PNO-IV-96-064A, on 961205,reactive Insp Initiated to Review Circumstances Associated W/Malfuntion of Licensee Theratron 780 Teletherapy Unit.Licensee Representatives Reported, Continued to Treat Patients After Problem Observed
| ML20135E442 | |
| Person / Time | |
|---|---|
| Site: | 03022280 |
| Issue date: | 12/10/1996 |
| From: | Cain C, Linda Howell NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| References | |
| PNO-IV-96-064A, PNO-IV-96-64A, NUDOCS 9612110272 | |
| Download: ML20135E442 (2) | |
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. December 10,1996 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE PNO-IV-96-064A This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without verification or evaluation, and is basically all that is known by Region IV staff in Arlington, Texas on this date.
i Facility Licensee Emeraency Classification Department Of Veterans Affairs Notification of Unusual Event Va Medical Center-West Los Angeles Alert 11301 WILSHIRE BLVD.
Site Area Emergency Los Angeles, California 90073 General Emergency Dockets: 03022280 License No: 04-00181-12 X Not Applicable
Subject:
TELETHERAPY UNIT MALFUNCTION - UPDATE This provides an update to a Preliminary Notification of Event or Unusual Occurrence issued on December 5,1996, regarding a teletherapy unit malfunction at the Veterans Administration Medical Center in West Los Angeles.
i On December 5 a reactive inspection was initiated to review circumstances associated with malfuntion of the licensee's Theratron 780 teletherapy unit.
NRC inspectors were accompanied by an investigator from the U.S. Food and Drug Administration (FDA), Los Angeles District Office. The device manufacturer, Theratronics International, had completed servicing the unit prior to the inspectors' arrival. Theratronics representatives subsequently reported to Region IV and NMSS staff that they believed the problem was isolated to a connector which had become loose, thus interrupting a circuit which activates a solenoid that drives the cobalt-60 source drawer to the exposed position.
Region IV had previously requested that the licensee not use the system for patient treatments until the NRC and FDA completed its review of circumstances associated with the failure and the repairs performed by Theratronics. Based on subsequent discussions with NRC staff, the licensee modified its procedures to provide specific instructions regarding the need to closely monitor visual indicators of the source position during patient treatments. The procedure changes were intended to emphasize guidance provided by Theratronics in the operating manual for the teletherapy unit regarding the need to observe visualindicators (source position indicator and room radiation monitor) to confirm the source position rather relying on the timer as an indication of source position. The licensee planned to complete staff training on the modified procedures on December 9.
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The licensee began using the Theratron 780 teletherapy unit for patient treatments on Monday, December 9,1996. At approximately 12:00 pm PST, the licensee provided notification, by telephone, to the Region IV Walnut Creek Field Office that the same problem was observed again on Monday during two attempts to complete port films on patients.
During subsequent conversations with licensee representatives, Region IV staff was informed that on two successive attempts to complete a port film for a patient, the staff noted that the source drawer failed to move to the exposed position when the staff attempted to start the unit. The staff noted that the timer on the teletherapy unit (which is activated by a circuit separate from the source drawer) appeared to operate properly. To remedy the situation, the staff turned the unit off and then on again and observed no further problems. Licensee representatives reported that they continued to treat patients after the problem was observed.
Region IV, in consultation with NMSS, has requested that the license discontinue any use of the teletherapy unit until further notice from the NRC. The licensee has scheduled service for the unit with Theratronics for December 10. Region IV and FDA have dispatched an inspector and investigator, respectively, to observe the Theratronics service representative perform diagnostics on the unit and to monitor repair of the unit.
The state of California has been informed.
Region IV has informed NMSS. NMSS plans to issue a generic communication regarding this event to alert other users of the system of potential problems in the near future.
This information herein has been discussed with the licensee and is current as of 6:15 p.m., CST, Decernber 9,1996.
Contact:
Linda Howell Charles Cain (8171860-8213 (817)860-8186 j