Radiation Waste Management, Inc.

A Large percentage of low-level radioactive waste generated primarily by hospitals, clinics, universities, research labs, etc., contains nuclides that have short half-lives, and can be held for decay, rather than be buried at a substantial cost. In addition to being much more economical than burial, this practice is also encouraged by state and federal regulars as a means to preserve limited burial space for longer lives nuclides that cannot be reasonably held for decay and release.

While the process of holding radioactive waste for decay and release is simple in concept, it is frequently difficult for generators to implement such a plan because of the many details involved in the basic procedure. In addition, a secure location within the facility to store and monitor the number of containers involved can present a problem to many generators, primarily because of the time and space constraints necessary to hold the waste to maturity. The process is usually started by characterizing the waste to determine the longest-lived nuclide, as this will determine the minimum holding period. A calculation to determine estimated date of maturity is performed. The accepted time period by most authorities would be 10 half-lives, but would also depend upon the initial isotope activity. Once a location is found to securely store the waste for the necessary time period, usually two years or more, the waste can be left without continuous monitoring, except for periodic checks to determine that the integrity of the containers has not been breached. After the calculated time period has elapsed, the waste must be removed from the containers and surveyed, to verify that radiation levels have indeed decayed to levels indistinguishable from background. This procedure can sometimes present a problem, given the unpleasant task involved. If the waste shows no evidence of radioactivity above background levels, it may be disposed of as non-hazardous waste at a landfill, or incinerated. Disposal at a landfill is not without potential problems, if the waste contains radiation labels and symbols that have not been defaced. There have been many instances where vials containing decayed radioactive material and displaying radioactive symbol(s) and vendor labels have turned up in landfills. Alarmed workers notify superiors, who in turn notify authorities, etc. At some point, the embarrassed generator must take action and claim responsibility. Potential legal considerations are obvious.

RWM-Utah, Inc., located in Salt Lake City, Utah, is a wholly-owned subsidiary of Thomas Gray & Associates, Inc., and was formed to handle and dispose of short-lived, low-level radioactive waste. Constructed in 1995 specifically for this purpose, RWM offers secure and complete service, handling both aqueous and solid waste. Manifested waste entering the facility is first entered into a computer program which calculates the maturity date. Waste containers are then stored on drum racks in a sprinklered and alarmed warehouse, where they are completely visible for periodic inspection. When the containers reach maturity, they are removed from the drum racks and transferred to a survey area. upon opening, each container is sample internally using liquid scintillation to verify the nonexistence of residual activity, specifically from unacceptable nuclides such as H3 and C14. Solid materials are mechanically dumped onto a conveyor system into tub containers provided to RWM by a medical waste incineration company located in Salt Lake City.

At RWM's request, the incinerator company picks up the tubs and transports them to their facility, where the contents are burned. The incinerator company provides RWM with certificates of destruction, which are then incorporated into RWM's permanent records. A generator may request a summary of the "cradle-to-grave" documentation of actions taken on his/her waste materials. To qualify for this "Decay in Storage" service, the waste must contain nuclides with a half-life of 90 days or less. The more typical nuclides would be I125, S35, P32, I131, and Cr51. RWM's "Decay in Storage" service is also available for those generators who manage their own decayed waste but choose not to perform the unpleasant inspection process, and wish to have their waste incinerated. Charges for this service are considerably reduced, as no storage time fees are involved.