scholarly journals Determination of VVER-1000 Thermal Power Based on Background Signals of Self-Powered Neutron Detectors

2019 ◽  
pp. 25-33
Author(s):  
V. Borysenko ◽  
D. Budyk ◽  
V. Goranchuk
Keyword(s):  
Neutron Flux ◽  
Thermal Power ◽  
Weight Coefficient ◽  
Random Errors ◽  
Neutron Detectors ◽  
Fundamental Possibility ◽  
Determination Error ◽  
Self Powered ◽  
Technical And Economic Indicators

The value of the reactor thermal power (RTP) is used in the VVER-1000 control systems in most algorithms for generation of control, blocking and protection signals. Besides, the technical and economic indicators of the power unit are determined by this parameter. Plans to increase VVER‑1000 RTP to 101.5%, and later to 104-107% of the nominal require additional justification of the accuracy of the RTP determination. Therefore, the task of increasing the accuracy of RTP determination is important. The paper describes the ways to improve the accuracy of weighted mean thermal power (WMTP) determination by selecting the optimal weight coefficient (that subsequently is used for WMTP determination) of each of the methods of RTP determination, namely: by thermotechnical parameters of the primary and secondary sides by neutron flux in the in-core monitoring system (ICMS) and in the neutron flux control equipment (NFCE). Another possibility of increasing the accuracy of WMTP determination, namely by increasing the number of methods of RTP determination, is also considered in the paper. The analysis of changes in the background signals of self-powered neutron detectors (SPNDs) during the VVER-1000 fuel campaigns shows the fundamental possibility of using the total background signal as a separate and independent method for RTP determination. The paper presents the results of the calculation of RTP determination error taking into account the coefficients of the components of the total RTP determination error: systematic, dynamic and random errors, which must be determined during the commissioning phase. The results of reduction of the error of WMTP determination in case of application of the additional method of RTP determination based on background signals of the SPNDs are presented. Theoretically, possible minimum values of the WMTP determination error are given depending on the values of the error of the RTP determination by separate methods.

Robust Filtering for Dynamic Compensation of Rhodium Self Powered Neutron Detectors

2014 ◽  
Author(s):  
Xingjie Peng ◽  
Kan Wang ◽  
Qing Li
Keyword(s):  
Neutron Flux ◽  
Noise Suppression ◽  
Response Speed ◽  
Linear Matrix ◽  
Neutron Detectors ◽  
Dynamic Compensation ◽  
Flux Dynamic ◽  
Compensation Methods ◽  
Monitoring And Surveillance ◽  
Self Powered

Self-Powered Neutron Detectors (SPNDs), which are widely used in nuclear reactors to obtain core neutron flux distribution, are accurate at steady state but responds slowly to changes in neutron flux. Dynamic compensation methods are required to improve the response speed of the SPNDs and make it possible to apply the SPNDs for core monitoring and surveillance. In this paper, three digital dynamic compensation methods are proposed. All of the three methods are based on the convex optimization framework using linear matrix inequalities (LMI). The simulation results show that three methods all can provide a reasonable balance between response speed and noise suppression.

Implantable self-powered detector for on-line determination of neutron flux in patients during NCT treatment

2004 ◽  
Vol 61 (5) ◽  
pp. 1033-1037 ◽  
Author(s):  
M.E Miller ◽  
L.E Mariani ◽  
M.L.Sztejnberg Gonçalves-Carralves ◽  
M Skumanic ◽  
S.I Thorp
Keyword(s):  
Neutron Flux ◽  
On Line ◽  
Self Powered

Development of self-powered neutron detectors for neutron flux monitoring in HCLL and HCPB ITER-TBM

2014 ◽  
Vol 89 (9-10) ◽  
pp. 2194-2198 ◽  
Author(s):  
M. Angelone ◽  
A. Klix ◽  
M. Pillon ◽  
P. Batistoni ◽  
U. Fischer ◽  
...  
Keyword(s):  
Neutron Flux ◽  
Neutron Detectors ◽  
Flux Monitoring ◽  
Self Powered

Application of Prompt Self-Powered Neutron Detectors to the Lead-Cooled Fast Reactor Demonstrator ALFRED: Validation of the Monte Carlo Model for Selected SPNDs

2017 ◽  
Vol 3 (4) ◽  
Author(s):  
Luigi Lepore ◽  
Romolo Remetti
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Neutron Flux ◽  
Fast Neutron ◽  
Fast Reactor ◽  
Monte Carlo Model ◽  
Neutron Detectors ◽  
Pure Lead ◽  
Neutron Spectra ◽  
Self Powered

The advanced lead fast reactor European demonstrator (ALFRED) is a European research initiative into the framework of the Generation IV International Forum facilities. ALFRED is a scaled down reactor compared to the industrial prototype European lead fast reactor proposed in lead-cooled European advanced demonstration reactor. It has a relatively low power (125 MWe) with a compact design to reduce the cost but maintaining its representativeness and it is cooled by pure lead. One of the open issues is linked to the neutron flux in-core monitoring system because of the harshness of the environment the detectors should be installed in, due to high temperatures, and the neutron-gamma radiation field levels. Monte Carlo simulation is a possible way of facing the problem, reproducing into a virtual world the reactor core, the surrounding environment and radiation interactions. In previous works, neutron spectra and gamma doses at possible detectors' locations in ALFRED were retrieved, with consideration on the applicability of each suitable device currently available. Fission chambers (FCs) were found to be exploited at reactor start-up and intermediate power range. Prompt self-powered neutron detectors (SPNDs) seemed to be the best solution to monitor the reactor full power, becoming the main research target: their effective applicability on field has to be demonstrated. SPND applications do not include reactor control purposes usually. Moreover, their irradiation experience involved thermal and epithermal neutron spectra monitoring, mainly. The lack of data when SPNDs sense fast neutron fluxes in terms of prompt-response pushed the authors to deepen the study in such direction. The work herein shows the mathematical approach based on Monte Carlo simulation of SPNDs by the Monte Carlo N-particle eXtended code (MCNPX), so as to study the capability of the code in reproducing real devices' signals while experimented on field. Such a verification turned out to be the preliminary stage for studying new concepts for SPNDs, in terms of sensitive materials and geometries, envisaging the possibility for designing, prototyping, and testing new devices in suitable fast neutron-flux facilities.

Statistics and parallaxes

1978 ◽  
Vol 48 ◽  
pp. 7-29
Author(s):  
T. E. Lutz
Keyword(s):  
Experimental Design ◽  
Statistical Methods ◽  
Review Paper ◽  
Systematic Errors ◽  
Past Experience ◽  
Random Errors ◽  
Trigonometric Parallaxes ◽  
Systematic And Random Errors

This review paper deals with the use of statistical methods to evaluate systematic and random errors associated with trigonometric parallaxes. First, systematic errors which arise when using trigonometric parallaxes to calibrate luminosity systems are discussed. Next, determination of the external errors of parallax measurement are reviewed. Observatory corrections are discussed. Schilt’s point, that as the causes of these systematic differences between observatories are not known the computed corrections can not be applied appropriately, is emphasized. However, modern parallax work is sufficiently accurate that it is necessary to determine observatory corrections if full use is to be made of the potential precision of the data. To this end, it is suggested that a prior experimental design is required. Past experience has shown that accidental overlap of observing programs will not suffice to determine observatory corrections which are meaningful.

Sign in / Sign up

Export Citation Format

Share Document