NDTnet 1998 Aug, Vol.3 No.8

Abstract

"ENUSA NDT Integrated Applications To Nuclear Fuel Rod Manufacturing" exhibits the experience and technology used in ENUSA on Non Destructive Testing (NDT) to inspect and assure fuel rods quality.Fuel rods manufacturing are completed with a strict inspection program with NDT testing made at 100 per cent shown in Fig. 1.

Fuel tubes certified by the supplier are labelled and are checked with an Eddy Current probe to assure correct use of fuel tubing before first welding. First welds are Ultrasonic tested to control weld integrity (pores, thickness, lack of penetration, cracks, ...) and Radiograph inspected to control absence of tungsten inclusions and significant welding defects. Finally Dimensional and Visual inspection is performed to control surface aspects. Accepted fuel tubes are loaded with UO₂ or UO₂ +Gd₂O₃ pellets that have been 100 % diameter checked with a Laser Micrometer and then 100 % Visually inspected for surface imperfections. Afterwards, fuel rods are welded (final and seal welds) and go to fuel rods inspections where they are inspected by Ultrasonic and Radiograph as in first weld. Seal welds are controlled by radiograph when seal penetration is checked. Later Leak Test is made to control fuel rod hermeticity. To control fuel rods internal components two equipments are used. The Active Gamma Scanner, to inspect UO₂ fuel rods, with a Californium source and the Passive Gamma Scanner with a Gd Detector to inspect UO₂ + Gd₂O₃ fuel rods. With these equipments we control rod, plenum and zone stacks length; gaps, average contents in fissile material and Gd2O3; and deviant pellets on enrichment and gadolinium content. Finally Eddy Current and Dimensional and Visual inspection is made to control surface defects and scratches in fuel rods.

Fuel Rods Non Destructive Testing is one part of ENUSA commitment for quality and tray to use the best combination of NDT methods to guarantee Fuel rods behavior during operation.

Fig.1 Fuel rods inspection process

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

Publication Contact:
7th ECNDT, Park Alle 345, DK-2605 Broendby, Denmark, Fax: +45 46 26 70 11, Email: 101373.3414@compuserve.com