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[en] Introduction: Increase the initial enrichment of nuclear fuel result in possible reduce the fuel cycle cost due to lengthening the reactor campaign from 12 to 18 or even 24 months, or due to reduction of fuel batch every year 1/3, 1/4 or 1/5 part of the core Currently, the initial enrichment of fuel is steadily approaching the mark of 5% and average burnup has already exceeded the level of 50 MWd/tU Now an objective of the transition of initial enrichment to the range of 5 -10% and the burn up to 100 MWd/tU becomes on the agenda.
[en] Highlights: • A short description of nuclear fuel behaviour and its modelling in a fuel performance code. • A list of uncertainty sources in fuel behaviour modelling area. • Some examples of uncertainty quantification in modelling. • Some requirements for a generalization of uncertainty quantification in the future. - Abstract: Fuel performance codes describe the physical phenomena occurring in fuel during its irradiation in steady-state and transient conditions. In this paper, the principles of the modelling of nuclear fuel behaviour are presented. Many reasons show that it is also important to consider uncertainties in the fuel modelling process. It can be experimental reasons (validation database and material properties determination), uncertainties in the modelling process itself (lack of knowledge for example). This paper also presents several applications of uncertainty quantification and sensitivity analysis applied to fuel behaviour modelling. The first example is about the validation process of the fuel performance code, which results in a quantification of the uncertainty of the calculated quantities. The second application is about the use of the code in safety analysis to determine probabilities of failure considering epistemic and random uncertainties. In the last application, we show how important it is to quantify modelling uncertainties in the calibration process of complex physical models.
[en] Neutron absorption resonance spectroscopy (NRS) is a unique tool with various potential applications that could play an important role in advanced nuclear fuel characterization by providing advanced characterization techniques.
[en] Physical security in nuclear fuel cycle facility means detection, prevention and response to threat, theft, sabotage, unauthorized access and illegal transfer involving radioactive and nuclear material. This paper proposes a physical security system designing concepts to reduce the risk associated with variant threats to nuclear fuel cycle facility. So, we will study the unauthorized removal and sabotage in a hypothetical nuclear fuel cycle facility considering deter, delay and response layers. Also, we will perform any required upgrading to the security system by investigating the nuclear fuel cycle facility layout and considering all physical security layers design to enhance the weakness for risk reduction. (author)
[en] Any State’s ability to carry out an indigenous, proliferation programme is directly related to its industrial and technological capabilities. Open source trade statistics can provide valuable insights into the global trade flows of nuclear-related equipment and materials, and the underlying industrial capabilities of States as possible users or manufacturers of such goods. It is postulated that monitoring of trade data for non-controlled items can be useful in better understanding a State’s potential to undertake nuclear fuel cycle related activities. The paper describes the logic for the selection of a groups of products that require similar industrial and technological capabilities to those required for the different stages of the nuclear fuel cycle on the basis of the international nomenclature for the categorization of trade. (author)
[en] Challenges for safeguarding a geological repository of spent nuclear fuel pose many high-level opportunities. First, being a relative late-comer among the various types of nuclear facilities subject to safeguards, the geological repository is an ideal candidate for applying ―safeguards by design‖ (SBD). Second, a repository is unlike all other nuclear facilities such that containment and surveillance (C/S) arguably should constitute the primary safeguards approach, rather than material accountancy. Several states have already invested many years and resources toward implementing final disposal of spent nuclear fuel in a geological repository. We consider the unfolding safeguards consideration of geological repositories from the perspectives of SBD, safety, security and safeguards (3S), and C/S. In this paper, a proposed approach for efficient implementation of Safeguards-by-Design (SBD) early into the design process of repository of spent nuclear fuel is proposed. The proposed approach describes the involved parties, their roles and responsibilities, ways of coordination and collaboration as well as main areas to be considered. International best practices in this regards are also presented and discussed. (author)
[en] Highlights: • Proximity to spent nuclear fuel has no discernible residential property value impact. • 1% point property tax increase associated with 4.31% decrease in home price. • Evidence of positive impact of nuclear sites on property values via tax payments. - Abstract: This paper examines potential property value impacts when a nuclear power plant closes and spent fuel remains on site. We confirm earlier research that fails to find an impact on property values of proximity to a nuclear power site. Another contribution of this paper is our finding that a one percentage point increase in property taxes is associated with a 4.31% decrease in the sale price of a home. These results provide evidence for a positive impact of operating nuclear facilities on surrounding communities in the form of reduced residential property taxes for a given level of public expenditures.
[en] Through the statistical data of the nuclear material that it had been used in the project, the date of Material Unaccounted For (MUF) is calculated, then it is used to calculate the standard deviation (σMUF) and relative standard deviation (δMUF) by the method of MUF evaluation. The one of results showed that the date of MUF is less than the double σMUF, it accounts for that the confidence coefficient of MUF is more than 95%, it conforms with the standard of the national laws and regulations; but another showed the date of δMUF is more than 0.3%, it did not meet the requirements of evaluation standards. The possible reasons were discussed in this article, it is suggested to establish and improve the system retention measurement method, select appropriate measurement method, analysis method and sampling method to improve the nuclear material balance work. (authors)
[en] 45 years since it was first conceived and after reprocessing over 9,300 tonnes of fuel, THORP sheared its last fuel assembly on 9th November 2018. Providing a vital service to UK, European and international reactor operations, the facility will continue to store fuel for at least the next 50 years. This presentation will look back at some of the history, the economics and lessons learnt more than 24 years of successful operation and forward to a new future for the staff and facility. (author)