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Published byRaymond Arnold Modified over 9 years ago
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Pre-Lehman Review Briefing Reiersen December 18, 2006
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Purpose of briefing We need to have and present a common understanding of our risks and mitigation plans We need to work together to update our near term plans ASAP –DOE has given us the nod on ECP53, an accounting windfall where we will assign budget to near term risks –We do not yet have a resource loaded schedule that hangs together. This needs to be priority one following the review. –A possible outcome of the Lehman Review is that they recommend re-baselining. That is months away and will not impact what we do with our hands and feet right now.
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Current assessment of significant risks Risks previously identified at the May review have been retired or capped (MC winding costs) Emerging risks include… –Modular coil assembly cost and schedule –Field period and final assembly risks –Future procurement (Structures, PF coils) cost risks –150C bakeout system
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Modular coil assembly cost and schedule The time and resources required to assemble the modular coils into 3-packs on FPA Station 2 was re-estimated –Design did not change but ETC did –Large amount of time devoted to Metrology Installing shear plates Custom fitting (grinding) shims –Number of shifts and labor costs more than doubled relative to the previous estimate for Station 2 Holding the schedule would require a second Station 2 plus some second shift work Assembly working group formed to bring fabrication and assembly input into design development
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Assembly of modular coils
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Assembly time on Station 2 more than doubled since September estimate [f] based on two stations, one 8hr shifts per day, and 21 days per month [g] based on 8 hours days at $85/hr
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Options for reducing costs are being aggressively pursued Eliminate or reduce shear plates –Add bolts to the inboard legs Reduces required COF from 0.75 to 0.45 –Use high friction (diamond coated) shims on inner leg (not outboard) COF of 0.6 achieved on NSTX Prototype the shear plates, shims, and bushings to refine the installation procedure and the estimate for the time and resources Stock shims in multiple thicknesses so custom grinding is not required Issues to be resolved in January
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Friction required to prevent IL slippage
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Key activities to resolve MC interface design Friction testing (Gettelfinger) –Diamond coatings Grit size Binder Shim surface condition (mill, machined, ground, blasted) –Shim testing Shim surface condition (mill, machined, ground, blasted) G11CR on steel (flange) Steel (shim) on steel (flange) –Eventually do static and cyclic testing at 80K Bolted joint analysis (Myatt) –Determine capacity of pin joint –Determine max preload with through-bolts and with threaded holes Finalize design criteria for hybrid joints (friction joints with tight fitting bolts) Identify best locations for the minimum set of bolts to get us down below mu=0.45 in Brooks’ analysis Resolve bladder issues –Steel v. Teflon v. fabric –At wing tip only or under whole wing
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Field period assembly risks Input at the FPA Peer Review gave us a keener appreciation of assembly risks Concerns raised included… –measurement accuracy and approach –metrology equipment type and number –alignment mechanisms –bolted joints and reaming operations –use of prototypes and mockups –schedule allowances Assembly risks extend to final assembly as well Do not appear to have a coherent plan for addressing these risks – need to get on this ASAP
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FPA risks have been identified and mitigation plans are being developed Dimensional control objectives are at risk if the measurement campaigns are not well planned –The accuracy of the Leica laser tracker and Romer arm under real world conditions will be determined –Line-of-sight studies will be performed to determine the optimum number and placement of fiducials –Stability of the tooling will be factored into the tooling design Schedule and technical objectives are at risk if suitable trial assemblies are not performed on prototypes –The use of prototypes and mockups is being expanded Alignment options Shear plate prototype Coil assembly prototype using two Type C coils (including interface hardware)
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FPA risks have been identified and mitigation plans are being developed Schedule and technical objectives are at risk if a sufficient complement of metrology equipment and support staff is not available –A metrology utilization study will be performed to determine the optimum metrology equipment type and number. Support staff requirements will also be assessed. –The budget for systems engineering support of metrology activities was recognized to be inadequate and is being increased in ECP53 to cover near term needs. –A metrology group has been organized within the Engineering Department in response to the support needs on projects like NCSX and NSTX –NCSX is pursuing options for involving experts outside NCSX in the project. Joe Error (ORNL/SNS) has said he would be glad to help. Need to get the elements of this plan into the resource loaded schedule ASAP
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Future procurement cost risks Unconventional components always carry the risk of cost surprises before bids are received –MCWF/VVSA are good examples Significant spread among bids submitted Significant difference between prior budgetary cost estimates and bids from the same supplier –Raw material prices, e.g. nickel and stainless steel, are volatile and recently have been increasing much faster than inflation with a big impact on procurement costs Budgetary cost estimates are solicited and potential suppliers engaged in discussions to identify cost risks and focus value engineering efforts to mitigate cost impacts
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PF Coils and Structures are the largest remaining procurements PF Coils (PF4, PF5, and PF6) –The diameter of the large ring coils (up to 18’) drives facility space requirements and raises transportation issues –Raw material costs (Cu) for conductor also a concern PPPL is investigating using internally cooled cable (QPS) conductor in the PF coil design –Fabrication costs are expected to be lower than with solid copper conductor –Transportation issue could be avoided by winding in the NCSX Mfg Facility with existing turntable –Could also be advantageous for PF1-3 (future upgrades) Estimates for outside procurement and in-house fab will be developed in the next two months –Possibly an $500K+ problem –Update on make-or-buy decision to follow
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PF Coils and Structures are the largest remaining procurements Structures ($1013K budgeted) –Baseline design features large SS castings to support TF and PF coils –Dramatic increases in raw materials costs (stainless steel) introduce significant cost risks –Another $500K+ problem
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Simplified structural support concept A radically simplified structural support concept is being considered which could reduce assembly time and cost as well as procurement costs –TF supported directly off the modular coil shell – no separate structure –Pre-load provided through ring above/below CS –PF5 supported off MC shell –PF6 supported off TF coils –CS and PF4 supported off floor –Modular coils supported directly by the base support structures Eliminates Stage 4 Allows access for C-C fit-up at final assembly if end TF coils are left out Need to evaluate performance, configuration, and C&S impacts ASAP and make a determination on whether to go ahead
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150C bakeout system Current design for 150C vacuum vessel bakeout system relies on induction heating via the coils Non-uniform heating of the vessel and unwanted heating of the modular coils and other cold structures pose potential technical risks that have not been addressed An alternative being investigated is to blow heated air through the vessel heating / cooling tubes –If adopted, would cost an estimated $314K –Most of the cost is in SS piping which could also be used for 350C bakeout system –Inexpensive upgrade path to a 350C once-through air system is an attractive feature
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Risks and mitigation options Emerging risks have been identified Options for reducing costs are being aggressively pursued Some cost risks appear unavoidable
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Near term priorities Come to closure on modular coil interface design –Reasonably addressed in update on 1421 Develop a coherent development plan for FPA –Develop a well constructed plan for metrology and prototype/mockup tasks –Activities to date seem ad hoc rather than steps in a well constructed plan Decide on whether to pursue simplified structure option Document the path forward in an updated resource loaded schedule – all pieces have to fit together
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