NE421 Introduction to Nuclear Criticality Safety

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HW#3: MAGICMERV Computational Exercise

As we will see in a couple of weeks, the ANSI standards require that the analyst "understand" the effect that changes in MAGICMERV parameters have on k-effective.

This exercise will give you a little practice in computing these effects.

We will begin with a simple model of a simple stand-alone fissile unit that is similar to (but a bit bigger than) the storage unit we will be using in our in-class studies:

=csas25 parm=centrm
MAGICMERV exercise
44GROUPNDF5
read composition
UO2 1 1 293 92235 100  end
end composition
read param gen=100000 sig=0.001 npg=10000 nsk=3 end param
read geometry
global unit 1 
  cylinder 1 1  8 8 -8
end geometry
end data
end

      

Assignment

What I want you to do is to develop some simple curves to demonstrate the unit's vulnerabilities to changes in several of the MAGICMERV parameters.

So, perform and give me a simple writeup of the following parametric studies. Each of them should be a modification of the above deck (i.e., they do NOT build on each other):

Fissile mass sensitivity

Geometry sensitivity

Moderation sensitivity

Reflection sensitivity

For each of these, run the Oktoc calculation to a sigma of 0.001, plot up the results in a spreadsheet, and write me up a short description of what you found.

Email me a WORD or PDF document of your results (or bring it to class).