Characteristics of Hydride Precipitation and Reorientation in Spent-Fuel Cladding.

Chung, H. M. ; Strain, R. V. ; Billone, M. C.

Technical Information Center Oak Ridge Tennessee

关键词: Spent fuel elements;    High-level radioactive wastes;    Thermodynamics;    Characteristics;    Metallurgy;   

RP-ID  :  DE2001768617

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

The morphology, number density, orientation, distribution, and crystallographic aspects of Zr hydrides in Zircaloy fuel cladding play important roles in fuel performance during all phases before and after discharge from the reactor, i.e., during normal operation, transient and accident situations in the reactor, temporary storage in a dry cask, and permanent storage in a waste repository. In the past, partly because of experimental difficulties, hydriding behavior in irradiated fuel cladding has been investigated mostly by optical microscopy (OM). In the present study, fundamental metallurgical and crystallographic characteristics of hydride precipitation and reorientation were investigated on the microscopic level by combined techniques of OM and transmission electron and scanning electron microscopy (TEM and SEM) of spent-fuel claddings discharged from several boiling and pressurized water reactors (BWRS and PWRS). Defueled sections of standard and Zr-lined Zircaloy-2 fuel claddings, irradiated to fluences of =3.3 x 1021 n cm-Q and =9.2 x 1021 n cm-Q (E > 1 MeV), respectively, were obtained from spent fuel rods discharged from two BWRS.