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French Nuclear Test Caused Leak of Radioactive Material

By William Drozdiak
The Washington Post
PARIS

France acknowledged Tuesday that radioactive materials have leaked into the sea from its nuclear tests in the South Pacific but insisted that the quantities were so minimal that they posed no threat to the environment.

The confirmation that radioactive elements such as iodine 131 have seeped into the lagoon near the Mururoa test site seemed likely to revive the storm of protests that followed President Jacques Chirac's decision to conduct a final series of underground nuclear explosions before signing a global test-ban treaty.

Japanese Foreign Minister Yukihiko Ikeda said he will demand a full explanation from France about the nature of the leaks. Other countries in the Pacific region, notably Australia and New Zealand, are expected to follow suit, French officials said.

Defying international criticism, France has carried out five nuclear tests since September to verify a new warhead and to perfect simulation technology that will be used to monitor the reliability of its nuclear weapons.

A final test will take place next month before the test site is shut down permanently, French officials said.

But the latest accounts of radioactive leakage at the Mururoa test site have raised questions about the credibility of the French government's arguments that the nuclear explosions present no menace to the environment.

"There is no way to assess whether there is a coverup because the French do not allow independent verification," said Tom Cochran, a nuclear-testing specialist at the Natural Resources Defense Council in Washington. "What makes people suspicious about whether they are hearing the truth is the fact that these tests were really unnecessary in the first place."

France has always contended that its underground nuclear blasts inflict no damage on the fragile ecology of the Mururoa coral atoll, 750 miles southeast of Tahiti, which serves as its principal test site. Explosive devices are bored deep within the basalt foundation of the atoll, and French scientists say the intense heat from the blast vitrifies the rock and traps all radioactivity before it can escape.

But Alain Barthoux, director of nuclear tests at France's Atomic Energy Commission, acknowledged that traces of radioactive material are usually "vented" into the lagoon when scientists drill down into the rock to obtain samples after every blast.

Barthoux claimed, however, that such leaks involve "insignificant amounts" of radioactive substances, such as cesium, tritium or iodine, that vanish quickly in the environment. Quantities of iodine 131, for example, which can cause cancer when ingested by humans, shrink by half within eight days and disappear entirely within 80 days, he said.

Barthoux denied a report in the Japan's Yomiuri Shimbun newspaper that small amounts of radioactive iodine were continuing to leak into the water as a result of the latest round of nuclear tests and that officials from his agency were striving to suppress the information.

The paper quoted sources at the Geneva disarmament conference, where the global test-ban treaty is being negotiated, as saying a French nuclear expert disclosed the radiation leakage at a meeting in Washington last November.

The French specialist was quoted as saying the information was "extremely confidential" and as requesting that participants in the meeting "forget what they had just heard."

France first acknowledged the release of radioactivity from its nuclear tests when oceanographer Jacques Cousteau visited the Mururoa site in 1987 and was allowed to conduct independent tests of the water in the lagoon. He found the presence of radioactive iodine, cesium, cobalt and europium, but in quantities that were not considered dangerous.

But he warned that Mururoa's coral crown was deeply cracked and could pose a problem if testing continued. He said risks grew that higher levels of radioactive residue could seep into the lagoon.

French Defense Minister Charles Millon denounced reports from last year of widening fissures in the atoll as "unreliable." Foreign Minister Herve de Charette told the National Assembly that "never have any cracks of any kind been spotted."

But a confidential Defense Ministry report acknowledged that the government has been aware, at least since 1979, that Mururoa's underwater basalt foundation is fractured in several places.