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consume when thorium is used An example of such can be shown from the inspections of the closed Light Water Breeder Reactor in Shippingport, Pennsylvania. When the reactor was shut down in 1982 after 7 years of production, it was revealed that there had been 1.39 % more fissile fuel at the end of core life than when it began. Other factors should also come into consideration in terms of thorium usage. In May 2005, the International Atomic Energy Agency (IAEA) published a report on thorium and its potential benefits and challenges. Among other things, it outlined several advantages that the element has over uranium and plutonium for use in nuclear reactions. For one, thorium is three to four times

of current nuclear proliferation concerns. With the advantages of thorium made obvious, it is clear why India has decided to go with it as its domestic electricity demand has increased dramatically. Although its 830 billion kilowatt hour (kWh) production in 2008 was triple that of the 1990 output, there loomed transmission losses of 28.8 percent, which meant only 591 billion kWh could be consumed. 68% of its domesticallyproduced electricity currently comes from coal, and coal reserves are limited in the region. Meanwhile, its per capita electricity consumption is expected to double by 2020 to 1400 kWh, with 6.3 percent annual growth, reaching 5000-6000 kWh by 2050. To put it simply, India needs an alternative energy source. In response, it has conceived a program

“In May 2005, the International Atomic Energy (IAEA) published a report on thorium and its potential benefits and challenges. Among other things, it outlined several advantages that the element has over uranium and plutonium for use in nuclear reactions.” that would maximize energy production from domestic reserves of thorium. This program was outlined in a report by Dr. S.K. Jain, the Chairman and Managing Director of the Nuclear Power Corporation of India Limited (NPCIL), a governmentowned entity, consisting of three stages. The first of three stages utilizes natural uranium powered by pressurized heavy water reactors (PHWRs). Since only 0.7% of natural uranium is U235 and the rest is U238, the latter is often used instead. When reacted in PHWRs, uranium produces Pu239, which will later be the fuel for the second stage of electricity production. The second stage of the program is comprised of fast breeder reactors (FBRs) that are fuelled by a mixed oxide of U238 and Pu239, both recovered by reprocessing of the spent fuel of the first stage. Over a period of time, these breeder reactors will build up an inventory of Pu239 by the transmutation of U238. Once sufficient stores of Pu239 have been built up, thorium will be introduced to the reactor as a “blanket material” to be converted to U233. There

03 PENN SUSTAINABILITY REVIEW

more abundant in nature than uranium, and it is easily exploitable. Thorium can also be converted to U233 more efficiently than U235 or Pu239. Another advantage with regards to nuclear storage is that thorium dioxide, a by-product of the nuclear reaction, is relatively inert and does not oxidize, unlike uranium oxide. In simple terms, it means that long-term storage and permanent disposal will be easier. Regarding short-term application in the U.S., there are currently five nuclear reactors in the United States that are utilizing thorium as a fuel. To take it a step further, the IAEA report says that thorium cycles are feasible in all existing thermal and fast reactors. Not only does the U.S. have the technology, but it could also be applied to many more reactors without major modifications in engineering systems or reactor controls. According to the IAEA report, one of the biggest advantages that thorium has is that the conversion of thorium could be done though the incineration of weapons grade plutonium. The potential reduction of weapon making material is all the more significant in light

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