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gmax137
Science Advisor
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candice_84 said:Can you guide me through calculating actual nuclear plants efficiency?
OK. You start, by telling us what you mean by 'efficiency.'
candice_84 said:Can you guide me through calculating actual nuclear plants efficiency?
One could start with Carnot efficiency.candice_84 said:Can you guide me through calculating actual nuclear plants efficiency?
Well one could take 1000/3030 = ~0.33 or 33% efficiency.candice_84 said:Ok, for example ap1000 produces 3030 MWth and 1000 MWe. I'd like to know how do we start from 3030 and produce 1000 MWe. I am aware of the fact that is Rankine Cycle and we reuse the steam from High pressure turbine to low pressure turbine. I am interested to know which formula to be used step by step.
Reactivity within a fuel lattice is a function of enrichment (i.e., concentration of fissile nuclides), the geometry and composition of structural material and coolant, concentration of burnable (depletable) neutron absorbers, and temperature. Also, in an LWR, pressure and temperature of the coolant determine its density which has an effect on moderation and neutron spectra.candice_84 said:Does small lattice pitch make -reactivity?
Delayed neutrons account for about 0.0065 or 0.65% of the neutrons in the given population. Basically the reactor goes critical with delayed neutrons. They last long enough to effectively increase the mean lifetime of neutrons which allows for controlled power changes.candice_84 said:Delayed neutrons are very few in compare to prompt neutrons, but how could they be so effective in controlling the reactor. When neutrons fission, 2.47neutrons are released. most of those neutron are 95% prompt. By the time the delayed neutrons emission (few millisecond), the prompt neutrons would have many fission chain cycle. so how could that delayed neutron be so effective in terms of control?
Fast reactors produce fission products as well. They can push fuel to higher burnups - maybe 50-100 GWd/tHM (HM = heavy metal) or 5-10% FIMA (fission(s) per initial metal atom), and even higher. If one considers spent fuel, then fast could produce more energy for the same amount of waste. On the other hand, fast reactor fuel is usually of higher enrichment, so there is generally more up front DU produced for a given mass of fast reactor fuel. The selling point of fast reactors is the recycling of Pu and transuranics - but that complicates the fuel cycle because the fuel then has to be manufactured and handled remotely - which makes it much more expensive than conventional LWR fuel.candice_84 said:Do fast reactors lower the amount of waste? since U238 fissions. but we only convert a little portion of the U238 to energy.