While scientists say that there is no danger to the public from ships carrying nuclear waste, environmentalists are not convinced
Fiona Macleod
South Africa’s top nuclear scientists say the shipment of nuclear waste that passed by the Western Cape en route to Japan this week poses less of a threat to human health than smoking. The scientists moved to allay public panic about the shipment, pointing out that even in the unlikely event there was a disaster and the nuclear waste leaked into the sea, it would have a minimal effect on humans and the environment. “Much is said about the two ships carrying enough nuclear waste to build 20 atomic bombs, but they are actually less of a threat to the environment than the oil spills we have seen off the Western Cape coast,” says Neil Jarvis, head of radiochemistry at the South African Nuclear Energy Corporation. Jarvis and two other local scientists the University of Cape Town’s Peter Linder and Peter Wade from the Council for Scientific and Industrial Research undertook extensive research into the safety of plutonium in the marine environment after the first shipment of nuclear waste to Japan rounded the Western Cape in the early 1990s.
The material, which is shipped from European countries, is used in Japanese reactors to provide nuclear energy. A paper produced by the three scientists at a workshop convened by the Royal Society of South Africa a multi-disciplinary scientific body has been used by governments and shipping authorities around the world.”Our research showed that if plutonium oxide somehow leaked into the sea, the impact would be minimal,” says Jarvis. “The ships passing the Cape now contain reprocessed mixed oxide [MOX] nuclear waste, which is even less harmful because it is made up of compacted pellets.” MOX is a combination of uranium and plutonium. The scientists argue that if there was a leakage, the nuclear waste would not dissolve in the sea water but form a sediment that would sink to the seabed. Laboratory tests, as well as the controlled release of plutonium into the Irish sea from the Sellafield plant of British Nuclear Fuels, indicate that the spreading of this sediment would be minimal and easy to contain. “The realistic scenario is that plutonium oxide will come into contact with sea water and remain in an insoluble form, which will sink to the ocean floor. From data collected from real situations where plutonium oxide had been released into the sea, it can be seen that the physical spreading is minimal.” A 25-year study on radioactive waste dumped in the sea showed radiation affected the “bottom feeders” most in the deep sea, where there is a small biomass. Concentrations in mussels and clams were 1/100th of those in zooplankton and 1/1000th of those in seaweed. Radiation in marine organisms was tested after a United States Air Force B-52 bomber carrying nuclear weapons crashed in the sea near the Thule air base in Greenland in 1968. “By 1970 the plutonium levels in bottom animals had decreased by a factor of 10. Plutonium levels in higher animals such as fish, seabirds and marine mammals showed no increase. The conclusion of the study was that plutonium originating from the accident was confined to the bottom fauna, and that man had not been at risk,” the scientists say. Even if someone swallowed contaminated seafood, the risks would be minimal because the greatest danger is inhaling radioactive material. “You would need to eat as much as one gram to induce leukaemia within five to 10 years,” says Jarvis. The scientists dismiss claims that radioactivity in the marine environment would find other pathways to man. “Although workers in Britain have shown there is an excess of childhood leukaemias near certain nuclear establishments, French and American workers have not been able to find a similar tendency in their countries. This phenomenon became known as the Gardiner hypothesis. It has subsequently been shown that there is no correlation between childhood leukaemia and proximity to nuclear installations. “Perhaps the greatest evidence against the Gardiner theory is that after 40 years of study, no evidence of harmful mutations in the children of Japan’s atomic bomb survivors has been demonstrated.”
The scientists point to a report published in the early 1990s on the 42- year medical follow-up of US workers who worked with plutonium during World War II. Four of the original study group of 26 had died by 1987, with a median age of 66. “The mortality rate of the group is considerably lower than expected US rates. Lung cancer was the most frequent malignancy, as is expected for white males. All could be attributed to smoking, with the additional risk due to plutonium inhalation indiscernible from the data. “These are the medical records of workers exposed to doses of plutonium far greater than members of the public would ever receive as a result of plutonium shipping. We therefore conclude from the scientific evidence available that the shipping of plutonium around the Cape is a safe activity.”
Anti-nuclear activists and members of the Green Party of South Africa, who staged a protest against the nuclear shipments in Cape Town this week, are not convinced by the arguments and point out the scientists stand to benefit from public complacency around nuclear issues. “The important thing is not how much of a spin the scientists can put on nuclear energy to make it seem like it’s not a threat, but that it is totally unnecessary and the people who benefit from it are the investors, not the energy users,” says Earthlife Africa’s Richard Worthington.
He says that nuclear waste needs to be carefully managed for thousands of years, and adds there is no scientifically proven safe exposure to nuclear products. “We are not saying that if a ship goes down, people will die tomorrow. There probably won’t be any measurable effects on animals and the land,” Worthington says. “The impact is more long-term, and it is an unacceptable risk from an industry that is neither economically viable nor sustainable.”