openmc-dev
Feature Request: Gamma-Ray Dose Constants Γ
Description
Implementation of specific gamma-ray dose constants in OpenMC. Tabulated and available in a library.
Then accessible in the Python API, so that analysts can take a Depletion calculated inventory and quickly make a 1st pass judgement of the doserate from an activated material.
Ideally the method would allow one to select at what distance (radius) the point of interest is from the activated material and the quantity of said material. Perhaps defaulting to 1 meter and 1 gram.
There seems to be several approaches to this and several sources of these gamma constants. Peplow 2020 seems to be the most recent.
References https://www.osti.gov/servlets/purl/1607209 https://www.nrc.gov/docs/ML1121/ML11210B521.pdf http://www.iem-inc.com/information/tools/gamma-ray-dose-constants https://www.osti.gov/biblio/6246345 https://courses.grainger.illinois.edu/npre441/sp2021/course%20materails/chapter%205%20part%203%20basic%20methodology%20for%20dose%20calculation.pdf
Alternatives
The FISPACT method appears to be slightly different, they don't seem to use gamma constants but have the gamma energy in the emission rate
https://fispact.ukaea.uk/wiki/Keyword:DOSE https://fispact.ukaea.uk/manual/user_manual.pdf#subsection.C.7 https://www.epj-conferences.org/articles/epjconf/pdf/2016/01/epjconf-ISRD2015_04016.pdf https://www.nrc.gov/docs/ML0101/ML010170180.pdf
Compatibility
Should be no issues
For some medical and laboratory purposes, the gamma dose constants are applicable. They can give answer on the actual question "How far away we should being from the bare point source?".
For radioactive waste management, the second approach with simplified engineering shielding calculation can be only used. It is usually required for answer on the question "What the thickness of a given shielding material is needed to obtain the dose rate not exceeded the limit?" or something similiar. The calculation can be done with pre-caclulated tabulated data for self-infinite uniform homogeneous source and slabs of several typical shielding materials in combination with log-log interpolation by the energy and the shield thickness. In this case, the specific to mass source intensity, source material, shielding material, and the slab shield thickness are on input, the contact dose rate is on output. This approach can be actually low-cost, precise and reliable for cask dose rate prediction related to the on surface regulatory control level, from my experience. Alternatively, the mass attenuation coefficients handbook data can also be used.
For other purposes, not mentioned above methods can be applied. Thus, as usual, a simplified engineering approach is always related to a specific purpose.
