SCIENTISTS SAY the fight to bring Japan’s crippled nuclear power plant under control could take three months or more, even if not hampered by further earthquakes. The announcement comes after another day of aftershocks, including one with an epicentre about 25km from the Fukushima plant.

The head of the Atomic Energy Society of Japan, Takashi Sawada, said yesterday that fuel rods in reactors 1 and 3 have melted and settled at the bottom of their containment vessels, confirming fears that the plant suffered a partial meltdown after last month’s huge earthquake and tsunami.

Engineers have been struggling since to bring four reactors under control by pouring water onto overheating nuclear fuel, and that water is highly contaminated as a result. Mr Sawada warned the condition of the plant could worsen if another strong quake knocks out power to its cooling systems.

“That would destabilise pressure and temperatures inside the reactors and the situation would become extremely unpredictable again,” he said.

The nuclear crisis is adding to the political woes of embattled Prime Minister Naoto Kan, who yesterday inaugurated a council of experts charged with leading Japan’s reconstruction from the triple disaster, which has left 28,000 dead or missing and 150,000 people homeless.

Lawmakers and council members are debating a so-called “disaster tax” to pay for the cost of rebuilding, including an immediate 4 trillion yen (€33 billion) relief package. “All the people should support and share the burden,” said Makoto Iokibe, a senior adviser to the prime minister.

Ichiro Ozawa, a former president of the ruling Democrats (DPJ), however, led a withering attack on the prime minister yesterday, criticising his poor leadership amid Japan’s worst crisis since the second World War.

“The irresponsible way the cabinet is dealing , with Prime Minister Naoto Kan himself not exercising his leadership, could lead to further disasters,” Mr Ozawa said in a letter to the party.

Some lawmakers within the DPJ want Mr Kan to resign following a drubbing in last weekend’s nationwide local elections. Mr Ozawa said the elections had “served notice” to the prime minister.

Mr Kan faces growing criticism for what Mr Ozawa called “his slow response” to the nuclear crisis and his failure to take a harder line with Tokyo Electric Power Co (Tepco), the operator of the Fukushima plant. Tepco has frustrated and puzzled observers with its reluctance to reveal information about what’s happening inside the plant, or to speculate on its future.

The criticism has worsened since a rare press conference this week held by Tepco’s beleaguered president, Masataka Shimizu, who provoked reporters with a string of evasive replies about the state of the Fukushima plant. Toshiba, which built four of the plant’s six reactors, has warned it will take at least 10 years to decommission them, even if the damaged reactors can be brought under control.

Meanwhile, Japan’s Nuclear Safety Commission revealed this week that it had waited weeks to publish information on elevated radiation levels from the plant last month partly to avoid panic. “Some foreigners fled the country even when there appeared to be little risk,” said Seiji Shiroya, an official with the independent government panel. “If we immediately decided to label the situation as Level 7, we could have triggered a panicked reaction.”