RE:RE:Ohi Unit 3 in commercial operation. Ohi 4 being loaded withThat is a great question....answer is not very straightforward though.
The basic fuel for a PWR (Ohi 3 & 4 are both pressurised water reactors) is Uranium Dioxide in pelletes. UO2 is a black powder (looks a bit like coal dust) and is sintered (baked at high temperatures under pressure) to form pellets. PWR's cannot operate on natural uranium (only CANDU reactors operated in Ontario and New Brunswick can do that) so the fuel needs to be enriched to greater than the 0.7% U235 that occurs naturally. Not all fuel rods are enriched to the same level so it is not easy to determine exactly how much Natural Uranium in the form of U3O8 (yellowcake) is required to create a single fuel rod for a PWR....because they are all different enrichments.
Also the fuel assemblies are different sizes. Combustion Engineering PWR's are either 14x14 or 16x16, Westinghouse plants are 14x14, 15x15 and 17x17 and so on so there is no standard size.
Anyhow to answer your question a typical 1000MW PWR (OHI 3 & 4 are slightly larger than that) will contain about 100 tonnes of enriched Uranium which is equivalent to around 113 tonnes of natural Uranium dioxide. Since Ohi 3 & 4 both have 193 fuel assemblies on average each fuel assembly contains about half a tonne of enriched UO2 or about 0.6 tonnes of naturam UO2 equivalent. Now what is produced from a mine is not UO2 it is U3O8 which has to be first converted to UF6 (Uranium Hexaflouride), then enriched to the required amount (3 to 5%) and the enriched fuel converted from UF6 into UO2.
So you need about 1.18 tonnes ot U3O8 to make 1 tonne of Uranium Dioxide which means that if the 1000MW reactor needs 113 tonnes of non-enriched UO2 you needed 113x1.18 = 133 tonnes of U3O8 to make it and out of that you get 100 tonnes of enriched reactor fuel.
So the amount of U3O8 in each fuel assembly is around 133/193 = 0.69 tonnes or 0.69x2204lb=1521 lbs of U3O8 required to make one fuel bundle.
These are average numbers only and the lbs of U3O8 required depends on the enrichment level of the fuel and the exact number of fuel pellets in each fuel assembly.
But it is a reasonable assumption that on average each fuel assemble requires around 1500 lbs of U3O8.
If someone has the time p-lease check my calcs here but it looks around the right number.
Now the other complication is that a new reactor needs all new fuel but PWR designs use core shuffling of fuel assemblies to achieve hoigher burnup and to keep the neutron flux as flat asa possible both vertically and diametrically across the reactor core. So after they have been running for a few years they will move the fuel around and on average only put about one third of new fuel assemblies in the core. Ohi had been running already so they have re-used much of the fuel stored in the fuelling ponds and only changed out about 64 assemblies for new ones.
I hope that makes sense but this latter point is key to Uranium demand over the next few years since NEW reactors need three times more fuel than steady state reactors do because the entire core is new. In a new reactor of the size of OHI 3 and 4 you will need 193 brand new fuel assemblies. In a reactor that has already been operating the fuel requirement is only about 64.
That means that the 56 plants under construction are the U3O8 equivalent of 168 steady state reactors.
That is why I am bullish on Uranium. Mines are not producing that amount of Uranium and there are no new mines under construction...so where is it going to come from. Inventory will only last so long before there is none left and at these levels of demand that inventory will decrease quickly.
Most of thos 56 plants are due to come on line in the next two or three years hence my focus on the 2020 period as being crunch time for utilities.
Hope that was useful.
Best regards
Malcolm