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SEE upsets in collimator control Mitigation options. K. Foraz & Perrot A. L., EN/MEF - R2E Project LMC 25th May 2011. Thanks to EN/EL, EN/HE, EN/MEF, equipment owners the LHC integration team & the R2E team. R2E events.
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SEE upsets in collimator control Mitigation options K. Foraz & Perrot A. L., EN/MEF - R2E Project LMC 25th May 2011 Thanks to EN/EL, EN/HE, EN/MEF, equipment owners the LHC integration team & the R2E team
R2E events • - 1rst May 2011: SEU in UJ14 collimation control rack -> beam dump • (see presentation of Markus in LMC 4th May) • 5th May 2011: emergency action plan request • May 2011: SEU in UJ14/16 cryogenics • SEU in UJ14/16 biometry ; • SEU in others areas (see RADWG for details) TODAY cryogenics UL16 collimation QPS current leads heaters UJ16 transport reserved volume UJ14/16 racks layout PC PIC BPM Courtesy A. Tursun, Y. Muttoni PC spare Symmetrical layout in UJ14 LMC, 25 May 2011, A. L. Perrot1
Mitigation options • 4 mitigation options can be considered • Option # 0: full relocation + shielding • activities during 7 months for 10 groups • Option # 1: relocate only the 2 collimation racks • Option # 2: relocate all the racks except the Power Converters • Option # 3: shielding • Duration & sequence optimized with Katy, EN/EL & EN/HE LMC, 25 May 2011, A. L. Perrot 2
Option 1- collimation racks relocation Time estimation per side Time estimation for both sides EN/EL 7 days activity EN/STI 10 days activity Total= 15 days Work anticipation in a Technical Stop Phase I: EL (cables + optical fibers) 5 days during 1 TS Phase II: EL (cables connection), EN/STI 12 days emergency or Christmas break Advantage: EL manpower available for other activities during ‘Christmas break’ Partial equipment relocation not an effective R2E approach LMC, 25 May 2011, A. L. Perrot 3
Option 2 – UJ14/16 racks relocation RYCA01 RYCA02 UL16 after relocation RYMCB01 RYMCB02 RYMCB03 RYMCB04 TODAY PC cryogenics (profibus-> moves FIP -> stays) RYLC01 RYLB01 RYMCC01 QYC02 collimation QYC01 RTQX2.R1 exclusion area Courtesy P. Orlandi, JC Guillaume RQX.R1 QPS current leads heaters UJ14/16 racks layout UJ16 UL16 Relocation 6 racks /side (without power converters) 5 groups impacted RYSC01 transport reserved volume PC spare PIC BPM CYCIP01 +DYPG02 DYPG01 Courtesy A. Tursun, Y. Muttoni TYCFL01 LMC, 25 May 2011, A. L. Perrot 4
Option 2 – UJ14/16 racks relocation Fluence decrease by factor 8-30 ‘crash program for EN/EL’ possible manpower issue for the other activities co-activity Study under progress Christmas break 2011-2012: 11 weeks activities in tunnel Conclusion: not possible to relocate the 12 racks during next Christmas break LMC, 25 May 2011, A. L. Perrot 5
Option 3 - Shielding RB16 RB16 UJ16 UJ17 UJ16 L shielding= 28 m After relocation & shielding UJ17 UL16 CourtesyF.Delsaux Courtesy JP Corso Shielding installation in RB16 CourtesyF.Delsaux LMC, 25 May 2011, A. L. Perrot 6
Option 3 - Shielding Fluence decrease by factor 7-10 Time estimation for both sides Parallel activities Empty He liquid in 1 sector Depressurize the triplet He line (discussed with Safety) EN/HE: manpower effort (*) if chicane replaced by a ‘plug’ -> 2 additional weeks ALARA : installation during Christmas break (residual dose rate along the triplets) Conclusion: shielding installation could be scheduled for next Christmas break LMC, 25 May 2011, A. L. Perrot 7
Options comparison Courtesy K. Foraz, M. Brugger & R2E simulation team (*) EN/EL ‘crash program’ (**) depending of the location General remark: co-activity not possible between shielding & relocation (~1000 transports of blocks are foreseen in each UL i.e. lift 4000 up/down) LMC, 25 May 2011, A. L. Perrot 8
Conclusions • R2E proposals: • No independent equipment relocation unless clear impact on LHC operation • Shielding installation during next Christmas break (ALARA) R2E monitors constantly radiation levels, failures & scenarios ‘R2E review’ in November: presentation/discussions of the optimization solutions LMC, 25 May 2011, A. L. Perrot 9