Follow up meeting Protecting the experimental caverns and personnel from a "sector 34 like" incident: work planned in the LHC tunnel

Prepared by M GASTAL with contributions from EN-MEF: David HAY (EAM team)CMS: Christoph SCHAEFER (CMS Glimos), Nicolas Siegrist (Ansys simulations),

Teresa RODRIGO Mar SOBRON Joao ANTUNES (Alignment),Nebojsa SMILJKOVIC & Jean BOS (CMS design office)

TE-VSC: Nicolas ZELKO, Patrick LEPEULEEN-MME: Jean-Pierre BRACHET Pascal MESENGE Gilles FAVRE (Central

workshop), and Giuseppe FOFFANOEN-CV: Antonio Romanazzi (computations in fluid dynamics)

31/08/2009 1

Agenda:

1- Modifications in the CMS TAS regions2- Sealing all remaining openings3- Pressure resistant doors and ODH sensors

martin.gastal@cern.ch

The CMS TAS region: an overview

31/08/2009 2martin.gastal@cern.ch

31/08/2009 3martin.gastal@cern.ch

CMS TAS is inside the Fixed Iron NoseFIN is fixed to Cubical Steel FrameRotating Shielding closes around FIN

Cubical steel frame

Rotating Shielding

Fixed Iron Nose

The CMS TAS region: an overview

31/08/2009 4martin.gastal@cern.ch

CMS TAS is inside the Fixed Iron NoseFIN is fixed to Cubical Steel FrameRotating Shielding closes around FIN

Cubical steel frame

Rotating Shielding

Fixed Iron Nose

The CMS TAS region: an overviewTAS

31/08/2009 martin.gastal@cern.ch 5

The CMS TAS region: an overview

Fixed Iron Nose

Rotating Shielding

31/08/2009 martin.gastal@cern.ch 6

The CMS TAS region: an overview

TAS and its survey & alignment systems Modifications cannot prevent the TAS to be aligned in X and Y

Inner triplet side

31/08/2009 martin.gastal@cern.ch 7

The CMS TAS region: an overview

IP side

Modifications in the TAS region

→ Goals to achieve: → Restrict the TAS movements in Z during alignment→ Prevent longitudinal TAS movement in case of an September 19th type

of incident→ Prevent a flow of He from the tunnel to propagate into the UXC55→ Avoid having to stay in the vicinity of the TAS once it is activated

→ E.g. alignment and removal operations

→ Limitations:→ Stay clear of vacuum equipment→ Keep a fixed point on tunnel side for TAS bake-out purposes→ Keep the air flow around TAS for cooling purposes→ Allow for a removal of the TAS during the phase 1 upgrade with

minimal radioprotection risks

31/08/2009 martin.gastal@cern.ch 8

How to restrict the TAS movements longitudinally?

→In the event of a September 19th type of incident

→During alignment & bake out

31/08/2009 martin.gastal@cern.ch 9

31/08/2009 10martin.gastal@cern.ch

Restrict TAS movements in Z

• Use of a spring to allow disengaging the TAS quickly, without using spanners, from a distance if using a stick

• Reuse of existing holes in TAS & Access to vacuum equipment remains the same

31/08/2009 11martin.gastal@cern.ch

Restrict TAS movements in Z

→Assuming an over pressure of 110mb in the tunnel, each Z-stop will experience a maximum deflexion of 0.11mm

→Stability of the TAS is insured by using 2 Z-stops on opposite sides of beam pipe→Installation scheduled to start on 02/09→Manufactured in B530 workshop

How will the TAS behave in the CMS magnetic field?

→ Both TASs have been instrumented and monitored while ramping up the B field from 0T to 3.8T

→ No significant movement was recorded56 TAS:

Delta(X): 60 microns Delta(Y): < 10 microns Delta(Z): 100 microns (towards IP)

54 TAS:

Delta(X): < 10 microns Delta(Y): < 10 microns Delta(Z): 90 microns (away from IP)

→ Safe to assume that the TAS is unaffected by the CMS B field31/08/2009 martin.gastal@cern.ch 12

How to prevent an overpressure in the tunnel to propagate into the UXC55 through the TAS area?

→ Installation of an annular clapper→ Allows the flow of air from the UXC55 to the tunnel, but prevent an

overpressure to propagate from the tunnel to the experimental area

31/08/2009 martin.gastal@cern.ch 13

31/08/2009 martin.gastal@cern.ch 14

Membrane design

Material: 0.5mm thick Stainless steelManufactured in central workshopLeaves a 2cm gap for air flowTrigger pressure for closure is 8mbarWhen exposed to 110mbar

Max deformation = 9.10-6 mmGuided by existing structures

31/08/2009 martin.gastal@cern.ch 15

Membrane: Configuration during Bake Out

→ When DC power is applied to the TAS built in resistors, the membrane must not be in contact with the connectors

→ An electrically insulated shim will be inserted to hold the membrane away from the conductors while blocking the air flow

How to cool down the TAS?→ Initial study by Egon Hoyer in Engineering Note M7801

31/08/2009 martin.gastal@cern.ch 16

31/08/2009 martin.gastal@cern.ch 17

How to cool down the TAS?→ FLUKA simulations by S Muller give consistent values

→ The TAS equilibrium temperature in the absence of air flow was calculated to be ~ 100deg C. The temperature limit for the TAS vacuum chamber being set to 75 deg C, it would be reached within 2.5 month.

31/08/2009 martin.gastal@cern.ch 18

How to cool down the TAS?

→ FLUKA simulations were performed by A Romanazzi to see what the impact of the air flowing from the UXC55 to the tunnel will be.

→ Boundary conditions:

31/08/2009 martin.gastal@cern.ch 19

How to cool down the TAS?

• Copper : 400W volume heat generation• Inlet : 20 Pa overpressure, 19°C• Outlet : 0 Pa overpressure• Steel : 19°C fixed temperature on outside wall

outlet inlet

Fixed temperature

→ Two configurations were studied:

31/08/2009 martin.gastal@cern.ch 20

How to cool down the TAS?

Without annular clapper With annular clapper

→ Conclusions and implementation→ Active air cooling using the UXC55 nominal overpressure should be sufficient to keep the

temperature of the TAS in a range acceptable for TE-VSC throughout its life time.→ The temperature of the TAS will be monitored at all times by CMS DSS using

thermocouples already installed by TE-VSC→ The water cooling pipe installed on the tunnel face of the TAS has been tested up to

10Bars and would be available if needed→ A first section of water pipes will be installed by EN-CV in the vicinity of both TASs

shortly as an extra precaution. This would allow installing active water cooling without having to get near a potentially hot TAS

31/08/2009 martin.gastal@cern.ch 21

How to cool down the TAS?

→ Deadline set by start of powering tests phase 2 in sector 56: 14/09 → Membranes are both manufactured and installed→ Z-stops are being mounted on mock-up→ Installation scheduled for Tuesday 01/09

→ A dedicated EDMS page will be set up by 04/09; all relevant documents (text, pictures, simulations, models) will be stored at this location

31/08/2009 martin.gastal@cern.ch 22

When will the whole system be fully installed?

31/08/2009 23martin.gastal@cern.ch

Seal UXC55 from tunnel

→Holes between the CSF and the FIN have been closed→The resulting seal will withstand 110mBar→New system uses metal plates and blocks filled up with concrete

31/08/2009 24martin.gastal@cern.ch

Seal UXC55 from tunnel

→FIN doors will be bolted and remaining gaps will be sealed by PH-CMX during week 36

31/08/2009 25martin.gastal@cern.ch

Seal UXC55 from tunnel

→Examples of jobs done by AGI→All ducts, cables and cables trays will be sealed to guarantee 20Pa between Tunnel and UXC55

martin.gastal@cern.ch31/08/200926

martin.gastal@cern.ch22/07/200826

5 pressure resistant fire proof doors have been installed

All blast doors open towards the incoming pressure

Additional ODH sensors installation scheduled for week 36

Remove existing door, include the UPX56 into the ventilated volume of the USC55

Pressure resistant doors and ODH sensors

Responsibility Crew

Integration CMS design office

Design PH-CMX H Gerwig & crew

Project coordination CMS TC + EAM team

Metallic structures + doors installation

EN-HE - A Foreste & crew

Ventilation EN-CV – F Josa & crew

Access Control CMS Bulgarian cabling crew + GS-ASE

Fine fire proof sealing AGI

31/08/2009 martin.gastal@cern.ch 27

Installing pressure resistant doors: Responsibility matrix

Before After

31/08/2009 martin.gastal@cern.ch 28

UPS54/56 doors→ Door + frame + metallic structures:100% Installed→ Overpressure resistant cladding: 100% Installed→ Fire resistant cladding: NA

→ Access control: 20% installedCables installed, instrumentation to be installed during week 36→ Ventilation: 50% installed

Former ducts removed, new ducts will be reinstalled during week 36 including Fire/pressure clappers

→ Final air tightness: To be done during week 36

RZ54 door→ Door + frame + metallic structures:100% Installed

→ Fire resistant cladding: 80% installedPlaster boards to be installed during week 35

Final sealing to be done during week 35→ Overpressure resistant cladding: 0%

to be installed during week 36→ Access control: 20% installed

Cables installed, instrumentation to be installed during week 36→ Ventilation: 90% installed

→ fans to be connected to power during week 35

31/08/2009 martin.gastal@cern.ch 29

UJ561 door→ Door + frame + metallic structures:100% Installed

→ Overpressure resistant cladding: 0%to be installed during week 35

→ Fire resistant cladding: 80% installedHeat resistant mortar to be injected during week 34

Plaster boards to be installed during week 35Fine sealing to be done during week 35

→ Access control: 20% installedCables installed, instrumentation to be installed during week 36→ Ventilation: 90% installed

Fans to be connected to power during week 35

UL55 door→ Door + frame + metallic structures:100% Installed

→ Overpressure resistant cladding: NA→ Fire resistant cladding: 80% installed

Heat resistant mortar to be injected during week 34Plaster boards to be installed during week 35

→ Access control: 20% installedCables installed, instrumentation to be installed during week 36

→ Ventilation: NA

1st LTEX meeting Protecting the experimental caverns and personnel from a "sector 34 like" incident: work planned in the LHC tunnel

31/08/2009 30

Conclusions:

1- Modifications in the CMS TAS regions:→To be done by September 7th

2- Sealing all remaining openings:→To be done by September 7th

3- Pressure resistant doors and ODH sensors: →Fully equipped doors by September 7th

martin.gastal@cern.ch