4D synchrotron X-ray microtomography of fracture in nuclear graphite after neutron irradiation and radiolytic oxidation

International Thermonuclear Experimental Reactor (ITER) Radial X-ray Camera (RXC) is installed in the equatorial port #12 (middle drawer) to measure the poloidal profile of the plasma x-ray emission with high spatial and temporal resolution. According to the irradiation test results with Co-60 gamma ray source, Cf-252 neutron source and the result in Deuterium - Tritium (DT) accelerator neutron irradiation experiment for RXC electronics before, the weak parts of the circuit have been improved by radiation resistance design such as using radiation-hard power chip and optimizing the Field Programmable Gate Array (FPGA) code. Other factors related to radiation, such as easiness of maintenance, compact electronics structure and remote state monitoring are also considered in the design. The performance of the electronics and chassis has been preliminarily verified in Experimental Advanced Superconducting Tokamak (EAST) experiments showing resistance to interference from discharge environment. Besides, the irradiation resistance of electronics was investigated in high fluence neutron irradiation experiment in fission reactor, where the detector, pre-amplifier, mid-amplifier and cables under test received the accumulated neutron fluence over 9.89×1013n/cm-2 (1MeV equivalent), and the quality of output signal was monitored in real time. It’s found after the experiment that the pre-amplifier worked well, while the detector and mid-amplifier were partly damaged.

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X-ray Diffraction Study of the Effect of Neutron Irradiation on the Defect Formation in Silicon Crystals Grown by the Czochralski Method and Annealed at High Temperatures

Physics of the Solid State ◽

10.1134/1.2087738 ◽

2005 ◽

Vol 47 (10) ◽

pp. 1863

Author(s):

V. A. Makara

Keyword(s):

Diffraction Study ◽

High Temperatures ◽

Neutron Irradiation ◽

Defect Formation ◽

Czochralski Method ◽

X Ray Diffraction ◽

X Ray ◽

Silicon Crystals

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The local atomic environment of Cu and Ni in Fe-Cu-Ni alloys following thermal ageing and neutron irradiation: A study using fluorescence mode X-ray absorption fine-structure spectroscopy

Philosophical Magazine A ◽

10.1080/01418619908210362 ◽

1999 ◽

Vol 79 (6) ◽

pp. 1295-1319 ◽

Cited By ~ 7

Author(s):

A. Bryan Edwards ◽

Kevin J. Robert ◽

Stefania Pizzini ◽

William J. Phythian

Keyword(s):

Fine Structure ◽

Neutron Irradiation ◽

Thermal Ageing ◽

X Ray ◽

Ni Alloys ◽

Absorption Fine ◽

Local Atomic Environment ◽

X Ray Absorption

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Chemical shift of characteristic X-ray wavelength in silicon-containing ceramics due to neutron irradiation

Journal of Nuclear Materials ◽

10.1016/j.jnucmat.2007.03.182 ◽

2007 ◽

Vol 367-370 ◽

pp. 1038-1043

Author(s):

Toyohiko Yano ◽

Saisyun Yamazaki ◽

Hiroko Kawano ◽

Keiichi Katayama

Keyword(s):

Chemical Shift ◽

Neutron Irradiation ◽

X Ray

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Development of Surface Marker System for the Observation of Microstructural Changes in Nuclear Graphite using Micro X-ray Tomography

MRS Proceedings ◽

10.1557/opl.2012.560 ◽

2012 ◽

Vol 1475 ◽

Author(s):

Rosemary A. Holmes ◽

Abbie N. Jones ◽

Lorraine McDermott ◽

Barry Marsden

Keyword(s):

Thermal Treatment ◽

Nuclear Energy ◽

Ex Situ ◽

X Ray ◽

Power Stations ◽

Nuclear Graphite ◽

Irradiated Graphite ◽

The Matrix ◽

Treatment And Disposal ◽

The Uk

ABSTRACTCurrent energy demands and future energy needs are a growing industry which at present attracts a large amount of research and investment of which nuclear energy is an integral part. Eight new nuclear stations are proposed to be developed in the UK over the next ten years to meet this demand. In order for nuclear energy to sustain growth and development, nuclear decommissioning of first and second generation power stations needs to be addressed in the U.K. and worldwide. Presently the UK has 36 graphite moderated reactors as a result of the UK military and civil programs, which over the next twenty years will close. This will result in ∼99’000 tonnes of irradiated graphite waste for which no current national decommissioning strategy exists. The main issues associated with this waste are the large volume and activation products associated. By far the greatest inventory is from 3H and 14C. An EU Euroatom FP7 Program; CARBOWASTE was established in 2008 with the aim of developing treatment and disposal options for graphite.This research is based within CARBOWASTE, the main objectives are to understand the mechanisms involved in the production, location and removal of radioisotopes from nuclear graphite. Computed X-ray Tomography (CT) will be used in order to quantify the initial porosity in conjunction with thermal treatment (ex situ) in order to eventually identify the location of 14C within the matrix of irradiated graphite, through the preferential chemically controlled oxidation of graphite. Unirradiated Pile Grade A graphite samples have been laser and manually marked in order align the samples prior to and post thermal treatment to determine the degree of porosity changes and weight loss under a range of thermal oxidation parameters.

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