Nevada National Security Site Underground Test Area (UGTA) Tour

Bill Wilborn UGTA Activity Lead U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office Bob Andrews Navarro-Intera December 10, 2014 Nevada National Security Site (NNSS)

• NNSS has many diverse roles to support the U.S. nuclear weapons stockpile stewardship missions and also supports other U.S. Department of Energy (DOE), Department of Defense, and Department of Homeland Security programs • DOE National Nuclear Security Administration Nevada Field Office responsible for oversight • ~1,360 square miles of federally-owned and controlled land, surrounded by ~4,500 square miles of federally-owned and controlled land (U.S. Air Force) • Located ~65 miles northwest of Las Vegas

ID 876 Tour Booklet 12/10/2014 – Page 2 PageLog 2Title No. 2014-xxxPage 2 U.S. Nuclear Testing, 1945 – 1992 • 1,149 total U.S./ U.S.-U.K. nuclear detonations – 1,021 at NNSS

° 100 atmospheric

° 921 underground • A nuclear test may include more than one (1) detonation

ID 876 Tour Booklet 12/10/2014 – Page 3 PageLog 3Title No. 2014-xxxPage 3 NNSS Nuclear Testing 1951 – 1992 70 First detonation contained underground: RAINIER Last U.S. atmospheric nuclear test 60 at the NNSS: LITTLE FELLER I

50 BANEBERRY: Accidental release of radioactivity detected off site; better site characterization and containment evaluation resulted First underground test at 40 NNSS: UNCLE

Count 30 First NNSS nuclear test: Last U.S. nuclear underground test: DIVIDER 20 ABLE

10

0 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995

Atmospheric Underground

DOE/NV, 2000

ID 876 Tour Booklet 12/10/2014 – Page 4 PageLog 4Title No. 2014-xxxPage 4 EMPLACEMENT

D R I L L I N G C O L L A C P O S L E L D A P C S R E A T E ACCIDENTAL R RELEASE OF S RADIOACTIVITY

ID 876 Tour Booklet 12/10/2014 – Page 6 PageLog 6Title No. 2014-xxxPage 6 Photographs from CMS-05-010_JMK, 2005

POST-TEST SAMPLE ANALYSISID 876 Tour Booklet 12/10/2014 – Page 7 PageLog 7Title No. 2014-xxxPage 7 Regional Geologic Setting

} NNSS lies within the Southwestern Nevada Volcanic Field, which includes 8 known calderas that formed between 15 million years ago (Ma) and 8 Ma

Modified from Drellack and Prothro (2010)

Generalized geologic map showing the outline of the Southwestern Nevada Volcanic Field

ID 876 Tour Booklet 12/10/2014 – Page 8 Page 8Title Page 8 April 2014 Log No. 2014-xxx8 Regional Geologic Setting – Rocks at the NNSS ~ 12,200 m (40,000 ft) thick and span more than 500 million years in age

– Diverse depositional environments and geologic processes

° Marine clastic and carbonate deposition

° Volcanic activity

° Igneous intrusion

° Alluvial basin-filling deposition Generalized stratigraphic column of the NNSS vicinity Drellack and Prothro, 2010

ID 876 Tour Booklet 12/10/2014 – Page 9 Page 9Title Page 9 April 2014 Log No. 2014-xxx9 NNSS Geologic Setting • At the NNSS, contractional structural events are older than 100 Ma and resulted in – Thick deposits of Mississippian siliciclastic rocks – Formation of thrust faults, and associated imbricate thrusts and folds

Major Pre-Cenozoic structural features of the NNSS region Modified from BN (2006)

ID 876 Tour Booklet 12/10/2014 – Page 10 Page 10Title Page 10 April 2014 Log No. 2014-xxx1 NNSS Geologic Setting • Widespread basin-and-range extensional faulting at the NNSS – Normal and strike-slip faults – Alluvium-filled basins (e.g., Frenchman Flat and Yucca Flat)

Detailed geologic quadrangle map Geologic compilation map of the NNSS Hinrichs and McKay, 1965 Workman et al., 2002

ID 876 Tour Booklet 12/10/2014 – Page 11 Page 11Title Page 11 April 2014 Log No. 2014-xxx1 NNSS UGTA Corrective Action Units

• CAU 97: Yucca Flat/Climax Mine – 747 detonations

• CAU 98: Frenchman Flat – 10 detonations

• CAU 99: Rainier Mesa/Shoshone Mountain – 68 detonations

• CAU 101: Central Pahute Mesa – 64 detonations

• CAU 102: Western Pahute Mesa – 18 detonations

ID 876 Tour Booklet 12/10/2014 – Page 12 PageLog 12Title No. 2014-xxxPage 12 Frenchman Flat Geologic Setting

ID 876 Tour Booklet 12/10/2014 – Page 13 PageLog 13Title No. 2014-xxxPage 13 Frenchman Flat Geologic Cross Section

ID 876 Tour Booklet 12/10/2014 – Page 14 PageLog 14Title No. 2014-xxxPage 14 Yucca Flat Geologic Setting • Yucca Flat is an alluvium-filled basin surrounded by highlands composed of volcanic and sedimentary rocks • Topographically closed basin with a playa (seasonally dry lake) at its southern end

Generalized geologic map of the Yucca Flat area Modified from BN (2006)

ID 876 Tour Booklet 12/10/2014 – Page 15 Page 15Title Page 15 April 2014 Log No. 2014-xxx1 Yucca Flat Geologic Setting

• The main Yucca Flat basin consists of a series of west-tilted half grabens with the main basin-forming faults near the center of the basin • Basin began forming approximately 10 Ma in response to basin-and-range extension

Modified from BN (2006)

ID 876 Tour Booklet 12/10/2014 – Page 16 Page 16Title Page 16 April 2014 Log No. 2014-xxx1