05000397/LER-2001-001

LER-2001-001,

Docket Number
Event date:	02-06-2001
Report date:	04-10-2001
3972001001R00 - NRC Website

Event Discription:

Traversing Incore Probe (TIP) System containment isolation valves TIP-V-1, 2, 3, 4, and 5 are considered inoperable due to the potential for spurious opening of the valves with the TIP drive units energized. Technical Specification (TS) LCO 3.6.1.3, Note 1 states "Penetration flow paths may be unisolated intermittently under adminstrative controls." TS Bases 3.6.1.3 states: "These controls consist of stationing a dedicated operator at the controls of the valve, who is in continuous communication with the control room. In this way, the penetration can be rapidly isolated when a need for primary containment isolation is indicated." At the time the concern with TIP valve spurious operation was identified, the power supply circuit breakers for the TIP drive units were danger tagged "open" per a clearance order. On those occasions when the danger tags were lifted for TIP System operation, one individual was assigned the responsiblity to verify closure of the TIP containment isolation valves should a valid containment isolation signal occur. This clearance order was removed permanently after the TIP operating procedure was revised to maintain the TIP drive power supply circuit breakers normally open. There are several steps in the TIP operating procedure that require the TIP drive power supply breakers to be closed. However, no guidance was included in the procedure to require "stationing a dedicated operator at the controls of the valve" to satisfy the TS requirements. On February 6, 2001, a Local Power Range Monitor calibration surveillance was being performed which required the operation of the TIP System. While the TIP System was energized the requirement of TS LCO 3.6.1.3, Note 1 for administrative control of containment penetration flow paths was not met.

An individual was not assigned to be the dedicated operator of TIP System valves to ensure isolation of containment penetration flow paths in the event of a valid containment isolation signal.

Immediate Corrective Action:

Caution tags were hung on TIP System drive mechanism breakers and control switches so that the TIP System containment isolation valves will be controlled administratively per TS LCO 3.6.1.3.

Cause of the Event:

The cause of this event was the lack of a procedural standard for establishing administrative controls in accordance with the Technical Specifications and Bases. A standard was not available when changing the method of administrative control of TIP System containment isolation valves from the use of a clearance order and tags to a revised procedure for operating the TIP System. Two contributing causes were that control room personnel did not recognize key information available for determining the necessary TS actions while the TIP System was being operated, and that information regarding the inoperability of TIP System containment isolation valves was not adequately reviewed by the individuals who revised the procedure used to operate the TIP System.

Further Corrective Action:

Procedures associated with operation of the TIP System have been revised to provide explicit direction for satisfying TS administrative requirements when the TIP System is energized. Also, Columbia Generating Station will implement a procedural standard for establishing administrative controls when required for Technical Specification compliance.

Assessment of Safety Consequences:

There are no safety consequences associated with this event. Had there been an actual plant accident or transient requiring containment isolation while performing the LPRM surveillance, failure of the TIP containment isolation valves to close would have been identified and corrected by operations personnel as required by accident response procedures.

Similar Events:

There have been no similar events at Columbia Generating Station.