CY-04-252, Supplemental Information Request for Approval of Proposed Procedures in Accordance with 10 CFR 20.2002

Supplemental Information Request for Approval of Proposed Procedures in Accordance with 10 CFR 20.2002

ML043570446
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	12/17/2004
From:	Gerard van Noordennen Connecticut Yankee Atomic Power Co
To:	Document Control Desk, NRC/FSME
References
CY-04-252, FOIA/PA-2005-0203
Download: ML043570446 (3)

Text

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CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT 362 INJUN HOLLOW ROAD - EAST HAMPTON, CT 06424-3099 DEC 17 M Docket No. 50-213 RE: 10 CFR 20.2002 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D C 20555 Haddam Neck Plant Supplemental Information Request for Approval of Proposed Procedures in Accordance with 10 CFR 20.2002 Connecticut Yankee Atomic Power Company (CYAPCO) proposes to transfer c6rtain of.its solid waste from decommissioning of the Haddam Neck Plant (HNP) facilities.(e g., structures and buildings) to a disposal facility. Specifically, CYAP.CO proposes .to dispose' of demolition debris from decommissioning of th'e HNP facilities to theos'&S Ecolotdgy' IdahoFacilitiy, located in Grand View,-idaho.

The purpose of this letter is to provide supplemental information requested by the NRC Staff in teleconferences with CYAPCO on December 9 and 15, 2004.

CYAPCO has performed a conservative radiological assessment of the demolition debris material and determined that the potential dose to workers involved in the transportation and placement of the waste at the site and to members of the public after closure of the facility will be no more than a few

-_ milliren per year Total Effective Dose Equivalent (TEDE) and a small fraction of NRC limits for exposure to members of the public of 25 millirem/yr TEDE. This assessment was provided to the NRC by letter dated September 16, 2004.1 To further support this conclusion, CY has performed Microshield2 runs to determine an on-site survey limit for the disposition of waste in appropriate containers that can be shipped to US Ecology Idaho RCRA disposal site.

,.G.' H..Bouchard (CYAPCO) letter to the US NRC Document Control Desk,'

'dated September 16, 2004, RequLst f&o Approval of Proposed Procedures in accordance with 10 CFR 20.2002", CY-04-168.

2 MicroShield 5. Grove Engineering, Rockville, MD, 1998.

Document Control Desk CY-04-252 / Page 2 An action level has been developed to identify when it is appropriate to transport a container to US Ecology or to an alternate disposal site should the container dose rates exceed the alternate waste disposal procedure criteria of 10 CFR 20.2002. These action levels are expressed as a dose rate (in pr/hr), and are based upon the assumption that all gamma emissions are produced by the decay of Cs-1 37. The action levels also assume that the contents of the container contain Cs-137 contamination at a maximum allowable activity concentration of 30 pCi/gm for disposal at US Ecology.

It should be noted that as the weight (and effective density) of the contents of each container is variable, the action levels will also vary. Accordingly, action levels were determined for B-25 containers as well as intermodal containers using appropriate software (i.e., MicroShield).

The survey data in CY's submittal requesting approval of alternative waste disposal procedures for disposal at US Ecology Idaho show Cs-1 37 as approximately 70% of the total radioactivity (Co-60 making up most of the remaining percentage) and Am-241 more then 2 orders of magnitude below Cs-137. Considering this and the waste activity concentration limits for US Ecology Idaho, it is considered appropriate to base the survey criteria on Cs-137. This approach is conservative, as any Co-60 present in the waste will drive the total activity concentration at the action levels to lower values due to the higher energy gamma resulting from decay of Co-60 versus that from Cs-1 37.

Using a nominal container fill height for an intermodal container corresponding to 55 %, a 1 meter dose rate of 4 pr/hr is selected as a reliable and conservative action level for determining compliance with the alternate disposal procedure survey criteria. It is considered that containers exhibiting dose rates below the action level may be shipped to US Ecology Idaho and those exhibiting higher dose rates need to shipped to alternate facilities or investigated further to determine radionuclide concentrations.

Using a dose rate at 1 meter from each intermodal container of 4 pR/hr the dose to-offloading workers is acceptable. Considering such a-close distance to each--

container (1 meter), an exposure time of 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> at this distance would be needed to approach the criteria of 5 mrem per year requirement established by NRC for this alternative disposal procedure. This exposure scenario is conservative and provides evidence that the use of a 30 pCi/g limit (or 4 pR/h for an intermodal at 1 meter) for waste to be disposed at the US Ecology site would result in worker exposures well within the NRC criteria for approval of the alternate disposal request in accordance with 10CFR20.2002.

CYAPCO hereby requests expedited review and approval of this request to support our decommissioning activities at the HNP.

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• Document Control Desk CY-04-252 / Page 3 If you should have any questions regarding this submittal, please contact Mr. G.

P. van Noordennen at (860)-267-3938.

Sincerely,

6. vs T n ~ 12-17-11'o G. P. van Noordennen Date Regulatory Affairs Manager cc: S. J. Collins, NRC Region 1 Administrator T. B. Smith, NRC Project Manager, Haddam Neck Plant R. R. Bellamy, Chief, Decommissioning and Laboratory Branch, NRC Regionl E. L. Wilds, Jr., Director, CT DEP Monitoring and Radiation Division