Neutron measurements

Evaluating the neutronic state (neutron flux, power . . . ) of the whole nuclear core is a very important topic that has strong implication for nuclear core management and for security monitoring. The core state is evaluated using measurements and calculations.

9p christabelhuynh 31-05-2020 17 1   Download

The paper describes the main challenges justifying research in these different areas, and summarizes the recent progress reported. It offers researchers and engineers a way to quickly and efficiently access knowledge in highly specialized areas.

49p christabelhuynh 30-05-2020 19 3   Download

This paper presents a Bayesian approach based on integral experiments to create correlations which do not appear with differential data. Some quantities such as the fission cross section (s), neutron multiplicity (n¯p), neutron spectra (x), etc. are usually neither modeled together nor measured in coincidence, thus there is no correlation matrices in evaluated nuclear data libraries.

8p christabelhuynh 30-05-2020 15 0   Download

This review paper describes the destructive and non-destructive measurements implemented or under development at CEA, in view to perform the most complete radioactive waste characterization.

24p christabelhuynh 29-05-2020 5 2   Download

This study deals with the thermal neutron induced fission of 235U. The mix of data is non-unique and this topic will be discussed using the Shannon entropy criterion in the framework of the statistical methodology proposed.

7p christabelhuynh 29-05-2020 16 2   Download

A template for estimating uncertainties (unc.) of measured neutron-induced fission, (n,f), cross-sections (cs) is presented. This preliminary template not only lists all expected unc. sources but also supplies ranges of unc., estimates for correlations between unc. of the same and different experiments which can be used if the information is nonexistent.

9p christabelhuynh 29-05-2020 6 1   Download

The ability discrimination of neutrons/gamma-rays of the detector was evaluated by the charge comparison (CC) method using an 252Cf source. The total efficiencies when measured on 22Na, 137Cs, 60Co and 252Cf sources were obtained 17.8%, 3.9%, 9.8% and 14.8%, respectively. The Figure of Merit (FoM) values of CC method were 0.4–1.55 for the range of energy 50–1000 keVee (keV electron equivalent).

6p gildur 30-11-2019 8 2   Download

Mechanical shim is an advanced technology for reactor power and axial offset control with control rod assemblies. To address the adverse accuracy impact on the ex-core power range neutron flux measurements-based axial offset control resulting from the variable positions of control rod assemblies, the lead-lag-compensated in-core self-powered vanadium detector signals are utilized.

7p minhxaminhyeu4 26-06-2019 9 2   Download

This report presented the method for thermal neutron dosimetry on base of determination of specific radioactive activity of measured 24 Na in the irradiated Human blood. Stable sodium contents of 23 Na in blood samples (for 150 people in Lamdong province, in which there are 85 staffs working at the Nuclear Research Institute) determinated by the method of instrumental neutron activation analysis at the Reactor and have the average value of 1.90±0.27 mg/ml blood.

3p uocvong04 24-09-2015 42 3   Download

Radiochemical Neutron Activation Analysis (RNAA) for gold determination in sulfide ores was studied. The sample was ignited in a porcelain for one hour at 600o C and dissolved then with aqua regia. The gold was absorbed on an ion exchange resin AG 1 × 8 in medium 1N HCl. The resin sample was then irradiation in Da Lat nuclear reactor with neutron flux about 2.4× 1012 n/cm2 s. The radioactivity of gold was measured by Au-198 isotope on a detector GeHP connected Multichannel analyser (MCA) and PC pentum 586.

3p uocvong04 24-09-2015 66 5   Download

An active neutron method for measuring the inherent neutron emission of spent fuel assembly is proposed. The count rate of the inherent neutron emission can be determined by changing intensity of neutron irradiating source. The practical meaning of the method is presented. Some attractive features of the method are shown.

5p nganga_02 09-09-2015 43 2   Download

Small-angle neutron scattering experiments were performed on horse azidometmyoglobin (MbN3) at pressures up to 300 MPa.Other spectroscopic techniques have shown that a reorganization of the secondary structure and of the active site occur in this pressure range. The present measurements, performedusingvarious concentrations ofMbN3, showthat the compactness of the protein is not altered as the value of its radius of gyration remains constant up to 300 MPa.

7p research12 23-04-2013 54 3   Download

Work on the relationship between hyperthermophile protein dynamics, sta-bility and activity is reviewed. Neutron spectroscopy has been applied to measure and compare the macromolecular dynamics of various hyper-thermophilic and mesophilic proteins, under different conditions.

10p media19 04-03-2013 37 2   Download

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài:" Comparison of soil water-contents as measured with a neutron probe and time domain reflectometry in a "

9p toshiba4 20-09-2011 56 2   Download