# Presentation: 061645

## 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)

- Cal Poly Meeting

- 15 March 2004

## 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.
**Exel****o****n:**
*“**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)

## Detector Concept

- ~200 m

- ~1600 m

- Sensitivity goal: sin22~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

## 3-zone Gd-based Detector

- I

- II

- III

- I. Gd-loaded liquid scintillator
- II.  catcher: liquid scintillator (no Gd)
- III. Non-scintillating buffer

- R=1.9 m, m=25 tons
- R=2.4 m
- R=3.25 m

- 6.5 m

- R=2.4 m, m=50 tons
- R=2.7 m
- R=3.25 m

- Total detector mass ~150 tons

- PMTs

- Two examples:

## 750-ton capacity Crawler Crane 

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

## Braidwood Site

- Reactors

- Controlled perimeter

## Layout for underground construction estimate

- Far shaft

- Near shaft

- Near detect. hall

- Reactors

- Braidwood

## Basis of Underground Construction Estimate

## Near & Far Shaft Layouts

- Not to Scale

- Tunnel cross section

## Two Styles of Detector Halls

- Near hall:

- Far hall:

- 12 14 15 m

- 12 14 32 m

- 12 m

- 12 m

- 2 m

- Detector hall cross section

## 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

- Far shaft

- Reactors

- Braidwood

- Site near shaft
- to shorten or
- eliminate tunnel

## 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.)