Fukushima draws world's focus on power plants

By Dhaneshi YATAWARA

Japan continues to suffer from a chain of earthquakes since Great East Japan Earthquake struck on March 11 caused by a 9.0-magnitude undersea megathrust earthquake off the coast of Japan that occurred at 14:46 Japan Standard Time (05:46 Coordinated Universal Time). Subsequent to a series of earthquakes since then, unfortunately another earthquake of magnitude 5.8 hit central Japan on Saturday morning, according to the US Geological Survey. Going by the data at the US Geological Survey the quake struck Eastern Honshu at around 11:19 hours according to local time at the epicentre. (0219 hours Coordinated Universal Time) at a depth of 20.1 kilometres.

Serious

"Overall, the situation at the Fukushima Daiichi nuclear power plant remains very serious but there are early signs of recovery in some functions, such as electrical power and instrumentation", said the International Atomic Energy Agency last Friday.

Coincidently on April 26 Belarus, Ukraine and Russia will mark the 25th anniversary of the nuclear reactor explosion in Chernobyl, the place where the world's worst civil nuclear accident took place in 1986. Fukushima Daiichi Nuclear Plant disaster joins the list as the second same level member. The world witnessed the world's largest nuclear disaster for the second time. Chernobyl reactor No. 4 exploded on April 26, 1986, contaminating a large part of Northern Europe, including Belarus and Russia, with harmful radiations. Around 50,000 Pripyat residents were evacuated. Even 25 years after the disaster they cannot return yet.

The nuclear accident left many dead and the city of Prypiat was evacuated across a radius of 48 kilometers. Prypiat is an abandoned city in the 30 km (19 miles) exclusion zone around the closed Chernobyl nuclear power plant. The plant is however, now opened to tourists. Only "officially developed" and "medically safe" tour of the region is recommended for any visitor.

According to the media statements given by the Japanese National Police Agency as of April 14 the number of dead from the disaster stood at 13,456. As of last Thursday (April 14) a total of 4,902 people had been injured, and another 139,020 displaced by the disaster.

According to the Police Agency on Friday for the first time rescue and search teams entered six kilometres close to the damaged Fukushima Daiichi nuclear power plant to carry out their mission.

On April 12 the Japanese Nuclear and Industrial Safety Agency (NISA) issued a new provisional rating for the accident at the Fukushima Daiichi nuclear power plant assessing it as a Level 7 on the IAEA International Nuclear and Radiological Event Scale (INES). The nuclear accident at Fukushima Daiichi is now a "Major Accident" on INES. Level 7 is the most serious level on INES and is used to describe an event comprised "A major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures".

Earlier on March 18, Japanese authorities rated the core damage at the Fukushima Daiichi 1, 2 and 3 reactor Units caused by loss of all cooling function to have been at Level 5 on the INES scale. They further assessed that the loss of cooling and water supplying functions in the spent fuel pool of the Unit 4 reactor to have been rated at Level 3. NISA estimates that the amount of radioactive material released to the atmosphere is approximately 10 percent of the 1986 Chernobyl accident, which is the only other nuclear accident to have been rated a Level 7 event. The INES was introduced in 1990 by the International Atomic Energy Agency (IAEA) in order to enable prompt communication of safety significance information in case of nuclear accidents.

As INES ratings are not assigned by a central body, high-profile nuclear incidents are sometimes assigned INES ratings by the operator, by the formal body of the country, but also by scientific institutes, international authorities or other experts which may lead to confusion as to the actual severity.

A number of criteria and indicators are defined to assure coherent reporting of nuclear events by different official authorities.

There are 7 levels on the INES scale; 3 incident-levels and 4 accident-levels. There is also a level 0. The level on the scale is determined by the highest of three scores: off-site effects, on-site effects, and defence in depth degradation.

Earthquakes

As of April 15 records of US Geological Survey four earthquakes have hit near the east coast of Honshu in Japan and three off the East Coast of Honshu and another to Eastern Honshu. Japanese authorities may revise the INES rating at the Fukushima Daiichi nuclear power plant as further information becomes available. Japan's nuclear safety agency has told plant operators to check and improve outside power links to avoid earthquake-related outages similar to those causing the country's current nuclear crisis.

On the latest updates from the operator company of Fukushima Daiichi, Tokyo Electric Power Co., Inc (TEPCO) its President Masataka Shimizu has said at a press conference held by the company on April 13 that he wishes to step down from all his posts. Shimizu also serves as Vice Chairman of the Nippon Keidanren with a membership of many leading companies and Chairman of the Federation of Electric Power Companies of Japan. TEPCO nuclear power plant to compensate tens of thousands of households forced to evacuate due to radiation leaks. Evacuated people who lived within 30 kilometers of the plant will be eligible for provisional damages, which have been set at 1 million Yen per family and 750,000 Yen for single-persons.

Gamma dose in the air as a result of the radiation leak rates are measured daily in all 47 prefectures of Japan. Perfectures are administrative divisions of Japan. The values have tended to decrease over time. For Fukushima, on April 14 a dose rate of 2.0 microsiverts per hour ( µSv/h) was reported. In the Ibaraki prefecture, a gamma dose rate of 0.14 µSv/h was reported.

The gamma dose rates in all other prefectures were below 0.1 µSv/h. Dose rates are also reported specifically for the Eastern part of the Fukushima prefecture, for distances beyond 30 km from Fukushima Daiichi. On 14 April, the values in this area ranged from 0.1 to 21 µSv/h. The desperate struggle to bring the defunct reactors under control continues in Japan while the world watch the event every millisecond.

A new government panel plans to outline guidelines in July on compensation for damage caused by radioactive substance leaks from the Fukushima Daiichi power plant, its chairman Yoshihisa Noumi from Gakushuin University has told the media on Saturday. Lessons learnt at Fukishima will surely be a turning point in the world's history.