ML102510225

Request for Additional Information E-mail, Round 2, Relief Request RBS-ISI-014, Proposed Alternative to Examination Requirements for Reactor Pressure Vessel Weld Inspections,Third 10-Year Inservice Inspection Interval (ME2818)

ML102510225
Person / Time
Site:	River Bend
Issue date:	09/07/2010
From:	Wang A Plant Licensing Branch IV
To:	Burmeister B, Lorfing D Entergy Operations
Wang, A B, NRR/DORL/LPLIV, 415-1445
References
TAC ME2818
Download: ML102510225 (3)

Text

From: Wang, Alan Sent: Tuesday, September 07, 2010 8:39 PM To: David Lorfing (DLorfin@entergy.com); 'BURMEISTER, BARRY M' Cc: Lent, Susan; Burkhardt, Janet

Subject:

River Bend 1 Request for Alternative RBS-ISI-014 (ME2818) - Followup RAI Barry and David, By letter dated November 30, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML93380292), Entergy Nuclear Operations, Inc. (the licensee) submitted Request for Alternative RBS-ISI-014, for the third 10-year inservice inspection (ISI) interval at River Bend Station, Unit 1 (RBS), pursuant to paragraph 50.55a(a)(3)(i) of Title 10 of The Code of Federal Regulations (10 CFR). Relief request RBS-ISI-014 proposes an alternative to ISI requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, and the augmented inspection requirements of NRC Generic Letter (GL) 88-01, NRC Position on IGSCC in BWR Austenitic Stainless Steel, January 25, 1988, including Supplement 1 to GL 88-01, in order to implement the alternative inspection guidance of BWRVIP-75-A, BWRVIP-75-A: BWR Vessel and Internals Project Technical Basis for Revisions to Generic Letter 88-01 Inspection Schedules, October 2005, for several ASME Code Examination Category B-F components.

By letter dated June 22, 2010 (ADAMS Accession No. ML101800265), Entergy Nuclear Operations, Inc. (the licensee) submitted a response to the NRC staffs request for additional information (RAI) concerning Request for Alternative RBS-ISI-014 for the third 10-year ISI program at RBS. In its RAI response, the licensee stated it will assume credit for its hydrogen water chemistry (HWC)/online noble metal chemical application (NMCA) program in establishing specific examination criteria based on BWRVIP-75-A, BWR Vessel and Internals Project, Technical Basis for Revisions to Generic Letter 88-01 Inspection Schedules, October 2005, for all of the subject ASME Code,Section XI, Examination Category B-F reactor vessel (RV) nozzle-to-safe end welds addressed in RBS-ISI-014. In its RAI response, the licensee also stated that if the alternative proposed in RBS-ISI-014 is authorized, 10% of subject welds will receive the ASME Code, Section XI-required examinations during every 10-year ISI interval, consistent with Table 3-1 of BWRVIP-75-A for plants crediting their HWC/NMCA programs.

In accordance with the above BWRVIP-75-A criteria for requests for alternatives, pursuant to 10 CFR 50.55a(a)(3)(i), the NRC staff has determined that the following additional information is needed to complete its review of the subject relief request for RBS. This request was discussed with Barry Burmeister of your staff on September 7, 2010, and it was agreed that a response would be provided by October 29, 2010. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1445 or via e-mail at Alan.Wang@nrc.gov.

In order to assume credit for its HWC/online NMCA program in establishing RV nozzle-to-safe end weld inspection criteria under BWRVIP-75-A, the NRC staff requests that the licensee demonstrate that the implementation of the HWC/online NMCA program at RBS provides effective mitigation of IGSCC for the subject Examination Category B-F (GL 88-01 Category C) components. The criteria for demonstrating an effective HWC/traditional NMCA program (one in which the addition of the noble metal catalyst is carried out during outages) are specified in the NRC staffs April 21, 2010 safety evaluation (SE) for the BWRVIP-62 report, BWR Vessel and Internals Project, Technical Basis for Inspection Relief for BWR Internal Components with Hydrogen Injection (BWRVIP-62), December 31, 1998. A summary of the key provisions

stated in the SE for demonstrating an effective HWC/traditional NMCA program are provided below:

As stated in the NRC staffs SE for BWRVIP-62, the effective implementation of HWC/traditional NMCA, with respect to IGSCC mitigation, can be demonstrated by meeting all of the following criteria, which are specified in Section 3.3.3.3 of the SE for BWRVIP-62:

(1) measuring the electrochemical corrosion potential (ECP) of the stainless steel surface in contact with reactor coolant system (RCS) water at specified locations and demonstrating that the measured ECP values at these locations remain less than the proprietary bounding value specified in the SE; (2) ensuring that the hydrogen-to-oxygen molar ratio at the specified locations (where the ECP is measured) is maintained above the proprietary bounding value specified in the SE; (3) ensuring that the noble metal catalyst loading at these locations is maintained above the proprietary bounding value specified in the SE.

The SE for BWRVIP-62 also states that feedwater hydrogen flow rate or concentration should be effectively maintained to ensure HWC/NMCA protection at all of these locations.

Although the staff did not specify criteria necessary for the demonstration of an effective HWC/online NMCA program in its SE regarding BWRVIP-62, for the purposes of this review, the NRC staff will accept that meeting the aforementioned criteria would demonstrate the effectiveness of the RBS HWC/online NMCA program. Regarding criterion (1) above, and with the understanding that the HWC/online NMCA program at RBS is based on a cycle of approximately one year between online injections of noble metal catalyst, if a full set of ECP measurements taken over the course of a one-year injection cycle is not yet available, then provide any existing initial ECP data and commit to provide remaining ECP data for the one-year injection cycle to demonstrate HWC/NMCA effectiveness when ECP data for the remainder of the injection cycle becomes available.

If the licensee is unable satisfy these provisions, the licensee should modify Request for Alternative RBS-ISI-014 and to implement the alternative provisions of BWRVIP-75-A for the subject components assuming credit for normal water chemistry conditions (e.g, the modified request must specify an inspection scope of at least 25% of the subject ASME Code,Section XI, Examination Category B-F Components), or withdraw the request in its entirety.

Alan Wang Project Manager (River Bend Station)

Division of Operating Reactor Licensing Nuclear Regulatory Commission E-mail Properties Mail Envelope Properties (C0A338EE37A11447B136119705BF9A3F7B9F0ADD51)

Subject:

River Bend 1 Request for Alternative RBS-ISI-014 (ME2818) - Followup RAI Sent Date: 9/7/2010 8:42:00 PM Received Date: 9/7/2010 8:42:00 PM From: Wang, Alan Created By: Alan.Wang@nrc.gov Recipients:

DLorfin@entergy.com (David Lorfing (DLorfin@entergy.com))

Tracking Status: None BBURMEI@entergy.com ('BURMEISTER, BARRY M')

Tracking Status: None Susan.Lent@nrc.gov (Lent, Susan)

Tracking Status: None Janet.Burkhardt@nrc.gov (Burkhardt, Janet)

Tracking Status: None Post Office:

HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 19789 9/7/2010 Options Expiration Date:

Priority: olImportanceNormal ReplyRequested: False Return Notification: False Sensitivity: olNormal Recipients received: