scholarly journals Nuclear heating rates in the pressure vessel, flight environment

1971 ◽  
Author(s):  
J.C. Courtney
Keyword(s):  
Pressure Vessel ◽  
Heating Rates ◽  
Nuclear Heating

scholarly journals Computational support on the development of nuclear heating calorimeter detector design

2020 ◽  
Vol 225 ◽  
pp. 04033
Author(s):  
Klemen Ambrožič ◽  
Damien Fourmentel ◽  
Hubert Carcreff ◽  
Vladimir Radulović ◽  
Luka Snoj
Keyword(s):  
Energy Deposition ◽  
Detector Response ◽  
Heating Rates ◽  
Triga Reactor ◽  
Computational Support ◽  
Nuclear Heating ◽  
Gamma Flux ◽  
Fission Reactors ◽  
High Neutron ◽  
Detector Design

Heating due to energy deposition of intense ionizing radiation in samples and structural materials of nuclear reactors poses severe limitations in terms of cooling requirements for safe reactor operation, especially in high neutron and gamma flux environments of material testing fission reactors (MTRs) and novel fusion devices. A bilateral CEA-JSI research project was launched in 2018 with the objective to measure the gamma heating rates in standard reactor-related materials (graphite, aluminium, stainless steel and tungsten) as well as fusionrelevant materials (low-activation steel Eurofer-97 and Nb3Sn superconductor) in the JSI TRIGA reactor my means of gamma calorimeters. The calorimeter design will be based on the the CALMOS-2 calorimeter developed at the CEA and used to perform gamma heating measurements in the OSIRIS MTR in Saclay. In order to optimize the detector response inside the JSI TRIGA reactor field and not to perturb the measurement field, a detailed computational analysis was performed in terms of energy deposition assessment and measurement field perturbation using the MCNP v6.1 code, and in terms of heat transfer using the COMSOL Multiphysics code. The abovementioned activities enabled us to finalize the detector design with the experimental campaign planned for the end of year 2019.

scholarly journals Confirmation of Nuclear Heating Rate for Installation of Cold Neutron Source at HANARO

2020 ◽  
Vol 225 ◽  
pp. 04004
Author(s):  
Kim Myong-Seop ◽  
Park Byung-Gun
Keyword(s):  
Heating Rate ◽  
Neutron Source ◽  
Cold Neutron ◽  
Reactor Core ◽  
Reactor Power ◽  
Electric Heater ◽  
Lead Wire ◽  
Heating Rates ◽  
Cold Neutron Source ◽  
Nuclear Heating

In order to determine the capacity of the cold neutron source refrigerator of HANARO, the nuclear heating rate at CN vertical hole is measured by using the heat-flow calorimetric method and confirmed by the calculation. The heating rate measurement device of HANARO was composed of a calorimeter sensor, an air containing aluminum sleeve for fitting the sensor to the CN hole, aluminum weight and a lead wire assembly. The calorimeter sensor consists of a cylindrical Al sample and container, two thermocouples and the electric heater for the calibration of the calorimeter. The sample is separated by an air gap from the Al container surrounded by an air containing Al sleeve. After installation of the calorimeter at a measurement position of HANARO, the heat transfer inside the calorimeter was simulated by the electric heating for the sample. The nuclear heating rates at the CN hole were determined at three reactor powers of 1, 4 and 8 MW by using the calibration curve and the temperature measurements at each reactor power. The measured nuclear heating rate per unit mass of Al sample at 8 MW reactor power is 0.143 W/g and it is equivalent to the 0.494 W/g at 30 MW. The nuclear heating rate was calculated by using the MCNP code. The calculation model for the whole facility including the reactor core and the reflector tank were established. In the calculation procedure, the heat generations by various radiations were evaluated with considering the prompt, delayed and activation effects. The measured heating rate was reasonably well supported by the calculation using the cold neutron facility design code. It will be very useful for the moderator cell of cold neutron source of HANARO.

scholarly journals Last Improvements of the CALMOS Calorimeter Dedicated to Thermal Neutron Flux and Nuclear Heating Measurements inside the OSIRIS Reactor

2018 ◽  
Vol 170 ◽  
pp. 04002 ◽  
Author(s):  
H. Carcreff ◽  
L. Salmon ◽  
V. Lepeltier ◽  
J.M. Guyot ◽  
E. Bouard
Keyword(s):  
Neutron Flux ◽  
Thermal Neutron ◽  
Thermal Neutron Flux ◽  
Heating Rates ◽  
The Core ◽  
Calibration Methods ◽  
Calorimetric Probe ◽  
Nuclear Heating ◽  
Complete Cell ◽  
Heating Up

Nuclear heating inside an MTR reactor needs to be known in order to design and to run irradiation experiments which have to fulfill target temperature constraints. To improve the nuclear heating knowledge, an innovative calorimetric system CALMOS has been studied, manufactured and tested for the 70MWth OSIRIS reactor operated by CEA. This device is based on a mobile calorimetric probe which can be inserted in any in-core experimental location and can be moved axially from the bottom of the core to 1000 mm above the core mid-plane. Obtained results and advantages brought by the first CALMOS-1 equipment have been already presented. However, some difficulties appeared with this first version. A thermal limitation in cells did not allow to monitor nuclear heating up to the 70 MW nominal power, and some significant discrepancies were observed at high heating rates between results deduced from the calibration and those obtained by the “zero method”. Taking this feedback into account, the new CALMOS-2 calorimeter has been designed both for extending the heating range up to 13W.g-1 and for improving the “zero method” measurement thanks to the implementation of a 4-wires technique. In addition, the new calorimeter has been designed as a real operational measurement system, well suited to characterize and to follow the radiation field evolution throughout the reactor cycle. To meet this requirement, a programmable system associated with a specific software allows automatic complete cell mobility in the core, the data acquisition and the measurements processing. This paper presents the analysis of results collected during the 2015 comprehensive measurement campaign. The 4-wires technique was tested up to around a 4 W.g-1 heating level and allowed to quantify discrepancies between “zero” and calibration methods. Thermal neutron flux and nuclear heating measurements from CALMOS-1 and CALMOS-2 are compared. Thermal neutron flux distributions, obtained with the Self-Power Neutron Detector suited to the CALMOS-2 calorimetric probe, are compared with those obtained with current devices. This campaign allowed to highlight advantages brought by the human machine interface automation, which deeply refined the profiles definition. Finally, the decay of the reactor residual power after shutdown could be performed after shutdown, demonstrating the ability of such type of calorimeter to follow the heating level whatever the thermohydraulic conditions, forced or natural convection regimes.

Qualification of a New Differential Calorimeter Configuration Dedicated to Nuclear Heating Rates up to 20 W.g−1

2020 ◽  
Vol 67 (11) ◽  
pp. 2405-2414
Author(s):  
A. Volte ◽  
J. Brun ◽  
A. Lyoussi ◽  
M. Carette ◽  
C. Reynard-Carette
Keyword(s):  
Heating Rates ◽  
Nuclear Heating ◽  
Differential Calorimeter

scholarly journals Nuclear heating measurements by gamma and neutron thermometers

2020 ◽  
Vol 225 ◽  
pp. 04003 ◽  
Author(s):  
R. Van Nieuwenhove ◽  
L. Vermeeren
Keyword(s):  
Finite Element ◽  
Monte Carlo ◽  
Heating Rates ◽  
Monte Carlo Calculations ◽  
Relative Contribution ◽  
Finite Element Calculations ◽  
High Gamma ◽  
Gamma Absorption ◽  
Nuclear Heating ◽  
Better Than

A gamma thermometer suitable for very high gamma heating levels (up to 20 W/g) has been designed and modelled by means of detailed finite element calculations. Based on a sensitivity analysis, the predicted accuracy of this gamma thermometer is better than 5 %. A novel miniaturized gamma thermometer is proposed in which a single thermocouple is used as the gamma absorption element, allowing a reduction of the sensor diameter down to 3 mm. Monte Carlo calculations (by MCNP) have been performed to assess the relative contribution of neutrons to the nuclear heating in a gamma thermometer. Calculations have been performed for gamma thermometers with an inner body made of various materials, such as stainless steel, tungsten, molybdenum and rhodium. By using gamma thermometers made of different materials, it will be possible to deduce the nuclear heating rates in these materials and also to separate out the neutron and gamma heating contributions. The Monte Carlo calculations show that nuclear heating of rhodium is mainly due to neutrons, converting the rhodium gamma thermometer effectively in a neutron thermometer. The sensitivities of the gamma thermometers with W, Mo or Rh as heated materials have been modelled by finite element calculations. It is found that both the Mo and the Rh based sensor have a very linear response up to a nuclear heating of 20 W/g.

Comparing fast inductive tempering and conventional tempering: Effects on microstructure and mechanical properties

2018 ◽  
Vol 115 (4) ◽  
pp. 407 ◽  
Author(s):  
Annika Eggbauer Vieweg ◽  
Gerald Ressel ◽  
Peter Raninger ◽  
Petri Prevedel ◽  
Stefan Marsoner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Charpy Impact ◽  
Heat Treating ◽  
Processing Route ◽  
High Heating Rate ◽  
Heating Rates ◽  
High Heating ◽  
Tempering Treatment ◽  
Carbide Distribution

Induction heating processes are of rising interest within the heat treating industry. Using inductive tempering, a lot of production time can be saved compared to a conventional tempering treatment. However, it is not completely understood how fast inductive processes influence the quenched and tempered microstructure and the corresponding mechanical properties. The aim of this work is to highlight differences between inductive and conventional tempering processes and to suggest a possible processing route which results in optimized microstructures, as well as desirable mechanical properties. Therefore, the present work evaluates the influencing factors of high heating rates to tempering temperatures on the microstructure as well as hardness and Charpy impact energy. To this end, after quenching a 50CrMo4 steel three different induction tempering processes are carried out and the resulting properties are subsequently compared to a conventional tempering process. The results indicate that notch impact energy raises with increasing heating rates to tempering when realizing the same hardness of the samples. The positive effect of high heating rate on toughness is traced back to smaller carbide sizes, as well as smaller carbide spacing and more uniform carbide distribution over the sample.

Mcc Corrosion Tests at Reference Testing Conditions for A27 Cast steel in Hanford Ground Water

1986 ◽  
Vol 84 ◽  
Author(s):  
M.D. Merz ◽  
F. Gerber ◽  
R. Wang
Keyword(s):  
Pacific Northwest ◽  
Pressure Vessel ◽  
Static Pressure ◽  
Cast Steel ◽  
Statistical Treatment ◽  
Testing Conditions ◽  
Corrosion Tests ◽  
Corrosion Rates ◽  
High Level Nuclear Waste ◽  
High Level

AbstractThe Materials Characterization Center (MCC) at Pacific Northwest Lab- oratory is performing three kinds of corrosion tests for the Basalt Waste Isolation Project (BWIP) to establish the interlaboratory reproducibility and uncertainty of corrosion rates of container materials for high-level nuclear waste. The three types of corrosion tests were selected to address two distinct conditions that are expected in a repository constructed in basalt. An air/steam test is designed to address corrosion during the operational period and static pressure vessel and flowby tests are designed to address corrosion under conditions that bound the condi ring the post-closure period of the repository.The results of tests at reference testing conditions, which were defined to facilitate interlaboratory comparison of data, are presented. Data are reported for the BWIP/MCC-105.5 Air/Steam Test, BWIP/MCC-105.1 Static Pressure Vessel, and BWIP/MC-105.4 Flowby Test. In those cases where data are available from a second laboratory, a statistical analysis of interlaboratory results is reported and expected confidence intervals for mean corrosion rates are given. Other statistical treatment of data include analyses of the effects of vessel-to-vessel variations, test capsule variations for the flowby test, and oven-to-oven variations for air/steam tests.

Sign in / Sign up

Export Citation Format

Share Document