05000250/LER-2006-001
Docket Numbersequential Revmonth Day Year Year Month Day Yearnumber No. | |
Event date: | 03-12-2006 |
---|---|
Report date: | 5-11-2006 |
Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
2502006001R00 - NRC Website | |
�DOCKETFACILITY NAME (1) LER NUMBER (6) PAGE (3)NUMBER (2)
DESCRIPTION OF EVENT
On March 11, 2006 at 21:37 with Turkey Point Unit 3 in mode 6, Core Alterations commenced in the form of unlatching the control rods. Shortly thereafter, there were communication problems (headsets cutting out). It was later learned that the normal refueling communications were inoperable. The decision was made to utilize radios set to a dedicated channel. On March 12, 2006, at approximately 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br />, the plant commenced removal of the upper reactor vessel (RV)/ERCI1 internals. This evolution is considered a Core Alteration as defined in the Technical Specifications (TS). TS 3.9.5 states "Direct communications shall be maintained between the control room and personnel at the refueling station.
The Shift Manager had granted permission to lift the upper internals, based upon communications having been previously tested and assumed that communications would be re-established just prior to the actual lifting of the upper internals. The Shift Manager (SM) was monitoring the evolution via video monitors and recognized that communications had not been established and immediately paged the Senior Reactor Operator (SRO) inside containment at the refueling station to re-establish communications. However, since the evolution was in progress, the SRO inside containment completed the evolution and placed the RV internals on its stand, and then responded to the page from the Shift Manager. This event was a TS 3.9.5 violation for having performed Core Alterations without first establishing direct communications between the Control Room and the Refueling Station SRO. There was no adverse impact on the health and safety of the public due to this event.
ANALYSIS OF THE EVENT
Technical Specification Limiting Condition for Operation 3/4.9.5 states that direct communication shall be maintained between the control room and personnel at the refueling station during Core Alterations.
Technical Specification Definition 1.9 states that a Core Alteration shall be the movement of any fuel, sources, reactivity control components, or other components affecting reactivity within the reactor vessel with the reactor vessel head removed and fuel in the vessel.
As stated in the Technical Specification Bases 3/4.9, Refueling Operations, the core unload sequence begins with control rod unlatching, followed by removal of the upper internals, followed by unloading fuel assemblies to the Spent Fuel Pool. At the start of unlatching of the control rods on March 11, 2006,communications between the control room and the refueling station were tested and established via the headsets. At approximately 2250 hours0.026 days <br />0.625 hours <br />0.00372 weeks <br />8.56125e-4 months <br />, during rod unlatching, personnel manning the headsets experienced difficulties with communications. To overcome these difficulties, radios were delivered to the refueling platform to be used instead of headsets and subsequently, communications were re-established in accordance with 3-OP-38.1 Attachment 4, "Minimum Equipment Checklist for Restart for Movement of Control Rods or Upper Internals.
Subsequently, commencing reactor vessel upper internals movement without having re-established direct communications between the control room and the refueling station is considered a Technical FACILITY NAME (1) NUMBER (2)� Le., NUMBER (6) PAGE (3) 2006 - 001 - 911111011111111
- 11,11=9".� Specification 3/4.9.5 violation. This event is reportable in accordance with 10CFR50.73(a)(2)(i)(B) as an operation or condition that is prohibited by the plant's Technical Specifications.
CAUSE OF THE EVENT
The apparent cause of the event was that the shift manager failed to verify communications were re established or have it performed. Additionally, the procedure used to lift the internals by the containment crew did not require verification of communications prior to the lift.
SAFETY SIGNIFICANCE
The Technical Specification Bases indicate that the requirement for communications capability ensures that refueling station personnel can be promptly informed of significant changes in the facility status or core reactivity conditions during Core Alterations. The reactor was shutdown and the refueling outage was in progress. There was no adverse impact to safety systems or components that are needed to shutdown the reactor and maintain safe shutdown conditions, remove residual heat, control the release of radioactive material, or mitigate the consequences of an accident due to this event. All systems maintained their ability to perform as designed. Technical Specifications 3/ 4.9.5 applies only during refueling operations and only when moving items within the reactor vessel as specified in TS definition for Core Alterations. Based on the above, there was no impact to the health and safety of the public.
CORRECTIVE ACTIONS
1) Immediately re-established and maintained communications between the control room and refueling station during core alterations.
2) The shift manager was coached to maintain his oversight role.
3) The procedures for removal and installation of the reactor vessel upper internals will be revised to ensure compliance with Technical Specification 3.9.5
ADDITIONAL INFORMATION
EUS Codes are shown in the format [EIIS SYSTEM: JEFF system identifier, component function identifier, second component function identifier (if appropriate)].
FAILED COMPONENTS:� None
SIMILAR EVENTS:
A review of the LERs issued over the last three years revealed no similar occurrences