Corrosion behavior of high burnup spent fuel in highly alkaline solutions

A. Loida, R. Gens, V. Metz, K. Lemmens, C. Cachoir, T. Mennecart, B. Kienzler

Research outputpeer-review

Abstract

This study is focused on the alteration behavior of spent nuclear fuel when exposed to highly alkaline groundwater. Contact of highly alkaline solution with the waste product is considered in the Belgian concept for disposal in the Boom Clay formation. According to the "supercontainer design" the fuel will be encapsulated in carbon steel canisters, surrounded by a concrete overpack. After saturation of the engineered barriers by porewater, interactions with the concrete will result in solutions rich in NaOH, KOH and Ca(OH) 2. Using this type of solution at pH 12.5, spent nuclear fuel corrosion experiments were conducted over 378 days. Under anoxic conditions, parallel experiments were performed (a) in the absence of Fe phases and (b) in the presence of solid Fe phases representing container (corrosion) products. Both types of experiments resulted in relatively low matrix dissolution rates, around 10-7 per day, according to the fractional release of Sr. Solution concentrations of actinides are close to or below the detection limit, indicating an effective retention of these radioelements in the system. The observed precipitation of a Ca rich phase onto the surfaces of the corroded fuel samples may be related to the inhibited release of actinides, Sr and other matrix bound radioelements.

Original languageEnglish
Title of host publicationScientific Basis for Nuclear Waste Management XXXIII
Subtitle of host publicationSymposium Proceedings
Place of PublicationWarrendale, PA, United States
PublisherMRS - Materials Research Society
Pages597-604
Number of pages8
Volume1193
ISBN (Print)9781605111667
DOIs
StatePublished - 2009
Event33rd International Symposium "Scientific Basis for Nuclear Waste Management". MRS - V.G. Khlopin Radium Institute, St. Petersburg
Duration: 24 May 200929 May 2009

Publication series

NameMaterials Research Society Symposium Proceedings
Volume1193
ISSN (Print)0272-9172

Conference

Conference33rd International Symposium "Scientific Basis for Nuclear Waste Management". MRS
Country/TerritoryRussian Federation
CitySt. Petersburg
Period2009-05-242009-05-29

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this