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UNITED STATES
NUCLEAR REGULATORY COMMISSION REGION IV
1600 E LAMAR BLVD ARLINGTON, TX 76011-4511
June 12, 2014
MEMORANDUM TO: Jim Drake, Senior Reactor Inspector Plant Support Branch 2
Division of Reactor Safety
FROM: Kriss Kennedy, Director /RA/T. Pruett for
Division of Reactor Projects
SUBJECT: SUPPLEMENTAL INSPECTION CHARTER TO EVALUATE LICENSEE ACTIONS RELATED TO PI FOR UNPLANNED SCRAMS PER 7000 CRITICAL HOURS, WHICH CROSSED
THE GREEN- WHITE THRESHOLD DURING THE FIRST QUARTER 2013
In response to the White PI for Unplanned Scrams per 7000 Critical Hours at the Grand Gulf Station, a supplemental inspection team is being chartered. You are hereby designated as the team leader. A. Basis As a result of the licensee experiencing three unplanned scrams between December 29, 2012, and January 14, 2013, the Performance Indicator for “Unplanned Scrams per 7000 Critical Hours,” crossed the threshold into White. The following are the descriptions of each of these scrams:
December 29, 2012 Scram from 100% due to phase A unit differential signal resulting in a main generator lockout and turbine trip
January 4, 2013 Scram from 94% power due to a phase A unit differential signal resulting in a main generator/turbine trip. Returned to 100% power on January 11
January 14, 2013 Scram from 100% power due to a turbine generator trip caused by a generator neutral time overcurrent relay tripping. Commenced startup activities on January 27
The licensee had originally indicated that they were prepared for the IP 95001, “Supplemental Inspection for One or Two White Inputs in a Strategic Performance Area,” to be performed in August 2013. However, the licensee experienced another reactor scram (below), which resulted in their request to delay the inspection while they evaluated this new event against the planned actions that they had developed for the previous events.
J. Drake - 2 -
July 30, 2013 Scram from 100% power due to high reactor pressure. Cause was a failure of the B turbine stress evaluator (TSE) transmitter
On February 28, 2014, the licensee notified the NRC that they were ready for the IP 95001 inspection. Subsequently, the licensee experienced two more reactor scrams.
March 17, 2014 Operators inserted a manual scram from 41 percent thermal power due to a steam leak in the turbine building
March 29, 2014 Scram from 87% power due to a main generator load reject, resulting in a turbine control valve fast closure
As a result, the licensee contracted an outside firm to perform an independent evaluation of these events and the licensee’s proposed corrective actions. This supplemental inspection is being performed to obtain a better understanding of each of the referenced events; to assess the licensee’s understanding and response; and to assess whether all underlying contributing causes were appropriately considered and evaluated in the development of the licensee’s corrective actions. The team inspection plan has been documented separately. B. Scope
1. To provide assurance that the root causes and contributing causes of risk-significant performance issues are understood. 2. To provide assurance that the extent of condition and extent of cause of risk- significant performance issues are identified.
3. To provide assurance that the licensee’s corrective actions for risk-significant performance issues are sufficient to address the root and contributing causes and prevent recurrence.
C. Guidance The team will report to the site and conduct an entrance meeting. Prior to the team’s exit with the licensee, it will brief the DRP Branch Chief on the results of the inspection and any associated findings. The inspection results will be documented in inspection report 05000416/2014009. The guidance in NRC Inspection Procedure 95001 applies to your inspection. This Charter may be modified should the team develop significant new information that warrants review. If you have any questions regarding this charter, contact Don Allen at (817) 200-1144.
Docket: 50-416 License: NPF-29
J. Drake -2-
July 30, 2013 Scram from 100% power due to high reactor pressure. Cause was a failure of the B turbine stress evaluator (TSE) transmitter
On February 28, 2014, the licensee notified the NRC that they were ready for the IP 95001 inspection. Subsequently, the licensee experienced two more reactor scrams.
March 17, 2014 Operators inserted a manual scram from 41 percent thermal power due to a steam leak in the turbine building
March 29, 2014 Scram from 87% power due to a main generator load reject, resulting in a turbine control valve fast closure
As a result, the licensee contracted an outside firm to perform an independent evaluation of these events and the licensee’s proposed corrective actions. This supplemental inspection is being performed to obtain a better understanding of each of the referenced events; to assess the licensee’s understanding and response; and to assess whether all underlying contributing causes were appropriately considered and evaluated in the development of the licensee’s corrective actions. The team inspection plan has been documented separately. D. Scope 1. To provide assurance that the root causes and contributing causes of risk-significant performance issues are understood. 2. To provide assurance that the extent of condition and extent of cause of risk-significant performance issues are identified.
3. To provide assurance that the licensee’s corrective actions for risk-significant performance issues are sufficient to address the root and contributing causes and prevent recurrence.
E. Guidance The team will report to the site and conduct an entrance meeting. Prior to the team’s exit with the licensee, it will brief the DRP Branch Chief on the results of the inspection and any associated findings. The inspection results will be documented in inspection report 05000416/2014009. The guidance in NRC Inspection Procedure 95001 applies to your inspection. This Charter may be modified should the team develop significant new information that warrants review. If you have any questions regarding this charter, contact Don Allen at (817) 200-1144.
Docket: 50-416 License: NPF-29 DISTRIBUTION: See Next Page
DOCUMENT NAME: R:\_Reactors\GG\2014\GG Charter for 95001 Inspection.pdf ADAMS ACCESSION NUMBER:
SUNSI Review By: DAllen
ADAMS Yes No
Publicly Available Non-Publicly Available
Non-Sensitive Sensitive
OFFICE DRP/RIV DRS/RIV DRS/RIV DRP/RIV
NAME DAllen HGepford AVegel KKennedy
SIGNATURE /RA/ /RA/ /RA/ /RA/
DATE 6/12/14 6/12/14 6/12/14 6/12/14
OFFICIAL RECORD COPY
DISTRIBUTION:
Regional Administrator ([email protected]) DRP Director ([email protected]) DRP Deputy Director ([email protected]) DRS Director ([email protected]) Deputy DRS Director ([email protected]) Senior Resident Inspector ([email protected]) Resident Inspector ([email protected]) GG Administrative Assistant ([email protected]) Branch Chief, DRP/C ([email protected]) Senior Project Engineer ([email protected]) Public Affairs Officer ([email protected]) Public Affairs Officer ([email protected]) Project Manager ([email protected]) Branch Chiefs, DRP ([email protected]) Branch Chiefs, DRS ([email protected]) RITS Coordinator ([email protected]) ACES ([email protected]) Regional Counsel ([email protected]) Technical Support Assistant ([email protected]) Congressional Affairs Officer ([email protected]) RIV/ETA: OEDO ([email protected]) Regional State Liaison Officer ([email protected]) NSIR/DPR/EP ([email protected]) ROPreports
