THE star-crossed Sellafield nuclear complex in north-west England is at the
centre of yet another row over radioactive releases. Neighbouring countries have
been astonished to discover that the site鈥檚 operator, British Nuclear Fuels
(BNFL), could be allowed to pump large amounts of radioactive technetium-99 into
the Irish Sea for the next six years.
Ireland and the Nordic countries are incensed: they don鈥檛 like their marine
life being contaminated. Yet state-owned BNFL does not see why it should fork
out millions, especially at a time when it still hopes to become a public
company. Sadly, the loose wording of the OSPAR convention governing marine
pollution lets both sides claim that right is on their side.
The case of technetium is unusual. In contrast to releases of most other
radionuclides, discharges of technetium have shot up
(see p 18).
Levels have increased 20-fold since 1994, when BNFL opened a plant to treat a backlog of
waste produced by reprocessing spent fuel from Britain鈥檚 ageing Magnox reactors.
This plant removes plutonium, americium and caesium from liquid discharges, but
not technetium.
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But does pouring technetium into the Irish Sea do any harm? No, says BNFL. It
gives a maximum annual radiation dose of 50 microsieverts to the most exposed
group鈥攖hose who live around the complex and eat a lot of seafood. This is
only 5 per cent of the international safety limit for the public. The company
says that reducing technetium discharges to pre-1994 levels would save 鈥渁bout
0.1 statistical lives鈥� over the next 500 years.
Environmentalists point out, however, that because technetium has a half-life
of 213,000 years it will persist in the environment and cannot be retrieved.
Even on BNFL鈥檚 figures, it could claim dozens of lives.
The pollution may also threaten marine ecosystems, though no one has a clear
idea of what damage is being done. This is because regulations governing
radioactive releases are based only on the effects on humans. But there is a
growing consensus among radiation scientists that it is time to develop
standards to govern the impact of radiation on other species.
Welcome though these would be, they will not come in time to solve the
technetium dilemma. Britain鈥檚 Environment Agency, which sets BNFL鈥檚 discharge
levels, is left trying to juggle economic, environmental and safety factors,
which are often conflicting and horribly uncertain. At present, the agency wants
the technetium discharged into the sea.
There is another way. BNFL has enough capacity to store up to eight years鈥�
worth of Magnox reprocessing waste. So, the company could stop treating this
waste and cease pumping technetium into the sea while it develops ways to
retrieve the metal. There is some doubt about the integrity of tanks used to
store the waste, but the government鈥檚 Health and Safety Executive reckons
they鈥檙e good for another six years.
This gives BNFL an achievable deadline for developing new extraction methods.
If it rises to the challenge, it could help to convince the public that it is a
world-class company with an environmental conscience. Who knows, people might
even buy shares in it.
