05000416/LER-2013-004
| Grand Gulf Nuclear Station | |
| Event date: | 08-06-2013 |
|---|---|
| Report date: | 10-3-2013 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4162013004R00 - NRC Website | |
A REPORTABLE OCCURRENCE This Licensee Event Report (LER) is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(B) for operation or condition which was prohibited by the plant's Technical Specifications,
B. INITIAL CONDITIONS
At the time of the event the reactor was in Mode 1 with reactor power at 93.5 percent. There were no inoperable structures, systems, or components that contributed to this event_
C. DESCRIPTION OF OCCURRENCE
On August 3, 2013, at 03:04 Central Daylight Time (CDT) Grand Gulf Nuclear Station (GGNS) entered Mode 2 (Startup) from Mode 4 (Cold Shutdown). Subsequently, GGNS entered Mode 1 on August 4, 2013, at 05:31. On August 6, 2013, at 10:15 with the unit in Mode 1 at 93.5 percent thermal power, during a supervisory review of procedures in progress, GGNS discovered that it was not in compliance with Technical Specification (TS) 3.3.6.1, Primary Containment and Drywell Isolation Instrumentation, (EllS:JE) due to the jumpers that disable the function not being removed prior to startup. Upon discovery, GGNS entered TS 3.3.6.1 Limiting Condition for Operation (LCO) Actions A.1, 8.1. C.1, F.1 and H.1. Also, TS LCO 3.0.4 was not satisfied. This condition existed until 11:11 CDT on August 6, 2013, when the jumpers were removed.
D. CAUSE
The cause of the event was a lack of Integrated Operating Instruction (101) 03-1-01-3, Cold Shutdown to Generator Carrying Minimum Load, to include the requirements of EN-DC-136, Temporary Modifications, for adequate procedural control of temporary modifications. Additionally, a failure of the Shift Manager (SM) to initiate a potential TS Limiting Condition for Operation Tracking Record (LCOTR) as required by procedure 02-S-01-17, Control of Limiting Conditions for Operation was identified as a contributing cause.
E. CORRECTIVE ACTIONS
To correct the condition that caused this event. the jumpers were removed restoring the function to an Operable status_ A prompt investigation of the issue was performed. A review of 101 03-1-01-3 and 03- 1-01-4, Scram Recovery, was performed. The review included a walkdown of procedurally referenced jumper locations which verified no other configuration control issues existed due to steps not completed.
101 03-1-01-1 was revised to require verification that the affected jumpers were removed prior to entering Mode 2 and that all applicable 10103-1-01-3 steps were completed prior to entering Mode 2. GGNS expectations on the requirements of EN-OP-115, Log Keeping, were revised to provide clarity of the requirements. An action to review all 10Is to ensure proper ties exist for transitioning between them, as well as incorporating necessary temporary modification tracking, is currently in progress_ An apparent cause evaluation (ACE) is being performed.
F. SAFETY ASSESSMENT
From Technical Specification 3.3.6.1 Bases Safety Analyses: Function Reactor Steam Dome Pressure-High. The Shutdown Cooling System Reactor Steam Dome Pressure-High Function is provided to isolate the shutdown cooling portion of the RHR System. This interlock is provided only for equipment protection to prevent an intersystem Loss Of Coolant Accident (_OCA) scenario and credit for the interlock is not assumed in the accident or transient analysis in the Updated Final Safety Analysis Report (UFSAR).
The event posed no threat to public health and safety as this interlock is provided only for equipment protection to prevent an intersystem LOCA scenario and credit for the interlock is not assumed in the accident or transient analysis in the updated final safety analysis report (UFSAR). The RHR system isolation valves were able to be remotely opened if needed for post-LOCA shutdown cooling operations.
Immediate actions performed by the Operations staff were adequate and appropriate. The actions included:
1) Review of 10103-1-01-1, Cold Shutdown to Generator Carrying Minimum Load, 03-1-01-2, Power Operations, 03-1-01-3 Plant Shutdown, and 03-1-01-4, Scram Recovery, from forced outage FO-19-5 for jumper configuration items.
2) Verification (through plant walkdowns) that the jumpers are in proper configuration.
3) Performance of 100 percent peer reviews of all procedure and surveillances turned into the control room supervisor (CRS) for review for 7 days. This included both completed and in-progress (at that time) procedures/surveillances.
4) Operations Management implemented guidance to require assistant operations manager (AOM) review and approval prior to transitioning from one101 to another with incomplete steps.
During the event, no Technical Specification defined Safety Limits were challenged.
Radiological Safety was not affected as there was no radiological release to the public during the event.
Response of the crew did not challenge established industrial safety protocol or requirements, There was no impact to the health and safety of the public, industrial safety or radiological safety as a result of this event.
G. ADDITIONAL INFORMATION
A review of the GGNS Corrective Action Program and Licensee Event Reports, for the past two years, revealed one similar occurrence of a condition prohibited by Technical Specifications caused by a procedural inadequacy:
Technical Specifications resulting in condition prohibited by Technical Specifications.