Drell-Yan W/Z electroweak boson production at the LHC is an essential standard candle which is used for calibration of beam luminosity and detector properties. In addition to proton-proton collisions, the LHC has measured heavy nuclei lead-lead and proton-lead W/Z production. Comparison of these data sets can provide discriminating information of the nuclear modifications present in the Parton Distribution Functions (PDFs).

The nCTEQ collaboration has recently released the nCTEQ15 set of nuclear PDFs (nPDFs) with Hessian error estimation sets for various values of A. These new nPDFs will be presented along with an analysis of W/Z production in lead-lead and proton-lead collisions at the LHC. Cross-sections are calculated at NLO with the FEWZ program at 2.76 and 5.02 TeV. We identify observables where the nuclear modifications are larger than the predicted uncertainty, and we compare these calculations to recent CMS measurements.