05000325/LER-2002-001, Oscillation Power Range Monitor (OPRM) Inoperability Due to Non-Conservative Setpoint

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Oscillation Power Range Monitor (OPRM) Inoperability Due to Non-Conservative Setpoint
ML030280657
Person / Time
Site: Brunswick Duke Energy icon.png
Issue date: 01/20/2003
From: Noll W
Carolina Power & Light Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
BSEP 03-0011 LER 02-001-00
Download: ML030280657 (6)


LER-2002-001, Oscillation Power Range Monitor (OPRM) Inoperability Due to Non-Conservative Setpoint
Event date:
Report date:
3252002001R00 - NRC Website

text

16V'a' CP&L A Progress Energy Cormany JAN 2 0 2003 SERIAL: BSEP 03-0011 U. S. Nuclear Regulatory Commission AiTTN: Document Control Desk Washington, DC 20555-0001 10 CFR 50.73 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NO. 1 DOCKET NO. 50-325/LICENSE NO. DPR-71 LICENSEE EVENT REPORT 1-2002-001 Gentlemen:

In accordance with the Code of Federal Regulations, Title 10, Part 50.73, Progress Energy Carolinas, Inc. submits the enclosed Licensee Event Report. This report fulfills the requirement for a written report within sixty (60) days of a reportable occurrence.

Please refer any questions regarding this submittal to Mr. Edward T. O'Neil, Manager - Support Services, at (910) 457-3512.

Sincerely, Z),2 W. G Noll Plant General Manager Brunswick Steam Electric Plant MAT/mat

Enclosure:

Licensee Event Report 1-2002-001 Brunswick Nuclear Plant PO Box 10429 Southport, NC 28461 1 t5,2) "-)-

Document Control Desk BSEP 03-0011 / Page 2 cc (with enclosure):

U. S. Nuclear Regulatory Commission, Region II A'TN: Mr. Luis A. Reyes, Regional Administrator Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, GA 30303-8931 U. S. Nuclear Regulatory Commission ATTN: Mr. Theodore A. Easlick, NRC Senior Resident Inspector 8470 River Road Southport, NC 28461-8869 U. S. Nuclear Regulatory Commission ATTN: Ms. Brenda L. Mozafari (Mail Stop OWEN 8G9) (Electronic Copy Only) 11555 Rockville Pike Rockville, MD 20852-2738 U. S. Nuclear Regulatory Commission ATTN: Mr. Leonard N. Olshan (Mail Stop OWFN 8H12) (Electronic Copy Only) 11555 Rockville Pike Rockville, MD 20852-2738 U. S. Nuclear Regulatory Commission ATTN: Mr. Allen G Howe (Mail Stop OWEN 8G9) (Electronic Copy Only) 11555 Rockville Pike Rockville, MD 20852-2738 Ms. JoA. Sanford Chair - North Carolina Utilities Commission P.O. Box 29510 Raleigh, NC 27626-051

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Abstract

On November 22, 2002, GE Nuclear Energy (GE) identified a reportable condition in accordance with 10 CFR 21.21(d) (i.e., SC02-21, "Stability Option III: OPRM Tmin Specification"). SC02-21 states that the Stability Option III period based detection algorithm (PBDA) range for minimum period of detection (i.e.,

Tmin) values specified in Licensing Topical Report NEDO-31960-A, "BWR Owner's Group Long-Term Stability Solutions Licensing Methodology (Supplement 1)," was non-conservative and recommended that the Oscillation Power Range Monitor (OPRM) be considered inoperable if the Tmin value is set greater than 1.2 seconds. Stability Option HI is installed on Unit 1 and the Tmin value was set at 1.4 seconds. Therefore, at 1328 Eastern Standard Time (EST) on November 22, 2002, all OPRM channels were declared inoperable in accordance with Technical Specification (TS) 3.3.1.1, "Reactor Protection System (RPS) Instrumentation," and an alternate method to detect and suppress thermal hydraulic instability oscillations was placed into effect as directed by Condition I of TS 3.3.1.1. Subsequently, the Tmin value was changed to 1.2 seconds and all OPRM channels were declared operable at 0917 EST on November 27, 2002. The safety significance of this occurrence is considered minimal.

The apparent cause of the event is an incomplete analysis, performed by GE, when establishing oscillation period ranges to be used for the PBDA.

NRC FORM 366 (7-2001)

(If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17) these conditions, SC02-21 states that the failure of automatic detection at these conditions is not expected to result in fuel failures but may lead to violation of the TS MCPR Safety Limit.

In addition, although considered inoperable with Tmin set greater than 1.2 seconds, the OPRM Upscale trip function was fully operational and would have continued to protect the plant from thermal-hydraulic instabilities throughout the operating range. If such protection was not provided, operators are trained to recognize instabilities and to take appropriate actions should an instability occur.

PREVIOUS SIMILAR EVENTS

A review of reportable events for the past three years has not identified any previous similar events.

COMMITMENTS

No commitments are being established in this report.