ML101950585

Second Set of Draft RAI on Relief Request Dated 3/12/10

ML101950585
Person / Time
Site:	Monticello
Issue date:	07/14/2010
From:	Tam P Plant Licensing Branch III
To:	Loeffler R Northern States Power Co
Tam P
References
GL 98-005, TAC ME3526
Download: ML101950585 (3)

Text

Accession No. ML101950585 From: Tam, Peter Sent: Wednesday, July 14, 2010 4:20 PM To: Loeffler, Richard A.

Cc: Mitchell, Matthew; Pascarelli, Robert; McLellan, Thomas; Parks, Benjamin

Subject:

Monticello - Second set of draft RAI re. Relief Request dated 3/12/10 (TAC ME3526)

Rick:

On 7/9/10 I transmitted to you a draft RAI (Accession No. ML101930333) consisting of two questions raised by our Reactor Systems Branch. Following please find draft RAI questions raised by our Vessels and Internal Integrity Branch.

On November 10, 1998, the NRC staff issued Generic Letter (GL) 98-05, "Boiling Water Reactor Licensees Use of the BWRVIP-05 Report to Request Relief from Augmented Examination Requirements on Reactor Pressure Vessel Circumferential Shell Welds," which states that BWR licensees may request permanent (i.e., for the remaining term of operation under the existing, initial license) relief from the ISI requirements of 10 CFR 50.55a(g) for the volumetric examination of circumferential RPV shell welds (ASME Code,Section XI, Table IWB-2500-1, Examination Category B-A, Item No. B1.11, "Circumferential Shell Welds") by demonstrating that:

(1) At the expiration of the license, the circumferential shell welds will continue to satisfy the limiting conditional failure probability for circumferential shell welds in the NRC staffs July 28, 1998, safety evaluation report (SER), and (2) Licensees have implemented operator training and established procedures that limit the frequency of cold overpressure events to the amount specified in the NRC staffs July 28, 1998, SER.

Licensees will still need to perform the required inspections of "essentially 100%" of all axial shell welds.

Criterion 2 of GL 98-05 requires that the licensee implement sufficient procedures and/or operator training to ensure that the probability of a cold overpressure event is minimized. To satisfy this criterion, the licensee has provided analyses of the potential high-pressure injection sources, administrative controls, and operator training, that help to minimize the risk of cold overpressure events. The licensee noted that it examined a number of conditions that may be precursors to cold overpressurization; however, the licensee did not discuss any of the conditions.

(1) Provide a discussion on the following systems regarding minimizing a cold overpressure event: e.g. flow rates; inadvertent injections; overfill; etc..

High Pressure Core Spray Injection Reactor Core Isolation Cooling System Feed Water System Control Rod Drive and Reactor Water Cleanup System

Standby Liquid Control System RPV Pressure Testing (2) Provide a brief summarization of the Operator Training and Operating Procedures as they pertain to minimizing a cold overpressure event.

We look forward to discussing the above issues with you. This e-mail aims solely to prepare you and others for the proposed conference call. However, with or without the conference call, we intend to formally issue the information need set forth above as a formal RAI within 2 weeks of the date of this e-mail, and request a formal response from you within 45 days of the formal RAI.

This e-mail does not formally request for additional information and does not convey an official NRC staff position.

Peter S. Tam Senior Project Manager (for D. C. Cook and Monticello)

Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Tel. 301-415-1451 E-mail Properties Mail Envelope Properties (0A64B42AAA8FD4418CE1EB5240A6FED11B56AAC1B4)

Subject:

Monticello - Second set of draft RAI re. Relief Request dated 3/12/10 (TAC ME3526)

Sent Date: 7/14/2010 4:20:20 PM Received Date: 7/14/2010 4:20:00 PM From: Tam, Peter Created By: Peter.Tam@nrc.gov Recipients:

Richard.Loeffler@xenuclear.com (Loeffler, Richard A.)

Tracking Status: None Matthew.Mitchell@nrc.gov (Mitchell, Matthew)

Tracking Status: None Robert.Pascarelli@nrc.gov (Pascarelli, Robert)

Tracking Status: None Thomas.McLellan@nrc.gov (McLellan, Thomas)

Tracking Status: None Benjamin.Parks@nrc.gov (Parks, Benjamin)

Tracking Status: None

Post Office:

HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 21218 7/14/2010 Options Expiration Date:

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