Effects of radiation exposure on SRL 131 composition glass in a steam environment

Conference · Mon Nov 01 04:00:00 EST 1993

OSTI ID:10105249

Wronkiewicz, D J; Bradley, C R; Bates, J K ^[1]; Wang, L M ^[2]

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1. Argonne National Lab., IL (United States)
2. New Mexico Univ., Albuquerque, NM (United States). Dept. of Geology

Monoliths of SRL 131 borosilicate glass were irradiated in a saturated air-steam environment, at temperatures of 150{degree}C, to examine the effects of radiation on nuclear waste glass behavior. Half of the tests used actinide and Tc-99 doped glass and were exposed to an external ionizing gamma source, while the remaining glass samples were doped only with uranium and were reacted without any external radiation exposure. The effects of radiation exposure on glass alteration and secondary phase formation were determined by comparing the reaction rates and mineral paragenesis of the two sets of samples. All glass samples readily reacted with the water that condensed on their surfaces, producing a smectite clay layer within the first three days of testing. Additional crystalline phases precipitated on the altered glass surface with increasing reaction times, including zeolites, smectite, calcium and sodium silicates, phosphates, evaporitic salts, and uranyl silicates. Similar phases were produced on both the nonirradiated and irradiated samples; however, the quantity of precipitates was increased and the rate of paragenetic sequence development was accelerated in the latter. After 56 days of testing, the smectite layer developed at an average rate of {approximately}0.16 and 0.63 {mu}m/day for the nonirradiated and irradiated samples, respectively. These comparisons indicate that layer development is accelerated approximately four-fold due to the radiation exposure at high glass surface area/liquid volume (SA/V) conditions. This increase apparently occurs in response to the rapid concentration of radiolytic products, including nitric acid, in the thin films of water contacting the sample monoliths.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 10105249
• Report Number(s): ANL/CMT/CP--79803; CONF-931108--6; ON: DE94003207
• Country of Publication: United States
• Language: English

Related Subjects

052002
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
36 MATERIALS SCIENCE
360602
360605
BOROSILICATE GLASS
GROUND WATER
PHASE TRANSFORMATIONS
RADIATION EFFECTS
RADIOACTIVE WASTES
STRUCTURE AND PHASE STUDIES
TRANSMISSION ELECTRON MICROSCOPY
UNDERGROUND DISPOSAL
WASTE DISPOSAL AND STORAGE
WASTE FORMS