This error occurs whenever any of the Fire Involving Uranium Oxide or Explosion Involving Uranium Oxide source terms is released from a building via a filtered pathway. The source term calculation module (STCalc) displays a Problem Report where the technical details section indicates that the data name “filters” was not found.
Reason for Error: There is an error in the RASCAL source term module that prevents the code from recognizing the release pathway option of “Inside building – Filtered Pathway? – Yes” and applying the appropriate reduction mechanism.
Error Resolution: NUREG-1940 Sections 3.4.2 and 3.5.2 discuss the release pathways and the reduction mechanisms that are used by the code when the user selects one of the three release pathway options. The release pathway option “Outside building” results in no additional reduction (1.0) and the options “Inside building – Filtered Pathway? – No” and “Inside building – Filtered Pathway? – Yes” result in a reduction factor of 0.5 and 0.01 respectively. Since the release pathway option of “Inside building – Filtered Pathway? – Yes” is not working correctly, the user can work-around this error by manually applying the filter reduction factor to the airborne release fraction (ARF) on the RASCAL source term screen instead of selecting the filtered pathway on the release pathway screen. A summary of the suggested steps is:
1. Enter the material at risk as usual on the fire or explosion source term screen reflecting the real amount.
2. Also on the source term screen, adjust the ARF from the default value (or whatever you would normally use) by either:
a. multiplying by 0.01 if the “Outside building” release pathway option will be chosen, or
b. multiplying by 0.02 if the “Inside building – Filtered Pathway? – No” release pathway option will be chosen.
3. On the release pathway screen, choose either the option of “Outside building” or “Inside building – Filtered Pathway? - No” depending on your ARF adjustment choice in the step above.”
4. Make notes in the case description that the ARF was reduced (multiplied) by a factor of 0.01 or 0.02 to account for filtering in the release pathway.
The RASCAL Development Team is working on a code modification to the Fire Involving Uranium Oxide or Explosion Involving Uranium Oxide source terms for next released update to the RASCAL code.