ML20205G870
| ML20205G870 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 03/24/1987 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Ebneter S NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| GL-84-24, GL-85-15, GL-86-15, NUDOCS 8703310566 | |
| Download: ML20205G870 (13) | |
Text
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TENNESSEE VALLEY AUTHORITY j
CH ATTANOOGA. TENNESSEE 374o1 SN 157B Lookout Place MAR 241987 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Office of Nuclear Reactor Regulation Washington, D.C.
20555 Attention:
Mr. Stewart Ebneter In the Matter of
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Docket Nos. 50-327 Tennessee Valley Authority
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50-328 SEQUOYAH NUCLEAR PLANT (SQN) - COMPLIANCE WITH 10 CFR 50.49, ENVIRONMENTAL QUALIFICATION OF ELECTRICAL EQUIPMENT IMPORTANT TO SAFETY FOR NUCLEAR POWER PLANTS In accordance with the requirements of Ceneric Letter 84-24 dated December 27, 1984 TVA submitted by letter dated February 25, 1985, a certification of compliance to 10 CFR 50.49 for Sequoyah Nuclear Plant. TVA efforts to consolidate Environmental Qualification (EQ) files continued following this response. Ceneric Letter 85-15 dated August 6,1985, provided NRC positions relating to the deadlines for compliance with 10 CFR 50.49 and further defined unqualified equipment as equipment for which there is not adequate documentation to establish that this equipment will perform its intended functions in the relevant environment. Consideration of the presented positions, along with results of a management review team inspection of EQ documentation files, prompted TVA to shut down its Sequoyah units 1 and 2 rather than operate in noncompliance with the rule. Documentation had been found inadequate to support qualification and was not considered readily auditable.
Since shutdown, extensive reworking and reevaluation of the EQ program at Sequoyah have taken place and a redefined program (and baseline qualification documentation) has been established.
Subsequent to NRC program review and inspections, a draft Safety Evaluation Report (SER) on the Sequoyah electrical equipment environmental qualification program was issued December 5,1986.
The SER concluded the Sequoyah program complies with the requirements of 10 CFR 50.49 and that TVA's proposed resolutions to identified EQ deficiencies are acceptable; nine confirmatory items were listed for TVA certification of completion or resolution before restart. Generic Letter 86-15, dated l
September 22, 1986, further clarified NRC staff positions regarding compliance with 10 CFR 50.49.
Specifically provided are additional guidelines on l
appropriate licensee actions in situations where environmental qualification of equipment is indeterminate or becomes suspect and definition of current NRC policy with regard to enforcement.
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l U.S. Nuclear Regulatory Commission The establishment and implementetion of the revised EQ program at Sequoyah, in conjunction with the guidelines established in this most recent generic letter, provide the basis for TVA to baseline the Sequoyah program. We are, therefore, resubmitting TVA's response to Generic Letter 84-24 for Sequoyah (enclosure 1), affirming we have established and are implementing a program in accordance with the requirements of 10 CFR 50.49 and guidance provided in Generic Letters 84-24, 85-15, and 86-15.
Additionally, we are providing a response to the draft SER (enclosure 2) to include review comments on the SER text and specific response to the nine confirmatory items listed at the end of the SER text.
The revised response to Generic Letter 84-24 (enclosure 1) establishes the Sequoyah baseline for meeting 10 CFR 50.49 certification requirements and provides the current status of the Sequoyah EQ program implementation. This status consists of identifying percent completion of program baseline efforts (QMDS implementation / verification), a statement of program compliance with 10 CFR 50.49, and a listing of identified technical issues / field work which must be resolved / completed or acceptably dispositioned before restart. The response to the draft SER nine confirmatory items (enclosure 2) certifies completion / resolution of six of the items. Outstanding efforts for the three remaining items involve NRC staff approval of TVA resolution to one technical issue and completion of fieldwork.
These outstanding SER items are also reflected in the implementation status provided in attachment B to enclosure 1 (i.e., the status provided in enclosure 1 is all-inclusive). Outstanding identified issues and fieldwork will be resolved and completed within the provisions and requirements of the established Sequoyah 10 CFR 50.49 implementing program.
As provided in Generic Letter 86-15, it is expected that issues or questions regarding qualification may arise after initial program certification, and guidance in handling of these emergent issues is reflected in the overall design / operation program at Sequoyah. A site-specific program has been established for the Sequoyah plant to ensure environmental qualification of 10 CFR 50.49 equipment is established and maintained, and potential deficiencies are promptly identified, evaluated, and resolved within these established program requirements. As a result of extensive ongoing Sequoyah design review efforts (and ancillary activities), various technical issues have been identified and, upon full definition, addressed for impact to equipment within the scope of 10 CFR 50.49.
As a result, the number of activities relating to EQ program implementation fluctuates as other TVA activities progress.
It should be noted that such identification of issues reflects the status of completion of overall design review activities and not upon the adequacy of the Sequoyah 10 CFR 50.49 program.
An these review efforts near completion, it is expected that emergent issues affecting 10 CFR 50.49 equipment will correspondingly diminish.
Nonetheless, EQ is an ongoing program and is, therefore, subject to TVA review and revision within the scope and requirements of 10 CFR 50.49 and the implementing Sequoyah program.
. U.S. Nuclear Regulatory Commission If there are any question regarding the disposition provided, please call M. R. Harding at 615/870-6422.
Very truly yours, TENNESSEE VALLEY AUTHORITY I
R.
. Gridley Director Nuclear Safety and Licensing Sworn subscri before me thi ay of 1987 Afh
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Enclosures cc (Enclosures):
Mr. J. J. Holonich Sequoyah Project Manager U.S. Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, Maryland 20814 Mr. G. G. Zech, Director TVA Projects U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379 i
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ENCLOSURE,19 REVISED RESPONSE TO NRC GEhERIC LETTER 84-24 FOR SEQUOYAH HUCLEAR PLANT j
DOCKET NOS. 50-327 AND 50-328,
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TVA's revised response to NRC Ceneric Letter 84-24-for.Sequoyah is provided as' follows. TVA herein establishes a baseline within the existing Sequoyah 10 CFR 50.49 program with the exception of full completion of some remaining -
baseline efforts (QMDS implementation / verification status) and resolution or completion of identified technical issues / fieldwork (attachments,A and B) s which will be addressed within the program requirements before, restart'of the affected unit.
As of February 13,1987, QND3 baseline verification'is s.
approximately 99-percent complete for unit 2/conson and approximate.ly 95-percent complete for unit 'l.
(a)
Sequoyah has in place and is implementing an electrical' equipment environmental qualification (EQ) program to satisfy,the requirements of 10 CFR 50.49.
The EQ documentation now represented by Sequoyah's 10 CFR 50.49 list and EQ binders complies with the requirements of 10 CFR 50.49 and establishes initial qualification of equipment.
Continued qualification of equipment is ensured through the CequoyahlEQ program requirements.
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(b,c) For Sequoyah, all electrical equipment within the scope of 10 CFR,50.49 will be environmentally qd111 fled. Sequoyah's overall design /operatico program reflects guidelines provided'in Generic Letter 86-15 for identification, operability evaluation, dispositioning, and 5,' gs1 establishment of a reasonable schedule to correct deficiencies for any s unqualified piece of equipment.
l The IE Bulletin and Information Notices referenced in Generic Letter 84-24
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i have been reviewed with consideration to the requirement!s of 10'CFR 50M9, and any appropriate response / actions determined from that review have been' incorporated into the EQ program at Sequoyah. Additioral bulletiins apd notices received or to be received by TVA in the future with 10 CFR 50.49 s
applicability have been or will be similarly addressed.'
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- - ATTACHMENT A
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Technical Issues To Be Resolved For 10 CFR 50.49 Compliance s
'(o of February 13, 1987) v The follpwing technical issues were identified after the Sequoyah EQ program wasscubstantially complete. The issues were identified at a broader level and outside the EQ program but have been recognized as affecting environmental qualification of associated 50.49iaquipment.
Issue resolution (s) will be input! to r.nd addressed under ccotrolled provisions of the existing EQ program reqtii.rements for any 50.49 affected equipment.
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4 Determine qualification requirements for containment cooling for certain events Review of piece parts purchased as QA Level II s
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ATTACHMENT B Fieldwork to be Completed For 10 CFR 50.49 Coasliance las of February 13. 1987) f Fieldwork is considered to reflect program implementation efforts, i.e., may include completion of any requireG modifications, associated QMDS, and associated program documentation (binder updates, etc.).
All presently identified EQ fieldwork (excluding ampacity issue affected work) is currently scheduled for completion by the end of March'1987. Neither scope nor schedule for fieldwork arising from the technical issues listed in attachment A are yet defined.
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o Seal conduits below flood level in Main Steam Valve Vault I
X and Auxiliary Building b -
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Replace cable for damper operator due to degraded voltage X
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o Finalize QMDS implementation including installation of new X
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pump and motor on H2 analyzer
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o Change'setpoints for 10 devices due to accuracy considerations X X
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' Provide isolation of certain Categorf C devices and upgrade X
X and replace other Category C devices due to the interaction study of Category A and Category C devices o
Replace unqualified terminal blocks X
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Relocat.e four solenoid valve are suppression networks X
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o Modify ice condenser drains for in containment-superheat X
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Replace cables based on revised ampacity tables X
X R,eplace cables and refurbish equipment in Main Steam Valve X
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Vault.s (MSVV) due to localized high temperature and 5,
i implement minor modifications due to MSVV superheat o
Field verify splice configurations and repair as necessary X
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Regear two motor-operated valves X
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f> t ATTACHMENT B Unit 1/ Unit 2 o
Implement any fieldwerk required including QMDS requirements I
for unit 1 equipment required to support unit 2 operation
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Complete work on various" concerns for Limitorque operators X
(e.g., resear, final field verification, rewire, replace motors) o Complete minor work on Liraitorque operators on MFIVs X
o Replace two unqualified cables inside containment X
o Relocate steam generator PORY solenoids outside the valve X
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ENCLOSURE 2 RESPONSE TO DRAFT SER ON EQUIPMENT QUALIFICATION FOR SEQUOYAH NUCLEAR PLANT UNITS 1 AND 2 a
DOCKET NOS. 50/327 AND 50/328 The following provides TVA response to NRC's draf t Safety Evaluation Report (SER) on Equipment Qualification for Sequoyah units 1 and 2 transmitted by letter to S. A. White from B. J. Youngblood dated December 5, 1986.
Included are proposed revisions to the draft SER text resulting from TVA review and response to nine confirmatory items identified in the draft SER for certification of completion or_ resolution by TVA before restart. The proposed text revisions are identified and discussed below under " Clarification of l
Statements." The response to the confirmatory items follows.
I Clarification of Statements TVA proposes the following revisions to or clarification of statements made within the text of the draft SER for Equipment Qualification for Sequoyah units 1 and 2.
1.
Revise two sentences on page 5-4; the remainder of the sentence from section 5.3.1 at the top of the page and a similar sentence in the third paragraph under section 5.3.2.
The sentences address 1986 staff inspections and the proposed changes would include an inspection which occurred subsequent to issuance of the draft SER.
The sentences should read:
. November 18-22, 1985, and the staff equipment qualification inspections January 6-17 February 10-14, June 23-27, December 8-12, 1986, and
, 1987.
On January 6-17, February 10-14 June 23-27, December 8-12, 1986, and
, 1987, the staff and its consultants from Sandia National Laboratories, inspected the Sequoyah EQ binders and selected equipment, and reviewed Sequoyah's implementation of the 10 CFR 50.49 program.
2.
Revise pages 5-5 and 5-6, fourth and fifth paragraphs under section 5.3.3, which address the 10 CFR 50.49 DBEs at Sequoyah that produce harsh environments. The proposed revisions are necessary to accurately reflect all Sequoyah FSAR chapter 15 events which produce a harsh environment.
The proposed text is excerpted from the revised pages to the summary status report of TVA's compliance to 10 CFR 50.49 transmitted by letter from R. L. Gridley to B. Youngblood on September 11, 1986. The substantive difference between the current SER text and the proposed l
revision is the inclusion of the Fuel Handling Accident (FRA), occurring in the fuel handling area, as a Sequoyah FSAR chapter 15 event which l
produces a harsh environment.
The fourth and fifth paragraphs should read as follows:
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. TVA has also evaluated other accidents in chapter 15 of the Sequoyah FSAR that did not fit the 10 CFR 50.49 DBE definition as interpreted above, but that have the potential to produce environments more severe than those encountered during normal operation or anticipated operational occurrences.
These accidents are the waste gas decay tank rupture (WGDTR), the fuel handling accident (FRA), and the steam generator tube rupture (SGTR). The WGDTR and SGTR do not produce unusual temperature or pressure environments, and the radiation environments associated with them are not significant. Radiation doses to equipment necessary for mitigation of these events are less than 104 rads.
The FHA results in relatively mild radiological consequences that are restricted to zones-of-influence about the Auxiliary Building Gas Treatment System (ABGTS) charcoal beds in both units. The only equipment in the scope of 10 CFR 50.49 affected by the FRA is reflected in the category and operating times document for Sequoyah and is qualified to more harsh environments than that produced by the FHA.
In summary, the 10 CFR 50.49 DBEs at Sequoyah that produce harsh environments are only those events which are LOCAs, HELBs inside containment, and HELBs outside containment. The FHA, occurring in the fuel handling area, is the only other Sequoyah FSAR chapter 15 event which produces a harsh environment.
3.
Revise page 5-8, the first, third, and fourth full paragraphs in the center of the page, which address environmental qualification of equipment within the scope of Regulatory Guide (RG) 1.97.
proposed revisions are primarily focused on simplifying and clarifying the discussion of current and future scope of environmental qualification of RG 1.97 equipment. An apparent word processing error is corrected in the first paragraph by inserting a negative in the third sentence, and the third and fourth paragraphs are combined following revision for continuity of discussion. The proposed text attempts to eliminate potentially confusing statements by more closely reflecting current and future program scope as presented in the Summary Status Report of TVA's Compliance to 10 CFR 50.49, " Environmental Qualification of Electrical Equipment Important to Safety for Nuclear power plants." Additionally, reference details are removed which may be subject to current or future change and/or which are not germane to the substance of the 10 CFR 50.49 and RG 1.97 program interactions being discussed.
. The first full paragraph should read as follows:
With regard to 10 CFR 50.49(b)(3), TVA evaluated existing system arrangements and identified equipment for the variables defined in RG 1.97.
A report outlining the results of the review and schedules for modifications has been submitted to the staff for review. Because the report is still being reviewed, some of the equipment items jointly within the scope of NUREG-0737 and RG 1.97 have not been included in the 10 CFR 50.49 scope. When the RG 1.97 report and equipment lists contained therein have been finalized and accepted by the staff, appropriate equipment not already in the 10 CFR 50.49 scope will be added in accordance with the RG 1.97 implementation schedule.
The third and fourth full paragraphs should be revised and combined as follows:
For instrumentation that is not considered operable or not installed but that will be complete in accordance with the implementation schedule for RG 1.97 or post-TMI KUREGs, environmental qualification will be complete when the equipment is installed and operable.
For that instrumentation that exists at the plants but that was not included in the original PAM instrumentation set but that will be Category 1, RG 1.97 instrumentation, TVA will complete environmental qualification in accordance with the implementation schedule for RG 1.97.
Response to Confirmatory Items Under section 5.4 " Conclusions," of the draf t SER, nine confirmatory items were listed on page 5-10.
The staff stated TVA would be required to certify that the issues had been completed or resolved before restart. The following provides certification of completion or resolution of these items except as indicated. Remaining fieldwork associated with the first three items below is reflected in attachment B to enclosure 1 and will be completed in accordance with program requirements before restart of the affected unit.
Confirmatory Items:
(1) Resolution or staff approval of the main-steam-line break with superheat release and its effect on the environmental qualification of equipment in the east and west valve vault rooms (A1, A2, A10, All)
TVA Responso: TVA resolution (submittal) currently undergoing NRC staff review.
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(2) All EQ fieldwork TVA Response: Complete except for those items shown on attachment B of enclosure 1 to this submittal or resulting from issues identified in attachment A of enclosure 1.
(3) Mainsteam vault submergence review TVA Response: Complete except for fieldwork shown on attachment B to enclosure 1 of this submittal.
The technical issue is resolved.
(4) Management review of EQ binders TVA Response:
Complete.
(5) Supplemental vendor information TVA Response: Complete.
(6) Cable load study TVA Response: Complete.
(7)
Inside containment flood analysis for 5-minute operability TVA Response: Complete.
(8) Verification of instrument accuracy calculation TVA Response: Complete.
(9) Finalization of the EQ master list TVA Response: Complete.
Refer to letter from J. A. Domer to Victor Stello, Jr., dated August 13, 1986.
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References:
1.
TVA letter from J. W. Hufham to B. J. Youngblood dated December 23, 1985, transmitting a revised summary status report of TVA's compliance with 10 CFR 50.49, " Environmental Qualification of Electrical Equipment Important to Safety For Nuclear Power Plants."
2.
TVA letter from R. L. Gridley to B. Youngblood dated January 29, 1986, transmitting revised pages to the summary status report of TVA's compliance with 10 CFR 50.49, " Environmental Qualification of Electric Equipment Important to Safety For Nuclear Power Plants."
3.
TVA letter from J. A. Domer to Victor Stello, Jr., dated August 13, 1986, which provided the 10 CFR 50.49 list for Sequoyah.
4.
NRC letter from Robert F. Heishman to S. A. White dated August 15, 1986,
" Inspection Report Nos. 50-327/86-01; 50-328/86-01."
5.
TVA letter from R. L. Gridley to B. Youngblood dated September 11, 1986, transmitting revised pages to the summary status report of TVA's compliance with 10 CFR 50.49, " Environmental Qualification of Electrical Equipment Important to Safety For Nuclear Power Plants."
6.
NRC letter from B. J. Youngblood to S. A. White dated December 5,1986, "Trans.uittal of Draft Safety Evaluation on Equipment Qualification for Sequoyah, Units 1 and 2."
7.
TVA letter from R. Gridley to B. Youngblood dated December 19, 1986, "Sequoyah Nuclear Plant Units 1 and 2 - Draft Safety Evaluation Report (SER) on Environmental Qualification (EQ)."
8.
NRC letter from James M. Taylor to S. A. White dated January 16, 1987, regarding an equipment qualification inspection of Sequoyah Nuclear Plant Units 1 and 2 which was conducted by the Office of Inspection and Enforcement on December 8-12, 1986.
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ENCLOSURE 3 LIST OF COMMITMENTS CONTAINED IN ENCLOSURES 1 AND 2 1.
Resolution or completion of identified technical issues / fieldwork (listed in attachments A and B to enclosure 1) will be addressed within the Sequoyah EQ program requirements before restart of the affected unit.
2.
Remaining fieldwork associated with the first three confirmatory items from the draft SER on EQ for Sequoyah (listed in enclosure 2) will be completed in accordance with Sequoyah EQ program requirements before restart of affected unit.
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