Exposure assessment of groundwater transport of tritium from the Central Nevada Test Area

Corrective Action Investigation Plan for the CNTA Subsurface Sites (CAU Number 443), Revision 1

“…Based on scoping-level calculations (Pohlmann et al, 1995), the downgradient model boundary is likely to extend no farther than the UC-3 withdrawn area, approximately six kilometers to the south ( Figure 5-1). …”

“…Pohlmann et al (1995) modeled potential migration of tritium away from the cavity and evaluated the risk due to tritium to an individual consuming groundwater for a lifetime centered around the peak tritium concentration as part of the Environmental Impact Statement for DOE activities in Nevada. Johnson et al (1996) employed the same scenario and transport parameters identified by Pohlmann et al (1995), but used a nuclear reactor computer code to calculate the source term. In addition, they considered risk due to cesium and strontium, but found that the risk due to these two contaminants is effectively zero.…”

Corrective Action Investigation Plan for the Central Nevada Test Area Subsurface Sites (Corrective Action Unit No. 443)

“…Two analyses of the human health risk caused by migration of contaminants in groundwater from the Faultless cavity have been performed. Pohlmann et al (1995) modeled potential migration of tritium away from the cavity and evaluated the risk due to tritium to an individual consuming groundwater for a lifetime centered around the peak tritium concentration as part of the Environmental Impact Statement for DOE activities in Nevada. Johnson et al (1996) employed the same scenario and transport parameters identified by Pohlmann et al (1995), but used a nuclear reactor computer code to calculate the source term.…”

“…The amount (if any) of unburned nuclear fuel (including isotopes of plutonium, uranium, and hydrogen) and the precise types and quantities of radionuclides produced are available in a classified report (Goishi et al, 1995), but unclassified analyses of groundwater from the post-shot well UC-1-P-2SR are publicly available (Thordarson, 1985;Davisson et al, 1994;Chapman et al, 1994). Using the unclassified data and estimates of chimney volume, Pohlmann et al (1995) calculated a tritium source term for the Faultless event of 4.3 x 10 pCi.…”

Exposure assessment of groundwater transport of tritium from the Shoal Site

“…These early evaluations were not considered sufficient for the EIS, so DOE decided to perform a new exposure assessment for the Shoal site. A separate evaluation of the Central Nevada Test Area was also performed and is reported by Pohlmann et al (1995).…”