Sat Dec 17 10:13:44 CST 2011
What inherent aspects of the systems under development will guard against
Along with the physical and administrative monitoring, control and security
measures currently in place, careful selection of the fuel composition and
of the reprocessing techniques may further increase the proliferation
resistance of the nuclear fuel cycle. Making nuclear material less suitable
for use in a nuclear weapon, or less prone to diversion for such use, can be
achieved in three different ways, which are not reactor but fuel cycle
a) By increasing the radiological intensity of the material itself, so that
it cannot be handled without severely exposing the people handling it or
without heavy and specialized shielding equipment,
b) By assuring that at no point during the fuel cycle will the isotopic
composition of the fuel be suitable for the production of an explosive
nuclear device, without prior complex reprocessing,
c) By minimizing the opportunities for diversion, such as during
intermediate storage, transport to and from reprocessing, etc.
Most of the Generation IV systems involve fast reactors relying on multiple
reprocessing and recycling of fuel, which essentially address all three of
the above strategies.
Whereas current reprocessing techniques such as the PUREX process use
aqueous chemistry (dissolution of spent fuel in strong acids) to extract
uranium and plutonium, independently of each other, from the remaining
mixture of minor actinides and fission products, advanced reprocessing
techniques aim at separating a mixture of all actinides (including U and Pu)
from the fission products. This mixture of actinides can be recycled in a
fast reactor but is not suitable for use in nuclear weapons.
Non-aqueous reprocessing techniques are also under development. These
techniques are pyro-metallurgical processes, known as pyro-processing, and
are based on the electrolysis of spent fuel using molten salts as an
electrolytic bath. Heavy metals are separated on one electrode and fission
products remain in the salt. The main advantage of pyro-processing, and its
use for the separation of all actinides, is the relative simplicity of the
process and its compactness. This allows the reprocessing facility to be
installed on the same site as the fast reactor thereby maintaining maximum
physical protection of sensitive material by avoiding transport to and from
a central reprocessing plant.
An even more advanced version of on-site reprocessing is possible in the
most futuristic of the six systems selected in Generation IV, the Molten
Salt Reactor (MSR). In this reactor, the fuel and coolant are one, and
co-exist as a molten salt circulating through the core. A small fraction of
this liquid is continuously extracted from the primary circuit and
processed, to extract fission products only, in an chemical plant integrated
in the reactor building. The "cleaned" salt is then fed back into the
primary circuit. Here again, all actinides stay together and are recycled
thereby avoiding transports to a central reprocessing facility.
A cross-cutting activity in the Generation IV framework aims at developing a
methodology for the evaluation of the proliferation resistance of the
different Generation IV systems using number of criteria and quantitative or
qualitative indicators (see
From: radsafe-bounces at health.phys.iit.edu
[mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Karen Street
Sent: June-10-12 6:06 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: [ RadSafe ] Gen IV questions
I know that Gen IV has plans to make nuclear power more
proliferation-resistent, eg, poison the plutonium for those who reprocess so
no bomb could be made, and deliver uranium with the power plant, so no one
need make their own fuel.
First, is what I know true?
Second, will these generally be true? True of all plants sold to Iran? What?
Friends Energy Project
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