ML063390116

Fax - Draft Request for Additional Information Regarding Post-Maintenance/Modification Surveillance Requirements

ML063390116
Person / Time
Site:	Millstone
Issue date:	12/19/2006
From:	Nerses V NRC/NRR/ADRO/DORL/LPLI-2
To:	Chernoff H NRC/NRR/ADRO/DORL/LPLI-2
Nerses V
References
TAC MD0693
Download: ML063390116 (5)

Text

December 19, 2006 MEMORANDUM TO: Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM: Victor Nerses, Senior Project Manager /G. E. Miller RA for/

Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

SUBJECT:

MILLSTONE POWER STATION, UNIT NO. 3 - FACSIMILE TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING POST-MAINTENANCE/MODIFICATION SURVEILLANCE REQUIREMENTS (TAC NO. MD0693)

The attached draft request for additional information (RAI) was transmitted on December 19, 2006, to Mr. Paul Willoughby, at Dominion Nuclear Connecticut, Inc. (DNC) by facsimile. This was done to support a telephone conversation to facilitate the review being conducted by the Nuclear Regulatory Commission (NRC) staff in order to clarify certain items in the licensees submittal. The draft RAI is related to DNCs submittal dated March 28, 2006, regarding a request for deleting redundant surveillance requirements pertaining to post-maintenance/post-modification testing. Review of the draft RAI will allow DNC to determine and agree upon a schedule for response to the RAI. This memorandum and the attachment do not represent an NRC staff position.

Docket No. 50-423

Enclosure:

As stated

December 19, 2006 MEMORANDUM TO: Harold K. Chernoff, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM: Victor Nerses, Senior Project Manager /G. E. Miller RA for/

Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

SUBJECT:

MILLSTONE POWER STATION, UNIT NO. 3 - FACSIMILE TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING POST-MAINTENANCE/MODIFICATION SURVEILLANCE REQUIREMENTS (TAC NO. MD0693)

The attached draft request for additional information (RAI) was transmitted on December 19, 2006, to Mr. Paul Willoughby, at Dominion Nuclear Connecticut, Inc. (DNC) by facsimile. This was done to support a telephone conversation to facilitate the review being conducted by the Nuclear Regulatory Commission (NRC) staff in order to clarify certain items in the licensees submittal. The draft RAI is related to DNCs submittal dated March 28, 2006, regarding a request for deleting redundant surveillance requirements pertaining to post-maintenance/post-modification testing. Review of the draft RAI will allow DNC to determine and agree upon a schedule for response to the RAI. This memorandum and the attachment do not convey a formal request for information or represent an NRC staff position.

Docket No. 50-423

Enclosure:

As stated DISTRIBUTION:

PUBLIC LPL1-2 R/F RidsNrrLACRaynor RidsNrrPMGMiller RidsNrrDorlLpl1-2 ADAMS Accession Number: ML063390116 OFFICE LPL1-2/PM LPL1-2/LA EEEA/BC SCVB/BC LPLI-2/BC NAME VNerses CRaynor GWilson RDennig HChernoff

/Ed Miller for/

DATE 12/19/06 12/14/06 12/17/06 12/01/06 12/18/06 OFFICIAL RECORD COPY

DRAFT REQUEST FOR ADDITIONAL INFORMATION MILLSTONE POWER STATION, UNIT 3 POST MAINTENANCE/MODIFICATION SURVEILLANCE REQUIREMENTS DOCKET NO. 50-423 By letter dated March 28, 2006, Dominion Nuclear Connecticut, Inc. (DNC, the licensee) submitted a request for deleting redundant surveillance requirements (SRs) pertaining to post-maintenance/post-modification testing. The Nuclear Regulatory Commission (NRC) staff requests the following additional information to complete its review.

In the submital, dated March 28, 2006, DNC requested to amend SR 4.6.6.1.b, SR 4.7.7.c and SR 4.7.9.b. The proposed amendment would be similar for all three SRs. The three SRs respectively, pertain to the Supplementary Leak Collection and Release Systems, the Control Room Emergency Air Filtration System, and the Auxiliary Building Filter Systems.

In each SR, the requirement to demonstrate the subject filter train OPERABLE following (1) after any structural maintenance on the HEPA [high-effiency particulate air] filter or charcoal adsorber housings... would be removed from the Technical Specifications (TSs).

1. The licensee requested these proposed amendments to the TSs on the bases of:

(a) indicating that the deleted post structural maintenance SR test requirements are bounded by and redundant of the generic requirement contained in SR 4.01 regarding performance of appropriate retest activities following maintenance or modification. SR 4.01 is generic in scope and reads:

4.0.1 Surveillance Requirements shall be met during the OPERATIONAL MODES or other conditions specified for individual Limiting Conditions for Operation unless otherwise stated in an individual Surveillance Requirement. Failure to meet a Surveillance, whether such failure is experienced during the performance of the Surveillance or between performances of the Surveillance, shall be failure to meet the Limiting Condition for Operation. Failure to perform a Surveillance within the specified surveillance interval shall be failure to meet the Limiting Condition for Operation except as provided in Specification 4.0.3.

Surveillances do not have to be performed on inoperable equipment or variables outside specified limits.

Please provide additional information as to how SR 4.01 assures that the in-place bypass testing results obtained during the 24-month surveillance are still valid after structural maintenance on the filter housing if the test is not repeated.

(b) invoking verbiage pertaining to Surveillance Requirements from 10 CFR [Title 10 of the Code of Federal Regulations] 50.36(c)(3) and stating that the proposed SR changes ... will not impact requirements related to test, calibration, or inspection to ensure that the necessary quality of systems and components is maintained.

Enclosure

As the licensee indicates, 10 CFR 50.36(c)(3)... sets forth the requirements to be used in determining whether a surveillance requirement is required is to be included in technical specifications. These requirements are: (1) ensure that the necessary quality of systems and components is maintained (2) ...

Structural maintenance on the subject filter trains HEPA filters or charcoal filter housings potentially impacts the ability of the filter trains to meet or surpass In-place Testing Criteria of Regulatory Guide 1.52, Revision 2, Sections C.5.c and C.5.d. Therefore, this activity potentially impacts the necessary quality of the subject systems and components.

Please explain in more detail how the necessary quality of the system is being maintained if an in-place bypass leakage test is not performed after structural maintenance, since the maintenance may have increased the bypass leakage rate.

(c) crediting compliance with 10 CFR [Part] 50 Appendix B, Criterion XI, Test Control.

Please provide information on how compliance with 10 CFR Appendix B, Criterion XI Test Control assures that increases in the bypass leakage rate as a result of structural modifications will be detected.

In summary, the leakage detected in the in-place bypass leakage test is an unfiltered release to the environment. Typically, this release is ignored in dose calculations when the test criteria is < 0.05%. If the leakage rate increases due to structural maintenance, it impacts the release to the environment and may need to be considered in the design basis analysis dose assessment.

2. SR 4.0.1 and 10 CFR Part 50, Appendix B, Criterion XI were cited as justification for the removal of the phrase, or after any modifications which could affect diesel generator interdependence. However, the NRC staff noted that neither SR 4.0.1 nor Criterion XI specify what post-modification testing must be completed to fulfill the portion of SR 4.8.1.1.2.h that was proposed to be deleted. Also, it is not clear to the staff that the requirement to start both emergency diesel generators (EDGs) simultaneously and to verify required voltage and frequency after any modification that could affect EDG interdependence would be established in SR 4.0.1 or by Criterion XI. Please provide justification that SR 4.0.1 and Criterion XI provide an equivalent level of requirement for removing the phrase that was proposed to be removed. Additionally, please provide assurance that the fundamental requirements to start both EDGs simultaneously, and to verify required voltage and frequency after any modification that could affect EDG interdependence, will be preserved.

3. Identify the specific post-modification testing requirements (EDG interdependence, frequency, and voltage acceptance criteria) in the relevant procedures and documentation that verify that the test requirements (to start both EDGs simultaneously, and to verify required voltage and frequency after any modification that could affect EDG interdependence) will be completed and are equivalent to the deleted portion of the SR discussed in question 2. In addition, please provide the bases for the acceptance criteria for the test requirements to start both EDGs simultaneously, and to verify required voltage and frequency after any modification that could affect EDG interdependence.