Third-Generation Test Facility for Strain-Controlled EAF

Meeting the stringent requirements of strain-controlled testing standard ASTM E606 in simulated reactor coolant is challenging. Two earlier generations of bellows-based testing devices have proven direct strain control to be possible in deoxygenated PWR water at up to 350 °C and 150 bar. To meet future research demands, a third-generation device has been designed and is in the final phase of commissioning. The first-generation miniature bellows loading device was designed as a prototype to prove the applicability of the technology for strain-controlled fatigue testing. All standard criteria for valid experimental results were not aimed to be met with the prototype, but the technology was successfully demonstrated. This encouraged later development of the second-generation “FaBello” devices. FaBello was designed to comply, as far as possible, with ASTM E606. However, pneumatic load train and certain technology-related boundary conditions placed limits on the range of controllable test parameters. With the emphasis on overcoming past limitations without straying from standard requirements, the third-generation “FaVite” devices were designed. Through the various improvements FaVite can be used to generate quantitative experimental results to assist in filling multiple environmentally-assisted fatigue knowledge gaps, as outlined in an EPRI report. This paper gives a technical overview of the main challenges in conducting valid LCF experiments in simulated reactor coolant environment. Some proven solutions are introduced as well.