Challenge
This job required segmenting and removing for burial over 1500 tons of highly activated concrete surrounding the previously-removed reactor vessel. To access the activated concrete, the bio-shield overburden concrete had to be removed. This concrete was cut and removed in 50 pieces, each weighing approximately 40,000 lbs.
To minimize burial costs the activated concrete surrounding the reactor cavity was cut into individual concrete blocks, leaving the balance of the non-activated mass concrete intact. In order to access the activated concrete cuts, we core drilled 8 horizontal holes 16’ long at intersecting 45 degree angels, and drilled vertical holes at the intersection points.
Using brackets specially designed in our Machine Shop, vertical cuts were made by placing pulleys inside the reactor cavity and down the vertical intersecting holes. Cutting was done from the top down in a plunge cut or band saw fashion. In all, 4 rows of 8 blocks were cut and removed, each weighing approximately 40,000 lbs.
In addition, 8 ion guide tubes 6” in diameter, 8’ deep and wrapped in 2” of lead were overdrilled with 18” diameter diamond core bits 10’ long, and removed as single units for packaging and burial.
The project was completed on schedule with no lost time, injuries or first aid cases.