In October 1992, the DOE ordered the facility to be placed in a standby mode and scheduled de-fueling, radioactive materials removal, and building demolition for 2009. All safeguards commensurate with nuclear security and reactor safety had to be maintained throughout this period. With the events of September 11, 2001 and the resultant need for increased security, DOE included TSF and TSR-II on its list of facilities targeted for accelerated closure. In the first quarter of 2003, DOE Assistant Secretary for Environmental Management Jessie Roberson directed that the reactor be de-fueled, the fuel dispositioned to the DOE Savannah River Site, and any radioactive source materials removed in preparation for controlled demolition. With these actions taken, the facility could be downgraded to a “radiological” facility, yielding an estimated $1.95 million in savings between 2004 and its original fuel removal date of 2009.

Duratek brought in experienced and specially trained personnel from Master-Lee Energy Products (MLEP), with known capabilities in the commercial nuclear industry for refueling and radiological decontamination. A full-scale mockup of the reactor was constructed from original design drawings, hand-drawn 25 years ago, in the ORNL archives. Thirty percent of the fuel assemblies were fabricated to demonstrate safe fuel handling and movement techniques.

During the initial characterization and radiological surveys, Duratek discovered that sludge and debris had accumulated in the bottom of the reactor pool, and analysis indicated elevated levels of PCB and lead contamination. Further investigation showed that the concrete pool floors, walls, and steel support structures were painted with a surface coating known as zinc chromate paint that was developed in the early 1960s and contained various components that were not regulated at that time, such as chromium, lead, and PCBs. The pool was coated with a liner developed by MLEP (InstaCote®) to make the pool viable through the full duration of mockup training and reactor de-fueling activities. Before application of the liner, the existing coating was stripped using a 40,000-psi hydro-blaster.

Duratek designed an innovative dewatering system to extract the PCB and lead contaminants, leaving solids in the dewatering box. Additional carbon filtration was used to perform the final contaminant stripping from the water. The filtered water was tested and met the Waste Acceptance Criteria for PCB and lead. These liquids were trucked to the Duratek-operated ORNL Liquid Waste Processing System for further processing.

PCB and lead contaminants, along with the power of the hydro-blast equipment, required the use of waterproof or resilient personal protective equipment (PPE) and full-face supplied air. Heat indexes between 85º and 100ºF were frequently encountered, which mandated constant monitoring of vital signs of all personnel for heat stress. Work durations were limited to 15 minutes in ambient temperatures between 85º and 95ºF, followed by monitoring of vital signs, core body temperature logging, and a minimum one-hour rest and fluids rehydration period. Severe ambient temperatures above 95ºF resulted in the reduction or suspension of heavy work activities until conditions improved.

By successfully completing this important project for DOE, Duratek reduced the radioactive facility “footprint” at the Laboratory, resulting in a net savings of about $2 million in maintenance and security costs. The facility has been placed in a safe shutdown condition awaiting ultimate demolition of the buildings and towers in 2009.

Said Bob Sleeman of DOE’s Oak Ridge Operations Office (ORO), “These cost savings will be used for other high-priority projects in our accelerated cleanup of the Oak Ridge Reservation.” Added John Gadd, Project Manager for ORO prime contractor Bechtel Jacobs Company, “[The Duratek project team] made this project the benchmark for safe, successful project execution [and] contributed to its success by taking ownership for tasks and performing them safely and professionally. The project epitomized [the DOE Integrated Safety Management System] in action with [Duratek’s] input to the work, before and after execution.”