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The Panorama of the Future Radioactive Areas from now to 2020

The Panorama of the Future Radioactive Areas from now to 2020. S. Roesler on behalf of DGS-RP. Workshop on remote manipulations and diagnostics in radioactive areas and handling of radioactive material CERN, May 6, 2013. Outline. Present radiological classification

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The Panorama of the Future Radioactive Areas from now to 2020

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  1. The Panorama of the Future Radioactive Areas from now to 2020 S. Roesler on behalf of DGS-RP Workshop on remote manipulations and diagnostics in radioactive areas and handling of radioactive material CERN, May 6, 2013

  2. Outline • Present radiological classification • Measured residual dose rates and comparison to FLUKA simulations • Operational scenarios until LS3, scaling factors for dose rates • Evolution of dose rates 1. LHC: 2. LHC injectors: • SPS, PS, PSB • Residual dose rates and present radiological classification 3. Target Areas: • North, East and AD target areas • Measured dose rate maps • Evolution of dose rates with cooing time 4. ISOLDE: • Measured and calculated residual dose rate maps • Calculated dose rates for target recovery scenario 5. ALARA: • Reminder on ALARA rules • Work-and-dose planning • Optimization during design Not covered: CNGS, nTof, Linacs, Experimental Areas,… Remote Manipulations Workshop, 6 May 2013

  3. Radiological classification of the LHC during 2012 low-occupancy permanent

  4. LHC Point 7 Ambient dose equivalent rates in µSv/h at 40cm measured on Dec 20, 2012 (last “good” fill on Dec 5, i.e. cooling time >1week) Scaling factors based on generic Studies for IR7: Remote Manipulations Workshop, 6 May 2013

  5. LHC Point 7 FLUKA calculations for nominal parameters Collimator (1 week cooling) Absorber (1 week cooling) good agreement between FLUKA results and measurements (after scaling to nominal conditions) Remote Manipulations Workshop, 6 May 2013

  6. LHC Point 6 500 µSv/h 222 µSv/h Ambient dose equivalent rates in µSv/h at 40cm measured on Dec 17, 2012 (~1 hour after last dump) 83 µSv/h 17. Dec 2012, 8am 40 µSv/h factor 4 110 µSv/h factor 2 1 week 1 day Remote Manipulations Workshop, 6 May 2013

  7. LHC Point 6 40 µSv/h 110 µSv/h FLUKA calculations for nominal parameters 100 µSv/h 10 µSv/h FLUKA calculations: J.Vollaire et al. Remote Manipulations Workshop, 6 May 2013

  8. LHC Point 1 FLUKA calculations for LS1 (1 week cooling) Courtesy: C.Urscheler et al. Ambient dose equivalent rates in µSv/h at 40cm measured on Dec 17, 2012 (last “good” fill on Dec 5, i.e. cooling time >1week) Remote Manipulations Workshop, 6 May 2013

  9. LHC Point 5 FLUKA calculations for LS1 (1 week cooling) Courtesy: C.Urscheler et al. Ambient dose equivalent rates in µSv/h at 40cm measured on Dec 17, 2012 (last “good” fill on Dec 5, i.e. cooling time >1week) Remote Manipulations Workshop, 6 May 2013

  10. Operational scenario(s) L.Rossi / HiLumi Workshop, Frascati Assumptions on the operational parameters as obtained from ATLAS and CMS Remote Manipulations Workshop, 6 May 2013

  11. Dose rate evolution until LS3 – ATLAS LS1 Ambient dose equivalent rates in µSv/h after one week of cooling (also representative for a TS during the run prior to the respective LS) Courtesy: C.Urscheler et al. LS3 LS2 Remote Manipulations Workshop, 6 May 2013

  12. Dose rate evolution until LS3 – CMS LS1 Ambient dose equivalent rates in µSv/h after one week of cooling (also representative for a TS during the run prior to the respective LS) Courtesy: C.Urscheler et al. LS2 LS3 Remote Manipulations Workshop, 6 May 2013

  13. Dose rate evolution until LS3 – Scaling factors Short cooling times: - dominated by short-lived nuclides - dose rate reflects interaction rate (instantaneous luminosity) - increase, e.g., ATLAS from now until 2021: (peak lumi: 2.0×1034 / 0.7×1034) 2.9 (energy) ~1.5 (total) ~4.4 Long cooling times: - dominated by longer-lived nuclides - dose rate reflects integrated luminosity - e.g., as calculated with FLUKA Remote Manipulations Workshop, 6 May 2013

  14. Residual dose rates LS3 – ATLAS one month 6 months 4 months one year Remote Manipulations Workshop, 6 May 2013

  15. Residual dose rates LS3 – CMS one month 6 months 4 months one year Remote Manipulations Workshop, 6 May 2013

  16. Residual dose rates LS3 – TAS at Point 5 one week 4 months 1 month one year Remote Manipulations Workshop, 6 May 2013

  17. Residual dose rates LS3 – TAN at Point 1 4 month cooling top side inside Remote Manipulations Workshop, 6 May 2013

  18. SPS – Ring Survey (1) • Performed during annual shutdown • Usually done 30 hours after beam stop and at end of annual shutdown • Use of motorized tractor • Measurements with plastic scintillator every meter • Complemented by more detailed measurement at specific work-sites and most radioactive components in order to define radiological classification Remote Manipulations Workshop, 6 May 2013

  19. SPS SPS – Ring Survey (2) 1 mSv/h 10 µSv/h 1 mSv/h 10 µSv/h Remote Manipulations Workshop, 6 May 2013

  20. SPS – Detailed Survey Example: Sextant 1 • Radiological classification as Limited Stay Area with local • postings of “hot spots” • Dose rates not expected to change dramatically during coming • years Remote Manipulations Workshop, 6 May 2013

  21. PS • shown here: results 32hrs after beam stop 18/12/2012 • radiological classification as Limited Stay Area • dose rates not expected to change dramatically • during coming years • several optimization measures planned • (e.g., dummy septum) Remote Manipulations Workshop, 6 May 2013

  22. PSB Ring Remote Manipulations Workshop, 6 May 2013

  23. PSB Injection 600 µSv 300 µSv • Dose rate reduction: • factor of two between 1-2 hours and 32 hours • factor of two between 32 hours and two months cooling time Remote Manipulations Workshop, 6 May 2013

  24. North target area Residual dose rates in µSv/h 25 Oct 2002 (38 days after proton run) Remote Manipulations Workshop, 6 May 2013

  25. North target area 2 hours 5 hours factor 2 1 day factor 2 1 week Remote Manipulations Workshop, 6 May 2013

  26. East target area • Shown here: 2 months of cooling • Dose rates higher by about a factor of 7 • after 1-2 hours cooling • Very crowded and not optimized w.r.t. • modern RP Remote Manipulations Workshop, 6 May 2013

  27. AD target area • Shown here: 3 months of cooling • Dose rates higher by about a factor of 9 • after 1-2 hours cooling Remote Manipulations Workshop, 6 May 2013

  28. ISOLDE Example: Survey measurements from shutdown 2011 (about 2 months cooling time) 170 mSv/h 60 mSv/h 650 mSv/h (1 m from target) 450 mSv/h (2 m from target) 60 mSv/h 15 mSv/h 10 mSv/h Remote Manipulations Workshop, 6 May 2013

  29. ISOLDE • (Pessimistic) Example: • Five years of operation with UC target at 1020 protons/year • Residual dose rate calculated with FLUKA for different cooling times after target removal 1 day of cooling Courtesy: J.Vollaire et al. Remote Manipulations Workshop, 6 May 2013

  30. ISOLDE Probibited area (100 mSv/h) • (Even more pessimistic) Example: • target recovery scenario • About 9 days of operation with UC target at • 1019 protons delivered (~2 µA) • Residual dose rates calculated with FLUKA 3 days of cooling 3 days of cooling Courtesy: J.Vollaire et al. Remote Manipulations Workshop, 6 May 2013

  31. Optimization – Safety Code F Optimization starts with the design! Remote Manipulations Workshop, 6 May 2013

  32. Optimization – ALARA procedure Optimization is legal requirement if accumulated dose exceeds 100 μSv (ALARA) Optimization includes: • work coordination • work procedures • handling tools • design • material Group 1 criteria 5 mSv Group 1 criteria: determine ALARA Level classification Group 2 criteria: can be used by RP/RSO to increase classification Formal work-and-dose-planning (DIMR) as from ALARA Level 2 ALARA committee if ALARA Level 3 Group 2 criteria

  33. Optimization – ALARA procedure Work- and dose planning (DIMR)

  34. Optimization during design – Intervention doses Methodology: Calculation of residual dose rate maps Calculation of individual and collective intervention doses Revision of design and/or work scenario • for cooling times typical for interventions on the respective component • based on nominal operational parameters • definition of geometry and materials as detailed as needed (and available) • based on as realistic as possible work scenarios, including locations, duration, number of • persons involved,.. • identification of cooling times below which work will be impossible • (design criterion: 2 mSv/intervention/year) • communication of results and constraints to equipment groups • start with work steps that give highest individual or collective doses • consider optimization measures (distance, tooling, material choices, etc.) • identify if remote handling is possible New design ? Step 1 Revised work scenario ? Step 2 Start of iteration: Remote Manipulations Workshop, 6 May 2013

  35. Recent example – Linac 4 dump 1 2 3 4 Courtesy: D.Grenier Remote Manipulations Workshop, 6 May 2013

  36. Summary (1) • LHC: • Activation and residual dose rates in LSS1, 5, 3, 7 will increase until LS3 by factors up to 16 and • approach levels of the present SPS. • LSS1 and LSS5 will become Limited Stay Areas until LS3 with residual dose rates (few months • cooling) in the aisle of about 100 µSv/h, reaching several mSv/h close to most radioactive objects. • LSS7 may become High Radiation Area with dose rates of 2-10 mSv/h (few days of cooling) around • collimators and absorbers. • Dose rate around the inner parts of the experiments and their forward shielding will increase to • several mSv/h. • Upgrade studies should include the development of tools and work procedures for maintenance, • repair and dismantling. • As successfully done during the LHC design, all components to be installed in high-loss regions • must be optimized for future handling and radioactive waste disposal (see also next presentation) • Radiological assessments, including detailed FLUKA calculations, will be performed as soon as design • choices have been made which may then serve as input to assess design options. Remote Manipulations Workshop, 6 May 2013

  37. Summary (2) • SPS, PS, PSB: • Dose rates have reached saturation and remain at the present levels. They are classified as • Limited Stay Areas with local areas where dose rates exceed 2mSv/h. • Loss locations may vary and, if possible, should be moved to passive robust elements that need • little maintenance (e.g., PS dummy septum 15). • Target areas: • The North, East and AD target areas are among the most radioactive areas at CERN and not • always optimized with regard to modern RP (crowded, corrosion, ageing components, some • without ventilation,…). • In order to reduce waiting times before interventions and dose to personnel they are presently • in the focus for development of remotely operated devices. • Consolidation projects are ongoing for all of them. Remote Manipulations Workshop, 6 May 2013

  38. Summary (3) • ISOLDE • The ISOLDE target area is one of the very few areas at CERN where fully remote handling is • mandatory. Its robot will be replaced during this LS (see presentation by J. L. Grenard). • Its laboratory area will change completely and include in the future significant handling activities • of highly radioactive objects (ISOLDE targets, Medicis samples). • ALARA: • CERN’s ALARA rules are being used with great success since several years now and have just • been revised. • - Moreover, they are now fully integrated into the activity planning and approval process (IMPACT). Many thanks to: C. Adorisio, C.Urscheler, D. Forkel-Wirth, N. Conan, H.+H. Vincke, J. Vollaire, C. Tromel, R. Fröschl, G. Dumont,… Remote Manipulations Workshop, 6 May 2013

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