Measures of closing report of outside waste storage pits; Separate Volume Part I; Photographs sbout improvement step of outside waste storage pits

Yoshida, Michihiro; Suzuki, Satoshi*; Sukegawa, Yasuhiro*; Miyo, Hiroaki

JNC TN8440 2000-021, 180 Pages, 2000/10

JNC-TN8440-2000-021.pdf:42.37MB

At outside waste storage pits, containers for storage of wastes corroded and were flooded, and it was confirmed on August 26, 1997. Confirmation of contamination of the pits outskirts, installation of sheets to prevent rainwater from flowing into the pits, drawing stay water were executed, promptly. Design and authorization works of the work house and waste treatment devices to take out wastes of the pits were executed too. After construction of the work house, taking out wastes of the pits started, and finished on April 10, 1998. Investigations of the inflow point of rainwater and leak of stay water were executed next. The results were reported to Science and Thechnology Agency (STA), adjoining authorities on December 21, 1998. After decontamination of the pits inner walls to background level of the radioactivity which included general concrete, control area was removed, and the pits were closed by concrete. Measures of closing of the pits were prepared from the middle of August, 1999, and dismantlement of unnecessaly instruments started. Decontamination of the pits started fiom the beginning of September, 1999. The above works finished on June 30, 2000. After decontamination of the pits, STA, adjoining authorities confirmed the circumstances. Work pouring concrete into the pits was executed three times (three levels), and finished on August 31, 2000. In addition to above, the amount of concrete poured into the pits was about 1,200 m. This report compiled the photographs of the works from confirmation of stay water at August, 1997 by finish of measures of closing of the pits at September, 2000.