It is difficult to evaluate complex, publicly sensitive nuclear project proposals. Scientists, subject matter experts, politicians, and citizens often differ on scope, budget, time, and quality priorities. There are numerous qualitative factors and quantitative variables. Experts could widely disagree on criteria or neglect to discriminate between seemingly identical alternatives. An ineffective portfolio selection method could lead to safety problems, budget overruns, or outright project failures. This case study develops and examines a mixed-method, integrated qualitative and quantitative portfolio selection model, applied to a “tritium extraction facility” project concept.