ML19207A370
| ML19207A370 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/25/1979 |
| From: | Crerar D PRINCETON UNIV., PRINCETON, NJ |
| To: | Hendrie J NRC COMMISSION (OCM) |
| Shared Package | |
| ML19207A358 | List: |
| References | |
| NUDOCS 7908170280 | |
| Download: ML19207A370 (1) | |
Text
..
'UNIOC UCIVCTE.E'.
DEPARTMENT OF GEOLOGICAL AND GEOPHYSICAL SCIENCES CUYOT H ALL, PRINC ETON, NEW JZR5ET 08340 PHONE: 609-45:-41o1 June 25, 1979 Dr. Joseph M. Hendrie, Chairman U.S. Nuclear Regulatory Cocaission Washington DC 20555
Dear Dr. Hendrie:
With this letter I wish to express my concern about the proposed decontmaination of the Dresden No. 1 nuclear power plant, and to request a rigorous environ = ental assessment or i= pact statement. As you know, this will be the first large scale decontamination of a commercial plant and as such sets an important precedent for future operations of this type.
Clearly chemical decontamination of reactor primary systema is going to become necessary with aging nuclear plants.
As I understand the procedure, the primary coolant system is to be flushed with roughly 85,000 gallons of Dow solvent SS-1 which contains a cheJating agent; the formulation of this solvent is a proprietary secret.
The solvent will then be concentrated by evaporation, solidified, and finally buried in 55 gallon drums.
My concern lies with the use of chelating agents. While these are a logical choice for initial leaching of radionuclides, they can pose serious problems if leaked into disposal ground cediments.
Chelating agents typically bind cations so strongly that these cations are only weakly adsorbed by typi-cal soil and sediment minerals.
In a study carried out on the Oak Ridge burial grounds J. Means, J. Duquid (both now at Battelle, Columbus) and I 60Co were being mobilized through sedt-found that significant quantities of ments into groundwater by EDTA concentrations on the order 10-7 molar. Copies of this papcr and an earlier report are included.
In the present decontamination experiment, much higher concentrations of chelates are to be expected, hence my concern about radionuclide migration.
Several questions and suggestions come to mind.
First, what is the expected lifetime of the solidified polymer, particularly if under worst circumstances it becomes submerged in a rising groundwater system? What is the leach or diffusion rate of the chelate within the solid? What are tne probabilities of leakage either during decontamination or following burial.
Finally, I would strongly recommend here, as we did on page 1480 of our Science article, that the chelating agent be physically or chemically degraded before final storage.
With many thanks for your consideration, Very *ruly yours,
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