Large-scale unit commitment under uncertainty: an updated literature survey

The Unit Commitment problem in energy management aims at finding the optimal production schedule of a set of generation units, while meeting various system-wide constraints. It has always been a large-scale, non-convex, difficult problem, especially in view of the fact that, due to operational requirements, it has to be solved in an unreasonably small time for its size. Recently, growing renewable energy shares have strongly increased the level of uncertainty in the system, making the (ideal) Unit Commitment model a large-scale, non-convex and uncertain (stochastic, robust, chance-constrained) program. We provide a survey of the literature on methods for the Uncertain Unit Commitment problem, in all its variants. We start with a review of the main contributions on solution methods for the deterministic versions of the problem, focussing on those based on mathematical programming techniques that are more relevant for the uncertain versions of the problem. We then present and categorize the approaches to the latter, while providing entry points to the relevant literature on optimization under uncertainty. This is an updated version of the paper "Large-scale Unit Commitment under uncertainty: a literature survey" that appeared in 4OR 13(2), 115--171 (2015); this version has over 170 more citations, most of which appeared in the last three years, proving how fast the literature on uncertain Unit Commitment evolves, and therefore the interest in this subject

Radiological assessment on spent resin treatment facility and transportation for radioactive waste disposal

Several radionuclides including tritium generated in heavy-water reactor nuclear power plants are managed through ion-exchange resins, and these spent resins are then stored in storage tanks. To maintain the capacity of the storage tanks, the waste sludge should be treated using appropriate methods. Dose assessments are conducted to ensure radiological safety during the treatment and disposal of the spent resin. In this study, it is performed that a radiological evaluation of the operation of spent-resin waste treatment facilities and transportation of the radioactive waste???in a polymer concrete high-integrity container (PC-HIC) for spent resin disposal???of Wolseong Nuclear Power Plant, a heavy-water reactor nuclear power plant in Korea. Radiation workers using the spent resin treatment equipment, as well as radiation workers transporting PC-HIC to the disposal site and public spaces in the transportation route, were considered in the evaluation. The maximum dose received by radiation workers was 11.2 mSv, which is below the annual average dose limit of 20 mSv/year. Doses were below the limit at all routes, objects, and sampling locations. For waste truck drivers, the individual dose was 6.10E-03 mSv, which is also below the driver dose limit of 6 mSv. The treatment and disposal of the spent resin operations are performed while maintaining the individual doses below the dose limits set for the practices