20.08.2015   Design of Reactor Containment Systems for Nuclear Power Plants

PROTECTION AGAINST EXTERNAL EVENTS

1.25. The containment structures and systems should be so designed that all those components of the reactor coolant pressure boundary that cannot be safely isolated from the reactor core, as well as the safety systems located inside the containment that are necessary to keep the core in a safe state, are protected against the external events included in the design basis.

BIOLOGICAL SHIELDING

1.26. In operational states and in accident conditions, the containment structures contribute to the protection of plant personnel and the public from undue exposure due to direct radiation from radioactive material contained within the containment and containment systems. Dose limits and dose constraints as well as the application of the ‘as low as reasonably achievable’ principle (for the optimization of radiation protection) should be included in the design basis of the structures [1, 9, 10]. The composition and thickness of the concrete, steel and other structural materials should be such as to ensure that the dose limits and dose constraints for operators and the public are not exceeded in operational states or in the accident conditions that are considered in the design.