Added activities
Initial Commit - for thin absrober testing

Initial commit of the file to check for the effect of having a thin
neutron absorber.
Updated material compositions

Updated the material compositions to only include water, enriched /
depleted boron carbide, zricaloy-4 and the fuel.
Edited nitwal block

Edited the nitwal block to use the new isotopes.
Fixed Nitwal block

Fixed the nitwal block to use the most common isotopes.
Working reference case

Working reference case. The k-effective is 1.35
Working enriched boron carbide

Working 100 micron enriched boron carbide.  I needed to add carbon into
the nitwal database and add the fourth zone into the input deck.
Added all Enriched Boron Carbide thickness

Added enriched boron carbide up to 1 mm.
Working on added enriched coatings

Working on adding the enriched coatings into the simulation.  It doesn't
seem to work using the correct material number, but seems to work using
material the depleted with an enriched isotope.
Added a seperate file for depleted and enriched

Added a seperate file for the depleted and enriched boron carbide.  Both
simulations run without error, and the results seem to make sense.  I
want to try using a slightly thinner films to test the limits.
Added thickness down to 10 microns

Added the thickness down to 10 microns for the depleted and the enriched
cases.  I expected that the depleted should approach the refrence, while
the enriched should also go towards the reference.
Added enriched down to 1 micron

Testing the enriched down to 1 micron film coating.  The depleted showed
no change from the reference at around 10 microns.
Fixed error radius error in 1 um test

Fixed an error in the cladding radius of the  1 um test.
Description of Thin Films Boron Carbide in README

Added a description of the thin film boron carbide simulations into the
readme.