RA M I Research Thrusts and Issues from a Remote M aintenance Perspective

1. RAMI Research Thrusts and Issues from a Remote Maintenance Perspective Tom Burgess Remote Systems Group Leader (burgesstw@ornl.gov, 865-574-7153) ReNew Workshop Harnessing Fusion Power Theme March 2 - 4, 2009 UCLA Nuclear Science and Technology Division

2. Outline • FESAC 2007 report RAMI knowledge gap • G-15 Maintainability Gap • ITER–era device design maintainability • ITER and ST CTF examples • RAMI remote maintenance specific research thrusts and issues in Fusion Nuclear Science (FNS) • FNS Facility (FNSF) role in closing the maintainability gap as a fully enabled fusion nuclear environment T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

3. FESAC 2007 Report RAMI Knowledge Gap • Identifies “Reliability, Availability, Maintainability” (and Inspectability, or RAMI) as one of the 15 knowledge gaps between ITER and Demo that must be closed in order to provide the technology base to design and construct Demo • More specifically, RAMI is cited as critical to Demo success in order to “demonstrate the productive capacity of fusion power and validate economic assumptions about plant operations by rivaling other electrical energy production technologies” • In addition, RAMI research is necessary to build “the knowledge base for efficient maintainability of in-vessel components to guarantee the availability goals of Demo are achievable” T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

4. FESAC Report on Opportunities, etc. identified 15 gaps for fusion energy – 9 in engineering and nuclear science and technology 3 Themes: A BC A - Creating predictable high-performance steady - state plasmas: ITER + stellarators + superconducting tokamaks + modeling; plasma control technologies (magnets, plasma heating and current drive, fueling etc.) – likely via international collaborations. B - Taming the plasma-material interface: plasma wall interactions (sputtering, melting etc), plasma facing materials and components (high heat flux, rf antennas etc.) under very high neutron fluence C - Harnessing fusion power: tritium breeding & handling, high grade heat extraction, low activation materials, safety, remote handling 4 T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

5. The Fusion Remote Maintenance Challenge • The fusion nuclear environment is viewed by many as the most challenging of the remote handling applications • Characterized by: • Extreme shutdown radiation levels (≥ 106 rad/hr gamma) • State-of-the-art rad hardness RH tech = 108 rad TAD • Space-constrained in-vessel access ports that are in direct conflict with simple, expedient handling and maintainability • “Ship-in-a-bottle” maintenance approach • Large, heavy in-vessel components with complex mounting and service connections • Precision component positioning and complex handling kinematics by robotic mechanisms that are well beyond today’s state-of-the-art technology • Handling and transport of large activated components through plant facilities, followed by refurbishment in hot cell laboratories • Operations that are challenging and unprecedented in themselves T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

6. Dexterous Manipulation of Heavy Payloads Involves Significant Scientific and Technical Challenges • The precision with which certain components in burning plasma experiments (ITER and beyond) are to be manipulated is beyond the realm of the state of the art • R&D in the areas of advanced control algorithms based on non-linear mathematical modeling and advanced telerobotic control architectures are needed • Development and implementation of human-in-the-loop control of remote manipulation systems are also needed T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

7. Where We Are • Only one fusion experiment has applied remote maintenance technology to an appreciable extent - JET • No fusion experiment ever built and operated is representative of a nuclear fusion power source • ITER is expected to operate only a small percentage (annual plasma duty factor ~ 1 to 2 %) • ITER remote maintenance is performed in a very time inefficient manner with remote maintenance outage durations that range from several months to multiple years • Availability goal of Demo (≥ 50%) is extremely challenging and unprecedented given the very limited operation and power production of fusion experiments to date, and the inherent complexity of all envisioned fusion reactors T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

8. Current Baseline Requirements for In-vessel/ex-vessel RH Interventions COMPONENTS MAINTENANCE REQUIREMENTS PLAN • The ITER remote handling equipment design and procurement is based on a maintenance requirement plan. A. Tesini, June, 2007 Prefit Workshop, Culham Lab T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

9. Example ITER Scheduled Annual Remote Maintenance • * Assuming 16-hr days, 6 work days per week • The remote maintenance operation time (alone) would be ~ 26 weeks (50% of year) • The time to shutdown, cool down, vent and then pump down and condition back to plasma operation adds ~ 4 weeks for 30 weeks (58% of year) • One unscheduled failure requiring separate VV intervention will add 4 weeks and the additional remote maintenance activities, or ~ 8 or more weeks for a port assembly, for 38 weeks (73% of year) or more T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

10. The Vision • The most agreed and foreseen solution to acceptable component MTTR time is large integrated in-vessel component modules that are time efficient for remote exchange between the core and hot cell, with off-line refurbishment performed in the hot cell • Concepts of FNSF, ARIES and Demo developed to date by multiple organizations include this common feature • But no representative fusion device is officially planned before Demo and the design efforts are small T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

11. ST Component Test Facility (CTF) Diverter/SOL Shaping Coil Access Hatch (VV/TFC Return) Inlet Piping TFC Center Leg Sliding Joint Outlet Piping • Provides fusion nuclear technology test environment in support of Demo development • ITER-era • Wall load: ~ 1 MW/m2 • Fluence,~ 3 MW-yr/m2, (6 MW-yr/m2 later phase) • High Plasma Duty Factor Goal (~ 10 to 30%) • User Facility maximizing test ports • Builds on ITER RH approach and technology Plasma R0=1.2 A=1.5 к=3.2 δ=0.4 Ip = 12 Upper Diverter Inboard FW (10cm) Upper Breeding Blanket Poloidal Field Coils Outboard FW (3cm) Test Module Blanket Test Section Lower Breeding Blanket Neutral Beam Duct Shielding Lower Diverter TFC Return Leg / Vacuum Vessel Vacuum Seals Support Platform T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

12. ST CTF has High Maintainability, Low MTTR, Using Large Integrated In-Vessel Modules • Similar to fission power plants, large vertical top access with large component modules with simple vertical motion expedites remote handling, minimizes MTTR and maintenance outages • All welds are external to shield boundary are hands-on accessible • Parallel mid-plane/vertical RH operation Centerstack Assembly Upper Blanket Assy Lower Blanket Assy Upper PF coil Upper Diverter Lower Diverter Lower PF coil Upper Piping Electrical Joint Top Hatch Shield Assembly NBI Liner Test Modules Disconnect upper piping Remove sliding electrical joint Remove top hatch Remove upper PF coil Remove upper diverter Remove lower diverter Remove lower PF coil Extract NBI liner Extract test modules Remove upper blanket assembly Remove lower blanket assembly Remove shield assembly Remove centerstack assembly T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

13. CTF Vacuum Vessel, Blanket and Port Assembly Shielding Allows Ex-Vessel Hands-on Access VV, blanket and port shielding (steel & water) T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

14. ST CTF Top Vertical Port Facilitates Large Component Replacement To Minimize Maintenance Time Vertical cask docking port Vertical port handling cask (18 meters) Midplane cask docking port Midplane port assembly handling cask Activated component hot cell In-cell servomanipulator ST CTF Remote Handling • To reduce maintenance time / significantly increase plasma duty factor (~ 10 to 30 % goal), a large in-vessel component module approach with vertical replacement is employed T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

15. ST CTF Preliminary RH Class 1 Annual Maintenance Time Estimate = ~ 1/4 Year • Typical annual RH Class 1 (scheduled) remote maintenance campaign might replace: • 2 divertor modules (6 weeks*) • 6 midplane port assemblies (3 weeks ea.*) • NBI ion sources (1 week ea.*) • * Two 8 hr shifts per day, 6 work days per week during shutdown • Each uses a different RH system, parallel operations are possible, and the midplane port changeouts are limiting provided at least 2 are being changed (6 weeks serial time) • Assuming 3 midplane port RH casks are available for parallel operations, it is estimated to take ~ 8 weeks to complete the above tasks provided spare units are available. • Add shutdown and machine pump down / conditioning time of 1 month, and the total outage from plasma burn to plasma burn is ~3 month or0.25 of the year • One unplanned port assembly failure (TBM, RF heating or diagnostics) that shuts the machine down, and that can't be delayed until the scheduled maintenance time, will consume ~ 6 weeks of maintenance time and 1 month of shutdown / startup time, or ~ 0.25 of the remaining year. • Every shutdown requiring opening and venting of the vessel will require in excess of a month to recover, hence in-vessel maintenance should be planned and grouped together • If components are operated to failure, 1 divertor + 1 midplane port failure not occurring at the same time frame could consume ~ 5 to 6 months of the year T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

16. FNS Cross-Cutting Remote Maintenance Technology R&D Gap Thrust Areas • Credible, low MTTR in-vessel component design solutions (time efficient and reliable remote mounting and service connections) that are also highly reliable (high MTBF) • Large scale, radiation-hard robotic devices that can provide dexterous manipulation and precise positioning of highly activated in-vessel components; preferably with simple linear and time efficient motions • Multitude of specialty remote tooling and end-effectors, including precision remote metrology systems to measure PFC alignment and erosion in the extreme fusion environment (high radiation, bake-out temps, vacuum) • Supporting hot cell facility remote handling systems and tooling necessary to refurbish and/or waste process the activated in-vessel components • Methods to expedite vessel opening and conditioning back to plasma operation (reduce the 1 month adder to every intervention) T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

17. The Path Forward • First step in the R&D process is the development of the conceptual and more advanced designs of the high plasma DF / high Availability device, whether a ST CTF or other tokamak, including: • the remote maintenance features of the components • the supporting remote handling systems • facility and hot cell laboratories • This must be done working in close collaboration with the various component designers in order to develop reliable, fully functional, and efficiently maintainable component solutions • Many remote handling elements of these designs will be new and unique, and must be prototyped, tested and demonstrated in mock-ups ranging from relatively small to large in scale • The final and most important step of the development process is the construction and operation of a FNSF from the break-in through the final advanced stages of science and technology demonstration • A FNSF during the ITER era, and beyond, should address all elements of the remote maintenance knowledge gap to Demo, and provide the required step towards developing the experience and knowledge base for credible Demo design solutions. T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

18. Summary and Recommendations • Nuclear fusion remote maintenance solutions are very undeveloped and critical to the success of Demo (current TRL quite low*) • ITER will certainly add to the knowledge base but is very unrepresentative, and major changes are needed to gain efficiency • A TRL level of ~ 6 is needed to close the Maintainability Gap to Demo • In the near term, a strong fusion base program in RAMI with more effort on next step and Demo-representative machines (e.g., FNSF and ARIES) engineering design and R&D is recommended to investigate and advance viable solutions, including the necessary hardware R&D (cold and hot testing) as identified • Ultimately, a FNSF (ST CTF / FDF) device is required to provide the “fully enabled fusion nuclear environment” next step to close the knowledge gap to Demo if it is to achieve an acceptable availability • In addition to closing many other FNS knowledge gaps to Demo * M.S. Tillack et al, “An evaluation of fusion energy R&D gaps using technology readiness levels”, (TRLS), 18th TOFE, September, 2008 T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

19. Back-up slides

20. How Do We Get There (Demo)? • A major change (expediency) in fusion remote maintenance design and techniques must be developed to achieve the specified availability goals of Demo, or even to achieve a plasma duty factor (DF) an order of magnitude greater than ITER (>10%) • An order of magnitude increase in plasma DF is representative of a FNSF and its ST based design concept has shown that major changes in remote maintenance techniques must be employed • A FNSF combining all the aspects of a nuclear environment is necessary to investigate and close the RAMI gap to Demo T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

21. Fusion Nuclear Science Facility Benefits • If acceptable mean-time-to-repair (MTTR) time for all activated fusion components is not developed and demonstrated in conjunction with high component reliability, or high mean-time-before-failure (MTBF), an acceptable fusion power source availability cannot be achieved • A FNSF would provide a major step towards fusion nuclear energy representative remote maintenance techniques, in addition to providing the knowledge base needed in many other important FESAC Report technology gap areas • From “Scientific Exploration” through “Component Engineering Development and Reliability Growth”, all aspects of RAMI would be investigated and advanced in the fully enabled fusion nuclear environment T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

22. ITER Remote Handling • REMOTE HANDLING OPERATION THEATER • Inside the Vacuum Vessel • Inside the Cryostat • Inside the Neutral Beam Cell • Inside the Hot Cell • (under nominal operating conditions) • ITER MAINTENANCE SYSTEM (IMS) • Remote Handling equipment and tools • Hot Cell facility T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

23. Main ITER In-VV Components to be Remotely Handled BLANKET MODULES PORT PLUGS DIVERTOR CASSETTES • Design features • 54 cassettes (∽ 11 ton) • with removable PFC’s • Mechanical connection to vessel • via toroidal rails • Independent hydraulic connection • to cooling circuit • Design features • ˜ 400 modules (∽ 4.5 ton) • Mechanical connection to vessel • via bolts • Independent hydraulic connection • to cooling circuit • Design features • 45 ton (equator plugs) • 20 ton (upper plugs) • Maintenance features • 3 access ports • Handling by robotic movers • & manipulator + • TRANSFER CASKS • Maintenance features • 4 access ports • Handling with special robotic • vehicle & manipulator + • TRANSFER CASKS Maintenance features Handling with special robotic vehicle & manipulator + TRANSFER CASKS T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

24. Blanket Remote Handling System JAPAN Blanket module Max 4.5 tons, exchanged via an In-Vessel Vehicle (IVT) running on a 250mm wide) x 500mm (high) passive rail deployed around the equatorial region. T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

25. Divertor Remote Handling System EUROPE Divertor cassette 3.5m (l) x 2m (h) x 0.8m (w) weight = 8 -10 tonnes. Exchange via “cassette movers” to lift and carry the cassette coupled with dextrous manipulators to handle tooling. Access to the divertor region is via 3 equi-spaced maintenance ports. T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

26. ITER Remote Maintenance Philosophy 12 t 45 t ITER remote maintenance is based on the removal of relativelylarge modular systemsfollowed by refurbishment in a Hot Cell. The main in-vessel sub-systems comprise: • Blanketmodules • Divertorcassettes • Portplugs(containing diagnostics and heating systems) T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

27. Transfer Cask System EUROPE / CHINA Lift between Tokamak levels J.P.Martins T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

28. Hot Cell Remote Handling System ITER FUND T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

29. Blanket handling Upper port handling Divertor handling Equatorial port handling In-vessel viewing system ST CTF Builds on ITER Remote Maintenance Approach • Most time-efficient ITER RH (i.e., port assembly handling) design and experience leveraged and applied • Inefficient “ship-in-a-bottle” handling approach for in-vessel components avoided • Hands-on maintenance employed to the fullest extent possible • Activation levels outside vacuum vessel low enough to permit hands-on maintenance ITER Remote Handling Systems T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

30. Compact Design Allows Close-fitting Shielding, Allowing Ex-Vessel Hands-on Access and Reduces MTTR TFC Center Leg Inboard First Wall RF System • Midplane ports • Minimize interference during remote handling (RH) operation • Minimize MTTR for test modules • Allow parallel operation among test modules and with vertical RH • Allow flexible use & number of mid-plane ports for test blankets, NBI, RF and diagnostics Shielding TBM Remote Handling Cask Plasma Test Module being extracted into cask Neutral Beam Test Module Diagnostic TFC Return Leg/Vacuum Vessel T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

31. Activated Components Transferred Between Machine and Service Hot Cell by RH Casks Midplane Port RH Cask • In-vessel components removed as integral assemblies and transferred to hot cell for repair or processing as waste • In-vessel contamination controlled and contained by sealed transfer casks that dock to VV ports • Remote operations begin with hands-on disassembly and preparation of VV closure plate at midplane port or top vertical port • Midplane ports provide access to test blanket modules, heating, and diagnostic systems housed in standard shielded assemblies that are remotely removed Test Blanket Module Cask Docking Ports Hot Cell T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

32. ST CTF Preliminary RH Classification of Components • Remote maintenance is an important design and interface requirement, particularly for frequently handled items • Components are given a classification to guide the level of design optimization for ease and speed of replacement T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

33. ST CTF Preliminary Component RH Time Estimates T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

34. Example Port Assembly Replacement Tasks and Time Estimates (from ITER and FIRE) • Conditions and Assumptions • Midplane port assembly is removed as an integrated assembly that is lip-seal welded to port, structurally attached at end of port (bolts and/or wedges) and is removed or installed in a single cask docking. • Port assembly is transferred to hot cell and is replaced with a new or spare unit. If the removed assembly is to be reinstalled, the hot cell processing time must be added. • If a port assembly is removed for other than a short period of time, the open port may be shielded to allow personnel access in the ex-vessel region of the machine. The time to install a shielded enclosure at the port is not included in the following estimate and would add days to the estimate. • Operations are conducted in two 8-hour shifts per day (16 hrs total), 6 days per week. • Time to leak check welded lip-seals and pipes not included. Could add a few days to campaign. • Time to detritiate and vent the vessel after shutdown, and pump down and clean the vessel after maintenance are not included. Could add ~ 1 month to shutdown period. T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

35. Example Port Assembly Replacement Tasks and Time Estimates (ITER and FIRE based) • Task and Time Summary(assuming 16-hr days, 6 work days per week) 1) Hands-on prepare port for cask docking and 60 hrs 3.75 days port assembly removal 2) Remotely remove port assembly and transfer to hot cell (remote) 28 hrs 1.75 days • 3) Remotely exchange port assembly at hot cell and return to port 20 hrs 1.25 days • 4) Remotely replace port assembly in port 25 hrs 1.5 days • 5) Hands-on port assembly recovery tasks 56 hrs3.5 days • 189 hrs 11.8 days • Subtotal = 11.8 days + 2 days for leak tests, misc items = 13.8 days = 2.3 weeks (6 work days/week) • With 27.5% contingency = 17.6 days = ~ 3 weeks (6 work days/week, 16 hrs per day) • Assuming 24/7 continuous work weeks = [189 hrs + (2 x 16 hrs)] 1.275 = 282 hrs = 12 days or ~ 2 weeks T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009

36. Examples of Manipulation of Relatively Heavy Payloads JAERI In-Vessel Transporter/Blanket Module Demo ORNL Next Generation Munitions Handler T Burgess, Renew Workshop, UCLA, March 2 – 4, 2009