Letter Report: Review of the Identification of Radionuclides Released from the Hanford Nuclear Reservation's Facilities to the Columbia River (2002) / Chapter Skim
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Appendix A: Specific Comments
Appendix A: Specific Comments
Pages 10-25
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Page 1 1 What does "The highest radionuclide concentrations in media, primarily river water and sediment, are required to ensure that exposure consequences are not underestimated" mean? The screening analysis is supposed to be performed at Ringold (river miles 354 and 340)
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."? Page 17 "An uncertainty factor of 5 is applied to these source terms." Why is it applied and how was 5 chosen?
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Measurement data 1968 32p 45Ca 6oco 64cu 122sb soy 89Sr 90Sr 93y 95zr 137cs 131 1331 65Zn 69mZn Ratios to 32p NA 0.016 13 NA Ratios to 90Y 27 1.0 2083 158 NA Ratios to 3lI 8.3 l Ratios to 65Zn NA 1 4.0 NA = No measurement available for computing ratio 12 Draft report 1964 0.035 0.060 0.020 0.020 30 66 .
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Is the uncertainty factor 5 or 2 associated with the multiplier relating them to 32p, or is this distribution applied after estimating medial values from the median of 32P? If the latter, how do the factors of 2 and 5 compare with the uncertainties associated with nuclides that were studied by the HEDR Project?
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From page 14... ...
assumed to be a function of the river water concentration. What is actually used is a sorption coefficient (usually called a partition coefficient)
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f. "The infinite series computation is performed for 20 terms or until no significant change in the returned value is achieved." Instead, Codell et al.
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Cw = dissolved concentration in river water, C = total concentration in river water (dissolved plus adsorbed to suspended sediment) , Ke = sediment water partition coefficient, Ss = suspended sediment load, Tb = thickness of the sediment bed on the bottom of the river that is in equilibrium with river water but does not move with the water, EX = longitudinal turbulent dispersivity (in direction x, along the river)
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From page 17... ...
states clearly that a "significant break in the slope of the flow-time curves is apparent when the data are plotted on logarithmic paper" and goes on to discuss the reason for the break in the slope (at that time, the main river channel shifted at the higher flow rate at two places between 100-D and Pasco pumping stations)
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However, it provides depth estimates of about 300 m for typical flow rates, clearly too deep; and indeed this relation was not used. Instead the relation used in the flow-rate file (flowrate.data)
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, but such releases are incorrectly apportioned between all the reactors operating at the time of the fuel-element failure instead of being assigned only to the reactor in which the failure occurred. Page 29 The physical quantity represented by Cs is an activity per urut mass, not a concentration (activity per unit volume)
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What is a "returned value"? There is no need for computer codes to numerically integrate equation (3)
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Even if those analytic integrals are not used in the calculations, they provide an accurate way to test any code that is used, and such tests should be performed. The draft report notes on page 3 1 that "the infinite series calculation is performed for 20 terms or until no significant change in the returned value is achieved." For small values of t, there is no need for 20 terms.
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From page 22... ...
Page 32 The matter of model verification According to the draft report, "Model verification is defined here as confirmation that the model has been coded and implemented in the computer code correctly." That objective was purportedly achieved by comparison with the RIVLAK code for a single case corresponding to release of "a total of 39.217 Ci released over 13 s", and the "agreement" is documented in Table 3 of the draft report. The committee does not agree that the results shown in Table 3 of the draft report provide adequate verification of the RVRDSP code according to the stated definition.
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From page 23... ...
as equal to a time corresponding to the start of the source, the result produced by RIVLAK is erroneously slightly low. The first ordinate in the Simpson's rule integration is given the value zero, instead of the finite value required; this error affects both the BASIC and FORTRAN versions of the code given by Codell et al.
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From page 24... ...
Taking account of the coding errors, the cotrunittee could reproduce both incorrect and correct results with RIVLAK—using a copy of the RIVLAK code (with or without the errors corrected) and an alternative implementation—to the expected precision (the six digits shown in Codell et al.
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From page 25... ...
Additional material The spreadsheet "release rates.xls" provided to the committee contains misleading information. The reactor operating periods are documented in the report and apparently in the spreadsheet "reactor operations.xls." However, in apportioning releases (apportionment governs the effective release history used)
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