The intent of the ART R&D program is to conduct R&D on non-LWR design SMRs to address their respective technology challenges leading ultimately to the design, licensing, and operation of enhanced SMR designs in the future. This class of reactors, A-SMRs, is defined within the context of the ART program as non-LW-SMR designs. The non-LWR coolants for which R&D is underway include such coolants as liquid metals (principally sodium), helium, and liquid salts. DOE-NE’s objective is to conduct impactful R&D to accelerate the development of the technologies for these innovative concepts that obviously are candidates for deployment beyond the more near term. The principal R&D areas or pathways that make up the ART program at this time are (1) development of advanced instrumentation, controls, and human-machine interface (ICHMI) that is potentially applicable to LW-SMRs as well, (2) development and testing of materials, fuels, and fabrication technologies, (3) resolution of key regulatory and safety issues, (4) development of assessment methods for evaluating A-SMR technologies and characteristics, and (5) A-SMR concept evaluations. The first four elements were initiated in fiscal year 2012 with the fifth element started in fiscal year 2014. The A-SMR concept evaluations involve early efforts at characterizing and evaluating a set of three A-SMR design concepts employing each of the three aforementioned coolants — liquid metal, helium, and liquid salts. These evaluations will be summarized in this chapter after the four principal R&D areas are discussed.

DOE-NE also has several initiatives that complement the ART program including its Nuclear Energy University Program (NEUP), Integrated Research Program (IRP), and Industry R&D Partnership program that all include R&D elements and interactions associated with A-SMRs. These various R&D programs and initiatives as related to A-SMRs are summarized later in this chapter.

Use of these non-light water coolants in A-SMR designs offers a number of potential advantages in terms of potential economic, safety, and operational benefits. However, to realize these benefits, a number of technology challenges need to be addressed, thus forming the basis for undertaking the various R&D elements as described below.