EARLY this month 鈥� unless last-minute protests are unexpectedly successful 鈥� a powerful shock wave will be registered at seismic monitoring stations around the world. This will be the unmistakable sign that France has defied international public opinion and resumed nuclear testing, ending the moratorium announced by former president Fran莽ois Mitterrand in 1992.
If the series of tests goes ahead, France will carry out its 124th underground nuclear test on Mururoa, an uninhabited coral atoll about 1200 kilometres southeast of Tahiti in the South Pacific (see Map). The French will explode the device between 600 and 1200 metres down a 1.5 metre-diameter shaft drilled in the ancient volcanic rock under the atoll鈥檚 lagoon.
Fractured rock
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The blast will only last a few microseconds. In the split second before they are destroyed, instruments mounted in the shaft will transmit data about the blast to receivers on the surface. The rock surrounding the explosion will melt and vaporise, forming a cavity. According to Australian scientists, a 50-kiloton explosion at a depth of 600 metres would form a cavity 80 metres wide. It would also fracture rock for almost 300 metres around the test site.
杏吧原创s watching the tests from the safety of platforms erected on the 27 kilometre-long atoll will see a mist form over the lagoon and a shimmering arc of white foam spread uniformly, almost gracefully, across the water.
President Jacques Chirac says that the series of eight tests, due to be held between now and next May, will be the last, and that France will sign the Comprehensive Test Ban Treaty next year (鈥淭ickling the dragon鈥檚 tail鈥�, New 杏吧原创, 26 August). The French say that they need to conduct the tests before they sign the treaty so that they can perfect computer simulations of nuclear explosions. But critics say that the main reason for the tests is the development of a new warhead (This Week, 24 June).
With the Cold War over, many nations have condemned the French. But, understandably, opposition from Pacific nations has been fiercest. New Zealand鈥檚 foreign minister Don McKinnon accused France of 鈥淣apoleonic arrogance鈥�. In Australia, French companies have been prevented from bidding for government contracts. Nauru, one of the South Pacific鈥檚 most influential island nations 鈥� because of the wealth generated by mining phosphate 鈥� will break off diplomatic relations with France if the tests go ahead.
Two weeks ago, environment ministers from Australia, New Zealand and 13 island nations in the South Pacific met in Brisbane, Queensland, to discuss the tests. A team of 20 Australian scientists headed by Peter Davies, a marine geologist from the University of Sydney, was commissioned by the Australian environment minister, John Faulkner, to analyse the impact of testing on the atolls.
Information about the tests is sparse. The French have allowed only three visits by international scientific teams to Mururoa, in 1982, 1983 and 1987. None lasted more than a few days and none was allowed to visit nearby Fangataufa, where some of the largest atmospheric and underground tests have been carried out.
In their report, the Australian scientists complain about a lack of access to data. Although the French last month published three glossy volumes on the effects of previous tests, the report鈥檚 authors say that the data released so far are mostly irrelevant or inadequate. The environment ministers want independent scientists to be given 鈥渇ull and unfettered鈥� access to data from the tests. Refusing access, the ministers say, suggests that the French have something to hide. Chirac has agreed to allow scientists to visit Mururoa, but only after the tests have been completed.
Drawing on information from the visits in the 1980s, the report says that compaction of the limestone on which the coral grows has caused the atoll to subside by an average of 1 metre. Material has slipped from the sides of the limestone outcrop and fissures have appeared. The report, says Faulkner, 鈥渇inds unequivocally that there has been environmental damage to Mururoa atoll鈥�. In their report the scientists say: 鈥淭here are no grounds to suggest that a major rupturing of the atoll will occur as a result of the forthcoming tests, although there is insufficient evidence publicly available to rule out the possibility altogether.鈥� However, they add, testing has affected both the limestone and the underlying volcanic rock in a way which is likely to increase 鈥渢he longer-term potential for leakage of radioactive material鈥�.
At Brisbane, Davies offered two forecasts of the best and worst outcomes of the tests. In the best case, based on a 100-kiloton blast at a depth of 1000 metres and well away from the edge of the atoll, radioisotopes would take 750 years to reach the limestone, where fissures stretching to the ocean have appeared as a result of previous tests. By then, most of the radioactive products would have decayed to such an extent that their impact would be negligible. In the worst case, based on a 100-kiloton blast at a depth of 700 metres close to the edge of the atoll, radioisotopes could reach the ocean in 25 to 50 years.
According to Davies, both scenarios are possible, but far more data are needed from the French about the chemistry of the rocks and the extent of fracturing to know which is the more likely. Opponents of the tests have warned that potentially harmful radioisotopes, especially caesium-137, strontium-90 and plutonium isotopes, will leach from rocks fractured by the blasts. These, they say, could enter the food chain and eventually spread by currents to other areas of the Pacific.
The Cook Islands are about 1500 kilometres west of Mururoa. In July, 14 doctors from the islands signed an open letter claiming that leukaemias, cancers and fish poisoning had increased among the 18 000 residents as a result of nuclear contamination. Many islanders are suffering from stress. 鈥淥ur people are scared,鈥� says Vaine Tairea, the Cook Islands鈥� agricultural and conservation minister. Elderly people, he says, are refusing to eat fish caught on the eastern side of the islands 鈥� the side facing Mururoa.
Tairea admits that the evidence of contamination is anecdotal and that there are no data to prove the two are connected. But the report plays down any risk to the health of the islanders. It says that the total radioactivity produced by underground testing at the two atolls is only about 1 per cent of that produced by all atmospheric tests carried out around the world since 1945. Also, any radioactivity that does leak into the ocean will be substantially diluted before it reaches any inhabited islands. 鈥淭he effects [on health] are likely to be small and limited to Mururoa and nearby island ecosystems,鈥� it says.
However, ministers from the Cook Islands, Papua New Guinea, Tuvalu, Nauru and Western Samoa say they do not accept that there is no health risk.
Tilman Ruff from the Monash Medical School in Melbourne is not surprised that the health aspects have been discounted. 鈥淭he report was written by radiation scientists not by public health specialists,鈥� he says. 鈥淭hey should not be commenting on health risks.鈥� Ruff, who was in Paris last week as part of a last-ditch attempt by members of International Physicians for the Prevention of Nuclear War to stop the tests, says that 60 underground tests have been carried out by the French since the 1983 scientific visit and that in 1987 scientists found caesium-137 on Mururoa. 鈥淟eakage is occurring and isotopes such as caesium-137 accumulate in the food chain.鈥�
The French steadfastly deny that any significant environmental damage is being done. They say concrete will be poured into the shaft before the blast, sealing the site. After the blast, the intense heat will melt and vitrify the rock around the concrete and this, say the French, will prevent any possible escape of radiation.
鈥淲e believe that the level of radioactivity in the lagoon or ocean will never reach the level of background radioactivity that is there naturally,鈥� says Alain Barthoux, director of the nuclear test division of the French Atomic Energy Agency and the man responsible for the safety of the tests.
However, the report insists that neither of the two atolls has 鈥渢he desirable engineering or geological characteristics of a nuclear waste repository鈥�. Contaminated water can leak out, the Australian scientists say. The claim is denied by Barthoux. 鈥淭he repository is up to world standards,鈥� he says.
鈥淚 know as a scientist that a direct link to health from the tests is hard to prove,鈥� says Davies. 鈥淏ut if I was living in the South Pacific, I would be concerned because eventually radionuclides will leak out and no one knows how the reefs are connected.鈥�
Unrecorded cancers
Other medical scientists are worried about the long-term health of the 8000 to 13 000 Polynesians brought in to work in unskilled or semiskilled jobs connected with the tests. Three members of M茅decins Sans Fronti猫res, the international relief agency, visited French Polynesia in July. In a report published last month they said that they were 鈥渁larmed鈥� by the French authorities鈥� lack of concern.
鈥淲hatever the real level of risk, the French authorities are not fulfilling their ethical responsibilities towards the populations that have been potentially exposed. The inadequacies in the medical data do not justify their conclusion that the tests are harmless.鈥� The MSF team said that a database of cancers was not established until 1985 and, even now, not all cancers are being recorded.
Regardless of the rights and wrongs of the scientific arguments, the environment ministers maintained last month that the French had no moral right to explode nuclear devices in someone else鈥檚 back yard. 鈥淚f they are so safe, why don鈥檛 they do this on their own soil?鈥� asks Bernard Dowiyogo, president of Nauru.
The Australians have gone one step further. They have told the French exactly where they should hold their tests. Granite is far better than Mururoa鈥檚 basaltic rock for nuclear tests. The rock of the Massif Central, northwest of the French town of Clermont-Ferrand, is particularly suitable. As is the granite of Corsica. And if the tests are really safe then they will not damage the island鈥檚 tourist industry.