High-level neutron coincidence counter (HLNCC): users' manual

Abstract

Relative coincidence counts per gram of effective • Pu vs the PuOsample mass. The upper and lower curves show the data before and after correction for multiplication, respectively. (From ref. 35). ZPPR drawer containing two rows of plutonium plates interspersed with plates of depleted uranium, sodium, aluminum, carbon, and iron to mock up structure and coolant materials in a fast critical assembly. (From ref. 28.) Measurement setup for a ZPPR drawer, showing the HLNCC for neutron coincidence counting and the IAEA intrinsic germanium detector with its collimator for measurement of plutonium gamma-ray line ratios. (From ref. 28.) Axial coincidence efficiency for the two-position count to obtain a uniform sum over an extended region (40 cm). (From ref. 24.) Mixed-oxide BWR fuel-rod assembly mockup for measurement with the HLNCC. (From ref. 25.) Coincidence response measured with the HLNCC vs number of fuel rods in a PuO 2-UO 2 fuel assembly mockup. (From ref. 25.

A proposed semi-empirical method for 235U mass calibration of the active-well neutron coincidence counter

“…f c5 (z) of the counter is the average number of real coincidence counts measured per event after dead time correction. It is a function of the absolute detector efficiency, time parameters of the shift register (coincidence gate utilization factor, used to estimate the fraction of fission neutron pulses detected while the shift register coincidence gate is open), and the prompt neutron-induced fission multiplicity and energy distributions of the source material [32,33].…”

Introduction to Neutron Coincidence Counter Design Based on Boron-10

“…The response of the same ENMC model with a configuration using 121 boron-lined tubes is shown as the plus sign. The dashed curves show the FOM contours in epsilon-tau space for two example coincidence counter systems (AWCC and HLNC-II) where their FOMs (15.7 and 7.1 respectively) were evaluated from the data given in references [Krick 1979;Menlove 1979]. It can be seen that the 121 boron lined tube configuration of the ENMC can meet the performance of the HLNC-II.…”

“…Figure 3.6 shows a schematic of the HLNCC [Krick 1979]. The HLNCC is termed high-level because it is designed to handle the high countrates from several kg of Pu.…”

Video image processing for nuclear safeguards

“…Common to all of these automated nuclear safeguards systems is the need to store large quantities of video and other sensor data, and with regard to video data, to achieve a minimal loss of quality in the reconstructed image [3]. To achieve the required compression ratios and maintain minimal loss of Video Image Processing for Nuclear Safeguards quality in the reconstructed images, we adopted a wavelet transform compression algorithm based on predictive image coding strategies currently being developed at Los Alamos.…”

“…The sub-band coder is a two-channel perfect-reconstruction multi-rate filter bank (PR MFB) with linear-phase FIR filters corresponding to a family of regular, bi-orthogonal wavelets; this same PR MFB is used in the FBI's wavelet/scalar quantization (WSQ) standard for coding digital fingerprint images [3,4]. The filters are applied to row and column vectors of an image using symmetric extrapolation at the image boundaries; this "symmetric wavelet transform" technique is detailed in [51.…”