This paper describes a comparative methodology that is based on an equal amount of energy generated and an equal amount of weapons plutonium being burned or directly disposed of. The United States and Russia were in the midst of deciding how plutonium from surplus weapons should be disposed of so that it will never be used again to make nuclear weapons. This report discusses whether burning or direct disposal of weapons plutonium would generate more waste heat and consume more repository space. It should be of interest to analysts and policymakers in plutonium disposition and in nuclear nonproliferation. Waste heat has significant implications for repository space requirements and effective waste management.