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GLOBAL warming and the price of crude oil were among the reasons the
Association of Southeast Asian Nations (Asean) energy ministers, in
a recent meeting, agreed to recommend to their respective
governments the inclusion of advanced nuclear technologies in their
energy plans.
Our own energy secretary, Angelo Reyes, has
already taken tentative steps towards such a policy. What holds him
back are the vexed questions of safety and disposal of nuclear
wastes.
Secretary Reyes’s caution was seconded by Dr.
Tomihiro Taniguchi, the Deputy Director-General for Nuclear Safety
and Security of the International Atomic Energy Agency (IAEA) who
said in their report to the Philippine government that “commercial
interests should not take precedence over safety issue in the
current expansion of nuclear power worldwide.”
Maybe this also applies to the other Asean
countries. Memories of Chernobyl and Three Mile Island are hard to
erase.
To sustain economic growth in the Asean region,
base load power has to be increased without—as much as possible,
in the immediate term—adding to the greenhouse gases that are
already in the atmosphere. Wind turbines and solar cells are not
reliable for base load power. Hydro and geothermal are at present
the main sources of clean base load electricity. Even so-called
clean coal will have to be phased out gradually. Gasification, an
expensive process, removes NOx and SOx but not CO2, the main and
long-lasting greenhouse gas. Burying the CO2 is a limited and
equally expensive option. Until a way is found to rid coal of its
CO2, it will be, at best, a bridge to cleaner fuels. A 1-percent
annual growth of GDP requires about 10 gigawatts of additional
capacity every year for the larger economies of the region. This is
why nuclear energy has become necessary.
Matters would be simpler if the energy ministers
could convince their publics that there are some nuclear reactors
that are fail safe.
The High-Temperature Gas-Cooled Reactor (HTGR)
that was developed in the ’50s by General Atomic is one example.
According to Freeman Dyson, who helped design
it, the HTGR which is cooled by helium and graphite-moderated is
more efficient and less vulnerable to mishandling than the
light-water reactors of that period. It’s “roughly a thousand
times as safe as a light-water reactor of equal power,” he said.
A 1000-megawatt HTGR was assessed by two
independent groups of safety analysts. They came to similar
conclusions. The HTGR with the “combination of stupidity and
extreme bad luck” could have an accident “once in a billion
years.” (Dyson, Infinite in All Directions, 1988).
The HTGR was a commercial failure. Only two were
sold. The first to a power company at Peach Bottom, Pennsylvania and
the second, a 300-megawatt version, to a utility at Fort St. Vrain
in Colorado. But General Atomic continued to operate its own HTGR in
Pennsylvania that ran on a mixture of uranium and thorium from 1967
to 1974. Another General Atomic plant at Fort St. Vrain was tested
on thorium-based fuels from 1976 to 1989. General Atomic also tried
a mixture of thorium oxide and enriched uranium oxide for a reactor
in Shippingport, Pennsylvania, from 1977 to 1982. The purpose was
to develop a fuel that produces more fissile material than it
consumes. The results were positive. (Tim Dean, Cosmos, Issue 8,
www.cosmosmagazine.com).
The other example is called Accelerator Driven
System (ADS) that runs completely on thorium.
Thorium is a lighter element than uranium. The
waste produced by thorium in a reactor is much less radioactive
compared to uranium or plutonium. Thorium wastes are radioactive for
about 500 years compared to uranium wastes that are toxic for tens
of thousands of years.
Unlike U-235 or Pu-239, Th-232 is sub-critical,
meaning that it cannot undergo nuclear fission nor sustain a chain
reaction, once one starts, by itself. It needs a shot of neutrons to
start a chain reaction.
The ADS is based on the Energy Amplifier (EA)
that was invented by Carlos Rubbia, a Nobel laureate in physics, who
at one time was the Director-General of CERN, the European Center
for Nuclear Research.
To start an ADS reactor, a particle accelerator
fires protons at a lead target that, when hit, releases neutrons
that collide with the nuclei in the thorium fuel to begin a cycle
that ends in the fission of U-233. Once the particle accelerator is
switched off, the chain reaction stops.
According to Reza Hashemi-Neshad, an Australian
physicist, an ADS reactor “has a zero chance of a Chernobyl-type
accident.” (Dean, Cosmos, Issue 8).
ADS, it must be said, has only been tested in
laboratories. Whether it can be scaled up for the production of
commercial power remains to be seen.
The countries that are actively engaged in
thorium-reactor research are Australia, India, Russia, the USA,
Germany, Canada, Japan, France, Brazil and Norway.
Only Norway of these countries has taken the
political decision to do “an in-depth study” leading to a
full-scale thorium reactor. (Daniel Clery, Science, February 9,
2007).
Last year, CERN published a detailed report on
the financial viability of a thorium reactor for power generation.
It is at least 3 times cheaper than coal and 4.8 times cheaper than
natural gas at 2007 prices. However, building an ADS or an EA is
very expensive and technically very demanding.
These are two options for Asean. Perhaps the
Asean energy ministers should also consider coordinating their
decision on the choice of nuclear technology. For this purpose, a
bureau in the Asean Secretariat could be set up to collect relevant
information, convene technical meetings and organize study visits.
The IAEA is useless for this work. Its remit does not include giving
advice on which nuclear technology is appropriate for specific
national objectives.
In the meantime, Secretary Reyes—or his
successor—may want to wait before giving the go-ahead on the
activation of the Bataan Nuclear Power Plant.
opinion@manilatimes.net
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