Nuclear NDT development at Harwell

A review is presented of nuclear-oriented NDT development work at Harwell, illustrating the synergy between this and the National NDT Centre's non-nuclear programme. Most of the work in recent years has been concerned with automated ultrasonic inspection techniques for the proposed Sizewell 'B' PWR pressure vessel, and Harwell's part has been to develop the time-of-flight diffraction method (TOFD) as a stand-alone technique for defect detection and sizing. Currently the main item in the nuclear programme is the improvement of ultrasonic inspection capability for austenitic castings and welds, for both PWR and fast reactor applications, by means of advanced scanning and signal processing techniques. The development of automatic defect classification techniques makes use of the image analysis resources at Harwell. (author)