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- CHERNOBYL and two other ageing
Soviet bloc nuclear reactors may help to fulfil prophecies of millennial
disaster if work is not done swiftly to adapt their computers.
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- The head of the Vienna-based International Atomic Energy
Agency, Muhammad al-Baradei, has identified three nuclear plants that are
lagging seriously behind in preparing for the Year 2000 software problem:
the Medzamer reactor in Armenia and the Ignalina reactor in Lithu-ania
as well as the still-functioning reactor in Chernobyl.
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- The locations have long been a headache for Western experts.
Even after considerable investment, the safety standards are well behind
those in the West. The Medzamer plant, consisting of two pressurised light
water reactors, is in an earthquake zone.It had to be closed in early 1989
after an earthquake, but by 1995 it was reopened. Armenia is dependent
on nuclear-generated electricity. Before the re-opening, residents of Yerevan,
the capital, were rationed to two hours of electricity a day.
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- There are Western worries about the plant's ability to
withstand another earthquake, about the level of staff training and the
plant emergency planning. But Armenia's dependence on the reactor is such
that politicians refused to close it for tests or maintenance.
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- Computers are central to nuclear plant safety: they gather,
compare and contrast data received from the different stages of electricity
production and monitor temperatures and possible leakages.
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- Dr al-Baradei said the "millennium bug" problem
in the atomic energy sector of the former Soviet Union was due to lack
of money - maintenance is chronically underfinanced - and lack of adequate
planning.
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- The nuclear plant that attracts the most attention is
Chernobyl in Ukraine. It was there that a meltdown in 1986 triggered the
world's worst nuclear accident. The people of Ukraine and Belarus are still
feeling the consequences of that disaster; much agricultural land is irradiated
and there has been a sharp increase in certain illnesses.
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- The Chernobyl reactors are of the RBMK type - graphite-moderated
channel reactors. There are more than a dozen such reactors still in operation
in the former Soviet Union and the chief concern is about the lack of a
sufficiently large steel or concrete containment structure to block large
releases of radiation. At Chernobyl, the plant's accident localisation
system could not cope with the force of the explosion.
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- Despite these and other misgivings, one Chernobyl reactor
has just reopened. It was closed for six days after leaks were discovered
in the secondary cooling system for radioactive water. Two other reactors
have been out of operation because of serious technical defects. The fourth,
which blew up in 1986, is buried under a concrete sarcophagus.
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- A Chernobyl-style reactor is in operation in Lithuania.
The European Commission has demanded a closure plan for the Ignalina reactor,
threatening delays in Lithuania's entry to the European Union unless it
complies. The first block has been active since 1983, the second since
1987. Together they account for 85 per cent of the republic's electricity.
For the Lithuanians, the plant guarantees their energy, and therefore political
independence from Russia. Electricity exported to Latvia and Belarus is
also profitable. There is no hurry to close the plant.
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- Despite the safety improvements, introduced largely with
the help of the Swedes, the West is growing increasingly nervous about
the reliability of the plant.
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- Weak links in the chain reaction
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- The key Western reservations are:
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- Accident mitigation systems are very limited.
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- If cooling water is lost the reactors produce faster
and less stable nuclear chain reactions.
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- All plants have inadequate fire protection.
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- Electrical and safety systems are poorly separated.
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- There is limited capability for suppressing steam in
the graphite stack.
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- Only precise computerised control can deal with these
problems. This will be under threat if the "millennium bug" problem
is not solved in the next fortnight.
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