Sodium-bearing Waste Treatment Technology Evaluation Report

Abstract

A Settlement Agreement between the U.S. Department of Energy (DOE) and the State of Idaho mandates treatment of sodium-bearing waste (SBW) stored at the Idaho Nuclear Technology and Engineering Center located within the Idaho National Engineering and Environmental Laboratory (INEEL). One of the requirements of the Settlement Agreement is to complete treatment of SBW by December 31, 2012. Hence, SBW disposition is one of the Idaho Operation Office's (NE-ID) and State of Idaho's top priorities at the INEEL.The INEEL has been working over the past several years to identify a treatment technology that meets NE-ID and regulatory treatment requirements, including consideration of stakeholder input. Many studies, including the High-Level Waste and Facilities Disposition Environmental Impact Statement, have resulted in the identification of five treatment alternatives that form a short list of perhaps the most appropriate technologies for the DOE to select from. The alternatives are (a) calcination with maximum achievable control technology (MACT) upgrade, (b) steam reforming, (c) cesium ion exchange (CsIX) with immobilization, (d) direct evaporation, and (e) vitrification. Each alternative has undergone some degree of applied technical development and preliminary process design over the past four years.Applied technology development and preliminary process design activities have been required to provide the data necessary for informed decision making and evaluation of the treatment options. A technically defensible selection of a SBW treatment process has been a key driver for the collection of needed data. This document presents a summary of the data gathered in recent years and evaluates the technical maturity of each option by listing and discussing the identified higher-risk technical uncertainties. The SBW issue and the five alternatives are described, and their technical performance (throughputs, waste product descriptions and volumes, preliminary facility footprints, etc.) is summarized in the main body. Details of preliminary process design and applied development activities for three of the alternatives (steam reforming, CsIX with immobilization, and direct evaporation) are presented in three appendices; a recent feasibility study provides the details for calcination. There have been no recent activities performed with regard to vitrification; that section summarizes and references previous work.