Properties of zirconium alloys and their applications in light water reactors (LWRs) - Materials' Ageing and Degradation in Light Water Reactors - page 116

(a) Results of ring tensile tests

50

As-received
200 ppm
400 ppm
500-650 ppm
650-800 ppm
800-950 ppm
1000-1300 ppm
1300-1450 ppm
>1550 ppm

PWR 17×17

Hydrogen
concentration

40

30

20

10

0

0 100 200 300 400

Temperature (°C)

Cladding

(b)

100 m

μ

￿ ￿ ￿ ￿ ￿ ￿

4.28 (a) Hydride rim and associated cracks in cladding failed in a room
temperature burst test (Nagase & Fuketa, 2005). (b) Temperature effect
on cladding ductility (Fuketa et al ., 2003).

temperature but not at 300°C (573K). All specimens are unirradiated
and are tested with applied stress normal to the hydride platelet. For
similar materials having the applied stress parallel to the hydride plate-
let, no hydride effect is seen (Yagnik et al ., 2004 ).

Hydride orientation

Careful metallographic examinations show hydrides to be short, thin plate-
lets that have precipitated along a variety of crystallographic planes, very