Occupational Intakes of Radionuclides Part 4

Draft document: Occupational Intakes of Radionuclides Part 4
Submitted by Kevin Konzen, Fluor Idaho, LLC
Commenting on behalf of the organisation

Line 5729: 
The statement “Blood consists of two compartments, Blood 1 and Blood 2” should be revised as “Blood consists of three compartments, Blood, Blood 1 and Blood 2” to capture discussion in Line 5809.  Suggest that the following sentence be added: “The initial Blood compartment serves to rapidly distribute Pu between the ST0 and Blood 1 compartment to support the initial systemic absorption, such as from the HRTM.”

Line 5734: 
Suggest that the first sentence be revised to: “The initial input to the Blood compartment distributes rapidly (half-time of 1 min) between the Blood 1 compartment (70%) and a soft tissue compartment called ST0 (30%).”  The following sentences need periods added to denote end of sentence.  

Line 5809, Table 18.6, Suggestion: 
Adding the “Blood” compartment was a great improvement to the systemic model, allowing for easier implementation when paired with intake models (e.g., HRTM, Wound).  The “Blood” compartment should be included as an additional compartment on Figure 18.4, illustrating the initial absorption before it is rapidly divided into the “Blood 1” and “ST0” compartments.

Line 5809, Table 18.6:
The source “Cortical volume” should be paired with “Cortical marrow” as the destination (not “Cortical surface”) to be consistent with Leggett et al. (2005) and the discussion in Line 5765.

Line 5899, Table 18.8:
Fraction of Am from Liver 1 departing to Blood (i.e., 0.974) and Liver 2 (i.e., 0) appear to be reversed and contrary to the discussion starting on Line 5820, where Liver 1 departs to Liver 2. This may also apply to several other radionuclides listed in Table 18.8.
Also, Liver 2 retention half-time of 1 year is not specified for Am-241 per discussion in Line 5823.

Line 5937 to 5947:
There should be a basis described on why the progeny biokinetic model is complicated further by splitting the ST1 compartment to the spleen and skin.  If these organs and tissues are of importance then they should also be added to the parent biokinetic model.  Suggest removing modification of the ST1 compartment for progeny calculations.

Line 5953:
Removing the Blood compartment for progeny would not support calculations when the systemic model is paired with an intake model (e.g., HRTM, Wound).  In the case where the parent and daughter both have an ST0 compartment, Pu generated as progeny in the parent ST0 compartment should transfer to the daughter ST0 compartment, without a need of making further modifications to the model.  Suggest keeping the Blood compartment and to not add the Blood 1 to ST0 transfer coefficient of 0.33 d-1 for the Pu model.

Line 10031:
Revise the following statement “two major isotopes of plutonium” to “two major isotopes of americium”.

Line 10863, Table 23.6:
Table 23.6 was not consistent with Table 18.9 in the following:

  • Liver 1 to Blood transfer rate was listed as 0.00185/d; this should be Liver 2 to Blood.
  • The Liver 1 to Liver 2 pathway was not defined with a transfer rate of 0.0225/d, that needs to be added.
  • Liver 0 to SI path, should be Liver 1 to SI (there is no Liver 0 in the Am model); also the transfer rate is listed as 0.000049/d, whereas Table 18.9 is 0.00006/d
  • Testes to Blood transfer rate was listed as 0.00019/d, Table 18.9 lists this as 0.00038/d.
  • Ovaries to Blood transfer rate was listed as 0.00019/d, Table 18.9 lists this as 0.00038/d.