Via RT News: Fukushima water decontamination suspended indefinitely. Excerpt:
Treatment of radioactive water at Fukushima Daiichi nuclear power plant might be indefinitely suspended after malfunctions crippled the water purification process and recontaminated thousands of tons of partially purified water, Japanese media report.
The failure in the system, known as the Advanced Liquid Processing System (ALPS), is the latest setback in Tokyo Electric Power Co.’s (TEPCO) uphill battle to stockpile radioactive water, which is ballooning at a rate of 400 tons per day.
TEPCO said up to 900 tons of water, which had not been sufficiently cleaned in the ALPS equipment, flowed into a network of 21 tanks that were holding 15,000 tons of treated water. Not only have the 21 tanks been rendered unusable, but all 15,000 tons of previously cleaned water will now have to be retreated.
While efforts are underway to measure the full extent of the contamination, TEPCO officials said the problem was not noticed prior to March 18 because no abnormalities were detected in water sampled on March 14, Japan’s Asashi Shimbun daily reports.
“We never expected radioactive water to flow into the storage tanks,” Masayuki Ono, acting general manager of TEPCO’s Nuclear Power & Plant Siting Division, told the paper. “We should have been better prepared. We have no idea how long it will take to clean them if we decided to do so.”
The ALPS system was developed to dramatically curb the radiation level of highly contaminated water that is accumulating at the plant. The APS consists of 14 steel cylinders through which the contaminated water is filtered. After the filtering, waste materials like the absorbent and remaining sludge are transferred to high-integrity containers (HICs) that are transported to a temporary storage facility.
The ALPS can remove 62 different types of radionuclides, including strontium and cobalt from contaminated water. While the system cannot remove tritium – a radioactive isotope of hydrogen – the purification of water through the system is expected to reduce damage levels if water leaks from storage tanks.
The equipment, which is supposed to be able to treat up to 750 tons of contaminated water a day, has been undergoing trial runs since March 2013. The system, however, has been plagued with problems from the outset. The latest glitch and the subsequent recontamination was caused when one of the three ALPS lines failed to remove radioactive substances to a sufficient level.