scholarly journals QUALIFICATION OF ANC9 GENERIC INSERT METHODOLOGY (GIM)

2021 ◽  
Vol 247 ◽  
pp. 02003
Author(s):  
Baocheng Zhang ◽  
Boyan D. Ivanov ◽  
Kevin Hoskins ◽  
Harish Huria ◽  
Andre Luiz Pereira Rebello
Keyword(s):  
Fuel Assembly ◽  
Temperature Coefficient ◽  
Power Distribution ◽  
Code System ◽  
Fuel Performance ◽  
Loading Cycle ◽  
Burnable Poison ◽  
The Core ◽  
Burnable Absorber

Discrete burnable poisons like the Wet Annular Burnable Absorber and Pyrex have been used in PWR core to improve core power distribution and provide more negative moderator temperature coefficient. The burnable absorber in the burnable poison rods burns fast and is completely gone after one cycle exposure in the core. Traditionally, the burnable poison rods are designed to be part of the fuel assembly. They are burned together with the fuel in the first loading cycle and discharged after one cycle. In recent years, different insertion scenarios of the burnable poison rods have been introduced in the PWR plants operation to improve the fuel performance, for instance, fresh burnable poison rods are inserted into a burned assembly; burned burnable poison rods stay in the original assembly or are replaced in a different assembly. A Generic Insert Methodology [1] was developed in Westinghouse and implemented in NEXUS/ANC9 code system. With this new methodology, ANC9 is able to follow the assembly history and model all types of absorber insert components for all kinds of insertion scenarios. An extensive methods validation and qualification effort has been completed by modeling different insertion cases. This paper provides details of the qualification cases along with the analysis of the results.

Burnable Poison Design for Supercritical Water Cooled Reactor With Annular Fuel

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Zhao Chuanqi ◽  
Wang Kunpeng ◽  
Cao Liangzhi ◽  
Zheng Youqi
Keyword(s):  
Rare Earth ◽  
Fuel Assembly ◽  
Supercritical Water ◽  
Power Distribution ◽  
Rare Earth Oxide ◽  
Burnable Poison ◽  
The Core ◽  
Power Peak ◽  
Supercritical Water Cooled Reactor ◽  
Control Rods

Burnable poison (BP) is used to control excess reactivity in supercritical water cooled reactor (SCWR). It helps reduce the number of control rods. Over all BP designs, the design in which rare-earth oxide mixes with fuel is widely used in SCWR. BP has influence on fuel assembly neutronics performance. After comparing four kinds of rare-earth oxide, Er2O3 is chosen as BP for the annular fuel assembly. The effect of different BP loading patterns on assembly power distribution is analyzed. The safety of annular fuel assembly is estimated with different BP contents. Core performance with and without BP is compared. The results had shown that the core radial power peaking factor decreased after introducing BP. It was also shown that the core axial power peaking factor increased, and the power peak moved toward the top of the core. The reason of this effect was studied. Two optimizations were given based on this study: decreasing the temperature of lower plenum and increasing the gradients of axial enrichments. By applying these optimizations, core axial power peaking factor and maximum cladding surface temperature decreased.

Implementation of Erbia With ZrB2 in 17×17 Assemblies for a 4-Loop Core With a 24-Month Cycle

2002 ◽  
Author(s):  
James E. Platte ◽  
Ernesto Pitruzzella ◽  
Youssef Shatilla ◽  
Baard Johansen
Keyword(s):  
Fuel Assembly ◽  
Temperature Coefficient ◽  
Cycle Length ◽  
Zirconium Diboride ◽  
Fuel Rods ◽  
Fuel Assemblies ◽  
Burnable Absorber

There are many types of burnable absorbers currently used in power reactors. They are used to provide reactivity and power peaking control. Westinghouse reactors most commonly use Zirconium Diboride Integral Fuel Burnable Absorbers (ZrB2) while Combustion Engineering reactors most commonly use Erbia Integral Fuel Burnable Absorbers (Erbia) in Combustion Engineering reactors. This paper documents the study to determine the effect of placing Erbia and ZrB2 within a Westinghouse 17×17 fuel assembly, and the effect of these ZrB2/Erbia assemblies on the physics characteristics of a representative Westinghouse 4-loop, 24 month cycle length design. The study consisted first of producing optimal within-assembly burnable absorber configurations where ∼25% of the ZrB2-bearing fuel rods within an assembly were replaced with Erbia-bearing fuel rods. This ratio was selected in order to provide an effective balance between potential peaking factor improvements and the known Erbia disadvantage of increased residual absorber penalty compared with ZrB2. The optimal patterns were selected as the ones that most reduced the assembly-wise cumulative peak-to-average rod power during the depletion compared with existing all-ZrB2 BA configurations with the same BA rod quantity loading. The second part of this study consisted of substituting various quantities of these ZrB2/Erbia feed fuel assemblies in a representative Westinghouse 4-loop, 24 month cycle core design to study the effect on power peaking factors, moderator temperature coefficient (MTC), and cycle length.

scholarly journals WHOLE CORE COUPLING METHODOLOGIES WITHIN WIMS

2021 ◽  
Vol 247 ◽  
pp. 06006
Author(s):  
Brendan Tollit ◽  
Alan Charles ◽  
William Poole ◽  
Andrew Cox ◽  
Glynn Hosking ◽  
...  
Keyword(s):  
Fuel Assembly ◽  
Cross Sections ◽  
Diffusion Flux ◽  
Thermal Hydraulics ◽  
Reactor Physics ◽  
Fuel Performance ◽  
The Core ◽  
Small Modular Reactors ◽  
Core Solution ◽  
Multiphysics Modelling

The ANSWERS® WIMS reactor physics code is being developed for whole core multiphysics modelling. The established neutronics capability for lattice calculations has recently been extended to be suitable for whole core modelling of Small Modular Reactors (SMRs). A whole core transport, SP3 or diffusion flux solution is combined with fuel assembly resonance shielding and pin-by-pin differential depletion. An integrated thermal hydraulic solver permits differential temperature and density variations to feedback to the neutronics calculation. This paper presents new methodology developed in WIMS to couple the core neutronics to the integrated core thermal hydraulics solver. Two coupling routes are presented and compared using a challenging PWR SMR benchmark. The first route, called GEOM, dynamically calculates the resonance shielding and homogenisation with the whole core flux solution. The second coupling route, called CAMELOT, separates the resonance shielding and pincell homogenisation from the whole core solution via generating tabulated cross sections. Both routes can use the MERLIN homogenised pin-by-pin whole core flux solver and couple to the same integrated thermal hydraulic solver, called ARTHUR. Heterogeneous differences between the neutronics and thermal hydraulics are mapped via thermal identifiers for neutronics materials and thermal regions. The ability for the integrated thermal hydraulic solver to call an external code via a Fortran-C-Python (FCP) interface is also summarised. This flexible external coupling permits one way coupling to an external fuel performance code or two way coupling to an external thermal hydraulic code.

scholarly journals FUEL BURN-UP DISTRIBUTION AND TRANSURANIC NUCLIDE CONTENTS PRODUCED AT THE FIRST CYCLE OPERATION OF AP1000

2016 ◽  
Vol 18 (2) ◽  
pp. 101 ◽  
Author(s):  
Jati Susilo ◽  
Jupiter Sitorus Pane
Keyword(s):  
Fuel Assembly ◽  
Input Data ◽  
Reactor Core ◽  
Fission Products ◽  
Life Time ◽  
Fuel Loading ◽  
The Core ◽  
Fuel Burn ◽  
Burnable Absorber ◽  
High Level

ABSTRACT FUEL BURN-UP DISTRIBUTION AND TRANSURANIC NUCLIDE CONTENTS PRODUCED AT THE FIRST CYCLE OPERATION OF AP1000. AP1000 reactor core was designed with nominal power of 1154 MWe (3415 MWth), operated within life time of 60 years and cycle length of 18 months. For the first cycle, the AP1000 core uses three kinds of UO2 enrichment, they are 2.35 w/o, 3.40 w/o and 4.45 w/o. Absorber materials such as ZrB2, Pyrex and Boron solution are used to compensate the excess reactivity at the beginning of cycle. In the core, U-235 fuels are burned by fission reaction and  produce energy, fission products and new neutron. Because of the U-238 neutron absoption reaction, the high level radioactive waste of heavy nuclide transuranic such as Pu, Am, Cm and Np are also generated. They have a very long half life. The purpose of this study is to evaluate the result of fuel burn-up distribution and heavy nuclide transuranic contents produced by AP1000 at the end of first cycle operation (EOFC). Calculation of ¼ part of the AP1000 core in the 2 dimensional model has been done using SRAC2006 code with the module of COREBN/HIST. The input data called the table of macroscopic crossection, is calculated using module of PIJ. The result shows that the maximum fuel assembly (FA) burn-up is 27.04 GWD/MTU, that is still lower than allowed maximum burn-up of 62 GWD/MTU.  Fuel loading position at the center/middle of the core will produce bigger burn-up and transuranic nuclide than one at the edges the of the core. The use of IFBA fuel just give a small effect to lessen the fuel burn-up and transuranic nuclide production. Keywords: Fuel Burn-Up, Transuranic, AP1000, EOC, SRAC2006   ABSTRAK DISTRIBUSI BURN-UP DAN KANDUNGAN NUKLIDA TRANSURANIUM YANG DIHASILKAN BAHAN BAKAR PADA SIKLUS OPERASI PERTAMA TERAS AP1000. Reaktor AP1000 didesain dengan daya nominal 1154 MWe (3415 MWth), mampu beroperasi selama umur reaktor sekitar 60 tahun dan memiliki panjang tiap siklus sekitar 18 bulan. Pada siklus operasi pertama, teras AP1000 menggunakan tiga jenis pengkayaan bahan bakar UO2 yaitu 2,35 w/o, 3,40 w/o dan 4,450 w/o. Penyerap neutron ZrB2, Pyrex dan larutan Boron digunakan sebagai kompensasi reaktivitas lebih pada awal siklus. Di dalam teras reaktor, bahan bakar U-235 mengalami pembakaran melalui reaksi fisi yang akan menghasilkan energi, produk fisi dan neutron baru. Karena adanya reaksi serapan neutron oleh U-238 maka reaktor juga menghasilkan limbah radioaktif tingkat tinggi berupa nuklida transuranium yang mempunyai waktu paruh sangat panjang seperti Np, Pu, Am, dan Cm. Dalam penelitian ini dilakukan analisis hasil perhitungan distribusi burn-up bahan bakar dan kandungan nuklida transuranium yang dihasilkan oleh teras AP1000 saat akhir siklus operasi pertama. Perhitungan model geometri 2 dimensi teras AP1000 bentuk ¼ bagian dilakukan dengan paket program SRAC2006 modul COREBN/HIST. Sedangkan input data berupa tabel tampang lintang makroskopik diperoleh dari perhitungan dengan modul PIJ. Hasil prhitungan menunjukkan bahwa burn-up perangkat bahan bakar (Fuel Assembly, FA) tertinggi  adalah sebesar 27,04 GWD/MTU dan ini masih jauh lebih rendah dari batas maksimum burn-up yang diijinkan yaitu 62 GWd/MTU. Posisi pemuatan perangkat bahan bakar di bagian tengah teras akan menghasilkan burn-up dan nuklida transuranium yang lebih besar dibandingkan dengan ditepi teras. Penggunaan bahan bakar Integrated Fuel Burnable Absorber hanya sedikit berpengaruh terhadap penurunan burn-up dan nuklida transuranium yang dihasilkan. Kata kunci: Fuel burn-up, kandungan nuklida transuranium, AP1000, siklus operasi pertama, SRAC2006 

scholarly journals MODELLING ASTRID-LIKE SODIUM-COOLED FAST REACTOR WITH SERPENT-DYN3D CODE SEQUENCE

2021 ◽  
Vol 247 ◽  
pp. 02028
Author(s):  
Wojciech Rydlewicz ◽  
Emil Fridman ◽  
Eugene Shwageraus
Keyword(s):  
Monte Carlo ◽  
Fuel Assembly ◽  
Fast Reactor ◽  
Power Distribution ◽  
Fast Reactors ◽  
The Core ◽  
Fuel Assemblies ◽  
Complex Core ◽  
Nodal Diffusion ◽  
Full Core

This study explores the feasibility of applying the Serpent-DYN3D sequence to the analysis of Sodium-cooled Fast Reactors (SFRs) with complex core geometries, such as the ASTRIDlike design. The core is characterised by a highly heterogeneous configuration and was likely to challenge the accuracy of the Serpent-DYN3D sequence. It includes axially heterogeneous fuel assemblies, non-uniform fuel assembly heights and large sodium plena. Consequently, the influence of generation and correction methods of various homogenised, few-group crosssections (XS) on the accuracy of the full-core nodal diffusion DYN3D calculations is presented. An attempt to compare the approximate time effort spent on models preparation against the accuracy of the result is made. Results are compared to reference full-core Serpent MC (Monte Carlo) solutions. Initially, XS data was generated in Serpent using traditional methods (2D single assemblies and 2D super-cells). Full core calculations and MC simulations offered a moderate agreement. Therefore, XS generation with 2D fuel-reflector models and 3D single assembly models was verified. Super-homogenisation (SPH) factors for XS correction were applied. In conclusion, the performed work suggests that Serpent-DYN3D sequence could be used for the analysis of highly heterogeneous SFR designs similar to the studied ASTRID-like, with an only small penalty on the accuracy of the core reactivity and radial power distribution prediction. However, the XS generation route would need to include the correction with SPH factors and generation of XS with various MC models, for different core regions. At a certain point, there are diminishing returns to using more complex XS generation methods, as the accuracy of full-core deterministic calculations improves only slightly, while the time effort required increases significantly.

Conceptual Core Design of HAPPY200 Reactor

2018 ◽  
Author(s):  
Xiaosheng Li ◽  
Linsen Li ◽  
Lianghui Peng ◽  
Xiaosong Chen ◽  
Zhaocan Meng ◽  
...  
Keyword(s):  
Temperature Coefficient ◽  
Power Distribution ◽  
Reactor Core ◽  
Design Parameters ◽  
Coolant Temperature ◽  
Control Rod ◽  
The Core ◽  
Passive Safety System ◽  
Reactivity Coefficients ◽  
Full Power

The pressure and coolant temperature of Heating-reactor of Advanced low-Pressurized and Passive safetY system (HAPPY200) is significantly lower than PWR of the NPP, the core design and analysis were completed according to the design parameters and features of HAPPY200. The fuel assembly and its feature was firstly designed and studied based on the investigation of different types of fuel assemblies. Then the core configuration was studied and optimized according to the design parameters of HAPPY200; Eventually, neutronics calculation of the core was performed and key parameters were obtained including cycle length, power distribution, control rod worth, reactivity coefficients and etc. The study shows that with the core design HAPPY200 can be operated for 18 months in full power and reactivity control system can maintain criticality of the core in the full cycle. Due to the non-soluble boron design of the reactivity control scheme, moderator temperature coefficient and isothermal temperature coefficient are both negative, the Doppler temperature coefficients and power coefficients in different phase of the lifetime and in different power levels are also negative, therefore, the reactivity safety of the reactor core can be ensured.

Comparison between standard solid fuel and a new annular fuel performance in the core of a PWR

Kerntechnik ◽  
2020 ◽  
Vol 85 (3) ◽  
pp. 161-168
Author(s):  
N. El-Sahlamy ◽  
M. Hassan ◽  
A. Khedr
Keyword(s):  
Solid Fuel ◽  
Fuel Performance ◽  
The Core

Analysis of Advanced PWR Loading Schemes for Transuranic Incineration in Thorium

2013 ◽  
Author(s):  
Benjamin A. Lindley ◽  
N. Zara Zainuddin ◽  
Fausto Franceschini ◽  
Geoffrey T. Parks
Keyword(s):  
Temperature Coefficient ◽  
Preliminary Analysis ◽  
Detrimental Effect ◽  
Spatial Separation ◽  
Trade Off ◽  
The Core ◽  
Positive Reactivity ◽  
Fuel Pin ◽  
Control Rods

It is difficult to perform multiple recycle of transuranic (TRU) isotopes in PWRs as the moderator temperature coefficient (MTC) tends to become positive after a few recycles and the core may have positive reactivity when fully voided. Due to the favorable impact on the MTC and void coefficient fostered by use of thorium (Th), the possibility of performing Th-TRU multiple-recycle in reduced-moderation PWRs (RMPWRs) is under consideration. The simplest way to reduce the moderation in a PWR is to increase the fuel pin diameter. This configuration improves the trade-off between achievable burn-up and MTC, but is ultimately limited by thermal-hydraulic constraints. Heterogeneous recycle with the bred uranium (U3) and the TRU are arranged in separate pins was found to be neutronically preferable to a homogeneous configuration. Spatial separation also enables the U3 and TRU to be refueled on different batch schemes. These techniques allow satisfactory discharge burn-up while ensuring negative MTC and fully voided reactivity, with the pin diameter of a standard PWR increased from 9.5 mm to 11 mm. Reactivity control is a key challenge due to the reduced worth of neutron absorbers and their detrimental effect on the void coefficients, especially when diluted, as is the case for soluble boron. It seems necessary to control the core using control rods to keep the fully voided reactivity negative. A preliminary analysis indicates that this is feasible.

Neutronic Analysis of Accident-Tolerant Fuel Assemblies With Silicon Carbide Cladding in Pressurized Water Reactors

2017 ◽  
Author(s):  
Zhixiong Tan ◽  
Jiejin Cai
Keyword(s):  
Silicon Carbide ◽  
Fuel Assembly ◽  
Power Distribution ◽  
Safety Margin ◽  
Severe Accident ◽  
Pressurized Water Reactors ◽  
Fuel Pellet ◽  
Pressurized Water ◽  
Neutronic Parameters ◽  
Water Reactors

After Fukushima Daiichi Nuclear Power Plant accident, alternative fuel-design to enhance tolerance for severe accident conditions becomes particularly important. Silicon carbide (SiC) cladding fuel assembly gain more safety margin as novel accident tolerant fuel. This paper focuses on the neutron properties of SiC cladding fuel assembly in pressurized water reactors. Annular fuel pellet was adopted in this paper. Two types of silicon carbide assemblies were evaluated via using lattice calculation code “dragon”. Type one was consisted of 0.057cm SiC cladding and conventional fuel. Type two was consisted of 0.089cm SiC cladding and BeO/UO2 fuel. Compared the results of SiC cladding fuel assembly neutronic parameters with conventional Zircaloy cladding fuel assembly, this paper analyzed the safety of neutronic parameters performance. Results demonstrate that assembly-level reactivity coefficient is kept negative, meanwhile, the numerical value got a relatively decrease. Other parameters are conformed to the design-limiting requirement. SiC kinds cladding show more flat power distribution. SiC cases also show the ability of reducing the enrichment of fuel pellets even though it has higher xenon concentration. These types of assembly have broadly agreement neutron performance with the conventional cladding fuel, which confirmed the acceptability of SiC cladding in the way of neutron physics analysis.

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