not 5 in the remote area, say sort of like in Alaska.
6 So, right now, we are going to work with 7 the meteorologists over in NRR to implement these 8 based upon the needs and to allow that option so that 9 we can, in this consolidated atmospheric transport 10 module, so that we can implement those as needed based 11 upon the siting in remote areas based upon what the 12 reviewers at NRR deem as appropriate or acceptable 13 then from typical ones we use right now, which are the 14 Pasquill-Gifford ones.
15 MEMBER KIRCHNER: Yeah, I just, well, I 16 guess what I'm objecting to is just that I wouldn't 17 call Oak Ridge a remote area anymore, but, you know, 18 we did an early site permit for Oak Ridge and they had 19 rather interesting meteorology there. I mean, they've 20 got -- you probably know the site, so I'm just 21 reacting to it's not a remote siting issue.
22 It's just the basic physics of the models 23 that you incorporate, but you have sites in the U.S.
24 that have some peculiarities and Oak Ridge is 25 certainly one that's, you know, prone to atmospheric NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
68 1 inversions, et cetera.
2 MR. TOMON: Yeah, well, what we really 3 want to do is kind of be ready for the needs of the 4 reviewers at NRR, so to listen to their needs based 5 upon what they need if the code as consolidated 6 doesn't do exactly what it does.
7 But we're hoping since we're going to this 8 kind of standard input/output XML data transfer, that 9 making changes to the code and providing updates as 10 needed with verification and validation would not be 11 a long process.
12 It would be relatively quick to do what 13 the reviewers need for different scenarios based upon 14 whether it's remote or not remote, or just because of 15 the environmental conditions of the site.
16 So, this slide is showing an example of 17 some thoughts we had for the user inputs and features 18 that could be incorporated into the atmospheric engine 19 prototype along with the data flow between the 20 interface and the engine.
21 After selecting a dispersion distance 22 model, i.e., the near, mid, or far field, the user 23 could provide source receptor inputs such as distance, 24 intake height, and direction using 2D and 3D graphical 25 displays.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
69 1 The user would then choose a 2 meteorological file and visualize the wind 3 distribution. The terrain data could be imported from 4 a public database such as the National Elevation 5 Dataset.
6 And once the inputs are set up, the data 7 shall be transferred using extensive markup language, 8 XML schema, to the atmospheric engine where the 9 calculations are performed.
10 After the calculations are completed, the 11 atmospheric dispersion engine would allow the user to 12 select various outputs for both reporting and plotting 13 results depending upon the needs and the regulatory 14 requirements.
15 A dose coefficient module, the fourth task 16 involved developing a dosimetry engine that has the 17 flexibility to use different vintage dosimetric models 18 and dose coefficient values, and also examining the 19 dose coefficient models with respect to aerosol 20 particle size since most of the non-light water 21 reactor and technologies could release particles 22 smaller than the one to ten micron range that are 23 currently considered for the current codes.
24 Current regulations such as 10 CFR 20 25 require that licensees use dose coefficient values NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
70 1 from older dosimetry models and systems. Typically 2 for the codes, the dose coefficients and dosimetry 3 models are hardwired into the code and the user has 4 few options to edit or change these values.
5 An important element of this task is to 6 design the module with an understanding of the 7 different dosimetry endpoints of siting, licensing, 8 and emergency response for non-light water reactor 9 designs.
10 The vision for the dose --
11 MEMBER REMPE: You'll have to be careful 12 because of the folks that are your users that may not 13 have the technical background to do too much, right?
14 MR. TOMON: Yes, ma'am. Yes, we'll have 15 to be careful of that, plus they'll have to -- the 16 goal would be to make it flexible, but also at the 17 same time, where necessary, add how they're using or 18 what they're using, or what they choose for different 19 dose coefficient and dosimetry models and how that 20 would affect or what -- you know, just make sure that 21 there's a warning in the system somehow along those 22 lines as well.
23 The vision for the dose coefficient module 24 is it would be a flexible module that allows the user 25 to select from Federal Guidance Reports 11 and 12 dose NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
71 1 coefficients used by the current regulations, as well 2 as future Federal Guidance Report dose coefficients 3 such as FGR 15.
4 Another part of this module would consider 5 options to allow the user to select aerosol particle 6 size for radionuclides.
7 The dose coefficient forms may also need 8 to be modified to account for various different forms 9 of volatile carbons such as carbon monoxide, carbon 10 dioxide, and other organic molecules, as well as a 11 modification for tritium dosimetry models for the high 12 temperature gas cool reactors and the molten salt 13 reactors.
14 Currently, the SNAP/RADTRAD code allows 15 the user to enter user-defined dose coefficients in 16 addition to the hardwired Federal Guidance Report 11 17 and 12 values.
18 The remaining dose assessment codes as 19 currently configured do not possess an option for the 20 user to select user-defined coefficient values.
21 Codes like NRCDose and RASCAL do allow the 22 user to choose between dose coefficient values from 23 different hardwired dosimetric models such as ICRP 2, 24 26 and 30, and ICRP 6072.
25 The final task in Volume 5 consists of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
72 1 further developing aquatic pathways, river, lake, 2 ocean dispersion, environmental accumulation, and 3 human and non-human bio consequences.
4 These tasks are in future phases because 5 they are less dependent on the non-light water reactor 6 design and fuel types, and we're considering that in 7 the five to ten-year range.
8 The task will also look to explore the 9 feasibility of radionuclide particle size behavior in 10 the environment for some of the non-light water 11 designs.
12 The task will also leverage models from 13 the Generation 2 code and the decommissioning codes 14 like RESRAD and work plan for the max mode to examine 15 deposition models to the environment.
16 Some other considerations and challenges, 17 as I stated in the beginning of my presentation, we 18 are looking to implement these tasks in phases 19 depending on several factors such as the timing of 20 non-light water reactor submittal versus code 21 readiness.
22 For example, as I mentioned before, the 23 radiation protection staff is monitoring the Oklo 24 submittal and meeting with the staff from NRR.
25 However, there is currently no source term to the NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
73 1 environment in the current application.
2 We also need to take into account code 3 consolidation versus non-consolidation as was brought 4 up in the meeting, which includes the availability of 5 resources, both the staff and contract farming on a 6 year to year basis for near, mid, and long-term code 7 consolidation projects, and will be a continuing 8 consideration and challenge.
9 And finally, the radiation protection 10 branch staff has already reached out and has had 11 several meetings with the various branches at NRR and 12 NMSS to collect, to collaborate in developing a 13 targeted and agreed upon code consolidation plan.
14 My final slides show some of the near and 15 midterm planning milestones for the licensing and 16 siting dose assessment code readiness.
17 We are planning for the developing and 18 piloting of the consolidated atmospheric transport 19 engine hopefully by the end of fiscal year '21, and we 20 will continue to meet and collaborate with our co-21 developers, contractors, and counterparts in the 22 program office in developing and coordinating 23 implementation plans for the code consolidation, and 24 that concludes my presentation.
25 MEMBER REMPE: Thank you, John. Do any NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
74 1 members have any additional questions at this time?
2 So, not hearing any response, I'd like to ask that the 3 public line be opened and we provide the public an 4 opportunity to comment, and then we'll go around like 5 we used to when we were meeting together and ask the 6 members if they have any final thoughts before we end 7 this public session, and then my plan is to have a 8 break before we transition to the nonpublic session.
9 Does that sound good to everybody?
10 MS. WEBBER: Yes, thanks.
11 MEMBER REMPE: Okay, so let's open up the 12 public line.
13 OPERATOR: The public line is open for 14 comment.
15 MEMBER REMPE: Great, if there are any 16 members of the public who'd like to make a comment, 17 please state your name and provide that comment at 18 this time.
19 So, not hearing any comments, let's close 20 the public line, and let's go through the member list 21 and see if any of them would like to make some closing 22 comments, and we'll start with you, Charlie.
23 MEMBER BROWN: Nothing else. I asked 24 mine. Thanks, Joy.
25 MEMBER REMPE: Okay, Walt?
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
75 1 MEMBER KIRCHNER: Nothing further at this 2 point. Thank you, Joy.
3 MEMBER REMPE: Okay, Jose?
4 MEMBER MARCH-LEUBA: Jose's trying to get 5 the mouse to work. No, I have no further comment.
6 MEMBER REMPE: Okay, thank you. Dave?
7 MEMBER PETTI: Nothing further.
8 MEMBER REMPE: Okay, Ron?
9 MEMBER BALLINGER: Only that this whole 10 process sounds like an enormous effort and 11 rebaselining all of the codes. It just seems like a 12 very, very large effort which I wonder whether the 13 schedule actually reflects what will actually happen.
14 MEMBER REMPE: Okay, thank you for your 15 comment. Matt?
16 MEMBER SUNSERI: Joy, I don't have any 17 other comments. Thanks for the presentation.
18 MEMBER REMPE: Vesna, do you have any 19 comments?
20 MEMBER DIMITRIJEVIC: No, nothing further.
21 Thanks.
22 MEMBER REMPE: Okay, so before we close 23 and take a break, I need to acknowledge I was given 24 this information and Kim was correct. The letter for 25 this will be on Volumes 4 and 5, and we have plans to NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
76 1 work on that letter in February of next year, and so 2 in the interim, Dennis and I will work on it together 3 and I'll give him input from this meeting.
4 And so at this point, my clock says it's 5 five after the hour, so how about a --
6 MEMBER BROWN: Joy?
7 MEMBER REMPE: Yes, sir?
8 MEMBER BROWN: Before you hang us up, I 9 don't know whether I'm the only one that has the 10 problem. I just looked at my chart and I do not see 11 a closed meeting session, so if I hang up from this, 12 I don't have anything to go to your closed session.
13 MEMBER REMPE: Okay, so --
14 MEMBER BALLINGER: Same goes for me. This 15 is Ron.
16 MEMBER REMPE: It's the same place, right, 17 Derek? You help me out, because again, I wasn't 18 involved in how you were planning this with Dennis, 19 but my understanding is that we will be using the same 20 line and they'll monitor it, right, Derek?
21 MR. WIDMAYER: That's correct.
22 MEMBER REMPE: So, we're going to take --
23 and I know, Walt, you like longer first morning 24 breaks, so should I say we're going to start up at 25 9:20 or are you okay at 9:15?
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
77 1 MS. WEBBER: Well, I think the, so the 2 staff was preparing for noon, so I'm not sure if all 3 of the staff are, you know, available to start 4 earlier. I can try to see offline if they are ready 5 to start earlier, but I'm just not sure.
6 MEMBER REMPE: Well, in light of that, we 7 can't tell members to come back in 15 minutes and then 8 tell them we don't want them, so should we just go 9 with the plan and we're going to take a very long 10 break unless I hear differently from our Chairman.
11 Matt, do you have a better suggestion?
12 MEMBER SUNSERI: No, I don't. I guess 13 we'll be finished in time for the next meeting this 14 afternoon though, right?
15 MEMBER REMPE: Tim, could you --
16 MS. WEBBER: I'm sorry. What was the 17 question? I was trying to --
18 MEMBER REMPE: If we wait until noon --
19 MS. WEBBER: Yeah.
20 MEMBER REMPE: -- D.C. time, will you give 21 us adequate time for a -- we have another meeting that 22 starts at 1:30, so this is basically going to be a 23 tighter schedule at that point. Is that --
24 MS. WEBBER: Right, so what we have 25 planned for the other session is to talk about some of NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
78 1 the things that I already showed you on the public 2 website, and there's a few other things that are not 3 publicly available at this point in time that we plan 4 to discuss with you.
5 So, you know, we have a lot of information 6 to present, but because we talked about some of it, I 7 think we could go fairly quickly unless you have a lot 8 of questions.
9 MR. WIDMAYER: So, hey, Kim? Hey, Kim, 10 this is Derek.
11 MS. WEBBER: Hey, Derek.
12 MR. WIDMAYER: Yeah, hey, in answering 13 emails and stuff with your staff, I'd encourage them 14 to come on early. Could you check and see --
15 MS. WEBBER: Right.
16 MR. WIDMAYER: -- if everybody is 17 available?
18 MS. WEBBER: Okay, do you want to hold on?
19 Because I see some of them. I see some of them on the 20 call, so let me Skype them individually and I'll see 21 if they're available, and then if you give me five 22 minutes or so, I'll report back to you.
23 MEMBER REMPE: So, let's take a ten-minute 24 break --
25 MS. WEBBER: Sure.
NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
79 1 MEMBER REMPE: -- and come back at --
2 well, it's 9:08 right now, so let's come back at 9:20, 3 and let's hope we're going to have a meeting, but if 4 not, we will take a longer break and deal with it.
5 Does that sound -- does everybody understand what 6 we're going to do here, members?
7 MEMBER KIRCHNER: Yeah, it's really 11:08.
8 MEMBER REMPE: Oh, I'm in Idaho, so I'm 9 looking at -- yeah, you're right. We all are having 10 trouble with that.
11 MEMBER BROWN: Let me just make sure --
12 Joy? Joy?
13 (Simultaneous speaking.)
14 MEMBER REMPE: This weekend, they were 15 saying good morning, good night, and good afternoon 16 depending on where everyone was.
17 MEMBER BROWN: Joy? Joy, Joy, Joy?
18 MEMBER REMPE: Yes, sir?
19 MEMBER BROWN: Just to make sure, we are 20 not hanging up. We're just going to come back?
21 MEMBER REMPE: Yes, you can --
22 MEMBER BROWN: Great.
23 MEMBER REMPE: You can rejoin the same 24 session at 11:20 if you're in D.C. time.
25 MEMBER BROWN: Well, I'm just going to NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
80 1 mute.
2 (Simultaneous speaking.)
3 MEMBER KIRCHNER: Could we give --
4 MEMBER REMPE: Pardon?
5 MEMBER KIRCHNER: Could we give the staff 6 a little more time to rally and take a break until 7 11:30?
8 PARTICIPANT: Sure.
9 MEMBER REMPE: That sounds good. And Kim, 10 whoever you can get, just go out of order and let's 11 really hope we can start at 11:30, okay?
12 MEMBER BROWN: Joy, Joy, my --
13 MEMBER REMPE: Yes, sir.
14 MEMBER BROWN: Yeah, my agenda showed on 15 Eastern Standard Time this session starting at 11:30 16 Eastern Time.
17 MEMBER REMPE: This whole thing, like I 18 have an agenda that's a final agenda, and the agenda 19 started at 9:00 D.C. time instead of at 8:30, and so 20 we've had a lot of, or instead of 9:30, so there's 21 been some time issues that are confusing, Charlie.
22 Let's just go with what we're going to be 23 doing. At 11:30 D.C. time, we're going to come back, 24 okay?
25 MEMBER BROWN: Okay, that works. Yes, NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
81 1 thank you.
2 MEMBER REMPE: Thank you very much, 3 everyone, for your patience with the changes that are 4 occurring in real time. Okay, see you at 11:30 D.C.
5 time. Thank you.
6 (Whereupon, the above-entitled matter went 7 off the record at 11:09 a.m.)
8 9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1323 RHODE ISLAND AVE., N.W.
(202) 234-4433 WASHINGTON, D.C. 20005-3701 (202) 234-4433
Implementation Action Plan (IAP)
Strategy 2 Volume 4 - Licensing and Siting Dose Assessment Codes September 22, 2020 Kimberly A. Webber, Ph.D.
Division of Systems Analysis Office of Nuclear Regulatory Research
Agenda
- Staff Introduction
- Overview
- Radiation Protection Code Modernization
- Non-LWR Code Development, Volume 4, Licensing and Siting Dose Assessment Codes
- Discussion of Codes
- Discussion of Volume 4 Tasks
- Leveraging Other Non-LWR Code Readiness Work
- Other non-NRC Dose Assessment Codes for Non-LWR Readiness and Other Considerations 09/22/2020 2
NRCs Be Ready Attitude
- Improve mission value while BlueCRAB enabling safe operations
- Deliver cost savings
- Develop regulatory tools
- Build staff expertise
- Leverage collaborations 3
NRCs Integrated Action Plan (IAP) for Advanced Reactors Near-Term Implementation Action Plan Strategy 1 Strategy 4 Knowledge, Skills, Industry Codes and Capacity and Standards Strategy 5 Strategy 2 ML17165A069 Technology Analytical Tools Inclusive Issues Strategy 3 Strategy 6 Flexible Review Communication Process 4
Strategy 2: Computer Code Readiness Code Development Plans These Volumes outline the specific analytical tools to enable independent analysis of non-LWRs, gaps in code capabilities and data, V&V needs and code development tasks.
Introduction Volume 1 Volume 2 Volume 3 ML20030A174 ML20030A176 ML20030A177 ML20030A178 5
NRCs Integrated Action Plan (IAP) Status 6
Strategy 2 - Volumes 4 & 5
- Volume 4 Licensing and Siting Dose Assessment Codes (ML20028F255)
Development Plan (living document)
- Volume 5 Computer Code Development Plans for Criticality, Shielding, and Accident Analysis in the Nuclear Fuel Cycle ACRS Subcommittee meeting December 1, 2020 09/22/2020 7
Volume 4: Licensing and Siting Dose Assessment Codes
- Landscape
- Potential for a spectrum of Non-LWR and fuel designs
- Over 10 licensing and siting dose assessment codes
- Inconsistent code development practices, by various contractors, over decades
- Overlap in code capabilities and need to use resources pragmatically
- Approach (Tasks)
- 1. Consolidate/Modernize Dose Assessment Codes
- 2. Improve characterization of Source Terms
- 3. Improve Atmospheric Transport & Dispersion Models
- 4. Update Dose Coefficient values
- 5. Develop Environmental Pathway Models 09/22/2020 8
Volume 4 - Licensing and Siting Dose Assessment Codes John Tomon, CHP Chief, Radiation Protection Branch Office of Nuclear Regulatory Research
Volume 4: Licensing and Siting Dose Assessment Codes
- This report describes the licensing and siting dose assessment computer codes and how they would be applied and consolidated for the non-LWR design types.
o Section 1 Introduces the regulatory requirements.
o Section 2 Describes each code and uses.
o Section 3 Tasks related to non-LWR designs including code consolidation.
o Section 4 Discusses code readiness.
o Section 5 Conclusions.
09/22/2020 10
Non-LWR Technologies Non-LWR Plant Description Examples Fuel Types 1 HTGR; prismatic core, thermal spectrum Framatome TRISO (rods or plates)
X-energy, 2 PBMR; pebble bed core, thermal spectrum TRISO (pebbles)
Starcore 3 GCFR; prismatic core, fast spectrum GA SIC clad UC (plates)
PRISM, ARC, 4 SFR; sodium cooled, fast spectrum Metallic (U-10Zr)
TerraPower Westinghouse, (Possibly nitride 5 LMR; lead cooled, fast spectrum Columbia Basin, fuel.)
Hydromine 6 HPR; heat pipe cooled, fast spectrum Oklo, Westinghouse Metallic (U-10Zr) 7 MSR; prismatic core, thermal spectrum AHTR TRISO (plates) 8 MSPR; pebble bed, thermal spectrum Kairos TRISO (pebbles)
MFSR; fluoride fuel salt, Terrestrial Thorcon, 9 Fuel salt thermal/epithermal spectrum FliBe 10 MCSR; chloride fuel salt, fast spectrum TerraPower, Elysium Fuel salt 09/22/2020 11
Regulatory Needs for Dose Assessment Codes 09/22/2020 12
Licensing and Siting Dose Assessment Codes Over 10+ codes used for NPP licensing and Siting.
Image adapted from BNWL-1754, Models and Computer Codes for Evaluating Environmental Radiation Doses.
09/22/2020 13
Safety & Environmental Review Codes ARCON SNAP/RADTRAD (DBA)
(/Q)
LPZ Control EAB Room PAVAN
(/Q)
Image adapted from BNWL-1754, Models and Computer Codes for Evaluating Environmental Radiation Doses.
09/22/2020 14
Safety & Environmental Review Codes Control Room EXTRAN CHEM DEGADIS SLAB HABIT (Chemical)
Image adapted from BNWL-1754, Models and Computer Codes for Evaluating Environmental Radiation Doses.
09/22/2020 15
Safety & Environmental Review Codes NRCDose GASPAR GALE 80 km XOQDOQ
(/Q)
RADTRAN GALE LADTAP Image adapted from BNWL-1754, Models and Computer Codes for Evaluating Environmental Radiation Doses.
09/22/2020 16
Dose Consequences Code RASCAL Accident 129 km 129 km Image adapted from BNWL-1754, Models and Computer Codes for Evaluating Environmental Radiation Doses.
09/22/2020 17
Decommissioning Codes
- DandD (Decontamination and Decommissioning): compliance with the dose criteria of 10 CFR Part 20, Subpart E. Perform simple estimates of the annual dose from residual radioactivity in soils and on building surfaces.
- RESRAD (Residual Radioactivity): Family of codes used to analyze human and biota radiation exposures from environmental contamination of residual radioactive materials.
09/22/2020 18
Research and Other Purposes
- GENII (Generation II computer code): a set of programs for estimating radionuclide concentrations in the environment and dose to humans from acute or chronic exposures from radiological releases to the environment or initial contamination conditions.
- Dose Coefficient File Package (DCFPAK):
that includes nuclear decay data and dose and risk coefficients for exposure to radionuclides.
- SCALE and MELCOR are used in development of core radionuclide inventory and severe reactor accident source terms as described in Volume 3. Plan to leverage work done for Volume 3 in the licensing and siting dose assessment codes.
09/22/2020 19
Volume 4: Code Readiness Tasks
- Code Consolidation & Modernization (Task 1)
- Source Term (Task 2)
- Atmospheric Transport & Dispersion (ATD) Module (Task 3)
- Dose Coefficient Module (Task 4)
- Environmental Pathways (Task 5) 20
Code Consolidation and Modernization (Task 1)
- Given the large number of Non-LWR technologies being conceived and developed, it will be resource intensive to modify each of the siting, licensing, and emergency response codes for each design type.
- Therefore, the staff is proposing to consolidate and integrate them into several codes (i.e., two or three) that are modular, flexible, efficient, and user-friendly.
09/22/2020 21
Code Consolidation Approach The three pillars to the dose assessment code consolidation process:
- Create consolidated engines
- Develop a standardized data transfer schema
- Build a single user interface PNNL-29717, Health Physics Codes Consolidation and Modernization 09/22/2020 22
Conceptual Model for the Consolidated Code PNNL-29717, Health Physics Codes Consolidation and Modernization 09/22/2020 23
Source Term (Task 2)
- Identify source terms inputs (i.e., radionuclide fuel inventories, reactor coolant inventories, plant design and operational data) for each of the Non-LWR designs.
- Normal (Routine) source terms
- Severe Accident source terms
- Design-Basis Accident source terms
- Transportation source terms 09/22/2020 24
Source Term (Task 2)
- Source Term Considerations:
- Source term/release rate framework database will:
- Leverage activities from Volumes 1, 2 and 3
- Estimate inventory in core/release from core
- Identify dominate release pathways
- Characterize mechanism to reduce release (e.g. filters)
- Estimate release rates,
- Use operational data where applicable 09/22/2020 25
ATD Module (Task 3)
- ATD consolidation in Phases:
- Phase 1: Consolidate ARCON, PAVAN & XOQDOQ.
- Phase 2: Evaluate the applicability of the near-field and ATD models for Non-LWR technologies.
- These phases would leverage the experience of the meteorology staff and MACCS near-field modelling efforts from Volume 3.
09/22/2020 26
Atmospheric Engine Prototype 09/22/2020 27
Dose Coefficient Module (Task 4)
- This task involves:
- Developing dosimetry modules/engines that have the flexibility to use different dose models and dose coefficient values
- Examining dose coefficient models with respect to aerosol particle size in addition to exploring the impact of tritium and carbon-14 biokinetics since these radionuclides may be in higher quantities in non-LWRs.
09/22/2020 28
Dose Coefficient Considerations
- Vision for module:
- Flexible Engines for different dose coefficient values
- Dose Coefficient Package Code (DCFPAK)
- Aerosol particle size relative to dose coefficients
- H-3 and C-14 relationship to dose coefficients
- Current State
- Some codes can choose different data sets.
- Leveraging DCFPAK datasets with US EPA.
- Possibly acquiring international dosimetry codes.
- Training RPB staff on specific designs where internal dosimetry could be significant such as MSRs.
09/22/2020 29
Environmental Pathways (Task 5)
- Further developing the aquatic pathways (river/lake/ocean dispersion), environmental accumulation, and human/non-human biota consequence modules for codes.
- Lower priority because they are less dependent on Non-LWR designs and fuel types.
- Explore the feasibility of radionuclide particle size behavior in the environment for some non-LWR designs.
09/22/2020 30
Other Considerations/Challenges
- Timing of Non-LWR submittals vs code readiness
- Consolidation vs no consolidation
- Wide range of program office participation and input
- Managing expectations 09/22/2020 31
Code Readiness
- Next Steps for Volume 4: (Near- & Mid-Term)
Activity Date Brief SC and Full ACRS Sept 2020/Feb 2021 Build Consolidate Code Framework FY 2021 Obtain Source Terms from Most Probably Designs Ongoing Pilot of Atmospheric Models FY 2021 Include Non-LWR HP Operational Experience FY 21 and beyond (Domestic and International)
Dose and Environmental Engines FY 23 and beyond 09/22/2020 32
Background Slides 09/22/2020 33
09/22/2020 34