A comparative study of engineering options for the disposal of high-level radioactive waste with regard to thermal effects and chemical degradation. Issue 9 (1st September 2016)

• Record Type: Journal Article
• Authors: Heierli, Joachim
• Is Part Of: Journal of nuclear science and technology. Volume 53:Issue 9(2016)
• Page Start: 1276
• Page End: 1295
• Publication Date: 2016-09-01
• Subjects: Geological disposal -- high level radioactive waste -- comparative evaluation -- uncertainty -- thermal activation -- illitisation; Nuclear engineering -- Periodicals; Nuclear physics -- Periodicals; Nuclear energy -- Periodicals; 621.4805
• DOI: 10.1080/00223131.2015.1105163
• Languages: English
• ISSNs: 0022-3131

Abstract

ABSTRACT: The disposal of high-level radioactive waste in deep geological repositories requires stable and foreseeable physical conditions over very long time scales. During this period, the chemical stability of both the natural and the engineered barriers is governed by thermally activated processes. These in turn are driven by the heat pulse generated by the nuclear decay of waste products. The technical concept to cap the temperature peak in the repository is thus an important aspect for the proof of safety of disposal facilities. It is shown that densely stocked repositories, as currently foreseen in several countries, do not necessarily represent the optimal choice with regard to temperature effects, long-term reaction kinetics and chemical degradation of components. It is suggested that the optimization of the temperature peak rather than the fulfillment of cut-off conditions for peak temperature should be a cardinal issue in engineering concepts.