27. The long-term prediction of corrosion damage in nuclear waste containers

Title: 27. The long-term prediction of corrosion damage in nuclear waste containers
Author(s): P. Fennell
Paper category : conference
Book title: NUCPERF 2009 - Long Term Performance of Cementitious Barriers and Reinforced Concrete in Nuclear Power Plants and Waste Management
Editor(s): V. L'Hostis, R. Gens, C. Gallé
Print-ISBN: 978-2-35158-072-1
e-ISBN: 978-2-35158-087-5
Publisher: RILEM Publications SARL
Publication year: 2009
Pages: 245 - 253
Total Pages: 9
Nb references: 3
Language: English

Abstract: The research programme described in this paper is a summary the UK nuclear generation industry work to simulate the internal corrosion behaviour of full-size intermediate level radioactive waste containers by using specially adapted 50-litre and thick walled 500 litre test containers. For comparison, the standard NDA RWMD waste containers are the 500-litre drum, the 3 m3 drum and box and the 4 m box, the latter of which has a usable volume of about 11 m3. The 50 litre and thick-walled 500 litre test containers are filled with a number of simulated Magnox Electric Ltd. and British Energy Generation Ltd. waste streams and they are provided with monitoring instrumentation that allows wasteform properties and internal corrosion-related variables to be monitored with time. Both sealed and vented containers have been prepared although two of the initially sealed containers have now been deliberately vented. The data collected in this programme are used to give reassurance that full-size containers and wasteforms will perform as required. The tests also provide data on how the environment within a waste container will evolve with time; this would be difficult to predict from smaller scale laboratory tests alone.

Throughout the programme containers have been regularly dismantled and the test material coupons analysed for depth type of corrosion. The 8.5 year old, container 18 was selected for dismantling. No significant corrosion has been found on the coupons. The internal container base was found to have a sub-micron thick deposit of a mixed magnetitechromium oxide spinel. This thickness was less than the 3 to 4 µm estimated for the coupon on the basis of the electrochemical measurements. No evidence for crevice corrosion was found on the stainless steel coupon. Some crevice corrosion occurred on the mild steel paddle where it had been masked to prevent contact with the container wall.

Online publication: 2009-11-16
Publication type : full_text
Public price (Euros): 0.00