PNNL

Abstract

Fluor Hanford is responsible for cleanup of legacy wastes, old production facilities, and environmental contamination that remain at the Hanford site. New technologies and technical information are being introduced to improve cost efficiency and assure safety. This paper presents recent advances in four of Fluor's projects. Supporting the Plutonium Finishing Plan Closure Project, laboratory evaluations and thermal analyses were conducted to quantify the potential for self-heating reactions that can develop in materials used to remove plutonium from contaminated equipment. Four commercial products were tested, and safe limits for packaging these wastes have been developed. The Groundwater Remediation Project is testing two technologies that show promise of preventing groundwater contaminants from reaching the Columbia River by innovative in situ methods. Laboratory tests are showing that the mineral apatite can sequester Sr-90, and current work to control in situ placement of the barrier is supporting a field deployment in late FY 06. In another location, a new approach using zero valent iron is being tested to "mend" areas breached in the in situ redox manipulation barrier, which was installed to convert soluble chromium +6 to the less mobile +3 state. The Waste Stabilization and Dispostion Project has successfully operated a process to grout sludge from spent fuel storage basins which controls the dose below contact handled limits. An in-line sensor and a nomogram that correlates dose to curies provide the operators with a simple and effective method to assure all waste drums meet WIPP acceptance specifications. The K Basins Closure Projecdt will be transferring sludge containing fuel fragments using hoses and several pump booster stations. Selection of equipment fabrication materials required testing with a simulant, which in turn required laboratory evaluations of irradiated fuel hardness so that an appropriate non-radioactive material could be selected. A tungsten alloy was selected and used for testing system components.