Nuclear

1. Presentation

Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Just as many conventional thermal power stations generate electricity by harnessing the thermal energy released from burning fossil fuels, nuclear power plants convert the energy released from the nucleus of an atom via nuclear fission that takes place in a nuclear reactor. The heat is pulled from the reactor core by a cooling system removes heat and used to generate steam which drives a steam turbine connected to a generator which produces electricity.

2. Market Analysis

As of December, 2011, a total of 433 nuclear reactors were operating in 30 countries providing about 6% of the world's energy and 14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity. The current world reactor fleet has a total nominal capacity of about  369 gigawatts and 62 Gw are currently under constructions. There are a considerable number of new reactors being built in China, South Korea, India, Pakistan, and Russia.

World number of reactors and capacity:

• Current:                   433 reactors for 369 GW 
• Under construction:   62 reactors for 62 GW 
• Planned:                  156 reactors for 173 GW

China has 26 nuclear power reactors under construction, with plans to build many more, while in the US the licenses of almost half its reactors have been extended to 60 years, and plans to build another dozen are under serious consideration.

However, Japan's 2011 Fukushima Daiichi nuclear disaster prompted a rethink of nuclear energy policy in many countries. Germany decided to close all its reactors by 2022, and Italy has banned nuclear power. Switzerland and Spain have banned the construction of new reactors.  Japan’s prime minster has called for a dramatic reduction in Japan’s reliance on nuclear power. Taiwan’s president did the same. Mexico has sidelined construction of 10 reactors in favor of developing natural-gas-fired plants. Belgium is considering phasing out its nuclear plants, perhaps as early as 2015. Following Fukushima, the International Energy Agency halved its estimate of additional nuclear generating capacity to be built by 2035.

On the other hand, according to the World Nuclear Associtation (WNA), over 45 countries are actively considering embarking upon nuclear power programs with front runners being UAE, Turkey, Vietnam, Belarus and Jordan.

- See the world reactors database: CHART or MAP

3. Commercial Potential for the Carnot engine

Basically, in most nuclear power stations, after the steam turbine has expanded and partially condensed the steam, the remaining vapor is condensed in a condenser. The condenser is a heat exchanger which is connected to secondary side such as a river or a cooling tower. Because its ability to work out of low temperature, the Carnot engine could retrieve this waste heat which is not used in nuclear power plant. Since this condensation process occurs in the non-radioactive side of the power plant, a Carnot engine implementation may not be too complicated. 

After leaving the turbine, there is still a large amount of energy that could potentially be used by the Carnot engine to generate more electricity. (ie: PWR Figure)

4. Conclusion 

Since about 2001 there has been much talk about an imminent nuclear revival or renaissance which implies that the nuclear industry has been dormant or in decline for some time (during the 2 decades post Three Mile Island and Chernobyl accidents). Whereas this may generally be the case for the Western world, nuclear capacity has been expanding in Eastern Europe and Asia but the March 2011 Fukushima accident has set back public perception of nuclear safety. Nuclear power growth will not be as strong as previously anticipated. Some western countries are phasing out their nuclear capacity while others have delayed their projects. Some experts say that governments should invest in energy efficiency and renewables rather than nuclear energy.

However, there is still a strong demand in Asia, with India and China currently building dozens of new plants and planning some more. Other parameters like climate change, increasing energy demand and security of supply might boost the nuclear energy in the future.

But whether it is for new or existing nuclear power stations, our Carnot engine could use the currently untapped waste heat commonly found in these facilities to produce more electricity out of the same resources, increasing the overall output of these power plants.