Assistance in the development of a pragmatic Defence-in-Depth evaluation method and in conduct of safety analysis reviews

The Canadian Nuclear Safety Commission (CNSC) is an independent agency of the Government of Canada that acts as the nuclear energy and materials watchdog in Canada. CNSC regulates the use of nuclear energy and materials and ensures that Canada's international commitments on the peaceful use of nuclear energy are respected.

The Reactor Behaviour Division (RBD) is seeking a contractor to assist and support the CNSC when requested with the following planned activities:

• development of regulatory requirements and guidance, in particular with respect to the interpretation, adaptation and application of Defence-in-Depth (DiD) approach to maintain and strengthen safety of nuclear installations • evaluations of safety analysis programs implemented by the licensees of operating power reactors • support in evaluation of accident management programs as being modified in response to the Fukushima accident lessons learnt.

The importance of these activities is reflected through a recommendation made in the Nuclear Energy Agency (NEA) report “The Fukushima Daiichi Nuclear Power Plant Accident” which calls for guidance from regulatory authorities in each country on the application of DiD in such areas as:

• prevention and mitigation at each level of DiD • to ensure that actions taken and resources relied upon at one level of DiD can be made independent from the other levels • to minimise the potential for common-cause failures propagating from one level to another