A comparison of radiation doses and risks between spent fuel transport/storage and selected non-nuclear activities

2003 ◽  
Vol 14 (3-4) ◽  
pp. 187-191
Author(s):  
C. W. Pennington
Keyword(s):  
MRS Advances ◽  
2017 ◽  
Vol 2 (13) ◽  
pp. 711-716 ◽  
Author(s):  
Lovisa Bauhn ◽  
Christian Ekberg ◽  
Patrik Fors ◽  
Kastriot Spahiu

ABSTRACTIn a scenario where ground water enters a canister for spent nuclear fuel in a deep geological repository, the presence of dissolved ions in the water could possibly influence the fuel dissolution due to effects on radiolysis yields. One species of particular interest in this context is bromide, which has a proven ability to scavenge hydroxyl radicals much faster than molecular hydrogen does. As a result, bromide could inhibit the beneficial effect of dissolved hydrogen, which has been shown in γ-radiolysis experiments. However, already a few hundred years after repository closure, α-decay starts to dominate in the radiation field from the spent fuel. Hence, the effects of α-radiolysis are expected to govern the fuel dissolution over the geological timeframes of the repository. In the present work, α-radiolysis experiments have been performed to determine the effect of bromide ions on the yield of hydrogen peroxide by mass spectrometric measurement of its decomposition product oxygen. The use of high activity 238Pu solutions has made it possible to study this effect during pure α-radiolysis from a homogeneously distributed radiation field. To simulate deep bedrock repository conditions, and to minimize the influence of in-leaking O2 from air, the studies were performed using graphite sealed stainless steel autoclaves with an initial atmosphere of 10 bar H2. The results show that addition of 1 mM Br- to the solution gives no significant effect on the O2 yield for radiation doses up to 2 MGy. This lack of effect is most likely explained by the limited radical escape yields from radiation tracks in pure α-radiolysis.


2004 ◽  
Vol 824 ◽  
Author(s):  
William M. Murphy

AbstractIsolation in a geologic setting has been the generally favored solution to the high-level radioactive waste (HLW) problem since a scientific basis for nuclear waste management began to be formulated over half a century ago. Although general features of suitable settings have been enumerated, quantitative measures of the safety of geologic isolation of HLW are challenging to devise and to implement. Some regulatory measures of isolation for the proposed repository at Yucca Mountain, Nevada, have be devised and revised involving considerations of global releases, groundwater travel time, and time and space scales for isolation. In current Yucca Mountain specific regulations, the measure of long-term safety hinges on probabilistic estimates of radiation doses to the average member of a maximally exposed group of people living about 18 km down the groundwater flow gradient within 10,000 years after permanent closure of the repository. From another perspective, hydrogeochemical studies provide quantitative measures of system openness and the ability of geologic systems to isolate HLW. Hydrogeochemical data that bear on geologic isolation of HLW at Yucca Mountain include precipitation of radionuclides in stable mineralogical products of spent fuel alteration, ages of natural secondary mineralization in the mountain, uranium decay-series isotopic data for system openness, bomb-pulse isotope occurrences, and ambient carbon-14 distributions.


1987 ◽  
Author(s):  
K.J. Schneider ◽  
C.J. Hostick ◽  
W.A. Ross ◽  
R.W. Peterson ◽  
R.I. Smith ◽  
...  

1965 ◽  
Vol 05 (01) ◽  
pp. 56-67
Author(s):  
I. Pál ◽  
J. Földes ◽  
I. Krasznai

SummaryThe authors investigated the use of 197Hg EDTA complex for kidney scanning. They describe the physical, biological and toxicological properties of the compound; its distribution within the organism, its excretion with urine and faeces and its uptake by the kidneys. The authors have established that the renal cortex selectively secretes the material which makes it suitable for kidney scanning. Some scintigrams of both normal and pathologic kidneys are presented.Finally a detailed discussion of the dosimetry is included. The radiation doses due to 197Hg EDTA are compared with those due to 203Hg-neohydrin and to intravenous pyelography. This comparison shows clearly that the use of 197Hg EDTA considerably decreases the radiation dose to the patient.


1984 ◽  
Vol 23 (02) ◽  
pp. 87-91 ◽  
Author(s):  
K. Flemming

SummaryIn the beginning of medical radiology, only the benefit of ionizing radiation was obvious, and radiation was handled and applied generously. After late effects had become known, the radiation exposure was reduced to doses following which no such effects were found. Thus, it was assumed that one could obtain an optimal medical benefit without inducing any hazard. Later, due to experimental findings, hypotheses arose (linear dose-effect response, no time factor) which led to the opinion that even low and lowest radiation doses were relevant for the induction of late effects. A radiation fear grew, which was unintentionally strengthened by radiation protection decrees: even for low doses a radiation risk could be calculated. Therefore, it was believed that there could still exist a radiation hazard, and the radiation benefit remained in question. If, however, all presently known facts are considered, one must conclude that large radiation doses are hazardous and low doses are inefficient, whereas lowest doses have a biopositive effect. Ionizing radiation, therefore, may cause both, hazard as well as benefit. Which of the two effects prevails is determined by the level of dose.


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