NUCLEAR POWER

A nuclear power plant does not emit carbon dioxide and hence not contribute to greenhouse effect and global warming. So the leaders of various nations are thinking of reviving it in a big way to resist global warming and climate change linked to greenhouse effect.  Once upon a time, after the discovery of nuclear fission in early 20^th century, nuclear power emerged as an alternative to thermal and hydro power with a promise of providing electric power too cheap to meter. But the dream could not be fulfilled due to two main reasons, (1) chances of fatal accidents and the (2) hazard of nuclear waste. The third reason was the proliferation of nuclear weapons, as nuclear reactors that use natural uranium as the fuel produce weapon grade plutonium. As a result, the world average of generation of nuclear power stands at only 16 per cent today.

Another reason for looking back to nuclear power seriously, after 20 years of Chernobyl and 30 years of Three Mile Island accidents, is the present hike in oil and gas prices and the steeply rising demand of energy. Experts estimate that the demand will rise by another 50 per cent, even by 90 per cent in the developing world, in next 20 years.  Though there are other remedies like solar and wind power, many emerging nations, including India, have declared recently that nuclear energy is the most viable alternative.

 A nuclear reactor uses natural uranium, that contains mainly uranium-238 and small quantity of uranium-235, and only the uranium-235 undergoes fission and produces heat.  A reactor uses thousands of uranium rods placed in a frame made of graphite, which act as the moderator. Water or heavy water, called coolant, is circulated around the reactor for carrying the heat out of the reactor for producing steam. Most of the accidents occur when the coolant circulation fails leading to overheating and melting of the uranium rods. The Advanced Boiling Water Reactor (ABWR) is an improved version where overheating is prevented even when a failure of the coolant circulation occurs. Further improvement of the ABWR technology has been achieved by continuous research during the past two decades.  “If operated properly, could improve the accident rate tenfold”, says Mr. John Deutch, an expert of the Massachusetts Institute of Technology (MIT). At present, Japan is operating 3 ABWRs and Taiwan is readying 2.

            The Pebble-bed Reactors (PBR) are the latest, most advanced and the safest version that use natural uranium oxide, in the size of tennis balls and covered by hard ceramics, as the fuel and they dissipate heat so efficiently that overheating is avoided even in the event of a failure of the coolant circulation. China and South Africa are emerging as the forerunners in using the technology and presently they are setting up pilot plants for testing.

As mentioned above, nuclear technology faces two potentially fatal problems, firstly, the problem of radioactive waste, which could either be disposed off or recycled. Both are hazardous - the former is technically and environmentally risky, while recycling leads to producing pure bomb grade plutonium, the stuff that could be used by the rogue states leading to dangerous proliferation. Recent developments in Iran and North Korea are examples.

            Today China is racing ahead in its future programme of using nuclear energy for generating power, using the above mentioned PBR technology. In fact, the technology was invented in Germany more than three decades ago. China is now busy in setting up a commercial PBR power plant, capable of generating 195 MW of power, in the eastern province of Shandong, which is expected to be ready within next five years. In a PBR, uranium ( or its oxide) balls, wrapped in hard silicon carbide and graphite, are used as fuel. As the melting point of silicon carbide is much higher than that of uranium, liquid metal, in case of an accident, is trapped inside the coating and hence incidents like that of Chernobyl and Three Mile Island are averted. The other advantage of the technology is that it uses inert helium gas, not water, as the coolant. A conventional reactor is housed in a concrete containment vessel to mitigate damage, but PBR does not need such a robust enclosure. And hence it is easier to erect. At the same time, it resists nuclear weapon proliferation as it is difficult as well as expensive to extract plutonium from the spent fuel trapped in hard silicon carbide balls.

            An American firm is now making a pilot plant at a site northwest of Beijing under the supervision of Ms Chang Wei, a Chinese nuclear scientist. The plant will use 27,000 balls of uranium dioxide as the fuel wrapped with ceramic. The Huaneng Power is one of the largest electricity companies of China, which is supposed to undertake the task of building Chinese nuclear power plants using the pebble-bed technology.

As a matter of fact, China is going to play a key role in arresting global warming by reviving the nuclear power in a big way. As mentioned above, the country has emerged as the second largest greenhouse gas emitter, after USA, as 80 per cent of its energy is derived from burning coal from its rapidly reducing reserve. So it has determined  to switch over to nuclear energy and intends to increase its production, at least fourfold, from 8,7000 to 36,000 MW by 2020. The target could be reached by building at least 3 reactors per year. Nearly 30 such reactors are therefore coming up at various sites scattered over 16 provinces in the next 10 years. The programme is the biggest nuclear construction the world has ever seen. Experts believe that it will also inspire many other nations. “We are quickly running out of coal, but demand for electricity has been a double digit growth for past three years. Renewable energy sources won’t come close to meet China’s needs. We need energy of every type. We are hungry”, says Mr Zhang Zuoyi, a nuclear scientist.

            China is now buying equipments and designs, amounting to $8 billion, mainly from 3 foreign firms – Areva of France, Atomstroyexport of Russia and Westinghouse Electric Company of USA, for a plant to be built in the eastern province of Zhejiang. Not only in the field of nuclear technology, but in every other field of modern technology, the fastest growing Chinese economy has now become the world epicenter for business and commerce. As a result, the West, mainly the US, is now facing a stiff competition in international commerce and trade and, in fact, losing its hegemony. While lamenting over the developments, Mr Andrew Kadak, a professor in the Nuclear Science and Technology of Massachusetts Institute of Technology (MIT), says, “I think that, unfortunately, in the US, we have lost over market leadership. … We are going to be watching how emerging nations of the world such as China and South Africa, do with these technologies and perhaps follow them, which is sad to say”.

            After completion, the facility in Zhejiang will be run by the scientists of the Institute of Nuclear and New Energy Technology of the Beijing based Tsinghua University and the engineers of the state owned China Nuclear Engineering Group. At the same time, China is organizing vigorous propaganda campaign to popularize nuclear power among the people. “Construct Nuclear Power, Make the People Wealthy” is the most popular slogan used by the government.

            India also desperately needs more energy and is eager to build nuclear plants to cope with the situation. The US President George W Bush has signed an accord last July, with the Indian Prime Minister Mr Manmohan Singh, to help India develop civilian nuclear power industry. The treaty has recently been ratified by the US Senate and the Congress, despite the fact that India, though a nuclear country, not a signatory to the Nuclear Non-Proliferation Treaty (NPT). In fact, USA wants India to develop its own nuclear infrastructure so that it could counter the nuclear threats from China and Iran. In the present context, it may be mentioned that Iran has signed the NPT and therefore it has the right to enrich uranium. Regarding the above mentioned Indo-US treaty, many are afraid that India may utilize the opportunity for making more bombs and set off a nuclear arms race in Asia, despite New Delhi’s repeated assurance that the American assistance would be utilized for civilian purposes only.

Like China, India is not intending to use the said Pebble-bed technology in a big way, because it has to choose a technology that would use fuels available in India. It is well known that India does not have large deposits of uranium, which is essential to run Pebble-bed Reactors. On the contrary, it has world’s largest deposits of Thorium, which itself does not undergo fission, but may be converted to plutonium, which is a fissile material. The technology that India intends to use may be divided into three parts. Firstly, to burn natural uranium in High Pressure Heavy Water Reactors (HPHWR), where heavy water at high pressure is circulated as the coolant and the nuclear wastes that contain plutonium are recycled along with natural uranium and thorium, in the First Breeder Reactors. The nuclear wastes from the First Breeder Reactors, with added thorium, are to be used in Second Breeder Reactors. The aim is to avoid perpetual dependence on imported uranium and to be self reliant in nuclear fuel. In this context, one may recall the bitter experience with the Tarapur Power Plant, when USA declined to supply enriched uranium rods to be used as the fuel.  

It has been pointed out earlier that nuclear energy resists global warming as a nuclear power plant does not emit greenhouse gases. But according to the environmentalists, problem of nuclear waste is no less frightening. This nuclear waste, which is left after the uranium fuel is spent, is a mixture of radioactive substances that contains 1 per cent plutonium, a highly toxic material used for making bombs. More importantly, plutonium stays radioactive for tens of thousands of years and hence it must be dumped in a facility that lasts for a longer time.

In fact, nuclear wastes cannot be dumped without environmental pollution as it turns everything in its vicinity radioactive. USA has so far spent $9 billion for decades of research for the proposed Yucca Mountain repository programme, but with little success. The effort of France is also in deep trouble while Germany has abandoned all its programmes in 1990. On the other side, as nuclear wastes are piling up, the risk of falling bomb grade plutonium into wrong hands is also rising.  Scientists estimate that the nuclear wastes so far dumped contains enough plutonium for making 200,000 bombs. So, reviving nuclear power in a big way could, to a certain extent, rein in emission of greenhouse gases and consequent global warming. But it may worsen the situation creating more serious problems (See Tables below).

Table-I

Table-II

 (Current % of generation of Nuclear power)