Bundle geometry design influence on fuel burnup and performances in a CANDU reactor

• Published in: Annals of nuclear energy 2020-08, Vol.143, p.107488, Article 107488
• Main Authors: Prodea, Iosif, Radut, Alina Cristina, Olteanu, Gheorghe
• Format: Article
• Language: English
• Subjects: 61-Rods bundle; Advanced bundle geometry; CANDU; Fuel burnup management; Linear power
• ISSN: 0306-4549; 1873-2100
• DOI: 10.1016/j.anucene.2020.107488

•A significantly reduced thermal stress is shown by a new designed 61-rods CANDU bundle.•The 52-rods bundle design proved promising fuel management features.•Improved operational performances have been revealed by advanced bundle designs. The paper evaluates burnup and fuel performance aspects of some advanced CANada Deuterium Uranium (CANDU11CANDU=CANada Deuterium Uranium; 2CFS=Core Follow Simulations; 3ICB=Instantaneous Critical Burnup; 4TA=Time Average; 5ADB=Average Discharge Burnup; 6ZCU=Zone Control Units; 7FPD=Full Power Day; 8RAB=Refuelling Average Burnup; 9(M)OELP(B)=(Maximum) Outer Element Linear Power (Boost)) bundle geometry designs with more than 37 fuel elements and containing natural uranium dioxide pellets. Three advanced bundle geometries have been considered: the 43, 52 and 61-rods ones. Lattice calculations were performed to generate cross section tables with respect to the burnup and to find out instantaneous critical burnups. The burnup efficiency expressed as Uranium consumption for a reference period was evaluated through Core Follow Simulations (CFS). Outer element linear powers and power boosts together with thermo-mechanical parameters were calculated and discussed. The conclusions underline the burnup efficiency and associated uncertainties along with normal operation safety improvements brought by the advanced CANDU bundle geometry designs with increased numbers of fuel elements. Proposals for future work are made in order to get more reliable results using advanced modelling computer tools.