ML20236K912
| ML20236K912 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 11/05/1987 |
| From: | Mark Miller Office of Nuclear Reactor Regulation |
| To: | James O'Reilly GEORGIA POWER CO. |
| References | |
| TAC-66461, NUDOCS 8711100022 | |
| Download: ML20236K912 (6) | |
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r Docket No.: 424 z5 NOV 1987
,1 Mr. James' P. O'Reilly
? i Senior Vice President _.-~ Nuclear Operations-W Georgia Power Company
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P.O.. Box 4545 -
Atlanta,-Georgia 30302'
Dear.Mr. O'Reilly:
Subject:
Residual. Heat Removal'(RHR) System Surveillance Testing.
g (TAC'66461)
L 1
At the. staff's request, Georgia Power; Company-(GPC) submitted information by letter dated October 27,!1987, to support its. proposal.to perform sur.-
veillance testing'of the RHR pumps and certain valves in the RHR system piping which would involve closure of selected RHR system-v'alves (valves 1HV-8716A and B and;IHV-8809A and B). The staff had infomed GPC.that-these valve mariipulations could notibe performed until the staff had re-viewed and approved the analysis indicating tha'; safety considerations
. continue to be met. The staff has completed its review of the October 27 submittal and concludes that the closure of valves 1HV-8716A:and B'in Mode' I and of valves 1HV-8809A and 8 in Mode 3 is--acceptable. The staff'further -
concludes that no Technical Specification changes are necessary to perform the surveillance.
The staff's' detailed evaluation is' enclosed.
While the technical basis presented in the October.27 letter is acceptable, we require GPC to include a discussion of'the analysis'in the'next Vogtle FSAR amendment and further that the proposed FSAR. changes be' submitted.to the staff within three weeks of'the date'of this letter so'tnat any questions-can be resolved before formal submittal of the next ;FSAR amendment.' '
s If there are any questions, I can be reached at (301)-492-7357'.
Sin ely,.
8711100022 871105 PDR ADOCK 0500 4
Mel e. A. Miller, Project Manager Project Directorate-11-3 Division of Reactor Projects I/II
Enclosure:
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Enclosure Evaluation of Residual Heat Removal System Surveillance Testing On January 6,1987, the staff issued Information Notice (IN) 87-01, "RHR Valve Misalignment Causes Degradation of ECCS.in PWRs," which discussed a potentially significant problem pertaining to residual heat removal (RHR) valve alignment in the low-pressure emergency core cooling system (ECCS).
Specifically, closure of the RHR crossover valves or of the pump discharge valves (valves 1HV-8716A and B and 1HV-8809A and B in the sinclified Vogtle flow diagram of Figure 1) could potentially incapacitate the i' R system by preventing injection into all four reactor coolant system (RC ' cold legs, i
l An enforcement conference was held with the licensee on October 21, 1987, in the Region II offices to discuss seven instances in which one of valves
-l 1HV-8716A and B and 1HV-8809A and B had been closed at Vogtle Unit 1 between February and August 1987.
In order to preclude closure of these valves in t
Mades 1, 2, and 3, the licensee had submitted revisions to the Unit 1 Inservice A
Testing (IST) program providing cold shutdown justification for closure of these valves.* However, at the enforcement conference, based on its additional review of closure of these RHR system valves, the licensee indicated its belief that closure of the valves was technically supported and the best surveillance techniques necessitated closure of valves 1HV-8716A and B in Mode 1 and of valves 1HV-8809A and B in Mode 3.
The staff infomed the licensee that it could not perfonn these valve manipulations until the staff had reviewed and approved the analysis indicating that safety considerations. continue to be met and thereby addressing the issue raised in IN 87-01.
Subsequently, the licensee submitted its technical-basis for closure of these s
g RHR velves by letter dated October 27, 1987. The staff's evaluation of the closure of each valve follows.
E Closure of Valve 1HV-8716A and B in Mode 1 u
In its October 27, 1987, letter, the licensee described two surveillance which would require closure of valves 1HV-8716A and B.
These valves are required to operate following a loss-of-coolant accident (LOCA) in order to allow initiation of hot leg recirculation, and therefore, stroke testing of these valves at power allows detection of any valve degradation.
For stroke i
testing, the valves would be individually closed for.approximately three minutes every 90 days.
In other respects, the configuration would be the same as that shown in Figure 1.
During surveillance, additional single failures are not required to be assumed. Therefore, flow would continue to be available from two RHR pumps into all four RCS cold legs..This configuration has no impact on the capability of the RHR system to perform its functicm.
N;ih
- IST Program, Revision 1, submitted by letter dated October 31, 4 986, provided the cold shutdown justification for valves 1HV-8809A and B.
IST Program, Revision 2 submitted by letter dated August 27, 1987, provided the cold shutdown justification for valves IHV-0716A and B, and was provided in re-sponse to IN 87-01. The staff approved Revision 1 in SSER 6 dated March 1987 and approved Revision 2 by letter dated September 22, 1987.
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Closure of valves lHV-8716A and B would also be required during Mode I for quarterly fiow testing of the RHR pumps.
During this test, the opposite RHR crosstie valve from the pumps being tested 1s-closed for less than two hours, and the flow path to the refueling water storage tank is opened. This con--
figuration allows essentially full flow testing of the pump (approximately-3000gpm). Again, being in the surveillance mode does not require assumption of an additional single failure. Therefore, should a LOCA occur, partial flow 1s available into two cold legs from the pump being tested, and full flow into t
the remaining two cold legs is available from the RHR pump not being tested.
Further, flow is available from the two intermediate head safety injection pumps and the two high head charging pumps, and the operator can take action to close the open crosstie valve in order to obtain full. flow into the RCS from the pump being. tested.
Even if assuming that during a LOCA one of the cold legs receiving flow from the RHR pump not being tested is spilling to the broken ' reactor coolant loop, the total ECCS flow without operator action to close the crosstie valve still exceeds minimum cooling requirements described e
in the Vogtle FSAR. The FSAR analysis assumes loss of one RHR pump, one 3'
intennediate head safety injection pump, and one high head charging pump.
The licensee has connitted to perform RHR pump testing at partial flow through the i
recirculation line (see Figure 1) if the redundant RHR pump or its associated s
components are inoperable.
On the basis that the period of closure of valves 1HV-8716A and B is short and that in both surveillance described above, minimum ECCS flow requirements would continue to be met, the staff concludes that closure of these volves during Mode 1 operation is acceptable.
The licensee has also committed to revise its IST program to reflect its intent regarding RHR pump testing and thereby withdraw its cold shutdown j
r" justification associated with valves-1HV-8716A and B.
The staff requires that the IST revision be submitted in a timely manner.
mg Closure of Valves 1HV-8809A and B in Mode 3 O
The licensee has proposed to close valves 1HV-8809A and B (one at a time) in a
Mode 3 in order to perfonn leak tests of the check ' valves downstream of valves 1HV-8809A and B on each of the RCS cold legs. The licensee described an analysis for a LOCA in Mode 3 with portions of the ECCS disabled in submittais dated December 9, 1985, and Jurse 13, 1986 The ECCS configuration in the analysis is more conservative than that during check valve leak testing with one 1HV-8809 valve closed. The analysis assumed that flow was available from only one RHR pump, one intennediate head saf-ty injection pump,.and one high head charging pump. The analysis also assun.ed that automatic safety injection actuation on low pressurizer pressure was blocked and that only automatic safety injection on containment high pressure was available.
In actuality, during check valve leak testing all ECCS pumps an~d accumulators Mbove 1000 psig) are available. Also, automatic safety injection actuation on pressure is available above approximately 1900 psig when the'. pressurizer low sperator unblocks this signal.
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i The December 9, 1985, and June 13, 1986, submittals were evaluated by the staff in its review of open item 19 (derived from confirmatory item 22), "LOCA j
mitigation in Modes 3 and 4."
In Section 6.3.5 of SSER 4 dated December 1986, the staff concluded that the Vogtle ECCS design is adequate for LOCA in Mode 3.
On the basis that the minimum ECCS flow require.nents would continue to be met should a LOCA occur in Mode 3 with one IHV-8809 valve. closed.. the staff con-l cludes that closure of valves 1HV-8809A and B during Mode 3 operation is acceptable.
The licensee has shown, and the staff agrees, that based on analysis closure l
of one of the valves in question would not render the RHR system inoperable.
Rather, the minimum ECCS flow requirement would continue to be met. Therefore, the licensee can perform the surveillance discussed above in accordance with
.i the current Technical Specification (TS) 3.5.2 without requirina any TS 1
modification. However, the licensee is required to include a 'liscussion of the supporting analysis for LOCA in Mode 3 in the next FSAR cmendment.
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'Mr.LJ. P.'0'Reilly' GeorgiaiPower Company-Vogtle Electric Generating. Plant:
CC:
Mr. L. T. Gucwa Resident Inspector Chief Nuclear Engineer Nuclear Regulatory Connission Georgia Power Company.
P. 0. Box 572.
30830 P.O. Box'4545'
. Waynesboro, Georgia :
Atlanta,. Georgia 30302 Mr. Ruble A. Thomas
.Deppish Kirkland, III, Counsel-Vice President - Licensing
' Office of -the Consumers' Utility Vogtle Project
. Council Georgia Power Company /
. Suite 225-Southern Company Services, Inc.
32 Peachtree Street. N.W.
P.O. Box ~2625
n' Paul D. Rice Troutman, Sanders, Lockerman, f?
'/4 a President & Project General-Manager -
& ~ Ash.nore i
Georgia Power Company -
Candler Building Post Office Box 299A, Route 2 127 Peachtree. Street,.N.E.
'g Waynesboro, Georgia 30830 Atlanta,' Georgia 30303-Danny Feig Mr. J. A. Bailey 1130 Alta Avenue Project Licensing Manager
. Atlanta c Georgia 30307
. Southern Ccapany Services -Inc.
P.O. Box 2625
. Carol Stangler.
1 Birmingham, Alabama 35202 Georgians Against Nuclear Energy 1
425 Euclid Terrace:
J h
Ernest L. Blake, Jr.
Atlanta, Georgia '30307 E
Bruce W. Churchill, Esq.
Shaw, Pittman, Potts and Trowbridge
{y 2300 N Street, N, W.
g Washington, D. C.
20037 b
Mr. G.Bockhold,'Jr.
i Vogtle Plant Manager Georgia Power Company 1
Route 2, Box 299-A Waynesboro,' Georgia 30830 Regional Administrator, Region II U.S. Nuclear Regulatory Connission
]j 101 Marietta Street, N.W., Suite 2900 e
Atlanta, Georgia 30323 3.
Mr. R. E. Conway l#f
' Senior Vice President and Project Director l
-y' I
Georgia Power Company Y:
Rt. 2 P. O. Box 299A 1
1 Waynesboro,' Georgia 30830 1
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