Use of Boron in Structural Materials for Transport Packagings

The use of borated materials for criticality control is a well-proven technique in the lield of spent-fuel transport packagings. Because these packagings are usually designed for a class of spent fuels with a range of enrichment, bumup ratios, and decay time. the safe approach and accepted practice is to consider that the fuel is new and in pure water. Low levels of bumup credit have been considered only if the burnup can be and is measured individually on each spent-fuel assembly (SF A) betore loading it into the packaging. Furthermore, no credit is taken for boron present in the loading pool water, contrary to what is sometimes done by the designers of \"storage only\" casks. Theretore. boron has been included in the internal arrangements (baskets) of transport packagings in a number of ways described in previous PA TRAM conterences (see references). The advantages of aluminum and/or boron aluminum tor efficient decay heat transfer in dry transport/storage casks have also been described previously. The present paper reviews the developments ofTransnucleaire in basket technology and shows the advantages for public and operators health and safety of taking into account the structural contribution ofthese materials to mechanical behavior of the basket.