DCL-12-023, Third Interval Snubber Program, Revision 1

Third Interval Snubber Program, Revision 1

ML12059A328
Person / Time
Site:	Diablo Canyon
Issue date:	02/28/2012
From:	Becker J Pacific Gas & Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
DCL-12-023
Download: ML12059A328 (8)

Text

Pacific Gas and Electric Company James R. Becker Diablo Canyon Power Plant Site Vice President Mail Code 104/6 P. O. Box 56 Avila Beach, CA 93424 805.545.3462 February 28,2012 Internal: 691.3462 Fax: 805.545.6445 PG&E Letter DCL-12-023 U.S. Nuclear Regulatory Commission 10 CFR 50.55a ATTN: Docu ment Control Desk Washington, DC 20555-0001 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Power Plants (DCPP) Units 1 and 2 Diablo Canyon Power Plant Third Interval Snubber Program. Revision 1

Dear Commissioners and Staff:

In accordance with the provisions of 10 CFR 50.55a(b)(3)(v), Pacific Gas and Electric Company (PG&E) submits Diablo Canyon Power Plant (DCPP) Third Interval Snubber Program, Revision 1. The third 10-year interval began January 1, 2006, for Unit 1 and July 1, 2006, for Unit 2.

DCPP Third Interval Snubber Program, Revision 0, was submitted in December 2010 (PG&E Letter to NRC, DCL-1 0-157, dated December 21,2010). This document has been revised, effective February 06, 2012, to clarify the visual examination method in accordance with IWA-2213 and qualification of the inspectors, along with several other editorial changes that improve clarity.

Visual examinations of snubbers will be performed by individuals specifically qualified for snubber inspection in accordance with DCPP procedures, consistent with the applicable requirements of ASME OM Code, Subsection ISTA-1500, Paragraph (e), 2001 Edition with 2003 Addenda. The attributes of the VT-3 method as described in IWA-2213 are fully implemented in the snubber program procedures. However, the term "VT-3" has been removed from our snubber program implementing procedures, because this qualification is not a requirement of the ASME OM Code.

There are no new or revised regulatory commitments as defined by the Nuclear Energy Institute 99-04, "Guidelines for Managing NRC Commitment Changes,"

dated July 1999, in this submittal.

If you have any questions regarding the information enclosed, or other Inservice Inspection Program for Snubbers, please contact Mr. Nozar Jahangir, Manager, Project Engineering, at (805) 545-6512.

A member of the STARS (StrategiC Teaming and Resource Sharing) Alliance Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde

• South Texas Project

• Wolf Creek

I I

I Document Control Desk

&~ February 28,2012 Page 2 PG&E Letter DCL-12-023 Sincerely,

~".tt~ -k-James R. Becker Site Vice President rnttl4231 I SAPN 50403209 Enclosure cc: Diablo Distribution cc/enc: Elmo E. Collins, NRC Region IV Michael S. Peck, NRC Senior Resident Joseph M. Sebrosky, NRR Project Manager Alan B. Wang, NRR Project Manager State of California, Pressure Vessel Unit A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde

• South Texas Project

• Wolf Creek

Enclosure PG&E Letter DCL-12-023 Diablo Canyon Power Plant Third Interval Snubber Program Revision 1

Enclosure PG&E Letter DCL-12-023 Diablo Canyon Power Plant Third Interval Snubber Program Revision 1 Unit 1 USNRC Docket: 50-275 Facility Operating License.: DPR..80 Commercial Operation Date: May 7) 1985 Third Interval Start Date: January 1, 2006 Unit 2 USNRC Docket: 50-323 Facility Operating License: DP~";82 Commercial Operation Date: March 13, 19.86 Thlrd Interval Start Date: July 1,2006 Approval Record Prepared by; _ _ _ _ _-..... &.-~_

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Enclosure PG&E Letter DCL-12-023 Third Interval Snubber Program (Revision 1)

Diablo Canyon Power Plant

1.0 General

1.1 In order to ensure the required operability of all safety related snubbers for both Units 1 and 2 during a seismic or other event, initiating dynamic loads, the inspection and testing of these snubbers shall be implemented and performed in accordance with the requirements of Equipment Control Guideline (ECG) 99.1, "Snubbers."

1.2 The Snubber Program, as defined within ECG 99.1, establishes visual examination, functional testing and service life monitoring requirements, pertaining to mechanical and hydraulic safety related snubbers.

1.3 The examination boundaries shall include the snubber assembly from pin to pin inclusive. The lSI program owner will be required to complete the surveillance requirements for piping and structural attachments in accordance with appropriate Section XI requirements.

1.4 The Snubber Program described in ECG 99.1 adheres to the requirements of the ASME OM Code, Subsection ISTA and ISTD, 2001 Edition with 2003 addenda, as allowed by 10CFR50.55a(b)(3)(v) in lieu of ASME Section XI, IWF-5200(a) and (b) and IWF-5300(a) and (b).

1.5 Surveillance Test Procedure, STP M-78B, in conjunction with ECG 99.1 includes a snubber service life monitoring program for hydraulic and mechanical snubbers that adheres to the requirements of ISTD-6000.

2.0 Examination, Testing and Service Life Monitoring Requirements:

2.1 Visual examinations and functional testing shall be performed to the extent specified within ECG 99.1.

2.2 Snubbers are grouped into DTPG's by design type, in accordance with ISTD-5252 for testing purposes. The groups at DCPP are as listed below:

Snubber Design Unit 1 Unit 2 Type DTPG Includes DTPG Includes AD40, AD70, AD40, AD70, AS AS AD151 AD151 Anchor Darling AM AD500 AM AD500 AD1600, AD 5500, AD1600, AD AL AL AD12500 5500, AD12500 1

Enclosure PG&E Letter DCL-12-023 Snubber Design Unit 1 Unit 2 Type DTPG Includes DTPG Includes PS 1/4NF, 1/2NF PS 1/4NF, 1/2NF Basic PSA PM 1NF, 3NF, 10NF PM 1NF, 3NF, 10NF PL 35NF,100NF PL 35NF,100NF Paul Munroe M 20x3 LG Bore M 20x3 LG Bore Grinnell G All Sizes G All Sizes Anvil A All Sizes A All Sizes 2.3 The service life of all snubbers shall be monitored and snubbers replaced or reconditioned as required to ensure that the service life is not exceeded between surveillance inspections, during a period when the snubber is required to be operable. The replacement or reconditioning shall be documented and records retained in accordance with DCPP Procedures.

3.0 Examination and Testing Methods:

3.1 Visual examinations shall be performed by individuals qualified in accordance with DCPP procedures. These examinations are conducted in accordance with the attributes as described in IWA-2213 to determine the mechanical and structural condition of the snubber support location and to observe conditions that could affect functional adequacy. Visual examinations and functional testing shall be performed to verify the requirements specified within ECG 99.1 are met in accordance with Subsection ISTD.

4.0 Examination and Testing Frequency:

4.1 Visual examinations and functional testing shall be performed at the frequency specified within ECG 99.1. DCPP currently performs accessible and inaccessible snubber visual examinations during separate refueling outages, which results in approximately one half of the snubber population being examined during each examination campaign.

4.2 Post installation checklists shall be completed whenever new snubbers are installed, reinstallation of existing or swapped snubbers that were functionally tested, or after repairs, replacements or modifications.

4.3 Functional testing requirements for new installations or spares shall be equal to or more stringent than that specified within ECG SR 99.1.

5.0 ASME OM Code Case, OMN-13 5.1 Code Case OMN-13, which allows the extension of the visual examination 2

Enclosure PG&E Letter DCL-12-023 interval, has been implemented for snubber inspections during this interval.

Code Case OMN-13 is approved for use by the NRC in Regulatory Guide 1.192 (June 2003).

5.2 DCPP will continue to perform accessible and inaccessible snubber visual examinations separately, which results in approximately one half of the snubber population for each Unit being examined during a campaign.

However, the interval will be extended as allowed by Code Case OMN-13 for each group, accessible and inaccessible.

6.0 Examination, Testing and Service Life Monitoring Evaluation:

6.1 Snubbers that do not appear to conform to the visual examination requirements of ECG 99.1, shall be reported for evaluation and appropriate corrective action.

6.2 Snubbers that do not appear to conform to the visual examination acceptance requirements and are later confirmed as operable as a result of functional testing may be declared operable for the purpose of establishing the next visual inspection interval, providing that the unacceptable condition did not affect operational readiness.

6.3 Snubbers that do not meet the operability testing acceptance criteria in ECG 99.1 shall be evaluated to determine the cause of the failure and appropriate corrective action taken.

6.4 The service life of a snubber is evaluated using manufacturing input and engineering information gained through consideration of the snubber service conditions and inservice functional test results. A service life monitoring program is included in ECG 99.1 and Surveillance Test Procedure STP M-78B.

7.0 Repair, Replacement and Modification Requirements:

7.1 Repairs, Replacements and Modifications performed on snubbers under this program shall conform, as applicable, to the requirements specified within the ASME Code,Section XI.

8.0 Scheduling

8.1 The visual examinations and functional testing schedules shall be established, tracked and maintained within the DCPP Project Engineering Department.

8.2 The Snubber Program Owner shall identify and track expanded or additional 3

Enclosure PG&E Letter DCL-12-023 testing and/or examinations as required by ECG 99.1 and Subsection ISTD.

9.0 Reports and Records:

9.1 Reports and records for snubber visual examinations and functional testing shall be maintained for all snubbers included within the Snubber Program.

9.2 Applicable records and reports, as required for repair and replacements, shall be maintained for snubbers.

9.3 Records of the service life of all hydraulic and mechanical snubbers listed in this program, including the date at which the service life commences or expires, and associated installation and maintenance records will be maintained.

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