* PM Abe vows to speed up rebuilding from triple calamaties
* Two years on, more than 300,000 still living as evacuees
* Anti-nuclear activists fear media, public forgetting Fukushima
By Linda Sieg and Kiyoshi Takenaka
TOKYO, March 11 (Reuters) - Prime Minister Shinzo Abe vowed on Monday to speed up rebuilding from the huge earthquake, tsunami and nuclear crisis that struck Japan's northeast two years ago, promising that the nation would emerge stronger from its worst disaster since World War Two.
The 9.0 magnitude earthquake struck at 2:46 p.m., triggering tsunami waves as high as 30 metres (100 feet) that swept away residents and their homes. Nearly 19,000 people died and some 315,000 evacuees were stranded, including refugees from radiation spewed from the devastated Fukushima atomic plant.
Walls of water 13 metres high smashed into Tokyo Electric Power Co's Fukushima Daiichi nuclear plant north of Tokyo, knocking out its main power supply and backup generators and crippling the cooling system. Three reactors melted down in the world's worst atomic accident since Chernobyl in 1986.
The triple calamaties stunned a nation that had thought itself prepared for disasters and been taught to believe that nuclear power, which supplied nearly 30 percent of electricity at the time, was clean, safe and cheap. A panel of experts commissioned by parliament to probe the nuclear crisis dubbed it a man-made disaster resulting from "collusion" among the government, regulators and the plant operator.
"Our ancestors have overcome many difficulties and each time emerged stronger," Abe, 58, who took office in December vowing to revive a stagnant economy and restore national pride, told a memorial service in Tokyo also attended by Emperor Akihito and Empress Michiko.
"We pledge anew to learn from them and move forward, holding each other's hands."
Abe had earlier run an advertisement in English-language newspapers on Monday extolling the virtues of a resilient "New Japan" two years after 3.11.
Two years after the disasters, rebuilding the northeast - a region already suffering from a fast-ageing population and stagnant local industries, including farming - is patchy. Almost 300,000 people still live in temporary housing.
"We are standing at the crossroads of having to decide how we will live and what actions we should take," said Sakari Minato, 49, an auto dealer in the town of Yamada in Iwate prefecture, now living in a house damaged by the tsunami.
"In Tokyo, the economy might be improving as stock prices rise, but it takes a long time for that effect to permeate to the periphery."
He was referring to the share price boom since Abe's Liberal Democratic Party's(LDP) landslide election to oust the Democratic Party, in charge when the disasters struck.
The Fukushima Daiichi plant has been brought into a stable state, but decommissioning its damaged reactors will take decades and cost billions of dollars. Many of the 160,000 who fled will never be able to return.
"BATTLE AGAINST TIME"
Clean-up of communities further from the plant is haphazard and slow and concerns remain about the impact on health from radiation. A study by the World Health Organisation said last month that people in the worst-affected area have a higher risk of developing certain cancers, although for Japan's general population, the predicted health risks were low.
Abe told a news conference that he would speed up the reconstruction of devastated areas.
"Reconstruction is a battle against time," he said. "The Abe cabinet will promote a reconstruction that people can truly feel by implementing (policies) one by by."
Abe has boosted the reconstruction budget to 25 trillion yen ($260 billion) from the 19 trillion yen over five years allocated by the previous government.
Abe plans to restart off-line nuclear reactors if they meet new safety standards as he pushes policies to revive the economy, the latest sign that Japan's powerful nexus of politicians, bureaucrats and utilities known as the "nuclear village" is again dominating the corridors of power.
"People and the media are starting to forget Fukushima and what happened there," said a 32-year-old mother of two marching with thousands of anti-nuclear protestors in Tokyo on the eve of the anniversary.
All but two of Japan's 50 nuclear reactors have been halted for safety checks to see if they could withstand an earthquake and tsunami of similar magnitude to the March 2011 disaster.
More than 1,600 residents who had lived near Fukushima sued the government and Tokyo Electric Power Co on Monday seeking damages expected to reach at least 5.36 billion yen, Jiji news agency reported.
"Families and communities are breaking up, some are in financial ruin and the divorces and mental breakdowns are mounting. The companies that caused this nuclear crisis must be held fully responsible," said Kumi Naidoo, executive director for environmental group Greenpeace International in a statement.