A lead-lithium based breeding blanket for DEMO and its corresponding Test Blanket Module (TBM) to be tested in ITER is being developed in EU. The same approach is pursued in other countries involved in the development of fusion nuclear technologies. The eutectic lithium lead alloy (Pb-16Li) includes the tritium breeder material (Li) and the neutron multiplier (Pb) and, used in liquid form, it can be recirculated outside the blanket module to facilitate the tritium extraction and the alloy purification. However, it shows also some drawbacks. In fact, besides the issues related to the magnetohydrodynamic (MHD) effects and the compatibility of liquid lead lithium alloy with structural materials, it is known that the tritium Sieverts' constant in Pb-16Li is low. As a consequence, an high tritium permeation rate from the liquid metal to the primary cooling system is expected, at least in absence of efficient tritium permeation barriers. This aspect affects the whole blanket tritium cycle, whose main steps consist of tritium extraction from the liquid breeder (TES, Tritium Extraction System) and tritium removal from He primary coolant (CPS, Cooling Purification System). This chapter is focused on the description of tritium processing systems and tritium technologies related to the adoption of the lead-lithium alloy in DEMO breeding blankets. The first section describes the DEMO fuel cycle giving a particular accuracy to the description of the breeding blanket part. The second section introduces the hydrogen isotopes transport parameters in Pb-16Li which have a strong impact on the process strategy of the blanket fuel cycle. Then, the above-mentioned tritium processing systems and technologies will be described in detail. In particular, an assessment of the tritium systems that can meet the requirements of a lead-lithium based DEMO blanket is carried out presenting the suitable technologies together with their drawbacks and advantages. © 2013 Nova Science Publishers, Inc. All rights reserved.
|Titolo:||Tritium technologies for pbli based breeding blankets|
|Data di pubblicazione:||2013|
|Appare nelle tipologie:||2.1 Contributo in volume (Capitolo o Saggio)|