Groundwater released into sea (follow-up)

 May 21, 2014

TEPCO begins releasing groundwater diverted at Fukushima plant into sea

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201405210035 

THE ASAHI SHIMBUN

Tokyo Electric Power Co. has started diverting uncontaminated groundwater at the crippled Fukushima No. 1 nuclear power plant into the sea, in an attempt to reduce the vast quantity of radioactive water accumulating on site.

At a news conference on May 21, Chief Cabinet Secretary Yoshihide Suga said the start of the water bypass project represents a “small step” in tackling the buildup of contaminated water, which has been a major source of public concern.

At 10:25 a.m. on May 21, the utility started releasing about 560 tons of water that it had pumped from 12 wells located in the plant compound in April. It took about two hours to release the water.

Each day 400 tons of groundwater have been seeping into contaminated reactor and turbine buildings at the Fukushima No. 1 plant. TEPCO estimates that the groundwater bypass project will reduce the amount by 20 to 100 tons per day.

TEPCO released water from storage tanks into the sea at locations south of the No. 1 to No. 4 reactor buildings through drainpipes it installed in spring 2013.

The Fukushima Prefectural Federation of Fisheries Cooperative Associations gave its consent to the water bypass project in March.

“It was an agonizing decision for fishermen in the area to endorse the plan,” Suga said. “We will have the industry ministry strictly instruct TEPCO to abide by its rules on contamination levels of water to be released.”

The 12 wells intercepting the underground flow of water were dug into the mountainside of the reactor buildings. Contamination levels of the water pumped from the wells are checked while it is stored in surface tanks.

TEPCO said it confirmed that the concentration of radioactive materials in the water released on May 21 was below its standard on water allowed to be released into the sea.

Local municipalities have endorsed the bypass project on condition that contamination levels of intercepted water remain below the standard and the water is closely monitored by TEPCO.

The utility and Fukushima Prefecture will conduct sample checks of seawater off the plant to investigate the impact of the water bypass project.

After the nuclear crisis unfolded, TEPCO drew criticism from local fishermen and others when it released water with relatively low contamination levels into the sea to make space in storage tanks for highly contaminated water.

Local residents have come to feel mistrust toward the utility after the plant experienced a series of accidental contaminated water leaks.

In new phase, Fukushima workers begin releasing groundwater

http://www.japantimes.co.jp/news/2014/05/21/national/in-new-phase-fukushima-workers-begin-releasing-groundwater/#.U3xzICji-1s 

Kyodo

Tokyo Electric Power Co. said Wednesday it began dumping into the Pacific Ocean hundreds of tons of groundwater collected at the crippled Fukushima No.1 nuclear complex after the water passed radiation tests.

The water was pumped last month from wells uphill of the reactors and stored in tanks, in a cycle that aims to reduce the amount seeping into heavily contaminated ground and into the building basements. By repeated pumping and dumping, Tepco now aims to slow the buildup of too-hot-to-release water, which it must collect and store.

A company official said if the so-called groundwater bypass is found to work, it is projected to reduce the water reaching the reactor buildings by up to 80 tons per day.

The release of groundwater has long been seen as an important milestone, but the operation has been delayed until now because repeated problems such as leaks damaged public confidence in the recovery effort.

To allay fears, Tepco and the government jointly decided to begin releasing groundwater only after confirming that it passes stringent safety tests.

The limits, which Tepco says are tighter than World Health Organization guidelines for drinking water, state that released groundwater should contain less than 1 becquerel per liter of cesium-134 and cesium-137, 5 becquerels of beta ray-emitting radioactive material such as strontium-90, and 1,500 becquerels of tritium.

Tepco pumped a total of 560 tons of groundwater from wells above the plant between April 9 and 14 and tested it ahead of Wednesday’s release.

The next release is expected to involve about 790 tons of groundwater stored since last year, although a Tepco official stopped short Tuesday of saying when that may take place.

Tepco plans to step up the rate at which it pumps groundwater from the wells and feeds into tanks. If Wednesday’s procedure becomes a routine cycle, the official said there could be a water discharge roughly every week.

Highly radioactive water has been increasing by around 400 tons a day at the plant because the same volume of groundwater is seeping into the basement of reactor buildings and mixing with water used to cool three reactors that suffered meltdowns in the 2011 disaster.

Short of storage, Tepco is installing more tanks, but it also wants to prevent a major increase in the total amount of water it needs to store.