IN REACTOR PHYSICS ANALYSIS

Transcription

1 BARILOCHE, ARGENTINA HUMAN RESOURCES TRAINING AND QUALIFICATION IN REACTOR PHYSICS ANALYSIS By: Eduardo Villarino / men@invap.com.ar Nuclear Engineering Department / Nuclear Projects Division

2 Introduction Contents Design Methodology Calculation Line & Uncertainties User Dependencies Conclusions ISMTR-6 Oct S.C de Bariloche

3 Introduction INVAP designs and builds research reactors with very demanding requirements. Each new reactor needs increasingly detailed analysis. Better prediction capabilities are needed to reduce the design margins due to the numerical and engineering uncertainties. This detailed analysis must be performed with a consistent level of detail from all the engineering variables. The analysts play key role in the development of accurate models, which are used to simulate the system. ISMTR-6 Oct S.C de Bariloche 2

4 Introduction Flux/Production Levels Facilities with minimum values Facilities with a flux range Spectra Cold Neutrons Thermal neutrons Hot Neutrons Fast Neutrons Flux Homogeneity Within W a facility ISMTR-6 Oct S.C de Bariloche Axial and radial 3 Perturbation Operation Target movement Operational Requirements Fixed Cycle Minimum Burnup Xe Build-Up. (Restart Capability) Beams Transport Reactor eco Pool Neutron Beam

5 Introduction The variables needed in reactor physics analysis depend on the interaction of the neutron with the matter. The properties of the matter: XS and eng. data. Eng. data depends on operational conditions. XS depends on eng. data: crystal and molecular structure of the materials, temperature, etc. The neutron distribution is solved with different methods & tools. Models describing the system to be analyzed has approximations and they are defined with a given user or analyst criteria. ISMTR-6 Oct S.C de Bariloche 4

6 Design Methodology ISMTR-6 Oct S.C de Bariloche

7 Design Methodology ISMTR-6 Oct S.C de Bariloche 6

8 Design Methodology Safety as Priority ISMTR-6 Oct S.C de Bariloche 7

9 Design Methodology Custom Designed Reactor ISMTR-6 Oct S.C de Bariloche 8

10 Design Methodology Qualified Methods, Tools & Procedures ISMTR-6 Oct S.C de Bariloche 9

11 Design Methodology Well Trained Nuclear Analyst ISMTR-6 Oct S.C de Bariloche 10

12 Design Methodology Reactor Models ISMTR-6 Oct S.C de Bariloche 11

13 Calculation Line ISMTR-6 Oct S.C de Bariloche

14 Calculation Line New innovative methods improve the analysis of the calculated systems. Un-experienced user: Ventures in the design of a new model design. Performs calculations without a solid understanding of the system under calculation. Makes very detailed geometrical model without the proper temperatures information or without the impurities of the materials. ISMTR-6 Oct S.C de Bariloche 13

15 Calculation Line NJOY ENDF ESINLM XS Library CONDOR ARCANE OUTPUT CONDOR HXS PARCS HGEO Eng. Data Cell Data Core Data NDDUMP MCNP HGEO INVAP CODE INVAP Utility PUMA CITVAP CITVAP Storm V2.0 DB & Procedures Code Graphic Utilities OUTPUT ISMTR-6 Oct S.C de Bariloche 14

16 Calculation Uncertainties Nuclear data: The nuclear data is continuously improved by the international community (ENDF/B, JENDL, JEFF, etc). We still have high level of uncertainties of ~500 pcm. Engineering data: No practical way to eliminate the eng. data uncertainties. Tolerances need to be in agreement with the design uncertainties. This is an important parameter to be evaluated in order to achieve a solid understanding of the reactor design. ISMTR-6 Oct S.C de Bariloche 15

17 Calculation Uncertainties Calculation Codes: The validation of the codes is a continuous process and it is normally carried out by the code developer and the users. It is good practice to use the design calculation tools in a wide range of different reactor designs to acquire confidence in the calculated parameter. Calculation Models: The accuracy of the models depends on the specific analyst, and currently the only way to measure his/her capability to model different systems with acceptable level of accuracy is his/her experience or engineering judgment. ISMTR-6 Oct S.C de Bariloche 16

18 User Dependencies ISMTR-6 Oct S.C de Bariloche

19 Principles( People are fallible, and even the best make mistakes. Error-likely situations are predictable, manageable, and preventable. Individual behavior is influenced by organizational processes and values. People achieve high levels of performance based largely on the encouragement and reinforcement received from leaders, peers, and subordinates. Events can be avoided by understanding the reasons mistakes occur and applying the lessons learned from past events. ISMTR-6 Oct S.C de Bariloche 18

20 Mitigating user dependency Specific practices & procedures to verify the proper utilization of the tools. Training to become familiar with the computational tools. Will to cross-check between analyst s works, formally and informally Every model developed will serve a future purpose and will bereviewed by another analyst. Inquisitive attitude to pursue small differences or issues. Any unexpected difference observed between models or results when using different tools are clearly understood. ISMTR-6 Oct S.C de Bariloche 19

21 Training Formal acquisition of the knowledge: universities, internal training courses, or international training courses. Self-training: i as a natural response of his/her inquisitivei iti nature. Teaching: internal training courses, assistant or professors. Technical advisors: In thesis (Engineering, Magister and PhD degree). Become familiar with the computational tools (capabilities and limitations): it ti Performing calculation of different reactors. NPP, RR Using different methods: Different computational tools. ISMTR-6 Oct S.C de Bariloche 20

22 Review Process Different procedures for different review process: Documentation: Any parameter are properly documented in a report, which is issued by the analysts and reviewed at least by the reactor physics project leader. Model preparation: The input, auxiliary and output files are stored in afoldertogether with its table of contents explaining the purpose of each file. In complex or more sensitive models, these files are reviewed by another analyst that verifies the proper modeling of the system. Specific design parameters: In complex reactor designs, there are additional levels of verification in an integrated view with the rest of the project. ISMTR-6 Oct S.C de Bariloche 21

23 Document Review Process Issued: Responsible for the veracity, accuracy, and significance, as to the resulting effects, of all information contained and transmitted in the document. Reviewed: Indirectly responsible, they manifest that nothing as to content t of the document contradicts t their experience. Approved: Not responsible for the content of the document. Responsible for certifying that the content of a document is coherent with all other project documentation. In interdisciplinary and complex projects the PDR (preliminary design review) and CDR (critical design review) meetings are used for the verification of the analysis of the work carried out. ISMTR-6 Oct S.C de Bariloche 22

24 Projects 23

25 Integration Integrate design, calculation and documentation information. One set of databases per project: Design Criteria: Safety and User Requirements. Verification Procedures. Tools (specific version of codes and libraries). Engineering Data (geometries, materials, operating states) Engineering, cell and core models ISMTR-6 Oct S.C de Bariloche 24

26 Integration Reduce errors Data, Interfaces, Calculation l Methodology. Facilitate the revision Generate knowledge Different user level/responsibilities Share between the different analyst and reviewers using the same set of tools, data, procedures and documentation ISMTR-6 Oct S.C de Bariloche 25

27 Preparing data for review The analyst is responsible to move the Input, Output and any auxiliary files (spreadsheets, (p auxiliary programs, etc) for revision. A Table Of Contents is required with the following information: Filename. File type. CRC file information (To verify the integrity of the file). A short description of the purpose p of the file. Unneeded files are a future problem. This process is done with an automatic script doing additional contextual checks. ISMTR-6 Oct S.C de Bariloche 26

28 Reviewing Another analysts review the I/O files. Perform the following activities: Review the input files checking for proper modeling. Verify the objective and scope of the calculated parameters. Verify the input (engineering) data was properly used. Check the output files and their agreement with the documented data. Cross check outputs with different tools (Output pos- processor or Arcane program). Fill the review document with the recommendations or changes needed to be done. ISMTR-6 Oct S.C de Bariloche 27

29 Verification Review Process Level of verification Different options. Important t parameters are calculated l It can be the same or different by INVAP personnel using different INVAP personnel. calculation lines. Different group, normally non INVAP staff, perform calculation using the INVAP calculation l codes. Different group, normally costumer staff, perform calculation using different codes. Customer staff performing on the job training. Subcontractors performing calculations. ARN perform independent analysis. Customer staff using their own calculation line. Subcontractors performing totally independent analysis. 28

30 Conclusions INVAP s methodologies were developed to mitigate the analyst dependence in the development of accurate models. Basically these methodologies are divided in training and utilization of procedures for themodel preparation. The training is carried out not only during the formal acquisition of the knowledge (Theories and utilization of computational codes), but also promoting academic activities and certain specific attitudes based on fomenting the inquisitive nature of the personnel. ISMTR-6 Oct S.C de Bariloche 29

31 Conclusions The procedures used for documentation, input and output handling and calculated parameter allow to the sharing of knowledge, databases and models between the analysts of a project, or different projects, giving to the analysts a solid understanding di of the reactor design. The main aspects discussed in this paper can be extended to other engineering areas of nuclear reactor design. ISMTR-6 Oct S.C de Bariloche 30

32 Thank you for your attention Questions?