Extraction of Tritium from ceramic breeder material

Progress in Nuclear Energy, 2014

Fusion Technology, 1988

Nuclear Fusion

The experimental qualification of the tritium extraction unit (TEU) from the LiPb eutectic alloy (15.7 at. % Li), the breeder material of the water-cooled lithium–lead breeding blanket concept, is one of the fundamental items for the demonstration of tritium balance sustainability for ITER and DEMO fusion reactors. Several technologies have been proposed as TEU, but the selection of the reference technology can be carried out only after the experimental measurement of the tritium extraction efficiency. For this purpose, a dedicated facility, called TRIEX-II, was designed and installed at ENEA Brasimone Research Centre, Italy. The facility is able to qualify gas–liquid contactor (GLC), permeator against vacuum and liquid-vacuum contactor technologies at different temperatures, lithium–lead mass flow rates and hydrogen isotopes concentrations. In TRIEX-II, the hydrogen or deuterium, used to simulate tritium, are solubilised inside the LiPb with a dedicated saturator and are then extra...

Journal of Radioanalytical and Nuclear Chemistry, 2017

Lithium titanate and lithium aluminate, proposed as tritium breeding blanket materials in D-T fusion reactor, were analyzed by nuclear analytical techniques as a part of chemical quality control exercise. Concentrations of Li, Ti and Al were quantified by particle induced gamma-ray emission using 4 MeV proton beam from folded tandem ion accelerator facility. Trace elemental concentrations belonging to long-lived nuclides were determined by instrumental neutron activation analysis using neutron flux from Dhruva research reactor at BARC. The analysis results are useful in designing a shielded facility for tritium release studies of these irradiated breeder materials.

• Breeding benchmark experiment on LLCB TBM in ITER was performed. • Nuclear responses measured are TPR and reaction rate of 115 In(n, n) 115m In reaction. • Measured responses are compared with calculations by MCNP and FENDL 2.1 library. • TPR measurements agree with calculations in the estimated error bar. • Measured 115 In(n, n) 115m In reaction rates are underestimated by the calculations. a b s t r a c t Experiments were conducted with breeding blanket mock-up consisting of two layers of breeder material lithium titanate pebbles and three layers of pure lead as neutron multiplier. The radial dimensions of breeder, neutron multiplier and structural material layers are similar to the current design of the Indian Lead–Lithium cooled Ceramic Breeder (LLCB) blanket. The mock-up assembly was irradiated with 14 MeV neutrons from DT neutron generator. The local tritium production rates (TPR) from 6 Li and 7 Li in breeder layers were measured with the help of two different compositions of Li isotopes (60.69% 6 Li and 7.54% 6 Li) in Li 2 CO 3. Tritium production in the multiplication layers were also measured with above mentioned two types of pellets to compare the experimental tritium production with calculations. TPR from 6 Li at one location in the breeder layer was also measured by direct online measurement of tritons from 6 Li(n, t) 4 He reaction using silicon surface barrier detector and 6 Li to triton converter. Additional verification of neutron spectra (E n > 0.35 MeV) in the mock-up zones were obtained by measuring 115 In(n, n) 115m In reaction rate and comparing it with calculated values in all five layers of mock-up. All the measured nuclear responses were compared with transport calculations using code MCNP with FENDL2.1 and FENDL3.0 cross-section libraries. The average C/E ratio for tritium production in enriched Li 2 CO 3 pellets was 1.11 in first breeder zone and 1.09 in second breeder zone with uncertainty 8.3% at 1 level. The experimental details and results are discussed in this paper.

Fusion Science and Technology, 2005

1994

Fusion Technology, 1989

The next fusion experimental reactor such as ITER requires tritium breeding because of the high tritium cost and its limited availability from non-fusion sources, in addition to demonstrating breeding capability of commercial D-T reactors. A tritium fuel cycle model was developed to compute the required tritium breeding ratio(TBR) by taking into account reactor down-time. The results show that TBR should be unity to achieve 3 MW * Year/m 2 of neutron fluence in 10 years for a steady-state reactor with 600 MW fusion power and 25% system availability provided 5 kg of initial tritium supply. If the external tritium supply is increased to 20 kg, the required TBR is 0.9. The estimated TBR is very sensitive to the variation of the tritium burn-up fraction in plasma and the tritium residence time in the tritium processing system. For example, decreasing the burn-up fraction from 5% to 1% leads to a 25% increase in the required TBR. Thus these parameters must be carefully examined in future work.

Fusion Engineering and Design, 2017

h i g h l i g h t s • We estimate tritium losses from the FNSF using a TMAP model. • Permeation losses are minimized without permeation barriers in a DCLL blanket. • An efficient tritium extraction system is designed. • Parameter uncertainties are shown to profoundly effect predicted tritium loss rates.

1979

A particularly difficult problem for first generation fusion power reactor systems is the recovery of tritium at very low con centration levels from the reactor blanket when lithium metal is the principal tritium breeding medium. On the basis of recent data and reasonable extrapolations, we show that it is likely that yttrium metal can be used to extract tritium from lithium at concentrations as low as 10" atom fraction tritium in lithium under conditions that are practicable for commercial power machines. This report was prepircd ti in iccoum of work (pcniorrd by the United Siatet Government. Neither (he Lfnlitd Stiiei nor the Uniied Sunt Depuutxnt af tnctgy, nor iny of thdi employee!, not tny of their contncfofi, mbcantnclon. or their employee*, mikrt my wuranry, expreu or implied, tt ucumei my kpl ttifailily or rapamlblliiy (a the jeeuncy, cample ui>eu or uwfulneiiofany InronTHiion, ippintui, produci j/1 prtxxs duelaied, or reprwenb thil la u« wuld not infringe primely owned rffhu. I ••• '•ruiou-fiu.ij a^siiaia i.xt.i.wn