Regulatory Review of CANDU Fuel Thermal Hydraulic Analysis and Associated Challenges

Abstract of the technical paper presented at:
5th International Workshop on Current CANDU Safety Issues and Resolutions for CANDU Safety and Sustainability
October 12–14, 2016

Prepared by:
Yujun Guo
Canadian Nuclear Safety Commission

Abstract

Fuel thermal hydraulics is one of the key aspects in reactor fuel and core design and safety analysis. In Canada and worldwide, the CANDU industry has made significant efforts to improve CANDU fuel thermal hydraulic design and quantify various thermal hydraulic characteristics important to fuel and fuel channel performance and safety. Recent activities include, but are not limited to, re-optimization of the fuel bundle assembly and better quantification of fuel-coolant heat transfer characteristics under post-dryout thermal hydraulic conditions. Such activities involve conducting complex large-scale experimental measurements, improving sophisticated prediction methods and assessing intricate uncertainties. The primary objective of these activities is to help restore the eroded margins to fuel and fuel channel safety due to plant aging.

From a regulatory perspective, it is challenging to evaluate the industry’s activities and results so as to ensure a high level of confidence in the safety margins after they have been restored. This presentation provides a high level overview of the Canadian regulatory requirements, guidance, and review criteria pertaining to CANDU fuel thermal hydraulic design and analysis, and addresses some of the challenges in assessing CANDU fuel thermal hydraulic design and analysis.

To obtain a copy of the abstract’s document, please contact us at cnsc.info.ccsn@cnsc-ccsn.gc.ca or call 613.995.5894 or 1.800.668.5284 (in Canada). When contacting us, please provide the title and date of the abstract