An interim evaluation of the thermal stability of Cu--Y--/sup 85/Kr sputter deposits and plans for evantual disposal

Technical Report · Fri Apr 01 04:00:00 EST 1988

DOI:https://doi.org/10.2172/7103665· OSTI ID:7103665

McClanahan, E D; Bradley, E R

A pilot process was developed and demonstrated for trapping and storing /sup 85/Kr from the dissolver off-gas stream of a nuclear fuel reprocessing plant. Ions produced in a low-pressure krypton discharge are implanted on the inner wall of a krypton trapping storage device (KTSD). Objectives were to measure the release of /sup 85/Kr implanted in a copper--yttrium alloy, outline the characterization work to be performed on the Cu/endash/Y/endash//sup 85/Kr waste form, and identify the options available for disposing of the remaining /sup 85/Kr. Release rates were obtained from periodic measurements of the krypton released from both radioactive and nonradioactive krypton-loaded KTSDs. Sampling is expected to continue as long as the extrapolated release rates remain acceptable for a period not to exceed one half-life (/approximately/10 y). Seven tests were performed on a nonradioactive KTSD at 180 to 450/degree/C. Three KTSDs loaded with 80 to 150 Ci of /sup 85/Kr stored at 150, 250, and 350/degree/C were sampled four times each. Proposed post-elevated-temperature storage characterization of the Cu/endash/Y/endash//sup 85/Kr waste form is outlined. Both radioactive and nonradioactive test specimens stored below 350/degree/C showed release rates less than 0.1%y/sup /minus/1/. Release rates for the radioactive specimens were obtained for storage periods of 1.6, 1.1, and 0.4 y at 150, 250 and 350/degree/C. The nonradioactive specimen has been held at temperatures between 180 and 450/degree/C, but mainly at 350/degree/C for a total storage time of 2.1 y. Tests should continue for a period not exceeding 10 y, and then the remaining Cu/endash/Y/endash//sup 85/Kr waste form should be evaluated to better predict the overall stability. Three options for the disposal of the remaining /sup 85/Kr. 3 refs., 2 figs., 2 tabs.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 7103665
• Report Number(s): PNL-6541; ON: DE88010330
• Country of Publication: United States
• Language: English

Related Subjects

050800 -- Nuclear Fuels-- Spent Fuels Reprocessing
052002* -- Nuclear Fuels-- Waste Disposal & Storage
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ALLOYS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COPPER ALLOYS
DEPOSITION
DISSOLVERS
EVEN-ODD NUCLEI
FISSION PRODUCT RELEASE
FUEL REPROCESSING PLANTS
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ION IMPLANTATION
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KRYPTON 85
KRYPTON ISOTOPES
MANAGEMENT
NUCLEAR FACILITIES
NUCLEI
OFF-GAS SYSTEMS
RADIOACTIVE WASTE STORAGE
RADIOISOTOPES
STORAGE
WASTE FORMS
WASTE MANAGEMENT
WASTE STORAGE
YEARS LIVING RADIOISOTOPES
YTTRIUM ALLOYS