Selection of important nuclides from the viewpoint of safety assessment for disposal of radioactive waste arising from research institutes, 2; Analytical scheme for nuclide composition in radwastes arising from research and testing reactor and post-irradiation examination facilities

Asai, Shiho; Sakai, Akihiro; Yoshimori, Michiro; Kihara, Shinji

JAERI-Tech 2003-071, 46 Pages, 2003/08

JAERI-Tech-2003-071.pdf:4.31MB

As part of survey concerning radioactive inventory of radwastes arising from research institutes, an analytical scheme has been studied for verifying their nuclide composition based on calculation analysis and record, in consideration of the its characteristics. In this study, radwastes are used as samples, which arise from research and testing reactors and post-irradiation examination facilities (PIE facilities). Though separation procedures are simplified and rationalized, quantifiable values could be obtained with relative errors under 10% for almost all the samples containing nuclides like Ni and U which concentrations are low, and recoveries were high on the whole. These show that the analytical scheme is useful for chemical separation of radwastes arising from research and testing reactors and PIE facilities.

Technical approach of disposal system for radioactive waste arising from radioisotope utilities and research institutes; Preliminary safety assessment for near surface disposal facilities

Sakai, Akihiro

KURRI-KR-56, p.58 - 79, 2001/03

no abstracts in English

Countermeasure of decommissioning wastes; Review of reuse and recycle

Miyasaka, Yasuhiko

Enerugi Rebyu, 15(9), p.24 - 28, 1995/00

no abstracts in English

Accuracy verification for calculation of inventory in JPDR due to neutron activation

Sukegawa, Takenori; Sasamoto, Nobuo; Fujiki, Kazuo

INDC(JPN)-164, 38 Pages, 1993/03

no abstracts in English

Experience of the radioactivity inventory evaluation in NPP in Japan (Experience in JPDR)

Shimada, Taro

no journal, , 

Evaluation of accurate radioactivity inventory is essential for preparing a dismantling plan, estimating the amount of radioactive wastes for each radioactivity level arising from dismantling activities and controlling occupational radiation dose. In the JPDR dismantling project, neutron-induced radioactivity inventory was evaluated by calculations combined with measurement, and the secondary contamination was evaluated by measurement. Calculated radioactivity concentrations were agreed with measured values within a factor of two for reactor core components, while calculated values were an order of magnitude larger than measured values for outer part of bio-shielding concretes. It was cleared that water content and weight ratio of steel bars to concrete materials significantly influenced the neutron flux distribution in the bio-shielding concretes. The measured radioactivity inside of the reactor pressure vessel wall and at the inner part of the bio-shielding concretes was compared in detail with the calculations to verify the methodology applied to calculations of radioisotope production. Then it was found that the radioactivity inventory could be estimated accurately with combination of calculations and measurement of radioactivity in samples and dose rate distribution for planning of dismantling activities.