ML18139B574
| ML18139B574 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 10/08/1981 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Leasburg R VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| Shared Package | |
| ML18139B575 | List: |
| References | |
| REF-GTECI-B-24, REF-GTECI-IS, TASK-2.E.4.2, TASK-B-24, TASK-OR, TASK-TM NUDOCS 8110280634 | |
| Download: ML18139B574 (6) | |
Text
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Docket Nos. 50-280 and 50-281 Mr. R.H. Leasburg OC1 Vice President-Nu'clear Operations Virginia Electric and Power Company Post Office Box 26666 Richmond, Virginia 23261 Deai Mr. Leasburg:
DISTRIBUTION Dockets NRC PDR L PDR TERA NSIC ORB#l Rdg DEisenhut OELD IE-3 ACRS-10 SVarga DNeighbors CParrish EReeves Gray File
SUBJECT:
STATUS OF GENERIC ITEM B-24 AND COMPLETION OF TM! ACTION ITEM II.E.4.2.5 In our letter of November 2B, 1978, we *identified the generic concerns of purging and venting of containments to all operating reactor licensees and requested your response to these concerns. Our review of your response was interrupted by the TMI accident and its demands on staff resources. Conse-quently, as you know, an Interim Position 011 containment purging and venting was transmitted to ycu on October 23, 1979.
You were requested to implement short-term corrective actions to remain in effect pending completion of our longer-term reviei1 of your response to our November 28~ 1978 letter.
Over the past several months we and our contractors have been reviewing tile responses to.our November 1978 letter to close out our long-tenn review *of this rather complex issue. The components of this reviet1 are as follows:
- 1.
Conformance to Standard Review Plan Section 6.2.4 Revision 1 and Branch Technical Position CSB 6-4 Revision 1.
These documents were provided as enclosures to our November 1978 letter.
Valve Operability We requested a program demonstrating operability of the valves in accordance with our 11Guidelines for Demonstrative Operability of Purge and Vent Valves." These Guidelines *were sent to you in our letter of September 27, 1979. There is an acceptable alternative ~*Jhich you may wish to consider in lieu of completing the valve qualifica.-
tion program for the large butterfly-type valves. This would be the installation of a fully-qualified mini-purge system with valves 8-inches or smaller to hyj:>ass the larger valves.
Such a system change might prove more timely and more cost-effective.
The system would meet BTP CSB 6-4 item B.l.c.
\\
OFFICE
- SURNAME~,........................
DATE. \\,:....................
~.'.,NRG FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
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Mr. R. 3.
Safety Actuation Signal Override This involves the review of safety actuation signal circuits to ensure that overriding of one safety actuation signal does not also cause the b§!pass of any other safety actuation signal.
- 4. ~tainment [eakage Due to Seal Deterioration Position B.4 nf the BTP CSB 6-4 requires that provisions be made to test the availability of the isoa:ation function and the leakage rate of the isolation valves in the vent and purge lines, individually, during reactor operations. But CSB 6-4 does not explain when or how these tests are to be performed. is an amplification of Position B.4 concerning these tests.
T.be status of our long-term review of the above items for the Surry 1 and 2 facilities is as follows:
- l. Conformance to Standard Review Filan Section 6.2.4 RevisH>nnl and Branch Technical Position CSB 6-4 Rev*i si.on 1.
He have completed our review of this item and our Safety Evaluation is provided as Enclosure 2.
We have concluded that maintaining the 42-inch purge valves and the 8-inch valves on the steam ejector lines closed above the cold shutdown and refueling modes wil1 pre-clude the release of radioactivity should a LOCA occur.
You shbuld proposed a change to the Technical Specifications to maintain these valves sealed or locked closed unless you intend to qualify these valves for operation.
We request that you respond within 45 days of receipt of this letter.
- 2.
Valve Onerabili~y Either provide Technical Specifications or provide a qualification report as stated in paragraph l.
- 3.
Safety Actuation Signal Override This item is still under review.
We recently visited the Surry facilities and will issue our Safety Evaluation Report on this issue by separate correspondence in the near future~ Our revt.ew team which visited Surry felt that the cooperation of the plant staff was of great value in resolving this issue expeditiously.
OFFICE'........................
SURNAME&,........................
DATE~........................................................................................................................................................................
NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
Mr. R. 4. Containment Leakage Oue to Seal Deterioration addresses the requirements for this item.
We request that you propose a Technical Specification change incorporating the test requirements together with the details of your proposed test program within 45 days of receipt of this letter.
- 5. Containment Pressure Setpoint for Containment Isolation He have completed the review and our Safety Evaluation Report is Enclosure 3. This item is complete.
In closing, you may have noted the similarity of this long-term generic issue with Item Il.E.4.2 of NUREG-0737, TMI Action Plan. Except for Posi-tions 6 & 7 of Item II.E.4.2, the review of the remaining outstanding positions of Item II.E *.t1.2 will be co.'T!pleted by this purge and vent review.
Our schedule of the purge and vent review agrees with the schedule.for Item II.E.4.2.
Please contact your NRC Project Manager should you have any questions.
Enclosures:
As stated cc w/enclosures:
See next page Sincerely,
.Original signed by;
-, o:-'1 Steven A. Varga, Chief Operating Reactors Branch #1 Division of Licensing OFFICE~ *** 9.R~Jl *.1........ QB.~.~~Jt...... ~
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SURNAME~... o~. ghtlur.::i.... E~v.rs::-.......v DATE* *** lQL.. L.?.J.........J.Q/..i.'L.aJ....... J...... tu....................................................
--- NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
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l Mr. R. H. Leasburg Vfrgi ni a Electric and Power Company cc:
Mr. Michael W. Maupin Hunton and Williams Post Office Box 1535 Richmond, Virginia 23213 Mr. J. L. Wilson, Manager P. 0. Box 315 Surry, Virginia 23883 S\\'Jem Library College of Hilliam and Mary Williamsburg, Virginia 23185 Donald J. Burke, Resident Inspector Surry Power Sta ti on U. S. Nuclear Regulatory Co~mission Post Office Box 166 Route 1 Surry, Vi rgi ni a 23883 Mr. J. H. Fergus.on Executive Vice President - Power Vi rgi ni a Electr'i c and Power Company *
. Post Offic~ Box 26666 Richmond, Virginia 23261 e
e PURGE/VENT VALVE LEAKAGE TESTS The long tenn resolution of Generic Issue B-24, "Containment Purging During Nonnal Plant Operation," includes, in part, the implementation of Item B.4 of Branch Technical Position (BTP) CSB 6-4.
Item B.4 specifies that provisions should be made for leakage rate testing of the (purge/vent system) isolation valves, individually, during reactor operation. Although Item B.4 does not address the testing frequency, Appendix J to 10 CFR Part 50 specifies a maximum test interval of 2 years.
As a result of the numerous reports on unsatisfactory performance of the resilient seats for the isolation valves in containment purge and vent lines (addressed in OIE Circular 77-11, dated September 6, 1977), Generic Issue B-20, "Containment Leakage Due to Seal Deterioration, 11 was established to evaluate the matter and establish an appropriate testing frequency for the isolation valves. Excessive leakage past the resilient seats of isolation valves in purge/vent lines is typically caused by severe environmental con-ditions and/or wear due to frequent use.
Consequently, the leakage test frequency for these valves should be keyed to the occurrence of severe environ-mental conditions and the use of the valves, rather than the current require-ments of 10 CFR 50, Appendix J.
It is recommended that the following provision be added to the Technical Specifications for the leak testing of purge/vent line isolation valves:*
"Leakage integrity tests shal 1 be performed on the containment isolation valves with resilient material seals in (a) active purge/vent systems (i.e., those which may be operated during plant operating Modes 1 through 4) at least once every three months and (b) passive purge systems (i.e., those which must be administratively controlled closed during reactor operating Modes 1 through 4) at least once every six months."
By way of clarification, the above proposed surveillance specification is predicated on our expectation that a plant would have a need to go to cold shutdown several times a year.
To cover the possibility that this may not occur, a maximum test interval of 6 months is specified. However, it is not our intent to require a plant to shutdown just to conduct the valve leakage integrity tests. If licensees anticipate long duration power oper-ations with infrequent shutdown, then installation of a leak test connection that is accessible from outside containment may be appropriate. This will pennit simultaneous testing of the redundant valves. It will not be possible to satisfy explicitly the guidance of Item B.4 of BTP CSB 6-4 (which states that valves should be tes.ted individually), but at least some testing of the valves during reactor operation wil 1 be possible.
e e It is intended that the above proposed surveillance specification be applied to the active purge/vent lines, as well as passive purge lines: i.e., the purge lines that are administratively controlled closed during reactor oper-ating modes 1-4. The reason for including the passive purge lines is that B-20 is concerned wtih the potential adverse effect of seasonal weather con-ditions on the integrity of the isolation valves. Consequently, passive purge lines must also be included in the surveillance program.
The purpose of the leakage integrity tests of the isolation valves in the containment purge and vent lines is to identify excessive degradation of the resilient seats for these valves. Therefore, they need not be conducted with the precision required for the Type C isolation valve tests in 10 CFR Part 50, Appendix J. These tests would be perfonned in addition to the quantitative Type C tests required by Appendix J and would not relieve the licensee of the responsibility to confonn to the requirements of Appendix J.
In view of the wide variety of valve types and seating materials, the acceptance criteria for such tests should be developed on a plant-specific basis.