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Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Adam Bernstein Lawrence Livermore National Laboratory May 01 2014 WATCHMAN Collaboration Meeting
1
WATCHMAN: a WATer CHerenkov Monitor for ANtineutrinos
Meeting Goals Project Status
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Meeting Goals
Today Thursday May 1 • Bring collaborators and guests up to date on WATCHMAN
scope and status of all tasks • Discuss reactor and supernova physics, and large Cherenkov
detector R&D potential Tonight – Banquet at Sal’s Restaurant in Blacksburg Tomorrow Friday May 2 Morning: KURF Tour and talks for WATCHBOY/MARS detectors Afternoon: Review and discuss ISODAR beam physics Throughout Consider synergies with ISODAR, ANNIE, and other physics efforts
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The WATCHMAN collaboration
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UC Davis
UC Berkeley
UC Irvine
U of Hawaii
Hawaii Pacific
A. Bernstein, N. Bowden, S. Dazeley, D. Dobie
P. Marleau, J. Brennan, M. Gerling, K. Hulin, J. Steele, D. Reyna K. Van Bibber, K. Vetter, C. Roecker, T. Shokair R. Svoboda, M. Askins, M. Bergevin, Daine Danielson Students getting WATCHMAN-related Ph.D. s Undergraduate
J. Learned, J. Maricic S. Dye M. Vagins, M. Smy S.D. Rountree, B. Vogelaar, C. Mariani, Patrick Jaffke
World Leaders in the Development and Use of Large Water Cherenkov Detectors
2 Na;onal Laboratories 6 Universi;es 25 collaborators 15 physicists 5 engineers 2 Post-‐docs 3 Ph.Ds 1 Undergrad
We need to add collaborators if full project goes forward
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Remote Reactor Monitoring is an NNSA Strategic Goal
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§ Now: 3 year scoping project with 4 Tasks
§ 2014-15 Decision point to deploy WATCHMAN, a kiloton scale antineutrino detector, ~10 km from a US reactor
§ Proposed joint funding with Office of Science, High Energy Physics (DOE-SC-HEP)
2015 Federal budget defers start to 2016 (we believe)
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Top level view of schedule
A. Low risk option, 2016 start: – 2015 Intermediate Design, continued KURF data-
taking – Conservative 4 year installation plan to reach
operational state – 2016-2019
B. High risk option: October 2014 start: – Gd-H2O fill and partial instrumentation with 50% of
PMTs by December 2016 to observe reactor antineutrinos by the original Strategic Plan date
– Highly constrained schedule with no contigency
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Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
A budget-informed guess about project timing
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Page 473
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Post-WATCHMAN goal: find/exclude hidden 10 MWt reactors at up to ~1000 km
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Goal
Detector target mass standoff
5 events in 1 year from a 10 MWt reactor (negligible background, 50% efficiency, includes oscillations) >99% exclusion if 0 events observed, 5 expected Zero false positive rate for zero expected, 5 observed
24,000 ton
100 km
2 Megaton
1000 km
Global reactor antineutrino fluxes simulation courtesy Jocher/Learned NGA/UH
• Gadolinium-‐doped (light) water is the most viable option for scaling to the largest sizes
• Strong synergy with fundamental physics research – Many groups/countries are already investing in this technology
• SuperKamiokande is today’s largest comparable detector -‐ 50,000 tons of H2O
Science & Global Security, 18:127–192, 2010
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
WATCHMAN Technical Goals
1+4 year Construction and Operation Phase (2015, 2016-2019) • Demonstrate sensitivity to reactor ON/OFF transition at ~10 km standoff, with
at most 30 days of ON and OFF data, with at least 99% confidence, with a kiloton scale detector.
• Demonstrate innovative, scalable, cost-effective Gd-H2O Cherenkov technology, pioneered and patented by WATCHMAN collaborators
• Provide a data-sharing and joint funding model for the scientific community to make use of antineutrino data from WATCHMAN and future nonproliferation detectors
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3 year Scoping Phase (2012-2014) 1. Consider Use and Gap Analysis 2. Select a Site 3. Create a Preliminary Design, Budget and Schedule 4. Measure of Shallow Depth Backgrounds – October deliverable
May 19 deliverables
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
A new Task: study relevance for nonproliferation
• Similar to other joint global nonproliferation and science efforts – CTBT’s International Data Center regularly shares seismic
data with the science community (Intl. Science Ctr.) – infrasound and hydroacoustic also shared
– The SESAME synchroton project in Jordan – “"SESAME…will serve as a beacon, demonstrating how shared scientific initiatives can help light the way towards peace” 45 Nobel Laureates
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• WATCHMAN will demonstrate a capability to exclude or discover undeclared reactors with high confidence in a wide geographical region
• Small reactor 10 MWt standard: 4 kg Pu/year à 0.5 IAEA Significant Quantity • New Task: Gap analysis for alternative technologies, use case for antineutrino monitor
– Radionuclide sensing and satellites are the current open-source methods for reactor finding
– Possible relevance to Treaties, Agreements, Confidence Building Measures is now being studied – Not relying only the Strategic Plan goal for justification
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Preferred and Backup sites identified
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Preferred Backup Reactor Location PERRY Reactor
Perry Ohio Advanced Test Reactor,
Idaho Falls, Idaho
Thermal Power (MWt) 3875 120
Detector Location Morton Salt/IMB mine (!) Painesville, Ohio
New excavation Idaho National Laboratory
Standoff 13 km - the only reactor in the US at a suitable distance from a deep mine
1 km
Overburden (mwe) 1430 ~360
Approval status Morton Salt has approved installation !
INL has approved excavation studies
Physics potential Greater physics potential due to greater depth
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Antineutrino signal and background
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n (100-‐200 MeV)
n
n
µ
µ
9Li β
Signal in 1 kiloton of water
n νe p
Σγ ~ 8 MeV
511 keV
511 keV e+
Gd
τ ~ 30 µs prompt e+ signal + n capture on Gd
• Exactly two Cerenkov flashes • within ~100 microseconds • Within a cubic meter voxel
‘The antineutrino heartbeat’
Backgrounds: 1. Real antineutrinos 2. Random event pair coincidences 3. Muon induced high energy neutrons 4. Long-lived radionuclide decays
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Full Signal and Background Monte Carlo using GEANT/RMSIM
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Depth Dependent per day • Fast Punch-through Neutrons ~1 • Radionuclides à not well known ~1-10 Depth-Independent • PMT and Rock Gamma/Neutrons <1 ?
Other Reactors <1 Geoantineutrinos negligible ___________________________________________ Total Background ~10 Perry Reactor Signal 8-12
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Preliminary Design Task
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• Largest possible cylindrical tank at Morton - 3:1 kTon total:fiducial
• Stainless tank, assembled in place
• PMTs mounted on a frame in the tank. - 5500 Target PMTS looking “in” - 480 Veto PMTs on same frame looking “out”
Drift layout at Morton Salt Mine Close-up of Veto PMT Wall
78 feet
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
We’re not alone: other large water detector R&D
Detector EGADS WATCHMAN Hyper-K
Status Ongoing 2016 start 2021 start (approx.) Mass (ton) 200 1,000 - 10,000 560,000
Type Gd-WCD Gd-WCD Pure H2O or Gd-WCD
Purpose Measure background materials,energy threshold Too small to see reactor antineutrinos
Remotely detect reactor antineutrinos – beam and reactor physics potential
Neutrino oscillations, proton decay, supernovae… WATCHMAN would demonstrate Gd option for HyperK or other future big detectors
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Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Physics Synergy WATCHMAN will provide: • The U.S.’s only supernova watch detector
• A demonstration of technologies for future large neutrino detectors (advanced PMTs, water-based scintillator…)
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Requires nearby neutrino beam
Requires upgrade to scint.
DOE Office of Science co-investment is critical to the project’s success ‘Positive dual-use’ aspect strengthens the long term case for remote monitoring
WATCHMAN may also provide: • a measurement of the ordering of the neutrino masses
– a major question for 21rst century physics
e,µ,τ• A search tool for a proposed 4th neutrino flavor
( are the only currently known flavors) • A search tool for non-standard neutrino interactions
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Background Measurements at the Kimballton Underground Research Facility
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• Drive in access don to 1500 foot depth
• First-‐ever continuous measurement as a function of depth
• Most important at shallow depths (300 feet, alternative site)
• Final measurement will be at the 1400 foot depth of preferred site Multiplicity and Recoil Spectrometer
for fast neutron energy spectrum
Small version of WATCHMAN (WATCHBOY) to measure muogenic radionuclide backgrounds
Time between muons in WATCHBOY
Entering KURF
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Next Steps
May 2014: • Provide detailed information to DNN as part of their
review process – May 27 review • Generate white paper on WATCHMAN physics
potential for DOE Office of Science – submit full proposal
• Summer 2014: Possible reference in HEP advisory committee long term planning report (‘P5 committee’)
October 2014: • Publish first experimental results on depth
dependent backgrounds
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Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Backup slides
18
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Prior work and technical challenges
• 2004 KamLAND project: Japanese team demonstrates 400 km detection of reactor antineutrinos, but using an expensive and difficult-to-scale technology (oil-based liquid scintillator)
• 2012 LLNL DNN funded project – first-ever demonstration of time-tagged neutron detection in water (1 ton detector)
• 2014 EGADS project: WATCHMAN collaborator Vagins demonstrates long term recirculation/purification of 200 tons of Gd-doped water (engineering prototype, no antineutrino sensitivity)
• All individual steps have been separately tested to high Technical Readiness: integration is the key technical challenge
19
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Historical examples indicate that satellite imagery is a favored tool
20
Country(and(location(
Reactor(characteristics(
Discovered(before(
complete?(
NPT(party(at(the(time(of(
discovery?(
(obligated(to(have(declared(the(reactor(?(
How(was(the(reactor(discovered?(
DPRK,&Yongbyon& ~25&MWt& Yes& No& No& satellite&imagery&at&known&Yongbyon&facilityi&
Algeria,&Birine& 15&MWt&& Yes& No& No& news&article,ii&claims&construction&had&been&observed&in&satellite&imagery.&China&reportedly¬ified&the&U.S.&of&its&intention&
to&supply&the&reactor.iii&Pakistan,&Khushab&
~50&MWt& Yes&?& No& No& Announced&by&Pakistan&in&April&1998,iv&but&open&sources&references&suggest&it&was&known&to&U.S.&intelligence&before&then.v&
Iran,&Arak& 40&MWt&& Yes& Yes& No& officially&announced&4Q2004&vi&Q&publicly&disclosed&by&NCRI&in&August&2002.vii&&U.S.&Intelligence&discovery&may&have&preceded&
that&date&Syria,&Dayr&Alzour& 25&MWt&?&& Yes& Yes& Yes& 4Q2008&DNI&briefing&showed&satellite&and&
ground&photography.viii&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&i&Don&Oberdorfer,The&Two&Koreas,&p.&25;&see&also&declassified&reports&at&http://www2.gwu.edu/~nsarchiv/NSAEBB/NSAEBB87/&&ii&Bill&Gertz,&Washington&Times,&11&April&1991.&iii&&Letter,&Ambassador&Richard&Kennedy&to&Editor&of&the&New&York&Times,&20&November&1991&(http://www2.gwu.edu/~nsarchiv/nukevault/ebb228/index.htm)&
iv&"Pakistan's(Indigenous(Nuclear(Reactor(Starts(Up,"(Islamabad,(The$Nation,(April(13,(1998.&v&Mark&Hibbs,&"Bhutto&May&Finish&Plutonium&Reactor&without&Agreement&on&Fissile&Stocks,”&Nucleonics&Week,&October&1994.&vi&Jeffrey&T.&Richelson,&Spying&on&the&Bomb,&p.&504&.&vii&National&Council&of&Resistance&on&Iran,&“Information&on&Two&Top&Secret&Nuclear&Sites&of&the&Iranian&Regime&(Natanz&and&Arak),”&pp.&1Q2&viii&"Background&Briefing&with&Senior&U.S.&Officials&on&Syria's&Covert&Nuclear&Reactor&and&North&Korea's&Involvement,"&Office&of&the&Director&of&National&Intelligence,&24&April&2008,&available&at&the&Council&on&Foreign&Relations&Website,&www.cfr.org.&&
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Siting Study: Map of US Power Reactors
21
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Siting Study: US Reactors + Active Mines
22
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Two Possible Use Cases - Large Detectors
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Exclusion: Ensure no reactors are operating at 10-1000 km standoff
Absence of undeclared reactors: ensure only declared reactors are
operating at a known site
Ø Simplest scenario • Searches for excess antineutrino
signal above background
Ø Most sensitive • Low background levels
Ø Best suited to finding or excluding new reactors in areas without existing reactors
Ø Potential countermeasures are
politically or financially costly • Build a declared reactor near the
detector • Physically attack the detector
Ø More complex • Requires knowledge of signal
from declared reactors
Ø Higher backgrounds due to other reactors
Ø Adjusting power of declared reactors is a potential countermeasure
We are not yet claiming significance for any particular Treaty or Agreement
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Reactor Antineutrino Emissions
The famously low antineutrino interaction probability is good and bad
ü Detectable at long ranges ü Effectively impossible to falsify, disguise, or shield without another
reactor ☓ Requires big detectors for remote sensitivity
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• 1021 fissions per second in a 3,000-MWt reactor
• 6 antineutrinos per fission from beta decay of neutron-rich daughters
Defense Nuclear Nonproliferation
Lawrence Livermore National Laboratory Sandia National Laboratories
Technical approach
• For the first time: Use water Cherenkov technology to detect low-energy reactor antineutrinos (1-10 MeV).
• 0.1% doping with neutron capture agent Gadolinium provides good ’tagging’ efficiency for the neutron - essential for background rejection
• High Quantum Efficiency PMTs enable sensitivity to the ~10-100 photoelectron signals arising from the positron and neutron created by antineutrino interactions on protons in water
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νe + p à e+ + n
n νe p
Σγ ~ 8 MeV
511 keV 511 keV e+
Gd
τ ~ 30 µs prompt e+ signal + n capture on Gd