bl1u at triumf ucn beamline shielding layout & costs (nov 2011) l.lee

BL1U at TRIUMFUCN Beamline

Shielding Layout & Costs

(Nov 2011)

L.Lee

CONCRETE STEEL

SPALLATION TARGET, D2O & GRAPHITE

MODERATOR

70 mm CHANNELFOR LIQUID HELIUMSERVICES

300 mm CHANNELFOR UCN GUIDE

h ~ 2370 mm

x ~ 1400 mm

General Layout of Shielding Structure

Inner layer of Steel ; Outer layer of Concrete

UCN Shielding Requirements

(Overall Size/Scale?)

A.Trudel calculations (TRIUMF Safety Group) Modified Moyer Model (for 500 MeV protons)

40 A, 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 Requirement to reduce dose rate to 3Sv/hr

Theta (degrees)

Met

ers

of

Sh

ield

ing

Shielding Cost Estimates (Initial)

2010 UCN BeamLine Layout (no PIF)

Vendor Quotes:Concrete $1251 kSteel (radioactive) $ 360 k (66%)Steel (new) $ 480 k (33%)Staging/Installation $ 20 kTotal $2111 k

2010 UCN-BL Layout: Concrete $ 834 kSteel (radioactive) $ 240 k (66%)Steel (new) $ 320 k (33%)Staging/Installation $ 20 kTotal $1414 k

Original Cost Estimate (CFI prop):Concrete $ 900 kSteel (radioactive) $ 200 k (66%)Steel (new) $ 700 k (33%)Staging/Installation $ 20 kTotal $1820 k

Above estimates based on bulk volume estimates+20% contingency

More detailed block layoutTRIUMF Design Office (A.Prorok)

Block Layout of UCN Shielding (Version 1)

Extent of existing Shielding Wall

UCN ConcreteShielding

UCN SteelShielding

UCN Shielding – Layer 1Concrete shielding blocks – YellowSteel shielding blocks – Black/Silver


UCN Shielding – Layer 4

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)

Reuse existing concrete blocks from M11/M13 1836 ft3 ~50 m3

Block Layout (Ver.1): Concrete $ 580 kSteel (radioactive) $ 481 kSteel (new) $ 113 k Staging/Installation $ 20 kTotal $1194 k

Status as of Sep-2010 Review

2010 UCN-BL Layout: Concrete $ 834 kSteel (radioactive) $ 240 kSteel (new) $ 320 kStaging/Installation $ 20 kTotal $1414 k


(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

Surface-finish

52¼”+ ¼”– ¾”

26¼” + ¼”– ¾”

52¼”+ ¼”– ¾”

Tolerances

Surface QC: Free from loose or fused slag: runners,risers, fins, and other cast-on featuresground flat

Depressions: 1” max

‘S2’ (and ‘S4’) Steel Blocks at JLab

‘STACKABILITY’

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

UCN Shielding – Layer 1Concrete shielding blocks – Yellow‘S2’ Steel shielding blocks – Silver

EDM Experiment(Keep-Out Zone)


UCN Shielding Structure & Costs (2011)


2010 UCN-BL Layout: Concrete $ 834 kSteel (radioactive) $ 240 kSteel (new) $ 320 kStaging/Installation $ 20 kTotal $1414 k



• 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 isrequired to keep Dose Rates at ~ 3Sv/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)

First Results from new Shielding Simulations

Shielding Requirement to reduce dose rate to 3Sv/hr

Theta (degrees)

Met

ers

of

Sh

ield

ing

Theta (degrees)

Modified Moyer Model (TRIUMF) MCNPX/MCNP/MicroShield (ACSION)

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 3Sv/hr constraint irrelevant)

Shielding around nEDM Apparatus Optimize Shielding Layout around nEDM apparatus Enclose nEDM in Shielded “Hut” (?) 1st Iteration Layout shielding block interference with nEDM Apparatus

Interference

Interference

3 Sv/hr boundary

Approximate location of UCN valve & startof nEDM apparatus

Remove &ReplaceBlocks

Shielding Costs

ORIGINAL (“With PIF”) UCN Layout NEW (“No PIF”) UCN Layout

Shielding Budgets

Original cost estimate (total) $1820 k (from CFI proposal)


Latest UCN Layout: Concrete $ 834 kSteel (radioactive) $ 240 k (66%)Steel (new) $ 320 k (33%)Staging/Installation $ 20 kTotal $1414 k

Shielding Costs

2010 UCN Layout (no PIF)


2010 UCN Layout: Concrete $ 834 kSteel (radioactive) $ 240 k (66%)Steel (new) $ 320 k (33%)Staging/Installation $ 20 kTotal $1414 k

Original Cost Estimate (CFI prop):Concrete $ 900 kSteel (radioactive) $ 200 k (66%)Steel (new) $ 700 k (33%)Staging/Installation $ 20 kTotal $1820 k

Above estimates based on bulk volume estimates+20% contingency

More detailed layoutTRIUMF 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)

Extent of existing Shielding Wall

UCN ConcreteShielding (“New”)

UCN SteelShielding (“New”)

Top (2) Layers of Shielding Structure

4’ x 6’ x 18’ Concrete shielding blocks(on-hand, outside “Electronics” Trailer)

Additional blocks forShielding 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

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”)

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”) 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

NOV-2011

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 aswell 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 geometryCarry 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)*

Shielding Calculation Request to ACSION:

bl1u at triumf ucn beamline shielding layout & costs (nov 2011) l.lee

Documents

designeducn shielding

anymoreucn shielding

steel shielding layersissues

edm shielding hut

radioactive steel blocks

s4 steel blocks

k2010 ucnbl layout

review2010 ucnbl layout