Nuclear problems require heavy-duty solutions
A nuclear reactor vessel generates a large amount of power, but periodically requires inspection and re-fueling. This necessary maintenance can only be performed while the reactor is powered down. Time is critical in this case, the longer the reactor is powered down, the less overall electricity produced. To re-fuel the reactor, a maintenance crew needs to unbolt the vessel by removing all 54 studs that secure the head. Each individual screw weighs upwards of 600-700 lb, and calls for an overhead crane to lift. Traditionally, these studs would be placed in square racks that constantly needed re-positioning under the overhead crane for successful loading. This made the time required for unloading the studs to rise excessively and caused a potential risk factor for the maintenance crew.
The PBC Linear Solution
To solve the problem a company called Quality Engineered Products turned to Hevi-Rail®, the cam roller technology with a strong reputation for long-lasting linear motion in the toughest of environments. Utilizing Hevi-Rail, Quality Engineered Products designed a rotating “lazy susan” system for nuclear reactor vessel stud racks. About 42" in diameter, the new circular stud rack could be hand-rotated to facilitate easy loading from the crane. Hevi-Rail® works to promote an even dispersion of loads and forces being acted upon it. Machined into a circular rail, the hardened steel rail and bearings had no problem tolerating the total weight of 9 reactor studs! The Hevi-Rail bearing’s innovative linear and axial bearings also allowed for a smooth rotating motion that immediately pleased the maintenance crew due to the new-found ease in their job.
Results / ROI
Thanks to the ingenuity of Quality Engineered Products and the long-lasting heavy-duty performance of Hevi-Rail, the maintenance crew no longer needed to waste time re-positioning the stud rack under the crane in order to proceed with the loading process. The time saved is doubled as the entire process is performed in reverse during reactor re-assembly after refueling.