ML20244A907
| ML20244A907 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 04/05/1989 |
| From: | SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | |
| Shared Package | |
| ML20244A905 | List: |
| References | |
| NUDOCS 8904180263 | |
| Download: ML20244A907 (4) | |
Text
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Attachment:
1 to Document' Control Desk Letter N
iApril.5,-1989' fage 1 of 2 I
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PROPOSED t.MENDMENT MARKED-UP PAGES Paae Technical Specification 3/4 7-9a 3/4.7.1.6, "Feedwater Isolation Valves"~
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l Attachmant I'to Document Control Desk Letter
.,e April 5, 1989' Page 2 of 2 I
PLANT SYSTEMS
'FEEDWATER ISOLATION VALVES
-LIMITING-CONDITION FOR OPERATION o
3.7.1.6 'Each feedwater isolation valve shall be OPERABLE.
APPLICABILITY: ' MODES 1, 2, and-3 Y
i ACTION:
MODE 1 With one feedwater isolation' valve inoperable but' open, POWER j
OPERATION may continue provided the inoperable valve is restored
'l to.0PERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; Otherwise, be in HOT STAND 8Y within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
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MODES 2 With one&feedwater isolation valve 3e) inoperable, subsequent and 3 operation in MODES 2 or 3 may proceed provided:
rXoFERA6t4 w
The isolation valve is(424) maintained closed.
a.
b.
The provisions of Specification 3.0.4 are 'not applicable.
Otherwise, be in HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SH TDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
U SURVEILLANCE REQUIREMENTS 4.7.1.6 Each feedwater isolation valve shall be demonstrated OPERABLE by verifying full closure within 5 seconds when tested pursuant to Specification 4.0.5.
l SUMER - UNIT 1 3/4 7-9a Amendment No. 23
~ to Document Control Desk Letter April.5, 1989
.Page 1 of 2 1
SIGNIFICANT HAZARDS EVALUATION FOR VIRGIL C. SUMMER NUCLEAR STATION FEEDWATER ISOLATION VALVES
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Description of amendment request:
The proposed amendment revises the action statement of Technical Specification 3.7.1.6, "Feedwater Isolation Valves," to allow one or more feedwater isolation valves to be inoperable in MODES 2 and 3 provided that the affected isolation valves are maintained closed. Currently, the Licensee can have only one isolation valve inoperable in MODES 2 and 3.
Basis forproposed no significant hazards consideration:
The operability of open feedwater isolation valves in MODES 2 or 3 is necessary to ensure the feedwater isolation function in the event of a secondary side high-energy line break.
Further, a closed feedwater isolation valve in MODES 2 or 3 is in its required position for plant safety. An inoperable status for a feedwater isolation valve is oniy a concern if the affected valve is open and cannot be closed.
For this case, a planned shutdown must be executed. This requirement is reflected in the current Technical Specification and remains valid.
The number of closed but inoperable feedwater isolation valves would not have an impact on plant safety. Thus, the Technical Specification requirement regarding an inoperable feedwater isolation valve in MODE 2 or 3 being maintained in the closed position supports the licensing-basis safety analysis assumptions of closed feedwater isolation valves upon receipt of a signal to do so.
The Commission has provided certain examples (61 FR 7744) of actions likely to involve no significant hazards considerations. The request involved in this case does not match any of those examples.
However, the Licensee has reviewed the amendment request and determined that should this request be implemented it will not:
(1)
Involve a significant increase in the probability or consequences of any accident previously evaluated because the feedwater isolation valves will be maintained in a safe although inoperable status. The feedwater isolation valves are required to close to mitigate the consequences of a postulated main steam line break, feedwater line break, or steam generator blowdown line break. This modified Technical Specification l
requires that any feedwater isolation valves must be maintained closed if inoperable.
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- to Document' Control Desk Letter April. 5, 1989 Page 2 of 2 (2) Create the possibility of a new or different kind of accident from any accident previously evaluated because this proposed. revised Technical l
Specification continues to maintain the feedwater isolation valves in a safe position.
(3)
Involve a significant reduction in a margin of safety because the feedwater isolation valves will be maintained in their safe position.
The margin of safety is not reduced as long as the inoperable feedwater isolation valves remain closed.
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