THE DOUNREAY FAST REACTOR VAULT CHARACTERISATION USING THE MONTE CARLO N-PARTICLE CODE AS A TOOL TO SUPPORT DECOMMISSIONING PLANNING

A combined empirical and theoretical characterisation approach was taken in order to investigate the activity distribution and inventory in the Dounreay Fast Reactor (DFR) vault, so as to aid with the decommissioning and waste management strategy of the cooling circuits located within the shielded vault. The DFR vault is a no-man access, shielded void, which surrounds the reactor core and the graphite shield. Empirical data was collected through various Non-Destructive Assay methods, utilising all available accesses into the reactor vault. This collection of information was then used to make a first assumption about the activity distribution within the vault; this was then included into a MCNP model of the vault as the source terms. The model was run and a dose rate map of the vault obtained, and compared to the empirical dose rate data previously gathered in the accessible penetrations in the vault; the model was altered until a satisfactory agreement was obtained between theoretical and measured data. Once this was obtained then, the model was used to provide an estimate of the activity inventory within the vault, and specifically within the various reactor components.

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Measurements of the High Dose Rate Profiles Inside a Shutdown CANDU® Reactor

AECL Nuclear Review ◽

10.12943/anr.2012.00005 ◽

2012 ◽

Vol 1 (1) ◽

pp. 27-34

Author(s):

C. Jewett ◽

J. Chow ◽

D. Comeau ◽

G. Jonkmans ◽

B. Smith ◽

...

Keyword(s):

Monte Carlo ◽

Monte Carlo Simulations ◽

Dose Rate ◽

High Dose Rate ◽

Measured Data ◽

High Dose ◽

Dose Rates ◽

Diode Detector ◽

Γ Ray ◽

Rate Profile

The positions of the components of a reactor can change over time, due to radiation damage, sagging, etc. Thus, it is important to determine their positions. To satisfy this requirement of the staff at the Point Lepreau Generating Station, a method to determine the positions of reactor components has been developed and demonstrated. This method combines the use of dose rate measurements and Monte Carlo simulations. It first involves measuring the high γ-ray dose rates as a function of position within a reactor. Then it entails comparing these measurements with Monte Carlo simulations. In order to perform such measurements, a silicon diode detector and a scan drive system have been developed. In 2009, measurements of the γ-ray dose rate profile of the shut down Point Lepreau Generating Station reactor were conducted. By comparing the locations of the local peaks in the dose rate data, it was possible to determine the distances between the steel reactor components. The measured data were then compared with Monte Carlo simulations to determine how precisely one could locate the positions of the adjuster rods. Using this technique, it was found that the retracted adjuster rods were 440 ± 60 mm below their designed positions.

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Lead Cooled Fast Reactor Core Physics Parameters Calculation Based on Monte Carlo Method

Proceedings of The 20th Pacific Basin Nuclear Conference ◽

10.1007/978-981-10-2317-0_74 ◽

2017 ◽

pp. 783-791

Author(s):

Yang Lyu

Keyword(s):

Monte Carlo ◽

Monte Carlo Method ◽

Fast Reactor ◽

Reactor Core ◽

Parameters Calculation

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Precision neutronic calculations of experiments on the neutron transmission through the reflector layers at the BFS critical facilities for expanding the verification database to justify lead cooled fast reactor designs

Nuclear Energy and Technology ◽

10.3897/nucet.6.60303 ◽

2020 ◽

Vol 6 (4) ◽

pp. 269-274

Author(s):

Olga N. Andrianova ◽

Evgeniya S. Teplukhina ◽

Gennady M. Zherdev ◽

Zhanna V. Borovskaya ◽

Andrey P. Zhirnov

Keyword(s):

Monte Carlo ◽

Fast Reactor ◽

Experimental Studies ◽

Reactor Core ◽

Heterogeneous Structure ◽

Neutron Data ◽

The Monte Carlo Method ◽

Critical Facilities ◽

Data Library ◽

Neutronic Characteristics

The paper presents the results of the efforts concerned with expanding the verification database and estimating the calculation uncertainty of the power density in the steel reflector of lead cooled fast reactor designs based on experiments performed in different years at the BFS critical assemblies by analyzing and revising earlier calculation and experimental studies on the transmission of neutrons through the steel reflector layers. The discussion includes experiments at the BFS-66 critical assembly to model neutron and photon fluxes in the reactor core shielding compositions, as well as experiments at the BFS-64 and BFS-80-2 critical assemblies to model the transmission of neutrons and gamma quanta through the reflector layers of various materials. The information provided in earlier materials with the descriptions of the above experiments has been analyzed and expanded through respective data required to prepare precision calculation models for Monte-Carlo neutronic codes. Precision neutronic models have been developed based on actualized and updated data with a detailed description of the BFS heterogeneous structure and experimental devices, and test calculations have been carried out to confirm their efficiency. The calculations of key neutronic characteristics measured at the BFS-66, -64 and -80-2 assemblies were performed using codes based on the Monte Carlo method (MCU-BR, MCNP, MMK-RF, MMK-ROKOKO) with BNAB-RF and MDBBR50 neutron data and the ROSFOND evaluated neutron data library. The developed precision calculation neutronic models of the experiments discussed can be used to justify lead cooled fast reactor designs, to verify neutronic codes and neutron data, and to evaluate the associated uncertainties.

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A technique for estimating neutron fluxes in a large number of in-core detectors by the Monte Carlo code PRIZMA for a full-scale model of a water-moderated reactor core

SNA + MC 2013 - Joint International Conference on Supercomputing in Nuclear Applications + Monte Carlo ◽

10.1051/snamc/201405313 ◽

2014 ◽

Cited By ~ 1

Author(s):

Y.Z. Kandiev ◽

E.A. Kashaeva ◽

G.N. Malyshkin ◽

K.E. Khatuntsev

Keyword(s):

Monte Carlo ◽

Reactor Core ◽

Full Scale ◽

Scale Model ◽

Monte Carlo Code

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Modular MA-XRF Scanner Development in the Multi-Analytical Characterisation of a 17th Century Azulejo from Portugal

Sensors ◽

10.3390/s21051913 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1913

Author(s):

Sergio Augusto Barcellos Lins ◽

Marta Manso ◽

Pedro Augusto Barcellos Lins ◽

Antonio Brunetti ◽

Armida Sodo ◽

...

Keyword(s):

Monte Carlo ◽

Monte Carlo Simulations ◽

17Th Century ◽

Scanning System ◽

X Ray ◽

Portable Instruments ◽

Complementary Techniques ◽

Non Destructive ◽

Suitable Technique ◽

Cobalt Blue

A modular X-ray scanning system was developed, to fill in the gap between portable instruments (with a limited analytical area) and mobile instruments (with large analytical areas, and sometimes bulky and difficult to transport). The scanner has been compared to a commercial tabletop instrument, by analysing a Portuguese tile (azulejo) from the 17th century. Complementary techniques were used to achieve a throughout characterisation of the sample in a complete non-destructive approach. The complexity of the acquired X-ray fluorescence (XRF) spectra, due to inherent sample stratigraphy, has been resolved using Monte Carlo simulations, and Raman spectroscopy, as the most suitable technique to complement the analysis of azulejos colours, yielding satisfactory results. The colouring agents were identified as cobalt blue and a Zn-modified Naples-yellow. The stratigraphy of the area under study was partially modelled with Monte Carlo simulations. The scanners performance has been compared by evaluating the images outputs and the global spectrum.

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