ESS-Bilbao Initiative Workshop. SNS Studies towards a rotating solid target.

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SNS Studies towards a rotating solid target.
Thomas McManamy (SNS)

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ESS-Bilbao Initiative Workshop. SNS Studies towards a rotating solid target.

  1. 1. !!quot;
  2. 2. •# $$ $% & & %' ( )* & $% & +* , , - % ' ' '( !! & &' . !!quot; – %& ' & / 01!! !!! $ – $ $ % & % & ' $ & ' ' % & .). & ' +. . - & & $ $ % – $% % $ & % % $ 1 2& ' '$ & & & •, ' $ . & ' . +. . - & $ ' 3, ! –4 % & & ' ' & % % & &$ – % % &$ ' $5 2 2 2 Managed by UT-Battelle for the U.S. Department of Energy
  3. 3. •, ' &$ 1 2 1 6 !78 • % &%' % &$ % – 9. 9. & :;). < ' & $ – =, $ & %& ' & '$ &% ' + >-& &% & % • 3)?@ & ' & ' % '& % & & 8& % & & $'% & $ $ & ' •? , &, $ & $$ & $ & ' 3)? $ % $'% $ & & •, & #).A. && &$ ' ' & % & $ &' • ' & ' & & •? ' ' & & ' & & $ ' ' 3 Managed by UT-Battelle for the U.S. Department of Energy
  4. 4. ! 2 Proton Beam Profiles Studied Target Configuration 2-D Gaussian: Tungsten & Ta clad height 7 cm Vertical Sigma - 1.5 cm Diameter 1.2 m Horizontal Sigma - 4.5 cm Tungsten & Ta clad radial depth 25 cm Flat: D2O Channel heights 1.5 mm Vertical: 6 cm Steel shroud thickness 1 cm Horizontal: 18 cm Proton Energy: 1.3 GeV Repetition rate: 20 Hz 4 Managed by UT-Battelle for the U.S. Department of Energy
  5. 5. quot;# $%& Vertical cut H2 0 Beryllium Horizontal cut On mid-plane H2 ss protons W Horizontal cut Through moderator * 1.5 mm D20 cooling channels * Lower moderator not modeled 5 Managed by UT-Battelle for the U.S. Department of Energy
  6. 6. ' An optimized Para-hydrogen moderator configuration and center cooling channel step location in the target was calculated with MCNPX for maximum moderator brightness • H2 radius 11cm • Target height: 7 cm • H2 height 12 cm • Step Location of central cooling • Moderator axis with regard to channel: 7.5 cm target nose: 11 cm Rotating target configuration gave nearly the same cold moderator brightness as the STS mercury target ( + 7% for flat profile, + 3% Gaussian profile). 6 Managed by UT-Battelle for the U.S. Department of Energy
  7. 7. ( # )*+ , ! quot; - Central D2O Central Tantalum Bulk tungsten Channel Cladding 7 Managed by UT-Battelle for the U.S. Department of Energy
  8. 8. . /0 12 3 / 2 4 1 MW .5 mm clad 8 Managed by UT-Battelle for the U.S. Department of Energy
  9. 9. ! # #% 5 /0 12 Shaft Gas conduction – 5 mm gap to 50 C surface plus radiation ( ε = 0.8 all external surfaces) k=1.5 w/m-k 1.5 mm gas gap with radiation 5 mm ( 10% steel ( ε = 0.2 all internal surfaces) ribs) and water vapor or air 12 mm Stainless Steel Shell Nu=3 Tungsten & clad .035 m Steel hub 18 kW uniform heat generation .1 m .6 m .3 m 9 Managed by UT-Battelle for the U.S. Department of Energy
  10. 10. /6 72 # 8# 69 0.55 0.50 0.45 Temp (°C) 0.40 500 450 0.35 400 350 0.30 300 250 y 200 0.25 150 100 0.20 0.15 0.10 0.05 0.00 0 0.1 0.2 0.3 0.4 0.5 0.6 x 10 Managed by UT-Battelle for the U.S. Department of Energy
  11. 11. # • . & ' % % ' ' ' ' – ' &' % % • 7 % ' % & $ ' & $ 5! 3 2 %' & . % $% $ & & % 3 6 – < % %' % / 5!! 3 • # ' & ' 'B $ %' & 5! 3 B . % C $% $ ' & % – < % %' % / D!! 3 • %' E & / !! 3 – ) 8 $ ' %& % – ? % / 5!! 3 • 2 $ % $% %& &$ .. % & ' 11 Managed by UT-Battelle for the U.S. Department of Energy
  12. 12. /6 12 #% • The proposed SNS target includes several layers of defense: • Seismic qualification for core vessel components and target • Primary cooling system with UPS low flow capability • Independent backup (UPS) cooling within structural shell • 3 mm diameter holes on 30 spacing • 1 m/s water flow ( ~ 10 gpm total) • Passive radiation and gas conduction to reflector assemblies • 5 mm gaps to reflector/shielding assemblies • 0.8 emissivity coating on target and reflectors Backup Cooling Channels Target Segments 12 Managed by UT-Battelle for the U.S. Department of Energy
  13. 13. / 2 quot;(: ; • ;< 3 ' $ &$ & $ % & •3 3 ' & % % & $ & ' '8 Comparison for Gaussian Beam ? ? . % +3 - ? ;< 3 ' 1! 1! External Cooling 3 3 ' D! ! Neutronic Performance loss with center cooling < 3% Center Cooling 13 Managed by UT-Battelle for the U.S. Department of Energy
  14. 14. < ! Peak = 152 0C 30 0C water inlet temperature 25 l/s flow 14 Managed by UT-Battelle for the U.S. Department of Energy
  15. 15. # Thermal Hydraulic Conditions for Flat Profile, 60rpm, 0.1s after pulse 100 1.40E+06 90 1.20E+06 80 1.00E+06 70 Temperature (C) Heat Flux (W/m^2) 60 8.00E+05 Water Temperature 50 Surface Temperature Heat Flux 6.00E+05 40 30 4.00E+05 20 2.00E+05 10 0 0.00E+00 0 10 20 30 40 50 60 Distance Along Flow Channel (cm) 15 Managed by UT-Battelle for the U.S. Department of Energy
  16. 16. 8 5 bar pressure Gravity & inertia Flat beam profile ~ 210 MPa peak Von Mises 16 Managed by UT-Battelle for the U.S. Department of Energy
  17. 17. # = $ # 5 / 2 4 < % < % < % . . &+ - +F3 - ? . ? . 2+?- & +?- % 1! D! quot; 5quot; ( $$ 1! ! D % 1! ! ! 51 ! G !G 5! All stress levels are well below 500 MPa unirradiated tungsten yield or 180 MPa Tantalum yield and have margin for fatigue and irradiation effects 17 Managed by UT-Battelle for the U.S. Department of Energy
  18. 18. ! 1 / 2quot; 3 % ' quot;5 & E & E +. . 1 - % && ' D& E & E %' % 1 & E & E & %% & E & E +# ! - 5000 Beam Hours = 1 year 18 Managed by UT-Battelle for the U.S. Department of Energy
  19. 19. : Backup Cooling Coupling Water Coupling • This arrangement provides for hands-on maintenance access after a few days of decay time. Proton Beam Window Module • The drive unit can be replaced without removing the target module • Potential water or grease Core Vessel leaks from rotating seals outside of vessel • The drive, seal and bearings Rotating are located away from the Target high radiation area. Activated target cooling Reflector water is expected to generate approximately 1 G/hr in the drive enclosure Proton Beam during beam-on operations. Moderators 19 Managed by UT-Battelle for the U.S. Department of Energy
  20. 20. Concentric Shaft Channels Gun Drilled Hub Circumferential Manifolds Tantalum Clad Tungsten Blocks Shroud Cooling Channels • ' &% %& G! & ' %& &< •3 & < H% & $$ < 20 Managed by UT-Battelle for the U.S. Department of Energy
  21. 21. > > Lower Bearing Ports on Shaft Drive/Target Mechanical Joint Seals Intermediate seal ring Upper Bearing Graphite packing seal with intermediate gas injection Lower Section Upper Section 21 Managed by UT-Battelle for the U.S. Department of Energy
  22. 22. ? Proton Beam • $ < $ ' 5 $ !& $ & • < &$ $ & / + ! & -I % $ • & &% & ' ' •# 8 %& % & $ 8 % & & &% $ ' • $'% % & &% & ' % & % $ ' ' Moderator Cart 22 Managed by UT-Battelle for the U.S. Department of Energy
  23. 23. > <8 5 # # Support frame Mechanical water seal Water boundary tube 23 Managed by UT-Battelle for the U.S. Department of Energy
  24. 24. Rails for Removable Moderator target Monolith Maintenance Cells Shielding Service Cell cask The use of curved beam guides is expected to eliminate the need for large vertical shutters within the monolith 24 Managed by UT-Battelle for the U.S. Department of Energy
  25. 25. ? •2 &' E %% ' $ •, $ $$ •? $ B2 E E = $ % • $ ' ' • $ J &K & % $ ' •# $ %' $ & B &% $ & % •%' &% $ & •3 & = % ' &$ H% 25 Managed by UT-Battelle for the U.S. Department of Energy
  26. 26. # •9 & ' %& $ 1 2 '%' ' & ' & ' –. ' % $ & % ' –* ' ' $ /5 $ !& 1 * .. %% – $ & ' –, ' & &$ & '% ' – $ & & &% & –? ' & ' & & ' & •. . % & '$ 5 2 C% ' 26 Managed by UT-Battelle for the U.S. Department of Energy
  27. 27. ! quot; Rotating target configuration gives about the same neutron performance as STS stationary mercury target ( + 7% for flat profile, + 3% Gaussian profile). 27 Managed by UT-Battelle for the U.S. Department of Energy
  28. 28. •7' ? . ' & & & && ' H% & •4 & $$ % 2 ' –. & ' & ' &% $ & '& & – * H% & ' & & &$$ % & H% < & '$ • ' & ' & ' $$ % ' $ ' ' & $ % $ % $ ' ' & B, % $ ' $% $ % ' π σ • R= sqrt(π/2)*D/σhorizontal – For D ~ 1 m and σhorizontal ~ 50 mm this gives factors of ~ 25 increase in life and reduction in Managedaverage heating 28 by UT-Battelle for the U.S. Department of Energy

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