Event Notification Report for August 05, 2009

DOSAGE TO PATIENT WAS POTENTIALLY DIFFERENT FROM PRESCRIBED DOSE DUE TO EQUIPMENT MALFUNCTION

"Two patients were scheduled for treatment using a Leksell GammaKnife Model C/B-2 stereotactic radiosurgery unit on August 5, 2009. This model uses an Automatic Positioning System (APS) to automatically change patient position during the treatment. The APS reported positioning error codes to the treatment console and the operators called Elekta, the manufacturer's US representative for help. They were told to undock the patient and reinitialize the APS system and then to complete treatment. This happened again during the second patient treatment and the local Elekta service person was called to inspect the unit.

"The service representative arrived after the completion of treatment to the second patient and it was noted then that while trying to drive the APS system back to it's nominal position, one of the axis indicators was off by 5 mm. It is not known if this happened during the treatment, so this is a provisional report until a thorough analysis can be performed. The console logs have to be analyzed by the manufacturer's representatives to see if the error occurred during treatment and as a result of an APS malfunction."

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.

UNUSUAL EVENT DECLARED DUE TO TOXIC GAS FROM A SWITCHGEAR FIRE IN THE TURBINE BUILDING

At 0750 PDT the licensee experienced a turbine trip and reactor scram. At approximately the same time, a fire was detected in the non-safety related 6.9 kV feed bus to switchgear SH-5 and SH-6 in the turbine building. The fire and associated fault to the switchgear feed bus caused a loss of power to both reactor recirculation pumps and the automatic reactor scram. The fire produced smoke and potentially toxic gases. Due to the presence of potentially toxic gas in the power plant, an Unusual Event was declared at 0812 PDT based on EAL 9.3.U.3. At the present time, the fire is out and the smoke is being cleared from the plant.

All rods fully inserted upon the reactor scram. Systems functioned as expected except for problems with the EHC system which resulted in the bypass valves remaining open which caused the reactor to depressurize to approximately 390 psi. MSIVs were manually shut to halt the reactor depressurization and cooldown. Decay heat is being removed via relief valves to the suppression pool with reactor pressure being maintained between 500 and 600 psi. Suppression pool cooling is via RHR. Makeup water to the reactor is via normal feed. Licensee is on natural circulation at the time of this report. Normal shutdown electrical alignment is established with the exception of Division II emergency switchgear which is aligned to the backup transformer.

A request for assistance was made to the Hanford fire department, however, the fire was out prior to their arrival on site.

The licensee has notified State, local agencies and the NRC Resident Inspector.


* * * UPDATE FROM JOHN SLACK TO DONALD NORWOOD AT 1332 ON 08/05/09 * * *

The Unusual Event has been terminated as of 1006 PDT. The licensee is taking the unit to cold shutdown.

The licensee will notify the NRC Resident Inspector.

Notified NRR EO (Ross-Lee), R4DO (Walker), DHS (Enzer), and FEMA (Eaches).

* * * UPDATE FROM NICK RULLMAN TO PETE SNYDER AT 1827 ON 08/05/09 * * *

"Following the reactor scram, with the turbine bypass valves failed fully open, the inboard main steam isolation valves had to be manually closed to prevent excessive cool down. The outboard main steam isolation valves automatically closed from the inability to maintain condenser vacuum. The inability to maintain condenser vacuum was due to limited equipment access in the Turbine Building from heavy smoke. This is reportable under Part 50.72(b)(3)(iv)(A) as a valid actuation of one of the systems listed in Part 50.72(b)(3)(iv)(B)(2)."

The licensee notified the NRC Resident Inspector.

Notified R4DO (Walker).

AGREEMENT STATE REPORT - MEDICAL DOSE DIFFERENT THAN PRESCRIBED

During an embolization procedure delivering Yttrium-90 spheres to the liver an interruption occurred resulting in only 35 Gy of the 52 Gy prescribed dose being delivered. The interruption was due to unexpected contamination due to a leaking septum v-vial Contamination was contained in a container and did not enter the patient. The patient and referring physician will be notified.

GA report number: 2009-09i.

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.

AGREEMENT STATE - LOSS OF CONTROL OF NUCLEAR MATERIAL

The following was received from the state via email:

"On 08/05/09 during the evening a T.C. Inspection radiographer was performing radiography at the Chevron refinery in Richmond, CA. The job was completed around 8:30 p.m. The radiographer loaded the gear into the truck leaving the locked camera (INC, Model IR100, S/N 7019, 49 Ci activity) at the job site. Approximately 10 to 15 minutes later, Chevron maintenance noticed the exposure device and notified the Chevron fire department. The A T.C. Inspection radiographer who was at the refinery heard the call on the radio and responded to the event location, however, he did not have a survey meter to approach the camera. He noticed that the plug was in and the device appeared to be locked with no key in the lock. They barricaded the area, and kept the camera under surveillance until a survey meter was brought in. The radiographer surveyed the camera and confirmed that the source was in a shielded position and transported the camera to the storage location. The radiographer who left the camera at the job site is no longer employed by T.C. Inspections."

CA Report #: 80609