Radiological Radiological Aspects of ILCAspects of ILC

2004. 12. 28.2004. 12. 28.

Hee-Seock LeeHee-Seock Lee

Pohang Accelerator LaboratoryPohang Accelerator Laboratory

2nd Workshop of Korean ILC at PAL

High Power, High Energy High Power, High Energy Electron Accelerator, ILCElectron Accelerator, ILC

Underground FacilityUnderground Facility (Natural Shield : 20 m for TESLA, 30 m for ILS) (Natural Shield : 20 m for TESLA, 30 m for ILS) Near Resident Area ( long facility ~ 30 km) Near Resident Area ( long facility ~ 30 km) Limited No. of Access PointLimited No. of Access Point Air Conditioning System with Long Path Air Conditioning System with Long Path Water & Cooling SystemWater & Cooling System High Power Beam DumpHigh Power Beam Dump (10 ~ 20 MW, e-beam dump, Bremsstrahlung ph(10 ~ 20 MW, e-beam dump, Bremsstrahlung ph

oton dump)oton dump) Huge IP (Interaction Point)Huge IP (Interaction Point)

Radiological Impacts of ILCRadiological Impacts of ILC

EM Shower, Photonuclear, SR, Hadron EM Shower, Photonuclear, SR, Hadron Primary Radiation Primary Radiation Secondary RadiationSecondary Radiation Muon (LMuon (LSoilSoil = 400 m for 250 GeV ) = 400 m for 250 GeV ) Residual Activity Residual Activity Environmental ProblemEnvironmental Problem Beam DumpBeam Dump Radiation DamageRadiation Damage

Shielding

Radiation for Radiation Radiation for Radiation WorkerWorker

Tunnel Concrete ActivationTunnel Concrete Activation Equipment ActivationEquipment Activation Activated Air near Access Point(AP)Activated Air near Access Point(AP) Activated Coolant in/out of TunnelActivated Coolant in/out of Tunnel Shielding at APShielding at AP One tunnel or Two tunnelOne tunnel or Two tunnel (Access & Rescue)(Access & Rescue)

Radiation for Publics & Radiation for Publics & EnvironmentsEnvironments

Activated Air near Access PointsActivated Air near Access Points Soil ActivationSoil Activation Ground Water ActivationGround Water Activation Tritium & Be-7Tritium & Be-7

TESLA

Shielding

Air & Coolant ActivationAir & Coolant Activation

Air (near IP)Air (near IP) Short Half-life Radioisotopes : C-14, N-13, O-15Short Half-life Radioisotopes : C-14, N-13, O-15 Open Loop (long distance from release point)Open Loop (long distance from release point) Closed Loop (3 h cooling time after 1 month Op, Closed Loop (3 h cooling time after 1 month Op,

100 kW)100 kW) Water Coolant (Specially, Dump)Water Coolant (Specially, Dump)

Tritium, Be-7 : Control of NPP Level for 1Tritium, Be-7 : Control of NPP Level for 1stst coolant coolant Helium Helium

Tritium : negligible for average loss of 0.1 W/m) Tritium : negligible for average loss of 0.1 W/m)

High Power Beam DumpHigh Power Beam Dump

Mechanical Issues Mechanical Issues 10 ~ 20 MW, preventing leakage10 ~ 20 MW, preventing leakage

Residual Activity around Beam DumpResidual Activity around Beam Dump Coolant ActivationCoolant Activation Fail-safeFail-safe InterlockInterlock Heavy Local Shield to reduce Env. ProblemsHeavy Local Shield to reduce Env. Problems Large Hall & Many Beam Dumps of ILCLarge Hall & Many Beam Dumps of ILC Dump for Beam and Bremsstrhalung PhotonDump for Beam and Bremsstrhalung Photon

Water DumpWater Dump In ILC, One dump for e-bIn ILC, One dump for e-b

eam and bremsstrahlung eam and bremsstrahlung photonphoton

No Vacuum TroubleNo Vacuum Trouble

SLAC type SLAC type Beam Dump Beam Dump for ILCfor ILC

Beam Dump Beam Dump for TESLAfor TESLA

Collimations and DamagesCollimations and Damages

Multi-stage collimators and Magnetized Multi-stage collimators and Magnetized Iron SpoilersIron Spoilers

Life-times of Equipments and DetectorsLife-times of Equipments and Detectors

Other Issues and AccidentsOther Issues and Accidents

Radiation Monitoring System distributed Radiation Monitoring System distributed along long facility : Budget & Operationalong long facility : Budget & Operation

Publics always exist over the accelerator Publics always exist over the accelerator

AccidentsAccidents Cooling Water LeakageCooling Water Leakage Melting and Evaporation of Activated MaterialsMelting and Evaporation of Activated Materials Access Control FailAccess Control Fail

Recent ActivitiesRecent Activities

KEK : Study on High Power Beam DumpKEK : Study on High Power Beam Dump Fermi : Collimation and Background(BDIR)Fermi : Collimation and Background(BDIR) TESLA : General Safety AnalysisTESLA : General Safety Analysis (Dump and problems near dump are not declared)(Dump and problems near dump are not declared)

KEK & PALKEK & PAL 2, 2.5 GeV Electron Beam2, 2.5 GeV Electron Beam Photonuclear Reaction StudyPhotonuclear Reaction Study Activation Study of Low Activity Activation Study of Low Activity ConcreteConcrete Activity around Water DumpActivity around Water Dump Since 2003(1998)Since 2003(1998)