ML18093A551
| ML18093A551 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 12/24/1987 |
| From: | Corbin McNeil Public Service Enterprise Group |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NLR-N87231, NUDOCS 8801040511 | |
| Download: ML18093A551 (6) | |
Text
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Public Service Electric and Gas Company Corbin A. McNeil!, Jr.
Senior Vice President -
Nuclear Public Service Electric and Gas Company P.O. Box236, Han cocks Bridge, NJ 08038 609 339-4800 December 24, 1987 NLR-N87231 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:
ATWS MITIGATION SYSTEM ACTUATION CIRCUITRY SALEM GENERATING STATION DOCKET NOS. 50-272/50-311 Public Service Electric and Gas Company (PSE&G) submitted the plant specific information related to the Salem ATWS Mitigation System Actuation Circuitry (AMSAC) via PSE&G letter NLR-N87136, dated July 31, 1987.
Following that submittal, PSE&G personnel were contacted by Mr. R. Stevens of NRC/NRR on November 9, 1987, for additional information related to the AMSAC submittal.
As a result of that conversation, additional information is being provided to support review of our submittal.
Attached is a listing of NRC questions with the PSE&G response to each question.
Spould you have any further questions, please feel free to contact us.
Sincerely, Attachment
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PDR ADOCK 05000272 P
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Document Control Desk 2
C Mr. D. c. Fischer USNRC Licensing Project Manager Mr. T. J. Kenny USNRC Senior Resident Inspector Mr. w. T. Russell, Administrator USNRC Region I Mr. D. M. Scott, Chief Bureau of Nuclear Engineering Department of Environmental Protection 380 Scotch Road Trenton, NJ 08628 12-24-87
ATTACHMENT NRC QUESTION/PSE&G RESPONSE QUESTION 1:
Provide the make and model number of AMSAC output side isolation devices.
Include information on how these devices meet the NRC criteria for isolation devices as provided in Appendix A to the NRC AMSAC SER.
RESPONSE
The electrical isolation devices provided as part of the Westinghouse AMSAC system are Struthers-Dunn model 219DX181NE relays used along with model CX4039NE sockets.
These relays and sockets provide isolation of the non-class lE AMSAC circuits from class lE actuation circuits in the plant.
The CX4039NE socket provides for separation of the relay coil and contact wiring via metal barriers.
The use of this socket, metal barriers, conduit and distance ensure separation of non-class lE wiring, train A wiring and train B wiring groups within the AMSAC cabinet.
To demonstrate that the Struthers-Dunn isolation relay will not propagate a fault from the non-safety related to safety related circuits, fault tests on the isolators have been carried out.
The summary of the test results on Struther-Dunn relays is provided in Table 1.
QUESTION 2:
Provide a statement of recommended test frequencies for AMSAC circuitry and, if possible, a reference to test procedures.
RESPONSE
Westinghouse has recommended that AMSAC is tested every three months in the bypass mode with the plant on-line.
Testing of the AMSAC outputs to the final actuation devices may be performed with the plant shutdown every refueling outage.
PSE&G surveillance procedure (in preparation) IC-18.1.014 titled "AMSAC Functional Test" will implement the Westinghouse recommendations.
QUESTION 3:
Provide a discussion on the C-20 timer setpoint discrepancy between PSE&G's submittal and Revision 1 to WCAP 10858, "AMSAC Generic Design Package."
Is the timer setpoint generic or plant specific?
RESPONSE
For the Salem AMSAC low steam generator level logic, the time delay on de-energizing the C-20 permissive is set at 260 seconds.
This is based on the results of the analyses performed for Revision 1 of WCAP-10858P-A.
The longer time delay on de-energizing will ensure that the AMSAC actuation logic can be satisfied for a sufficient period of time for intermediate power ATWS events.
The 260 seconds value differs from the value on page 3-2 of WCAP-10858P-A Revision 1.
This latter value is a
conservative generic value which falls within the range of 180 to 420 seconds shown in Figures 1-1, 1-2, and 1-3 of WCAP-10858.
The Salem specific value (260 seconds) was compared to the results of a generic study for Model 51 steam generators.
The study examined the minimum expected steam generator inventory reduction rates for intermediate power level ATWS events.
The minimum rates were used to determine time required to maintain the C-20 permissive.
The Salem specific value falls within the acceptable range (180-420 seconds) and is conservative in relation to the analysis performed by Westinghouse for the steam generator (Model 51) level to drop.
TABLE l ISOLATION TEST
SUMMARY
A series of tests have been completed at the Westinghouse Instrumentation Technology and Training Center to determine the isolation capability of the Struthers-Dunn Type 219 plug-in relay.
This relay is used in the output of the ATWS Mitigation Systems Actuation Circuitry (AMSAC) for isolating the non-Class lE AMBAC circuits (relay coil) from the Class lE final actuation circuits (relay contacts).
Three type 219 relays with four single-breaker double-throw (4PDT) contacts, built to Westinghouse Design Specification 405Al0 were taken from stock for this series of tests.
Testing was done between 11/10/87 and 11/25/87.
TEST 1 0
0 0
TEST 2 0
0 TEST 3 0
0 TEST 4 0
0 0
TEST 5 0
0 Hypot using 1500 VAC across open contacts (wired in series) to coil.
Hypot tester was factory set to alarm when leakage current exceeded 1 mA.
No alarm on any relay.
Meggered, using 600 VDC, from coil to frame, each contact to frame, each contact to coil and each contact to contact.
Lowest resistance -
30,000 M ohm, contact to contact.
582 VAC across open contacts (wired in series) to coil.
Lowest leakage impedance -
47.5 M ohm.
582 VAC across open contacts (wired in series) to frame.
Lowest leakage impedance -
42.5 M ohm.
Greatest induced coil voltage -
0.29 mV.
582 VAC across sets of open contacts Lowest leakage impedance -
70.8 M ohm.
TEST 6 0
0 0
TEST 7 0
0 RELAY #
1 2
3 0
0 582 VAC across open contacts wire in parallel.
Lowest leakage impedance -
26.0 M ohm.
Highest induced coil voltage -
2.0 mV.
590 VAC across the coil.
Results TIME FOR COIL TO OPEN (SEC) 19.45 19.92 20.40 INDUCED CONTACT DIGITAL MULTIMETER (VOLTS)
NOT OBSERVED 0.618 1.40 VOLTAGE RECORDER TRACE (VOLTS) 0.731 0.774 1.032 All the by products resulting from the coil burning open contained within the clear polycarbonate relay cover.
The cover was warm to the touch immediately after the coil burned open.
Testing results greatly exceeded the acceptance criterion of greater than one megohm of leakage path resistance and for leakage current less than one milliampere.
The criterion is stated in EIA Standard RS-407A (July 1978) "Testing Procedures for Relays for Electrical and Electronic Equipment."
Complete test results will be available in the near future.