NHFLUX reader improvement

[aaswenson]

The ARMI nhflux reader (nhflux.NhfluxStreamVariant.readBinary) cannot not read VARSRC binary files. This is because the VARSC files do not contain the 2D card with pointers partial flux currents. The file format description (provided by ANL) for the NHFLUX_VARIANT file indicates that a 2D card is only present if NSURF is greater than 1.

Consider modifying line 257 of the nhflux.py file:

armi/armi/nuclearDataIO/cccc/nhflux.py

Line 257 in 8a332c9

self._rwGeodstCoordMap2D()

to only read the 2D coordinate pointers

if self._metadata['nSurf'] > 1:
    self._rwGeodstCoordMap2D() 

This should allow the reader to read the VARSRC files. I made this change locally on my installation and tested it against the CCCC_PrintTable.exe binary file reader that ships with DIF3D, I was able to read VARSRC moments successfully after implementing this change.

[john-science]

@aaswenson Welcome to ARMI!

It seems like a fair request. Off the top of my head, I don't see a problem. Though I would love to be able to write a unit test to prove your code suggestion works as intended.

Just FYI: We are currently in an ARMI feature freeze until the New Year. So no PR for this ticket will get merged until then. BUT we can, of course, open a PR with the solution and get all our ducks in a row and ready for the New Year.

(Also, I took the liberty of modifying your question a little bit to make it easier to read. Feel free to holler if I have something wrong.)

[Nebbychadnezzar]

I can address this PR when the time comes.