| dc.description | Conversion coatings have been used to protect aluminium surfaces from
corroding. Hence use of this type of coating was considered to protect the
aluminium cladding of spent research reactor fuels during extended wet storage.
A conventional chemical process, as opposed to an electrochemical process, is
preferred due to the shape of the fuel and its high radioactivity. In this context
hydrotalcite (HTC) and boehmite coatings were considered. This paper presents
the results of further development of HTC coatings, from the stand point of
eventually being able to coat highly radioactive spent fuels using remote handling
equipment. More specifically: (a) preparation of HTC coatings from different baths
on AA 6061 alloy surfaces that were given pre-treatments to simulate spent fuel
surfaces; (b) characteristics of the HTC coatings as a function of bath
temperature; (c) corrosion behaviour of HTC coated AA 6061 alloy; (d) results of
field studies in which dummy fuel elements, consisting of Al alloy plates coated
with HTC from different baths (with or without post coating treatments), were
immersed in the IEA-R1 reactor???s spent fuel basin for periods of up to 2 years.
This study demonstrates that Al surfaces can be coated with HTC using an allroom
temperature process. The field tests revealed marked increase in corrosion
resistance of HTC coated plates. The mechanism of corrosion protection is
discussed and a mock-up arrangement to remotely handle dummy-fuel elements
to pre-treat, coat with HTC and post-treat is presented. | |
