The Dutch Energy Research Foundation (ECN) in Petten organized a workshop on transmutation of nuclear waste on November 13, 1998. The
researchers claimed that results are so favorable that further reprocessing and vitrification of nuclear waste better be stopped: if nuclear
waste has been reprocessed and vitrified, transmutation is not possible any longer.
(503.4965) WISE Amsterdam -By transmutation of long-lived radio- isotopes, the ECN researchers claim, it is technically possible
to shorten the period of storage to 1,000 years instead of the present 250,000 to 1 million year. If these results are realized in practice,
they remark, public acceptance of future nuclear energy would be better. The large inventories of separated civil and military plutonium,
more than 250,000 kg worldwide, could also be eliminated by transmutation. Too good to be true?
What is P&T?
Since some decades now, it is claimed by some nuclear researchers that Partitioning and Transmutation (P&T) is the solution for the
problem of the storage of nuclear wastes. With successful P&T, this storage period could be brought down to 1,000 or even to 250 years,
it is claimed. Partitioning is just another word for reprocessing of spent nuclear fuel. Transmutation is changing long-lived nuclides into
other nuclides through irradiation with neutrons.
The ECN is doing research on partitioning and transmutation since about 1988. An actinide laboratory was built for
l 2 million
(US$1.1 million). The present program, called
Recycling of Actinides & Fission Products (RAS), is funded by the Dutch Ministry of
Economic Affairs with
l 5.85 million (US$3.21 million) and the European Union (EU). The ECN cooperates mainly with French
transmutation researchers. In Marcoule, France, new reprocessing technologies are being developed to separate all important actinides and
long-lived fission products from spent fuel.
Two groups of radio-isotopes, ECN says, must undergo P&T:
- Actinides, most with very long lifetimes,
- Long-lived fission products (See Table I)
Actinides are formed by neutron irradiation of uranium-238. The group includes plutonium (which is the major actinide) and the minor
actinides: neptunium, americium and curium. Spent fuel contains ± 1% plutonium and ± 0.1% minor actinides. Fission products
represent about 3.4% of spent fuel. The rest (95.5%) are uranium isotopes, mainly uranium-238.
ECN concentrates on life-reduction of actinides. They have experimented with transmutation of americium-241, which seems to be a very
cunning choice. Their result: "transmutation of 35% of americium-241 in a uranium-free fuel by `fast neutron' irradiation". It all sounds
optimistic, but is it true?
Does it work?
No, and for a number of reasons.
- The isotope ECN experimented with is not a long-lived one. Americium-241 has a half-life1 of "only" 430 years. Americium-243 should have been a more logical choice: it has a halflife of 7,400
years. The technique of partitioning and transmutation of americium-241 is internationally rather advanced: ECN estimates it would take
only some decades before it can be industrialized. Neptunium-237, with a half-time of 2.1 million years or curium-245 with a half-life of
8,500 years, are much more difficult to separate and transmute.
- The present reprocessing plants don't separate all actinides, only plutonium. New reprocessing technologies which separate all
actinides are only in the research stage. It is questionable if such new reprocessing plants would be built. Reprocessing costs are to be
much higher than at present, while the trend is that reprocessing costs have to come down significantly if nuclear energy is to compete
with other methods of electricity production.
- Many fission products (28% of them) are long-lived isotopes: zirconium-93, cesium-137, iodine-129, palladium-10. These fission products
cannot be separated in present reprocessing plants and will not for at least the next two decades. Moreover, the ECN researchers admit that
transmutation of several fission products is not considered feasible.
- Direct storage of spent fuel at reactor sites is much less dangerous and many times cheaper: less transports; almost no discharges of
radioactive elements into the environment; many times less volume of waste and less proliferation risks.
- Transmutation à la ECN needs the large-scale introduction of fast breeder reactors (FBR) and the development of new types of
nuclear fuel, which do not contain uranium-238. In the last decade, almost all FBRs have been closed due to technological and economical
problems. The method promoted by Nobel prize winner Rubbia, transmutation in Thorium Accelerated Based Systems, so-called Rubiatrons (or
TABS), is only in the paper stage and is also based on Fast Breeders. Realization will take billions of dollars and many decades. The
present Light Water Reactors are not suited for transmutation of acinides or long-lived fission products.
- To reach practical results (almost 100% transmutation of all long-lived radio-isotopes is necessary), long-lived fission products and
all actinides must undergo many cycles of reprocessing and transmutation. This has grave environmental, risky and financial consequences:
each time spent fuel is reprocessed, much radioactivity is released into the sea and into the air. Reprocessing plants are notorious for
their large discharges of radioactivity into the environment.
Spent fuel and reprocessed materials, including plutonium, have to be transported worldwide which endangers people along the routes and has
proliferation problems.
- The planned construction of new reprocessing plants and new fast breeders is neither economically nor politically attainable.
- An almost 100% separation during reprocessing of all long-lived isotopes is necessary. If only 10% of the isotope stays behind, the
storage period of nuclear waste will remain some hundreds of thousands of years. This advanced reprocessing techniques do not yet
exist.
The researchers at the ECN admit their research is only directed on the future: to enable expansion of nuclear energy later on. It has no
relevance whatsoever for present-day nuclear energy problems. Their claim that transmutation is the solution for the nuclear waste problem
is unfounded and sounds like mere fraud.
Their attitude is to get more money for further research.
All over the world, more and more money is spent on transmutation research: mainly in the US, France, Japan.
P&T research began over 20 years ago and many more decades of research is needed, researchers admit. The nuclear lobby presents it as
the final nuclear waste solution which would bring about public acceptance of nuclear energy. But even experts of the International Atomic
Energy Agency (IAEA) are critical.
Drawing conclusions on partitioning & transmutation is easy:
- Partitioning and transmutation is a hype: the next decades
it is neither technically nor practically possible, because existing reprocessing plants separate plutonium, but not other actinides or
long-lived fission products;
- For the largest part of spent fuel, it cannot be a solution: P&T presumes reprocessing of spent fuel, but about 2/3 of all spent
fuel is not and will not be reprocessed;
- P&T can only be achieved after building new reprocessing plants, new fast breeder reactors, Rubbia accelerators and designing and
making new types of nuclear fuel which would take at least several decades and cost many billions of US dollars; and
- Even partial transmutation would have very negative safety, environmental and economic consequences.
Partitioning and transmutation is not and cannot be a solution for nuclear waste problems. Therefore all money spent on it is spilled:
funding and research should be stopped by the Netherlands and by the European Union.
Tabel I: Half-lifes of some radio-isotopes:
Group |
Isotope |
half-life (years) |
Plutonium |
Pu-238
|
88
|
|
Pu-239 |
24,000 |
|
Pu-240 |
6,500 |
|
Pu-241 |
14.4 |
|
Pu-242 |
376,050 |
Some Minor Actinides |
Np-237 |
2.14 million |
|
Am-241 |
432 |
|
Am-243 |
7,385 |
|
Cm-245 |
8,506 |
|
Cm-247 |
15.6 million |
Some Long-Lived |
Zr-93 |
1,5 million |
Fusion Products |
Tc-99 |
210,000 |
|
Pd-107 |
6.5 million |
|
Sn-126 |
100,000 |
|
I-129 |
16 million |
|
Cs-135 |
1.3 million |
footnote:
1] Half-life: Period in which 50% of the isotope atoms decay into other atoms, which are mostly radioactive, too. Short-lived
nuclear isotopes can decay into long-lived isotopes. One example: plutonium-241 (T 1/2: 14.4 yr) decays into americium- 241 (T 1/2: 430 yr)
which radiates much more. Transmutation can also result in creating long-lived isotopes from short- or medium-lived isotopes.
Sources:
- NRC (Nl), 14 November 1998
- La Gazette Nucléaire, August 1998
- H. Gruppelaar, ea, Advanced Technologies for Reduction of Nuclear Waste, ECN Netherlands, 1998
- The Rubbia TABS: Solutions or illusions?, WISE Paris, January 1997
- Laka Foundation, Fact Sheet on Transmutation, November 1998.
Contact: Laka, Ketelhuisplein 43, 1054 RD Amsterdam. The Netherlands.
Tel: +31-20-6168 294; Fax: +31-20-6892 179
Email:
laka@antenna.nl
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