Hundred of tons of radioactive water seep into soil

March 11, 2015

FOUR YEARS AFTER: Tons of radioactive rainwater seeps into soil at Fukushima plant

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201503110070

By HIROMI KUMAI/ Staff Writer

Tokyo Electric Power Co. reported a massive leak of radioactive rainwater at its crippled Fukushima No. 1 nuclear power plant on March 10.

It said hundreds of tons of contaminated rainwater breached barriers surrounding storage tanks for highly radioactive water and seeped into the ground.

According to TEPCO, the level of rainwater accumulating behind the outside weir of two barriers around storage tanks for contaminated water was 15 centimeters as of 10:30 p.m. on March 9. But the water level had dropped to 7 cm by a little past 8 a.m. on the following day.

Based on the decrease, TEPCO estimated that 747 tons of radioactive rainwater seeped into the soil.

The plant operator measured levels of beta-ray-emitting materials in the leaked water and detected a maximum reading of 8,300 becquerels per liter at one location. The average level of radioactivity at five sample locations was 2,300 becquerels per liter, according to TEPCO.

Highly contaminated water also leaked from the same area and seeped into the ground in summer 2013. As a result, TEPCO paved the surrounding area with asphalt to prevent a recurrence in the event of radioactive water spilling out.

In the latest leakage, workers discovered bubbles at the junctions of side ditches in the area. Officials said this indicated that contaminated rainwater had seeped through the junctions and into the ground.

According to the plant operator, although highly contaminated water with radioactive levels of tens to hundreds of millions of becquerels per liter is stored near the leakage site, no problems have been reported with the tanks and pipes of those nearby storage facilities.

Radioactive rainwater leak at Fukushima plant

http://www3.nhk.or.jp/nhkworld/english/news/20150311_08.html

Mar. 11, 2015 - Updated 02:21 UTC+1

The operator of the Fukushima Daiichi nuclear plant says an estimated 750 tons of rainwater with relatively high levels of radioactivity has been leaked. But company officials say they believe this water has not flowed into the Pacific Ocean.

Tokyo Electric Power Company says its workers discovered the leakage in an area called H4 in the western part of the complex where radioactive water is stored in 58 tanks. The rainwater had leaked from a dam surrounding these tanks.
The H4 area is located on the hillside of the plant, near the No. 4 reactor building.

Workers had closed a valve for a drainage channel last week following the detection in the area of rainwater with relatively high levels of radioactivity.

TEPCO officials said the rainwater was 15 centimeters deep at 10:30 PM on Monday, but the figure had fallen to 8 centimeters shortly after 8 AM on Tuesday.

Workers traced the leak after finding 2 puddles of radioactive water outside the dam.

They say the water inside the dam contained up to 8,300 becquerels per liter of beta-particle-emitting substances.

TEPCO officials say all the water has now been collected. They say the drainage channel to the ocean is buried underground and it is unlikely that the water flowed into the ocean.