Safety Matters !

11th LSC, 7. 6. 2013

- Evacuation at Point 5- First LS1 Accident in LHC- Miscellaneous: Barriers, Helmets

Thomas Otto, Safety Officer, TE Dept.

Thomas Otto, TE Safety Officer 3

Evacuation at Point 5• Summary of Facts

11th LSC, 7. 6. 2013

13:26 One ODH alarm (level 3) triggered in CMS underground gas room. Three flashing lights.

FB sends fire engine to Point 5

CMS FGSO independently alerted by personnel working underground. Goes to XCR, but cannot see the alarm on-screen

13:43 FB arrives at Point 5. Reconnaissance team to underground

Recon team detects no gas, but visitor’s group

13:46 Telephone discussion with CMS Deputy TC.Based on the available information, evacuation of USC55 and UXC55 is decided. ULs and UJs are included in evacuation matrix

SMACC collaborator in UL55 hears alarm, phones 74444 and is told that personnel in arcs who entered by Point 5 should also evacuate.

Thomas Otto, TE Safety Officer 4

Trace of the ODH Detector

11th LSC, 7. 6. 2013

Detector close to ground , detects heavy gases. 2nd detector close to ceiling, for light gases.

No true redundancy for alerting.

Thomas Otto, TE Safety Officer 5

Principle of the ODH system• One detector triggered:

• Level 3 alarm, visible on CSAM screen• FB sends fire engine for reconnaissance and

intervention, if necessary• BE-OP-TI alerts GS-ASE piquet

• Two adjacent detectors triggered:• Automatic evacuation alarm in an area defined

by the “Matrix”• Here: USC55, UXC55, ULs, UJ56, UJ53• Evacuation assisted by FB

11th LSC, 7. 6. 2013

Thomas Otto, TE Safety Officer 6

Reasons for the manual order to evacuate

• Three flashing lights were (falsely) interpreted as if more than one detector fired

• A visitor’s group in the CMS underground• No alarm in the Detector Safety System,

(falsely) interpreted as a potential fault. • The deputy TC was far and based his

acquiescence on information received by telephone only.

• Thanks to previous training, evacuation was extremely professional

11th LSC, 7. 6. 2013

Thomas Otto, TE Safety Officer 7

Evacuation zone

11th LSC, 7. 6. 2013

UJ56 level 0

5UPS56UPS54

UL55

RZ54

UL54

UP53

ARC 45 UJ 53 UJ 56

USC55

UXC55

UL 55

ARC 56

Thomas Otto, TE Safety Officer 8

What happened to the Arcs ?• One SMACC collaborator walked from Arc56

to Arc45 and heard the alarm in UL55.• He cross-checked with his colleagues in the

arcs, they did not hear an alarm.• He phoned 74444 and was told that

everybody who entered by Point 5 should evacuate and meet at the assembly point.

• This message is contrary to the evacuation matrix

11th LSC, 7. 6. 2013

Thomas Otto, TE Safety Officer 9

Conclusions• Evacuation of the Experimental area until

the UJs was • a conservative measure • justified by the limited and apparently

contradicting information available.

• The partial evacuation of the tunnel was • result of erroneous communication between

workers in the tunnel and the SCR operator of the Fire Brigade.

11th LSC, 7. 6. 2013

Thomas Otto, TE Safety Officer 10

Recommendations• CMS shift crew must be able to see L3 alarms.

• Keep CSAM window open or integrate in DSS

• Improve ODH detection in CMS gas room• Create true redundancy of detectors

• FB adapts SCR message during evacuation:• Persons hearing the alarm loud & clearly evacuate

• FB cannot rely on the correct “head count” when evacuating an LHC underground area.• An S&R patrol may be necessary

11th LSC, 7. 6. 2013

Thomas Otto, TE Safety Officer 11

1st LS1 Accident in LHC• A worker went underground to

verify vacuum bake-out controls• He did not intend to touch the

heating blankets, no PPE (overall, mask, safety glasses)

• He realised that one heating blanket had to be fixed

• While doing this work, glass fibre dust entered his eye

• Effect aggravated by contact lens• Serious eye irritation, 2 days sick

leave, under medical observation.

11th LSC, 7. 6. 2013

Situation similar to real accident

Use prescribed PPE even for the shortest intervention in a

hazard zone.

Thomas Otto, TE Safety Officer 12

Barriers

• All temporary barriers must bear an identifying sign with

• Name• Telephone number

of the person or service responsible

11th LSC, 7. 6. 2013

Thomas Otto, TE Safety Officer 13

Is your helmet up-to-date ?lifetime

5 years

10 years

Annual self- check:- Appearance- Scratches, cracks, burn

marks- Functional check of

adjustable elements

11th LSC, 7. 6. 2013

Vintage models from LEP must be changed.Models from early LHC construction : verify production date.

See: https://espace.cern.ch/be-dep/safety.aspx

Thomas Otto, TE Safety Officer 14

Safety Matters !

We control risks, not people

11th LSC, 7. 6. 2013

11th LSC, 7. 6. 2013 Thomas Otto, TE Safety Officer 15