Abstract
ABSTRACTA preliminary evaluation of gaseous radiocarbon (14C) behavior under geological repository conditions for Italian radioactive high level waste-long-lived and intermediate level waste disposal has been performed. Although in Italy there is still no defined project for a geological disposal facility, current work may support future safety assessment studies for a hypothetical future repository in deep salt rock. In the Italian context of radioactive waste, the percentage of 14C bearing waste to be disposed in a possible geological repository is low; irradiated graphite is the most important radiological source. Data about the radiological inventory has been collected to simulate production and migration of gaseous 14C in a hypothetical geological repository. Three different conceptual models have been developed and simulated. The first model has considered a preliminary evaluation of the radiological impact referred to the whole inventory; the second and third model have evaluated the impact only due to the irradiated graphite. A preliminary sensitivity analysis has been carried out, highlighting the importance of geometry and of distribution coefficients (Kd) in materials used to seal the disposal underground facility. Results show the possibility to correlate the Kd values, the volume and the location of the sealing materials to the amount of 14C migrating toward the surface.
Highlights
The present work has been carried out within the EC CAST project (CArbon-14 Source Term), which aims to develop understanding of the generation and release of radiocarbon (14C) from radioactive waste materials under conditions relevant to waste packaging and disposal in geological repositories
The paper reports a preliminary analysis of the radiological impact of gaseous 14C from HLWLL and intermediate level waste (ILW) disposed in a hypothetical Italian geological repository hosted in salt rock
No safety assessment or generic safety studies had been developed in the Italian context for geological disposal
Summary
The present work has been carried out within the EC CAST project (CArbon-14 Source Term), which aims to develop understanding of the generation and release of radiocarbon (14C) from radioactive waste materials under conditions relevant to waste packaging and disposal in geological repositories. In the framework of different analyses supporting the long-term radiological safety of underground repositories, the migration of 14C into the environment is a key issue. The understanding of the key mechanisms influencing 14C transport from the repository to the surface is critical in this context and within the safety assessment of geological waste disposal. Until a site for underground disposal is selected, these waste products will be placed in a near surface repository for interim storage along with the final disposal of low level waste (LLW). The hydraulic conductivity of the backfill material for organic 14C, and its distribution coefficient Kd (m3/kg) for inorganic 14C, that quantify the mass partitioning between the solid and the gaseous phase, represent the key parameters influencing the gaseous carbon flux into the geosphere
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
