High-level Waste Canisters Research Articles

Very Rough Preliminary Estimate of the Colloidal Sodium Induced in Rock Salt by Radioactive Waste Canister Radiation

ABSTRACTVery rough estimates have been made of the total amount, the formation rate and spatial distribution of the Na metal colloid particles induced in rock salt adjacent to four types of radioactive waste canisters. A number of extrapolations were required. Salt immediately adjacent to a lightly shielded, 2.16 kW, high level waste canister could be converted entirely to colloidal Na (and presumably chlorine gas) in 200-400 years. The total Na metal formed will be 250-300 kg. A heavily shielded, 3.3 kW, spent fuel canister will convert roughly 0.3 percent of the salt at the canister surface to colloidal Na and the total sodium metal will be roughly 0.5 kg. Even at the lowest colloid levels the Na metal formed should greatly influence interactions between canisters and the surrounding salt, particularly if brine enters.

Thermal expansion effects in deep-sea sediments

Understanding how in situ heating affects unlithified deep-sea sediments is important for both geological and practical reasons. Deep-sea drilling by Glomar Challenger over the past decade has revealed several places where magma has intruded sediment to form sills and the heat released by a large sheet of molten rock has been shown to produce substantial changes on the sediments in its vicinity1. Another example is the burial of hot canisters of high-level radioactive waste within the sediments of the ocean floor, which has been proposed as a solution to the problem of disposing of this material2. I consider here the physical effects which high temperatures might produce in deep-sea sediments. Substantial chemical effects are also likely, but these are not discussed. In practice, the physical and chemical effects would work together in modifying the original sediment.

Instrumentation and Computer Based Data Acquisition for in-Situ Rock Property Measurements

This paper discusses instrumentation and computer based data acquisition for in-situ rock property measurements as applied to an experiment conducted at Stripa, Sweden in cooperation with the U. S. Department of Energy and the Swedish government. Electrical heaters were installed in an underground granite mass to simulate thermal loading by canisters of high-level nuclear waste. Extensometers, borehole deformation gages, vibrating wire stress meters, and thermocouples were used to monitor the thermomechanical response of the granite. A computer based data acquisition system recorded data, performed on-line computations and provided graphic output. A summary description is given of the experiment areas, heater systems, data acquisition hardware, and four types of instruments used for the in-situ rock property measurements.