By Osamu Tsukimori
TOKYO (Reuters) - Most Japanese mayors and governors whose communities host nuclear plants want fresh safety assurances beyond government-imposed stress tests before agreeing to the restart of reactors taken off line after the Fukushima crisis, a Reuters poll showed, amid concerns about a looming power crunch this summer.
All but two of Japan's 54 reactors have been taken off line since the March 2011 nuclear disaster, mostly for checks or maintenance, and the remaining pair will be shut by early May.
Nuclear power supplied about 30 percent of Japan's electricity before the crisis and the government is keen to get some up and running again before electricity demand peaks in the summer.
But Prime Minister Yoshihiko Noda has vowed to get the understanding of local residents, many made wary by the world's worst nuclear accident in 25 years, before giving the go-ahead.
Trade Minister Yukio Edano said on Friday he hoped Japan could get through the peak season without mandatory power restrictions such as those imposed last year in eastern and north-eastern Japan. But he also said the possibility of power shortages should not affect decisions on reactor restarts.
"On safety checks (of nuclear power plants), I have said that this should not be influenced by any timing or other conditions," Edano told a news conference.
The poll of 21 mayors and 13 governors whose localities host Japan's 54 nuclear reactors showed that nine mayors were willing to approve restarts on condition of added safety assurances or steps. Eight mayors were undecided but also want similar steps.
Six mayors, including four of the above, cited a thorough probe of the causes of the crisis at Tokyo Electric Power Co's (Tepco) Fukushima plant as a precondition for restarts.
All 11 governors who responded also wanted safety assurances and/or a complete investigation of the accident. Fukushima Governor Yuhei Sato declined to reply, but has stated he wants his region to become a model for a nuclear-free society.
A massive tsunami knocked out cooling systems at Tepco's Fukushima Daiichi plant, 240 km (150 miles) northeast of Tokyo, on March 11 last year, causing the reactors to melt down and spew radiation, forcing mass evacuations.
"The government must give clear answers about the impact of the earthquake and the age of the nuclear units on the (Fukushima) accident, the reasoning for demanding the shutdown only of the Hamaoka plant and not others, and provisional safety guidelines reflecting findings from the accident," Fukui Governor Issei Nishikawa said in a written reply to the survey.
"There is no change in the stance that we won't allow the restart of nuclear plants currently under maintenance unless the government responds to the prefecture's request," added Nishikawa, whose prefecture hosts 13 commercial reactors, more than any other region.
LACK OF CLARITY
Chubu Electric Power's plant in quake-prone Hamaoka, central Japan, was halted last May under pressure from then-premier Naoto Kan.
Japan's Atomic Energy Commission is widely expected to endorse computer-simulated stress tests on Kansai Electric Power's No.3 and No.4 reactors in the town of Ohi in Fukui prefecture as early as Friday, clearing the way for the prime minister and three other ministers to meet to discuss the restarts.
But a delay in setting up a new Nuclear Regulatory Agency due to deadlock in a divided parliament is further clouding the outlook since the new body would oversee safety guidelines.
Ohi Mayor Shinobu Tokioka backed the restart of the two reactors on condition the government conducts a thorough probe of Fukushima and explains clearly to the public why nuclear power was needed.
A government-appointed panel of experts is aiming to finish a report on Fukushima by summer, but there is no firm date.
Matsue Mayor Masataka Matsuura, whose city hosts Chugoku Electric Power's Shimane plant just 9 km (6 miles) from city hall, said the lack of clarity made it impossible to decide now.
"We cannot judge whether to back the restart under the current circumstances in which the cause of the Fukushima Daiichi nuclear plant accident has not been clear," he said.
Tatsuya Murakami, the mayor of Tokai village northeast of Tokyo, said he was opposed to restarts because Japan lacked policies to ensure nuclear safety. Murakami has been calling for scrapping unlisted Japan Atomic power's Tokai Daini plant.
Nineteen mayors and 11 governors replied to the survey, which was conducted between late February and mid-March.
(Reporting by Osamu Tsukimori; Editing by Linda Sieg and Paul Tait)