Interim Report on Status of Containment Integrity Studies for Continued in-Tank Storage of Hanford High-Level Defense Waste

摘要

This interim report supplements technical information reported in RHO-LD-52, Status of Containment Integrity Studies for Continued In-Tank Storage of Hanford Defense High-Level Waste, September 1978. Only new data from the continuing laboratory programs and those studies initiated in the past year are included. Analyses of waste tank concrete integrity continued through the year. Laboratory tests to determine the effect of long-term elevated temperatures on the strength and elastic properties of concrete showed that the modulus of elasticity, compressive strength, and splitting tensile strength continued to decrease as a function of temperature; Poisson's ratio was relatively unchanged. The durability tests of reinforced concrete specimens exposed to simulated waste chemicals showed no evidence of deterioration after 6 months exposure. Temperature cycling effects after 17 cycles showed little change in the compressive strength but a large reduction in the modulus of elasticity. A structural failure mode analysis was initiated to estimate the effect of constant dead load, elevated temperature, and aggressive chemicals on tank structural integrity after 100 years of waste storage. No results are presently available. A report is scheduled for completion in early 1980. An electron microscopy analysis was initiated to determine if microstructural changes in concrete can be detected which would provide a key for correlating relatively short-term laboratory data to predicting long-term structural behavior. Documented results are scheduled for late 1980. (ERA citation 04:056120)