A demonstration section of Zircaloy fuel-element sheathing for the 19-element fuel bundles used initially at NPD (and later at Douglas Point Nuclear Generating Station). Initially, NPD used 7-element fuel but later was converted to use 19- element bundles that had a higher power rating. The tube shown is 52 cm in length, about 2.5 cm longer than used in an actual assembly.
The lower photo and caption taken from “A Description of NPD” – an illustrated talk presented at the Seventh AECL Symposium on Atomic Energy, Chalk River, September 18, 1961 by J. L. Olsen of CGE, describes the process of assembling a 7-element bundle and gives details of final sizes for both types of bundles.
