Low Cost, High Efficiency Krypton Capture Technology

There is a need for more efficient and lower cost systems that can capture and store the 85Kr produced in nuclear fuel cycle systems. Even though a number of technologies have been proposed, the cost of implementing these technologies in shielded radioactive environments with the associated safety systems is very high. Hence there is a need for advanced materials and processes to reduce the cost of 85Kr management from reprocessing plants and molten salt reactors. In this SBIR project TDA Research is developing an efficient near-ambient temperature krypton capture process for nuclear fuel reprocessing and molten salt reactor plants. TDA’s process uses a radiation resistant advanced physical sorbent to capture Kr in an integrated off-gas treatment system, at a lower cost than current systems. Our specific Phase I objective was to complete the laboratory scale proof-of-concept demonstration of the Kr capture process from simulated off-gases representative of nuclear fuel reprocessing plants. In Phase I, we optimized the operation of the new sorbent to best match the operating conditions of the off-gas treatment system. We optimized the Kr capture process to minimize the capital, operating and energy requirements for the overall off-gas treatment process. Finally, a detailed process design and system analysis were completed for near-ambient temperature Kr capture process that can be integrated with the balance of the off-gas treatment system; our process provides cost reductions of about 60% over the current state-of-the-art technologies such as cryogenic distillation and sub-ambient adsorption using silver zeolites. In Phase II, we will further optimize and scale-up the production of the radiation tolerant sorbent and complete a detailed bench-scale evaluation with trace ppm levels of noble gases (Xe and Kr). We will first validate the sorbent’s post-irradiation performance. We will use the most radiation tolerant sorbent formulation in the Kr capture process and complete a detailed design to build and test a sub-scale prototype unit. We will then carry out a proof-of-concept demonstration of the sub-scale prototype using simulated nuclear waste reprocessing facility exhaust. Finally, we will complete the detailed design of the Kr capture system for a full-scale nuclear waste reprocessing facility. There is a large potential commercial market for the sorbents and processes developed here, for use in nuclear fuel reprocessing facilities and future molten salt reactor based nuclear power plants, to reduce emissions of the radionuclides (radioactive gases). There is also a market for the sorbents and process in the commercial production of noble gases and in the monitoring of radioactive Xenon levels in atmosphere as part of nuclear non-proliferation monitoring.