Abstract
A steam generator at Three Mile Island is about 73 feet long, 12.5 feet across and 510 tons, and replacing one means cutting it out and welding a new one in. The narrow-groove weld process that makes that economic – far less weld time, so far less plant downtime – is also what forces the measurement: nozzle weld fit-up tolerances of zero to minus forty thousandths of an inch on gap, and sixty thousandths on axis offset. Charlie Ellison, a metrology technician who did the work, explains what precision measurement is for on a job like this and how it was done.
Cite this paper
Charlie Ellison. AREVA. Presented at the Coordinate Metrology Systems Conference 2010, Reno, Nevada, July 12-16, 2010. Coordinate Metrology Society, reference CMS-2010-008.