Developments in CANDU MOX Fuel Fabrication

Abstract

As a strategic component of its advanced fuel cycle program, AECL continues to implement the MOX fuel development program involving MOX fuel fabrication and characterization, irradiation testing, post-irradiation examination, as well as reactor physics and fuel management studies. AECL performs its MOX fuel fabrication activities in the Recycle Fuel Fabrication Laboratories (RFFL) located at the Chalk River site. The RFFL facility is designed to handle alpha-active fuel material and produce experimental quantities of MOX fuel for reactor physics tests and demonstration irradiations. From 1979 to 1988, several fabrication campaigns were conducted in the RFFL, producing close to two tonnes of MOX fuel with various compositions. RFFL operations were suspended from 1989 until 1994, at which time the facility was needed to fabricate MOX fuel for physics testing in the ZED-2 reactor. After completion of an extensive rehabilitation and recommissioning of the RFFL, MOX operations were resumed in the facility in August 1996. An up-to-date description of the facility, including the fabrication process and the associated equipment, as well as the upgraded safety systems and laboratory services, is presented. Since the resumption of MOX operations in the RFFL in 1996, several MOX fuel fabrication campaigns have been conducted in the facility; increasing the total amount of MOX fuel fabricated to-date in the RFFL to about three tonnes of MOX fuel. An overview of each of the fabrication campaigns is discussed. The fabrication processes used to manufacture the fuel from the starting powders to the finished elements are summarized. The various fabrication campaigns involved different technical requirements mainly due to the different intended uses of the fuel, i.e., test irradiations in NRU, physics tests in ZED-2, and dissolution experiments in support of the waste management program. Fabrication data including production throughputs and typical inspection results are discussed, including characterization techniques that were developed during the campaigns.