The radiological protection principles of justification, optimisation and dose limits are applied through national legislation to safeguard workers, the public and the environment from the short and long‐term effects of ionising radiation. This paper analyses how these principles, as implemented in England, align with differing interpretations of sustainable development. This analysis finds that the framework is oriented toward sustaining all natural capital by applying stronger sustainability for human protection and nearly strong sustainability for non‐human species. It is argued that the 1 mSv yr−1 public dose limit is representative of an environmental limit and is a potential candidate ‘safe operating space’ for ionising radiation within the novel entities’ planetary boundary. Circumstances are also identified during low radiological risk activities such as decommissioning and remediation where very strong sustainability may be applied. Further research is therefore recommended to test the use of the 1 mSv yr−1 limit as a global safe operating space and to define clearer criteria to understand and control transitions from stronger to very strong sustainability in low radiological risk activities.