ML041460308
| ML041460308 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 05/25/2004 |
| From: | Gratton C NRC/NRR/DLPM/LPD2 |
| To: | Sumner H Southern Nuclear Operating Co |
| Gratton C, NRR/DLPM 415-1055 | |
| Shared Package | |
| ML041460106 | List: |
| References | |
| TAC MC1946, TAC MC1947 | |
| Download: ML041460308 (3) | |
Text
SDV Vent and Drain Valves 3.1.8 3.1 REACTIVITY CONTROL SYSTEMS 3.1.8 Scram Discharge Volume (SDV) Vent and Drain Valves LCO 3.1.8 APPLICABILITY:
Each SDV vent and drain valve shall be OPERABLE.
MODES 1 and 2.
ACTIONS
NOTES--------------------------------------------------------------
- 1.
Separate Condition entry is allowed for each SDV vent and drain line.
- 2.
An isolated line may be unisolated under administrative control to allow draining and venting of the SDV.
CONDITION REQUIRED ACTION COMPLETION TIME A.
One or more SDV vent A.1 Isolate the associated 7 days or drain lines with one line.
valve inoperable.
B.
One or more SDV vent B.1 Isolate the associated 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or drain lines with both line.
valves inoperable.
C.
Required Action and C.1 Be in MODE 3.
12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> associated Completion Time not met.
I HATCH UNIT 2 3.1 -22 Amendment No. 41 8.3
SDV Vent and Drain Valves B 3.1.8 BASES APPLICABLE the instrument volume exceeds a specified setpoint. The setpoint is SAFETY ANALYSES chosen so that all control rods are inserted before the SDV has (continued)
Insufficient volume to accept a full scram.
SDV vent and drain valves satisfy Criterion 3 of the NRC Policy Statement (Ref. 4).
LCO The OPERABILITY of all SDV vent and drain valves ensures that the SDV vent and drain valves will close during a scram to contain reactor water discharged to the SDV piping. Since the vent and drain lines are provided with two valves In series, the single failure of one valve in the open position will not Impair the Isolation function of the system.
Additionally, the valves are required to open on scram reset to ensure that a path Is available foi the SDV piping to drain freely at other times.
APPLICABILITY In MODES 1 and 2, scram may-be required; therefore, the SDV vent and drain valves must be OPERABLE. In MODES 3 and 4, with the mode switch in shutdown, control rod block prevents withdrawal of control rods. This provides adequate controls to ensure that only a single control rod can be withdrawn. Also, during MODE 5, only a single control rod can be withdrawn from a core.cell containing fuel assemblies. Therefore, the SDV vent and drain valves are not required to be OPERABLE In these MODES since the reactor is subcritical and only one rod may be withdrawn and subject to scram.
ACTIONS The ACTIONS Table is modified by Note 1 Indicating that a separate Condition entry is allowed for each SDV vent and drain line. This Is acceptable, since the Required Actions for each Condition provide appropriate compensatory actions for each inoperable SDV line.
Complying with the Required Actions may allow for continued operation, and subsequent Inoperable SDV lines are governed by subsequent Conditi6n entry and application of associated Required Actions. When a line is isolated, the potential for an inadvertent scram due to high SDV level is increased. During these periods, the line may be unisolated under administrative control. This allows any accumulated water in the line to be drained, to preclude a reactor scram on SDV high level. This is acceptable since the administrative controls ensure the valve can be closed quickly, by a dedicated operator, If a scram occurs with the valve open.
(continued)
I Amendment No: 183 HATCH UNIT 2 B 3.1 42
SDV Vent and Drain Valves B 3.1.8 BASES ACTIONS A.1 (continued)
When one SDV vent or drain valve is Inoperable in one or more lines, the associated line must be Isolated to contain the reactor coolant l
during a scram. The 7 day Completion Time Is reasonable, given the level of redundancy In the lines and the low probability of a scram occurring during the time the valve(s) are inoperable and the line Is not isolated. The SDV is still isolable since the redundant valve In the affected line is OPERABLE. During these periods, the single failure criterion may not be preserved, and a higher risk exists to allow reactor water out of the primary system during a scram.
8.1 If both valves In a line are inoperable, the line must be isolated to contain the reactor coolant during a scram.
The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time to Isolate the line is based on the low probability of a scram occurring while the line is not Isolated and unlikelihood of significant CRD seal leakage.
C.1 If any Required Action and associated Completion Time is not met, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The allowed Completion Time of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Is reasonable, based on operating experience, to reach MODE 3 from full power conditions in an orderly manner and without challenging plant systems.
SURVEILLANCE SR 3.1.8.1 REQUIREMENTS During normal operation, the SDV vent and drain valves should be in the open position (except when performing SR 3.1.8.2) to allow for drainage of the SDV piping. Verifying that each valve is in the open
'(continued)
Amendment No:183 HATCH UNIT 2 B 3.1-43