[email protected] [e-mail]

Name of Authorized Derivative Classifier: Terry Vail, (509)373-2092

Name of Reviewing Official: J. C. Bickford, (509)373-7664

Priority Descriptor: Blue/Information

Functional Category: 440/General

Keywords: Smoke Detector, contamination, radioactive material.

References: OCCURRENCE REPORT NUMBER: RL--WHC-PFP-1995-0003

A review of the ORPS data base identified two other occurrences which
indicate problems with smoke detectors. In one of these occurrences,
Pyrotronics Model F3/5A smoke detectors were cited specifically as the
source of contamination.
CH-AA-ANLE-ANLEESH-1991-1001
RL--WHC-SOLIDWASTE-1993-0015

Lesson Learned Statement: When handling smoke detectors containing radioactive sources, care should be taken not to damage the detector, which could result in a loss of the source's integrity. Consideration should also be given to the age of the detector and the environment in which it is installed.

Facilities having these types of detectors should consider including this information in maintenance procedures used to service these types of smoke detectors to warn against a potential contamination hazard and to require radiological surveys before and after handling these types of detectors.

A good practice realized as a result of this occurrence was the survey performed by one of the individuals involved. This survey was not mandatory due to the nature of the work being performed, but the individual routinely performed precautionary radiological surveys as part of his normal work practices. This allowed the detection of a contamination problem, and prevented the spread of contamination to other areas in the facility.

Discussion of Activities: On February 1, 1995 three personnel at the Plutonium Finishing Plant (PFP) were contaminated while placing old used smoke detectors into a radioactive material waste drum for disposal. A radiological survey found about 21,000 disintegrations per minute (dpm) alpha and about 30,000 dpm beta/gamma contamination on one person's gloves and 500 dpm to 700 dpm alpha contamination was found on the hands of the other two individuals.

In late January, old Pyrotronics high voltage smoke detectors were removed from PFP as part of a fire system upgrade project. They were turned over to operations personnel for disposal as radioactive solid waste. Operations personnel removed the smoke detectors one at a time from a bag and placed them into a radioactive material waste drum. Smoke detectors already in the drum were handled to make room for the additional detectors as they were placed in the drum. Upon exiting the area, an operator performed a radiological survey of his gloves and detected contamination. He informed the other two operators and they performed surveys and both detected low levels of contamination. The Radiological Control Technician (RCT) office and the operators' manager were notified. An RCT performed surveys and identified contamination on the operators as well as minor contamination on the lid of the drum and on a plastic drum lid cover. All personnel were taken to the Decontamination Room, decontaminated and released. Contamination samples were sent for analysis. The results of the samples identified the primary isotope involved as Americium 241, the radioactive source used in the smoke detectors.

Investigative surveys were performed for other involved personnel and for the areas traversed when the smoke detectors were transported from and to Building 234-5Z. No contamination was detected.

Analysis: The most likely cause of contamination is the failure or degradation of the Americium 241 source located in one or more Pyrotronics smoke detectors. The exact cause of the source leakage was not determined, however, the following information is provided which identifies some potential reasons for the source to lose its integrity.