Normal conduction linac commissioning - update on shielding, radiation monitoring and fire safety Andreas Jansson, Lali Tchelidze Riccardo Bevilacqua, Konstantin Batkov, Alan Takibayev ESHAC meeting, October 1-2, 2018 www.europeanspallationsource.se

NC Linac Beam Commissioning Steps NC linac beam commissioning is planned in the following steps: Ion source and LEBT beam commissioning – currently on-going RFQ and MEBT beam commissioning (3.6 MeV) DTL1 beam commissioning (22 MeV) DTL2 to DTL4 beam commissioning (40 MeV, 57 MeV, 74 MeV) M. Eshraqi, ESS-0149990

Ion source and LEBT beam commissioning Ion source and LEBT beam commissioning – currently on-going applying ESS operational limits and conditions. Limits: Personnel is NOT categorised as exposed workers (less than 1 mSv/year). Beam commissioning shall not exceed proton beam energy of 80 keV. Systems important to safety: A safety fence containing 2 mm lead shielding around the entire ion source with a height of 2.5 m. A Personnel Safety System 0 (PSS0), that controls the access to the area inside the fence (PSS0 controlled area). Passive environmental dosimeters around the safety fence, for monitoring radiation levels outside the fence.

Ion source and LEBT beam commissioning Administrative controls: At least one trained shift leader shall be present in the control room when the ion source is running with beam. Shift leaders shall be trained and qualified on their safety, operational and emergency responsibilities. Handling, functional check and calibration of any measuring instruments used for radiation monitoring shall be performed according to Chapter 7 of the RP handbook. 8:30 am meetings in Local Control Room with agenda: summary of the previous day Shift leader announced and plans of the day discussed and agreed

RFQ – DTL4 Beam Commissioning Shielding is designed and limits are set for: Beam on FC at the end of RFQ/MEBT – 3.6 MeV Beam on FC at the end of DTL1 – 22 MeV Beam on FC at the end of DTL2 – 40 MeV Beam on FC at the end of DTL3 – 57 MeV Beam on FC at the end of DTL4 – 74 MeV Distributed losses – 1 W/m – scaled by the average beam current, for the commissioning stage

Reminder - Radiological Hazard Analysis – Summary Safety function SSCI2S Event class Functional Group RSF-3 Attenuate radiation emitted from proton beam line Structural part of the tunnel and earth berm; All other permanent and movable shielding H1 Operational RSF-138 Stop the proton beam at pre-defined destination Faraday cup (in MEBT, end of DTL2 and end of DTL4) MPS RSF-139 attenuate radiation from beam on FC interaction FC shielding and TSW RSF-140 monitor and limit average beam current BPCS (for monitoring) MPS (for limiting) RSF-32 Detect elevated prompt dose rates outside accelerator (normal conducting linac) shielding and alert/shut the beam off Dose rate shall be calculated over any one-hour period outside of TSW REMS & PSS1 H1, H2 AM-10 Limit exposure by applying ALARA approach NA

RFQ – DTL4 Beam Commissioning – shielding status Shielding consists of permanent and movable shielding Permanent shielding - tunnel concrete structure and berm around Movable shielding in 6 (six) areas: 1. Front end building (FEB) chicane wall, 2. shielding in FEB side wall penetrations, 3. drop hatch shielding, 4. alignment penetration shielding, 5. stubs shielding, 6. temporary shielding wall. All of you should be able to see this dashboard via the link

Shielding structure with major penetrations Opening for alignment penetration Concrete tunnel Drop hatch Stubs FEB FEB side wall penetrations FEB chicane (wall)

RFQ – DTL4 Beam Commissioning – shielding status Movable shielding: FEB chicane wall – ESS-0060233 – released Shielding in FEB side wall penetrations – ESS-0399529 – in review Drop hatch shielding – ESS-0120796 – released Alignment penetration shielding – ESS-0120796 – released Stubs shielding – ESS-0398626 – not in CHESS yet Temporary shielding wall – ESS-0136227 – in review

RFQ – DTL4 Beam Commissioning – shielding status FEB chicane wall – 1 m thick ordinary concrete wall. 1 m thick concrete wall R. Bevilacqua, ESS-0060233

RFQ – DTL4 Beam Commissioning – shielding status Shielding in FEB side wall penetrations – best available filling material will be used as shielding. Additional space is reserved in FEB if measurements show it necessary. A. Takibayev, ESS-0399529

RFQ – DTL4 Beam Commissioning – shielding status Drop hatch shielding – 1 m thick ordinary concrete Alignment penetration shielding – a combination of concrete/iron as defined in ESS-0120796

RFQ – DTL4 Beam Commissioning – shielding status Stubs shielding – shielding filling in the first two stubs is NOT required. K. Batkov, ESS-0398626

RFQ – DTL4 Beam Commissioning – shielding status Temporary shielding wall – 1.5 m ordinary concrete is sufficient to have supervised area outside the wall. K. Batkov, ESS-0136227

Radiation Monitoring

Fire safety Radiological consequences during fire in the tunnel is negligible (ESS-0111185), thus we don’t need to mitigate against releases of radioactive material. Temporary shielding wall will be designed in such a way that a portion of it is movable and an emergency exit will be created when we plan work in the tunnel.

Thank you!