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Transcript of the Advisory Committee on Reactor Safeguards - Accident Analysis Thermal Hydraulics - EPRI Data Validation, June 7, 2023, Page 1-32, (Open)
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Official Transcript of Proceedings NUCLEAR REGULATORY COMMISSION

Title:

Advisory Committee on Reactor Safeguards Accident Analysis Thermal Hydraulics Open Session Docket Number:

(n/a)

Location:

teleconference Date:

Wednesday, June 7, 2023 Work Order No.:

NRC-2427 Pages 1-20 NEAL R. GROSS AND CO., INC.

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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 THERMAL-HYDRAULICS ACCIDENT ANALYSIS SUBCOMMITTEE 7

+ + + + +

8 OPEN SESSION 9

+ + + + +

10 WEDNESDAY 11 JUNE 7, 2023 12

+ + + + +

13 The Subcommittee met via hybrid in-person 14 and Video Teleconference, at 8:30 a.m. EDT, Jose 15 March-Leuba, Chairman, presiding.

16 17 COMMITTEE MEMBERS:

18 JOSE MARCH-LEUBA, Chair 19 RONALD G. BALLINGER, Member 20 CHARLES H. BROWN, JR., Member 21 VICKI BIER, Member 22 VESNA DIMITRIJEVIC, Member 23 GREGORY HALNON, Member 24 WALT KIRCHNER, 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 DAVID PETTI, Member 1

JOY L. REMPE, Member 2

MATTHEW SUNSERI, Member 3

4 DESIGNATED FEDERAL OFFICIAL:

5 KENT HOWARD 6

7 ALSO PRESENT:

8 KURTIS CRYTZER, EPRI 9

LOIS JAMES, NRR 10 JOSHUA KAIZER, NRR 11 SCOTT KREPEL, NRR 12 SILAS ROGERS, GSES 13 14 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com

3 C-O-N-T-E-N-T-S 1

Opening Remarks and Objectives 4

2 NRC Opening Remarks...............

6 3

EPRI Opening Remarks 8

4 Public Comments................. 20 5

6 7

8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com

4 P-R-O-C-E-E-D-I-N-G-S 1

8:30 a.m.

2 CHAIR MARCH-LEUBA: The meeting will now 3

come to order. This is a meeting of the Accident 4

Analysis Thermal-Hydraulics Subcommittee.

5 I am Jose March-Leuba, the SC Chair. In 6

addition to in-person attendance at NRC headquarters, 7

the meeting is broadcasted via MS Teams. Members in 8

attendance are Ron Ballinger, Vicki Bier, Charles 9

Brown, Vesna Dimitrijevic, Greg Halnon, Walter 10 Kirchner, Dave Petti, Joy Rempe, and Matthew Sunseri.

11 Today we are reviewing EPRI's Topical 12 Report Number 3002018337, entitled Use of Data 13 Validation and Reconciliation Methods for Measurement 14 Uncertainty Recapture.

15 Portions of our meeting may be closed to 16 the public to protect EPRI proprietary information.

17 We have not received requests to provide comments, but 18 we'll have an opportunity for public comments before 19 the beginning of the closed section of the meeting.

20 The ACRS was established by a statute and 21 is covered by the Federal Advisory Committee Act, 22 FACA. As such, the Committee only speaks to its 23 published letter reports.

24 The rules for participation in all ACRS 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 meetings were announced in the Federal Register on 1

June 13, 2019. The ACRS section of the U.S. NRC 2

public website provides our charter, bylaws, agendas, 3

letter reports, and full transcripts for the open 4

portions of all full and Subcommittee meetings --

5 including the slides presented there.

6 The Designated Federal Official today is 7

Kent Howard.

8 A transcript of the meeting is being kept, 9

therefore speak into the microphones clearly, and 10 state your name for the benefit of the Court Reporter.

11 And if you're in a conference room with multiple 12 people on the line, please remember to identify 13 yourself regularly for the accuracy of the transcript.

14 Please keep all your electronics and microphone on 15 mute when not in use.

16 As I said earlier, let me remind you that 17 ACRS only speaks through its public letters, written 18 by the Full Committee.

19 Today we're having a Subcommittee meeting 20 with the purpose of obtaining information that will be 21 considered by the Full Committee, likely in July. The 22 comments you hear today are not from ACRS, but ideas 23 from individual members.

24 So, I should have checked earlier, but 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

6 Scott on the line? Scott Krepel?

1 MR. KREPEL: Good morning. Yes, this is 2

Scott Krepel here -- speaking through a sign language 3

interpreter, of course.

4 CHAIR MARCH-LEUBA: Thank you. So, at 5

this point let's request that Scott and his 6

interpreter from the NRC Staff to present his opening 7

remarks, and then introduce the staff that will 8

present the Open Session.

9 Scott?

10 MR. KREPEL: Great, thank you.

11 As I just mentioned, my name is Scott 12 Krepel, speaking through a sign language interpreter.

13 I currently am the Acting Director for the Division of 14 Safety Systems.

15 Josh Kaizer is one of my staff who works 16 under me, as my official role as a Branch Chief in the 17 Nuclear Systems and Methods -- and Fuel Branch.

18 For opening comments on DVR for this 19 topical report, I just want to mention that I 20 understand this is a priority for a number of licenses 21 and industry. This method will allow them to 22 recapture the measurement of uncertainty, to be able 23 to do power upright without necessarily having to use 24 a more better flow meter, among other items.

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 With that being said, I will turn it over 1

to Josh Kaizer who I believe is present in the room 2

with you.

3 CHAIR MARCH-LEUBA: I believe it's James 4

Lois who'll do the open portion?

5 MS. JAMES: Hello --

6 (Simultaneous speaking.)

7 MS. JAMES: My name is Lois James --

8 (Simultaneous speaking.)

9 CHAIR MARCH-LEUBA: Yeah. Lois.

10 MS. JAMES: I was going to do the NRC 11 opening slides but, due to time constraints, we are 12 volunteering -- can you hear me?

13 We are volunteering not to actually speak 14 our slides. They're just introductory, they've got 15 the ML numbers, they've got the history. And so, at 16 this point we would like to turn it over to EPRI so we 17 can get started with the technical discussion.

18 CHAIR MARCH-LEUBA: As I said earlier, 19 ACRS only speaks through letters, so this is a comment 20 from a one member of ACRS. I applaud your decision, 21 thank you --

22 (Simultaneous speaking.)

23 MS. JAMES: Okay.

24 (Laughter.)

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 MS. JAMES: Thank you.

1 CHAIR MARCH-LEUBA:

And for the 2

transcript, for the record, the slides will be part of 3

the transcript. So, you can read them yourself, if 4

you're reading the transcript.

5 MS. JAMES: Thank you, that would be 6

great.

7 CHAIR MARCH-LEUBA: So, let me go back.

8 We are ready now for Kurtis Crytzer from EPRI, to 9

present his opening remarks on an introduction to the 10 topic in open session.

11 We will have a full-scope discussion 12 during -- including the proprietary aspects during the 13 closed session.

14 Kurtis?

15 MR. CRYTZER: Thank you. As mentioned, my 16 name is Kirk Crytzer, I am with EPRI. I'm a --

17 CHAIR MARCH-LEUBA: They need to show the 18 slide. I don't know who is in charge of that.

19 MR. CRYTZER: I'm plugged in --

20 CHAIR MARCH-LEUBA: Do you have his 21 slides?

22 MS. JAMES: I will get them up there as 23 soon as I can.

24 CHAIR MARCH-LEUBA: Okay. So, keep going, 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 we have your slides.

1 MR. CRYTZER: Thank you.

2 Okay. Yeah, so I'm a Principal Project 3

Manager in the Plant Engineering Group. Today I want 4

to talk at a high level for the opening presentation 5

about the use of data validation reconciliation 6

methods, as evaluated for a measurement uncertainty 7

application.

8 CHAIR MARCH-LEUBA: As I said earlier, 9

feel free not to read every bullet.

10 MR. CRYTZER: Yeah, absolutely --

11 CHAIR MARCH-LEUBA: Because you have very 12 dense slides.

13 MR. CRYTZER: Yeah. So, I apologize for 14 all the content -- I'll touch briefly on the objective 15 of each slide, so --

16 CHAIR MARCH-LEUBA: No, you don't need to 17 apologize. This is good, I mean --

18 MR. CRYTZER: Okay.

19 CHAIR MARCH-LEUBA: The purpose of the 20 Subcommittee is to inform the members present so we --

21 and obtain information so we can report to the Full 22 Committee.

23 As it happens today, we have the Full 24 Committee members -- everybody is here. But, the 25 NEAL R. GROSS COURT REPORTERS AND TRANSCRIBERS 1716 14th STREET, N.W., SUITE 200 (202) 234-4433 WASHINGTON, D.C. 20009-4309 www.nealrgross.com

10 process is still to inform, but the secondary purpose 1

is to inform the public of what you're doing.

2 So, by placing all this information in the 3

record, you're informing the public. So, that's good.

4 MR. CRYTZER: Okay, great. Thank you.

5 So, the objective of the topical report 6

was to evaluate the methodology for data 7

reconciliation for measuring uncertainty recapture, 8

and specifically used as an input into the core 9

thermal power calculation.

10 The topical report is built around a 11 German code, VDI code. And the VDI standard, VDI-12 2048, captures that methodology. And the idea behind 13 the topical report was to evaluate the methodology, 14 capture it within the EPRI document, evaluate the 15 technical basis, evaluate the uncertainty claims 16 against those that are commonly used in other 17 scenarios within nuclear power, perform a failure 18 modes and effects analysis.

19 And we wanted to develop this around the 20 use of the ultrasonic flow meter as a guide, since 21 that was the currently accepted license practice for 22 MUR.

23 CHAIR MARCH-LEUBA: And again, ACRS will 24 always interrupt you -- and I will more. When you say 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 code, VDI code, you don't mean computer code, you mean 1

the standard?

2 MR. CRYTZER: That's correct. Standard, 3

yeah, thank you for that clarification.

4 So, without repeating myself, the VDI code 5

that this is based on uses first principles of 6

thermodynamics and statistical analysis. It takes 7

measurements all across the secondary side of the 8

plant, and in the steam side of the plant --

9 individually and in aggregate -- to provide more 10 accurate data points for each value -- the true 11 physical value. And we'll talk about that a little 12 bit more as we go into the closed session.

13 Again, DVR -- we're looking at this for 14 MUR, but has been used for power recovery. It has 15 been used in Europe, so it's been around since -- at 16 least, we're aware of, since 1999. EPRI didn't really 17 get engaged until 2014, in which case we got engaged 18 in looking at a power recovery application.

19 So, this is somewhat of a repeat. But, 20 the point that I wanted to stress here is, what we are 21 not trying to do is have one specific software 22 approved. We're trying to look at the methods 23 themselves in the VDI-2048 methodology and keep it 24 agnostic to the software vendor, as long as 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 software is compliant with VDI-2048.

1 CHAIR MARCH-LEUBA: And off the top of 2

your head, how implemented is it in Europe -- 90 3

percent of the plants use it, five percent of the 4

plants use it? Half of them?

5 MR. CRYTZER: Yeah, that's a good -- as 6

far as data reconciliation process in itself, that I'm 7

aware of -- and this is a guess -- I would say 50 8

percent. With respect to measurement uncertainty 9

recapture, I'm just aware of one country that has 10 that.

11 So, in fact --

12 CHAIR MARCH-LEUBA: If it's a whole 13 country ever since 1999, it's a lot of experience.

14 MR. CRYTZER: Yeah. I know Germany and 15 Switzerland for sure, and we've just recently received 16 some questions from Sweden that have come in, that use 17 this methodology. But, for specific for MUR, it's --

18 (Simultaneous speaking.)

19 CHAIR MARCH-LEUBA: As the Staff will talk 20 about in their presentation, what we need to review is 21 what can possibly go wrong.

22 MR. CRYTZER: Yes.

23 CHAIR MARCH-LEUBA: And when you go into 24 smart technologies -- which this is one of the smart 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 technologies -- the question is, will it work nicely 1

on the table top but then, once every 10 years, it 2

will fail catastrophically.

But, by having 3

experience, you know, when it applies, we know it 4

doesn't. So, that provides a lot of confidence.

5 MR. CRYTZER: Yes. So, with that, using 6

in the core thermal power calculation, currently is 7

largely dominated by feedwater flow. So, if there's 8

an inaccuracy in the feedwater flow measurement due to 9

either, filing of a differential pressure flow meter 10

-- such as Venturi -- or an inoperability of an 11 ultrasonic flow meter, that directly has a substantial 12 impact on the core thermal power calculation.

13 Within the industry itself, reliability 14 issues with the ultrasonic flow meters -- EPRI has 15 heard multiple discussions about that. And, you know, 16 there is costs to maintain the MUR condition through 17 the ultrasonic flow meter. So, there is a desire to 18 find a potential alternate technique to --

19 (Simultaneous speaking.)

20 CHAIR MARCH-LEUBA: This goal to eliminate 21 loose parts, because the ultrasonic flow meters are in 22 contact -- are inside the pipe. If they fail to work, 23 because they break and they go into the --

24 (Simultaneous speaking.)

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14 MR. CRYTZER: Yeah, they're --

1 (Simultaneous speaking.)

2 MEMBER HALNON: The ultrasonic --

3 MR. CRYTZER: Yeah. They're --

4 (Simultaneous speaking.)

5 MR. ROGERS: It depends --

6 MR. CRYTZER: Yeah, go ahead.

7 MR. ROGERS: On the flow meter --

8 MEMBER HALNON: state your name.

9 MR. ROGERS: This is Silas with GSES. It 10 depends on the flow meter, whether it's drilled into 11 the pipe or if it's on the surface of the pipe.

12 MR. CRYTZER: There have been at least one 13 more recently, that I'm aware of, where the actual 14 inside condition of the pipe does affect the quality 15 of the ultrasonic. In this case, there was, I guess 16 a eccentricity was smoothed out on one side causing an 17 error in that calculation.

18 So, what we have done within EPRI, at 19 least with the VDI-2048 methods -- as I mentioned, 20 it'd been around since '99, we started in 2014 -- we 21 did an evaluation on a Boiling Water Reactor that was 22 underpowered. That evaluation actually showed about 23 15 megawatt electric under power, due to a fouled 24 Venturi.

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15 The second research that we did was, we 1

understood that there are certain times where the 2

differential pressure flow meter is changing during 3

time. And this is times during polyacrylic acid 4

injection, you'll defoul a Venturi as a result of 5

injecting that into a pressurized water reactor to 6

control deposit inventory. And also during on-line 7

noble metal chemistry for the boiling water reactors, 8

where you're shifting the redox potential during 9

periods of time.

10 So, we wanted to evaluate the two 11 scenarios with that to see the data reconciliation was 12 robust enough to be able to accurately and effectively 13 monitor the feedwater flow, while the Venturi itself 14 was changing. And so, we published that report.

15 And then we decided there needed to be a 16 guidance document for implementation, not only for 17 power recovery, but for use in condition-based 18 maintenance or condition-based monitoring.

19 So, you'll see through the process, 20 because you are reconciling various data points within 21 the plant, that this can be used for condition 22 monitoring, for condition-based maintenance or even 23 calibration of equipment. And it can quickly and 24 effectively identify off normal conditions.

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16 So, with that, the usefulness that we're 1

looking at here -- again, the pie chart we'll go into 2

in a little bit more detail, but the top one is 3

heavily dominated by the feedwater flow for the power 4

calculation. And the VDI code allows you to take in 5

more measurements to exploit those redundancies 6

available, and correct the errors -- or, the 7

uncertainties, with the instruments.

8 There are commercial software products 9

that are available that are compliant with VDI-2048, 10 you'll see them under data validation and 11 reconciliation, or process data reconciliation. And 12 there's currently, under the performance test code, 13 there's discussions of bringing the VDI-2048 methods 14 into our domestic codes.

15 So, just to finalize where we are. We 16 started this initial development -- we had a pre-17 meeting right before the pandemic in 2020, in 18 February. And then, we had had that pre-meeting 19 following our topical report publications.

20 So, we published in November of 2020, we 21 provided

both, proprietary and non-proprietary 22 versions. We had a pre-meeting, as well, before 23 publishing this. We'd have an industry technical 24 advisory group that has utility personnel, we've also 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 brought in academia from -- Texas A&M has looked at 1

it. And we've had two separate vendors of the 2

software, VDI-2048 software compliant.

3 We've gone through two audits, one of 4

which was an on-site audit. Currently, we have 5

responded to 17 requests for additional information.

6 And, with that, I'll take questions.

7 CHAIR MARCH-LEUBA: Let me ask a general 8

question. For what purpose do you submit this topical 9

report to the Staff? And let me give you a multiple 10 choice. You're essentially asking for a safety 11 evaluation report for a topical report, but this is 12 not an application that is ready to go into the field, 13 the way I see it. I mean, this just kind of creates 14 an umbrella, guidelines. And then, we have a specific 15 license amendment request, we will look at the details 16

-- by we, I mean the Staff.

17 So, what are you asking the Staff to do 18 for you in the SER?

19 MR. CRYTZER: Yeah. So, the staff is --

20 I guess what we're trying to do is, really have the 21 evaluation of the acceptability of the methods of VDI-22 2048, so they --

23 (Simultaneous speaking.)

24 CHAIR MARCH-LEUBA: More like, 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

18 concept?

1 MR. CRYTZER: Yeah, the concept. And --

2 CHAIR MARCH-LEUBA: And then, the method, 3

the particular application will be up to the first 4

licensee?

5 MR. CRYTZER: Yeah. So, within the 6

license amendment request, the specific type of 7

software, the auxiliary conditions that are defined, 8

all that would be included.

9 CHAIR MARCH-LEUBA: But, we are reviewing 10 the concept, does this makes sense.

11 MR. CRYTZER: Yes.

12 CHAIR MARCH-LEUBA: Or, don't bother 13 sending because we don't like it. That's what 14 basically we're talking about?

15 MR. CRYTZER: That's right.

16 CHAIR MARCH-LEUBA: Members, anymore 17 questions in the open session for EPRI, or the Staff?

18 MEMBER HALNON: Yeah, I just had a -- I 19 guess it's more of a curiosity. Since we got time 20 frames back to 1999, you know, 20-plus years. It 21 struck me when you said there was, what, 17 RAIs. Can 22 you generally group those, were they technical in 23 nature, admin in nature, or was it trying to train the 24 reviewers on heat balance?

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19 MR. CRYTZER: I would say -- if you want 1

to answer some, and then I'll give my opinion.

2 MR. ROGERS: I think they were mostly 3

technical in nature. There were a few related to, you 4

know, how things would be handled. But, mostly they 5

were technical and trying to clarify certain concepts 6

with the reviewers.

7 MEMBER HALNON: Because it didn't seem 8

that these were very exotic concepts that we're 9

presenting here, they're relatively straightforward 10 thermodynamics and heat-balance type --

11 (Simultaneous speaking.)

12 MR. ROGERS: That part is very simple, 13 actually. And then, the complicated part is the 14 application of corrections and --

15 (Simultaneous speaking.)

16 MEMBER HALNON: Is that generally -- I 17 mean, when I say generally, is that more of the 18 technical issues were generally -- the statistical 19 portions?

20 MR. ROGERS: There were quite a few 21 questions related to those, yes.

22 MEMBER HALNON: All right, thanks. I just 23 wanted to get a sense of why it seemed to be so many 24 questions for such an established methodology.

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20 Especially if it's been used in Europe for quite a 1

while.

2 MR. CRYTZER: Yeah, I think the other part 3

of it that goes to the earlier point was, what were we 4

actually trying to get approved. And --

5 (Simultaneous speaking.)

6 MEMBER HALNON: Goes to the regulatory 7

admin portion of it.

8 CHAIR MARCH-LEUBA: Any questions, Vesna?

9 Giving you an opportunity while we ask a --

10 Okay. Vesna says no.

11 Members of the public, if this will be the 12 last opportunity for you to present some comments on 13 this topic on the record. So, if a member of the 14 public wants to make a comment, please do so.

15 Hearing none, we are going to close this 16 open session Teams meeting. And everybody that can be 17 in the closed session will have a secondary link where 18 you're supposed to go and call in right now.

19 We are going to finish the open transcript 20 right now, and we'll start the new closed transcript 21 in five minutes.

22 (Whereupon, the above-entitled matter went 23 off the record at 8:50 a.m.)

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w w w. e p r i. c o m Kurt Crytzer Principal Project Manager ACRS Subcommittee - Open Session June 7, 2023 Use of Data Validation and Reconciliation Methods for Measurement Uncertainty Recapture EPRI Topical Report 3002018337

2 EPRI Topical Report on use of Data Validation and Reconciliation Methods (DVR) for Measurement Uncertainty Recapture (MUR)

Objective:

- Evaluate if the DVR methodology is an effective technology for use as an input to the calculation of plant CTP and the detection of plant measurement errors with CTP related or other plant instrumentation

- Developed for implementation of the German Standard VDI-2048 Data Reconciliation methodology to reduce the uncertainty of determinations of nuclear plant core thermal power (CTP)

- Evaluate the use of DVR Acceptability for use in MUR in conjunction with and/or in lieu of an ultrasonic flow meter (UFM)

Topical Report Considerations

- Developed for implementation of VDI-2048 Data Reconciliation methodology to reduce the uncertainty of determinations of nuclear plant core thermal power (CTP)

- Establish the technical basis for Data Validation and Reconciliation/Process Data Reconciliation (DVR/PDR) methodology

- Conducts evaluations to substantiate the uncertainty claims of the DVR process

- Captures failure modes and effects analyses (FMEA) to identify errors in the results and objective justification for self-identification of process failure

- Developed using the topical report for MUR with an Ultrasonic Flow Meter (UFM) as a guide

3 Data Validation and Reconciliation Process Background Data Validation and Reconciliation (DVR)

- Captured in the German standard VDI-2048 Uses first principals and statistical analysis of multiple plant measurements, in aggregate, to provide accurate core thermal power Uses the data points collected by plant equipment Defined physical relationships between measurements are used to evaluate the most probable value for each measurement in the power calculation DVR used for power recovery

- The DVR process provides an opportunity to accurately determine CTP using significantly more instrumentation, reducing the vulnerable of single element failure DVR may be used for condition monitoring and condition-based maintenance DVR software has been used by the nuclear power industry in the U.S. and Europe since 1999 to assess turbine cycle thermal performance, balance of plant feedwater flow metering and accuracy of the plant calorimetric MUR has been achieved in Europe using DVR Methods

4 DVR Methodology/Technology VDI-2048 (DVR Methodology)

Developed as an industry code for balance of plant turbine acceptance testing

Statistical analysis is performed to calculate the overall uncertainty for the system and the individual measurement uncertainties

Determine the uncertainty errors associated with a measurement based on the instrument uncertainty and other measurements functionally related to each other Software / DVR methodology uses the functional relationships between the measurements to create a system of redundant measurements Errors are determined by solving for mass and energy balances around the components and the entire system of measurements.

Objective statistical standards are used to verify that the calculation is providing the best possible solution DVR Combines:

Closed mass, energy and material balances

First Principle of Thermodynamics Gaussian compensation theorem

Redundant instrument measurement / parameter use and statistical modeling to reduce uncertainty This Result in:

Elimination of systematic error Minimization of random error Determination of process values to get closer to the true process value

5 Data Validation and Reconciliation for CTP - MUR Relevance Current Practice of Determining Core Thermal Power (CTP)

Current determination of Core Thermal Power (CTP) has significant reliance on feedwater flow measurements Inaccuracies in the direct measurement of feedwater flow have resulted in lost generation and documented cases of overpower conditions

Ultrasonic flow measurement devices (UFM) have been used to gain measurement accuracy, but are often single element and a failure of the instrumentation will result in an error of the power calculation UFM measurement reliability issues or failures result in the need to use less accurate venturi measurements, backing down from MUR to lower power conditions A utility may incur costs to maintain, correct, or upgrade equipment Data Validation and Reconciliation (DVR)

Data Validation and Reconciliation techniques (DVR), as captured in the German standard VDI-2048, uses first principles and statistical analysis of multiple plant measurements, to provide accurate CTP

The DVR process provides an opportunity to accurately determine CTP using significantly more instrumentation, reducing the vulnerable of single element failure

DVR uses the data collected by plant equipment and using defined physical relationships between the measurements, to evaluates the most probable value for each measurement to be used in the power calculation

DVR can provide input for condition-based maintenance

6 EPRI Research in Data Validation and Reconciliation Prior EPRI Research:

Initial EPRI Research on Data Reconciliation started in 2014 (BWR with a fouled venturi)

Program on Technology Innovation: Evaluation of Data Reconciliation Methods for Power Recovery. EPRI, Palo Alto, CA: 2015. 3002005345.

Research report Evaluated DVR Methods when Feedwater Flow was changing (PAA &

OLNC)

Using Data Validation Techniques to Evaluate the Impact of Chemical Addition at Nuclear Power Plants: Effects of Polyacrylic Acid and Online Noble Metal Injections on Steam Side Parameters. EPRI, Palo Alto, CA: 2018. 3002013194.

Technical Report: Guidance for Implementation of DVR Guidance for Implementing a Data Validation and Reconciliation Program at Nuclear Power Plants. EPRI, Palo Alto, CA: 2018. 3002013197 Additional Benefits Increased reliability of the power cycle measurement system Improve overall plant operations in the event of a failure of specific important instruments Reduced upgrade, obsolescence, and maintenance costs Higher confidence in plant instrumentation improving operational evaluation of events

7 Usefulness of Data Validation and Reconciliation VDI-2048 Code introduces the concept of using Gaussian corrections and mass-energy balance calculations of the plant components and cycle to Exploits measurement redundancies to make use of all available measurements Correct errors with the test instruments Assess the quality of the test measurements and results Data reconciliation methods have been used in Europe since 1999 to provide corrections to core thermal power measurement Provides an opportunity to accurately determine CTP using significantly more instrumentation Reducing the vulnerable of single element failure More robust approach to more accurately measure CTP as it is based on statistical reconciliation of instrumentation with the plants actual operating condition DVR has been previously evaluated for power recovery and has been used in Europe for MUR DVR has been evaluated by EPRI for power recovery at a BWR Commercial software products are available that implement the VDI-2048 methods Terms process data validation and data validation and reconciliation used by the commercial products to describe use of the VDI-2048 methods

8 EPRI Topical Report on use of Data Validation and Reconciliation Methods (DVR) for Measurement Uncertainty Recapture (MUR)

EPRI Development of Topical Report

- Initial Data Reconciliation Evaluations from EPRI Demonstrated DVR Reliability

- VDI-2048 International Experience/Evaluations lend robust credibility

- US Nuclear Industry experiences feedwater flow measurement challenges Fouling/defouling and general precision Reliability and associated costs associated with Ultrasonic Flow Meters Topical Report Status

- Topical Report Published in November 2020 Submitted to NRC January 2021 (Both -P and -NP versions)

Reviews Occurred during initial Topical Report publication

- Technical Advisory Group - thermal performance subject matter experts Initial Report Responses to Request for Additional Information

- NRC Review Two Audits (one onsite)

Responses to 17 Requests for Additional Information

9 Questions?

10 TogetherShaping the Future of Energy

ML23186A104

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