Browse > Article

CRITICALITY SAFETY OF GEOLOGIC DISPOSAL FOR HIGH-LEVEL RADIOACTIVE WASTES  

Ahn, Joon-Hong (Department of Nuclear Engineering, University of California, Berkeley)
Publication Information
Nuclear Engineering and Technology / v.38, no.6, 2006 , pp. 489-504 More about this Journal
Abstract
A review has been made for the previous studies on safety of a geologic repository for high-level radioactive wastes (HLW) related to autocatalytic criticality phenomena with positive reactivity feedback. Neutronic studies on geometric and materials configuration consisting of rock, water and thermally fissile materials and the radionuclide migration and accumulation studies were performed previously for the Yucca Mountain Repository and a hypothetical water-saturated repository for vitrified HLW. In either case, it was concluded that it would be highly unlikely for an autocatalytic criticality event to happen at a geologic repository. Remaining scenarios can be avoided by careful selection of a repository site, engineered-barrier design and conditioning of solidified HLW. Thus, criticality safety should be properly addressed in regulations and site selection criteria. The models developed for radiological safety assessment to obtain conservatively overestimated exposure dose rates to the public may not be used directly for the criticality safety assessment, where accumulated fissile materials mass needs to be conservatively overestimated. The models for criticality safety also require more careful treatment of geometry and heterogeneity in transport paths because a minimum critical mass is sensitive to geometry of fissile materials accumulation.
Keywords
Autocatalytic; Positive Feedback; Geologic Repositories; Thermally Fissile Materials; Radionuclide Transport;
Citations & Related Records
연도 인용수 순위
  • Reference
1 J. Ahn, 'Mass Transfer and Transport of Radionuclides in Fractured Porous Rock,' Ph.D. Dissertation, University of California, Berkeley (1988)
2 R. A. van Konynenburg, 'Comments on the Draft Paper 'Underground Supercriticality for Plutonium and Other Fissile Material,' ' UCRL-1D-120990 COM, Lawrence Livermore National Laboratory (May, 1995)
3 M. J. Bell, 'NRC Comments on the Report 'Underground Supercriticality from Plutonium and Other Fissile Material,' ' U. S. Nuclear Regulatory Commission (Aug., 1995)
4 P. L. Chambre, T. H. Pigford, A. Fujita, T. Kanki, H. Lung, A. Kobayashi, D. Ting, Y. Sato and S. J. Zavoshy, 'Analytical Performance Models for Geologic Repositories,' LBL Report, LBL-14842 (1982)
5 G. H. Canavan, et al., 'Comments on 'Nuclear Excursions and Criticality Issues,' ' LA-UR-95-0851, Los Alamos National Laboratory (Mar, 1995)
6 P. B. Parks, M. L. Hyder and T. G. Williamson, 'Final Issue of 'Consequences of the Bowman-Venneri Nuclear Excursion Thesis on the Prospects for Placing Vitrified Plutonium Canisters in Geologic Repositories'(U),' PD1-SPP-95-0023, Westinghouse Savannah River Company (June, 1995)
7 J. Ahn, Criticality Safety Assessment for a Conceptual High-Level-Waste Repository in Water-Saturated Geologic Media, Nuclear Technology, 126, 303 (1999)   DOI
8 R. Sanchez et al., 'Criticality Characteristics of Mixtures of Plutonium, Silicon Dioxide, Nevada Tuff, and Water,' LA-UR-95-2130, Los Alamos National Lab., 1995
9 J. Ahn, Environmental Impact of Yucca Mountain Repository in the Case of Canister Failure, Nuclear Technology, in press
10 J. Ahn, E. Greenspan and P. L. Chambre, A Preliminary Consideration for Underground Autocatalytic Criticality by Vitrified High-Level Waste in Water-Saturated Geologic Repository, Journal of Nuclear Science and Technology, 37(5), 465 (2000)   DOI   ScienceOn
11 J. Ahn, E. Greenspan and P. L. Chambre, Mechanisms and Possibility of Autocatalytic Criticality by High-Level Wastes Buried in Water-Saturated Geologic Formation, Journal of Nuclear Fuel Cycle and Environment, 4(2), 3 (1998)   DOI
12 W. E. Kastenberg, P. F. Peterson, J. Ahn, J. Burch, G.Casher, P. L. Chambre, E. Greenspan, D. R. Olander, J. Vujic, B. Bessinger, N. G. W. Cook, F. M. Doyle, and B. Hilbert : Consideration of Autocatalytic Criticality of Fissile Materials in Geologic Repositories, Nuclear Technology, 115, 298？310 (1996)   DOI
13 W. E. Kastenberg, P. F. Peterson, J. Ahn, J. Burch, G.Casher, P. L. Chambre, E. Greenspan, D. R. Olander, J. Vujic, B. Bessinger, N. G. W. Cook, F. M. Doyle, and B. Hilbert : Mechanisms for Autocatalytic Criticality of Fissile Materials in Geologic Repositories, UCB-NE-4214 (1996)
14 J. Ahn, Transport of Weapons-Grade Plutonium and Boron Through Fractured Geologic Media, Nuclear Technology, 117, 316 (1997)   DOI
15 B. F. Gore, U. P. Jenquin and R. J. Serne, Factors Affecting Criticality for Spent-Fuel Materials in a Geologic Setting, Pacific Northwest Laboratory, PNL-3791, April (1981)
16 'Final Storage of Spent Nuclear Fuel ？ KBS-3,' Volume IV, Chapter 21, Swedish Nuclear Fuel Supply Co., Division KBS (SKBF/KBS) (May, 1983)
17 P. K. Kuroda, On the infinite multiplication constant and the age of the uranium minerals, J. Chem. Phys., 25, 1295 (1956)   DOI
18 L. J. Carter and T. H. Pigford, 'NUCLEAR WASTE: Proof of Safety at Yucca Mountain,' Science, 310(5747), 447 (October 21, 2005)   DOI   ScienceOn
19 J. Ahn, 'Integrated Radionuclide Transport Model for an HLW Repository in Water-Saturated Geologic Formations,' Nuclear Technology, 121(1), 24-39 (1998)   DOI
20 J. Ahn, Possibility of Safety Improvement for Vitrified HLW Geologic Disposal by Partitioning and Transmutation, Global '99, International Conference on Future Nuclear Systems, August 29-September 3, 1999, Jackson Hole, Wyoming (1999)
21 P. K. Kuroda, On the nuclear physical stability of the uranium minerals, J. Chem. Phys., 25, 781 (1956)   DOI
22 G. A. Cowan, A Natural Fission Reactor, Scientific American, 235, 36 (1976)   DOI
23 E. D. Clayton, Anomalies of Nuclear Criticality, Pacific Northwest Laboratory, Richland, WA, PNL-SA-4868 Rev. 5, June (1979)
24 C. D. Bowman and F. Venneri, Underground Autocatalytic Criticality from Plutonium and Other Fissile Material, Los Alamos National Laboratory, LA-UR-94-4022A, March (1995)
25 E. A. Sudicky and E. O. Frind, 'Contaminant Transport in Fractured Porous Media: Analytical Solution of a Two-Member Decay Chain in a Single Fracture,' Water Resources Research, 20, 2021 (1984)
26 D. P. Hodgekinson and P. R. Maul, '1-D Modelling of Radionuclide Migration Through Permeable and Fractured Rock for Arbitrary Length Decay Chains Using Numerical Inversion of Laplace Transform,' Ann. Nucl. Energy, 15(4), 175 (1988)   DOI   ScienceOn
27 A. Talbot, 'The Accurate Numerical Inversion of Laplace Transforms,' J. Inst. Math. Appl., 23, 97 (1979)   DOI