Technology Department Second LHC Splices Review Review of actions from last review List of recommendations of the first review Status Category A.Various B.Design of main splices consolidation C.Validation/Verification of main splices consolidation D.Management (Schedule, resources) Conclusions 29th of November 2011 Review of actions from last review Second LHC Splice Review 1/28 J.Ph. Tock

Technology Department Review of actions from last review 29th of November 2011 Review of actions from last review Second LHC Splice Review Report form the first LHC Splices Review: “Although the design is well beyond the conceptual stage, it is not yet a final design, and this review cannot be considered a final design review. Therefore, although the conceptual design appears to be good, the committee cannot fully assess the soundness of the design until it is final. Another review, when the design is final, or nearly so, may be advised.” On-going Various 2/28 J.Ph. Tock

Technology Department 29th of November 2011 Review of actions from last review Second LHC Splice Review II.2 4) p5/14 : Make necessary changes so that ground current monitors are installed on all lower current circuits. These ground current signals should be included in the control system to be logged and to be alarmed when above a pre-set level. The alarm level should be substantially below the power supply hardware interlock for high ground current.  uAmp level was targeted  To be studied at QPS (level): See next presentation: R Schmidt [TE-MPE]  To be studied at PC level (See next slide: Courtesy V Montabonet [TE-EPC] Splices Task Force : Review of actions from last review: Ground current monitor (TE-EPC) Various 3/28 J.Ph. Tock

Technology Department Review of actions from last review: Ground current monitor (TE-EPC) 29th of November 2011 Review of actions from last review Second LHC Splice Review Courtesy V Montabonnet  Earthing of the LHC circuits are defined by an Engineering Specification : ‘ Earthing of the LHC DC Electrical Circuits’ LHC-D-ES-0001 EDMS N°  Earthing of the LHC circuits has 4 roles  earthing of the circuits for safety reasons: the load can not be floating,  detection of an earth fault,  limitation of the earth current in case of an earth fault to avoid damaging the circuit elements (mainly instrumentation),  monitoring of the leakage current. Used for the superconducting magnet circuits Various 4/28 J.Ph. Tock

Technology Department Review of actions from last review: Ground current monitor (TE-EPC) 29th of November 2011 Review of actions from last review Second LHC Splice Review Courtesy V Montabonnet RB earth leakage current during precycle RB earth leakage current at 3.5 TeV  Other circuits : LHC600A-10V  Common Mode = 10V (-  neg polarity)  Fuse 1A Various 5/28 J.Ph. Tock

Technology Department Review of actions from last review: Ground current monitor (TE-EPC) Conclusions 29th of November 2011 Review of actions from last review Second LHC Splice Review Courtesy V Montabonnet  Actual LHC earthing circuit role is  earthing of the circuits for safety reasons: the load can not be floating,  detection of an earth fault, [ ‖ Iearth ‖ > 50 mA]  limitation of the earth current in case of an earth fault to avoid damaging the circuit elements (mainly instrumentation),  monitoring of the leakage current without any accuracy, especially around 0mA.  The earth leakage current is the LHC circuits is not well-known and can come from several systems connected to the DC parts.  The uAmp level is not reasonably achievable; the 1-10 mA level could be targeted  No automatic analysis tool on possible drift or a warning except the 50 mA threshold  This could be studied but no action is on-going  ELQA checks the earth current yearly with an accpetance threshold of 1 to 50 uAmp [20 for RQF/D – 50 for RB]  Ground current monitor in QPS will be presented by R Scmidt Various 6/28 J.Ph. Tock

Technology Department Review of actions from last review: Consolidation requirements 29th of November 2011 Review of actions from last review Second LHC Splice Review  See presentation by P Fessia yesterday: “Specification of the consolidation of the main IC splices” II.3 Com3 p6/14: We cannot assess whether or not the shunt meets the requirements, since clear requirements were not set (or at least not presented to us). II.3 Rec2 p7/14: Develop and document a clear set of requirements, calculations and tests to validate the design, and a defined list of additional tests and criteria against which tests can be evaluated. Design of main splices consolidation 7/28 J.Ph. Tock

Technology Department Review of actions from last review: Double shunt on quadrupole busbars (1/2) 29th of November 2011 Review of actions from last review Second LHC Splice Review  See presentation by F Savary yesterday: “The consolidated 'shunt' design”  Thanks to delay of the LS1, this recommendation was actively pursued (6 months) in order to reach a final informed decision. [TF 29/06/2010] Several options for a second MQ shunt were studied, including their feasibility and consequences. Among all these, the external soldered side shunt was the most feasible. However even this option results in several negative consequences: A soldering operation that becomes strongly operator dependent A degradation on the soldering quality of the main shunt A loss in precision of the Quality Control process in its current baseline In addition the expected “redundancy” of this second shunt is extremely limited (no copper surfacing, simultaneous soldering process with the main shunt). In comparison to the MB situation, the margin of safety of soldered surface is larger for the MQ situation. In conclusion, TF recommended to have a single main shunt for MQ and two shunts for MB (per each splice extremity). II.3 Rec1 p7/14: The Committee recommends that a double shunt be applied to the quad bus. Design of main splices consolidation 8/28 J.Ph. Tock

Technology Department Review of actions from last review: Double shunt on quadrupole busbars (2/2) 29th of November 2011 Review of actions from last review Second LHC Splice Review Examples of studied configurations: Design of main splices consolidation 9/28 J.Ph. Tock

Technology Department Review of actions from last review: Clamping system 29th of November 2011 Review of actions from last review Second LHC Splice Review  See presentation “The consolidated electrical insulation” H Prin yesterday II.3 Rec6 p8/14: Continue the development of the design for a clamp that would hold together the shunt and splice in the absence of solder, to help limit the damage during the time of an energy extraction, and implement the chosen design. Design of main splices consolidation 10/28 J.Ph. Tock

Technology Department Review of actions from last review: Industrialisation 29th of November 2011 Review of actions from last review Second LHC Splice Review II.4 1) p9/14: The Splice Task Force needs to work on improving the manufacturing procedures and the tooling in such a way these are reproducible and not depending on the individuals doing the work. This includes developing adequate QC plans. The review committee recognized the fact that, at this stage of the consolidation programme, this is more important than working out a detailed schedule. On-going This review ! Your comments are welcome Design of main splices consolidation 11/28 J.Ph. Tock

Technology Department Review of actions from last review: Radiation protection 29th of November 2011 Review of actions from last review Second LHC Splice Review II.5 2) p11/14: Radiation safety issues related to the splice repair work should be evaluated and considered in any decision to extend the current run. See presentations by C Adorisio yesterday And task force meetings 35 & 55, Chamonix 2011 Design of main splices consolidation 12/28 J.Ph. Tock

Technology Department Review of actions from last review: Lead containing solder 29th of November 2011 Review of actions from last review Second LHC Splice Review II.5 3) p11/14: The Splices Task Force should consider the potential hazards for workers associated to the utilization of lead-containing solder, and work with the Safety Commission to plan the work to minimize or eliminate this risk. See presentation by F Savary yesterday DSO informed Design of main splices consolidation 13/28 J.Ph. Tock

Technology Department Review of actions from last review: Cold test results 29th of November 2011 Review of actions from last review Second LHC Splice Review Report was sent to the reviewers beforehand II.3 Com2 p6/14: The Committee finds results from high current shunt testing between FRESCA and SM18 confusing. Modelling of all test cases should be documented and qualified based on experimental data, and then applied to the shunt design with worst case assumptions. Done Validation/verification of main splices consolidation 14/28 J.Ph. Tock

Technology Department Review of actions from last review: Splices lifetime validation ? 29th of November 2011 Review of actions from last review Second LHC Splice Review  See presentation by Z Charifoulline this afternoon: “Long term evolution of main splices resistance” in the LHC II.3 Com7 p6/14: Simulations or laboratory tests to verify the lifetime of the old splice against fatigue failure of that solder joint were not presented or discussed. This would need to be done on the old splice and to be repeated for the new design with shunt(s) applied. Validation/verification of main splices consolidation 15/28 J.Ph. Tock

Technology Department Review of actions from last review: Multiple samples / trials 29th of November 2011 Review of actions from last review Second LHC Splice Review  Extensive tests already done and further tests are planned in the qualification of procedures, tooling and operators (See previous presentations: F Savary & C Scheuerlein) II.3 Rec3 p7/14: Make multiple samples/trials of critical steps, as part of a qualification plan to be developed, to get a statistically significant basis for assessing the risks of there being any important imperfections in the machine after installation Validation/verification of main splices consolidation 16/28 J.Ph. Tock

Technology Department Review of actions from last review: Mechanical calculations 29th of November 2011 Review of actions from last review Second LHC Splice Review  Extensive calculations were done, presented at the task force II.3 Rec4 p8/14: Make mechanical calculations for the shunt design and the insulating part (3D stress analysis including fatigue and thermal stresses) and document them to support the final design. All the new model calculations need to incorporate shunts in the most severe conditions assumptions (for example no mechanical connections internal to the original splice due to the lack of soldering). Validation/verification of main splices consolidation 17/28 J.Ph. Tock

Technology Department Review of actions from last review: Mechanical tests (some up to rupture) 29th of November 2011 Review of actions from last review Second LHC Splice Review  Extensive tests were carried out, results have been presented at the task force II.3 Rec5 p8/14: Utilizing representative sample joints in the laboratory, test the mechanical strength of the shunt assembly by various stress and deflection measurements, under static and fatigue conditions, both warm and cold. Test several samples to destruction to determine the limits of the design. Validation/verification of main splices consolidation 18/28 J.Ph. Tock

Technology Department Review of actions from last review: Visual inspection 29th of November 2011 Review of actions from last review Second LHC Splice Review II.4 6) p10/14: The Review Committee recommends the Splices Task Force to consider visual inspection as part of the standard QC plan. This does not necessarily need to be done by a specific QC team as it can easily be done by the operators themselves, at least by their supervisors or team leaders. The Review Committee also recommends a systematic documenting by photos On-going See presentations by C Scheuerlein & F Savary Work is on-going to define a user-friendly web interface for the data repository To be finalised for review 3 Validation/verification of main splices consolidation 19/28 J.Ph. Tock

Technology Department Review of actions from last review: Mechanical test 29th of November 2011 Review of actions from last review Second LHC Splice Review II.4 7) p10/14: The Review Committee recommends also to consider simple mechanical tests applying minimal stress to the joint, as part of the standard QC plan, to check the mechanical continuity of the splices. See presentations by C Scheuerlein & F Savary Mechanical (destructive) tests done off-line in laboratory To be finalised for review 3 Validation/verification of main splices consolidation 20/28 J.Ph. Tock

Technology Department Review of actions from last review: Tooling validation 29th of November 2011 Review of actions from last review Second LHC Splice Review II.6 2) p12/14: The Splices Task Force should draw out a work plan for redesigning and optimizing the various tooling needed for the consolidation activities. These tooling should be validated on the surface simulating as real working conditions as possible (e.g. space constraints). See presentation by F Savary yesterday On-going To be finalised for review 3 Validation/verification of main splices consolidation 21/28 J.Ph. Tock

Technology Department Review of actions from last review: Calibration plan for tooling 29th of November 2011 Review of actions from last review Second LHC Splice Review II.5 4) p11/14: A verification and calibration plan for the special tooling should be drawn up and implemented to assure a constant quality of the work throughout the production.. See presentation by F Savary & C Scheuerlein yesterday On-going QA/QC aspects Validation/verification of main splices consolidation 22/28 J.Ph. Tock

Technology Department Review of actions from last review: Technicians Qualification 29th of November 2011 Review of actions from last review Second LHC Splice Review II.6 4) p12/14: At least for the critical operations, the technicians and mechanics should be qualified following a strict qualification process similar to what is done for the welding operations (qualification of the process that is to be done once and qualification of each technician/mechanics for each critical operation he is going to carry out). See presentations by F Savary & C Scheuerlein yesterday On-going To be finalised for review 3 Validation/verification of main splices consolidation 23/28 J.Ph. Tock

Technology Department Review of actions from last review: Scheduling 29th of November 2011 Review of actions from last review Second LHC Splice Review II.4 2) p9/14: It is necessary to have a preliminary work plan with its associated schedule and WBS. II.4 3) p9/14: It would be advantageous for the Splice Task Force to work with an experienced/ professional planner/scheduler. The planning needs to be integrated with the planning for other work that will be done in the tunnel during the same shutdown. II.5 1) p11/14: Continue to review plans to ensure that the work planning is complete. On-going See presentation by F Savary, K Foraz, JPh Tock To be finalised for review 3 Management 24/28 J.Ph. Tock

Technology Department Review of actions from last review: Resources 29th of November 2011 Review of actions from last review Second LHC Splice Review II.4 4) p9/14: The planning needs to take account of the possibility of unforeseen developments that will slow down or disrupt the orderly work flow. For example, a larger number of splices than the currently estimated 15% may be required to be remade, or problems with the machining of the copper stabilizer could arise. Include schedule contingency into the baseline and ensure that additional resources are available to able to maintain the schedule II.4 5) p9/14: The Splices Task Force (or CERN more generally speaking) should not repeat the experience of the installation of the splices, i.e. qualified and experienced technicians and mechanics should be identified within CERN including departments/groups other than the MSC Group. The Review Committee is aware of ongoing discussions in this respect but this measure should be given (very) high priority. In addition, the people new to this job should be integrated to the Splices Task Force as soon as possible so that they can be trained to the specific activities constituting the scope of the consolidation plan. On-going See presentation by JPh Tock To be finalised for review 3 Management 25/28 J.Ph. Tock

Technology Department Review of actions from last review: Resources management 29th of November 2011 Review of actions from last review Second LHC Splice Review II.6 1) p12/14: Study alternate scenarios in view of optimizing the utilization of the critical resources that will certainly be limited (in terms of qualification and experience). Study unforeseen/unexpected scenarios. II.6 3) p12/14: It is clear to the Review Committee that utilizing contract labour people is inevitable. However the work should be organized in such a way these contract labour people are not left working on their own in the tunnel but are accompanied and supervised by CERN staff of which one can expect the necessary commitment to assure the objective of 100% quality. In other words, CERN needs to keep the full responsibility of the work(this cannot be given to a contractor). See presentation by JPh Tock yesterday On-going  Experienced resources are limited and focused on the critical activities (Electrical connections, Special Interventions).  Mixed team of internal resources, FSU, collaborations Management 26/28 J.Ph. Tock

Technology Department Review of actions from last review: Resources management 29th of November 2011 Review of actions from last review Second LHC Splice Review II.7 1) p13/14: CERN should insure that enough resources are allocated to ensure that the risk assessment and subsequent risk analysis can be executed on the planned time scale. See presentations by H ten Kate and next one by R Schmidt today Comment on further needs Management 27/28 J.Ph. Tock

Technology Department Review of actions from last review: Conclusions 29th of November 2011 Review of actions from last review Second LHC Splice Review  All recommendations have been studied and  Implemented or  Amended or  Are under implementation  With the LS1 rescheduling, deadlines have been updated Review 3 will be a Production Readiness Review  Priority ? Criticality ? What do you consider still open ? Many thanks to … 28/28 J.Ph. Tock

Technology Department 29th of November /28 J.Ph. Tock Review of actions from last review Second LHC Splice Review

Technology Department 29th of November /28 J.Ph. Tock Review of actions from last review Second LHC Splice Review Spare slides

Technology Department 29th of November /28 J.Ph. Tock Review of actions from last review Second LHC Splice Review