Event Notification Report for February 18, 2000

24 HOUR NOTIFICATION - FAILURE OF THE UF6 RELEASE DETECTION SYSTEM

At 1325 CST, on 2/18/00, the Plant Shift Superintendent (PSS) was notified of an air leak on the C-310 Cylinder Valve Closure System. The function of this system is to close the cylinder valve in the case of an actuation of the UF6 Release Detection and Isolation System Low Voltage ("New") System at the UF6 Withdrawal Stations. TSR 2.3.4.1 requires this system to be operable while operating in mod 2. At the time the leak was discovered, the air pressure on the Cylinder Valve Closure System was being maintained within allowed parameters. However due to the size of the leak, it was questionable as to if the system could maintain enough air pressure to perform its intended safety function, if it were called upon. After discussing with the C-310 building System Engineer, the PSS could not be provided with reasonable assurance of operability. The UF6 Release detection System was declared inoperable by the PSS, and repair of the system was initiated. TSR required LCO actions were implemented. Repair of the air leak was completed, and the UF6 Release Detection System was returned to Operable status at 1706 CST, on 2/18/00.

This event is reportable under 10 CFR 7B.120(c)(2) as an event in which equipment required by the TSR is disabled or fails to function as designed.

The NRC Senior Resident inspector has been notified of this event and the DOE on site representative was also informed.

* * * UPDATE ON 3/13/00 @ 1438 BY WALKER TO GOULD * * * RETRACTION

THIS EVENT HAS BEEN RETRACTED. Engineering Evaluation EN-C-826-00-018 concluded that the capacity of the backup nitrogen supply regulator was sufficient to provide for this backflow and loss of system air, and still capable of providing flow to close two cylinder valves simultaneously. Thus, the system was capable of performing its intended safety function using nitrogen had it been called upon during the time of the subject event and the 10CFR76.120 reporting criteria were not met. Given the results of this Engineering Evaluation, this event is being retracted.

The NRC Resident Inspector was informed and the Reg 3 RDO(Jacobson) and NMSS EO(Smith) were notified.

- 24-hour Report, Violation of Operating License, condition existing longer than permitted by Plant Tech Specs -

During Unit 1 plant coastdown operations in preparation for a refueling outage, Charging Header Pressure - Low Channel [Plant Technical Specification 3.3.2, Table 3.3.3.3.d.(2)] failed at 2130 CST on 02/18/00. The licensee discovered the failure at 0600 CST on 02/19/00. The licensee placed the instrument in a tripped condition at 0615 CST on 02/19/00 in compliance with Action #16 of the Limiting Condition for Operation. LCO Action #16 requires placing an inoperable Charging Header Pressure Channel in the tripped condition within one hour. The Charging Header Pressure Channel had been inoperable for 8 hours and 45 minutes before the licensee placed it in a tripped condition. The licensee restored the channel to operable status at 1431 CST on 02/19/00.

This notification is being made pursuant to Operating License NPF-76, Condition 2.G for operation or condition prohibited by Plant Technical Specifications.

The licensee plans to notify the NRC Resident Inspector.

At 1335 hours on 02/17/00 a see and flee emergency was initiated at the X-330 building Tails position #1. The see and flee was Initiated as a result of a process gas release from the pigtail on Tails position #1. The release was large enough to exceed the capacity of portable mini-gulper staged In the area. The mini-gulper is used to divert and contain any small releases that may occur during pigtail connect/disconnect operations. The release of process gas caused a valid actuation of the pyrotronics smokehead safety system. The pyrotronics smokeheads and pigtail line isolation safety systems operated as designed during this event.

UPDATE AT 1445EST ON 3/300 FROM KURT SISLER TO S.SANDIN * * *

The Regulatee is retracting this report based on the following:

"Nuclear Regulatory Affairs has reviewed the basis for Portsmouth Event Report Notification PTS-2000-017, 'X-330 Tails Withdrawal, Pyrotronics Smokehead Actuation due to PG Release Exceeding the Capacity of the Gulper', and determined that the event should be retracted. (Reference problem report PR-PTS-00.-0096S).

"On February 17, 2000 at 1335 hours, an outgassing occurred during the connection of an empty cylinder at Tails position 1. The outgassing was attributed to pressure inside the evacuation manifold due to a cylinder burping operation which had just been completed at Tails position 3. When position 3 was burped, the 1-inch diameter evacuation piping and the position 1 pigtail, which was valved into the evacuation header, would have been exposed to UF6 at above atmospheric pressure. When the burping operation was completed, the position 3 evacuation was valved off and UF6 withdrawal was restarted.

"The operator proceeded to complete the connection of a new cylinder at position 1. The operator, who was wearing appropriate personal protective equipment, cracked open and closed the pigtail safety valve per procedure, to evacuate the small space between the cylinder safety valve and the pigtail safety switch, which plugs the safety valve when it is not connected to a cylinder This exposed the space to UF6. As the operator began to remove the pigtail safety switch, he observed smoke which was contained by the gulper. The operator closed the valve and attempted to tighten fittings. When the pigtail safety valve was again cracked open and closed to evacuate the line, smoke exceeded the capacity of the gulper to contain the release and set off both Pyrotronics smokeheads above position 1. The pigtail safety valve was already closed and the Pigtail Line Isolation System closed the manifold safety valve at position 1 automatically. The event was initially determined to be reportable as a Safety System actuation of the Pigtail Line Isolation System in accordance with the Safety Analysis Report Section 6.9, Table 6.9-1, J.2.

"The TSR 2.5.3.4 Basis Statement indicates that the purpose of the Pigtail Line Isolation System is to minimize a release of liquid UF, due to pigtail failure during a withdrawal (Modes II and III). Since the pigtail was isolated from the liquid UF, system while the cylinder was being connected, Tails Withdrawal position 1 was in preparation mode (Mode I) and the Pigtail Line Isolation System safety function was not required.

"The reporting criteria in Table 6.9-1, J.2 states that an actuation is reportable for events having the potential for significant impact on the health and safety of personnel. Events having the potential for significant impact are those events where actual plant conditions existed that the system was designed to protect against. Since position 1 was not in a Mode for which the safety system was required to be operable, this event has been determined to not be reportable to NRC. Accordingly, this was not a valid actuation of a safety system. The event notification PTS-2000-017 may be retracted."

Operations informed the NRC Resident Inspector and the DOE Site Representative. Notified R3DO(Jordan) and NMSS(Cool).