05000335/LER-2015-001, Regarding Reactor Trip While Performing Reactor Protection System Logic Matrix Test
| ML15301A254 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 10/07/2015 |
| From: | Costanzo C Florida Power & Light Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-2015-252 LER 15-001-00 | |
| Download: ML15301A254 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(iv), System Actuation |
| 3352015001R00 - NRC Website | |
text
0FPLo October 7, 2015 L-20 15-252 10 CFR 50.73 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Re:
St. Lucie Unit 1 Docket No. 50-335 Reportable Event: 2015-001-00 Date of Event: August 9, 2015 Reactor Trip While Performing Reactor Protection System Logic Matrix Test The attached Licensee Event Report 2015-001-00 is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.
Sincerely, Christopher R. Costanzo Site Vice President St. Lucie Plant__
CRC/rcs Attachment Florida Power & Light Company 6501 S. Ocean Drive, Jensen Beach, FL 34957
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BYO0MB: NO. 3150-0104 EXPIRES: 113112017 (02-014)Estimated
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 13. PAGE St. Lucie Unit 1 05000335 1 OF 3
- 4. TITLE Reactor Trip While Performing Reactor Protection System Logic Matrix Test
- 5. EVENT DATE 6.LRNME7.RPRDAE 8OTEFALTESIVVD MONH AY EA 6yp_*.I UMBR N
! u"pIER UMER 17.REORu*TATFACILI" TYE NAME IIE ANVLE DOCKET NUMBER MOT AY YA YEARI SEQUENTIALl REVMOTH DA YEAR NAAM 08 09 2015 2015 -
001 00 10 07 2015 IFACILITY NAME NADOCKET NUMBER NA 9.OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
El 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)
El 20.2203(a)(3)(ii)
El 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)
El 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL
[] 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
[] 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4)
El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 100%
El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
El OTHER.
El 20.2203(a)(2)(vi)
El 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in Failed Component(s)
None Manufacturer Combustion Engineering Inc.
Description of the Event On August 9, 2015 with St. Lucie Unit 1 in Mode 1 at 100% reactor power, an unplanned reactor trip occurred.
The trip occurred while Operators were performing a reactor protection system (RPS) logic matrix test.
The logic matrix test involves opening and closing sets of reactor trip circuit breakers (TCBs)
The team performing the test had worked through approximately half of the test before taking a break between test sections.
It was at this point that the team progressed through a section without completing all of the steps in that section.
The team did not implement acceptable placekeeping and unknowingly lost configuration control when they inadvertently left two TCBs open that should have been closed.
After the break when the test
- resumed, the test personnel did not perform a jobsite review.
As they recommenced the test a reactor trip occurred when the next set of trip circuit breakers was opened.
Cause
The individuals performing the logic matrix test did not follow the test procedure, resulting in a loss of configuration control during the test.
Analysis of the Event
During the logic matrix testing, the individuals performing the role of the reader-doer did not restore two TCBs to their normal closed position, resulting in a loss of configuration control during the test.
Had they maintained awareness of the configuration of the TCBs through proper verification techniques, then the two TC~s would have been closed prior to moving on to the next section of the logic matrix test procedure, and the reactor trip would not have occurred.
Safety Significance
This reactor trip event is reportable pursuant to 10 CFR 50.73 (a) (2) (iv)
(A) as an actuation of the RPS.
This event had no significant safety consequence.
All safety related systems functioned as designed.
There were no safety systems actuations as a result of the trip.
With no complications and all systems responding as designed, the associated risk impact is considered very small.
Given the response of the plant and the insignificant risk, the health and safety of the public were not affected by this event.
Corrective Actions
The corrective action listed below has been entered into the site
corrective action
program.
Any changes to the action will be managed under the corrective action program.
- 1. To correct the problem, the procedure for performing the RPS logic matrix test is being revised to ensure configuration control of the TCBs is maintained through additional verification techniques.
Failed Component(s)
None Manufacturer Combustion Engineering Inc.