Reactor Theory (II)

Question 1

Neutron multiplication

Answer 1

neutrons in current generation divided by neutrons in previous generation; critical k=1, supercritical k>1, subcritical k<1

Question 2

infinite multiplication factor formule

Answer 2

fast fission * resonance escape probability* thermal utilization * reproduciton

Question 3

fast fission

Answer 3

number of neutrons below fast fission threshold energy divided by number of initial fission neutrons

Question 4

resonance escape probability

Answer 4

number of neutrons below resonance threshold energy divided by number of neutrons below fast fission threshold energy

Question 5

thermal utilization

Answer 5

number of thermal neutrons absorbed in fuel divided by number of neutrons below resonance threshold energy

Question 6

reproduction factor

Answer 6

average number of fission neutrons produced divided by number of thermal neutrons absorbed in fuel

Question 7

effective multiplication factor formula

Answer 7

infinite fomula * thermal and fast neutron non-leakage

Question 8

fast non-leakage

Answer 8

number of fast neutrons that don’t leak divided by number of fast neutrons produced by all fissions

Question 9

thermal non-leakage

Answer 9

number of thermal neutrons that don’t leak from reactor divided by number of neutrons that reach thermal energies

Question 10

Reactivity

Answer 10

departure from criticality; (Keff - 1) divided by Keff

Question 11

Neutron poisons

Answer 11

absorbs neutrons that don’t contribute to any return; Xe-139 for 72 hours post shutdown and Sm-149 no decay after shutdown

Question 12

Differential rod worth

Answer 12

reactivity change per movement of control rod

Question 13

Integral rod worth

Answer 13

total reactivity worth of rod at withdraw positions