Fig. 2
Dependence of neutron detector count rate on reactor power and isotopic inventory. a Relative measured neutron detector count rate (with background subtracted) per unit reactor power (ordinate) vs. weighted isotopic composition of the reactor core (abscissa). The abscissa values are determined by individual TRIAD simulation core followings during particular periods of time as indicated in the graph legend. The ordinate values are determined by neutron measurements conducted with either the boron-coated straw (BCS) detector or the B10+detector at the time corresponding to each TRIAD core following. All quantities here are presented relative to a reference case, chosen as the average of data from the time period 2014/11 to 2014/12. Ordinate error bars are standard deviations of the normalized neutron count rates per unit power measured over the time period between each TRIAD core following calculation. The data points are plotted against a line of slope 1, with zero intercept. b Data from (a), averaged together in 1-month-long periods, as indicated in the graph. Data points in black squares were recorded at Location A with the BCS detector, and data points in magenta circles were recorded at Location B with the B10+ detector. These points collectively are seen to coincide well with a line of slope 1, and zero intercept. The error bars are standard deviations of the mean of data points from (a) for each time period. c Representative BCS detector count rate (at location A, from 2014/11 to 2014/12 time period) versus time, including periods of reactor start-up and shutdown. d Data from (c), relative to reactor power, and excluding shutdown periods, to illustrate how the detector count rate per unit reactor power can vary over the course of a month
