ML20215N173
| ML20215N173 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/24/1986 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Grace J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 8611040396 | |
| Download: ML20215N173 (9) | |
Text
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BED TENNESSEE VALLEY AUTHORITY 4'.
CHATTANOOGA. TENNESSEE 374o1 f
SN 157B Lookout Place n
06 0Ci27 pjj. 05 0CT 2 4 886 U.S. Nuclear Regulatory Commission Region II ATTN:
Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323
Dear Dr. Grace:
SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 - NRC-OIE REGION II INSPECTION REPORT 50-327/86-42 AND 50-328/86 RESPONSE TO VIOLATIONS Enclosed is our response to Gary G. Zech's September 26, 1986 letter to.
S. A. White which transmitted IE Inspection Report Nos. 50-327/86-42 and 50-328/86-42 for our Sequoyah Nuclear Plant (SQN) and which cited TVA with one Severity Level IV Violation (327, 328/86-42-06) and one Severity Level V i
Violation (327, 328/86-42-01). is our response to the subject violations and our commitments are listed in enclosure 2.
We do not recognize any other actions described herein or the subject inspection report as conniteents.
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If you have any questions, please call M. R. Harding at 615/870-6422.
L To the best of my knowledge, I declare the statements contained herein are complete and true.
Very truly yours, TENNESSEE VALLEY AUTHORITY l
l R.Gridley,Dirhetor Nuclear Safety hnd Licensing Enclosures cc (Enclosures):
Mr.' James Taylor, Director Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. G. G. Zech Director, TVA Projects l
U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 8611040396 861024 PDR ADOCK 05000327 f
0 PDR An Equal Opportunity Employer i \\
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o ENCLOSURE.1 RESPONSE - NRC-OIE INSPECTION REPORT NOS. 50-327/86-42 AND 50-328/86-42 GARY G. ZECH'S LETTER TO S. A. WHITE DATED SEPTEMBER 26, 1986 Violation 50-327/86-42-06 and 50-328/86~42-06 Technical Specification 6.8.1 states that written procedures shall be established, implemented and maintained covering the maintenance of safety related equipment. Standard Practice SQA-119 establishes the procedure to implement a PORC approved temporary alteration to a safety-related system.
The standards established for the temporary alteration and the Unreviewed Safety Question Determination are documented in a Temporary Alteration Change Form (TACF). TACF 0-85-097-234 established the standard for the total amount of wattage applied by a replacement heat trace tape in a safety-related portion of the Chemical Volume Control System.
Contrary to the above, Work Requests A-529926 and A-539170, among others, did not adequately control the configuration of replacement heat trace tape application. This resulted in a condition where the wattage requirements of TACF 0-85-097-234 were not complied with.
This is a severity Level IV violation (Supplement I).
1.
Admission or Denial of the Alleged Violation TVA admits the violation occurred as stated.
2.
Reason for the Violation Work Requests which failed to address the effect of crossing replacement heat trace (wrapping over itself) resulted in wattage requirements of TACF 0-85-097-234 not being satisfied. As identified in the Inspection Report, this violation is related to a group of licensee-identified violations involving the installation of Chemelex heat trace on the Chemical and Volume control System (CVCS). Tho overall issue was identified by the onsite QA staff and specific deficiencies are being addressed by Corrective Action Report (CAR) SQ-CAR-86-07-038.
The root cause of the whole issue, and accordingly of this specific violation, is attributed to personnel error in failing to implement installation of the subject heat trace in accordance with requirements for CSSC equipment due to uncertainty over the safey-related classification for the heat trace. As a result, adequate procedures and instructions were not provided to ensure requirements of the TACFs were satisfied for installation and replacement of Chemelex heat trace.
3.
Corrective Steps Taken and Results Achieved In order to resolve both the NRC-and licensee-identified deficiencies, Division of Nuclear Engineering (DNE) has been requested to evaluate whether heat trace for the CVCS should be considered safety related so that clarification of all requirements is clearly established.
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The SQN site CSSC Subcommittee will then use this evaluation to determine whether selected.CVCS heat trace circuits should be removed from the SQN CSSC' listing..SQN Standard Practice SQA-134, " Critical Structure, Systems, and Components (CSSC) List." The appropriate corrective actions to resolve individual deficiencies are presently under consideration, pending the final classification. For the interim, the Electrical Maintenance (EN) supervisor has. issued an internal memorandum to appropriate EM personnel restricting future use of or-maintenance on Chemelex heat trace pending resolution to these issues.
While unresolved ' deficiencies exist for current chemelex heat trace installations on the CVCS, temperatures are verified acceptable in accordance with SR 4.1.2.1 when a flow path from the boric acid tanks is used to: satisfy LCO 3.1.2.1.
This verifies the boron injection flow' path
-remains operable and available to provide negative reactivity control.
'Any problems resulting from existing deficiencies in affected heat trace circuits would be identified by performance of the associated surveillance, SI-8, " Boric Acid Flow Path - Temperature-Verification" and the restrictions of the action statement complied with as required.
4.
Corrective' Steps Which Will Be Taken To Avoid Further Violations The results of the determination by the SQN site CSSC Subcoumittee regarding the.CSSC designation for heat trace'will dictate the appropriate corrective steps which will be taken to avoid inadequate heat trace installations in the future and to address any identified deficiencies in existing installations.
Future installation of Chemelex heat trace on CSSC circuits, pending DNE approval, will be done by an approved instruction and requirements established by any associated TACFs will be satisfied. Appropriate Electrical Maintenance personnel will be cautionedilo observe all requirements involving CSSC equipment by October 31, 1986. The resolution to this individual violation will be affected by the resolution to the overall heat trace issue being-addressed under the previously referenced CAR.
5.
Date When Full Compliance Will Be Achieved Resolution will be achieved before startup of the affected unit.
Violation 50-327/86-42-01 and 50-328/86-42-01 10 CFR 50, Appendix B, Criterion V, requires that activities affecting quality shall be prescribed by procedures of a type appropriate to the circumstances and shall be accomplished in accordance with these procedures.
1.
Sequoyah Nuclear. Plant Construction Procedure P-30, Rev. 1, " Fabrication and Installation of Seismic Supports," requires that a support variance sheet be used to alter an existing typical support drawing and shall be applicable to.one specific support at's specified location.
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. Contrary to:the'above, this. procedure was not implemented in that solenoid valve 1-FSV-63-42 was mounted in a way which did not conform to the specifications of the typical drawing, and a support variance sheet was not used.
2.
~ Administrative Instruction 19, Rev. 12. " Plant Modifications After Licensing," was established to provide that work instructions shall give a step-by-step sequence of events required to perform the work correctly and that the procedure identify the results of improper action.
Contrary to the above.this procedure was not implemented in that Work Plan 11806 did not give' adequate instructions for craft personnel to reconfigure 10 CFR 50.49 qualified ASCO solenoid valves for proper installation and did not give the results of improper actions associated with modifying the valves.
This is a Severity Level V violation (Supplement I).
1.
Admission or Denial Of The Alleged Violation TVA admit's example 1 of the violation concerning mounting of solenoid valve l'-FSV-63-42 in a way not conforming to a typical support drawing and without a support variance sheet.
TVA, however, denies example 2 of the violation concerning inadequate instructions for instal: stion of 10 CFR 50.49 qualified ASCO solenoid valves.
2.
Reason For Violation (Example 1)
The support for solenoid valve 1-FSV-63-42 differed from the typical support drawing and a variance sheet was not retrievable to document the deviation as required by Sequoyah Nuclear Plant Construction Procedure P-30, Rev. 1, " Fabrication and Installation of Seismic Supports." As such, proper seismic evaluation of the support could not be verified.
It is not believed that a willful violation occurred.
It is rather believed that a variance sheet was initially submitted in accordance with the referenced construction procedure but that-the document is not retrievable from the plant history flies. When new solenoids were to be installed, the workplan and the ECN were written to replace the valves with new valves which were equivalent in weight and mounting-bolt pattern to the old solenoids. The workplan assumed that the original installation had been seismically qualified, and since the weight and mounting-bolt pattern did not change, there was no reason to believe that the seismic qualification would not apply to the new valve.
3.
Corrective Steps Taken and Results Achieved (Example 1)
Due to considerations of. current loads and recent testing of support configurations for model NP8316 solenoid valves, a modification to the hanger was required. A variance sheet for the modified hanger was submitted for solenoid valve 1-FSV-63-42 and approved as a seismically qualified support. Modification of the support was performed under Workplan (WP) 11927.
l 4.
Corrective Steps To Be Taken To Avoid Further Violstions (Example 1)
All 10 CFR 50.49 qualified model NP8316 solenoid valves are being reviewed to ensure that they are seismically mounted and that the seismic qualification of.those installations is documented.
Results of this review will be used to determine if further review is appropriate. This is being performed in accordance with ECN 6787 and will be complete before startup of the affected unit.
5.
Date When Full Compliance Will Be Achieved (Example 1)
Full compliance was achieved'on August 13, 1986 when installation of the modified hanger was field complete. A variance sheet had been submitted and approved before installation.
6.
Reason For Denial (Example 2 - Inadequate Instructions For Installation of 10 CFR 50.49 Qualified Solenoid Valves)
The licensee considers that WP 11806, as required by Administrative Instruction 19 (AI-19), provided adequate instructions for craf t personnel to perform the scope of work correctly, that is, remove existing solenoid valves and install 10 CFR 50.49 qualified solenoid valves. The WP stated that the modification would not violate the internal integrity of the valves, therefore, improper actions which could result in degrading the environmental qualification (EQ) of the valves were administratively controlled. The instruction's provided, including a functional test following installation, were appropriate to the circumstances and were adequate to ensure the work was performed correctly, i.e., to ensure that the functions which could have been affected by the replacement were retained as acceptable.
Background:
In order to install the subject 10 CFR 50.49 qualified solenoid valves, two of four screws in the valve body endplate had to be removed in order to remove a small vendor-supplied mounting bracket. The vendor-supplied bracket was attached to the bottom portion of the endplate by the lower two endplate screws.
The replacement valves were to be mounted using existing supports or with supports field-fabricated in accordance with typical hanger drawings to facilitate adaptation and use of pre-existing connections.
(Drawings and work instructions for fabrication and installation of these TVA designed hangers were referenced in the WP.)
During the installation of the qualified solenoid valves, neither the valve nor the solenoid housing were disassembled and the WP stated that the modification would not violate the internal integrity of the valves.
Reinstallation of the two screws was performed under accepted general guidance of plant Maintenance Instructions (MI) 6.15. " General Procedure, Tightening Bolted Joints," and 11.4,
" Maintenance of CSSC Valves." Following valve replacement, the WP required a leak-test (snoop) be performed on connections broken during valve removal and connections were to be tightened as required. The functional operability J
could have been.affected~by improper valve replacement, e.g.,
incorrect air or electrical connections, therefore, a functional test following the replacement further ensured that work had been properly performed.
Had the subject screws not been properly installed (for example, if the two screws had been loose enough such that pneumatic control was affected), the'1eak-test and/or functional test would have identified such a deficiency. The environmental.
qualification of the solenoid valve could not have been affected by reconfiguring the support since the solenoid housing was not in any way affected. Additionally, the attached valve-body assembly was not modified to a configuration which could in some way translate changes into the solenoid such that required electrical characteristics would be unacceptably compromised under. harsh environmental conditions.
The Inspection Report, paragraph 3.b., states that the lack of special torquing requirements in WP 11806 for reinstallation of' screws removed'from valve endplates caused the "10 CFR 50.49 boundary" for the valves to not be maintained, inferring the lack of requirements compromised environmental qualification of the solenoid valves. This interpretation was used to conclude that the requirements of AI-19 were violated in that adequate instructions were not provided to ensure work was performed correctly, i.e.,
to ensure the "10 CFR 50.49 boundary" and therefore qualification was maintained. This is identified as a further example of violation 327, 328/86-42-01.
TVA disagrees with both this interpretation and the conclusion.
position: The licensee disagrees with the basis for this example of violation 86-42-01 in that adequate instructions were provided to ensure-that the work was performed correctly, that is, to ensure the functions which could be affected by the replacement were not compromised. The licensee disagrees that-the environmental qualification of the solenoid valves was affected by the reconfiguration of the mounting support as performed under WP 11806. The area of the valve which could have in any way been affected by improper installation of the screws is internally isolated from the portion of the solenoid valve which contains the electric coil. Reinstallation of two screws, in conjunction with postmodification leakage and functional tests, adequately verified that the work had been performed correctly. The level of detail of work instructions is normally determined by the complexity of the assignment, the potential results of improper actions, and the ability to perform postmaintenance/ modification testing to ensure operability. SQN's plant procedure for tightening bolted joints, MI-6.15, paragraph 5.1, states,
" Components seeing medium and low pressure service (up through pressures of 300 psi) normally will not require torquing to specific values." SQN's plant procedure for maintenance of CSSC valves, MI-11.4, states, "For reassembly of bolted bonnets and pressure seals, verify proper bolt lubrication and use of correct torquing procedure and torque values per validated vendor manual, responsible supervisor / engineer, or MI-6.15..." Under consideration of this guidance and the specific circumstance, the referenced WP provided details consistent with the task being performed as evaluated at that time.
w a The NRC basis for stating that the instructions were not adequate to ensure the work was performed correctly involves the vendor-supplied torquing values for the subject screws, as provided in the vendor manual for ASCO model NP8316 solenoid valves.
WP 11806 was prepared in the early fall of 1985 and was field-complete in November _1985.
The vendor manual for the solenoid valves was first cleared for validation at SQN on December 3, 1985, and the EQ binder for ASCO solenoid valves was officially issued December 27, 1985. The vendor-supplied torquing values for the subject screws are not part of the Qualification Maintenance Lata Sheets (QMDS) for these valves; the vendor manual is provided as part of the binder for revision reference only.
Evaluation for implementation of non-QMDS vendor recommendations, in the context of normal maintenance, is normally provided'through the vendor manual document control program.
In clarification, while all QMDS vendor recommendations or requirements must be certified as implemented before startup (regardless of identification or issuance dates), non-QMDS vendor recommendations may or may not be implemented depending upon evaluation of significance and importance.
For this specific situation it is apparent that the workplan was implemented before issuance and evaluation of the ASCO vendor manual and special torquing values were not considered necessary to maintain qualification of the valves (not on QMDS); therefore, detail provided in the workplan (which is in compliance with MI-ll.4, specifically "...
supervisor / engineer, or MI-6.15...") was considered consistent with the task being performed.
The philosophy regarding adaptation or evaluation of non-QMDS vendor recommendations into normal maintenance programs has been evolving over the course of EQ program implementation.
Questions concerning the generic 4
methodology / philosophy for maintaining the environmental qualification of electrical components by incorporating vendor-supplied requirements and recommendations into replacement or reconfiguration activities is being addressed by URI 327, 328/86-42-02.
The program for maintaining environmental qualification of electrical components exposed to a harsh environment at SQN is based upon the special requirements provided in the QMDS for these components above and beyond normal maintenance. The torquing values for the subject screws that are provided in the vendor manual for ASCO solenoid valves are not part of the QMDS requirements for maintaining qualification of the valves and were not considered as required to maintain qualification of the solenoid valves. The licensee considers that for the subject valve replacements, normal " maintenance",
i.e.,
reinstallations, was performed as considered appropriate.
Resolution to the aforementioned URI may or may not dictate changes in generic philosophy regarding normal maintenance for 10 CFR 50.49 qualified components. Regardless of the resolution to this URI, it is clearly not appropriate to assess a violation upon the licensee for not adapting an as yet unresolved philosophy into a work instruction written and performed nearly a year before.
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O Summary: The subject ASCO solenoids were replaced with 10 CFR 50.49 qualified solenoid valves using work instructions which were, at that time, appropriate to the circumstances and adequate to ensure that the work was performed correctly. The results of improper actions were addressed in that the WP stated that the modification would not violate the internal integrity of the solenoid valves and postmodification testing was performed to verify-acceptable those functions which could have been affected by the modifications. The licensee believes that the detail of the instructions provide 1 in the WP were consistent with the work to be performed and the requilrements and philosophy in effect at the time of the replacements. Therefore, no violation of any regulatory requirements occurred during the subject replacment of ASCO solenoid valves.
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__m ENCLOSURE 2 LIST OF COMMITMENTS 1.
DNEwillevaluatewhetherChCSheattraceshouldbeconsideredsafety related.
2.
The SQN site CSSC Subcommittee will utilize the DNE evaluation to revise the CSSC list in SQA-134 if appropriate by startup of the affected unit.
3.
Appropriate Electrical Maintenance personnel will be cautioned to observe all requirements involving CSSC equipment in the future by October 31, 1986.
4.
Resolution of CAR-86-07-038 will be completed before restart of the affected unit.
'll 10 CFR 50.49 qualified model NP8316_ solenoid valves are being 5.
A reviewed to ensure that they are' seismically mounted and that the seismic qualification of those installations is-documented.
Results of this review will be used to determine if further review is appropriate.
This is being performed in accordance with ECN 6787 and will be completed before startup of the affected unit.
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