1. 1 MYRRHA A Multipurpose European ADS for R&D State-of-the-art at mid.2003 International Workshop on New Applications of Nuclear Fission (NANUF03) Bucharest (RO), September 7-12, 2003 Hamid Aït Abderrahim On behalf of the MYRRHA Team SCKCEN Boeretang 200, B-2400 Mol, BELGIUM myrrha@sckcen.be

2. 2 Contents 1. Introduction 2. Applications 3. Accelerator 4. Spallation target module 5. Sub-critical reactor engineering 6. Remote handling & ISIR 7. Conclusions

3. 3 Introduction (1) Europe : 35% of electricity from nuclear energy produces about 2500 t/y of used fuel: 25 t (Pu), 3.5 t (MAs: Np, Am, Cm) and 3 t (LLFPs). social and environmental satisfactory solution is needed for the waste problem The P&T in association with the ADS can lead to this acceptable solution. Therefore we need an experimental ADS demo facility in Europe. We are willing to make MYRRHA to be The European XADS demo facility We are also willing to serve as an IRRADIATION FACILITY for Fusion and Gen.IV material research & development in a later stage

4. 4 Introduction (2) MYRRHA is intended to be:  A full step ADS demo facility  A P&T testing facility  A flexible irradiation testing facility in replacement of the SCK  CEN MTR BR2 (100 MW)  A fast spectrum testing facility in Europe, beyond 2010 complementary to RJH (F)  A testing facility for fusion program  An attractive tool for education and training of young scientists and engineers  A medical radioisotope production facility

5. 5 R&D Applications (1) ADS full concept demonstration  coupling of the 3 components at reasonable power level (ca 40 MWth), operation feed-back, reactivity effects mitigation scalable to an industrial demonstrator Safety studies for ADS  beam trips mitigation  sub-criticality monitoring and control  restart procedures after short or long stops  feedback to various reactivity injection  spallation products monitoring and control  … MA transmutation studies  need for high fast flux level (Φ >0.75MeV = 10 15 n/cm².s) LLFPs transmutation studies  Need for high thermal flux level (Φ th > 10 15 n/cm².s)

6. 6 R&D Applications (2) Radioisotopes for medical applications  Need for high thermal flux level (Φ th = 2 to 3.10 15 n/cm².s) Material research for PWR and BWR  Need for large irradiation volumes with high constant fast flux level (Φ >1 MeV = 1 ~ 5.10 14 n/cm².s) Material research for Fusion  Need for large irradiation volumes with high constant fast flux level (Φ fast = 1 ~ 5.10 14 n/cm².s with a ratio appm He/dpa(Fe) = ~15 ) Fuel research  Need irradiation rigs with adaptable flux spectrum and level (Φ tot = 10 14 to 10 15 n/cm².s)

7. 7 Accelerator 1) NC Cyclotron Initial choice “Normal Conducting Cyclotron” was motivated by:  start from existing technology  the most powerful CW accelerator in the world is the PSI cyclotron : 590 MeV * 1.8 mA  IBA technology : Cyclone-80 (80 MeV but tested up to 7 mA) and cyclotron of proton therapy (250 MeV but limited to few µA)

8. 8 Accelerator 2) NC Cyclotron solution 4 sector cyclotron physical magnet diameter of 16 m diameter total weight ~ 5000 t

9. 9 Accelerator 3) LINAC Now considering :  Supra-conducting magnets cyclotron for reducing the dimensions (factor 2)  Even better for the ADS demonstration a LINAC approach is now favoured as a result of the WP3 of FP5 PDS-XADS project, indeed  The LINAC, with SCRF (super-conducting radio- frequency) cavities for the high energy part is considered as "the solution of choice" for high- power accelerator applications, that is for a power level which exceeds, say, 2 MW

10. 10 Accelerator 4) LINAC WP3 is presently investigating in more detail that :  such a LINAC matches perfectly the required energy regime,  its inherent modularity allows an easy upgrade to whatever energy finally demanded for industrial transmutation,  the projected beam currents of such a LINAC, very safely fulfil the industrial request, two other considerations emerge as being in particular support for a SCRF based LINAC for ADS:  reliability, availability, maintainability  cost-optimisation of the operation

11. 11 Accelerator 5) LINAC sketch for ADS

12. 12 Spallation Target: 1) Radial Geometrical Constraints Small assembly configuration

13. 13 Spallation Target: 2) Boundary Conditions 350 MeV, 5 mA proton beam for fast neutron fluxes for transmutation, i.e. 1.75 MW of which 80 % is heat 130 mm penetration depth for 350 MeV - Bragg peak 72 mm ID radial extent of the beam tube + 122 mm OD radial extent of the feeder - limited by neutronics Windowless target due to high beam load - despite vacuum Pb-Bi because of neutronic and thermal properties  1.4 MW heat in ~ 0.5 l to be removed while meeting thermal and vacuum requirements

14. 14 Spallation Target: 3) Desired Target Configuration Volume-minimized recirculation zone gets lower ‘tailored’ heat input Example of radial tailoring High-speed flow (2.5 m/s) permits effective heat removal Irradiation samples Fast core BEAM

15. 15 Spallation Target: 4) Design and R&D Approach Interaction between: Experiments with increasing complexity and correspondence to the real situation (H 2 O–Hg–PbBi) CFD simulations to  predict experimental results  optimize nozzles for experiments  simulate heat deposition which can not yet be simulated experimentally

16. 16 Hg Experiments at IPUL  Main flow  Adding/Removing Hg from cylinder  Vacuum system 8 ton Hg Q up to 11 l/s Vacuum above free surface < 0.1 mbar Minimal pump load is necessary (to avoid pump cavitation)

17. 17 DG16.5 Hg Experiments nominal volume flow 10 l/s 60 16.5° Close to desired configuration !  intermediate lowering of level  some spitting  axial asymmetry

18. 18 DG16.5 H 2 O Experiments nominal volume flow 10 l/s vacuum pressure 22 mbar  Similarity check: OK !

19. 19 Spallation Target: 5. Future Steps Pb-Bi Experiments at FZK (KALLA)  Similar size as IPUL loop  Similar complexity as MYRRHA loop: 2 free surface + mechanical impeller pump  fall 2003 Pb-Bi Experiments at ENEA (CHEOPE)  Minimum closed loop configuration  MHD pump  Speed feedback regulation test  fall 2003 Proton beam heating  Simulation with CFD code (e.g. FLOW-3D)  Simulated or measured flow field

20. 20 Spallation Loop Technical Lay-Out

21. 21 Sub-Critical Reactor 2) Pb-Bi: benefits and drawbacks Undergoes spallation Reasonable melting temperature (123 °C) Water can be used for the secondary cooling  High coolant density (steel and fuel float)  Opaque: blind fuel handling  Possible problems in case of variation of the eutectic composition (deposits of high melting point phases)  Bi activates into Po  The compatibility of Pb-Bi with structural and cladding materials is to be addressed by design

22. 22 Sub-Critical Reactor 3) Engineering Pool type vessel of  4 m X 7 m height Standing vessel to alleviate the highest T in case of LOHS at the most stressed line of the hanging vessel Low high flux exposure => no risk of irrad. embrittlement Internal interim fuel storage (2 full cores, no coupling) 4 HX groups (2 HX + 1 PP) => total capacity ~80 MW T in = ~200°C, T out = 350°C, secondary fluid = water Spallation loop interlinking with the core, cooled via LM/LM HX with the cold Pb-Bi of the core as secondary fluid Fuel handling from beneath via rotating plug

23. 23 MYRRHA Core

24. 24 Radial Layout

25. 25 Vertical View Proton beam line Spallation loop Target nozzle Fast core Main containment vessel

26. 26 Remote Handling & ISIR Due to the high activation on the top of the sub-critical reactor due to the neutron leakage through the beam-line, Due to the a Po contamination when extracting components from the reactor pool, Due to non-visibility under Pb-Bi, We decided from the very beginning to consider the operation and maintenance of MYRRHA with remote handling systems and develop appropriate ISIR and visualisation systems

27. 27 Remote Handling & Building We committed a feasibility study with OTL (UK) - in charge of the RH of JET. We defined:  the plant - by identifying the main components to be considered from the point of view of the RH  the working conditions:  100% inert atmosphere  0% humidity  Particulate and gaseous contamination  Max normal dose rate exposure of 7 Gy/hr  Worst case dose rate exposure of 21.5 Gy/hr  Total dose of 46500 Gy  the tasks to be fulfilled

28. 28 2. PLANT DEFINITION Spallation Loop Core Support Tube Heat Exchangers Main Pumps Internal Robots Lid Diaphragm with chemical insert module Emergency Heat Exchanger Beam Line in MYRRHA Hall Experimental devices Pb-Bi vessel (for decommissioning)

29. 29 Task Requirements Removal and replacement of plant items Plant maintenance (e.g Spallation zone replacement) Decontamination of plant items Packaging of waste items Recovery from failure during plant handling (e.g jamming) Recovery of a failed Ex-vessel Fuel Transfer machine Recovery of debris from Pb-Bi

30. 30 REMOTE HANDLING SYSTEM REQUIREMENTS Fully remote System Availability >95% Fail-safe system Recoverable after failure Perform replacement of Spallation loop within a 3 month shutdown Reach and examine all parts of the MYRRHA Hall Be easy to operate Be easy to support and maintain Be able to deal with unexpected tasks Minimise the secondary wastes Operate in the specified radiation environment for 30 yrs. Manipulate loads up to 60 tonne Perform specialist operations (e.g cutting, welding, 3-D metrology)

31. 31 Remote Handling Approach Man-In-The-Loop using a Bi-lateral, force- reflecting, Master-Slave Servo-manipulator. Robotic features to ease operation Cameras for visual feedback Independent crane for lifting heavy loads Independent tool service system All remote handling work to be done within the same hall Remote equipment and tooling to be stored and maintained within the same hall Use of air-locks for transfers between areas

32. 32 PLANT LAYOUT AND INFRASTRUCTURE MYRRHA Hall Contamination control Commissioning, Assembly, Test and Mock-up facilities Decontamination Waste Packaging Active workshop Remote handling control rooms Health Physics Laboratory

33. 33 7. PLANT LAYOUT AND INFRASTRUCTURE

34. 34

35. 35 MYRRHA RH in action Removal of the spallation loop from the reactor and its positioning in the maintenance pit

36. 36 MYRRHA Visualisation in action Deployment of the In Vessel Inspection Manipulator (IVIM) to inspect the MYRRHA Core internals

37. 37 MYRRHA ISIR system in action Deployment of the In Vessel Recovery Manipulator (IVRM) :  to recover a miss-placed fuel assembly  To inspect the spallation loop circuit ducts

38. 38 R&D Support Program Summary (1) Accelerator  Ion beam optics, beam profile control  Development of the pre-injector system  Extraction efficiency  Demonstration of a high energy SC cavities Spallation module  Flow pattern  Vacuum / LM interface compatibility Instrumentation  Visualisation under LM (US sensors under development for high T, high radiation environment, under Pb-Bi)  Sub-criticality monitoring

39. 39 Corrosion under LM  Assessment of candidate structural material (T91, A316 and EUROFER) at MYRRHA operating conditions and under neutron irradiation in BR2 and via FP5  LME assessment  Corrosion control methods assessment (O 2 control, Inhibitors, coating) via FP5 Material embrittlement under irradiation  Assessment of candidate structural material (T91, EM10, HT9) in BR2 and via FP5  High dpa irradiation under consideration with RIAR in BOR-60 under negotiation Fuel Development : pin & assembly  Irradiation programme under preparation in BR2 and BOR-60 R&D Support Program Summary (2)

40. 40 R&D Program Partnership Network Accelerator  IBA (B) Spallation source  Basic spallation data  NRC Soreq (I) + PSI (CH)  Feasibility of the windowless design  UCL (B) + FZR (D) + FZK(D) + NRG (NL) + CEA (F) + ENEA (I) + IPUL (Latvia)  Compatibility of the free surface with the proton beam line vacuum  ATL (UK), SDMS (F) Subcritical assembly  ENEA (I) + CEA (F) + BN (B) + UoK-UI (LT), IPPE & GIDROPRESS (Russia), TEE (B), CIEMAT (Sp), RIAR (Russia) Safety  TEE (B), AVN (B) & FANC (B) (Information & contacts) Robotics  OTL (UK) Building  IBA (B), OTL (UK)

41. 41 Conclusions MYRRHA design is progressing continuously towards the detailed engineering design MYRRHA is developing many innovative feature that can be deployed in any future nuclear facility MYRRHA is allowing to maintain high skills in the nuclear field MYRRHA is intended to serve the European ADS programme

42. 42 Conclusions The best merits of ADS and P&T are:  the rejuvenation of our field of activity and you can see that through the amount of requests for PhDs or trainings from young people in this field,  The renewal of bringing fundamental and applied Physics community together,  The revisiting of reactor physics theory and experimental reactor tools