Idaho Site - Integrated Waste Treatment Unit (IWTU)


One of the biggest tasks faced by CH2M-WG Idaho (CWI) when it assumed management of the Department of Energy’s Idaho Cleanup Project in 2005 was closure of the tank farm at the Idaho Nuclear Technology Engineering Center at the Idaho National Laboratory.

This task was complicated because three of the 15 tanks still contained a total of approximately 1 million gallons of radioactive sodium bearing waste (SBW) that would have to be removed and treated. The THOR® process was selected for treatment of the SBW and is currently being deployed. TTT has a contract to design, build, and assist operations of the THOR® process IWTU, and is applying the resources of its parent companies, URS and Studsvik, to staff the design and fabrication effort.

The technology was selected, in part, because it can provide flexible and cost effective disposal options to accommodate the final disposal path selected for the SBW. The THOR®  Process can produce a final end-product in carbonate form that will meet requirements for disposal as Remote-Handled TRU waste at the WIPP Facility in Carlsbad, NM; or, through the use of appropriate additives, the THOR® Process can produce a final mineralized product that can be qualified for disposal at a Federal Deep Geologic Repository.

Early design funding was provided by the DOE Idaho Operations Office (DOE-ID) in April 2005 to prepare a Conceptual Design package to support Critical Decision 1 (CD-1) approval in accordance with DOE Order 413.3. The CD-1 package was submitted to DOE-HQ in June 2005 and was ap­proved in July 2005. The preliminary design pack­age, with long-lead procurement purchase requisi­tions, was submitted to DOE-ID on October 3, 2005, for CD-2 approval. A resubmission was re­quired due to seismic criteria changes. This pack­age was resubmitted to DOE in May 2006 and was approved in December 2006. The CD-3 packages was submitted in June 2007 and approved in August 2007.   Key environmental permits have been granted by the State of Idaho and construction of the facility began in April 2007 with excavation of the site. Facility cold commission is scheduled to start in the 4th Quarter of 2010.

The integrated process for treating the waste was fully demonstrated using a one-tenth scale pilot plant located at Hazen Research in Golden, Colorado.

Status and Accomplishments

IWTU Project Datasheet

Construction progress

Facility Drawing
ITWU 1st Dig
2007 Construction Progress
Location of IWTU Facility
Below you can find pictures of the 2007 progress of the IWTU construction by quarter.
First Quarter '07 – Groundbreaking
Second Quarter '07 – Site Preparation
Third Quarter '07 – Foundation Construction
Fourth Quarter '07 – Site Enclosure for Winter and Continued Foundation Work