05000443/LER-2004-002, Regarding Accident Monitoring Instrumentation Inoperable Due to Recorder Malfunction
| ML043420160 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 12/01/2004 |
| From: | Warner M Florida Power & Light Energy Seabrook |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| SBK-L-04114 LER 04-002-00 | |
| Download: ML043420160 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 4432004002R00 - NRC Website | |
text
FPL Energy Seabrook Station FPL Energy Seabrook Station P.O. Box 300 Seabrook, NH 03874 (603) 773-7000 DEC 1 2004 Docket No. 50-443 SBK-L-04114 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Seabrook Station Licensee Event Report (LER) 2004-002-00 for Accident Monitoring Instrumentation Inoperable Due to Recorder Malfunction Enclosed is Licensee Event Report (LER) 2004-002-00. This LER reports an event that occurred at Seabrook Station on October 5, 2004.
This event is being reported pursuant to the requirements of 10 CFR 50.73(a)(2)(i)(B).
Should you require further information regarding this matter, please contact Mr. James M.
Peschel, Regulatory Programs Manager, (603) 773-7194.
Very truly yours, FPL Energy Seabrook, LLC Mark E. Warner Site Vice Presidnet cc:
S. J. Collins, NRC Region I Administrator V. Nerses, NRC Project Manager, Project Directorate I-2 G. T. Dentel, NRC Senior Resident Inspector an FPL Group company
ENCLOSURE TO SBK-L-04114
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/3012007 (62004)
, the NRC (See reverse for required number of may not conduct or sponsor, and a person Is not required to respond to, the digits/characters for each block) informtion collection.
- 3. PAGE Seabrook Station 05000 -0443 1 OF 4
- 4. TITLE Accident Monitoring Instrumentation Inoperable Due to Recorder Malfunction
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIALFREV FACI~LY NAME DOCKET NUMBER MONTH DAY YEAR EAR NUMBER NO.
MONTH DAY lYEAR N/A 05000 FACILITY NAME DOCKET NUMBER 10 05 2004 2004 002 -
00 12 01 2004 N/A 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 1 20.2201(b)
D 20.2203(a)(3)(i) a 50.73(a)(2)(I)(C) 5 50.73(a)(2)(vii)
O 20.2201(d) 5 20.2203(a)(3)Cli) a 50.73(a)(2)Cii)(A) a 50.73(a)(2)(viii)(A) a 20.2203(a)(1) 0 20.2203(a)(4) 0 50.73(a)(2)(fi)(B) 5 50.73(a)(2)(vifl)(B) a 20.2203(a)(2)(i)
D 50.36(c)(1)(i)(A) a 50.73(a)(2)(iii) 50.73(a)(2)Cix)(A)
- 10. POWER LEVEL a
20.2203(a)(2)(ii) 5 50.36(c)(1)(ii)(A)
D 50.73(a)(2)(iv)(A) 0 50.73(a)(2)(x) 100 0 20.2203(a)(2)(iii) 5l 50.36(c)(2) 5 50.73(a)(2)(v)(A) a 73.71 (a)(4)
[5 20.2203(a)(2)(iv)
[5 50A.6(a)(3)Cti) 5 50.73(a)(2)(v)(B) 5 73-71(a)(5) 5 20.2203(a)(2)(v) 5 50.73(a)(2)Ci)(A) a 50.73(a)(2)(v)(C) l OTHER 5 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B)
D 50.73(a)(2)(v)(D)
Specify In Abstract below or In (if more space is required, use additional copies of (if more space Is required, use additional copies of NRC Fainm 366A) is 10 million cycles while the process cyclic input to the potentiometer was approximately one million cycles per day. Formal troubleshooting activities identified the causal relationship between the cyclic behavior of the process-input signal and the design life of the feedback potentiometer to result in a nominal failure interval of approximately 10 days.
The evaluation for extent of condition for this event concluded that Foxboro model 227 recorder RC-LR-460 is the only recorder that is subjected to signal oscillations such that premature potentiometer failures could be expected. The second accident monitoring pressurizer level instrument channel, RC-LR-459, does not have a similar problem as the design includes an additional process card that acts as a signal filter. All other PAM recorders monitor a temperature or pressure (not level) instrument loop that is not susceptible to the excessive signal oscillations.
Ill. Analysis of Event The design function of the pressurizer level instrumentation is to provide primary information for the control room operators to take specific preplanned manual actions for which no automatic control is provided. These actions are required for safety systems to accomplish their safety function for design basis accident events. The operators rely on indication of pressurizer level to make key decisions in both the abnormal and emergency operating procedures.
This event resulted in no adverse safety consequences as the second channel of pressurizer level instrumentation was operable and available. The redundant pressurizer level recorder, 1-RC-LR-459, has not experienced frequent, similar failures and alternate normal and post' accident qualified instruments were unaffected by the condition of 1-RC-LR-460. However, the event has regulatory significance in that it constituted a condition prohibited by the Technical Specifications.
This event was classified as a Maintenance Rule Functional Failure as defined in Maintenance Rule system function PAM-01 for 1-RC-LR-460.
(If more space is required, use additional copies of NRC Fonr 366A)
IV. Corrective Actions
A design modification has been implemented to filter out the noise signal that is causing premature feedback potentiometer failure.
The feedback potentiometers are being verified operable on a periodic basis to ensure the design modification has corrected the premature potentiometer failure.
Supplemental training will be provided to Plant Engineering on performance of Apparent Cause Evaluations related to equipment failures.
Plant Engineering Guideline PEG 45, "Maintenance Rule Goal Setting and Monitoring," will be revised to provide specific guidance for conducting Maintenance Rule Functional Failure (MRFF) evaluations to include (1) identification of failure modes and effects, (2) monitoring for effectiveness of corrective actions, and (3) peer and supervisor reviews of completed failure analysis.
V. Similar Events
None