ML20198A257

Forwards Request for Addl Info Re Topical Rept ER-80P in Support of Request for Exemption from App K to 10CFR50 ECCS Evaluation Models for Comanche Peak Steam Electric Station, Units 1 & 2

ML20198A257
Person / Time
Site:	Comanche Peak
Issue date:	12/14/1998
From:	Polich T NRC (Affiliation Not Assigned)
To:	Terry C TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
References
TAC-MA2268, TAC-MA2269, TAC-MA2298, TAC-MA2299, NUDOCS 9812160210
Download: ML20198A257 (8)

Text

_. _ ._ _ _ _ _ _ _ . _ _ . - - -

, ,. ~

p untoq gj k S UNITED STATE 8  ;

U NUCLEAR REGULATORY COMMISSION E WASHINGTON. D.C. 30806 4 001 8'"

%,*****/ l December 14, 1998 l

Mr. C. Lance Terry TU Electric

. Senior Vice President & Principal Nuclear Officer Attn: Regulatory Affairs Department P. O. Box 1002 Glen Rose, TX 76043

SUBJECT:

TOPICAL REPORT ER-80P IN SUPPORT OF REQUEST FOR EXEMPTION l FROM APPENDIX K TO 10 CFR PART 50 ECCS EVALUATION MODELS FOR i COMANCHE PEAK STEAM ELECTRIC STATION, UNITS 1 AND 2 (TAC NOS.

MA2268, MA2269, MA2298, AND MA2299) l l

Dear Mr. Terry:

On July 17,1998, the licensee submitted Topical Report ER 80P (TXX-98180) In support of a request for exemption to Appendix K to 10 CFR Part 50. The actual exemption request was submitted on August 13,1998 (TXX-98183). The staff has determined that the additional ,

Information is required to support the review of the Topical Report and the exemption request. I I

On September 29,1998, a public meeting was held with the licensee to discuss some of the questions the staff had. The licensee prepared answers to the 30 questions discussed at that meeting. The staff has reviewed the answers and determined that some of the responses neec' to be supplemented or clarified and subsequently develoned further additional questions.

Subsequent to the September 29,1998, meeting the Nuclear Regulatory Commission held a follow up phone call was held on November 24,1998, to discuss five additional questions that l are included in the enclosure. Those questions are numbered 31 to 35. The staff requests the responses to these additional questions and the original questions be submitted in both a proprietary and non-proprietary version.

QQO I

9812160210 981214 PDR ADOCK 05000445 '

P- PDR hp pt:TQf k,,,,,gQ D3

C. Lance Terry .

1

, The enclosed request was discussed with Mr. Jimmy Seawright of your staff on November 24, l

1998. A mutually agreeable target date of December 18,1998, for your response was established. If circumstances result in the need to revise the target date, please contact me at the earliest opportunity 301-415-1038.

1 Sincerely, ORIGINAL SIGNED BY:

l l

Timothy J. Polich, Project Manager L Project Directorate IV-1' Division of Reactor Projects Ill/IV Office of Nuclear Reactor Regulation Docket Nos. 50-445 and 50-446

Enclosure:

Request for Additional Information

- cc w/ encl: See next page DISTRIB_VTION:

! Weeketfile] OGC PUBLIC GHill (4)

ACRS TPolich (2) TGwynn, RIV PDIV-1 r/f CHawes ' JHannon EAdensam (EGA1) CDoutt JDonoghue- JMauck RCaruso Document Name: RAIA2298.WPD OFC PM/PD4-1 LA/PD4-1 PD/RD4-1, l NAME TPolich/vw CHawe JHknb DATE /#/I/98 M//

/ /98 klV798 COPY YES/NO YES/NO YES/NO I

OFFICIAL RECORD COPY l

l l

l l

C. Lance Terry 2-The enclosed request was discussed with Mr. Jimmy Seawright of your staff on November 24, 1998. A mutually agreeable target date of December 18,1998, for your response was established. If circumstances result in the need to revise the target date, please contact me at the earliest opportunity 301-415-1038.

Sincerely, f

Timothy J. Polich, Project Manager Project Directorate IV-1 Division of Reactor Projects Ill/IV Office of Nuclear Reactor Regulation Decket Nos. 50-445 and 50-446

Enclosure:

Request for AdditionalInformation cc w/enci: See next page

l Mr. C. Lance Terry l TU Electric Company Comanche Peak, Units 1 and 2 cc:

Senior Resident inspector Honorable Dale McPherson l U.S. Nuclear Regulatory Commission County Judge P. O. Box 2159 P. O. Box 851 l Glen Rose, TX 76403-2159 Glen Rose,TX 76043 l Regional Administrator, Region IV Office of the Governor l U.S. Nuclear Regulatory Commission ATTN: John Howard, Director 1 611 Ryan Plaza Drive, Suite 400 Environmental and Natural Arlington, TX 76011 Resources Policy P. O. Box 12428 Mrs. Juanita Ellis, President Austin, TX 78711 Citizens Association for Sound Energy 1426 South Polk Arthur C. Tate, Director Dallas, TX 75224 Division of Compliance & Inspection

, Bureau of Radiation Control

! Mr. Roger D. Walker Texas Department of Health TU Electric 1100 West 49th Street Regulatory Affairs Manager Austin, TX 78756 3189 l P. O. Box 1002 Glen Rose, TX 76043 Jim Calloway ,

Public Utility Commission of Texas l l

George L. Edgar, Esq. Electric Industry Analysis Morgan, Lewis & Bockius P. O. Box 13326 1800 M Street, N.W. Austin, TX 78711-3326 Washington, DC 20036 5869

_ __ _ _.m._. _ _ _ . _ __ _ _. _ _ _ _ _ _ - _ . . _ . _ _ _ _ _

t REQUEST FOR ADDITIONAL INFORMATION REGARDING TOPICAL REPORT ER-80P IN SUPPORT OF REQUEST FOR EXEMPTION FROM APPENDIX K TO 10 CFR PART 50 ECCS EVALUATION MODELS FOR COMANCHE PEAK STEAM ELECTRIC STATION. UNITS 1 AND 2 l

l

1. Describe Caldon's understanding of the background for 1.02 being ascribed just for )

instrument uncertainty in power determination.

l- 2. On page 5-2 of the Topical Report, explain the justification for the use of PTC-6.

3. Describe how the LEFM is used in calorimetric power determinations.

4. Address LER 94 00101 which applied to older LEFM models and how the event would be avoided in the LEFM.

I

5. Who is responsible and how are Calibration, Maintenance, and Training performed and achieved?

6. How will monitoring, verification, and error reporting be handled?

7. What is the methodology used to confirm t"at hydraulic modeling actually represents the hydraulic profile at the LEFM installation site?

8 Is coherent noise constant and [ ] an adequate indicator for coherent noise?

9. Clarify that the 0.5% used in the Topical Report is 95% confidence level (26).

10. How does the LEFM uncertainty compare to the venturi uncertainty at Comanche Peak, in measuring reactor thermal power?

11. Confirm equations in A-19 of Topical Report for venturi. There appears to be an extra

- term.

, 12. Does cross flow = transverse velocity?

13. Clarify the usage of 26 and 95% confidence in the Topical Report.

14. Provide the references sited in the temperature correlation uncertainty and an explanation of the field data provided in this analysis.

15. Explain non-fluid time delay .

l. 16. What is the transducer firing sequence?

17. Reference page D-13 of the Topical Report. Is the spool piece alignment uncertainty

, [ }7  ;

i ENCLOSURE

- '-*v-

7.y_.-.

2 l

18. Reference D-14 of Topical Report. Explain the [ ] of the non fluid time delay.

19. Reference page E-14. Explain how [ ] uncertainty can be bounded for a spool piece that has not been calibrated at a hydraulic lab.

20. Reference Table E-1 of the Topical Report. Explain how reference to ISA RP67.04 l applies, l

21. Reference page F-6 of the Topical Report. Clarify the spool piece tolerance limits, e.g.,

16,2 6,95% confidence interval.

22. What fluid velocities can be achieved during laboratory testing? Explain how extrapolation for Reynolds Number is handled and how its uncertainty is bounded and confirmed in the plant.

23. How are swirl and cross flow handled with the LEFM?

.i

24. Provide additional information to support the claim in the Topical Report analysis that l many LER overpower events would have been prevented with the LEFM. I

25. Are the LEFM failure modes different than a venturi? If so, explain. Could any LEFM failure modes cause an overpower event?

26. What is the LEFM averaging period and how is it selected?  !

27. Clarify where [ ] uncertainty referenced on page 5 6 of the Topical Report is included in i the overall uncertainty. Explain the sources of [ ] uncertainty and appropriate averaging period. Explain how [ ]is determined [ ] as noted in the Topical Report.

28. Provide more data on the historical performance of the LEFM. (CPSES use and expenence)

29. How is the LEFM used currently to provide correction factors to the venturis? Is the correction determined on the basis of the absolute accuracy or the repeatability of the LEFM?-

30. What action is taken when the LEFM fails?

At the meeting the proprietary and non-proprietary responses to 30 questions were discussed.

The staff has reviewed the responses presented at the meeting. The following list of additional questions refers to the 30 original questions discussed at the public meeting on September 29, 1998.

1. Submit response as is.

~

2. Add to response what methodology will be used by licensees in determination of LEFM to venturi uncertainty improvement.

, ,- - - - , ,--y-- - -

3

3. Submit response as is.

4. Add a discussion on LER 91-010-00 Ginna LEFM (Ascension Number 9202060130).

5. Submit response as is.

6. Provide clarification (list) of Quality Control standards used by Caldon in the design and manufacturing of the LEFM. Provide clarification (list) as to the standards followed under Caldron's verification and validation program.

7. Add a discussion on the practices used by Caldon or required by licensees to ensure that as-built plant configurations are modeled correctly. See page 4 of 8 LER 94-001-01.

8. Submit response as is.

9. Submit response as is.

10. Submit response as is.

11. Submit response as is.

12. Submit response as is.

13. Submit response as is.

14. Submit response as is.

15. Submit response as is.

16. Submit response as is.

17. Submit response as is.

18. Add long path and short path definition.

19. Add a discussion on spool piece uncertainties (calibrated, non-calibrated). Explain how the single loop uncertainty in the topical report is different from the CPSES case. What uncertainty assumptions have changed at CPSES?

20. Submit response as is.

21. Clarify the use of " tolerance limits" (tolerance interval?). It also appears the number of spool pieces tested is discounted in the confidence interval development.

22. If there are flow components that cannot be seen by the LEFM 4 path arrangement add a discussion on those type of flow components.

23. Submit response as is.

9 8

4

24. Submit response as is. l

25. Submit response as is.

26. Submit response as is.

27. Submit response as is. 4

28. Submit response as is. Provide clarification of "EPRI standards".

29. Submit response as is.

30. Submit response as is.

Additional clarifications as diccussed during the September 29,1998, meeting will also need to be addressed and can be incorporated into the above responses as appropriate.

Subsequent to the September 29,1998, meeting the Nuclear Regulatory Commission held a follow-up phone call was held on November 24,1998, to discuss five additional questions that i are include below. The question numbering continues sequentially after the initial 30 questions, j

31. Explain how figure 5-2 in the topical report was made. Specifically address how the curves were fitted to the information presented in Table 51.

32.' Regarding the answer to Question 10 in the handout material from the most recent meeting. Were the uncertainty values for both the venturi and LEFM arrived at using the same methodology? What methodology was used? Give a detailed description of inny differences in the combination of uncertainties as presented in the topical report.

33. Explain in specific terms why the venturi uncertainty at Comanche Peak is so much lower than that discussed in the topical report (i.e., what uncertainty factors are different and why)?

34. Provide a figure analogous to figure 5 2 in the topical using the Comanche Peak site-specific uncertainty values for the venturi and LEFM instruments.

35. The Caldon Topical report and the answer to Question 25 explain that a benefit of the LEFM is that it b a self-contained " integrated" system. Beyond on line diagnostics capability, discuss in the application of LEFM at Comanche Peak, how common mode failures are avoided such that the uncertainty values assumed for the LEFM remain valid during plant operation. Was any type of failure modes and effects analysis conducted during system design?

s