Event Notification Report for May 30, 2001

FIRE PROOF COVER OVER A PROCESS OPENING COULD NOT PERFORM ITS INTENDED FUNCTION.


NRC BULLETIN 91-01 24 HOUR NOTIFICATION


At 1400, 05/30/01 the Plant Shift Superintendent (PSS) was notified that the Zetex material used as a fire proof cover on the # 3 low speed purge and evacuation pump has deteriorated to the point of failure such that it could not perform its intended function. The material was being used according to CP2-CO-CN2030, as a fire proof cover over a process opening. The material has become brittle and failed to the point of leaving openings to the process system. NCSA GEN-10, Removal and Handling of Contaminated Equipment from the Cascade at PGDP, requires fire proof covers to be installed on cascade system openings to prevent the introduction of moderation from a sprinkler activation, lube oil leak, or RCW leak. Double contingency for this scenario is established by implementing two controls on moderation. One leg of double contingency is based on the fire proof cover preventing a moderator release from entering the open process system. Since the fire proof cover deteriorated to the point of leaving openings to the process system, the ability to prevent introduction of moderator was lost. This control was violated and double contingency was not maintained.

SAFETY SIGNIFICANCE OF EVENTS:
A material credited to perform a criticality safety related function was not able to perform its function.

POTENTIAL CRITICALITY PATHWAYS INVOLVED [BRIEF SCENARIO(S) OF HOW CRITICALITY COULD OCCUR]:

In order for criticality to be possible, greater than 10 kg of a moderator would have to enter the open process system and interact with a uranium deposit greater than the minimum critical mass in a geometry favorable for a criticality.

CONTROLLED PARAMETERS (MASS, MODERATION, GEOMETRY, CONCENTRATION, ETC.):

Double contingency for this scenario is established by implementing two controls on moderation.

ESTIMATED AMOUNT, ENRICHMENT, FORM OF LICENSED MATERIAL (INCLUDE PROCESS LIMIT AND % WORST CASE CRITICAL MASS):

Maximum assay of 1.08 wt.% U235.

NUCLEAR CRITICALITY SAFETY CONTROL(S) OR CONTROL SYSTEM(S) AND DESCRIPTION OF THE FAILURES OR DEFICIENCIES:

The first leg of double contingency is based on the unlikelihood of a moderator release (Sprinkler, RCW, oil) into the open process system during the time the system is open. Since there was no moderator release into the system, this leg of double contingency was maintained.

The second leg of double contingency is based on the fire proof cover preventing a moderator release from entering the open process system. Since the fire proof cover deteriorated to the point of leaving openings in the process system, the ability to prevent introduction of moderator was lost. The control was violated and double contingency was not maintained.

Since double contingency is based on two controls on moderation, double contingency was not maintained.

CORRECTIVE ACTIONS TO RESTORE SAFETY SYSTEMS AND WHEN EACH WAS IMPLEMENTED:

The degraded Zetex fire proof material was replaced with an approved AQ-NCS aluminum cover. Other cascade openings using Zetex material are being inspected for signs of degradation and will be replaced as necessary. The use of Zetex material as a fire proof cover will be re-evaluated.

The NRC Resident Inspector was notified of this event by the certificate holder.

On 4/27/01 Syncor reportedly shipped 68 I-125 bracytherapy seeds each containing 250 microcuries, to a facility in Atlanta, GA. The facility reported receiving 66 seeds. An investigation was unable to determine how many seeds were actually shipped. The discrepancy is believed due to a miscount at the time of shipment from Syncor. They are still investigating.

REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM WAS DECLARED INOPERABLE.

The RCIC system was inoperable and available for planned maintenance and surveillance testing. During the planned surveillance testing, the mechanical overspeed mechanism for the RCIC turbine was discovered to be tripped with no overspeed trip testing having been performed. The overspeed trip mechanism may be degraded thereby constituting a condition that could have prevented the system from performing its function. RCIC is currently in standby and inoperable but available. Troubleshooting is in progress to determine the cause of the trip. This report may be retracted if the cause of the trip is determined to not affect the operability of the system.

The NRC resident inspector was notified.

***** RETRACTION FROM THOMAS SCWALECK TO LEIGH TROCINE AT 1537 ON 07/20/01 *****

The following text is a portion of a facsimile received from the licensee:

"On 5/30/01, during Reactor Core Isolation Cooling (RCIC) surveillance testing, the overspeed trip mechanism was discovered tripped with no overspeed testing having been performed. The overspeed trip mechanism was discovered tripped after a section of the surveillance testing that closed the trip/throttle valve and then cycled the trip solenoid several times. Nine Mile Point determined that, because of degraded engagement between the trip tappet nut and the head lever, the overspeed mechanism was susceptible to tripping during the cycling of the trip solenoid with the throttle valve tripped. Additionally, Nine Mile Point concluded that with the throttle valve latched open and RCIC aligned for operation, the overspeed trip mechanism would not have been susceptible to tripping. Therefore, the conditions that resulted in the tripping of the RCIC overspeed trip mechanism during the surveillance would not have prevented RCIC from performing its function. Based on the above, we are retracting the 50.72(b)(3)(v)(D) notification made on 5/30/01."

The licensee notified the NRC resident inspector. The NRC operations officer notified the R1DO (Cook).