Hostname: page-component-6bf8c574d5-t27h7 Total loading time: 0 Render date: 2025-02-20T14:42:13.525Z Has data issue: false hasContentIssue false
  • English
  • Français

Application of Supplementary Safety Indicators for H12 Performance Assessment

Published online by Cambridge University Press:  21 March 2011

A. Takasu ,
M. Naito ,
H. Umeki  and
S. Masuda
A. Takasu
Affiliation:
Geological Isolation Research Program Group, Nuclear Cycle Backend Division, Japan Nuclear Cycle Development Institute, NKK Bldg., 1-1-2, Marunouchi, Chiyoda-ku, Tokyo, Japan
M. Naito
Affiliation:
Geological Isolation Research Program Group, Nuclear Cycle Backend Division, Japan Nuclear Cycle Development Institute, NKK Bldg., 1-1-2, Marunouchi, Chiyoda-ku, Tokyo, Japan
H. Umeki
Affiliation:
Geological Isolation Research Program Group, Nuclear Cycle Backend Division, Japan Nuclear Cycle Development Institute, NKK Bldg., 1-1-2, Marunouchi, Chiyoda-ku, Tokyo, Japan
S. Masuda
Affiliation:
Geological Isolation Research Program Group, Nuclear Cycle Backend Division, Japan Nuclear Cycle Development Institute, NKK Bldg., 1-1-2, Marunouchi, Chiyoda-ku, Tokyo, Japan
Get access

Abstract

The safety of a geological disposal system can be assessed using defined indicators such as risk and dose level, which directly measure radiological effects on human beings. Since the safety assessment of a geological disposal system covers a very long period of time, there are inherent uncertainties involved in assumptions about future human activities and environmental conditions, which increase the longer the time frame becomes.

To allow for some of these uncertainties, it has been proposed to supplement assessment results based on dose levels (or equivalent risks) by other independent indicators, without relying on assumptions made in the biosphere model. Safety indicators such as nuclide concentration, flux and radiotoxicity can usefully supplement dose calculations in the evaluation of overall system performance. In particular, they may be more indicative of the isolation capability of a disposal system and the potential risks of radioactive waste disposal over the very long timescales of safety assessment.

In the H12 study, which is the project aimed at establishing a technical basis for HLW disposal in Japan, supplementary safety indicators have been applied to increase confidence in the safety assessment. The nuclide concentrations evaluated in the geosphere and biosphere in the H12 repository system were compared with measurements of naturally occurring nuclides. The comparison indicated that the concentration of radionuclides released from the repository would be several orders of magnitude lower than that of natural radionuclides. This suggests that application of supplementary safety indicators could increase the reliability of long-term safety by more rigorous measurements of concentrations of naturally occurring radionuclides in the characterization phase at a specific site, which will be compared with concentrations of relevant nuclides predicted by site-specific performance assessment models.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 663: Symposium – Scientific Basis for Nuclear Waste management XXIV , 2000 , 907
Copyright
Copyright © Materials Research Society 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. AEC (1997): Guidelines on Research and Development Relating to Geological Disposal of High-Level Radioactive Waste in Japan, Advisory Committee on Nuclear Fuel Cycle Backend Policy, Atomic Energy Commission of Japan.Google Scholar
2. Baba, T., Ishihara, Y., Suzuki, Y., Naito, M. and Ishiguro, L. (1999): Biosphere Modeling for Safety Assessment of High-level Radioactive Waste Geological Disposal, JNC TN8400 99-084 (in Japanese).Google Scholar
3. BIOMASS (1999): Long-Term Releases from Solid Waste Disposal Facilities: The Reference Biosphere Concept, BIOMASS Theme 1 Working Document: BIOMASS/T1/WD01, International Atomic Energy Agency, Vienna.Google Scholar
4. IAEA (1994): Safety Indicators in Different Time Frames for the Safety Assessment of Underground Radioactive Waste Repositories, First Report of the INWAC Subgroup on Principles and Criteria for Radioactive Waste Disposal, IAEA-TECDOC-767.Google Scholar
5. JNC (1999): Final Report of Kamaishi in-situ Experiments, JNC TN7410 99-001 (in Japanese).Google Scholar
6. JNC (2000): H12: Project to Establish the Scientific and Technical Basis for HLW Disposal in Japan - Project Overview Report -, JNC TN1410 2000-001.Google Scholar
7. Kametani, K. and Tomura, K. (1976): Concentrations of 226Ra and 210Pb in Tap Water, Well Water and Rain Water and Adsorption of 210Pb on Soil, Radioisotopes, Vol.25, No.7, pp.38–40 (in Japanese).Google Scholar
8. Kametani, K. and Matsumura, T. (1983): Determination of 238U, 234U, 226Ra and 228Ra in Spring Waters of Sanin District, Radioisotopes, Vol.32, No.1, pp.20–23 (in Japanese).Google Scholar
9. Kametani, K., Matsumura, T. and Asada, M. (1991): An Analytical Method for Uranium and Investigation of 238U and 234U Concentration in River Waters, Radioisotopes, Vol.40, No.3, pp.26–29 (in Japanese).Google Scholar
10. Miller, W., Smith, G., Savage, D., Towler, P. and Wingefors, S. (1996): Natural Radionuclide Fluxes and their Contribution to Defining Licensing Criteria for Deep Geological Repositories for Radioactive Wastes, Radiochimica Acta 74, pp.289–295.Google Scholar
11. Miyake, Y., Sugimura, Y. and Tsubota, H. (1964): Content of Uranium, Radium and Thorium in River Water in Japan, The Natural Radiation Environment, pp.219-225.Google Scholar
12. Nagra (1994): Kristallin-I; Safety Assessment Report, Nagra Technical Report, NTB 93-22, Nagra, Wettingen, Switzerland.Google Scholar
13. Neall, F. (ed.), Baertschi, P., McKinley, I.G., Smith, P.A., Sumerling, T.J. and Umeki, H. (1994) Kristallin-I, Results in Perspective, Nagra Technical Report, NTB 93-23, Nagra, Wettingen, Switzerland.Google Scholar
14. Röthemeyer, H., Hermann, A.G. and Salewski, H. (1996): The Influence of Radioactive Waste Disposal on Natural Activity, Heat Production and Radiotoxicity, KERNTECHNIK, Vol. 61, No. 5-6, pp.245–250.Google Scholar
15. STA (1988): Notification No.15 by Science and Technology Agency.Google Scholar
16. Tsumura, A. and Yamasaki, S. (1992): Direct Determination of Rare-earth Elements and Actinides in Fresh Water by Double-Focusing and High Resolution ICP-MS., Radioisotopes, 41, pp.185–192 (in Japanese).Google Scholar
17. Umeki, H. (2000): Key Aspects of the H12 Safety Case, MRS 2000, 24th International Symposium on the Scientific Basis for Nuclear Waste Management, August 27-31, 2000, Sydney, Australia.Google Scholar
18. UNSCEAR (1993): Sources and Effects of Ionizing Radiation, UNSCEAR 1993 Report to the Assembly, with Scientific Annexes, United Nations Scientific Committee on the Effects of Atomic Radiation.Google Scholar
19. WHO (1998): Guidelines for Drinking-water Quality, World Health Organization.Google Scholar