IMPLICATIONS OF THE AMERICAN SALT CORPORATION'S UNDERGROUND WORKINGS ON THE PROPOSED FEDERAL WASTE REPOSITORY AT LYONS, KANSAS

摘要

A study has been made of excavations in the rock salt deposit in the vicinity of Lyons, Kansas, where a site, which includes the abandoned Carey Salt Mine, has been considered for the location of a proposed Federal Repository for radioactive wastes. The nearby American Salt Corporation's underground workings consist of mechanically mined openings in the rock salt deposit as well as solution-mined cavities. The solution or hydraulic mining operations, which consist generally of pumping fresh water into wells that penetrate the salt formation and withdrawing the ensuing brine, extend over an area of about 140 acres and are situated some 3 miles south of the proposed location of the high level portion of the proposed Federal Repository. It is estimated that only 5 to 7% of the salt has been removed from the area. Furthermore, cavity closure and the resulting land subsidence within the area are expected to proceed at a very slow rate. In an attempt to enhance the removal of salt within the solution extraction area, two wells, 600 ft apart, were connected by hydraulic fracturing. The test was concluded after 16 days when the input of fluids was found to greatly exceed fluid recoveries. Although the exact disposition of the unrecoverable fluids is unknown, tests showed that the fractures in the vicinity of the injection and recovery wells were subsequently healed, and apparently the test did not change significantly the impermeable nature of the salt deposit.