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Colin Judge: Testing structural materials in Idaho’s newest hot cell facility
Idaho National Laboratory’s newest facility—the Sample Preparation Laboratory (SPL)—sits across the road from the Hot Fuel Examination Facility (HFEF), which started operating in 1975. SPL will host the first new hot cells at INL’s Materials and Fuels Complex (MFC) in 50 years, giving INL researchers and partners new flexibility to test the structural properties of irradiated materials fresh from the Advanced Test Reactor (ATR) or from a partner’s facility.
Materials meant to withstand extreme conditions in fission or fusion power plants must be tested under similar conditions and pushed past their breaking points so performance and limitations can be understood and improved. Once irradiated, materials samples can be cut down to size in SPL and packaged for testing in other facilities at INL or other national laboratories, commercial labs, or universities. But they can also be subjected to extreme thermal or corrosive conditions and mechanical testing right in SPL, explains Colin Judge, who, as INL’s division director for nuclear materials performance, oversees SPL and other facilities at the MFC.
SPL won’t go “hot” until January 2026, but Judge spoke with NN staff writer Susan Gallier about its capabilities as his team was moving instruments into the new facility.
Janez Perko, Eef Weetjens
Nuclear Technology | Volume 174 | Number 3 | June 2011 | Pages 401-410
Technical Paper | TOUGH2 Symposium / Radioactive Waste Management and Disposal | doi.org/10.13182/NT11-A11748
Articles are hosted by Taylor and Francis Online.
Assessment of gas generation and transport is inevitable for evaluation of the safety of nuclear waste disposal in deep geological formations. The long-term safety of the geological disposal facility is guaranteed by several engineered and natural barriers. The reference disposal concept in Belgium consists of a concrete-based repository situated in Boom Clay, which is a low-permeability plastic clay. Hence, the mobility of gas and liquid within these barriers is very small and may lead, in combination with increased temperatures due to decay heat of the waste, to pressure buildup and the potential structural failure of barriers. The focus of this study is on coupling two-phase water and gas flow with a heat source, originating from the heat dissipating waste. The main gas production mechanism within the considered geological repository system is (anaerobic) corrosion of metal barriers, generating H2 gas. The corrosion process itself and therefore the intensity of the gas source is temperature dependent. Furthermore, the heat source is time dependent due to the decaying nature of the radioactive material. This property, in turn, makes the gas generation rate time dependent as well. The cases presented in this work couple variable gas generation with a time-variable heat source and are modeled with TOUGH2. Because of large uncertainties associated with the yet-uncharacterized engineered materials (e.g., concrete), two bounding material permeabilities with a span of two orders of magnitude are chosen for comparison. Results demonstrate that the peak pressures for the isothermal and nonisothermal cases do not differ considerably in the case of high-permeability buffer material. On the contrary, the peak pressures differ considerably for low-permeability material, which hinders the flow of water induced by thermal expansion of water with temperature increase. This peak pressure is not related to the gas-generation process and occurs a little earlier than the gas pressure peak, which is in this case comparable to the high-permeability case. Overall, this near-field analysis showed that the effect of pressure increase remains relatively localized and should not affect the structural integrity of the host formation. The behavior of the system is additionally refined by the implementation of temperature-dependent hydrogen solubility within the numerical code, which slightly modifies the transition to H2 gas phase.
