Calculation of the Nuclear Material Inventory in a Sealed Vault by 3D Radiation Mapping

2013 ◽  
Author(s):  
Ian Adsley ◽  
Yevgeniy Tur ◽  
Alexander Klepikov ◽  
David Wells
Keyword(s):  
Dose Rate ◽  
Nuclear Material ◽  
Source Distribution ◽  
Nuclear Materials ◽  
Manipulator Arm ◽  
Enriched Uranium ◽  
Rate Profile ◽  
Global Threat ◽  
The Uk

The paper relates to the determination of the amount of nuclear material contained in a closed, concrete lined vault at the Aktau fast breeder reactor in Kazakhstan. This material had been disposed into the vault after examination in an experimental hot cell directly above the vault. In order to comply with IAEA Safeguards requirements it was necessary to determine the total quantities of nuclear materials — enriched uranium and plutonium — that were held with Kazakhstan. Although it was possible to determine the inventory of all of the accessible nuclear material — the quantity remaining in the vault was unknown. As part of the Global Threat Reduction Programme the UK Government funded a project to determine the inventory of these nuclear materials in this vault. This involved drilling three penetrations through the concrete lined roof of the vault; this enabled the placement of lights and a camera into the vault through two penetrations; while the third penetration enabled a lightweight manipulator arm to be introduced into the vault. This was used to provide a detailed 3D mapping of the dose rate within the vault and it also enabled the collection of samples for radionuclide analysis. The deconvolution of the 3D dose rate profile within the vault enabled the determination of the gamma emitting source distribution on the floor and walls of the vault. The samples were analysed to determine the fingerprint of those radionuclides producing the gamma dose — namely 137Cs and 60Co — to the nuclear materials. The combination of the dose rate source terms on the surfaces of the vault and the fingerprint then enabled the quantities of nuclear materials to be determined. The project was a major success and enabled the Kazakhstan Government to comply with IAEA Safeguards requirements. It also enabled the UK DECC Ministry to develop a technology of national (and international) use. Finally the technology was well received by IAEA Safeguards as an acceptable methodology for future studies.

scholarly journals Nuclear Fuel Assay through analysis of Uranium L-shell by Hybrid L-edge/XRF Densitometer using a Surrogate Material

2018 ◽  
Vol 170 ◽  
pp. 07009
Author(s):  
Seunghoon Park ◽  
Sungyeop Joung ◽  
Jerry Park
Keyword(s):  
Radiation Effects ◽  
Nuclear Material ◽  
Minor Actinide ◽  
Nuclear Materials ◽  
Promising Candidate ◽  
X Ray ◽  
Liquid Nitrogen Cooling ◽  
Material Solution ◽  
X Ray Absorption

Assay of L-series of nuclear material solution is useful for determination of amount of nuclear materials and ratio of minor actinide in the materials. The hybrid system of energy dispersive X-ray absorption edge spectrometry, i.e. L-edge densitometry, and X-ray fluorescence spectrometry is one of the analysis methods. The hybrid L-edge/XRF densitometer can be a promising candidate for a portable and compact equipment due to advantage of using low energy X-ray beams without heavy shielding systems and liquid nitrogen cooling compared to hybrid K-edge/XRF densitometer. A prototype of the equipment was evaluated for feasibility of the nuclear material assay using a surrogate material (lead) to avoid radiation effects from nuclear materials. The uncertainty of L-edge and XRF characteristics of the sample material and volume effects was discussed in the article.

The Nuclear Fuel Services, Inc. Program to Support Disposition of Enriched Uranium-Bearing Materials

2007 ◽  
Author(s):  
Stephen M. Schutt ◽  
Norman P. Jacob
Keyword(s):  
Nuclear Fuel ◽  
Fuel Cycle ◽  
Nuclear Fuel Cycle ◽  
Nuclear Material ◽  
Nuclear Materials ◽  
Bearing Materials ◽  
Enriched Uranium

The disposition of surplus nuclear materials has become one of the most pressing issues of our time [1, 2]. Numerous agencies have invoked programs with the purpose of removing such materials from various international venues and dispositioning these materials in a manner that achieves non-proliferability. This paper describes the Nuclear Fuel Services, Inc (NFS) Nuclear Material Disposition Program, which to date has focused on a variety of Special Nuclear Material (SNM), in particular uranium of various enrichments. The major components of this program are discussed, with emphasis on recycle and return of material to the nuclear fuel cycle.

Determination of alpha dose rate profile at the HLW nuclear glass/water interface

2015 ◽  
Vol 462 ◽  
pp. 258-267 ◽  
Author(s):  
S. Mougnaud ◽  
M. Tribet ◽  
S. Rolland ◽  
J.-P. Renault ◽  
C. Jégou
Keyword(s):  
Dose Rate ◽  
Water Interface ◽  
Rate Profile

Determination of alpha dose rate profile at the UO2/water interface

2006 ◽  
Vol 932 ◽  
Author(s):  
A. Poulesquen ◽  
C. Jégou ◽  
S. Peuget
Keyword(s):  
Dose Rate ◽  
Average Energy ◽  
Spherical Geometry ◽  
Water Interface ◽  
Spherical Form ◽  
Alpha Emitters ◽  
Maximum Penetration Depth ◽  
Maximum Penetration ◽  
Rate Profile

ABSTRACTIn this paper, an evaluation of the alpha dose rate profile at the UO2/water interface is presented. The calculation is performed in spherical geometry by considering the position of alpha emitters in the material. Moreover it proceeds to an iterative way. The fuel matrix and water is divided in spherical layers of 0.1 μm of thickness. The alpha emitters have an average energy of 5.3 MeV corresponding to a maximum distance of 13.2 μm in UO2 matrix and 42 μm in water. The direction of emission and the energy deposition, described by the Bragg curve, in the nuclear fuel are also taken into account. It appears that the alpha dose rate strongly decreases towards the calculated maximum penetration depth in water namely 42 μm. The concentrations of oxidising and reducing species are largely higher at the UO2/water interface than in solution. This alpha dose profile is used as input file in a model coupling a radiolysis kinetic model and a diffusion model. This kind of calculation is particular suitable for HTR kernels which have a spherical form of few hundreds microns of diameters (200-500 μm).

DOE’s Stewardship of Government-Owned Uranium Materials

2002 ◽  
Author(s):  
J. Dale Jackson ◽  
Dale E. Donaldson
Keyword(s):  
The United States ◽  
Nuclear Material ◽  
Department Of Energy ◽  
Nuclear Materials ◽  
Oak Ridge ◽  
Shipping Containers ◽  
Governmental Institutions ◽  
Enriched Uranium ◽  
Management Functions ◽  
Effective Use

Beginning in the 1980’s, a significant number of Department of Energy facilities have been shut down and are in the decommissioning process. The shutdown of additional facilities is planned. In addition, during the past several decades, the Department of Energy has loaned nuclear material to a wide variety of private and governmental institutions for research and educational purposes. Subsequent changes in the Department’s priorities have reduced the need for nuclear materials to support the Department’s programs. Similarly, there has been a reduction in the need for borrowed nuclear materials by organizations and institutions using nuclear materials “on loan” from the Department. As a result, inventories of uranium material from the Department’s facilities and “on loan” must be removed and returned to the Department. This material is in the form of low enriched uranium (LEU), normal uranium (NU), and depleted uranium (DU) in various forms. This uranium material is located at over one hundred sites within the United States and overseas, including universities and laboratories. Much of this uranium is not needed to support national priorities and programs. The Department of Energy has assumed a stewardship role in managing nuclear materials throughout their life cycle, from acquisition to storage. Surplus uranium has created challenges for DOE in managing and storing the material as well as identifying opportunities for its further use. On behalf of the Department, the Oak Ridge Operations Office has been given the responsibility to implement the Department responsibilities in meeting these challenges and managing the Department’s uranium materials. To support this effort, the Office of Nuclear Fuel Security and Uranium Technology within the ORO complex coordinates uranium management functions across the Department of Energy. This coordination provides DOE with a number of important benefits, among which are: consolidated management and storage of uranium; improved security; a reduction of operating costs; effective use and reuse of DOT certified shipping containers; and accelerated site closure.

scholarly journals Nuclear Fuel Assay through analysis of Uranium L-shell by Hybrid L-edge/XRF Densitometer using a Surrogate Material

2018 ◽  
Vol 170 ◽  
pp. 08007
Author(s):  
Seunghoon Park ◽  
Sungyeop Joung ◽  
Jerry Park
Keyword(s):  
Radiation Effects ◽  
Nuclear Material ◽  
Minor Actinide ◽  
Nuclear Materials ◽  
Promising Candidate ◽  
X Ray ◽  
Liquid Nitrogen Cooling ◽  
Material Solution ◽  
X Ray Absorption

Assay of L-series of nuclear material solution is useful for determination of amount of nuclear materials and ratio of minor actinide in the materials. The hybrid system of energy dispersive X-ray absorption edge spectrometry, i.e. L-edge densitometry, and X-ray fluorescence spectrometry is one of the analysis methods. The hybrid L-edge/XRF densitometer can be a promising candidate for a portable and compact equipment due to advantage of using low energy X-ray beams without heavy shielding systems and liquid nitrogen cooling compared to hybrid K-edge/XRF densitometer. A prototype of the equipment was evaluated for feasibility ofthe nuclear material assay using a surrogate material (lead) to avoid radiation effects from nuclear materials. The uncertainty of L-edge and XRF characteristics of the sample material and volume effects was discussed in the article.

Thromboplastin Related Differences in the Determination of International Normalised Ratio: A Cause for Concern?

1994 ◽  
Vol 72 (03) ◽  
pp. 426-429 ◽  
Author(s):  
S Kitchen ◽  
I D Walker ◽  
T A L Woods ◽  
F E Preston
Keyword(s):  
Patient Management ◽  
External Quality Assessment ◽  
Oral Anticoagulant Therapy ◽  
Warfarin Dosage ◽  
External Quality ◽  
External Quality Assessment Scheme ◽  
International Normalised Ratio ◽  
The Uk ◽  
The Relationship

SummaryWhen the International Normalised Ratio (INR) is used for control of oral anticoagulant therapy the same result should be obtained irrespective of the laboratory reagent used. However, in the UK National External Quality Assessment Scheme (NEQAS) for Blood Coagulation INRs determined using different reagents have been significantly different.For 18 NEQAS samples Manchester Reagent (MR) was associated with significantly lower INRs than those obtained using Diagen Activated (DA, p = 0.0004) or Instrumentation Laboratory PT-Fib HS (IL, p = 0.0001). Mean INRs for this group were 3.15, 3.61, and 3.65 for MR, DA, and IL respectively. For 61 fresh samples from warfarin-ised patients with INRs of greater than 3.0 the relationship between thromboplastins in respect of INR was similar to that observed for NEQAS data. Thus INRs obtained with MR were significantly lower than with DA or IL (p <0.0001). Mean INRs for this group were 4.01, 4.40, and 4.59 for MR, DA, and IL respectively.We conclude that the differences between INRs measured with the thromboplastins studied here are sufficiently great to influence patient management through warfarin dosage schedules, particularly in the upper therapeutic range of INR. There is clearly a need to address the issues responsible for the observed discrepancies.

scholarly journals New Results on Radioactive Mixture Identification and Relative Count Contribution Estimation

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4155
Author(s):  
Bulent Ayhan ◽  
Chiman Kwan
Keyword(s):  
Deep Learning ◽  
Noise Source ◽  
Simulated Data ◽  
Nuclear Material ◽  
Machine Learning Algorithms ◽  
Detector Response ◽  
Nuclear Materials ◽  
Ratio Estimation ◽  
Analysis Software ◽  
Detector Distance

Detecting nuclear materials in mixtures is challenging due to low concentration, environmental factors, sensor noise, source-detector distance variations, and others. This paper presents new results on nuclear material identification and relative count contribution (also known as mixing ratio) estimation for mixtures of materials in which there are multiple isotopes present. Conventional and deep-learning-based machine learning algorithms were compared. Realistic simulated data using Gamma Detector Response and Analysis Software (GADRAS) were used in our comparative studies. It was observed that a deep learning approach is highly promising.

scholarly journals Effect of data quality on estimates of farm infectiousness trends in the UK 2001 foot-and-mouth disease epidemic

2006 ◽  
Vol 4 (13) ◽  
pp. 235-241 ◽  
Author(s):  
Nicholas J Savill ◽  
Darren J Shaw ◽  
Rob Deardon ◽  
Michael J Tildesley ◽  
Matthew J Keeling ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Data Quality ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Inaccurate Data ◽  
Foot And Mouth ◽  
The Uk ◽  
Parameter Values

Most of the mathematical models that were developed to study the UK 2001 foot-and-mouth disease epidemic assumed that the infectiousness of infected premises was constant over their infectious periods. However, there is some controversy over whether this assumption is appropriate. Uncertainty about which farm infected which in 2001 means that the only method to determine if there were trends in farm infectiousness is the fitting of mechanistic mathematical models to the epidemic data. The parameter values that are estimated using this technique, however, may be influenced by missing and inaccurate data. In particular to the UK 2001 epidemic, this includes unreported infectives, inaccurate farm infection dates and unknown farm latent periods. Here, we show that such data degradation prevents successful determination of trends in farm infectiousness.

scholarly journals An Experimental Demonstration of a Multi-element Flame Photometer: Determination of Salt Concentration in Soy Sauce

2015 ◽  
Vol 8 (1) ◽  
pp. 25 ◽  
Author(s):  
Hiu Tung Chu ◽  
Spencer E. Taylor
Keyword(s):  
Salt Content ◽  
Direct Analysis ◽  
Atomic Emission ◽  
Soy Sauce ◽  
Flame Photometry ◽  
Emission Spectrometry ◽  
Wide Range ◽  
Group 2 ◽  
The Uk

<p>The routine determination of some group 1 and group 2 metals is important because of their biological, physiological and industrial relevance. Flame atomic emission spectrometry, or flame photometry (FP), is well-suited to the determination of several alkali and alkaline earth metals which are easily ionized in a gas flame. Here, we consider the application of flame photometry as a simple but sensitive analytical method which is normally restricted to the determination of one element at a time. We have demonstrated the use of a new multi-element instrument for the simultaneous determination of four cations, namely Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup> and Ca<sup>2+</sup> in six different brands of soy sauce currently available in the UK. The Na<sup>+</sup> concentrations are compared with quoted nutrition values given on the product labels, and found to be in very good agreement for “low-salt” soy sauce, but some departures were noted in the higher salt products, the present results indicating higher salt content than the supplied data. Li<sup>+</sup> concentrations were below the detection limit (i.e., &lt;1 mg/L under the conditions used in this study). This demonstration study has shown multi-element flame photometry to be a straightforward means of analysing water-based products that could be more widely adopted for many different applications. Typical maximum concentrations for the direct analysis of aqueous solutions were found to be 50 mg/L (Li<sup>+</sup>), 200 mg/L (Na<sup>+</sup>, K<sup>+</sup>) and 1000 mg/L (Ca<sup>2+)</sup>. Although not the primary goal of this study, we noted some variance between the present results and values quoted on some of the products. This may relate to the use of indirect methods for estimating salt (sodium) concentrations. The use of flame photometry, however, would provide a rapid measurement of important cations in a wide range of applications.</p>

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