BEHAVIOR OF IODINE IN ZIRCALOY CAPSULES.

The behavior of iodine in Zircaloy capsules under conditions similar to those on the inner cladding sur face of a fuel rod in water-cooled reactors has been investigated.The thermodynamic equilibrium in the system has been attained over the following reaction chain: Chemisorption of the iodine, on the metal sur face, reaction of the chemisorbed iodine with the metal to form Zrl4, chemisorption of the Zrl4 on the metal surface, and reaction of the chemisorbed Zrl4 with the metal to form lower iodides.For equilibrium con ditions the experimental results do not agree with thermodynamic calculations.The results can be ex plained by assuming different intermediate phases of zirconium iodides at different temperatures.1.