HEALTH & SAFETY RISK ASSESSMENT FOR CCLRC CMS ECAL PERSONNEL IN CRYSTAL PALACE AT CERN
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File: http://kwb.home.cern.ch/kwb/cms/ecal/eeassembly/CMS-Crystal-Palace-risk.html
K.W.Bell - March 2005
Last updated: 24-Oct-06, 09-Nov-06 - K.W.Bell (minor updates)
To Be added:
* Extend to cover the area outside the main door.
* Crane only to be used by an authorised operator.
* Area in vicinity of crane work to be roped off.
* Reference to explicit instructions on handling and rotating Dees.
* Diagram of area
* Text to be revised following RMB & PSF Feedback
* DJAC to be declared "Installation Manager" of Crystal Palace,
& thereby overall responsible for Safety there.
* Modifications to take care of Aymar's email of 28-Nov re CERN Safety Reorganization.
(01) INTRODUCTION
All RAL staff should have read and be fully aware of the contents of the
RAL "Safety Handbook" (revised April 2003) from which one can access both the
CCLRC and RAL Safety Notices and the
CCLRC and RAL Safety Codes.
Remember that, as stated in the Foreword of the RAL Safety Handbook:
"Everyone has an obligation to take care of personal health and safety,
to avoid endangering others and to co-operate in the implementation of
safety measures."
Correspondingly, all RAL staff working at CERN should also have read
and be fully aware of the contents of the
CERN "Safety Policy at CERN" (SAPOCO 42) document (revised February 2003), the
CERN "Safety Guide for Experiments at CERN" (2004) and the
CERN Physics (PH) Department Safety Plan.
Further information about safety at CERN, e.g. links to the
CERN Safety Codes,
CERN Safety Instructions,
CERN Safety Notes,
CERN Safety Bulletins and the
CERN Safety Forms
can be found from the
CERN Safety Commission (SC) web pages.
(The former CERN Technical Inspection and Safety (TIS) Department was
disbanded at the end of 2003. The replacement Safety Commission Unit
is presently (Nov-06) attached to the Director-General's Office.
However, not all CERN documentation presently reflects this change.)
In addition, all RAL staff working at CERN should have attended the
CERN basic safety courses (video) and thereby be trained for Levels 1-3.
There is also a specific
CMS Safety Web Page
set up by the CMS GLIMOS (Group Leader in Matters of Safety),
presently Christoph Schaefer, 16-0202.
However the CMS-specific information is of rather limited extent.
You are encouraged to contact either your supervisor, or the author of
this document, or Christoph Schaefer directly, should any CMS-specific
clarification be needed.
A reminder: the CERN general emergency number ("Pompiers") is 74444.
In the remainder of this document we only consider explicitly the risks
associated with the equipment of the CMS Endcap Electromagnetic calorimeter
(EE), in which the RAL group participates, inside and near to the "Crystal Palace",
itself inside B168 on the CERN Meyrin site. The risks associated with standard
office working at CERN main site should be broadly comparable to those whilst
working in offices at RAL - one obvious exception being that when at CERN one is
more likely to be working outside standard office hours, and appropriate care
should be taken whenever working alone.
Comments on and suggestions as to how to improve this document are most
welcome, and should be directed to K.W.Bell@rl.ac.uk or Ken.Bell@cern.ch.
[All links to CCLRC/RAL work from off-site without needing PTPP,
but DO require a valid CCLRC UserName/PassWord.]
(02) SPECIFICS
"Crystal Palace" (CERNx73692) is the area at CERN where the EE "supercrystals"
will be built (or at least their "High Voltage" cards installed) and tested,
the supercrystals will be installed on the Dee backplates, the mothercards,
moderator and cooling system will be added to the rear of the backplates, and all
will be re-tested before being transported to B867 to be equipped with the readout
electronics. In addition, lack of floor-space in Crystal Palace means that some
of the heavy mechanical work is undertaken just in front of Crystal Palace,
but still within B168. This document also generally applies also to this
additional floor-space, except for specifics relating to the interior
air-conditioning and extractor fans etc.
Thus various related activities will be carried out in parallel in Crystal
Palace, by teams of various nationalities and of very varied background, culture,
experience and capability. Not everyone working in the area may show
the same level of safety awareness as yourself, and therefore staying safe
requires a certain level of personal vigilance and may require proactive behaviour.
Claude-Charles Detraz (16-3648) of CERN set up the infrastructure of the Crystal
Palace, but Claude is now Departmental Safety Officer for CERN-PH department.
Suggestions for improvements to the infrastructure should be directed to
Joolz Williams (71642, 16-2433) in the first instance.
Anyone working ALONE in Crystal Palace must comply fully with the requirements of
RAL HSN 47 (Personnel Working Alone) and
CERN Safety Code A6 (The two-person rule of working). Furthermore, solo working in
Crystal Palace during silent hours (including solo working during any weekend
or CERN holiday) should only be undertaken in exceptional circumstances, and after
notifying an appropriate nearby responsible person (the defaults being
D.J.A.Cockerill (71642), K.W.Bell (16-0746), W.Funk (16-3125) or A.H.Ball (16-0408));
this notification must include an estimate of the time by which the work will be
completed. Anyone working alone in Crystal Palace should also consider carrying a
mobile phone.
* CAUTION should be exercised at all times.
* Use as many of your senses as possible to maximise your awareness of possible danger.
* Plan ahead.
* Think before you act.
* Do not run (except perhaps in an emergency).
* Wear appropriate clothing and protective equipment
e.g. regular occupants of Crystal Palace should consider wearing safety shoes.
(Such material is available from CERN stores ("urgences") on Wednesday
afternoons, or is available any working day for the basics such as
safety shoes - better to take along someone who speaks decent French.)
* At the recommendation of the PH Departmental Safety Officer, the doors into
Crystal Palace are arranged such that ONLY the "normal" door into the "Supercrystal"
area can be opened from outside. However, all the other doors can be opened from
the inside (unless someone has inadvertently locked them!). So, if you're working
inside Crystal Palace, ensure the "normal" door on the Jura side of the
"supercrystal" area is unlocked. Thereby ALL doors of Crystal Palace should give
you egress in an emergency.
* 74444 is the CERN phone extension number to use in an emergency (fire/ambulance...).
* Emergency mains power-off buttons "Coupure General" for INSIDE Crystal Palace
are sited in the two main working areas.
* Emergency mains power-off button "Coupure General" for ALL of B168 is nearby
in the corner of B168 joining the Jura and Divonne sides of the hall.
* A CO2 fire extinguisher should be sited near the main exit of the two main
working areas.
* A first-aid box can be found near the main entrance of the "supercrystal" area.
* The controls for the ventilation system and extraction ducts inside Crystal Palace
are located on the "Jura" wall of the "supercrystal" area.
* There is a custom-built Supercrystal "loader"/"robot" for mounting supercrystals
onto the Dee backplates. It was manufactured by the Italian company "Dalmec".
It is a pneumatic "pantograph" which supports the 35kg weight of the supercrystal,
and allows the supercrystal to be moved in 3D with minimal effort.
It also incorporates a mechanism for rotating the supercrystal for easier
installation of the Saclay laser monitoring fibres, just prior to mounting.
The loader is run by Jose Mulon and Claude Detraz.
NO-ONE ELSE MAY OPERATE THE LOADER UNTIL THEY HAVE
a) BEEN TRAINED TO DO SO BY JOSE OR CLAUDE, and
b) BEEN AUTHORISED TO DO SO BY DAVE COCKERILL.
Possible hazards in the Crystal Palace include:
* trip hazards (cables, pipes, rails, unstored items...)
* slip hazards (oil, grease, spillages... (the floor is smooth and non-absorbent))
* falling objects (from Dees, or from the supercrystal loader, or from the hall crane
above the thin transparent roof covering Crystal Palace)
* moving objects (e.g. when supercrystals are being mounted onto a Dee,
or when supercrystals are being moved around on dedicated trolleys)
* badly positioned objects (e.g. "flying leads", temporary installations...)
* manual handling (supercrystals weigh ~35kg, and so a copious supply of handling jigs
and trolleys have been acquired, and a custom built "loader" will
take the weight of a supercrystal during its mounting onto a
Dee backplate - we believe this should obviate the need to
man-handle the supercrystals)
* sharp edges/corners (remove them, or at least cover them with suitable tape/foam...)
* 3-phase and single-phase mains electricity (a "normabarre" system is in use)
* hand tools (including scalpels, Stanley knives, soldering irons, power drills...
In particular, look out for poorly protected blades whenever "rummaging"
in a well-filled tool-box or drawer)
* assorted storage equipment and materials
(e.g. glassware, solid and liquid chemicals,
including various lab solvents and adhesives.
A proper chemicals cupboard is located just inside the entrance to Crystal
Palace - store any lab solvents inside whenever not in use (e.g.overnight))
* lead tungstate crystals
* what we commonly term "High Voltage" and "Low Voltage" supplies and crates
(e.g. when testing EE cables or supercrystals or readout electronics)
(Note that RAL Safety Code No.3 (Electrical Safety) defines
"High Voltage" as "a voltage normally above 1000V a.c. or 1500V d.c."
"Low Voltage" as "a voltage normally above 50V a.c. or 120V d.c.
but not exceeding 1000V a.c. or 1500V d.c. between conductors
or 600V a.c. or 900V d.c. between any conductor and earth"
"Extra Low Voltage" as "a voltage normally not exceeding 50V a.c. or 120V d.c.
whether between conductors or to earth".
Similarly, CERN Safety Instruction No.33 follows the IEC classification
of Voltage Domains:
"High Voltage A" is 1001-50000V a.c. or 1501-75000V d.c.
"Low Voltage B" is 501- 1000V a.c. or 751 -1500V d.c.
"Low Voltage B" is 51- 500V a.c. or 120 -750V d.c.
Since our VPTs run at +800/+600V, they are formally classed as Low Voltage.
And our "HV" cables are tested in Crystal Palace and after installation at IP5
to +1490V wrt earth, so that work is again formally classed as Low Voltage.
In final CMS, the HV supplies will be rated at ~3kV, albeit normally operated
at 800V maximum. Given the possibility of remote (and erroneous!) HV control,
work on the EE "HV" system may have to be classified as High Voltage.)
* VDU equipment
* fire (e.g. from the various pieces of test equipment is use,
either for testing individual VPTs glued to crystals, or completed
supercrystals, or for testing supercrystals once mounted on the Dees.
Take appropriate care around these set-ups,
e.g. +800V, low (<1mA) current,
e.g. 7V but 35A for pwering a 25-channel block of readout)
* fumes from soldering or lab chemicals
(extraction ducts are provided - check they're operational whenever you need them;
a proper chemicals cupboard is located just inside the entrance to Crystal Palace
- store any lab solvents inside whenever not in use (e.g.overnight))
* compressed air (available from the wall in both main areas)
As of November 2006, I'm UNAWARE of any:
* flammable gasses (save for evaporation from lab solvents)
* lasers [although they may be used in the future, for testing supercrystals mounted
on the Dees, in which case appropriate measures may then need to be taken.
But the CMS Tracker and ECAL optical links are now classified as Class-1,
as is described in Karl Gill's documentation. ] or
* radioactive sources
in Crystal Palace.