Joban expressway

March 1, 2015

Final section of Joban Expressway opens following decontamination

http://mainichi.jp/english/english/newsselect/news/20150302p2a00m0na005000c.html

Cars travel along the Joban Expressway after its full opening on March 1, 2015, in this picture taken from a Mainichi helicopter in Okuma, Fukushima Prefecture. The expressway is surrounded by temporary storage sites for soil contaminated with radiation from the Fukushima nuclear disaster. The Fukushima No. 1 Nuclear Power Plant is seen far in the background. (Mainichi)

The last section of the Joban Expressway opened to traffic on March 1, three years later than scheduled, following a temporary suspension of construction due to the March 2011 Great East Japan Earthquake and tsunami and the ensuing Fukushima nuclear disaster.

The final section of the expressway extends 14.3 kilometers between the Joban Tomioka and Namie interchanges in Fukushima Prefecture. The 300.4-kilometer expressway, which runs from Misato Junction in Saitama Prefecture to the Watari Interchange in Miyagi Prefecture is expected to help boost the recovery of areas hit by the March 2011 disasters.

A total of 8.7 kilometers of the newly opened section runs through a contaminated area where the yearly radiation dosage exceeds 50 millisieverts -- deemed difficult for residents to return. The remainder runs through an area where dwelling restrictions are in place, marking radiation readings of over 20 millisieverts but under 50 millisieverts per year.

According to the Cabinet Office, a car traveling at 70 kilometers per hour for one trip along the expressway would be exposed to a radiation dosage of 0.17 microsieverts. The dosage received during a chest X-ray is about 60 microsieverts, or nearly 340 times this amount. If an accident occurred and someone waited outside their vehicle for an hour, the maximum radiation dosage would be 6.4 microsieverts. East Nippon Expressway Co. officials therefore say the level on the expressway poses no problems. Large signboards displaying radiation levels at three monitoring points have been placed along the opened route.

Radioactive soil removed during decontamination efforts remains in temporary storage along the expressway. According to East Nippon Expressway Co., decontamination work lowered the maximum airborne radiation level (at a height of one meter above the road) from 35.9 microsieverts per hour to 4.8 microsieverts per hour. In the town of Futaba, where radiation levels are high, slopes outside the guardrails have been covered with concrete to a depth of 15 centimeters for 715 meters along the expressway. This is to limit users' exposure to radiation absorbed by vegetation and soil.

Construction of the expressway began in 1970 as a project to aid economic development in areas along the Pacific coastline. The total cost of the project reached 1.061 trillion yen.

Prime Minister Shinzo Abe attended a ceremony on March 1 to mark the opening of the last section of the expressway. Fukushima Gov. Masao Uchibori said he hoped the expressway would serve as a "path of hope" for prefectural residents and boost the recovery of disaster-hit areas.