ML053470056

10 CFR Part 21 Notification of an Error in BWR Safety Limit

ML053470056
Person / Time
Site:	Susquehanna, PROJ0728
Issue date:	12/05/2005
From:	Gardner R AREVA, Framatome ANP
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
+kBR1SISP20060522, NRC:05:069
Download: ML053470056 (3)

Text

AR EVA December 5, 2005 NRC:05:069 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 10 CFR Part 21 Notification of an Error in BWR Safety Limit This letter provides notification of a reportable defect in accordance with 10 CFR Part

21. This situation was reported to the NRC Operations Center by facsimile at 9:50 AM PST on December 2, 2005.

The defect consists of an error in the calculation of the minimum critical power ratio (MCPR) safety limit.

The affected utility has been informed and the planned actions and actions already taken to address the issue are provided in the attachment to this letter.

Sincerely, Ronnie L. Gardner, Manager Site Operations and Regulatory Affairs Framatome ANP, Inc.

Enclosures cc: G. S. Shukla Project 728 FRAMATOME ANP, INC. An AREVA and Siemens company 3315 Old Forest Road, P.O. Box 10935, Lynchburg, VA 24506-0935 Tel.: 434 832 3000 - Fax: 434 832 3840 - www.areva.com

Document Control Desk NRC:05:069 December 5, 2005 Page A-1 Reportable Defect (i) Name and address of the individual informing the Commission Jerald S. Holm, Framatome ANP, 2101 Horn Rapids Road, Richland, WA 99354 (ii) Identification of the facility, the activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect.

The Safety Limit Minimum Critical Power Ratio (SLMCPR) for Susquehanna Unit 1 Cycle 14.

(iii) Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect.

Framatome ANP (iv) Nature of the defect or failure to comply and the safety hazard which is created or could be created by such a defect or failure to comply.

The mean bow and standard deviation from recent channel measurements during a Susquehanna Unit 1 Cycle 14 (SQ1C14) mid-cycle outage exceed the values in the current database used in licensing analyses for Susquehanna Unit 1.

The majority of data acquired at Susquehanna Unit I during the mid-cycle outage were in the exposure range of 35 to 45 MWd/kgU. In that range, the new measurements exceed both the mean and the standard deviation of bow from the existing database. Preliminary results from the measurements indicate that the mean from the new data is approximately 60% higher and the standard deviation is approximately 50% higher.

The SLMCPR Technical Specification limit for Susquehanna Unit I Cycle 14 was too low (by about .01) when calculated with the channel bow values from the Framatome ANP channel bow database, since channel bows measured for Cycle 14 exceeded those in the channel bow database. Therefore a safety limit could have been violated.

(v) The date on which the information of such a defect or failure to comply was obtained.

This issue was determined to be a deviation on November 15, 2005.

Document Control Desk NRC:05:069 December 5, 2005 Page A-2 (vi) In the case of a basic component which fails to comply, the number and the location of all such components in use at, supplied for, or being supplied for one or more facilities or activities subject to the regulations in this part.

Susquehanna Unit 1 Cycle 14.

The other plants supported by Framatome ANP analyses, or using Framatome ANP supplied channels, are not impacted.

(vii) The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for this action; and the length of time that has been or will be taken to complete the action.

A new SLMCPR for the remainder of the Susquehanna Unit 1 Cycle 14 (denoted Cycle 14a) operation has been provided by Framatome ANP which bounds channel bow experienced during Susquehanna Unit 1 Cycle 14.

Susquehanna Unit 1 also applied a conservative interim CPR penalty (.04) during Cycle 14 operation when slow settling of the control blades was encountered.

(viii) Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees.

In order to assure that other plants are not impacted in the future by unanticipated channel bow, recommended surveillance actions will be provided in January 2006 to all customers using Framatome ANP channels.