Utilization of the Differential Die-Away Self-Interrogation Technique for Characterization and Verification of Spent Nuclear Fuel

Abstract

SINGLE DETECTOR DEFINITION LEFT BANK ***** c ***** 4 atm =-4.99e-4, atm =-7.488e-4, 7.5 atm =-9.359e-4 g/cc 10 atm-1.248e-3 ***** 940-7.488e-4-901 904-905 u=500 imp:n=1 $ He3 tube at 6.0 atm 901 870-2.699 901-902-906 u=500 imp:n=1 $ Al tube 902 920-9.58e-4 902 u=500 imp:n=1 $ air gap around He-3 tube 903 870-2.699-902 906 u=500 imp:n=1 $ Void above each tube 904 940-7.488e-4-901-904 u=500 imp:n=1 $ Lower dead 905 940-7.488e-4-901 905-906 u=500 imp:n=1 $ Upper dead c c SINGLE DETECTOR DEFINITION LEFT BANK NON-DDSI tube c ***** 4 atm =-4.99e-4, 6 atm =-7.488e-4, 7.5 atm =-9.359e-4 g/cc 10 atm-1.248e-3 ***** 950 940-7.488e-4-911 904-905 u=501 imp:n=1 $ He3 tube at 6.0 atm 951 870-2.699 911-912-906 u=501 imp:n=1 $ Al tube 952 920-9.58e-4 912 u=501 imp:n=1 $ air gap around He-3 tube 953 870-2.699-912 906 u=501 imp:n=1 $ Void above tube 954 940-7.488e-4-911-904 u=501 imp:n=1 $ Lower dead 955 940-7.488e-4-911 905-906 u=501 imp:n=1 $ Upper dead c c DETECTOR ASSEMBLY, LEFT BANK 800 0 900 u=2 fill=500 imp:n=1 $ Initial detector # 60 (at left) 811 0-910 u=2 fill=501 imp:n=1 $ NON-DDSI TUBE c Left bank of He-3 tubes, first row 801 like 800 but trcl=(0-3.5 0) u=2 $ 58 802 like 800 but trcl=(0-7.0 0) u=2 $ 56 803 like 800 but trcl=(0-10.5 0) u=2 $ 54 804 like 800 but trcl=(0-14.0 0) u=2 $ 52 805 like 800 but trcl=(0-17.5 0) u=2 $ 50 806 like 800 but trcl=(0-21.0 0) u=2 $ 48 807 like 811 but trcl=(3 12.25 0) u=2 $ 62 DOWN IN OCTOBER c Left bank of He-3 tubes, second row 808 like 800 but trcl=(-3.0 1.75 0) u=2 $ 61 809 like 811 but trcl=(0 7.00 0) u=2 $ 59 DOWN IN OCTOBER 810 like 800 but trcl=(-3.0-5.25 0) u=2 $ 57 812 like 800 but trcl=(-3.0-12.25 0) u=2 $ 53 813 like 800 but trcl=(-3.0-15.75 0) u=2 $ 51 814 like 800 but trcl=(-3.0-19.25 0) u=2 $ 49

Comparison Of ²⁵²Cf Time Correlated Induced Fisssion With AmLi Induced Fission On Fresh MTR Research Reactor Fuel

“…Better computing power has helped in the advancement of NDA techniques by allowing large data collection and complex Monte Carlo simulations and calculations. [10] NDA can be used in all steps of nuclear fuel cycles such as mining/milling, fabrication plant, enrichment plant, reactor operation as well as in the backend of a fuel cycle. The technique is used to identify any undeclared material and operation, and verify operator declared fuel parameters such as initial enrichment, burnup, cooling time, residual fissile mass, or any diverted assembly from a reactor core or a spent fuel pool.…”

“…The NDA systems can collect and store data from different detectors simultaneously, and at the same time analyze data immediately after the measurement completion. [10] Unlike destructive analysis (DA), in which the fuel sample is physically destroyed for the sample fuel characterization, the AEFC is one of the NDA techniques that uses neutrons and gamma ray signals from the fuel sample. DA techniques are more accurate than NDA because they use techniques like mass spectroscopy in which material is characterized relative to reference standards.…”

“…Neutrons are removed from a system by getting captured in a detector tube, absorption in a surrounding material, and leakage from a system. The die away time in a system is represented by an exponential decay of the form: [10]…”

“…The totals rate consists of both accidental rates as well as real rates. [10] complex as correlated and uncorrelated events cannot be separated easily.…”

“…S(t) = A + Re −t τ ⁄10Where A is accidental coincidences, R is real coincidence, and is the die away time. [7][10]…”