Early construction and operation of the highly contaminated water treatment system in Fukushima Daiichi Nuclear Power Station (III) - a unique simulation code to evaluate time-dependent Cs adsorption/desorption behavior in column system

• Published in: Journal of nuclear science and technology Vol. 51; no. 7-8; pp. 906 - 915
• Main Authors: Inagaki, Kenta, Hijikata, Takatoshi, Tsukada, Takeshi, Koyama, Tadafumi, Ishikawa, Keiji, Ono, Shoichi, Suzuki, Shunichi
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 03.08.2014
• Subjects: adsorption; contaminated water; Fukushima Daiichi Nuclear Power Station; simulation; zeolite
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/00223131.2014.921580

A simulation code was developed to evaluate the performance of the cesium adsorption instrument operating in Fukushima Daiichi Nuclear Power Station. Since contaminated water contains seawater whose salinity is not constant, a new model was introduced to the conventional zeolite column simulation code to deal with the variable salinity of the seawater. Another feature of the cesium adsorption instrument is that it consists of several columns arranged in both series and parallel. The spent columns are replaced in a unique manner using a merry-go-round system. The code is designed by taking those factors into account. Consequently, it enables the evaluation of the performance characteristics of the cesium adsorption instrument, such as the time history of the decontamination factor, the cesium adsorption amount in each column, and the axial distribution of the adsorbed cesium in the spent columns. The simulation is conducted for different operation patterns and its results are given to Tokyo Electric Power Company (TEPCO) to support the optimization of the operation schedule. The code is also used to investigate the cause of some events that actually occurred in the operation of the cesium adsorption instrument.