Radiation From Japan’s Damaged Nuclear Plant Off the Charts

TOKYO, Japan, April 5, 2011 (ENS) – Workers at Japan’s Fukushima Daiichi nuclear power plant are being exposed to levels of radiation so high that monitoring devices are useless, a worker measuring radiation at the plant told NHK television today.

No one can enter the Unit 1, 2, and 3 reactor buildings at the power plant because radiation levels are so high, he said, adding that pools and streams of water contaminated by high-level radiation are being found throughout the plant, crippled by a killer earthquake and tsunami March 11.

TEPCO’s Fukushima Daiichi nuclear power plant on the Pacific Ocean before the March 11 earthquake and tsunami (Photo courtesy TEPCO)

The plant’s operator, Tokyo Electric Power Company, says 7.5 million times the legal limit of radioactive iodine 131 has been detected from samples of seawater near the plant in the Pacific Ocean off the northeast coast of Honshu island.

While iodine 131 has a short half life of eight days and will decay away in 16 days, Monday’s sample also contained 1.1 million times the legal limit of cesium 137, which has a half life of 30 years.

The Nuclear and Industrial Safety Agency says the radioactive substances are from nuclear fuel which leaked from the reactor into the water.

Today, TEPCO injected liquid glass as a hardening agent under a cracked and leaking concrete pit near the Unit 2 reactor to stop the flow of highly radioactive water into the sea.

Company officials say the leak appears to be diminishing. The crack was discovered Saturday. Previous attempts to seal it with concrete or polymer have failed.

TEPCO is considering building underwater barriers at three locations to contain the highly radioactive water.

On Monday evening, TEPCO began deliberately discharging wastewater containing low-level radioactive substances into the sea from the Fukushima Daiichi nuclear power plant to try and stablize the plant.

Explosions last month damaged three reactors at Fukushima Daiichi. (Photo courtesy Japan’s Ministry of Defense)

The leaking concrete pit at the Fukushima Daiichi nuclear power plant’s Unit 2 reactor (Photo courtesy TEPCO)

The release is aimed at making room in facilities to store the more highly contaminated water from the Number 2 reactor’s turbine building and a nearby tunnel, which is hindering restoration work.

The company says the level of iodine-131 in the wastewater is about 100 times the legal limit. But TEPCO says that if someone were to eat fish and seaweed harvested near the plant every day for a year, that person’s radiation exposure would be 0.6 millisieverts. The annual permissible level for the general public is one millisievert.

The Nuclear and Industrial Safety Agency approved the disposal of the wastewater as an emergency measure. The agency says it will strengthen its monitoring of the seawater to limit any adverse effects caused by the disposal.

Chief Cabinet Secretary Yukio Edano said the government approved the plan because removing the water from the Unit 2 reactor is a more urgent matter.

Edano called the operation an emergency measure to ensure the safety of the plant. The government has ordered the utility to monitor radioactivity in the seawater and closely track its environmental impact.

Chief Cabinet Secretary Yukio Edano April 5, 2011 (Photo courtesy Office of the Prime Minister)

Fukushima Daiichi nuclear power plant, April 2, 2011 (Photo courtesy TEPCO)

Japan today imposed a legal limit for radioactive iodine in fish after elevated levels were discovered in a small fish caught off the coast of Ibaraki prefecture, south of the Fukushima Daiichi power plant.

Edano announced a legal limit of 2,000 becquerels per kilogram for radioactive iodine in seafood, the first time the government has imposed such a limit on fish.

“We have called on fishermen to voluntarily halt the shipment of the fish in question. At present, the government has no plan to regulate the shipment immediately. We will rather continue to conduct monitoring thoroughly and grasp the overall situation,” Edano said.

Fishing has been banned within 20 kilometers (12 miles) of the damaged plant, matching the radius of the evacuation zone on land, where tens of thousands of residents have been moved out.

Neighboring South Korea has expressed its concern to Japan over the massive discharge of radioactive water into the Pacific Ocean from the Fukushima Daiichi nuclear plant, foreign ministry officials said Tuesday.

No international guidelines exist as to the level of radiation allowed to be discharged into the ocean, according to South Korea’s foreign ministry, although treaties state that countries should keep levels as low as possible.

“The government has notified the facts about the release of contaminated water into the sea to related countries,” said Edano. “But the level of radiation in the water in question will not immediately pose imminent risks of contamination to adjacent countries. It is natural that adjacent countries have great interests in the situation. Therefore, we will fully provide appropriate explanations of the situation to them through diplomatic channels.”