TCC2/TDC2 consolidation WG ALARA COMMITTEE PREPARATION for Xmas stop activities S. Evrard T. Wijnands

2 Radiation classification of SPS SPS: Limited Stay Area LSS1 injection/dumpHigh Radiation Area LSS2 extraction High Radiation Area SPS North Area: Target Area TDC2 TCC2:High Radiation Area Target Area TDC8 TCC8:High Radiation Area Transfer tunnel TT83-TT85: Limited Stay Area Transfer tunnel TT81-TT82: Simple Controlled Radiation Area Experimental Areas North:Supervised Radiation Area CNGS:Limited Stay Area Target Area TCC4:High Radiation Area

EXPERIENCE FROM 2002 (N°EDMS ) Les travaux de changement de TAX dans la zone TCC2 sur les TAX de la station 2 au cours du shut-down 2002 ont entraîné des doses importantes. Les chiffres sont les suivants. Dose collective totale shut-down =>56.97mSv pour 194 personnes (74% de la dose annuelle) ; Dose collective totale des travaux TAX => 29.09mSv pour 36 personnes (soit 51% de la dose du shut-down et 38% de la dose annuelle de cette zone) ; Dose individuelle maximale => 4206µSv (la dose maximale annuelle a en réalité été intégrée sur la période du shut-down et plus particulièrement pendant les travaux sur le TAX T2).

RP SURVEY

ALARA levels Level 3 Level 2 or 3 Level 3 Level 1 TAX table repair case

ALARA in practice 1.Establish the list of provisional interventions 2.RP, Superintendent, RSO together will make a first estimate of the ALARA level 3.If Level I : -RP representative and persons accessing will discuss on site -RP representative will decide if the intervention can take place as discussed 4.If Level II : -Establish a DIMR (list of tasks/actions, time needed, estimated dose) -Inform the RP group and the departmental RSO of the DIMR -Preparative meeting if needed 5.If Level III : -Establish a DIMR (list of tasks/actions, time needed, estimated dose) -Group Leader, RP group and the departmental RSO must be informed and approve the DIMR -The DIMR needs to be presented in the ALARA committee -Approval of the CERN Complex Manager (S. Myers) is mandatory This requires a team approach between operation, experiments, equipment groups, contractors, radiation protection group, safety officers etc.

Establish the list of provisional interventions Overhead crane modification (D. Lafarge) – Optical fiber pulling – Overhead cabine modification – Electrical cabinet modification TAX table repair (S. Girod) – Bunker setup and removal – Shielding and other equiment (removal and re-installation if needed) – TAX table handling (removal and re-installation) – TAX table modification (motorization) Vacuum short term repair (P. Chiggiato) Infrastructure check for consolidation in LS1 (S. Evrard) – Survey (laser scanning or other means) – Magnets – Cabling

TAX: Mock-up exercises TAX cast iron blocks Spare table and lifting beam available in storage area Refurbishment in EHN1 Holes in main workshop Test in EHN1 before Xmas