Thirty reinforced concrete columns were suspected of freezing when this structure was originally built in 1969. Although the columns were not in a critical area of the building at the time of original construction, a later expansion of the reactor building put new emphasis on their structural integrity. CTLGroup was engaged to do nondestructive pulse-velocity testing, in combination with testing of cores extracted from the columns, to determine which columns were sufficiently durable and which ones required removal and replacement.
In a separate investigation, CTLGroup conducted an independent review of cracks in safety-related containment vessels at Idaho Falls. This investigation was commissioned at the insistence of the NRC. Cracks had developed and the long-term durability of the vessels was at issue.