A case history of CFD support to Accelerator Driven System plant

A case history of CFD support to Accelerator Driven System plant Vincent Moreau CRS4, Energy & Environment Program Luigi Mansani, Maurizio Petrazzini Ansaldo Nucleare A case history of CFD support to ADS system plant

What is an Accelerator Driven System ? • An Accelerator Driven System, or ADS, consists in a sub-critical nuclear fission reactor coupled with a proton accelerator by means of a target system. A case history of CFD support to ADS system plant

THE EUROTRANS PROJECT • The Integrated Project EUROTRANS, funded by the European Commission (FP6, 2006-2010) is aimed at providing: • the advanced design of a multi purpose research oriented ADS, called XT-ADS (600 Mev, 80 MWth) • The preliminary design of an industrial scale ADS, called EFIT (800 Mev, 400 MWth) A case history of CFD support to ADS system plant

ENEA, Bologna Neutronics Ansaldo, Genoa coordination, design CRS4, Pula CFD A case history of CFD support to ADS system plant

EFIT European Facility for Industrial Transmutation • Beam power: 800 Mev • Beam intensity: ~20 mA • Plant power: ~400 MWth • Primary coolant: pure lead • Primary coolant flow rate: 36,000 kg/s • Core inlet temperature: 400 C • Core outlet temperature: 480 C • Reactor vessel size: 10 m diameter, 12 m high A case history of CFD support to ADS system plant

EFIT Ansaldo design (1/2) A case history of CFD support to ADS system plant

EFIT 2D CFD simulation • Bottom + Core + Inner Plenum • Nominal power and flow rate • Differentiated core porous resistance • Objectives: • Preliminary simulation for support to discussion • Set up physical properties • Get confident with object under study A case history of CFD support to ADS system plant

EFIT 2D CFD simulation A case history of CFD support to ADS system plant

EFIT 2D CFD simulation Effects: • Withdraw from core CFD analysis (done by another partner ENEA, making also the core arrangement and the neutronic calculation) • Separation of bottom and top concern • Change of the bottom grid orientation • Investigate on pump entrance flow A case history of CFD support to ADS system plant

Change of the bottom grid A case history of CFD support to ADS system plant

3D CFD check A case history of CFD support to ADS system plant

EFIT inner plenum A case history of CFD support to ADS system plant

EFIT simplified inner plenum A case history of CFD support to ADS system plant

EFIT Down-comer A case history of CFD support to ADS system plant

EFIT Down-comer After Before After, After 3min transient A case history of CFD support to ADS system plant

XT-ADS • Beam power: 350 or 600 Mev • Beam intensity: max 5 or 2.5 mA • Plant power: ~70 MWth • Primary coolant: Lead-Bismuth Eutectic • Primary coolant flow rate: 6,000 kg/s • Core inlet temperature: 300 C • Core outlet temperature: 380 C • Reactor vessel size: ~ 5 m diameter, 8 m high A case history of CFD support to ADS system plant

XT-ADS Ansaldo design, strongly inspired from SCK-CEN Myrrha design A case history of CFD support to ADS system plant

XT-ADS A case history of CFD support to ADS system plant

XT-ADS: shut-down transient Extreme scenario • Beam interrupted: core decay heat • Pump stops in 3s • SGU stops in 3s • Internal DHR system fails • Only external RVACS operative • 20,000s of transient A case history of CFD support to ADS system plant

XT-ADS: shut-down transient Initial condition A case history of CFD support to ADS system plant

XT-ADS: shut-down transient First 50s A case history of CFD support to ADS system plant

XT-ADS: shut-down transient Modified colour scales: from 50s to 20,000s A case history of CFD support to ADS system plant

XT-ADS: shut-down transient Situation at time=20,000s A case history of CFD support to ADS system plant

XT-ADS: shut-down transient A case history of CFD support to ADS system plant

Concluding words • We have presented some situations in which CFD proved to be a useful support to the designer and led to design variants. • The extensive use of “over-simplified but not rigid” treatment of pumps, heat exchangers, by-pass, core heat release allowed to investigate medium and large scale 3D behaviours in a rather consistent way. • This work has been made possible because the designers and the CFD engineer took time to exchange information and motivation, both explaining and listening… • More images and animations on: http://people.crs4.it/moreau/HTML/EUROTRANS/index_EUROTRANS.html A case history of CFD support to ADS system plant

Thank you for your attention A case history of CFD support to ADS system plant

A case history of CFD support to Accelerator Driven System plant