# Activation Analyses of Disposal Options for Irradiated Be\({}_{12}\)Ti
###### Abstract  
The activity and disposal options for irradiated Be\({}_{12}\)Ti were assessed for the HCPB DEMO blankets making use of a code system that enables performing 3D activation calculations by linking the Monte Carlo transport code MCNP and the fusion inventory code FISPACT through an appropriate interface. The dedicated full-scale geometry MCNP model of the 11.25 degree HCPB DEMO torus was adapted to the requirements for the coupled 3D neutron transport and activation calculations. Special attention was paid to the use in the activation calculations of the commercial materials containing technological impurities. This has a crucial effect on the results and the impurities must be accounted for in any nuclear safety analyses. The short-term activity is formed by the radionuclides produced through the activation of Be and Ti nuclei and the long-term activity is formed by the products of the neutron irradiation taking place on the impurities. A prerequisite for the disposal or the recycling of the irradiated Be\({}_{12}\)Ti is its deep detritition; otherwise, the very high-tritium activity would fully prevent any attempt for its treatment. The most preferable is the use of the Be\({}_{12}\)Ti with the composition including less material impurities, especially uranium. There could be the option to dispose the Be\({}_{12}\)Ti intermediate-level wastes in the French repository after 1 year of cooling, assuming the detailed control of the impurities that fulfil the French authority requirements. The USA near-ground repositories could be an alternative to the European sites. The recycling of the irradiated Be\({}_{12}\)Ti must first be elaborated and approved to ensure its treatment in a safe and efficient way. The remote handling technique must be developed for the re-fabrication of the Be\({}_{12}\)Ti blocks. DEMO; neutron multiplier; Be\({}_{12}\)Ti; neutronics; activation; disposal +
Footnote †: journal: Applied  
Accepted: 20 June 2023  
The cost factor is extremely important for public acceptance of the fusion facility and the fusion energy. The main disadvantages of the Be\({}_{12}\)Ti neutron multiplier utilized in the HCPB breeder blanket are costs due to limited natural resources [4]. The price of raw beryllium increases continually with an annual rate of \(\sim\)2.5%/year and it is estimated currently to be \(\sim\)610 \(\div\) 650 USD/kg [4; 5]. A conservative reasoning of the future price for the Be\({}_{12}\)Ti industrial production for the DEMO needs could be estimated to be at least 1000 \(\div\) 2000 USD/kg in 30 years depending on the beryllium market evolution. Namely, the restricted Be resources are the reasons for the initiated research activity to find a reasonable solution for a possible Be recycling or, in the worst case, to define conditions for a possible disposal of the irradiated Be\({}_{12}\)Ti. A total load of the Be\({}_{12}\)Ti in the HCPB demo was estimated to be \(\sim\)600 tons that corresponds to \(\sim\)418 tons of Be [6]. In spite of the fact that the world's identified resources of beryllium have been estimated to be more than 100,000 tons, the total world Be production does not exceed \(\sim\)260 tons [5]. It is highly probable that the total Be amount required for the production of the Be\({}_{12}\)Ti blocks for the HCPB breeder blankets will be provided from different global sources. Each Be ore possesses a specific chemical composition with various chemical element contents. As a result, the chemical composition of the Be (including impurities) used for the future HCPB breeder blankets cannot be defined exactly but it can be approximately assessed to make use of the available information for different Be ores. An accumulation of radioactive nuclides in the Be\({}_{12}\)Ti is inherent in the process accompanying its utilization in the HCPB DEMO blanket due to intensive neutron irradiation. Depending on the initial chemical composition of the Be\({}_{12}\)Ti, its final inventory can differ significantly, affecting its treatment and processing strategy.