Dennis L. Strenge

Inventory Data Package for Hanford Assessments

This document presents the basis for a compilation of inventory for radioactive contaminants of interest by year for all potentially impactive waste sites on the Hanford Site for which inventory data exist in records or could be reasonably estimated. This document also includes discussions of the historical, current, and reasonably foreseeable (1944 to 2070) future radioactive waste and waste sites; the inventories of radionuclides that may have a potential for environmental impacts; a description of the method(s) for estimating inventories where records are inadequate; a description of the screening method(s) used to select those sites and contaminants that might make a substantial contribution to impacts; a listing of the remedial actions and their completion dates for waste sites; and tables showing the best estimate inventories available for Hanford assessments.

Risk computation for environmental restoration activities

Abstract Environmental restoration activities planned by the U.S. Department of Energy (DOE) and other agencies will require consideration of long-term environmental and public health risks. These restoration activities will require risk computations capabilities in support of baseline, reme- diation, and residual risk assessments. During the initial stages of problem characterization, risk screening approaches are useful; then, as more data become available, more detailed risk evaluations are appropriate. While a wide variety of models address specific site characteristics, transport media, and impact type, only a few models address the broad range of long-term public health issues encountered in environmental resto- ration activities. One such model, the Multimedia Environmental Pollutant Assessment System (MEPAS®) (© Battelle Memorial Institute, 1989, 1993), integrates radioactive and hazardous materials risk computations for major exposure routes via air, surface water, groundwater, and over- land flow transport. By considering a broad range of potential environmental issues, models such as MEPAS can be used to help prioritize potential environmental problems. An illustrative application is described involving relative risk-based evaluation of the mixed waste in underground tanks. The results provide an indication of (1) the relative importance of each of the constituents from a public-health standpoint, and (2) the sensitivity of those rankings to important input parameters.

Overview of the Remedial Action Priority System (RAPS)

All environmental regulations are intended to minimize the risks to man and his environment resulting from a regulated activity. Because lower risk levels are generally accompanied by higher environmental control costs, optimum management is achieved by balancing risks and costs. The U.S. Environmental Protection Agency (EPA) currently employs the Hazard Ranking System (HRS) to preliminarily assess inactive hazardous waste disposal sites for potential placement on the National Priorities List. Recently, modifications to HRS have been proposed to more realistically assess the risks posed by radioactive waste constituents. These modifications significantly increase the applicability of the HRS to the U.S. Department of Energy (DOE) hazardous waste disposal sites.

User Instructions for the Systems Assessment Capability, Rev. 1, Computer Codes Volume 3: Utility Codes

This document contains detailed user instructions for a suite of utility codes developed for Rev. 1 of the Systems Assessment Capability. The suite of computer codes for Rev. 1 of Systems Assessment Capability performs many functions.

Composite Analysis for Low-Level Waste Disposal in the 200 Area Plateau of the Hanford Site, Southeast Washington

A composite analysis of low-level radioactive waste disposal and other radioactive sources was recently completed for the Hanford Site in Southeast Washington State. Impacts from source release and environmental transportwere estimated for a 1 000-year period following Site closure in a multi-step process involving 1) estimation of radiological inventories and releases, 2) assessment of contaminant migration through the vadose zone, groundwater, and atmospheric pathways, 3) and estimation of doses. The analysis showed that most of the radionuclide inventory in past-practice liquid discharge sites and pre-1988 solid waste burial grounds on the 200 Area Plateau will be released in the first several hundred years following Hanford Site closure, well before projected releases from active and planned disposals of solid waste. The maximum predicted agricultural dose was less than 6 mrem/y in 2050 and declined thereafter. The maximum doses for the residential, industrial, and recreational scenarios, were 2.2, 0.7, and 0.04 mrem/y, respectively, and also declined after 2050.

Using FRAMES to Manage Environmental and Water Resources

The Framework for Risk Analysis in Multimedia Environmental Systems FRAMES) is decision-support middleware that provides users the ability to design software solutions for complex problems. It is a software platform that provides seamless and transparent communication between modeling components by using a multi-thematic approach to provide a flexible and holistic understanding of how environmental factors potentially affect humans and the environment. It incorporates disparate components (e.g., models, databases, and other frameworks) that integrate across scientific disciplines, allowing for tailored solutions to specific activities. This paper discusses one example application of FRAMES, where several commercialoff-the-shelf (COTS) software products are seamlessly linked into a planning and decision-support tool that helps manage water-based emergency situations and sustainable response. Multiple COTS models, including three surface water models, and a number of databases are linked through FRAMES to assess the impact of three asymmetric and simultaneous events, two of which impact water resources. The asymmetric events include 1) an unconventional radioactive release into a large potable water body, 2) a conventional contaminant (oil) release into navigable waters, and 3) an instantaneous atmospheric radioactive release.

Combining Multiple-Module Output Boundary Conditions to Produce a Single-Input-Module Boundary Condition in FRAMES

The Plus Operator thus provides a mechanism to group modules of similar output so that the output can be combined and supplied to downstream modules. This document provides requirements, the design, data-file specifications, the test plan, and the quality assurance/quality control (QA/QC) protocol for the Plus Operator.

Addendum to Composite Analysis for Low-Level Waste Disposal in the 200 Area Plateau of the Hanford Site

This report summarizes efforts to complete an addendum analysis to the first iteration of the Composite Analysis for Low-Level Waste Disposal in the 200 Area Plateau of the Hanford Site (Composite Analysis). This document describes the background and performance objectives of the Composite Analysis and this addendum analysis. The methods used, results, and conclusions for this Addendum analysis are summarized, and recommendations are made for work to be undertaken in anticipation of a second analysis.