The adsorption and desorption of water from a carbonaceous deposit layer on the surface of stainless steel representing spent AGR nuclear fuel cladding

• Published in: Journal of nuclear science and technology 2018-04, Vol.55 (4), p.374-385
• Main Authors: Walters, W. Stephen, Durham, Peter, Hodge, Nicholas A.
• Format: Article
• Language: English
• Subjects: Adsorption; AGR spent fuel; Carbon; Desorption; disposal; dry storage; dry-out; Drying; Nuclear fuel elements; Power plants; Spent nuclear fuels; Surface chemistry; Vapor phases; Water
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/00223131.2017.1403384

Spent fuel discharged from advanced gas-cooled reactor power stations carries a deposit of carbon firmly attached to the cladding surface. The fuel route involves contact with water, for cooling and transport. Long-term storage potentially includes dry storage, however, the carry-over of water entrained within the carbon deposit needs to be considered regarding the storage environment. Drying of the fuel is possible, but little is known concerning the drying characteristics of such deposits. This work reports preparation of a laboratory simulant of a carbon deposit on a fuel pin surface and measurement of its adsorption and desorption properties regarding liquid and vapour phase water. This work found that water vapour equilibration is rapid and reversible. Liquid water uptake is appreciable (up to 5.7 times the mass of carbon) and most (up to 88%) is removed on standing for 12 h. Heating removes little more. The implications for spent fuel management are discussed.