January-February 2019 NPJ

32 NuclearPlantJournal.com Nuclear Plant Journal, January-February 2019 Small Modular... ( Continued from page 31) TheNuScale reactors can safely shut down without operator or computer action, and without supplemental AC or DC power in the event the plant becomes disconnected from the grid. The large inventory of water inside the reactor vessel, combined with a large pool of water in the below- ground structure in which each NuScale Power Module ™ is immersed, ensures such a large heat sink that all decay heat under accident conditions can be safely removed. Additional water would only be required for the spent fuel pool after 150 days through dedicated external connections on the reactor building. In January 2018, the U.S. NRC approved NuScale’s “Safety Classification of Passive Nuclear Power Plant Electrical Systems” Licensing Topical Report in which the company demonstrated that its design approach eliminates the requirement for Class 1E power systems. This is a major safety advance limited by the NRC to the NuScale design. Historically, all nuclear plants in the U.S. have required class 1E power supplies to ensure safety. In July 2017, the NRC approved the highly integrated protection system (HIPS) platform, which serves as the basis for the NuScale control room digital instrumentation and control. This advanced digital instrumentation and control system provides redundancy as well as protection from cyberattacks. Taken together, these improvements not only address increased public concerns for plant safety in the wake of Fukushima, it is expected they will permit the siting of a NuScale plant with a significantly reduced emergency planning zone (EPZ). Where licensed nuclear plants currently require a ten- mile radius EPZ surrounding the plant, recently U.S. NRC staff preliminarily agreed that an SMR design could meet the conditions for a much smaller EPZ at the site boundary. This was based on a draft safety evaluation report for the emergency planning aspects of Tennessee Valley Authority’s early site permit at its Clinch River site, which used NuScale technology as its basis. These advances not only provide greater assurances of public safety, the reduced EPZ will both lower costs and open markets for coal plant retrofits, which are currently constrained by siting limitations. Licensing Validation of Control Room Operations In September 2018, NuScale became the first SMR vendor to complete an integrated system validation (ISV) of its control room using its full scale control room simulator (see Figure 1). This validation tested conduct of operations under numerous accident conditions to verify that the integrated system meets the safety requirements imposed by the NRC regulations. During these validation tests, three crews of six NuScale licensed operators received 56 classroom lectures over nine weeks followed by 36 simulator sessions for each crew over 10 weeks. This training program culminated in 12 full-scope, evaluated scenarios over 11 weeks that will be documented and provided to NRC in support of its staffing plan. It was demonstrated that no operator actions were required to ensure plant safety and protection of the public for all design basis scenarios. Potential Markets and Opportunities Is there customer interest in SMRs, including commercial utilities, the federal government, and possible interest in other applications such as process heat and desalination? NuScale’s experience and the global surge in emerging SMR designs suggests that there is. xi In the domestic commercial market, NuScale meets twice annually with 29 utility members of its NuScale Advisory Board to review design and regulatory progress, plant costs, and suitability relative to their integrated resource plans. Work is currently underway with Utah Associated Municipal Power Systems (UAMPS) Carbon-Free Power Project to construct a first NuScale plant at DOE’s Idaho National Laboratory, a 720 MWe 12-module plant with commercial operation scheduled to begin in 2026. NuScale also has work underway with customers in other countries. The cost of natural gas in other parts of the world is significantly higher than in the United States, giving SMR-generated power a clearer cost advantage, especially when the value of non-carbon energy or energy security is included. The National Nuclear Laboratory in the Figure 1. NuScale Control Room Simulator.