05000244/LER-2008-001

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LER-2008-001, Plant Heatup with Required Residual Heat Removal Loops Inoperable Due to Personnel Error (Voluntary Report)
R. E. Ginna Nuclear Power Plant
Event date:
Report date:
2442008001R00 - NRC Website

A. PRE-EVENT PLANT CONDITIONS

On May 8, 2008, Ginna was completing its 2008 Refueling Outage (RFO). The plant was in Mode 4 with plant heatup in progress. Temperature was approximately 240 degrees, pressure was approximately 305 psig.

B. EVENT:

On the morning of May 8, 2008, plant personnel were performing steps of Procedure 0-1.1, "Plant Heatup from. Cold Shutdown to Hot Shutdown", in order to transition from Residual Heat Removal (RHR) to the Atmospheric Relief Valves (ARV) as a method of temperature control. The "B" Reactor Coolant Pump (RCP) was running, "A" Reactor Coolant System (RCS) Loop had been inoperable at the time of shift turnover due to low "A" Steam Generator water level; however, by the time of the event the "A" Steam Generator water level had been increased to a level adequate to support operability of a Reactor Coolant System loop.

The "A" RCP was under evaluation the morning of the event due to thrust bearing temperature concerns. The "A" RCP had not been formally declared inoperable as a result of these concerns but it had been shut down on the previous shift because of the elevated bearing temperatures. The Operations day shift considered the requirements of Technical Specification Limiting Condition of Operation (LCO) 3.4.6 to be met by the "B" RCS loop and the two available RHR loops. The Control Room Supervisor, however, after performance of a pre-job brief for part of the heatup procedure, mistakenly signed off on a procedural sub-step which verified two Reactor Coolant System loops available and one Reactor Coolant System loop in operation.

In order to continue with the heatup, RHR was isolated by shutting Motor Operated Valves (MOVs) 700, 701, 720, and 721 per procedure. The order was then given to lock open the respective breakers for these MOVs. Per the Technical Specifications Bases: "An operable RHR loop may be isolated from the RCS provided the loop can be placed into service from the control room." An on-duty operator questioned the order to open the breakers as it was given and questioned it again more forcefully when the report came back that the breakers were open. Entry into Technical Specifications (TS) Action 3.4.6.A was then confirmed, and the MOV breakers were immediately restored in compliance with the TS 3.4.6.A Required Actions. The two RHR loops were inoperable for a total time of approximately five minutes.

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C. INOPERABLE STRUCTURES, COMPONENTS, OR SYSTEMS THAT CONTRIBUTED

TO THE EVENT

None

D. DATES AND APPROXIMATE TIMES OF MAJOR OCCURRENCES

May 15, 2008 0630 EDST: Day shift assumes the duty.

0830 EDST: The Control Room Supervisor conducts a pre-job brief on removing Residual Heat Removal per procedure 0-1.1, "Plant Heatup from Cold Shutdown to Hot Shutdown".

0840 EDST: Level in the "A" Steam Generator is returned above the limit for the loop to be considered "Operable".

0856 EDST: The "B" Residual Heat Removal pump is stopped and the Residual Heat Removal isolation valves are closed per procedure 0-1.1.

0915 EDST: The RHR isolation valve motor breakers are opened.

0920 EDST: The RHR isolation valves returned to service due to breakers being closed.

0944 EDST: "A" RCP is formally declared inoperable.

E. OTHER SYSTEMS OR SECONDARY FUNCTIONS AFFECTED

None. In Mode 4, the flow from one RCS loop or one RHR loop is adequate for decay heat removal. Two paths are required to be available to provide redundancy.

F. METHOD OF DISCOVERY

The on-watch Shutdown Safety System Summary Senior Reactor Operator initially questioned the order given to open the isolation valve breakers and followed up on his question when the breakers were reported open.

G. MAJOR OPERATOR ACTION

The operator action was to close the RHR isolation valve breakers to restore RHR loop operability from the Control Room, per LCO 3.4.6.A.

This event resulted in the entry into a Limiting Condition of Operation action statement under TS Section 3.4.6, which required two RCS loops to be operable with one in operation. The event created a condition where the operating RCS loop was the only loop available, although the "A" loop could have been used for some period if required. The recently isolated RHR loops were quickly returned to service and the LCO condition exited.

This is a voluntary LER, being reported per the guidelines of step 5.1.4 of NUREG-1022.

IV. CORRECTIVE ACTIONS

A. ACTION TAKEN TO RETURN AFFECTED SYSTEMS TO PRE-EVENT NORMAL

STATUS

Residual Heat Removal Loops were restored to operable status by closing the breakers associated with the RHR isolation valves.

B. PREVIOUS LERs ON SIMILAR EVENTS:

Ventilation Isolation (CVO Inoperable C. THE EMERGENCY INDUSTRY IDENTIFICATION SYSTEM (EIIS) COMPONENT

FUNCTION IDENTIFIER AND SYSTEM NAME OF EACH COMPONENT OR SYSTEM

REFERRED TO IN THIS LER:

IEEE 803� IEEE 805 COMPONENT�FUNCTION IDENTIFIER�SYSTEM IDENTIFICATION Breaker� BKR� BP Valve 20 BP Pump� P� AB

D. SPECIAL COMMENTS

None.