ML20155C223

Forwards Draft Ltr from STP Nuclear Operating Co on Action Needed for Implementation of Graded QA for Plant Units 1 & 2 for Placement in PDR

ML20155C223
Person / Time
Site:	South Texas
Issue date:	10/29/1998
From:	Alexion T NRC (Affiliation Not Assigned)
To:	NRC (Affiliation Not Assigned)
References
NUDOCS 9811020150
Download: ML20155C223 (3)

Text

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October 29, 1998 MEMORANDUM TO: PD IV-1 File FROM: Thomas W. Alexion, Project Manager ORIGINAL SIGNED BY Project Directorate IV-1 Division of Reactor Projects - Ill/lV l

Office of Nuclear Reactor Regulation '

SUBJECT:

DRAFT LETTER FROM STP NUCLEAR OPERATING COMPANY ON ACTION NEEDED FOR THE IMPLEMENTATION OF GRADED QUALITY ASSURANCE, SOUTH TEXAS PROJECT, UNITS 1 AND 2 On October 6,1998, STP Nuclear Operating Company (STPNOC) provided the attached draft letter to the Nuclear Regulatory Commission (NRC) on the above subject. On October 14,1998, STPNOC subsequently finalized the letter and formally submitted it to the j i  !

NRC. The purpose of this memorandum is to place the draft letter in the Public Document Room. ,

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! Docket Nos. 50-498 and 50499 I

Attachment:

As stated l

l DISTRIBUTION:

[ EDocket File (50-498l50 499)*

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October xx,1998 J NOC-AE-STI File No.:

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U. S. Nuclear Regulatory Commission Attention: Document ControlDesk Washington, DC 20555 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499  !

Action Needed for the Imolementation of Graded Ouality Assurance at the South Texa STP Nuclear Operating Company (STPNOC) received a Safety Evalua on November 6,1997 granting approval from the NRC to implement a Graded Qu (GQA) program.

The South Texas Project GQA program utilizes risk ranking of structur systems, and components derived from the STP Probabilistic Risk Assessment(PRA),

' deterministic inputs from a Working Group. Those inputs are reviewed by an develop the final risk-informed results. The STP PRA has been reviewed and 4

! NRC and has been used for various licensing applications. Based on the credibility methods and the rigor of the STP review, STP has a high level of confidence in the ris results done for the GQA program. The risk evaluation results demonstrated that number of the current safety-related components have very low risk significance, or ha significance.

The results show that there is substantial safety and cost benefit available from implementation of a GQA program.

These beneSts derive from the potential reduction in regulatory and licensee resource allocation to systems and components that have no subs influence on safety or reliability of the station. However, as discussed with the NRC staff meeting on September 15,1998, there are regulatory cornpliance barriers which grea complete implementation of the GQA program. These barriers are embodied in the reg themselves, such as the definition of safety-related structures, systems, and compone 10CFR50.2, and the present requirements of 10CFR50.59. These barriers were reco carly on in the approval process for the GQA program, however, conversations with NRC sta clearly indicated that an interactive process was the prudent path to pursue. STP believes tha complete implementation of an effective GQA program requires that the conflicts with these

- deterministic regulatory requirements be clearly addressed and resolved.

As we discussed in a phone call with the NRC staff on September 23,1998, STP intends to request exemption from the appropriate regulations to allow downgrading of low or non-risk significant safety-related components identiSed by the risk ranking tool to non-safety related or n important to safety, thereby removing these components from the scope of various deterministic regulations. This would allow STP to recognize substantial results from the GQA program in the l near term without which the viability of the program is limited.

l ATTACle!ENT te/Ze*d 8628 246 EtS M SN3011 hiO3 DIN tt:80 866t-90-100

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p NOC-AE-Page 2 We believe this effort could serve to extend the scope of the existing GQA pilot activity would support the ongoing evaluation of risk based changes to regulations and can be appr implemented in the short term. It is also our belief that the end result will be a methodolo offers substantial benefit beyond STP and insight to the structure of risk informed regulatio pilot, some limitations on the overall scope of the effort and the NRC participation in the p appropriate, Specifically:

a The systems to which this exemption will be applied will be specifically identified.

The applicable exemptions are expected to focus on removing components from the  !

scope of the seismic, equipment qualification and ASME rules such that the complexity l of routine maintenance and replacement can be reduced without substantive reduction in overall plant safety.

STP would enter into this pilot with the expectation that NRC would approve expanding the scope at the successful conclusion of the pilot.

If you should have any questions conceming this matter please contact me at (512) 972-8787.

AWH/nl T. H. Cloninger

. Vice President Engineering and Technical Senices CO/C0*d 8628 22.6 2tS ONISN30I"I 8037 DON Et:80 866t-90-100