Damage Effects to Graphite Irradiated Up to 1000 C

PDF Version Also Available for Download.

Description

Irradiation effects at 500 deg C in experiemtal graphites with varied density, crystallinity, surface area, and pore distribution are discussed. Changes in macroscopic properties are dependent upon the initial crystallite structure; however, the mechanism by which the increase of interlayer spacing and decrease of apparent crystallite size effect these changes is not well understood. Macroscopic properties are also dependent upon the arrangement of crystallites and whole coke particles within the over-all structure which raniation may change slightly. Graphite irradiations in the Materials Testing Reactor extend exposure temperatures from 800 to 1000 deg C. The temperature coefficient of property damage decreases ... continued below

Physical Description

Pages: 13

Creation Information

Nightingale, R. E.; Davidson, J. M. & Snyder, W. A. October 31, 1958.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Publisher

  • Hanford Atomic Products Operation
    Publisher Info: General Electric Co. Hanford Atomic Products Operation, Richland, Wash.
    Place of Publication: Richland, Washington

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

Irradiation effects at 500 deg C in experiemtal graphites with varied density, crystallinity, surface area, and pore distribution are discussed. Changes in macroscopic properties are dependent upon the initial crystallite structure; however, the mechanism by which the increase of interlayer spacing and decrease of apparent crystallite size effect these changes is not well understood. Macroscopic properties are also dependent upon the arrangement of crystallites and whole coke particles within the over-all structure which raniation may change slightly. Graphite irradiations in the Materials Testing Reactor extend exposure temperatures from 800 to 1000 deg C. The temperature coefficient of property damage decreases with temperature, aad only slightly less damage occurs at 1000 deg C than at 500 deg C. Thermal conductivity decreases by a factor of 50 with 30 deg C irradiation, a factor of 3 with 500 deg C irradiation, and a factor of 2 with 750 deg C irradiation. Within the irradiation temperature range 500 to 1000 deg C, the contraction rate after the first 1500 Mwd/t is measurably the same: C/ sub 0/ spacing expands slightly: and apparent crystallite size decreases by one- half. The total stored energy content is decreased with increased irradiation temtemperature. The way in which damage effects in irradiated graphite are distributed may be measured by the ease with which they may be thermally annealed. By estimating an activation energy for a given temperaturetime annealing and measuring the amount of property annealed, at repeated increasing temperatures, it has been possible to characterize the damage with a damage distribution curve. Thermal annealing experiments on graphites with varied exposures and temperatures of irradiation have included property measurements of dimensions, thermal conductivity, interlayer spacing and crystallite size, A damage mechanism is discussed which attempts tp correlate and explain the changes in properties resulting from graphite irradiations at high crystallite does not contract (C/sub 0/ expands slightly) while the density of the graphite increases, reactor radiation of thigh temperature must result in a more efficient packing of the crystallites. Damage distribution curves of samples irradiated at a variety of temperatures can be understood in terms of a process whereby energetic carbon atoms transfer a large amount of energy to the lattice close to a crystal ddefect. In this way, the activation energy for annealing which is in excess of equilibrium lattice temperature is supplied to the damaged lattice. (auth)

Physical Description

Pages: 13

Notes

NTIS

Source

  • Other Information: Prepared for the Second U.N. International Conference on the Peaceful Uses of Atomic Energy, 1958. Orig. Receipt Date: 31-DEC-58

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Report No.: A/CONF.15/P/614
  • Grant Number: None
  • DOI: 10.2172/4328833 | External Link
  • Office of Scientific & Technical Information Report Number: 4328833
  • Archival Resource Key: ark:/67531/metadc1017764

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • October 31, 1958

Added to The UNT Digital Library

  • Oct. 15, 2017, 10:09 p.m.

Description Last Updated

  • Dec. 20, 2017, 3:01 p.m.

Usage Statistics

When was this report last used?

Congratulations! It looks like you are the first person to view this item online.

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Nightingale, R. E.; Davidson, J. M. & Snyder, W. A. Damage Effects to Graphite Irradiated Up to 1000 C, report, October 31, 1958; Richland, Washington. (digital.library.unt.edu/ark:/67531/metadc1017764/: accessed September 25, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.