ML13331B079
| ML13331B079 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 10/27/1988 |
| From: | SOUTHERN CALIFORNIA EDISON CO. |
| To: | |
| Shared Package | |
| ML13331B078 | List: |
| References | |
| NUDOCS 8811030473 | |
| Download: ML13331B079 (6) | |
Text
ATTACHMENT 1 EXISTING TECHNICAL SPECIFICATION P1103()
.-,8C027 PD A
0 3.20 OVERPRESSURE PROTECTION SYSTEMS APPLICABILITY:
Applies to operability of the overpressurization protection systems.
OBJECTIVE:
To preclude the potential for exceeding 10 CFR 50, Appendix G, in the event of a pressure transient while water-solid.
SPECIFICATION:
A. When the RCS pressure is < 400 psig* and pressurizer water level is greater than 50%, at least one of the following overpressure protection systems shall be operable:
(1) Two power operated relief valves (PORVs) with a lift setting of < 500 psig,** or (2) A reactor coolant system vent(s) of > 1.75 square inches.
B. With one PORV inoperable when required in accordance with Specification A above, either restore the inoperable PORV 103 to operable status within seven days or depressurize and 5/23/88 vent the RCS through a 1.75 square inch vent(s) within the next eight hours; maintain the rCS in a vented and tagged condition until both PORVs have been restored to operable status.
C. With both PORVs inoperable when required in accordance with Specification A above, depressurize and vent the RCS through at least a 1.75 square inch vent(s) within eight hours; maintain the RCS in a vented and tagged condition until both PORVs have been restored to operable status.
- 0. In the event either the PORVs or the RCS vent(s) are used to mitigate a potential RCS pressure transient, a Special Report shall be prepared and submitted to the Commission pursuant to Specification 6.9.2 within 30 days.
The report shall describe the circumstances indicating transient, the effect of the PORVs or vent(s) on the transient and any corrective-action necessary to prevent recurrence.
The placing in service of the OMS at < 400 psig is intended to assure that protection is provided whenever temperature is below 360*F. The alarm to arm the OMS being keyed to pressure assures that inadvertent opening of the PORVs does not occur due to placing the OMS into service with RCS pressure above the 500 psig initiation setpoint.
The 500 psig setpoint is based on the current heatup and cooldown curves for 16 EFPY. The setpoint requires -reevaluation for acceptability any time the curves are changed.
SAN ONOFRE -
UNIT 1 3-127 Revised: 6/22/88
BASIS:
The operability of two PORVs or an RCS vent opening of greater than 1.75 square inches ensures that the RCS will be protected from pressure transients which could exceed the limits of Appendix G to 10 CFR Part 50 when the initial RCS pressure is < 400 psig and the pressurizer water level is 1
greater than 50%, assuming a single failure of one PORV and 103 no operator action for 10 minutes. Either PORV has adequate 5/23/88 relieving capability to protect the RCS from overpressuri zation due to a design basis transient as described in submittal to the NRC dated October 12, 1977.
Tagged as it refers to the RCS vent, means tagged in accordance with current Southern California Edison procedures for tagging of equipment which must not be operated.
SAN ONOFRE -
UNIT 1 3-128 Revised:
6/22/88
ATTACHMENT 2 PROPOSED TECHNICAL SPECIFICATION
0 3.20 OVERPRESSURE PROTECTION SYSTEMS APPLICABILITY:
Applies to operability of the overpressurization protection systems.
OBJECTIVE:
To preclude the potential for exceeding 10 CFR 50, Appendix G, in the event of a pressure transient while water-solid.
SPECIFICATION:
A. When the RCS pressure is < 400 psig* or the Residual Heat Removal (RHR) System is in operation, and pressurizer water level is greater than 50%, at least one of the following overpressure protection systems shall be OPERABLE:
(1) Two power operated relief valves (PORVs) with a lift setting of < 500 psig,** or (2) A reactor coolant system vent(s) of > 1.75 square inches.
B. With one PORV inoperable when required in accordance with Specification A above, either restore the inoperable PORV to operable status within seven days or depressurize and vent the RCS through a 1.75 square inch vent(s) within the next eight hours; maintain the RCS in a vented and tagged condition until both PORVs have been restored to operable status.
C. With both PORVs inoperable when required in accordance with Specification A above, depressurize and vent the RCS through at least a 1.75 square inch vent(s) within eight hours; maintain the RCS in a vented and tagged condition until both PORVs have been restored to operable status.
D. In the event either the PORVs or the RCS vent(s) are used to mitigate a potential RCS pressure transient, a Special Report shall be prepared and submitted to the Commission pursuant to Specification 6.9.2 within 30 days. The report shall describe the circumstances indicating transient, the effect of the PORVs or vent(s) on the transient and any corrective action necessary to prevent recurrence.
The placing in service of the OMS at < 400 psig is intended to assure that protection is provided whenever temperature is below 360*F. The alarm to arm the OMS being keyed to pressure assures that inadvertent opening of the PORVs does not occur due to placing the OMS into service with RCS pressure above the 500 psig initiation setpoint.
The 500 psig setpoint is based on the current heatup and cooldown curves for 16 EFPY. The setpoint requires reevaluation for acceptability any time the curves are changed.
SAN ONOFRE - UNIT 1 3-127
BASIS:
The operability of two PORVs or an RCS vent opening of greater than 1.75 square inches ensures that the RCS will be protected from pressure transients which could exceed the limits of Appendix G to 10 CFR Part 50 when the initial RCS pressure is < 400 psig and the pressurizer water level is greater than 50%, assuming a single failure of one PORV and no operator action for 10 minutes.
Either PORV has adequate relieving capability to protect the RCS from overpressuri zation due to a design basis transient as described in submittal to the NRC dated October 12, 1977.
The requirement that the overpressurization protection systems be OPERABLE when the RHR system is in operation provides protection for this lower pressure system, which is connected to the reactor coolant system.
Tagged as it refers to the RCS vent, means tagged in accordance with current Southern California Edison procedures for tagging of equipment which must not be operated.
SAN ONOFRE -
UNIT 1 3-128