Evaluation of concrete properties by laser induced ultrasonic waves for reactor decommissioning

Yamada, Tomonori; Hanari, Toshihide; Shibata, Takuya; Nishimura, Akihiko; Koyama, Shinichi; Daido, Hiroyuki; Shimada, Yoshinori*; Kotyaev, O.*; Kurahashi, Shinri*

no journal, , 

To decommission the Fukushima Daiichi Nuclear Power Station, it is essential to dispose radioactive wastes resulting from the disaster. The wastes cannot be diagnosed manually on account of exposure to high-dose rate. Thus development of remote diagnostic technologies for the wastes must be indispensable. The aim of the present work is to develop a method of evaluating physical and mechanical properties of heat-deteriorated concrete. Non-contact measurement of the propagation time of ultrasonic waves through the concrete was performed with an LDV. The experimental result shows that the propagation time becomes longer as a result of heat processing. The difference in propagation time depends on the changes in physical and mechanical properties of concrete suffered from heat processing. From viewpoint of remote diagnostic technologies for the decommissioning, an LDV is a promising tool to evaluate heat-deterioration of concrete by measuring ultrasonic waves propagating through a concrete.