Event Notification Report for June 17, 2010

OFFSITE NOTIFICATION DUE TO INADVERTENT INITIATION OF EMERGENCY PREPAREDNESS SIRENS

"At 1045 [CDT] on 6/17/2010, the Monticello Nuclear Power Generating Plant (MNGP) received a report from the Sherburne County Sheriff Dispatcher that there had been an inadvertent manual initiation of Emergency Preparedness sirens in the county while performing siren testing in preparation for inclement weather anticipated later this evening. All plant conditions/parameters are normal. A total of 48 emergency sirens were on for approximately 1 minute before being secured. The inadvertent initiation of the sirens was determined to be reportable under 10 CFR 50.72(b)(2)(xi), 'News Release or Notification of Other Government Agency.'

"Sherburne County, the State of Minnesota, and the site NRC Resident Inspector have been notified."

OFFSITE NOTIFICATION DUE TO GRASS FIRE OUTSIDE PROTECTED AREA

"At 1400 EDT on 6/17/2010, a grass fire was reported by security officers at the main entrance facility. The fire was located outside of the protected area and outside the main entrance to the plant. The cause of the fire appears to be sparks from an 18 wheel truck's wheel contacting a curb. These sparks apparently ignited dry grass in the surrounding area. The site fire response team responded to the incident and discovered approximately a 20' x 20' area of grass burning. Extinguishing agent was applied by on site personnel and the fire was extinguished. Off site assistance (Saint Leonard Volunteer Fire Department) reported to the scene and provided makeup water to the site fire engine. There was no damage to any equipment or structures. A courtesy notification was made to Calvert Control Center at 1445 to ensure local agencies were informed of the call for assistance to the local fire department."

The licensee notified the NRC Resident Inspector.

AGREEMENT STATE REPORT - PATIENT RECEIVED LESS THAN PRESCRIBED DOSE FROM GAMMA KNIFE TREATMENT

"A patient undergoing Gamma Knife treatment received less than the prescribed dose in the eighth of eight planned treatments. The undertreatment exceeded 50% of the planned treatment dose for the final fractional treatment (only approximately 12 rads of the prescribed approximately 162 rads for the final fractional dose was administered).

"The final treatment was terminated approximately 15 seconds into the planned 3.5 minute treatment due to apparent pain on the part of the patient. Upon investigation, it was determined that the head immobilizing bracket was not fully secured. Only approximately 12 rads dose had been administered in the approximately 15 seconds before the treatment was terminated. The planned total treatment dose was 1300 rads. Approximately 1150 rads were administered in the eight treatments.

"The licensee reported they likely will not give the patient the remaining 150 rads of the planned treatment."

CA Event No.: 061810

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.

UNANALYZED CONDITION DUE TO CONTAINMENT SPRAY RECIRC SUMP ISOLATION VALVE FAILURE TO STROKE CLOSED

"At 0519 CDT on June 17th, Unit 2 was closing the 2CS009B, Containment Spray Recirc Sump Isolation Valve, as part of post maintenance testing when the valve stopped stroking (i.e. mid position). The 2CS009B valve was being stroked closed for restoration from a successful timed stroke in the open direction. The 2CS009B valve was manually closed and verified closed via limit switch indication.

"With the 2CS009B valve unable to be closed from the Main Control Room, an unanalyzed condition may have existed where, during a large break LOCA requiring cold leg recirc, the Refueling Water Storage Tank (RWST) had an additional flow path to the containment recirc sump. This potentially challenges the operators to complete the switchover prior to the RWST reaching 9%, the point at which pumps taking a suction from the RWST only are shutdown. This condition is still being evaluated."

The licensee notified the NRC Resident Inspector.

* * * RETRACTION FROM P. MOODY TO P. SNYDER AT 0404 ON 2/1/11 * * *

"At 0509 on June 17, 2010, Unit 2 was closing the 2CS009B, Containment Spray (CS) Recirculation Sump Isolation Valve, as part of post maintenance testing when the valve stopped stroking (i.e., mid-position). The 2CS009B was being stroked closed for restoration from a successful timed stroke in the open direction. The 2CS009B was manually closed and verified closed via limit switch indication.

"With the 2CS009B unable to close from the Main Control Room, an unanalyzed condition may have existed where, during a large break LOCA requiring cold leg recirculation, the Refueling Water Storage Tank (RWST) had an additional flow path to the recirculation sump. This potentially challenged the operators to complete the switchover prior to the RWST reaching 9%, the point at which pumps taking a suction from the RWST only are shutdown. While this condition was being evaluated, an ENS notification was made per ENS 46021 under 10CFR50.72(b)(3)(ii)(B).

"As the evaluation approached the 60-day reporting period, LER 2010-002 was issued in accordance with 10 CFR 50.73(a)(2)(ii)(B), assuming the results would yield an unanalyzed condition.

"Since then, an evaluation was completed. The results concluded the operators would have performed the switchover steps within the allowed time, before reaching the RWST empty alarm set point. Therefore, the Emergency Core Cooling System (ECCS) and CS system would have performed their design functions. The evaluation also determined the RWST outflows with 2CS009B in the open position during the ECCS switchover sequence did not affect the RWST vortex analysis. Based on no loss of design function, the plant was not in an unanalyzed condition and this event is not reportable per 10CFR 50.72(b)(3)(ii)(B) or 10CFR 50.73(a)(2)(ii)(B). This event was screened for additional reportability criteria contained in the Exelon Reportability Manual. Again, since there was no loss of design function there is no reportability requirement.

"Therefore ENS notification 46021 is being retracted."

The licensee notified the NRC Resident Inspector.

GENERAL LICENSE TRITIUM EXIT SIGN MISSING

During a remodel of Wal-Mart Store #566 in Boonville, Indiana, the remodeling contractor found one tritium sign. According to the Wal-Mart Radiation Safety Officer (RSO), the sign was an Isolite model with an estimated 11 Curie source strength. The contractor was instructed to properly isolate and store the tritium sign. When a Wal-Mart consultant arrived at the Wal-Mart store to inspect the tritium sign, the sign could not be found in the storage location. Wal-Mart considers the tritium sign to be lost.

THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL

Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

This source is not amongst those sources or devices identified by the IAEA Code of Conduct for the Safety & Security of Radioactive Sources to be of concern from a radiological standpoint. Therefore is it being categorized as a less than Category 3 source