PREVIEW-IAEA states to launch global nuclear safety drive

* IAEA safety meet biggest such event since Fukushima crisis

* Russia wants mandatory rules; others sceptical

* Strengthened expert review missions may offer way forward

By Fredrik Dahl and Sylvia Westall

VIENNA, June 17 (Reuters) - About 150 nations will launch a push next week to improve nuclear safety after Japan's atomic crisis but differences on how much international action is needed may hamper follow-up efforts to avert any new disaster.

In the biggest such gathering in the wake of the Fukushima emergency, ministers and regulators from across the world meet in Vienna to begin drafting a strategy to help address mounting public concern about the risks posed by nuclear energy.

The world's worst atomic catastrophe in 25 years has driven the issue up the political agenda especially in Europe, underlined by Germany's decision to shut down all its reactors by 2022 and an Italian vote to ban nuclear energy for decades.

Diplomats accredited to the International Atomic Energy Agency, the 151-member U.N. body, say the June 20-24 meeting will mark the start of a long process and will ask the IAEA chief Yukiya Amano to prepare a nuclear safety action plan.

They acknowledge that member states -- ranging from established atomic countries and newcomers to opponents and sceptics -- are split over the issue of mandatory international rules and whether a body like the IAEA should have more powers.

Russia wants to move towards making the U.N. agency's safety standards compulsory and France has called for the creation of new global regulations by the end of 2011. Both have important domestic nuclear industries which sell power plants abroad, and could benefit from having uniform standards around the world.

Many other countries -- believed to include the United States and India -- agree the need to enhance safety but argue it should remain primarily a national responsibility.

Some worry that stricter rules might discourage newcomers to the technology from signing up to any type of oversight.

"There is not a lot of enthusiasm among most nations for creating new legislation," one diplomat said."The road of hammering out new legal obligations is long and arduous."

Currently there are no mandatory, international nuclear safety regulations, only IAEA recommendations which national regulators are in charge of enforcing. A senior IAEA official this month said its standards should be given "more weight".

Group of Eight leaders agreed at a summit in France last month that more stringent safety rules were needed after the Fukushima disaster, where a huge earthquake followed by a massive tsunami caused a meltdown in three reactors.

NO IAEA "SUPER AUTHORITY"

Countries within the 27-nation European Union have agreed to proceed with stress tests on the region's 143 reactors and the bloc has called for them to be carried out worldwide.

A draft declaration expected to be adopted by next week's meeting was short on firm commitments or measures.

It emphasised "the importance of implementing enhanced national and international measures to ensure that the highest and most robust levels of nuclear safety are in place."

Ministers would also "consider the possibility of strengthening the international legal framework" on safety.

The vaguely-worded text may disappoint those hoping for concrete and quick international action on nuclear safety.

"The declaration can urge and exhort, but it cannot bind the IAEA or its member states to any commitments," Mark Hibbs, of the Carnegie Endowment for International Peace, said.

Nuclear expert Malcolm Grimston at London's Chatham House think-tank said he was "very sceptical as to whether an internationalisation of the safety regime would actually improve safety" in view of differences between countries.

"To try and impose an international standard over such a diverse set of national situations risks just introducing another level of unhelpful bureaucracy," Grimston said.

He and others suggested a strengthened system of so-called peer reviews and mutual oversight could offer an alternative way to address safety concerns, possibly with an increased role for IAEA missions which now only visit plants when they are invited.

"Every state operating major nuclear facilities should ask for independent, international teams to review the safety and security measures now in place," wrote Matthew Bunn and Olli Heinonen at Harvard University's Belfer Center.

Former IAEA chief Hans Blix said he did not believe anybody would agree to make the Vienna-based agency a sort of "super authority" that could order member states to take action.

But he suggested countries could be required to accept regular inspections by expert missions organised by the IAEA to examine nuclear power plants and issue recommendations.

"I don't think anyone really should escape those or say: 'we are so good, we don't need it'," Blix said.