Epokhé: Un espace de travail

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Modeling of UF6 Enrichment with Gas Centrifuges for Nuclear Safeguards Activities

The physical modeling of uranium isotopes (235U, 238U) separation process by centrifugation of is a key aspect for predicting the nuclear fuel enrichment plant performances under surveillance by the Nuclear Safeguards Authorities. In this paper are illustrated some aspects of the modeling of fast centrifuges for UF6 gas enrichment and of a typical cascade enrichment plant with the Theoretical Centrifuge and Cascade Simulator (TCCS). The background theory for reproducing the flow field characteristics of a centrifuge is derived from the work of Cohen [1] where the separation parameters are calculated using the solution of a differential enrichment equation. In our case we chose to solve the hydrodynamic equations for the motion of a compressible fluid in a centrifugal field using the Berman – Olander vertical velocity radial distribution [2] and the solution was obtained using the Matlab software tool [3]. The importance of a correct estimation of the centrifuge separation parameters at different flow regimes, lies in the possibility to estimate in a reliable way the U enrichment plant performances, once the separation external parameters are set (feed flow rate and feed, product and tails assays)[4]. Using the separation parameters of a single centrifuge allow to determine the performances of an entire cascade and, for this purpose; the software Simulink [3] was used. The outputs of the calculation are the concentrations (assays) and the flow rates of the enriched (product) and depleted (tails) gas mixture. These models represent a valid additional tool, in order to verify the compliance of the U enrichment plant operator declarations with the “on site” inspectors’ measurements.JRC.E.8-Nuclear securit

Nuclear Material Monitoring for the Reprocessing Plant RT-1 at Mayak

To enhance and modernise the Nuclear Material Accountancy and Control (NMAC) at Mayak RT-1 reprocessing plant the concept of near real time accountancy (NRTA) is applied. A defence in depth concept is proposed with the superposition of the following barriers: (i) continuous survey of the functional status, (ii) the follow-up of the nuclear material (NM) flow and inventory, (iii) Near real time control of declared NM in processed solutions, (iv) Periodical Physical Inventory Takings and Verifications. The combination of an operational network architecture, allowing automatic data acquisition and an efficient plant-specific data analysis and interpretation software enables to follow in near real-time the NM flow and inventory through the plant. The JRC data analysis and interpretation kernel DAI integrated with the commercial data historian Wizcon is proposed to establish the RT-1 specific NM monitoring software tool. The data analysis focuses firstly on a combination of the pressure signals (for level and density) and the temperature signal, determining the total volume. This is then combined with the volume concentration measurement performed by the hybrid K-edge to derive the total mass of nuclear material. Once the complete system is validated, it can be applied also to other Russian reprocessing plants at Seversk and Zheleznogorsk.JRC.G.8-Nuclear safeguard

Load cell monitoring in Gas Centrifuge Enrichment Plants: potentialities for improved safeguards verifications

This paper describes the principle of load cell monitoring in Gas Centrifuge Enrichment Plants (GCEP) and how this technique can be implemented in order to improve nuclear safeguards in this kind of installations. We present a few different possibilities of exploitation of the data that can be obtained by acquiring in continuous mode the weights of the cylinders in the feed and withdrawal (F/W) stations and how to derive conclusions concerning the operation of the plant (conformity or not with respect to ¿normal¿ operation). Finally the different diversion scenarios for GCEP are discussed and we show how mass monitoring techniques can contribute to detect each of them.JRC.DG.E.9-Nuclear security (Ispra

The JRC Advanced Safeguards Measurement, Monitoring and Modelling Laboratory

The innovative aspect of the Advanced Safeguards Measurement, Monitoring and Modelling Laboratory, AS3ML, subject of this paper, is that it aims to complement the classical approach of implementing nuclear safeguards by providing an innovative method to monitor the process of sensitive facilities such as Gas Centrifuge Enrichment and Nuclear Fuel Reprocessing plants and/or deploy innovative / smart sensors and technologies. AS3ML endeavors to enhance the “traditional safeguards measures” by the focus on and analysis of (other) process parameters, that may be used to understand & monitor better the whole plant. Some of new technologies investigated include: Indoor localization (RFID, UWB, Laser positioning), 2D/3D Camera, ID (OCR) of cans, Investigative Inspector, pulse shape generator to simulate Gamma and Neutron detectors The AS3ML is conceived as an R&D location, test bed, demo facility and training centre for innovative safeguards approaches where researchers, inspectors (and operators) can conceive and analyse different approaches (including competing technologies) for safeguarding nuclear facilities. The paper will describe techniques and approaches, not currently used in routine safeguards applications, including some recent return of experience on deploying AS3ML based approaches for a new way of safeguarding a plutonium storage location and an enrichment facility.JRC.G.II-Nuclear Security and Safeguards Department (Ispra

Recent HKED Instrumentations for Analytical Measurements in Conventional and Advanced Nuclear Fuel Reprocessing

Two Hybrid K-edge Densitometers (HKED¿s) recently designed at ITU for different applications are presented and described. One of them, designated for installation in the RT-1 reprocessing plant of Mayak, Russia, follows the well-known route of standard HKED applications, i.e. the analysis of process samples from Purex type reprocessing. The second HKED is embedded into a more enlarged non-destructive assay (NDA) station including an additional neutron coincidence counter and a highresolution gamma spectrometer for the analysis of minor actinides in process samples originating from pyro-reprocessing test facilities at ITU. In addition, the paper also provides an evaluation of new HKED analysis software recently developed at the Los Alamos National Laboratory.JRC.E.8-Nuclear safeguards and Securit

Advanced Safeguards Measurement, Monitoring and Modelling Laboratory (AS3ML)

Safeguarding declared nuclear facilities is a main duty of the nuclear safeguards inspectorates. Depending upon the amounts of nuclear materials present (and physical/chemical form), a certain inspection approach (and corresponding dedicated techniques and equipment) is developed. This approach will be very different for an item facility compared to a bulk-material handling process, whereby in each case we strive to a maximum efficiency and effectiveness of the safeguards system. Traditionally these safeguards measurements are executed with independent, safeguards approved, measurement equipment, complementary to the existing plant equipment and focusing on a variety of nuclear material diversion scenarios (and statistical considerations) The innovative aspect of the Advanced Safeguards Measurement, Monitoring and Modelling Laboratory, AS3ML, subject of this paper, is that it aims to complement the above approach by providing an alternative method to monitor the process of sensitive facilities such as Gas Centrifuge Enrichment and Nuclear Fuel Reprocessing plants. It endeavours thus to enhance the “traditional safeguards measures” by the focus on and analysis of (other) process parameters, which a priority each individually might not have a highly significant value, but which, taken all together, might allow to get a very good insight in the proper operation (thrust building measures) or alternatively to the deviations from the “theoretical” values of the behaviour of a facility. The AS3ML is thus conceived as an R&D location, test bed, demo facility and training centre for innovative safeguards approaches where researchers, inspectors (and operators) can conceive and analyse different approaches (including competing technologies) for safeguarding nuclear facilities. Techniques and approaches, not currently used in routine safeguards applications, will be discussed including a reference to a recent achievement for a fully new way of safeguarding a plutonium storage location which is presented elsewhere in this symposium.JRC.E.8-Nuclear securit

Il Security Training Centre del JRC di Ispra

Paper corresponding to a presentation given to a workshop organised by AIRP (Italian Association of Radiation Protection) and to be published on the Bulletin of the organisation.JRC.E.8-Nuclear securit

Development and Functionalities of a Software Tool to Perform the Monitoring for Safeguards Activities of Gas Centrifuge Enrichment Plants Making Use of Load Cell, Accountancy Scale and on-line Mass Spectrometer Plant Data

Safeguards verification of the flow and inventory of nuclear material at large scale Gas Centrifuge Enrichment Plants remains challenging because of the size of the facilities and because continuity of knowledge is not maintained on nuclear material over the process. Verifying the absence of facility misuse and undeclared production is also a challenge. Data analysis and evaluation has been experimented and demonstrated as a powerful tool to improve safeguards at the George Besse II GCEP in France where a data sharing system has been installed by the European Commission. This paper focuses on the data analysis and describes the functionalities of the “Inspector Studio GBII” application, which was developed by the Nuclear Security unit of the Joint Research Centre under the auspices of a joint support task France-European Commission to the International Atomic Energy Agency (IAEA). Acquisition of data from the process load cells, accountancy scales and on-line mass spectrometers is briefly reported including IT security concerns. Then the paper describes the application features aiming at verifying integrity of the data and producing evaluation reports in support of the verification of nuclear material flows and the physical inventory. Specific modules are designed to support Interim Inventory Verifications and perform calculations of the nuclear material flows, the UF6 mass balance over a selected time period making use of the load cell data and the accountancy weights resulting in a consistency check of the shared data. Masses of nuclear material directly comparable to operator declarations are independently calculated for each automatically identified cylinder. Other modules compute the uranium enrichment on the basis of the mass flow distribution in the process. Curves representing the different flow rate ratios are available to confirm that the plant has been operated as declared. “Inspector Studio GBII” is used by DG ENER and the IAEA during the plant Physical Inventory Verification and results in reducing the burden to the operator. The toolbox in support of the flow verification is in the validation stage but has already been demonstrated as a credible option for improving the effectiveness of the verification while potentially reducing the associated inspection workload.JRC.G.II.7-Nuclear securit

The Safeguards On-Site Laboratory at La Hague June 2000 - June 2005 - Experience over Five Years of Operation

see attachmentJRC.E.5-Nuclear chemistr