3. An action that has received a contribution from another Union programme may also receive a contribution under the 2026-2027 Euratom Programme, provided that the contributions do not cover the same costs. The rules of the relevant programme shall apply to the corresponding contribution to the action. The cumulative funding shall not exceed the total eligible costs of the action. The support from the different programmes may be calculated on a pro-rata basis in accordance with the documents setting out the conditions for support.