ML20207K830

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Rev 1 to Sequoyah Element Rept, Electrical Protection Design,Bypass of Over-Torque Limit Switches
ML20207K830
Person / Time
Site: Sequoyah  Tennessee Valley Authority icon.png
Issue date: 12/13/1986
From: Jordan A
TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20207K584 List:
References
237.4-(B), 237.4-(B)-R01, 237.4-(B)-R1, NUDOCS 8701090535
Download: ML20207K830 (12)
v • d • e


Text

v .

TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)

SPECIAL PROGRAN

, REPORT TYPE: SEQUOYAH ELEMENT REVISION NUMBER: 1 TITLE: ELECTRICAL PROTECTION DESIGN Bypass of Over-torque Limit Switches PAGE 10F 10 REASON FOR REVISION:

Revised per Senior Review Panel and Technical Assistance Staff comments. Added CATG #237.4-SQN-2. Revised to meet the recommended format for SQN element report.

o PREPARATION PREPARED Y:

. tkL hueo SIGNATURE u ahelu 8 DA1'E REVIEWS

. REV W OMMITTEE ll~E&'$&

SIGNATURE / DATE TAS:

SIGNATURE DATE CONCURRENCES _ _

__ ADO $$h0b00g7 .j b. fat) 12l3/f(

CEG-H: I? -l L-E 0

SRP:

SIGNATURE DATE SIGNATURE DATE APPROVED BY:

ECSP MANAGER DATE MANAGER OF NUCLEAR POWER DATE rimesmmemcc rcjumi nenmv nm m

, TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)

SPECIAL PROGRAM REVISION NUMBER: 1 PAGE 2 0F 10

1. CHARACTERIZATION OF ISSUE (S):

Concern: Jssues:

XX-85-020-001 a. Torque switch bypass modification for "An ECN # 5971 was issued at SIS valve nos. 332 and 333 per 1979 Sequoyah in 1979 that required ECN 2257 was not performed.

a bypass of the over-torque limit switches on certain limitorque operators. It was b. Adequacy of design compliance with recently discovered (3-4 months the torque switch bypass requirement ago) that this had not been for motor-operated valves (MOVs) is accomplished for SIS valve in question.

  1. 332 and 333. CI is concerned about ECN's applicability to W8NP."
2. HAVE ISSUE (S) BEEN IDENTIFIED IN ANOTHER SYSTEMATIC ANALYSIS? YES X NO Identified by Nuclear Saf_ely_ Review Staff (NSRS1 Date October 15.211, 1985, and Januar.y 15-22. 1985 Documentation Identifiers:

, NSRS Investigation Report No. I-85-612-SQN for Employee Concern XX-85-020-001 (SQN Applicability), "RCS Pressurizer Relief Flow Control Valves - Failure to Make lorque Switch Bypass Modifications"

! 3. DOCUMENT NOS., TAG NOS.. LOCATIONS. OR OTHER SPECIFIC DESCRIPTIVE l IDENTIFICATIONS STATED IN ELEMENT:

E l The two valves identified in the employee concern as SIS valve nos.

l 332 and 333 were interpreted by the evaluator as FCV-68-332 and FCV-68-333 (ECN No. 5971 referenced in the concern is not related to torque switch bypass and, therefore, the correct reference is I interpreted as ECN No. 2257, as documented in App. A, 5.n).

l l

4. INTERVIEW FILES REVIEWED:

File XX-85-020 was reviewed and no additional unreviewed l information for Sequoyah was identified for the concern addressed in this report.

l f

i' l 1103d - 11/15/86

TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)

SPECIAL PROGRAM REVISION NUMBER: 1 PAGE 3 0F 10

5. DOCUMENTS REVIEWED RELATED TO THE ELEMENT: -

See Appendix A.

6. WHAT REGULATIONS. LICENSING COMMITMENTS. DESIGN REQUIREMENTS. OR OTHER APPLY OR CONTROL IN THIS AREA?

See Appendix A.

7. REQUESTS FOR INFORMATION. MEETINGS. TELEPHONE CALLS. AND OTHER DISCUSSIONS RELATED TO ELEMENT:

See Appendix A.

8. EVALUATION PROCESS:
a. Reviewed available transcripts of NRC investigative interviews for additional information on the concern.
b. Identified the Sequoyah Nuclear Plant design approach to l satisfy NRC guidelines regarding torque switch bypass.
c. Reviewed existing reports (e.g., NSRS Report No. l I-85-612-SQN) and responses to recommendations in the reports to assess their adequacy and the extent to which they satisfy the issues raised in this concern.
d. Reviewed other documents (e.g., ECNs, sample schematics for l safety related MOVs, and criteria / standard drawings for MOVs) to verify adequacy of method of implementation in the design.
e. Reviewed existing TVA Construction, QA/QC, Operations, and Material Control reports for the Employee Concern Evaluation Program for applicability to the concerns discussed in this report.
f. Assessed overall design adequacy and identified findings as l applicable.
9. DISCUSSION. FINDINGS. AND CONCLUSIONS:

Di sc u_s_s. ion :

~

The torque switch bypass concern is a safety-related issue because premature operation of valve torque switches could cause the valve 1103d - 11/15/86

, TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)

SPECIAL PROGRAM REVISION NUMBER: 1 PAGE 4 0F 10 to stop before reaching its safe position, thus resulting in a condition adverse to plant safety.

Implementation of the torque switch bypass feature was initiated at Sequoyah Nuclear Plant (SQN) in 1979 through a Chandler to Pierce l memo (01/31/79, App. A, 5.g), which requested implementation of this change per Patterson to Chandler memo (01/12/79, App. A, 5.f). Note that IE Circular 81-13 ( App. A, 5.c), which recommends bypassing torque switches in safety-related MOVs to ensure that the valve safety function is not impaired by torque switch actuation before the valve has completed its travel, was not issued until

. 1981.

The Patterson to Chandler memo recommended that SQN remove the torque switches

. . . from the control circuits governing the opening stroke of all active valves and for those active valves whose closure can be governed by limit switches without potentially damaging the valves".

f*

12 For active valves whose closure must be governed by torque switches to prevent potential valve damage, the recommendation was to bypass

. . . the torque switches with limit switches for all but the last few percent of travel to the full closed position."

The memo also indicated that the active valves listed in the Watts Bar Nuclear Plant (WBN) Final Safety Analysis Report (FSAR) Tables 3.9-17 and 3.9-25 were also applicable to SQN. Although this memo was issued earlier than IE Circular 81-13, the recommendations in this memo fully satisfy the circular.

The subsequent memo from Chandler to Pierce (02/26/79, App. A, 5.h) l confirmed that SQN and WBN active valves are the same and the Engineering Change Notice (ECN) No. 2257 (03/31/79, Apn. A, 5.q) was issued to reflect the torque switch bypass on all SQN active MOVs. Although the ECN incorporated the changes as recommended, no design basis was issued to support these changes and for future applications.

Valves68-332 and 333 were added later to the WBN active valve list; however, SQN was not notified of this change. As a result of this and the lack of a design basis, these two valves were not modified in a timely manner and may have been the basis of the employee concern discussed in this element.

1103d - 11/15/86

' TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)

SPECIAL PROGRAM REVISION NUMBER: 1 PAGE 5 0F 10 NSRS Report No. 1-85-612-SQN (App. A, 5.k) documented an investigation conducted from 10/15/85 to 10/17/85 and from 01/15/86 to 01/22/86 to determine the validity of the concern. The report concluded that although the employee concern was substantiated, the problem had already been identified and corrected in ECN No. L6416 (06/19/85, App. A, 5.r) by modifying valves 332 and 333 as required. l The report also recommended verification of the modification of all active valves at SQN and to document via a Significant Condition Report (SCR) any failure to confirm this.

In response to the NSRS recommendations, the memo from Abercrombie to

. Seiberling (05/05/86, App. A, 5.n) indicated that MOVs listed in SNP FSAR Appendix 6.8c are comparable to the active valves listed in WBN FSAR. However, the response stated that SQN is not committed to keep an active valve list and no requirements exist for WBN to notify SQN of any changes to this list. Therefore, the response concludes that no SCR is required as recommended by the NSRS. Also Attachment 1 to this response includes a summary of active MOV at WBN that are not active at SQN. The evaluator's review of the different lists, however, indicated that kBN active valves 0-FCV-67-151,1-FCV-67-147,

  • 2-FCV-67-223, and 1-FCV-67-478, currently not included in Appendix (4 6.8c, are not listed in this attachment. These discrepancies are also the result of this current lack of design basis. 7his situation is further detailed below.

The memo from Rankin to Vineyard (03/19/86, App. A, 5.1) requested Sequoyah Engineering Project (SQEP) to review 36 additional MOVs (Units 1 and 2) to determine applicability of ECN No. 2257 changes to i

these valves.

l l

The memo from Wilson to Abercrombie (05/01/86, App. A, 5.m) indicated that changes similar to the ones in ECN No. 2257 are reconsnended for these 36 valves. Also, the memo identified 12 additional valves that require the same type of modification bringing the total number to 48 additional valves requiring torque switch modifications.

As in the past, ECN No. L6667 (06/03/86, App. A, 5.s) was issued to reflect the recommended changes for these 48 valves, however, no l design basis wa', generated to justify the addition of these 48 valves (note that of these valves, 1 & 2 - FCV-67-65, 1 & 2 - FCV-67-68,

~

1-FCV-67-72, and 2-FCV-67-63 are not even listed in SNP FSAR Appendix 6.8c).

Also, electrical Standard Drawings ( App. A, 5.t) show four different configurations for the torque switch circuits (two for torque seated valves and two for position seated valves). No clear definition exists, however, to determine when to use a specific configuration, particu~iarly in the case of torque seated valves.

}

1103d - 11/15/86

  • ~

, TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (8)

SPECIAL PROGRAM REVISION NUMBER: 1 PAGE 6 0F 10 Finally, a letter from Shell, TVA, to Grace, NRC (05/12/86, App. A, 5.0), in response to IE Bulletin 85-03, provided the SON commitment for meeting the requirements of this bulletin. No design bases were, however, generated to ensure compatibility between the guidelines of IE Circular 81-13 and the requirements of IE Bulletin 85-03.

Findings:

a. All valves requiring modification per ECN No. 2257 were so modified. Valve nos. 332 and 333 were later identified as active valves and were modified per ECN No. L6416.
b. The evaluator's investigation determined that no design bases currently exist for the MOV torque switch bypass design.

This results in an unclear definition of which valves are required to meet this torque switch bypass design. This, in turn, results in inconsistencies among the different lists of valves. Also, standard drawings do not provide a clear definition for selecting torque and limit switch configurations.

Conclusions:

a. It is concluded that the employee concern is valid and was corrected per ECN No. L6416.
b. No evidence exists that the design adequately complies with the torque switch bypass requirement because of lack of a design basis and of a controlled valve list.

+

1103d - 11/15/86

TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)

SPECIAL PROGRAM REVISION NUMBER: 1 PAGE 7 0F 10 APPENDIX A

5. DOCUMENTS REVIEWED RELATED TO THE ELEMENT:
a. Sequoyah Nuclear Plant FSAR, Chapters 7 and 8
b. Sequoyah Nuclear Plant FSAR, Appendix 6.8c revised by Aniendment 3, "Sequoyah Nuclear Plant Valve Program"
c. NRC IE Circular NO. 81-13, " Torque Switch Electrical Bypass Circuit for Safeguard Service Valve Motors," (09/25/81)
d. NRC IE Bulletin NO. 85-03, " Motor Operated Valve Common Mode Failures During Plant Transients Due to Improper Switch Settings," (11/15/85)
e. Watts Bar Nuclear Plant FSAR Tables 3.9-17 and 3.9-25
f. TVA memo f rom Patterson to Chandler (MEB 790115 390),

"Sequoyah Nuclear Plant - Recommendation to Modify the Control Circuits of Specified Motor Operated Valves,"

(01/12/79) e

g. TVA memo f rom Chandler to Pierce (EE8 790201921), "Sequoyah Nuclear Plant - Recommendation to Modify the Control Circuits of Specified Motor Operated Valves," (01/31/79)
h. TVA memo from Chandler to Pierce (EEB 790227 928), "Sequoyah and Watts Bar Nuclear Plants - Recommendations to Modify the l Control Circuits of Specified Motor Operated Valves,"

l (02/26/79) l l

i. 1VA memo from Chandler to Raulston (EEB 811112 915) "IE Circular NO. 81 Torque Switch Electrical Bypass Circuit for Safeguard Service Valve Motors," (11/13/81) and attached letter O'Reilly, NRC, to Parris, TVA (NEB 810930 225),

, forwarding IE Circular No. 81-13 to TVA, (09/25/81) --

l

j. TVA memo f rom Whitt to Schum, " Transmittal of Accepted Final Reports," (11/26/85) and attached NSRS Investigation Report No. I-85-612-WBN/SQN, "SQN ECN Applicability," dates of investigation 11/12/85 to 11/15/85 1103d - 11/15/86

~

TVA EMPLOYEE CONCERNS '

REPORT NUMBER: 237.4 (8)

SPECIAL PROGRAM REVISION NUMBER: 1 PAGE 8 0F 10

k. TVA memo from Whitt to Abercrombie, " Nuclear Safety Review

( Staff Investigation Report Transmittal," (03/07/86) and

- attached NSRS Investigation Report No. I-85-612-SQN, "RCS l Pressurizer Relief Flow Control Valves - Failure to Make Torque Switch Sypass Modifications," dates of investigation 10/15/85 to 10/17/85 and 1/15/86 to 1/22/86, and Employee Concern Disposition Report (12/17/85)

1. TVA memo from Rankin to Vineyard (S01 860310 950), "Sequoyah  ;

Nuclear Plant - Motor Operated Valve Opening Torque Switches," (03/19/86)

m. TVA memo from Wilson to Abercrombie (825 860501 018),

"Sequoyah Nuclear Plant - Motor Operated Valve Opening / Closing Torque Switches," (05/01/86) 4 n. TVA memo from Abercrombie to Seiberling " Nuclear Safety Review Staf f (NSRS) Report No. I-85-612-SQN, RCS Pressurizer Relief Flow Control Valves - Failure to Make Torque Switch '

Sypass Modifications," (05/05/86) and attached response to

, NSRS Report No. I-85-612-SQN V

o. Letter from Shell, TVA, to Grace, NRC (L44 860512 803),
" Office of Inspection and Enforcement Bulletin 85 Motor
Operated Valve Common Mode Failure During Plant Transients Due to Improper Switch Settings - Sequoyah Nuclear Plant,"

(05/12/86) and Enclosure 1 - Sequoyah Nuclear Plant (SQN)

Response to IE Sulletin 85-03 5

l.

p. Potential Reportable Occurrence (PRO) No. 2-85-45 (03/23/85)
q. Engineering Change Notice (ECN) No. 2257, Cover Sheet, dated i- 03/12/79 (SWP 790312 500) and Data Sheet (SWP 790402 532),

g (03/31/79) i

r. Engineering Change Notice (ECN) NO. L6416, Cover Sheet, dated

, 05/08/85 (B25 850508 585) and Data Sheet (825 850619 502),

l (06/19/85)

I

s. Engineering Change Notice (ECN) No. L6667, Cover Sheet (825 860611 503), (06/02/86) and Data Sheet (B25 860603 509),

(06/03/86) 4 l

1103d - 11/15/86 i t

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  • TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)

SPECIAL PROGRAM REVISION NUMBER: 1

( PAGE 9 0F 10

t. Electrical Standard Drawings: SD-E15. 5.1 -1, SD-E15. 5.1 -2, SD-E15.5.1-3, and SD-E15.5.1-4
u. Sequoyah Nuclear Plant Schematics E-45N779-31, R18 and E-45N779-15, R21
v. Letter f rom B. J. Youngblood, NRC, to S. A. White, TVA, with the attached transcript of the investigative interview conducted by the NRC on 02/21/86 at the First Tennessee Bank Building in Knoxville, TN, (06/25/86)
w. TVA memo f rom Abercrombie to Those Listed, "Sequoyah Nuclear Plant (SQN) - Employee Concern K-Forms - Generic Evaluation,"

(01/22/86)

6. WHAT REGULATIONS. LICENSING COMMITMENTS. DESIGN REQUIREMENTS. OR OTHER APPLY OR CONTROL IN THIS AREA?

The general NRC requirement is to minimize malfunction of safety-related motor operated valves as a result of premature

("Z"

"- actuation of torque switches (Ref. IE Circular No. 81-13).

Additional requirements regarding proper selection, setting, and maintenance of torque, torque bypass, position limit, and overload switches are contained in IE Bulletin No. 85-03.

7. LIST REQUESTS FOR INFORMATION. MEETINGS. TELEPHONE CALLS. AND OTHER DISCUSSIONS RELATED TO ELEMENT:
a. Nesbitt, Purcell, Romine (TVA)/ Don-Doncow, Hegyi (Bechtel) meeting at Sequoyah jobsite, (08/20/86)
b. Nesbitt, Brush (TVA)/ Don-Doncow (Bechtel) meeting in Knoxville, (08/21/86) s.-

1103d - 11/15/86

. TVA ENPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)

SPECIAL PROGRAM REVISION NUMBER: 1 PAGE 10 0F 10 CATO LIST The following CATD froms are included as part of this report:

237.04-SQN-1 237.04-SQN-2 (added 11/02/86) e u

1103d - 11/15/86

e ECTG C.3 Attachsnent A

(. Page 1 of 1 Revision 2 - A ECSP CORRECTIVE Action Tracking Document (CATD)

INITIATION

1. Immediate Corrective Action Required: AE Yes O No
2. Stop Wort Recomrnended: O Yes $5. No
3. CATD No ._'2.3 1.04 - 5 G R - t_ 4. INITIATIONDATE10[!((

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5. RESPONSIBLE ORGANIZATION: bME.
6. PROBLEM DESCRIPTION: 5 QR O NQR f40 MC /J GrArStS Of car 4T94t1E h i/ FK.\/E Lli I" MS AE:G34 E6TBBLiSRPA CodL r dG_. mot / ToAott6 Sufftil GMf%.55 h <=S uC M Ie _ s A O ATTACH! TENTS
7. PREPARED BY: NAME M _L_ 0 n,, LUn(AA.A ) W - DATE: (0/6184
8. CONCURRENCE: (CEG-H "h>-<w. . R, NW DATE: l't- Q F'
9. APPROVAL: TG PROGRAM MGR.
  • DATE:

i CORRECTIVE ACTION

10. PROPOSED CORRECTIVE ACTION PLAN:

l 1

O ATTACHMENTS

11. PROPOSED BY: DIRECTOR /MGR: DATE:
12. CONCURRENCE: CEG-H: -

DATE:

l SRP: DATE:

ECTG PROGRAM MGR: DATE:

i f VERIFICATION AND CLOSEOUT j 13. Approved corrective actions have been verified as satisfactorily l

implemented.

t i

SIGNATURE TITLE DATE I

1

, ECTG C.3 Attachment A Page 1 of 1 Revision 2 - A ECSP CORRECTIVE Action Tractine Document (CATD)

INITIATION

1. Imenediate Corrective Action Required: E Tes O No
2. Stop Wort Reconssended: O Tes E No
3. CATD No. 23~ZO4 - S (9 W 4 INITIATION DATE II 8$
5. RESPONSIBLE ORGANIZATION: bMf".
6. PROBLEM DESCRIPTION: 5 QR O NQR S T hub e%.b hf%r\Nid 6 s .

Sb - E l E. 5,1-1 S b - E. G. E.1 - 2. 6b - E l as . 5. t- A ' Anh sh - a i r.s .)-4 ' m uo r ertovi ss= o' f:-

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i. m O ATTACHMENTS
7. PREPARED BY: NAME N . LOh IgllPf DATE: fAl2 /fL
8. CONCURRENCEht'yEG-Mh (0 N M DATE: If ik-PC
9. APPROVAL: ECTG PROGRAM MGR.
  • DATE:

CORRECTIVE ACTION

10. PROPOSED CORRECTIVE ACTION PLAN:

3 l

1 0 ATTACHMENTS

11. PROPOSED BY: DIRECTOR /MGR: DATE:
12. CONCURRENCE: CEG-H: DATE:

SRP: DATE:

ECTG PROGRAM MGR: DATE:

VERIFICATION AND CLOSE0tfT

13. Approved corrective actions have been verified as satisfactorily imple.nen ted. .

SIGNATURE TITLE DATE

_

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