福島第一原発の汚染水対策における地下水バイパスヘの疑問

摘要

The "Mid-and-Long-Term Roadmap" for the reactor decommissioning of Fukushima Daiichi Nuclear Power Plant (hereafter referred to "FDNPP") is drastically behind schedule due to the inadequate management by Tokyo Electric Power Co., Inc. (hereafter referred to "TEPCO"). The contaminated water has been increasing with 400m3 /day on average continuously by the groundwater inflow into the reactor buildings after the earthquake disaster due to loss for the pumping function of the sub-drain which was originally installed by TEPCO. TEPCO and the Committee on Countermeasures for Contaminated Water Treatment (hereafter referred to as "CCCWT") have only considered the groundwater in the upper permeable layer as the inflow of groundwater into the reactor buildings, so that TEPCO excludes the role of the groundwater in the lower permeable layer as another source of contaminated water. The groundwater in the lower permeable layer plays an important role in flow into the reactor buildings based on the information in regards to the existing geological cross-section and groundwater table publicly announced by TEPCO. The data also suggest that the upper permeable layer is contiguous to the lower permeable layer in some parts. In addition, as the result of the analysis for the data measured by TEPCO, the amount of retaining water has not ever reduced after operation of the Groundwater Bypass. Not only the effective countermeasures by the Groundwater Bypass will not be expected, but also the expansion of the contaminated water into the sea area will be occurred by the misunderstanding of the aquifer structure by TEPCO. TEPCO and CCCWT should reconsider the method of the Groundwater Bypass for the protection of the contaminated water in FDNPP.