Minutes of 3rd Meeting on General Safety Alarm Systems in
Secondary Beams and Areas (SBA), 3rd February 2014
Present: Enrique Blanco Vinuela, Adrian Fabich, Silvia
Gschwendtner, Andre Henriques, Sonia Infante, John Pedersen.
Grau,
Edda
As a consequence of the last meeting on the PLC NANOs held on 10th September
2013, an inventory of the PLC NANO in the East Hall, West Hall1, AD Hall, EHN1
and EHN2 – a total of 20 PLCs – has been distributed. In addition the
implementation plans for fire/gas detection and a previous safety matrix have
been transmitted (see EDMS 1353798 V0.2 for documents).
Another action coming from that meeting in September 2013 was to establish a
safety recommendation file for fire and gas by the HSE Unit. After a follow-up
meeting between HSE, EN-MEF and GS-ASE and a visit to the EHN1 hall, this
document has been issued in December 2013 and can be found on EDMS (Nr.
1339774).
In the current PLC NANO system four safety element input signals (AUG/AUL,
temperature, fire, gas) are merged. However, this is done in an outdated way
with respect to functionality and supply (signals are bridged, unknown
input/output, etc.…).
In the meeting held on 3rd February 2014 the next steps towards changing the
outdated PLC Nano with a new strategy were discussed.
Based now on the safety request document from HSE, we agreed that the fire
detection system could be disconnected from the PLC NANO system; the reason
is that fire detection shall only act on evacuation alarms and flammable gas
supplies. Silvia confirmed that this could be done directly with the ASE system
without any connection to a PLC system.
HSE requests in their document that the detection of flammable gas should stop
the gas supply and trigger an evacuation alarm and in some cases cut the
electrical power in the ATEX hazardous area ( (if LEL > 20%). This could also be
implemented independently from being connected to any PLC system.
This gives the potential possibility, that all signals that go today from the GS-ASE
system to a PLC NANO could be directly connected to the point where ‘action’ is
needed. Action:  GS-ASE proposed to establish a detailed list of all signals (and
cables) that could leave the GS-ASE system. Consequently EN/EL can confirm
that these signals are currently routed to their PLC NANOs as a verification step.
The West Area is no longer a Secondary Beam Area. The responsibility in view of the renovation
of the general safety systems shall be clarified. The TSO (Philippe Canard for build. 180 and
Martin Jaekel for build. 190) shall be informed/invited.
1
Any temperature sensors are connected to the cooling and ventilation system
without safety impact. The areas, where cooling/ventilation should receive
signals from the general alarm systems, need to be identified (see also below).
EN-MEF will list all inputs (sensors) and outputs (actions) that are requested for
secondary beam and areas. As a start, this will be done for the specific case of
EHN1.
This list shall include information
 Per zone (including underground as well as global areas): which areas are
treated with special care concerning certain safety elements (e.g. GIF++
and gas).
 Per detection (i.e. input): fire, gas (flammable), ODH, AUL, AUG,
evacuation alarms.
 Per action (i.e. output): evacuation alarm, electricity, (flammable) gas
supply, and ventilation.
In addition it is stressed that in the technical implementation proposal from ENEL and GS-ASE the flexibility for future adaptations of experiments/test
beams/changes of zone definitions must be maintained.
A (almost completed) safety folder is available for the East Area, which could
serve as basis including its risk assessment.
John proposed that with the above information input Action:  EN-EL prepares
an ECR, which details the changes, the needed requirements and consequences
on the technical implementation.
Action:  EN-MEF will prepare and distribute this list within the next month.
Action:  GS-ASE, EN/EL will establish a list of removable signal lines between
ASE detectors and the PLC NANOs.
The next meeting is planned for mid-March 2014.