Spent nuclear fuel management is one of the most important and critical issues for nuclear power plants in the world. Spent nuclear fuel is stored for a long duration of time before the final disposal. Dry and wet interim storage are the commonly used methods to store spent nuclear fuel. Dry interim storage offers a flexible, safe, and cost-effective approach to store spent nuclear fuel. Increase in global demand for power, primarily in developing economies of Asia Pacific and North America, is driving the need for construction of nuclear power plants. Dry interim storage for spent nuclear fuel needs dry cask to store and contain the radioactivity within itself. Rise in construction of nuclear power plants around the globe has created the demand for spent nuclear fuel facilities (SNF).
About one-third of fuel is removed or replenished in most of the nuclear power reactors annually. The fresh nuclear fuel is added at each cycle of refueling. The spent fuel recovered from the reactor is then processed and finally placed into deep water pools located at the reactor site to reduce its radiation and heat before cask storage. Dry interim storage of the spent nuclear fuel can be carried out through different methods. Commonly followed methods for dry interim storage of SNF include metal cask, vault, concrete module, and other dry storage methods such as drywells and tunnels. Most technologies used for dry interim storage of SNF are distinguished from each other in terms of their technical characteristics such as degree of independence of the individual storage units, type of shielding, heat transfer method, storage location, storage structure, transportability, and type of geological surface. Construction of dry interim storage facilities also differs in terms of modularity, method of SNF handling, size, construction material, storage containers layout, and configuration of SNF.
Metal casks are generally designed for transportation and storage. Some metal casks are meant only for the storage of SNF. Shielding of radiations is primarily provided by the structure of the cask and its material. Metal casks for dry interim storage are made from forged steel, composite materials, or cast iron. Dry interim storage casks are generally stored in an upright vertical position installed on a concrete pad. Dry interim metal casks are primarily used for interim storage of SNF around the globe. Concrete interim storage casks are similar in shape as compared to metal interim storage casks. A concrete interim storage cask provides shielding effect from nuclear radiations. The steel liner present in the inner canister cavity of the concrete provides containment for the SNF. A typical interim concrete storage cask is made of the following components: fuel basket, transportable storage canister with welded bottom plate containment, shield lid, two penetration port covers, and structural lid. The concrete filler provides shielding, structural support, natural convection cooling, and protection from environmental conditions during long term storage of SNF. Other popular methods for dry interim storage of SNF are silos, horizontal concrete module system, vault, twin tunnel, and dry well. Twin tunnel dry interim storage method is a highly employed subsurface storage method that combines borehole type emplacement with the drywell concept within a single geological disposal repository. This type of interim storage method offers long term interim storage of SNF with an option of its retrieval for reuse. Majority of the SNF is generally stored in water pools. Only 30% of the SNF produced is stored in dry storage facilities around the globe.
Rise in demand for uninterrupted and low-cost electricity across the globe is resulting in the construction of nuclear power plants. This provides immense potential for the dry interim storage market. Increase in demand for power infrastructure in residential, commercial, and industrial segments and rise in environmental concerns are driving the market around the globe. The market for dry interim storage for SNF is driven by factors such as increase in nuclear power plants, rise in liquid and solid nuclear waste generation from existing nuclear plants, and growth in health and safety concerns in various countries around the globe. High investment in nuclear infrastructure and high cost of cask material and concrete are the major restraints of the dry interim storage market.
Currently, North America and Europe lead the global dry interim storage market for SNF. These regions are followed by Asia Pacific owing to the aggressive expansion of nuclear programs and infrastructure development in China, India, and Japan. Technological growth in infrastructure development and rapid economic growth in countries in Asia Pacific are expected to provide immense opportunities to the global players operating in the dry interim storage market for SNF. Prominent global players that produce dry interim storage for SNF are Augean PLC, SRCL Ltd., Bechtel Corporation, Areva SA, Fluor Corporation, and Holtec International are the major players operating around the world. Increase in investment for the improvement of power, led by the rise in per capita GDP of countries in Southeast Asia, and commencement of new nuclear power projects are anticipated to boost the demand for dry interim storage for SNF across the globe.