05000443/LER-2010-002, For Seabrook Station, Regarding Containment Penetration Protective Devices Found Inoperable
| ML101650057 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 06/08/2010 |
| From: | Freeman P NextEra Energy Seabrook |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| IE22 | |
| References | |
| SBK-L-10103 LER 10-002-00 | |
| Download: ML101650057 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 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)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 4432010002R00 - NRC Website | |
text
NEXTeraM ENERGAP-SEABROK June 8, 2010 10 CFR 50.73 Docket No. 50-443 SBK-L-10103 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Seabrook Station Licensee Event Report (LER) 2010-002-00 Containment Penetration Protective Devices Found Inoperable Enclosed is Licensee Event Report (LER) 2010-002-00. This LER reports an event that was discovered at Seabrook Station on April 9, 2010. 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. Michael O'Keefe, Licensing Manager, at (603) 773-7745.
Sincerely, NextEra Energy Seabrook, LLC Paul Freeman Site Vice President cc:
S. J. Collins, NRC Region I Administrator G. E. Miller, NRC Project Manager W. J. Raymond, NRC Senior Resident Inspector NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 (9-2007)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the
- 3. PAGE Seabrook Station 05000443 1 OF 3
- 4. TITLE Containment Penetration Protective Devices Found Inoperable
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR N/A 05000 NUMBER NO.
/
50 FACILITY NAME DOCKET NUMBER 04 09 2010 2010 002 -
00 06 08 2010 N/A 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
E-20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii) 1 [E
20.2201(d)
[1 20.2203(a)(3)(ii)
[: 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
[E 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
[1 50.73(a)(2)(x)
[E 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4)
[E 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
F1 50.73(a)(2)(v)(B)
El 73.71(a)(5) 100 [E
20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A),
El 50.73(a)(2)(v)(C)
Fl OTHER [J 20.2203(a)(2)(vi)
Z 50.73(a)(2)(i)(B)
E] 50.73(a)(2)(v)(D)
Specify in Abstract below
- 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (Include Area Code)
Michael O'Keefe, Licensing Manager (603) 773-7745CAUSE SYSTEM MPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE COMPETFACTURER TO EPIX FACTURER TO EPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR SUBMISSION YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
X NO DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On April 9, 2010 during operation in Mode 1 at 100% power, the instantaneous trip setpoints for the containment penetration conductor overcurrent protective devices for the train-B hydrogen recombiner were found at incorrect settings. Both the primary and secondary protective device trip setpoints were set at 8.75x (equal to 1094 amps) rather than the design value of 6.25x (equal to 781 amps). Following this discovery, the protective devices were reset to their correct setpoints. Technical Specification (TS) 3.8.4.2, Electrical Equipment Protective Devices, confirms operability of the protective devices by verifying the devices trip when current is injected within a specified range of the trip setpoint. A review of test data found that the protective devices failed this surveillance requirement (SR) in May 2004 and April 2008. Therefore, the inoperable protective devices were in service for longer than permitted by the TS. The cause of the overcurrent protective devices being set at incorrect settings was attributed to previously vague procedure guidance. Subsequent revisions clarified the procedure and led to the identification of the incorrect setpoints. Although the protective devices failed to meet the SR, reasonable assurance existed that the devices would have actuated within current levels and response times that would have protected the containment penetration.
NRC FORM 366 (9-2007
(If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17) could have remained operable with the trip setpoints outside their design values if surveillance testing demonstrated that the breakers were performing satisfactorily. With the trip setpoint at 8.75x, the range of test current specified for testing the protective devices is 821 - 1368 amps. Further evaluation of surveillance test data measured in May 2004 found that the secondary breaker failed to meet this acceptance criterion.
The measured current was less than the minimum allowable value of 821 amps. Similarly, during testing performed on the primary breaker in April 2008, test data shows that the primary breaker tripped at a current less than the minimum allowable value.
As a result, the primary and secondary containment penetration conductor overcurrent protective devices were inoperable from April 2008 and May 2004, respectively, until discovery of the condition on April 9, 2010.
Since the inoperable protective devices remained in service for more than the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> permitted by TS 3.8.4.2, this event is reportable in accordance with 10 CFR 50.73 (a)(2)(i)(B) as a condition prohibited by the TS.
This event is of regulatory importance because it resulted in a condition prohibited by the TS; however, the condition is not significant to safety. Reasonable assurance existed that the circuit breakers would have performed their intended function to protect the penetration. With the trip setpoint at the incorrect trip setpoint of 8.75x, past test data indicated that the circuit breakers operated at current levels and with response times within the capability of the electrical penetration. No adverse consequences resulted from this condition, and the event had no adverse impact on the health and safety of the public or the plant and its personnel. No other structures, systems, or components were inoperable at the start of the event and contributed to this event.
This event did not involve a safety system functional failure.
IV. Corrective Action
The trip setpoints for the primary and secondary protective devices were set to their correct setpoints.
However, the primary circuit breaker cannot be demonstrated operable until the plant enters an outage so that the motor control center can bede-energized to allow performing the SR on the breaker. As a result, this breaker is removed from service in accordance with the action of TS 3.8.4.2.
The vague procedure guidance that originally contributed to the incorrect trip setpoints has been corrected in subsequent procedure revisions. These procedure changes led to identification of this condition. Nonetheless, additional planned corrective actions include modifying the Motor Load List to remove the reference to the obsolete JL Type circuit breakers and revising the circuit breaker surveillance procedure to provide additional details regarding the adjustable trip setpoints.
V. Additional Information
The Energy Industry Identification System (EIIS) codes are included in this LER in the following format: [EIIS system identifier, EIIS component identifier].
VI. Similar Events
None