Status of Midwest  13 Effort

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

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

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…”

Braidwood site

Braidwood site • 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)

General Strategy of Experiment Detector Concept ~200 m ~1600 m Sensitivity goal: sin22~0.01 • 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

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

750-ton capacity Crawler Crane Test lift of 750 tons

Braidwood Site Reactors Controlled perimeter

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

Basis of Underground Construction Estimate

Near & Far Shaft Layouts Tunnel cross section Not to Scale

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

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

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

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.)

Status of Midwest  13 Effort