By Elaine Lies
TOKYO, Sept 10 (Reuters) - A triumphant Tokyo governor Naoki Inose returned home to the cheers of thousands gathered in a plaza on Tuesday, thanking everyone for the support that brought the 2020 Olympic Games to Japan and vowing to get down to work to make them successful.
Tokyo stocks rallied for a second straight day on optimism that Japan's decisive victory at the International Olympic Committee (IOC) meeting in Buenos Aires over rivals Madrid and Istanbul will bolster the chances of a lasting economic recovery to erase two decades of stagnation.
Welcomed back by a brass band and a crowd gathered in front of the futuristic Tokyo Metropolitan Government building lit up in the Olympic colours as dusk fell, Inose said Tokyo's success in its bid to host the Games for a second time was due to the enthusiasm at home.
"The voices and yells of support from Japan were heard in Buenos Aires and that's what led to our getting the Games," he said.
But later he told a news conference that now the city would have to get down to work to prepare for the world's greatest sports extravaganza only seven years in the future.
"We need to make the 2020 Games the best ever," he said. "So every Tokyo citizen needs to join together, with each person doing what they can according to their abilities."
The city touted a $4.5 billion war chest in the bank and its ability to tap into the vast markets of Asia, as well as its reputation for getting things done, appeals that helped win over an IOC worried about delays for the 2016 Summer Games in Rio de Janeiro and difficulties with the 2014 Winter Games in Sochi.
But even as Japan savoured its success and anticipated still further economic benefits, questions remained about the nuclear reactor at Fukushima, where the world's worst nuclear crisis in 25 years was set off by a March 2011 earthquake and tsunami and the crippled reactor continues to leak water.
Prime Minister Shinzo Abe promised at the IOC meeting that the situation was "under control," though surveys at the weekend found that 72 percent of Japanese thought the government's response was too late and 95 percent said it was a serious problem.
The plant's operator, Tokyo Electric Power Co, has recently been forced to reverse denials and admit that hundreds of tonnes of radioactive water are pouring into the Pacific Ocean each day. Radiation levels near tanks that leaked highly radioactive water have spiked, and the operator of the plant has voiced concerns that contamination may reach groundwater.
Tokyo pledged last week to spend nearly half a billion dollars on cleaning up the plant, with critics saying the announcement was aimed at the Sept. 7 Olympic vote.
"I will firmly take responsibility for carrying out our promises," Abe reiterated to reporters on Tuesday, referring to his presentation to the IOC in which he said the government had already decided on a programme to deal with the crisis.
Abe staked his reputation on winning the Games, even leaving a G-20 meeting early to attend the IOC meeting, and his presentation was a daring gamble that paid off in more ways than one.
The win has boosted his popularity and could potentially spur his signature pro-growth policies for the world's third-biggest economy.
Japanese media has gone into hyperdrive speculating about the changes that may come to Tokyo, with some saying the city's unattractive network of raised expressways - the core of which was built in 1964 - may be relocated underground.
Others have lauded the possibilities of new train lines and better transport to the city's airports, as well as bayside property development.
The Nikkei share average closed at a 5-1/2 week high. (Editing by Ed Osmond)