ジルカロイジルカロイMeanings1nounzircaloyA trademarked zirconium alloy used primarily as cladding for nuclear fuel rods.ジルカロイは原げん子し炉ろの燃ねん料りょう被ひ覆ふく管かんに使つかわれる合ごう金きんです。Zircaloy is an alloy used for nuclear fuel cladding tubes.