Nuclear Management Company
As of September 2008 the operating licenses for the last two plants overseen by NMC , Monticello and Prairie Island , were transferred to Northern States Power Company ( a wholly owned subsidiary of Xcel Energy ) , the owner of the plants . 
<triplet> Monticello <subj> Xcel Energy <obj> operator <triplet> Prairie Island <subj> Xcel Energy <obj> operator