ML033440343

Fwd: RI-IST Files to Be Forwarded to the NRC

ML033440343
Person / Time
Site:	South Texas
Issue date:	10/29/2003
From:	Head S South Texas
To:	Jaffe D NRC/NRR/DLPM/LPD4
Jaffe D, NRR/DLPM, 415-1439
References
Download: ML033440343 (7)

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Fwd: RI-IST Files to be Forwarded to the NRC Creation Date: 10/29/03 10:24AM From: "Scott Head" <smhead@stpegs.com>

Created By: smhead @ stpegs.com Recipients nrc.gov owf4_po.0WFNDO DHJ (David Jaffe)

Post Office Route owf4_po.0WFNDO nrc.gov Files Size Date & Time MESSAGE 14 10/29/03 10:24AM Mail Mime.822 76336 Options Expiration Date: None Priority: Standard Reply Requested: No Return Notification: None Concealed

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No Security: Standard

P d Jaffe - Fwd: RI-IST Files to be Forwarded to the NRC DaI Page- 1 From: 'Scott Head" <smhead @stpegs.com>

To: <Dhj~nrc.gov>

Date: 10/29/03 10:26AM

Subject:

Fwd: RI-IST Files to be Forwarded to the NRC As promised.

I David Jaffe - RI-IST Files to be Forwarded to the NRC Page 1 I From: 'Glen Schinzel <geschinzel@stpegs.com>

To: 'Scott Head" <smhead~stpegs.com>

Date: 10/29/03 8:33AM

Subject:

RI-IST Files to be Forwarded to the NRC Scott, here are the files to be forwarded to the NRC to support an RI-IST phone call on Thursday.

Glen CC: 'Bradley Scott <bjscott~stpegs.com>, "Carl Grantom" <crgrantom~stpegs.com>,

"Daniel Stillwell" <dwstillwell @stpegs.com>, "Mark McBurnett <mamcburnett @stpegs.com>, "Michael Berg" <mjberg@stpegs.com>, 'Philip Walker' <plwalker@stpegs.com>

STP's Approach for a Future RI-IST Resubmittal

• Resubmittal of RI-IST will comply with SONGS template

• F-V threshold adjusted

• Treatment of RAW common cause adjusted

• RG-1.175 satisfied

• RI-IST process will only be applied to those components remaining within the scope of IST following application of the Exemption allowances

• RI-IST will not affect the GQA categorization results nor the scope of components subjected to IST controls

• RI-IST treatments will comply with the SONGS approach

• RI-IST 'High' SSCs continue to receive full treatment

• RI-IST 'Low/High' SSCs can have intervals between tests extended as long as compensatory measures are put in place

• RI-IST 'Low' SSCs can have intervals extended up to a 6 year periodicity

• Determine if terminology of 'High, Low/High, Low' can be changed to something like 'IST Treatment Category 1, 2, 3'

• IST-scoped AOVs will follow JOG AOV recommendations (same as SONGS approach)

• RI-IST proposed testing strategies will be generated by a RI-IST Working Group, and approved by the Comprehensive Risk Management Expert Panel (same Panel that reviews and approves the GQA categorization results)

• While some RP-1ST treatment categories may initially appear inconsistent with GQA categorization results, the RI-IST treatment categories focus on defining required inservice testing only

• RI-IST component examples will be used to demonstrate how an RI-IST treatment category compares to the GQA categorization

Low Head Safety Injection Pump 1A Discharge MOV - 2N121XSIO018A GOA Rank: Medium Basis: Supports the following system functions

• High risk: Injection and Cold leg recirc modes

• Medium risk: Hot leg recirc mode

• Low risk: Pressure boundary and Containment Isolation GQA ranked Medium based on:

• Initial PRA rank of Medium (recently lowered to Low)

• Redundant Trains

• Valve is normally open and stays open (i.e., passive) to support the High-risk functions.

Transfer closed is not a credible failure.

• Valve is closed to isolate RHR from the LHSI pump when RHR is used for long-term accident recovery. Failure to close mitigated by the inside containment check valve.

RI-IST Treatment: Low Basis: Valve is normally open which satisfies its safety function The 'remain open' function is considered passive IST testable function is to 'close on demand' RI-IST Treatment of Low based on:

• F-V value of 4.3E-4 and a RAW value of 1.2

• Valve is normally in it's required safety position - no change of state required

• Redundancy exists with three 100% safety trains to satisfy the injection modes

• Diversity exists with 3 High Head pumps to support recirculation and injection

• Valve is routinely monitored by other means to check valve position and flow

==

Conclusion:==

The GQA categorization process initially determines the risk of system functions, and then determines the risk of individual components that support these functions. The RI-IST process focuses directly on IST-scoped components and determines their specific importance. The GQA approach introduces additional conservatisms into the categorization process since all components in a given system are assessed. In addition, the GQA Working Group deterministically ranked this component as Medium risk based on its support of High-ranked functions.

Low Head Safety Injection Pump 1A - 2N121NPA102A GOA Rank: High Basis: Supports the following system functions

• High risk: Injection and Cold leg recirc modes

• Medium risk: Hot leg recirc mode

• Low risk: Pressure boundary and positive RCS volume control GQA ranked High based on:

• Initial PRA rank of High (recently lowered to Medium*)

• Supports High risk functions

• No credit taken for redundancy RI-IST Treatment: Low Basis: Active function to 'start and run' to support injection and recirculation functions RI-IST Treatment of Low based on:

• F-V value of 7.78E-4 and a RAW value of 1.2

• Redundancy exists with three 100% safety trains to satisfy the injection modes

• Diversity exists with 3 High Head pumps to support recirculation and injection

==

Conclusion:==

The GQA categorization process initially determines the risk of system functions, and then determines the risk of individual components that support these functions. The RI-IST process focuses directly on IST-scoped components and determines their specific importance. The GQA approach introduces additional conservatisms into the categorization process since all components in a given system are assessed. Also, the GQA process conservatively addresses RAW common cause, whereas the RI-IST process addresses common cause using the SONGS template. In addition, the GQA Working Group deterministically ranked this component as High risk based on its support of High-ranked functions with no credit taken for redundancy.

RESIDUAL HEAT REMOVAL SYSTEM REDUNDANT 3-TRAIN rn~

i 0 RHR M RECIRC 0 LHSI ED ACC. SI O HHSI FIGURE 1