Discrepancy in MCDANCOFF results betweent SCALE6.2.3 and SCALE6.3.1

[Nuria GH]

Dear SCALE Team,

I am encountering significant discrepancies in the Dancoff factors when running MCDANCOFF with SCALE6.2.3 and SCALE6.3.1 for BWR fuel assemblies. To check it, I used a simple test case: a BWR pin-cell with reflective boundary conditions (see attached input file).

The results are as follows:

• SCALE6.2.3: Dancoff factor = 0.48
• SCALE6.3.1: Dancoff factor = 0.075

I used the same input file with both versions and verified these results on both Linux and Windows systems. Is there any reasons for this discrepancy?

Thank you for your assistance.

Best regards,

Nuria

[Rike Bostelmann]

Hi Nuria,

I only just came across your question. Sorry it took so long... you probably have moved on from this. 

For the record in the forum, I wanted to write that I confirmed the same bad Dancoff factors when using SCALE 6.3.1. It looks like there was an issue with the boundary condition when using the "ALL=" keyword. Our records show that this has been fixed in SCALE 6.3.2. I just re-ran your input with SCALE 6.3.3 and found again the correct Dancoff factors, consistent with SCALE 6.2.3.

If you have a SCALE 6.3.1 license, please note that you can request a patch for the latest minor release by emailing SCALE help.

Best regards,

Rike

SCALE Team