Nuclear Fuel Cycle (1)

Hello……

Today, we all study about nuclear fuel cycle…..

You all know about Uranium??? Ok…Before I go further let me explain definition of the Uranium…

Uranium is a very dense, radioactive metallic element, naturally occurring in most rocks, soil, and even in the ocean.

Uranium, a radioactive element, has existed since our planet was born.

²³⁸U – 99.29% and half life, λ= 4.47 x 109years

²³⁵U - 0.711 % and half life, λ= 7.04 x 108years

²³⁴U - 0.005 %

Its most stable isotope, Uranium 238 (92 protons + 146 neutrons), has a half-life of about4.5 billion years, or the age of the Earth.

Global Nuclear Power

Now in global, we have 436 commercial nuclear power reactors (+ 28 under construction). However 30 countries have their own nuclear power. Nowadays, 16% of world electricity supplied by nuclear as base-load. The total worl power capacity is 370000 MWe. To improve this nuclear power, 56 countries operate a total of 284 research reactors and a further 220 reactors power ships and submarines.

Uranium Requirements

•Principal demand is for nuclear fuel.

•Current Demand:

~ 441 reactors worldwide

Total output ~ 376,000 MWe

Each requires ~ 170 tonnes UOC per year

UOC requirement ~ 70,000 tonnes per year

•Current Production (2009):

Current UOC output = 50,772 tonnes per year

Nuclear Properties of Uranium

•U isotopes all alpha emitters.

•Some spontaneous fission (SF).

•Specific activity of U low due to long half-lives, but they can decay through chain of

  daughter products, ultimately leading to lead or bismuth.

•At secular equilibrium, all decay rates are same throughout the chain. Daughter product

  concentration in proportion to half-life. More or less, 95% of specific activity (Bq/kg) is

  due to daughter products.

Reference: Nuclear Fuel Cycle Lecture