* Eight-nation Arctic Council drafts oil spill plans
* Guidelines avoid details such as corporate liability
* Greenpeace says document vague, fails to address risks (Adds comments on lack of clean-up technology, paras 12-13)
By Environment Correspondent Alister Doyle
OSLO, Feb 4 (Reuters) - Plans by Arctic nations to start cooperating over oil spills are vague and fail to define corporate liability for any accidents in an icy region opening up to oil and gas exploration due to global warming, environmentalists said on Monday.
A 21-page document by the eight-nation Arctic Council, seen by Reuters and due to be approved in May, says countries in the region "shall maintain a national system for responding promptly and effectively to oil pollution incidents."
It does not say what that means in terms of staff, ships, clean-up equipment or corporate liability in a remote region that the U.S. Geological Survey estimates has 13 percent of the world's undiscovered oil and 30 percent of its undiscovered gas.
The countries have drafted the document as companies including Royal Dutch Shell, ConocoPhillips, Lukoil and Statoil are looking north for oil despite high costs and risks. Shell's Kulluk oil rig ran aground in Alaska on Dec. 31 in near hurricane conditions.
"The document doesn't get to grips with the risks of a spill in a meaningful way," said Ruth Davis of Greenpeace, which passed the document to Reuters. Officials confirmed the text was genuine.
Greenpeace, which wants the Arctic to be off-limits to drilling, said it was "so vaguely written as to have very little practical value in increasing the level of preparedness."
"We should be far beyond this rudimentary document," echoed Rick Steiner, an environmental consultant and former professor at the University of Alaska often critical of the oil industry. He said the Council should put more stress on preventing spills.
The Arctic Council - comprising the United States, Russia, Canada, Sweden, Finland, Norway, Iceland and Denmark including Greenland - sees cooperation as big progress for the region, where sea ice shrank to a record low in the summer of 2012, opening the area to further exploration.
"There will be a lot of improvements compared to today - quite simply by making it much easier for countries in the Arctic to help each other when needed," said Karsten Klepsvik, polar expert at Norway's foreign ministry until end-2012.
The document, for instance, sets up 24-hour emergency contacts in the eight nations, seeks national rules to allow quick transport of clean-up equipment across maritime borders, better monitoring and joint training exercises.
Environment ministers from the Arctic Council will meet in Jukkasjarvi, Sweden, on Feb. 5-6 to discuss the draft.
Separately, Norwegian shipping and energy classification group DNV urged common regulations for the Arctic and said current oil spill technologies were inadequate.
"Present oil spill response technology right now can't effectively collect oil in ice-covered waters and it remains difficult even to detect a spill on water in permanent darkness and bad weather", said Per Olav Moslet, DNV's top Arctic technology expert.
The Arctic document makes clear it is non-binding, except for repayment of costs when one country helps another. It says it is "subject to the capabilities of the parties and the availability of relevant resources."
Global warming is making the Arctic region more accessible to shipping, mining and oil exploration. Oil spills could be extremely hard to clean up, perhaps trapped in or under ice that can be carried across international boundaries by ocean currents and winds.
In 2011, Arctic Council foreign ministers including outgoing U.S. Secretary of State Hillary Clinton agreed a plan for search and rescue - a prelude to harder work on defining rules for oil and gas.
The document says it will apply a general principle that the polluter pays, but does not define corporate liability. Steiner said Arctic-wide unlimited liability would make companies and insurers more cautious.
"Greenland suggested that we should include a system of liability in the agreement. There was no agreement on this," Klepsvik said. "We are a consensus body. We realised that it would take years and years to reach a conclusion" on liability.
Klepsvik said big oil companies showed they do pay for damage. BP Plc had paid $23 billion in costs and claims by late 2012 after its 2010 blow-out in the Gulf, the worst offshore spill in U.S. history.
Exxon Mobil says it paid more than $4.3 billion after the Exxon Valdez tanker ran aground just south of the Arctic in 1989, spilling more than 250,000 barrels. (Reporting By Alister Doyle and Balazs Koranyi; Editing by Oliver Holmes)