PROGRESS IN HIGH-LEVEL WASTE TANK CLEANING AT THE IDAHO NATIONAL ENGINEERING AND ENVIRONMENTAL LABORATORY

摘要

The Department of Energy Idaho Operations Office (DOE-ID) is making preparations to close twornunderground high-level waste (HLW) storage tanks at the Idaho National Engineering and EnvironmentalrnLaboratory (INEEL) to meet Resource Conservation and Recovery Act (RCRA) regulations andrnDepartment of Energy (DOE) orders. Closure of these two tanks is scheduled for 2004 as the first phasernin closure of the eleven 300,000 gallon tanks currently in service at the Idaho Nuclear Technology andrnEngineering Center (INTEC).rnDesign, development, and deployment of a remotely operated tank cleaning system were completed inrnAugust 2001. The system incorporates many commercially available components, which have beenrnadapted for application in cleaning high-level waste tanks. The system also uses existing waste transferrntechnology (steam-jets) to remove tank heel solids from the tank bottoms during the cleaning operations.rnBy using this existing transfer system and commercially available equipment, the cost of developingrncustom designed cleaning equipment can be avoided. Remotely operated directional spray nozzles,rnautomatic rotating wash balls, video monitoring equipment, decontamination spray-rings, and tankspecificrnaccess interface devices have been integrated to provide a system that efficiently cleans tankrnwalls and heel solids in an acidic, radioactive environment. This system is also compliant withrnoperational and safety performance requirements at INTEC. Through the deployment of the tankrncleaning system, the INEEL High Level Waste Program has demonstrated the capability to clean tanks tornmeet RCRA clean closure standards and DOE closure performance measures.rnThe tank cleaning system deployed at the INTEC offers unique advantages over other approachesrnevaluated at the INEEL and throughout the DOE Complex. The system’s ability to agitate andrnhomogenize the tank heel sludge will simplify verification-sampling techniques and reduce the totalrnquantity of samples required to demonstrate compliance with the performance standards. This will reducerntank closure budget requirements and improve closure-planning schedules.