Is Water Depth Sufficient for Shielding Radiation in Spent Fuel Pools?

[atomicpedals]

I've done the leg work and have a method to go about a solution for this problem. I just need to get a second opinion before I crunch the numbers on the way I plan to go about this.

1. Homework Statement :

Determine the amount of water that needs to be over a spent fuel pool to provide enough shielding to reduce exposure to 5mGy/hr. Treat the fuel as a point source and I have a table of all the appropriate fission products and actinides.


2. Homework Equations :

Radiation Yield (to be applied to beta particles and associated Bremsstrahlung...which might be overkill as the accompanying gammas probably over shadow the betas)

Exposure rate x=(0.5CE)/d^2


3. The Attempt at a Solution :

Ok, what I want a sanity check on is this... my plan is to focus on the highest energy nuclides, then to ignore alpha radiation as it will be shielded by virtue of shielding for betas. Calculate the amount of water needed to shield for betas as well as the accompanying Bremsstrahlung. And then, perhaps most importantly, calculated the required depth of water to shield for gammas (which will probably be greater than that required for beta w/brem). I can safely ignore neutrons as any left would be very low energy and get lost in the gamma shielding (neutrons should be mostly used up by the time fuel becomes spent fuel).

Does that seem like a reasonable approach? Could I even ignore the beta shielding and just focus on the gammas? Have I lost all reason?

 

[M. Bachmeier]

I've done the leg work and have a method to go about a solution for this problem. I just need to get a second opinion before I crunch the numbers on the way I plan to go about this.

1. Homework Statement :

Determine the amount of water that needs to be over a spent fuel pool to provide enough shielding to reduce exposure to 5mGy/hr. Treat the fuel as a point source and I have a table of all the appropriate fission products and actinides.


2. Homework Equations :

Radiation Yield (to be applied to beta particles and associated Bremsstrahlung...which might be overkill as the accompanying gammas probably over shadow the betas)

Exposure rate x=(0.5CE)/d^2


3. The Attempt at a Solution :

Ok, what I want a sanity check on is this... my plan is to focus on the highest energy nuclides, then to ignore alpha radiation as it will be shielded by virtue of shielding for betas. Calculate the amount of water needed to shield for betas as well as the accompanying Bremsstrahlung. And then, perhaps most importantly, calculated the required depth of water to shield for gammas (which will probably be greater than that required for beta w/brem). I can safely ignore neutrons as any left would be very low energy and get lost in the gamma shielding (neutrons should be mostly used up by the time fuel becomes spent fuel).

Does that seem like a reasonable approach? Could I even ignore the beta shielding and just focus on the gammas? Have I lost all reason?

Are you talking about water containment of the entire site...? Please forgive my ignorance as physics is not my field of study. But if you could submerge the entire site in a short space of time...