Since 2006, as part of the transition to low-carbon technologies, UK energy policy has moved towards incentivising new nuclear power production. As a result, the UK has developed a (now delayed) strategy to deliver around 16GW of new nuclear power by 2030. This policy context provides an opportunity to reflect not only on the material infrastructure needed to meet transition targets, but also on who is responsible for the energy justice implications of these decisions. Using data collected from 26 semi-structured interviews with NGO and policy representatives, this paper presents a case study of energy justice concerns surrounding the Hinkley Point Nuclear Complex in Somerset, focusing particularly on the highly controversial Hinkley Point C developments. The results emphasise the importance of considering not only instances of energy justice or injustice, but of attributing responsibility for them, a concept that has been largely overlooked in the energy justice literature. NGOs, government and business allocate responsibility differently in nuclear energy decision-making. We find that perceptions of responsibility are highly dependent upon the level of transparency in decision-making. This article is part of a Virtual Special Issue entitled ‘Exploring the Energy Justice Nexus’.