Original Date: 11/03/1996
Revision Date: 01/18/2007

Containers that store nuclear material must periodically be examined to ensure that their seals (tamper indicating devices) have not been broken. Traditionally, seal inspections require a two-person team to enter the storage area and physically examine the containers for evidence of tampering. Oak Ridge has developed an optical time domain reflectometry (OTDR)-based active seal system to minimize the labor, time, and radiation-exposure aspects associated with seal inspections.

The OTDR-based active seal system works as an active sensor system that can continuously monitor the seals on the stored containers. The system uses reusable fiber optic connectors (as seals), an OTDR, an optical fiber multiplexer, and a control computer. Fiber optics are linearly setup throughout a storage area and in contact with each inventoried container. Using a laser (positioned in two, opposite directions), the system can pinpoint a container’s location within the storage area if a seal break occurs. In addition, the system will record the time of the breach.

Oak Ridge’s OTDR-based active seal system can monitor containers up to several kilometers away and is compatible with various indoor and outdoor storage configurations. The system operates on a significantly lower per-item cost than other active seal technologies and can be fully automated with minimal maintenance requirements. In addition, the OTDR-based active seal system will eliminate physical inspections, provide continuous monitoring capability, reduce labor costs, and eliminate radiation exposure of personnel.

For more information see the Point of Contact for this survey.