A pilot plant for tritium removal from tritiated water is in operation at Institute for Cryogenics and Isotopes Technologies, Ramnicu (Rm.) Valcea, and it is based on catalytic isotopic exchange between tritiated water and hydrogen/deuterium followed by cryogenic distillation (CD) aiming to recover tritium. A CD cascade consisting of four distillation columns is in operation and significant effort is required in various batch mode operations for achieving high-tritium concentration. Development of a thermal cycling absorption process (TCAP) began in the Experimental Pilot Plant at Rm. Valcea in order to complement the CD cascade, which has the main drawback the high-tritium holdup. With TCAP implementation, the drawback may be overcome. A mathematical model will be developed for the process and provisions will be considered in the view of scaling up for large throughputs having an ultimate goal the implementation in the Tritium Removal Facility at Nuclear Power Plant Cernavoda. The developments are also relevant for the fusion activities, such as International Thermonuclear Experimental Reactor and Demonstration Power Station.

We report on the experimental investigation of the magnetoresistance behavior of cryogenic temperature sensors based on single-walled carbon nanotubes (SWCNTs) as a function of temperature and magnetic flux density; one sensor was based on layers/networks of unsorted SWCNT of various chiralities, and one on SWCNTs layers of (7,6) chirality. SWCNT-based sensors were fabricated according to a straightforward method, and the electrical properties were measured from room temperature down to 2 K using a Quantum Design Physical Property Measurement System (PPMS). The two sensors present different magneto-transport behavior, with the magnetoresistance dependence on the magnetic field being a sum of two terms with positive and negative contributions respectively. The expression for magnetoresistance is derived together with its experimentally determined coefficients. For both sensors, the electrical resistance dependence on temperature below the 80 K mark is explained by Mott’s law of variable-range hopping. The experimentally obtained hopping dimension d values of 2.67 for the system comprised of purified (7,6) chirality SWCNTs and 2.97 for the system comprised of unsorted SWCNTs are in good agreement with the theory. As a second step, the magnetic field was kept constant and at different values, while the temperature was scanned over the investigated domain.