ML19345D274
| ML19345D274 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 11/21/1980 |
| From: | Ross W Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| TAC-43846, NUDOCS 8012120363 | |
| Download: ML19345D274 (5) | |
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NUCLEAR REGULATORY COMMISSION 3
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WASHINOTON, D. C. 20555
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LICENSEE: DUQUESNE LIGHT COMPANY Q
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i FACILITY : BEAVER VALLEY POWER STATION, UNIT N0. 1 StBJECT:
SUMMARY
OF MEETING WITH DUQUESNE LIGHT LW"'ANY RELATED TO OPERATION OF PRESSURIZER RELIEF AND SAFETY VALVES AT BEAVER VALLEY l On November 12, 1980, the staff met with representatives of Duquesne Light Company (the licensee) and Westinghouse to determine what regulatory action, if any, was required to assure safe operation of the relief and safety valves on *he pressurizer at Geaver Valley Unit 1.
The meeting had been requested by the staff to have the licensee fully describe the factors that led to draining water loop seals in front of these valves.
The staff desired to review the safety concerns of this action before the plant returned to power after the current lengthy refueling outage.
A list of participants is attached.
The current status of the pressurizer valves was summarized as follows.
With the plant in Startup (15% power and >350'F) the three Mason-Nieland PORVs and the three Target Rock safety vaTves are closed without water in i
the upstream loop seals. Because of excessive, yet small (<0.1 gpm),
leakage through the PORVs, two of these valves have been isolated by closure of the upstream block valves. The third PORV is leaking to the extent that the temperature in the tailpipe header for these valves is 230-250 F (s100 F higher than the temperature downstream of the safety val ves ). The licensee proposes to operate the plant under these condi-tions, or, if necessary, with all PORVs blocked during the entire Cycle 2.
Water seals were removed on the advice of the A/E for this plant (Stone and Webster) because of potential overstress conditions on the galves as the result of a two-phase water slug formed (from the 1.2 ft of water in the seal) if the valves are exercised during an overpressure transient.
Refined analyses are being made to determine if additional pipe supports are needed but will require several months for completion.
During the interim, the licensee considers the present course of action to meet ASME codes but operation with water seals to be preferable.
Modifications have been made on the loops to ensure continuous drainage back to the pressurizer. The licensee considers past experience (opening of PORVs during operation) has shown that water slugs from the PORVs do not cause unacceptable stresses.
Consequently, whenever the plant can be shutdown for approximately 10 days, the licensee proposes to restore the water seals in front of the three PORVs.
8 M 212 03(13 f
Meeting Summa ry for Beaver Vall ey 1 2-November 21, 1980 The licensee believes that the Target Rock safety valves will operate effectively without a water seal because:
(1) the valves have been modified to operate in a steam environment; (2) the valves were tested in a steam environment at the Wiley Labs and under the surveillance of the vendor; (3) the pressurizer system has a 10% " simmer" nargin; and (4) the plant has never had an overpressurization transient that approached the safety valves setpoint level.
The licensee prposes to operate with the following parameterc:
(a) all PORVs blocked if necessary (b) operating pressure - 2250 psig (c) PORV set paint - 2335 psig (d) High pressure reactor trip point - 2410 psig (e) Safety valve set point - 2500 + 1%
An analysis performed by Westinghouse indicates that the safety valves would be lifted (i.e., peak pressure would exceed 2500 psig) during an overpressure transient that included MSIV closure unless two PORVs are availa bl e.
Other transients would require at least one operable PORV to prevent the safety valves from opening.
At the conclusion of the meeting, the staff advised the licensee that an expedited review of the pertinent information would be made to reach a position on the licensee's proposed plan of operation.
The licensee committed to advise the staff by November 13, if it is possible to monitor leakage of steam through the pilot ~ valve of the safety valve - as a primary means of monitoring the integrity of these valves.
Vd k William J. Ross, Project Manager 1
Operating Reactors Branch #1 Division of Licensing
Attachment:
List of Attendees cc: w/a ttachment See next page i
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f Meeting Summary for Beaver Valley 1 November 21, 1980 Docket Files NRC PDR Local PDR NSIC TERA ORB 1 Reading NRR Reading H. Denton E. Case D. Eisenhut R. Purple T. Novak R. Tedesco G. Lainas G. Zech S. Varga T. Ippolito R. Clark R. Reid D. Crutchfield B. J. Youngblood A. Schwencer J. Miller J. Wetmore B. Grimes H. Collins F. Pagano EPDB, DL Project Manager OELD OSD (3)
S. Showe, I&E C. Parrish R. Fraley, ACRS (16)
Principal Staff Participants Licensee Short Service List
1 Meeting Summary for Beaver Valley 1
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November 21, 1980 cc: Gerald Charnoff, Esquire Mr. Janes A. Werling Jay E. Silberg, Esquire Plant Superintendent Shaw, Pittman, Potts and Trowbridge Beaver Valley Power Station 1800 M Street, N.W.
P. 0. Box 4 Washington, D. C.
20036 Shippingport, Pennsylvania 15077 Karin Carter, Esquire Mr. John A. Levin Special Assistant Attorney General Public Utility Commission 1
Bureau of Administrative Enforcement P. O. Box 3265 i
Sth Floor, Executive House Harrisburg, Pennsylvania 17120 Har~isburg, Pennsylvania 17120 M. J. D. Sieber, Superintendent Mr. Roger Tapan of Licensing and Compliance Stone and Webster Engineering Duquesne Light Coapany Corporation Post Office Box 4 P. O. Box 2325 Shipping; ort, Pennsylvania 15077 Boston, Massachusetts 02107 Irwi Popowsky, Esquire I
Mr. F. Noon Off e of Consumer Advocate i
R & D Center 1425 Strawberry Square Westinghouse Electric Corporation Harrisburg, Pennsylvania 17120 j
Building 7-303 Pittsburgh, Pennsylvania 15230 Mr. Charles E. Thomas, Esquire Thomas and Thomas 3
B. F. Jones Memorial Library 212 Locust Street 663 Franklin Avenue Box 999 Aliquippa, Pennsylvania 15001 Harrisburg, Pennsylvania 17108 Mr. John Carey, Director Resident Inspector Nuclear Operations U. S. Nuclear Regulatory Commission Duquesne Light Company Post Office Box 298 435 Sixth Avenue Shippingport, Pennsylvania 15077 Pittsbu rgh, Pennsyl vania 15219 Mr. R. E. Martin Duquesne Light Company j
435 Sixth Avenue Pittsburgh, Pennsylvania 15219 Marvin Fein Utility Counsel City of Pittsburgh i
313 City-County Building Pittsburgh, Pennsylvania 15219 i
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Attachment LIST OF ATTENDEES NRC DLC Westinghouse E. Blackwood J. Carey T. Adamas F. Cherny J. Sieber F. Chang E. Hemminger N. Tonet S. Chrenpolis W. Hodges E. Wooliver E. Murphy T. Nova k R. Steitler W. Ross J. Triggiant S. Varga Stone and Webster R. Bain l
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