ZPR-6 assembly 7 high {sup 240}Pu core experiments : a fast reactor core with mixed (Pu,U)-oxide fuel and a centeral high{sup 240}Pu zone.

Lell, R. M.; Morman, J.A.; Schaefer, R.W.; McKnight, R.D.

doi:10.2172/948806

Cited by 9 publications

(10 citation statements)

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“…BeO was placed in the drawers adjacent to the central sodium channel in Loading 106 and to the central mockup control rod in Loading 132, in order to determine whether addition of such a BeO ring would enhance control rod worth. [67,68] 2 -3/UNIC performed very well on the range of fast reactor problems. For all the four core loadings analyzed, the core reactivity was predicted within 1-σ (standard deviation) of the estimated experimental uncertainty (~80 pcm) including the geometry and composition uncertainties.…”

Section: Whole-core Calculation Toolsmentioning

confidence: 99%

Fast Reactor Physics and Computational Methods

Yang¹

2012

Nuclear Engineering and Technology

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Section: Whole-core Calculation Toolsmentioning

confidence: 99%

Fast Reactor Physics and Computational Methods

Yang¹

2012

Nuclear Engineering and Technology

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“…However, it is noted that the MCNP solutions generally underestimate the core reactivity compared to the measurements while the SN2ND solutions overestimate them. For all the four core loadings analyzed, the SN2ND solver predicted the core reactivity within 1σ of the estimated experimental uncertainty (~80 pcm) [17,18]. These results are comparable to the accuracy of MCNP solutions; the SN2ND solutions deviated from the measured values by 75, 43, 28 and -24 pcm for the Loadings 104, 106, 120, and 132, respectively, while the corresponding deviations of MCNP solutions were -56, -42, -132, and 0 pcm.…”

Section: Homogenized Drawer Modeling Of Zpr-6 Assembly 7 Experimentsmentioning

confidence: 72%

“…In FY2010, significant time was spent setting up the ZPR-6 Assembly 7 benchmark [15][16][17][18] using the BuildZPRmodel [2] to reduce input errors. The intent of that work was to define September 30, 2011 ANL/NE-11-40 a clear procedure for validating the heterogeneous modeling capability available with SN2ND+MC 2 -3 using ZPR benchmarks.…”

Section: Homogenized Drawer Modeling Of Zpr-6 Assembly 7 Experimentsmentioning

confidence: 99%

“…Each packet consisted of the four foil types sandwiched between a 1-mil (0.00254 cm) aluminum square and a 1-mil stainless steel square on both sides. The packets were placed in the fronts of the drawers of the stationary half between the Fe 2 O 3 plate and the fuel plate on the left side of the drawer as one faces the front of the drawer from a position between the halves [17,18]. Foil percent reaction rate errors ((C/E-1)%) are summarized in Table 3.2.…”

Section: Homogenized Drawer Modeling Of Zpr-6 Assembly 7 Experimentsmentioning

confidence: 99%

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FY2011 Status Report on SN2ND neutronics solver development.

Smith¹,

Mohamed²,

Marin-Lafleche³

et al. 2011

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SUMMARYA change in focus of NEAMS to a broader set of reactor types necessitated significant effort being diverted away from SN2ND development in FY2011. Nevertheless, significant gains were made with regard to building the new preconditioner and meeting the objectives of 1) parallelism in energy, 2) a spatial multigrid concept, 3) using S N vector spaces to accommodate the adjoint and time dependent functionalities needed for NEAMS work, and 4) complete manuals and documentation. While the desired goal of an exportable SN2ND solver usable within the NEAMS community for neutronics analysis was not completed, we can be confident that this year's work puts the SN2ND solver well on its way to meeting that objective. It is important to note that SN2ND is just as capable as any other methodology for doing thermal reactor analysis, but the motivation to execute on smaller scale machines has initiated focused development on simplified treatments such as those proposed in the MOCARV tool.All of the cited coding tasks were completed but not all are fully working (i.e. debugged). The spatial multigrid technique was by far the most time consuming part of the SN2ND development process. It required multiple new data structure concepts along with identifying the necessary changes in the vectors and their associated functions. Combining the spatial multigrid as part of a GMRES preconditioner operating on the full vector space, necessary for parallelization in energy, increased the complexity of that development. Research into spatial multigrid techniques for unstructured meshes, void treatments, and code optimization and acceleration are key development needs for SN2ND.Similar to previous years, a considerable amount of effort was spent on validation work. Again we focused on fast reactor problems such as ZPR experiments and the MONJU reactor in Japan. Conventional drawer homogenized models and partially heterogeneous models were used on the ZPR calculations. The drawer homogenized models produced excellent results for both eigenvalue and foil measurements on four loadings of ZPR-6/7. The partially heterogeneous models of ZPR-6/7 also produced good results, but additional work is necessary to generate consistent effective cross section data. Calculations for MONJU were homogeneous and also gave excellent results.Finally, mock-up heterogeneous calculations were setup and attempted to scope out the performance limitations of SN2ND on whole core heterogeneous calculations. Specifically, heterogeneous models of a PWR, a VHTR, and the MONJU reactor were created using anywhere from 2 group to 33 group cross section data. Meshes with greater than 100,000,000 vertices are necessary for accuracy and a specific non-scaling memory issue in PETSc restricted the SN2ND modeling (VHTR and PWR could not be solved). All of the calculations performed this year indicate that significant computational resources beyond those available today are required to obtain a high fidelity solution possible with SN2ND.The future goals for SN2ND are to get th...

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“…Figure 6.4 shows the material configuration for all four loadings while Figure 6.5 shows some selected flux plots from the 70 group calculation of Loading 106. The specific details of each loading are detailed elsewhere [25,28] and are not reproduced here. It is noted that in the Loadings 106 and 132 shown in Figure 6 For each plot in Figure 6.5, the right hand picture displays the face of the movable matrix half as viewed in Figure 6.4 while the left hand picture shows the flux solution for the active core portion of the stationary side (everything inside of the blankets).…”

Section: Eigenvalue Results For the Homogenized Drawer Calculationsmentioning

confidence: 99%

FY2010 status report on advanced neutronics modeling and validation.

Smith¹,

Mohamed²,

Marin-Lafleche³

et al. 2011

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SUMMARYUNIC is the neutronics component of the massively parallel, multi-physics SHARP (Simulation for High-efficiency Advanced Reactor Prototyping) framework under development at Argonne National Laboratory. During this fiscal year, the SN2ND solver, MOCFE solver, and NODAL solver received significant development to meet the needs of the SHARP project. Additional follow-on analysis of the ZPR-6/6A from the previous year was performed in addition to new analysis of the ZPR-6/7 experiments where UNIC predictions of ZPR foil activation were made against experimentally measured values.The SN2ND solver was applied to a plate-by-plate model of ZPR-6/6A using 294,912 cores of BlueGene/P and 222,912 cores of XT5, the two largest open-science high performance computing machines. The calculations proved that the SN2ND solver could be applied to heterogeneous reactor modeling problems, but more solver development (e.g., multigrid preconditioner) and computing power are required before such calculations are routine. As a consequence, the SN2ND solver was revised to incorporate a new multigrid preconditioner concept in addition to removing the remaining inappropriate spherical harmonics related quantities left over from its beginning (i.e. PN2ND). At the time of this report, the new version of SN2ND has not been completed, and the follow on work for SN2ND will continue to focus on updating the preconditioner as outlined in this report.The MOCFE solver was rebuilt into UNIC in the previous year such that it obeyed the basic concepts of parallelism (scalable memory and communication). The MOCFE parallel algorithm was fully debugged this year and initial scalability tests on over 2048 processors were carried out such that the parallel algorithm could be assessed. That work indicated that a significant load imbalance in the coefficient matrix-vector application exists. A possible solution was formulated, but it has not been fully tested at the time of this report. Various setbacks caused by numerous ray tracing problems and a mistake in the implementation were unanticipated thus delaying progress on the MOCFE solver and the targeted development tasks for MOCFE were not completed this year.In addition to the high fidelity solvers SN2ND and MOCFE, some time was spent implementing the NODAL solver. NODAL is similar to an existing legacy tool, but employs parallelism for enhanced performance and a capability to map a heterogeneous geometry into the homogenized geometry. This solver would provide a path to improve upon the existing homogenization approaches used for fuel cycle analysis, transient analysis, and perturbation theory calculations. An appropriate preconditioner was identified for NODAL this year and the solver algorithm was partially completed in UNIC. To facilitate the validation tests of UNIC using the ZPR-6 critical experiments, the BuildZPRmodel tool was also updated and a mesh merging algorithm was created. In addition to the newly implemented "solution along a line" analysis capability, these tools proved crucial t...

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ZPR-6 assembly 7 high {sup 240}Pu core experiments : a fast reactor core with mixed (Pu,U)-oxide fuel and a centeral high{sup 240}Pu zone.

Cited by 9 publications

References 0 publications

Fast Reactor Physics and Computational Methods

Fast Reactor Physics and Computational Methods

FY2011 Status Report on SN2ND neutronics solver development.

FY2010 status report on advanced neutronics modeling and validation.

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