1. Status Report from LHC Safety System Task Force Emmanuel Tsesmelis / TS-LEA on behalf of the Task Force LEAF 11 May 2007

2. Introduction Following the LHC Safety System Review for the experiments and experimental areas in February 2007, LEAF appointed a Task Force with the following mandate:  Address open requests made at the Review with the aim of providing a set of recommendations on their eventual implementation.  Requests have been detailed in document EDMS 825832 and in particular relate to issues concerning: Setting-up of protocols for safety interventions taking into account information from all safety systems. Safety constraints related to INB. Task Force Membership  Olga Beltramello (ATLAS)  Christoph Schaefer (CMS)  Ralf Trant (SC)  Emmanuel Tsesmelis (TS)

3. Introduction The Task Force is to recommend measures relating to the implementation of CERN’s safety policy in order to ensure the required level of safety for personnel, environment and material in the LHC experiments and experimental areas. Recommendations are to allow for the full utilisation of the various LHC safety systems and of the detailed emergency intervention procedures (i.e. IS 51) for the specific case of the experiments and experimental areas for the LHC exploitation phase.

4. Recommendation I – Experimental Control Rooms Experiments and experimental areas pose specific safety hazards and the evolution of the detector conditions needs to be monitored particularly for FB intervention in underground areas. XCRs provide central location for information, co- ordination and operation concerning all experiment- related parameters and activities. XCRs shall thus be used to support actions by the emergency intervention teams (FB) following an AL-3 inside the experimental areas.

5. Recommendation I – Experiment Control Rooms In practice:  FB head of intervention shall as soon as reasonably possible establish link with the experiment SLIMOS and as soon as the situation allows will go the XCR.  All AL-3 information as exists in the SCR shall be made available in the XCRs and both the XCR/SCR shall include the synoptic information available in the SY buildings.  Technical communication links shall be adequate to guarantee links between head of intervention and SLIMOS.  At the end of the intervention, a debriefing between FB head of intervention and SLIMOS shall take place and a written report produced.

6. Recommendation I – Experimental Control Rooms SNIFFER system information shall be made available in the XCRs. All AL-3 shall be made available reliably to the Detector Safety Systems (DSS) of the experiments to allow for certain automatic actions on the detectors.  To be implemented so that SIL-2 of CSAM is not compromised. Total number of persons and their names in the underground areas shall be made available to the XCRs and SCR.

7. Recommendation I – Experiment Control Rooms Safety Information Panels shall be implemented at the experimental areas. Reliable intercom system shall be installed between the top and bottom of the lifts leading from the surface buildings to the underground areas.  Facilitate evacuation procedure. A public address system shall be installed between the XCR and the underground caverns (UX and US).  Shall be used according to pre-defined procedures or directly by emergency intervention team

8. Categories under Evaluation All AL-3 to be integrated into a unique safety procedure which will provide the overall co- ordination and, depending on the specific incident, may trigger automatic safety actions of the various systems following a specific Safety Matrix to be agreed with SC. Radioprotection procedures to be issued and monitoring of radioactive material, reflecting special situation of the experimental areas, to be implemented.

9. Categories under Evaluation Establishment of safety procedures for the operation of the experiments concerning:  Common approach for patrols.  FB intervention procedures inside experimental areas with preferably common approach for all experiments.  Operation of fire fighting equipment – e.g. water mist and foam system.  Work outside normal working hours or working alone in experimental areas (in very special situations such as on-call).

10. Categories under Evaluation Specific safety training for members of the experiment collaborations.  Including specific training in radiation safety and protection. Responsibility for and organisation of safety systems during the maintenance and operations phase.  Ensure continuation of high safety standards through-out LHC exploitation phase.