Radiation Levels Hit Record Highs in Fukushima Seawater

Tokyo, May 16 (Jiji Press)--Record-high radiation levels have been observed at five monitoring points in waters off Tokyo Electric Power Co.'s <9501> crippled Fukushima No. 1 nuclear power station in northeastern Japan, TEPCO said Friday. The findings followed a recent series of record-high levels of radiation detected in groundwater at the plant damaged by the March 2011 earthquake and tsunami. But TEPCO officials said that the cause of the rises in seawater radiation levels is unknown. Inside the plant's port, 1,900 becquerels per liter of tritium was detected in seawater sampled Monday from a point between the water intakes for the No. 2 and No. 3 reactors at the plant, up from the previous record high of 1,400 becquerels found at the same point on April 14, according to TEPCO. At a nearby point, tritium levels rose to 1,400 becquerels from the previous record of 1,200 becquerels. At a point between the water intakes for the No. 1 and No. 2 reactors, seawater sampled on Thursday contained 840 becquerels of strontium-90 and other beta ray-emitting substances, up from the previous record of 540 becquerels. Outside the port, 8.7 becquerels of tritium were detected in seawater taken at one point on Monday and 4.3 becquerels at another point about 3 kilometers away the same day. How to prevent an increase in radiation-tainted water at the Fukushima No. 1 plant is a major challenge facing TEPCO. As part of the efforts, a project is under way to create shields by freezing soil around the plant in order to block groundwater from flowing into the reactor buildings and being contaminated with radioactive substances. In the project, 30-meter-deep, 2-meter-thick underground frozen soil shields with a total length of 1,500 meters will be built around the plant's No. 1 to No. 4 reactors. Soil will be frozen by pouring liquids with a temperature of minus 30 degrees Celsius into pipes buried around the reactor buildings. On Friday, the Ministry of Economy, Trade and Industry and general contractor Kajima Corp. <1812> demonstrated to the press the construction of such frozen soil walls at the premises of the Fukushima No. 1 plant. "We could confirm the frozen soil's water-shielding effects," a ministry official said after the experiment. The ministry aims to launch work to construct the shields next month. But the Nuclear Regulation Authority has not approved the plan, citing insufficient explanations about safety. The project is estimated to cost 31.9 billion yen, while 45.5 million kilowatt-hours of electricity, equal to annual power consumption at 13,000 average households, will be needed to maintain the frozen soil walls. END