(This post is by Christine McCann)
Here’s the latest news from the ongoing crisis at Japan’s Fukushima Daiichi nuclear power plant.
State of Nuclear Politics in Japan
As expected, Prime Minister Naoto Kan resigned today, after Japan's Diet passed a bill on renewable energy, which requires power companies to buy all power generated by wind and solar. Prices will be determined by a third-party government entity.
The Democratic Party of Japan will hold an election to choose Kan's successor on Monday; campaigning will begin on Saturday. Kan has requested that his cabinet prepare to resign and hand over their duties as soon as the election takes place.
Industry Minister Banri Kaieda, who announced in July that he would resign over confusion about restarting nuclear reactors (but then changed his mind), has once again announced he will step down, as Kan requested.
The pool for the DPJ leadership election continues to grow, but several candidates have risen to the top as front runners: Seiji Maehara, former Foreign Minister; Yoshihiko Noda, current Finance Minister; Banri Kaieda, Industry Minister who is currently overseeing the nuclear crisis; and Sumio Mabuchi, former Transport Minister, who supports reducing Japan's reliance on nuclear power.
The House of Representatives passed a bill making the government responsible for removal of nuclear waste. The bill stipulates that Japan can hold TEPCO liable for disposal costs.
The Nuclear and Industrial Safety Agency (NISA) admitted this week that a study done by Tokyo Electric Power (TEPCO) in 2008 showed that a tsunami exceeding 10 meters could hit Fukushima Daiichi. The plant was built to withstand a maximum tsunami of 5.7 meters. TEPCO reported the results to NISA on March 7, 2011, four days before the earthquake and tsunami hit, and said it did not reveal the results to the public because they were based on a simulation. Previously, the government and TEPCO both said they never imagined a 10-meter tsunami was possible, although this week TEPCO admitted that a senior vice-president was aware of the report three years ago. Chief Cabinet Secretary Yukio Edano said that TEPCO had plenty of time to fortify the plant before March 2011 but failed to do so, and criticized the company for keeping the study secret.
A study of TEPCO's personnel expenditures shows that they are higher than those of other power companies in Japan. The utility is studying ways to reduce costs.
Power Company Scandals
The head of the Nuclear Safety Policy Committee of Saga Prefecture admitted that he accepted 50,000 yen in campaign donations from executives of the Kyushu Power Company. He has refused to return the money, saying the donations were not illegal.
State of the Reactors/Cooling Efforts
Fukushima Daiichi's ill-fated water decontamination process was once again halted this week, when a highly radioactive leak in the SARRY system was discovered as workers were changing a section of pipe. Radiation readings reached 3 Sieverts per hour.
TEPCO said that the highest level of radiation received by workers was 3.47 millisieverts per hour. The current allowable limit is 5 millisieverts per hour.
A leak was discovered in the cooling system of the spent fuel pool of reactor Number 4. Radiation of the water, which was leaking one drop every 30 seconds, was measured at 10 Bq/L. A container was placed beneath the leak.
TEPCO will inject water via pipes directly onto the fuel in reactor Number 3 in an effort to reduce the amount of contaminated water building up at the plant. Temperature levels will be monitored to ensure the new system is effective.
Contamination (including human exposure)
The Nuclear Safety Commission (NSC) has revised the amount of radiation released from the Fukushima Daiichi plant between March 12 and April 5, 2011. The new estimate is 570,000 teraBecquerels, which is 10% less than the previous estimate, published in April.
Japan will use aerial radiation data in 22 prefectures to determine radiation rates closer to the ground. The surveys have already been conducted in four prefectures, including Fukushima, and are expected to be completed in all prefectures by October.
The government is drafting a plan to decontaminate Fukushima Prefecture, with a goal of reducing radiation rates by 50% over the next two years. The plan includes cleaning drainpipes, weeding gardens, power-washing rooftops, and removing contaminated topsoil. Priority will be given to schools, parks, and gardens.
A study conducted by the National Institute for Environmental Studies showed that 22% of radioactive cesium-137 dispersed by the explosion at the Fukushima Daiichi plant, as well as 13% of iodine-131, has settled in a widespread area over eastern Japan.
China's State Oceanic Administration announced that squid sampled in the Western Pacific Region showed levels of radioactive strontium-90 were 29 times higher than those found in the water off Japan. The squid also measured high levels of cesium-134 cesium-137. The agency urged increased radiation testing of seafood.
Fukushima City is re-evaluating the routes on which its students commute, after a study showed that roads surrounding 80% of the schools measured 1 microSievert or more of radiation per hour.
Japan will reduce the radiation exposure threshold at schools to 1 milliSievert per year. Children will not be required to stay inside, but must be immediately decontaminated if levels are high. The government plans to reduce children's radiation exposure by 60% over the next two years.
The town of Horonobe, in Hokkaido Prefecture, is trying to decide whether or not to become a permanent waste storage site for the aftermath of the Fukushima crisis, in exchange for government subsidies. Residents have expressed concerns. Horonobe is already the site of the Underground Research Center, which studies methods of nuclear waste disposal; in exchange, the town receives 100 million yen annually.
Japan lifted the ban on cattle shipments from Miyagi, Fukushima, Iwate, and Togichi Prefectures this week. Chief Cabinet Secretary Yukio Edano said that radiation testing would be conducted on all cattle in the region to ensure continued safety.
Officials from Fukushima reported that cattle shipped from a farm in the prefecture were probably fed cesium-contaminated hay, which had been stored in an open-sided structure.
Other Nuclear News
Reactor Number 2 at the Tomari plant, operated by Hokkaido Power Company, will shut down this week for routine maintenance. Other reactors across country will also be shut down in the next few months; by spring, if none are restarted, all nuclear plants will be idle.
Kansai Electric has begun safety checks on its reactors, which have been shut down for regular maintenance, a move that is required in order to gain government approval to restart them.