ML20114A840
| ML20114A840 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 08/12/1992 |
| From: | J. J. Barton GENERAL PUBLIC UTILITIES CORP. |
| To: | |
| Shared Package | |
| ML20114A838 | List: |
| References | |
| NUDOCS 9208240008 | |
| Download: ML20114A840 (6) | |
Text
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-GPU l4UCLEAR CORPORATI0li OYSTER CREEK NUCLEAR GENERATil4G STATION Facility Operating License No. DPR-16 Technical Specificatica Change Request No. 202 Docket No. 50-219 Applicant submits, by this Technical Specification Change Request No. 202 to the Oyster Creek Nuclear Generating Station Technical Specifications, a change to pages 3.1-8 and 3.1-19.
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By: __(J.J. D#Gi l ice
'e.ident and Director
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ste Sworn and Subscribed.o before me this /2 day of M8 1992.
anL9n. kn gotaryPublicofNewJersey JUDITH M. CROWE Notary Pubuc of NovgJersey
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Y208240008 920812 PDR ADOCK 05000219 P
l UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION IN THE MATTER OF
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DOCKET N0. 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.
202 for the Oyster Creek Nuclear Generating Station Technical Specifications, filed with the U.S. Nuclear Regulatory Commission on August 12
- 1992, has this day of August 12 1992, been served on the Ma.yor of Lacey Township, Ocean County, New Jersey by deposit in the Uniteo States mail, addressed as follows:
Mayor of Lacey Township 818 West Lacey Road Forked River, NJ 08731 pn
!m By:
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[J.J.
Bh1t6n-
, Vice Fr:sident and Director er reek
OYSTER CREEK NUCLEAR GENERATING STATION FACILITY OPERATING LICENSE NO. DPR-16 DOCKET NO. 50-219 TECHNICAL SPECIFICATION CHANGE REQUEST NO. 202 The licensee, GPU Nuclear Corporation, hereby requests the Commission to change Appendix A to the license for the Oyster Creek Nuclear Generating Station as described below.
Pursuant to 10 CFR 50.91, an analysis concerning the determination of no significant hazards considerations is also presented:
1.
Sections to be Chanced Technical-Specification (TS) Section 3.1, " Protective Instrumentation".
l II.
Extent of Chanaes L
Revise the operability requirement for the low condenser vacuum scram function in Table 3.1.1.of the TS to require a minimum of one operable trip system and three operable instrument channels per operable trip system.
Add a footnote to Table 3.1.1 which states " Instrument Channel" in the case of the low condenser vacuum scram function refers to the bellows which sense vacuum in each of the three condensers (A, B, and C), and
" Trip System" refers to vacuum trip system 1 and 2.
III. Chpnaes Reouested The changes requested are indicated on the attached revised TS pages 3.1-8 and 3.1-19.
IV.
Discussion The TS bases on page 3.1-4-state the low condenser vacuum scram trip of L
20 inches Hg has been provided to protect the main condenser in the event-that-vacuum is lost. A loss of condenser vacuum would cause the turbine stop valves to close, resulting _in a turbine trip transient.
The low condenser. vacuum trip provides a reliable backup to the_ turbine trip.
Thus, if there is a failure of the turbine trip on low vacuum, the reactor would automatically scram at 20-inches Hg.
The low condenser vacuum scram trip is not required for reactor protection.- In the anzlysis of the loss of condenser vacuum event.in Chapter 15 of the FSAR, no credit is taken for the reactor scram trip on low condenser vacuum.
This event is bounded by the turbine trip without bypass transient.
Further, no credit is taken for this trip in any oth_er transient analyzed in the FSAR. Operability requirements for this trip are retained in the TS in the interest of protecting condenser and turbine integrity.
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The logic diagram for the low condenser vacuum scram trip is shown in Figure 1.-
The protective function is provided by two redundant cam operated vacuum trip systems.
Each of these trip systems (VT-1 and VT-2) has three bellows, one for each condenser section (A, B, and C) which operate independently.
A low vacuum condition in any condenser section will cause cam rotation. The reactor protection system (RPS) monitors main condenser vacuum by four switches identified as RSCS-II, 12, 21 and 22.
These switches are operated by VT-1 and VT-2.
VT-1 operates vacuum switches RSCS-11 and 12 and VT-2 operates RSCS-21 and 22.
RSCS-Il and 21 input to RPS I and RSCS-12 and 22 input to RPS II.
Note that actuation of any one of the six bellows will cause a reactor scram.
The existing 13 require a minimum of two operable trip systems and two operable instrument channels per operable trip system.
This had been interpreted to mean that RPS I and RPS II must be operable (trip systems) and RSCS-II, 21,12 and 22 must be operable (instrument channels). However, this interpretation does not enutre that a low vacuum condition in any one of the three condenser sections will cause a reactor scram.
Despite the 48" crossover piping that interconnects the three condenser sections, vacuum can decrease faster in one condenser section than in the other two.
This behavior has been observed during actual condenser vacuum transients.
In an analysis that was conducted to evaluate the impact of the low vacuum scram trip on the main condenser using a RELAPS N002 computer model, the results showed that vacuum in the different condenser sections can vary significantly depending on the malfunction scenario. Because of this behavior, the operability requirement for this system should ensure that a low vacuum condition in any one of the three condenser sections will cause a reactor scram.
It is apparent from the logic diagram that this objective is met by requiring a minimum of one operable trip system (VT-1 or VT-2) and three operable instrument channels (bellows) per operable trip system.
Since the proposed technical specifications do not require both trip
. systems (VT-1 and VT-2) to be operable, redundancy is not provided for single failure protection.
The justification for not having single failure protection is that the trip is not required for reactor protection as stated above.
V.
Determination GPUN has determined that operation of the Oyster Creek Nuclear Generating Station in accordance with the proposed TS does not involve a significant hazards consideration as defined in 10 CFR 50.92.
A.
Operation of the facility in accordance with the proposed amendment would not involve a significant increase in the probability of occurrence or the consequences of an accident previously evaluated.
No credit is taken for the low condenser vacuum scram in any of the transients analyzed in the FSAR.
This change does not effect previously evaluated accidents.
B.
0peration't. the facility.in accordance with the proposed amendment would not create the possibility of a new or different kind of accidentLfrom any-accident previously evaluated.
The proposed ~ operability requirement will provide greater assurance that main condenser'and turbine integrity is protected in a loss of vacuum event.
-C..
Operation of the facility in accordance with the proposed
-amendment would not-involve a significant reduction in a margin of
- safety, The proposed operability requirement for the low condenser vacuum scram trip will enhance the protection of non-safety related equipment,
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Fiaure 1 Low Condenser Vacuum Scram Function condenser condenser condenser A
B C
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