some info ab8 FBR source wiki
The
fast breeder or
fast breeder reactor (
FBR) is a
fast neutron reactor designed to
breed fuel by producing more
fissile material than it consumes. The FBR is one possible type of
breeder reactor.
Fission of the nuclear fuel in any reactor produces neutron-absorbing fission products, and because of this it is necessary to
reprocess the fuel and breeder blanket from a breeder reactor if one is to fully utilise its ability to breed more fuel than it consumes. Reprocessing is generally considered a large proliferation concern because some reprocessing technologies can be used to extract weapons grade plutonium from a reactor operated on a short refuelling cycle.
However, to date all known weapons programs have used far more easily built
thermal reactors to produce plutonium, and there are some designs such as the
SSTAR which avoid proliferation risks by both producing low amounts of plutonium at any given time from the U-238, and by producing three different isotopes of plutonium (Pu-239, Pu-240, and Pu-242) making the plutonium used infeasible for atomic bomb use. Furthermore, several countries are developing more proliferation resistant
reprocessing methods that don't separate the plutonium from the other actinides. For instance, the Pyrex-A process when used to reprocess fuel from the
Integral Fast Reactor ( see below ) would leave large amounts of radioactive actinides in the reactor fuel. Removing these transuranics in a conventional reprocessing plant would be extremely difficult as many of the actinides emit strong neutron radiation, requiring all handling of the material to be done remotely, thus preventing the plutonium from being used for bombs while still being useable as reactor fuel.
The breeding of plutonium fuel in FBRs, known as the
plutonium economy, was for a time believed to be the future of nuclear power. It remains the strategic direction of the power program of Japan. However, cheap supplies of uranium and especially of
enriched uranium have made current FBR technology uncompetitive with
PWR and other
thermal reactor designs. PWR designs remain the most common existing power reactor type and also represent most current proposals for new nuclear power stations.
One design of fast neutron reactor, specifically designed to address the waste disposal and plutonium issues, was the
Integral Fast Reactor (also known as an
Integral Fast Breeder Reactor, although the original reactor was designed to not breed a net surplus of fissile material)
.
To solve the waste disposal problem, the IFR had an on-site
electrowinning fuel reprocessing unit that recycled the uranium and all the
transuranics (not just plutonium) via
electroplating, leaving just short
half-life fission products in the waste. Some of these fission products could later be separated for industrial or medical uses and the rest sent to a waste repository (where they would not have to be stored for anywhere near as long as wastes containing long half-life transuranics). It is thought that it would not be possible to divert fuel from this reactor to make bombs, as several of the transuranics spontaneously fission so rapidly that any assembly would melt before it could be completed. The project was canceled in 1994, at the behest of then-
Secretary of Energy Hazel O'Leary.
IndiaIndia has an active development program featuring both fast and
thermal breeder reactors.
Indias first 40 MWt Fast Breeder Test Reactor (
FBTR) attained criticality on 18th October 1985. Thus, India became the sixth nation to have the technology to build and operate a FBTR after US, UK, France, Japan and the former USSR. India has developed the technology to produce the plutonium rich U-Pu mixed carbide fuel. This can be used in the Fast Breeder Reactor.
At present the scientists of the
Indira Gandhi Centre for Atomic Research (
IGCAR), one of the nuclear R & D institutions of India, are engaged in the construction of another FBR - the 500 MWe prototype fast breeder reactor- at
Kalpakkam, near
Chennai.
India has the capability to use
Thorium Cycle based processes to extract nuclear fuel. This is of special significance to the Indian nuclear power generation strategy as India has large reserves of thorium about 360,000
tonnes that can fuel nuclear projects for an estimated 2,500 years. But the hitch is with the expensive nature of the construction of Fast Breeder Reactor in comparison with the
Pressurised Heavy Water Reactors (
PHWR) in use. This is one of the main reasons why India is looking at the cheaper option - Uranium fuel.
)
)