Technologies and Strategies that Enabled the D D of Pu/U Buildings at Rocky Flats

摘要

The Rocky Flats Environmental Technology Site (RFETS) has successfully accelerated the U.S. Department of Energy (DOE) target schedule for site closure in 2006. A significant contributing factor has been the rapid development and deployment of D&D technologies and work methods. Particular problems were posed by high levels ofrncontamination in the complex of buildings where Pu and U processing occurred. Since D&D work of this type and magnitude had not previously been undertaken, new approaches had to be employed and continually improved upon as thernwork progressed.rnGiven the uncertainties in the work plan under these pioneering circumstances, there were considerable risks in both the estimated cost and schedule for the closure project. Two important strategies towards the D&D program at Rocky Flats were followed to reduce these risks. One was to invest in many diverse technologies simultaneously, knowing that only a few of them would be successful and that of the technologies that were successful, only one or two would prove to be costrneffective and efficient enough to keep the project on schedule. The other strategy was to immediately deploy those technologies that were "ready" each year, while continuing to push the envelope to find yet more productive technologies forrnthe coming year.rnIn order to disposition process equipment, such as gloveboxes, tanks, machinery, pipework and ducting, we pursuedrntwo broad technical approaches. On the one hand, we looked for methods to size reduce the equipment so that it could bernpackaged in containers suitable for shipping and disposal. On the other hand, we looked for methods to decontaminate thernequipment to low level or free release level and thus minimize the need for size reduction work. Each of these pathwaysrninvolved different sets of container or packaging requirements, and different sets of instrumentation and measurementrnrequirements. Therefore, we pursued ever larger containers and packaging methods for each pathway, as well as thernmeasurement technology to support each approach.rnIn order to disposition the buildings after the equipment was stripped out, a similar plan was followed. One the one hand, we sought to decontaminate the floors, walls and ceilings of buildings to free release levels where feasible. This enabled various relatively aggressive demolition techniques. On the other hand, where the nature of the contamination and the building structure made it impossible to reach free release levels, methods were developed to demolish the buildings in arn"hot" state. In this case, methods were used that were necessarily less energetic and more controlled with respect to potential fugitive paniculate. Where decontamination was possible, we tested or developed and deployed various surfacern(primarily concrete) cleaning technologies. To support D&D of the millions of square feet of surface area required, we continuously tested, configured and deployed a range of instrument systems to detect and map the contamination ever morernaccurately and more quickly.rnIn retrospect, the D&D of the Pu and U buildings could technologically be called an experimental journey. The technologies ranged from "high tech" remote controlled size reduction and instrumentation, and decontamination chemistry, to "low tech" but innovative and efficient techniques that we adapted or modified for our own special D&D applications from our previous production processes or from other industries. The technologies include business systems, strategies, and D&D processes and equipment. This paper describes the technologies that best enabled each of the pathways outlined above. The outcome from this multiplicity of technologies has been a progressive reduction in the cost and schedule as we work towardrnfinal closure.