Considerations on the Disposal of Radioactive Wastes From Nuclear-Powered Ships Into the Marine Environment (1959) / Chapter Skim
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Evaluation of Harbors, Estuaries and Other Inshore Environments (Zone 1)
Evaluation of Harbors, Estuaries and Other Inshore Environments (Zone 1)
Pages 29-38
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From page 29... ...
Our attention is then confined to liquid wastes which might be discharged in such waters. The potential sources of low level liquid wastes which would occur under normal operation of a nuclear-powered ship using a water cooled reactor have been described in an earlier section of this report.
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From page 30... ...
Since these factors differ so markedly from one harbor environment to another, it is virtually impossible to make any precise general statement regarding the subsequent fate of liquid wastes discharged into harbor environments. The degree to which harbors, harbor approaches and other inshore environments might be utilized as receivers of liquid radioactive effluent from nuclear-powered ships must ultimately be determined through an evaluation of each specific location involved.
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From page 31... ...
Following the initial mechanical dilution, turbulent diffusion will lead to further dilution at approximately an exponential rate, at least during the early stages of diffusion when contaminated volume is small compared to the volume of the harbor. A major part of the analysis of the problem of disposal of nuclear wastes into the sea and coastal waters requires sufficient knowledge of the rates of mixing so that the dilution of any introduced liquid can be estimated correctly.
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From page 32... ...
This equation applies to a region of unrestricted horizontal dimensions. In restricted waterways, or near shore, the boundaries would limit diffusion.
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From page 33... ...
, there will be, for any finite amount of radioactive wastes introduced, an area within which the concentration exceeds, for a time, the ppc values for the environment. This area will at first increase in size to a maximum value, and thereafter will decrease in size until a time is reached at which the concentration is everywhere less than ppc values.
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From page 34... ...
Now consider a harbor having relatively poor mixing characteristics and a low rate of exchange with adjacent coastal waters. A review of available data indicates that most marine harbors of the United States have a half life of 30 days or less.
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From page 35... ...
Thus, for this sample situation, it would be considered unsafe to introduce a single discharge in which the ratio M/sppc TABLE 7 Sample computations for a "typical" small harbor of poor flushing characteristics, giving the time (tppc) for the maximum concentration resulting from a single discharge of M curies to be reduced to the ppc value for the environment Uppc)
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From page 36... ...
A comparison of the permissible activities given in Table 8 with the activities which have been predicted to exist in the warm-up volume discharge from the SAVANNAH, as given in Table 3, indicates that the predicted gross activity due to the listed isotopes exceeds the computed permissible activity even for only a single release per month. Also the predicted activity for Co 60 and Ta 182 both exceed the computed permissible activities for these individual isotopes.
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From page 37... ...
of discharges of primary coolant which can be made, per month, into a "typical" harbor, as a function of the ratio of total activity per discharge, M, in curies, to the ppc values for coastal waters in c ml.
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From page 38... ...
. ppc for coastal waters Permissible activity for 1 discharge per month Permissible activity for 1 discharge per day Permissible activity for 10 discharges per day Isotope (ne/ml)
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