ML20237E962
| ML20237E962 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 12/18/1987 |
| From: | Fiedler P GENERAL PUBLIC UTILITIES CORP. |
| To: | |
| Shared Package | |
| ML20237E952 | List: |
| References | |
| NUDOCS 8712290280 | |
| Download: ML20237E962 (4) | |
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i-GPU NUCLEAR CORPORATION OYSTER CREEK NUCLEAR GENERATING STATION Provisional Operating License No. DPR-16 Technical Specification Change Request No. 165 Docket No. 50-219 Applicant submits, by this Technical Specification Change Request No. 165 to the Oyster Creek Nuclear Generating Station Technical Specifications, changes to pages 3.7-1 and 3.7-2.
By -
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Pet #M'edler Vice President and Director Oyster Creek Sworn and Subscribed to before me this day of utdl4./1987.
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A Notary Public of NJ DIANA M. De3LASIO -
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0YSTER CREEK NUCLEAR GENERATING STATION PROVISIONAL OPERATING LICENSE NO. DPR-16 l
DOCKET NO. 50-219 TECHNICAL SPECIFICATION CHANGE REQUEST NO. 165 Applicant hereby requests the Commission to change Appendix A to the above captioned license as indicated below.
Pursuant to 10CFR50.91, an analysis concerning the determination of no significant hazards considerations is also presented:
1.
Section to be Changed Section 3.7 2.
Extent of Change Revise Specification 3.7.8 such that the plant may continue to operate for 7 days with the 125 VDC Motor Control Center "DC-2" out of service.
3.
Changes Requested The requested changes are shown on the attached Technical Specification pages 3.7-1 and 3.7-2.
4.
Discussion In the process of reviewing the existing Oyster Creek Technical Specifications, GPUN has identified what has been determined to be an overly restrictive specification.
The purpose of TSCR No. 165 is to change the LCO associated with the 125 VDC MCC "DC-2" in Specification 3.7 " Auxiliary Electrical Power" to be consistent with that of Specification 3.8 " Isolation Condensers".
The Oyster Creek Isolation Condenser System (ICS) is a standby, high pressure system for removal of fission product heat from the reactor vessel following a reactor trip and isolation of the reactor from the Main Condenser.
The system prevents overheating of the reactor fuel, controls the reactor pressure rise, and limits the loss of i
reactor coolant through the relief valves. The system is operable and ready for service at all times during power operation and whenever the reactor coolant temperature is greater than 212*F.
The ICS consists of two full capacity isolation condensers, four AC motor operated isolation valves, four DC motor operated isolation valves and three vent lines to the atmosphere.
Normally, all isolation valves are open except for two DC powered condensate return line valves located in the Reactor Building 75' elevation.
The system operates by natural circulation without the need for
driving power other than the DC electrical system used to place the ICS in operation. The system operates with steam flowing from the reactor pressure vessel through the condenser tubes' and condensate returning by gravity to the-reactor pressure vessel, forming a closed loop.
The valves in the steam inlet lines (V-14-32 and V-14-33 for condenser NE01-B; V-14-30 and V-14-31 for condenser NE01-A) are normally open so that the tube bundles are at reactor pressure even during standby. The AC operated condensate return isolat:on valves. (V-14-37 for condenser NE01-B; V-14-36 for condenser NE01-A) are normally open. The DC operated condensate return valves (V-14-35 for condenser NE01-B; V-14-34 for condenser NE01-A) are normally closed.
Only one DC operated isolation. valve associated with each condenser is required to be opened to place the ICS in operation.
The ICS is automatically initiated by a persistent signal of either high reactor vessel. pressure or low-low reactor water level.
The high points in the. steam supply' lines'to each loop are vented continuously to the main turbine steam header down stream of the mainsteam isolation valves when the plant is operating and the ICS is in standby. -This is done to remove noncondensible gases from the reactor steam, which would otherwisc collect at these high points in the system and impair the initial actuation and cooling capability of the ICS, Valves V-14-1 and V-14-19 isolate the vent lines for condenser NE01-B while valves V-14-5 and V-14-20 provide isolation of the vent lines for condenser.NE01-A.
The vent valves are air operated solenoid valves (energized to open) that close on the isolation signals indicated in Technical Specification Table 3.5.2.
The power systems noted in Technical Specification 3.7 provide reliable power to station auxiliaries that are important to plant f
safety.
These systems consist of both AC and DC sources.
For TSCR No.165, the power system of concern is the 125 VDC system.
Motor Control Center (MCC) "DC-2" of the 125 VDC system is used to provide power to the DC isolation valves (V-14-33, V-14-35, V-14-1 and V-14-19) associated with condenser HE01-B while MCC "DC-l" provides power to the DC isolation valves (V-14-34, V-14-31, V-14-5 and V-14-20) associated with the reducdant condenser NE01-A.
Valves V-14-33, V-14-35, V-14-1 and V-14-19 are the only components f ed from MCC "DC-2", it does not provide power to any other components.
A loss of MCC "DC-2" results in a loss of ICS redundancy (condenser NE01-B becomes inoperable) and the isolation of the condenser vent lines (valves are energized to open).
The overly restrictive specification was uncovered when comparing the LC0's associated with Specifications 3.7 and 3.8.
Specification 3.7.B requires the reactor be placed in the cold shutdown condition if MCC "DC-2" becomes unavailable.
In such an event, the reactor would be placed in cold shutdown within 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
In contrast, Specification 3.8.C allows the reactor to remain in operation for a period not to exceed 7 days (provided certain provisions are met) if j
one Isolation Condenser becomes inoperable.
Thus, the limits on plant operation are more restrictive with a loss of ICS redundancy
via Specification 3.7 " Auxiliary Electrical Power" than with the loss of ICS redundancy via Specification 3.8 " Isolation Condenser".
This is an unnecessary restriction when considering the resultant levels of protection associated with both sets of circumstances.
In both circumstances, the redundant condenser is available and NE01-B is isolated via Specification 3.8.E.
5.
Determination:
GPU Nuclear has determined that operation of the Oyster Creek Nuclear Generating Station in accordance with the proposed technical specifications does not involve a significant hazard. The change does not:
1.
Involve an increase in the probability or consequences of an accident previously evaluated.
Increasing the allowable out of service time to 7 days for the 125 VDC MCC "DC-2" does not alter the plant response to an accident nor reduce the availability of the Isolation Condenser System below that which is currently addressed in the Technical Specifications.
The 125 VDC MCC "DC-2" supplies power only to the isolation valves of the Isolation Condenser System.
2.
Create the possibility of a new or different kind of accident from any accident previously evaluated.
Increasing the allowable out of service time for the 125 VDC MCC "DC-2" does not alter the existing plant response.
The availability of plant systems is unchanged from that which is currently addressed in the Technical Specifications.
3.
Involve a significant reduction in margin of safety.
Changing the allowable out of service time for 125 VDC MCC "DC-2" to agree with the allowable out of service time for an inoperable i
Isolation Condenser does not reduce the margin of safety. The level of Isolation Condenser System availability and the isolation requirements associated with an inoperable condenser are currently addressed in the Technical Specifications and remain unchanged.
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