NE 406 Radiation Shielding

Take-Home Test#3

Due April 27, 2007 at 5:00 p.m.

Use the SCALE SAS1 sequence to solve the following problem:

  Design a spherical shipping cask in which to ship 1 gram of Cf-252.

      1. A central sphere of aluminum of radius 0.62035 cm containing the source;

      2. A surrounding sphere (outer radius your choice) of polyethlyene [poly(h2o)] mixed with natural boron; the boron should have a volume fraction equal to the LAST FOUR DIGITS OF your SS# divided by 10000.

3. A surrounding sphere of SS304 (outer radius your choice).

Use the following data:

      1. No void in the shield.

      2. Use the SCALE material library at SCALE-assumed density and temperature of 293.

      3. Adequate spatial mesh so that both the photon AND neutron doses vary by no more than a factor of 2 between adjacent spatial mesh points.

      4. For the dose response functions, use the default response functions for neutrons and photons from the SAS1 sequence.

      5. Use the 27N-18COUPLE library with the INFHOMMEDIUM option.

      6. Use the DETECTOR 1 dose from the XSDOSE output for your surface dose.

7.Design to a maximum surface dose rate of 0.5 mrem/hr (half gamma, half neutron) (The precision I am looking for is that BOTH neutron and gamma dose rates are between 0.2 and 0.3 mrem/hr and sum to less than 0.5 mrem.hr) .

Provide me an ELECTRONIC description of what you did and what the results were, including:

1. How you determined the group-wise energy distribution for the source--including any source code or EXCEL spreadsheet that you used.
2. A description of the model you built.
3. A description of the cases that you ran to arrive at your answer.
4. A copy of the final input deck and output decks, electronically.

In addition (and this is VERY IMPORTANT--I will not grade your test until I get it), include a statement that says:
1. You did the test by yourself, neither receiving or GIVING help to anyone else (besides me).
2. You performed the SCALE runs on your OWN computer with your OWN copy of SCALE and no one else used your version of SCALE.

If #2 is NOT TRUE, then the arrangements have to be cleared by me BEFOREHAND.  And, of course, an arrangement for #2 DOES NOT mean that the person whose computer you use can help you with the assignment.  This is NOT true.