07.12.12

ADO-PO Section MeetingSafety Group

LS1 Shutdown Safety Organization

Safety shifters:

Safety shifters will monitor the work execution and periodically patrol the UX15, US15, SR1 (including radioactive lab) and SX1 (including RBZ).

Their duty is to make sure all workers in the ATLAS premises are respecting the safety rules and are behaving as such.They have the authority to stop activities if judged dangerous and to expulse from the caverns people who are not respecting the safety rules in an important way

They report in first place to the EOD and have the authority to stop an activity or even expulse a person from the caverns if a major safety violation is done.

GLIMOS and in case TC will arbitrate any dispute.

The safety shifters report to the GLIMOS in general.

A Safety Shifter training will be organized in Jan/Feb.

SLIMOS :

Sergey is responsible for the SLIMOS organization, training and update of the documentation.

The SLIMOS will be one of the key safety persons for LS1. Main activities for the SLIMOS:

distributes Keys for Toroid area (if decided so)overview visitors accessoverview all alarms (infrastructure + detectors)assists remotely the EOD in his activities if requestedsupervise through the ATLAS Wireless Personal Supervision System the activities

which have been classified critical for radiation protection with assistance of one member of the ATLAS GLIMOS ALARA team when required.

New SLIMOS trainings and meetings will be organized in view of LS1.

Documentation will be revised and updated before LS1 shutdown.

Radiation protection – ALARA

Doses calculations and budgets have been performed for LS1 activities. ALARA optimization process is under progress with :

- procedures optimizations- change of tools - procurement of shieldings

New FLUKA doses calculations are being currently performed under Giuseppe coordination. The doses budgets will be updated accordingly.

The radiation protection safety measures are being discussed with the CERN RP group.

Classification of the ATLAS experimental areas:

USA15: Supervised Area

UX15 infrastructure zone: Supervised Area

UX15 toroid area: In general, the Toroid fenced area will be Supervised Area. Close to the center of the detector and to the beam pipe region, it is expected to have Simple Controlled Areas and some Limited Stay Areas.

SX1 Radioactive Buffer Zone - Simple Controlled Area

SR1 Radioactive Laboratory - Simple Controlled Area These classifications will be controlled and confirmed by the CERN RP group before beginning of the activities.

SR1 Radioactive Lab:

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Doses limitationsCERN Legislation

Area Classification Dose limit Ambient dose equivalent rate (permanent place)

Ambient dose equivalent rate (low-occupancy areas)

Non-designated area 1 mSv/y < 0.5 μSv/h < 2.5 μSv/h

Supervised area 6 mSv/y < 3 μSv/h < 15 μSv/h

Simple controlled area20 mSv/y

< 10 μSv/h < 50 μSv/h

Limited stay area < 2 mSv/h

High radiation area < 100 mSv/h

Prohibited area> 100 mSv/h

ATLAS workers are in category B (CERN rule Do not exceed 6 mSv/ year) ATLAS dose goal Do not exceed 2 mSv/ year

No exposure more than 50 μSv / day

Restrict activities for a few hours (max 20 hours per year) in regions between 20 and 50 μSv/hour and under strict supervision

Make use of individual shielding if possible to gain a factor 2 (2 cm Fe equivalent gains a factor 2)

Robotize interventions in regions > 50 μSv / hour

Permanent work place: 8 hours/day (2000 hours / year)Low occupancy area: < 1.6 hours/day

Radiation Protection training:

The personnel working in supervised radiation areas will follow the RP web based basic radioprotection Training.

The personnel working in Simple Controlled or Limited Stay Areas will follow the specific theory/ practical Radioprotection training delivered by the CERN RP group (all personnel working in Toroid area close to the center of the detector, in the SX1 radioactive buffer zone and in the SR1 radioactive laboratory).

These training are mandatory to obtain a dosimeter and be allowed to work in the radioactive areas.

Opening of working area and work authorization :

Each time, a new area is opened, during the opening process of the ATLAS detector or inside a detector or subsystem, a radioprotection survey will be performed :

• radiation measurement at work place and in the area • SMEAR test to control the possible contamination.

The survey results are communicated to the ATLAS RSO and GLIMOS who will decide in collaboration with RP group about specific safety measures for the opened area and RP will confirm the classification of the area.

RP will define the radiation controlled area boundaries (especially inside the toroid area close to the center of the detector).

The ATLAS RPE or RP technician assisted by the Safety Shifters will implement the required safety measures (fencing, information panels, radioactive waste bins, etc…).The area will be then open to activities.

The dose rates measured, the results of the contamination tests and the specific safety measures will be communicated to the personnel working in the area by the RSO / GLIMOS.

These data will be available at SLIMOS desk and on the ATLAS safety web page (restricted to the ATLAS collaboration).

A DIMR (Dossier Intervention en Milieu Radioactif) will be requested to all personnel working in the radiation controlled areas. The DIMR is filled by the ALARA team and is linked to the PPSPS and the IMPACT request.

The dose collected during the activity should be recorded and communicated by the responsible of the activity for all his personnel to the ATLAS ALARA team every day. We will do the Retour d’ experience for the DIMR.

General safety measures to work in radioactive areas:

The list of specific safety measures will be detailed in the activity PPSPS. Personnel working in the controlled radiation areas (Simple Controlled Areas and Limited Stay Areas) should wear an operational dosimeter.

The most critical tasks will be supervised remotely by the ALARA team.

The personnel working in controlled radiation areas must perform a hand and foot contamination check before leaving the area. For non destructive work on material from the radioactive waste area or the operational area:

Normal clothes should be worn, except specific instruction from the CERN RP group. Gloves will be worn and disposed in radioactive waste bins.

General safety measures to work in radioactive areas:

For destructive work on material from the radioactive waste area or the operational area:

All destructive works (including soldering, welding, machining, etc…), and work on equipment with a contamination risks like cooling circuits need prior approval by the CERN RP group and the ATLAS Safety team.In these cases, RP defines appropriate Personal Protective Equipment (PPE) and the appropriate safety measures.  

No destructive work on material coming the ATLAS radioactive waste area or the operational area is allowed without the specific agreement from the ATLAS GLIMOS and RSO (who are referring to RP group).

Removal of material from radioactive waste area:

At work place, the removed small material will be collected in yellow plastic boxes, stamped radioactive.

The material shall be removed from work place very regularly to be placed in the yellow boxes located in the ATLAS Forward trenches side A or side C.

The yellow radioactive storage boxes are regularly removed by the crane drivers from the trench to be brought to the SX1 RBZ, at least once per day.

The RPE or RP technician are in charge to fenced the area around the trench storage boxes in order the accessible area around remains supervised radiation area.

In general, the RP technicians will perform daily controls in the surface RBZ.