05000324/LER-2003-002, Oscillation Power Range Monitor (OPRM) Inoperability Due to Inadequate Confirmation Count Performance
| ML033360584 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 11/26/2003 |
| From: | Hinds D Progress Energy Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BSEP 03-0160 LER 03-002-00 | |
| Download: ML033360584 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| 3242003002R00 - NRC Website | |
text
Progress Energy NOV 2 6 2u3 SERIAL: BSEP 03-0160 10 CFR 50.73 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
Subject:
Brunswick Steam Electric Plant, Unit Nos. 1 and 2 Docket Nos. 50-325 and 50-324/License Nos. DPR-71 and DPR-62 Licensee Event Report 1-2003-002 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, David H. Hinds Plant General Manager Brunswick Steam Electric Plant MAT/mat
Enclosure:
Licensee Event Report 1-2003-002 Progress Energy Carolinas, Inc.
.- i 2
CL Brunswick Nuclear Plant A;
P.O.
Box 10429 Southport, NC 28451
Document Control Desk BSEP 03-0160 / Page 2 cc (with enclosure):
U. S. Nuclear Regulatory Commission, Region II ATTN: 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. Eugene M. DiPaolo, NRC Senior Resident Inspector 8470 River Road Southport, NC 28461-8869 U. S. Nuclear Regulatory Commission ATTN: Ms. Brenda L. Mozafari (Mail Stop OWFN 8G9) (Electronic Copy Only) 11555 Rockville Pike Rockville, MD 20852-2738 Ms. Jo A. Sanford Chair - North Carolina Utilities Commission P.O. Box 29510 Raleigh, NC 27626-051
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Abstract
On October 5, 2003, Progress Energy Carolinas, Inc. (PEC) received notification from GE Nuclear Energy (GENE) of a reportable condition in accordance with 10 CFR 21.21(d) (i.e., SC03-20, "Stability Option III Period Based Detection Algorithm Allowable Settings," dated October 4, 2003). SC03-20 identified the potential for numerous, unexpected confirmation count resets in the event of an instability condition. These confirmation count resets could result in the inoperability of Technical Specification (TS) Table 3.3.1.1-1, "Reactor Protection System Instrumentation," Function 2.f, "OPRM Upscale." Therefore, at 1100 Eastern Daylight Time (EDT) on October 5, 2003, the Unit 1 and Unit 2 Oscillation Power Range Monitor (OPRM) channels were declared inoperable in accordance with TS 3.3.1.1, "ReactorProtection 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. PEC is preparing modifications to implement the recommendations of SC03-20 and return the OPRM Upscale function to operable status for both Units. The safety significance of this occurrence is considered minimal.
The apparent cause of the event is an incomplete analysis, performed by GENE, when establishing the OPRM's period based detection algorithm (PBDA).
NRC FORM 3b (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) implemented and the OPRM Upscale trip functions returned to operable status by December 31, 2003, for both Unit 1 and Unit 2.
- 2. Plant procedure OMST-OPRM21R, "OPRM Tuning," will be revised in accordance with the recommendations of SC03-20. This procedure revision will be implemented by December 31, 2003.
SAFETY ASSESSMENT
The safety significance of this occurrence is considered minimal.
As discussed in SC03-20, there is no threat of fuel failure as a result of this condition. In addition, although considered inoperable, the OPRM Upscale trip function was fully operational and would have continued to protect the plant from thermal-hydraulic instabilities throughout the operating range. Although considered inoperable, the OPRM Upscale trip remains armed and functional. If such protection was not provided, operators are trained to recognize instabilities and to take appropriate actions should instability occur.
PREVIOUS SIMILAR EVENTS
LER 1-2002-001, dated January 20, 2003, documents a condition where the Unit 1 OPRM Upscale trip function was declared inoperable due to a non-conservative setpoint associated with the PBDA. This condition was identified by GENE in SC02-21, "Stability Option III: OPRM Tmin Specification," dated November 22, 2002. The corrective actions associated with LER 1-2002-001 could not have reasonably been expected to prevent the condition reported in the LER.
COMMITMENTS
Those actions committed to by PEC in this document are identified below. Any other actions discussed in this submittal represent intended or planned actions by PEC. They are described for the NRC's information and are not regulatory commitments. Please notify the Manager - Support Services at BSEP of any questions regarding this document or any associated regulatory commitments.
- 1. Engineering Changes (i.e., EC 46335 for Unit 1 and EC 46730 for Unit 2) are in progress to revise the Unit 1 and 2 OPRM variables to the settings recommended in SC03-20. These modifications will be implemented and the OPRM Upscale trip functions returned to operable status by December 31, 2003, for both Unit 1 and Unit 2.
- 2. Plant procedure OMST-OPRM21R, "OPRM Tuning," will be revised in accordance with the recommendations of SC03-20. This procedure revision will be implemented by December 31, 2003.