1 / 9

The Sector 3-4 incident at the LHC: fault tree and corrective measures

The Sector 3-4 incident at the LHC: fault tree and corrective measures. Ph. Lebrun Risk Analysis Review Committee CERN, 5 March 2009. Fault tree [1/3]. Observed on magnet. Absence of soldering. No sensitive detection on bus bar. Resistance 200 nOhm. Bad contact with stabili zer.

pearl
Download Presentation

The Sector 3-4 incident at the LHC: fault tree and corrective measures

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Sector 3-4 incident at the LHC:fault tree and corrective measures Ph. Lebrun Risk Analysis Review Committee CERN, 5 March 2009

  2. Fault tree [1/3] Observed on magnet Absence of soldering No sensitive detection on bus bar Resistance 200 nOhm Bad contact with stabilizer Electro-thermal model Thermal runaway Meltdown, open circuit Power converter fast discharge Electrical arc

  3. Fault tree [2/3] Electrical arc He vessel perforation Soot Beam pipe perforation He discharge in insulation vacuum Inadequate sizing of relief devices (MCI) Loss of beam vacuum Contamination by soot Mechanical damage to MLI Blast ODH in tunnel Pressurization of vacuum enclosures Trip AUG Break vent door Contamination by MLI

  4. Fault tree [3/3] Pressurization of vacuum enclosures Pressure forces on vacuum barriers Plastic deformation of shells Buckling of bellows Used to estimate max pressure reached Rupture of supports and ground anchors Displacement of magnets Damage to tunnel floor Mechanical damage to interconnects Secondary electrical arcs

  5. Corrective measures [1/3] Absence of soldering No sensitive detection on bus bar Resistance 200 nOhm Bad contact with stabilizer Additional quench detection on bus bars Measurement of joint resistance (calorimetry & electrical) Thermal runaway Meltdown, open circuit Power converter fast discharge Electrical arc

  6. Corrective measures [1/3] Absence of soldering No sensitive detection on bus bar Resistance 200 nOhm Bad contact with stabilizer Additional quench detection on bus bars Measurement of joint resistance (calorimetry & electrical) Thermal runaway Mechanical clamping of joints? Meltdown, open circuit Power converter fast discharge Electrical arc

  7. Corrective measures [2/3] Electrical arc He vessel perforation Soot Beam pipe perforation He discharge in insulation vacuum Inadequate sizing of relief devices (MCI) Loss of beam vacuum Contamination by soot New relief devices Revised MCI Mechanical damage to MLI Blast ODH in tunnel Pressurization of vacuum enclosures Harden AUG Harden vent door Trip AUG Break vent door Contamination by MLI

  8. Corrective measures [2/3] Electrical arc Fire q-heaters? He vessel perforation Soot Beam pipe perforation He discharge in insulation vacuum Trigger q-valves? Inadequate sizing of relief devices (MCI) Loss of beam vacuum Contamination by soot New relief devices Revised MCI Mechanical damage to MLI Blast ODH in tunnel Pressurization of vacuum enclosures Harden AUG Harden vent door Trip AUG Break vent door Contamination by MLI

  9. Corrective measures [3/3] Pressurization of vacuum enclosures Pressure forces on vacuum barriers Plastic deformation of shells Buckling of bellows Reinforce ground anchors Rupture of supports and ground anchors Displacement of magnets Damage to tunnel floor Mechanical damage to interconnects Secondary electrical arcs

More Related