Event Notification Report for June 04, 2003

APPENDIX R ISSUE

During an Appendix R design basis review, an Engineer noted that cables associated with normal operation of components used for one train (Primary Isolation Valves) of Appendix R mitigation were routed through an adjacent fire zone associated with the other train of Appendix R mitigation. During an Appendix R event, control of the affected components is transferred to the Standby Shutdown Facility, which electrically isolates the subject cables.

However, the area containing the subject cables does not have fire detection equipment. The Engineer noted that if a fire occurred and damaged the cables, it would be theoretically possible for a "smart short" to result in damage to equipment before action could be taken to transfer control to the Standby Shutdown Facility.

Initial Safety Significance:

This condition is similar to an example given in NUREG 1022, Section 3.2.4 (fire barrier missing such that the required degree of separation for redundant safe shutdown trains is lacking).

In order to result in a loss of safety function, the postulated fire would have to damage the cable, result in a smart spurious actuation of a component, damage that component such that it became inoperable (such as by burning out the motor of a valve), then also spread within the fire zone to damage the redundant component (for example by burning the power cable or motor control center).

The Oconee license basis is no spurious circuit operations for 10 minutes. Cable testing sponsored by the NRC, NEI, and EPRI for fire exposure has demonstrated that armored type cable construction used in this application is more rugged than other designs and that internal cable failure times usually extend beyond 30 minutes.

The area containing the cables is a high traffic area for both personnel and material - including low quantities of transient combustibles, but has no appreciable fixed fire loads. Thus the probability of a fire of sufficient energy to damage the cable is low. Pending a PRA analysis, it appears reasonable to credit prompt discovery of a fire and initiation of action to suppress the fire and/or transfer of control to the Standby Shutdown Facility prior to cable damage. Therefore the overall risk impact of this event is currently considered low.

Corrective Action:

The SSF has been declared inoperable pending establishment of a fire watch.

The NRC Resident Inspector will be informed of this event by the licensee.

MISSING OR LOST GAUGE CONTAINING A RADIOACTIVE SOURCE

A Texas Nuclear Product pipe mounted fixed gauge device, model 5202, Series SG, serial number B174 containing a Cesium 137 (Cs-137), 500 millicuries source (assay date of November 1984) could not be located in storage. The gauge was removed from a pipe on the evening of 1/28/03 by an independent contractor who placed the gauge in a temporary storage on the morning of 1/29/03 at the Buchanan Mine Preparation Plant located in Mavisdale, Virginia. The gauge was closed and pad locked before it was placed in the small building storage room. The independent contractor and the plant foreman looked for the gauge on 6/2/03 and could not locate it. They continued looking for the gauge until 6/4/02 when they declared that it was missing. The licensee has no reason to believe that the gauge left the property, is retracing the steps of the gauge movement and is interviewing their employees in an attempt to locate the gauge.

* * * UPDATE AT 0951 EDT ON 06/26/03 FROM REGION II IAT (BOLAND) to NRC HOC (GOTT) * * *

The following was emailed from Region II:

"The licensee searched their site for the gauge and interviewed employees who had access to the floc [floculant] building with negative results.

"There are two waste streams in which the gauge may have left the plant:

"The first is in scrap metal. Scrap metal waste goes to Mansbauch Metal in Ashland, Virginia. Incoming waste at Mansbauch must pass through an Exploranium portal monitor. The alarm set point for this type of monitor is normally set at twice background so they are very sensitive. The scrap metal is then put on a conveyor for further processing. Three Ludlum detectors monitor the loose scrap on the conveyor. The processed scrap must then pass through the portal monitor leaving the facility. The smelter accepting the scrap will also have a portal monitor. There were no alarms in the time period under consideration and there is no backlog of scrap at the facility. This does not seem to be a credible scenario for the loss of the gauge.

"The second waste stream is for normal industrial waste. The local sanitary landfill is not used and, according to the licensee, all waste other than scrap metal is supposed to be sent to the industrial waste stream. The waste is transferred by H&K Trucking Co. to the Cumberland Plateau Regional Waste Management Authority in Lebanon, Virginia for waste consolidation prior to being sent to the BFI Carter Valley Landfill in Hawkins Co. Tennessee. Waste coming into the Cumberland facility is dumped on the floor and then loaded into a larger container for shipment to the landfill. Periodically, individuals at this facility remove metal such as soft drink cans for further sale to a scrap dealer. The BFI Landfill has a portal monitor and was sensitive enough to recently detect in a large waste shipment, a facial tissue used by an individual that had been administered Tc-99m.

"On June 17, NRC inspectors discussed the issue with licensee representatives and surveyed areas of the site where the gauge might logically have been moved. The radiation detection instruments the inspectors used were sensitive enough to detect the gauge radiation unless it was significantly shielded above and beyond the shielding inherent in the gauge. The inspectors demonstrated that their survey instruments could easily detect the radiation from a similar gauge that was in place at the facility. The inspectors also traveled to the BFI landfill and discussed the issue with landfill operators.

"The operators of the Cumberland Plateau facility issued a memorandum to staff describing the gauge and stating the importance of its recovery. The Buchanan facility management was to also issue a similar memorandum and claims to still be looking for the gauge."

Notified NMSS (Broaddus), R2DO (Ogle), NRC IAT (Hahn).