Characterization of deposits on inside surfaces of lwr cladding

Iodine stress corrosion cracking of Zircaloy reactor cladding : Iodine chemistry (a review)

A phase-field model of fracture with frictionless contact and random fracture properties: Application to thin-film fracture and soil desiccation

The inhomogeneous deformation behaviour of neutron irradiated Zircaloy-2

The control of nuclear power plants covers a wide range of problems and requires understanding of the many interactions and objectives involved in obtaining operational flexibility and safety. Improved solutions must be developed as nuclear plants will increasingly require operation in a load-following mode. The authors discuss applications, problems, trends, and their perspectives. Areas where researchers developing control methods can contribute toward improved control design are outlined.

Control of nuclear power plants

Results of three related projects undertaken to elucidate the mechanism of Zircaloy cladding fracture caused by pellet-cladding interaction (PCI) in water reactor fuel rods are described. A detaile...

On the Pellet-Cladding Interaction Phenomenon

Results of three related projects undertaken to elucidate the mechanism of Zircaloy cladding fracture caused by pellet-cladding interaction (PCI) in water reactor fuel rods are described. A detailed microscopic examination of incipient i.d. cladding defects in some Maine Yankee Core I fuel rods determined that these defects and clad penetrations in related rods were caused by a PCI mechanism that was promoted by chemical species, i.e., stress corrosion cracking (SCC). A consideration of the internal fuel rod chemistry and fission product distribution indicates that one potential agent for SCC of Zircaloy cladding is iodine released from CsI deposited on the i.d. surface and another is cadmium metal. A simple analytical model of crack propagation in Zircaloy cladding based on linear elastic fracture mechanics indicates two possible rate-controlling events, depending on the value of the stress intensification K/sub ISCC/. If K/sub ISCC/ for irradiated Zircaloy is very low, i.e., on the order of 2.2 to 3.3 MN/m/sup 3///sup 2/ (2 to 3 ksi ..sqrt..in.), crack growth is relatively easy, and hence the rate-limiting step must be the nucleation of sharp cracks in the cladding i.d. surface. However, if K/sub ISCC/ for irradiated Zircaloy is relatively large, i.e., greater than or equalmore » to 11 MN/m/sup 3///sup 2/ (10 ksi ..sqrt..in.), a high interfacial friction coefficient, for example, caused by fuel-clad bonding, would be required to propagate the i.d. defect.« less

N. Fuhrman

Papers

On the Pellet-Cladding Interaction Phenomenon

Pellet-cladding interaction phenomenon