Prompt Neutron Decay for Delayed Critical Bare and Natural-Uranium-Reflected Metal Spheres of Plutonium and Highly Enriched Uranium

2011 ◽  
Author(s):  
John Mihalczo
Keyword(s):  
Natural Uranium ◽  
Prompt Neutron ◽  
Neutron Decay ◽  
Enriched Uranium

scholarly journals EXPERIMENTAL STUDY ON NEUTRON CORRELATION ANALYSIS FOR A SUBCRITICAL SYSTEM DRIVEN BY A PULSED SPALLATION NEUTRON SOURCE IN KUCA

2021 ◽  
Vol 247 ◽  
pp. 09019
Author(s):  
Kunihiro Nakajima ◽  
Kazuki Takahashi ◽  
Atsushi Sakon ◽  
Sin-ya Hohara ◽  
Tadafumi Sano ◽  
...  
Keyword(s):  
Experimental Study ◽  
Correlation Analysis ◽  
Neutron Source ◽  
Statistical Error ◽  
Prompt Neutron ◽  
Neutron Decay ◽  
Spallation Neutron Source ◽  
Decay Constants ◽  
Enriched Uranium ◽  
Subcritical Reactor

The Feynman-α and the Rossi-α methods have been frequently employed to determine the subcriticality of subcritical reactor systems driven by Poisson source such as Am-Be neutron source. In actual accelerator-driven systems (ADS), a spallation device will be applied as an intense neutron source. This device will be probably operated in a pulse mode and it is impossible to apply a conventional analysis method to determine the subcriticality in any ADS. In previous theoretical studies, some advanced formulae of neutron correlation analysis for spallation neutron source have been presented. However, the experimental study has been hardly reported to date. The major objectives of this study are to examine experimentally an applicability of these complicated formulae to a subcritical reactor system driven by an actual pulsed spallation neutron source and to determine the prompt-neutron decay constant α of the system. To achieve these goals, we constructed an ADS core at the Kyoto University Critical Assembly (KUCA). The core was composed of highly-enriched uranium fuel assemblies surrounded by many polyethylene reflector assemblies. We carried out a series of the Feynman-α and the Rossi-α analyses for the system driven by pulsed spallation source. As a result, the prompt-neutron decay constants were experimentally obtained by using a fitting formula. The prompt-neutron decay constants determined by Feynman-α and Rossi-α analyses agrees with each other within a statistical error range of least-squares fitting.

Large-Break Loss-of-Coolant Accident Phenomena Identification and Ranking Table (PIRT) for the Advanced CANDU Reactor

2004 ◽  
Author(s):  
N. Popov ◽  
H. E. Sills ◽  
V. G. Snell ◽  
B. Boyack ◽  
V. J. Langman
Keyword(s):  
Heavy Water ◽  
Computer Code ◽  
Natural Uranium ◽  
Summary Table ◽  
Regulatory Review ◽  
Loss Of Coolant Accident ◽  
Unit Energy ◽  
Wide Range ◽  
Loss Of Coolant ◽  
Enriched Uranium

The Advanced CANDU Reactor (ACR™)* is an evolutionary advancement of the current CANDU 6® reactor, aimed at producing electrical power for a capital cost and unit-energy cost significantly less than that of current reactor designs. The ACR retains the modular concept of horizontal fuel channels surrounded by heavy water moderator, as with all CANDU reactors. However, ACR uses slightly enriched uranium (SEU) fuel, compared to the natural uranium used in CANDU 6. This achieves the twin goals of improved economics (e.g., via reductions in the heavy water requirements and the use of a light water coolant), as well as improved safety. This paper is focused on the double-ended guillotine critical inlet header break (CRIHB) loss-of-coolant accident (LOCA) in an ACR reactor, which is considered as a large break LOCA. Large Break LOCA in water-cooled reactors has been used historically as a design basis event by regulators, and it has attracted a very large share of safety analysis and regulatory review. The LBLOCA event covers a wide range of system behaviours and fundamental phenomena. The Phenomena Identification and Ranking Table (PIRT) for LBLOCA therefore provides a good understanding of many of the safety characteristics of the ACR design. The paper outlines the design characteristics of the ACR reactor that impact the PIRT process and computer code applicability. It also describes the LOCA phenomena, lists all components and systems that have an important role during the event, discusses the PIRT process and results, and presents the final PIRT summary table.

Measurement of Prompt Neutron Decay Constant of CFBR-II at Near Delayed Criticality Using Randomly Pulsed Neutron Method

2013 ◽  
Author(s):  
Lingli Song ◽  
Jiansheng Li ◽  
Haojun Zhou ◽  
Yu Jin
Keyword(s):  
Liquid Scintillation ◽  
Decay Constant ◽  
Detection System ◽  
Prompt Neutron ◽  
Neutron Decay ◽  
Timing Uncertainty ◽  
Neutron Method ◽  
Pulsed Neutron ◽  
Liquid Scintillation Detector ◽  
Good Agreement

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.

scholarly journals Measurement of Prompt Neutron Decay Constant in Delayed Critical State of Heavily Reflected Reactor

1967 ◽  
Vol 4 (9) ◽  
pp. 462-467
Author(s):  
Yoshihiko KANEKO ◽  
Fujiyoshi AKINO ◽  
Ryòsuke KUROKAWA ◽  
Kenji SUMITA
Keyword(s):  
Critical State ◽  
Decay Constant ◽  
Prompt Neutron ◽  
Neutron Decay

Prompt Neutron Decay Constants in Multiplying Hydrogenous Media

1961 ◽  
Vol 11 (2) ◽  
pp. 199-210 ◽  
Author(s):  
D. R. Bach ◽  
S. I. Bunch ◽  
R. J. Cerbone ◽  
R. E. Slovacek
Keyword(s):  
Prompt Neutron ◽  
Neutron Decay ◽  
Decay Constants
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