A Radioactive Waste Transportation Package Monitoring System for Normal Transport and Accident Emergency Response Conditions

Shipments of radioactive material (RAM) constitute but a small fraction of the total hazardous materials shipped in the United States each year. Public perception, however, of the potential consequences of a release from a transportation package containing RAM has resulted in significant regulation of transport operations, both to ensure the integrity of a package in accident conditions and to place operational constraints on the shipper. Much of this attention has focused on shipments of spent nuclear fuel and high level wastes which, although comprising a very small number of total shipments, constitute a majority of the total curies transported on an annual basis. Shipment of these highly radioactive materials is made in what is described in the regulations as a Type B packaging. Type B transportation packages are designed to withstand a sequence of accident scenarios, including drop, puncture, fire, and immersion with virtually no release of contents. A bulk of the Type B packages currently in use are utilized in the transport of survey and well logging sources. These packagings, while extremely robust, are not large and move daily in general commerce. Large Type B packagings, or casks, are used to transport spent nuclear fuels and high level wastes. Due to the quantities of spent fuel and high level wastes carried in Type B casks and the public perception and apprehension regarding the potential consequences of a release, involvement of a packaging containing spent fuel or high level wastes in any accident will result in a very cautious emergency response until it can be determined that the integrity of the cask is maintained. Typically this involves closure of the transport link or pathway, evacuation of all unnecessary personnel, diversion of traffic from the area, and subsequent investigative and mitigative procedures from trained specialists. Cask integrity is not addressed without inspection, both visual and with radiation detection instruments. These actions are typically time consuming, due to the lack of first responders with specialized training in the mitigation of radioactive materials incidents and availability of specialized equipment. Detection instrument operational condition and calibration are also concerns, which, when combined with the lack of adequate training, have resulted in some states actually placing the equipment in a centralized storage area and relying on specialty responders for accident assessment. This results in long delays before normal transportation operations can be restored. An \"onboard\" instrumentation/communications package has been developed that, when affixed to a spent fuel or high level waste cask, can monitor key indicators of the integrity of the cask and communicate these parameters to emergency responders. Entitled the Transportation Intelligent Monitoring System (TRANSIMS), this package links a monitoring system located inside the transportation cask with instrumentation and communications modules on the vehicle. The first responder can then monitor the status and integrity of the cask remotely, thus lessening the need to approach the container. Use of this unit also relieves the first responder of the necessity of mobilizing specially trained response units unless a release is indicated or some doubt about the integrity of the cask remains. This will effectively minimize transportation system downtime for all but the most severe accidents. This paper addresses spent fuel and high level waste transportation history and prospects, discusses accident histories of RAM transport, discusses emergency responder needs and provides a general description of the TRANSIMS design.