1. CRS 7/14/2015 # 1 LLNL This work was partially performed under the auspices of the US Department of Energy by the University of California, Lawrence Livermore National Laboratory, under contract No. W-7405-Eng-48. Safeguards and Cooperative Monitoring of Reactors With Antineutrino Detectors Adam Bernstein P.I. Nathaniel Bowden P.I. Lawrence Livermore National Laboratory Sandia National Laboratories

2. LLNL How Does The IAEA Monitor Fissile Material Now ? (1-1.5 years) Months to years (months)(forever ) 1. Check Input and Output Declarations 2. Verify with Item Accountancy 3.Containment and Surveillance 1 ‘Gross Defect’ Detection 2 Continue Item Accountancy 3. Containment and Surveillance 1 Check Declarations 2 Verify with Bulk Accountancy: (months to years) Operators Report Fuel Burnup and Power History No Direct Pu Inventory Measurement is Made Until the Fuel is Reprocessed

3. LLNL Antineutrino Detectors Offer Unique Advantages for Reactor Safeguards A. Measure fissile content directly B. Measure thermal power, which constraints fissile content C. Operate continuously, nonintrusively, and remotely our experimental work has already demonstrated B and C with a simple detector, and our data are fully consistent with A This approach complements Item Accountancy of assemblies with Bulk Accountancy of plutonium at the earliest possible moment in the regime

4. LLNL Properties of Antineutrinos Rate and energy spectrum are sensitive to the isotopic composition of the core 200-250 kg of new plutonium is generated in a typical cycle Real data and detailed reactor simulations show a reduction in the antineutrino rate of about 8% through a 500 day cycle caused by Pu ingrowth Rates near reactors are high - 0.64 ton detector, 25 m from reactor core - Core thermal power = 3.46 GW - 4000 events/day/0.64 ton with a 100% efficient detector - Our detector is about 10% efficient and counts 400 events per day

5. LLNL The Basic Technical Idea A.Monitor operating reactors with ~1 m 3 antineutrino detectors placed a few tens of meters from the reactor core B.Compare measured and predicted antineutrino rate or spectra to identify changes in fissile content. U-238 Pu-241 Daily antineutrino count rate

6. LLNL How Does it Work Operationally ? 100% of rate 90-95% of rate Persistent antineutrino signal from distant reactor Non-antineutrino backgrounds The systematic shift in inventory is reflected by the changing antineutrino count rate over time days

7. LLNL Testing the Idea at a Reactor Site 20 meter heterogenous overburden 25 meters standoff from core A crack team of investigators

8. LLNL Cutaway Diagram of the LLNL/Sandia Antineutrino Detector Currently operational: 4 cells with 640 kg of scintillator; quasi-hermetic muon veto; hermetic water shield

9. LLNL The antineutrino interacts with a proton producing… – A 1-7 MeV positron – A few keV neutron – mean time interval 28  sec Both final state particles deposit energy in a scintillating detector over 10s or 100s of microsecond time intervals (depending on the medium) Both energy depositions and the time interval are measured Detection of Antineutrinos

10. LLNL Net 400 events/day Daily Power Monitoring Using Only Antineutrinos

11. LLNL A Preliminary Indication of the Burnup Effect

12. LLNL Current Work: Compare Effectiveness against Diversion Scenarios With and Without an Antineutrino Detector Use reactor and detector simulations and a ‘fault-tree analysis’ to compare safeguards with and without the antineutrino detector

13. LLNL Next Steps in the LLNL/SNL program Complete quantitative comparison with existing IAEA safeguards Solicit further input from Safeguards Agencies Applied Antineutrino Physics Workshop September 25-26 at Lawrence Livermore National Laboratory, Livermore CA (Link soon at www.llnl.gov/neutrinos) Reduce detector footprint and increase sensitivity Detector deployment is essential for demonstrating practical utility: Deployment in a non-nuclear weapons state under IAEA safeguards is the best way to demonstrate the effectiveness of this technology