A preliminary report of development of high resolution phase shift interferometry for the assessment of nuclear waster disposal

A newly designed phase-shift interferometer and a reaction cell have been developed to investigate the alteration process and the safety assessment of an artificial barrier and the surrounding rocks during interaction with high pH solutions in repository sites. We advanced a conventional interferometer with a laser to a phase-shift interferometer with a white-light. Developments and evaluations were also made on the reaction cells at high temperature, high pressure and high pH conditions. Potentials of our established system, involving a newly equipped image-processing, were practically tested by dissolution experiments on calcite in various aqueous solutions. It was successfully confirmed that the developed phase-shift interferometer system can detect very slow retreat in short-periods with high enough precision to evaluate the dissolution kinetics.