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 SEE upsets in collimator control Mitigation options

- 1 rst May 2011: SEU in UJ14 collimation control rack -> beam dump (see presentation of Markus in LMC 4 th May) - 5 th 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) LMC, 25 May 2011, A. L. Perrot 1 QPS PIC collimat ion current leads heaters BPM cryogenics UJ14/16 racks layout R2E events TODAY UL16 UJ16 Courtesy A. Tursun, Y. Muttoni transport reserved volume PC PC spare Symmetrical layout in UJ14

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 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’ Group ActivityDuration [days] EN/EL racks disconnection1 cable trays installation 1 pull cables1 connection // optical fibers2 EN/STI racks displacement5 commissioning Partial equipment relocation not an effective R2E approach LMC, 25 May 2011, A. L. Perrot 3 Time estimation for both sides

Option 2 – UJ14/16 racks relocation TODAY UL16 UJ16 Courtesy A. Tursun, Y. Muttoni transport reserved volume exclusion area QPS PIC collimation current leads heaters BPM cryogenics (profibus-> moves FIP -> stays ) CYCIP01 + DYPG02 DYPG01 TYCFL01 QYC01 QYC02 RYSC01 RYLC01 RYLB01 RYMCB01 RYMCB02 RYMCB03 RYMCB04 RQX.R1 RTQX2.R1 RYMCC01 RYCA01 RYCA02 UL16 after relocation Relocation 6 racks /side (without power converters) 5 groups impacted LMC, 25 May 2011, A. L. Perrot 4 Courtesy P. Orlandi, JC Guillaume UJ14/16 racks layout

‘crash program for EN/EL’ possible manpower issue for the other activities LMC, 25 May 2011, A. L. Perrot 5 Group activityDuration [week] EN/EL11 Equipment owners (without TE/EPC)7 displacement commissioning TOTAL18 Option 2 – UJ14/16 racks relocation Christmas break : 11 weeks activities in tunnel co-activity Conclusion: not possible to relocate the 12 racks during next Christmas break Study under progress Fluence decrease by factor 8-30

Option 3 - Shielding LocationWeight [t]Blocks #Bars CERN RB mid-July 2011 UJ Nov 2011 UJ Nov 2011 TOTAL /2 sides Courtesy F.Delsaux LMC, 25 May 2011, A. L. Perrot 6 UL16 UJ16 UJ17 RB16 After relocation & shielding Courtesy JP Corso UJ16 UJ17 RB16 Shielding installation in RB16 Courtesy F.Delsaux L shielding = 28 m

Parallel activities Empty He liquid in 1 sector Depressurize the triplet He line (discussed with Safety) Time estimation for both sides ActivityDuration [week] Preparatory work1 MAD removal Survey motors removal Tablotins' (AUG, siren, red phones, anti-panic lightning) Shielding installation (*)4 2 shifts Rehabilitation work1 MAD reinstallation test safety equipments TOTAL6 (*) if chicane replaced by a ‘plug’ -> 2 additional weeks Option 3 - Shielding EN/HE: manpower effort Conclusion: shielding installation could be scheduled for next Christmas break LMC, 25 May 2011, A. L. Perrot 7 ALARA : installation during Christmas break (residual dose rate along the triplets) Fluence decrease by factor 7-10

Courtesy K. Foraz, M. Brugger & R2E simulation team OptionMitigation actionwork duration [weeks] Fluence decrease factor Option 0 full relocation + shielding3040 to 100 (**) Option 212 racks relocated into UL18 (*)8 to 30 (**) Option 3 shielding + chicane (plug)6 (8)7 to 8 (8 to 10) (**) Option racks relocation into UL + shielding+ chicane2440 to 100 (**) Options comparison LMC, 25 May 2011, A. L. Perrot 8 General remark: co-activity not possible between shielding & relocation (~1000 transports of blocks are foreseen in each UL i.e. lift 4000 up/down) (*) EN/EL ‘crash program’ (**) depending of the location

Conclusions LMC, 25 May 2011, A. L. Perrot 9 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