Prompt-Neutron Decay Constant Estimation at Full-Power Operation

1987 ◽  
Vol 79 (3) ◽  
pp. 274-283
Author(s):  
Mo-Chen Hsu
Author(s):  
Lingli Song ◽  
Jiansheng Li ◽  
Haojun Zhou ◽  
Yu Jin

Prompt neutron decay constant of CFBR-II (China’s Fast Burst Reactor) was measured by the randomly pulsed neutron method when the reactor was at the reactivity of −0.1$. A liquid scintillation detector was used to detect the leakage neutrons and the timing uncertainty of the detection system was less than 3ns. The detector and the Cf-252 fast ionization chamber were placed at several positions. Totally 5 prompt neutron timing distribution curves were obtained and the prompt neutron decay constant was 0.610us−1 in average with the uncertainty of 0.030us−1, which was in good agreement with the M.C. calculation.


1967 ◽  
Vol 4 (9) ◽  
pp. 462-467
Author(s):  
Yoshihiko KANEKO ◽  
Fujiyoshi AKINO ◽  
Ryòsuke KUROKAWA ◽  
Kenji SUMITA

2021 ◽  
Vol 247 ◽  
pp. 09025
Author(s):  
M.Y. Hua ◽  
C.A. Bravo ◽  
A.T. MacDonald ◽  
J.D. Hutchinson ◽  
G.E. McKenzie ◽  
...  

In this work, Rossi-alpha measurements were simultaneously performed with a 3He-based detection system and an organic scintillator-based detection system. The assembly is 15 kg of plutonium (93 wt% 239Pu) reflected by copper and moderated by lead. The goal of Rossi-alpha measurements is to estimate the prompt neutron decay constant, alpha. Simulations estimate keff = 0:624 and α = 52:3 ± 2:5 ns for the measured assembly. The organic scintillator system estimated α = 47:4 ± 2:0 ns, having a 9.37% error (though the 1.09 standard deviation confidence intervals overlapped). The 3He system estimated α = 37 μs. The known slowing down time of the 3He system is 35-40 μs, which means the slowing down time dominates and obscures the prompt neutron decay constant. Subsequently, the organic scintillator system should be used for assemblies with alpha much less than 35 μs.


1996 ◽  
Vol 122 (1) ◽  
pp. 68-78
Author(s):  
Nela Zavaljevski ◽  
Ljiljana Kostić ◽  
Milan Pešić ◽  
Aleksandar Zavaljevski

1990 ◽  
Vol 104 (1) ◽  
pp. 53-65 ◽  
Author(s):  
Tsuyoshi Misawa ◽  
Seiji Shiroya ◽  
Keiji Kanda

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