Fuel channel inspection - using the AECL fuel channel inspection system

The AECL Fuel Channel Inspection System (AFCIS) is a 'wet' system capable of storing a closure plug and delivering inspection tooling into flooded channels. The first system was used in 1999, and a second one was delivered to Korea in 2001. To date, over 80 CANDU fuel channels have been inspected with this equipment - in six different CANDU-6 reactors. Three types of inspection head tooling have been delivered by AFCIS: The primary inspection head is capable of satisfying current and anticipated future requirements of Standard CAN/CSA-N285.4. It includes: a self-powered rotating inspection module that provides rapid inspection of 100% of the pressure tube volume, a direct pressure-to-calandria tube gap measurement capability, eddy current volumetric inspection to complement six-direction ultrasonic measurements. A re-inspection head is available to help characterize significant internal pressure tube flaws. It includes capabilities for video examination in flooded channels and flaw replication. A multi-head sampling tool permits the collection of micro-samples for deuterium/hydrogen analysis from four different axial locations in a pressure tube, during a single channel entry. It does not require any interface to station fuel handling equipment. In addition to the inspection heads, AFCIS consists of a slightly modified Advanced Delivery Machine (ADM), originally developed for delivering Spacer Location and Repositioning (SLAR) tools, and a state-of-the-art Data Acquisition System (DAS). The ADM includes a calibration tube that enables calibration of inspection functions immediately before and after each channel entry. The DAS hardware is modular to simplify maintenance and minimize coping with instrument and computer obsolescence problems in the future. DAS software is (Microsoft) Windows-based. This paper describes the AFCIS equipment and its capabilities. System performance is illustrated by typical inspection results. (author)