- #1
doublemint
- 141
- 0
I am trying to figure out what happens to the power when a prompt jump occurs. From Nuclear Reactor Analysis by Duderstadt and Hamilton, a prompt jump approximation can be done to yield the following equation:
[itex]\frac{P_{2}}{P_{1}}[/itex] = [itex]\frac{\beta-\rho_{1}}{\beta-\rho_{2}}[/itex]
Now the question is for a CANDU reactor that has 0.7% enriched uranium. If the delayed neutron fraction for U235 is 0.00682 then for the CANDU reactor the fraction of delayed neutron is 0.00682*0.007=4.77E-5. (Not sure if I did this part correctly).
Ignoring fast fission of U238, there was a step increase of +3mk in an initially critical reactor, then the power change is just:
[itex]\frac{P_{2}}{P_{1}}[/itex] = [itex]\frac{4.77E-5-0}{4.77E-5-0.003}[/itex]
but this yields a negative ratio which does not make sense..I am thinking I calculated the delayed neutron fraction incorrectly.
Any help is appreciated!
[itex]\frac{P_{2}}{P_{1}}[/itex] = [itex]\frac{\beta-\rho_{1}}{\beta-\rho_{2}}[/itex]
Now the question is for a CANDU reactor that has 0.7% enriched uranium. If the delayed neutron fraction for U235 is 0.00682 then for the CANDU reactor the fraction of delayed neutron is 0.00682*0.007=4.77E-5. (Not sure if I did this part correctly).
Ignoring fast fission of U238, there was a step increase of +3mk in an initially critical reactor, then the power change is just:
[itex]\frac{P_{2}}{P_{1}}[/itex] = [itex]\frac{4.77E-5-0}{4.77E-5-0.003}[/itex]
but this yields a negative ratio which does not make sense..I am thinking I calculated the delayed neutron fraction incorrectly.
Any help is appreciated!