Integrated energy systems for multi-purpose applications are garnering increased interest in the international nuclear energy community, energy system designers and planners and decision makers in the context of deep decarbonization and net zero targets. They are expected to reduce costs and increase flexibility in operation of nuclear reactors when coupled with intermittent renewable energy sources, while also producing various commodities such as hydrogen or potable water. Adaptive solutions must be considered for each geographical area and based on the involved components of the energy system, available infrastructure, and policy in place. This paper provides an in-depth look at the strengths, weaknesses, opportunities, and threats of such systems, while addressing different aspects related to the creation of the business case for such systems including decentralization and digitalization of future energy systems. The regulatory aspects are the ones that impose challenges on the emerging hybrid energy systems and this paper highlights some of the considerations that are needed for the couplings involved, in terms of licensing procedures and safety analysis. The potential contribution of such integrated energy systems towards achieving the United Nations Sustainable Development Goals (UN SDGs) are also discussed. Concerning the stakeholders, special attention should be paid to building social acceptance and trust as this lays the foundation for successful implementation of such projects. By focusing on areas such as research and development, integration of technologies, policy support, market development, grid integration, energy storage, efficiency improvement, system modelling and simulations, significant advances in integrated/hybrid energy systems deployment can be achieved.