ML22172A025
| ML22172A025 | |
| Person / Time | |
|---|---|
| Issue date: | 05/18/2022 |
| From: | Charles Brown Advisory Committee on Reactor Safeguards |
| To: | |
| Brown, C, ACRS | |
| References | |
| NRC-1960 | |
| Download: ML22172A025 (158) | |
Text
Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION
Title:
Advisory Committee on Reactor Safegards SHINE Subcommittee Docket Number:
(n/a)
Location:
teleconference Date:
Wednesday, May 18, 2022 Work Order No.:
NRC-1960 Pages 1-110 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 SHINE SUBCOMMITTEE 7
+ + + + +
8 OPEN 9
+ + + + +
10 WEDNESDAY 11 MAY 18, 2022 12
+ + + + +
13 The Subcommittee met via Video 14 Teleconference, at 8:30 a.m. EDT, Ronald Ballinger, 15 Chairman, presiding.
16 SUBCOMMITTEE MEMBERS:
17 RONALD G. BALLINGER, Chairman 18 VICKI M. BIER, Member 19 CHARLES H. BROWN, JR. Member 20 VESNA B. DIMITRIJEVIC, Member 21 GREGORY H. HALNON, Member 22 WALTER L. KIRCHNER, Member 23 JOSE MARCH-LEUBA, Member 24 DAVID A. PETTI, Member 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 JOY L. REMPE, Member 1
MATTHEW W. SUNSERI, Member 2
3 ACRS CONSULTANT:
4 DENNIS BLEY 5
KEN CZERWINSKI 6
7 DESIGNATED FEDERAL OFFICIAL:
10 ALSO PRESENT:
11 MICHAEL BALAZIK, NRR 12 JEFFREY BARTELME, SHINE 13 JOSH BORROMEO, UNPL Branch Chief, NRR 14 MIKE CALL, NMSS 15 ELIJAH DICKSON, NRR 16 JAMES HAMMELMAN, NMSS 17 CATHERINE KOLB, SHINE 18 JEREMY MUNSON, NMSS 19 ALEXANDER NEWELL, SHINE 20 TRACY RADEL, SHINE 21 MICHAEL SALAY, RES 22 JOSEPH STAUDENMEIER, RES 23 DEREK WIDMAYER, ACRS 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 TABLE OF CONTENTS 1
2 Opening Remarks by Ron Ballinger...................6 3
Presentation by Tracy Radel........................7 4
Presentation by Elijah Dickson....................29 5
Presentation by Mike Call.........................42 6
Presentation by Elijah Dickson....................66 7
Presentation by Mike Salay.......................73 8
Presentation by Elijah Dickson....................84 9
Presentation by James Hammelman...................98 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
4 P R O C E E D I N G S 1
8:30 a.m.
2 CHAIR BALLINGER: Good morning again, this 3
is a meeting of this SHINE Subcommittee of the 4
Advisory Committee on Reactor Safeguards. I'm Ron 5
Ballinger, Chairman of the Subcommittee.
6 ACRS Members in attendance, I won't need 7
to go through the list, it's the same as yesterday.
8 We're basically reconvening the meeting that we 9
started yesterday.
10 Today we'll cover Chapter 13 and we'll 11 have a closed session after Chapter 13's open session 12 on Chapter 13 and any other areas that we might need 13 to discuss as we mentioned yesterday.
14 Today's meeting is held in person and also 15 over Teams so Teams people, be careful, mute yourself 16 at all times unless you're making a comment. If you 17 make a comment, please state your name and make your 18 comment when we go to public comments so the court 19 reporter will know who you are.
20 Again, the transcript of the meeting is 21 being kept. What else do we need to be careful about?
22 That's about it. SHINE folks are up. Josh, do you 23 want to make a comment of any kind?
24 MR. BORROMEO: I don't have any.
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 CHAIR BALLINGER: So, I think we're ready 1
to roll. Is it Tracy that's going to present?
2 MS. RADEL: This is Tracy Radel. I'm 3
going to go over the accident analysis today.
4 Some of this will look familiar and it was 5
presented at an earlier ACRS session but I thought it 6
was good to go over the methodology again, refresh 7
that before diving into the specific accident 8
scenarios in the closed session.
9 SHINE applies a SHINE-specific risk-based 10 methodology similar to the guidance described in NUREG 11 1520. This is applied to both the DRH and the 12 irradiation facility and the radioisotope production 13 facility for consistency of the safety analysis across 14 the facility.
15 The SHINE safety analysis is developed 16 based on the following major steps. First, 17 identification and systematic evaluation of hazards at 18 the facility. This is generally done through HAZOPS 19 and failure of the effects analyses.
20 Then the confluence of identification of 21 potential accident sequences that would result in the 22 next topical concerns.
23 The identification of safety-related 24 controls, other controls as well as administrative 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
- controls, the identification of programmatic 1
administrative controls that intrude on the 2
availability and reliability of the identified safety 3
systems, and then the assessment of radiological and 4
chemical consequences for the postulated accident 5
sequences given the applied controls, demonstrating 6
that all scenarios are within acceptable limits.
7 CHAIR BALLINGER: This is Ron Ballinger.
8 Failure modes and effects analysis is a term of art.
9 Did you folks actually perform an FMEA, a formal one?
10 MS. RADEL: We have performed an FMEA and 11 it depends on the system that we're looking at so the 12 appropriate method was chosen based on the system.
13 So, those were either HAZOPS, FMEAs, or what-if 14 checklists and scenarios.
15 CHAIR BALLINGER: Thank you.
16 MS. RADEL: The acceptance criteria here, 17 acceptable risk is achieved by ensuring the event is 18 highly unlikely or the consequences are below the 19 SHINE safety criteria.
20 The SHINE safety criteria is listed here 21 and they include an acute worker dose of 5 rem or 22 greater, an acute dose of 1 rem or greater to any 23 individual located outside the owner-controlled area.
24 An intake of 30 millirem or greater 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
7 uranium to any individual located outside the owner-1 controlled area, and acute chemical exposure to an 2
individual from licensed material or hazardous 3
chemicals produced from licensed material that could 4
lead to irreversible or other serious long-lasting 5
health effects to a worker.
6 Or it could cause transient health effects 7
to any individual located outside the owner-controlled 8
area. Criticality where fissionable material is used, 9
handled, or stored with the exception of the solution 10 vessel or loss of capability to reach safe shutdown 11 conditions.
12 The relevant accident categories were 13 identified using the ISG-augmenting NUREG-1537.
14 Hazard evaluations identified potential initiating 15 event consequences and controls. These were HAZOPS, 16 FMEAs, or what-ifs.
17 The hazard evaluations also identify the 18 SHINE-specific accident types such as those in tritium 19 or the neutron driver. The hazards that are 20 identified through the different analyses are 21 summarized in the process hazard analysis.
22 DR. BLEY: May I interrupt you? This is 23 Dennis Bley. yesterday you folks talked about a lot 24 about how unique this facility is and I think I 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 certainly agree with you.
1 Why, then, is just using the guidance for 2
more standard facilities a complete enough search for 3
accident categories?
4 MS. RADEL: So, we evaluated the systems 5
for all failures, we identified that through the 6
HAZOPS, FMEAs and what-if checklist, going through 7
each component, its potential failure mechanisms.
8 We didn't limit ourselves in any way in 9
those hazard evaluations, just as we were rolling 10 those out into accident categories, we defined the 11 accident categories. Those were all rolled up into 12 NUREG-1537.
13 DR. BLEY: That helps, I'll let you go 14 ahead but one thing we hinted at I think a while back, 15 and I don't recall seeing anything that clarifies it, 16 when you did this search using HAZOPS and other 17 approaches, did you identify specific important human 18 actions?
19 I was looking for a table of those and how 20 you identified them.
21 MS. RADEL: There are administrative 22 controls identified within the safety analysis and we 23 can go into some specific ones when we get into closed 24 session and go through the different accident 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 scenarios that were evaluated.
1 DR. BLEY: I would appreciate that and I'm 2
oversimplifying what you just said back to me, it 3
would seem strange to me if every important human 4
action was handled strictly by administrative controls 5
but I can wait for the closed session to hear about 6
that.
7 MS. RADEL: The process hazard analysis is 8
a summary documenting the most significant events from 9
the HAZOPS, FMEAs and what-if checklist, and this is 10 documented in the SHINE safety analysis report.
11 The risk index for each potential 12 unmitigated accident sequence is provided there. This 13 is the likelihood times the consequence. It 14 identifies engineered and administrative controls.
15 The risk for the controlled event is 16 generated using the revised likelihood and consequence 17 of the controls in place. And this then results in a 18 comprehensive list of the safety-related controls for 19 the facility, both administrative and engineered.
20 MEMBER REMPE: This is Joy Rempe and I had 21 a question. First of all, I appreciated the Staff 22 identifying some of the documents where we could find 23 more details about the actual approach to perform the 24 safety analysis.
25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
10 Again, you can answer this in the closed 1
session but I was curious about -- I also appreciate 2
you guys providing those documents when I requested 3
them, or at least access to them.
4 But what I didn't see was much about the 5
sensitivity analysis you did that were referenced by 6
the Staff that gave them confidence.
7 At a high level here in the open session, 8
could you talk about extensive the sensitivity 9
analyses were and what assumptions were found to have 10 the most impact in the results?
11 MS. RADEL: Just for clarification, are 12 you talking about sensitivity analyses related to 13 activity assertions or just in general?
14 MEMBER REMPE: All of the safety analyses, 15 and when we get to the closed session I can even point 16 out which sequences the Staff referenced where they 17 talk about the sensitivity analyses gave them 18 confidence in the results.
19 But what I'm curious about is I thought a 20 long time ago I had seen something from you guys 21 saying that you did do some sensitivity analyses.
22 I don't think you did a full-fledged 23 uncertainty analyses where you propagated the 24 uncertainties through the analysis and you can confirm 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 that, but I didn't see anything that suggested that.
1 But if you did some sensitivity analyses 2
Id like to know what parameters were evaluated. I 3
think the Staff thought you picked the most 4
conservative values but was that the only scenario 5
where you did sensitivity analyses, the criticality?
6 I know for sure we mentioned it with 7
respect to the design basis accidents that you 8
analyzed. So, anyway, I just am curious if you could 9
give us any sort of insight about how extensive your 10 sensitivity analyses were?
11 MS. RADEL: Yes, we did perform extensive 12 uncertainty analysis on the different parameters 13 related to reactivity, coefficients, productivity 14 coefficients, the delayed neutron fraction.
15 Pretty much all of the different 16 reactivity parameters used benchmark cases to come up 17 with 95 percent confidence intervals for those 18 important parameters.
19 When we went to go evaluate specific 20 scenarios within the accident analysis that were more 21 along the lines of the releases, due to failures in 22 the process boundaries or events that resulted in 23 radiological release, the approach there was to take 24 a very conservative bounding approach to each of 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
12 different parameters in the scenario.
1 And you'll see that we get into the 2
specific scenario descriptions within the closed 3
session. But for each of the different aspects of the 4
accident, we looked at what would be the most bounding 5
situation even if they were quite a bit outside of the 6
normal operating parameters.
7 MEMBER REMPE: Let me repeat back to you, 8
and I think I heard you say you only did sensitivity 9
analysis with respect to the criticality events that 10 you evaluated.
11 And then with respect to the release 12 fractions, you didn't really do sensitivity analysis, 13 you just looked at it and said we're taking some 14 bounding assumptions. Is that true?
15 MS. RADEL: Yes, that's correct. Just to 16 clarify the reactivity insertions, those were not 17 reaching criticality but similar.
18 MEMBER REMPE: Reactivity insertions, 19 thank you for the correction. Could you tell us what 20 parameters you found to be the most sensitive in the 21 sensitivity analyses you did?
22 MS. RADEL: In the closed session we can 23 go into the uncertainties that we found on those and 24 the values themselves and talk through those numbers.
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 Both are proprietary.
1 MEMBER REMPE: Thank you.
2 MS. RADEL: This slide here shows the 3
different accident categories for the radiation 4
facility and the radioisotope production facility as 5
well as external events.
6 These categories primarily come out of 7
NUREG-1537 but extend as I said, we do have 8
facility-specific events and that covers anything that 9
didn't fit into those accident categories. So, we 10 make sure that everything is captured.
11 MEMBER MARCH-LEUBA: This is Jose. In the 12 open session, can you describe at a high level what 13 the MHA was?
14 MS. RADEL: Yes, the maximum hypothetical 15 accident was a release into the TSV off-gas cell. So 16 we release out of that gaseous support system for the 17 irradiation units.
18 MEMBER MARCH-LEUBA: So, it would be 19 similar to a large-break LOCA in the gas area of the 20 TSV?
21 MS. RADEL: It is a break of the system.
22 MEMBER MARCH-LEUBA: There is no loss of 23 coolant. So, it's a big break on top of the vessel.
24 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
14 MS. RADEL: Here are the risk matrices 1
that we have for development of those numbers within 2
the SHINE safety analysis, so on the upper left there 3
are the consequence categories.
4 These are similar to 1520 but we do adjust 5
the very routine low-consequence and intermediate 6
consequence to align with the SHINE safety criteria.
7 So, low consequence meets the SHINE safety criteria.
8 On the right there is the severity, we do 9
either require that events are highly unlikely, 10 essentially preventing the event or of low consequence 11 with the mitigations in place. We do not have an 12 intermediate unlikely event being acceptable.
13 The other values there, the highly 14 unlikely is defined as 10 to the -5 per event per 15 year.
16 MEMBER DIMITRIJEVIC: This is Vesna 17 Dimitrijevic, let me ask you a question on the risk 18 matrix. Can you hear me?
19 MS. RADEL: Yes.
20 MEMBER DIMITRIJEVIC: You have adjusted 21 this medium Category 4 to be unacceptable and modified 22 risk matrix but in that case you don't really need the 23 three categories.
24 You can simplify your calculation by 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 combining the 2 and 3 vote in likelihood and 1
consequences.
2 Once when you make this change, the vision 3
to the three categories is not necessary. So, I'm not 4
sure, why did you decide to make this change?
5 MS. RADEL: That's a very good point, that 6
we wouldn't need that extra row. At one point early 7
on in our development, we did have that four box as 8
being acceptable. But we made a change later on to 9
require that you reach either highly unlikely or below 10 the SHINE safety criteria.
11 MEMBER DIMITRIJEVIC: I just want to point 12 out that in that case, you just overly complicated the 13 vision. The vision could be significantly simplified 14 if you wanted do it this way. I just wanted to make 15 that point.
16 MS. RADEL: Thank you.
17 MEMBER REMPE: Just a little curiosity 18 question, why not call not unlikely anticipated 19 operational -- I always kind of stumble on it when I 20 read the phrase not unlikely.
21 MS. RADEL: Yes, that language does come 22 out of NUREG-1520 so we just used the consistent 23 language there.
24 MEMBER REMPE: 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
16 MEMBER MARCH-LEUBA: Plus it also has 10 1
to the -2. This is 10 to the -4.
2 MEMBER REMPE: Not unlikely.
3 MEMBER DIMITRIJEVIC: They did forget to 4
say likely.
5 MEMBER REMPE: This one comes across.
6 MEMBER MARCH-LEUBA: Once every 10,000 7
years is not likely.
8 MEMBER PETTI: There should be better 9
alignment.
10 MEMBER DIMITRIJEVIC: Less unlikely.
11 MEMBER REMPE: I like that, Vesna, I like 12 less likely, something like that, anyway.
13 MS. RADEL: Next slide. Here we have the 14 guidance that we used as far as the failure frequency 15 index numbers, the failure probability index numbers 16 and the duration index numbers that were used to get 17 the likelihoods.
18 Safety-related controls that are credited 19 for the prevention or mitigation of accidents are 20 either engineered controls, and this can be either 21 active or passive, and then specific administrative 22 controls.
23 Programmatic administrative controls are 24 also implemented to assure the safety-related controls 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
17 can perform their intended functions, and defense 1
in-depth controls are also identified.
2 They're not credited but they provide 3
additional margin for risk reduction.
4 MEMBER KIRCHNER: This is Walt Kirchner.
5 Are there any categories that stand out -- it's a 6
variation on Dennis's question I think -- in your 7
accidents where a significant release is prevented by 8
administrative or programmatic controls?
9 MS. RADEL: We do not have any scenarios 10 where operator action is credited to mitigate the 11 event once it has occurred. So, we've relied on 12 engineer controls for all of that mitigation once an 13 accident has initiated.
14 There are some administrative controls to 15 contribute the prevention for reduction in source term 16 prior to new events occurring that are outlined. For 17 the most part, though, the controls are engineered 18 controls.
19 MEMBER KIRCHNER: That's the answer I was 20 looking for. Thank you.
21 MEMBER DIMITRIJEVIC: Let me ask you a 22 question to follow this. You have open attachments, 23 you credited the elevating likelihood, so you have a 24 serious screen based on assumed operator actions, 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 right?
1 MS. RADEL: They're accredited operator 2
actions, yes, for prevention of scenarios.
3 MEMBER DIMITRIJEVIC: So, you're looking 4
in scenarios, not just initiating events? They 5
actually operator actions with each
- other, 6
complementing to the screening out some scenarios, 7
right?
8 MS. RADEL: Yes, that's correct.
9 MEMBER DIMITRIJEVIC: My question is why 10 you didn't really consider that to be an operator 11 action, do you know what I mean? You varied the 12 likelihood of this.
13 MS. RADEL: Those are operator actions 14 that are accredited are specifically called out in the 15 safety analysis and those accredited operator actions 16 are treated differently in the procedures and noted 17 that those are accredited actions.
18 They are given a low value as far as the 19 reduction in likelihoods. The administrative controls 20 get less credit in the likelihood evaluation because 21 we know that humans are less reliable than the 22 engineered controls.
23 MEMBER DIMITRIJEVIC: My point was that 24 you just responded to the previous question saying 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 that no operator action crediting mitigating but 1
that's a true statement because they're buried in the 2
prevention.
3 So, they operator action credited in 4
preventing the accidents.
5 MS. RADEL: Correct, in preventing. In 6
mitigation, once the accident has begun, the statement 7
made was that operator action is not credited after 8
the event has occurred to mitigate the consequences.
9 MEMBER DIMITRIJEVIC: Thanks.
10 MS. RADEL: Radiological consequences are 11 determined for members of the public and control room 12 operators.
13 The process includes calculation of 14 radiological inventories, definition of 15 accident-specific material at risk, transport of the 16 radionuclides, which leads to development of the 17 accident source term, and then the convergent 18 radiological dose.
19 Worker and public doses are generally 20 calculated over a 30-day period. The exception here 21 is tritium and the tritium confinement boundary which 22 uses a 10-day interval for the accident duration.
23 Conservatisms are applied to the dose 24 analysis. There's a list here of some of them 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
20 apply across all scenarios. The bounding TSV power 1
history and operational cycle is used.
2 We used minimum nuclide decay times, times 3
to transport nuclides out of the process systems are 4
neglected so the inventory is immediately transferred 5
out of the tank or the piping into the confinement if 6
there is a breach involved in the scenario.
7 Compensation is conservative and limited 8
as far as radionuclides depositing on the walls versus 9
remaining airborne. Non-credited filtration is 10 neglected.
11 There are a few filters in the system on 12 the outlet of the hot cells that are credited but for 13 the most part, the filtration within the facility is 14 not credited and is neglected.
15 MEMBER MARCH-LEUBA: This is Jose, how do 16 you treat the confinement, is it leakage tray or does 17 it fail completely?
18 MS. RADEL: The confinement has a defined 19 leak rate, each confinement has its own defined leak 20 rate and we make sure that it meets that leak rate 21 prior to going into operation.
22 MEMBER MARCH-LEUBA: So, you use the 23 nominal leak rate that you assume for confinement?
24 MS. RADEL: We use a leak rate based on 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
21 each confinement so it's not the same for, say, the IU 1
cell versus the hot cell boxes. It's defined based on 2
which --
3 MEMBER MARCH-LEUBA: How is that leak rate 4
estimated?
5 MS.
RADEL:
It's defined in the 6
requirement specifications for the different facility 7
components and then it is tested as part of the 8
testing as a safety function of that component.
9 MEMBER MARCH-LEUBA: That's what I wanted 10 to hear. After you build the facility you will test 11 for the leak rate?
12 MS. RADEL: Yes.
13 MEMBER KIRCHNER: Just to follow on, then, 14 those numbers are used for the leak path factor? This 15 is Walt Kirchner.
16 MS. RADEL: Yes, there's a leakage rate 17 that is used within the radiological dose 18 calculations. That leakage rate was determined in 19 those calculations applied to the equipment. It was 20 chosen based on what we knew that type of equipment 21 could achieve.
22 And it was specified for the equipment 23 when we tested prior to starting operations.
24 MEMBER REMPE: This is Joy, I just wanted 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 to add a comment here.
1 I really like the level of effort you went 2
to with this Fowski report, where you actually went 3
through and estimated leak factors and airborne 4
release fractions based on available data and actually 5
applied the model to other facilities.
6 I thought that was a level of effort I had 7
not yet seen with some of the other folks that are 8
coming in with unique facilities. And so I think a 9
kudos are in order.
10 MEMBER PETTI: So, Tracy, just a question, 11 a clarification, on the condensation. For tritium, do 12 you assume it's HT or HTO?
13 MR. NEWELL: This is Alex Newell, the 14 criticality safety lead.
15 For transports of material in that model, 16 it's assumed to be a gas but because the dose 17 conversion factor for tritiated water is higher, we 18 assume that the tritium exits the facilities in that 19 form.
20 MEMBER PETTI: So, you don't condense it, 21 per se, you assume it's a gas that doesn't condense 22 and then from a dose perspective, you use the higher 23 dose conversion of HTO.
24 MR. NEWELL: That's correct.
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23 MEMBER PETTI: Thanks.
1 MS. RADEL: And we use chi over Q values 2
that are the 95th percentile. This diagram here shows 3
the process of determining the radiological 4
consequences, it's a lot to go through so adjust it.
5 If you have any questions, I can answer those now.
6 MEMBER PETTI: Tracy, I don't recall from 7
when I read this the statistical adjustment. What is 8
that in the inventory?
9 MS. RADEL: We did do a statistical 10 analysis on the source terms. It was a very small 11 effect and it's another conservatism that I didn't 12 list in the previous slide because there's a small 13 change from the other ones.
14 MEMBER PETTI: Thanks.
15 MS. RADEL: The last slide here is just 16 touching on the hazard chemicals.
17 Chemical hazards of licensed material, 18 hazardous chemicals interacting with licensed material 19 and hazardous chemicals from licensed material are 20 evaluated in the SHINE safety analysis.
21 Chemical consequence assessments 22 demonstrate that consequences meet the SHINE safety 23 criteria for the public and the workers. And here the 24 workers include both the RCA worker and the control 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 room operator.
1 DR. BLEY: Tracy, it's Dennis Bley. Could 2
you go back one slide to your diagram? Down in the 3
bottom, you're doing a public dose and a control room 4
dose. Where do you do the workers who are not in the 5
control room?
6 (Simultaneous Speaking.)
7 MS. RADEL: We do evaluate the RCA worker 8
dose also within our dose calculation but it was not 9
something that was required from a regulatory 10 perspective to be provided. But we do calculate it 11 and verify that it is all for below the SHINE safety 12 criteria.
13 DR. BLEY: Thank you, and I guess you're 14 showing what's required on here so I get that. I'm 15 glad you're doing the other one though, because it's 16 got to be higher.
17 MS. RADEL: It depends on the scenario, 18 there are some scenarios where because it's more of an 19 external release, the control room dose is higher than 20 the RCA workers' dose. But the residence time within 21 the RCA is fairly short versus the time spent in the 22 control room.
23 DR. BLEY: Thank you.
24 MS. RADEL: The PAVAN computer code is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
25 used to perform consequence analysis for the public 1
and nearest resident and consistent with the accident 2
analysis overall, we used the 95th percentile chi over 3
Q values.
4 MEMBER PETTI: What code was used to do 5
the control room dose?
6 MS. RADEL: Can you repeat the question?
7 MEMBER PETTI: What code was used to do 8
the control room dose?
9 MR. NEWELL: We did the wrong calculation.
10 This is Alex Newell, we used ARCON96 to calculated the 11 control room chi over Q.
12 MEMBER KIRCHNER: This is Walt, just one 13 question on chemical exposures. I'm trying to think 14 of the different chemicals you're using in your 15 processes. Do you have any ground-huggers, so to 16 speak?
17 In other
- words, heavier than
- air, 18 chemicals that are part of your processes?
19 MS. RADEL: As far as those that are mixed 20 with licensed material, they were evaluated in Chapter 21
- 13. I would have to look through the list, it's 22 provided in the closed session slides.
23 I don't know offhand of any that were 24 denser than air that presented that.
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26 MEMBER KIRCHNER: Because using the chi 1
over Q doesn't make any sense if you've got chemicals 2
that are heavier, that's the plume-type model. If 3
you've got something like CO2 that's a ground-hugger, 4
then it's a different kind of analysis to account for 5
that.
6 MS. RADEL: I don't believe any of the 7
ones on that list provided at the end of the closed 8
session slides were of that type but we can verify 9
that.
10 MEMBER KIRCHNER: That's good, thank you.
11 MEMBER BIER: Are you done with your 12 comments on this slide, Tracy?
13 MS. RADEL: This is the last slide, so if 14 you have any questions for open session here, we can 15 take those. Otherwise, we are clear for the closed 16 session.
17 MEMBER BIER: This is Vicki Bier.
18 I wanted to go back to the risk matrix 19 slide if you can, I forget what number that is? I 20 wanted to raise an issue, not because I object to 21 using risk matrices but I just want to illustrate a 22 potential limitation of them.
23 Which is that in theory, there can be 24 events in the green area that are worse than events 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
27 the orange area, and that's because these bounds are 1
I don't want to say broad but they're not points.
2 So, if you take, for example, the middle 3
row and the dividing line between green and orange, 4
you could have an event in the green that is close to 5
the maximum dose, say, close to 100 rem for facility 6
staff.
7 But a low likelihood within that range of 8
likelihood -- sorry, high likelihood within that range 9
of likelihood. So, high on both so you can think of 10 it as being in the upper right-hand corner of the 11 green square, I wish we could annotate these.
12 And then in the orange square, the one 13 with the rating of 4, you can get an event that is 14 very low within the range of dose, say, 6 rem to 15 facility staff and low within the band of likelihood, 16 just barely above 10 to the -5.
17 And so the green event could be almost a 18 factor of 15 worse than the orange event. Like I 19 said, I don't object to using risk matrices as long as 20 people realize they're a pretty coarse tool.
21 But if interested, a colleague wrote a 22 paper on the pitfalls of risk matrices so I could 23 share that with the DFO to pass onto you if people are 24 interested, et cetera.
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28 MS. RADEL: That's a very good point.
1 MEMBER BIER: It's just awareness.
2 MS. RADEL: That would be great.
3 Some of the challenge here is defining the 4
likelihoods for the facility that has not been built 5
before, is new, and so we take conservative approaches 6
to assigning those likelihood numbers and take a more 7
simplified approach here.
8 Any other questions?
9 CHAIR BALLINGER: Is that the end, Tracy 10 MS. RADEL: Yes, it's the end of the open 11 session presentation.
12 CHAIR BALLINGER: Thank you, if there are 13 any comments from the Members before we switch to the 14 Staff? Hearing none, okay, there is the Staff 15 presentation. Who is the presenter?
16 MR. DICKSON: Hi there, this is Elijah 17 Dickson along with my colleagues, doing the Chapter 13 18 accident analysis. Can you hear me okay? They're in 19 the meeting room.
20 CHAIR BALLINGER: Yes.
21 MR. DICKSON: Good morning, ACRS Chairman 22 and Members, my name is Elijah Dickson, I'm a reactor 23 scientist in the Office of Nuclear Reactor Regulation, 24 Division of Risk Assessment, Radiation Protection 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
29 Consequence Branch.
1 I'd also like to thank Tracy for providing 2
the overview of SHINE's perspective of SHINE's 3
accident analysis. I'll be presenting, along with my 4
colleagues our review of the Chapter 13 accident 5
analysis today. Next slide, please.
6 This was very much a team effort with 7
technical expertise across several NRC organizations.
8 My organization, the Office of Nuclear Reactor 9
Regulation, NRR, but also the Office of Nuclear 10 Materials and Safety Safeguards, NMSS, and Office of 11 Research.
12 I'll be presenting with Mike Call today, 13 who will be presenting on the SHINE safety analysis, 14 and James Hammelman, who will be presenting 15 specifically on the SHINE chem safety analysis.
16 Jeremy Munson you heard yesterday speaking 17 in regard to criticality safety, Kevin Quinlan is our 18 meteorologist, Mike Salay from Office of Research 19 performed or helped review iodine transport 20 calculations and models.
21 Can we move on to the next slide, please?
22 Contents. I'll provide a little bit of a 23 background of our review and approach to Chapter 13 24 accident analysis. We'll then dive right into 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
30 SHINE SSA or SHINE safety analysis. I'll speak to 1
SHINE's design basis accident analyses, and again, 2
right on into chem safety by James Hammelman.
3 We'll discuss what we learned from our 4
audits and confirmatory analyses, and then finally 5
present to you our evaluation findings and 6
conclusions. Next slide, please.
7 Here's a list of regulatory requirements 8
and commitments, 10 CFR 5034 of course has SHINE 9
present to us a final safety analysis report for our 10 review.
11 5036 and the technical specifications help 12 us identify safety-related structured systems and 13 components for SSCs, their safety limits, and their 14 limiting safety system settings, or LSSSs, as well as 15 those limiting conditions of operations.
16 And in doing the dose analyses, we 17 particularly focus on the first three criterion of the 18 technical specifications, Criterion 1 includes tech 19 specs for instrumentation that are used to detect and 20 indicate in the control room significant abnormalities 21 or degradations in the reactor coolant pressure 22 boundary.
23 Criterion 2 are process variables, design 24 features and operational restrictions that are initial 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 conditions of a design basis accident or transient, 1
that either assumes failure or presents a challenge to 2
the integrity of the primary fission product barrier.
3 And then
- lastly, Criterion C
are 4
structures, systems, and components that are part of 5
the primary success pathway, which actually actuate or 6
mitigate design basis accidents that either assume a 7
failure or present a challenge to the integrity of the 8
primary fission product barrier.
9 We also have commitments that are similar 10 to those of 10 CFR Part 70. Jeremy Munson today 11 discussed what those commitments were.
12 Again, you can find those in Tech 13 specification 5.8.3, these are or additional reporting 14 requirements since much of the SHINE facility is very 15 similar to a materials facility.
16 Next slide, please. I'll go over the 17 regulatory guidance. There is quite a bit of 18 regulatory guidance that the Staff needs to utilize to 19 perform such a review. The two primary guidances are 20 NUREG-1537 Parts 1 and 2.
21 Part 1 is the guidance preparing reviewing 22 applications for licensing of non-power reactors.
23 This is the format and content guide. Part 2 is the 24 standard review plan and acceptance criteria that 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
32 Staff use.
1 Now, for both Part 1 and Part 2 of NUREG-2 1537, there is final interim staff guidance that's 3
specific to the licensing of radioisotope production 4
facilities and for aqueous homogeneous reactors.
5 Part 2 was leaned on heavily for the 6
information regarding our standard review plan and our 7
acceptance criteria. Onto Slide 6, please?
8 Continuation of regulatory
- guidance, 9
NUREG-1520 is the standard review plan for fuel cycle 10 facilities and licensing applications. This was the 11 primarily guidance that NMSS utilized which then 12 points you to NUREG-1513 which is the integrated 13 safety analysis guidance document.
14 This document was utilized to review 15 SHINE's safety analysis summary.
16 NUREG CR-6410, the nuclear fuel cycle 17 facility accident analysis
- handbook, was very 18 important for the Staff in performing the material of 19 risk calculations and transport of the source term 20 through the systems into the environment.
21 It provides methodologies to do those 22 calculations and then the last three bullets are in 23 regard to reviewing atmospheric and meteorological 24 characteristics of 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
33 NUREG CR-2858, Regulatory Guide 1.145, and 1
2 MEMBER PETTI: Elijah, just a question.
3 You've got mixed guidance here coming from the non-4 power reactors in the fuel cycle. Was there any case 5
where the guidance was contradictory or was it just 6
more additive or explanatory?
7 This is kind of a unique case but it would 8
be interesting to know if you guys had to make some 9
decisions, like one guide said X and the other guide 10 said anti-X and you had to figure out what made sense.
11 MR. DICKSON: From the Staff perspective, 12 I think we all probably have a short list of where 13 there might be some contradictions between the 14 different guidances. But working together, we're able 15 to work through some of those types of issues.
16 There's a couple areas of the guidance 17 that could use some improvement, or
- rather, 18 clarification really.
19 MEMBER PETTI: That's good to know because 20 I think we're going to see cases where we have unique 21 facilities and the rules may not always fit and 22 separate so nicely into these buckets.
23 MR. DICKSON: One, for instance, is the 24 use of dose conversion factors that align with 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
34 regulations, that's something that can probably be 1
spelled out pretty clear in regulatory guidance.
2 There's a whole host of dose conversion 3
factors, or DCS, out there that are designed for 4
different ICRP methodologies, the different tissue-5 weighting coefficients, and in pointing licensees to 6
the ones that we've endorsed that meet the regulation, 7
it's very much like a nuanced issue that we see every 8
couple of years, for instance.
9 That could be an improvement for the 10 guidance.
11 DR. BLEY: Elijah, I'm following up on 12 that. How or who on Staff keeps track of these sorts 13 of things so they either end up in interim Staff 14 guidance or in changed guidance documents?
15 MR. DICKSON: There's a Branch in the 16 Division of Advanced Reactors who are owners of our 17 guidance and I believe they keep track of these items 18 as they seek to update the guidance that are updated 19 every 10 years.
20 DR. BLEY: So, each of you, as you were 21 saying, found different things. I assume each of you 22 then passed those onto the people who own the 23 guidance?
24 MR. DICKSON: Yes, that's definitely 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
35 intent.
1 MEMBER MARCH-LEUBA: Basically, there is 2
a suggestion box at the door and you fill in a card or 3
you're supposed to know the guy and go to lunch with 4
him? How does that work?
5 MR. DICKSON: There's no suggestion box.
6 I know the guys that work on these things and I tell 7
them these things when I come across them.
8 But usually, when we do develop important 9
documents like this, we do go through internal 10 convergence processes and that's also a time where 11 things like this get identified when we go through 12 those internal concurrence processes between divisions 13 and offices.
14 MEMBER MARCH-LEUBA: Just to give you a 15 heads-up, on Slide 12 I was going to ask you to go 16 over the acceptance criteria, the 1 to 5 rem that you 17 guys chose.
18 And the SCR goes into very good detail of 19 all the criteria you could have used and I would like 20 you to explain what your rationale was and is related 21 to this.
22 There is a little confusion that you can 23 pick A, B, or C and it's up to the licensee to pick.
24 So, I'll ask you the question again on Slide 12.
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36 MR. DICKSON: Great.
1 MEMBER HALNON: Elijah, this is Greg 2
Halnon, I want to look at this list of guidance, all 3
but 1 to 20 years-plus old, some are 40 years old.
4 Part of me says that's great because they're tried and 5
true and if they needed a revision, there would be 6
one.
7 However, part of me thinks there's got to 8
be some learnings that we've had over the last 40 9
years that would assist in this review that would 10 require some updated guidance.
11 Is there other ISGs or other more 12 contemporary guidance that you're using behind the 13 scenes here?
14 MR. DICKSON: For a facility such as SHINE 15 or these non-power reactor facilities or NPUFs, NUREG-16 1537 is and the ISGs are the primary guidance that we 17 have right now.
18 As you mentioned, the meteorological 19 guidance, that's tried and true calcium plume 20 atmospheric dispersion modeling. But there's other 21 NUREGs that we utilized too for iodine transport and 22 things of that nature.
23 And I think Mike Salay could probably talk 24 to those types of guidance, too, that could get 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 wrapped up into these as well. But you asked for 1
other documents to be used, there are a handful of 2
other ones as well.
3 MEMBER HALNON: For instance, which one of 4
these or what other Reg Guides were used for the 5
ARCON96? That's just recently been updated in 4.28.
6 MR. DICKSON: I guess that would have to 7
get captured in an update to NUREG-1537.
8 MEMBER HALNON: I didn't see it in there, 9
I'll look.
10 DR. BLEY: Speaking of NUREG-1537, this is 11 Dennis again, my understanding of interim Staff 12 guidance is the Staff does that because there isn't 13 time to go through the process of updating NUREGs or 14 SRPs or whatever.
15 But the interim Staff guidance for this 16 one is 10 years old. How long do things live as 17 interim Staff guidance? I've seen some in the 18 electrical area that live forever.
19 Maybe somebody wants to comment?
20 MR. DICKSON: I don't have a good answer 21 for that one but I know that we are actively working 22 on updating this guidance.
23 (Simultaneous Speaking.)
24 MR. BALAZIK: I'm sorry, Elijah, to cut 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 you off. This is Mike Balazik, Project Manager for 1
SHINE. Yes, we plan on incorporating the ISG into 2
3 The ISG, and I'll use the term relatively 4
recent, we developed that guidance for the review of 5
production facilities, which wasn't captured in 1537.
6 We do plan on incorporating it within the 7
overall 1537 guidance.
8 DR. BLEY: Thank you.
9 MEMBER KIRCHNER: Just one question, Mike.
10 Someone made the suggestion of a suggestion box or 11 something but in the end doesn't RES own the 12 engineering division, own the responsibility for the 13 Reg Guide, updating and such?
14 Do they have an inbox for all these 15 observations that your Staff makes when they conduct 16 a
review like this and they see potential 17 discrepancies or alternatives or confusion.
18 Does that get fed back in some formal 19 manner to engineering?
20 MR. BALAZIK: This is Mike Balazik again, 21 no, our licensing branch actually has the 22 responsibility for NUREG-1537 and we would collect 23 lessons learned from the SHINE review. We've 24 collected them from past RTR license renewal efforts.
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39 That's how we would incorporate any 1
changes into 1537. So, I would say it's not 2
necessarily a formal process on providing feedback.
3 MEMBER KIRCHNER: I may have misspoken.
4 I guess now, more correctly, engineering owns the 5
Regulatory Guide
- process, if I
understand it 6
correctly, and you're mainly using a NUREG as the 7
basis for your reviews.
8 So, you own, so to speak, 1537?
9 MR. BALAZIK: Yes, sir, and the ISG.
10 MEMBER KIRCHNER: Thank you.
11 MR. DICKSON: Any other questions on 12 regulatory guidance? If not, we can move on to Slide 13 7.
14 SHINE presented to us two types of safety 15 analysis for Staff review, the first being the SHINE 16 safety analysis or SSA, the purpose of the SHINE 17 safety analysis is systematic analysis of facility 18 processes used to identify and evaluate facility 19 hazards associated with the processing and possession 20 of licensed material.
21 And then the design basis accident 22 analysis, the purpose is to evaluate the design and 23 performance of structures, systems, and components of 24 the facility with the objective of assessing 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 radiological consequences resulting from operation of 1
the facility.
2 Onto the next slide --
3 MEMBER REMPE: This is Joy, I'm going to 4
reiterate a question that Member Ballinger has raised 5
several times during this review.
6 In the SE, the Staff indicated they found 7
the application of SHINE's design criteria that was 8
discussed in Chapter 3 reflect the design features of 9
the safety-related SSCs.
10 And it goes on about, which include 11 redundancy, environmental qualification, et cetera.
12 What gives you that confidence? Because we haven't 13 seen your review of the design criteria.
14 Can you elaborate? We're kind of 15 wondering about that issue.
16 MR. DICKSON: Yes, I can definitely do 17 that. For Chapter 13, the primary purpose is to 18 assess radiological consequences.
19 And the primary design criteria that SHINE 20 presented to us that assesses radiological 21 consequences is Design Criterion 6, which is their 22 control room habitability criteria.
23 We assume, and the guidance tells us to 24 assume, that all other design criteria are being met 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 when we're performing the dose analyses.
1 I don't know if I answered your question 2
or not but we don't go line by line in the Chapter 13 3
analyses, or design criteria by design criteria in the 4
Chapter 13 analyses.
5 We're specifically assessing radiological 6
consequences.
7 MEMBER REMPE: That helps, thank you.
8 MEMBER KIRCHNER: When you do that, then 9
at least in the DBA category, now you only can credit 10 those SSCs that are safety-related?
11 MR. DICKSON: That's right, and I have a 12 slide on that. I receive some questions from the ACRS 13 and I've littered responses in this presentation and 14 that was one of the questions that I received, what is 15 the design basis accident methodology from a very high 16 level?
17 And I'll talk about that. If there's no 18 other questions, we can go onto Slide 8, and I believe 19 this will be Mike Call. Mike Call, are you on the 20 line?
21 MR. CALL: Yes, can you hear me?
22 MR. DICKSON: Yes, thank you.
23 MR. CALL: Good morning, this is Mike 24 Call, as mentioned earlier, I'm in the Office of NMSS 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 and was involved in the SSA review.
1 As you can see on the slide here, and has 2
been mentioned and presented by SHINE earlier, this is 3
one of their approaches to evaluating the accidents 4
for the facility.
5 In terms of our approach to looking at 6
that in NUREG-1537 and particularly, the ISG 7
augmenting the NUREG, it recognizes that the ISG 8
methodologies and performance criteria and 9
implementation of management measures is an acceptable 10 approach to demonstrating and ensuring safety, though 11 it does allow for alternatives if those are also 12 demonstrated to ensure adequate protection of safety 13 as well.
14 So, that was the approach. It's very 15 general in terms of how the ISG approaches that. So, 16 those methodologies are captured in Subpart 8 or Part 17 70 and NUREG-1520, which typically apply to your fuel 18 cycle facilities.
19 As was discussed earlier by SHINE, they 20 make use of these types of methodologies but there are 21 differences. We can probably go into a little bit 22 more of that if necessary.
23 You can see some of the differences listed 24 here such as terminology. Instead of having an ISA, 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 an integrated safety analysis, they have a SHINE 1
safety analysis.
2 In terms of Part 70, you typically have 3
things referred to as items relied on for safety or 4
IROFS, which can be administrative or engineering.
5 And for SHINE they have what they refer to 6
as safety-related controls and similar to Part 70 7
management measures, they have what they call 8
programmatic administrative controls or reliability 9
management measures.
10 In terms of the content, the purpose, the 11 function, the kinds of analyses, they're very similar.
12 Another interesting point for folks to be aware of, in 13 Part 70 for ISAs there is an ISA summary that is 14 submitted on the docket and reviewed by Staff.
15 In this case the SSA summary itself was 16 not a docketed report but is something that will 17 remain as a
licensee-controlled or Applicant-18 controlled document. Next slide, please.
19 As mentioned before, there are great 20 similarities to the approaches in Part 70, Subpart H, 21 and NUREG-1520. And so in that regard, the Staff made 22 use of 1520 which also refers to NUREG-1513 in terms 23 of providing guidance for the conduct of ISAs.
24 Such things are to evaluate the criteria 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 for the types of techniques used in the hazard 1
analysis to ensure that those are reasonable and 2
appropriate, also looking at the safety criteria, 3
looking at the application of the outcomes of the 4
analyses for the accidents in applying safety-related 5
controls and management measures or programmatic, 6
administrative controls.
7 With there being some alternatives, I 8
think a good example again with the terminology as 9
well as the approach, another example would be the 10 safety criteria, which SHINE mentioned before.
11 In NUREG-1537 it recognizes that for ISAs, 12 those criteria are typically in 7061 as the limiting 13 high-consequence events to be highly unlikely and what 14 the criteria in terms of radiological chemical dose 15 for what constitutes a high-consequence event or an 16 intermediate-consequence being limited such that it's 17 unlikely, and what those consequence criteria are.
18 You'll see some of what SHINE has used.
19 There are some differences there, for example, the 20 radiological criteria is actually lower than what's in 21 7061 for what 7061 would look like as an intermediate 22 consequence.
23 And so looking at the alternatives using 24 what's in Part 70 and 1520 is a starting 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
45 evaluating the acceptability of the alternatives to 1
demonstrate adequate safety.
2 Again, in consideration of this being a 3
Part 50 application instead of a Part 70, though there 4
are similarities to Part 70 facilities that have been 5
noted previously.
6 And some of the licensing approach, for 7
example in Part 70 there aren't tech specs whereas we 8
have tech specs for this application.
9 And the SSA and its implementation are a 10 key element of the SHINE safety program and in looking 11 at the SSA and doing the SSA review, a major objective 12 is ensuring that the SHINE safety program is adequate.
13 In doing so, the Staff did a broad review 14 considering the method for the SSA and the safety 15 program.
16 And then in terms of its implementation, 17 we do a narrow or vertical-slice reviews selecting 18 certain accident types to understand and evaluate the 19 implementation of the method, ensuring it's done 20 consistently with the definition of the method that 21 SHINE has provided.
22 And that ensures the program will be 23 adequate.
24 And part of that, also, another key 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 element is having these reliability management 1
measures in the
- programs, the programmatic 2
administrative controls, which are the programs that 3
establish an maintain those management measures.
4 If we can go to the next slide.
5 Just a little further elaboration on that, 6
in terms of looking at the method, the Staff looked to 7
ensure that the method identified and evaluated 8
facility hazards and identifying credible accident 9
sequences, including providing definitions of what 10 credible is as well as the definitions for the other 11 likelihood categories they've evaluated.
12 And again, assessing the radiological and 13 chemical consequences and likelihoods for, first, as 14 an uncontrolled or unmitigated accident and then 15 identifying and applying the safety-related controls 16 to either prevent or mitigate the accidents to meet 17 their safety criteria.
18 And then ensuring that reliability 19 management measures were identified that ensure the 20 safety-related controls will be available and reliable 21 to the extent evaluated in the safety analysis.
22 And then having the programs for 23 establishing and maintaining those measures. And 24 looking at how they defined those, the definitions, 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 the programs, the techniques, are they appropriate, do 1
they make sense for the way they've been used?
2 And that all figures into the Staff's 3
evaluation.
4 And then, of course, looking at the 5
implementation of that method to ensure that also is 6
reasonable and it will provide the confidence that the 7
method is being used appropriately and ensuring the 8
facility's operation will be conducted in a way that 9
ensures health and safety.
10 Again, just stressing that the SSA, the 11 method and the implementation are an important element 12 of the safety program.
13 And for that to be effective, the SSA 14 needs to reflect the as-built, as-operated facility 15 and demonstrate that it ensures the health and safety 16 of the public and personnel.
17 And with programs that SHINE has, some of 18 which are captured in the tech specs in the 19 administrative program section of the tech specs such 20 as Tech specification 5.5.1. for the nuclear safety 21 program in maintaining the accident analysis, which 22 includes identifying appropriate safety controls and 23 programmatic administrative controls.
24 That ensures the safety program would be 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 effective and adequate to demonstrate and ensure the 1
facility operations maintain public health and safety.
2 If there are no questions, this was my last slide and 3
I can turn it back to Elijah.
4 MR. DICKSON: This is Elijah Dickson.
5 Before jumping into the DBA analyses, Id 6
like to highlight some important facility design and 7
operational features that we considered in 8
characterizing radiological risks and ultimately the 9
impact to public health and safety.
10 The target solution itself is a low-11 enriched uranium in the form of uranium sulfate, which 12 is held in the target solution vessel, or TSD. During 13 operations, the target solution is close to ambient 14 pressure and temperature.
15 In the system, the primary system boundary 16 acts as the primary fission product boundary and this 17 is defined as the TSV, the TSV dump tank, the target 18 solution off-gas system, or TOGS, the associated 19 components such as piping and valves, all of which are 20 seismically qualified.
21 Within the irradiation unit, the target 22 solution is irradiated in a subcritical assembly by 23 neutrons produced by fission neutron source.
24 After irradiation the target solution is 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
49 then processed in the radioisotope production facility 1
for extraction to purify molybdenum-99 and other 2
medical isotopes.
3 Radioactive waste is then processed and/or 4
converted into solid waste for shipment to an offsite 5
disposal facility. They utilize a typical design 6
philosophy with defense in-depth and multiple 7
barriers, redundancy and diversity with their systems.
8 Each of the accelerators are independent 9
from each other so there's not knock-on effects 10 between the accelerator.
11 All design basis accidents which are 12 tripped by the target solution vessel reactivity 13 protection system, or TRPS, results in immediate safe 14 shutdown condition of the target solution within the 15 TSV dump tank, which is favorable geometry.
16 The lightwater pool has sufficient 17 capacity to passively handle decay heat following the 18 trip and the nominal source term is quite small when 19 you compare this to other Part 50 facilities.
20 Their materials at-risk source term or 21 their safety basis source term is conservative given 22 aggressive modeling assumptions. With that, Id like 23 to go onto the next slide.
24 MEMBER MARCH-LEUBA: Just a moment, 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
50 is Jose. When you stick to the reactivity protection 1
system, we are I wouldn't say concerned.
2 We are curious about how we're going to 3
calibrate the sensors that are used to trip the TRPS 4
system, especially because there is no plan to have a 5
calorimetric calibration of the power sensors. Do you 6
have an idea of how do we know we're tripping the 7
correct power?
8 We are still reviewing the technical 9
specifications and they have three LSSSs there, one 10 that protects against high power, one that protects 11 against a power average, and then for startup, there's 12 another LSSS that makes sure that when you're doing 13 your 1 over M type filling, you don't fill too 14 quickly.
15 Again, we're still reviewing those tech 16 specs but for the most part, we've reviewed a 17 tremendous amount of design calculations and they have 18 most certainly exercised MCMP to basically do a proof 19 of principle that their system works.
20 So, we reviewed MCMP calculations, we 21 looked at their geometries, the physics --
22 MEMBER MARCH-LEUBA: My question is more 23 mundane, about actual operating experience. When you 24 place an interim detector outside the vessel, wherever 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 the interim detector is, you end up having milliampere 1
signal coming out of it.
2 And you have to be able to convert those 3
milliamperes into a power level. So, that's with 4
calibration of the detectors and the way we do it 5
typically in power-plants is we have a calorimetric 6
operation.
7 You have the floor that goes into the core 8
and the T, and that gets you power. We don't have 9
that here, so maybe the question will be in the closed 10 session for SHINE.
11 MR. DICKSON: They've done a lot of 12 calculations that show that it works. I think we're 13 going to also have to lean heavily on startup physics 14 testing as well to ensure the calculations they do do 15 actually predict what is actually happening.
16 And that's another part of the 17 conversation that we'll have later on in this 18 presentation. I'll see that Joe Staudenmeier as well 19 has his hand up, who did the Chapter 4 analysis of 20 transience.
21 Joe, do you have something to say?
22 MR.
STAUDENMEIER:
- Yes, we've had 23 discussions with SHINE about calibration, I don't want 24 to say how they are doing but I'm not sure if it could 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 be said in the open session.
1 But they have ways that they're looking at 2
calibrating the detectors themselves and then the 3
power level in the irradiation unit. But I think it 4
maybe should hold off to the closed session and SHINE 5
could address it or we could address it based on the 6
discussions we've had with them.
7 MEMBER MARCH-LEUBA: The Staff has 8
followed up on these. Go ahead.
9 MS. RADEL: This is Tracy with SHINE. As 10 part of the Chapter 7 review, we did provide a 11 detailed response to an RAI related to how we will 12 calibrate the flex detectors.
13 Due to the design of the system, the 14 calometric method is not easy and straightforward and 15 we've had significant uncertainty on it.
16 And given that we had a liquid system, 17 we're using a method that's been used by liquid 18 systems in the past, which is looking at the 19 particular fission product isotopes in the solution.
20 So, running the system, getting the 21 profile of what was run power-wise, and then measuring 22 I believe it's four or five different fission product 23 isotopes and using that to calibrate the advanced 24 detectors.
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53 MEMBER MARCH-LEUBA: I would be glad to 1
wait until Chapter 7 or the closed session but since 2
you were volunteering, you are going to mention the 3
isotopes online as you start that?
4 Or is this a batch production after you 5
run it for X number of days?
6 MS. RADEL: It would be a batch, it would 7
be post-irradiation as it's been through the super 8
cell.
9 MEMBER MARCH-LEUBA:
That has the 10 potential of being very accurate, except, again, we go 11 back to the first cycle and we have to be very 12 conservative that we can be off by 20 percent with our 13 estimate until we do the calibration.
14 Thank you, I'll wait until Chapter 7, that 15 sounds like a good approach.
16 MEMBER REMPE: Is this response to an RAI 17 something recent? Could you have follow-up with our 18 DFO, Chris, and make sure that he makes us aware of 19 it. Because perhaps we already are but I'm curious 20 about your response.
21 CHAIR BALLINGER: That SHINE response was 22 just submitted back in April so it might be good to 23 follow up.
24 MEMBER REMPE: Thank you.
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54 MEMBER MARCH-LEUBA: This is Mike Balazik.
1 Dr. Rempe, I'll send that over to Chris after the 2
meeting.
3 MEMBER REMPE: Thank you.
4 MR. DICKSON: If there are no other 5
questions we can move onto Slide 12.
6 The design criteria and the radiological 7
acceptance criteria, as I've mentioned before, SHINE 8
has one particular design criterion, Design Criterion 9
6, that is specific to Chapter 13 analyses for the 10 control room.
11 It's your typical control room 12 habitability criteria where a control room is provided 13 from which actions can be taken to operate the 14 irradiation unit safely under normal conditions and 15 perform the required operator actions under postulated 16 accidents.
17 This is similar in effect to General 18 Design Criteria 19 for power reactors.
19 Now, for the acceptance criteria or dose 20 acceptance criteria, there are two, the first one 21 being the criterion, which typically referred to 22 members of the public.
23 It's where radiological consequences to an 24 individual located at the unrestricted area following 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 the onset of a postulated accidental release of 1
licensed material would not exceed 1 rem total 2
effective dose equivalent, or TEDE, for the duration 3
of the accident.
4 Then the second is the acceptance criteria 5
for the control room operator where radiological 6
consequences to the worker do not exceed 5 rem TEDE 7
during an accident. I know there's a couple questions 8
on this.
9 MEMBER MARCH-LEUBA: I have a new one, 10 I'll give you fair warning. On the SCR, the SCR goes 11 into some detail on all the criteria that could have 12 been chosen. Could you give us a summary of why this 13 one was the proper one?
14 MR. DICKSON: Currently, in the rule, in 15 the CFR, there's no accident dose criteria for NPUF-16 type facilities and so in writing the SCR, we provide 17 a bit of background as to what has been selected in 18 the past.
19 Typically, that has been some variation of 20 the Part 20 actual public dose criteria. Around the 21 time that SHINE had come in for their operating 22 license, the NRC had published for rulemaking the NPUF 23 rulemaking, which selected a regulatory dose criteria 24 of 1 rem TEDE and SHINE came to us and utilized 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
56 as the value for their accident dose criteria.
1 And it's effectively based off the EPA PAG 2
manual for protective action guidelines and guidances 3
for radiological instances.
4 MEMBER MARCH-LEUBA: Thank you, now we 5
have it on the record. When you read the CR, it looks 6
a little confusing that there are so many criteria 7
that one can choose from but there is a method to the 8
madness.
9 MR. DICKSON: Over time, over the last 30-10 some-odd years that we've been licensing these things, 11 in some place you'll see 100 millirem, in some places 12 you'll see 500 millirem, and then somewhere in 13 between.
14 So, we tried to flesh that out in the SCR.
15 If we need to do a little work on further explaining 16 it, we can.
17 MEMBER MARCH-LEUBA: I'm happy with your 18 explanation, thank you.
19 MEMBER KIRCHNER:
If I
- remember, 20 historically, a part of this 1 rem ties to the 21 protected action guidelines, the idea that these NPUF 22 facilities would not, in effect, exceed that 1 rem for 23 actuation of full-blown emergency planning 24 requirements.
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57 MR. DICKSON: That's right. We use the 1 1
rem for other regulatory actions as well as, for 2
instance, for decommission facilities the 1 rem is 3
used. It's something that we've used before.
4 Onto slide 13, please? This slide was 5
developed in response to the one question that was 6
received from the ACRS last week.
7 The methodology in assessing design basis 8
accident radiological consequence analyses, they're 9
generally divided into six parts, where you select 10 bounding design basis accidents.
11 These design basis accidents really are 12 categories, you'll do a number of different analyses 13 within each of these categories. You'll then derive 14 applicable accident source terms for each of the DBAs.
15 You identify the major safety-related 16 structures, systems, and components, or SSCs, intended 17 to mitigate the radiological consequences, you 18 estimate fission product release characteristics to 19 the environment, you review the meteorological 20 characteristics of the site location.
21 That's a very important step in the 22 process. And then you finally compute radiological 23 consequences for each of the bounding DBAs within 24 those categories.
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58 Generally, the Staff does not accept DBA 1
analyses that credit facility features that are not 2
safety-related, are not covered by the technical 3
specifications, do not meet single-failure criteria 4
reliability offsite power.
5 Now, I believe Dr. Rempe had asked a 6
little bit about the purposes of all of these 7
different nuances, and the purpose is to ensure the 8
reliability of the system is performing its safety 9
function to protect the public health and safety for 10 special events.
11 And so we can hang our hat on the final 12 dose results when we consider all of these different 13 aspects in the dose analyses if they need them. They 14 are in fact meeting their intended safety purpose 15 function.
16 Onto Slide 14, please. Here is a list of 17 the SHINE design basis accidents, which are consistent 18 with the interim Staff guidance. The SHINE facility 19 is unique but NUREG-1537 and the ISG were helpful in 20 developing and reviewing the DBAs applicable to SHINE.
21 It assisted both them and us and looking 22 at as many reasonable possible failures and 23 combinations, failures of combinations of SSCs, to 24 understand as many radiological health consequence 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 results as possible.
1 They did analyze classic accidents, such 2
as accessory activity, reduction of cooling, power 3
oscillations. What they did, SHINE and Tracy had 4
mentioned that they did identify facility-specific 5
events, which are typically tritium events.
6 For the most part, the failure reactive 7
systems do not lead to an uncontrolled upset of the 8
target solution, which would then cause a release to 9
the environment.
10 Accidents such as reactivity insertion and 11 power oscillations for their particular design intend 12 to be self-correcting. And more importantly, the 13 LSSSs and the tech specs have been set to protect the 14 primary system boundary.
15 We will talk briefly about their maximum 16 hypothetical accident in a few short slides. If we go 17 onto the next slide it just has --
18 DR. BLEY: Elijah, before you do that, 19 this is Dennis.
20 We're returning in this case and probably 21 in some others to the maximum hypothetical accident or 22 the maximum credible accident, depending on which 23 approach people want to take.
24 If one has a convincing case that 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
60 MHA is truly the maximum and even so, it's acceptable, 1
why do they need to go beyond that?
2 I think one reason, I'm going to maybe 3
help you out or maybe give you something to correct, 4
is having some confidence in the completeness of the 5
remainder of these 2 through 12 on this list gives 6
confidence that the MHA is in fact what it claims to 7
be.
8 You talk about that a bit and I'm thinking 9
not only of this application but of how the idea might 10 be applied in future applications.
11 MR. DICKSON: I think assessing the 12 facility from multiple different aspects is important.
13 It's hard to say that you can use one accident 14 category and then a number of bounding assumptions to 15 then say that you are covered, completely covered.
16 And so I do think, and I agree with you, 17 that looking at the other accidents helps identify 18 things that you may not have realized before when you 19 do your initial design of the facility.
20 We see for advanced reactors where they 21 utilize their PRAs to then make design modifications 22 as they're going through the design process. It's I 23 think similar in this case.
24 You may have a blind spot when you're 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
61 going into this and if you look at it from other 1
aspects, you might identify that you may need an extra 2
safety-related system to handle something you weren't 3
aware of.
4 DR. BLEY: Thanks, I just wanted to hear 5
the Staff's take on that idea.
6 MEMBER MARCH-LEUBA: This is Jose. Is 7
this question or topic related to what we're talking 8
about with the lack of or incompleteness of all the 9
regulations, they're not specific or exactly what 10 you're supposed to do?
11 And it's something maybe you can talk to 12 your friend on this in the suggestion box for future 13 applications. It will be nice if I'm designing an 14 NPUF next year, I get money from Wall Street to do it, 15 that I know what the Staff expects from me.
16 MR. DICKSON: Yes, SHINE looked at the 17 interim Staff guidance and this list of accidents is 18 effectively there.
19 They went and they reviewed them and if we 20 saw an application which is one accident and then 21 looked at our own guidance and said where is the rest 22 of them, it's a high bar to say --
23 MEMBER MARCH-LEUBA: Your recommendation, 24 as one member of the Staff, is to do an MHA to cover 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 your bases, but then again, run through a spectrum of 1
accidents to make sure you recover?
2 MR.
DICKSON:
- Yes, I'd definitely 3
recommend that. I think in the case of SHINE, they 4
did all of these analyses and then they identified 5
what their MHA was, it was kind of the other way 6
around.
7 MEMBER MARCH-LEUBA: If you think about 8
it, the MHA in SHINE does not cover tritium releases, 9
for example.
10 MR. DICKSON: No, it doesn't.
11 MEMBER MARCH-LEUBA: It's different. You 12 can even think it's a different facility, one is a 13 TSV, one is tritium purification.
14 MR. DICKSON: Right, that is the nuance, 15 and I'm glad you brought that up, about the SHINE 16 facility.
They have the fission-product-based 17 accidents and then they also have a lot of tritium on 18 site too.
19 They went and performed the analyses to 20 understand the consequences of tritium accidents. Go 21 ahead, I'm sorry.
22 DR. BLEY: Go ahead, you hadn't finished 23 yet.
24 MR. DICKSON: The guidance itself tells us 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 that the MHA is a fission-product-based-type accident 1
and that makes sense because the radionuclides that 2
you're most concerned of are those shortlived, highly 3
radioactive nuclides, specifically radioiodine, its 4
affinity for the thyroid can cause high doses.
5 SHINE also has these handful of tritium 6
events and their tritium events do result in high 7
doses too but tritium has a 12.3-year half-life and 8
the actions that you need to take to respond to a 9
tritium accident are much different than the actions 10 that you would need to take to respond to an upset of 11 the core.
12 In the sense of protecting public health 13 and safety, do you need to evacuate, not evacuate?
14 Things of that nature.
15 And so I might be going a little bit off 16 track here, they were able to utilize I think it was 17 the very, very last item here, the facility-specific 18 events who identified those tritium accidents.
19 And I think that's a good thing.
20 DR. BLEY: Elijah, that was following up 21 a little bit on Jose here. You mentioned that they 22 use the set from NUREG-1537 but when SHINE talked, and 23 I liked what they had to say, they used the HAZOPS and 24 the failure mode effects analysis ahead of that to 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 look for things that might not be in that list.
1 I think that's pretty important, you 2
didn't talk about that, you held onto that list. Can 3
you talk about that idea a little bit?
4 The thing you're sensing is some of us are 5
very concerned about how to be as complete as possible 6
when looking at new facilities.
7 MR. DICKSON: When SHINE initially came 8
in, they had their SHINE safety analysis and performed 9
that HAZOP. And that was primarily the NMSS side of 10 the house that performed that review.
11 That information then did feed into the 12 NUREG-1537 and ISG analyses, it did feed into it.
13 It made a pretty complete story I think at 14 the end of the day, since for the DBAs, we're 15 effectively assessing structures,
- systems, and 16 components and we're not necessarily assessing the 17 actual processes that humans are interacting with the 18 systems themselves.
19 Two important aspects looked at two 20 different perspectives, and it's all combined in 21 Chapter 13.
22 DR. BLEY: That covers what I wanted to 23 hear.
24 MEMBER HALNON: This is Greg, back 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
65 process question about going beyond other things 1
besides the MHA, isn't that required or necessary to 2
determine the scope of safety-related equipment and 3
what's covered by tech specs and that sort of stuff?
4 MR. DICKSON: Yes.
5 MEMBER HALNON: So, we just can't stop at 6
one accident, you need to do the full scope so you 7
know what other instruments and what other 8
safety-related equipment needs to be there.
9 MR. DICKSON: Yes.
10 MEMBER HALNON: I just wanted to make sure 11 I was thinking right.
12 MR. DICKSON: Yes. If there's no other 13 questions, we can move on. This is just the rest of 14 the identified applicable DBAs and then Slide 16, we 15 can now talk about the material risks and accident 16 source terms.
17 CHAIR BALLINGER: This is Ron Ballinger.
18 I've been searching for a time where we 19 could take a break, a convenient time, and this looks 20 like about as good as any. So, what I would like to 21 propose is that we take a break until 10:20 a.m.,
22 which would be 15 minutes from now.
23 Let's take a break and come back at 10:20 24 a.m. by the clock on that computer. 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
66 (Whereupon, the above-entitled matter 1
went off the record at 10:04 a.m. and 2
resumed at 10:20 a.m.)
3 It is 10:20 a.m., time to reconvene. So, 4
let's pick it up where we left off.
5 MR. DICKSON: This is Elijah Dickson 6
again. We are on Slide 16, design basis accident 7
analyses, material risk accident source terms.
8 SHINE presented to us two types of 9
materials at risk, the first being the fission-10 product-based source term, which is their safety basis 11 source term derived for the target solution vessel.
12 They also produced another fission-product-based 13 source term for the primary closed cooling system as 14 well I believe.
15 The other primary source term is the 16 tritium source term which is based off of maximum 17 quantities for the facility were used by an individual 18 irradiator assembly.
19 The NRC Staff reviewed the applicability 20 of the safety basis SHINE calculation documents which 21 were used to derive their material at risk source 22 term. We looked at validation calculations for their 23 reactivity solution system, the ways the estimated 24 neutron fluids target solution burnup over the length 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 of the target solution recovery.
1 They utilized two primary codes or classic 2
codes to perform these calculations, the first being 3
the Los Alamos National Lab, Monte Carlo N-Particle 5 4
code, MCMP5 Version 1.6. MCMP5 was used to compute 5
neutron flux spectrums and cross-sections with the 6
target solution as well as the PCOS.
7 SCALE was then used with a code developed 8
by Oak Ridge National Lab, it's the standardized 9
computer analysis for licensing evaluation code.
10 Specifically, the ORIGEN-S was used to perform the 11 depletion calculations.
12 MEMBER MARCH-LEUBA: Is there a reason 13 you're using MCMP5 instead of 6, and is 5 still 14 supporting and getting updates?
15 MR. DICKSON: I'm not sure, I use MCMP5 16 myself. I do believe they're onto just MCMP now, they 17 don't have a number after it.
18 MEMBER MARCH-LEUBA: I think it's MCMPX?
19 MR. DICKSON: MCMPX was discontinued I 20 believe a number of years ago. They wanted to the 21 MCMP6 but then I think the latest version is just MCMP 22 at this point.
23 MEMBER MARCH-LEUBA: The question is if 24 they're planning to use a frozen version but if Los 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 Alamos finds a bug in the implementation, then that 1
does not get translated into the flux version. Then, 2
on the downside, if you use a version that changes 3
daily with updates, then you never verified and 4
validated it.
5 So, maybe this is a good compromise.
6 MR. DICKSON: MCMP5 has been around for a 7
long time, it's certainly a tried and true version of 8
the code.
9 MR. MUNSON: This is Jeremy Munson, I 10 could make a quick comment on that.
11 MEMBER MARCH-LEUBA: Go ahead.
12 MR. MUNSON: I just wanted to say what 13 really matters is not just the code version but the 14 cross-section data that the code is validated with or 15 when it's validated, its area of applicability.
16 And known issues within the area of 17 applicability within the codes should come out in the 18 wash whenever you do the bias determination 19 calculation. That's part of the reason why we do the 20 validation.
21 So, regardless of which version of the 22 code they're using or which cross-section library 23 they're using, as long as they're operating or doing 24 their calculations within their area of applicability 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 as established by the validation report, they should 1
be okay.
2 MEMBER MARCH-LEUBA: I don't have any 3
problem with MCMP, either version, it's one of the 4
gold-standard goals on this. Go ahead.
5 MR. DICKSON: The last bullet is they 6
utilized NUREG CR-6410 to compute accident-specific 7
source terms utilizing the so-called five-factor 8
formula. Now, onto Slide 17.
9 Verified operational assumptions in 10 deriving their material at risk, for each of these 11 they did include margin.
12 The corresponding fission product power, 13 their license fission product power with additional 14 margin, irradiation times per cycle, total time 15 lengths between irradiations, extractions between 16 irradiations, and then the length of target solution 17 recovery were the primary parameters in which they 18 derived their material at risk.
19 We find that they used the most aggressive 20 usage of their target solution that would effectively 21 fit within their licensing basis.
22 They maximize cycle lengths, minimize 23 downtime lengths in their calculations and neglected 24 the evolution of iodine from their material at risk, 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 which is something that Mike Salay will be talking 1
about in a few slides.
2 The calculations do include the effects of 3
fission transmutation, activation, and decay. They 4
assessed burnup assesses different radionuclides' peak 5
at different burnups.
6 We asked some questions in regard to 7
making sure they're capturing peak radionuclides of 8
interest such as Item 131.
9 We find there's very large margin between 10 their material at risk and normal operations and the 11 Staff finds the conservative assumptions and treatment 12 of uncertainty to justify the material at risk to be 13 acceptable.
14 On Slide 18, the material at risk 15 transport and mitigation, this is Slide 1 of 3, we 16 reviewed NUREG CR-6410 which has a process in which 17 you developed a so-called leak path factors.
18 Leak path factors were developed for each 19 scenario where you identify major safety-related SSCs 20 intended mitigate radiological consequences and 21 estimate fission product release characteristics to 22 the environment using those leak path factors.
23 These factors include physical processes 24 such as control volumes, volumetric flow rates, 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 leakages through gaskets, differences in pressure, 1
barometric breeding, and other removal processes.
2 We find they did conservatively assume 3
with the five-factor formula damage ratios to be one, 4
that means that any piping or tank or piece of 5
equipment that breaks fully breaks and releases that 6
material.
7 Nothing is upheld within it and that 8
airborne release fractions, or ARFs, vary by accident 9
but typically, they assume an airborne release 10 fraction of one for most scenarios.
11 The leak path factors are generally 12 organized into four leak path combinations for the 13 entire facility.
14 You have the release location, the initial 15 confinement, leakage into the surrounding building and 16 then subsequently to the environment.
17 The Staff finds their leak path factors 18 are generally consistent with the methodology of NUREG 19 CR-6410. With that, if there's no questions --
20 MEMBER KIRCHNER: This is Walt Kirchner, 21 I have a question. When you get to the actual finish 22 of construction and you begin pre-op testing and 23 everything, do you go back and look at things? I'll 24 pick on one.
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72 The removable shield blocks, I imagine 1
these also have gaskets that help form the primary 2
confinements. Do you do leakage testing of those and 3
then check back to your calculations to see that the 4
appropriate leak path factors has been used, it's been 5
conservative?
6 MR. DICKSON: Yes, so that was something 7
the Staff did focus on, where these gaskets were used 8
to effectively establish confinement. We did a review 9
of their design calcs and they use first principles in 10 computing analytical leak values.
11 Once they do startup and testing, they'll 12 be able to actually then measure leak rates and then 13 those would be utilized in their design calcs.
14 MEMBER MARCH-LEUBA: Are you done, Walt?
15 MEMBER KIRCHNER: Yes.
16 MEMBER MARCH-LEUBA: I mentioned this in 17 an earlier meeting, that they calculated those rates 18 to the public are very close to limits, they're within 19 20, 30 percent of the limit because we used a very 20 conservative calculation method and assumptions.
21 Now, the danger here is that when we 22 actually test the as-built facility, we find the leak 23 factor through one of those gaskets is 25 percent 24 larger than we assume, and then we're over the limit.
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73 So, I'm just warning that if feels that 1
using an extremely conservative calculation method 2
with extremely assumptions is a good thing to do until 3
you get bitten by it.
4 So, let's just make sure that when the 5
facilities are built, the gaskets are placed properly 6
and they test within the numbers.
7 It's not a question, just a comment.
8 MR. DICKSON: I understand, thank you.
9 Are there any other questions?
10 With that, we'll move on to Mike Salay's 11 presentation, the iodine evolution calculations that 12 he had done in his assessment for material at risk 13 transport mitigation.
14 MR. SALAY: Can you hear me?
15 CHAIR BALLINGER: Yes.
16 MR. SALAY: Hi, I'm Mike Salay from Office 17 of Research, I reviewed iodine release and transport 18 and a few other things related to non-iodine release 19 and transport and this slide highlights some of the 20 relevant effects of iodine evolution.
21 These aren't specific to SHINE but rather, 22 generic to aqueous fission systems and even other 23 fluid systems that postulate an accident which evolved 24 iodine can leak into the environment.
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74 It also applies to other walled housing, 1
it can leak and perhaps in other systems. So, in 2
general scenarios you have normal operation with 3
fission and an accident by evolution without fission.
4 And fluid systems behave different than 5
typical solid LWR fuel since some radionuclides are 6
mobile, readily mobile. And these effects are often 7
not considered in dose analyses.
8 So, iodine that evolves from solution to 9
gas space, it can leak to the environment and 10 specifically it can be a significant contributor to 11 flow and the release rate generally depends on 12 geometry, temperature, and flow.
13 But there are many other factors and 14 internal flow within the fluid, but one thing that 15 needs to be realized is this process is always 16 occurring. Iodine evolves from solution during normal 17 operation and if you account for these effects, it has 18 implications for how much can be released during the 19 accident.
20 If evolution is fast relative to your 21 decay constant, it can deplete the inventory available 22 for release to the environment, so this results in 23 some effective reduction in your MAR by evolution.
24 And these effects aren't accounted 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
75 inventory codes such as SCALE or MCMP. And on the 1
other hand, if your evolution is slow relative to 2
decay, your evolving radionuclide will decay before 3
evolving.
4 I'm focusing on Iodine 131 since it's 5
typically the most dose-significant isotope. And so 6
this effectively limits on your airborne release 7
fraction and the combination of the two.
8 And these effects are shown in the figures 9
on the right and these effects are basically common to 10 all fluid systems, not just aqueous systems.
11 If your volatile radionuclides evolve and 12 are sequestered during normal operation, they're no 13 longer available for release from the main irradiation 14 facility or in this case, reactor to reactor, during 15 an accident.
16 Although, of course, wherever the location 17 where the radionuclides are sequestered can be another 18 radiation source.
19 Again, the figures on the right illustrate 20 some of these effects on Iodine 131 behavior and the 21 competition between decay and evolution during 22 operation in a postulated accident scenario using some 23 simplifying assumptions.
24 The key assumption here, one of the main 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 assumptions is that evolution removal constant from 1
solution during accident scenario is the same as that 2
during operation. And this may not necessarily 3
reflect actual scenarios.
4 The top figure shows the buildup of Iodine 5
131 inventory during normal irradiation and the 6
release history by evolution during the postulated 7
accident scenarios. The solid curve shows the build 8
up for stationary iodine in which there's no 9
evolution, the red curve.
10 For iodine that is evolving with the 11 removal constant, that's 10 times greater or one-tenth 12 that of the radioactive decay constant.
13 The longer-dash curve shows evolution of 14 airborne release fractions for these two evolution 15 cases, and the short-dashed curve shows the combined 16 effects of the reduction and inventory and release 17 fraction. And this timescale is about 70 days.
18 Xs simply represents the fractional 19 inventory relative to the steady state inventory, the 20 equilibrium inventory with no evolution.
Xe 21 represents the fractional equilibrium inventory due to 22 loss by evolution.
23 And this is essentially the equilibrium Xs 24 or Exs at the end of time. The bottom figure shows 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 effects but for equilibrium conditions way 1
beyond 70 days and as a function of the evolution 2
removal coefficient.
3 The solid red curve shows the effect on 4
equilibrium inventory, the green longer-dashed curve 5
shows the airborne equilibrium release fraction, and 6
the blue shorter-dashed curve shows the combined 7
effect of the two.
8 These figures show the combined effect of 9
inventory reduction airborne release fraction for 10 evolution limit overall releases during an accident 11 scenario starting from initial equilibrium inventory, 12 and the reduction is greatest when the evolution rate 13 constant is much larger or smaller than that of the 14 radioactive decay constant.
15 And I'll point out these curves are just 16 focused on evolution rates. They neglect the iodine 17 partitioning so these effective ARF airborne release 18 fraction values kind of provide an upper limit on 19 releases based on transfer condition alone for the 20 simplified assumption.
21 So, one can generally say it's 22 conservative to neglect these evolution rate effects.
23 However, it can be difficult because of the complex 24 and related behavior between aqueous speciation, 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 liquid gas partitioning evolution rate to demonstrate 1
that a given evolution rate provides a bounding 2
release.
3 Some NUREGs related to ion behavior often 4
focus on equilibrium iodine partitioning rather than 5
the evolution rate.
6 The effective evolution removal 7
coefficient, lambda E, in addition to depending on 8
typical mass transfer behavior including diffusion 9
through water and gas and recirculation of fluid, and 10 the surface to volume ratio, it also depends on the 11 iodine speciation in solution.
12 Depending on pH and the concentration of 13 all iodine isotopes in solution, some fraction of the 14 iodine will be in volatile I2 form, molecular iodine 15 form, whereas some other fraction will not be 16 volatile.
17 It is only the volatile I2, the volatile 18 iodine, that is subject to evolution of the gas phase 19 partitioning, and so the effective partitioning and 20 evolution rate depends on volatile iodine fraction.
21 In other words, since only the volatile 22 iodine evolves, the aqueous chemistry model affects 23 the effective iodine evolution rate on that second 24 curve, where you are on the X axis on that bottom 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 figure.
1 So, the chemistry model predicts that all 2
of the iodine solution is in volatile form, the 3
effective equilibrium partitioning and evolution rate 4
to match is the nominal partition coefficient and 5
nominal evolution removal coefficient.
6 Conversely, if the chemistry model 7
predicts a low fraction of iodine in solution, the 8
effect of equilibrium gas to liquid ratio and 9
evolution rates are correspondingly reduced.
10 So, uncertainties in the chemistry model 11 and the volatile iodine fractions lead to 12 uncertainties in the effective evolution removal 13 coefficient.
14 DR. CZERWINSKI: I've got a question, this 15 is Ken Czerwinski. Maybe you'll do this a little bit 16 later but can you give some information on this 17 speciation model that you're using?
18 MR. SALAY: This is the B model, it's 19 NUREG 5950 and this completely neglects that. I'm 20 just saying these are effects that --
21 DR. CZERWINSKI: I understand what you're 22 saying, where the speciation is going to drive the 23 formation of the volatile iodine species and that 24 would be the species of concern for that isotope.
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80 MR. SALAY: Yes, so it's whether you have 1
I2 or I-. I haven't put anything together for that, 2
it's more detailed, but of course it could be provided 3
in the future, unless SHINE provided some info.
4 I'll go on and I can provide more 5
information in the future about the different models 6
as needed.
7 CHAIR BALLINGER: Can that information be 8
provided in the closed session?
9 MR. SALAY: I haven't prepared anything 10 for that but I can.
11 CHAIR BALLINGER: I'm just trying to 12 capture what we should do with that.
13 MEMBER PETTI: It's also fair to say SHINE 14 didn't go into this level of detail. They made much 15 more conservative --
16 MR. SALAY: They did not consider the 17 transport effects but the speciation in partitioning, 18 they did include this based on the NUREG-5950 iodine 19 evolution pH control model.
20 MEMBER REMPE: And that was in the FAI 21 report? They actually, I thought, did a pretty good 22 job.
23 MEMBER PETTI: As I recall, they did.
24 MR. SALAY: Another effect is the higher 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 surface to volume ratio configuration such as bubbles 1
and froth. You can also enhance the effective iodine 2
evolution rate.
3 Although, for this illustrative example, 4
it considered the same evolution rate coefficient for 5
accident conditions as for normal operating 6
conditions. The evolution rate for an actual analysis 7
should consider the actual geometry.
8 And generally, one would expect that the 9
evolution rate during an
- accident, postulated 10 accident, would be lower than that during operation, 11 namely because your power generation can result in 12 more bubbles, it can result in more natural 13 circulation, all of which enhances the evolution rate.
14 And I don't know if I mentioned it, but 15 uncertainties in your volatile iodine fraction lead to 16 uncertainties in your effective coefficient. Anyways, 17 next slide, please.
18 MEMBER KIRCHNER: Before you go on, it 19 seems to me for the duty cycle, the operational cycle 20 that SHINE is using one could construct a composite 21 curve that includes some conservative assumptions and 22 then come up with a curve available for release as a 23 function of that multi-day duty cycle that they're 24 operating on.
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82 MR. SALAY: Yes, it seems like a comment 1
but, yes, I think you can account for the reduction 2
due to --
3 MEMBER KIRCHNER: So, this would take into 4
account the phenomena you identify on the previous-5 view graph but you would have an effective total I2 6
inventory available for release that then could be 7
used in a bounding calculation?
8 MR. SALAY: Yes, I think I agree with what 9
you're saying and this simplified illustration just 10 considered a constant irradiation, it didn't consider 11 any cycling.
12 And one thing that I forgot to say in the 13 previous slide was because of these interrelated 14 effects, it can be difficult to justify that you have 15 a bounding value for these rate effects.
16 So, this slide lists some of the evolution 17 transfer analyses. As mentioned before, iodine 18 evolution analyses can provide an estimate of 19 reduction in dose-significant inventory during 20 operation and the airborne release fractions.
21 For situations where any potential 22 reduction in inventory is not credited and all iodine 23 is assumed to be released to the gas, there's really 24 no need for an iodine evolution calculation because 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com
83 you're just assuming everything is released and 1
nothing is reduced during operation.
2 So, it of course did not conduct or 3
analyze any of those situations. One could to 4
estimate conservatism, instead it just went through 5
the simple generic analysis that I showed on the 6
previous page.
7 Other than that, I did look at some 8
specific scenarios that focused on higher-consequence 9
scenarios that involved iodine evolution.
10 The specific one they looked at was the 11 scenario in which the iodine was released to a pool 12 and started the calculation, went through just walking 13 through the process of release.
14 It was getting to the point where I was 15 getting a lower considering rate effects, I was 16 getting a
lower airborne release
- fraction, 17 substantially so, than SHINE.
18 And so even though like I said, the 19 analysis didn't actually continue, given that it was 20 clear that our analysis would have lower release 21 fraction than SHINE and airborne release fractions 22 that are released to the environment in a lower dose, 23 it wasn't clear whether it would be useful to continue 24 to perform the analyses, especially considering 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 was feeding into the NRC confirmatory calculation 1
track thread.
2 And I also provided feedback on the 3
technical basis used to derive the pressure during 4
flow rates, including non-iodine airborne release 5
fractions and phenomena used to calculate the leak 6
path factors that were used in the confirmatory 7
calculations.
8 And this is more of a high level review 9
that references the equation but I don't think I 10 calculated anything except for perhaps the flows 11 rates.
12 And if there are no other questions, I'll 13 turn it back over to Elijah.
14 MR. DICKSON: This is Elijah Dickson, 15 we'll move to Slide 21. I'll briefly talk about 16 atmospheric dispersion or meteorology.
SHINE 17 developed short-term atmospheric dispersion factors, 18 or chi over Qs, using traditional calcium plume 19 diffusion methodologies.
20 The chi over Qs were developed for both 21 the offsite public location and the control room 22 receptor. The chi over Q values were computed for 23 specific time periods following the event from 0 to 2 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, 0 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, 1 to 4 days, 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 and 4 to 30 days.
1 They conservatively assume a ground-level 2
release, the chi over Q values are 95th percentile chi 3
over Q values and they utilize the NRC computer code 4
PAVAN, which implements regulatory guidance from 5
1.145.
6 And there should be another bullet here in 7
regard to ARCON2 I think for computing chi over Qs for 8
the control room. Onto Slide 22 if there's not 9
questions, radiological consequences.
10 We find that they computed radiological 11 consequences to be consistent with the regulations so 12 in terms of total effective dose equivalent, which is 13 defined in 10 CFR 50.2 then of course in Part 20, 14 20.1002.
15 They utilize the appropriate dose 16 conversion factors to compute committed effective dose 17 equivalent, which is the internal doses, that's 18 utilizing DCS for Federal Guidance Report 11.
19 And then for external exposures, they 20 utilized dose recursion factors from Federal Guidance 21 Report 12. As Tracy had mentioned earlier this 22 morning, for the fission-product-based accidents, they 23 utilized a time duration of 30 days.
24 For the tritium accidents they utilized 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
86 time of 10 days. Receptor locations assume no 1
personal protective equipment or protected actions.
2 The individual effectively just stays put for that 3
period of time.
4 Any questions here? Onto Slide 23, we'll 5
just very briefly go over SHINE's maximum hypothetical 6
accidents since the intra-Staff guidance tells the 7
Staff to identify and focus on it.
8 Their MHA can be found in Subsection 9
13A2.2.7, it's under the design basis accident 10 category of mishandling or malfunctioning of 11 equipment.
12 Their most limiting scenario is the 13 failure of the target solution vessel off-gas system, 14 or TOGS, pressure boundary, resulting in the release 15 of off-gases into the TOG cell.
16 So, effectively, what they assume is a 17 break in the TOGS line in the upward section of the 18 TOGS lower in conjunction with the complete blockage 19 of piping in the process vessel ventilation system, or 20 heat PVVS.
21 This is effective multiple failures. The 22 blockage in the PVVS system creates the back-pressure 23 when the nitrogen purge system clicks on, pressurizing 24 the TOGS cell, and then the source term or material at 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 risk then leaks out of the TOGS cell.
1 No credit is taken for deposition of 2
radioiodine in this analysis. Onto Slide 24. As Mike 3
Salay had mentioned in the two or three previous 4
slides, they utilize a material at risk of 100 percent 5
of the halogens and noble gases.
6 Interim Staff guidance asks us to identify 7
the safety controls for the accidents and those would 8
be the primary confinement boundary, ventilation 9
radiation monitors and nitrogen purge
- system, 10 ventilation isolation mechanisms, and then for a brief 11 time, a hold-up in the radiological event Zone 1E 12 exhaust section.
13 For the calculated doses for the MHA 14 scenario, they computed a control room operator dose 15 of 1.94 and then for their MHA to a member of the 16 public is 0.727 rem.
17 The Staff finds these results are 18 acceptable since they're within their design accident 19 dose criteria for the control room as well as the 1 20 rem TEDE out at the site boundary.
21 MEMBER PETTI: Elijah, I'm just a little 22 confused. There is another scenario in the SHINE 23 accidents that products slightly larger public dose, 24 slightly lower worker dose. Why isn't that the MHA?
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88 MR. DICKSON: I'd have to look at my 1
notes. Are you referring to one of the tritium 2
accidents?
3 MEMBER PETTI: Yes.
4 MR. DICKSON: I had mentioned before in 5
our discussions that the MHA is a
fission-6 product-based source term and the guidance asks us to 7
assess the MHA as a fission-product-based source term.
8 Now, SHINE, because they have a lot of tritium on 9
site, they did perform other accident analyses with 10 tritium.
11 And I think the important distinction 12 between the two is that tritium does have quite a bit 13 longer half-life than Iodine 131 does, and the 14 immediate radiological threat to the public post-15 accidents is truly Iodine 131.
16 Because that's how you start to set up --
17 these calculations set up the reasons for protected 18 actions, right?
19 So, if you have this quick, fast-acting 20 accident with Iodine 131, you'd be taking protected 21 actions that are much different than those with the 22 release of tritium with the 12-year half-life.
23 These doses, Id like to mention, are 50-24 year committed doses so the intake is integrated over 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 a 50-year period upon intake. It's not just an 1
immediate 2 rem per se but it is dose that would be 2
integrated over 50 years.
3 So, the tritium dose takes a lot longer to 4
effectively deposit this material into the human body.
5 Again, that all goes into how you consider protected 6
actions.
7 DR. BLEY: I want to ask you, and again, 8
this is probably not fair to ask you, maybe somebody 9
else wants to comment on it, you confirmed the 10 calculations for control room operators and I'm a 11 little curious.
12 The NRC is charged with protecting public 13 health and safety, I guess that's why we look at the 14 control room operator, because the control room 15 operator would be important to protecting public 16 health and safety.
17 We don't seem to require looking at worker 18 risk. Now, SHINE did, they told us they looked at 19 people outside the control room.
20 I'm thinking back to the 1960s and the NRC 21 didn't look at environmental effects until there was 22 a court case that said you've got to do that, you're 23 putting reactors out there and they may have 24 environmental effects.
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90 We're putting reactors out there that 1
could have worker effects and they've been pretty 2
benign so far, but we're also looking at new systems 3
with very interesting chemistry and chemical risk for 4
workers.
5 Why doesn't the NRC concern introduce with 6
worker risk itself rather than just the worker risk 7
that affects the public?
8 MR. DICKSON: I do not have an answer for 9
you on that.
10 DR. BLEY: I didn't think you would, I was 11 hoping somebody else would jump in. I'm interested in 12 pursuing this because we have some systems that could 13 be introducing, this system in particular, much higher 14 worker risk than we've seen before.
15 Nobody from Staff wants to help?
16 MR. BORROMEO: This is Josh Borromeo, 17 Chief of the Nonpower Production Utilization Facility 18 Licensing Branch. For this SHINE review we evaluated 19 the items and regulations that are put forth to this 20 facility, the same type of facility.
21 The question you're asking I think is a 22 more broad question that is beyond the scope of this 23 review but we certainly understand it and we can bring 24 that back to the suggestion box that we were talking 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 about before.
1 DR. BLEY: I think you'll be hearing more 2
about this on other kinds of applications but it just 3
seems reasonable to me, and I see a parallel with the 4
environmental effects way back 60 years ago, that we 5
ought to be protecting the workers as well as the 6
public.
7 MEMBER PETTI: My view on this, because I 8
bumped into it in a fusion application, some of the 9
regulators, we allow more dose to workers because we 10 assume they're basically saving lives in the public so 11 we allow them to have a dose limit that's greater than 12 the general public.
13 What if you don't have a significant dose 14 to the public, then what's the right limit for the 15 worker? This is more in the reactor context. It's an 16 interesting discussion that can come up when the 17 relative risks are talked about and buried in the 18 actual ghost numbers that are allowed.
19 MEMBER SUNSERI: This is Matt and what I 20 hear you all talking about is there are limits for 21 workers and there is the ALARA rule for the general 22 design of the facility.
23 MEMBER PETTI: The question is, is that 24 numerical number the right number when you've got 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
92 facility that has, say, not significant offsite risk?
1 What is the right number? Is ALARA applied?
2 MEMBER HALNON: This is Greg, I think we 3
need to keep in mind this is a maximum hypothetical 4
accident perspective. There's no safety-related 5
actions that need to be done to mitigate real 6
accidents.
7 And it's hard to determine worker dose 8
when they can be evacuated and brought to low-dose 9
areas or even the control room for that matter or sent 10 offsite.
11 So, it would be very accident-specific, 12 operator-action specific, if somebody was stuck in one 13 position to operate one thing in a location.
14 So, it would be really difficult in my 15 mind to come up with an occupational dose for a 16 hypothetical accident that operators don't have to be 17 there. Now the control room is different because they 18 have to be there and that's why you calculate their 19 dose.
20 CHAIR BALLINGER: I guess I don't see an 21 issue because a combination of the worker dose limits 22 and ALARA, don't they just basically solve the 23 problem?
24 MEMBER MARCH-LEUBA:
I think 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
93 difference between the public and the employee is 1
mostly in DOE space you are monitored or you're not 2
monitored.
3 If you are not monitored, you better not 4
give me more than 100 millirem because I'm not 5
carrying out a dosimeter, I don't know how much you're 6
giving me.
7 Whereas, if I carry a dosimeter I can get 8
up to 5 rem and many studies suggest that 5 rem is the 9
limit where no adverse effects are seen. So, I have 10 high confidence that I'm not getting more than 5 rem 11 if I'm monitored and I'm an employee.
12 Whereas, if I'm a member of the public, 13 you're telling me I'm getting 100 rem but I don't 14 know.
15 MEMBER HALNON: I did an analysis 16 operating large light-water reactors and they needed 17 to put missile shields on the containment entry at 18 post-accident, and the dose rates were too high for 19 them to do that. So, that was a problem.
20 So, there is very localized effects that 21 could occur that would cause a problem but you have to 22 engineer your way out of those types of things.
23 MEMBER KIRCHNER: Just an observation, 24 there's a footnote in 5034 on the acceptable doses, 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 quote, unquote, acceptable doses, for purposes of 1
doing your design basis accident consequence analysis.
2 But the footnote makes it very clear that 3
the 25 rem and the other values that are cited are 4
not, what shall I say, expected or acceptable. I 5
haven't memorized the footnote.
6 These are limits, the presumption is that 7
the Applicant will demonstrate in the consequence 8
analysis that there's significant margin to that 25 9
rem.
10 Or in this case, I would hope for the 5 11 rem for the control room operator, if someone came up, 12 an Applicant with an analysis that said -- I'll make 13 up a number -- it's 4.6 rem, after this DBA I suspect 14 the Staff would look very hard at that and say, this 15 is not -- although it meets the, quote, unquote, 5 rem 16 requirement, this is questionable and would probably 17 result in further review by the Staff as to the 18 acceptability of that DBA.
19 DR. BLEY: There have been bits of history 20 floating around here, very historically, the reason 21 worker risk was allowed to be higher was because it 22 was assumed they were voluntarily there, where the 23 public wasn't voluntarily nearby.
24 We have evolved so that the guidance looks 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 at the control room operator. I maintain that still 1
because, Greg's right, they have to be there is one 2
thing but the other thing is we need them to protect 3
the public so it's still a public risk effect.
4 To Walt's last statement, the SHINE folks 5
weren't required to look at the operators outside the 6
control room. They did. NRC Staff is just reporting 7
on what the guidance requires and that's the operators 8
in the control room.
9 And as we move to new technologies where 10 the chemical risk to workers might be much higher than 11 the radiological risk, we don't have anything to fall 12 back on but perhaps OSHA.
13 So, I think it's something the NRC should 14 be thinking about.
15 MEMBER KIRCHNER: I agree with you, 16 Dennis.
17 MEMBER REMPE:
- Dennis, you're not 18 questioning heroic actions by workers, which is where 19 that would fall, but you're also saying, hey, we need 20 something for chemical releases to also address what 21 is required for their heroic actions?
22 Because the workers are there, if they 23 could be evacuated they would be but if they need to 24 be there it's because they're needed for heroic 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 actions, right?
1 DR. BLEY: I won't see that written down 2
anywhere, Joy. They often do heroic actions and if 3
you read some of the really detailed explanations of 4
what happened at Chernobyl, not Chernobyl, well, yes, 5
there too but Fukushima, it's very clear that they do 6
that.
7 But they're also there and, I don't know, 8
if you have a chemical kind of problem you might get 9
exposed before you can get out of there. So, I think 10 it's something that's just been a gap and ought to be 11 considered.
12 MEMBER KIRCHNER: Dennis, this is Walt 13 again.
14 Not to belabor this, but if I remember 15 correctly, with GDC19 for the power reactors, one also 16 has to look at toxic chemicals, not necessarily what 17 we are talking about here where the toxicity is a 18 result of the production operation but from when you 19 look at siting and offsite external
- hazards, 20 typically, am I not correct, toxic exposure is part of 21 the analysis for GDC-19.
22 DR. BLEY: You might well be correct, I 23 don't remember. I'd have to look it up.
24 MEMBER KIRCHNER: It's like things in 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
97 siting where they look at release of chlorine gas and 1
then do a dispersion calculation to see what the 2
control room and operators would be exposed to.
3 DR. BLEY: And the focus is on the control 4
room operators again, Walt.
5 MEMBER KIRCHNER: I agree with you.
6 (Simultaneous Speaking.)
7 DR. BLEY: And all those external kind of 8
events.
9 MEMBER REMPE: Could this come back to the 10 GDCs that we haven't reviewed yet may not be adequate?
11 DR. BLEY: I think the Staff can go on 12 with their presentations.
13 MEMBER KIRCHNER: I would observe, though, 14 that 10 CFR 53 draft does address this matter but it 15 doesn't distinguish control room from the other onsite 16 worker status.
17 MR. DICKSON: This is Elijah Dickson. Are 18 you ready for me to keep presenting?
19 CHAIR BALLINGER: Go ahead.
20 MR. DICKSON: Id like to mention that 21 part of control room habitability for power reactors 22 do look at chemical effects, there's some guidance on 23 that. Off the top of my head, I don't remember it but 24 that is assessed in some fashion for operating 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
98 reactors.
1 And then for events that actually do 2
occur, Part 20 does take into effect the actual 3
occupational dose limits and ALARA practices that 4
would be practiced by SHINE Staff there to ensure that 5
doses would be maintained below the actual 6
occupational dose limits of Part 20.
7 Onto Slide 25, just very briefly, a quick 8
discussion in regard to the technical specifications.
9 The interim Staff guidance asked us to take a look at 10 the tech specs and we are still reviewing the tech 11 specs as a whole.
12 We believe we'll have a presentation for 13 you in the future on them. The LSSSs for protecting 14 the primary system boundary are all set to protect the 15 primary systems boundary under a
variety of 16 conditions.
17 So, the first three of them themselves 18 protect against power excursions and boiling events 19 within the target solution vessel, others protect 20 against hydrogen buildup with the TOGS.
21 The second bullet, we'd like to discuss 22 here that we asked them to revise Tech Spec 3.4 to 23 include an LCO for the primary confinement boundary.
24 That way, they can ensure the primary confinement 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 boundary is performing its safety function.
1 When they do start operations, they're 2
limiting themselves to 85 percent power in the tech 3
specs and Tech Spec 5.8.4 states that SHINE will 4
conduct startup testing in accordance with the startup 5
testing program and it will submit a startup report to 6
the NRC within six months of completion of the startup 7
testing activities.
8 And so this will allow us to assess that 9
work that we've done and the work they've done up to 10 startup and see how well their analyses will predict 11 actual operations.
12 I have nothing else on this slide and if 13 there's no other questions we can move on to chemical 14 safety by James Hammelman.
15 MR. HAMMELMAN: Good morning, my name is 16 Jim Hammelman, I'm a senior chemical process engineer 17 at NMSS, Division of Fuel Management. I'll be 18 discussing the Staff's review and evaluation of 19 SHINE's chemical hazards analysis for their planned 20 medical isotope production facility.
21 The primary objective of the NRC review 22 was to examine SHINE's identification and evaluation 23 of chemical hazards to the public. Review was focused 24 on those chemical hazards that are under NRC'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
100 regulatory jurisdiction and the review will support 1
the Staff's licensing decision under the requirements 2
of Part 50.
3 The Staff evaluated the design against the 4
chemical safety criteria presented in Section 3.1 of 5
the FSAR. These criteria are more restrictive than 6
those identified in the ISG that augments NUREG-1537.
7 Next slide, please. The Staff reviewed 8
the SHINE description of the processes, the equipment, 9
the facilities used for irradiated material processing 10 that are presented in the FSAR.
11 The Staff noted the small scale of 12 operation, the shielded cells used for irradiated 13 material processing and the controls placed on 14 inventory of toxic and reactive chemicals.
15 The Staff also reviewed the accident 16 sequences identified and analyzed in the SHINE safety 17 analysis and in the FSAR. The Staff found the 18 identified accident sequences to be reasonable and 19 consistent with the process and facility information 20 presented in the FSAR.
21 The Staff performed independent analysis 22 of the consequences to offsite individuals from 23 chemical releases identified in the SHINE accident 24 analysis. Staff's independent analysis supports 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
101 SHINE conclusion that public exposure would be 1
minimal.
2 More specifically, the predictive 3
concentrations are less than those that would produce 4
mild transient health effects.
5 The Staff reviewed previous analysis of 6
similar operations and found that its conclusions are 7
consistent with those made by the Staff in its 1987 8
evaluation of the Cintichem facility, which also 9
produced moly-99.
10 And the conclusions are also consistent 11 with those made by DOE in an IES that it prepared when 12 it was considering medical isotope production. Next 13 slide, please. The Staff also performed independent 14 analysis of the impacts of chemical releases on SHINE 15 plant personnel.
16 The Staff used near-term fuel dispersion 17 estimates which were developed by SHINE and reviewed 18 and accepted by the NRC Meteorological Staff and 19 information about airflows through the control room.
20 In this case also, the Staff agrees with 21 SHINE's conclusion that worker exposure would be less 22 than those that would produce irreversible or other 23 serious health effects, which are the criteria listed 24 in Section 3.1.
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102 Next slide, please.
1 Overall, the chemical safety review 2
concluded that SHINE's process, the facility design 3
features and operational controls provide reasonable 4
assurance that SHINE will meet its chemical safety 5
design criteria presented in Section 3.1 of the FSAR 6
and that public health and safety will be adequately 7
protected from chemical hazards that are under NRC's 8
regulatory jurisdiction.
9 I'll return the mic to Elijah unless 10 there's any questions?
11 MEMBER HALNON: This is Greg, just one 12 question, and you can tell me this isn't the right 13 spot.
14 I
understand when we look at the 15 radiological portion and we have to respond to 16 accidents and do certain things, we look at the 17 chemical portion and we see a chemical spill or 18 something and we have to do certain things.
19 When we put those two together, is there 20 any conflict in mitigative actions that have to be 21 taken or should be taken where we're responding to a 22 chemical problem and there's a radiological issue that 23 we have to deal with, or anything vice versa?
24 Does that make any sense?
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103 MR. HAMMELMAN: I think what I hear you 1
asking is if there's concurrent accidents, 2
radiological and chemical --
3 MEMBER HALNON: Is there any conflict in 4
the actions?
5 MR. HAMMELMAN: Yes, and I guess it's that 6
concurrent accidents were not analyzed. So, I suppose 7
in some cases there might be but there's nothing 8
that's obvious to me.
9 In the case of the chemical analysis, we 10 were just focusing on what happens if the worker stays 11 in place for a little while before he evacuates.
12 There was no chemical response other than flee, for 13 the workers.
14 DR. BLEY: I want to expand on Greg's 15 question a little. I think that's something you folks 16 ought to really have on your ticket to look at when 17 you review or spot-check the procedures later on in 18 this process.
19 We've seen several events occur at 20 operating nuclear reactors where a fire, as it 21 evolved, has led to other situations and the fire 22 procedures were kind of written independently of the 23 other emergency procedures and the operators got in a 24 bit of a bind because the fire procedures took away 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
104 people that were urgently needed for what else was 1
going on in the control room.
2 So, looking through the procedures to see 3
if you get in places where your staffing for either 4
side of these events is challenged is something that 5
needs to be done at some point in time. It's not 6
here, it's later.
7 MEMBER HALNON: And Dennis, even going 8
further, I was thinking more of the co-located 9
facilities that we may be looking at down the road 10 where the chemical hazard is much greater, or maybe 11 even worse than the radiological hazard.
12 DR. BLEY: Good point.
13 CHAIR BALLINGER: This is Ron Ballinger.
14 Id like to reiterate that, I know of a 15 bunch of cases, non-nuclear, where a lack of knowledge 16 of issues in a facility by, in particular, fire 17 people, offsite fire brigades and stuff, has resulted 18 in serious injury or death because of that lack of 19 knowledge.
20 And so we're getting into, as Dennis said, 21 technologies that the Staff will be reviewing where 22 that interface between chemical technology and nuclear 23 technology may be more evident.
24 MEMBER REMPE: In listening to this, I'm 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
105 wondering if after we finish this review we ought to 1
do a lessons learned letter on insights that could 2
affect other applications.
3 And again, it doesn't have to be the same 4
math but I think we have to make a list and look at 5
and do such a letter in addition to the SHINE review.
6 CHAIR BALLINGER: We've certainly had 7
enough conversation that we ought to probably think 8
about that.
9 MR. MUNSON: This is Jeremy Munson, I 10 would just add that to a degree we do consider things 11 like that in criticality safety. For example, in 12 moderator-controlled areas or in areas where you're 13 primarily relying on moderation control.
14 Fire-fighting requirements in the event of 15 a fire are limited to mists, they can't do solid 16 streams.
17 We consider things like whatever 18 suppression agent they're using and the fire 19 suppression system whenever we do the safety 20 evaluations in terms of what type of moderation they 21 provide, reflection, things like that.
22 So, to a degree we do do that in 23 criticality.
24 CHAIR BALLINGER: But that's an internal 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
106 evaluation onsite with people that have been trained.
1 A lot of times, where the problem occurs is when you 2
get an external interaction with the public where they 3
need help in an area where they haven't been trained 4
or don't have any knowledge of.
5 That's where the problem arises. Anyway, 6
that's my story and I'm sticking to it.
7 MR. DICKSON: This is Elijah. I can move 8
on to Slide 30, onto some confirmatory analyses.
9 The Staff did audit SHINE safety basis 10 calculations, we performed a sampling of reviews of 11 their safety basis calculations and documents to 12 verify modeling assumptions, methodologies used, and 13 input values used for the design basis accident 14 analyses.
15 We did perform some confirmatory analyses 16 in areas where we felt that it was prudent. We did 17 perform simplified target solution inventory 18 calculations using MCMP and ORIGEN, and we did confirm 19 their results for the most part.
20 We performed, as Mike Salay had discussed, 21 transport calculations using simplified iodine 22 evolution and transport models. Our meteorologist did 23 assess the meteorological data and confirmed chi over 24 Q factors.
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107 And then lastly, radiological consequences 1
were confirmed using the NRC SNAP/Rad Trad Code 2
Version 4.0 to confirm their MHA dose results.
3 MEMBER REMPE: This is Joy and I 4
appreciate you adding this slide. In the SC, there 5
were some inferences that there was some confirmatory 6
calculations, but I appreciate the additional detail 7
here.
8 Tell me, is there a file system that if 9
four years from now somebody wants to look up what the 10 Staff did, it's connected to your SE in the process 11 that you did for this evaluation?
12 MR. DICKSON: No, to answer your question 13 there is not a central file. For many Staff analyses 14 we do have folders that we maintain and keep results 15 in there.
16 Specific to SHINE, though, a lot of the 17 information that we utilized, the confirmatory 18 analyses needed to be destroyed after we were using 19 it.
20 We have an agreement with them to review 21 certain documents and whatnot on their portal. And so 22 some of those calculations do need to be destroyed 23 afterwards. But for a lot of other calculations such 24 as power reactors, we do maintain files for that type 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
108 of work.
1 MEMBER REMPE: Thank you for your 2
response, although I'm not sure it leaves me happy.
3 MR. DICKSON: It's a matter of there's 4
proprietary information that we're reviewing and 5
specific information with regards to the design and 6
only certain Staff need to review those types of need-7 to-know-type analyses.
8 Onto Slide 31 if there's no other 9
questions, this slide will be handled by both Mike 10 Call and myself. Mike, would you like share your 11 evaluations and findings and conclusions?
12 MR. CALL: Sure, this is Mike Call in the 13 NSSA group review for NRC. Based on the review, as 14 was explained in earlier slides, the Staff was able to 15 make the findings you see here.
16 The NSSA method is an acceptable method 17 and supports the adequate identification of 18 capabilities and features to prevent or mitigate the 19 accidents and then protect the health and safety of 20 the public and workers.
21 And it provides reasonable assurance that 22 SHINE has identified accidents as required for 23 prevention and mitigation, and they have established 24 appropriate safety-related controls.
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109 I'll turn that back to you, Elijah.
1 MR. DICKSON: I'll start by saying that 2
for a facility such as SHINE, we did find the margin 3
to safety is large and that there are few credible 4
accidents that can sufficiently damage the system that 5
would result in a major release of radioactive 6
material to the unrestricted area.
7 With that, the Staff found reasonable 8
assurance that SHINE meets the siting criteria for 9
public health and safety and that we also found 10 reasonable assurance that the control room 11 habitability requirements for radiological 12 consequences have also been met.
13 And with
- that, that concludes our 14 presentation today and we can field any other 15 questions you may have.
16 CHAIR BALLINGER: Questions from Members?
17 Okay, this is a break-point session. After this, 18 which I'm sure will be after lunch, will be the --
19 yes, I'm getting there. So, now it's time for public 20 comments.
21 If there are members of the public that 22 are out there that would like to make a comment, you 23 may have to use star 6 to unmute your phone, or if 24 you're logged in through Teams, please state your name 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
110 and make your comment, please.
1 Hearing none, I think we're at an end to 2
this part of the session pretty much conveniently, or 3
whatever, just like yesterday. We don't have enough 4
time to switch before lunch to go into the closed 5
meeting because I think we're going to have longer 6
discussions than a half an hour.
7 So, I think we will recess the meeting 8
until 1:00 p.m., thank you very much.
9 (Whereupon, the above-entitled matter 10 went off the record at 11:28 a.m.)
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© SHINE Technologies, LLC 1
© SHINE Technologies, LLC Chapter 13 - Accident Analysis (Open Session)
TRACY RADEL, VICE PRESIDENT OF ENGINEERING
© SHINE Technologies, LLC 2 SHINE applies a SHINE-specific, risk-based methodology similar to the guidance described in NUREG-1520, Standard Review Plan for Fuel Cycle Facilities License Applications, in the development of the detailed accident analysis.
o This methodology is applied to both the irradiation facility (IF) and the radioisotope production facility (RPF) for consistency of the safety analysis across the facility.
The SSA is developed based on the following major steps:
o Identification and systematic evaluation of hazards at the facility o Comprehensive identification of potential accident/event sequences that would result in unacceptable consequences, and the expected likelihoods of those sequences o Identification and description of safety-related controls (i.e., structures, systems, components, or specific actions) that are relied on to limit or prevent potential accidents or mitigate their consequences o Identification of programmatic administrative controls that ensure the availability and reliability of identified safety systems o Assessment of radiological and chemical consequences for postulated accident sequences to demonstrate compliance with acceptable limits SHINE Safety Analysis (SSA) Methodology
© SHINE Technologies, LLC 3 SHINE Safety Criteria:
o An acute worker dose of 5 rem or greater total effective dose equivalent (TEDE).
o An acute dose of 1 rem or greater TEDE to any individual located outside the owner controlled area.
o An intake of 30 milligrams or greater of uranium in a soluble form by any individual located outside the owner controlled area.
o An acute chemical exposure to an individual from licensed material or hazardous chemicals produced from licensed material that could lead to irreversible or other serious, long-lasting health effects to a worker or could cause mild transient health effects to any individual located outside the owner controlled area.
o Criticality where fissionable material is used, handled, or stored (with the exception of the target solution vessel).
o Loss of capability to reach safe shutdown conditions.
Acceptance Criteria CONSEQUENCE ANALYSIS METHODOLOGY
© SHINE Technologies, LLC 4 Identification of relevant accident categories o Relevant accident categories as identified in the interim staff guidance (ISG) augmenting NUREG-1537 are carried forward o Hazard evaluations identify potential initiating events, consequences, and controls that may be applied o Hazard evaluations also identify SHINE-specific accident types (e.g., tritium, neutron driver)
Process hazard analysis (PHA) for internal and external events o Identify accident sequences based on the hazard evaluation results and the ISG guidance o Estimate a risk index for each potential unmitigated accident sequence (likelihood x consequences) o Identify engineered and administrative controls for those sequences which have an unacceptable risk o Evaluate controlled risk indices crediting risk reduction from controls o Develop list of safety-related controls Process Hazard Analysis and Accident Sequence Development
© SHINE Technologies, LLC 5
IF accident categories:
o Maximum hypothetical accident (MHA) o Insertion of Excess Reactivity o
Reduction in cooling o
Mishandling or malfunction of target solution o
Loss of off-site power o
External events o
Mishandling or malfunction of equipment o
Large undamped power oscillations o
Detonation and deflagration in the primary system boundary o
Unintended exothermic reaction other than detonation o
System interactions o
Facility-specific events (i.e., neutron driver assembly system [NDAS], tritium purification system [TPS], and heavy load drop events)
Process Hazard Analysis and Accident Sequence Development
RPF accident categories:
o Critical equipment malfunction o
Inadvertent nuclear criticality o
RPF fire (i.e., carbon delay bed fire, carbon guard bed fire) o Hazardous chemicals (e.g., uranium uptake)
External event accident categories:
o Seismic event o
Severe weather (e.g., tornado, high winds, heavy snow, lightning) o External flooding events (i.e., probable maximum precipitation) o External fire events (e.g., vegetation, natural gas, vehicle fires) o Transportation accidents (e.g., aircraft impact, chemical truck accident) o Flooding events internal to the IF and RPF o
On-site chemical/gas releases (e.g., spills) o Fire events internal to the IF and RPF are evaluated on a fire area basis
© SHINE Technologies, LLC 6 Risk Matrix Development
© SHINE Technologies, LLC 7 Likelihood Evaluation
© SHINE Technologies, LLC 8 The types of safety-related controls that are credited for prevention and/or mitigation of accident sequences are:
o Engineered controls (active or passive), identified as safety-related structures, systems, and components (SSCs); and o Specific administrative controls (e.g., procedural controls).
Programmatic administrative controls are also implemented to assure that safety-related controls can perform their intended functions.
Defense-in-depth (DID) controls may also be identified that are not credited in accident sequences but provide additional margin for risk reduction.
Safety-Related Controls
© SHINE Technologies, LLC 9 Radiological consequences are determined for members of the public and control room operators Process includes:
o Calculation of inventories o Definition of accident-specific material at risk (MAR) o Transport of radionuclides o Development of accident source terms o Conversion to radiological dose Generally, worker and public doses are calculated over a 30-day interval o The scenario resulting in the release of tritium into the tritium confinement boundary uses a 10-day interval because it is expected that tritium recovery can be accomplished in this time frame Accident Analysis and Determination of Consequences METHODS
© SHINE Technologies, LLC 10 Conservatisms applied in the dose analysis include, but are not limited to:
o Bounding TSV power history and operational cycle o Minimum nuclide decay times o Times to transport nuclides out of process systems are neglected o Condensation conservatively neglected o Non-credited filtration neglected Atmospheric dispersion values (/Q) used are 95th percentile Accident Analysis and Determination of Consequences CONSERVATISMS
© SHINE Technologies, LLC 11 Accident Analysis and Determination of Consequences
© SHINE Technologies, LLC 12 Hazardous Chemicals Chemical hazards of licensed material, hazardous chemicals interacting with licensed material, and hazardous chemical produced from licensed materials are evaluated in the SSA o These do not include substances prior to process addition to licensed materials or after process separation from licensed materials Hazardous chemical consequence assessment is performed to demonstrate that potential consequences meet the SHINE Safety Criteria for the public and workers (RCA worker and control room operator)
The PAVAN computer code is used to perform consequence analysis for the public and nearest residence o Chemical exposure to both receptors is calculated using the 95th percentile /Q values
Advisory Committee on Reactor Safeguards SHINE Medical Technologies, LLC Operating License Application Chapter 13 - Accident Analysis Elijah Dickson, NRR/DRA/ARCB Mike Call, NMSS/DFM/NARAB James Hammelman, NMSS/DFM/CTCFB U.S. Nuclear Regulatory Commission May 18, 2022
Review Team
- Technical Reviewers and Presenters
- Elijah Dickson - NRR/DRA/ARCB
- Mike Call - NMSS/DFM/NARAB
- James Hammelman - NMSS/DFM/CTCFB
- Jeremy Munson - NMSS/DFM/NARAB
- Kevin Quinlan - NRR/DEX/EXHB
- Michael Salay - RES/DSA/FSCB
- Project Managers
- Michael Balazik - NRR/DANU/UNPL
- Molly-Kate Gavello - NRR/DANU/UNPL
- Holly Cruz - NRR/DANU/UNPL 2
Contents
- Background and Review Approach
- SHINE Safety Analysis
- Design Basis Accident Analyses
- Chemical Safety
- Audits and Confirmatory Analyses
- Evaluation Findings and Conclusion 3
Background and Review Approach -
Regulatory Requirements and Commitments
- 10 CFR 50.34, Contents of applications; technical information, paragraph (b), Final safety analysis report.
- 10 CFR 50.36, Technical Specifications.
- 10 CFR 50.40, "Common Standards," paragraph (a).
- 10 CFR 50.57, "Issuance of Operating License," paragraph (a)(3).
- Commitments to 10 CFR Part 70-like requirements.
4
Background and Review Approach -
Regulatory Guidance NUREG-1537, Part 1, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors, Format and Content, issued February 1996 NUREG-1537, Part 2, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors, Standard Review Plan and Acceptance Criteria, issued February 1996 Final Interim Staff Guidance [ISG] Augmenting NUREG-1537, Part 1, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors: Format and Content, for Licensing Radioisotope Production Facilities and Aqueous Homogeneous Reactors, dated October 17, 2012 Final Interim Staff Guidance Augmenting NUREG-1537, Part 2, Guidelines for Preparing and Reviewing Applications for the Licensing of Non-Power Reactors: Standard Review Plan and Acceptance Criteria, for Licensing Radioisotope Production Facilities and Aqueous Homogeneous Reactors, dated October 17, 2012 5
Background and Review Approach -
Regulatory Guidance (Contd)
NUREG-1520, Rev. 2, Standard Review Plan for Fuel Cycle Facilities License Applications, issued June 2015 NUREG-1513, "Integrated Safety Analysis Guidance Document," issued May 2001 NUREG/CR-6410, Nuclear Fuel Cycle Facility Accident Analysis Handbook, issued March 1998 NUREG/CR-2858, PAVAN: An Atmospheric-Dispersion Program for Evaluating Design-Basis Accidental Releases of Radioactive Materials from Nuclear Power Stations, issued November 1982 Regulatory Guide 1.145, Rev. 1, Atmospheric Dispersion Models for Potential Accident Consequence Assessments at Nuclear Power Plants, issued February 1983 NUREG/CR-6331 Rev. 1, Atmospheric Relative Concentrations in Building Wakes, issued May 1997 6
Background and Review Approach -
Review Methodology SHINE presented two types of safety analyses for the staff to review:
1.
SHINE Safety Analysis (SSA)
Purpose:
Systematic analysis of facility processes used to identify and evaluate facility hazards associated with the processing and possession of licensed materials.
2.
Design Basis Accident (DBA) Analyses
Purpose:
Evaluate the design and performance of structures, systems, and components (SSCs) of the facility with the objective of assessing the radiological consequences resulting from operation of the facility.
7
SHINE Safety Analysis - Overview
- ISG Augmenting NUREG-1537
- 10 CFR Part 70 and NUREG-1520 Integrated Safety Assessment (ISA) methods acceptable to demonstrate safety
- Alternatives are acceptable if adequacy to ensure safety is demonstrated
- SHINE's approach: use of ISA methods with differences
- Differences in terminology but methodology are similar in content, function, analysis (e.g., SSA Summary, safety-related controls)
- SSA Summary: applicant-controlled document; not submitted on docket 8
SHINE Safety Analysis - Review Approach Similarities to NUREG-1520 approach Evaluate alternatives to NUREG-1520 approach Considerations of review: applicable regulatory requirements and unique aspects of facility and the application Ensure adequacy of safety program, including SSA method and implementation
- Broad (horizontal) review - evaluate method and safety program
- Narrow (vertical) reviews of select accident types - evaluate method implementation
- Reliability management measures 9
SHINE Safety Analysis - Method and Implementation SSA Method:
- Identify, evaluate facility hazards - HAZOP, FMEA.
- Identify credible accident sequences, define credible.
- Assess radiological, chemical consequences and likelihoods.
- Identify, describe safety-related controls to prevent/mitigate accidents, meet SHINE Safety Criteria.
- Identify reliability management measures, programs for establishing and maintaining these measures.
Method Implementation
- Assess by review of select accident types (facility-specific events, external hazards, equipment mishandling/malfunction, and select events for criticality).
Safety Program: SSA and SSA method are an important element; effective = reflect as-built, as-operated facility, demonstrate ensures health, safety of public and personnel.
10
Design Basis Accident (DBA) Analyses -
SHINE Facility Highlights Typical design philosophy of defense-in-depth and multiple barriers.
Eight independent accelerator-driven subcritical assemblies.
Seismic qualified design features.
TSV operates at relatively low power density, temperature and negative pressure.
All DBAs which trip the TSV reactivity protection system (TRPS) results in an immediate safe shutdown condition.
Light water pool has sufficient capacity to passively handle decay heat following a trip.
Nominal source term is small. Material at Risk source term (safety-basis) is conservative, given aggressive modeling assumptions.
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DBA Analyses - Design Criterion and Siting Criteria (Presented as NUREG-1537 and the ISG guides staff to review)
Design Criterion 6 - Control room A control room is provided from which actions can be taken to operate the irradiation units safely under normal conditions and to perform required operator actions under postulated accidents.
Siting and Control Room accident dose acceptance criteria:
- 1. Radiological consequences to an individual located in the unrestricted area following the onset of a postulated accidental release of licensed material would not exceed 1 rem total effective dose equivalent (TEDE) for the duration of the accident, and
- 2. Radiological consequences to workers [control room operator] do not exceed 5 rem TEDE during the accident.
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DBA Analyses - Methodology SHINE DBA analyses are consistent with NUREG/CR-6410 methodology.
Generally divided into six parts:
1.
Select bounding design basis accidents; 2.
Derive applicable accident source terms; 3.
Identify major SSCs intended to mitigate the radiological consequences; 4.
Estimate fission product release characteristics to the environment; 5.
Review meteorological characteristics; and 6.
Calculate radiological consequences from the bounding DBAs.
Generally, the staff does not accept DBA analyses that credit facility features that:
are not safety-related; are not covered by technical specifications; do not meet single-failure criteria; or rely on the availability of offsite power.
13
DBA Analyses - Identified Applicable DBAs SHINE DBA analyses are consistent with the ISG.
- 1. Maximum hypothetical accident (MHA) (Subsection 13a2.1.1);
- 2. Excess reactivity insertion (Subsection 13a2.1.2);
- 3. Reduction in cooling (Subsection 13a2.1.3);
- 4. Mishandling or malfunction of target solution (Subsection 13a2.1.4);
- 5. Loss of offsite power (LOOP) (Subsection 13a2.1.5);
- 6. External events (Subsection 13a2.1.6);
- 7. SHINE MHA - Mishandling or malfunction of equipment (Subsection 13a2.1.7);
- 8. Large undamped power oscillations (Subsection 13a2.1.8);
- 9. Detonation and deflagration in the primary system boundary (Subsection 13a2.1.9);
- 10. Unintended exothermic chemical reactions other than detonation (Subsection 13a2.1.10);
- 11. System interaction events (Subsection 13a2.1.11); and
- 12. Facility-specific events (Subsection 13a2.1.12).
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DBA Analyses - Identified Applicable DBAs (Contd)
- 14. Loss of Electrical Power (FSAR Section13b.1.2.2);
- 15. External Events (FSAR Section 13b.1.2.3);
- 16. Critical Equipment Malfunction (i.e., Malfunction or Mishandling of Equipment) (FSAR Section 13b.1.2.4);
- 19. Hazardous Chemical Accidents (FSAR Section 13b.1.2.7).
15
DBA Analyses - Materials at Risk - Accident Source Terms Two types of Materials at Risk (MAR):
1.
Fission-product based safety-basis source term derived for the TSV inventory.
- 2.
Tritium Based on maximum quantities at the facility or used by an irradiator assembly.
Primary codes and methods used to derive the MAR:
1.
Los Alamos, Monte Carlo N-Particle 5 (MCNP5), version 1.60.
2.
Oak Ridge, Standardized Computer Analyses for Licensing Evaluation (SCALE),
version 6.1.2, ORIGEN-S.
The staff finds these computer codes acceptable for the purposes of developing radionuclide inventories to derive a bounding SHINE-specific MAR.
Accident-specific source terms are consistent with five-factor formula methodologies described in NUREG/CR-6410.
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DBA Analyses - Materials at Risk (MAR) -
Accident Source Terms (Contd)
Verified operational assumptions with additional margin:
Corresponding fission power Irradiation time per cycle Total time between irradiations Extraction between irradiations Length of target solution recovery Calculation includes effects from fission, transmutation, activation, and decay.
Assessed burnup and radionuclide peaking.
Very large margin between the MAR and normal operations.
The staff finds that the conservative assumptions and treatment of uncertainty to justify the MAR are acceptable.
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DBA Analyses - MAR Transport and Mitigation (1/3)
Leak path factors (LPF) developed for each scenario by:
Identify major SSCs intended to mitigate the radiological consequences; Estimate fission product release characteristics to the environment.
Factors include important physical processes such as control volumes, volumetric flow rates, leakage through gaskets, pressure, barometric breathing, and removal processes.
Five-factor formula damage ratio is assumed to be 1 and airborne release fractions vary by accident.
Environmental pathways are:
Confinement by IU cell or concrete cell -> IF building -> environment Confinement by glove box -> IF building -> environment Confinement by hot cell -> RPF building -> environment Confinement by concrete vault -> RPF building -> environment LPFs are generally consistent with the methods described in NUREG/CR-6410.
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DBA Analyses - MAR Transport and Mitigation (2/3)
Iodine that evolves from solution to gas space can leak to environment.
Significant contributor to dose.
Geometry, temperature, flow.
Iodine also evolves from solution during normal operation.
If evolution is fast, it depletes inventory available for release to the environment.
Reduction in MAR by evolution not accounted for by inventory codes such as SCALE or MCNP.
If evolution is slow, most 131I will decay before evolving during an accident.
Limit on ARF Limit on Xe,MAR*ARF for 131I.
It is conservative to neglect evolution rate effects.
19 Effect of evolution on I131 buildup (Xs,Xe) and airborne release fraction
DBA Analyses - MAR Transport and Mitigation (3/3)
Evolution and Transport Analyses:
Evolution transport analysis to compare to SHINE pool release calculation.:
All iodine isotopes.
Stopped transport analysis after getting substantially lower ARF then SHINE.
ARF*LPF Reviewed technical bases for flow and LPF parameters.
Influence of evolution on combined MAR*ARF (evolution vs decay):
Evaluation of the reduction in MAR due to evolution and adsorption during normal operation.
Evaluation of the release fraction to gas during a postulated accident scenario, ARF Some time-dependent value between 0 and 1.
SHINE neglecting evolution/adsorption reduction in evaluation of MAR for accident analysis and assuming an iodine ARF of 1 for many accident scenarios eliminate the need for additional analyses by using most bounding assumptions.
Partial general analyses illustrate some of these effects.
Geometry and scenario-specific calculations can be used to estimate conservatism.
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DBA Analyses - Atmospheric Dispersion
- Developed short-term atmospheric dispersion (/Q) factors using traditional Gaussian plume diffusion methodology.
- /Q were developed at the offsite public and control room receptor.
- Conservatively assumed ground level release.
- Utilized bounding short-term 95th percentile /Q values.
- Calculations performed with NRC computer program, PAVAN, which implements the guidance provided in RG 1.145.
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DBA Analyses - Radiological Consequences Consequence results are consistent with the total effective dose equivalent (TEDE) methodology defined in 10 CFR 50.2 and 20.1003.
Dose-conversion-factors utilized are consistent with regulations.
Federal Guidance Report 11, Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion.
Federal Guidance Report 12, External Exposure to Radionuclides in Air, Water, and Soil.
For fission product-based accidents, the accident duration is assumed to be 30 days and tritium accidents for 10 days.
Receptor locations assume no personal protection equipment or protective actions.
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DBA Analyses - SHINE Maximum Hypothetical Accident Mishandling or malfunction of equipment (SHINE Subsection 13a2.2.7)
- Most limiting scenario, Failure of the TOGS Pressure Boundary Resulting in Release of Off-Gas into the TOGS Cell.
- Failure of the TOGS portion of the primary system boundary could allow escape of fission product gases or hydrogen into the primary confinement boundary and the radiologically controlled area.
- TOGS circulates sweep gas during the irradiation cycle, a portion of the iodine is removed by the zeolite beds, and hydrogen and oxygen are recombined by the catalytic recombiners.
23
DBA Analyses - SHINE Maximum Hypothetical Accident (Contd)
MHA MAR uses 100% of the MAR halogens and noble gases.
Identified the safety controls for this accident to be:
Primary confinement boundary; Ventilation radiation monitors; Nitrogen purge system; Ventilation isolation mechanisms; and Holdup volume in the RVZ1e.
The calculated doses for the MHA scenario are the following:
Control Room Operator - 1,940 mrem (1.94 rem)
Maximum exposed member of the public - 727 mrem (0.727 rem)
Staff finds results are within the acceptable limit siting criteria of 1 rem TEDE and the control room operator of 5 rem TEDE.
24
DBA Analyses -Technical Specifications
- SHINE Tech Spec. Limiting Safety System Settings are set to protect the Primary System Boundary.
- Revised Tech Spec. Section 3.4 to include an LCO for the primary confinement boundary.
- SHINE Tech Spec. Limiting Safety System Settings 85% power averaged over 45 seconds.
- TS 5.8.4 states that SHINE will conduct startup testing in accordance with the Startup Testing Program (FSAR Section 12.11) and submit a Startup Report to the NRC within 6 months of the completion of all startup testing activities.
25
Chemical Safety Review
- Evaluated impacts on public health and safety - criteria in 50.40
- Focused on chemical hazards under NRCs regulatory jurisdiction
- SHINE Safety Criteria for public exposure
- Acute chemical exposure to an individual from licensed material or chemicals produced from licensed material that could cause mild transient health effects to an individual outside the owner-controlled area should be highly unlikely.
26
Chemical Safety Review (Contd)
- Staff reviewed SHINE SSA accident sequences using information about processes and facility details and stated chemical quantity limits. Staff finds accident sequences reasonable.
- Staff reviewed SHINE public consequence calculations, performed independent dispersion calculations. Staff agrees with SHINE conclusion - public exposure would be less than PAC-1 levels which could produce mild, transient health effects.
- Staff noted that public chemical risk conclusion is consistent with other relevant analysis of Mo-99 production operations.
27
Chemical Safety Review (Contd)
- Staff reviewed SHINE worker consequence calculations and performed independent dispersion calculations. While the staff used different analytical methods, the staff agrees with SHINE conclusion - worker exposure would be less than PAC-2 levels, which could produce irreversible or other serious health effects.
28
Chemical Safety Review (Contd)
- Staff review was coordinated with other reviewers, particularly meteorology and SHINE Safety Analysis reviewer.
- Staff concluded that SHINE process, facility design, and control features provide reasonable assurance that the public health and safety will be adequately protected from chemical hazards that are under NRCs regulatory jurisdiction.
29
Audits and Confirmatory Analyses Staff audited SHINE safety-basis design calculations and documents to verify methodology assumptions and input values.
Select independent confirmatory analyses include:
- MAR: simplified target solution inventory calculations using MCNP5 and ORIGEN confirmed results presented in design calculations.
- Transport: simplified iodine evolution and transport calculations.
- Meteorology: assessed meteorological data and confirmed /Q factors.
- Consequences: confirmatory analyses with NRC SNAP/RadTrad Ver. 4.0 confirmed results presented in the Ch 13 FSAR.
30
Staff Evaluation Findings and Conclusions
- SHINE Safety Analysis (SSA)
- SSA method is an acceptable method and supports adequate identification of capabilities and features to prevent/mitigate accidents and protect health, safety of public and workers.
- SSA provides reasonable assurance SHINE has identified accidents that require prevention or mitigation and established appropriate safety-related controls.
- DBA Analyses
- Staff found reasonable assurance that SHINE meets the siting criteria for public health and safety.
- Staff found reasonable assurance that the control room habitability requirements for radiological consequences are met.
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Acronyms DBA Design Basis Accident FMEA Failure Modes and Effects Analysis FSAR Final Safety Analysis Report HAZOP Hazard and Operability Analysis ISA Integrated Safety Assessment ISG Interim Staff Guidance LCO Limiting Condition of Operation LOOP Loss of offsite power LPF Leak path factors MAR Materials at Risk MCNP5 Monte Carlo N-particle 5 MHA Maximum Hypothetical Accident NRC Nuclear Regulatory Commission RG Regulatory Guide RPF Radioisotope Production Facility SSA SHINE Safety Analysis SSC Structures, Systems, and Components TSV Target Solution Vessel TEDE Total Effective Dose Equivalent TRPS TSV Reactivity Protection System TOGS TSV Off-gas System 32
Chapter 13 Backup Slides
Startup Testing SHINE has a startup testing program to demonstrate operability of their systems, calibrate instrumentation, and make reactor physics measurements to confirm their design calculations.
The startup testing plan provides an outline of the tests that will be performed.
The reactor physics tests are support by calculations and the measured results will be compared to the design calculations.