MUF Calculation of Indonesian 10-MWt RDE Experimental HTGR Using Combined Uncertainty Approach

A safeguards assessment for the 10-MWt RDE Experimental HTGR needs to be established in order to fulfill the requirements needed to construct it. Methods and instruments used for the RDE’s nuclear material accounting and safeguards system are reviewed in this paper. Material unaccounted for (MUF) is calculated using the uncertainty of each method and instrument. The effectiveness of the safeguards system is examined by comparing the resulting MUF with the number of SQ ( = significant quantity, i.e. the approximate amount of nuclear material for which the possibility of manufacturing of a nuclear explosive device cannot be excluded). The total uncertainty from each KMP showed a number less than 10%. The number of MUF in each KMP according to total uncertainty showed a number below 1 kg of U-235 in one inventory period (~12 months). According to the number of MUF counted, it is impossible to reach 1 SQ if the diversion done is only by taking the advantage of MUF in the measurement. The result of total uncertainty and MUF calculation showed that the safeguards system and the material measurement designed for RDE is amendable. The sets of instruments and measurements designed will give a comprehensive data of each nuclear material in the RDE. The low number of MUF in comparison with the SQ showed that the RDE has a high proliferation resistance.

Information system for nuclear material accounting and control

A brief description of information system for nuclear material accounting developed for the national regulator in the field of nuclear and radiation safety - the Department for Nuclear and Radiation Safety of the Ministry of Emergency Situations of the Republic of Belarus (Gosatomnadzor) is given. The information system is a part of the Intellectual information system of a Gosatomnadzor employee to ensure control (supervision) in the field of nuclear and radiation safety. It is developed on the basis of free software. The system has been implemented in Gosatomnadzor and at present in the Republic of Belarus all nuclear material accounting with reporting to the IAEA is carried out with its help. The system, in full compliance with the IAEA requirements, provides automatic generation with all the necessary calculations based on the input data of the following reporting documents: physical inventory listing, inventory change report, material balance report, textual report, General Ledger. All reports are fully consistent each with other. An efficient mechanism has been developed for importing and exporting data from / to the system according to formats of fixed and labelled Code 10 required by the IAEA. All logs of the system describing reports contain a field “IAEA approved” (yes / no). If it set to “yes”, they are closed for editing and correction. A special tool has been developed for making adjustments to these documents in accordance with the IAEA rules. The system contains fully completed reference books (small journals referenced by all major journals in the database) with the necessary reference data in accordance with Code 10. The information system meets all the IAEA requirements for such systems of national regulators in the field of accounting, control and supervision of nuclear material. It can be easily translated into other languages and adapted for the needs of accounting and control of nuclear material in operating organizations.

Interactions of Cd2+, Co2+ and MoO42− Ions with Crushed Concrete Fines

Construction and demolition activities generate approximately two thirds of the world’s waste, with concrete-based demolition material accounting for the largest proportion. Primary aggregates are recovered and reused, although the cement-rich fine fraction is underutilised. In this study, single metal batch sorption experiments confirmed that crushed concrete fines (CCF) are an effective sorbent for the maximum exclusion of 45.2 mg g−1 Cd2+, 38.4 mg g−1 Co2+ and 56.0 mg g−1 MoO42− ions from aqueous media. The principal mechanisms of sorption were determined, by scanning electron microscopy of the metal-laden CCF, to be co-precipitation with Ca2+ ions released from the cement to form solubility limiting phases. The removal of Co2+ and MoO42− ions followed a zero-order reaction and that of Cd2+ was best described by a pseudo-second-order model. The Langmuir model provided the most appropriate description of the steady state immobilisation of Cd2+ and Co2+, whereas the removal of MoO42− conformed to the Freundlich isotherm. Long equilibration times (>120 h), loose floc formation and high pH are likely to limit the use of CCF in many conventional wastewater treatment applications; although, these properties could be usefully exploited in reactive barriers for the management of contaminated soils, sediments and groundwater.

Student Preference for Spreadsheet-Based Learning

Spreadsheets can be used as a learning tool to explore abstract concepts in quantitative-based disciplines such as accounting and finance. Given the rapid adoption of technology in the classroom, understanding how students perceive the use of spreadsheets in quantitative-based courses is imperative. This study examines how students perceive the use of spreadsheets in applied business courses. Student preference is viewed in terms of enhanced learning of course content, usage in class lectures, increased motivation, and presentation of material. Accounting and finance students attending an institute of higher education based in the Northeastern United States were surveyed. Results from this study using a Kolmogorov-Smirnov test indicate a preference among students for the use of spreadsheets as a teaching aid in classrooms.

Convergence consensus analyst earnings estimates and option pricing in modeling material accounting misstatements

Purpose The purpose of this paper is to introduce analyst estimates and option pricing-based variables in modeling material accounting misstatements. Design/methodology/approach The paper uses a logistic regression model to analyze a comprehensive sample of AAER and non-AAER firms listed in the USA. Findings By applying a cross-sectional, sequence of time-series logistic regression models, the authors find better identifiers of ex ante risk of fraud than prediction models based on an inspection of abnormal accruals. These identifiers include the managed earnings (ME) component of a firm and the change in a firm’s option contracts’ implied volatility (IV) prior to an earnings announcement. Practical implications The empirical findings contribute to an understanding of earnings manipulation (fraud) and should be of value to auditors and regulatory bodies interested in identifying financial statement fraud, particularly the Securities and Exchange Commission, which has been improving its accounting quality model (AQM or Robocop) fraud detection tool for many years. The results contribute substantially to enhancing the current accounting literature by introducing two non-accrual-based measures that significantly enhance the predictive power of an accrual-based accounting misstatement prediction model. Originality/value This paper radically departs from relying on the assumption that the clearest and easiest pathway to detect fraud reporting ex ante is through an examination of accruals. Instead, the authors use a richer source of information about the possibility of a firm’s misstatement of its financial accounting numbers, namely, analyst estimates of ex post earnings and the IV from exchange-traded option contracts.

Development of PYMUS+ Code for Quantitative Evaluation of Nuclear Material Accounting (NMA) System

The Nuclear Material Accounting (NMA) system is one of the main safeguards measures to detect the existence of nuclear material diversion. It has become more important for large reprocessing facilities to apply Near Real Time Accountancy (NRTA) system based on NMA and statistical techniques to meet quantitative and timeliness goals. It is also important to quantitatively evaluate the performance of NMA system including NRTA from the standpoints of Safeguards and Security by Design (SSBD) prior to construction of nuclear-material-handling facilities. Such evaluation improves safeguards effectiveness and efficiency. Modeling and Simulation (M&S) work is a good way to evaluate performance for various NMA systems and to determine the optimal one among different options. For these purposes, in the present study, the PYroprocessing Material flow and MUF Uncertainty Simulation+ (PYMUS+) code, which uses evaluation algorithms to calculate many safeguards factors such as MUF uncertainty, detection probability, and others, was developed. According to a previous report, the PYMUS code, the predecessor of PYMUS+, can calculate MUF uncertainties only for a fixed model having 10 tHM/year, whereas the PYMUS+ code can additionally calculate detection probabilities according to diverse nuclear diversion scenarios as well as MUF uncertainties. The most important feature of the PYMUS+ code is its capability to evaluate many process and NMA system model options that a user wants to evaluate. Furthermore, a user can make a static process model having simplicity and a matching NMA model based on the PYMUS+ code regardless of facility throughput and is not even required to have professional programming knowledge. In the present work, some intercomparative studies were conducted to verify the M&S techniques applied in this code. It is expected that this code will be a useful tool for evaluation of NRTA system of pyroprocessing and other reprocessing facilities.