ML20209E115
| ML20209E115 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 01/26/1987 |
| From: | Russell Gibbs TENNESSEE VALLEY AUTHORITY |
| To: | |
| Shared Package | |
| ML20209B481 | List: |
| References | |
| 237.4(B), 237.4(B)-R02, 237.4(B)-R2, NUDOCS 8702040601 | |
| Download: ML20209E115 (13) | |
Text
_ _ _ _ _ _ _ _ _ _ _ _.
TVA EMPLOYEE CONCERNS REPORT NUMBER:
237.4 (B)
SPECIAL PROGRAM REPORT TYPE:
SEQUOYAH ELEMENT REVISION NUMBER:
2 TITLE:
ELECTRICAL PROTECTION DESIGN Bypass of Over-torque Limit Switches PAGE 10F 12 REASON FOR REVISION:
1.
Revised to incorporate Senior Review Panel and Technical Assistance Staff consnents; to add CATD 237.4-SQN-2; and to confonn with the reconnended fonnat for SQN element report.
2.
Revised to add chronology and Section 10, Corrective Action.
PREPARATION PREPARED BY:
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- SRP Secretary's signature denotes SRP concurrences are in files.
TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)
SPECIAL PROGRAM REVISION NUMBER: 2 j
PAGE 2 0F 12 1.
CHARACTERIZATION OF ISSUE (S):
Concern:
Issues:
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.
- 332 and 333.
CI is concerned about ECN's applicability to WBNP."
?.
HAVE ISSUE (S) BEEN IDENTIFIED IN ANOTHER SYSTEMATIC ANALYSIS? YES X NO Identified by Nuclear Safety Review Staff (N5RS)
Date October 15-17, 1985, and January 15-22, 1986 Documentation Identifiers:
NSRS Investigation Report No. I-85-612-SQh for Employee Concern XX-85-020-001 (SON Applicability), "RCS Pressurizer Relief Flow Control Valves Failure to Make Torque Switch Bypass Modifications" 3.
DOCUMENT NOS., TAG NOS., LOCATIONS, OR OTHER SPECIFIC DESCRIPTIVE IDENTIFICATIONS STAltu IN ELEMENT:
The two valves identified in the employee concern as SIS valve nos.
332 and 333 were interpreted by tFe evaluator as FCV-68-332 and FCV-68-333 (ECH No. 5971 referenced in the concern is riot related to torque switch bypass and, therefore, the correct reference is interpreted as ECN No. 2257, as documented in App. A, 5.n).
4.
INTERVIEW FILES REVIEWED:
File XX-85-020 was reviewed and nc additional unreviewed infonnation for Sequoyah was identified for the concern addressed in this report.
1103d - 01/09/87
TVA EMPLOYEE CONCERWS REPORT NUMBER:
237.4 (B)
SPECIAL PROGRAM REVISION NUMBER:
2 PAGE 3 0F 12 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 7 See Appendix A.
7.
REQUESTS FOR INFORMATION, MEETINGS, TELEPHONE CALLS, AND OTHER DISCUSSIONS RELAltu TO ELD 4ENT:
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 satisfy NRC guidelines regarding torque switch bypass.
c.
Reviewed existing reports (e.g., NSRS Report No.
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 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 Concerns Special Program for applicability to the concerns discussed in this report.
f.
Assessed overall design adequacy and identified findings as applicable.
i 1103d - 01/09/87
TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)
SPECIAL PROGRAM REVISION NUMBER:
2 PAGE 4 0F 12 9.
DISCUSSION, FINDINGS, AND CONCLUSIONS:
Chronology:
01 / 31 / 7 9:
Sequoyah project requested to modify control circuits of active valves 03/31/79:
ECN No. 2257 issued to reflect use of torque switch bypass on all SQN active valves 10/01/85:
Concern received by TVA for WBN 06/19/85:
ECN No. L6416 issued to cover modification of valves cited in concern 03/06/86:
NSRS Report No. I-85-612-SQN confirmed essence of concern and recommended SQN verify the modification of all active valves 05/01/86:
SQH project confirmed the 36 valves plus 12 more valves requiring modification 03/19/86:
SQN project requested to review 36 additional valves for torque switch modification 05/12/86:
TVA responds to NRC on IE Bulletin 85-03 and commits to meeting requirements of the bulletin 06/03/86:
ECN No. L6667 issued to cover the additional 48 valve modifications l
l Discussion:
The torque switch bypass concern is a safety-related issue because premature operation of valve torque switches could cause the valve 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 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.
l 110?d - 01/09/87 1
TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)
SPECIAL PROGRAM REVISION NUMBER:
2 PAGE 5 0F 12 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".
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 recomendations in this memo fully satisfy the circular.
The subsequent memo from Chandler to Pierce (02/26/79, App. A, 5.h) confirmed that SQN and WBN active valves are the same and the Engineering Change Notice (ECN) No. 2257 (03/31/79, App. 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.
NSRS Report No. I-85-612-SQN ( App. A, 5.k) documented an investigation conducted from 10/15/E:i 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.
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.
1103d - 01/09/87
TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)
SPECIAL PROGRAM REVISION NUMBER:
2 PAGE 6 0F 12 1
In response to the NSRS recomendations, 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 comitted 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 recomended by the NSRS. Also Attachment 1 to this response includes a sumary of active MOVs at WBN that are not active at SQN.
The evaluator's review of the different lists, however, indicated that WBN active valves 0-FCV-67-151,1-FCV-67-147, 2-FCV-67-223, and 1-FCV-67-478, currently not included in Appendix 6.8c, are not listed in this attachment. These discrepancies also result from the current lack of design basis. This 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 detennine applicability of ECN No. 2257 changes to these valves.
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 recomended for these 36 valves.
Also, the memo identified 12 additional valves that require the same type of modification, thus increasino to 48 the total number of 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 recomended chages for these 48 valves; however, no design basis was 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, particularly in the case of torque seated valves.
Finally, a letter from Shell, TVA, to Grace, NRC (05/12/86, App. A, 5.o), in response to IE Bulletin 85-03, provided the SQN comitment 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.
1103d - 01/09/87
TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)
SPECIAL PROGRAM REVISION NUMBER:
2 PAGE 7 0F 12 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.
10.
CORRECTIVE ACTION TVA has developed a corrective action plan to resolve the findings. Revision 0 of this plan was transmitted to Bechtel by TVA letter TCAB-017 ( App. A, 5.x), and Revision 1 is documented in the TVA memo from Wilson to Denney (01/02/87; App. A, 5.y).
Thi s plan includes:
o Issuance of design criteria providing design basis for MOV torque switch bypass design o
Preparation of an active valve list, including justification for listing active valves only o
Revision of FSAR to clarify TVA design basis o
Revision of standard drawings for MOV to clarify and define design 1103d - 01/09/87
TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (c)
SPECIAL PROGRAM REVISION NUMBER: 2 PAGE 8 0F 12 o
Drawing review on all active valves to verify compliance with M0V torque switch bypass design TVA has indicated 02/09/87 as the scheduled completion date for the above corrective actions.
The evaluation team believes that implementation of the corrective action plan (CAP) will adequately resolve the findipps and provide sufficient design basis to cover M0V torque switch bypass design for active valves.
In particular, the above corrective actions are considered as responsive to the problems identified in Corrective Action Tracking Doctments (CATDs) 237.04-SQN-1 and -2.
The two CATDs describe problems resulting from the findings as the lack of design basis or a controlled valve list for the MOV torque switch bypass design and the lack of clear definition in TVA standard drawings E15.5.1-1 through E15.5.1-4 for selection of torque and limit switch configurations.
TVA's CAP is, therefore, considered sufficient to resolve the described problems, and it provides assurance through a drawing review that the required active valves have the proper torque switch bypass design.
l 1103d - 01/09/87 9
TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)
SPECIAL PROGRAM REVISION NtJMBER:
2 PAGE 9 0F 12 APPENDIX A E.
DOCUMENTS REVIEWED RELATED TO THE ELEMENT:
a.
Sequoyah Nuclear Plant FSAR, Chapters 7 and 8 b.
Sequoyah Nuclear Plant FSAR, Appendix 6.Sc revised by Anendment 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 Yalve Comon Mode Failures During Plant Transients Due to Improper Switch Settings," (11/1E/85) e.
Watts Bar Nuclear Plant FSAR Tables 3.9-17 and 3.9-25 f.
TVA memo fron Patterson to Chandler (MEB 790115 390),
"Sequoyah Nuclear Plant - Recomendation to Modify the Control Circuits of Specified Motor Operated Valves,"
(01/12/79) 9 TVA memo from Chandler to Pierce (EEB 790201 921), "Sequoyah Nuclear Plant - Recomendation 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 - Recomendations to Modify the Control Circuits of Specified Motor Operated Valves,"
(02/26/79) 1.
TVA 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 0 Reilly, NRC, to Parris, TVA (NEB 810930 225),
forwarding IE Circular No. 81-13 to TVA, (09/25/81) j.
TVA memo frcm Whitt to Schum, (no RIMS #), " Transmittal of Accepted Final Reports," (11/26/85) and attached kSRS Investigation Report No. I-85-612-WBN/SQN, "SQN ECh Applicability," dates of investigation 11/12/85 to 11/15/85 1103d - 01/09/87
TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)
SPECIAL PROGRAM REVISION NUMBER: 2 PAGE 10 0F 12 APPENDIX A (cent'd) k.
TVA memo from Whitt to Mercrombie, (no RIMS #), " Nuclear Safety Review Staff Investigation Report Transmittal,"
(03/07/86) and attached NSRS Investigation Report No.
I-85-612-SQN, "RCS Pressurizer Relief Flow Control Valves -
Failure to Make Torque Switch Bypass 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 Yalve Opening Torque Switches," (03/19/86) m.
TVA memo from Wilson to Mercrombie (B25 860501018),
"Sequoyah Nuclear Plant - Motor Operated Valve Opening / Closing Torque Switches," (05/01/86) n.
TVA memo from Abercrombie to Seiberling (no RIMS #), " Nuclear Safety Review Staff (NSRS) Report No. I-85-612-SQN, RCS Pressurizer Relief Flow Control Valves - Failure to Make Torque Switch Bypass Modifications," (05/05/86) and attached response to NSRS Report No. I-85-612-SQN 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 duclear Plant,"
(05/12/86) and Enclosure 1 - Sequoyah Nuclear Plant (SQN)
Response to IE Bulletin 85-03 p.
Potential Reportable Occurrence (PRO) No. 2-85-45 (03/23/85) q.
Engineering Change Notice (ECN) No. 2257, Cover Sheet dated 03/12/79 (SWP 790312 500) and Data Sheet (SWP 790402 532),
(03/31/79) r.
Engineering Change Notice (ECN) No. L6416, Cover Sheet dated 05/08/85 (B25 850508 585) and Data Sheet (B25 850619 502),
(06/19/85) s.
Engineering Change Notice (ECN) No. L6667, Cover Sheet (B25 860611 503), (06/02/86) and Data Sheet (B25 860603 509),
(06/03/86) 1103d - 01/09/87
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TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)
SPECIAL PROGRAM REVISION NUMBER: 2 PAGE 11 0F 12 i
APPENDIX A (cont'd) 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 from 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 from Abercrombie to Those Listed, (S01 860121 972),
"Sequoyah Nuclear Plant (SQN) - Employee Concern K-Fonns -
Generic Evaluation," (01/22/86) x.
Letter from G. R. McNutt, TVA, to G. L. Parkinson, Bechtel, i
TCAB-017, " Corrective Action Plan," (12/05/86) i y.
TVA memo from Wilson to Denney (B25 870102 018), " Report 237.4 - Corrective Action Plan Revision," (01/02/87) 6.
WHAT REGULATIONS, LICENSING C0pMITMENTS, DESIGN REQUIREMENTS. OR OTHER i
APPLY OR CONTROL IN THIS AREA?
The general NRC requirement is to minimize malfunction of l
safety-related motor operated valves as a result of premature actuation of torque switches (Ref. IE Circular No. 81-13).
l 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 DI5L,U55 IONS RELAltU TO ELtRtNI:
a.
Meeting between Nesbitt, Purcell, and Ramine, TVA, and Don-Doncow and Hegyi, Bechtel, at Sequoyah jobsite, IOM #530, (08/20/86) b.
Meeting between Nesb'itt and Brush, TVA, and Don-Doncow, Bechtel, in Knoxville, IOM #530, (08/21/86) 1103d - 01/09/87
TVA EMPLOYEE CONCERNS REPORT NUMBER: 237.4 (B)
SPECIAL PROGRAM REVISION NUMBER:
2-PAGE 12 0F 12 CATD LIST The following CATDs identify and provide corrective action for the findings included in this report:
237.04-SON-1 (01/02/87) 237.04-SQN-2 (01/02/87) l l
l 1103d - 01/09/87 L
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REFERENCE
- ECPSI20J-ECPS121C TENNESSEE VALLEY AUTHORITY PAGE 139 FREQUENCY
- REQUEST OFFICE OF NUCLEAR POWER RUN TIME - 12:57:19.
.I ONP - ISSS - RHM EMPLOYEE CONCERN PROGRAM SYSTEM (ECPS)
RUN DATE - 12/02/86 LIST OF EMPLOYEE CONCERN INFORMATION CATEGORY: EN DES PROCESS & OUTPUT SUBCATEGORY: 23704 BYPASS OF OVER-TORQUE LIMIT SHITCHES I
S GENERIC KEYHORD A H
APPL QTC/NSRS P
KEYHORD B CONCERN SUB R PLT BBSH INVESTIGATION S
CONCERN KEYHORD C NUMBER CAT CAT D LOC FLQB REPORT R
DESCRIPTION KEYHORD D XX 020-001 EN 23704 N SQN YYYY I-85-612-SQN SS AN ECN 85971 HAS ISSUED AT SEQUOYAH DESIGN CHANGES T50153 REPORT IN 1979 THAT REQUIRED A BYPASS OF TH CORRECTIVE ACTION E OVER-TORQUE LIMIT SHITCHES ON CERT PIPING
~b AIN LIMITORQUE OPERATORS. IT HAS RE MOTORS CENTLY DISCOVERED (3-4 MONTHS AGO) T HAT THIS HAD NOT BEEN ACCOMPLISHED F OR SIS VALVE S332 AND 333.
CI IS CD 1
NCERNED ABOUT ECN'S APPLICABILITY TO HBNP.
CONCERN IS IN CONSTRUCTION D Nb F0 LOH U REQ IRED.
I CONCERNS FOR CATEGORY EN SUBCATEGORY 23704
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