Approach in improving reliability of DEMO

Abstract Reliability, Availability, Maintainability and Inspectability (RAMI) are key elements in the engineering development of the Demonstration Power Plant (DEMO) reactor. RAMI assessments play an important role during all design cycle phases by focusing on different aspects depending on the development stage. In fact, system functions, related requirements and deriving constraints are the main objective of RAMI assessment during pre-conceptual and conceptual design phases, when getting insight on the rationale of the plant. The identification of potential failure mechanisms, needs of design updates to remove such mechanisms or mitigate related consequences, become the main goal of analysis as design details increase during subsequent plant development phases. Some of the RAMI analyses performed in the 2019 for different DEMO systems and breeding blanket configurations are here presented. Results in terms of expected annual frequency of failures of components, of specific failure events and reliability/availability parameters are reported together with indications about criticality and suggestions for designers to improve reliability and availability of the systems and of the reactor. The study is based on Failure Mode and Effect Analysis (FMEA) and Reliability Block Diagram (RBD) analysis methodologies.

[1]  R. Zanino,et al.  Recent progress in developing a feasible and integrated conceptual design of the WCLL BB in EUROfusion project , 2019, Fusion Engineering and Design.

[2]  B. Kiss,et al.  Consolidated design of the HCPB Breeding Blanket for the pre-Conceptual Design Phase of the EU DEMO and harmonization with the ITER HCPB TBM program , 2020, Fusion Engineering and Design.

[3]  G. Ramogida,et al.  Preliminary study of DEMO disruptions due to component failures , 2018 .

[4]  D. Maisonnier.  RAMI: The main challenge of fusion nuclear technologies , 2018, Fusion Engineering and Design.

[5]  W. Hering,et al.  Status of EU DEMO heat transport and power conversion systems , 2018, Fusion Engineering and Design.

[6]  Danilo Nicola Dongiovanni,et al.  RAMI analysis for DEMO HCPB blanket concept cooling system , 2015 .

[7]  Fabio Giannetti,et al.  Thermal-hydraulic modeling and analyses of the water-cooled EU DEMO using RELAP5 system code , 2019, Fusion Engineering and Design.

[8]  G. Bongiovì,et al.  On the effect of stiffening plates configuration on the DEMO Water Cooled Lithium Lead Breeding Blanket module thermo-mechanical behaviour , 2019, Fusion Engineering and Design.

[9]  Andrea Carpignano,et al.  Identification of accident sequences for the DEMO plant , 2017 .

[10]  Javier Dies,et al.  Fusion component failure rate database (FCFR-DB) , 2006 .

[11]  Maria Teresa Porfiri,et al.  Operating experiences from existing fusion facilities in view of ITER safety and reliability , 2010 .

[12]  Lee C. Cadwallader,et al.  Component failure rate data base for fusion applications , 2000 .

[13]  Risto Tuominen,et al.  Outlines of RAMI guidelines for DEMO systems , 2012 .