I fear that failing to prosecute in this case will lead to another disaster in the future.
The decision to prosecute neither government officials nor Tokyo Electric Power Co (Tepco) - the power company operating the nuclear plant at Fukushima in Japan when it suffered a triple reactor meltdown on 11th March 2011 - has been met with anger in Japan, if not surprise.
Almost three years on it now appears that no one is to be held responsible for what may prove to be the world's worst ever industrial accident, whose costs are currently estimated at some $500 billion, and which led to the total shutdown of all nuclear power stations in Japan.
A criminal complaint by 15,000 victims
Some 15,000 people whose homes or land were hit by radiation filed a joint criminal complaint against Tepco in 2012. This was dismissed by prosecutors in September 2013, but the complainants appealed.
They alleged that both officials and Tepco failed to take necessary measures to protect the plant against tsunamis, and that they delayed in announcing the real radiation levels emerging from the plant.
However prosecutors have exempted both officials and Tepco, insisting that it would be difficult to prove that either had been 'negligent' in connection with the disaster, so they would be unable to secure a conviction.
They could not reasonably have predicted an earthquake and tsunami of that size, prosecutors said, and there was nothing wrong with their disaster response given the unexpected nature of the emergency.
'We won't give up'
But lawyer Hiroyuki Kawai, representing the campaigners, said: "there were lots of measures that officials could have taken to prevent the disaster. We won't give up indictment of the officials."
An independent investigative committee set up by the government concluded in July 2012 that the Fukusima accident was a "man-made disaster". Among its causes were acute shortcomings in Japanese corporate culture, including a "reflexive obedience" to authority.
Aileen Mioko-Smith, of Kyoto-based Green Action Japan, said: "Absolutely no-one is taking responsibility for this huge accident and when all these people are suffering. The investigation clearly stated this was an accident created by humans, not a natural disaster, but the judicial system here has now decided to side with the powers-that-be."
She added: "The government will be happy with the decision, but it is completely irresponsible. And I fear that failing to prosecute in this case will lead to another disaster in the future."
The truth must be told!
"There are many victims of the accident, but there is no (charged) assailant", Ruiko Muto, 61, told hundreds of protestors in Tokyo on Sunday.
"We are determined to keep telling our experiences as victims to pursue the truth of the accident, and we want to avoid a repeat of the accident in the future."
More than 80,000 local people around the Fukushima site are unable to return permanently to their homes within the exclusion zone. The government has warned that it will be decades before life can return to normal in the most contaminated areas.
Meanwhile highly radioactive water continues to spill from the site, causing plumes of radiation that are spreading across the Pacific Ocean.