ML22132A158
| ML22132A158 | |
| Person / Time | |
|---|---|
| Issue date: | 04/07/2022 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| Howard, K, ACRS | |
| References | |
| NRC-1908 | |
| Download: ML22132A158 (73) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Docket Number:
(n/a)
Location:
teleconference Date:
Thursday, April 7, 2022 Work Order No.:
NRC-1908 Pages 1-45 NEAL R. GROSS AND CO., INC.
Court Reporters and Transcribers 1716 14th Street, N.W.
Washington, D.C. 20009 (202) 234-4433
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 2
3 DISCLAIMER 4
5 6
UNITED STATES NUCLEAR REGULATORY COMMISSIONS 7
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 8
9 10 The contents of this transcript of the 11 proceeding of the United States Nuclear Regulatory 12 Commission Advisory Committee on Reactor Safeguards, 13 as reported herein, is a record of the discussions 14 recorded at the meeting.
15 16 This transcript has not been reviewed, 17 corrected, and edited, and it may contain 18 inaccuracies.
19 20 21 22 23
1 UNITED STATES OF AMERICA 1
NUCLEAR REGULATORY COMMISSION 2
+ + + + +
3 694TH MEETING 4
ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 5
(ACRS) 6
+ + + + +
7 THURSDAY 8
APRIL 7, 2022 9
+ + + + +
10 The Advisory Committee met via 11 teleconference at 8:30 a.m., Joy L. Rempe, Chairman, 12 presiding.
13 COMMITTEE MEMBERS:
14 JOY L. REMPE, Chairman 15 WALTER L. KIRCHNER, Vice Chairman 16 DAVID A. PETTI, Member-at-Large 17 RONALD G. BALLINGER, Member 18 VICKI M. BIER, Member 19 CHARLES H. BROWN, JR., Member 20 VESNA B. DIMITRIJEVIC, Member 21 GREGORY H. HALNON, Member 22 JOSE A. MARCH-LEUBA, Member 23 MATTHEW W. SUNSERI, Chairman 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
2 DESIGNATED FEDERAL OFFICIAL:
3 4
5 6
7 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 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
3 P R O C E E D I N G S 1
(1:00 p.m.)
2 CHAIRMAN REMPE: So, good afternoon. It's 3
1:00 p.m. on the East Coast. We're back in session.
4 And at this point I'd like to ask Member March-Leuba 5
to introduce the discussion on the GE BWRX-300 6
Advanced Civil Construction and Design Approach.
7 MEMBER MARCH-LEUBA: Thank you, Member 8
Rempe, Chair Rempe. We have a GEH, again, person come 9
to us. And we are going to see a completely different 10 topical report. And this time it's about construction 11 engineering, civil construction.
12 George -- no, sorry. The staff is going 13 to make an introduction. Mike Dudek, please go ahead.
14 MR. DUDEK: Thank you. My name is Michael 15 Dudek. I'm the branch chief of new reactor licensing 16 for NRR. Thank you, Senior Technical Member March-17 Leuba, and the members of the commission, and Chairman 18 Rempe for hearing us again today on another important 19 topic associated with BWRX-300 technology.
20 We first heard and presented on this 21 topical report on March 18th, associated with the 22 advanced civil construction and design approach. We 23 had a very good discussion with the committee.
24 Several questions and answers were raised.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
4 We're here today for the full committee to 1
answer some of those questions and provide a high-2 level overview of the topical report and the staff's 3
review, which was approximately 8 months. And after 4
several RAIs, the staff issued their SER earlier this 5
year.
6 We've outlined several limiting conditions 7
that were discussed for this SER. And that will be 8
evaluated during future licensing activities.
9 So, without any further ado, I'll turn it 10 back to you, Member March-Leuba, and GEH for the 11 presentation.
12 MEMBER MARCH-LEUBA: Mike, before you go 13 away, just a clarification. We had a rather long talk 14 yesterday about the joint Canadian-NRC review for a 15 different topical report. My understanding, there is 16 no such thing for this report. Correct?
17 MR. DUDEK: That is correct. This topical 18 report was independent and only conducted by the NRC.
19 MEMBER MARCH-LEUBA: Excellent. Thank 20 you.
21 CHAIRMAN REMPE: Okay. I have a bit of an 22 echo. Let me try again.
23 (Pause.)
24 CHAIRMAN REMPE: Thank you. Go ahead.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
5 MEMBER MARCH-LEUBA: GE, George I believe 1
it's your turn.
2 And everybody remember, this is an open 3
session. You know, this is a non-proprietary document 4
anyway.
5 MR. WADKINS: Yes.
6 CHAIRMAN REMPE: But don't divulge 7
proprietary information.
8 MR. WADKINS: Good afternoon. My name is 9
George Wadkins. I'm the vice president of New Power 10 Plants and Products Licensing. Today we are going to 11 discussing our licensing topical report, NEDO-33914, 12 BWRX-300 Advanced Civil Construction and Design 13 Approach.
14 It is a non-proprietary document, and we 15 do not expect there to be the need for any proprietary 16 discussions involving this LTR.
17 The BWRX-300 design is built upon many 18 years of experience in plain water reactors. One of 19 the most innovative features, though, of the BWRX-300 20 is in the design of the seismic Category I reactor 21 building housing the safety-related components of the 22 facility, including the reactor containment building 23 and engineered safety features.
24 BWRX-300 reactor building is a deeply 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
6 embedded, vertical right cylinder structure that 1
eliminates the traditional foundation construction 2
method. Instead of a large initial excavation with 3
large amounts of required engineered backfill, the 4
reactor building is constructed inside a vertical 5
right cylinder shaft.
6 This LTR describes the vertical shaft 7
construction method and impacts on design, analysis, 8
construction, and monitoring of the BWRX-300 reactor 9
building.
10 I wish to thank the NRC staff for their 11 thorough review. I wish to thank the ACR subcommittee 12 for our previous meeting, which went very well, and 13 for you hearing us today and considering the approval 14 of the SER by the NRC staff.
15 So, with that, I will turn it over to Lisa 16 Schichlein. She is the U.S. licensing manager, 17 actually, for our naturing reactor, but also does work 18 with our licensing topical reports for BWRX-300.
19 MEMBER MARCH-LEUBA: And, Lisa, before you 20 start, the subcommittee will discuss how large this 21 reactor building was deep underground. Can you tell 22 us how large the building is? Say your name first.
23 MR. TODOROVSKI: My name is Luben 24 Todorovski. I am physical engineer for GE-Hitachi.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
7 The building is approximately 250 feet 1
high. Also, this one, approximately 120 feet below 2
ground. And it's 50 feet round.
3 MEMBER MARCH-LEUBA: So, wait. Half of it 4
is underground, half of it is above?
5 MR. TODOROVSKI: Approximately, yes. Half 6
of it is out, then half is below ground. And the rest 7
is above ground.
8 MEMBER MARCH-LEUBA: And 250 feet is 9
almost a football length. That will be 300.
10 MR. TODOROVSKI: Yeah. I actually know 11 that it's one-half below ground, so it's 250 feet is 12 more appropriate number.
13 MEMBER MARCH-LEUBA: Thank you.
14 MS. SCHICHLEIN: Good afternoon. My name 15 is Lisa Schichlein, and I'm the U.S. licensing manager 16 for new power plants and products at GE-Hitachi 17 Nuclear Energy Americas.
18 I'd like the ACRS full committee for the 19 opportunity to present the BWRX-300 advanced civil 20 construction and design approach licensing topical 21 report.
22 In addition to George Wadkins, we have in 23 attendance from GEH, who you've already met, Luben 24 Todorovski, a principal engineer in the civil 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
8 structural area; Brandon Gomer, a geologist from Black 1
& Veatch; Jesus Diaz, our U.S. licensing manager for 2
BWRX-300; and Mr. Ossama Ali, the engineering manager 3
for civil balance of plant systems.
4 On call in addition, supporting our 5
meeting today we have Tanya Kirby, a senior project 6
engineer for Jisukru (phonetic), a senior civil 7
structural engineer; Ai-Shen
- Liu, one of our 8
engineers; and David Hinds, principal engineer for 9
plant integration.
10 And, in addition, we'll be also supported 11 by a number of folks from the Black & Veatch team:
12 Wei Zheng, a geotechnical engineer; Michael Tzang, the 13 engineering manager; David Calhoun, the nuclear chief 14 engineer for Black & Veatch.
15 GEH, Asuki (phonetic), and Jisukru have an 16 alternative approach to the construction, analysis, 17 and design of the BWRX-300 below-grade reactor build.
18 To that end, the topical report presents design 19 analysis and monitoring guidelines and requirements to 20 support our request for approval for approach to the 21 construction of the below-grade BWRX-300 small modular 22 reactor, reactor building vertical right cylinder 23 shaft.
24 The scope of the topical report includes 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
9 the regulatory basis for this approach, guidelines for 1
characterizing subsurface conditions, guidelines for 2
performing the foundation interface analysis, the 3
design requirements, acceptance criteria and 4
guidelines for the analysis and design of the deeply 5
embedded reactor building, an approach for adjusting 6
Seismic Category II/I interactions in the reactor 7
building and surrounding structures' foundations, and 8
our generic seismic geotechnical design parameters.
9 This figure illustrates the conceptual 10 site plot plans for a BWRX-300 single unit plant. The 11 control building, turbine building, and rad waste 12 building structures are located adjacent to the deeply 13 embedded Seismic Category I
reactor building 14 structure, and are separated from the reactor building 15 by seismic gap.
16 The rad waste building, as you can see, is 17 categorized as RW2A. And the control building and 18 turbine building are non-seismic.
19 This figure also illustrates the relative 20 position at the ground level.
21 The design and analysis described in the 22 topical report comply with all applicable regulatory 23 requirements and guidance for the areas listed on the 24 slide: so define site subsurface conditions, site 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
10 design plan, seismic analysis, II/I interaction, and 1
testing, inspection and monitoring.
2 The features presented here meet the 3
intent of the current regulatory guidance for large 4
light water reactors and addresses specifics related 5
to the seismic structural design of deeply embedded 6
SMRs.
7 GEH is not requesting NRC approval for 8
exemptions from any regulatory requirements or 9
exceptions to the regulatory guidance.
10 The topical report discusses the property 11 characterization and monitoring approach which is 12 driven by the reactor building structure being deeply 13 embedded. This includes several investigation, 14 testing, and monitoring programs that will be used in 15 conjunction with the foundation interface analysis, 16 including a site investigation program, a subsurface 17 nuclear lab testing program, and construction and in-18 service monitoring program.
19 A
3-dimensional foundation interface 20 analysis will be performed, which includes interface 21 modeling, structural modeling, fluid soil interaction, 22 and consideration of all plant life stages.
23 The methodology also includes static and 24 seismic soil structure interaction analysis approaches 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
11 for designing a deeply embedded reactor building 1
structure, and a graded approach taken for the 2
evaluation of Seismic Category II/I interaction 3
between the Seismic Category I reactor building and 4
the adjacent control building, turbine building, and 5
rad waste building.
6 The topical report also includes the 7
method for developing generic seismological and 8
geotechnical site plans using generic design response 9
- spectra, subgrade dynamic properties, static 10 properties, and NRC generic guidance.
11 VICE CHAIRMAN KIRCHNER: Can I ask a 12 question?
13 MS. SCHICHLEIN: Yes, certainly.
14 VICE CHAIRMAN KIRCHNER: So, here you are 15 following Appendix S in your approach, and you'll just 16 use one -- can't see the slide.
17 MS. SCHICHLEIN: Oh, let me get that.
18 VICE CHAIRMAN KIRCHNER: GRDS.
19 MS. SCHICHLEIN: Yes.
20 VICE CHAIRMAN KIRCHNER: So, you will use 21 just one spec?
22 MS. SCHICHLEIN: I'd like to defer that to 23 Luben, please.
24 MR. TODOROVSKI: Yes. The generic design 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
12 for the --
1 VICE CHAIRMAN KIRCHNER: A little louder, 2
please.
3 MR. TODOROVSKI: The intent of this is to 4
develop a design that will be applicable for 80 5
percent of the sites, the sites in North America.
6 VICE CHAIRMAN KIRCHNER: Right.
7 MR. TODOROVSKI: And for the generic 8
design we expect to use three sets of those spectra 9
for firm, medium, and hard sites.
10 VICE CHAIRMAN KIRCHNER: So, three soil 11 types?
12 MR. TODOROVSKI: Yes. Three, three types 13 of soil.
14 VICE CHAIRMAN KIRCHNER: The bounds that 15 you went for certified or standard design, that would 16 bound, as you said, 80 percent of the sites you might 17 consider?
18 MR. TODOROVSKI: Right. It's based on 19 database of the reasonably --
20 MS. SCHICHLEIN: In conclusion, I would 21 like to wrap up this presentation by restating that 22 the design and analysis described in the licensing 23 topical report comply with all applicable regulatory 24 requirements and guidance.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
13 The approaches discussed in the topical 1
report meet the intents of the current regulatory 2
guidance for large light water reactors, and address 3
the specifics related to the seismic and structural 4
design of deeply embedded small modular reactors.
5 And just to restate, that GEH is not 6
requesting NRC approval for exemptions from any 7
regulatory requirements or any exceptions to any 8
regulatory guidance.
9 CHAIRMAN REMPE: And just remembering when 10 we talked in the subcommittee, just to put it on the 11 public
- record, we are always concerned about 12 underground structures that will not be inspected for 13 40, 60, 80 years. And you told us that. That is not 14 part of this topical report, what treatment you will 15 provide for that circumstance?
16 MS. SCHICHLEIN: Correct.
17 CHAIRMAN REMPE: And we will be seeing it 18 in a future topical report. We are only concerned 19 with the structural right now.
20 MS. SCHICHLEIN: Right. That is correct.
21 And with that, if there's any additional 22 questions or comments from the committee.
23 VICE CHAIRMAN KIRCHNER: Well, without 24 getting into any -- this is not a proprietary report; 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
14 right?
1 MS. SCHICHLEIN: Correct.
2 VICE CHAIRMAN KIRCHNER: Okay. Fine.
3 Then all right.
4 So, what did you see when you did your 5
structural soil interaction analysis with the three 6
different soil types? Did you see any dominant, 7
especially if embedded in hard, hard soil types, did 8
you see significant change in your spectra at the 9
higher frequencies.
10 MR. TODOROVSKI: So, just to clarify, we 11 tested with three types of -- soil types. But we have 12 up to nine profiles. So, basically, they can change 13 in terms of how the soil, what is the distribution of 14 the soil with that. And depending on the location of 15 the rock.
16 VICE CHAIRMAN KIRCHNER: So, for a deeply 17 embedded structure of this size, what, what turned out 18 to be dominant in terms of the actual g loads that are 19 transferred?
20 MR. TODOROVSKI: Unlike, unlike above 21 ground structures, this structure is driven by the 22 soil. And softer soil conditions actually lead to 23 higher structural demands for in the below ground.
24 But the type of soil will be bounding for 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
15 the above ground. So, it's kind of different.
1 VICE CHAIRMAN KIRCHNER: That makes sense.
2 Did you see amplification in the high, for 3
the hard soil types with this embedded concept on the 4
higher frequency over --
5 MR. TODOROVSKI: Yes. There are certain 6
local responses, local modes. But, in general.
7 VICE CHAIRMAN KIRCHNER: So, you didn't 8
see anything that would impose significant change in 9
terms of the g forces, the loading forces going in?
10 MR. TODOROVSKI: In general, the embedment 11 helps, this was (audio interference). We had 12 comparison with other technologies in terms of what 13 demands we share from different components. And by 14 the time that some of the components are below ground 15 that it reduces the demand, seismic demand.
16 VICE CHAIRMAN KIRCHNER: Thank you.
17 MEMBER MARCH-LEUBA: On occasions that we 18 have an expert here, I always have thought that 19 putting it underground, as being an engineer, would be 20 better than above ground. But you told me that indeed 21 it put higher stresses (audio interference) circle.
22 MR. TODOROVSKI: If you have a big 23 building, I'm not sure the building would determine 24 the design. It doesn't mean that in this case because 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
16 the structure is relatively small, when it's embedded 1
in the soil then the response of the soil will 2
determine the design of the structure.
3 So, that's why we have written this LTR to 4
address those specifics, the differences between the 5
design and what we are used to in the large light 6
water reactor.
7 MEMBER MARCH-LEUBA: But I should expect 8
an underground embedded structure to be more limiting 9
from the point of view of seismic than above ground?
10 MR. TODOROVSKI: Yes. It helps.
11 MEMBER MARCH-LEUBA: It helps or it is 12 bad?
13 MR. TODOROVSKI: No. The embedment helps.
14 It helps.
15 MEMBER MARCH-LEUBA: It helps. Okay. So, 16 I misunderstood what you said. I thought --
17 MR.
TODOROVSKI:
There's certain 18 uncertainty related to the rock --
19 MEMBER MARCH-LEUBA: Yes. But I would 20 have expected it to be better.
21 MR. TODOROVSKI: Not necessarily.
22 MEMBER MARCH-LEUBA: Okay, thank you.
23 Yeah?
24 VICE CHAIRMAN KIRCHNER: If you had a 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
17 really large building that's in -- a really large 1
building that's in soft soil, that will amplify it.
2 MEMBER MARCH-LEUBA: Yeah. I would have 3
expected an above ground to go like this, and teeter.
4 And underground it just cannot go.
5 MR. TODOROVSKI: Correct. And this is a 6
sleeve structure, it goes above ground in addition.
7 MEMBER MARCH-LEUBA: Okay. Thank you.
8 Anymore questions for GE? If not, we can 9
take a very short recess so we don't have to keep a 10 transcript while we're moving computers. And let's 11 change.
12 Joy?
13 CHAIRMAN REMPE: Five-minute recess.
14 MEMBER MARCH-LEUBA: It's not five 15 minutes. Just let's change, but there doesn't need to 16 be a transcript of everything we say while we're 17 moving computers. Thank you.
18 (Whereupon, the above-entitled matter went 19 off the record at 1:18 p.m. and resumed at 1:23 p.m.)
20 CHAIRMAN REMPE: Okay. We're back in 21 session. And I'm going to turn it back over to Member 22 March-Leuba.
23 MEMBER MARCH-LEUBA: Thank you. And I 24 want to go immediately to the NRR staff. Alina, are 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
18 you in charge, or who's going to start?
1 MS. SCHILLER: Yes. I'll start.
2 MEMBER MARCH-LEUBA: Go ahead.
3 MS. SCHILLER: My name is Alina Schiller.
4 I'm a project manager in the NRC Office of Nuclear 5
Reactor Regulations, Division of New and Renewed 6
Licenses, New Reactor Licensing Branch.
7 I'd like to thank the ACRS full committee 8
for this time to allow the NRC staff to present its 9
review of GEH BWRX-300 licensing topical report, 10 advanced civil construction and design approach.
11 GEH submitted the Revision 0 of this 12 licensing topical report on January 20th, 2021, and 13 Revision 1 On November 18th, 2021. The NRC staff 14 issued the advanced safety evaluation of the topical 15 report on February 16th, 2022.
16 As stated in the advanced safety 17 evaluation, the NRC staff will evaluate the compliance 18 of the final civil construction and design features 19 for the BWRX-300 small modular reactor during future 20 licensing activities in accordance with 10 CFR Part 21 15, or 10 CFR Part 52, as applicable, with the 22 limitations and conditions as outlined in Section 8-0 23 of the safety evaluation.
24 Today the staff will provide the high 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
19 level summary of the March 18th, subcommittee 1
presentation, with an emphasis on the staff's 2
limitations and conditions.
3 The NRC staff reviewers are Dr. Amitava 4
Ghosh, who is the lead technical reviewer and 5
presenter; Dr. David Heeszel, Edward Stutzcage, Angelo 6
Stubbs, and Sujit Samaddar. I am the topical report 7
project manager, supported by senior project manager 8
9 Before I introduce Dr. Ghosh, I'd like to 10 open the floor to NRC management, Joseph Colaccino, 11 branch chief of the Structures,
- Civil, and 12 Geotechnical Engineering Branch.
13 MR. COLACCINO: Thanks, Alina. I actually 14 have nothing to add. So, I'd like to send it directly 15 to Amit, unless you have other stuff, Alina.
16 MS. SCHILLER: Thank you, Joe. Okay. I'm 17 turning now over to Dr. Ghosh to proceed with his 18 presentation.
19 DR. GHOSH: Thank you, Alina. Good 20 afternoon, everybody. I am Amit Ghosh. I am a 21 geotechnical engineer at the NRR Structural, Civil, 22 and Geotechnical Engineering Branch.
23 We have a group of five individuals who 24 reviewed this entire LTR and developed this SER. So, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
20 today in my presentation I'll be presenting the 1
highlights of our review.
2 First, I will discuss the main differences 3
between the traditional light water reactor and the 4
GEH BWRX-300, talk about the basis against which we 5
reviewed, and then discuss highlights of the technical 6
area as well which has less limitations and 7
conditions, the L&Cs. And then I'll conclude.
8 The main difference is the major part of 9
the reactor is placing a vertical right cylinder shaft 10 which is located mostly below grade to mitigate some 11 effects of the aircraft crashes, external hazards, the 12 aircraft crashes, adverse weather, cladding class.
13 And also, as we just heard about that.
14 Next slide, please.
15 CHAIRMAN REMPE: Excuse me. This is Jose.
16 DR. GHOSH: Yes, sir.
17 CHAIRMAN REMPE: Looking at this figure 18 because we were talking about the advantages of 19 positioning of the reactor building below grade. Is 20 there a higher contact below grade between the 21 containment and the structure and the soil? I mean, 22 how is it packed, because obviously you have to dig a 23 hole that is a little bigger than containment, and 24 then you have to backfill it?
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
21 DR. GHOSH: Yes, sir. Yeah, you cannot 1
have exactly or even very small. You need to have 2
quite a bit of gap in there. And once the gap is 3
there, they are supposed to put some backfill, which 4
is kind of a cement mixture, not loose sand. But GEH 5
will be probably able to give a better answer.
6 MR. TODOROVSKI: That is correct. Luben 7
Todorovski with GEH. It is correct that our 8
construction process is such that we are trying to 9
minimize the amount of vector in excavation. But 10 still there would be some gap between the hole and the 11 escalation itself between these because the soil will 12 be supported by escalation support.
13 And in the, the backfill material will be 14 a material like a new concrete material.
15 DR. GHOSH: Yes.
16 MEMBER MARCH-LEUBA: You are aware, I 17 mean, we talked about the alkali-silica reaction 18 during the subcommittee, and all the plans to backfill 19 with concrete around the containment, as long as that 20 concrete expands. I'm sure you're aware of it.
21 MR. TODOROVSKI: Yes, we are aware. And 22 estimation is not part of this LTR. The concrete as 23 a vector does not have a structural role actually.
24 So, actually, any contribution in strength from that 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
22 vector will be reflected in the design.
1 Now, regarding the walls itself, the 2
structure itself, our design is steel concrete 3
construction. So, basically there will be steel 4
plates and the concrete will be between those steel 5
plates.
6 MEMBER MARCH-LEUBA: So, back to my 7
original question. So, what you're saying is there is 8
going to be a hard contact between the containment and 9
the soil around it. There's not going to be a gap?
10 MR. TODOROVSKI: No. The contact --
11 actually, the containment, the contact between the 12 soil and containment will be only at the base, at the 13 basement.
14 MEMBER MARCH-LEUBA: At the ground level?
15 MR. TODOROVSKI: Around the structure 16 actually we have a containment that we have a reactor 17 building structure, additional structure so the 18 containment will be between those structures. So, 19 only at the basement elevation the containment will 20 be.
21 MEMBER MARCH-LEUBA: Not even at ground 22 level there will be contact?
23 MR. TODOROVSKI: (Audio interference.)
24 MEMBER MARCH-LEUBA: And I assume that --
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
23 now, now I'm going to go back to ask questions of the 1
staff. I assume you have taken all this into account, 2
right, when making the models, and when you do the 3
final submittals.
4 Okay, staff, you can continue your 5
presentation.
6 DR. GHOSH: Thank you, sir. We use this 7
regulatory basis for subsurface conditions review, 10 8
CFR 100.20(c)(1), physical characteristics of the 9
site.
10 CFR 100.22, geological assessment 10 considerations.
11 And for development of site design 12 parameters, 10 CFR 550, Appendix A, general design 13 criterion to design for protection against natural 14 phenomena.
15 Next slide, please. This is one of the 16 pictures I used previously. And this picture shows 17 rock masses fractures. Placing the reactor in a soft 18 surface, we talked about the advantages, but there may 19 be some technical challenges maybe given by the rock 20 masses.
21 The rock mass, depending on the site 22 condition it may totally in the soil, totally in rock, 23 or mixture of both. The rock mass, the rock is 24 stronger than the soil. But the fractures controls 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
24 how the rock mass responds to a load, aspect load or 1
the construction load. Because the fractures are 2
significantly weaker than the intact rock, each 3
fracture -- the fractures forming a network with the 4
several sets of fractures in there.
5 Each fracture has a deep angle, the angle 6
at which it is dipping from the horizon, the direction 7
which -- direction it is dipping measured from the 8
north. And within each set there is a stressing 9
between the two consecutive fractures. In a 10 geotechnical or geological excursion project, these 11 fractures are generally mapped. And those are 12 measured.
13 These are important parameters because the 14 nature is stochastic. So, we will have a mean value 15 and the distribution around these for deep angle, deep 16 direction fractures placement. And as this is 17 commonly done, and probably has been done for nuclear 18 reactors where the nuclear island was placed on rock 19 layers, we did not put any limitation and conditions.
20 But in the site-specific application we'll review how 21 the fracture network has been met, how the parameters 22 have been developed and propagated into the next level 23 of modeling.
24 Next slide, please.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
25 So, in a very high level we, the LTR 1
proposes approaches conceptual level to deal with 2
differing technical issues, especially for deep 3
embedment of the reactor.
4 We reviewed each and every of these 5
proposed approaches and developed our SER. But in 6
this presentation I'll limit my talk to these five 7
areas where we have an L&T limitation and conditions:
8 Foundation interface analysis, FIA model, 9
stability of the reactor shaft, soil-structure 10 interaction (SSI) modeling, and development of the 11 parameters for this analysis, strain-compatible 12 dynamic properties, and non-linear SSI analysis which 13 will be only some specific activities not a regular 14 one.
15 Next slide, please.
16 GEH has proposed to do a FIA model, 17 foundation interface model. This will have the shaft 18 and the reactor, the reactor building will be in the 19 shaft. But it will not be modeled in detail, it will 20 be modeled at the high level where all the major 21 components will be modeled, and the surrounding 22 medium, and also the interfaces, the interface between 23 the reactor building and the surrounding medium.
24 And that will have a special element, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
26 called interface element, which we'll also model the 1
rock fractures which are joints, spreading place, 2
maybe small first. And this model, theoretical model 3
has many different parameters to be present how the 4
interface behaves. Or, I mean, its stiffness and its 5
displacement properties under a given load.
6 These parameters as developed are 7
determined using laboratory test called direct shaft 8
test. The samples will be collected during the site 9
investigation. And this is bottom half of the sample.
10 The top of the sample will have the majority major 11 fit. And these samples shows like it is a very rough 12 surface.
13 And this roughness gives the strength and 14 deformation values. Whitish part and the red part, 15 those are the high peaks. And the blue part is the 16 valleys. So, you can see there is a lot of features 17 in this sample.
18 We put in L&T limitation and conditions 19 that use large sample laboratory test. The reason is 20 if we take a very small sample, maybe quarter inch, 21 half inch, or inch size, something like that, we will 22 be missing a lot of these features. So, the actual, 23 the parameters determined from the laboratory test may 24 not be properly representative of the site, or 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
27 adequately representing the site characteristics.
1 So, in a site-specific application we'll 2
go and look at how the samples have been collected, 3
the testing that has been done in the laboratory to 4
estimate the properties, and how these properties has 5
been transferred to the FIA model and beyond.
6 Next slide, please.
7 The next one is the stability of the 8
reactor shaft. And in my opinion, this is the most 9
important aspect of it.
10 In this figure, we have this sketch. I 11 have excavated the shaft. And you can see, like, the 12 small blocks or deep blocks have started sliding.
13 Because, previously, before the excavation that place 14 was full. There was no place for these blocks to 15 slide into.
16 Because the void has been created, there 17 is a space now to move. That is the small blocks 18 which will go into the area, in the excavated area.
19 And that typically happens in every project, temporary 20 supports are given and they are not considered as a 21 formal type of support.
22 Like, if you go to the Washington, D.C.,
23 Metro, and beyond the stations you will see 24 shotcreting. Those are temporary support to give 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
28 mainly for the life safety point of view, that nobody 1
should get hurt.
2 But we do not want big blocks of the block 3
or blocks to move or slide into that. First of all, 4
before placing the reactor, then it sort of defeats 5
the purpose because it's -- we excavated it and that 6
is getting full.
7 Second thing is because if the thing 8
started moving it creates some instability around the 9
material because now everybody starts -- all the 10 blocks started moving, starts moving.
11 And if we have the reactor in place, then 12 these big blocks will start giving concentrated load 13 on the side of the reactor, which was not put into the 14 design. So, very prudently GEH says that there will 15 not be any unstable blocks in the upper region.
16 First of all, like, if they put parameter, 17 and there will not be any problem in support, because 18 if they put a parameter in support, it may not be 19 accessible after the reactor has been placed. And to 20 guarantee stableness for the entire life of the 21 reactor is a very tall order.
22 So, there will be section for unstable 23 blocks within the surrounding medium. We have several 24 ways it can be done. One is key block theory which is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
29 a very elegant geotechnical approach by Thomas Goodman 1
and Gen-Hua Shi at UC Berkeley. But it's very time 2
consuming because it takes a lot of manual work on 3
that.
4 Another approach is like FIA model. It's 5
that it has been constructed appropriately, the 6
numerical analysis where we have the shaft excavation 7
and also the rock and the soil features, fractures and 8
joints, if they are simulated.
9 And then you start excavating the shaft 10 numerically in the model. And we'll see that how the 11 stress concentrations are changing around the shaft.
12 And also where is there a large displacement taking 13 place in nearby.
14 GEH can verify that because they have 15 instrumentation in the field, so they can calibrate 16 the model at each stage and go further.
17 Next slide, please.
18 So, we put in L&C stable excavation that 19 in a site-specific application staff will review the 20 methods to identify the unstable blocks, block or 21 blocks, and to assess the pressure to determine 22 whether the subgrade is acceptable.
23 It may so happen, like, there are unstable 24 blocks which can be well excavated and backfilled, or 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
30 cement, or something can be done. So, that kind of 1
mitigation measure has been done. We'll also review 2
that and their efforts.
3 Next slide, please.
4 Number three is the soil structure 5
interaction analysis and how the measured properties 6
have been determined and used. They want to do the --
7 the soil structure interaction analysis will be done 8
using the SASSI code, which is System for Analysis of 9
Soil Structure Interaction.
10 This is, this code has been used 11 extensively in the nuclear industry. You can have 12 extensive experience on that, but mostly on the soil 13 side. When it comes to the rock side, or at least 14 partial rock, the rock mass model must be set into 15 this model. And the rock mass has fractures in that.
16 So, GEH has proposed to use rock mass 17 classification system to determine the rock mass model 18 mass.
19 The rock mass classification system used by the 20 rock engineering projects or mining engineers to 21 classify the rock into different groups according to 22 their behavior. In this case there are two methods 23 proposed by GEH. One is RMR, Rock Mass Rating system.
24 Another way is the GSI, Geological 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
31 Strength Index.
1 Each has brought some own parameters. And 2
each parameter depending on what is available at the 3
site to give it numerical validity. And if they add 4
all the values to get the final rock mass rating.
5 There are many empirical iterations 6
available to explore the rock mass that I now reckon 7
with the rock mass model less. And GEH will be using 8
one or more of those.
9 But one aspect -- the assumption is we are 10 getting like one number of the rock modulus. That 11 means it assumes, is rock mass is isotropic and 12 homogeneous. That may not be true for all cases.
13 Like, say there's a horizontal rating because it is 14 different rates at certain intervals, like limestone, 15 sandstone, and layers of that.
16 That rock mass, if you take the model, we 17 have differently across the fractures than along the 18 fractures. So, in a site-specific applications we 19 will be looking for the number of fracture sets 20 present in the rock mass so that can we measure the 21 deformational behavior, isotropic and homogeneous.
22 So, this is one of the L&Cs we have proposed that 23 we'll be reviewing it in the site-specific 24 application.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
32 Next slide, please.
1 Site-specific application of HCSCP. It is 2
Hazard Consistent Strength Compatible Properties.
3 Because SSI analysis is generally deterministic. We 4
get the motion, one motion but this soil sector, the 5
different soil properties we just have been used to 6
develop the site's down motion using the site response 7
analysis. So, they need to be consistent with that.
8 And GEH has a proposed method called 9
HCSCP. We reviewed the method and found it is 10 reasonable. But it has not been used before. So, 11 building a future application, we'll be watching that 12 go through the calculations and analysis process to 13 see how that has been used.
14 Next slide, please.
15 I did not talk much today about the non-16 linear aspects of it. But imagine if the reactor, if 17 the site is highly seismic again, high seismicity, or 18 highly non-linear subgrade materials. It may happen 19 like the active motion is so high that there may be 20 sliding along the structure and the subgrade mediums, 21 or opening up. It may open up.
22 Other factors may slide over each other.
23 So, these are all non-linear behaviors.
24 And GEH has proposed on that sensitivity analysis, 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
33 like, how sensitive the impact is on this non-linear 1
process at that particular site.
2 This is a very complex analysis and never 3
-- it has not been used in nuclear application before.
4 So, the application, in the future application this 5
non-linear SSI will go to the characterization of 6
modeling of each of the non-linear behavior, and also 7
the analysis part. Because all this non-linear 8
analysis, the numerical instability can develop 9
quickly.
10 Next slide, please.
11 MEMBER MARCH-LEUBA: No, before you move.
12 DR. GHOSH: Yes, sir.
13 MEMBER MARCH-LEUBA: This is Jose.
14 Do you take this non-linear analysis to be 15 site-specific for every location where we build the 16 reactor? We don't have a submittal yet, so we don't 17 know. But we strongly suspect that we're not going to 18 have a certified design, but a R50 type application 19 for every site.
20 Have you given any thought of how we will 21 do review of Plan No. 2? Is there going to be an 22 analysis that defines the structure and says it's good 23 for an envelope of soils like this. I don't know how 24 to define an envelope.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
34 And then for Plan No. 2, they just check 1
that the soil is within the envelope? Or will you 2
expect all this analysis to be performed for Plan No.
3
- 2. And especially for the non-linear effects that 4
might be difficult to do.
5 So, I will ask the staff first, have you 6
given any thought of how to define an envelope where 7
the analysis of Plan 1 is applicable to Plan N, and 8
then will transfer to G -- sorry, yeah, to the 9
applicant to see what their opinion is. So, I mean, 10 that, what do you think about that?
11 DR. GHOSH: Yes. That's a very good 12 question, very intriguing question. And let me try to 13 address it as best as I can.
14 If we look at the -- can I go back to that 15 rock face picture, any of those? Yes, yes.
16 So, if we look at this, it is also not 17 only the properties, but it is also the geometry which 18 is involved. And geometry is a site-specific 19 parameter.
20 So, whether, yes, I can have a high 21 seismicity, I can define, okay, this is my envelope of 22 high seismicity. This is my envelope of properties, 23 soil properties, rock properties. But the soil rock 24 properties are most -- I mean, very much dependent on 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
35 other factors, geometries, and geometry given by deep 1
angle and all. Like, it's site parameters.
2 So, although it may be relatively easier, 3
I'm not talking is easy, it's denotably easier in the 4
soil side, but in the rock side it's a big challenge.
5 The question you posed is something we really need to 6
think about.
7 MEMBER MARCH-LEUBA: So, I don't know if 8
I'm understanding between lines. Are you saying it 9
would be very difficult to define an envelope in every 10 case?
11 VICE CHAIRMAN KIRCHNER: No, I don't think 12 so. Obviously, if you pick a site like that you're 13 going to have problems. But we've seen this before 14 from other applicants, they've defined a generic 15 envelope by soil types, by seismic factor. They 16 analyze all the above and they can envelope to first 17 order most of the sites that they would go to.
18 Now, if you go to my house in Santa Fe, 19 New Mexico, it's highly non-linear because we have 20 magma, and then you have soot, which is volcanic ash, 21 and then you have another layer of fractured rocks, 22 and all this. Now, my house is on a non-linear site 23 and it already cracked.
24 So, they're not going to do that. They're 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
36 not going to pick a site like that where you'll hit a 1
potential for a massive split between different 2
formations. So, but in general, you can do, you can 3
envelope that for most sites.
4 CHAIRMAN REMPE: I don't have an opinion.
5 VICE CHAIRMAN KIRCHNER: Just when they 6
inspect at the actual site.
7 CHAIRMAN REMPE: And we'll ask GE. And 8
state your name, state your name on the microphone, 9
and speak directly into the microphone so it's clear.
10 MR. TODOROVSKI: Right. I will do just 11 that.
12 My name is Luben Todorovski.
13 First, I want to emphasize that when we 14 address non-linearities we address the non-linearities 15 of the site, of the rock and the soil, not the site.
16 So, basically, those, those parameters are highly 17 site-specific. So, the analysis will have to be site 18 specific. It will be very, very difficult to do a 19 generic or standard analysis of any site. You have to 20 assume a lot of, lot of things.
21 Like, for example, as mentioned, formation 22 of the rock surfaces, discontinuities and so on. So, 23 basically, the analyses are sensitivity analyses.
24 They will be geared to find what are those effects and 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
37 use the design envelopes, those in that effect.
1 Also, I have to mention that the design 2
generic, and the site-specific later, are all based on 3
we took site parameters which are conservative in 4
order to provide a bound in effects which will bound 5
these effects of non-linearity.
6 And in the LTR which we have proposed two 7
methodologies to address to ensure that the design 8
envelopes with sufficient margin to address the 9
uncertainties, the non-linear effects of the soil 10 response, but in the static sense. And this is 11 another aspect when we are coming to the site which 12 are characterized by also seismicity and also very 13 non-linear. This is a methodology to apply at this 14 site, not only seismic SSI.
15 MEMBER MARCH-LEUBA: So, if I can 16 summarize what I understood you said. And let me know 17 if I misunderstood.
18 You would prefer to have a generic 19 envelope if your site is benign. And then if you 20 happen to have a site where there is too much non-21 linearity, you will have to re-do the analysis at the 22 specific.
23 Is that what you said?
24 MR. TODOROVSKI: I mean, the design will 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
38 still be based on the linear elastic analysis because 1
the whole design process and the, like the spectra, is 2
a spectra is designed for linear elastic analysis 3
because it's the envelope. Many, many earthquake 4
events, not just one.
5 But the sensitivities, sensitivity 6
analysis and the motivational analysis don't ensure 7
that the design which is based on linear elastic 8
properties will bound those non-linear effects with 9
sufficient margin because there will be always 10 uncertainty in the, you know, how accurate we are 11 going to predict those non-linearities.
12 MEMBER MARCH-LEUBA: Thank you.
13 Board, do you have anymore questions?
14 I think Mike Dudek wants to say a few 15 words.
16 MR. DUDEK: Yeah. So, thanks. Thank you.
17 This is Michael Dudek.
18 So, I think there is a technical component 19 that you heard from both staff members. And I also 20 think that there is a licensing component to your 21 question, Member March-Leuba, and the fact of how you 22 envelope that and how you solve that and, second, and 23 the time designs.
24 And I think that's, you know, discussions 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
39 get to be how do we create them and whether they want 1
to -- after they have the CP application, whether they 2
want to certify the design under Part 52 or, you know, 3
they could, they could finalize it in the topical 4
report. There's several licensing venues in which 5
they could do this to put it more solidly, put it on 6
the books.
7 MEMBER MARCH-LEUBA: Okay, thank you.
8 Yeah, basically, we are not there because 9
we're just with topical reports and individual 10 concepts. When there is a submittal, we'll know for 11 sure.
12 Any staff -- Mita, were you done? Or you 13 were going to go into your conclusions?
14 DR. GHOSH: I have one more slide, yeah, 15 conclusions. Thank you, sir.
16 In conclusion, we reviewed the approaches 17 and we found the approach as to character is the 18 surrounding media site and of the rock are reasonable.
19 The design importance for the deeply 20 embedded RB structure are reasonable.
21 I got muted. I have to repeat. You told 22 me, like, I got muted.
23 The design importance for the deeply 24 embedded RB structures are reasonable.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
40 I did not talk about the construction 1
methods in this, my presentation. But there is in the 2
LTRs they have a discussion on that. And we found it 3
acceptable.
4 And the staff will make its final 5
regulatory determinations during its review of any 6
future license application.
7 That concludes my talk.
And any 8
questions?
9 MEMBER MARCH-LEUBA: Thank you. Any 10 questions from the table members or members on the 11 phone line?
12 (No response.)
13 MEMBER MARCH-LEUBA: Okay, five seconds 14 have gone through. I'm going to open the table for 15 our microphones for public comments.
16 Any member of the public that wants to 17 place a comment on the record, please identify 18 yourself and say so. If you are on the Teams meeting, 19 just unmute yourself. If you are on the phone line, 20 press star-6.
21 (No response.)
22 MEMBER MARCH-LEUBA: Five second rule 23 again. Nobody wanted a comment.
24 We are going to open the table of members 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
41 again if they want to make a comment.
1 Yes, Charlie?
2 MEMBER BROWN: Yeah. I'm trying to, 3
trying to think of addressing your last question.
4 Correct me if I'm wrong. But one of our 5
previous reviews, maybe even probably in two of them, 6
there was a considerable amount of evaluation of the 7
site. And there was a lot of excavation and tailoring 8
of the site. So, in terms of depth that they went 9
down to that they then filled and backfilled, put 10 columns in, and everything else in order to put the 11 facility on top of it.
12 And I guess I didn't think to ask the 13 question at the subcommittee meeting the way you did.
14 But I guess I kind of assumed that even with the 15 design the way it was there would be some amount of 16 site within a generic envelope of some sort that you 17 could backfill, excavate, and then tailor to some 18 extent to make an overall generic set.
19 I mean, maybe I'm wrong, but I just, it 20 seemed to me that if you had the capability you could 21 do that. I'm not -- this one's unusually deep. What 22 was it, 120 feet or a hundred and --
23 MEMBER MARCH-LEUBA: This one is 120 feet 24 deep below ground level and 120 above.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
42 MEMBER BROWN: Right. I can't remember 1
whether the ones, at least one or two we looked at, we 2
did have at least a couple that had pretty detailed --
3 and this was some years ago -- lost the bubble in my 4
own time. So, I guess the question was why couldn't 5
-- it's an interesting design and it seemed like an 6
interesting way. I don't know why, I guess I don't 7
understand why it couldn't be tailored to a kind of a 8
set of boundary conditions.
9 MEMBER MARCH-LEUBA: My train of thought 10 was the point if I was the applicant I would create a 11 generic design.
12 MEMBER BROWN: Exactly.
13 MEMBER MARCH-LEUBA: And I would build the 14 same design on every plan. Because that's a cost 15 savings and I don't have to re-do the analysis.
16 But then I have to either analyze it, what 17 I'm designing for, for the facility, for the site, see 18 which one is worth, or the final envelope. That's why 19 I asked for the envelope because I expect the fourth 20 BWRX-300 to be exactly the same as the first one as 21 far as concrete is concerned.
22 VICE CHAIRMAN KIRCHNER: And just to 23 refresh everyone's memory, we had another applicant 24 also, and the NRC reviewed the applicant's submittals 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
43 and its topical report that basically dealt with the 1
same thing, and much similar to what GEH team 2
explained.
3 They, they looked at three soil generic 4
types, and they looked at five or six certified 5
seismic design spectra. And then they looked at their 6
plant design and put it into that configuration, tried 7
to find -- ran it through five spectra, ran it through 8
three soil types. And then determined the loads of 9
the soil structure interaction, how that changed the 10 loads inside, and transmitted the frequencies inside 11 the actual plant. And determined that at this level 12 of stiffness, et cetera, et cetera, they could survive 13 an earthquake of X g's.
14 MEMBER MARCH-LEUBA: The problem is then, 15 let me just point out if somebody wants to build one 16 of these facilities in Hawaii where you have unstable 17 and non-linearity.
18 VICE CHAIRMAN KIRCHNER: Well, as the 19 staff said on this last vugraph, the last bullet, the 20 staff will always check, and so will the applicant.
21 I mean, they're the applicants and they do all the 22 soil bore holes and all the rest of it, determine the 23 soil type and composite. But the staff's always going 24 to check that. And that will always be site-specific.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
44 But you can envelope this. And I think they have, and 1
we've seen that with other applicants.
2 MEMBER BROWN: That was my thought. You 3
can see that for a reasonable --
4 VICE CHAIRMAN KIRCHNER: Yeah. I think 5
they said, I think 80 percent of the sites they could 6
bound that.
7 MEMBER MARCH-LEUBA: Let GE enlighten us.
8 MR. TODOROVSKI: Yes. This is Luben 9
again, Todorovski.
10 Our design the aim is to have a product 11 which will be applicable for 80 percent of the sites.
12 But when they address certain uncertainties, and I 13 want to point out, unlike the others, the previous 14 designs featured big structures on the soil. This 15 design is far more dependent on the site-specific 16 conditions.
17 And when we go to non-linearity there are 18 so many parameters that can change that it's very 19 difficult to envelope everything possible. So, the 20 idea is to have a generic design which is, we believe, 21 conservative, and it will envelope those non-22 linearities and other site-specific features. But at 23 the end, we will have to demonstrate for each site 24 that the design is safe.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
45 And so, that is the basic approach.
1 MEMBER MARCH-LEUBA: Thank you. I think 2
that's a good plan on this one.
3 We went to public comments. There's no 4
public comments. Anymore discussion on the table?
5 (No response.)
6 MEMBER MARCH-LEUBA: Chair Rempe, the 7
floor is yours.
8 CHAIRMAN REMPE: It's my understanding 9
that -- microphone. Thank you again. Thanks, 10
- everyone, for their presentation.
It's my 11 understanding that we have a draft letter. And we 12 would like to read it in in the near future.
13 MEMBER MARCH-LEUBA: Fine.
14 CHAIRMAN REMPE: So, let's take a break 15 and come back at 2:15 p.m. on the East Coast and we'll 16 read in your letter. Thank you.
17 (Whereupon, the above-entitled matter went 18 off the record at 2:04 p.m.)
19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
Staff Presentation to the ACRS Full-Committee GEH Licensing Topical Report BWRX-300 Advanced Civil Construction and Design Approach (NEDO-33914, Revision 1)
April 7, 2022
2 NRC Staff Reviewers:
Amitava Ghosh, Ph.D., Geotechnical Engineer, Presenter, NRR/DEX/ESEB David Heeszel, Ph.D., Geophysicist, NRR/DEX/EXHB Edward Stutzcage, Health Physicist, NRR/DRA/ARCB Angelo Stubbs, Sr. Safety and Plant Systems Engineer, NRR/DSS/SCPB Sujit Samaddar, Sr. Structural Engineer, NMSS/DFM/MSB Project Managers:
Alina Schiller, TR Project Manager, NRR/DNRL/NRLB James Shea, Sr. Project Manager, NRR/DNRL/NRLB GEH BWRX-300: ACRS Full Committee April 7, 2022
3 Agenda
- Introduction
- Difference Between Traditional Light Water Reactor and GEH BWRX-300
- Regulatory Bases
- Staff Limitations and Conditions (L&Cs)
GEH BWRX-300 Reactor
- Reactor Building (RB) is placed in a vertical right-cylinder shaft and located mostly below-grade to mitigate effects of possible external events, including aircraft crashes, adverse weather, flooding, fires, and earthquakes GEH BWRX-300: ACRS Full Committee 4
LTR Figure 1-3 April 7, 2022
Regulatory Bases
- Defining Subsurface Conditions o 10 CFR 100.20(c)(1): physical characteristics of the site o 10 CFR 100.23: geologic and seismic considerations
- Development of Site Design Parameters o 10 CFR Part 50, Appendix A, General Design Criteria 2: Design bases for protection against natural phenomena GEH BWRX-300: ACRS Full Committee 5
April 7, 2022
Rock Fracture Network
- Fractures control the response of a rock mass
- Fracture network:
- Dip angle
- Dip direction
- Fracture spacing
- Number of fracture sets
- Staff will review rock fracture network characterization in a site-specific license application GEH BWRX-300: ACRS Full Committee 6
From: Cao, et al. 2016. An Experimental and Numerical Study on Mechanical Behavior of Ubiquitous-Joint Brittle Rock-Like Specimens Under Uniaxial Compression. Rock mechanics and Rock Engineering.
April 7, 2022
NRC Staff Review
- LTR proposes approaches at conceptual level to deal with the technical issues
- Staff conducted a comprehensive review of each proposed approach(es)
- Foundation Interface Analysis (FIA) (LTR Section 4)
- Stability of reactor shaft (LTR Section 5.1.2 and others)
- Soil-Structure Interaction (SSI) modeling (including parameter estimation of equivalent linear elastic materials)
(LTR Section 5.1.2)
- Strain-compatible dynamic properties (LTR Section 5.2.4)
- Nonlinear SSI analysis (sensitivity) (LTR Section 5.3.11)
April 7, 2022 GEH BWRX-300: ACRS Full Committee 7
L&C #1: Interface Testing Large size samples collected at a site tested in the laboratory to have an acceptable estimate of the measured discontinuity, strength and deformation parameters Staff will review the sizes of the samples and their testing at the laboratory to estimate the properties of the discontinuities and interfaces in a site-specific license application with a BWRX-300 SMR GEH BWRX-300: ACRS Full Committee 8
From: Fan, et al. 2019. Geotechnical and Geological Engineering. Experimental and Numerical Study on the Damage Evolution of Random Rock Joint Surface During Direct Shear Under CNL Condition.
April 7, 2022
Stability of Reactor Shaft
- Stability of Embedded Reactor: Unstable rock mass without any permanent support systems is not acceptable
- Unstable blocks in surrounding region o Key block theory (Goodman and Shi, 1985) o Numerical simulation e.g.,
FIA model (LTR Section 4.0) o Results verified by instrumentation installed (LTR Section 3.3)
GEH BWRX-300: ACRS Full Committee 9
From: Cao, et al. 2016. An Experimental and Numerical Study on Mechanical Behavior of Ubiquitous-Joint Brittle Rock-Like Specimens Under Uniaxial Compression. Rock Mechanics and Rock Engineering.
April 7, 2022
L&C #2: Stable Excavation A stable shaft excavation would have no unstable blocks in its surrounding that may slide into the excavation A self-supported (even with some temporary reinforcement) excavation would be needed to place the RB and to estimate the earth pressure loads to be considered in the generic design of the RB structure Staff will review method(s) used to identify the unstable rock blocks and to assess the earth pressure imparted on the RB shaft for determining whether the subgrade is acceptable for siting the reactor in a site-specific application Any mitigation measures used to stabilize the surrounding materials would be reviewed by the staff GEH BWRX-300: ACRS Full Committee 10 April 7, 2022
L&C #3: Isotropic and Homogeneous Rock Mass Rock mass classification systems inherently assume isotropic and homogeneous rock mass to determine rock mass modulus for use in Soil-Structure Interaction (SSI) analyses A jointed (or a fractured) rock mass is assumed to contain a sufficient number of fracture sets so that its deformational behavior may be assumed to be isotropic and homogeneous Staff will review whether the fracture sets at the selected site would make the rock mass behavior isotropic and homogeneous in any future site-specific licensing application GEH BWRX-300: ACRS Full Committee 11 April 7, 2022
L&C # 4: Site Specific Application of the HCSCP
- GEH has proposed to develop Hazard Consistent Strain-Compatible Properties (HCSCP) so that properties used as input for SSI analysis to be consistent with soil/rock properties used in generation of input motion
- During review of future licensing applications, staff will audit the HCSCP approach GEH BWRX-300: ACRS Full Committee 12 April 7, 2022
L&C # 5: Sensitivity Nonlinear SSI Analysis May be important for sites with high seismicity and/or with highly nonlinear subgrade materials Separation and/or sliding at soil/rock-structure interface Nonlinearity at rock fractures NRC staff plans to review the characterization and modeling of the nonlinear behavior of the materials surrounding the reactor in any future licensing application utilizing a nonlinear SSI analysis approach GEH BWRX-300: ACRS Full Committee 13 April 7, 2022
Staff Conclusions
- The approaches to characterize the surrounding media (soil and/or rock) are reasonable
- The design approaches for a deeply imbedded RB structure are reasonable
- The construction methods for the BWRX-300, as described in this LTR, are acceptable with the associated L&Cs.
- The staff will also make its final regulatory determinations, as applicable, during its review of any future license application GEH BWRX-300: ACRS Full Committee 14 April 7, 2022
GEHitachiNuclearEnergy
George E. Wadkins GE-Hitachi Nuclear Energy Americas, LLC Vice President, New Power Plants and Products Licensing 3901 Castle Hayne Road Wilmington, NC 28402 USA T 910.200.3295 George.Wadkins@ge.com M220048 March 25, 2022 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555-0001 Canadian Nuclear Safety Commission 280 Slater Street P.O. Box 1046, Station B Ottawa, Ontario, K1P 5S9, Canada
Subject:
ACRS Full Committee Presentation Slides for NEDO-33914, BWRX-300 Advanced Civil Construction and Design Approach Licensing Topical Report Enclosed are the presentation slides that GE-Hitachi Nuclear Energy Americas, LLC (GEH) will present during the upcoming Advisory Committee on Reactor Safeguards (ACRS) Full Committee Meeting on April 7, 2022. These slides support the ACRS review of NEDO-33914 Revision 1, BWRX-300 Advanced Civil Construction and Design Approach, and the corresponding NRC Advanced Safety Evaluation Report (SER) with No Open Items. contains non-proprietary information and may be made available to the public.
If you have any questions, please contact me at 910-200-3295.
Sincerely, George E. Wadkins Vice President, New Power Plants and Products Licensing GE-Hitachi Nuclear Energy Americas, LLC
Enclosure:
- 1. ACRS Full Committee Presentation Slides for NEDO-33914, BWRX-300 Advanced Civil Construction and Design Approach Licensing Topical Report - Non-Proprietary Information
M220048 Page 2 of 2 cc:
James Shea, US NRC Chantal Morin, CNSC PLM Specification 006N9431 Revision 3 Document Components:
001 M220048 Cover Letter.pdf 002 M220048 Enclosure 1 Non-Proprietary.pdf
ENCLOSURE 1 M220048 ACRS Full Committee Presentation Slides for NEDO-33914, BWRX-300 Advanced Civil Construction and Design Approach Licensing Topical Report Non-Proprietary Information
ACRS Full Committee Presentation GE Hitachi (GEH)
Licensing Topical Report (LTR) NEDO-33914 BWRX-300 Advanced Civil Construction and Design Approach April 7, 2022
Copyright 2022 GE Hitachi Nuclear Energy Americas, LLC - All Rights Reserved 2
Licensing Topical Report Purpose GEH is seeking NRC approval for the application of an alternative approach to the construction, analyses, and design of the BWRX-300 below-grade Reactor Building.
The purpose of the LTR is to present design, analysis, and monitoring guidelines and requirements to support the request for NRC approval of the innovative and comprehensive construction approach for the construction of the below grade BWRX-300 small modular reactor Reactor Building vertical right cylinder shaft.
Copyright 2022 GE Hitachi Nuclear Energy Americas, LLC - All Rights Reserved 3
Licensing Topical Report Scope This request is supported by the following information in the LTR:
- Regulatory basis specific for the innovative approaches
- Guidelines and requirements for characterizing subsurface conditions, including geotechnical site investigations and laboratory testing programs, as well as the inspection and monitoring programs
- Requirements and guidelines for performing the foundation interface analysis
- Design requirements, acceptance criteria and guidelines for the deeply embedded Reactor Building
- An approach for addressing Seismic Category (SC) II/I interactions
- Generic seismic and geotechnical design parameters
Copyright 2022 GE Hitachi Nuclear Energy Americas, LLC - All Rights Reserved 4
BWRX-300 Building Seismic Categories Control Building (Non-Seismic)
Radwaste Building (RW-IIa)
Reactor Building (SC-I)
Turbine Building (Non-Seismic)
Ground Level
5 Copyright 2022 GE Hitachi Nuclear Energy Americas, LLC - All Rights Reserved Regulatory Basis
- The design and analyses described in the LTR comply with all applicable regulatory requirements and guidance for:
- Defining Site Subsurface Conditions
- Site Design Parameters
- Seismic Analysis
- II/I Interactions
- Testing, Inspection and Monitoring
- The implemented innovative approaches meet the intent of the current regulatory guidance for large light water reactors and address the specifics related to the seismic and structural design of deeply embedded small modular reactors.
- GEH is not requesting NRC approval for exemptions from any regulatory requirements or any exceptions to any regulatory guidance.
6 Copyright 2022 GE Hitachi Nuclear Energy Americas, LLC - All Rights Reserved BWRX-300 Monitoring, Analysis and Design Process
- Innovative property characterization and monitoring approaches driven by the RB structure being deeply embedded
- Investigation, testing, inspection, and monitoring programs, in conjunction with the results of a set of foundation interface analyses, ensure the safe siting of the BWRX-300 plant
- Non-linear constitutive 3D foundation interface analysis numerical modeling includes interface modeling, structural modeling, fluid soil interaction, and consideration of all plant life stages
- Static and seismic soil-structure interaction analysis approaches for designing the deeply embedded RB structure
- Graded approach for the design and II/I interaction evaluations of the structures adjacent to the deeply embedded Safety Classification I RB structure.
Copyright 2022 GE Hitachi Nuclear Energy Americas, LLC - All Rights Reserved 7
BWRX-300 Generic Design Approach
- Methodology for development of generic seismological and geotechnical site parameters for the conceptual design of the BWRX-300
- Generic Design Response Spectra (GDRS)
- Generic subgrade dynamic properties
- Generic static properties for different subgrade materials
- Friction coefficient values and groundwater table elevations
Copyright 2022 GE Hitachi Nuclear Energy Americas, LLC - All Rights Reserved 8
Conclusion In summary
- The design and analyses described in the LTR comply with all applicable regulatory requirements and guidance.
- The innovative approaches meet the intent of current regulatory guidance for large light water reactors and address the specifics related to the seismic and structural design of deeply embedded SMRs.
- GEH is not requesting NRC approval for exemptions from any regulatory requirements or any exceptions to any regulatory guidance.
Questions or Comments