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HIAT'09, 8-12.06.2009-Venezia0 D. Ene, D. Ridikas, B. Rapp, J.C David, D. Doré CEA-Saclay, IRFU/SPHN, F-91191 Gif-sur-Yvette, France for EURISOL Task#5.

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Presentation on theme: "HIAT'09, 8-12.06.2009-Venezia0 D. Ene, D. Ridikas, B. Rapp, J.C David, D. Doré CEA-Saclay, IRFU/SPHN, F-91191 Gif-sur-Yvette, France for EURISOL Task#5."— Presentation transcript:

1 HIAT'09, Venezia0 D. Ene, D. Ridikas, B. Rapp, J.C David, D. Doré CEA-Saclay, IRFU/SPHN, F Gif-sur-Yvette, France for EURISOL Task#5 Safety & Radioprotection: GANIL, France, FZJ, Germany, LMU, Germany, CERN, EU CEA, France, NIPNE, Romania, FI, Lithuania, Univ. Warsaw, Poland

2 HIAT'09, Venezia1 Radiation safety issues  the strategy used for the design of RNB facilities EURISOL-DS project (illustration) –early stage Problems addressed: Legislation framework sets-up safety requirements protection of the environment, public and staff Radioactive sources identification and estimation deciding the radiation safety features Safety design objectives: (Protection of workers, public & environment)

3 HIAT'09, Venezia2 1.Operation phase 1.Operation phase :  Protection against radiations optimum shielding configuration  Protection against radiations => optimum shielding configuration  Containment of radioactive materials risk analysis >  Containment of radioactive materials => risk analysis > equipments are adequate to minimize risk of radioactive material dispersion.  Compatibility with the environment impact of the radioactive releases  Compatibility with the environment => impact of the radioactive releases Radiological studies: Characterization of the prompt radiation field for normal and accident conditions Safety studies: Classification of the events & Risk assessment Environmental studies: Characterization of the specific site & impact assessment 2.Post -operational phase 2.Post -operational phase:  Protection against radiations measures to limit the exposure & working procedures  Protection against radiations => measures to limit the exposure & working procedures during maintenance and interventions machine will be dismantled and decommissioned waste transportation/disposal  Compatibility with the environment impact of the radioactive releases  Compatibility with the environment => impact of the radioactive releases >decommissioning & waste transportation/disposal Radiological studies: assessment of the residual radiation field => specifications on the exposure of the personnel Environmental studies: Characterization of the specific site & impact assessment

4 HIAT'09, Venezia3

5 4 Direct: high energy spallation 100 kW -Converter: neutron fission 4MW Al 2 O 3, SiC, UC x, Pb, etc p, 1GeV Direct method p, 1GeV Hg UC x Converter method (~10 15 fiss/s) 235 U + n( ~ 100 keV) 238 U + p( 1GeV) Direct target: R=1.8cm, L=40cm Fission target(30kW) (R ext =1.75cm, R int =0.4cm,H=20cm)

6 HIAT'09, Venezia5 H*(10) [  Sv h -1 ] Total_H*(10) [mSv y -1 ] Public areas: inside fence Controlled areas1020 / 2000 h Full beam loss: Total_H*(10) ≤ 50  Sv  JUSTIFICATION  LIMITATION  OPTIMISATION Design limits for occupied areas/ ICRP 60 H*(10) [mSv h -1 ] Maintenance constraints >0.1Planification and optimisation of all work >2+ limited intervention time & remote handling >20Remote handling essential CERN guidelines:

7 HIAT'09, Venezia6 Design guidelines & previous experience => Basic estimates Few exemples: EquipementprimaryEnergyIntensity (pps) Losses (pps) Specific sources Linacp1GeV(1-4)*6* *10 12 /E[MeV] m -1 -Few hot spots -Neutron backscatter Linac#1 (L=209m) 132 Sn (0.6 – 150) MeVu -1 6*10 12 (6* *10 8 )m -1 No spots specification Linac#2 (L=156m) 132 Sn (0.6 – 150) MeVu -1 6* *10 12 (6* *10 8 )m -1 ~4*10 12 ( stripper zone) No spots specification

8 HIAT'09, Venezia7 Prompt radiation PHITS, FLUKA, MCNPX-HI Mixed  & Conversion factors->H*(10) Ar(95MeV/u)+Cu  neutrons PHITS p(1.6 GeV) + Fe  neutrons (MCNPX) Neutron penetration in concrete shield MCNPX Benchmarks related to prompt radiation

9 HIAT'09, Venezia8 Residual radiation: Production of Residual Nuclei Benchmarks related to induced activity Neutron flux in i th cell Geometry and materials description DCHAIN- SP-2001/ CINDER PHITS/ MCNPX Residues in i th cell Irradiation Scheme H*(10) MCNPX Activation products & Photon sources 5000h irradiation at 4MW 40 years & duty factor 0.7

10 HIAT'09, Venezia9 Hg converter and secondary fission targets MAFF-like configuration => NEUTRON STREAMING Monte Carlo & generic studies -> choices of materials & shielding effect First version of design => BULK SHIELDING Biasing methods

11 HIAT'09, Venezia10 Prompt radiation: BULK SHIELDING + Attenuation formula Iron 100 cm concrete 1 m of iron For θ= 0, 90, 180°  9.0, 8.0 & 6 m of concrete FLUKA (CERN)

12 HIAT'09, Venezia11 Prompt radiation: NEUTRON STREAMING FLUKA (CERN) Ion extraction tubes Spallatio n target 600 cm Fission targets concrete Fission target handling room 6 m concrete RIB lines Laser portholes ~9 m Z=0 Fission target handling room

13 HIAT'09, Venezia12 A shield designed for a continous beam loss of m -1 (point loss of 6.25*10 9 ion s - 1 ) during the routine operation is also adequate for an accident loss of the full beam at a localised point, providing that the linac cutoff time is less than 1s. PHITS 132 Sn  Method (CEA)

14 HIAT'09, Venezia13 E [MeV/u]   [Sv m 2 ion -1 ]  [g cm -2] H  [Sv m 2 ion -1  [g cm -2 ] E E E E E E E E E MeV/u150MeV/u * Agosteo S, Nakamura T, at al. NIM/B 217, 2004 !! neutrons

15 HIAT'09, Venezia14 U-238 : 400 MeV/u He-3 : 777 MeV/uproton : 1 GeV Beam on stopping Cu target Ronningen & Remec, 2005 Beam direction Photon H*(10) < 3% Total H*(10) 3 m of concrete: Neutron H*(10) for 6 He (250MeV/u) Neutron H*(10) for 132 Sn (150MeV/u) ~ 5 Safety operation domain: energy range and beam intensities. !! Other species & secondaries

16 HIAT'09, Venezia15 Underground target position Front-end retracts vertically Hot-cell for target exchange Separator in 3 rd level Neighboring hot-cell accessible during run Effective dose rate E (Sv/h) Soil activation! Effective dose rate maps Conceptual design of 100kW target station (CERN)

17 HIAT'09, Venezia MeV/u RFQ 150 MeV/u beam dump L(1) L(2 ) Experiment rooms 21.3 MeV/u Experiment rooms 44 m 102 m 2.8 W m -1 => 7.92 W 6 W 4 W 2.4 W Stripper 1.68 kW Uncontrolled beam loss of m MeV/u RFQ L(1) L(2 ) Experiment rooms 21.3 MeV/u 150 MeV/u Experiment rooms 44 m 165 m 2.8 W m -1 => 19.8 W 15 W10 W 6 W beam dump Shielding of Postaccelerator (CEA) Staff Energy [MeV] Length [m] Thickness (cm) V staff (m 3 ) *  for a tunnel surface of 3 m x 4m PublicThickness (cm) V public (m 3 ) 536.6*  for a tunnel surface of 3m x 4m Energy [MeV] 21.3 Stripper Length (m) Staff Thickness (cm) V staff (m 3 ) 205.8*  for a tunnel surface of 3 m x 4 m PublicThickness (cm) V public (m 3 ) 343.4*  for a tunnel surface of 3 m x 4 m

18 HIAT'09, Venezia17 material   [Sv m 2 ]  [g cm -2 ] H  [Sv m 2 ]  [g cm -2 ] SHIELD [cm] StaffPublic concrete1.747E E steel E concrete concrete / steel soil void beam Bea m 5o5o Iron shield Copper + 10% water Graphite (1.84g/cm 3 ) 100 cm40 cm 8 cm16 cm 132 Sn 25+ Beam power = 19.8 kW (150 MeV/u) Beam size σ = 2 mm Beam Dump cavity: thickness of lateral wall (CEA)

19 HIAT'09, Venezia18 Dose in distance of 1m after 1 day decay time: fission/sec 235 U ion source ~ 10 kCi ‘open’ source Beam tube  Sv/h non-volatile activity ions slit aperture of pre-separator (m=95, 140: 97%) ~  Sv/h slit aperture of high-resolution separator ~ 10 4  Sv/h ~2% non volatile ~68% Dispersion of radioactivity: from MAFF EURISOL  10 higher! P. Thirolf et al. (LMU) exhaust storage tanks outer beam tube ~ 300  Sv/h ~30% ~ 0.02% atoms/ gases regeneration decay on the cryopump slits/targets of beam line ~  Sv/h large small Capability of Cryotrap 3 cryotraps prototypes tested: Retention capability (vs. pressure behind cryotrap) ‘carry over’: fraction of leaking gas load transported across cryotrap Cryotrap works within (simulated) expectations  99.98% of volatile radioactivity can be localized!

20 HIAT'09, Venezia19 EURISOL-DS RISK REGISTER EquipmentOperational phase and Risk RP [mSv/h] and intervention Risk assessment before mitigation Mitigation of Risk Risk assessment after mitigation OwnerName and location Acronym - Number Action typedesccription of failureDescription of associated riskDose rate Job duration ProbabilityImpactScoreComments - Needed actionsProbabilityImpactScore The methodology used The file format derived from the CERN-AB risk register elaborated by P. Bonnal (05/05/2003)

21 HIAT'09, Venezia20 EURISOL-DS RISK REGISTER EquipmentOperational phase and Risk RP [mSv/h] and intervention Risk assessment before mitigationMitigation of Risk Risk assessment after mitigation OwnerName and location Acronym - Number Action typedesccription of failure Description of associated risk Dose rate Job duration Probabi lity ImpactScoreComments - Needed actions Probabi lity ImpactScore T2CGS target vessel??? OperationRupture of the vanes Loss of Hg flow, flow blockage and cavitation 224 Instrumentation to control Hg flowrates 212 Explosion by Hg boiling 155Containement of Hg (safety hull)111 Overheating of the window 339 Instrumentation to control Window temperature 313 Partial melting of the window 155Containement of Hg (safety hull)111 Main risks for the Hg converter EURISOL-DS RISK REGISTER EquipmentOperational phase and Risk RP [mSv/h] and intervention Risk assessment before mitigation Mitigation of Risk Risk assessment after mitigation OwnerName and location Acronym - Number Action typedesccription of failureDescription of associated riskDose rate Job duration ProbabilityImpactScoreComments - Needed actionsProbabilityImpactScore T4 UC target/running RU-T- 06 operationfiring target stop of operation, target is lost, removal of target and replace with a new one, clean the pit region. The pit and beam line are highly contaminated. 1PBq avoid oxygen contamination, redondancy of safety valves. Neutral atmosphere during removal may be foreseen 155 Main risks for the Fission target

22 HIAT'09, Venezia21 1 year after irradiation10 years after irradiation ISABEL- ABLA CEM2kINCL4- ABLA ISABEL- ABLA CEM2kINCL4- ABLA Total activity Half life Au d Gd 74.6 y H3H y Hf 1.87 y Hg 444 y UCx Hg Direct target | CEM2k UCx( L=40cm, R=1.8cm) MMW target Hg 235 U: 7% halogens 10% rare gases 1% actinides

23 HIAT'09, Venezia22 Activity map at 100days Stainless steelConcrete Activities Mases Waste categories

24 HIAT'09, Venezia23 Activation of Cu structure (150 MeV/u) Activation of concrete (150 MeV/u) Air activation (150 MeV/u) Total activity due to implantation Contribution of the wall is not significant Air activation using PHITS (evaluated cross sections) 14,15 O, 13 N | 41 Ar 0.35Bq cm -3 Activity vs Discharge limit Inhalation dose received by workers intervening in tunnel Bq 132 Sn implantation 132 I accumulation after 1h

25 HIAT'09, Venezia24 21MeV/u 150MeV/u Points -> contact Lines -> 1m distance Total activity H*(10) Residual field: - high energy zone copper structure activation activation -low energy zone ion implantation In the high energy zone continuous accessibility after ~ week cooling time or occupancy factor of minimum 570 hours/year => 20 mSv y -1 Maintenance operations to be planed

26 HIAT'09, Venezia25 IsotopeT 1/2 SoilGroundwater 3H3H12.33y 3.149* * Be53.12d 3.662* * Na2.6y 7.782* * Na14.96h 7.551* * P14.26d 1.047* * S87.32d 2.262* * Ca162.61d 8.111* * Sc83.79d 6.833* * Mn312.3d 2.217* * Fe2.73y2.679* * Zn244.26d 3.867* * Specific activity [Bq cm -3 ] in first 100 cm of soil/groundwater surrounding the concrete wall after 40 y of continous irradiation 1.301*10 4 Bq < 10 5 Bq --LIMIT* *IAEA TECDOC-1000, 1998, Clearance of materials resulting from the use of radionuclides in medicine, industry and research *10 4 Bq < Bq --LIMIT* Transport of radioactive species into the ground does not represent a hazard for the population POSTACCELERATOR

27 HIAT'09, Venezia26 A schematic layout for liquid Hg-target disposal strategy Extrapolation from laboratory scale to “industrial” scale still to be done! Disposal of liquid Hg (FZJ) Chemical stabilization of Hg as an inorganic compound, e.g. HgS, HgSe, HgO, Hg 2 Cl 2, HgCl 2

28 HIAT'09, Venezia27 Further steps: Derived Intervention Levels (DIL) Exposure from underground water contamination Development of a resident GIS platform Cadastral Impact Analysis (GIS based) …  Methodology validated, recommended & accepted by safety authorities  Tools, data & knowledge to be used in Environmental and health Impact Assessment DESKTOP ASSISTANT Point Source Exposure Acute Exposure to Environmental Releases Prolonged Exposure to Environmental Releases E-BOOK DATA Libraries Nuclear Facilities Derived Release Limit The Map Manager Combination of knowledge on Accelerator & Research Reactor based nuclear installations  creation of dedicated toolkit for EURISOL DS Toolkit operational both for normal operation and accidental situations! Site dependent analysis to be performed! NIPNE

29 HIAT'09, Venezia28  Safety integration from the start hints innovative and flexible solutions in maters of safety  EURISOL has similarities with high-power spallation n-sources & small research reactors Very specific features: Use of pyrophoric actinide carbide targets; Presence of alpha-emitters; Distribution over extended buildings of intense RIBs and sources of all chemical nature Dedicated technical standards to be applied under utmost reliable safety rules and procedures.

30 HIAT'09, Venezia29 Back-up

31 HIAT'09, Venezia30 Target positions:  Geometry : Last design variant (L. Tecchio): 30kW load heat Last design variant (L. Tecchio): 30kW load heat Volume = 181cm 3 ( R ext =1.75cm, R int =0.4cm,H=20cm ) Volume = 181cm 3 ( R ext =1.75cm, R int =0.4cm,H=20cm )  Material: Targets: graphite + U, density=1.88 g cm -3, Targets: graphite + U, density=1.88 g cm -3, (mass U=15g | mase rate: U/C=1/20, MKLN) (mass U=15g | mase rate: U/C=1/20, MKLN) Moderator: H 2 O, Fe ( 232 Th) Moderator: H 2 O, Fe ( 232 Th) Reflector: BeO, Fe ( 232 Th) Reflector: BeO, Fe ( 232 Th)  Physics parameters: Source: p; E=1GeV,Gauss (σ = 1.5cm) Source: p; E=1GeV,Gauss (σ = 1.5cm) Model:CEM2k Model:CEM2k T=239K T=239K Moderator Reflector Mercury target Iron shielding Concrete Proton beam Fission target z = 0T#5T#1T#3 z = 15T#6T#2T#4 x=> y=> Reflector Iron Fission target Concrete x y z y Results normalised at 1mA

32 HIAT'09, Venezia31 Neutron Flux – distribution over the targets Neutron flux (n cm -2 s -1 ) Neutron Flux – energy distribution (T#1)

33 HIAT'09, Venezia32 Fission Rates –energy distribution (T#1) Fission Rates – distribution over the targets Fission Rates – total

34 HIAT'09, Venezia33 C( 235 U) vs D(UC 3 * ) Neutrons vs 1GeV protons Neutron fission rate: fission | spallationNeutron flux: fission | spallation * Direct target: R=1.8cm, L=40cm

35 HIAT'09, Venezia34 Yields – Kr: fission | spallation Yields – Xe: fission | spallation Yields – Sn: fission | spallation Yields – Ga: fission | spallation Neutrons vs 1GeV protons

36 HIAT'09, Venezia35 Major Risks: breaking of target container target firing Consequences : Dissemination of radioactivity in the environment fission fragments/sec per target (~ 5 x 10 4 Ci) 1 st container 2 nd container 1 st container 2 nd container Main risks for the Fission target Luigi Tecchio – Task 4

37 HIAT'09, Venezia36 large small Capability of Cryotrap 3 cryotraps prototypes tested: retention capability (vs. pressure behind cryotrap) ‘carry over’: fraction of leaking gas load transported across cryotrap 2 trap types operated at different temperatures: Cryotrap works within (simulated) expectations  99.98% of volatile radioactivity can be localized! (LMU) GP N 18K SP N 30K SP N 8K GP N 28K GP N 21K Carry over p R /p M P Cryo [hPa] design goal


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