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BL1U at TRIUMF UCN Beamline Shielding Layout & Costs (Nov 2011) L.Lee. D h ~ 2370 mm. General Layout of Shielding Structure. Inner layer of Steel ; Outer layer of Concrete. f 70 mm CHANNEL FOR LIQUID HELIUM SERVICES. STEEL. CONCRETE. SPALLATION TARGET, D 2 O & GRAPHITE
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BL1U at TRIUMF UCN Beamline Shielding Layout & Costs (Nov 2011) L.Lee
Dh ~ 2370 mm General Layout of Shielding Structure Inner layer of Steel ; Outer layer of Concrete f70 mm CHANNEL FOR LIQUID HELIUM SERVICES STEEL CONCRETE SPALLATION TARGET, D2O & GRAPHITE MODERATOR 300 mm CHANNEL FOR UCN GUIDE Dx ~ 1400 mm
UCN Shielding Requirements (Overall Size/Scale?) Shielding Requirement to reduce dose rate to 3mSv/hr Meters of Shielding Theta (degrees) A.Trudel calculations (TRIUMF Safety Group) Modified Moyer Model (for 500 MeV protons) 40 mA, 500 MeV protons stopping in W target Assumes 0.5 m empty space around target (no moderator) More detailed/realistic simulations using MCNPX underway
Shielding Cost Estimates (Initial) Original Cost Estimate (CFI prop): Concrete $ 900 k Steel (radioactive) $ 200 k (66%) Steel (new) $ 700 k (33%) Staging/Installation $ 20 k Total $1820 k Vendor Quotes: Concrete $1251 k Steel (radioactive) $ 360 k (66%) Steel (new) $ 480 k (33%) Staging/Installation $ 20 k Total $2111 k 2010 UCN BeamLine Layout (no PIF) 2010 UCN-BL Layout: Concrete $ 834 k Steel (radioactive) $ 240 k (66%) Steel (new) $ 320 k (33%) Staging/Installation $ 20 k Total $1414 k Above estimates based on bulk volume estimates+20% contingency More detailed block layout TRIUMF Design Office (A.Prorok)
Block Layout of UCN Shielding (Version 1) UCN Concrete Shielding UCN Steel Shielding Extent of existing Shielding Wall
Block Layout of UCN Shielding (Version 1) UCN Shielding – Layer 1 Concrete shielding blocks – Yellow Steel shielding blocks – Black/Silver
UCN Shielding – Layer 6 (Feedthru’s not yet designed)
UCN Shielding – Layer 8 (Feedthru’s not yet designed)
UCN Shielding Structure & Costs (Sep-2010) 4’ x 6’ x 18’ Concrete shielding blocks (on-hand, outside “Electronics” Trailer) 2010 UCN-BL Layout: Concrete $ 834 k Steel (radioactive) $ 240 k Steel (new) $ 320 k Staging/Installation $ 20 k Total $1414 k Block Layout (Ver.1): Concrete $ 580 k Steel (radioactive) $ 481 k Steel (new) $ 113 k Staging/Installation $ 20 k Total $1194 k Reuse existing concrete blocks from M11/M13 1836 ft3 ~50 m3 Status as of Sep-2010 Review
+ ¼” – ¾” + ¼” – ¾” + ¼” – ¾” 52¼” 52¼” 26¼” Block Layout of UCN Shielding (Version 2) (Steel Shielding Layers) Issues with Fabrication of (mildly radioactive) Steel Blocks: • Energy Solutions (ES) cannot pour custom 2’x3’x6’ steel blocks ($$$ NRE) • ES recommended using their normal “S-2” steel blocks (26” x 52” x 52”) • Redo layout using “S-2” steel shielding blocks (26” x 52” x 52”) • Questions: Tolerances, Surface-finish quality, Stackability Tolerances Surface-finish Surface QC: Free from loose or fused slag: runners, risers, fins, and other cast-on features ground flat Depressions: 1” max
‘S2’ (and ‘S4’) Steel Blocks at JLab ES ‘S2’ (26” x 52” x 52”) and ‘S4’ (13” x 26” x 26”) Steel Blocks used in JLab Hall-C Used to shield electronics rack from target-shine (as well as general BG) ‘S4’ Blocks not produced anymore ‘STACKABILITY’
Block Layout of UCN Shielding (Version 2) UCN Shielding – Layer 1 EDM Experiment (Keep-Out Zone) Concrete shielding blocks – Yellow ‘S2’ Steel shielding blocks – Silver
UCN Shielding – Layer 8 EDM Experiment (Keep-Out Zone)
2010 UCN-BL Layout: Concrete $ 834 k Steel (radioactive) $ 240 k Steel (new) $ 320 k Staging/Installation $ 20 k Total $1414 k EDM Experiment (Keep-Out Zone) Block Layout (Ver.1): Concrete $ 580 k Steel (radioactive) $ 481 k Steel (new) $ 113 k Staging/Installation $ 20 k Total $1194 k Block Layout (Ver.2): Concrete $ 580 k Steel (radioactive) $ 365 k Steel (new) $ 315 k Staging/Installation $ 20 k Total $1280 k UCN Shielding Structure & Costs (2011) • Cost estimate for EDM Shielding “Hut” not yet included • Re-use M11/M13 Concrete blocks (~1836 ft3) $145 k • Skyshine direction “defer” top 2 layers of shielding savings of 2/8 ~ 25% $175 k
Summary: Next Tasks for Shielding Design Next Iteration: Integration of UCN Shielding Structure into BL1A Main Shielding • Include UCN guides () and EDM apparatus elements (and shielded “hut”) • Define (more realistic) Keep-Out Zone for EDM setup Include next level of details (spall.n target, access for services, warm moderator,…) Before proceeding too far with next iteration of Shielding Layout/design, need to carry out more realistic Shielding/Dose-Rate Simulation: • Verify/Validate earlier Dose Rate estimates (Modified Moyer Model) () • Extend simulation/calculation to include Moderator (warm & cold) materials • More realistic Dose Rate simulation with Shielding Block Layout as designed (also need Dose Rate estimates at access ports for LHe services) ACSION contracted to carry out Dose Rate simulation; Present Status: • Simulation: MCNPX (2.6/2.7) and MicroShield/MCNP • First Results: Using 2 m concrete at outer shielding layers, between 2.2–3.3 m (depending on angle) of steel shielding is required to keep Dose Rates at ~ 3mSv/hr level (Consistent with earlier TRIUMF estimates) Re-running simulation with fine-tuning to reduce relative errors New Shielding simulations to include Moderator materials (warm & cold)
Modified Moyer Model (TRIUMF) MCNPX/MCNP/MicroShield (ACSION) Meters of Shielding Theta (degrees) Theta (degrees) First Results from new Shielding Simulations Shielding Requirement to reduce dose rate to 3mSv/hr Preliminary Results: Reasonably good agreement at forward angles. At backward angles ( > 120°), Moyer Model underpredicts shielding requirements slightly. But little or no cost impact in this region (150°–180°) because this would be within the main BL1A shielding (and the 3mSv/hr constraint irrelevant)
Approximate location of UCN valve & start of nEDM apparatus Interference Interference 3 mSv/hr boundary Shielding around nEDM Apparatus • Optimize Shielding Layout around nEDM apparatus • Enclose nEDM in Shielded “Hut” (?) • 1st Iteration Layout shielding block interference with nEDM Apparatus Remove & Replace Blocks
Shielding Costs ORIGINAL (“With PIF”) UCN Layout NEW (“No PIF”) UCN Layout Shielding Budgets Original cost estimate (total) $1820 k (from CFI proposal) Vendor Quotes: Concrete $1251 k Steel (radioactive) $ 360 k (66%) Steel (new) $ 480 k (33%) Staging/Installation $ 20 k Total $2111 k Latest UCN Layout: Concrete $ 834 k Steel (radioactive) $ 240 k (66%) Steel (new) $ 320 k (33%) Staging/Installation $ 20 k Total $1414 k
Shielding Costs Original Cost Estimate (CFI prop): Concrete $ 900 k Steel (radioactive) $ 200 k (66%) Steel (new) $ 700 k (33%) Staging/Installation $ 20 k Total $1820 k Vendor Quotes: Concrete $1251 k Steel (radioactive) $ 360 k (66%) Steel (new) $ 480 k (33%) Staging/Installation $ 20 k Total $2111 k 2010 UCN Layout (no PIF) 2010 UCN Layout: Concrete $ 834 k Steel (radioactive) $ 240 k (66%) Steel (new) $ 320 k (33%) Staging/Installation $ 20 k Total $1414 k Above estimates based on bulk volume estimates+20% contingency More detailed layout TRIUMF Design Office (A.Prorok)
Shielding Costs (cont’d) Estimated Shielding Costs for new UCN Configuration $ 1394 k Possible savings: Dose in skyshine/upward direction can be higher (May be able to remove ~1m shielding from uppermost layers) Existing Concrete blocks at TRIUMF (~10%, $125K) More detailed layout (A.Prorok, Design Office) (vs bulk volume estimates+20% contingency) Detailed Layout of UCN Shielding (1st Iteration) UCN Concrete Shielding (“New”) UCN Steel Shielding (“New”) Extent of existing Shielding Wall
Top (2) Layers of Shielding Structure 4’ x 6’ x 18’ Concrete shielding blocks (on-hand, outside “Electronics” Trailer) Additional blocks for Shielding BL1U
Next Tasks for Shielding Layout • Redo layout using “S-2” steel shielding blocks (26” x 52” x 52”) from ES • Include/Incorporate all existing “on-hand” shielding blocks 2nd Iteration • Include nEDM apparatus elements & UCN guides (and shielded “hut”) Include next level of details (spall.n target, access for services,…) Include UCN beamline elements
AUG-2010 Shielding Costs from 1st Iteration Layout • Concrete Blocks • 2’ x 3’ x 6’ (145 blocks); 2’ x 3’ x 3’ (15 blocks); 2’ x 3’ x 3’ triangles (15 blocks) • 5625 ft3 @ $79/ft3 $ 444 k(vs $ 834 k) • additional 48 blocks (2’ x 3’ x 6’) to shield BL1U *maybe* $ 136 k • Steel Blocks (Used/Radioactive – from “Energy Solutions”) • 2’ x 3’ x 6’ (131 blocks) • 4716 ft3 @ $102/ft3 $ 481 k(vs $ 240 k) • Steel Blocks (New/Non-radioactive/Custom) • 2’ x 3’ x 3’ (17 blocks); 2’ x 3’ x 3’ triangles (12 blocks) • 414 ft3 @ $272/ft3 $ 113 k(vs $ 320 k) • Caveat: Still some custom shielding missing (e.g. along UCN guides, He-II cryostat,…) Total:$1174 k (so far) vs budget $1394 k • ISSUES: • “Skyshine” dose limits are higher remove uppermost 2 layers of shielding (?) savings of 2/9 ~ 22% $228 k • Existing Concrete blocks in M11/M13 (~1836 ft3) possible savings of $145 k • Cost estimate for possible(?) nEDM Shielding “Hut” not included yet • Energy Solutions (ES): It turns out that the NRE (molding & development) costs for pouring custom/matching 2’x3’x6’ steel blocks will be prohibitively high (~$500 k); ES now recommends using their normal “S-2” steel blocks (26” x 52” x 52”)
NOV-2011 Shielding Costs from 1st Iteration Layout • Concrete Blocks • 2’ x 3’ x 6’ (145 blocks); 2’ x 3’ x 3’ (15 blocks); 2’ x 3’ x 3’ triangles (15 blocks) • 5625 ft3 @ $79/ft3 $ 444 k(vs $ 834 k) • additional 48 blocks (2’ x 3’ x 6’) to shield BL1U *maybe* $ 136 k • Steel Blocks (Used/Radioactive – from “Energy Solutions”) • 26” x 52” x 52” (19+10+8+8+9+6+13+15 = 88 blocks) x 40.7 ft3/block = 3580 ft3 • 4716 – 1136 = 3580 ft3 @ $102/ft3 $ 365 k(vs $ 240 k) • Steel Blocks (New/Non-radioactive/Custom) • 26” x 26” x 52” (0+5.5+8+8+6+8+4+4 = 43.5 blocks) x 20.3 ft3/block = 883 ft3 (9.5 [plate1] + 4 [plate2] = 13.5 blocks) x 20.3 ft3/block = 274 ft3 • 883 + 274 = 1157 ft3 @ $272/ft3 $ 315 k(vs $ 320 k) • (alt) zero-sum calc: 414 + 1136 = 1550 ft3 @ $272/ft3 $ 422 k(vs $ 320 k) • Caveat: Still some custom shielding missing (e.g. along UCN guides, He-II cryostat,…) Total:$1260 k (so far) vs budget $1394 k • ISSUES: • “Skyshine” dose limits are higher remove uppermost 2 layers of shielding (?) savings of 2/9 ~ 22% $228 k • Existing Concrete blocks in M11/M13 (~1836 ft3) possible savings of $145 k • Cost estimate for possible(?) nEDM Shielding “Hut” not included yet
Shielding Calculation Request to ACSION: An estimate of the time required to carry out the following shielding simulations for the main UCN steel-concrete shielding structure is requested. The scope of the calculations/simulations comprises 2 parts, at present. Part 1 entails a validation (check) of an existing ("idealized") shielding calculation carried out by TRIUMF personnel a few years ago. Part 2 consists of a "more realistic" simulation including *some* geometric details associated with the UCN source. The requested deliverable will be a report describing the calculations as well as output tables of expected doses and particle fluxes. Shielding Calculation Details: Part 1) Validation & Extension of TRIUMF Shielding Calculation (a) Validate/recheck the results from the TRIUMF Safety Group - use the same basic geometry as Anne Trudel (see Fig.1) - solid volumes of steel & concrete (not in blocks) - central moderator area "empty" (i.e. MCNPX model layout -- but no graphite or D2O cryostat, only solid cylindrical target) - Tungsten target (geometry of target from UCN MCNPX); Beam of 500 MeV protons, 40 uA, stopping in target - Vary/optimize thickness of shielding (use Fig.1 as starting reference) to: (i) meet dose requirements (< 3 uSv/hr outside) (ii) minimize costs (trade-off between steel & concrete), but also meet spatial constraints ( < 5.5-6.0 m in R) *CALCULATE Dose & Spectrum of particles versus angle* (b) Extend calculation to include "filled" moderator area - repeat part (a), but fill central moderator area with graphite and D2O cryostat (i.e. geometry from MCNPX) Part 2) Shielding Calculation with "more" realistic geometry Carry out simulation with full geometry from MCNPX, and also - include "blocking" in the steel (blocks ~ 26”52”52”) and concrete (blocks ~ 24”36”72”) layers of the shielding structure (along with custom/irregular sized steel and concrete blocks, as needed) - include the 2 main "access" channels into shielding structure (i.e. a horizontal channel for the UCN guide and a vertical channel for the Liquid Helium services, see Figs.2a and 2b) *CALCULATE Dose & Spectrum of particles versus angle; also in the "skyshine" direction (and at exit ports of 2 main channels)*