ML20236V768

Forwards RAI Re Comanche Peak Steam Electric Station License Amend Request LAR 96-006 to Increase Allowed Outage Time for Charging Pumps from 72 H to 7 Days

ML20236V768
Person / Time
Site:	Comanche Peak
Issue date:	07/30/1998
From:	Polich T NRC (Affiliation Not Assigned)
To:	Terry C TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
References
TAC-M97809, TAC-M97810, NUDOCS 9808040195
Download: ML20236V768 (5)

Text

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l l-Mr. C. Lance Terry.

July 30, 1998 l

TU Electric l

Group Vice President, Nuclear Attn: Regulatory Affairs Department P. O. Box 1002 i

Glen Rose, TX 76043 l

SUBJECT;.. REQUEST FOR ADDITIONAL INFORMATION ON COMANCHE PEAK STEAM

~ ELECTRIC STATION (CPSES) LICENSE AMENDMENT REQUEST (LAR)96-006 -

INCREASED ALLOWED OUTAGE TIME FOR CHARGING PUMPS FROM 72 HOURS TO 7 DAYS (TAC NOS. M97809 AND M97810) l

Dear Mr. Terry:

l Based on our review of the Texas Utilities Electric LAR 95-006 (TXX-96434) dated August 2,

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1996, the NRC staff has identified additionalinformation needed to continue its review. The L

. detailed request for additional information (RAl) is discussed in the enclosure.

l

.We reque:t your response to our RAI within 60 days of receipt of this letter, if you have any 1

questions, please call me at (301) 415-1038.

l l

Sincerely, s ORIGINAL SIGNED BY:

Timothy J. Polich, Project Manager l

L Project Directorate IV-1 Division of Reactor Projects Ill/IV j

Office of Nuclear Reactor Regulation Docket Nos. 50-445 and 50-446 l

Enclosure:

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July 30, 1998 Mr. C. Lance Terry TU Electric Group Vice President, Nuclear

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i Attn: Regulatory Affairs Department P. O. Box 1002 Glen Rose, TX 76043

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION ON COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) LICENSE AMENDMENT REQUEST (LAR)96-006 INCREASED ALLOWED OUTAGE TIME FOR CHARGING PUMPS FROM 72 HOURS TO 7 DAYS (TAC NOS. M97809 AND M97810)

Dear Mr. Teny:

Based on our review of the Texas Utilities Electric LAR 95-006 (TXX-96434) dated August 2, 1996, the NRC staff has identified additionalinformation needed to continue its review. The detailed request for additional information (RAI) is discussed in the enclosure.

We request your response to our RAI within 60 days of receipt of this letter, if you have any questions, please call me at (301) 415-1038.

N ; 'erely, Timothy J. Polich, Project Manager Project Directorate IV-1 Division of Reactor Projects lil/IV Office of Nuclear Reactor Regulation Docket Nos. 50-445 and 50-446

Enclosure:

RAI cc w/ encl: See next page i

i L-____-----_-----__---_--_---.

Mr. C. Lance Terry TU Electric Company Comanche Peak. Units 1 and 2 cc:

Senior Resident inspector Honorable Dale McPherson U.S. Nuclear Regulatory Commissian County Judge P. O. Box 2159 P. O. Box 851 l

Glen Rose, TX 76403-2159 Glen Rose, TX 76043 l

Regional Administrator, Region IV Office of the Govemor U.S. Nuclear Regulatory Commission ATTN: John Howard, Director 611 Rysn Plaza Drive, Suite 400 Environmental and Natural Arlington, TX 76011 Resources Policy l

P. O. Box 12428 Mrs. Juanita Ellis, President Austin, TX 78711 Citizens Association for Sound Energy 1426 South Polk Arthur C. Tate, Director l

Dallas, TX 75224-Division of Compliance & Inspection 1

i Bureau of Radiation Control Mr. Roger D. Walker Texas Department of Health l

TU Electric 1100 West 49th Street Regulatory Affairs Manager Austin, TX 78756-3189 l

P. O. Box 1002 Glen Rose, TX 76043 Jim Calloway Public Utility Commission of Texas i

George L. Edgar, Esq.

Electric Industry Analysis Morgan, Lewis & Bockius P. O. Box 13326 1800 M Street, N.W.

Austin, TX 78711-3326 Washington, DC 20036-5869 f

I l

i

n Additional PRA-Related Information Reauired for the Review of the Procesed Comanche l

Peak Charoina Pump AOT Extension from 3 to 7 davs Comanche Peak used a risk argument to justify the proposed allowed outage time (AOT) l extension for the centrifugal charging pumps (CCPs). The staff evaluation of the amendment generally follows the recently approved Regulatory Guide (RG) 1.174' and 1.1772, in which a l

three-tiered approach has been identified for licensees to eva uate the risk associated with risk-l informed modifications to technical specifications (TS). In short, Tier 1 is an evaluation of the l

impact on plant risk, Tier 2 is an identification of potentially high risk configurations, and Tier 3 is l

the establishment of an overall configuration risk management program. Therefore, the following information is needed for the review of the requested application for CCP AOT extension.

Tier 1: Risk Impact and Probabilistic Risk Assessment (PRA) Validity 1.

Provide the following risk measures for the staff review of the risk impact of the proposed change. The results from extemal events should be addressed quantitatively or qualitatively, Instantaneous core damage frequency and Large Eariy Release Frequency given a a.

CCP is out of service. Discuss the difference in results between preventive maintenance and corrective maintenance.

b.

Change in LERF due to the proposed change.

I 2.

Discuss, quantitatively or qualitatively, the averted risk (during transition and shutdown) i stemming from being able to perform m sintenance at power instead of during shutdown, j

which would be possible by the longer AOT. Describe your, or industry, experience j

associated with forced shutdown due to the current three-day AOT for CCPs. What is your expected frequency that you would use the proposed longer AOT?

3.

Provide the following information regarding PRA adequacy for the proposed application, a.

We believe that your current intemal event PRA is still the same as the original Individual Plant Examination (IPE) in 1992. Explain how the IPE is still an adequate tool for the proposed application by discussing the changes made to the plant since the development of the iPE and their impact on risk.

I b.

Describe any independent peer reviews performed on your PRA. Discuss your current effort to update your PRA. (include discussion on both intemal and extemal events).

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3 RG 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Current Licensing Basis" 2 RG 1.177,"An Approach for Plant-Specific, Risk-informed Decisionmaking: Technical Specifications" ENCLOSURE

f 2

Describe the success cdteria used for CCPs for different initiating events in your c.

PRA and briefly exp!ain the justifications.

d.

Describe your reliability and caavailability data for CCPs during last three years and compare with the data used in your PRA. Describe the result of any sensitivity study associated with the reliability and unavailability data.

Describe any uncertainty / sensitivity analysis per.ormed in support of the requested e.

change.

j Tier 2: Restriction on Hiah Risk Configuration i

4.

What are risk significant components / systems (according to your PRA) given a CCP is out of service? For those component / systems, describe what type of restrictions, or compensatory actions, e.g., TS and plant administrative procedures, would be in place to avoid / reduce potential ritk-significant configurations.

Tier 3: Configuration Risk Manaaement Proaram 5.

Describe your programs that provide reasonable assurance that the risk impact of out-of-service equipment is appropriately evaluated prior to and while performing any i

maintenance activity.

l 6.

The staff has determined that the TS Administrative Control section should describe the licent ee's program for performing a contemporaneous assessment of the overallimpact on safety of proposed plant configurations. In addition, the Bases for TS for which an i

extended AOT is granted should reference this program description. The program

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description, which is described in RG 1.177, should be incorporated into the TS l

Administrative Controls section.

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