Nuclear Power/Actinides.

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Question
Dear Osman

http://en.wikipedia.org/wiki/Actinide
http://en.wikipedia.org/wiki/Nuclear_power

Other than Uranium and Thorium heavy elements, which other Actinides can be considered for generating nuclear power in a nuclear power plant ?.

Thanks & Regards,
Prashant S Akerkar

Answer
Hi Prashant,

If one checks the stability of Actinides one finds few stable or near stable nuclei  within the series. Thorium, Uranium (233,235,238) as well as Pu 239 isotopes are suitable as nuclear fuel for fission reactors used in nuclear power plants. Depending on the type of nuclear reactor, some of these isotopes are used as fissile fuel and some are used as fertile fuel. When considering a nuclear fuel one needs to study the fission and capture cross sections of the fuel to be used at a particular reactor configuration. Some isotopes have reasonable nuclear properties at either low or high neutron energies.  You can see the fission and other cross sections for various isotopes by using JANIS (http://www.oecd-nea.org/janisweb/index.html). Most of the Actinides have reasonable fission cross sections but also large absorption cross sections. Also in order to have a working reactor the amount of fission neutrons produced per fission reaction is important. These are some of the neutronics challenges  that have to be addressed in designing a reactor fueled with a different Actinide isotopes.

Also, the half-life of the fuel is important. Present day fuels have rather large half-lives, almost close to the age of the earth. Other than Th and U there are no stable elements that can be used as fuel for fission reactors.  If the half-life is short fuel  disintegrates via radioactive decay, thus producing subatomic particles and heat. ( When USSR scientist first transmuted U to Pu and presented a small sphere of Pu to Stalin,  after holding in his hand for few minutes he remarked that it feels warm!)  Subatomic particles can start unplanned fission reactions. Also there is the price of the fuel to be considered when designing a nuclear power plant. If the fuel  is a form of transmuted material most probably it is very  expensive. (Th $50/kg, U $100/kg, Pu $4000/g, Am $1500/g)

A nuclear engineering student can design a nuclear reactor core using any Actinides as fuel as he/she likes, but it would be a paper reactor just showing his/her ability in reactor analysis. In real life we only have Th and U. For very specific applications, like powering space vehicles some other fuels are used but I tried to focus my attention to nuclear power plant reactor cores as you have stated in your question.

Best Regards  

Nuclear Power

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Osman Kemal Kadiroglu

Expertise

Nuclear Engineering, Nuclear Engineering Education, Nuclear Reactors, Pebble Bed Modular Reactors, Engineering Education

Experience

Has been teaching Nuclear Engineering for more than 20 years and been in this field for more than 30 years

Organizations belong to
American Nuclear Society
Society of Nucelar Engineers of Turkey
Emeritus Prof. Nuclear Engineering Department, Hacettepe University Ankara Turkey

Extra-ordinary Prof. Nuclear Engineering Department, North-West Uni. Potchefstroom South Africa

Education/Credentials
(Mak. Y. Müh.) MS in Mech. Eng. Istanbul Technical University '68
MS in Nuclear Eng. MIT'72
Sc.D. in Nuclear Eng. MIT'76

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