Graphite Reflector
This happens when a sample with positive reactivity is lowered into the reflector at power. Give an example of a material with positive reactivity.
What is power will increase/reg blade will lower?
This type of can/sample/spacer has neutral reactivity in the flux trap.
What is a water spacer?
This is the administrative limit for the total reactivity worth of flux trap samples.
What is 0.005 Δk/k?
This type of neutron has been slowed to energies near equilibrium with the surrounding moderator and is most likely to cause fission in U-235.
What is a thermal neutron?
This type of advanced reactor uses passive cooling and smaller modular components for factory fabrication.
What is a Small Modular Reactor (SMR)?
This happens when a sample with positive reactivity is removed from the reflector at power. Give an example of a material with positive reactivity.
What is power will decrease/reg blade will rise?
These two types of cans/samples/spacers have negative reactivity in the flux trap.
What are iridium cans and titanium spacers?
This is the worth of the flux trap sample holder for the 6-barrel configuration.
What is 0.005 Δk/k?
This name is given to atoms of the same element with different numbers of neutrons.
What is an isotope?
This U.S. company developed the first SMR design approved by the NRC.
What is NuScale?
This happens when a sample with negative reactivity is inserted into the reflector at power. Give an example of a material with negative reactivity.
What is power will decrease/reg blade will rise?
This type of can/sample/spacer maintains the same reactivity value regardless of its content.
What is a flooded host can?
This is the reactivity limit for a secured removable experiment.
What is 0.006 Δk/k?
This factor describes the ratio of neutrons produced by fission in one generation to the number of neutrons lost through absorption and leakage in the preceding generation.
What is the effective multiplication factor (k_eff)?
This advanced reactor company is developing a sodium-cooled fast reactor demonstration in Wyoming.
What is TerraPower?
This happens when a sample with negative reactivity is removed from the reflector at power. Give an example of a material with negative reactivity.
What is power will increase/reg blade will lower?
This type of can/sample/spacer has different reactivity values depending on the quantity/mass of the material.
What are therasphere samples?
This is the maximum absolute value of reactivity worth for each movable experiment or the movable parts of any individual experiment.
What is 0.001 Δk/k?
These are the two main fission products that act as poisons in the reactor.
What are Xe-135 and Sm-149?
In October of 2025, this reactor had a contractor fall into the pool during refueling.
What is the Palisades Nuclear Plant?
This method is used to measure the reactivity worth of movable samples/experiments. Bonus: name the procedure.
What is doubling time? Bonus: RP-RO-202 (legacy ID)
This type of can/sample/spacer has different reactivity values depending on where it is located in the flux trap.
What is a titanium spacer?
This is the absolute value of the reactivity worth limit for each unsecured experiment.
What is 0.0025 Δk/k?
This is the average energy (eV) of a thermal neutron. Bonus points for speed (km/s).
What is 0.025 eV? Speed: 2.19 km/s
This company recently began construction of a mile-deep 15-MW SMR in Parsons, Kansas.
What is Deep Fission?