ML20213C919
| ML20213C919 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 11/05/1986 |
| From: | Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | |
| Shared Package | |
| ML20213C892 | List: |
| References | |
| NUDOCS 8611100352 | |
| Download: ML20213C919 (9) | |
Text
F1 BEFORE THE UNITED. STATES NUCLEAR REGULATORY COMMISSION In the Matter of Docket No. 50-352 PHILADELPHIA ELECTRIC COMPANY APPLICATION FOR AMENDMENT OF FACILITY OPERATING LICENSE NPF-39 Edwar'd G. Bauer, Jr.
Eugene J. Bradley 2301 Market Street Philadelphia, Pennsylvania 19101 Attorneys for Philadelphia Electric Company-hDR DO!
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BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION In the Matter of Docket No. 50-352 PHILADELPHIA ELECTRIC COMPANY APPLICATION FOR AMENDMENT OF FACILITY OPERATING. LICENSE NPF-3.9 Philadelphia Electric Company, Licensee under Facility Operating License NPF-39 for Limerick Generating Station Unit 1, hereby requests that the Technical Specifications contained in Appendix A of the Operating License be amended as indicated on the attached proposed revised page 3/4 3-37 of Appendix A.
The proposed change is indicated by a vertical bar in the margin of the page.
The changes to the Technical Specifications proposed herein consist of revisions of Trip Setpoint(SP) and Allowable Values (AV) for Low Pressure Coolant Injection (LPCI) injection valve differential pressure instrument loops.
The setpoint revisions are required in support of a proposed modification,
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which will increase the range of the differential' pressure instrument loops.
The LPCI injection valve differential pressure instrument loops are provided to protect the low pressure Residual Heat Removal (RHR) piping from high reactor-pressure by interlocking the LPCI injection valves so that they cannot be
. opened if the pressure on the reactor side of the injection valve is greater by a given amount than the pressure in the RHR pump discharge piping.
The differential pressure setpoint is established so that the injection t'alves are permitted to open in sufficient time to establish LPCI flow into the reactor-to satisfy reactor water level requirement's during a design basis Loss of Coolant Accident (LOCA), but not until reactor pressure has decreased to the allowable rated pressure for the low pressure RHR piping.
This interlock, which prevents the motor-operated LPCI injection valves from opening until the differential pressure across the valves is below a specified.
value, has been evaluated in the U.S. Nuclear Regulatory Commission's Safety Evaluation Report for the Limerick _ Generating i
i Station, Units 1 and 2 (page 7-47, August 1983).
l The instrument loops are presently calibrated to monitor a range of 0 to 800 psid.
The specified allocations for instrument loop accuracy and calibration accuracy are 6 psid and l
2'psid, respectively.
The upper analytical limit for the differential pressure across the valves is 95 psid.
The trip units are-calibrated for a SP of 78 psid and AV of 68 psid $ AV $
88 psid.
The RHR pump discharge piping is normally pressurized i
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Y to a nominal 125 psig via the' condensate transfer system.
During normal plant shutdowns, reactor pressure is reduced'to below the RHR pump discharge piping pressure and the measured differential pressure relative to the RHR discharge piping becomes negative.
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Under these circumstances,.the differential pressure is no longer within the calibrated range of the instrument loop, causing the transmitter output to go below the normal minimum of 4 milliamperes (mA).
Eventually, the measured differential pressure will become sufficiently negative to drive the transmitter output to a value which causes the associated trip unit to sense a low signal / gross failure condition, thus actuating a.RHR loop out-of-service annunciation in the control room.
This false out-of-service annunciation can be corrected by increasing the range of the differential pressure instrument loop to -200 to 800 psid.
With this range, the transmitter output will remain above 4 mA as long as the sensed differential pressure remains above -200 psid.
The new range is sufficient to envelope the expected differential pressures during plant shutdowns, thereby eliminating the ' conditions which presently' cause the trip units to sense a low signal / gross failure condition.
As a result of increasing the instrument loop range, the specified allocations for instrument loop accuracy and calibration accuracy must be increased to 10 psid and 3 psid, respectively, thereby requiring a change to Table 3.3.3-2 for the instrument loop SP and AV.
The proposed values for.the.
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instrument. loop SP and AV are 74 psid, 64 1 AV $ 84 psid, respectively..
Safety Analysis:
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.There are two safety functions associated with the differential pressure setpoint of the LPCI injection valve differential pressure instrument loops:
a.
to protect the low pressure RHR piping from high reactor pres'sure by interlocking the LPCI injec' tion valves to prevent them_from opening when reactor pressure is greater than the allowable, pressure for the low pressure RHR piping, b.
to enable the LPCI injection valves to open in sufficient time-to establish LPCI flow into the reactor in order to satisfy reactor water level requirements during a design basis LOCA.
i The proposed change to the Technical Specifications constitutes a change to a safety-related SP which will decrease the excess margin available between the value of the SP and the value of the SP assumed in the original ECCS analysis ~ (General i
Electric Company; General Electric Standard Application for Reactor Fuel; NEDE-240ll-P-A and NEDE-240ll-P-A-US).
To maintain an adequate level of protection against exposing the low pressure i
the SP and AV have to be RHR piping to high reactor pressure, i
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~ decreased to. account for the increase in the specified allocations for instrument ~ accuracy and calibration accuracy resulting from the increased instrument loop range.
The upper analytical limit of 95 psid, established in the original design, remains unchanged.
General Electric has evaluated the proposed setpoint changes and has concluded that the new calibration range
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and values for the SP and AV meet all the safety requirements of the RHR/LPCI system and will not affect system reliability.
The safety function to permit the LPCI injection valves to open in sufficient time to establish LPCI flow into the reactor and satisfy reactor. water level requirements during a design basis Loss of Coolant Accident (LOCA) is maintained; there is no effect on the safety of the plant.
Significant Hazards Consideration Determination:
The Commission has provided guidance concerning the application of standards in 10 CFR 50.92 for determining whether license amendments involve significant hazards consideration by providing certain examples which were published in the Federal Register on April 6, 1983 (48 FR 14870).
One of the examples of an action involving no significant hazards consideration (vi) is a change which may in some way reduce a safety margin, but where the results of the_ change are clearly within all acceptable criteria.
The foregoing requested change fits this example as an item not involving any significant hazards. -
7 The proposed amendment to the Limerick Operating License does not constitute a significant hazards consideration in that it would not:
(1) involve a significant increase in the probability or consequences of an accident previously evaluated because the subject instrument loops continue to maintain the original level of overpressure protection provided for the low pressure RHR piping and the operation of the LPCI system remains within the safety requirements for the LPCI system.-
(2) create the possibility of.a new type of accident or a different kind of accident from any accident previously analyzed because the amendment merely lowers the setpoints and the subject instrument loops contin ~e to u
maintain the original level of overpressure protection provided for the low pressure RHR piping.
The operation of the LPCI system remains within the safety requirements of the LPCI system.
(3) involve a significant reduction in the margin of safety because the lower setpoints account for'the increase in allocations for instrument accuracy and calibration accuracy and do not decrease the margin of safety assumed in the bases of the Technical Specifications.
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The requested amendment will not result in a significant change in the amounts or types of effluents that may be released off-site.
There will be no significant increase in individual or cumulative occupational radiation exposure as a result of the requested amendment.
The Plant Operations Review Committee and the Nuclear Review Board have reviewed these proposed changes to the Technical Specifications and have concluded that they do not involve an unreviewed safety question or a significant hazards consideration and will not endanger the public health and safety.
Respectfully Submitted, PHILADELPHIA ELECTRIC COMPANY By dAbw' N
Vice President &.
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COMMONWEALTH OF PENNSYLVANIA :
ss.
COUNTY OF PHILADELPHIA S. L. Daltroff, being first duly sworn, deposes and says:
That he is Vice President of Philadelphia Electric Company, the Applicant herein; that he has read the foregoing Application for Amendment of Facility Operating License and knows the contents thereof; and that the statements and matters set forth therein are true and correct.to the best of his knowledge, information and belief.
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Subscribed and sworn to before me this I ay krf.
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C Notary Public MELANtE R. CAMPANELt.A Notary Public, Philadelp5f4. Phda&tphia Co.
hly Commission Emptres february 12, 1930
.