Innovative non-destructive tool for CANDU fuel channel pressure tube evaluation.

Kinectrics provides turnkey engineering and fabrication capabilities for advanced Non-Destructive Evaluation (NDE) Tools.

CWEST* Tool Description

The Circumferential Wet Scrape Tool (CWEST)* System collects up to 8 pressure tube scrape samples from a “wet” CANDU fuel channel in a single entry, at both the near and far rolled joint regions as well as the body-of-tube.

The CWEST tool head is delivered to a precise axial location using existing delivery machines. On-board ultrasonic (UT) sensors verify the sampling location. Hydraulic clamps are then actuated to centre the tool in the pressure tube and resist cutting torque forces, while a hydraulic cutter actuator mechanism advances cutter cartridges radially outward.

The CWEST non-destructive evaluation tool employs a rotating multi-cutter head equipped with three pairs of cutters. The scrape sampling sequence involves two cuts—an oxide cut followed by a sample cut. During the cutting process, light water is injected around the cutters to prevent deuterium contamination of the sample. The outer surface of the cutter cartridge rides against the pressure tube during the cut operation, as a means of limiting cut depth.

Pressure tube samples are collected in an 8-compartment Sample Tray, which is located axially within the centre of the tool head. Upon completion of sampling within the fuel channel, the circumferential wet scrape tool head is removed by the delivery machine and moved to a staging area where the Sample Tray is ejected using long-reach manual tools.

The scrape samples are visually inspected using a video system as the Sample Tray is inserted into a shielded Transfer Flask. The CWEST tool head is recharged with an empty Sample Tray and is then delivered to the next fuel channel for scrape sampling.

Kinectrics offers a wide range of CWEST products and services, from full systems to turnkey field deployment.

Key Features

  • Capability for near and far rolled joint sampling as well as body of tube
  • Up to 8 scrape samples in a single fuel channel entry
  • Operates in a wet channel environment
  • Deployable with BRIMS or UDM or delivery systems
  • Integrated sample tray and transfer flask to minimize operator dose
  • Fail-safe cutter actuation and retraction
  • Axial datum verification with UT probes
  • Optimized scrape sample profile for improved analysis accuracy
  • Light water injection to prevent deuterium uptake by scrape sample
  • Designed to CSA N286.2 and built to CSA Z299.2 Standards
  • Software qualified to COG-95-179, Cat III


  • Reduction in Outage sampling campaign durations, reducing critical path by 50%
  • Eliminates the use of ice plugs and removes a nuclear safety risk
  • Reduces dose from 2 to 0.5 REM/channel (satisfying the principles of ALARA)
  • Reduced risk of human performance errors
  • Lower maintenance and operation costs
  • Simplifies the overall operation, as only one tool is required, Previously two separate tools were required to acquire Rolled joints and Body of Tube samples.

* not available for sale outside of Canada until after November 30, 2027​