Engineering topics

Ralston-Hooper, Kimberly

Publications and source records attributed to Ralston-Hooper, Kimberly.

5 records

DOE OSTI2023

Updates to Composite Analysis Base Case and Null Space Monte Carlo Sensitivity Based on New Unit Dose Factors

This environmental calculation file (ECF) presents the results of the exposure route-specific and total radiological dose assessments for the groundwater exposure pathway as a part of the updated Composite Analysis for Low-Level Waste Disposal in the Hanford Site Central Plateau (FY 2022), based on revised unit dose factors (UDFs) published in CA Special Studies: Updates to the Groundwater Pathway Radiological Dose. The reason for these radiological dose assessments is to estimate the cumulative radiological impacts from all screened sources of ionizing radiation and exposure routes that could potentially contribute to the projected dose to a hypothetical member of the public. Sources of ionizing radiation can include existing or future disposal facilities and other sources including past-practice discharge sites. Additionally, the results of the exposure route-specific and total radiological dose assessments have been revised for the groundwater pathway based on the null space Monte Carlo (NSMC) groundwater concentrations and the most recent updates to the UDFs as a part an uncertainty analysis for the updated Hanford Site CA.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2022

CA Special Studies: Updates to the Groundwater Pathway Radiological Dose

This environmental calculation file (ECF) summarizes the groundwater pathway exposure assumptions and methodologies used to revise radionuclide specific unit dose factors (UDFs) published in CP-64491, Hanford Site Composite Analysis Data Package – Exposure Scenarios and Radionuclide Specific Dose Conversion Factors. Specifically, this ECF describes the updated exposure-related parameters used to calculate radionuclide specific UDFs based on recommendations from the Low-Level Waste Disposal Facility Federal Review Group (LFRG) and updates to Adult External DCFs included in EPA 402-R-93-081, External Exposure to Radionuclides in Air, Water, and Soil hereinafter called Federal Guidance Report [FGR]).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2022

Calculation of Groundwater Pathway Radiological Dose for the Hanford Site Composite Analysis Null-Space Model Carlo Flow Model Set

The purpose of this environmental calculation file (ECF) is to present the results of the exposure route-specific and total radiological dose assessments for the groundwater pathway based on the null space Monte Carlo (NSMC) groundwater concentrations as a part an uncertainty analysis for the updated Hanford Site Composite Analysis (CA). The Plateau-to River (P2R) Groundwater Model (CP-57037, Model Package Report: Plateau to River Groundwater Model Version 8.3) is the CA base case that simulates the fate and transport of radiological contaminants within the saturated zone of the uppermost aquifer beneath the Central Plateau and downgradient to the Columbia River. An NSMC analysis was performed to identify and quantify the potential uncertainties associated with the P2R Model. The result of the NSMC analysis is a set of flow and transport simulations that provide an estimated range of possible outcomes that are used to quantify the uncertainty associated with the simulated base case concentrations.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2022

Hanford Site Composite Analysis: Dose Sensitivity Analyses

This environmental calculation file (ECF) documents the methodologies, assumptions, and results of five analyses that evaluate parameter changes to the revised Hanford Site Composite Analysis (CA) (DOE-RL-2019-52, Composite Analysis for Low-Level Waste Disposal in the Hanford Site Central Plateau). Specifically, this ECF describes the impact on total dose and analyte-specific doses for five sensitivity cases where changes to the following exposure-related parameters were implemented – (1) inventory, (2) recharge rate, (3) external dose conversion factors (DCFs) based on Federal Guidance Report (FGR) No. 15 in (EPA-402-R-19-002, Federal Guidance Report No. 15, External Exposure to Radionuclides in Air, Water, and Soil) instead of FGR No. 12 (EPA 402-R-93-081, Federal Guidance Report No. 12, External Exposure to Radionuclides in Air, Water, and Soil) for groundwater pathway scenario; (4) use of mean instead of 95th percentile intake assumptions for groundwater pathway scenario; and (5) consideration of limited sources based on U.S. Department of Energy (DOE) owned waste sites regulated under DOE O 435.1, Radioactive Waste Management. It should be noted that dose assessments for both base and sensitivity cases are based on the all-pathways representative person groundwater exposure scenario presented in DOE/RL-2022-52, Composite Analysis for Low-Level Waste Disposal in the Hanford Site Central Plateau.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2022

Hanford Site Composite Analysis Data Package: Exposure Scenarios and Radionuclide Specific Dose Conversion Factors.

This data package summarizes the exposure assumptions, equations, and methods used to calculate radionuclide-specific unit dose factors and the radiological doses for both groundwater and atmospheric pathways as a part of the revised Hanford Site Composite Analysis. An All-Pathways Representative Person exposure scenario is considered to evaluate exposure via both groundwater and atmospheric transport pathways. The radiological dose assessments for both groundwater and atmospheric pathways are included in the performance assessments for various Waste Management Areas at the Hanford Site. This data package calculates exposure route-specific and total unit dose factors for composite-analysis-specific radionuclides of concern based on the exposure assumptions used in the composite analysis and performance assessments. This data package presents the results and comparison of the radionuclide-specific unit dose factors based on the exposure assumptions used in the revised composite analysis and various performance assessments.

61 RADIATION PROTECTION AND DOSIMETRY↗