Boccaccini, L.V.

Chiovaro, P.

Ciattaglia, S.

Cismondi, F.

Day, C.

Del Nevo, A.

Di Maio, P.A.

Federici, G.

Hernandez, F.

Moreno, C.

Moscato, I.

Rapisarda, D.

Santucci, A.

Spagnuolo, G.A.

Utili, M.

Boccaccini, L. V.

Di Maio, P. A.

Spagnuolo, G. A.

KITopen

This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratomresearch and training programme 2014‐2018 and 2019‐2020 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.Progress of the conceptual design of the European DEMO Breeding Blanket, Tritium Extraction and Coolant Purification Systems14th International Symposium on Fusion Nuclear TechnologyF. Cismondi, L.V. Boccaccini, P. Chiovaro, S. Ciattaglia, I. Cristescu, C. Day, A. Del Nevo, P.A. Di Maio, G. Federici, F. Hernandez, C. Moreno, I. Moscato, P. Pereslavtsev, D. Rapisarda, A. Santucci, G.A. Spagnuolo, M. Utili G.A. Spagnuolo and F. CismondiOutline• Introduction• HCPB design• WCLL design• HCPB BB shielding performance studies• Water activation• TER HCPB design• TER WCLL designo PAV technologyo GLC technology• Tritium transport analysis• Tritium permeation experiments• Helium and water CPS pre-conceptual design • ConclusionG.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 2Introduction• The Helium Cooled Pebble Bed (HCPB) and the Water Cooled Lithium Lead (WCLL)concepts are the two TBM concepts to be tested in ITER and are being developed aspossible candidates to become driver Breeding Blanket (BB) for the EU DEMO.• Some technical features of the BB (the type of coolant and breeder, the technologyused for the tritium extraction/control and for the coolant purification) impact not onlythe design of the BB system but also the design of the interfacing systems and, as aconsequence, of the overall tokamak layout.• Design and integration studies have been carried out in a holistic way (thinking aboutthe big picture) in order to verify that architectures being developed are consistent andthe major issues are addressed and tackled.• Two main design and integration cross fields have been identified:• Radiation protection in the blanket and adjacent systems;• Definition of the Tritium management systems (extraction, inventories andreleases)  selection of the technology and definition of working pointG.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 3A-AB-BSegment chimneysPurge gas pipingHCPB designG.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 4Active areas of research: • TBR margin (1.20) and possibly room fordedicated VV shielding;• Improve removal of high heat flux in FW andBZ with turbulence promoters;• Focus on holistic design:• BoP-PHTS: simplification of internals toreduce p: Pelectr ≈ 90 MW;• RAMI and costs: focus on reliability andcost improvement;• Safety: functional materials with low Tinventory and resilient against accidents;• TER and CPS: studies on alternative purgegas chemistry.Key issues still need to be solved: • Integral manufacturing demonstrators;• Need for integral, large scale experiments onthermal-hydraulics and thermo-mechanics;• Cost reduction of functional materials,recycling of Be12Ti.• Fuel-breeder pin hexagonal assembly• Li4SiO4 + 35mol% Li2TiO3 ceramic breeder (CB) pebble bed• Be12Ti prismatic blocks• He coolant (inlet 300°C, outlet 520°C, 8 MPa). • Purge gas (0.2 MPa): He + 0.1% wt. H2 (H2O alternative)F. A. Hernández et al., Consolidated Design of the HCPB Breeding Blanket for the pre‐Conceptual Design Activities of the EU DEMO and Harmonization with the ITER HCPB TBM Program (POSTER)A-AFuel-breeder pinBZ backplatePurge gas manifold platesShieldingBSS outlet pipingBZ manifoldFW manifoldB-BCoolant pipingWCLL designG.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 5• PbLi as breeder, n-multiplier and T carrier.• Water coolant at PWR conditions: 295 – 328 °C@ 15.5 MPa.• Two independent loops: FW and BZ. BZ coolingsystem relies on Double-Wall Tubes (DWT).A. Del Nevo et al., Recent progress in developing a feasible and integrated conceptual design of the WCLL BB in EUROfusion project, Fus Eng Des (2019), article in press, https://doi.org/10.1016/j.fusengdes.2019.03.040A. Tassone et al., P1‐122F. Edemetti et al., P1‐075I. Catanzaro et al., P1‐067M. Eboli et al., P2‐038F. Moro et al., P1‐031 P. Chiovaro, P1‐071I. Mocato, P1‐101F. Galleni, P2‐044S. Khani, P2‐049Presented @ ISNFT-14Active areas of research:• Integration of water and PbLi pipes inUpper and Lower Ports;• Optimization of FW and BZ cooling enhanced TBR (target > 1.15);• PbLi flow modelling under magnetic field;• EXP and numerical studies of H2O/PbLireaction;• R&D on permeation barriers: Al2O3coating;• Water coolant chemistry R&D.Key issues still need to be solved:• Water drainage procedure;• Integral manufacturing demonstrators;• Need for integral, large scale experimentson H2O and PbLi technologies.HCPB BB shielding performance studies G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 6• Assessment of shielding options for the HCPB blanket to reduceVV long term activation.• The following nuclear responses have been assessed: Effect on DPA accumulation in the VV; VV Activation.• Two shield integration options: inside the manifolds and on theback of the BSS.P. Pereslavtev et al., Analyses of the shielding options for HCPB DEMO blanket (POSTER)DPA/FPY ZrH1.6 TiH2 WBInside 0.015 0.014 0.019Outside 0.010 0.008 0.012Achievements:• DPA accumulation in the VV inner shell: In the HCPB original – 0.14 dpa/FPY; In the HCPB with TiH2 shielddecreased up ~15 times with a 18 cmshield.• With 18 cm TiH2 shield reduction of VVactivation by a factor of ~10;Issues to be still addressed:• Integration feasibility (TH/TM);• Impact on cost of the HCPB BB.ShieldBSSWater activationG.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 7Design activityNuclear analysis to assess N prod. rate distribution3-D CFD analysis to assess In-Vessel N concentration1-D lumped approach analysis to assess Ex-Vessel PHTS N distributionConvergence?Dose rates assessment around PHTSs key locations Acceptable?EndYESNOYESNO16N/ 17N16N/ 17NPossible location of PHTS isolation valvesP. Chiovaro et al., Investigation of the DEMO WCLL Breeding Blanket Cooling Water Activation (POSTER)I. Moscato et al., Assessment of the Dose Rates due to Water Activation on an Isolation Valve of the DEMO WCLL Breeding Blanket Primary Heat Transfer System (POSTER)Water activationG.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 8• Assessment of the dose in FW and BZ cooling circuit due to  and neutron radiationfrom 16N and 17N has been carried out;• The  and neutron source has been implemented in the water domain of the UpperPipe Chase considering the inventory of 16N and 17N concentration;• A period of 7 FPY has been considered.Photon Dose [MGy]Neutron Dose [MGy]TER HCPB design • The HCPB TER technology is based on HTO trapping (@ 20°C) on reactive molecular sieve beds(RMSB) followed by cryo-absorption (CMSB @ 77 K);• Large amount of liquid nitrogen (~ 400 - 500 kg/h);• Bulky system due to the large He purge gas flowrate ~ 10,000 Nm3/h;G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 9The former cold trap for HTO has been replaced with RMSB and T will be recovered by D2 swampingBB(1)(8)(7) (6)(2)(3a)(4)(5a) (5b)(9)(3b)(1)/(4)      Heat exchangers(2) Cooler(3a)/(3b) RMSBs(5a)/(5b) CMSBs(6) Heater(7) Circulator(8) He processing plant(9) TankHe-0.999H2-0.00110,000 Nm3/hHe-0.999H2-9.5E-04HT-7.3E-06HTO-3.5E-07H2O-3.4E-05I. Cristescu et al., Developments on the Tritium Extraction and Recovery system for HCPB (POSTER)• Possibility to use purge gas containing steam to mitigate the T permeation in the BB coolant is currentlyinvestigated.Vacuum channelV-sheet1.2 m1.4 mVanadium PAV for CLIPPERNiob TR EX-IIDesign ParametersCIEMAT PAV mock-upValuePbLi velocity 1-4E-2 m/sPbLi mass flow rate ~160 kg/sPbLi temperature 330°CChannel height 5E-3 mMembrane thickness 1E-3 mTotal membrane area 2800 m2Volume of PbLi 7.00 m3Vacuum volume 7.07 m3TER WCLL design – PAV technology G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 10• Permeator Against Vacuum (PAV) is the selectedtechnology for the WCLL TER;• Gas Liquid Contactor (GLC) is the back-upsolution;• PAV is based on tritium permeation through amembrane in contact with Pb-16Li/vacuum.• Two PAV design:• Vanadium membrane to be qualified inCLIPPER facility (CIEMAT);• Niobium membrane to be qualified in TRIEX-IIfacility (ENEA). ENEA PAV mock-up0.5 m/sPbLi mass flow rate 250 kg/sPbLi temperature 330°CPr ssure Drops <0.3 MPaVessel Diamater 4 mHeight tank 7 mDesign Parameters for WCLL BB TERPb-16Li mass flow rate [kg/s] ~956N. Pb-16Li Loops (IB+OB) 6Pb-16Li mass flow rate IB/Pb-16Li loop [kg/s]55Pb-16Li mass flow rate OB/Pb-16Li loop [kg/s]264TER Pb-16Li inlet Temperature  [°C] 330-500TER efficiency [%] 80-90• TRITON: first PAV prototype (V membranes) was assembled and first tests performed:• Two new approaches for complex manufacturing process : EB welding (satisfactory preliminarytests) / use of special gaskets.TER WCLL design – PAV technology G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 11Planned activities• First PbLi injection Oct 2019• First experiments Jan-2020• First phase: demonstrate the technique at mostfavorable scenario (high H partial pressure,temperature, reduced mass flow rate);• Second phase: test matrix operation focused onWCLL conditions.O3‐1.2, D. Rapisarda et al., Tritium extraction from PbLi: Technologies and Progresses (TALK)• CLIPPER (CIEMAT) aims to demostrate the feasibility of PAV in different scenarios (test section: 300- 500 ºC / 0.1 - 1 m/s)CLIPPERV PAV for CLIPPERTER WCLL design – GLC technology G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 12The Gas/Liquid Contactor technology• Diffusion interchange between gas and liquid phase;• Vertical columns filled with a packing → large interfacialsurface, count.r-current and co-current flow;b h (5 units)[cm]D [cm]Qgas[Nl/h]IB 50 kg/s PbLi153,8 150 117586,5 200 1175OB 250 kg/s PbLi793 150 5877432,5 200 5877• 5 units foreseen for each PbLi circuit → modules arranged in series (OB total heightmodule 5 m);• Large size of GLCs → compromise can be achieved (shorter height, larger diameter);GLC for TRIEX-IIDesign Parameters for WCLL BB TERTER WCLL design – GLC technology G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 13• GLC mock-up was qualified in TRIEX-II loop in 2019 showing a tritium extraction efficiency up to 44%(He and He + H2 used as stripping gas).Mass spectrometer resolution: 1- 5amu and 1- 200 amuTRIEX-II (ENEA) SaturatorGLC -ExtractorParameters ValueDesign Pressure 1.0MPaDesign Temperature 530°CPbLi Mass flow rate 0.1-8kgH2 concentration  in PbLi 0 - 3.000 PaD2 concentration in PbLi 0-3.000 PaStripping gas HeliumHe (4.002 a.m.u.)D2 (4.028 a.m.u.)M. Utili et al., Characterisation of Tritium Extraction Unit from Liquid Pb‐16Li alloy of WCLL‐TBM in TRIEX‐II facility (POSTER)Tritium transport analysis • The HCPB/WCLL models have beendeveloped using the object orientedsoftware EcosimPro;• The HCPB/WCLL systems aremodelled using a process flowdiagram;• Each component computes a certainamount of dynamical equations.• Current HCPB and WCLL modelsintegrate the ancillary systems:• PHTS;• IHTS;• TER;• CPS.G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 14Issues to be still addressed:• He leakage from the PHTS;• T permeation from plasma through the FW.• Correct implementation of co-permeation.Tritium transport analysis G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 15HCPB Permeation Rate (in 25 days) ValueFrom Purge Gas to Coolant, g/d 1.12From PHTS to Environment, g/d 0.002From Purge Gas to Environment, g/d 0.006Input for HCPB ValueTritium generation rate, g/d ~ 320Purge gas G, kg/s ~ 0.5H2 in purge gas, % wt. 0.1TES efficiency, % 80H2 addition in coolant, % vol. 0.1CPS efficiency, % 95CPS bypass, % 0.083HCPBInput for WCLL ValueTritium generation rate, g/d ~ 320TES efficiency, % 80H2 amount in coolant, ppm 8CPS efficiency, % 90CPS bypass, % 0.01WCLL• Tritium permeation rate into coolant between~16-38 g/d depending on CPS mass flow rateand assumptions on anti-permeation barriers;• The isotopic exchange reaction between HTand H2O trap most of the permeated tritium asHTO.Tritium permeation experiments• Experiments have been designed to calibrate the key WCLL and HCPB permeation parameters (e.g.Sievert’s constant) into the modelling tool (e.g. EcosimPro);• Results are relevant also for the EU TBM program.G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 16 Inner volume  (V1)Outer volume (V2)Gap (V3)BD101BD102,BD103Experiments relevant for the WCLL Permeation from BZ to coolant:o NO PbLi. He with a T partial pressure asexpected in WCLL breeder is applied (V1);o Water at ~ 350°C (V2). Permeation through SG:o Tritiated water at ~ 350 °C (V1).Assessment of dissociation and atomicpermeation;o NO tritiated Water at ~ 350°C (V2).Experiments relevant for the HCPB Permeation from BZ to coolant:o He with T (V1);o He with hydrogen/deuterium at various partialpressure (V2).O3‐2.4, A. Ying et al., Recent Advances in Tritium Modeling and Impacts on Tritium Management for Outer Fuel Cycle (TALK)Helium CPS pre-conceptual design G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 17• CPS main function  extract H isotopes from coolant;• Two processes are currently considered:1. Scale-up of the ITER-based solution (CuO + ZMS beds);2. New approach based on Non-Evaporable Getter, NEG.• T permeation rate into Helium primary coolant is in the order of 0.1 – 1 g d-1;• Presently No anti-permeation barriers.• CPS unit coolant by-pass of 3 kg s-1;• The resulting HT concentration inside HCS is between 4×10-3 – 4×10-4 Pa;1. ITER‐based solution(CuO + ZMS beds) 2. New approach (NEG technology) O3‐2.5, A. Santucci et al., The issue of tritium in DEMO coolant and mitigation strategies (TALK)Water CPS pre-conceptual design • T permeation rate into Water primary coolant is about 40 g d-1;• Anti-permeation barriers from blanket into primary are required (PRFBB>100);• If a PRFBB ≥100 is applied, the water CPS has to treat a coolant flow rate of about 20 kg d-1 (i.e. like ITERWater Detritiation System);• And the resulting T concentration in water primary coolant is below 1.85×1011 Bq kg-1 (limit assumed inCANDU reactors).Water CPS on‐lineG.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 18O3‐2.5, A. Santucci et al., The issue of tritium in DEMO coolant and mitigation strategies (TALK)Summary and OutlooksSummary• Significant progresses have been made on the design of the HCPB and WCLL BB segments and ofthe HCPB and WCLL TERs.• The impact of the BB systems design on the interfacing DEMO components and system have beenstudied focusing on the BB radiation protection and on the tritium management system.• No showstopper are identified: for different issues (HCPB shielding, WCLL coolant activation, CPSfeasibility, TER feasibility) dedicated solutions have been identified and will be further investigated.• A focused R&D program is running to validate technologies (TER, CPS) and assumptions made intritium modelling (co‐permeation, Sievert constant).Outlooks• BB design simplification for improving manufacturability and reliability.• Selection of the technologies for the Tritium management systems and definition of the workingpoint.• Qualification of TER and CPS technologies by R&D program.• Associate to BB segments and TER system design a sound cost estimate, implementing from theconceptual phased cost reduction measures.G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 19G.A. Spagnuolo | 14th ISFNT | Budapest 22nd - 27th September 2019 | Page 20

Progress of the conceptual design of the European DEMO Breeding Blanket, Tritium Extraction and Coolant Purification Systems

Progress of the conceptual design of the European DEMO  Breeding Blanket, Tritium Extraction and Coolant Purification Systems    F. Cismondia*, L.V. Boccaccinib, P. Chiovaroc, S. Ciattagliaa, I. Cristescub, C. Dayb, A. Del Nevod, P.A. Di Maioc, G. Federicia, F. Hernandezb, C. Morenoe, I. Moscatoc, D. Rapisardae, A. Santuccid, G.A. Spagnuolob, M. Utilid    aEUROfusion Consortium, Programme Management Unit, Garching, Germany  bKarlsruhe Institute of Technology, Karlsruhe (KIT), Germany cDipartimento di Ingegneria, Università di Palermo, Viale delle Scienze, 90128, Palermo, ITALY dENEA, Fusion and Technology for Nuclear Safety and Security Department, Italy eCIEMAT, Fusion Technology Division, Madrid, Spain  *Corresponding author: fabio.cismondi@euro-fusion.org  In the frame of the EUROfusion consortium activities the Helium Cooled Pebble Bed (HCPB) and the Water Cooled Lithium Lead (WCLL) concepts are being developed as possible candidates to become driver Breeding Blanket (BB) for the EU DEMO, which aims at the tritium self-sufficiency and net electricity production. The two BB design options encompass water or helium as coolants and solid ceramic with beryllium/beryllides or PbLi as tritium breeder and neutron multipliers. The BB segments have evolved towards a more stable conceptual design taking into account multiple feasibility aspects and requirements imposed by interfacing systems. The reference and back-up technologies for the Tritium Extraction and Removal (TER) from the helium purge gas and the PbLi are developed addressing key feasibility aspects and implications on the tokamak layout. The impact of water coolant activation is assessed by studying the spatial distribution of 16N and 17N isotopes dose rates, in particular in proximity of isolation valves. As the BB internals offer and ideal environment (high temperatures, thin structural material) to promote the tritium permeation, studies are devoted to the assessment of the permeation rate and inventory in the coolant. Those are the key parameters for the feasibility assessment and technology selection for the Coolant Purification Systems (CPS) as well as for assessment of the tritium permeation at the Steam Generator and the associated Safety analyses of the DEMO plant.   Keywords: Breeding Blanket, Coolant Purification, Tritium Extraction and Removal   Topic Category  Blanket Technology, Fuel Cycle and Tritium Processing  Presentation Preference x Oral Presentation □ Poster Presentation 

https://publikationen.bibliothek.kit.edu/1000092104/40777222

Progress of the conceptual design of the European DEMO Breeding Blanket, Tritium Extraction and Coolant Purification Systems

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