* Greenpeace: Spent-fuel pools not safe against attacks
* Reactor cooling pools hold equivalent of 1-3 cores
* La Hague site holds equivalent of 114 reactors cores
By Geert De Clercq
PARIS, Oct 10 (Reuters) - The spent-fuel pools of French utility EDF's nuclear reactors are highly vulnerable to attacks, Greenpeace said in a report published on Tuesday.
Written by a group of nuclear experts and delivered to French authorities, the report says that spent-fuel pools, which typically contain the equivalent of one to three nuclear reactor cores, have not been designed to withstand external aggression.
An attack leading to a loss of cooling water could spark a spent-fuel fire that could contaminate areas as far as 250 kilometres away, Greenpeace's Yannick Rousselet said.
"EDF must address this issue and reinforce its spent-fuel pools," he said.
EDF, which operates 58 reactors, denied its spent-fuel pools are at risk and said they have been designed to withstand earthquakes and flooding as well as terror attacks.
"Our nuclear fleet is safe and EDF, in close cooperation with the authorities, permanently evaluates the risk of terror attacks," and EDF spokeswoman said.
Once uranium fuel is burned, the waste - which remains radioactive and very hot for years - typically is cooled in pools 2-3 years before being shipped to processing plants.
Greenpeace experts estimate the cost of upgrading the pools' safety at about one billion euros ($1.2 billion) per reactor.
The group said that since France has built many nuclear plants right by its borders, citizens of Belgium, Germany, Switzerland, Germany and Luxembourg are at risk.
"Nuclear facilities could be an attractive target for a terror organisation," said German nuclear expert Oda Becker.
Becker said the biggest risk is a complete loss of cooling water, which could happen if the building's walls are hit by an airplane, a helicopter loaded with explosives or wall-penetrating rocket-propelled grenades.
Areva's La Hague plant is seen as particularly vulnerable.
"With the equivalent of about 114 reactor cores in its pools ... La Hague is the nuclear facility that presents the highest risk in Europe," said Yves Marignac, one of the experts.
Areva said that since the Sept. 11 attacks in 2001, Areva and French authorities have been vigilant about terrorism risk.
Much of the fuel at La Hague has largely cooled after years in storage and the site is highly secured, Areva said.
It has permanent radar coverage in cooperation with the air force and no planes are allowed to fly over it at altitudes of less than 2,000 metres in a 3 kilometre radius. La Hague's pools are also surrounded by large buildings that protect from airplane attacks, Areva said.
State secretary for the environment Sébastien Lecornu said the government would study the Greenpeace report.
"France has the most robust nuclear safety and security measures in the world," he said on RTL radio. ($1 = 0.8489 euros) (Additional reporting by Simon Carraud; Writing by Geert De Clercq; Editing by Bate Felix and David Evans)