ML18087A655
| ML18087A655 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 01/03/1983 |
| From: | Liden E Public Service Enterprise Group |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.D.1, TASK-TM NUDOCS 8302020351 | |
| Download: ML18087A655 (8) | |
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PS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Nuclear Department January 3, 1983 Director of Nuclear Reactor Regulation
- u. s. Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, Maryland 20014 Attention:
Mr. Steven A. Varga, Chief Operating Reactors Branch #1 Division of Licensing
Dear Mr. Varga:
NUREG 0737 ITEM II.D.l PLANT SPECIFIC REPORT ON PWR SAFETY AND RELIEF VALVE TEST PROGRAM UNITS 1 AND 2 SALEM GENERATING STATION DOCKET NOS. 50-272 AND 50-311 This letter, in its attachment, provides plant specific data for Salem Units 1 and 2 regarding safety and relief valve performance and the adequacy of associated piping and block valves.
Our plans for valve and piping modifications identified in our review and an implementation schedule are also included in the attachment.
Should you have any additional questions, we will be pleased to discuss them with you.
CC:
Mr. D. Fisher Very truly yours, u~
/A. Liden
/~~nager -
Nuclear Licensing and Regulation NRC Licensing Project Manager Mr. Leif Norrholm NRC Senior Resident Inspector 8302020351 830103 PDR ADOCK 05000272 P
PDR The Energy People 95-2168 (5M) 10-82
SALEM GENERATING STATION, UNITS l AND 2 PLANT SPECIFIC REPORT ON SAFETY AND RELIEF VALVE TEST PROGRAM 1.0 VALVE OPERABILITY:
1.1 Power Operated Relief Valves:
Salem PORV's are 2" NPS Copes Vulcan valves with 17-4PH plug and cage.
Three inch Copes Vulcan valves similar to the Salem valves (Ref. 3.1) were tested by EPRI in a test configuration similar to that of the configuration at the Salem Plant.
The fluid condition for the PORV's addressed in the Salem FSAR were identified by Westinghouse (Ref. 3.2) and were the basis for the fluid condi-tions for the test.
Salem cold overpressurization conditions were reviewed by PSE&G and were found to be enveloped by EPRI test conditions.
Tests conducted on the valve have confirmed that the valve opened and closed on demand and that the valve suffered no damage that would preclude future operation.
Specific information related to these tests is given in Section 4.7 of the Safety and Relief Valves Test Report (Ref. 3.4).
Although the tests indicated acceptable valve per-formance, test valve disassembly showed galling of the cage and plug guiding surfaces.
In view of this observation, PSE&G has changed the internals of Salem Unit 1 PORV's to 316 stellited plugs instead of 17-4PH.
The Salem valves with this combination of internals have shown no indication of leakage or galling.
Similar modifications on Unit 2 will be made during the first refueling outage currently scheduled to start in January, 198 3.
1.2 Safety Valves:
Salem safety valves are 6M6 Crosby valves which were tested by EPRI in a test configuration simi-lar to that of the actual pressurizer configura-tion at the Salem plant.
The fluid conditions for the tests enveloped fluid conditions identified by Westinghouse (Ref. 3.2).
The safety valves have been shown to open and close.
The functionability of the valves to pro-vide overpressure protection for the FSAR events have been found to be adequate (Ref. 3.5).
How-ever, depending upon the test conditions (steam -
transition - water), the valves were shown to flutter and/or chatter during loop seal dis-charge.
The observed instability of the safety valves during loop seal discharge has been evalu-ated and, based on Westinghouse and PSE&G assessments, it is not projected to be a safety concern.
Upstream piping and valve ring adjustments have been shown to have a substantial effect on valve performance.
Performance of the Salem safety valves during steam discharge conditions have been judged stable through the use of a valve dynamic model developed by Continuum Dynamics, Inc. (Ref.
3.8).
The model also predicted blowdown of less than ten percent which is considered acceptable.
Liquid discharge challenges to safety valves are predicted to occur significantly less frequently than a LOCA and the consequences of such liquid discharge are certainly much less severe; liquid discharge from the Salem safety valves has been shown to be an extremely unlikely event (Ref.
3.9).
Thus, the safety valve liquid discharge is an insignificant concern when compared with FSAR transient events and hence is considered not to be a significant factor in either plant safety or risk to the public.
1.3 Block Valves Salem block valves are 3" Velan valves with SMB-00-15 motor operators which were tested by EPRI at the Marshall Facility.
The Velan valve fully opened and closed on demand for each of the 21 test cycles (Ref. 3.6).
No operability concern has been identified.
2.0 PIPING ADEQUACY:
2.1 Inlet Piping During a portion of the tests performed on safety valves, it was noted that the pressure upstream of the valve tended to oscillate, especially for loop seal configurations.
These oscillations are thought to be related to valve instability which, in turn, is related to the valve and the inlet.
piping parameters.
The tests that exhibited pres-sure oscillations are summarized in Volume 10, Section 4, of the EPRI safety and Relief valve Test Report.
For the test configuration that most nearly approximates the Salem configuration, it was determined that a maximum peak transient pressure of 6300 psi was experienced.
We have performed an analysis of the expected behavior of the Salem 1 and 2 safety valve inlet piping assuming unstable valve behavior.
The analysis indicates that the peak transient pressure for Salem 2 will be less than the test value (6300 psi) whereas the expected peak transient pressure for Salem 1 will be below 7100 psi.
When compared with ASME Code allowables, it was determined that the pressure pulses are within acceptable limits.
(The maximum permissible pressure for the inlet piping is calculated to be 7130 psi by Westinghouse.)
Necessary inspection of the inlet piping subsequent to a safety valve discharge will be instituted to comply with the ASME requirement.
Hence, our review of inlet pressure oscillations indicates no safety concern.
2.2 Discharge Piping PSE&G has engaged EDS Nuclear, Inc. to evaluate the effects of rapid valve actuation of the safety and relief valves on the discharge piping.
The EDS evaluation thus far indicates loadings which may result in modifying some supports on the discharge piping along with insulating the loop seal.
Upon completion of the EDS evaluation and PSE&G efforts in analyzing Unit 2 discharge piping, determination of any required corrective actions will be made.
We plan to implement any necessary modifications during the fifth refueling outage on Unit 1 and the second refueling outage on Unit 2.
3.0 REFERENCES
3.1 Valve Selection/Justification Report 3.2 Test Condition Justification Report 3.3 Westinghouse Plant Condition Justification Report 3.4 Safety and Releif Valve Test Report 3.5 Review of Pressurizer Safety Valve Performance as Observed in the EPRI Safety and Relief Valve Test Program Westinghouse Report WCAP-10105 3.6 EPRI PWR Safety and Relief Valve Test Program -
PORV Block Valve Information Package 3.7 Application of RELAP 5/MOD 1 of Safety and Relief Valves Discharge Piping Hydrodynamic Loads 3.8 Valve Dynamic Model Performance Simulation for the Salem PWR Plant Unit 1.
Report No. 82-19 from Continuum Dynamics, Inc.
3.9 Report 1-231-01-052-00 from Science Applications, Inc., Draft Copy on Results of Probabilistic Evaluation of Liquid Discharge Challenges to Salem Units 1 & 2 Safety Valves.
-4~
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POWER OPERATED RELIEF VALVE INFORMATION:
(SALEM l AND 2)
- 1.
VALVE PARAMETERS Number of Valves Manufacturer Type Set Point Size 2/unit Copes-Vulcan Division Diaphragm Operated Relief Valve 2315 psig 2" Valve with 3" inlet and outlet BW connection Orifice 2" Rated Capacity (Steam) 210,000 lb/hr at 2335 psig Design Pressure and Temp.:
2485. psig and 680°F Valve 1500 #ASA
- 2.
INLET PIPING PARAMETERS:
Type Loop Seal SAFETY VALVE INFORMATION:
(SALEM 1 AND 2)
- 1.
VALVE PARAMETERS Number of Valves 3/unit Manufacturer Crosby Valve and Gage Co.
Type Crosby HB-BP-86 6M6 Safety Valve (Loop Seal Internals)
Set Point 2485 psig Size 6" Inlet x 6" Outlet Orifice Size = 2.154 (3.644 in2)
Rated Capacity (Steam) 420,000 lb/hr each Design Pressure and Temp.:
2485 psig and 680°F Inlet Flange Rating 1500 #ASA Discharge Flange Ratinci 600 #ASA
- 2.
INLET PIPING PARAMETERS:
Diameter Length Type Loop 3 Loop 4 Loop 5 6 11 Sch 160 Unit 1 14.553' 12.873' 12.309' Loop Seal Unit 2 12.054' 12.241'
- 11. 719'
BLOCK VALVE INFORMATION:
(SALEM 1 AND 2)
Number of Valves 2/unit Valve Manufacturer Velan Engineering Co.
Operator Manufacturer Limitorque Type 3" Motor Operated Gate Valve 3GM58FN with BW ends and SMB-00-15 motor operator Valve Rating 1500 #ASA