On Wednesday, workers at the Fukushima Daiichi nuclear power plant were forced to halt the Advanced Liquid Processing System (ALPS) water treatment system used to decontaminate radioactive water at the crippled nuclear facility.
The ALPS system is a critical part of the water decontamination and storage process, but has had a series of problems during test operations which have raised serious questions about its long-term viability.
According to TEPCO officials the performance of one of three lines in the ALPS system, Line B, had drastically deteriorated.
On Monday, analysis of water after processing in the ALPS system found that beta emitting radioactive materials were only reduced to 1/10th of the level before processing, while the system is designed to reduce those contaminants to 1/1,000,000th the initial level.
Workers shut all three of the lines in the treatment system down in order to determine the cause of the problem and to acid clean the filters.
The utility hopes to bring the system online after April, but there are concerns that contaminated water may have found its way into the plants water storage tanks, but has not determined the cause of the malfunction at this time.
Workers found high levels of beta-emitting radioactive materials in three tanks used to store treated wastewater and in other tanks used to transfer the treated water. All of these tanks must now be decontaminated before the ALPS system is brought back online.
“We don’t know yet when we can resume operating the system as we have not detected the cause of the defect yet,” a TEPCO spokeswoman said.