Abstract: The spacer envelope measurement system includes a generally U-shaped fixture having support plates extensible into positions overlying the spacer for supporting the fixture from the spacer. Extensible heads are carried by the fixture for engaging the spacer, followed by the heads of measurement gauges whereby, upon extending the heads into clamping engagement with the spacer along opposite sides thereof, the measurement gauges accurately determine the lateral dimensions of the irradiated spacer. A spacer bar clamp member is pivotal between positions opening the fixture opposite the base leg of the U-shaped fixture, enabling the bundle to reside within the U-shaped opening and a second position closing the opening for aligning the fixture and the bundle. The measurements are taken under water in a nuclear fuel service pool.

Abstract: The spring force measurement system includes a draw rod standard, an insertion tube and an extension tube, together with a cable received through the tubes connecting the standard and a load cell, in turn connected by the cable to a winch. The draw rod standard is located in the fuel bundle below the spacer having a spring whose spring force is to be measured. By drawing the standard through the spacer cell, the spring force is computed using the measured tension in the connecting cable as the standard is withdrawn and the known values of the coefficient of friction between the spacer spring projection and the draw rod standard and the combined weight of the cable and draw rod standard. The measuring process is repeated for next higher spacers.