  Miles of contaminated pipe must be measured, foot by foot, as part of the
decommissioning effort at deactivated gaseous diffusion enrichment facilities.
The current method requires cutting away asbestos-lined thermal enclosures and
performing repeated, elevated operations to manually measure pipe from the
outside. The RadPiper robot, part of the Pipe Crawling Activity Measurement
System (PCAMS) developed by Carnegie Mellon University and commissioned for use
at the DOE Portsmouth Gaseous Diffusion Enrichment Facility, automatically
measures U-235 in pipes from the inside. This improves certainty, increases
safety, and greatly reduces measurement time. The heart of the RadPiper robot
is a sodium iodide scintillation detector in an innovative disc-collimated
assembly. By measuring from inside pipes, the robot significantly increases its
count rate relative to external through-pipe measurements. The robot also
provides imagery, models interior pipe geometry, and precisely measures
distance in order to localize radiation measurements. Data collected by this
system provides insight into pipe interiors that is simply not possible from
exterior measurements, all while keeping operators safer. This paper describes
the technical details of the PCAMS RadPiper robot. Key features for this robot
include precision distance measurement, in-pipe obstacle detection, ability to
transform for two pipe sizes, and robustness in autonomous operation. Test
results demonstrating the robot's functionality are presented, including
deployment tolerance tests, safeguarding tests, and localization tests.
Integrated robot tests are also shown.
