Significant Progress In The Deployment Of New Technologies For The Retrieval Of Hanford Radioactive Waste Storage Tanks - 8102

摘要

Significant enhancements in the development and deployment of new technologies for removing waste from storage tanks at the Hanford Site have resulted in accelerated progress and reduced costs for tank cleanup.CH2M HILL Hanford Group, Inc. is the U.S. Department of Energy, Office of River Protection's prime contractor responsible for safely storing and retrieving approximately 53 million gallons of highly-radioactive and hazardous waste stored in 177 underground tanks. The waste is stored in 149 older single-shell tanks (SST) and 28 newer double-shell tanks (DST) that are grouped in 18 so-called farms near the center of the Hanford Site, located in southeastern Washington State. Tank contents include materials from years of World-War II and post -war weapons production, which account for 60 percent by volume of the nation's high-level radioactive waste.A key strategy for improved cleanup is the development and deployment of innovative technologies, which enhance worker safety, resolve technical challenges, streamline retrieval processes, and cut project costs and durations. During the past seven years of tank cleanout projects we have encountered conditions and waste chemistry that defy conventional approaches, requiring a variety of new tools and techniques. Through the deployment of advanced technology and the creative application of resources, we are finding ways to accomplish the retrieval process safely, swiftly, and economically.To date, retrieval operations have been completed in seven tanks, including a record six tanks in a two-year period. Retrieval operations are in progress for another three tanks.This paper describes the following tank cleanup technologies deployed at Hanford in the past few years and being developed for future use:1. Modified sluicing, using recycled supernatant2. Vacuum retrieval3. High-pressure mixer (Rotary Viper)4. Chemical Addition5. Oxalic acid dissolution 6. Caustic solution7. Saltcake Dissolution8. Modified sluicing using raw water9. Remote water lance10. Pulse jet mixer pumps11. Mobile retrieval tools12. Sand Mantis 13. FoldTrack 14. Squeegee15. Mobile Retrieval SystemThis paper will also discuss the beneficial effect these technology deployments have had on improving safety, reducing costs, and improving the quality of waste cleanup.