ML20035A253
| ML20035A253 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 03/16/1993 |
| From: | Engle L Office of Nuclear Reactor Regulation |
| To: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| REF-GTECI-070, REF-GTECI-094, REF-GTECI-NI, TASK-070, TASK-094, TASK-70, TASK-94, TASK-OR GL-90-06, GL-90-6, TAC-M77363, TAC-M77364, TAC-M77433, TAC-M77434, NUDOCS 9303250055 | |
| Download: ML20035A253 (5) | |
Text
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WASHINGTON, D.C. 20 % 5 4001 March 16,1993 Docket Nos. 50-338 and 50-339 Mr. W. L. Stewart Senior Vice President - Nuclear Virginia Electric and Power Company 5000 Dominion Blvd.
Glen Allen, Virginia 23060
Dear Mr. Stewart:
SUBJECT:
NORTH ANNA UNITS 1 AND 2 - STAFF REVIEW 0F GENERIC LETTER 90-06,
" RESOLUTION OF GENERIC ISSUE 70, ' POWER-OPERATED RELIEF VALVE AND BLOCK VALVE RELIABILITY,' AND GENERIC ISSUE 94, ' ADDITIONAL LOW-TEMPERATURE OVERPRESSURE PROTECTION FOR LIGHT-WATER REACTORS,'
PURSUANT T010 CFR 50.54(f)" (TAC NOS. M77363, M77433 AND M77364, M77434)
By letter dated December 21, 1990, you responded to Generic Letter 90-06. The generic letter represented the technical resolution of two generic issues and included plant backfits which were cost-justified safety enhancements.
Generic Issue 70 included upgrades in quality requirements, inservice testing (IST) requirements, and modified Technical Specifications for all pressurized water reactor facilities that incorporate power-operated relief valves (PORVs) and block valves in their design. The intended purpose was to enhance the overall reliability of the PORVs and block valves so that they could better perform the safety functions identified in the generic letter. Generic Issue 94 included modified Technical Specifications for all Westinghouse and Combustion Engineering facilities to reduce the allowed outage time for an inoperable low temperature overpressure (LTOP) channel and thus reduce the probability of overpressurization events during shutdown conditions.
We have reviewed your submittal and find that you have not provided an acceptable response. At the time of your submittal, the North Anna facility was to be the lead Westinghouse plant to adopt the MERITS Technical Specifications.
Your submittal stated that technical specification changes would not be proposed because the MERITS Technical Specifications met the intent of the generic letter. However, we understand that the North Anna facility is no longer pursuing the MERITS Technical Specifications.
j It is our position that a regulatory analysis has been performed in accordance with 10 CFR 50.109(a)(3) and 50.109(c) which justifies the backfit.
j Therefore, absent any information that demonstrates that your facility is not i
s bounded by the regulatory analysis that accompanied the generir letter, you
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are requested to resubmit a response that is in keeping with the intent of the
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generic letter. The specific areas of concern are as follows.
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Mr. W. L. Stewart.
Our position requires that valves in PORY control air systems be included within the scope of a program covered by Subsection IWV, " Inservice Testing of Valves in Nuclear Power Plants," of Section XI of the ASME Boiler and Pressure Vessel Code.
Your submittal did not adequately meet this position. We are not accepting the position that successful completion of the PORV stroke test indirectly verifies operability of the control air valves.
Most plant configurations which have air-operated PORVs include both a normal (non-safety) air supply and a safety backup (either air or nitrogen accumulator) supply. The intent of this testing is to assure the capability of the safety backup supply.
In addition, the air check valves which isolate the safety backup accumulator supply in the event of loss of normal air supply should also be tested. A consideration regarding control air valves is found in Generic Letter 89-04 which was issued to provide guidance on IST. Because some components, such as these control air system valves, may not be classified as ASME Class I, 2 or 3 components, they may not be included in the ASME Code IST programs. This is addressed in Attachment I of GL 89-04, Item t
No. II.
In accordance with this guidance, it is an acceptable alternative to test these non-code class components as required in plant test procedures, outside the IST program. Therefore, commitments to this effect are acceptable.
In order to assure the capability of the safety backup (either air or nitrogen accumulator) supply to adequately operate the PORVs, the normal (non-safety) air supply should either be isolated during PORV stroke testing, or the valves in the safety backup supply, including the check valves which isolate the safety backup and normal supplies, should be individually testad to assure their capability.
If these components are not tested in the IST program, they should be periodically tested and verified according to other specific plant testing procedures.
In your response discuss host you intend to verify the capability of the valves in the safety backup supply.
Our position for the resolution of Generic Issue 70 required Technical Specification upgrades as presented in the generic letter. Our review of your submittal indicates that you have yet to respond to our position. We will not accept, without sufficient justification, the position that the Technical Specification upgrades are unnecessary because the PORVs are not the primary means of dealing with the three safety functions identified in the generic letter.
As discussed in NUREG-1316, most of the safety enhancement for the proposed backfit is derived from the increase in feed-and-bleed capability. Therefore, for those facilities that can accomplish the three safety functions identified in the generic letter without relying on PORVs for the feed-and-bleed function, the allowed outage time (A0T) for an inoperable PORV (for reasons other than excessive leakage) may be increased from the recommended 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days.
In addition, for those f acilities that have three safety-related PORVs and can accomplish the three safety functions and feed-and-bleed with only two, the A0T for one inoperable PORV may be increased to 7 days while the A0T for two inoperable PORVs remains at 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Mr. W. L. Stecart March 16, 1993 The staff positi
' r the resolution of Generic Issue 94 included the Technical Specif
>n upgrades as presented in the generic letter.
The staff review determu.ed that you have not responded to our position. We will not accept, without significant technical justification, statements that the maximum A0T will not support flexible plant operations.
In addition, the staff will not accept PRA-based arguments to expand A0Ts.
Only differences in plant hardware relative to that assumed in our cost / benefit analysis will be co: sidered.
It is our position that in view of the recently completed regulatory analysis supporting the proposed outage times, and the uncertainties inherent in PRA analyses, that consideration of PRA-based arguments (which is tantamount to re-opening the issue) is not warranted.
The intent of the resolution of Generic Issue 94 was to decrease the probability of cold overpressurization while in a water-solid condition by increasing the availability of the LTOP system.
Generic Issue 94 did not apply to Babcock & Wilcox (B&W) facilities because they maintain a nitrogen bubble in the pressurizer and do not operate in a water-solid condition.
Similarly, we would be receptive to extending the recommended 24-hour A0T with an inoperable LTOP channel to 7 days provided the plant is not water-solid.
For such cases, you must identify a pressurizer level which provides a level of protection against cold overpressurization comoarable to t'
t provided by the nitrogen bubble in B&W facilities.
Therefore, based on the additional guidance provided above, you are requested to resubmit your response to the generic letter.
You are requested to respond within ti0 days following receipt cf this letter.
If you would like to further discuss these issues prior to your resubmittal, please feel free to contact me.
The information requested by this letter is within the scope of the overall burden estimated in Generic Letter 90-06 for the resolution of Generic Issue 70 and Generic Issue 94, which was a maximum of 320 person-hours per licensee response. This request is covered by Office of Management and Budget Clearance Number 3150-0011, which expires May 31, 1994.
Sincerely, (Original Signed Ey)
Leon B. Engle, Project Manager Project Directorate 11-2 Division of Reactor Projects - 1/II Office of Nuclear Reactor Regulation cc:
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OFFICIAL RECORD COPY FILENAME: NA9006.LTR
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i tir. W. L. Stewart North Anna Power Station Virginia Electric & Power Company Units 1 and 2 cc:
Mr. William C. Porter, Jr.
Robert B. Strobe, M.D., M.P.H.
County Administrator State Health Commissioner Louisa County Office of the Commissioner P.O. Box 160 Virginia Department of Health Louisa, Virginia 23093 P.O. Box 2448 Richmond, Virginia 23218 Michael W. Haupin, Esq.
Hunton and Williams Regional Administrator, Rll P.O. Box 1535 U.S. Nuclear Regulatory Commission Richmond, Virginia 23212 101 Marietta Street, N.W., Suite 2900 Atlanta, Georgia 30323 Dr. W. T. Lough Virginia State Corporation Commission Mr. G. E. Kane, Manager Division of Energy Regulation North Anna Power Station P.O. Box 1197 P.O. Box 402 Richmond, Virginia 23209 Mineral, Virginia 23117 Old Dominion Electric Cooperative 4201 Dominion Blvd.
Glen Allen, Virginia 23060 Mr. M. L. Bowling, Manager Nuclear Licensing & Programs Virginia Electric and Power Company l
Innsbrook Technical Center 5000 Dominion Blvd.
Glen Allen, Virginia 23060 Office of the Attorney General Supreme Court Building 101 North 8th Street Richmond, Virginia 23219 Senior Resident Inspector North Anna Power Station U.S. Nuclear Regulatory Commission Route 2, Box 78 Mineral, Virginia 231172 l
-b DISTRIBUTION FOR GL 90-06 LETTER FOR NORTH ANNA Docket File.
NRC and Local PDRs i
PDII-2 RF S. Varga G. Lainas H. Berkow L. Engle E. Tana OGC ACRS (10)
D. Pickett, 13/H/15 M. Sinkule, RII i
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