Allows electrical corporations to charge for services based on the costs of certain construction work in progress

HB 2122 allows Missouri electrical corporations to include the costs of constructing new nuclear power plants (under 600 MW) in their rate base *before* the plants are completed and operational. This means utilities can recover these pre-completion construction costs through customer rates immediately, rather than waiting until the plant is finished. The Public Service Commission must approve the exact amount based on estimated project costs and actual spending during construction, with refunds required if costs were wasted or the plant isn't completed on time. The provision expires in 2036 unless extended by the Commission, and applies only to new nuclear plants not in operation by August 2026. This directly affects utilities and their ratepayers by changing how construction costs are recovered.