Many of them will remain standing for years to come due to the large amount of work required to demolish them. The Oak Ridge Office of Environmental Management (OREM) is tasked with keeping them safe until then.
That sometimes requires improvements to maintain safe conditions and prepare the structures for deactivation. A precursor to demolition, deactivation is the process of placing an excess facility into a stable condition to minimize existing risks and protect workers, the public and the environment.
The Molten Salt Reactor Experiment (MSRE) facility at ORNL is a prime example of a structure requiring such improvements, and OREM cleanup contractor UCOR is taking several steps to address associated challenges.
Upgrades to the high bay — where the critical systems reside — are underway, and employees have improved infrastructure through work such as installing electrical upgrades and an emergency generator.
For the first time in 26 years, workers recently conducted sampling at the reactor. They measured the amount of fluorine generated in gases produced as byproducts from salt tanks. Plans had long been underway to sample the gases but concerns over brittle pipes and safe access presented challenges difficult to resolve. Following installation of new robust piping and enhanced safety features, the team was able to safely perform the work.
OREM and UCOR’s plans for the reactor’s eventual deactivation and demolition are progressing.
Crews have prepared for that work by removing components in the facility. That project led to a downgraded radiological level in a work area there.
They also installed a new portable maintenance shield that enables workers to use long-reach tools, reducing risk of injury and radiological exposure. That system is scheduled to go operational next year. It replaces the current gas removal system, minimizes failure points in the facility, and reduces hazards and required maintenance and oversight.
A study is underway to develop cleanup alternatives for MSRE. The study evaluates alternatives that incorporate one or more basic types of remedial actions, including grouting and removal of contaminated equipment. MSRE came to prominence when it achieved criticality for the first time in June 1965. That achievement led to a four-year campaign of research and development to prove the viability, safety and efficiency of molten salt reactors