1.76. In the design and layout of containment systems, sufficient space and shielding should be provided to ensure that maintenance and operations can be carried out without causing undue radiation exposure of personnel. The point of access to the containment should be inside the controlled area and access should be subject to the approval of the radiation protection officer.

1.77. Consideration should be given to the potential exposure to radiation associated with operations that are planned to be conducted after an accident, or with operations that it may be necessary to conduct following the emergency procedures as well as with the recovery actions following an accident. Evaluations should include the consideration of access paths, such as possible open doors and hatches. If the doses due to such exposures exceed the applicable dose limits and dose constraints, additional shielding or even the repositioning of components should be considered.

1.78. Maintenance related factors considered in the containment design should include the provision of adequate working space, shielding, lighting, air for breathing, and working and access platforms; the provision and control of proper environmental conditions; the identification of equipment; the provision of hazard signs; the provision of visual and acoustic alarms; and the provision of communication systems.

1.79. The accessibility of both the containment and the systems contained within it should be considered for all operational states. The ability to ensure that radiation doses to operators remain within the acceptable dose limits will determine whether access can be allowed to the primary and/or the secondary containment (if applicable) during power operation, or whether plant shutdown is required for permitting such access.

1.80. If entry into the primary or secondary containment during power operation for the purposes of unplanned maintenance or even for routine (planned) maintenance is envisaged, proper provision should be made to ensure the necessary radiological protection and industrial safety of plant staff. This provision should include the application of the principle of keeping exposure as low as reasonably achievable, the provision of the necessary communication systems and alarms, and proper monitoring of the containment atmosphere, especially in the case of inerted containments or containments at subatmospheric pressure. At least two emergency escape routes from the containment should be provided. In addition, security provisions for controlling access to the containment should be considered.