One of the "crucial" units to decontaminate toxic wastewater at the Fukushima nuclear power plant was shut off Sunday after a leak of hydrochloric acid was found.
According to a statement by the Tokyo Electric Power Co (TEPCO), hydrochloric acid—which is used to neutralize contaminated alkaline water—was found seeping from a pipe joint in one of three Advanced Liquid Processing System units. Thus far, roughly one liter of the acid has collected in a vinyl bag wrapped around the pipe joint to contain the leakage.
The units, according to Agence France-Presse, are "expected to play a crucial role" in the treatment of "huge amounts" of contaminated water that have accumulated at the site since the crisis began in March 2011.
The leaking unit is one of two that had been in trial operation and was scheduled to go into full operation Sunday.
In late September plastic padding clogged up a drain in the same system, causing it to shut down. In October, it was halted due to a programming mistake.
Thousands of tonnes of water, used since the meltdown to cool reactors or polluted by other radioactive material, are being stored in huge tanks at the site on Japan's northeast coast.
Last month TEPCO began the highly dangerous process of removing more than 1,500 spent nuclear fuel rods from the damaged No. 4 reactor. According to the TEPCO website, by Monday they had removed 44 fuel assembles including 22 irradiated used rods.