DCLL TBM R&D Summary Compiled by Neil Morley for the TBM Conference Call Oct 27, 2005
Main DCLL TBM R&D areas R&DMorley Tritium PermeationMerrill Thermofluid MHDSmolentsev SiC/SiC Fab Process & PropertiesKatoh SiC/PbLi/FS CompatibilityPint FS Box Fabrication & Material IssuesRowcliffe,Kurtz Helium Systems Subcomponent TestsWong PbLi Hydrogen ProductionMerrill Be Joining to FSZinkle,Ulrickson Virtual TBMAbdou Advanced DiagnosticsMorley Integrated mockup testsUlrickson,Tanaka Are more tasks required for Engineering R&D??
Categorizing R&D Tasks A system needs to be established to categorize R&D tasks to give a cost range. Suggestion: E = Essential for the qualification and successful execution of the TBM experiment, and no other party is doing it I = Important for the qualification and successful execution of the TBM experiment, or Essential but is definitely being done by another party D = Desirable but the risk is acceptable if not performed R&D subtasks should be categorized separately, if a task includes many subtasks. Costs need to be broken down by subtasks then, if not already done Level 3 and 4 WBS coordinators should categorize tasks, as should R&D performers, to see if there is clear consensus on relative priorities. Deadline for input ??
The following information is requested from each responsible person: What critical need does this R&D address –Establish basic TBM feasibility –Understand/predict TBM performance –Design and fabricate first TBM – EM/S Recommended scheduling of listed R&D tasks Description of each task including: –Main purpose and method (numerical, experimental, …) –Identification of facility/code or description of new/upgraded facility/code required –Description of test section and diagnostics to be fabricated –Anticipated duration and person-years of effort –Any perceived overlap with another US R&D area and similar international R&D Your categorization and justification
R&D Cost Estimate Summary (burdened, 2005 dollars, no contingency) R&D~$34.3M Tritium Permeation($2.8M) Thermofluid MHD$12M SiC/SiC Fab Process & Properties$2.25M SiC/PbLi/FS Compatibility$.75M FS Box Fabrication & Material Issues- Helium Systems Subcomponent Tests$.84M PbLi Hydrogen Production$2.4M Be Joining to FS (TBM PFC)$4.7M Virtual TBM$4.3M Advanced Diagnostics$2.7M Integrated mockup tests$4.34M
Schedule Summary
Modifications/Discussions since the last call
Tritium Permeation Issue and Originally Proposed R&D Issue: Based on current analysis with conservative assumptions, annual tritium permeation to the ITER building appears be higher than projected allowable annual limit Proposed Solution: aluminum or alumina coatings on exterior of PbLi and Helium pipes from TBM to transporter cask and from transporter cask to TCWS building. Proposed R&D: measure tritium permeation from short pipe samples subjected to typical thermal cycling and coated with different materials and different coating techniques to quantify permeation reduce factors. Cost ~ $2.8M
High Performance TBM Tritium Permeation Results TBM concentrations reach an oscillatory equilibrium after ~20 consecutive pulses, while helium pipe SS wall not reach an equilibrium after ~ 2000 consecutive pulses Annual release based on 3000 consecutive pulses is 290 mg-T/a from helium pipes, and 180 mg-T/a from inlet PbLi pipe (total ~470 mg-T/a with limit of 100 mg-T/a); permeation barrier (alumina) or concentric pipe are required Tritium pressure above PbLi (Pa) Number of pulses Number of pulses Tritium release (mg-T/a) Helium piping Pb-17Li piping ITER limit
Key points from tritium permeation conference call discussion The following factors should greatly reduce the permeation –Inclusion of T removal from He coolant –More representative pulse sequences with longer down times –Optimization of the tritium permeator system (longer FS tubes or Nb/Ta tubes) –Natural oxide layers on steels Off-normal factors might significantly increase permeation –Weld cracks, mistaken valve opening, other helium leaks, etc. HCLL situation should be significantly worse due to high T partial pressure More analysis of various cases needed Testing in HH/DD phases to quantify permeation (and even mockups?) New proposed solution if analysis and experience indicate a tritium permeation problem: 1.Swept secondary containment around transporter cask and TCWS skid for controlling leaked or permeated tritium 2.More aggressive permeator development to reduce tritium partial pressure in PbLi 3.Swept secondary containment around all PbLi (and He) piping 4.Operation at lower He/PbLi temperatures if limit is approached
Clarifications on the FCI Fabrication tasks Irradiation experiments –do not include 18J doped samples, –All rabbit capsules to characterize property change and differential swelling of first generation recipe – timing is important to feed 2 nd gen choices –2 nd irradiation is confirmatory on property changes of final FCI SiC/SiC recipe, could potentially be deferred several years
Clarifications on the FCI Fabrication tasks Target electrical conductivity range is not critical for ITER testing –Sergey’s latest paper suggested that optimum FCI of around 100 S/m for a DEMO application at the FW, but other effects, design variation and locations still must be analyzed. –Right now (for ITER testing) we can live with any transverse electrical conductivity (1-500 S/m) and transverse thermal conductivity (2-15 W/mK), but we do want to have a range to explore in testing – Structural integrity, thermal expansion, differential swelling in low dose irradiation, are also important
Thermofluid MHD Tasks - R&D to support reference design - Development of modeling tools - Planning tests in ITER with supporting experiments and modeling; - Contribution to VTBM 900 K 900 K 900 K 900 K 400 K 250 K 250 K 200 K 300 K 300 K 300 K 200 K 200 K 200K 300 K 300k 300 K 300 K 200 K 200 K 300 K 400 K 300 K 200 K 200 K 200 K 200 K 200 K 200 K ? ? TOTAL COST for 10-year: $12 M including hardware
Virtual TBM Schedule and Resources 1.5 man-yr/yr.5 man-yr/yr Cost Estimate $4.3M
Schedule and Budget for PbLi/SiC tasks Total = $0.75M