GEMINI+ DESIGN OPTIONS FOR HTGR FITTING THE REQUIREMENTS FOR COGENERATION USE IN EUROPE

摘要

GEMINI+ is an EU-funded project led by NCBJ(Polish National Centre for Nuclear Research) andincludes many international partners. The project aims toprovide a conceptual design for a high temperaturenuclear cogeneration system supplying process steam toindustries, a framework for the licensing of such systemand a business plan for a full scale demonstration.It relies on the modular High Temperature Gas cooledReactor (HTGR) technology which can be of use formultiple types of cogeneration systems. These includesteel degassing, hydrogen production and other chemicalprocesses. In addition, the use of chemically inert heliumas a coolant, the low power density and large thermalinertia combined with strong negative Doppler and hightemperature-tolerant coated particle fuel (TRISO) allowsthe HTGR design to have a high degree of inherent safety.This has led to a revival of interest in building modularHTGR in Europe. This can be attested by the fact that, inrecent years, multiple research projects have been fundedby the European Commission in addition to GEMINI+(HTR-N, RAPHAEL, ARCHER, EUROPAIRS) and by theBritish Government (the Advanced Modular Reactor BEIScompetition).The paper presents the key requirements for a modularHTGR for cogeneration use in Europe that have beencaptured as well as the design choices made so far tomeet these requirements.First, the paper details the methodology used to capturerequirements the different lifecycle stages of the plant.Safety requirements were captured through a review ofthe IAEA safety standards and WENRA safety objectives,end-user, operator and economic requirements wereidentified based on experience, collected from publiclyavailable studies and reviewing the needs of potentialend-users in Europe.These requirements led to the following findings: First, asmall unit satisfies most European customers as largeindustrial complexes are sparse. Multiple units could bepurchased by customers requiring a larger supply. Thisapproach has the added benefit to favour themodularisation and standardisation of the design. Second,maximum decoupling between the industrial process andthe primary circuit is necessary for both safety andstandardisation reasons. The design thus includes awater/steam loop between them. In addition, a smallturbine or heat storage capabilities are required to allowthe reactor to continue working at low power in case of aloss of load. Finally, the design relies on proventechnologies to ease regulatory approval, keep the costslow, reduce uncertainties and focus innovation on thestandardisation of the design.