ML20217P839

Application for Amends to Licenses NPF-10 & NPF-15,revising Containment Isolation Valves Completion Times

ML20217P839
Person / Time
Site:	San Onofre
Issue date:	04/06/1998
From:	Nunn D SOUTHERN CALIFORNIA EDISON CO.
To:	NRC
Shared Package
ML20217P827	List: ML20217P822 ML20217P839 ML20217P847
References
NUDOCS 9804100207
Download: ML20217P839 (9)

Text

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1 UNITED STATES OF AMERICA I

NUCLEAR REGULATORY COMMISSION Application of SOUTHERN CALIFORNIA

)

Docket No. 50-361 EDISON COMPANY, H AL.

for a Class 103

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License to Acquire, Possess, and Use

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Amendment Application j

a Utilization Facility as Part of

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No.158, Supplement 1 Unit No. 2 of the San Onofre Nuclear

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Generating Station

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SOUTHERN CALIFORNIA EDIS0N COMPANY, H AL. pursuant to 10 CFR 50.90, hereby submit Supplement 1 to Amendment Application No.158.

This amendment application supplement consists of Proposed Change Number (PCN)-460 to Facility Operating License No. NPF-10.

Supplement 1 to PCN-460 is a request to revise Technical Specification (TS) 3.6.3, " Containment Isolation Valves." The Proposed Change will provide Completion Times (cts) for Sections D.1 and D.2 valves which are consistent with the cts for the valves in the systems in which they are installed.

Supplement 1 provides additional information, including the results of a Probabilistic Risk Assessment. Supplement 1 also revises the requested change to clearly identify that the Limiting Condition for Operation of the Engineered Safety Feature System in which the valve is installed provides the completion time.

1 P

b Subscribed on this 6

day of APOL.

, 1998 Respectfully submitted, SOUTHERN CALIFORNIA EDIS0N COMPANY By:

Dwight Nunn Vice President State of California County of San Diego On 'And 6,19@before me, LdAAAoM M,

personally appeareddAuw W6 w, personally known to me to be the person whose name is subscribed to the within instrument and acknowledged to me that he executed the same in his authorized capacity, and that by his signature on the instrumert the person, or the entity upon behalf of which the person acted, executed the instrument.

WITNESS my hand and official seal.

4 mgm p

Comrrenton # 1130906 l

Nolary Puble-CaWowte 4

My 23,2001 >

Signature ho l'N LA4

4 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION Application of SOUTHERN CALIFORNIA

)

Docket No. 50-362 EDIS0N COMPANY, H AL.

for a Class 103

)

License to Acquire, Possess, and Use

)

Amendment App ication a Utilization Facility as Part of

)

No. 142, Supplement 1 Unit No. 3 of the San Onofre Nuclear

)

Generating Station

)

SOUTHERN CALIFORNIA EDIS0N COMPANY, H AL. pursuant to 10 CFR 50.90, hereby submit Supplement 1 to Amendment Application No.142.

This amendment application supplement consists of Proposed Change Number (PCN)-460 to Facility Operating License No. NPF-15.

Supplement 1 to PCN-460 is a request to revise the Unit 3 Amendment No. 116 approved Technical Specification (TS) 3.6.3, " Containment Isolation Valves." The Proposed Change will provide Completion Times (cts) for Sections D.1 and 0.2 valves which are consistent with the cts for the valves in the systems in which they are installed.

Supplement 1 provides additional information, including the results of a Probabilistic Risk Assessment. Supplement 1 also revises the requested change to clearly identify that the Limiting Condition for Operation of the Engineered Safety Feature System in which the valve is installed provides the completion s

time.

i 1

-Subscribed on this

[o day of A PRIL-1998.

Respectfully submitted, SOUTHERN CALIFORNIA EDISON COMPANY 1

S l

s l

By:

A k

W_ -

Y Dwight Nunn Vice President State of California

' County of San Diego On 3(Md 6,149"( before me, L4; personally appeared M d YW, personally known to me to be the person whose name is subscribed to the within instrument and acknowledged to me that he executed the same in his authorized capacity, and that by his signature on the instrument the person, or the entity upon behalf of which the person acted, executed the instrument.

1 mANCES M.THUMBt WITNESS my hand and official seal.

Commisson s HE06 Nokry Pub!Ic-Colferria San De County

)

i vi r-- r-1 t,'ar 23.2)tn Signature j

• N

DESCRIPTION AND SAFETY ANALYSIS-OF PROPOSED CHANGE NPF-10/15-460 This is a request to revise Unit 2 Technical Specification (TS) 3.6.3,

" Containment Isolation Valves," for the San Onofre Nuclear Generating Station.

1 Specifically, an allowance is proposed to extend the 4-hour Completion Time (CT) for Sections D.1 and D.2 valves during the conduct of maintenance or surveillance testing for these valves.

Amendment Nos.127 and 116 Acoroved Specifications b

Unit 2:

See Attachment "A" Unit 3:

'See Attachment "B" Proposed Specifications j

Unit 2:

.See Attachment "C" Unit 3:

See Attachment "D" Proposed Bases Chanaes Units 2 and 3: See Attachment "E" (For Information Only)

DESCRIPTION l

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The Probabilistic Risk Assessment (PRA) performed for Section D.1 and D.2 valves shows that the appropriate condition for Emergency Safety Feature (ESF) system penetrations is unisolated.

TS 3.6.3, " Containment Isolation Valves," requires that Section D.1 and D.2 valves be secured in their Engineered Safety Feature Actuation Signal (ESFAS)-

actuated position within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of becoming inoperable. This requirement is intended to ensure these valves will be able to perform their ESFAS functions.

Because-the TS requirement for Section D.1 and D.2 valves is to open these valves within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, the performance of on-line valve maintenance is precluded. This results in an increased work scope for the refueling outages and potentially extended outages. NRC approval of this license amendment request will' allow Southern California Edison (SCE) to schedule on-line Motor Operated Valve Testing (M0 VAT).

The Completion Times (cts) for these valves in their ESFAS function TSs are considerably longer than the 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> allowed in TS 3.6.3.

To resolve this inconsistency, St.E proposes to revise TS 3.6.3 to allow use of the appropriate cts for Section D.1 and D.2 valves as follows:

Under the Completion Time for Required Actions E.1 and F.1, change "4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />" to "In accordance with the applicable LC0 pertaining to the ESF system in which it is installed."

This proposed change will restore the cts for Required Actions E.1 and F.1 to the pre-Amendment Nos.'119 and 108 cts for D.1 and D.2 valves.

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SCE is planning to conduct on-line maintenance and Motor-0perated Valve Actuator Testing (MOVAT) for these valves to reduce refueling outage work scopes and budget.

These activities require more than 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to complete.

The Bases for Actions E.1 and F.1 are being revised accordingly to incorporate the proposed change.

The revised Bases for Units 2 and 3 are shown in Attachment E, and they are provided for information only.

DISCUSSION D.1 and 0.2 valves in TS 3.6.3, " Containment Isolation Valves," provide containment isolation and ESFAS functions. These valves are opened for their ESFAS function and closed for their containment isolation function.

Because of this dual function, the appropriate TSs are entered simultaneously when they become inoperable.

For example, when one or more High Pressure Safety Injection (HPSI) Section D.1 valve (s) becomes inoperable, both TSs 3.5.2, "ECCS-Operating," and 3.6.3 are entered.

TS 3.5.2 is the TS for the system in which these valves are installed, and it permits a 72-hour CT. TS 3.6.3 is the TS for these valves in their containment isolation function, and it requires that these valves be secured in their ESFAS actuated position within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> after becoming inoperable.

In such a case where more than one TS action simultaneously applies, the more restrictive action must be followed (i.e., the 4-hour CT).

SCE is planning to perform Motor-0perated Valve Actuator Testing (MOVAT) for D.1 and 0.2 valves online to reduce refueling outage work scope. However, the TS 3.6.3 4-hour CT precludes the conduct of these activities because SCE's maintenance and MOVAT programs are very intensive and completion of these activities normally requires between 42-52 hours. The maintenance and MOVAT activities and the times required to complete them are typically as follows:

ACTIVITY TIME RE0VIRED Work Authorization / Tag Hanging 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> Investigation / Repair 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Includes: Actuator maintenance /

repair as necessary Installation /repl acement/

{

calibration of strain i

gages, as appropriate l

Modification of Work Authorization to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> conduct MOVAT Motor-0perated Valve Actuator Testing 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> Closure / release of Work 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Authorization Contingency-applied to repair time 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> above if the work is significant TOTAL 52 hours6.018519e-4 days <br />0.0144 hours <br />8.597884e-5 weeks <br />1.9786e-5 months <br /> J

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i In addition to MOVAT, this change supports on-line valve maintenance and post maintenance testing. This capability facilitates returning full operating function to these valves, thereby improving the systems' material condition.

This proposed allowance to extend the 4-hour CT during maintenance or surveillance activities up to the CT of the systems in which these valves are installed is consistent with the CT for these valves prior to the issuance of San Onofre Unit 2 Amendment No. 119 and Unit 3 Amendment No. 108, which were i m 'd in response to PCN-430.

PCN-430 was a request to revise TS 3.6.3 to add the requirements of Actions E.2 and F.2 based on the results of a Probabilistic Risk Assessment (PRA), which estabb shed specific limits on the length of time D.1 and D.2 valves may be pi nea in their ESFAS actuated positions.

The results of the PRA concluded that these time limits would not result in a significant increase in the risk of either core damage frequency or significant radioactive release frequency.

The results of the PRA also concluded that the existing CT in TS 3.6.3 (i.e., the CT for the system in which the valves are installed) should be maintained in Actions E.1 and F.1.

The PRA study for PCN-430 was updated using the current living PRA model to re-assess the risk associated with the proposed change. The results of the analysis concluded that extending the 4-hour CT for D.1 and D.2 valves, up to the CT for the system in which the valve is installed, would result in a "very small" risk increase in core damage or large early release (i.e.,

< 5.0E-07/ year for core damage probability and < 5.0E-08/ year for large early release probability per the NRC risk acceptance criteria in DG-1061 and DG-1065).

Furthermore, several risk reduction compensatory measures associated with the proposed change are expected to offset the calculated very small increase in risk, resulting in a risk neutral change, as follows:

Performing these on-line maintenance and M0 VATS during non-outage periods can be effectively scheduled using in-house personnel with no interference with usually very busy outage activities. This would reduce the potential for human error and hence reduces risk.

The proposed CT allowan e provides sufficient time to methodically perform on-line maintenance (preventive and corrective) and surveillance activities (e.g., MOVAT). This enhances the quality of maintenance and MOVAT work and ultimately the reliability of the motor-operated valves.

The proposed CT allowance is intended to be used during maintenance and surveillance testing activities on D.1 and D.2 valves, and as has always been SCE's policy, work on these valves will be around-the-clock to ensure these valves are returned to operable status as soon as practicable.

Performing on-line maintenance or M0 VAT without the need to shutdown the plant eliminates the shutdown transition risk.

This change will allow maintenance and testing to be performed on-line.

This will increase the capability to restore these valves to OPERABLE status and to periodically verify they remain OPERABLE.

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SAFETY ANALYSIS The pro'osed change described above shall be deemed to involve a significant p

hazards consideration if there is a positive finding in any one of the following areas:

1.

Will operation of the facility in accordance with this proposed change involve a significant' increase in the probability or consequences of an accident previously evaluated?

Response: No-The proposed note in Conditions E and F of Technical Specification (TS) 3.6.3 allows additional time during on-line maintenance and/or surveillance testing (e.g., motor-operated valve actuator testing) for D.1 and D.2 containment isolation valves.

This proposed Completion Time (CT) extension of up to the CT of the Engineered Safety Feature (ESF) systems in which these valves are installed is consistent with the CT for these valves prior to the issuance of San Onofre Unit 2 Amendment No. 119 and Unit 3 Amendment No. 108, which were issued in response to Proposed Change Number (PCN) 430, of the existing TSs.

PCN-430 was a request to revise TS 3.6.3 to add the requirements of Actions E.2 and F.2 based on the results of a Probabilistic Risk Assessment (PRA) which established specific limits on the length of time D.1 and D.2 valves may be placed in their ESFAS actuated positions. The results of the PRA concluded that these time limits would not result in a significant increase in the risk of either core damage frequer.cy or significant radioactive release frequency. The results of the PRA also concluded that the existing CT (the CT for the ESF system in which these-valves are installed) for Actions E.1 and F.1 should be maintained in TS 3.6.3.

The probability of an accident and the consequences of an accident are not affected since no physical change is made and the Safety Analysis f

remains unaffected. Therefore, operation of the facility in accordance with this change will not involve a significant increase in the probability or consequences of an accident previously evaluated.

2.

Will operation of the facility in accordance with this proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No The proposed change does not influence the possibility of a new or different kind of accident from any previously evaluated because no physical change is made and the Safety Analysis is not affected.

Therefore, operation of the facility in accordance with this proposed change will not. create the possibility of a new or different kind of accident from any accident previously evaluated.

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3.

Will operation of the facility in accordance with this proposed change involve a significant reduction in a margin of safety?

Response: No The margin of safety is. unaffected since this proposed change is consistent with the cts in the TSs governing the system in which.these valves are installed. Therefore, this proposed change will not involve a significant reduction in a' margin of safety.

Safety and Sianificant Hazards Determination Based on the above Safety Analysis, it is concluded' that: 1) the proposed change does not constitute a significant hazards consideration as defined by 3

10 CFR 50.92 and 2) there is reasonable assurance that the health and safety of the public will not be endangered by the proposed change. Moreover,

.because this action does not involve a significant hazards _ consideration, it will also not result in a condition which significantly alters the impact of the station on the environment as described in the NRC Final Environmental Statement.

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