I have to agree with the statements about NNPP.
For a critical reactor, K
eff=1.0000 NOT K
eff=1, as I tried to answer on a test.
I know, I tried arguing the point that answering 1 mathematically implies 1.000000000000000......

Sometimes acceptance is best. Resistance is futile. Its kinda like the AA serenity prayer:
God, Grant me the Serenity
To accept the things I cannot change,
Courage to change the things I can,
and Wisdom to know the difference.
It took me awhile to accept this at nuke school. I thought I could think and understand my way thru an exam.
Understanding is really important, but it won't get you thru school on its own. Memorization is at least 30% of making it thru. Remember...sometimes you have to play the game. That will serve you well in boot camp and nuke school.
Don't think too hard and don't sweat it.