ML17223A241

Proposed Tech Spec,Revising Section 3.7 to Clarify Testing Requirements for Main Feedwater Line Isolation Valves & Main Steam Line Isolation Valves

ML17223A241
Person / Time
Site:	Saint Lucie
Issue date:	07/21/1989
From:	FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17223A240	List: ML17223A239 ML17223A241
References
NUDOCS 8908020353
Download: ML17223A241 (13)

Text

ATTACHMENT 1 St. Lucie Unit 1 Marked-Up Technical Specification Pages 3/4 7-9 85'08020353 85'072i PDR ADOCK 0500033 j P PDC

PLANT SYSTEMS MAIN STEAM LINE ISOLATION VALVES LIMITING CONOITION FOR OPERATION 3.7.1.5 Each main steam line isolation valve shall be OPERABLE.

APPLICABILITY: MOOES 1, 2 and 3.

ACTION:

MOOE 1 - Mith one main steam line isolation valve inoperable, POMER OPERATION may continue provided the inoperable valve is either restored to OPERABLE status or closed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />; otherwise, be in HOT with>n the nex hours. b MODES 2 main steam line isolation valve inoperab and 3 equen MODES 1, 2 or 3 er the inoperable valve ' is r E status or the isolation ned clos be in HOT in the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

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SURVEILLANCE RE UIREMENTS 4.7.1.5 Each main steam line isolation valve that is open shall be demonstrated OPERABLE by verifying full closure within 6.0 seconds when tested pursuant to Specification 4.0.5.

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ST. LUCIE - UNIT 1 3/4 7-9 Amendment No. 90

ATTACHMENT 2 St. Lucie Unit 2 Marked-Up Technical Specification Pages 3/4 7-9 3/4 7-10

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PLANT SYSTEMS MAIN 7EAM LINE ISOLATION VALVES LIMITING CONOITION FOR OPERATION 3.7.1.5 Each main steam line isolation valve shall be OPERABLE.

APPLICABILITY: HOOES 1, 2, 3 and 4.

ACTION:

MOOE 1 With one main steam line isolation valve inoperable but open, POWER OPERATION may continue provided the inoperable valve is restored to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />; otherwise, be in at least HOT STANDBY within the next 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />s~'sBpH CQ.

MOOES 2, 3- With one<main steam line isolation valve>inoperable, and 4 subseqent operation in HOOfS 2, 3 or 4 may proceed provided:

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a. The isolation valveAis~maintained closed.

b. The provisions of Specification 3. 0.4 are not applicable.

Otherwise, be in at least HOT STANOBY within the next 6 hours and in COLO SHUTOOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

r SURVEILLANCE RE UIREMENTS 4.7.1.5 Each main steam line isolation valve shall be demonstrated OPERABLE by verifying full closure within 6.75 seconds when tested pursuant to Specification 4.O.5.

ST. LUCIE - UNIT 2 3!4 7-9 Amendment ".o- 35

MAIN FEEDWATER LINE ISOLATION VALVES LIMITING CONDITION FOR OPERATION 3.7. 1.6 Each main feedwater line isolation valve shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTION:

MODE 1 With one main feedwater line isolation valve inoperable but open, POWER OPERATION may continue provided the inoperable valve is restored to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />; otherwise, be in at least 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 />, n,

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MODES 2, With one>main feedwater line isolation valve<inoperable, and 4 subseqent operation in MODE 2, 3, or 4 may proceed provided:

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a. The isolation valve> is<maintained closed.

b. The provisions of Specification 3.0.4 are not applicable.

Otherwise, be in at least 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 COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

SURVEILLANCE RE UIREMENTS 4.7.1.6 Each main feedwater line isolation valve shall be demonstrated OPERABLE by verifying full closure within 5.15 seconds when tested pursuant to Specification 4.0.5..

ST. LUCIE " UNIT 2 3/4 7-10 Amendment No. 9'> 35

ATTACHMENT 3 SAFETY ANALYSIS Introduction During a recent refueling outage at the St. Lucie Plant, noted that the Technical Specifications for the main steam it was isolation valves (MSIVs) on Units 1 and 2, and the main feedwater line isolation valves (MFIVs) on Unit 2, could be interpreted to require surveillance testing prior to entering and/or changing modes. The proposed license amendment will clarify requirements for the plant to achieve the required Modes to conduct testing necessary to meet the Limiting Condition for Operation. The Action statements in the referenced specifications are also corrected to denote that both MSIVs and'FIVs perform their required safety function when closed.

Additionally, a statement regarding the inapplicability of Specification 3.0.4 is being added to the Unit 1 requirements for MSIV operability. The proposed change is conservative in nature, in that all isolation valves are required to be maintained closed until surveillance testing is complete. The addition of a statement regarding inapplicability of Specification 3.0.4 renders the Unit 1 specification the same as the Unit 2 specifications.

This change is considered to be administrative in nature.

Discussion Technical Specification 3.7.1.5 Action Statements permit MSIV to be inoperable in Modes 2 and 3 on Unit 1 and Modes 2,3 and 4 on Unit 2. Subsequent, operation is permitted in these Modes inoperable valve is maintained closed, or if if the the valve is restored to operability. Similar operability requirements are specified for the Unit 2 MFIVs, as stated in Specification 3.7.1.6. The proposed license amendment will provide two clarifications:

Clarification of the requirements for the conduct of surveillance testing prior to power operation, and 2 ~ Action statements also amended to denote that when both MSIVs and MFIVs are maintained closed they perform their required safety function.

The design function of the MSIVs is to limit steam generator blowdown; requiring an inoperable MSIV to be closed until returned to operable status ensures that no more than one steam it is generator will blowdown in an excess steam demand event. By requiring that one. or both MSIVs remain closed until verified operable in accordance with Surveillance Requirement 4.7'.1.5, the ability of these valves to perform their required safety function is assured.

Safety'nalysis Page two A similar change is requested for Unit. 2 Technical Specification 3.7.1.6, concerning, the MFIVs. As this specification is currently written, one valve is allowed to be out of service when in Modes 2 through 4 as long as the inoperable valve is maintained in the closed position. This specification ensures that the MFIVs will close upon demand, minimizing any post-trip return to power due to plant cooldown after a steam line break, while maintaining the pressure increase within the bounds of the containment vessel design pressure in the event of a steam line break inside containment. Operation in Modes 2 through 4 with all MFIVs closed will assure this design function.

In accordance with the Combustion Engineering (CE) Standard Technical Specifications, Unit 2 Technical Specification 3.7.1.5 allows for passage into Modes 2,3 and 4 by stating that the provisions of Specification 3.0.4 are not applicable; the corresponding Unit 1 specification does not allow a similar exception. The proposed change would incorporate the exception to the provisions of Specification 3.0.4 in the Unit 1 Technical Specifications to allow for the testing of the MSIVs at operating conditions. The change would make both units specifications consistent and provide the necessary clarification that the valves remain closed during heatup until the required testing can be completed.

ATTACHMENT 4 DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATIONS The standards used to arrive at a determination that a request for amendment involves no significant hazards considerations are included in the Commission s regulations, 10 CFR 50.92, which states that no significant hazards considerations are involved the operation of the facility in accordance with the proposed if amendment would not (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety. Each standard is discussed as follows:

(1) Operation of the facility in accordance with, the proposed amendment would not involve a significant increase in the probability or consequences of an accident previously evaluated.

The bases for Technical Specifications 3.7.1.5 for Units 1 and 2 and Technical Specification 3.7.1.6 for Unit 2, state that the main steam isolation valves and main feedwater isolation valves are maintained in the closed position to ensure that the consequences of an excess steam demand event are limited. With the main steam line isolation valves and the main feedwater line isolation valves maintained closed the functional design bases under accident conditions are met.

by prohibiting the blowdown of both steam generators and ensuring that all main feedwater flow is stopped. Therefore, the potential for excessive cooldown of the reactor coolant system, and the accompanying return to power from subcritical conditions, are reduced by the proposed license amendment.

Adding the statement regarding the inapplicability of Technical Specification 3.0.4 to the Unit 1 MSIV specification is administrative in nature, and brings the Unit 1 specification into agreement with the Combustion Engineering (CE) Standard Technical Specifications. Changing Modes with the MSIVs closed does not involve any increase in accident probability or consequences because these valves will already be in their required accident position.

Determination of No Significant Hazards Considerations Page two

2) Use of the modified specification would not create the possibility of a new or different kind of accident from any accident previously evaluated.

Maintaining the main steam isolation valves and main feedwater isolation valves closed in Modes 2 through 4 does not create a new or different kind of accident from any previously established. Overpressurization of the main steam lines when the main steam line isolation valves are closed is prevented by the safety valves on the main steam lines.

The availability of feedwater to the steam generators is ensured by the operability requirements for the auxiliary feedwater system.

Allowing Unit 1 to change Modes while both main steam line isolation valves are closed is in accordance with the CE Standard Technical Specifications, and will not create the potential for a new or different kind of accident or event.

3) Use of the modified specification would not involve a significant reduction in a margin of safety.

By maintaining the main steam line and main feedwater isolation valves in a closed position, the potential consequences of a steam line break event are minimized, and the margins of safety provided in the accident analyses of record are increased.

Based upon the above, we have determined that the amendment request does not (1) involve a significant increase in the probability or consequences of an accident previously evaluated, (2) create the possibility of a new or different kind of accident from any previously evaluated, or (3) involve a significant reduction in a margin of safety, and therefore does not involve a significant hazards consideration.