ML20150E142

Responds to Re Status of NRC Technical Position on Waste Form Stability.Topical Repts for Cement Solidification Media Must Address Each Waste Stream for Which NRC Review & Approval Requested

ML20150E142
Person / Time
Issue date:	03/01/1988
From:	Tokar M NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
To:	Phillips W STOCK EQUIPMENT CO.
References
REF-WM-92 NUDOCS 8803290414
Download: ML20150E142 (3)

Text

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. lawM,/S P MAR 011988 William S. Phillips, Director Contracts and Sales Stock Equipment Company 16490 Chillicothe Road Chagin Falls, Ohio 44022-4398

Dear Mr. Phillips:

Thank you for your January 8, 1988 letter, which responded to cur letter of December 21, 1988 concerning our review of Stock's topical report on cement solidification of low-1cvel waste. In your letter you asked several questions regarding (1) the status of NRC's Technical Position on waste form stability.

(2) cement waste sample cure periods, (3) cement waste specimen accelerated curing, and (4) boric acid loaded resins. Responses to those questions are as follows:

1. Technical Position on Waste Form - In your letter you asked about the status of a so-called "draft" Branch Technical Position.

Inasmuch as there is no such draft Technical Position, we assure that you were referring to a workirg draft of a Regulatory Guide on Waste Form Stability, which was distributed for informal coment over a year ago. We presentec a paper on the status of that draft Regulatory Guide in August 1987, at the DOE Low-Level Radioactive Waste Management Conference. In that paper we discussed the results of some work on cement waste forms performed at Brookhaven National Laboratory (BNL) (to which you allude in your January 1988 letter). We also pointed out in the paper that as a result of the BNL and other test results we were including two new provisions; (a) that the waste form exhibit no significant surface or bulk degradation e'fects (such as cracking, spalling, or disintegration),

and (b) that tne waste forms exhibit typical cement strength behavior (such as increasing strength with time). In our December 21, 1987 letter to you we asked you to submit information regarding items (a) and (b) by May 30, 1988. We reiterate that we still require that information, for the maximum waste loadings and corresponding maximum and minimum waste / binder rations, by May 30, 1988. If we have not received the requested information by that time, we will assume that Stock has no further interest in NRC review and approval of their topical report and we will discontinue our review. Please notify me of your intentions in this regard so that we may budget cur resources accordingly.

2. Cure Perio_d_ - Enclosed with this letter is a copy of the report on the BNL cement work mentioned above, as requested in your January 1988 letter.

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MAR 011988 William S. Phillips 2

3. Accelerated _ Curing - The statements included in Paragraph 1 of our December 21, 1987 letter are not based on comparisons to other vendors' data, as alluded to in your January 1988 letter. The acceptability of Stock's cement solidification media for low-level waste will be decided essentially on the basis of Stock's data.

Please note, however, that in the absence of definitive data on Stock's formulations, the NRC will rely on test data and field experience that lend themselves to generic interpretation. In that regard there is ample evidence that cement waste forms are being prepared with waste / cement loadings that appear to be too high to ensure long-terra (300 year) structural stability as required by 10 CFR Part 61. It is for that reason that we reconirended, in our December 21, 1988 letter, that cement waste forms be limited to 18 weight percent waste loading. Please be advised that, for bead resin waste in particular, we are considering implementing a rnandatory, rather than voluntary, upper limit on loading, such as 18 weight percent, because of the increasingly strong evidence that excessive loading can create unstable waste forms.

4. Boric Acid Loaded Res_ ins _ - The topical reports for cement solidification media must address each waste stream for which NRC review and approval is requested. In other words, data must be presented (in accordance with the 1983 Technical Position on Waste Form - as modified to include the surface / bulk degradation and strength information addressed above) for each waste stream and for the range of concentrations for those waste streams. In that regard and as noted in our December 21, 1988 letter, you must submit a separate topical report for all Stock waste stream formulations not covered by your current report, before the end of March 1988. Any fortnulations not addressed in your current or new topical report should be discontinued.

5. Suninarial Questions from your January 1988 Letter - Regarding the further questions in your January 1988 letter, our response in brief is as follows: We do not at this time believe that it is necessary to define a uniform cure period for all cement formulations; the time period and conditions for curing may vary appropriately as the waste form composition varies. It is the vendor's responsibility to provide a sufficient technical basis for the cure period / condition used for his formulation. As for additional criteria that a new Technical Fcsition cr Regulatcry Guide may possess, the NRC staff is studying this issue and has not reached any final conclusions regarding the necessity for additional criteria or tests. l

MAR 011988 William S. Phillips 3 1 trust that we have responded satisfactorily to your questions. If there is a need for further clarification, you may contact me at (301) 492-0590 or, as indicated in our December 1987 letter, we would welcome a meeting to discuss any additional concerns or issues you may have.

Sincerely, 3

Michael okar, Section Leader Technical Branch Division of Low-level Waste Panagement and Deconinissioning, hMSS

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