In-situ tube burst testing and high-temperature deformation behavior of candidate materials for accident tolerant fuel cladding

Abstract

One of the most essential properties of accident tolerant fuel (ATF) for maintaining structural integrity during a loss-of-coolant accident (LOCA) is high resistance of the cladding to plastic deformation and burst failure, since the deformation and burst behavior governs the cooling efficiency of flow channels and the process of fission product release. To simulate and evaluate the deformation and burst process of thin-walled cladding, an in-situ testing and evaluation method has been developed on the basis of visual imaging and image analysis techniques. The method uses a specialized optics system consisting of a high-resolution video camera, a light filtering unit, and monochromatic light sources. The in-situ testing is performed using a 50 mm long pressurized thin-walled tubular specimen set in a programmable furnace. As the first application, ten (10) candidate cladding materials for ATF, i.e., five FeCrAl alloys and five nanostructured steels, were tested using the newly developed method, and the timedependent images were analyzed to produce detailed deformation and burst data such as true hoop stress, strain (creep) rate, and failure stress. Relatively soft FeCrAl alloys deformed and burst below 800°C, while negligible strain rates were measured for higher strength alloys.

Optimized properties on base metal and thin-walled tube of generation II ATF FeCrAl

“…Twelve (12) new candidate cladding materials have been acquired and tested in this investigation as listed in Table 4. In addition to the materials from the original work scope (see Chapters 2 and 3), few more potentially useful alloys were included in the test program.…”

“…In parallel to the ATF FeCrAl alloy development, the evaluation of tube burst characteristics was also conducted by using pre-pressurized FeCrAl tubes and in situ tube deformation observation during continuous heating. The development of evaluation methodology was summarized in the previous report [11,12]. It was concluded that the rupture temperatures of Phase I alloys at a given hoop stress were comparable to commercial zirconium alloys.…”

Handbook of the Materials Properties of FeCrAl Alloys For Nuclear Power Production Applications

“…Where appropriate, recommendations for applications of the data is provided and current knowledge gaps are identified. [61].…”

Materials selection for nuclear applications: Challenges and opportunities

“…Four systems have been studied: 1) silicon-carbide (SiC)-based composites [16][17][18], 2) iron-chromium-aluminum (Fe-Cr-Al) alloys [19,[21][22][23], 3) coated zirconium [24], and 4) molybdenum (Mo) [25]. These four systems were chosen as balanced compromise among the application's requirements.…”