ML20057B358
| ML20057B358 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 09/17/1993 |
| From: | Levis W CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BSEP-0155, BSEP-155, NUDOCS 9309210235 | |
| Download: ML20057B358 (5) | |
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@P&L gewmemmmmmmangg:ggg Carolina Power & Light Company naumsmmmaremmarman SEP 171993 SERIAL: BSEP 93-0155 United States Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 i
DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. OPR-71 & DPR-62 SUPPLEMENTAL INFORMATION REGARDING 2X LOCA LOGIC TESTING i
Gentlemen:
The purpose of this letter is to provide the NRC staff with supplementalinformation regarding the testing of the 2X LOCA logic in the jet assist feature of the emergency diesel generators at Carolina Power & Light Company's (CP&L) Brunswick Steam Electric Plant, Units 1 and 2.
On March 16,1993, CP&L provided the NRC statf with a position with respect to the safety basis of the 2X LOCA logic and the associated testing to be performed on this logic.
On August 26,1993, CP&L agreed to supplement the March 16,1993 letter to address the NRC staff questions regarding the proposed testing. Enclosure 1 cf this letter provides the CP&L response to the NRC questions.
Please refer any questions regarding this subrnitial to Mr. M. A. Turkal at (919) 546-3066.
Yours very truly, W. Levis Manager Regulatory Affairs Section MAT / mat (bnp930155.002)
Enclosure cc:
Mr. S. D. Ebneter Mr. P. D. Milano Mr. R. L. Prevatte J
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j ENCLOSURE 1 a
BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 NRC DOCKET NOS. 50-325 & 50-324 l
OPERATING LICENSE NOS. DPR-71 & DPR-62 SUPPL.EMENTAL NFORMATION REGARDING 2.X LOCA LOGIC TESTING l
1 NRC ITEM 1:
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Provide the 2X LOCA logic test methodology and purpose.
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,QPSL RESPONSE:
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The purpose of testing the "2X LOCA" logic is to ensure the applicable portion of the Emergency Diesel Generator (EDG) control logic will perform in the event a true LOCA l
were to occur on cae unit simultaneously with a spurious (false) LOCA on the second unit, j
The "2X LOCA" logic test consists of four parts which collectively ensure that a detailed, i=
comprehensive test is performed. The " parts" include: 1) a functional test of the logic downstream of the 2X LOCA initiation contacts,2) a point to point continuity check of the i
circuit not verified by the functional test,3) a verification of the various breaker position l
l contacts (52S), and 4) a verification of the 2X LOCA initiation contacts which are not l
l tested as part of the functional test.
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F Plant procedures were developed, or revised, to provide the guidance needed to ensure the log was adequately tested. OSPP LOG-006 was developed to perform the logic i
functional test, the point to point continui" est, and the 52S breaker contact verification.
Maintenance surveillance tests 1-MST-DG11R,1-MST-DG12R, 2-MST-DG13R, and 2 MST-DG14H for EDGs 1,2,3, and 4 respectively were revised to provide verification of the 2X LOCA contact (s) operability.
i MLQ lTEM 2:
i Provide the test frequency for the proposed 2X LOCA logic testing.
t CP&L RESPONSE:
The 2X LOCA logic testing will be completed on a 54-month testing cycle. The 54-month testing cycle was established based on in already existing.18-month preventive i
maintenance schedule for individual rt: o e imponents and the results of the logic j
functional and poie.' tu point continun g et eformed on EDGs 1 and 2.
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9 N_RC ITEM 3:
Descnbe the extent of testing which will be performed prior to startup of Unit 1.
_CP&L RESPONSE:
The following table details both the completed testing and the schedule for future testing for each of the EDGs.
TESTS EDG 1 EDG 2 EDG 3 EDG 4 Logic Functional Test Complete Complete Note 2 Note 2 Point to Point Complete Complete Note 2 Note 2 Continuity Test Breaker Position Note 1 Note i Note 1 Note 1 Contact Verification 2X LOCA initiation Note 1 Note 1 Note 1 Note 1 Contact Verification Note 1: Scheduled to be performed prior to Unit 1 startup.
Note 2: Scheduled to be performed prior to startup from the Unit 21994 spring outage.
In summary, the 2X LOCA tests will be completed for EDG 1 and EDG 2 prior to Unit 1 startup. Verification of breaker position contacts (52S) associated with the 2X LOCA logic-ar.
~ it 1 startup. The logic functional test and point to point continuity test for EDu.
c, EDG 4 will be completed during the spring 1994 Unit 2 outage.
NRC ITEM 4:
Provide the results of all testing to date.
CP&L RESPONSE:
During the initial performance of OSPP-LOG 006 on July 15,1993 the JATR-X relay f ailed on EDG 1. An investigation identified the problem to be circuit current drawn by the parallel conected Jet Assist Solenoid Valves (rated at 65 watts each). The current rating exceeded the 1 amp rating of the JATR-X relay contacts resulting in contact failure. The 65 watt solenoid valves weru replaced by 35 watt solenoid valves and the testing was successfully completed. ACR 93-238 was initiated to investigate the problem associated-l with the r ;nent rating of the relay contacts.
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After the f ailure on EDG 1, the solenoid valves on the remaining EDGs (2, 3, and 4) were inspected and confirmed to have a 65 watt and a 35 watt solenoid valve combination.
The originalinstallation of the jet assist junction used 65 watt solenoid valves. In October 1991, EER 91-0341 was written to allow replacement of the 65 watt solenoid valves with 35 watt solenoid valves. This was a design enhancement since the lower wattage solenoid valves generate less heat and provide a potential for longer coil life. This accounts for the 35/65 watt solenoid valve combination found in EDGs 2,3, and 4. A successful "as found" functional test with the 35/65 watt combination was performed on EDG 2.
t Based on the positive results of the "as found" test on EDG 2, functional testing of EDG 3 and EDG 4 will be scheduled for the 1994 spring Unit 2 outage.
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i NRC ITEM 5:
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i Provide further explanation of Brunswick's position regarding the safety function of the 2X LOPA logic. Explain how the jet-assist feature will be maintained with respect to the safety significance of the feature.
6 CP&L POSITION:
The March 16,1993 CP&L letter stated that the 2X LOCA jet assist function was not l
considered safety-related. The basis for this determination is that the event for which this function is needed is a severe accident scenario similar to the Station Black-Out (SBO) event. The 2X LOCA jet assist components do not perform an active function for coping with the design basis scenario (an accident on one unit, a safe shutdown of the other unit,
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loss of of fsite power, and a single failure). This position is consistent with that described in Draf t 9 of ANS-58.14, " Safety and Pressure Integrity Classification Criteria for Light Water Reactors," which was reviewed by the NRC. Comments on ANS-58.14 were resolved and the standard is with ANSI for approval, s
This determination establishes that the components needed to support the 2X LOCA jet assist feature do not perform active safety-related functions. However, the functions are needed to maintain circuit continuity in the diesel generator control logic. As such, the JATR-X, JATR-1, and JATR-2 relays and their contacts are classified as passive -
safety-related, i
The remaining contacts in the circuit (LOCA initiation relay contacts and pump start contacts) are needed Mr continuity of the 2X LOCA circuit. These contacts are also part of components that serve functions other than 2X LOCA event mitigation. Therefore, these contacts are classified as safety-related. The determination of active or passive classification are based on the functions performed by the individual component.
The maintenance status of components is not significantly different between active and -
passive safety-related components. General maintenance practices and record retention requirements are the same. Design control and configuration control requirements are also the snme. Periodic functional testing is based on the applicable licensing and regulatory requirements (such as Appendix B) necessary to demonstrate the capability of the -
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components to perforrn their function. The periodic functional testing that will be performed on these components is described above. The primary difference between an
- active and a passive safety-related classification is in the development of procurement requirements for replacement components and the determination of OPERABLE status.
The safety'related function, including active / passive classifications, is considered in these evaluations.
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