ACR-1000™ Level 1 PSA Summary Available to Purchase

The ACR-1000™ developed by Atomic Energy of Canada Limited (AECL) is a 1200 MWe - pressure tube type, light-water-cooled and heavy-water-moderated reactor, which has evolved from the well-established CANDU™ line of reactors. It retains the basic proven CANDU design features while incorporating innovations and state-of-the-art technologies to ensure fully competitive safety, operation, performance and economics. The major innovation in the ACR-1000 is the use of slightly enriched uranium fuel and light water coolant. ACR-1000 is a four-quadrant design (for easier maintenance and improved reliability). There are five safety systems in the ACR-1000; (i) two independent, diverse and fast acting shutdown systems (SDS1 and SDS2), which are physically and functionally independent from each other and from the reactor regulating system; (ii) Emergency core cooling system; (iii) Emergency Feedwater system; and (iv) Containment system, which includes a strong steel-lined containment structure. In addition the Reserve water system provides feedwater to the heat transport system, steam generators, moderator and shield cooling system for beyond design basis accidents. The Level 1 Probabilistic Safety Assessment (PSA) is conducted in support of the design phase of the ACR-1000. The purpose of Level 1 PSA is to identify whether the ACR-1000 design targets and the regulatory safety goal for severe core damage frequency (SCDF) are met with adequate margin and provide design feedback. An interim Level 1 PSA was conducted for internal at-power events. Interim assessments were conducted for shutdown state, internal fire and flood at-power events. An interim seismic margin assessment was conducted for the seismic events. The Level 1 PSA results show that the ACR™ design targets and safety goal for SCDF are met with significant safety margin. Based on the ACR-1000 Level 1 PSA, the accident behaviours of the ACR-1000 are well understood and their consequences can be predicted with a high-level of confidence. It also provides sufficient assurance that the release based regulatory safety goals are achievable for ACR-1000. The Level 1 PSA results also signify a robust design that provides a strong foundation for the ACR-1000 design. The paper summarizes the Level 1 PSA program, methodology followed, the results obtained, and insights gained during the development of the ACR-1000 Level 1 PSA.