Self-Shielding and Power Share

[Syed Alam]

1. What is "Resonance Self-shielding"?
2. What is the "self-shielding of the burnable poison"? How does it help burnable poison not to burnout quickly?
3. I have found that in a paper "POWER SHARE OF THE THORIUM CHAIN" and "The denaturing is necessary in some cases in order to reduce the power peaking in the seed-type fuel by improving the power share of the thorium region at the beginning of fuel irradiation. " What is that Power Share? How is it helpful?

 

[Astronuc]

Resonance shielding refers to the effect of increased neutron absorption in the resonance energy range, such that some fast neutrons do not slow to thermal energies, but are absorbed in the resonance energy range.

Self-shield by enrichment or burnable poisons means that the U-235 or burnable poison toward the interior pellet sees a lower neutron flux than the U-235 or burnable absorber near the surface.

Power sharing refers to power distribution such that peaking is controlled by allowing different regions of the core to produce power. Seed-type fuel is usually in the blanket region or in certain fuel assemblies. Ideally, one tries to reduce peaking in the core so that fuel does not exceed thermal or burnup limits.

 

[raining Pete]

1. "Resonance self-shielding" refers to the phenomenon in which certain materials, such as fuel in a nuclear reactor, absorb more neutrons at particular energies than at others. This can lead to a decrease in reactivity and affect the overall performance of the reactor.

2. The "self-shielding of the burnable poison" refers to the ability of certain materials, known as burnable poisons, to absorb neutrons and reduce the reactivity of the fuel. This helps prevent the burnable poison from being consumed too quickly, allowing it to maintain its effectiveness over a longer period of time.

3. The "Power Share" in the context of the "POWER SHARE OF THE THORIUM CHAIN" refers to the distribution of power or energy production within a nuclear reactor. In this case, the paper is discussing how denaturing, or adding a small amount of a different material, can help balance the power distribution within the reactor by increasing the contribution of the thorium region. This can help improve the overall efficiency and stability of the reactor.