ML19346A024

Response to Intervenor Citizens for Fair Util Regulation Fourth Set of Interrogatories.Response Contains Info Re Contention 3,use of Computer Codes in Fsar.Affidavit & Certificate of Svc Encl

ML19346A024
Person / Time
Site:	Comanche Peak
Issue date:	06/01/1981
From:	Horin W, Reynolds N DEBEVOISE & LIBERMAN, TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	CITIZENS FOR FAIR UTILITY REGULATION
References
NUDOCS 8106040378
Download: ML19346A024 (11)

Text

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Juno 1, 1981 UNITED STATES OF AMERICA N g

NUCLEAR REGULATORY COMMISSION BEFORE TH5' ATOMIC FAFETY AND LICENSING BOARD  % ~

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TEXAS UTILITIES GENERATING ) Docket Nos. 50-445 '\ s3,

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(Comanche Peak Steam Electric ) (Application for

'e-Station, Units 1 and 2) ) Operating Licenses I t % K', 0) g Ab$$f{D'9, APPLICANTS' ANSWERS TO CFUR'S  ; M 0 319g;, '

FOURTH SET OF INTERROGATORIES -- 8% *

'O Pursuant to 10 C.F.R. $2.740(b), Texas Utilit J s

! w%I .. s Generating Co., et al. (" Applicants") hereby submit answers ~

to "CFUR's Fourth Set of Interrogatories to Applicant [ sic]

and Requests to Produce," dated May 13, 1981. 1_/ Applicants will respond to CFUR's requests to produce pursuant to and on the schedule provided for in 10 C.F.R. $2.741(d).

I. Scope of Interrogatories As with CFUR's previous sets of interrogatories, CFUR does not identify in this fourth set the contention at which each of the interrogatories is directed. It appears 1/ The date on the first page of CFUR's interrogatories

' is May 13, 1981. However, the attached " Certificate of Service" is undated and mislabeled (it reads " Answers to NRC Staff's Fourth Set of Interrogatories and Request to Produce from CFUR.") Although this is not acceptable proof of service pursuant to 10 C.F.R. $2 712, Applicants hereby provide timely responses on the assumption service was, in fact, made on May 13, 1981. $

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Q d to the Applicants that the interrogatories are directed solely at Contention 3. Accordingly, Applicants' responses are predicated on the assumption that the interrogatories are concerned with contention 3, which reads, as follows:

Contention 3: The computer codes used in CPSES/

FSAR must be tested and, if necessary, modified  ;

to accept the parameters reflecting the sequence of events at Three Mile Island and then to realistically predict plant behavior.

II. Answers to Interrogatories Each answer is identified by the number of the i corresponding interrogatory as set forth in CFUR's Fourth Set of Interrogatories. l

1. Applicants object to Interrogatory 1 as not  ;

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relevant to the " sequence of events at Three Mile Island" and thus as not relevant to Contention 3. l For purposes of evaluating accident sequences such j as TMI, the analysis in the FSAR assumes an initiating  ;

event and then the subsequent failure of a single ,

, active component. One possible mechanism for such {

j component failure is human error. j l .

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j. 2. See response to Interrogatory 1.  !

3. Applicants object to Interrogatory 3 to the extent ,

it seeks information regarding accident analyses  !

listed in Exhibit A to CFUR's interrogatories which are not relevant to the " sequence of events j at TMI" and/or are not evaluated by the use  !

of computer codes. Contention 3 is concerned l solely with whether computer codes used in the l FSAR adequately reflect the particular TMI sequencs l t

of events. However, CFUR has for the most part  !

simply listed in Exhibit A the accident sequences I identified in the table of contents of Chapter 15 of the Comanche Peak FSAR, most of which do not relate to or reproduce the TMI scenario. Accordingly, 1 Applicants' response to Interrogatory 3 (and l l subsequent interrogatories which concern accident l sequences listed in Exhibit A) is directed to the. '

following accident sequences:

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Y. Inadvertent opening of a pressurizer safety or relief valve. (This sequence is the relevant subset of small break LOCA's iden-tified in item AB. of Exhibit A.) I AI. Loss of feedwater.

(This sequence includes the sequence involving loss of normal feedwater flow identified in item K. of Exhibit A. )

- . In the interest of explaining and providing complete information on the use of computer codes in the FSAR to evaluate these accident sequences, Applicants provide the following discussion of the manner in which computer codes are used to evaluate events such as operator error and the required scope of such evaluation.

The analyses presented in the CPSES FSAR which relate .tua the relevant accident sequences of Exhibit A each commence with the initiating event described in Exhibit A. Then each accident analysis considers the subsequent failure of a single active component. The choice of the component assumed to fail is based on a deter-mination of the failure that would result in the most severe consequences. The practice of assuming this single active failure satisfies NRC requirements for FSAR accident analyses. See 10 C.F.R. Part 50, Appendix A. The single failure chosen for each accident analysis is not assumed to result from any particular cause. One possible mechanism for such component failure is human error. Thus, the assumption of a single active failure in accident analyses as required by NRC regulations encompasses possible human error as a cause for the component failure assumed in the analyses.

Further, it is important to define properly what constitutes a computer code in terms of accident sequence analyses in order to distinguish the computer code models themselves from the input and boundary conditions applied to the codes. The computer codes used in the FSAR accident sequence analyses are those collections of computer code language statements that reflect the engineering equations for defining plant behavior under various conditions. These programmed equations (i.e., computer codes) are independent of any  ;

assumed transient sequence or operator actions.  ;

The connection between the computer codes themselves i i

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O and the accident' event sequences, including operator actions, is made via the input and/or boundary conditions applied to the codes. Those conditions define the particular event sequences ,

for which the codes will predict plant behavior.

Thus, human error is accounted for in accident analyses by the application of selected input and/or boundary conditions reflecting component failure to computer codes, rather than by modifi-  ;

cation of the codes themselves.

4. Applicants object to this interrogatory as seeking information which is irrelevant to Contention 3. That contention is concerned ,

, solely with the evaulation of certain acci-i dent' sequences using computer codes. This interrrogatory, however, is concerned with the separate topfes of operator training and grocedures. Accordingly, this interrogatory .

ls'frrelevant to Contention 3. . .

5. a-f. Applicants object to this interrogatory as seeking information which is irrelevant to Contentien 3. That contention is concerned solely with the evaulation of certain acci-dent sequences using computer codes. This i interrrogatory, however, is concerned with the separate topics of operator training and crocedures. Accordingly, this interrogatory ,

is irrelevant to Contention 3.

6. No interrogatory propounded.

7. Applicants assume this interrogatory refers to the

" changes and additions" referred to in Interrogatory 5.f. Accordingly , Applicants object to this ,

interrogatory for the same reasons set forth in  !

their response to Interrogatory 5.

8. Applicants object to this interrogatory as seeking information which is irrelevant to contention 3.

That contention is concerned solely with the eval-untion of certain accident sequences using computer '

codes. This interrogatory, however is concerned with the separate topics of maintenance training and procedures. Accordingly, this interrogatory is irrelevant to Contention 3.

9. Fpplicants object to this interrogatory for the same reasons set forth in their response to Interrogatory 8.

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10. Applicants object to this interrogatory as seeking information which is irrelevant to Contention 3.

That contention is concerned solely with the evaluation of certain accident sequences using

> computer codes. This interrogatory is, however, concerned with the separate topic of human factors

engineering. Although accident analyses may ,

aasume component failures which may be attributable to human errors (see response to Interrogatory 3),

those analyses do not take into account the causes ,

of such human errors. Accordingly, this inter- ,

rogatory is irrelevant to contention 3.

11. See response to Interrogatory 10. i

12. Applicants have not taken exception to any items in ,

NUREG-0737 which are relevant to Contention 3, viz.,

Items I.C.l., II.K.3.5 and II.K.3.30.

13. Not applicable.

14. Not applicable. l l

15. Not applicable. I

16. Applicants have not taken exception to any of the items in NUREG-0660 which are relevant to Contention 3, viz., applicable portions of Items I.C. and II.K. from which NUREG-0737 Items I.C.l.,

II.K.3.5 and II.K.3.30 were derived.

17. Not applicable.

18. Not applicable.

19. Not applicable.

20. Applicants do consider human error in analyzing i small break accidents in the manner described in i the response to Interrogatory 3.

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21. Applicants object to this interrogatory as not being  ;

sufficiently specific to provide a response. The. 1 interrogatory does not identify the accident sequences with which it is concerned, and thus Applicants are unable to determine whether the interrogatory addresses accident analyses which are relevant to Contention 3.

22. Applicants object to this interrogatory as seeking seeking information which is irreleYant to Contention 3.

That contention is concerned solely with analyses of certain accident sequences using computer codes.

Interrogatory 22,' on the other hand, seeks informa-tion regarding the separate and unrelated toyic of maintenance errors at all nuclear power planns.

Accordingly, this interrogatory is irrelevant to contention 3. ,

23. See response to Interrogatory 22.

24. Applicants object to this interrogatory as seeking information which is irrelevant to contention 3.

,. That contention is concerned solely with analyses of certain accident sequences using computer codes.

Interrogatory 24, on the other hand, seeks informa-tion regarding operator errors at all nuclear

power plants. Accordingly, this interrogatory is irrelevant to Contention 3.

25. See response to rhterrogatory 24.

26. Condition II faults, as defined in the FSAR, are those faults which could be expected to occur with moderate frequency over the full lifetime of plant operations.

27. The definition of Condition II faults precludes eval-uation of a fault which would propagate to a more serious event. Events which are of a more serious nature (or expected with less frequency) are analyzed appro-priately as Condition III or IV events.

28. Applicants object to this interrogatory since Applicants' views on the credibility of common mode failures are irrelevant to Contention 3. In

! any event, NRC requirements for accident analyses do not require consideration of common mode failures. Accident analyses account for component failures in the manner described in the response to Interrogatory 3. ,

29. See responses to Interrogatories 3 and 28.

30. See responses to Interrogatories 3 and 28.

31. The short term effects of the inadvertent opening of a pressurizer PORV are analyzed with respect to the criteria of Condition II faults. The long term effects of the failure of a pressurizer PORV to close are analyzed with respect to the criteria of Condition III fault, since the failure of a pressuriter PORV to close is an event expected to occur very. infrequently during the life of the i

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1 plant. Since 1970, the American Nuclear Society classification of plant conditions has been used, which divides plant conditions into four categories (including Condition II) in accordance with anticipated frequency of occurrence and potential radiological consequences. See FSAR 315.0.1 32-38. Applicants object to these interrogateries as seeking information which is irrelevant to contention 3.

That contention is concerned solely with analyses

, of certain accident sequences using computer codes.

Interrogatories 32-38 are concerned with the separate and unrelated topics of mitigation of the consequences of accidents (Interrogatories 32, 33, 35, 37 and 38) and actions taken to prevent accidents, i.e., equipment or procedures, (Interrogatories 34 and 36). Accordingly, these interrogatories are irrelevant to Contention 3.

39-41. Applicants object to these interrogatories as seeking information which is irrelevant to contention 3. That contention is concerned solely with analyses of certain accident sequences using computer codes. Interrogatories 39 to 41, on the other hand, are concerned with the separate and unrelated topics of handling the consequences of accidents and the extent of such consequences. Accordingly, these interrogatories are irrelevant to Contention 3.

42. Applicants object to this interrogatory since it calls for a legal conclusion and since Applicants' views on the legal affect of the documents specified are irrelevant to Contention 3.

43. See response to Interrogatory 42.

44. See response to Interrogatory 42.

45. Applicants refer CFUR to FSAR Volume XIV, " Response to the NRC Action Plan Developed as a Result of the TMI-2 Accident," pp. I.C.-l to I.C.-3. In addition, the Westinghouse Owners Group submitted to the NRC on March 18, 1981 the description of a program to comply with the requirements of Item I.C.l.

46. Applicants object to this interrogatory as seeking information which is irrelevant to contention 3.

That contention is concerned solely with analysis of certain accident sequences with computer codes.

This interrogatory, however, involves the separate topic of operator procedures. Accordingly, Inter-rogatory 46 is irrelevant to Contention 3.

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- 8-47-48. Applicants will r'espond to these requests to produce pursuant to and on the schedu e provided for in 10 C.F.R. $2.741(d).

f Nicholl S}Reynolds th ! L G. E D William A. Horin DEBEVOISE & LIBERMAN 1200 Seventeenth Street, N.W.

Washington, D.C. 20036 (202) 857-9817 Counsel for Applicants June 1, 1981 r

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STATE OF TEXAS COUNTY OF DALLAS Homer C. Schmidt, being duly sworn, deposes and says:

That he is Manager, Nuclear Services, Texas Utilities Services Inc., and knows the contents of the foregoing Applicants' Answer to CFUR's 4th Set of Interrogatories; l that the same is true of his own knowledge except as to matters therein stated on information and belief, and as to that, he  :

believes them to be true.

l SWORN to and subscribed before me on this ltt day of June,1981 ,

Ao. /l_.:Ir v Notary ~Publ ic l

My Commission Expires: -

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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE T9E ATOMIC SAFETY AND LICENSING BOARD In the Matter of )

)

TEXAS UTILITIES GENERATING ) Docket Nos. 50-445 COMPANY, et al.

) 50-446

)

(Comanche Peak Steam Electric ) (Application for

' ' Station, Units 1 and 2) ) Operating License)

CERTIFICATE OF SERVICE I hereby certify that copies of the foregoing " Applicants' Answers To CFUR's Fourth Set Of Interrogatories," in the above-captioned matter were served upon the fellowing persons by deposit in the United States mail, first class postage prepaid this 1st day of June 1981:

Valentine B. Deale, Esq. Chairman, Atomic Safety and Chairman, Atomic Safety and Licensing Appeal Panel Licensing Board U.S. Nuclear Regulatory 1001 Connecticut Avenue, N.W. Commission Washington, D.C. 20036 Washington, D.C. 20555 Dr. Forrest J. Remick, Member Marjorie Ulman Rothschild, Esq.

Atomic Safety and Licensing Office of the Executive Board Legal Director 305 E. Hamilton Avenue U.S. Nuclear Regulatory ,

State College, Pennsylvania 16801 Commission Washington, D.C. 20555 Dr. Richard Cole, Member '

Atomic Safety and Licensing David J. Preister, Esq.

Board Assistant Attorney General U.S. Nuclear Regulatory Environmental Protection Commission Division Washington, D.C. 20555 P.O. Box 12548 Capitol Station Chairman, Atomic Safety and Austin, Texas 78711 Licensing Board Panel U.S. Nuclear Regulatory Mr. Richard L. Fouke -

Commission CFUR t Washington, D.C. 20555 1668B Carter Drive Arlington, Texas 76010  ;

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Arch C. McColl, III, Esq. Dwight H. Moore, Esq.

701 Commerce Street West Texas Legal Services Suite 302 100 Main Street (Lawyers Bldg.)

Dallas, Texas 75202 Fort Worth, Texas 76102 Jeffery L. Hart, Esq. Mr. Chase R. Stephens 4021 Prescatt Avenue Docketing & Service Branch Dallas, Texas 75219 U.S. Nuclear Regulatory

'... Commission Mrs. Juanita Ellis Washington, D.C. 20555 President, CASE 1426 South Polk Street Dallas, Texas 75224 I

Nicholas . Leynolds cc: Homer C. Schmidt Spencer C. Relyea, Esq.

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