Event Notification Report for November 13, 1999

- EMERGENCY RESPONSE DATA SYSTEM INOPERABLE FOR LONGER THAN 1 HOUR -

DURING TESTING OF THE SAFETY PARAMETER DISPLAY SYSTEM, THE LICENSEE DISCOVERED THAT THE EMERGENCY RESPONSE DATA SYSTEM WAS INOPERABLE FOR LONGER THAN 1 HOUR.

THE LICENSEE PLANS TO NOTIFY THE NRC RESIDENT INSPECTOR.

REPORTABLE OCCURRENCE NO. 21 - REACTOR OPERATION IN VIOLATION OF TECHNICAL SPECIFICATION 3.5, AIRBORNE EFFLUENTS

This is a preliminary report to inform the Commission of a violation of Technical Specifications 3.5.2.a and 3.5.2.b due to improper retest of the Radiation Recorder. Due to an improper range setting, the Mobile Air Particulate monitors (MAP) provided incorrect lower readings of Airborne Effluent Concentration (AEC) for approximately 1 week.

On 11/05/99, the Radiation Recorder was retested following repairs. The retest consisted of a channel check of the Bridge Radiation Recorder and verification of signals present on the remaining 9 channels.

On 11/08/99, the reactor was placed into operation to perform core reloading activities.

On 11/09/99, the reactor was placed into operation to perform the remaining portions of the core reloading and remained in operation at zero power. At 1840, a reactor startup to 20 kW was performed for rod testing followed by continued operation at 2 MW.

On 11/11/99 at 1037, the health physics staff reported that during the weekly checks of the MAPs, the indication in the control room was 25 - 30% of the locally indicated count rates. A review by the Assistant Manager for Operations and the Shift Supervisor concluded that the MAPs were operational and that 24 hours were allowed for review of the operability determination.

On 11/12/99 at 0738, the Reactor Manager was notified of the discrepancy between the local and control room readings for the MAPs and, at 0900, ordered a reactor shutdown. A review board reversed the operability determination and determined that this incident is reportable as per Technical Specification 6.6.2.a.

Safety Implications: It has been determined that the pool floor MAP was indicating one half the actual reading and that the stack MAP was indicating one fifth the actual reading. In this condition, the AEC necessary to exceed the alarm setpoint had been increased by a factor of two and five, respectfully. These decreased indications and increased alarm set points would have still allowed for the MAPs to notify the operator upon release of a significant quantity of particulate radioactivity which would have threatened to increase the yearly averaged AEC. The area radiation monitoring system and gaseous activity detectors would have also provided the operators an indication of a significant release. A review of the count rates recorded showed that, during this period, the effluent from the facility did not exceed the normal particulate release of less than 1% of the AEC specified in 10 CFR Part 20.

Corrective Action: The Radiation Recorder was repaired and fully channel tested or channel checked. Review of this event is ongoing and will include Reportable Occurrence No. 19, "Reactor Operation with In-Operable Alarm Circuit on the Bridge Radiation Monitor." Further corrective actions will be presented in the required followup report. Analysis of the isokinetic sampling locations is in progress.

The licensee considers this event to be significant due to its similarity with Reportable Occurrence No 19.

TWO INJURED PERSONNEL TRANSPORTED TO THE LOCAL HOSPITAL WITH GUNSHOT WOUNDS

At 1055 on 11/13/99, the Shift Manager requested an off-site ambulance to transport two people from the Cook Plant indoor rifle range to the Lakeland Hospital. Local law enforcement personnel were using the Cook Plant indoor rifle range when a weapon inadvertently discharged. The bullet ricocheted off the concrete floor striking one person in the lower leg. A second person was also hit in the leg by either a piece of the bullet or some concrete debris. Responding Emergency Medical Technicians reported that the injuries were not life threatening and that both officers were in good spirits.

The rifle range is located on Cook Plant controlled property, outside the restricted area. The personnel involved, Benton Township Police Officers, are not employees or contractors at the Cook Plant and do not have unrestricted access. Michigan State Police are investigating this accidental shooting.

The Resident Inspector was notified. The licensee does not plan on a press release at this time.

4-HOUR 91-01 BULLETIN RESPONSE - VACUUM SWEEPER FIRE/LOSS OF ONE CONTROL (GEOMETRY)

At 1110 hours on 11-13-99, Emergency Forces responded to report of a vacuum sweeper fire in X-326 Process Building. The Fire Department reported light smoke in the area. Dry extinguishing agent was used to put out a smoldering fire. The smoldering fire was verified extinguished at 1124 hours. There was no activation of any safety system during this response. All air samples were less than detection.

At 1145 hours, during the air quality and radiological assessment, it was reported to the incident Commander that a GP container failed on a favorable Geometry Vacuum Cleaner. This constituted a loss of one control (geometry) of NCSA PLANT012.A01. Interaction (spacing) was maintained throughout this event.

Initial assessment of the GP container attributes the failure to a chemical reaction that occurred inside the container. All maintenance and cleanup activities utilizing Favorable Geometry Vacuum Cleaners in X-326 Side Purge have been stopped pending further evaluation.

1) Safety Significance of Events:

The safety significance of this event is low. The GP container is a favorable geometry container made of polyethylene. This container was less than 1/2 full on a favorable geometry vacuum cleaner. The nominal enrichment of the Side Purge piping is less than 10%, and the maximum credible enrichment is 40% based on historical operation. The material in the container reacted with moisture in the air. This reaction generated heat which melted the container and caused the container to break into two pieces. The spilling of a full GP container on to a concrete floor reflected by a sprinkler discharge was analyzed by NCSE-PLANT 006.E03 and found to be subcritical for up to 80% enriched optimally moderated material.

2) Potential Criticality Pathways Involved (Brief scenario(s) of how criticality could occur):

The potential pathway to criticality is that a full container is spilled, and then another container or piece of equipment is brought within 2 feet of the spill.

3) Controlled Parameters (Mass, Moderation, Geometry, Concentration, Etc.):

The controlled parameters for this event are geometry and interaction.

4) Estimated Amount, Enrichment, Form of Licensed Material (include process limit and % worst case of critical mass):

The estimated amount of material is unknown, but the container was known to be less then 1/2 full. The GP container dimensions are nominally 5 inches inside diameter and 24 inches tall. The nominal enrichment of the Side Purge piping is less than 10%, and the maximum credible enrichment is 40% based on historical operation.

5) Nuclear Criticality Safety Control(s) or Control System(s) and Description of Failures or Deficiencies:

The material being vacuumed generated heat which melted the GP container causing a failure of the geometry control spilling the fissile material on to the floor. A spill from a full container has been shown by calculations to be subcritical. The present configuration is a slab with no material greater than an inch in depth.

The NRC resident Inspector was notified. The Department of Energy Representative will be notified.

TWO INDUSTRIAL GAUGES CONTAINING Cs -137 WERE OVERHEATED AT A FOUNDRY.

THE WAUPACA FOUNDRY REPORTED THAT TWO TN TECHNOLOGIES MODEL-5200 DEVICES CONTAINING 100 MILLICURIES OF Cs -137 PER DEVICE WERE OVERHEATED AT A FOUNDRY. THESE DEVICES WERE MOUNTED 10' APART ABOVE ONE ANOTHER ON THE SIDE OF A CUPOLA (A TALL SILO TYPE TANK WHICH IS USED TO MELT IRON). THE CAUSE OF THE OVERHEATING OF THESE TWO GAUGES WAS CAUSED WHEN THE IGNITION SOURCE FOR THE CUPOLA WAS INADVERTENTLY IGNITED WITHOUT COOLING IN PLACE FOR 3.5 HOURS. THE CAUSE OF THIS COULD POSSIBLY BE DUE TO PERSONNEL ERROR, BUT THEY ARE STILL INVESTIGATING. THERE IS NO APPARENT DAMAGE TO THE SOURCE CONTAINERS, BUT A SURVEYED @ 15' MEASURED 3.5 mR WHEN THE NORMAL READING IS APPROXIMATELY 0.2 mR. THEY HAVE ISOLATED THE AREA AND HAVE CONTACTED THE MANUFACTURER WHO IS SENDING A TEAM TO THE SITE.

(CALL THE NRC OPERATIONS OFFICER FOR CONTACT INFORMATION.)