6.71. Acceptance of the necessity for ongoing institutional control in such cases could be seen as a violation of Principle 7 of Ref. [1] by imposing a burden on future generations. However, in assessing this burden, it needs to be considered what is practically and economically achievable for large volumes of waste containing naturally occurring radionuclides. In this sense, a decision to accept disposal options involving ongoing institutional control may be the result of a generic optimization of protection that recognizes technical and economic limitations. However, each case should be considered on its merits and specific optimization studies should be carried out with the aim of ensuring that the level of protection is optimized in the long term. This should include consideration of the implementation of measures to promote passive safety. Such optimization studies should be conducted as part of the development of the safety case for the facility.