ML20128D782
| ML20128D782 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 02/02/1993 |
| From: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | |
| Shared Package | |
| ML20128D776 | List: |
| References | |
| NUDOCS 9302100226 | |
| Download: ML20128D782 (1) | |
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,Exig:nt TSCR - PBAPS Unit 2 Februory 2, 1993 Page'4 Docket No. 50-277 The proposed TS change involves a change in the allowable out of service time of an SRV.
SRV's are not an initiator for any of the over pressurization transients that the SRVs are designed to help mitigate.
A stuck open relief-valve is an accident initiator; however, the condition which has caused the SRV-to be inoperable does not increase the probability of a stuck open relief valve.
The design of the valve is such that a failed bellows will equalize the pressure across the first stage pilot t
piston and thus p event the piston from moving and the valve from opening.
e The analysis provided in the safety discussion clearly shows that the co sequences of any of the over pressurization transients do not increase with the SRV inoperable.
- Further, p
while the probability of a stuck open relief valve remains
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unchanger. by this condition, the stuck open relief valve transler.t was analyzed and the station can fully handle this event.
11)
The proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.
The proposed TS change involves a change in the allowable out of service time for an SRV.
The proposed change does not introduce any new accident initiators since there are no physical changes being made to the facility.
iii) The proposed change does not involve a significant reduction in a margin of safety.
The Technical Specification Bases define two design bases for the pressure relief system; first, to meet ASME overpressurization criteria, and second, to prevent opening of the unpiped spring safety valves during normal plant isolations and load rejections.
First, analysis has shown that ASME overpressurization criteria will be met.
Second, this same analysis has shown that an unpiped spring safety valve may potentially lift if two SRVs are inoperable.
However, the analysis assumptions associated with the ASME overpressurization criteria are much more conservative than the analysis assumptions required for demonstration:that unpiped spring safety valves are not opened during normal plant isolations or load rejections.
Analysis of the MSIV closure overpressure event with a functional MSIV position switch scram signal and two inoperable SRVs yields a peak steam line pressure below the unpiped spring safety valve setpoint.
Environmental Assessment An environmental assessment is not required for the changes proposed by this Application because the changes conform to the criteria'for " actions eligible for categorical exclusion" as specified in 10 CFR 51.22(c)(9).
9302100226 930202 PDR ADOCK 05000277 P
,Exigant TSCR - PBAPS Unit 2 February-2, 1993-
., Docket No. 50-277-Page 5' Conclusion The Plant Operations Review Committee and the Nuclear Review-Board have reviewed this proposed change and have concluded that they do not-involve an unreviewed safety question and are not a threat.to the health and safety of:the public.
REFERENCES 1.
PECo letter to NRC dated 4/2/81, Information Requested by NUREG-0737, Clarification of TMI Action Plan Requirements",
Item II.K.3.16.
2.
Fuel Management Section Design Record File (DRF) 9299,-
" Peach Bottom Overpressurization: Analysis" 3.
GE Letter to PEco G92-PBPR-042, dated December 21, 1992-4.
OPL-3 for Peach Bottom Unit 2, Cycle ~10 5.
NEDC-32162P, " Maximum Extended Load Line Limit and ARTS Improvement Program for PBAPS Units 2 and 3," December 1992.
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Unit 2 PBAPS LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.6.D Safety and Relief Valves 4.6.D Safety and Relief Valves
-1.
During reactor power operating 1.
At least one safety valve conditions and prior to and 5 relief valves shall be reactor startup from a Cold-checked.or repleace with bench Condition, or whenever reactor checked valves every 24 coolant pressure is greater months. - All valves will be 3
than atmospheric and temp-
_ tested every two cycles, erature greater than 212'F, both safety valves and the The set point of-the safety
. safety modes of all relief valves shall_ be as specified -
valves shall be-operable, in Specifications 2.2.
except as specified in 3.6.D.2.
2.
At least one of the relief 2.
valves shall be disassembled n
(a)
From and after the date that and inspected every 24 months.
the safety valve function of one relief valve is made or' 3.
The integrity.of the relief safety:
i found to-be inoperable, con-valve-bellows shall be continuously tinued reactor operation is monitored. -The switches-shall permissible only during the be calibrated once per operating-succeeding thirty days unless cycle. The accumulators and such valve function is sooner air piping shall be inspected I
made operable.*
for leakage using leak test fluid once per operating cycle.
i (b)
From and after the date that the safety valve functi.on of 4.
With the reactor pressure-L two relief valves is made or
- t100 psig, each relief valve i
found to_be inoperable, shall be manually opened once continued reactor operation per operating _ cycle. Verification l
is permissible only during_the that-each relief valve has opened succeeding seven days unless shall either be by observation such valve. function is sooner of compensating turbine bypass made operable.-
valve closure or load reduction or.
change.in measured steam flow i
3.
If Specification 3.6.D.1 is not depending on the operating met, an orderly. shutdown shall configuration existing during be initiated and the reactor the test.
4 coolant pressure shall be reduced to atmospheric with 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
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o This 30 day LC0 has a one time extension until the next outage of sufficient
-duration that requires a drywell entry.
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-147-Amendment No. 16, 38, 169
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