The head of the UN nuclear agency has urged a worldwide rethink of safety measures to prevent new nuclear disasters.
Yukiya Amano, chief of the International Atomic Energy Agency, said that in the wake of the Fukushima catastrophe "business as usual is not an option."
But he also acknowledged that improvements are only effective if countries apply them, in opening comments to the IAEA's conference on nuclear safety.
While some countries at the 150-member IAEA's meeting want any new safety regime to be mandatory, most prefer them to be voluntary. If the IAEA cannot enforce safety standards, those rules will be only as good as they are enforced by IAEA nations.
"Even the best safety standards are useless unless they are actually implemented," Mr Amano said.
A draft of the conference's final statement reflected that it was content to work on upgrading present safety practices and emergency measures without giving the IAEA an enforcing role.
It called only for "a strengthened role of the IAEA in emergency preparedness and response by promoting and possibly expanding existing IAEA response and assistance capabilities." And it urged countries on the threshold of civilian nuclear programs to "create a nuclear safety infrastructure based on IAEA safety standards."
Outlining a five-point plan to strengthen nuclear reactor safety, Mr Amano called for strengthening IAEA standards and ensuring they are applied; establishing regular safety reviews of all the world's reactors; beefing up the effectiveness of national regulatory bodies; strengthening global emergency response systems, and increasing IAEA input in responding to emergencies.
He also urged that the INES scale - which classifies nuclear incidents on a seven-point scale - be revamped. The March accident at Japan's Fukushima Dai-ichi accident was upgraded to seven - the highest on the scale - only on April 12. That was more than a month after a the earthquake and devastating tsunami overwhelmed the Fukushima reactor's cooling system and radiation started leaking into the atmosphere.
"Safety standards ... in particular those pertaining to multiple severe hazards such as tsunamis and earthquakes should be reviewed," Mr Amano told the meeting. He proposed "IAEA international expert peer reviews" to complement national safety checks, and establishing stockpiles of emergency equipment by reactor operators to try and prevent a replay of Fukushima.