ML24177A224
| ML24177A224 | |
| Person / Time | |
|---|---|
| Issue date: | 05/16/2024 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | |
| References | |
| NRC-2856 | |
| Download: ML24177A224 (1) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safeguards Kairos Power Licensing Subcommittee Docket Number:
(n/a)
Location:
teleconference Date:
Thursday, May 16, 2024 Work Order No.:
NRC-2856 Pages 1-100 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 ADVISORY COMMITTEE ON REACTOR SAFEGUARDS 4
(ACRS) 5
+ + + + +
6 DESIGN-CENTERED REVIEW: KAIROS SUBCOMMITTEE 7
+ + + + +
8 THURSDAY 9
MAY 16, 2024 10
+ + + + +
11 The Subcommittee met via Teleconference, 12 at 11:00 a.m. EDT, David A. Petti, Chair, presiding.
13 COMMITTEE MEMBERS:
14 DAVID A. PETTI, Chair 15 RONALD G. BALLINGER, Member 16 VICKI M. BIER, Member 17 VESNA B. DIMITRIJEVIC, Member 18 WALTER L. KIRCHNER, Member 19 JOSE A. MARCH-LEUBA, Member 20 ROBERT MARTIN, Member 21 THOMAS ROBERTS, Member 22 MATTHEW W. SUNSERI, Member 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
2 ACRS CONSULTANTS:
1 CHARLES BROWN 2
5 6
DESIGNATED FEDERAL OFFICIAL:
7 WEIDONG WANG 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
11:00 a.m.
2 CHAIR PETTI: Okay, the meeting will now 3
come to order.
4 This is a meeting of the Kairos Power 5
Licensing Subcommittee of the Advisory Committee on 6
Reactor Safeguards.
7 I'm Dave Petti, Chairman of today's 8
subcommittee meeting.
9 ACRS Members in attendance are Ron 10 Ballinger, Tom Roberts, Vicki Bier.
11 Online, I see --
12 MEMBER SUNSERI: I'm online and --
13 CHAIR PETTI: Yes, Member Sunseri.
14 That's all I see.
15 I also see --
16 MEMBER DIMITRIJEVIC: I'm online.
17 CHAIR PETTI: Oh, okay, thank you.
18 MEMBER KIRCHNER: And I'm here, too, Dave.
19 CHAIR PETTI: Okay.
20 MEMBER MARTIN: And Bob, Bob's here.
21 CHAIR PETTI: Okay, good, it's not showing 22 up.
23 So, Member Martin, Member Dimitrijevic --
24 MEMBER MARCH-LEUBA: And Jose, too.
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 CHAIR PETTI: -- Member Kirchner, and 1
Member March-Leuba also with us.
2 Also, our consultants, Charlie Brown, 3
Dennis Bley, and Steve Shultz are here.
4 Weidong Wang of the ACRS staff is the 5
Designated Federal Official of the meeting.
6 During today's meeting, the subcommittee 7
will review the staff safety evaluation on selected 8
chapters of Kairos Power Hermes 2, non-power reactor 9
preliminary safety analysis report.
10 Like Kairos has proposed and NRC approved 11 Hermes, which we sometimes call Hermes 1 test reactor, 12 large portions of the two unit Hermes 2 reactor PSAR 13 are identical to the Hermes 1.
14 The ACRS has reviewed the Hermes 1 PSAR on 15 May 2023.
16 The Hermes 2, if you will focus on the 17 design differences from Hermes 1.
18 The subcommittee will hear presentations 19 by and hold discussions with the NRC staff, Kairos 20 Power representatives and other interested persons 21 regarding this matter.
22 The part of the presentations by the 23 Applicant and the staff may be in order to discuss 24 information that is proprietary to the licensee 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
5 its contractors pursuant to 5 USC 552(b)(c)(4).
1 Attendance at the meeting that deals with 2
such information will be limited to the NRC staff and 3
its consultants, Kairos Power, and those individuals 4
and organizations who have entered into an appropriate 5
confidentiality agreement with them.
6 Consequently, we'll need to confirm that 7
we only have eligible observers and participants in 8
the closed part of the meeting.
9 The ACRS was established by statute and is 10 governed by the Federal Advisory Committee Act, FACA.
11 The NRC implements FACA in accordance with 12 its regulations found in Title 10 of the Code of 13 Federal Regulations Part 7.
14 The rules for participation in all ACRS 15 meetings, including today's, were announced in the 16 Federal Register on June 13th, 2019.
17 The ACRS section of the U.S. NRC public 18 website provides our charter, bylaws, agendas, letter 19 reports, and full transcripts of all full and 20 subcommittee meetings, including slides presented.
21 The meeting notice and the agenda for this 22 meeting were posted there.
23 We've received no written statements or 24 requests to make an oral statement from the public.
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 We have set aside time in the agenda for 1
comments from members of the public listening to this 2
meeting.
3 Our subcommittee will gather information, 4
analyze relevant issues and facts and formulate 5
proposed positions and actions as appropriate for 6
deliberation by the full committee.
7 A transcript of the meeting is being kept 8
and will be made available.
9 Today's meeting's being held in person and 10 over Microsoft Teams for the ACRS staff and members, 11 NRC staff, Applicants, and members of the public.
12 The Teams link information for telephone 13 bridge line was placed in the agenda on the ACRS 14 public website.
15 When addressing the subcommittee, the 16 participants should first identify themselves and 17 speak with sufficient clarity and volume so that they 18 may be readily heard.
19 When not speaking, we request that 20 participants mute their computer microphone or their 21 phone by pressing star six.
22 We'll now proceed with the meeting and I'd 23 like to start by asking NRR Josh Borromeo, branch 24 chief, to begin.
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 MR. BORROMEO: First try, you got it.
1 Thank you, Dr. Petti for the opportunity 2
to meet with you and the Kairos subcommittee today.
3 I'm Josh Borromeo and I'm the chief of the 4
Advanced Reactor Licensing Branch in the Office of 5
Nuclear Reactor Regulation.
6 Today will be the first of several 7
meetings in which the staff and Kairos will present 8
the preliminary safety analysis report and the safety 9
evaluation chapters to the subcommittee for the Kairos 10 construction permit application for a two unit non-11 power test reactor, known as Hermes 2.
12 This construction permit application was 13 submitted in July of 2023 and is similar to Kairos 14 Hermes construction permit application which the ACRS 15 reviewed last year.
16 In a letter dated December 4th, 2023, NRR 17 provided ACRS staff with an overview of the key 18 technical differences between Hermes and Hermes 2.
19 During the NRC staff's presentation today, 20 you will hear about how the staff's review was focused 21 on the changes between Hermes and Hermes 2.
22 As always, the staff appreciates ACRS's 23 flexibility when scheduling and reviewing these 24 chapters and I look forward to the discussions today.
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 If there's no questions for me, thank you, 1
Dr. Petti.
2 CHAIR PETTI: I guess we'll now hear from 3
Kairos.
4 MR. PEEBLES: All right, thank you, Dr.
5 Petti. Can you hear me okay?
6 CHAIR PETTI: Hold on, maybe it's us.
7 Give me a minute.
8 MR. PEEBLES: Okay.
9 CHAIR PETTI: Try again.
10 MR. PEEBLES: Okay, can you hear me okay?
11 CHAIR PETTI: I think that's a little 12 better, a little echoy, like you're in a big room.
13 DR. BLEY: Dave, it sounds good for those 14 of us on the line.
15 CHAIR PETTI: Okay, then maybe it is us.
16 It's okay, I mean, I can hear.
17 (Off microphone comments.)
18 MR. PEEBLES: Okay, I'll try to speak up, 19 but if you can't understand something, feel free to 20 stop me and I'll go back over it.
21 So, my name is Drew Peebles. I'm a senior 22 licensing manager here at Kairos Power.
23 I would like to thank the committee for 24 the chance to present on our construction permit 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 application for Hermes 2.
1 I will be presenting today along with Jim 2
Tomkins, our fuels licensing manager on the Hermes 2 3
PSAR chapters listed on this slide.
4 We are joined by various subject matter 5
experts for each of these chapters and they will 6
introduce themselves if they're called for Q&A.
7 So, we like to begin every presentation 8
with our mission statement to ground ourselves with 9
our company's objectives.
10 Our mission is to enable the world's 11 transition to clean energy with the ultimate goal of 12 dramatically improving peoples' quality of life while 13 protecting the environment.
14 We recognize that focusing on our clean 15 energy and KPFHRs, like Hermes 2, and ensuring they 16 are affordable and safe is the way that we achieve 17 this mission.
18 So, this first slide covers the reason 19 we're here.
20 Kairos submitted the construction permit 21 application, or CPA, for Hermes 2, which is a two unit 22 test reactor in July of last year.
23 We are seeking a test reactor construction 24 permit under the provisions of 10 CFR 50.21© and the 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 Atomic Energy Act, Section 2134© to test and 1
demonstrate the items on this bulleted list.
2 First, an intermediate heat transport loop 3
separating the primary heat transport system and the 4
power generation systems.
5 And the steps shown on the intermediate 6
loop design is currently scheduled for the 7
subcommittee meeting for June 12th.
8 Hermes 2 will also demonstrate a shared 9
electrical power production capability for a three 10 unit plant.
11 We plan to discuss the power generation 12 system design at the subcommittee meeting on June 4th.
13
- Finally, Hermes 2
is intended to 14 demonstrate an increased component lifetime which we 15 will discuss in a few slides.
16 Aside from the items on this list, the 17 content of the application is very similar to and 18 relies extensively on content provided in the Hermes 19 CPA.
20 Now, we will be jumping back and forth 21 between Hermes and Hermes 2 quite a bit in the 22 presentations, so I do want to take a moment to 23 address the naming conventions.
24 The test reactor application the committee 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 reviewed last year is for the reactor called Hermes.
1 You may hear people informally refer to is 2
at Hermes 1, but the official name of the reactor is 3
Hermes.
4 The two unit test reactor application 5
currently in front of you is for the reactor facility 6
called Hermes 2.
7 So, the reactors are referred to as Hermes 8
2, unit one, and Hermes 2, unit two.
9 Jim will be discussing the design 10 differences between Hermes and Hermes 2 on the next 11 slide.
12 But a simplified way of thinking about it 13 would be that Hermes 2 is a set of two Hermes reactors 14 that, instead of rejecting their waste to the 15 atmosphere, are connected to a shared power generation 16 system via intermediate salt loops.
17 So, given how similar the designs are, 18 Kairos Power requested that the NRC staff conduct a 19 delta review of the Hermes 2 CPA by leveraging their 20 safety evaluation of the Hermes CPA.
21 This is similar to a design centered 22 review approach and is appropriate given the 23 similarities found in the design and siting 24 information of the two facilities.
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 To facilitate this delta review, the 1
Hermes 2 PSAR content is annotated with blue text in 2
if the content was different than the Hermes PSAR 3
content.
4 And I'm sure you've noticed, as you looked 5
over the application, there isn't very much blue text.
6 And where there is blue text, it's not in 7
the sections describing SSCs that are safety related.
8 So, that covers the type of application we 9
submitted.
10 Are there any questions before I hand it 11 over to Jim to go through the design differences?
12 CHAIR PETTI: Keep going.
13 MR. PEEBLES: Okay.
14 MR.
TOMKINS:
- Okay, good
- morning, 15 everyone.
16 Are you able to hear me okay?
17 CHAIR PETTI: Yes.
18 MR. TOMKINS: So, one of the key 19 differences between the two units, they are very 20 similar, but as Drew kind of said, Hermes 2 is a two 21 unit facility separate reactor operating unit.
22 Hermes license is licensed for an 11 year 23 time frame.
24 Hermes itself was licensed for this 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 license for four.
1 Hermes 2 generates electric power and 2
provides it to the grid.
3 There is some sharing of systems in Hermes 4
2, certainly the power generation is shared.
5 And then, there's limited sharing of some 6
parts of not safety systems and components.
7 Once example is the main control room, we 8
expect to have a common control room for the two 9
units.
10 Each unit at Hermes 2 has an intermediate 11 loop, intermediate salt loop to exchange heat to the 12 power generation system.
13 There's additional tritium management that 14 is incorporated because of the presence of the end 15 radium loop pan, the power generation system.
16 And there are some additional hazards that 17 we will need to consider in the safety analysis you 18 will hear about when we discuss Chapter 13 in the 19 subsequent meeting.
20 So, these are some chapters that are, you 21 know, virtually, I mean, these are almost word for 22 word identical.
23 Chapter 6, 10, 12, 16, 17, and 18, so 6 is 24 decay heat removal, obviously a very important 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 chapter, but that is identical other than there's one 1
statement in there about no-sharing, just to affirm 2
that there is no sharing of systems.
3 Ten is experimental facilities. We don't 4
have any in Hermes and there won't be any in Hermes 2.
5 Twelve goes over organization, review, and 6
audit procedures,
- reports, records, emergency 7
planning.
8 There is a statement in this chapter 9
that's a two way plan that was written for Hermes will 10 apply to Hermes 2.
11 And there is a statement in 12.1 which is 12 organization saying that there may be some sharing of 13 staffing between the two units.
14 Now, Chapters 16 and 17 are really short 15 chapters and there's effectively no change to those.
16 So, I'm going to go over Chapter 1 and 17 then, I'm going to talk about Chapter 4.
18 So, Chapter 1 is --
19 MEMBER ROBERTS: Yes, this is Tom Roberts.
20 Can I ask a quick question on the slide 21 you just had up?
22 MR. TOMKINS: Sure.
23 MEMBER ROBERTS: Chapter 12, some staffing 24 may be shared for the 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
15 I didn't see any details on the scope of 1
that sharing of staff.
2 But do you intend to have separate senior 3
reactor operators or reactor operators for the two 4
units or do you intend to share, you know, control of 5
both plants from, you know, one operator in a shared 6
control room?
7 MR. TOMKINS: Yes, I don't know if a 8
position to answer that.
9 But I think, clearly, we were talking 10 about things like security staff and possibly 11 radiation protections.
12 I doubt we would have SROs sharing.
13 MR. PEEBLES: This is Drew Peebles.
14 So, Jim's right. If you think of site 15 services like emergency
- planning, things like 16 security, those are obvious areas where we might share 17 across the site, not just between the two units.
18 And the control room operators may be able 19 to work on both units, but not on a shift.
20 So, we will have a dedicated operator for 21 each unit.
22 And I think we clarify that in Chapter 7.
23 MR. TOMKINS: Yes, and the OOA will 24 provide a bit more detail on that when we submit 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
16 Does that answer your question?
1 MEMBER ROBERTS: Okay, thank you.
2 Yes, thank you.
3 MEMBER MARTIN: This is Bob Martin.
4 I had raised my hand here but I'm not sure 5
you saw it.
6 Real quick, you know, of course, looking 7
at your list of changes and as you, of course, noted, 8
not major changes going here.
9 So, I'm a little surprised actually on the 10 previous
- slide, the very last statement, the 11 additional hazards from design deltas that will be 12 considered in safety analysis.
13 Could you briefly just kind of mention 14 where those are? Because I didn't -- wouldn't have 15 expected that.
16 MR.
TOMKINS:
So, you've got an 17 intermediate loop. So, that something to be 18 considered.
19 And then, you've got high pressure power 20 generation equipment that could create hazards.
21 MEMBER MARTIN:
The high pressure 22 equipment, specifically where?
23 MR. TOMKINS: In power generation.
24 MEMBER MARTIN:
Oh, in the power 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 generation side, okay.
1 All right, all right.
2 MR. TOMKINS: That was Jim Tomkins.
3 Okay, so, are we ready to go through 4
Chapter 1?
5 CHAIR PETTI: Sure.
6 MR. TOMKINS: Okay, so Chapter 1 is titled 7
The Facility.
8 Yes, it's Jim Tomkins again.
9 So, Chapter 1 is The Facility. And it has 10 a Section 1.1 of Chapter 1 has an introduction.
11 And the purpose of this facility is to 12 demonstrate key technologies of the design features of 13 the KPFHR.
14 Part of our design, no test strategy to an 15 enter relay on approach the design ultimately for a 16 commercial power reactor.
17 The application meets the requirements of 18 10 CFR 34(e) and it generally follows NUREG-1537 which 19 is the SRP for non-power reactors.
20 This really has no changes from Hermes.
21 1.2 is Summary and Principle of Safety 22 Considerations.
23 The inherent safety features and design 24 bases are covered here.
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 The only change to this section is to add 1
some language that there's intermediate heat transfer 2
systems.
3 1.3 is the Facility. The facility, as 4
we've said, is two 35 megawatt thermal reactors, two 5
IHT's with one turbine producing power.
6 The -- this section also talks about R&D 7
feathers. There is one new R&D item that we have to 8
address which is compatibility between the slide and 9
the salt that's in the intermediate heat transfer 10 system.
11 The salt in that system is B&F we call it.
12 It's beryllium -- it's sodium fluoride and beryllium 13 fluoride, sort of a mixture of the two and pretty 14 similar to Flibe.
15 And then, the facility, on this site, we 16 will have, of course, Hermes 1 in addition to the 17 Hermes 2.
18 There'll be an engineering test unit.
19 Engineering test unit is, again, part of our design 20 and build and test philosophy. And so, that will be 21 on the site.
22 And there's also the potential for future 23 fuel manufacturing facility on that site as well.
24 And then, of course, will be a switch yard 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 for Hermes unit 2.
1 Shared systems is covered in this chapter.
2 As we said before, there's no sharing of 3
any safety related systems or components.
4 There is a list actually in this section 5
of some of the systems and components we envision 6
sharing.
7 We mentioned the control room, normal and 8
backup
- power, service water
- systems, plant 9
communication systems, facility physical security 10 would be some examples.
11 There's a little bit longer list in this 12 section.
13 The next section is Comparison with 14 Similar Facilities, and there's no changes to this 15 section.
16 Summary of Operations, so this the output 17 of the two units is 20 megawatts electric, that's what 18 we estimate at least.
19 It's an 11 year lifetime.
20 The -- this is licensed as a non-power 21 test facility because the cost of running this exceeds 22 by more than a factor of two of revenue we would get.
23 And that's allowed for in the regulations 24 under 10 CFR 50.22.
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 The ones that we just mentioned are the 1
only changes to this section.
2 And the last two sections are really small 3
as well.
4 National Waste Policy Act, which there's 5
no change from our commitment to comply with that.
6 And modification history is -- we don't 7
have any plans so that really apply.
8 So, there's no changes to those sections.
9 So, that concludes Chapter 1.
10 Any questions on Chapter 1?
11 CHAIR PETTI: Just this quick question, 12 and if you'll address later, that's fine.
13 What happens when you mix the two salts?
14 Are you going to talk about that in a subsequent 15 chapter?
16 MR. TOMKINS: Yes, but that will probably 17 be in Chapter 5 probably be the more likely.
18 MR. PEEBLES: We'll briefly --
19 Sorry, this is Drew Peebles again.
20 We'll briefly touch on the fact that we've 21 added LCOs in the expected tech specs for impurities 22 in the intermediate loop.
23 But as far as compatibility of the salt, 24 we'll talk a little bit more about that in the Chapter 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 5 discussion.
1 MR. TOMKINS: The short answer is the 2
physical and chemical properties are very similar --
3 CHAIR PETTI: Right.
4 MR. TOMKINS: -- testing --
5 CHAIR PETTI: And again, for the staff's 6
benefit, when you mix them, there's a different 7
eutectic you get, something called Flibe is how I was 8
told to pronounce it.
9 The fusion program had looked at it 10 actually. So, there's a little bit of work out there.
11 They looked at some properties going back in my 12 memory.
13 And I didn't have access to the paper 14 service that would allow me to download the paper.
15 But there is some information out there 16 that's a good starting point.
17 MR. TOMKINS: Anymore questions on Chapter 18 1?
19 CHAIR PETTI: No, I don't see any.
20 Keep going.
21 MR. TOMKINS: So, Chapter 4.
22 Chapter 4 is, obviously, a very important 23 chapter, but there, again, there are no changes to the 24 systems design and materials that they're going to use 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 in Chapter 4 other than 11 year operating lifetime.
1 So, the sections Chapter 4 covers, 4.2 is 2
fuel, control elements, neutron source.
3 4.4 is biological shield.
4 4.5 is nuclear design.
5 4.6 is T&H design.
6 And 4.7 is reactor vessel support system.
7 The only changes to those sections other 8
than the lifetime, just about to talk to them about 9
our -- to make statements that certain aspects of the 10
-- of section -- or not share, but the system is not 11 shared with the other unit.
12 So, the one change we did make is we added 13 five tables to the -- to Section 4.3 14 4.3 is reactor vessel.
15 So, again, there were no changes to the 16 vessel design and materials other than the --
17 qualifying it for a longer lifetime.
18 We did add five tables, 4.3-3 to 4.3-8 19 that characterize the reactor vessel metal and 20 graphite qualification testing requirements in Hermes 21 2.
22 This section references two topical 23 reports that the committee previously reviewed, high 24 temperature materials and graphite qualification.
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 These topical reports provide a
1 methodology for qualifying these materials and they 2
provided actually a range of testing conditions.
3 They included a five year operating 4
license for a test reactor and a commercial power 5
reactor 20 year.
6 So, the testing requirements that are 7
detailed in these tables for 11 years are somewhere in 8
between the two.
9 And the -- we wanted -- you know, we 10 clarified that in the application. It was actually a 11 question the NRC asked us about.
12 And so, in those tables, it gives 5 year 13 requirements, 11 year requirements, and 20 year 14 requirements.
15 CHAIR PETTI: So, I have a question and 16 this goes back to Hermes as well as Hermes 2.
17 In getting ready for Hermes 2, I kept 18 thinking about redox and I ran into some papers from 19 Oak Ridge reports by people who worked on the MSRE 20 that basically argued that using beryllium as the 21 redox agent will result into reducing a system and 22 that you'll form carbides and degrade graphitic 23 components, particularly, I would imagine, the pebbles 24 because of their higher surface area, probably 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
24 last the graphite reflector.
1 And I guess I had never recalled us 2
talking about that during Hermes.
3 And just wondered, A, what, you know, what 4
your position was.
5 And B, whether the -- I mean, all the 6
testing that's going to be done could evaluate that?
7 Because the thermodynamics I think are 8
pretty clear that you either get a fluoride or carbide 9
in the system.
10 I mean, that it's a noble element, so it 11 makes sense to me, chemically, what they're saying.
12 And you know, they made very strong 13 statements, they said that basically it won't work in 14 FHRs. And so, it was, you know, of course, it raised 15 my eyebrow when I read it.
16 MR. HAUGH: This is Brandon Haugh, Senior 17 Director of Modeling Simulation.
18 As you went the updated process, it's for 19 this we didn't focus on carbonization, the potential 20 for that and our internal vesting program is looking 21 at that.
22 In terms of
- balance, what we're 23 discovering in testing, even though it's in the early 24 phases, it's a balance of how you're doing the 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 reduction, like how much beryllium you're adding, what 1
you're adding.
2 And so, we're exploring that.
3 Right
- now, we've not observed any 4
significant carbonization in our test apparatus in our 5
in situ mechanical testing which includes both the 6
candidate materials, the constructed loop, and the 7
appropriate ratio of graphite in there.
8 So, right now, that is within the scope of 9
the PERT, but it was a later discussion as we became 10 more of, I'll say, informed and educated like you did.
11 CHAIR PETTI: Okay.
12 So, you're hopeful that the testing will 13 inform, let's call it redox strategies, I guess, is a 14 way to say?
15 MR. HAUGH: Exactly, yes, but it's also 16 part of our ETU test campaigns at full scale as we're 17 looking at that and optimizing the chemistry.
18 CHAIR PETTI: Because, I mean, you're 19 fighting thermodynamics and that's always challenging, 20 right?
21 MR. HAUGH: Yes.
22 CHAIR PETTI: And kinetics, yes. We don't 23 know what the kinetics will be in the system and 24 that's why you've got to test these things.
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 MR. HAUGH: Exactly.
1 CHAIR PETTI: Yes, and I just -- I mean, 2
I just wonder about whether or not have you guys got 3
to the point of the tech specs that you're envisioning 4
going to be adequate or do you think you might need 5
some additional tech specs or tweaking of, you know, 6
proposed values, you know, based on this?
7 That was -- the only -- you know, I'm not 8
saying you shouldn't build the thing, I'm just saying 9
here's something that, really, the true answer you may 10 never really know until you build it and test it.
11 So then, the question is, how are we going 12 to know, right?
13 MR. HAUGH: Yes, and so, yes, we haven't 14 devised the exact numerical values, but that's part of 15 the development program is to try to understand what 16 we actually need to track and what coupons and 17 materials we'll be examining during the piping system, 18 what type of inspections we do.
19 CHAIR PETTI: Right.
20 MR. TOMKINS: As Brandon said, he's 21 engineering testing and it's good information and some 22 variance.
23 MR. HAUGH: Yes, they give us some help on 24 how we're going to manage the process and it won't 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 have the big lifetime, so it'll be something we'll be 1
surveilling.
2 CHAIR PETTI: I see George's hand up.
3 DR. YOUNG: Yes, let must add to Brandon's 4
comments, which I think were spot on.
5 We're fully aware of the risk of over 6
reducing the salt.
7 And we've done a lot of testing and plan 8
to do more on demonstrating reasonable potential 9
control without these concerns with over reduction.
10 CHAIR PETTI: Okay, thanks.
11 No, yes, no that helps, at least at this 12 point, you know, we're certainly in hearing about the 13 results.
14 MR. TOMKINS: Any more questions on 15 Chapter 4?
16 MEMBER KIRCHNER: Yes, Dave, this is Walt.
17 Either Drew or Jim, just for the public 18 record, you know, and it may be for economic reasons, 19 which is very valid, but just for the record, explain 20 why it's an 11 year life that you're seeking.
21 On one hand, we know the first unit -- not 22 the first unit, sorry, Hermes was an experimental 23 facility. You wanted a four year lifetime out of it.
24 And then, looking ahead to a commercial 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 reactor, you're looking at a 20 year lifetime.
1 So, just for the record, could you explain 2
the 11 year -- the reason for an 11 year lifetime?
3 And as I said, it could be for economic 4
reasons.
5 MR. PEEBLES: Yes, well, this is Drew 6
Peebles, again.
7 It -- even though this is a non-power 8
reactor, there will be agreements set out for the 9
power.
10 So, you're right, this does get into 11 economics and it is a little business sensitive at 12 this time to talk about the specific reason for a ten 13 year
- life, plus an allowance for start up, 14 commissioning, all of that we've added to the margin 15 for that.
16 So, that's why it's not a round number.
17 MEMBER KIRCHNER: Okay, that's fair 18 enough.
19 I just want you to say on -- for the 20 record, it's not because there's some clip out there 21 if you went beyond 11 years that you're expecting in 22 the performance of the system.
23 MR. PEEBLES: No, nothing like that.
24 And as we talked about, the materials 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 qualification, we have methods and plans that go all 1
the way up to the power reactor at 20 years.
2 MEMBER KIRCHNER: Thank you.
3 MR. PEEBLES: Other questions?
4 CHAIR PETTI: I don't see anymore.
5 Keep going.
6 MR. PEEBLES: All right, so this is Drew 7
Peebles, again.
8 So, next up is PSAR Chapter 7,
9 Instrumentation and Controls.
10 The majority of the deltas in Chapter 7 11 are associated with the non-safety related portions of 12 the I&C.
13 The safety related portions of the Hermes 14 2 I&C systems are not shared between the units.
15 So, the design is mostly identical to that 16 occurrence.
17 One minor difference is the trip on the 18 intermediate salt pump to limit potential over 19 cooling.
20 However, the rest of the RPS trips are the 21 same as those for Hermes 1.
22 Since there's no sharing, there's no 23 safety related trip in one unit that would cause a 24 trip in the other.
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 The majority of the changes in this 1
chapter are related to the non-safety related portions 2
of the I&C. These changes are associated with the two 3
unit configuration as well as the additional controls 4
needed for the ISTS and PGS as the intermediate loop 5
and the power generation system.
6 The non-safety plant control system has 7
two subsystems in addition to the subsystems described 8
in the Hermes PSAR.
9 One, the intermediate heat transport 10 control system, which is unit specific, that controls 11 and monitors the transport of intermediate coolant 12 through the intermediate loop.
13 And second, the power generation control 14 system which is shared between the units. That 15 controls and monitors systems and components that 16 support the operation of the turbine generator system.
17 The shared main control room for Hermes 2 18 is configured for two unit operation with dedicated 19 controls for each unit.
20 The detail of control room configuration 21 will be available at the operating license application 22 phase.
23 Are there any questions on Chapter 7?
24 MEMBER ROBERTS: Hey, Drew, this is Tom 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 Roberts.
1 On Chapter 7 and 8, so I've questions, but 2
I'd like to have you present Chapter 8 and then, go 3
back and maybe provide a clear basis for some of the 4
questions.
5 MR. PEEBLES: Okay, sounds good.
6 So, like Hermes, the safety case for 7
Hermes 2 is passive in that it does not rely on backup 8
power for any safety functions.
9 So, the only differences in the electrical 10 power system description are associated with the two 11 unit configuration and the power generation 12 capabilities of Hermes 2.
13 Portions of the A/C power and backup power 14 generators are shared between units, but again, do not 15 perform any safety functions.
16 The power generated by the turbine system 17 is provided to an on site switch yard and distributed 18 off site to the electrical grid.
19 And the switch yard is designed to protect 20 against external electrical hazards. And that's 21 pretty generic, straightforward switch yard design.
22 We're not doing anything new or novel there.
23 So, that's it on Chapter 8.
24 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
32 MEMBER ROBERTS: Okay, Drew, it's Tom 1
Roberts.
2 Starting with
- this, the chapter 3
discussions using the plant TG to power the plants 4
rely on auxiliary loads, and that doesn't show up on 5
this slide and kind of my main question is trying to 6
understand what that does in terms of transient 7
accident scenarios where common events may cause 8
complete loss of A/C at above plant because of an 9
upset in the generator.
10 I guess, the first question is, this is 11 not on the slide, it's at a capability to be dropped 12 or just not on the slide.
13 MR. PEEBLES: So, now, can you repeat the 14 first part of the question?
15 MEMBER ROBERTS: Yes, it deals with using 16 the plant TG to power the plant's auxiliary loads, but 17 that's described as capability in Chapter 8 of the 18 PSAR, but not on this slide.
19 And so, a lot of my questions deal with 20 the consequence of TG set issues and electrical issues 21 that could cascade to both plants because of the 22 common feed from the plant TG to the plants.
23 But, as I said, that capability doesn't 24 show up on this slide, so I'm trying to understand 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 why.
1 MR. CILLIERS: This is Anthonie, so, 2
you're speaking of the director of station controls 3
and electrical.
4 And so, I think you're referring to the 5
house line supply that's coming from the street shorts 6
that is interrupted?
7 MEMBER ROBERTS: Yes, but I read the very 8
beginning of Chapter 8, if I could read part of this.
9 During normal operation, off site A/C 10 electrical power provided either from the off site 11 local utility thermal A/C or by on site A/C power 12 generated from the operating turbine generator, A/C 13 power shared between unit 1 and unit 2.
14 MR. CILLIERS: Yes, so, it functions in 15 the same way as what we have in Hermes where we supply 16 the site electrical requirements normally from the 17 utility itself.
18 In the event of that loss of power, we 19 revert back to our backup power supplies.
20 I want to stress here that this PSAR is 21 not safety related supply, so it's merely by investing 22 protection and operational stability really for 23 ourselves.
24 In the event of the backup supply not 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 turning on, that will result in loss of power so that 1
we do allow for the period of time using uninterrupted 2
power supplies and on our reactor protection system 3
and critical loads and that will allow for that switch 4
up to happen.
5 And that switch up doesn't happen on the 6
backup supplies to come on as when a trip will occur.
7 So, yes, it's immaterial if that trip is 8
on one reactor or both, although we do have switching 9
between the systems, I'm not sure if it's buried here 10 in the drawing because we've shown the dedication of 11 both systems and with the switching between them.
12 But we can actually have switching off the 13 backup supply to either one or both of the reactors 14 and make that selection as is required.
15 MEMBER ROBERTS: Yes, the figure at the 16 beginning of this chapter is a little bit confusing 17 because it shows two ways to get external power into 18 the plant's distribution systems.
19 One is the plant TG which could be in 20 parallel with a switch yard.
21 And the other source is the existing 22 source from the Hermes design which brings in an 23 external, I think it's 4.16 TV.
24 MR. CILLIERS: Yes.
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 MEMBER ROBERTS: So, when you're using the 1
plant TG to provide electrical, does that really mean 2
you're using it in parallel with the other switch yard 3
feed?
4 MR. CILLIERS: So, the idea that once we 5
feed from the switch yard, that will just be placed in 6
the feed supply, but we do have the flexibility in the 7
same way to use backup supply as utility supply as 8
well.
9 So, we essentially, once we start it after 10 a black start which will use the utility supply and we 11 expect repeats on switch out supply, the utility 12 supply as well as the backup supply. And we do switch 13 between them.
14 And this is happening in parallel with the 15 sector.
16 MR. BROWN: Tom, can I ask a question?
17 MEMBER ROBERTS: Sure, go ahead, Charlie.
18 MR. BROWN: I didn't want to interrupt you 19 if you hadn't finished.
20 Based on the discussion that they've just 21 been going through, I'm still not clear.
22 Is the intent in general, I understand the 23 backup supplies, you've got the grid feeding the main 24 bus, and you've got the TG feeds the main bus.
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 Is the intent to operate the TG in 1
parallel simultaneously with the feed from the grid as 2
well or is it TG only or grid?
3 MR. CILLIERS: I don't know if I have a 4
good answer for you right now.
5 MR.
BROWN:
- Okay, that's a
very 6
significant piece --
7 (Simultaneous speaking.)
8 MR. CILLIERS: -- if it will be parallel 9
or not.
10 MR. BROWN: Okay.
11 Well, the point being is that's a very 12 small TG set relative to the overall grid demands.
13 And monitoring where load is going from 14 that share is just difficult.
15 So, you're going to address that later if 16 you can't address that now, is what you're saying, 17 correct?
18 MR. CILLIERS: Yes, that's right, yes.
19 MR. BROWN: Okay.
20 Now, second question then, the backup 21 supplies, assuming, I'm just going to hypothetical 22 this, that the TG set is supplying power to both 23 plants, the grid, let's assume it's not connected, and 24 there's a problem with being able to connect to the 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 grid in the first place.
1 Now, you lose the TG set, you've lost all 2
your power and you're now down to the UPSs scattered 3
throughout the plant.
4 But you said the backup power would come 5
on.
6 Is there a timing requirement? Are we 7
talking it takes half an hour to go out and energize 8
9 MR. CILLIERS: No.
10 MR. BROWN: -- the backup power? You have 11 no indications or is it a ten second transfer or what?
12 It's not covered.
13 MR. CILLIERS: Right.
14 So, I wouldn't go on a hard limit for 15 that, but we've worked on a 20 second requirement for 16 the automatic transfer switch to take place and the 17 generator to come on.
18 So, yes, it's not a two hour, one, it's --
19 we work on 20 seconds.
20 MR. BROWN: Okay.
21 So, the motive -- whatever the supplies --
22 the fuel supplies, gas turbine generator, diesel 23 generator, whatever it is, you're planning on 24 something like a 20 second response to be up 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
38 supplying regulated power to that bus then?
1 MR. CILLIERS: That is correct.
2 And the UPSs will maintain the critical 3
loads like the reactor protection system, the plant 4
control system, control room, all of that will run on 5
UPSs until that power is back on.
6 If that transfer does not happen 7
successfully, that's when the reactor protection 8
system will issue a trip and we will go into a passive 9
safety. I think it would require electrical power for 10 that shutdown.
11 MR. PEEBLES: And that's an important 12 point.
13 This is Drew Peebles, again.
14 I want to echo that, that we're not 15 crediting anything that Anthonie was just going over 16 to perform any safety function.
17 So, that's all --
18 MR. BROWN: Well, I --
19 I'm sorry, go ahead.
20 MR. PEEBLES: Okay.
21 MEMBER ROBERTS: If you want me to jump 22 back in Charlie, the concern that I have is that if 23 you have a common tie between the two units such that 24 a plant TG transient would cause simultaneous loss of 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 both, now that's going to be an additional stressor on 1
the control room crew.
2 There's two plants now that they're 3
fighting simultaneous events with.
4 And just want to make sure that has been 5
considered.
6 And it really starts with what is the 7
implication of loss of the plant TG to powering both 8
plants.
9 Because, again, from the slide and from 10 the information in the PSAR, it's hard to tell what 11 the intent is in terms of powering the plant just from 12 the plant TG or, as Charlie pointed out, powering the 13 plant from external power with what is a relatively 14 small, you know, TG paralleled with it, which from a 15 grid perspective, they won't even know the difference 16 if you lost it.
17 And so, the power would just continue 18 seamlessly to the reactor sets.
19 Really, it's just a matter of what the 20 intent is to run the plant TG or use the plant TG to 21 power the electrical loads for the plant and whether 22 that creates new transient scenarios will need to be 23 included in Chapter 13.
24 MR. PEEBLES: So, again, even if both 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 reactors trip, our safety case doesn't rely on any 1
operator actions.
2 So, there may be some excitement in the 3
control room, but we're not crediting anything that 4
goes on in the control room for mitigating any kind of 5
effects of any positive event.
6 MR. BROWN: I understand.
7 This is Charlie, again.
8 Tom, did I interrupt you? Did you have 9
something else to say? I'll wait.
10 MEMBER ROBERTS: No, go ahead.
11 MR. BROWN: I understand -- we understand 12 fully that the fact that if the safety system -- it 13 doesn't require -- the plant's so safe, it doesn't 14 require electric power.
15 However, it's not a good idea to be 16 sitting up in the plant control -- main control room 17 and having no idea what the plant parameters are.
18 You don't know what temperatures are. You 19 don't know what flows are. You don't know what 20 pressures are. You don't know anything if the lights 21 go out.
22 And in the previous Hermes diagram that 23 you had, you had UPSs supplying all the stuff that ran 24 up there and they were designated as 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> UPSs.
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 That 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> requirement has been deleted 1
from the figure in the Hermes 2 design PSAR.
2 MR. CILLIERS: I'll agree with that, 3
because nothing has changed there. So, I'll have a 4
look -- I'll look at that again. That specification 5
has not changed, we merely moved the timing 6
requirement of that trip from a small UPS into 7
dominant RPA system.
8 But the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> UPS system remains and, of 9
course, you're right, it's a good idea for us to have 10 this ability in the plant even after an event like 11 that.
12 I want to stress that, if you look at the 13 whole schematic of that, at this point, we are not 14 making our decisions on how we would like to operate 15 the system itself. We are merely providing the 16 functionalities that we have the flexibility to 17 operate it when that decision comes.
18 MR. BROWN: Well, my concern when I 19 reviewed the deltas between the Hermes and Hermes 2 20 was that the electric plant wiring diagram, you know, 21 schematic, very clearly deleted the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> 22 requirement -- specification from every one of the 72 23 hour2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br /> UPSs that were shown in the Hermes 1 a year and 24 a half ago review.
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 So, that just triggered the thought 1
process about no indications of anything and what was 2
the intention or are we just going to rely on backup 3
power generators to come on in time?
4 So, you're saying that the UPSs are all 5
there, they were there but they just didn't have a 6
time of operation that they would be able to be relied 7
on.
8 Seventy-two hours is a good time. If you 9
can't recover other power systems within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, 10 you've got a lot of other difficulties indication wise 11 or monitoring wise.
12 MR. CILLIERS: Yes, our philosophy has not 13 changed at all. We want to have visibility in the 14 plant for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, even at loss of power.
15 So, we'll have a look at that.
16 MR. BROWN: Okay.
17 Just nice to have it reflected in the 18 PSAR, that's all.
19 MR. PEEBLES: Well, I think we took that 20 out of the Hermes -- the first Hermes application as 21 well. But it was more about the fact that we weren't 22 crediting it.
23 MR. BROWN: Yes, but not -- I don't have 24 any problem with not crediting it, we fully understand 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 that safety posture of the plant.
1 It's just you still want to be able to 2
monitor parameters, even if the plant is known to be 3
safe. It's just not a good situation.
4 I'm done with that, unless Tom wants to 5
amplify my comments.
6 MEMBER ROBERTS: Yes, just following the 7
thread some more on the loss of TG, going back to 8
Chapter 7, there's discussion in Chapter 7 in the 9
control system of run back of various system pumps on 10 a loss of a TG set to bring the power down gracefully 11 to accommodate the loss of, you know, heat load from 12 the turbine.
13 And it seems like you would need 14 electrical power, you know, to -- for those run back 15 functions to work because, even if the control systems 16 have UPSs, the pumps themselves presumably require the 17 actual bus.
18 So, I, again, I didn't really understand 19 but the assumption seemed to be that the loss of the 20 TG would not cause loss of electrical power to the 21 plants.
22 And if that's a requirement, then using 23 the plant TG to provide electrical power to the plants 24 seems like a problem.
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 Do you understand what I'm asking?
1 MR. CILLIERS: I think I do.
2 You're saying if we lost electrical power 3
to one unit only, then there could be a -- you're 4
expecting that they could be an additional transient 5
that the other plant sees?
6 MEMBER ROBERTS: No, actually, not quite, 7
even simpler than that is if the plant TG is providing 8
electrical power to both reactors, then the run back 9
function wouldn't work in either, right?
10 MR. CILLIERS: Right.
11 MEMBER ROBERTS: So, you need electrical 12 power from some other source during that time period 13 between the loss of the TG and whatever, you know, 14 assumptions are in the plant analysis to get to the 15 power down.
16 MR. CILLIERS: I think what -- I want to 17 be clear on the scenarios that we are looking at.
18 If we are -- if we lose power from any of 19 the supplies, we move over to a backup supply.
20 That would result in a loss of power to 21 both units and the backup supply will then supply 22 those.
23 So, the scenario described in Chapter 7 24 where we have a graceful shutdown of one unit and the 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 loss of the other is not applicable in the loss of a 1
power event, that would be on any other scenario 2
actually causing a tripping in that.
3 Electrical -- loss of electrical power 4
would affect both and that is what we have the backup 5
supply for.
6 Again, that would trip the units, not as 7
a graceful shutdown, but as a full on tripping. We 8
are not able to get the backup power on.
9 So, a loss of -- a trip of one unit that 10 results -- that is the cause of anything other than 11 electrical loss is where that graceful shutdown really 12 comes in. Electrical losses is affecting the whole 13 system.
14 MEMBER ROBERTS: Sure, that section in 15 Chapter 7 talked about two scenarios.
16 One of them is the point you just 17 described which is loss of one reactor.
18 The other, the scenario is loss of the TG.
19 And loss of the TG, both reactors would have the run 20 back functions to control power gracefully, which, 21 again, would seem to require electrical power that's 22 coming from the TG. That's what started the whole 23 transient. And so, you wouldn't have it --
24 MR. CILLIERS: Yes.
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
46 MEMBER ROBERTS: No, it just seems like 1
the concept of operations with the plant TG providing 2
power to the plants, it may need more development.
3 It may be, again, going back to the slide 4
that we're looking at, that that wasn't really your 5
intent. It just happens to be that the TG's in 6
parallel with the external power source that's 7
powering the plants, in which case, loss of the TG 8
wouldn't do much of anything.
9 So, I just wanted to understand what the 10 intent was and if the intent was truly to run the two 11 units on just the plant TG, I'm assuming there's a 12 whole bunch of scenarios that would need to be 13 accounted for.
14 MR. CILLIERS: Well, I hear what you're 15 saying with adding the backup supply coming on in 20 16 seconds, I'm not sure if that -- it is very much 17 different from losing power from the utility.
18 But we'll look at it again.
19 MEMBER ROBERTS: Okay, thank you.
20 I do have a couple other questions that 21 you've heard from Charlie Brown. He reviewed this 22 from the perspective of having reviewed the Hermes 1 23 or Hermes to make sure that we were doing a proper 24 delta review.
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
47 And in that review, he noted that -- he 1
asked first if you had a comment back on Hermes about 2
the ethernet feed that goes from the main control 3
panel to external sources.
4 And the suggestion from the latter was to 5
look at the access controls and that will -- to ensure 6
the external feed isn't allowed to affect plant 7
operations.
8 And Charlie, I don't know if you want to 9
elaborate anymore on that comment.
10 But we're wondering if you had any 11 response to that comment yet or is that still being 12 referred to DOL?
13 MR. CILLIERS: Yes, our philosophy hasn't 14 changed from our response, so I don't think there's 15 any blue text there at all, but we're still looking at 16 how that will be done.
17 Yes, right, I can't comment.
18 MEMBER KIRCHNER: So, this Walt Kirchner.
19 May I just ask a question?
20 If you have this scenario that Tom was 21 just outlining and, as I -- I'm not sure who made the 22 comment earlier, one of the things you want to protect 23 against is an over cooling transient.
24 If you had a 20 second loss of power 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
48 then, you're backup power came on, would the pumps 1
come on at full speed in that intermediate loop?
2 MR. CILLIERS: Yes, I think it's more of 3
a design question than an I&C question.
4 MEMBER KIRCHNER: Well, it's both, I mean, 5
I don't -- I haven't studied the wiring diagram 6
carefully enough to know how the -- when you shed --
7 when you lose electric and then you restore it, does 8
it want to -- does the system want to go back to 9
normal operating condition if it does.
10 So, is there an FFAST function equivalent 11 on that intermediate loop pump to prevent an over 12 cooling transient?
13 MR. CILLIERS: At this point, I would say 14 this is going to be specified in the OLA.
15 I know that we have actually tested some 16 of these at this point, they have options of return to 17 power to return either to an off state or on state or 18 the same state in what it was before it lost the 19 power.
20 So, we do have options that are on deck, 21 but that exact way of how we would operate that will 22 be specified in the OLA.
23 MEMBER KIRCHNER: Okay, all right, thank 24 you.
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
49 MEMBER ROBERTS: Yes, Walt, this is Tom.
1 I would think, and I guess I'd like to 2
hear from Kairos, if the control system never lost 3
power because of the UPSs, and so, the controller 4
should have been trying to run back the pumps in that 5
case based on the algorithms that it's running for the 6
loss of a load.
7 And they're not being able to achieve the 8
control that they want because of the loss of power to 9
the pumps themselves.
10 I would think they would be prepared to 11 bring them back to where they should be when power 12 comes back.
13 But that's a good question that the, you 14 know, it certainly is worth looking at in the OL.
15 MEMBER KIRCHNER: Yes, it's just, you 16 know, you don't want this, as you were -- I think I 17 was just following your line of thinking that you 18 don't want a momentary interruption of power to all of 19 a sudden insert a big transient on the reactor system.
20 So, that was my intent of my question.
21 MEMBER ROBERTS: Right.
22 Charlie, did you have any more on the 23 ethernet question?
24 MR. BROWN: Yes, I just -- I guess the 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
50 answer we got back was the ethernet -- you're talking 1
about the ethernet connection?
2 MEMBER ROBERTS: Yes, the ethernet 3
connection from the control room.
4 MR. BROWN: Yes, that's fundamentally been 5
maintained the same, if I go back and look at the 6
pictures for both of them.
7 And it -- one of the comments that was 8
made during our a year and a half ago in April for 9
Hermes, Hermes, somebody made the comment that that 10 line was intended as a unidirectional line out to so 11 that people could get data outside the plant.
12 And I know both Jose -- I think if he's on 13 the line, he may remember this also -- we both made 14 the comment or the observation, I should say, that, if 15 that's the intent, then it ought to be shown as a data 16 diode as opposed to just a straight ethernet 17 connection that it's literally a super highway to the 18 world because, obviously, you cannot embed active --
19 very active software -- cyber software into all those 20 control systems.
21 I mean, you can do stuff on boot up and 22 shutdown, but you don't want to slow the systems down 23 because you're off doing scans all the time.
24 So, that's still very much my concern 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
51 we don't have any external connections that are 1
bidirectional, you only have no problem with sending 2
data out, that means a data diode would work just 3
fine.
4 But that's not -- it's not illustrated 5
that way on the diagrams, either one, either Hermes or 6
Hermes 2. It's just -- it's not --
7 It'd be nice to not have this get lost by 8
the time we get to the operating license, that's all, 9
since this is the documentation.
10 So, that --
11 MR. CILLIERS: Yes, understood.
12 We are actively working on -- and we've 13 actually demonstrated a
couple of methods of 14 functioning in the data diode functionality.
15 And we don't want to commit to anything 16 right now before we really have to submit other 17 studies.
18 MR. BROWN: Well, if we -- we're just 19 letting you know we will be looking at that or at 20 least hopefully we will.
21 MR. CILLIERS: Sure, sure.
22 MR. BROWN: I'm just a consultant now, so 23 hopefully we will be looking at that again when you 24 come in for an OL.
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
52 That's all I had, Tom.
1 MEMBER ROBERTS: Yes, and we -- one more 2
question on that Chapter 7 which is the architecture 3
for the two plants control panels.
4 There's a control panel for each plant and 5
a control panel for the supervisor.
6 So, the question is, what is expected on 7
the control panel? Do you expect the second operator 8
to use the supervisor's control panel? Do you have 9
other means to route the controls and indications to 10 some other place so you don't have use the primary 11 control panel?
12 Just wondering what your overall plan was 13 for loss of one plant's control panel?
14 MR. CILLIERS: For loss of one plant's 15 control panel?
16 MEMBER ROBERTS: They're called operator 17 workstation in the diagram.
18 MR. CILLIERS: I'm just thinking through 19 the question.
20 Okay, so, I'll briefly just to provide our 21 philosophy.
22 We have one supervisor control panel that 23 has got access to both the units itself so it can 24 bring up the screen of both units.
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
53 It could also bring up the screen of the 1
power generation unit.
2 Then, we have individual reactor operator 3
unit panels for each reactor so, we've got one 4
operator, one reactor, another operator for the other 5
reactor. And they have the ability to either --
6 either one of them can also have access to the power 7
generation unit.
8 And that's the philosophy there.
9 On the loss of -- and that's the real 10 purpose of the supervisor, on the loss of one of those 11 panels, the supervisor's screen can bring, as it's got 12 access to both, can take over controls for the unit 13 control panel that's been lost.
14 And we also have, as you can see, I think 15 three large screen where we have all indications of 16 opening as well as the power generation unit so that 17 all operators as well as the supervisor have visuals 18 of everything that is happening on the screens.
19 So, we deem that being sufficient and 20 sufficiently reflects the options when you have more.
21 MR. BROWN: Can I draw a conclusion from 22 that?
23 It's like operator workstation one, say 24 that's plant one, operator workstation two is plant 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
54 two and the supervisor is independent and he's 1
observing, can do what he wants.
2 The flat panels are just data, you can't 3
operate from them?
4 MR. CILLIERS: No.
5 MR. BROWN: So, if you lost operator 6
workstation one, you're saying what Tom said to me and 7
you agreed with is that the supervisor workstation has 8
the -- you immediately have the ability to take over 9
and understand and operate the, say, plant one if 10 you've lost the plant one workstation.
11 So, you've got a backup and it's just the 12 supervisor workstation would just be doing dual duty 13 at that point?
14 MR. CILLIERS: That is correct.
15 And I want to be clear, I'm not specifying 16 that the actual procedure what will happen to the 17 operator at this time, I'm just specifying the 18 flexibility that we have for that.
19 MR. BROWN: Okay, I got that, thank you.
20 Did that get you, Tom?
21 MEMBER ROBERTS: Yes, thank you.
22 Yes, that's all the questions that I have 23 for Chapter 7 and 8.
24 MR. PEEBLES: Okay.
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
55 So, next up is Chapter 11.
1 Chapter 11 of the PSAR covers radiation 2
protection and waste management.
3 The description of the RAD protection 4
program and waste management is mostly identical to 5
that of Hermes.
6 The difference in content is mostly for 7
normal effluent accounting.
8 For Hermes, the normal F1 analysis was not 9
representative of the expected actual F1 memorandum of 10 a bounding one.
11 For Hermes 2, that same bounding dose from 12 Hermes was doubled to conservatively account for both 13 units of Hermes 2 and considering new potential 14 gaseous effluent release points from the power 15 generation system.
16 The doses from Hermes 2 are some with the 17 doses from Hermes and reported as a site total, 18 effectively tripling the bounding dose from Hermes.
19 These estimates do not account for the 20 additional tritium capture capability that we have in 21 the intermediate loop which we will describe at the 22 next subcommittee meeting.
23 But it does demonstrate that the doses 24 from all site effluents are below Part 20 limits 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
56 individual members of the public.
1 CHAIR PETTI: So, this is Dave.
2 I have a question on this.
3 As I understand the system, the tritium 4
will permeate through the intermediate heat exchanger.
5 In Hermes, it went through the air and up 6
your HVAC when elevated release of HT.
7 Here, it will permeate into the secondary 8
coolant and, I would say the majority of it will 9
probably permeate through the steam generator into the 10 power conversion system.
11 And that would be released, you know, sort 12 of ground level and it probably is HTO once the 13 tritium hits the water.
14 So, did you do a calculation of dose 15 ground level HTO? Because that's a very different 16 dose number than 100 meter stack HT.
17 MR. PEEBLES: Matt Denman?
18 MR. DENMAN: Hi, this is Matt.
19 CHAIR PETTI: Again, you may still be 20 within Part 20, I don't know.
21 MR. DENMAN: Dave, this is Matt Denman 22 from Kairos Power.
23 CHAIR PETTI: Yes, hey, Matt.
24 MR. DENMAN: So, all of our dose 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
57 calculations, even though the tritium is assumed to 1
permeate through the
- steel, it's assumed to 2
instantaneously oxidize on the other side of that and 3
come up.
4 So, we are using the HTO dose conversion 5
factors for our off site effluent calculations, not 6
the HT dose conversation factors.
7 So, that's one part of your question.
8 CHAIR PETTI: Okay.
9 MR. DENMAN: Can you repeat the --
10 CHAIR PETTI: Good.
11 That one is just -- it's a ground level 12 release that's coming out of the conversion system.
13 At the start we have people usually 14 account for -- this is -- I guess in Hermes, it went 15 up through the HVAC system and it's elevated release.
16 MR. DENMAN: So, as part of -- in the CP, 17 we state that the power generation system flash vessel 18 and evaporator are considered radionuclide pathways 19 which would each vent heat at greater than.4 20 megawatts thermal which is the upper limit of heat 21 generation for TD emission rates that the XOQDOQ code 22 can analyze anything with a heat generation rate 23 greater than that is going to come off with a plume 24 that has similar thermal rise characteristics.
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
58 And we also say that the stacks are going 1
to be 100 foot release heights for that release 2
pathway. Thus, even though, you know, you might 3
traditionally have releases for a power conversion 4
system closer to ground level in a traditional system, 5
per the CT, the release characteristics are going to 6
be similar for releases from that power conversion 7
system than for the main stacks.
8 CHAIR PETTI: So, somehow it -- the 9
leakage path from the power conversion system goes up 10 a stack?
11 MR. DENMAN: Correct.
12 CHAIR PETTI: Okay.
13 DR. SCHULTZ: Matt, this is Steve Schultz.
14 Do you have any -- given these two 15 potential release points, do you have additional 16 monitoring systems that you're going to put in place 17 for Hermes 2?
18 MR. DENMAN: I'm going to pass it back to 19 Drew to talk about monitoring.
20 MR. PEEBLES: Yes, will monitor each 21 effluent path. So, each stack where we would 22 potentially emit radioactive material, we will be 23 monitoring it in compliance with Part 20 limits.
24 DR. SCHULTZ: Thank you.
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
59 CHAIR PETTI: So, let's keep going, I 1
guess, so we can try to stay on time.
2 MR. PEEBLES: All right. So, this is the 3
last
- chapter, Chapter 14 which is technical 4
specifications, or tech specs.
5 Consistent with the Hermes PSAR and the 6
guidance and NUREG-1537, the PSAR only identifies 7
suspected variables to be control.
8 The final tech specs will be provided with 9
the application for an operating license.
10 Most of the limiting conditions for 11 operation or LCOs that are expected for Hermes 2 are 12 already captured by the LCOs that were described in 13 the Hermes PSAR.
14 However, the addition of the IHTS and PGS 15 or intermediate loop and power generation system added 16 a few more parameters of interest.
17 The LCO for limiting material at risk for 18 release was expanded to include material in the IHTS 19 and the PGS to ensure postulated releases from those 20 systems remain found in the safety analysis.
21 And then, additional LCOs were included t 22 cover the operability of the safety related rupture 23 discs on the IHTS.
24 Limitations on the amount of Flibe and the 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
60 intermediate coolant and limitations on the amount of 1
water in the intermediate coolant.
2 Any questions on Chapter 14?
3 Okay. That completes our presentation for 4
today's subcommittee meeting. We're happy to take any 5
remaining questions.
6 CHAIR PETTI: Any other questions, 7
Members?
8 Okay. We are scheduled for lunch, one 9
hour lunch break.
10 And then, I don't think there'll be a need 11 for the closed session that's on the agenda at 1:10, 12 so we'll move directly into the staff's presentations 13 at 1:10, just for any of the public listening in, 14 there will not be a closed session.
15 So, we'll just come back here in one hour, 16 1:10. Thank you all.
17 (Whereupon, the above-entitled matter went 18 off the record at 12:08 p.m. and resumed at 1:10 p.m.)
19 CHAIR PETTI: Great, we're going to turn 20 to the staff now. Michael?
21 MR. ORENAK: Good afternoon, everyone.
22 My name is Mike Orenak, I'm the lead 23 project manager in the division of Advance Reactors 24 and Non-Power Production New Utilization Facilities in 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
61 the Office of Nuclear Reactor Regulation.
1 We're here today to discuss NRC staff's 2
review of the Hermes 2 preliminary safety analysis 3
report.
4 Up here with me are Pravin Sawant who's 5
the lead technical reviewer.
6 Alexander Chereskin is a
materials 7
engineer.
8 And then, later on in the presentation, 9
we'll have Calvin Cheung and Joe Ashcraft who are 10 electronics engineers to talk about Chapter 7.
11 Feel free to stop me with any questions 12 during the presentation. I'll try my best to answer 13 of Pravin or anyone of the staff that are here.
14 The agenda for today for our presentation, 15 first I'm going to provide a little bit of a 16 background and an overview of the Hermes 2 PSAR.
17 Then, I'm going to into the staff's review 18 strategy since this a little bit of a unique review 19 since Hermes 1 was recently done and is relatively the 20 same.
21 And then, I'm going to review the notable 22 changes for each of the chapters listed here.
23 Please note at the bottom, again, it was 24 also discussed earlier when -- during Kairos's 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
62 presentation that Chapters 2, 3, 5, 9, and 13 will be 1
discussed at future subcommittee meetings.
2 Two, 3, and 9 will be discussed on June 3
4th and 5 and 13 will be discussed on June 12th.
4 Kairos submitted their Hermes 2
5 construction permit application on July 14th and the 6
staff accepted it for review on December 11th of last 7
year.
8 For purpose of Hermes 2 is the same as 9
Hermes 1 which is demonstrate the technology for their 10 full scope scale power reactor, the KP-FHR.
11 The Hermes 2 facility will be located 12 about 200 feet from the Hermes 1 facility. So, of 13 course, quite close on the site, at least from the 14 diagram they provided in Chapter 2.
15 Like Hermes 1, it will be a Class 104 16 license.
17 And the CP does not approve any design 18 features and Kairos has the option to request, but did 19 not, for this -- any finality for the Hermes 2 design 20 at this point.
21 The Hermes 1 and Hermes 2 design --
22 MEMBER KIRCHNER: And just for the record, 23 may I interrupt? This is Walt Kirchner.
24 Could you just go ahead and state for the 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
63 record why this is not under 10 CFR 50 as a power 1
reactor? Why it's under a test reactor?
2 MR. ORENAK: It is under the test reactor 3
because they will still meet the requirements of 10 4
CFR 5022, it states that --
5 MEMBER KIRCHNER: Twenty-two, right.
6 I'm sorry, I misspoke earlier, I meant to 7
say that.
8 But could you elaborate just for the 9
record so that's part of the record?
10 MR. ORENAK: It's their maintenance and 11 operational costs that they are double of what -- more 12 than double of what they receive in revenue from 13 electricity and sales.
14 MEMBER KIRCHNER: Right.
15 CHAIR PETTI: So, it's only maintenance 16 and operation, it doesn't include construction costs 17 in that calculation?
18 MR. ORENAK: I don't think so. I think 19 it's --
20 MR. BORROMEO: Yes, so, this is Josh 21 Borromeo, Chief of New Advanced Reactor Licensing.
22 So, it's the cost of owning and operating 23 the facility can't be more than 50 percent geared 24 towards revenue generating products, whether that's 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
64 energy, or you know, some of the regional test 1
reactors out there produce medical isotopes for sale, 2
right, they're just going to stay under that 50 3
percent threshold and Kairos is going to stay under 4
that.
5 And that's what makes them a test reactor 6
and 104 license.
7 CHAIR PETTI: Right, but the construction 8
cost is figured in that cost, right?
9 MR. BORROMEO: I think so, yes. I think 10 so according to regulation, yes.
11 CHAIR PETTI: Thanks.
12 MEMBER KIRCHNER: Yes, the only reason I 13 bring this up is, notionally, you know, when a reactor 14 is connected to the grid, then it's a utilization 15 facility and it normally would come under 10 CFR 50 16 then like most commercial power reactors.
17 But this is in that class of a test 18 reactor.
19 I just wanted that to be part of the 20 record.
21 Thank you.
22 MR. BORROMEO: And that is -- and this is 23 Josh Borromeo, again.
24 That is unique for this facility, but 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
65 there's not regulation against producing electricity 1
for a research test reactor.
2 MR. ORENAK: All right.
3 Hermes 1 and Hermes 2 designs are very 4
similar, especially in the safety related components.
5 There is one exception, the rupture discs 6
which are part of the intermediate loop and will be 7
discussed in detail in Chapter 5 and 13 on June 12th.
8 Because of the similarities of the 9
facilities, we can leverage the Hermes 1 review to the 10 extent possible which I will discuss in upcoming 11 slides.
12 The ACRS should be familiar with the 13 Hermes 1 and the Hermes 2 designs.
14 There are five subcommittee meetings over 15 2022 and 2023, one full committee, and of course, the 16 letter report to the Chairman that was issued in May 17 of last year.
18 The letter report was relatively clean for 19 Hermes 1 awarding for the operating license special 20 construction permit, it was a clean letter.
21 These are the regulations that we used to 22 review Hermes 2, and of course, the same ones were 23 basically used for Hermes 1.
24 This is a quick overview of what the staff 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
66 used to review Hermes 2, which is also, at the same 1
time, as Hermes 1.
2 NUREG-1537 which is the staff guidance and 3
applicant guidance for non-power reactors.
4 Of course, we used, you know, multiple 5
regulatory guides and codes of standard, specifically, 6
ASME boil and pressure vessel coolant Sections 3 and 7
Sections 8.
8 And as I've gone over before, we've used 9
the Hermes 1 CP application to inform our review and 10 also we did quite a bit of incorporation by reference 11 which I'll discuss next.
12 Our review strategy, we reviewed the 13 entire PSAR. So, each one of our conclusions were 14 specifically to Hermes 2, but we did focus on Hermes 15 1, especially in the write ups.
16 Seventy-five or more percent of the 17 information is the same between the two PSARs.
18 There were some differences, the way that 19 these differences were highlighted were in several 20 ways.
21 First, as Kairos discussed in their 22 presentation, the PSAR had blue text for all the 23 differences which made it relatively easy for us.
24 Additionally, they provided a summary of 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
67 lead information on the Hermes 2 PSAR compared to the 1
Hermes 1 PSAR.
2 And this was provided inside the CP 3
application because the PSAR only provided what was 4
new and updated, they didn't talk about what was 5
deleted. But this is a summary of deletions.
6 And our last, in response to one of our 7
audit questions, they provided some docketed letters 8
stating what part of the extra information, REIs, a 9
lot of summaries were applicable to Hermes 2 that were 10 also to Hermes 1 and that provided a few slight 11 differences.
12 But almost everything from Hermes 1 in 13 that other docketing information was applicable to 14 Hermes 2.
15 One little note at the bottom, you 16 probably recognize in all of the PSAR sections that we 17 wrote -- I'm sorry, not the PSAR, the SE sections that 18 we provided you, there was a Hermes Revision 1 of the 19 PSAR reference that will be coming probably in the 20 next week that incorporates all of the docketed 21 information we've received so far that was on the 22 website that we hope to issue to everybody.
23 Our review strategy for Hermes 2, we 24 leveraged the Hermes 1 safety evaluation to the extent 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
68 possible.
1 And we specifically incorporated by 2
reference many sections of the Hermes 1 SE within the 3
Hermes 2 SE to highlight the differences between the 4
5 Also to prevent reopening of technical 6
issues that have already been reviewed.
7 And finally, to shorten and simply the SE.
8 We would image the whole SE to be about half the 9
length or a little less since we already have a full 10 SE that covers many of the other -- many of the 11 subjects.
12 For the parts that did change, like I 13 said, we, you know, completed a full review.
14 The depth of the written review depended 15 on the significance of the change.
16 For totally new sections, such as those 17 regarding the intermediate heat
- IHTS, the 18 intermediate heat transfer
- loop, and a
power 19 generation system, we just developed a whole new SE 20 for that section. There was no incorporation for 21 that.
22 And plausible that there is -- we have a 23 complete review section and each conclusion is 24 specific to Hermes 2.
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
69 In our
- review, we focused on the 1
differences. These were listed in a previous 2
discussion by Kairos, but 4 to 11 years operational 3
lifetime.
4 The staff focused on materials issues for 5
those concerns.
6 The shared systems, the multiple shared 7
systems such as the power protection system, the 8
intermediate heat transfer loop containing the, you 9
know, the different salt and associated structural 10 system components like the rupture discs.
11 The power generation system between the 12 units.
13 Super heater which is essentially the 14 steam generator enclosed in a common header in a 15 single turbine that will create 20 megawatts of 16 electricity.
17 Finally, the tritium management system 18 because of the tritium leakage from the primary end of 19 the intermediate loop and possibly into the power 20 generation loop, the tritium management system needed 21 to expanded.
22 Features that did not charge regarding 23 Hermes 1 to Hermes 2 that were important, you know, 24 the regarding safety related and dose consequences.
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
70 The reactor vessel when engineering safety 1
systems, the DHR has decay heat removal system didn't 2
change.
3 Functional containment and the Flibe did 4
not change.
5 And all the new proposed accidents still 6
bounded by the maximum critical accident.
7 Now, I'll go over the differences or the 8
notable changes between Hermes 1 and Hermes 2 and how 9
the staff reviewed them.
10 For Chapter 1 in the PSAR Section 1.4, 11 they discussed all the shared facilities and 12 equipment.
13 We did a short review and all the systems 14 are non-safety related and they are also all reviewed 15 in different sections inside of the Hermes 2 SE, if 16 you'll notice on the right side and each one in 17 parentheses.
18 So, each one of the shared systems are 19 non-safety related.
20 Loss of function would not affect safety 21 related SSEs or lead to controlled release of 22 radioactive material.
23 Additionally for Chapter 1, they talked 24 about compatibility evaluation between their 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
71 intermediate coolant salt, BNAF and a reactor coolant 1
salt which is Flibe.
2 Our staff, specifically, Alex here, will 3
be tracking that closely and determining results, 4
reviewing the results of that research.
5 And then, finally, for Chapter 1, the 6
increased operational lifetime and power generation 7
was briefly mentioned.
8 Both of those will be reviewed in later 9
chapters of the SE.
10 Chapter 6, Engineered Safety Features, 11 there's very few changes in this chapter.
12 The only real difference was stating that 13 each reactor has its own decay heat removal system.
14 We don't have much to say, other than, you 15 know, we reviewed it before in a separate SE.
16 Chapter 8, Electrical Power Systems, as 17 with Hermes 1, Hermes 2 is a passive plant and does 18 not require any electrical power to perform safety 19 related functions.
20 Because Hermes 2 generates power, the 21 necessary structure systems and components were added 22 to the PSAR.
23 However, the switch yard isn't relevant to 24 PDC2 because it's not a safety related component.
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
72 Additionally, regarding the backup power 1
systems, the UPS and the generators are sufficiently 2
sized and an appropriate numerical strength for the 3
two units.
4 Overall, the staff found that the revised 5
Chapter 8 provides sufficient descriptions to meet the 6
regulatory requirements and guidance for a preliminary 7
construction permit.
8 MEMBER ROBERTS: Yeah, this is Tom 9
Roberts. I asked you earlier about the capability of 10 powering the two units from the plant TG. Is that 11 something you looked at? Because the detail is 12 somewhat limited in the chapter as to how you do it or 13 the new transient scenarios that might create because 14 of the feedback between loss of the TG in both plants.
15 MR. ORENAK: I can't answer that. We had 16 a review. Sheila, go ahead.
17 MS. RAY: Hi, this is Sheila Ray, Senior 18 Electrical Engineer in NRR. We did not look at that 19 because the electrical systems are nonsafety.
20 MEMBER ROBERTS: But the ability to meet 21 the control system requirements by running back pumps, 22 you control power during losses of TG, seen the 23 capability of leading to more design basis events. It 24 may need to be considered in the Chapter 13. I'm just 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
73 wondering in general. So because it was considered 1
nonsafety, the capability to power the two units from 2
the TG set which is a pretty major change in this 3
iteration. That was not looked at in detail I think 4
is what I just heard.
5 MS. RAY: This is Sheila Ray. That's 6
correct. We did not look at that. I appreciate the 7
feedback. We'll have to coordinate with our Chapter 8
13 colleagues. But that's not something we look at in 9
the right of electrical systems in accordance with 10 their PDC for electrical.
11 MEMBER ROBERTS: Okay. Thank you.
12 MR. ORENAK: Chapter 10, experimental 13 facilities and utilization, there were no changes from 14 Hermes 1 that we use the same review. Chapter 11, 15 radiation protection program and waste management.
16 For Chapter 11, the nodal changes that they calculated 17 had combined all the proposed effluent doses from all 18 three reactor sites. Total effluent dose is well 19 below the Part 20 public dose limits.
20 Additionally, PSAR Chapter 11 also 21 included -- not mentioned on the slide -- the 22 radiation sources of potential release points for the 23 new Hermes 2 systems, the IHTS and the power 24 generation system. Chapter 12, conduct of operations, 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
74 there were very few minor changes in this section 1
highlighted here. Staffing may be shared to support 2
the license reactors on site.
3 However, the plan is sharing the staff 4
across all three units, at least in our discussion 5
with them. Practice of sharing staff across units to 6
perform certain operations has been a practice of 7
power reactors for decades. Therefore, we find it 8
sufficient. And the last change here for Chapter 12 9
is we chose to use the same quality assurance program 10 description for both Hermes 1 and Hermes 2. And we 11 found that it's independent of the facility 12 differences between Hermes 1 and Hermes 2 and it's 13 acceptable to us the same QAPD.
14 MEMBER KIRCHNER: Just a minor point here.
15 On that last slide, yeah, thank you. The Hermes which 16 you call number 1 is a non-power reactor and Hermes 2 17 is now a power reactor. So there is some degree of 18 difference between the two because now you have an 19 active intermediate loop and some of the issues that 20 Tom raised with regard to the turbine generator set.
21 I don't see a big challenge for moving the 22 staff across the two reactor -- however you describe 23 them, individual facilities. But typically, don't you 24 issue a license to operate a reactor based on the 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
75 actual reactor? So just I'm asking, a formality.
1 One reactor operator license for Hermes 1 2
wouldn't necessarily be licensed to operate number 2.
3 But the other way around makes more sense to me. So 4
I'm just -- how do you even handle that so that you 5
ensure that the licensed operators have the 6
appropriate skill set for the plant that they were 7
operating?
8 (Simultaneous speaking.)
9 MEMBER KIRCHNER:
And this is a
10 technicality, but --
11 MR. ORENAK: But this section, they 12 weren't necessarily talking about licensed operators.
13 They're talking about security and maintenance staff, 14 et cetera. When it comes to moving licensed operators 15 across units or across facilities, I'd have to --
16 Jesse is online. I don't want to --
17 MEMBER KIRCHNER: It's a technicality. It 18 will be addressed at the OL stage.
19 MR. ORENAK: Yes.
20 MEMBER KIRCHNER: I just highlight it.
21 Thank you.
22 MR. BORROMEO: So this is Josh Borromeo, 23 Chief of the Advanced Reactor License Branch. And Mr.
24 Kirchner, maybe I'm a little bit confused about the 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
76 question, right? So while Hermes 2 is going to be 1
producing power, it is still considered a non-power 2
reactor by our regulations which is a little bit of a 3
nomenclature confusion I would say.
4 But they're both considered non-power 5
reactors. Both the regulations that apply for Hermes 6
1 are the same for Hermes 2. And we also use NUREG 7
1537 as our guidance document for both.
8 So yeah, so one does produce power. We're 9
treating them the same in regulation space. Is that 10 kind of getting at the question that you have?
11 MEMBER KIRCHNER: Yeah, I understand that.
12 MR. BORROMEO: Okay, okay.
13 MEMBER KIRCHNER: But when you go to 14 license the operators, they wouldn't necessarily be 15 interchangeable from one side to the other unless they 16 were trained on Hermes 2 which has the addition of the 17 intermediate heat loop and the power production 18 capability.
19 MR. BORROMEO: Yeah, that's correct.
20 Right. So we're a little bit far away from operator 21 licensing. They would have to be given licenses for 22 each one of the facilities.
23 MEMBER KIRCHNER: Okay. I was just 24 reading the -- it just struck me in the viewgraph 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
77 the same staff are interchangeable. And that's likely 1
the case. But the actual operators will be trained 2
according to the facility that they're going to 3
operate. And the license is issued accordingly.
4 MR. BORROMEO: Yeah, that's correct. And 5
I think Kairos did address some of that this morning 6
about the potential for some crossover. And that's 7
something that we'll also have to take a look at, at 8
the operating license stage as well like you 9
mentioned.
10 MEMBER KIRCHNER: Thank you.
11 MR. ORENAK: Okay. Chapter 14, technical 12 specifications, changes to this chapter centered 13 around Hermes 2 having two units in addition to the 14 intermediate loop, the IHTS, and the power generation 15 system. These changes include proposed LCOs for 16 limiting the material at risk for release inside the 17 IHTS and PGS, ruptured disk operability, and limits 18 for the contamination of the intermediate salt, 19 whether it be from Flibe or water from the generation 20 system.
21 Staff review found that in addition of 22 these proposed LCOs as probable subjects in the TS are 23 acceptable. They had all the necessarily LCOs for 24 what they've added for the design. Chapter 16, other 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
78 license conditions, there's no changes from Hermes 1.
1 We still found that all equipment will be 2
new and purpose built. And there will be no direct 3
medical administration of isotopes or other radiation-4 based therapies. Chapter 17, again, no changes from 5
Hermes 1.
6 It will include the decommissioning plan 7
with the OL application. And they're not seeing a 8
possession-only license at this time. And then, 9
Chapter 18, unenriched to low enriched uranium 10 conversion, also no changes from Hermes 1.
11 The reactor fuel is the same, TRISO fuel 12 which is enriched to 20 percent. And the only 13 chapters we have left to discuss are Chapter 4 which 14 I'm going to turn over to Pravin and Alex. And then 15 after, Calvin and Joe will come up here for Chapter 7.
16 (Simultaneous speaking.)
17 DR. BLEY: This is Dennis Bley. I have a 18 comment, and I'd be interested in an answer from the 19 staff but not in a particular discipline. And it 20 mainly applies for construction permits and I think it 21 will probably the same way for operating licenses.
22 Sheila Ray's explanation brought up 23 something that's troubled the committee many times in 24 the past. And if the way the staff reviews each 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
79 system, each chapter, closes off things that are 1
linked to other chapters. Or even though electric 2
power is not required for safety, if a failure 3
associated with a TG could lead to additional 4
scenarios. If we don't pick those up when we're 5
reviewing the local chapter like electric power 6
chapter, when do we look for those interaction among 7
systems that can lead to -- not we. When does the 8
staff look for those interactions that could lead to 9
scenarios that you might not pick up otherwise?
10 MR. ORENAK: The way we viewed Hermes 1 11 and Hermes 2 is using a core team approach where a 12 group of -- sorry. The way we review Hermes 1 and 13 Hermes 2 is in the core team approach where we use a 14 group from our division, DANU. And they have a 15 holistic view of the application.
16 And that's led by Pravin who's the lead 17 technical reviewer. And those types of interactions 18 between chapters we hope to catch in that way because 19 they don't silo themselves into individual chapters 20 but trying to get an overall view at the same time.
21 And for example, for the evaluation, Pravin had 22 reviewed every chapter and I also on top it as a 23 project manager had reviewed every chapter, so I'm not 24 in a silo. In that way, we attempt to catch all those 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
80 different issues.
1 DR. BLEY: Well, instead of Sheila being 2
stuck with the -- coming up with an answer for that 3
one when Tom asked his questions. And I would have 4
liked to heard from some of you who are looking at the 5
cross cutting effects to explain either why you 6
haven't thought about that or when you think those 7
would get picked up. Because I think this kind of 8
stove piping will apply during the operating licenses 9
here. We can't just say, oh, that will get picked up 10 in the operating license.
11 MR. BORROMEO: So this is Josh Borromeo, 12 Chief Advanced Reactor Licensing Branch. So while we 13 didn't explicitly look at electrical failures of those 14 types, like, we didn't run a transient through 15 anything, it is bounded by the events in Chapter 13.
16 So, you know, while it might not be explicitly written 17 down that we took a look at that in Chapter 13, that 18 is something that our guidance drives us to take a 19 look at. And in this circumstance for Hermes 2, we 20 didn't see an issue with it. And maybe Pravin could 21 take -- have some discussion about how we took a look 22 at loss of power type issues, right, to inform our 23 regulatory determination here.
24 MR. SAWANT: And this is Pravin Sawant.
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
81 Yeah, this is loss of normal power is one of the 1
initiating event in Chapter 13. And it is right now 2
categorized under loss of heat removal -- loss of poor 3
circulation event category. So in that sense, we have 4
looked at it. Like we have considered that event in 5
Chapter 13.
6 DR. BLEY: I think that's a -- the idea 7
that everything else will be bounded by what you've 8
looked at can fall apart if you don't look at some of 9
these specifics that come up. And the people who will 10 really see them or could are the ones who are digging 11 deeply into each individual system. So that response 12 wasn't particularly convincing to me.
13 MR. BORROMEO: So this response or the one 14 before? And maybe I'll just add on a little bit.
15 DR. BLEY: The one before --
16 MR. BORROMEO: Okay, okay.
17 DR. BLEY: -- was devoid of a helpful 18 answer.
19 MR. BORROMEO: Apologies.
20 DR. BLEY: This one I understand the 21 claim. I haven't heard anybody say, yeah, we looked 22 at that specific thing. And for these reasons, we 23 were convinced that it's bounded.
24 MR. BORROMEO: And maybe I'll add on 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
82 little bit more to what Member Roberts was I think 1
driving at before. So during the operating licensing 2
stage, whenever we -- we'll consider things like 3
failures of this nonsafety-related electrical system 4
and how that plays into what the operators are going 5
to see. That'll be more prevalent for the human 6
factors evaluation at that point, right?
7 We saw that in recent reviews with Shawn 8
where that was a lot more focus during the operating 9
license review because all the details were there, 10 right? It was a lot easier to kind of see and 11 understand. So that's definitely going to be a much 12 larger focus during that portion compared to the CP 13 review that we're at right now.
14 DR. BLEY: You're getting closer to a 15 convincing answer. But we've run into problems like 16 this and looking at designs and operating license 17 applications. So it's something to keep in mind.
18 Somebody needs to be doing that 19 integration, making sure we don't let these drop out.
20 And Tom didn't talk deeply about it. But when you 21 give operators either wrong indications or no 22 indications, they are operators and they don't just 23 say, oh, I know there's a safety analysis. It says 24 everything is bounded, so I'll just close my eyes.
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
83 They operate. They do something. And you 1
need to think about that. Now the way you just 2
phrased it, it will be nice to hear that they think 3
about it at DOL stage.
4 MR. BORROMEO: Certainly understand. I 5
certainly understand the comment. And I'll take 6
getting close to an answer right now a success.
7 MEMBER ROBERTS: Yeah, thanks, Dennis.
8 That's exactly where I was heading. The loss of AC 9
power event from Hermes 1 becomes three events where 10 you have a loss of TG, at least a loss of AC power in 11 two plants. And so how the operators respond to that 12 and where they try to take the plant based on their 13 best understanding of what's going on could create new 14 scenarios that warrant concern.
15 So it seems like this question started 16 with is the intent to be able to power the plant with 17 the plant TG because the Kairos slide didn't have that 18 listed as an option. And there's very little 19 discussion in Chapter 8. So it seemed like the 20 question was started with clarification of what do 21 they intend.
22 And if the intent is that you would never 23 power both plants with the TG set, all these issues 24 going away. But that too is the other aspect of this 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
84 is just understanding what they had in mind with 1
somewhat limited detail. And it's a CP versus an OL.
2 And so to some degree, that's absolutely expected.
3 But at least understanding what they have in mind will 4
probably help in terms of bounding what the evaluation 5
would need to be.
6 MR. BORROMEO: And this is Josh Borromeo 7
again. I think it's fair to understand what they have 8
in mind. But I think there's another category of, 9
hey, what do the regulations require us to make a 10 regulatory determination on, right?
11 We certainly need to have an understanding 12 of how the plant works and operates and how maybe 13 these nonsafety-related systems could impact a safety 14 facility, right? That's certainly something that the 15 staff looks at and ensures, right? But how deep down 16 that rabbit hole we go is sometimes dictated by our 17 regulations.
18 CHAIR PETTI: I just note, you know, 19 you're going to see this in all the event systems 20 where the need for offsite power is very different in 21 terms of how it's implemented than the current fleet.
22 And so there's a bunch of new questions you have to 23 sort of ask yourself. And we'll see, I think, as we 24 continue looking at some of these other systems as 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
85 well.
1 DR. BLEY: And the regulations are 2
supplemented by the applicable standards. And now 3
there are some standards that apply here. And they 4
certainly, the newest ones, tell you, you have to dig 5
deeply to think about what would be initiating events 6
or accidents at these plants.
7 CHAIR PETTI: Jesse has his hand up.
8 Jesse, go ahead.
9 MR. SEYMOUR: Yes, hi, this is Jesse 10 Seymour. So I'm the human factors technical reviewer 11 for the CP. And I just want to kind of build upon 12 what Josh said earlier.
13 And it's just important to realize what 14 stage of licensing that we're at right now. For a CP, 15 what we have here in the PSAR is a commitment to apply 16 human factors engineering principles to the design of 17 the control room. When we get to the OLA stage, then 18 at that point, we'll have the detailed accident 19 analysis information and a better way to look at sort 20 of the role of the operator and the fulfillment of 21 safety and then to go ahead and take a scoped and 22 graded review of that human factors engineering 23 approach to make sure that it's going to support that 24 role.
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
86 But again, there's just a wide spectrum 1
for how that can play out when you have that detailed 2
information for OLA. A plant could walk away safe, or 3
there could be a credited operator role. There could 4
be an operator role in defense in depth that needs to 5
be considered.
6 But again, the intention for the OLA is to 7
essentially perform the Chapter 7 review from NUREG 8
1537 which would have us look at the availability of 9
indications, the availability of controls, the 10 availability of alarms, the accessibility of that 11 equipment. And then to review that and to look for 12 that application of human factors engineering too.
13 Make sure all that's viable for how it's needed.
14 And that's all in conjunction with the 15 broader review of Chapter 12 which will entail the 16 licensed operator training and the procedures set.
17 But again, I just wanted to emphasize that we're at 18 this earlier CPA stage right now. So in many regards, 19 we're just looking for the commitment that that's 20 going to happen during the evolution of the detailed 21 design.
22 MEMBER KIRCHNER: Well, this is Walk 23 Kirchner. I just wanted to weight in, in a more 24 general sense. And Dennis raised a good point. 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
87 I'll see if I can just amplify a little.
1 And I'm not suggesting that Sheila stated 2
it quite this bluntly. But using what safety-related 3
and nonsafety-related as a way to discriminate what 4
one reviews is not a systems approach to revealing a 5
reactor application because we do know and we've 6
learned from the past that nonsafety-related systems 7
often can have a significant impact on the performance 8
of the plant. And I'll just stop there.
9 When we do a delta review, we are 10 interested in effectively and efficiently using our 11 past efforts. I understand that. But it's not as 12 simple as just saying, well, this is not safety-13 related. So we don't need to review it. And I'm not 14 saying that anyone was implying that. But it does as 15 Dennis raised a good point that it takes a systems 16 view to really do a reactor application review by the 17 staff as well as the committee.
18 MEMBER BALLINGER: In the previous slide, 19 it prompted me to ask probably a dumb question. Since 20 this reactor is going to be 11 years now, did they 21 have to sign a standard contract with DOE? In other 22 words, they have to have a disposition path for the 23 fuel. And that's the standard -- so called standard 24 contract with DOE that says DOE is going to take the 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
88 fuel.
1 MR. ORENAK: I'm unaware. I haven't heard 2
that yet. Ed, have you heard anything along those 3
lines yet?
4 MEMBER BALLINGER: I know for commercial 5
reactors, they have to sign a standard -- they have a 6
standard contract. That's what it's called.
7 (Simultaneous speaking.)
8 MR. HELVENSTON: This is Ed Helvenston 9
from the staff. I can speak to that. At the 10 construction firm, it's stage -- in accordance with 11 the Nuclear Waste Policy Act, Kairos is required to 12 show evidence of good faith effort of negotiations 13 with the Department of Energy towards getting a 14 contract for the disposal of the fuel. They aren't 15 required to have a contract in place at the CP stage.
16 But that is something that we look at, at the 17 operating license.
18 MEMBER BALLINGER: Got it. Thank you.
19 MR. BORROMEO: I forgot about that. And 20 we have received that letter from DOE saying they were 21 making an effort.
22 CHAIR PETTI: Right. I remember the 23 letter for Hermes as well.
24 MR. BORROMEO: Yeah, we have the letter 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
89 from Hermes too. Thanks, Ed.
1 MR. SAWANT: My name is Pravin Sawant, a 2
nuclear engineer at DANU. I will talk about our 3
Chapter 4 review. Chapter 4 describes a reactor 4
design that includes a reactor core, reactor vessel, 5
and internals, biological shield, nuclear designs, and 6
reactor vessels of our systems.
7 And as to tritium monitoring, Kairos 8
informed that all of these ISFSIs on the reactor 9
design are identical to Hermes 1 or Hermes 2 design.
10 So I will go through some of the minor changes. But 11 our stops -- our review was primarily focused on 12 impact of operating life change from 4 to 11 years and 13 how will that affect the qualifications for the 14 metallic and graphite material.
15 And next we'll talk about our evaluation 16 on that aspect of the review shortly. So one of the 17 minor change we saw in the chapter was identification 18 of some of the key systems, reactor control shut down 19 system, portions of plant control systems that 20 controls these reactor control and shut down system 21 and neutron startup. They are not shared between Unit 22 1 and Unit 2, all which was kind of an acceptable 23 approach as it increases the degree of independence 24 between the two units and postulated events from one 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
90 unit to a failure operation of the other unit, 1
consistent with requirements of 10 CFR 111(b)(1).
2 So I find this change acceptable. There 3
are another minor change in Chapter 4 in Section 4.6, 4
IHTS, that intermittent heat transfer system was 5
identified as one of the systems that graphic 6
thermodynamic design of the reactor system. So the 7
IHTS -- design of IHTS is presented in Chapter 5.
8 We will have a much more detailed review 9
of that system in Chapter 5, including impact of IHTS 10 on some of the postulated events. And also in Chapter 11 13, we consider some of the initiating events 12 starting from the IHTS. So our evaluation in Chapter 13 13 is supported by our independent scoping 14 calculations.
15 And so we'll talk about that review and 16 our conclusions during Chapter 13 presentations. But 17 I can say that here that our preliminary analysis 18 shows that these are expected to maintain its 19 integrity during the postulated events that were 20 considered in Chapter 13 as well as MHA still remains 21 bonding for Hermes 2 design also. And basically in 22 Chapter 4, we kind of concluded that opportunity and 23 permission provides there is assurance the reactor 24 system will be designed with operate margin to ensure 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
91
- SARRDLs, that is specified acceptable system 1
radiological release design limits are not accident 2
during normal operation as postulated events. So 3
these are small changes in Chapter 4. And as I said, 4
our evaluation of IHTS, we'll be doing Chapter 5 and 5
13 discussions.
6 DR. SCHULTZ: Pravin, this is Steve 7
Schultz. Just -- I might be jumping ahead to what you 8
just described in detail in Chapters 5 and 13. But I 9
wanted to ask about the thermal hydraulic codes that 10 were used in Chapter 4, the draft safety evaluation.
11 You describe that, the detailed approval of those 12 codes doesn't happen until the operating license.
13 But you did take a look at the codes and 14 its application to the intermediate heat transfer 15 system. And you also remark in the safety evaluation 16 that you looked at treatment of uncertainties to a 17 degree. And I just wanted to ask if you could provide 18 or characterize what was your review of the thermal 19 hydraulic codes and this treatment of uncertainties at 20 this point.
21 MR. SAWANT: So the applicant is using a 22 code named SAM for the thermal hydraulic analysis.
23 And with respect to the modeling of IHTS specifically, 24 right now, they are modeling it as a condition for the 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
92 IHTS. However, independent scoping calculations, 1
though we had used MELCOR to explicitly model as well 2
as IHTS. And we are using EGS as a monitoring 3
condition.
4 But all of these models right now are 5
preliminary given the design formation. And so there 6
is a topical report coming on postulated event 7
analysis methodology which will grant how much 8
complete information on methodology for analysis of 9
these postulated events. And that report is going to 10 support this operating license. So at this stage, the 11 available information specifically on the design side 12 was primary and not that clear because that would 13 allow us to model -- represent IHTS specifically with 14 greater level of details.
15 DR. SCHULTZ: But you did your own scoping 16 calculations?
17 MR. SAWANT: Yeah.
18 DR. SCHULTZ: Tell us what's been done so 19 far.
20 MR. SAWANT: Yes. So up to extent that is 21 possible, we at least look at that, the event 22 progressions, to see whether they make sense as 23 compared to what is presented in the PSAR. The scope 24 of the review for Chapter 13 was like just really 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
93 making sure that, like, a number of events are 1
identified. They are classified properly.
2 DR. SCHULTZ: We can get to that when 3
we're in Chapter 13.
4 MR. SAWANT: Yeah, yeah.
5 DR. SCHULTZ: I appreciate your comments 6
on what you put in the safety evaluation for Chapter 7
- 4. Thank you.
8 MR.
CHERESKIN:
Hi, this is Alex 9
Chereskin, and I'm a materials engineer in Advance 10 Reactor Technical Branch too. And I'm going to be 11 presenting on the NRC staff review of Section 4.3. So 12 in Section 4.3, the review focused on the longer 13 component lifetime and its impact on material 14 qualification.
15 As noted on the slide, there were tables 16 that were added to Section 4.3 of the PSAR. And these 17 were added because the referenced material 18 qualification topical reports only discussed 19 qualification for component lifetimes for the Hermes 20 reactor and for the full power reactor. It didn't 21 explicitly cover a lifetime of falling between the two 22 of those.
23 So the tables that I referenced in the 24 PSAR are based off of the topical reports I just 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
94 mentioned. The difference is the tables in the PSAR 1
describe the modifications that were needed for that 2
intermediate lifetime. So there are tables in the 3
PSAR that cover both qualifications. Here's the 4
slides.
5 CHAIR PETTI: Slide 23.
6 MR. CHERESKIN: All right. Well it looks 7
like we're back on the slides, so I'll continue the 8
presentation. So there are tables that cover both 9
material qualification for the metallic materials 10 using Hermes 2 as well as the graphite materials.
11 Starting with the metallics, one change 12 that I wanted to note is that the metallic material 13 qualification testing will now include corrosion tests 14 with the intermediate salt added which is different 15 from Hermes 1 which did not have the presence of an 16 intermediate salt. And other qualification tests use 17 justifications for either extrapolating the test times 18 or conditions that were already described in the 19 topical reports for the Hermes 1 life or for the power 20 reactor life. And some of these tests also take a 21 bounding approach by using the longer lived power 22 reactor which was deemed conservative.
23 And for the metallic materials, these 24 qualification tests are described in PSAR Tables 4.3-3 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
95 through 4.3-6.
For the graphite material 1
qualification, the intent is to -- that it will 2
demonstrate that graphite components will remain pre-3 turnaround and that plant parameters stay within the 4
qualification envelope that was previously described 5
in the graphic qualification topical report. And if 6
this can't be demonstrated, Kairos will collect the 7
additional data for radiation creep and/or expand the 8
qualification envelope.
9 This qualification testing is described in 10 PSAR Tables 4.3-7 as well as 4.3-8. And so the 11 overall staff finding in the safety evaluation is that 12 the preliminary information is sufficient to provide 13 reasonable assurance that the reactor vessel system 14 will be designed to main integrity for its anticipated 15 life. And so I can take questions at this time or 16 I'll make room for Joe and Calvin up at the table.
17 Thank you.
18 MR. CHEUNG: Good afternoon. My name is 19 Calvin Cheung, Electronics Engineer in Division of 20 Engineering External Hazards, Office of Nuclear 21 Reactor Regulation. I'll be presenting the Chapter 7 22 review.
23 So this slide summarizes notable changes 24 for the Hermes 2 I&C system. There's the intermediate 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
96 heat transport control system located in its 1
respective unit reactor building. And it's a 2
subsystem of the plant control system for intermediate 3
heat.
4 Transport control system controls and 5
monitors systems and components that support normal 6
operation of the intermediate loop which removes heat 7
from the primary loop. For the auxiliary monitored 8
systems which are also part of the plant control 9
system, they are unit specific and are located in 10 their respective unit reactor building. The auxiliary 11 monitored systems are made up of the five systems 12 listed, and they support normal operations and are 13 identified on this slide here.
14 And finally, the dedicated consoles in the 15 main control room are shared -- sorry, they are in the 16 shared main control room and provide means for the 17 operators to monitor the behavior of each unit and the 18 shared systems, control performance of each unit and 19 shared systems, and manage the response to postulated 20 units -- postulated events in each unit. And I'll 21 note the control of the shared systems require 22 coordination between each unit's operators before the 23 control can be manipulated. And finally, we have the 24 power generation and control system.
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
97 This is also part of the control system.
1 But it is shared between the units. It controls and 2
monitors systems and components that support the 3
normal operation of the turbine generator. And the 4
power generation control system does not perform 5
safety-related function.
6 In review of these changes, the staff 7
grouped them under each main I&C system, the first 8
with updates and changes for the plant control system.
9 The staff evaluated changes for the -- resulting from 10 the intermediate heat transport control system, the 11 auxiliary monitored system, and the power generation 12 control system. The staff reviewed the updated PSAR 13 sections to confirm sufficient information provided 14 and focused the review on the overall I&C system 15 architecture Figure 7.1-1.
16 And based on the review, the staff finds 17 the design of the plant control system is consistent 18 with acceptance criteria found in NUREG 1537. For the 19 updates and changes impacting the reactor trip system, 20 staff reviewed the updated PSAR sections. The overall 21 I&C system architecture, Figure 7.1-1, the reactor 22 protection system trip logic schematic, Figure 7.3-1, 23 the intermediate heat transport control system 24 controls the intermediate salt pump.
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
98 And the reactor protection system trip 1
removes that power from the intermediate salt pump to 2
eliminate inadvertent overcooling. And the staff 3
finds the removal of that power of the nonsafety 4
intermediate salt pump is similar to the trip of other 5
nonsafety-related subsystems previously evaluated as 6
part of the original Hermes design except for 7
acceptable. And for changes for the main control 8
room, the staff reviewed the dedicated consoles as 9
described in the updated PSAR sections.
10 And reflected in the architecture of the 11 main control room, Figure 7.4-1, consoles are provided 12 to control and monitor each unit individually and to 13 control and monitor the shared systems. And the staff 14 finds the main control room is consistent with the 15 acceptance criteria found in NUREG 1537. And as 16 discussed earlier, we did coordinate that with human 17 factors reviewers. In summary, based on information 18 in the Hermes 2 PSAR Chapter 7 and other sections 19 within the PSAR, the staff confirms there's no 20 negative
- impact, especially with the reactor 21 protection system and concludes there is sufficient 22 information for the construction permit. And further 23 information can be reasonably left for the operating 24 license 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
99 (Simultaneous speaking.)
1 MR. ORENAK: And that is it for our 2
presentation today. The next is just acronyms.
3 MEMBER ROBERTS: Charlie, did you have any 4
questions you wanted to ask?
5 MR. BROWN: No, we think we covered them 6
before or at least I did.
7 MEMBER ROBERTS: That's what I thought 8
too. If they're ready for questions, I figure we had 9
to ask something. But I'm good.
10 CHAIR PETTI: So I think we can finish 11 early. I think what we should do maybe is see if 12 there's public comments and then we can talk as a 13 committee. So if there's any member of the public 14 that has a comment, please identify yourself, your 15 affiliation, and your comment.
16 Okay. I'm not hearing anything. Let's 17 chat a little bit about what we heard. I would first 18 say that anybody who owes a chapter memo who feels 19 they need a chapter memo, send it to Weidong and 20 myself.
21 And if you need to update a draft, please 22 do based on what you've heard. I'm certainly going to 23 update some of mine and get those in to us on time.
24 Second, just so everyone is aware, June 4th is the 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
100 next time in front of a full committee that we'll 1
review the next chunk of chapters.
2 And then June 12th is a special virtual 3
meeting for the last two chapters. And then in May-4 June subcommittee, we'll kind of bring it all together 5
and discuss the final thoughts and prep for the letter 6
in July. That's the plan. Anybody have any questions 7
or comments? Not hearing any then, we are adjourned.
8 Thank you all.
9 (Whereupon, the above-entitled matter went 10 off the record at 2:07 p.m.)
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
KP-NRC-2405-004 Kairos Power LLC www.kairospower.com 707 W Tower Ave, Suite A 5201 Hawking Dr SE 2115 Rexford Rd, Suite 325 Alameda, CA 94501 Albuquerque, NM 87106 Charlotte, NC 28211 May 10, 2024 Docket No. 50-611 Docket No. 50-612 US Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Kairos Power LLC Presentation Materials for Kairos Power Briefing to the Advisory Committee on Reactor Safeguards, Kairos Power Subcommittee on Hermes 2 Preliminary Safety Analysis Report Chapters 1, 4, 6-8, 10-12, 14, and 16-18
References:
- 1. Letter, Kairos Power LLC to Document Control Desk, Submittal of the Preliminary Safety Analysis Report for the Hermes 2 Kairos Power Fluoride Salt-Cooled, High Temperature Non-Power Reactor (Hermes 2), Revision 0, July 14, 2023 (ML23195A122)
In July 2023, Kairos Power submitted Revision 0 of the Preliminary Safety Analysis Report (PSAR) as part of the Construction Permit Application for the Hermes 2 non-power reactor (Reference 1). This letter transmits the presentation slides for the May 16, 2024 briefing for the Advisory Committee for Reactor Safeguards (ACRS), Kairos Power Subcommittee. During the May 16 meeting, participants will discuss Hermes PSAR Chapters 1, 4, 6-8, 10-12, 14, and 16-18 submitted for NRC review.
provides the non-proprietary slides for the May 16, 2024 briefing. Kairos Power authorizes the Nuclear Regulatory Commission to reproduce and distribute the submitted content, as necessary, to support the conduct of their regulatory responsibilities.
If you have any questions or need any additional information, please contact Drew Peebles at peebles@kairospower.com or (704) 275-5388 or Darrell Gardner at gardner@kairospower.com or (704) 769-1226.
Sincerely, Peter Hastings, PE Vice President, Regulatory Affairs and Quality
KP-NRC-2405-004 Page 2
Enclosure:
Presentation Slides for the May 16, 2024 ACRS Kairos Power Subcommittee Meeting (Non-Proprietary) xc (w/enclosure):
Joshua Borromeo, Chief, NRR Advanced Reactor Licensing Branch Michael Orenak, Project Manager, NRR Advanced Reactor and Licensing Branch Matthew Hiser, Project Manager, NRR Advanced Reactor Licensing Branch Cayetano Santos, Project Manager, NRR Advanced Reactor Licensing Branch Weidong Wang, Senior Staff Engineer, Advisory Committee for Reactor Safeguards
KP-NRC-2405-004 Presentation Slides for the May 16, 2024 ACRS Kairos Power Subcommittee Meeting (Non-Proprietary)
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
HERMES 2 PSAR (CH. 1, 4, 6-8, 10-12, 14, 16-18)
DREW PEEBLES - SENIOR LICENSING MANAGER JIM TOMKINS - FUELS LICENSING MANAGER MAY 16, 2024 ACRS Kairos Power Subcommittee Meeting 1
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Kairos Powers mission is to enable the worlds transition to clean energy, with the ultimate goal of dramatically improving peoples quality of life while protecting the environment.
In order to achieve this mission, we must prioritize our efforts to focus on a clean energy technology that is affordable and safe.
2
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Introduction
- Kairos Power submitted a construction permit application (CPA) for a two-unit test reactor named Hermes 2 in July 2023
- Hermes 2 will be licensed as a test reactor under the provisions of 10 CFR 50.21(c) and Atomic Energy Act Section 2134(c) to test and demonstrate:
An intermediate (salt) heat transport loop between the primary and power generation systems An electrical power production (shared) and power generation system An increased component lifetime
- The content of this application is similar to and relies extensively on content provided in the Hermes construction permit application.
Kairos Power requested that the NRC leverage the safety evaluation of the Hermes CPA to the maximum extent possible (similar to a design-centered review approach) due to similarities found with the design and siting information
To facilitate this delta review, the Hermes 2 PSAR content is annotated with blue text if the content was different than Hermes PSAR content 3
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Key Differences between Hermes and Hermes 2
- Hermes 2 (Unit 1 and Unit 2) is identical to Hermes except for the following high-level changes:
Two reactor unit facility with separate reactor buildings for each unit Licensed lifetime is 11 years Electrical power generation capability Some sharing of SSCs No sharing of safety-related SSCs The two units will share a power generation system (some portions are not shared)
Some sharing of other non-safety related SSCs (e.g., site-related utility services)
Shared main control room Each unit will use an intermediate salt loop to exchange heat from the primary salt to the common power generation system Additional tritium management strategies due to addition of intermediate loop and power generation system The additional hazards from the design deltas are considered in safety analysis 4
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Hermes 2 PSAR Chapters Identical to Hermes PSAR
- Hermes 2 PSAR chapters 6, 10, 12, and 16-18 have no substantive changes from the Hermes PSAR:
Chapter 6 The functional containment strategy and decay heat removal system (DHRS) design for each Hermes 2 unit are identical to Hermes.
Chapter 10 Like Hermes, the Hermes 2 facility will not include dedicated experimental facilities.
Chapter 12 The program descriptions for Hermes 2 are identical to those of Hermes (with the minor exception that some staffing may be shared for the site).
Chapters 16-18 Like Hermes, these sections are not applicable to the Hermes 2 CPA.
5
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
PSAR Chapter 1: The Facility
- Hermes 2 PSAR Ch. 1 is a summary chapter that points to content in the rest of the PSAR, therefore it contains differences from the Hermes PSAR Chapter 1 that reflect the Hermes 2 design and operating characteristic changes (e.g., Ch. 1 has a summary of site information, but the detailed site information is in Ch. 2).
6
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
PSAR Chapter 4: Reactor Description
- Design of reactor core, reactor vessel system, biological shield, nuclear, thermal hydraulic, and reactor vessel structural support for each Hermes 2 unit is identical to Hermes, except for a longer material lifetime.
- Material qualification for an 11-year life of metallic and graphite materials follows the previously approved methodologies in:
KP-TR-013-P-A Metallic Materials Qualification for the Kairos Power Fluoride Salt-Cooled High Temperature Reactor KP-TR-014-P-A Graphite Material Qualification for the Kairos Power Fluoride Salt-Cooled High Temperature Reactor
- The specific testing requirements in the referenced topical reports provide testing commitments ranging from a non-power reactor with a 5-year lifetime to a commercial power reactor with a 20-year lifetime.
PSAR Table 4.3-3 through 4.3-8 provide the specific qualification test requirements for an 11-year non-power reactor lifetime.
7
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
PSAR Chapter 7: Instrumentation and Controls
- The design of the safety-related portions of the I&C systems for Hermes 2 is identical to Hermes except for an additional trip on the intermediate salt pump to limit potential overcooling.
The safety-related portions of the I&C systems are not shared between units
- Portions of the non-safety related I&C systems for Hermes 2 are shared between units. The design of these systems is similar to the non-safety related portions of the I&C systems for Hermes except for the following:
The plant control system for Hermes 2 has two subsystems in addition to the subsystems described in the Hermes PSAR:
Intermediate heat transport control system (not shared)
Power generation control system (shared)
The main control room for Hermes 2 is configured for two-unit operations. The main control room is shared.
8
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
PSAR Chapter 8: Electrical Power Systems
- The electrical power system for Hermes 2 is also non-safety related and only differs from Hermes to incorporate the two-unit facility and power generation capabilities Portions of the AC power are shared between Unit 1 and Unit 2 but does not perform a safety function The backup power generators are shared between Unit 1 and Unit 2 but do not perform a safety function AC power generated from the turbine generator system is provided to an onsite switchyard and distributed to the offsite electrical grid The switchyard includes protection from electrical faults and grid fluctuations 9
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
PSAR Chapter 11: Radiation Protection and Waste Management
- The preliminary description of the radiation protection and waste management programs for Hermes 2 is identical to the description in the Hermes PSAR except for the following:
The Hermes normal radiological effluent screening analysis was evaluated for Hermes 2 Bounding dose from Hermes analysis is conservatively doubled to account for both units of Hermes 2 Considers new potential gaseous effluent release points including the power generation system evaporator, flash vessel, deaerator, and condenser vent pipes Total site emissions include bounding contributions from the Hermes test reactor facility Results of Hermes 2 screening analysis demonstrate that doses from all site effluents are below Part 20 limits for individual members of the public 10
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
PSAR Chapter 14: Technical Specifications
- Consistent with the Hermes PSAR, the Hermes 2 PSAR only provides expected variables to be controlled by technical specifications. The technical specifications will be provided with the application for an operating license.
- The anticipated limiting conditions for Hermes 2 operation (LCO) include the same parameters from the Hermes PSAR with the following modifications:
The LCO for materials at risk includes the intermediate heat transport system and power generation system.
Additional LCOs for operability of IHTS overpressure relief devices, limitations on the quantity of Flibe in the intermediate coolant, and limitations on the quantity of water in the intermediate coolant.
11
Copyright © 2024 Kairos Power LLC. All Rights Reserved.
No Reproduction or Distribution Without Express Written Permission of Kairos Power LLC.
Questions
Office of Nuclear Reactor Regulation NRC Staff Safety Review of the Kairos Hermes 2 Testing Facility Construction Permit Application Briefing for the Advisory Committee on Reactor Safeguards Kairos Subcommittee May 16, 2024
Agenda
- Introduction
- NRC Staff Review Strategy
- NRC Staff Review of the Hermes 2 Preliminary Safety Analysis Report (PSAR)
- Chapters 1, 4, 6, 7, 8, 10, 11, 12, 14, 16, 17, and 18 Note: Chapters 2, 3, 5, 9, and 13 will be discussed at future subcommittee meetings.
2
Introduction
- Kairos Power LLC submitted a construction permit (CP) application for a two-unit non-power test reactor facility known as Hermes 2
Purpose:
test and demonstrate key technologies, design features, and safety functions for the commercial Kairos Power fluoride salt-cooled, high temperature reactor (KP-FHR) structures, systems, and components (SSCs)
- Location: East Tennessee Technology Park near Oak Ridge; adjacent to Hermes 1
- Hermes 2 would be licensed as a non-power reactor under Title 10 of the Code of Federal Regulations (10 CFR) Part 50
- Class 104 license per 10 CFR 50.21(c) for testing, research, and development
- A CP allows a licensee to proceed with construction based on preliminary design information
- A CP does not approve the safety of any design feature or specification unless specifically requested by the applicant.
3
==
Introduction:==
Hermes 1 and Hermes 2
- Hermes 1 and Hermes 2 designs are similar
- All safety-related structures, systems, and components (except for one addition for Hermes 2) are the same between the two designs
- The NRC staff leveraged its review of Hermes 1 CP, as applicable
- Subcommittee meetings in April 2022 and March & April 2023
- Full committee meeting in early May 2023
- Letter report to Chairman issued on May 16, 2023 (ML23130A183) 4
==
Introduction:==
Regulatory Requirements
- 10 CFR 50.2, Definitions.
- 10 CFR 50.21, Class 104 licenses; for medical therapy and research and development facilities, paragraph (c).
- 10 CFR 50.33, Contents of applications; general information, paragraph (f).
- 10 CFR 50.34, Contents of applications; technical information, paragraph (a), Preliminary safety analysis report.
- 10 CFR 50.35, Issuance of construction permits.
- 10 CFR 50.40, Common standards.
- 10 CFR 50.41, Additional standards for class 104 licenses.
- 10 CFR 50.50, Issuance of licenses and construction permits.
- 10 CFR 50.55, Conditions of construction permits, early site permits, combined licenses, and manufacturing licenses.
- 10 CFR 50.58, Hearings and report of the Advisory Committee on Reactor Safeguards.
- 10 CFR 100.11, "Determination of exclusion area, low population zone, and population center distance"
- 10 CFR Part 50, Appendix C, A Guide for the Financial Data and Related Information Required to Establish Financial Qualifications for Construction Permits and Combined Licenses.
- 10 CFR Part 50, Appendix E, Emergency Planning and Preparedness for Production and Utilization Facilities.
5
==
Introduction:==
Guidance and Precedent Guidance
- NUREG-1537, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors
- Regulatory Guides
- Codes and Standards (e.g., American Society of Mechanical Engineers Boiler and Pressure Vessel Code Sections III and VIII)
Precedent
- Hermes 1 CP application safety evaluation 6
Hermes 2 Review Strategy
- Staff reviewed entire Hermes 2 PSAR, but focused on changes from Hermes 1
~75% of information is the same between the two PSARs
- Hermes 2 PSAR changes are identified through:
Letter to ACRS summarizing key differences between Hermes 1 and 2 facility designs (ML23325A178)
Docketed Information Hermes 2 PSAR, Revision 0*, with new and modified text specified (ML23195A124)
Summary of information deleted from Hermes 1 PSAR (ML23195A132)
Summary of audit and requests for additional information from Hermes 1 that are applicable to Hermes 2 (ML23300A141 and ML22300A144)
- Revision 1 with all docketed changes incorporated to be submitted soon.
7
Hermes 2 Review Strategy
- Due to the significant amount of similar content between the Hermes 2 PSAR and Hermes 1 PSAR, staff leveraged the Hermes 1 safety evaluation (SE) to the extent possible.
- The Hermes 2 SE:
- Identifies information consistent with the Hermes 1 SE and incorporates by reference applicable contents from the Hermes 1 SE
- Evaluates new design information and non-editorial Hermes 2 PSAR changes Depth of staff review was dependent on significance of change
- States technical findings specific to Hermes 2.
8
Hermes 2 Review Strategy
- Focused on the following differences between Hermes 1 and Hermes 2 11-vs. 4-year operating lifetime Two units instead of one (e.g., shared systems)
Intermediate salt loop for each unit containing a different salt than the primary salt loop and the associated SSCs Common power generation system 20 megawatts (MW) electric Steam, turbine, and condensate & feedwater systems Expanded tritium management system
- Important design features that did not change Reactor vessel system and engineering safety systems Functional containment Maximum hypothetical accident (MHA) 9
Chapter 1, The Facility Notable Changes:
- PSAR Section 1.4, Shared Facilities and Equipment mentions:
SE finding: All Hermes 2 shared systems are non-safety related, and a loss of function in these shared systems would not affect the safety-related SSCs, or lead to uncontrolled release of radioactive material to unrestricted areas Plant control system (SE Section 7.2)
Treated water system (SE Section 9.7.2)
Main control room (SE Section 7.4)
Auxiliary site services (SE Section 9.8.5)
Normal and backup power (SE Chapter 8)
Facility physical security (PSAR Section 12.8)
Power generation system (SE Section 9.9)
Sensors (SE Section 7.5)
Plant communication systems (SE 9.5)
Fire protection (SE Section 9.4)
Service water system (SE Section 9.7.1)
Radiation monitoring (PSAR Section 11.1.4) 10
Chapter 1, The Facility Notable changes (contd)
- PSAR Section 1.3.9, Research and Development mentions completing compatibility evaluations of the intermediate coolant and reactor coolant chemical interaction
- The staff is tracking this additional activity and will verify their resolution prior to the completion of construction
- PSAR Section 1.6, Summary of Operations states Hermes 2 would operate over its full range of power during a 11-year lifetime and produce approximately 20 MW of electrical power.
SE finding: Information is consistent with relevant assumptions and analyses in later Hermes 2 PSAR chapters in which any safety implications of the proposed operations are evaluated 11
Chapter 6, Engineered Safety Features Notable Changes:
- PSAR Section 6.3, Decay Heat Removal System
- Functional containment approach remains same as Hermes 1
- Hermes 2 will have one decay heat removal system (DHRS) per unit, and the DHRSs do not share components between units.
SE finding: the DHRS design did not change relative to Hermes 1 and having a separate DHRS for each unit is acceptable 12
13 Chapter 8, Electric Power Systems Notable Changes:
- PSAR Section 8.2, Normal Power System
- Grounding and lightning protection
- Switchyard protection in accordance with IEEE Standard 242-2001
- The staff views grounding and lightning protection and switchyard protection to be a good engineering practice; however, not appliable for principal design criteria (PDC) 2
- PSAR Section 8.3, Backup Power System
- Two backup generators, shared between the units which are sufficiently sized to supply both units
- Three universal power systems (UPS) per unit
- Two shared UPS supplying the main control room and emergency lighting and communication SE finding: the descriptions of the power systems is sufficient and meets the applicable regulatory requirements and guidance for the issuance of construction permits.
Chapter 10, Experimental Facilities and Utilization
- No notable changes from Hermes 1
- Hermes 2 will not include special facilities dedicated to the conduct of reactor experiments or experimental programs 14
Chapter 11, Radiation Protection Program and Waste Management Notable Changes:
- The calculated total effective dose equivalent (TEDE) gaseous effluent dose results for each Hermes 2 unit were added together, and also further combined with the gaseous effluent dose results for the Hermes 1 reactor to give the site total.
SE findings:
The results of the effluent screening analysis provide reasonable assurance that 10 CFR Part 20 limits will be met during Hermes 2 operation, including consideration of both the Hermes 1 and Hermes 2 facilities for site total effluent releases.
- The estimated combined site total doses from gaseous effluent for maximally exposed individual and nearest individual are well below the 10 CFR Part 20 public dose limits.
15
Chapter 12, Conduct of Operations Notable Changes:
- PSAR Section 12.1, Organization
- Staffing may be shared to support each of the licensed reactors on the site SE finding: Hermes 2 is sufficiently similar to Hermes 1 such that use of the same staff across both facilities would be appropriate for certain functions
- PSAR Section 12.9, Quality Assurance
- Quality assurance program description (QAPD) provided in Appendix 12B is also applicable to Hermes 2 SE finding: the information contained in the QAPD is independent of the facility differences between Hermes 1 and Hermes 2 and that use of the Hermes 1 QAPD for Hermes 2 is acceptable.
16
Chapter 14, Technical Specifications Notable changes:
- Technical specification (TS) variables and conditions apply to both Hermes 2 units
- Operating modes apply to both Hermes 2 units SE finding: the clarifications are appropriate for the two-unit Hermes 2 facility because all reactors must have TSs and the two units are proposed to be identical
- Intermediate heat transport system (IHTS) and power generation system (PGS) included as probable subjects of TSs SE finding: Kaiross addition of the IHTS and PGS parameters as probable subjects of TS limiting conditions for operation to be acceptable 17
Chapter 16, Other License Considerations
- No changes from Hermes 1
- All equipment to be installed in the Hermes 2 facility will be new and purpose-built. No prior use components will be used in the construction of the reactor or support systems
- Hermes 2 will not contain equipment or facilities associated with the direct medical administration of radioisotopes or other radiation-based therapies 18
Chapter 17, Decommissioning and Possession-Only License Amendments
- No changes from Hermes 1
- Hermes 2 decommissioning plan will be provided with an operating license application
- Kairos is not seeking a possession-only license 19
Chapter 18, Highly Enriched to Low Enriched Uranium Conversion
- No changes from Hermes 1
- Hermes 2 reactor fuel is a hightemperature graphitematrix coated TRISO particle using high assay, low enriched uranium
- Hermes 2 will not utilize highly enriched uranium, i.e., uranium that is enriched to 20 percent or more in uranium-235 20
Chapter 4, Reactor Description Describes key aspects of reactor design:
- Reactor core (fuel, control and shutdown system, neutron startup source)
- Reactor vessel and internals
- Biological shield
- Nuclear and thermal-hydraulic designs
- Reactor vessel support system Notable Changes:
- Section 4.2, Reactor Core
- Reactor control and shutdown system (RCSS) SSCs, portions of plant control system (PCS) that controls RCSS, and neutron startup sources are not shared between Unit 1 and Unit 2.
SE finding: this design approach increases degree of independence between two units and reduces potential for postulated event in one unit affecting safe operation of other unit consistent with requirements of 10 CFR 100.11(b)(1).
21
22 Chapter 4, Reactor Description Notable changes (contd)
- PSAR Section 4.6, "Thermal-Hydraulic Design"
- IHTS is added to the list of systems that affects thermal-hydraulic design of the reactor system
- Detailed safety evaluation of IHTS will be discussed in Chapter 5 and 13:
- Preliminary evaluations and independent scoping calculations show that the TRISO fuel is expected to maintain its integrity during the postulated events and the MHA remains bounding for all the postulated Hermes 2 events SE finding: Preliminary information provides reasonable assurance that the reactor system will be designed with appropriate margin to ensure that specified acceptable system radionuclide release design limits (SARRDL) are not exceeded during normal operations, transients, or accident conditions.
23 Notable changes (contd)
- Section 4.3, Reactor Vessel
- Tables added to describe plans for graphite and metallic material qualification testing for an 11-year lifetime Metallic materials qualification:
Included corrosion tests with the intermediate salt
- Certain qualification testing justifications used either extrapolation or times/conditions for the KP-FHR Graphite materials qualification:
- Demonstrates the graphite components remain pre-turnaround and that plant parameters stay within the qualification envelope. If this can't be demonstrated, Kairos will collect additional data for irradiation creep and/or expand the qualification envelope.
SE finding: the preliminary information was sufficient to provide reasonable assurance that the reactor vessel system will be designed to maintain integrity for its anticipated life.
Chapter 4, Reactor Description
Chapter 7, Instrumentation and Control Systems Notable Changes:
- New unit-specific subsystems
- Intermediate heat transport control system (IHTCS)
- 5 auxiliary monitored systems (compressed air, chilled water, electric supply/loads, reactor building HVAC, environmental monitoring)
- Dedicated consoles in the main control room (MCR) are provided to control and monitor each unit and shared system
- New shared subsystem
- Power generation control system 24
Chapter 7, Instrumentation and Control Systems
- Staff evaluated new design information and significant changes to the:
- Plant Control System (PCS)
SE finding: the level of detail provided on the PCS, including its reactor control system, is consistent with the applicable acceptance criteria in NUREG-1537, Part 2, Section 7.3, Reactor Control System, and demonstrates an adequate design basis for a preliminary design
- Reactor Trip System (RTS)
SE finding: Kairos provided the necessary design basis information for the reactor protection system trip of the intermediate salt pump and meets the guidance of NUREG-1537, Part 2, Section 7.4, Reactor Protection System
- Main Control Room SE finding: the consideration of human factors engineering and addition of the Power Generation Control System and Auxiliary Monitored Systems on the MCR control boards and to Figures 7.1-1 and 7.4-1 is acceptable for a test reactor CP application.
25
ACRONYMS CP Construction permit DHRS Decay heat removal system HVAC Heating, ventilation, and air conditioning IHTCS Intermediate heat transport control system IHTS Intermediate heat transport system MCR Main control room MHA Maximum hypothetical accident MW Megawatts PCS Plant Control System PDC Principal Design Criteria 26 PGS Power generation system PSAR Preliminary safety analysis report QAPD Quality assurance program description RCSS Reactor control and shutdown system RTS Reactor trip system SE Safety evaluation SSC Structure, system, or component TEDE Total effective dose equivalent TS Technical specification UPS Universal power system