ML120860541

NRC Verbal Approval for Calvert Cliffs RR-ISI-04-06A

ML120860541
Person / Time
Site:	Calvert Cliffs
Issue date:	03/26/2012
From:	Pickett D Plant Licensing Branch 1
To:	Furio P Constellation Energy Group
Pickett , D. NRR/DLPM, 415-1364
References
TAC ME7790
Download: ML120860541 (3)

Text

From: Pickett, Douglas Sent: Monday, March 26, 2012 2:59 PM To: 'Furio, Patricia S' Cc: Collins, Jay; Alley, David; Wilson, George; Dentel, Glenn; Kennedy, Silas

Subject:

NRC Verbal Approval for Calvert Cliffs RR-ISI-04-06A Ms. Furio:

In accordance with Nuclear Reactor Regulation Office Instruction LIC-102, Relief Request Reviews, (ADAMS ML091380595) the staff may provide verbal approval of relief requests provided:

• The proposed alternative is in writing and all information that the staff requires to write the SE has been docketed.

• An identified need for the verbal authorization is recognized given the circumstances of the licensees request.

• The NRC technical staff has completed its review and determined that the proposed alternative is technically justified, but has not yet formally documented it in an SE.

• The technical branch and the Division of Operating Reactor Licensing (DORL) branch chiefs have agreed to the verbal authorization.

It is the NRR staffs understanding that Calvert Cliffs Unit No. 1 is currently in a refueling outage and that approval of Relief Request RR-ISI-04-06A is necessary before the facility can enter MODE 3. It is also NRRs understanding that Calvert Cliffs Unit No. 1 currently plans to enter MODE 3 on Thursday, March 29, 2012. Therefore, the staff believes that the above criteria for granting temporary verbal approval has been met. Temporary verbal approval is being granted via the script below and the staff expects to provide a written safety evaluation within 150 days of todays date.

Participants in todays discussion were:

David Alley, Acting Chief, Piping and NDE Branch, Division of Engineering George Wilson, Chief, Plant Licensing Branch I-1, DORL Jay Collins, Piping and NDE Branch, Division of Engineering Doug Pickett, Calvert Cliffs Project Manager, DORL

[David Alley speaking]

By letter dated December 29, 2011, and supplemented by letters dated February 9, 2012, March 13, 2012, and March 19, 2012, Constellation Energy Group, Inc. proposed an alternative to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g)(6)(ii)(F) for Calvert Cliffs Nuclear Power Plant, Unit 1. The requirements, for which alternative is requested, define the volumetric inspection coverage requirements for reactor coolant system dissimilar metal butt welds. The requirements are dependent on the categorization of the welds under Table 1 of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME) Case N-770-1, with NRC conditions.

Alternatives to requirements under 10 CFR 50.55a(g) may be authorized by the Nuclear Regulatory Commission (NRC) pursuant to 10 CFR 50.55a(a)(3)(ii). The licensee proposed an alternative, RR-ISI-04-06A, in accordance with 10 CFR 50.55a(a)(3)(ii) for relief from the requirements of 10 CFR 50.55a(g)(6)(ii)(F)(2) and 50.55a(g)(6)(ii)(F)(3) for seven DM butt welds at Calvert Cliffs U1.

The licensee requests relief from 10 CFR 50.55a(g)(6)(ii)(F)(2) to permanently re-categorize weld 12-SC-1004-1 as inspection category D of N-770-1.

The licensee requests relief from 10 CFR 50.55a(g)(6)(ii)(F)(3) to use the previous examinations of welds 30-RC-11A-7, 30-RC-11B-7, 30-RC-12A-7, 30-RC-12B-7, 12-SI-1009-19, and12-SI-1012-13 from the 2010 refueling outage to meet the baseline inspection requirement for each weld. This is a onetime request.

The reason for this relief request is that the licensee was not able to obtain the full required inspection coverage for each of these welds.

The Piping and NDE staff reviewed the licensees proposed alternative under the requirements of 10 CFR 50.55a(a)(3)(ii). The licensee explained its hardship to improve the inspection coverage included weld buildup, additional contouring and radiographic examination. The licensees inspection coverage limitation was for axial flaw coverage. The concern for axial flaws is leakage rather than a loss of structural integrity for each weld. Further, the licensees limited coverage does allow for the finding of larger axial flaws as they grow. Due to the effect of cold leg temperature for most of these welds, the cracking mechanism should take significantly longer than the re-inspection frequency for each weld. Finally, for each weld, 100% coverage was obtained for circumferential flaws in the susceptible material, which is the structural integrity concern.

Therefore, given the hardship, the staff finds the licensee provided sufficient information from the previous inspections and future visual examination schedules, to provide reasonable assurance of the structural integrity of the welds identified in the licensees proposed alternative. The Piping and NDE Branch recommends authorizing the licensees relief request RR-ISI-04-06A.

[George Wilson speaking]

As set forth above, the NRC staff concludes that the licensee provided sufficient technical basis to demonstrate that compliance with the requirements of 10 CFR 50.55a(g)(6)(ii)(F) would cause an unnecessary burden on the licensee without a compensating increase in the level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(a)(3)(ii), the proposed alternative provides reasonable assurance of structural integrity, and is in compliance with the Code of Federal Regulations requirements. Therefore, in accordance with 10 CFR 50.55a(a)(3)(ii) the NRC staff authorizes the licensees proposed alternative, RR-ISI-04-06A, at Calvert Cliffs Unit 1, for the spring 2012 refueling outage.

All other ASME Code,Section XI requirements for which relief was not specifically requested and approved in this relief request remain applicable, including third party review by the Authorized Nuclear Inservice Inspector.

[Conclusion of discussion]

A copy of this email will be made publicly available in ADAMS.

Douglas V. Pickett, Senior Project Manager Calvert Cliffs, R.E. Ginna U.S. Nuclear Regulatory Commission 301-415-1364 Email: douglas.pickett@nrc.gov