Nuclear contamination at Moruroa


By Jennifer Thompson

In 1990, Professors Hochstein and O'Sullivan, two New Zealand scientists, experts in geothermal fluid mechanics, presented the results of their four-year "reservoir model" computer study to the conference of the New Zealand branch of the Physicians for the Prevention of Nuclear War.

Their study, begun in 1985, constructed a detailed model of Moruroa and found that the explosions had seriously weakened the hard basalt core of the atoll. They also estimated that radioactive ground water was moving through fractures in the atoll at a rate as high as 100 metres a year and that radioactive waste would be likely to reach the surface in about 30 years.

Their findings were supported by data collected by French oceanographer Jacques Cousteau during a 1988 visit to the atoll. The evidence collected showed the presence of leached radioactive isotopes in the Moruroa lagoon, including caesium 137, strontium 90 and plutonium as well as short-lived radionuclides caesium 134 and iodine 131.

According to Hochstein, the shafts at Moruroa contain about 100 times the amount of radioactive material dropped on Hiroshima. The Cousteau report also included evidence of the cracking and sinking of the atoll due to continual testing. Divers from Cousteau's ship filmed large underwater fissures to a depth of 230 metres in the base of the atoll. The minimum depth of the bomb shafts is 700 metres and the extent of cracking is not publicly known.

The French military's rejection of Cousteau's report resulted in the production of a sanitised version produced by the New Zealand National Radiation Laboratory (NZNRL). This evaluation was then used by the French military to justify continued testing. The NZNRL accepted that both venting and leaking was occurring at Moruroa, and suggested that the dilution of the radioactivity into the ocean was the solution to the contamination problem.

Mounting evidence of serious contamination led Greenpeace to propose, in October 1990, a sampling program. This was rejected by the French government on the grounds that Moruroa is a military exclusion zone. The Greenpeace program was designed to: look for potential venting and leakage from tests; detect fissures in the base of the atoll; trace radioactive plumes and analyse marine plankton and other sea life to gain an initial picture of whether, and to what extent, serious leakage was occurring.

Despite the French refusal, Greenpeace activists travelled to the atoll to protest nuclear testing and begin sampling in December 1990. The presence of radioactive caesium-134 was confirmed by an analysis of plankton sampled in international waters close to Moruroa. The five-person Greenpeace scientific team was arrested and deported by the French military in December after trying to take samples closer to Moruroa.

Greenpeace concluded that artificial radioactivity near the test site raised serious environmental questions further undermining confidence in the ability of Pacific coral atolls to contain the radioactivity from underground nuclear explosions.

It called for scientific sampling to evaluate the environmental impact and implications of the nuclear testing program. Fifteen leading scientists published an open letter to then French Prime Minister Edith Cresson supporting Greenpeace's demand.

No independent scientific investigation has been carried out inside the 19.4 kilometre military exclusion zone around Moruroa, although in 1991 the International Atomic Energy Agency found elevated levels of plutonium in samples taken 32.2 kilometres from Moruroa.

Similarly, no independent health study has been undertaken of the people of French Polynesia, and the health statistics of the French military have been kept secret. Despite this, there are indications that the incidence of particular illnesses related to radioactive exposure is higher. Testimonies from islanders, published by Greenpeace, indicate higher than normal occurrences of cancers, birth abnormalities and other illnesses.