Full Content is available to subscribers

Subscribe/Learn More  >

Estimation of Radioactivity of Graphite Blocks in Tokai Power Station Using Statistical Method

[+] Author Affiliations
Masaaki Nakano

Fuji Electric Holdings Co., Ltd., Kawasaki, Kanagawa, Japan

Hisashi Mikami

Fuji Electric Systems Co., Ltd., Kawasaki, Kanagawa, Japan

Hideaki Ichige, Shinich Tsukada

Japan Atomic Power Company, Tokyo, Japan

Paper No. ICEM2010-40105, pp. 355-358; 4 pages
  • ASME 2010 13th International Conference on Environmental Remediation and Radioactive Waste Management
  • ASME 2010 13th International Conference on Environmental Remediation and Radioactive Waste Management, Volume 1
  • Tsukuba, Japan, October 3–7, 2010
  • Conference Sponsors: Nuclear Engineering Division and Environmental Engineering Division
  • ISBN: 978-0-7918-5452-5 | eISBN: 978-0-7918-3888-4
  • Copyright © 2010 by ASME


Tokai Power Station (graphite moderated, gas-cooled reactor, GCR) stopped its commercial operation in March 1998 and is decommissioning now. Since graphite blocks in Tokai reactor core are major low level wastes (LLWs), the realistic and reasonable method to estimate radioactivity of graphite blocks is required for final disposal and its licensing procedure. In general, LLWs, which were installed in or around a reactor core, have large radioactivity, theoretical calculations can be applied to the estimation of the radioactivity. This paper describes the concept of the method using statistical approach to determine the radioactivity of the graphite blocks in the reactor core. This method directly considers the variations of input calculation conditions, for example, compositions of impurity elements, irradiation neutron flux and irradiation period. In this paper, the variations of the compositions of impurity elements were statistically considered with the mean value and the standard deviation that were determined with elemental analyses. Many activation calculations were performed with the compositions that were determined with pseudorandom numbers, the mean value and the standard deviation. The calculated radioactivities distribute also statistically and a mean value and a standard deviation of radioactivity can be determined. The distribution of calculated radioactivities shows consistency to radiochemical analyses of graphite blocks from the reactor core and this shows that the method is applicable to the estimation of the graphite block radioactivity. Furthermore, this method can be considered to reduce over-excess estimation margin and can obtain reasonable radioactivity rather than using maximum or conservative values of all input conditions. This method is now being developed and approved as one of basic procedure for determining the radioactivity of wastes by Standards Committee of the Atomic Energy Society of Japan.

Copyright © 2010 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In