Japan’s idled nuclear plants are likely to stay offline beyond a summer power supply crunch, say analysts, after a government plan for “stress tests” sparked confusion in regions hosting reactors.

Tokyo has not given specific details of the new tests or when they start, but will base them on similar moves in the European Union to survey the ability of atomic complexes to withstand extreme events in the wake of the Fukushima crisis.

Those tests are expected to take at least two to three months. Japan has been forced to undertake power saving measures amid fears that high demand will raise the risk of blackouts in the summer months and possibly beyond.

“Japanese nuclear facilities are unlikely to restart before the stress tests are finished, so the prospect of nuclear power being available before summer peak demand is now remote,” Goldman Sachs said in a note yesterday.

Japan’s move to order more safety checks has also prompted confusion, given that Tokyo had earlier urged local governments to restart suspended reactors, saying sufficient steps had been taken to operate them safely.

The Nikkei business daily said in an editorial yesterday that “the sudden announcement of additional inspections has fuelled confusion when local governments face tough decisions over resuming halted reactors”.

“If things carry on like this, all (of Japan’s) 54 reactors will be stopped within a year, worsening the power shortage and affecting the whole economy.”

Japan last week began restricting electricity consumption in the Tokyo and Tohoku regions by 15 per cent for big users for three months, to limit the risk of blackouts as temperatures rise and demand for air-conditioning spikes.

Debate has been ignited in Japan about the safety of nuclear power after the March 11 tsunami tore into the Fukushima Daiichi nuclear plant, triggering reactor meltdowns, radiation leaks and widespread evacuation.

Prime Minister Naoto Kan has ordered a reappraisal of the country ’s energy policy and oversight of a nuclear industry seen as too close to the government body charged with regulating it.

Utilities not directly affected by the seismic disaster have refrained from restarting reactors that were under maintenance at the time, amid objections from local governments and a wave of anti-nuclear sentiment.

As a result only 19 of Japan’s 54 reactors are now operating, with more due to shut down for regular checks soon. Under Japanese law, reactors must halt for inspection every 13 months.

Amid warnings Japan could face huge power shortages if reactors do not resume, imports of fossil fuels have soared in an effort to compensate for lost nuclear capacity.

Critics say the order for stress tests serves as a further illustration of an absence of coordin-ation in the Kan administration, which is under fire for its hand-ing of the crisis.

Trade and Economy Minister Banri Kaieda earlier visited regions to ask governors to restart nuclear facilities that had initially been deemed safe by the Nuclear Industrial Safety Agency (NISA).

But yesterday Mr Kan said: “After the major accident, however, I think it is difficult to win people’s understanding with that procedure alone.”

He added: “We cannot gain the understanding of the public if we assign NISA to do everything, as we have done in the past.

“NISA is a party that failed to prevent the disaster.”

In May Mr Kan told the oper-ator of another quake- and tsunami-prone plant, the ageing Hamaoka facility southwest of Tokyo, to shut down its reactors until it builds higher sea defences.

The governor of Saga prefecture in Kyushu, southern Japan, said the restart of two reactors at the region’s Genkai plant would be delayed due to the surprise stress test announcement.

“Why has the topic of stress tests come up now, after we were told the plants are safe?” Yasushi Furukawa told reporters yesterday.

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