High Efficiency Gamma-Beta Blind Alpha Spectrometry for Nuclear Energy Applications

2014 ◽  
Author(s):  
Jeffrey A. Webster ◽  
Alexander Hagen ◽  
Brian C. Archambault ◽  
Nicholas Hume ◽  
Rusi Taleyarkhan
Keyword(s):  
Nuclear Energy ◽  
Nuclear Reactor ◽  
High Efficiency ◽  
Detection Efficiency ◽  
Power Level ◽  
Bubble Chamber ◽  
Alpha Decay ◽  
Sensor Technology ◽  
Spent Fuel ◽  
Selective Sensitivity

A novel, Centrifugally Tensioned Metastable Fluid Detector (CTMFD) sensor technology has been developed over the last decade to demonstrate high selective sensitivity and detection efficiency to various forms of radiation for wide-ranging conditions (e.g., power level, safeguards, security, and health physics) relevant to the nuclear energy industry. The CTMFD operates by tensioning a liquid with centrifugal force to weaken the bonds in the liquid to the point whereby even a femto-scale nuclear particle interactions can break the fluid and cause a detectable vaporization cascade. The operating principle has only peripheral similarity to the superheated bubble chamber based superheated droplet detectors (SDDs); instead, CTMFDs utilize mechanical “tension pressure” instead of thermal superheat offering a lot of practical advantages. CTMFDs have been used to detect a variety of alpha and neutron emitting sources in near real-time. The CTMFD is selectively blind to gamma photons and betas allowing for detection of alphas and neutrons in extreme gamma/beta background environments such as spent fuel reprocessing plants or under full power conditions within an operating nuclear reactor itself. The selective sensitivity allows for differentiation between alpha emitters including the isotopes of Plutonium. Mixtures of Plutonium isotopes have been measured in ratios of 1:1, 2:1, and 3:1 Pu-238:Pu-239 with successful differentiation. Due to the lack of gamma-beta background interference, the CTMFD’s LLD can be effectively reduced to zero and hence, is inherently more sensitive than scintillation based alpha spectrometers or SDDs and has been proven capable to detect below femtogram quantities of Plutonium-238. Plutonium is also easily distinguishable from Neptunium making it easy to measure the Plutonium concentration in the NPEX stream of a UREX reprocessing facility. The CTMFD has been calibrated for alphas from Americium (5.5 MeV) and Curium (∼6 MeV) as well. The CTMFD has furthermore, recently also been used to detect spontaneous and induced fission events which can be differentiated from alpha decay allowing for detection of fissionable material in a mixture of isotopes. This paper discusses these transformational developments which are also being entered for real-world commercial use.

High-Efficiency Gamma-Beta Blind Alpha Spectrometry for Nuclear Energy Applications

2015 ◽  
Vol 1 (3) ◽  
Author(s):  
Jeffrey A. Webster ◽  
Alexander Hagen ◽  
Brian C. Archambault ◽  
Nicholas Hume ◽  
Rusi Taleyarkhan
Keyword(s):  
Nuclear Energy ◽  
High Efficiency ◽  
Detection Efficiency ◽  
Bubble Chamber ◽  
Alpha Decay ◽  
Sensor Technology ◽  
Spent Fuel ◽  
Energy Applications ◽  
Nuclear Particle ◽  
Selective Sensitivity

A novel, centrifugally tensioned metastable fluid detector (CTMFD) sensor technology has been developed over the last decade to demonstrate high selective sensitivity and detection efficiency to various forms of radiation for wide-ranging conditions (e.g., power, safeguards, security, and health physics) relevant to the nuclear energy industry. The CTMFD operates by tensioning a liquid with centrifugal force to weaken the bonds in the liquid to the point whereby even femtoscale nuclear particle interactions can break the fluid and cause a detectable vaporization cascade. The operating principle has only peripheral similarity to the superheated bubble chamber-based superheated droplet detectors (SDD). Instead, CTMFDs utilize mechanical “tension pressure” instead of thermal superheat, offering a lot of practical advantages. CTMFDs have been used to detect a variety of alpha- and neutron-emitting sources in near real time. The CTMFD is blind to gamma photons and betas allowing for detection of alphas and neutrons in extreme gamma/beta background environments such as spent fuel reprocessing plants. The selective sensitivity allows for differentiation between alpha emitters including the isotopes of plutonium. Mixtures of plutonium isotopes have been measured in ratios of 1∶1, 2∶1, and 3∶1 Pu-238:Pu-239 with successful differentiation. Due to the lack of gamma-beta background interference, the CTMFD is inherently more sensitive than scintillation-based alpha spectrometers or SDDs and has been proved capable to detect below femtogram quantities of plutonium-238. Plutonium is also easily distinguishable from neptunium, making it easy to measure the plutonium concentration in the NPEX stream of a UREX reprocessing facility. The CTMFD has been calibrated for alphas from americium (5.5 MeV) and curium (∼6  MeV) as well. Furthermore, the CTMFD has, recently, also been used to detect spontaneous and induced fission events, which can be differentiated from alpha decay, allowing for detection of fissionable material in a mixture of isotopes. This paper discusses these transformational developments, which are also being considered for real-world commercial use.

Pseudo-Capacitor Structure for Direct Nuclear Energy Conversion

2008 ◽  
Vol 1100 ◽  
Author(s):  
Liviu Popa-Simil
Keyword(s):  
Energy Conversion ◽  
Nuclear Power ◽  
Nuclear Energy ◽  
Nuclear Reactor ◽  
High Efficiency ◽  
Nuclear Reactors ◽  
Direct Conversion ◽  
Space Applications ◽  
Power Sources ◽  
Conversion Efficiencies

AbstractThe advanced space missions need for more power opened the way for advanced nuclear reactors and for alternative power conversion procedures. The most advanced power systems available in space are the fuel cells and nuclear reactors. Both systems manifest low efficiencies for converting the primary energy into electricity and as consequence are requiring high heat dump into space mainly by infrared radiation. The thermo-nuclear power generator also requires a high temperature gas turbine and a mechano-electric generator, finally driving to low conversion efficiencies. The new nano-materials offer the possibility of creating direct energy conversion devices able of achieving high conversion efficiencies up to 99% in the cryogenic versions. The interest for direct conversion of the nuclear energy into electricity appeared in early 1940th, by the invention of the thermo-ionic fission device by Linder. Then a series of patents and scientific papers improved gradually the designs and performances of the devices, up to the actual concepts of beta-voltaic and liquid-electronics. The most intuitive direct conversion device looks mainly like a super mirror- or a heterogeneous super-capacitor. The issues on its operation are related to global conversion efficiencies and the stable operation life-time in high radiation field. There are combinations of nano-structures and actinides assuring both the neutron flux stability, by meeting criticality conditions and the direct conversion or the nuclear energy into electricity. Achieving a high efficiency internal conversion of the nuclear energy into electricity is not enough if it is not completed by a high efficiency power extraction system from the nuclear reactor core into the outside load. The development of the new MEMS devices and micro electronics in the 40 nm technologies provides an excellent background for the production of the electric power harvesting and conversion devices embedded in the fuel. The new nano-structured materials may be produced as radiation energy harvesting tiles that are free of actinides, using them for harvesting the energy of radioactive sources and controlled fusion devices, or may include actinides in their structure achieving critical or sub-critical accelerator driven nuclear reactor assemblies. Another predictable advantage of the nano-structure is the property of self-repairing and self-organizing to compensate the radiation damage and improve the lifetime. Due to direct conversion the power density of the new materials may increase from the actual average of 0.2 kw/cm3 to about 1 kw/mm3 driving to miniaturization of nuclear power sources and reductions of the shield weight. At these dimensions and power densities of few thousands horse power per liter the nuclear power source becomes suitable for mobile applications as powering trains, strategic airplanes, etc. These new developments may drive to the production of high power solid-state compact nuclear battery for space applications, leading to a new development stage.

scholarly journals Realization of a new large research infrastructure in Belgium: MYRRHA contribution for closing the nuclear fuel cycle making nuclear energy sustainable

2020 ◽  
Vol 246 ◽  
pp. 00012
Author(s):  
Hamid Aït Abderrahim
Keyword(s):  
Nuclear Energy ◽  
Fuel Cycle ◽  
Power Level ◽  
Nuclear Fuel Cycle ◽  
Geological Storage ◽  
Spent Fuel ◽  
Current State ◽  
Partitioning And Transmutation ◽  
Large Research

In order to provide an appropriate level of energy to the whole world, nuclear energy is still going to play an important role. Nuclear energy can help reducing the CO2 emissions, which today are excessive. The problematics of nuclear waste can be solved using long-term geological storage in deep suitable formations. Partitioning and transmutation can help reducing the radiotoxicity of spent fuel to more acceptable durations of time. The MYRRHA project investigates since more than 20 years the possibility to demonstrate transmutation at a reasonable power level. In this paper we present the current state of the MYRRHA reactor design and the associated research and development activities.

Investigation of Fuel Burnup Impacts on Nuclear Reactor Safety Parameters in the Canadian Pressure Tube Supercritical Water-Cool Reactor

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Ahmad Moghrabi ◽  
David Raymond Novog
Keyword(s):  
Nuclear Reactor ◽  
High Efficiency ◽  
Fission Products ◽  
Neutron Cross Section ◽  
Fuel Mixture ◽  
Pressure Tube ◽  
Candu Reactors ◽  
Safety Parameters ◽  
Nuclear Reactor Safety ◽  
The Impact

The Canadian pressure-tube super critical water-cooled reactor (PT-SCWR) is an advanced generation IV reactor concept which is considered as an evolution of the conventional Canada Deuterium Uranium (CANDU) reactor that includes both pressure tubes and a low temperature and pressure heavy water moderator. The Canadian PT-SCWR fuel assembly utilizes a plutonium and thorium fuel mixture with supercritical light water coolant flowing through the high-efficiency re-entrance channel (HERC). In this work, the impact of fuel depletion on the evolution of lattice physics phenomena was investigated starting from fresh fuel to burnup conditions (25 MW d kg−1 [HM]) through sensitivity and uncertainty analyses using the lattice physics modules in standardized computer analysis for licensing evaluation (SCALE). Given the evolution of key phenomena such as void reactivity in traditional CANDU reactors with burnup, this study focuses on the impact of fission products, 233U breeding, and minor actinides on fuel performance. The work shows that the most significant change in fuel properties with burnup is the depletion of fission isotopes of Pu and the buildup of high-neutron cross section fission products, resulting in a decrease in cell k∞ with burnup as expected. Other impacts such as the presence of protactinium and uranium-233 are also discussed. When the feedback coefficients are assessed in terms of reactivity, there is considerable variation as a function of fuel depletion; however, when assessed as Δk (without normalization to the reference reactivity which changes with burnup), the net changes are almost invariant with depletion.

scholarly journals Emission of Noble Gases Binary Mixtures under Excitation by the Products of the 6Li (n, α)3 H Nuclear Reaction

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Kuanysh Samarkhanov ◽  
Mendykhan Khasenov ◽  
Erlan Batyrbekov ◽  
Inesh Kenzhina ◽  
Yerzhan Sapatayev ◽  
...  
Keyword(s):  
Nuclear Reaction ◽  
Nuclear Energy ◽  
Alkali Metals ◽  
Nuclear Reactor ◽  
Noble Gases ◽  
Noble Gas ◽  
Direct Conversion ◽  
Reaction Products ◽  
Gas Molecules ◽  
Sodium And Potassium

The luminescence of Kr-Xe, Ar-Kr, and Ar-Xe mixtures was studied in the spectral range 300–970 nm when excited by 6Li (n, α)3 H nuclear reaction products in the core of a nuclear reactor. Lithium was deposited on walls of experimental cell in the form of a capillary-porous structure, which made it possible to measure up to a temperature of 730 K. The temperature dependence of the radiation intensity of noble gas atoms, alkali metals, and heteronuclear ionic noble gas molecules was studied. Also, as in the case of single-component gases, the appearance of lithium lines and impurities of sodium and potassium is associated with vaporization during the release of nuclear reaction products from the lithium layer. The excitation of lithium atoms occurs mainly as a result of the Penning process of lithium atoms on noble gas atoms in the 1s states and subsequent ion-molecular reactions. Simultaneous radiation at transitions of atoms of noble gases and lithium, heteronuclear ion molecules of noble gases allows us to increase the efficiency of direct conversion of nuclear energy into light.

scholarly journals Remote Monitoring and Evaluation of Damage at a Decommissioned Nuclear Facility Using Acoustic Emission

2018 ◽  
Vol 8 (9) ◽  
pp. 1663 ◽  
Author(s):  
Marwa Abdelrahman ◽  
Mohamed ElBatanouny ◽  
Kenneth Dixon ◽  
Michael Serrato ◽  
Paul Ziehl
Keyword(s):  
Acoustic Emission ◽  
Remote Monitoring ◽  
Nuclear Reactor ◽  
Corrosion Damage ◽  
Monitoring And Evaluation ◽  
Structural Condition ◽  
Spent Fuel ◽  
Nuclear Facility ◽  
Nuclear Facilities ◽  
Accelerated Corrosion

Reinforced concrete systems used in the construction of nuclear reactor buildings, spent fuel pools, and related nuclear facilities are subject to degradation over time. Corrosion of steel reinforcement and thermal cracking are potential degradation mechanisms that adversely affect durability. Remote monitoring of such degradation can be used to enable informed decision making for facility maintenance operations and projecting remaining service life. Acoustic emission (AE) monitoring has been successfully employed for the detection and evaluation of damage related to cracking and material degradation in laboratory settings. This paper describes the use of AE sensing systems for remote monitoring of active corrosion regions in a decommissioned reactor facility for a period of approximately one year. In parallel, a representative block was cut from a wall at a similar nuclear facility and monitored during an accelerated corrosion test in the laboratory. Electrochemical measurements were recorded periodically during the test to correlate AE activity to quantifiable corrosion measurements. The results of both investigations demonstrate the feasibility of using AE for corrosion damage detection and classification as well as its potential as a remote monitoring technique for structural condition assessment and prognosis of aging structures.

scholarly journals Large High-Efficiency Thermal Neutron Detectors Based on the Micromegas Technology

Universe ◽  
2018 ◽  
Vol 4 (12) ◽  
pp. 134 ◽  
Author(s):  
Georgios Tsiledakis ◽  
Alain Delbart ◽  
Daniel Desforge ◽  
Ioanis Giomataris ◽  
Thomas Papaevangelou ◽  
...  
Keyword(s):  
Thermal Neutron ◽  
Large Scale ◽  
High Efficiency ◽  
Detection Efficiency ◽  
Rate Capability ◽  
High Rate ◽  
Thermal Neutrons ◽  
Neutron Detectors ◽  
Electron Multiplier ◽  
Detection Techniques

Due to the so-called 3He shortage crisis, many detection techniques for thermal neutrons are currently based on alternative converters. There are several possible ways of increasing the detection efficiency for thermal neutrons using the solid neutron-to-charge converters 10B or 10B4C. Here, we present an investigation of the Micromegas technology. The micro-pattern gaseous detector Micromegas was developed in the past years at Saclay and is now used in a wide variety of neutron experiments due to its combination of high accuracy, high rate capability, excellent timing properties, and robustness. A large high-efficiency Micromegas-based neutron detector is proposed for thermal neutron detection, containing several layers of 10B4C coatings that are mounted inside the gas volume. The principle and the fabrication of a single detector unit prototype with overall dimension of ~15 × 15 cm2 and its possibility to modify the number of 10B4C neutron converter layers are described. We also report results from measurements that are verified by simulations, demonstrating that typically five 10B4C layers of 1–2 μm thickness would lead to a detection efficiency of 20% for thermal neutrons and a spatial resolution of sub-mm. The high potential of this novel technique is given by the design being easily adapted to large sizes by constructing a mosaic of several such detector units, resulting in a large area coverage and high detection efficiencies. An alternative way of achieving this is to use a multi-layered Micromegas that is equipped with two-side 10B4C-coated gas electron multiplier (GEM)-type meshes, resulting in a robust and large surface detector. Another innovative and very promising concept for cost-effective, high-efficiency, large-scale neutron detectors is by stacking 10B4C-coated microbulk Micromegas. A prototype was designed and built, and the tests so far look very encouraging.

Analysis Contour Plots in RELAP/SCDAPSIM/MOD 3.4 and MOD 4.1

2018 ◽  
Author(s):  
Heriberto Sánchez-Mora ◽  
Carlos Chávez-Mercado ◽  
Chris Allison ◽  
Judith Hohorst
Keyword(s):  
Nuclear Energy ◽  
Nuclear Reactor ◽  
Severe Accident ◽  
Energy Industry ◽  
Contour Plot ◽  
Input File ◽  
Systems Software ◽  
Contour Plots ◽  
Core Components ◽  
Control Rods

RELAP/SCDAPSIM is a nuclear reactor simulator and accident analysis code that has been used in the nuclear energy industry for many years. Currently, Innovative Systems Software is developing a new tool that will show the behavior of the core components during a simulation of an accident. The addition of contour plots for the SCDAP components showing different properties: temperature, hydrogen production, etc. will allow a better understanding of core behavior during a severe accident in a nuclear reactor. The SCDAP components are fuel rods, electrically heated simulator rods, such as those used in the CORA experiments, control rods, a shroud and a BWR blade/box. This paper describes the progress in the development of the contour plot tool based on the OpenGL and FORTRAN90 libraries. The purpose of this tool is help to the user analyze the simulation of an accident and to debug an input file.

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