Off-gas treatment and characterization for a radioactive in situ vitrification test

Conference · Wed Aug 01 04:00:00 EDT 1984

OSTI ID:6380783

Oma, K H; Timmerman, C L

Effluents released to the off gas during the in situ vitrification (ISV) of a test site have been characterized by Pacific Northwest Laboratory. The site consisted of a 19 L waste package of soil containing 600 nCi/g transuranic and 30,000 nCi/g mixed fission products surrounded by uncontaminated soil. Radioactive isotopes present in the package were /sup 241/Am, /sup 238///sup 239/Pu, /sup 137/Cs, /sup 106/Ru, /sup 90/Sr, and /sup 60/Co. The ISV process melted the waste package and surrounding soil and immobilized the radionuclides in place, producing a durable, 8.6 metric ton glass and crystalline monolith. The test successfully demonstrated that the process provides containment of radioactive material. No release to the environment was detected during processing of cooldown. Due to the high temperature during processing, some gases were released into the off-gas hood that was over the test site. The hood was maintained at a slight negative pressure to contain any volatile or entrained material during processing. Gases passed from the hood to an off-gas treatment system where they were treated using a venturi-ejector scrubber, a tandem nozzle gas cleaner scrubber followed by a condenser, heater, and two stages of HEPA filters. The off-gas treatment system is located in the semi-trailer to allow transport of the process to other potential test sites. Retention of all radionuclides by the vitrified zone was greater than 99%. Soil-to-off-gas decontamination factors (DFs) for transuranic elements averaged greater than 4000 and for fission products, DFs ranged from 130 for /sup 137/Cs to 3100 for /sup 90/Sr. 7 references, 15 figures, 4 tables.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6380783
• Report Number(s): PNL-SA-12000; CONF-840806-11; ON: DE85000358
• Country of Publication: United States
• Language: English

Related Subjects

052001* -- Nuclear Fuels-- Waste Processing
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALKALI METAL ISOTOPES
ALKALINE EARTH ISOTOPES
ALPHA DECAY RADIOISOTOPES
ALPHA-BEARING WASTES
AMERICIUM 241
AMERICIUM ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CESIUM 137
CESIUM ISOTOPES
COBALT 60
COBALT ISOTOPES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FISSION PRODUCTS
GASEOUS WASTES
HEAVY NUCLEI
IN-SITU PROCESSING
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MANAGEMENT
MATERIALS
MINUTES LIVING RADIOISOTOPES
NUCLEAR FACILITIES
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
OFF-GAS SYSTEMS
PLUTONIUM 238
PLUTONIUM 239
PLUTONIUM ISOTOPES
PROCESSING
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE FACILITIES
RADIOACTIVE WASTE PROCESSING
RADIOACTIVE WASTES
RADIOISOTOPES
RUTHENIUM 106
RUTHENIUM ISOTOPES
SOILS
STABILIZATION
STRONTIUM 90
STRONTIUM ISOTOPES
VITRIFICATION
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
YEARS LIVING RADIOISOTOPES