Single-Specimen Uniaxial-Stress Thermal Creep Facility

CNL’s Single-Specimen Uniaxial-Stress Thermal Creep Facility (SSUSTCF) is located at the Chalk River Laboratories. The SSUSTCF or Creep Facility was designed to support deformation/creep studies on reactor materials such as zirconium and inconel alloys, using irradiated and unirradiated small-scale material specimens. The development of predictive equations for the maintenance and design of CANDU® fuel channel components is enabled through this facility.

The SSUSTCF has four Bellows Creep Testing Units with data acquisition that provide a sealed gas and elevated-temperature environment that ranges from 250°C to 350°C. The Bellows Creep Testing Units also has control ability for pneumatic load application. The SSUSTCF has two Gravity Creep Testing Units with data acquisition, which also have elevated-temperature controls reaching up to 350°C.

There are many facilities within CNL which work in conjunction with the SSUSTCF. The Laser Welder Facility with pressurizing capability is used to pressurize capsule specimens to achieve a biaxial-stress state on the material. Before testing materials in the SSUSTCF, specimens can be irradiated at specific temperatures and neutron fluxes using irradiation facilities within the NRU reactor, including Fast-Neutron rods, and U-1 and U-2 loops.

The SSUSTCF also works in conjunction with the Analytical Chemistry Branch, which has performed activity counting of irradiated iron flux monitors for industry, enabling the quantification of fast-neutron flux measurement, which is a critical parameter in irradiation creep studies. The Electron Microscopy Facilities enables microstructural characterization of unirradiated and irradiated materials tested in the SSUSTCF.

Recently, the facility has been used to study feeder integrity and cracking studies for the CANDU industry. The Single-Specimen Uniaxial-Stress Thermal Creep Facility would welcome further partnerships with universities and industry.