ML20215K539
| ML20215K539 | |
| Person / Time | |
|---|---|
| Issue date: | 03/29/1985 |
| From: | Starmer R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Dayal R BROOKHAVEN NATIONAL LABORATORY |
| Shared Package | |
| ML20215G205 | List: |
| References | |
| FOIA-87-235 NUDOCS 8706250360 | |
| Download: ML20215K539 (2) | |
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, MRKnapp MAR .? 9 Jggg RJStarmer & r/f LHigginbotham, WMLU Dr. Ramesh Dayal, Group Leader KJackson, WMLU Nuclear Waste Management Division -99R-Department of Nuclear Energy Brookhaven National Laboratory Upton, Lonc Island, New York 11973
Dear Dr. Dayal:
Thank you for the information copy of your submittal' to Nuclear Technoloav entitled "0xidation Induced Geochemical Changes in Trench Leachates From the Maxey Flats Low Level Radioactive Waste Disposal Site." As we discussed in our !
recent telephone conversation, I believe that this kind of work is of importance to understanding the behavior of radionuclides released from low-level radioactive waste disposal units. While much data has been gathered which could be apolied to assess the viability of the shallow land burial concept, only analyses of the type you report here will ellow the interpretation of the collected data.
There are several interesting implications which can be drawn # rom your analyses. It would seem that there is some advantaae to siting waste disposal sites in carbonate bearino sediments. Such sediments could add to the buffering capacity of the waste disposal " system," Addition of carbonate to waste trenches or addition of hydroxides or reactive oxides might he suggested as either an operational or remedial action measure based on your findings.
This miaht buffer the system and help control radionuclide release. Finally, I would like to point out that the experimental data that you have on leachate oxidation offers a unique opportunity to test the ability of reaction path models such as PHREEQE on real data. As you probably are ware, one of the latent problems with this class of models, ard all geochemical models that I know of, is the handling of oxidation. reduction processes. The models are based on eouilibrium thermodynamics and equilibrium is often not reached in natural systems where the reacting comoonents are often Dresent in trac':
amounts end where equilibrium is often not achieved. Your systems have large amounts of iron, making determinations of relatively high precision easy and making t:1e achievement of ecuilibrium more likely than in dilute natural waters. I encourage you to follow up on this svagestion, particularly since you have data at many intermediate points along the reaction path.
I found one somewhat negative aspect to your paper. I agree that the information that you present suogests problems for sites where trench 'leachates exist and particularly where they are acid and contain organic comolexants,-
however I found that your previous submittal to Nuclear Technoloay struck a -
better balance and indicated that we can learn from existina sites. On page 3 of that manuscript you stated "In accordance with current disposat orocedures, 8706250360 870616 PDR FOIA >
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stabili7ed and packaged waste ret only ensures trench stability bLt also l decreases the rate and extent of leachina and microbial dep actrior, of waste materials." I would point out that in addition there are ;occial re't.f rements for disposal of waste containing organic comolexants. I do believe r. hat your study shows that requiring soecial treatment of some tvoes af wastec makes sense.
In closino, I would like to reitorate that I feel that the t"re. of analysis of
.f.he existing data base that you have performed is a lona c<erdue exercise. You have made a'cood start and I encourage vou to continue the good work. )1 Sincerely yours,.
011gTnal Signed Y Robert J. Starmer, PhD.
Sectior Leader-Geochemistry Section. I Geotechnical Branch- -
Division of Waste Manacement Office of Nuclear Material Safety and Safeguards 3
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