1. 15 March 2004Cal Poly Meeting Status of Midwest  13 Effort Status of Braidwood site General strategy and layout of experiment Civil construction estimate Plans Ed Blucher (A vertical shaft access experiment)

2. Midwest   Collaboration ANL: Maury Goodman, David Reyna Chicago: Erin Abouzaid, Kelby Anderson, Ed Blucher, Jim Pilcher, Matt Worcester Columbia: Janet Conrad, Jon Link, Mike Shaevitz FNAL: Larry Bartoszek, Dave Finley, Hans Jostlein, Chris Laughton, Ray Stefanski Kansas: Tim Bolton, Noel Stanton Oxford: Steve Biller, Nick Jelley Pittsburgh: Donna Naples, Vittorio Paolone Texas: Josh Klein

3. We considered several sites in Illinois and Kansas. We have focused on the Braidwood site managed by Exelon. Exelon has been very cooperative, providing extensive geological information, detailed site drawings, etc. No objection to detector just outside controlled perimeter. Exelon: “We are excited about the possibility of participating in a scientific endeavor of this nature” “At this time we see no insurmountable problems that would preclude going forward with this project…”

4. Braidwood site

5. Features of Braidwood site: 2  3.6 GW reactors – 7.17 GW maximum power Flat: flexibility, equal overburden at near and far sites, surface transportation of detectors Favorable geology (dolomitic limestone): good for excavation, low radioactivity (order of magnitude lower U, Th than granite)

6. Detector Concept ~200 m~1600 m Sensitivity goal: sin 2 2   ~0.01 General Strategy of Experiment 1 near detector and 2 far detectors 6.5 m diameter spherical detectors with 3 zones (Gd-loaded scint.) 25-50 ton fid. mass per detector, depending on required buffer regions. Movable detectors with surface transport for cross-calibration Near and far detectors at same depth of 450 mwe (contingent on bore holes) Near detector at ~200 m security perimeter (L~270 m) Far detector at ~1800 m Full detector construction above ground

7. 3-zone Gd-based Detector I II III I. Gd-loaded liquid scintillator II.  catcher: liquid scintillator (no Gd) III. Non-scintillating buffer I.R=1.9 m, m=25 tons II.R=2.4 m III.R=3.25 m 6.5 m I.R=2.4 m, m=50 tons II.R=2.7 m III.R=3.25 m Total detector mass ~150 tons PMTs Two examples:

8. 750-ton capacity Crawler Crane Test lift of 750 tons

9. Braidwood Site Reactors Controlled perimeter

10. Layout for underground construction estimate Far shaft Near shaft Near detect. hall Reactors Braidwood

11. Basis of Underground Construction Estimate

12. Near & Far Shaft Layouts Not to Scale Tunnel cross section

13. Two Styles of Detector Halls Near hall: Far hall: 12  14  15 m 12  14  32 m 12 m 2 m Detector hall cross section

14. Layout used for underground construction estimate: 300 mwe, two shafts, different detector hall designs, 300m tunnel ~ $35 million, 39 months (sequential shaft construction) Revised layout: Increase depth to 450 mwe (160 m rock + 20 m soil) contingent on bore hole results Additional cost: $5 million + 6 months (3 months per shaft) Site near detector shaft to shorten or eliminate tunnel stub Potential savings: $9 million and 9 months Use near hall design at both near and far sites Savings: $1 million Cost of revised layout: ~$30 million ($25-35 million) Construction time: ~36 months with sequential construction of near and far sites; reduced time with simultaneous construction

15. Revised Layout Far shaft Reactors Braidwood Site near shaft to shorten or eliminate tunnel

16. Plans Settle location of shafts (in consultation with Exelon) Bore holes to full depth at both shaft positions: info about geology, radioactivity, density; will reduce required contingency for construction Complete surface layout: (e.g.,surface building(s), infrastructure for detector movement) Optimize detector design (buffer regions, calibration system, active and passive shielding, etc.)