ML20012G570

License Amend Request 208 to License DPR-16,proposing Reduction of Setpoint of Ninth (Highest) Safety Valve from 1,230 to 1,221 Psig

ML20012G570
Person / Time
Site:	Oyster Creek
Issue date:	03/03/1993
From:	J. J. Barton GENERAL PUBLIC UTILITIES CORP.
To:
Shared Package
ML20012G567	List: ML20012G566 ML20012G570 ML20012G571
References
NUDOCS 9303090266
Download: ML20012G570 (6)

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L GPU NUCLEAR CORPORATION OYSTER CREEK NUCLEAR GENERATING STATION Facility Operating License No. DPR-16 i

Technical Specification Change Request No. 208 Docket No. 50-219 Applicant submits, by this Technical Specification Change Request No. 208 to the Oyster Creek Nuclear Generating Station Technical Specifications, proposed changes to pages 2.3-2 and 4.3-1.

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r ent and Director Dyster Creek Oday of N 1993.

Sworn and Subscribed to before me this 3

/?t. f Y tary Public of NJ JUDITH M.CROWE Notary Publicof Newp9 Mr Commission Expires

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9 9303090266 930303 DR ADDCK 05000219 PDR

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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the matter of

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Docket No. 50-219 GPU Nuclear Corporation

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CERTIFICATE OF SERVICE This is to certify that a copy of Technical Specification Change Request No. 208 for Dyster Creek Nuclear Generating Station Technical Specifications, filed with the U.S. Nuclear Regulatory Commission on March 3, 1993, has this day of March 3, 1993, been served on the _ Mayor of Lacey Township, Ocean County, New Jersey by deposit in the United States mail, addressed as follows:

The Honorable Louis A. Amato Mayor of Lacey Township 818 West Lacey Road Forked River, NJ 08731 f

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J. J. Bh (tc n Vice Pr3

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OYSTER CREEK NUCLEAR GENERATING STATION l

Docket No. 50-219 Technical Specification Change Request No. 208 Applicant hereby requests the Commission to change Appendix A to the above captioned license as described below, and pursuant to 10 CFR 50.91 an analysis concerning the determination of no significant hazards considerations is also preseated:

1.0 Section to be Chanced Sections 2.3 and 4.3.

2.0 Extent of Chanae Reduces the setpoint of the ninth (highest) safety valve from 1230 to 1221 psig.

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3.0 Chanaes Recuested The requested changes are shown on the attached Technical Specification pages 2.3-2 and 4.3-1.

4.0 Discussion The purpose of this Technical Specification Change Request is to propose the reduction of the setpoint of the ninth (highest) safety valve from 1230 psig to 1221 psig. Oyster Creek has nine safety valves with setpoints as follows:

Number of Valves Technical Specification Setooints (psia) 4 1212 1 12 4

1221 1 12

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1 1230 2 12 The modification would change the setpoint to:

Number of Valves Technical Specification Setnoints (psia) 4 1212 1 12 5

1221 1 12 Lowering the setpoint of the ninth safety valve would result in a reduced peak system pressure for transients.

In addition, reducing the setpoint of the ninth safety valve would eliminate ordering and warehousing safety valves with three different setpoints. This wculd result in a significant cost and time savings in maintenance and surveillance testing.

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License Basis Analysis The safety valves are provided to satisfy the overpressure protection j

requirement of the ASME code. This system has no function during normal operation, and it is anticipated that there is a low probability of safety valve actuation since overpressure is relieved by the isolation condensers, the turbine bypass valves and the electromatic relief

. valves. A plant performance evaluation has been performed to j

demonstrate that there is an acceptably low probability of a safety valve opening as a result of an anticipated transient.

With the reduced setpoint of the highest safety valve, the margin of safety previously defined in the SAR would not be reduced because i

lowering the safety valve setpoint will rosult in lower peak pressures during abnormal transients / postulated acc1Jents. The margin of safety l

l defined in the SAR is contained in Chapter 15, Accident Analysis. These analyses demonstrate the ability of the plant to mitigate the consequences of postulated accidents and transients without undue hazard to the health and safety of the public.

The safety result for transients / postulated accidents which would be affected by the reduction 4

in safety valve setpoint is:

Reactor coolant system stresses will not exceed that allowed for accidents by applicable ASME and ANSI codes. This means limiting l

4 peak pressure in the reactor vessel to 110% of design pressure and to 115% of design pressure for the recirculation piping. The RPV design pressure is 1250 psig which requires the limit to be 1375 psig (1390 psia). The recirculation piping design pressure is 1200 psig which results in a limit of 1380 psig (1395 psia).

j The most limiting overpressure event analyzed in the FSAR is the 5

MSIV closure with scram on high neutron flux and failure of EMRVs, turbine bypass valves, isolation condensers and recirculation pump trip (RPT). This transient was analyzed with safety valve setpoints as follows:

d No. of Valves Tech Spec Setooints (osia)

Analysis Setooints (osia)

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4 1212 1 12 1240

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4 1221 1 12 1243 1

1230 12 1257 A re-analysis of this transient for Cycle 13 with the single j

safety valve set at 1249 instead of 1257 psia resulted in a peak i

i pressure at the bottom of the RV of 1383 psia which is below the code limit and lower than the peak pressure using a safety valve setpoint of 1257 psia (1384 psia). The peak pressure in the recirculation piping was 1391.5 psia which is also below the code limit.

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Thus,-with the proposed setpoint change of reducing th'e highest'

'i safety valve setpoint from 1230 psig_to 1221 psig, the margin of safety in the SAR is not reduced. For the purposes of this

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evaluation, margin of safety i_s defined as the margin between the.

safety limit and fission product barrier failure. Because the-1

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event does not exceed the event limit (1375 psig), the margin of-i safety is not reduced.

Nuclear safety or safe plant operations will not be adversely i

affected. As mentioned previously, it is anticipated that the

.i safety valves are unlikely to be actuated for normal.(non-ATWS).

anticipated events since overpressure is relieved by the isolation condensers,_the turbine bypass vaIves and the electromatic relief valves. There has been no transient at Oyster Creek that has

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resulted in the opening of a safety valve.

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Eliminating the third setpoint would minimize the potential for an incorrect setpoint of the ninth valve.

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5.0 Determination The proposed Technical Specification Change Request does not-involve a significant hazards consideration for the reasons as stated below:

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1.

Involve a significant increase in the probability or consequence of

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an accident previously evaluated:

The change in setpoint of the ninth safety valve will not increase the

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probability of occurrence or the consequences of an' accident previously l

evaluated in the SAR because there is no change to the number or function of the nine safety valves. The only event initiator that involves a safety valve is a spurious valve opening which is not affected by the change-in-

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setpoint.

I The activity will not increase the probability of occurrence or consequence i

of a malfunction of equipment important to safety previously evaluated:in the SAR based on a reliability analysis of RPT, EMRVs and safety valves which shows that the likelihood of reactor vessel overpressure due to an ATWS remains very small.

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3 2.- Create the possibility of a new or different kind of accident from i

any accident previously evaluated.

The proposed activity does not create a possibility for an accident f

of malfunction of a different type than any previously identified.in the SAR since existing safety valves remain unchanged, and no

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systems are affected by this modification. Analyses demonstrate

that all of the appropriate event acceptance limits have been satisfied for the proposed new setpoint.

3.

Involve a significant reduction in the margin of safety.

i The margin of safety as presently defined in the basis for the i

Technical Specifications will not decrease as a result of this proposed changa For the purposes of this evaluation, the margin.of safety.is defined j

as the margin between the safety limit and fission product barrier failure. Because the event does not exceed the event limit (1375 psig), the margin of safety is not reduced.

j 6.0 Implementation It is requested that the amendment authorizing this change become

-effective prior to the next refueling outage.

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