Plan B: Japanese government unveils proposal for backup city in case earthquake cripples Tokyo

By Wil Longbottom

Concerned about the impact a crippling earthquake could have on Tokyo, the Japanese government has unveiled plans to develop an entire backup city in case.

Snappily called the IRTBBC - or Integrated Resort Tourism, Business and Backup City - the spare city will be built on a 1,236-acre site 300 miles west of the capital Tokyo.

It could be home to 50,000 residents and 200,000 workers and will also feature offices, resorts, casinos and parks - as well as essential government facilities in case of disaster.

The potential site is on the site of Itami Airport - which is politically unpopular and has been superceded by other airports including Kansai and Kobe, according to wired.co.uk., and could also boast a 1,900ft-tall office tower.

Hajime Ishii, a member of the ruling Democratic Party, told the website: 'The idea is being able to have a back-up, a spare battery for the functions of the nation.'

Nearly 16,000 people were killed after a magnitude 9.0 earthquake struck off the east coast of Japan on March 11, 2011 - sparking a tsunami with up to 133ft waves which devastated the country.

Although Tokyo, home to 12.79million people, was not among the cities severely damaged by the quake, electricity supplies and fresh water were cut off for days in the capital.

The city has been badly damaged by earthquakes in the past, notably 1923, and video footage taken earlier this year showed skyscrapers in Tokyo wobbling as the massive quake struck.

A group of planners has requested £115,000 to study whether the project is feasible.

It comes after the operators of the nuclear power plant crippled by the tsunami were forced to deny further nuclear incidents today.

Tokyo Electric Power Co said radioactive gas leaking from one of the damaged reactors came from spontaneous fissions that occurs in any idle reactor.

Radioactive xenon was found at the Fukushima Daiichi site earlier this week, hinting that unexpected nuclear fission had taken place.

Boric acid was injected into the reactor as a precaution, but further examination determined the xenon was produced by curium - a nuclear fuel component that causes spontaneous fission.