ML113220455

Request for Additional Information Regarding Risk-Informed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program (Adoption of Technical Specification Task)

ML113220455
Person / Time
Site:	Millstone
Issue date:	12/08/2011
From:	Sanders C Plant Licensing Branch 1
To:	Heacock D Dominion Nuclear Connecticut
Sandeers, Carleen, NRR/DORL, 415-1603
References
TAC ME6695
Download: ML113220455 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 December 8, 2011 Mr. David A. Heacock President and Chief Nuclear Officer Dominion Nuclear Connecticut, Inc.

Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711

SUBJECT:

MILLSTONE POWER STATION, UNIT NO.3 - REQUEST FOR ADDITIONAL INFORMATION REGARDING RELOCATION OF SPECIFIC SURVEILLANCE FREQUENCY REQUIREMENTS TO A LICENSEE-CONTROLLED PROGRAM ADOPTION OF TECHNICAL SPECIFICATION TASK FORCE 425, REVISION 3 (TAC NO. ME6695)

Dear Mr. Heacock:

By letter dated July 5, 2011, as supplemented by letter dated September 12, 2011, 1 Dominion Nuclear Connecticut, Inc. (DNC or the licensee) submitted a license amendment request for Millstone Power Station, Unit NO.3 (MPS3). The proposed amendment would relocate certain technical specification (TS) surveillance frequencies to a licensee-controlled program by adopting Technical Specification Task Force (TSTF)-425, Revision 3, "Relocate Surveillance Frequencies of Licensee Control - RITSTF [Risk-Informed Technical Specification Task Force Initiative] 5b." The proposed change would also add a new program, the Surveillance 2

Frequency Control Program (SFCP), to the TSs, in accordance with TSTF-425. TSTF-425 is approved for use by the U.S. Nuclear Regulatory Commission (NRC) and a Notice of Availability was issued in the Federal Register on July 6, 2009 (74 FR 31996). The NRC staff has reviewed the information submitted by the licensee, and based on this review, determined that additional information is required to complete the evaluation.

The draft questions were sent to Mr. William Bartron, of your staff, to ensure that the questions were understandable, the regulatory basis for the questions was clear, and to determine if the information was previously docketed. On November 29, Ms. Wanda Craft, of your staff, agreed that you would provide a response by January 19, 2012. Please note that if you do not respond to this letter by the agreed-upon date or provide an acceptable alternate date in writing, we may reject your application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108.

1 Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML11193A225 and ML11262A003, respectively 2 ADAMS Accession No. ML090850642

D. Heacock - 2 If you have any questions regarding this matter, please contact me at 301-415-1603.

Sincerely, c~ lders~ager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-423

Enclosure:

Request for Additional Information cc w/encls: Distribution via ListServ

REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST REGARDING RELOCATION OF SPECIFIC SURVEILLANCE FREQUENCY REQUIREMENTS TO A LICENSEE-CONTROLLED PROGRAM DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION, UNIT NO.3 DOCKET NUMBER 50-423 By letter dated July 5, 2011, as supplemented by letter dated September 12, 2011, 1 Dominion Nuclear Connecticut, Inc. (DNC or the licensee) submitted a license amendment request for Millstone Power Station, Unit NO.3 (MPS3). The proposed amendment would relocate certain technical specification (TS) surveillance frequencies to a licensee-controlled program by adopting Technical Specification Task Force (TSTF)-425, Revision 3, "Relocate Surveillance Frequencies of Licensee Control- RITSTF [Risk-Informed Technical Specification Task Force Initiative] 5b." The proposed change would also add a new program, the Surveillance Frequency Control Program (SFCP), to the TSs, in accordance with TSTF-425. TSTF-4252 is approved for use by the U.S. Nuclear Regulatory Commission (NRC) and a Notice of Availability was issued in the Federal Register on July 6,2009 (74 FR 31996).

The NRC staff has reviewed the information submitted by the licensee, and based on its review, determined the following information is required to complete the evaluation:

1. The licensee has identified five "gaps" in the MPS3 probabilistic risk assessment (PRA) model's conformance to the American Society of Mechanical Engineers internal events PRA standard. These gaps collectively cover eight deficiencies in meeting the supporting requirements (SRs) of the PRA standard, Capability Category II. The "description" and "current status" columns in Table 1, Attachment 2, of the July 5, submittal, adequately describe these gaps. However, the "importance to application" column only restates that the gap is a model logic issue and that sensitivity studies will be conducted. The significance of these gaps to the overall PRA results and to the risk calculations supporting changes to surveillance frequencies is not discussed, and must be addressed in order for the NRC staff to reach a conclusion on the significance of these gaps as related to this amendment request.

Provide a discussion of the significance of each of the five gaps identified in Table 1 of Attachment 2. Where applicable, provide a quantitative assessment of the sensitivity of core 1 Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML11193A225 and ML11262A003, respectively 2 ADAMS Accession No. ML090850642 Enclosure

-2 damage frequency (CDF) and large early release frequency (LERF) results. In addition, the following specific concerns should be addressed in your response:

Gap 1: The lack of modeling ventilation dependencies was specifically identified as a recommendation from the NRC staffs review of the MPS3 Individual Plant Examination (lPE). According to the model update timeline provided in the July 5, submittal, this was completed in December 1995. It is not clear how this same issue arises in a 2007 self assessment. What is unique about these three specific ventilation subsystems which led to them not being modeled as a required support system following the 1995 IPE?

Gap 2: Changes to surveillance test intervals can directly impact an associated pre-initiator human error probability by reducing the opportunities for identification and restoration of a system misalignment. What is the scope of pre-initiator human errors currently in the PRA model, and what is the basis for their inclusion in the model, absent a review of plant procedures and practices? Is resolution of this gap expected to add to the pre-initiator scope significantly?

Gap 4: The NRC staff review of the internal flooding analysis for the IPE also identified the lack of discussion regarding maintenance-induced flooding. What internal flooding sources are currently considered and what is the basis for their frequencies? Is resolution of this gap expected to increase the contribution of internal floods to CDF and LERF significantly? What is the schedule for addressing these contributors?

2. The licensee identified an industry peer review being conducted in 1999, and stated that the "A" and "8" findings from the review have been addressed. Are there other remaining open findings, from that review, which are related to different issues than those identified in the self-assessment conducted in 2007? Describe any such findings and their potential impact on this application.

3. The self-assessment results identified 39 SRs, related to documentation and uncertainty evaluations, which do not meet PRA Capability Category II. The details of these SRs are not discussed in the July 5, submittal. The characterization of uncertainties is essential to assure that PRA results supporting changes in test frequencies are understood by the independent decision-making panel in order to adequately implement TSTF-425. Further, proper documentation is essential for maintaining the PRA model and understanding the results. Finally, the NRC staff is concerned about the number of SRs in these specific areas, and notes that its review of the MPS3 IPE submittal also identified several specific areas where documentation needed enhancement.

Describe the nature of the deficiencies in documentation and uncertainty evaluations, including the current state of the PRA documentation and uncertainty analyses, and schedule for resolution of these items.

D. Heacock -2 If you have any questions regarding this matter, please contact me at 301-415-1603.

Sincerely, IraJ Carleen J. Sanders, Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-423

Enclosure:

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PUBLIC LPLI-2 R/F RidsAcrsAcnw_MailCTR Resource RidsNrrDorlDpr Resource RidsNrrDorlLpl1-2 Resource RidsNrrDraApla Resource RidsNrrPMMilistone Resource RidsNrrLAABaxter Resource RidsOgcRp Resource RidsRgn1 MailCenter Resource A. Howe, NRR ADAMS A ccesslon NO ... ML113220455 *b>y Memo D ated OFFICE NRR/LPLI-2/PM NRR/LPLI-2/LA NRRIDRAIAPLA NRR/LPLI-2/BC NAME CSanders ABaxter D. Harrison* HChernoff DATE 12/6/11 12/5/11 09/28/2011 12/8111 Official Record Copy