This paper presents a large-scale modeling study characterizing fluid flow and tracer transport in the unsaturated zone of Yucca Mountain, Nevada, a potential repository site for storing high-level radioactive waste. The study has been conducted using a three-dimensional numerical model, which incorporates a wide variety of field data and takes into account the coupled processes of flow and tra...

No public policy issue has been as difficult as high-level nuclear waste. Debates continue regarding Yucca Mountain as a disposal site, and-more generally-the appropriateness of geologic disposal and the need to act quickly. Previous research has focused on possible social, political, and economic consequences of a facility in Nevada. Impacts have been predicted to be potentially large and to e...

The IAEA's Programme on BlOsphere Modelling and Assessment (BIOMASS) provided an international forum for information exchange, development and collaboration in the area of environmental assessment modelling. This paper contains a brief overview of the work and results of the three themes of BIOMASS, namely: radioactive waste disposal, environmental releases and biosphere processes. The BIOMASS ...

The EPA Regional Ground Water Forum is a group of EPA professionals representing Regional Superfund and Resource Conservation and Recovery Act (RCRA) Offices, committed to the identification and resolution of ground-water issues impacting the remediation of Superfund and RCRA sites. The Forum is supported by and advises the Superfund Technical Support Project. Emerging technologies that could p...

This paper describes the development work, and design and engineering tasks performed, to provide a fully automated sampling system for the Waste Treatment Plant (WTP) project at the Hanford Site in southeastern Washington State, USA. WTP is being built to enable the emptying and immobilization of highly active waste resulting from processing of irradiated nuclear fuel since the 1940s. The Hanf...

Composting is a natural biological process which results in the degradation of organic waste to a stable end product, commonly referred to as compost, which can be utilized for various agricultural purposes. Increasing landfill costs and regulations which limit many types of waste accepted at landfills has increased interest in composting as a component of waste management (Goldstein and Spence...

The article argues that insufficient attention has been paid to the operational aspects of the U.S. radioactive waste management system when it grows to the scale necessary to handle wastes produced by a fully deployed plutonium economy. Without such information, many of the unsettling speculations which have become part of the public debate and are summarized herein cannot be clearly addressed...

DL_POLY_3 is a general purpose molecular dynamics (MD) simulation package designed to simulate systems of the order of tens of millions of particles and beyond by efficiently harnessing the power of modern computer clusters. Here we discuss the package design, functionality and report on performance and capability limits. We then report the application of DL_POLY_3 to study radiation cascades i...