Re: Material composition

[Pavlo Ivanusa]

For ATOM materials, you need a density multiplier after your isotopic composition but before your temperature. It looks like your temperature of 500 is actually being read as the density multiplier.

On Tuesday, September 7, 2021 at 11:05:59 PM UTC-7 A.S.M. Fakhrul Islam wrote:

Hi,

I am trying to create the following two compositions at 500 C in KENO:

17.53 g/cc U-Mo fuel (92.7% U, 7.3% Mo, 19.9% U235):
wtptUMo 1 17.53 2 92000 92.7 42000 7.3 1 500 92234 0.0476 92235 19.9000 92236 0.0225 92238 80.0339 end 

4.24 g/cc YH2 moderator:

ATOM-YH2 2 4.24 2 39089 1 1001 2 500 END

Does the way I have defined the compositions look good? When I use this composition for YH2 instead of BeO, the k-eff dropped from 1.2 to 0.5. I am perplexed by this big decrease in k-eff.

Thank you!

Fakhrul

[A.S.M. Fakhrul Islam]

Hi Pavlo,

Would you doublecheck what you are suggesting is accurate? Please see the screengrab below from the SCALE user manual.

I am seeing similar drop in the k-eff value for ZrH2 moderator as well. I tried each of the following:

ZrH2 2 den=5.61 1 500 end

H-ZrH2 2 den=5.61 1 500 end

ZrH2 2 den=5.61 1040000 500 end

atomZrH2 2 5.61 2 1040000 1 1001 2 1 500 end

ZrH2 2 den=5.61 1 500 1040090 51.45 1040091 11.22 1040092 17.15 1040094 17.38 1040096 02.80 end

Thank you!