ML20135B535

Responds to to E Easton & to Question Re Environ Radiation Associated W/Isfsis.Licensees Required to Provide Annual Rept of Effluents Released from Reactor Facilities & ISFSIs

ML20135B535
Person / Time
Site:	Prairie Island
Issue date:	02/25/1997
From:	Marcus G NRC (Affiliation Not Assigned)
To:	Smit C AFFILIATION NOT ASSIGNED
References
NUDOCS 9703030089
Download: ML20135B535 (6)

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% * * * * * [$ February 25, 1997 l

l Charles Thomas Smit P.O. Box 103  :

Wabasha, Minnesota 55981 i

Dear Mr. Smit:

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As the lead manager for dry cask issues in the Office of Nuclear Reactor i Regulation (NRR), Nuclear Regulatory Commission (NRC), I am responding to your I letter dated January 18, 1997, to Earl Easton. l In regard to your question regarding environmental radiation associated with independent spent fuel storage installations (ISFSIs), licensees are required to provide an annual report of effluents released from the reactor facilities and ISFSIs. The annual effluent reports for the Prairie Island ISFSI for 1995 i and 1996 are provided as Enclosures 1 and 2. The reports for the Prairie l Island ISFSI are typical for the other ISFSIs in the United States in that radioactive effluents have not been released from dry storage casks. In order for radioactive material to escape from a dry storage cask, an unlikely event j or condition would need to occur and cause a failure of the integrity of the i storage cask. The safety analysis report for the Prairie Island ISFSI ~

includes an analysis of a hypothetical loss of confinement- barrier that assumes the total inventory of radioactive gases within a cask are released.

This hypothetical scenario results in a maximum individual whole body dose of 0.15 rem for a member of the public. Any credible accident involving a dry  !

storage cask at Prairie Island would result in less exposure to the general j public than does this hypothetical scenario. A general study of the possible  !

offsite consequences of possible accidents involving spent fuel was provided in NUREG-1140, "A Regulatory Analysis on Emergency Preparedness for Fuel Cycle and Other Radioactive Material Licensees." A copy of that report is provided as Enclosure 3.

On the basis of its reviews of specific cask designs, expected doses associated with direct radiation from storage casks, and possible radiological consequences of hypothetical accidents, the NRC staff has determined that the safeguards included in the existing designs are adequate to ensure that ISFSIs l do not pose an undue risk to public health and safety. Therefore, additional  ;

! measures, such as ISFSI enclosures or additional cask shielding, are not required to satisfy the regulatory requirements established by the NRC.

Since dry storage casks prevent the release of radioactive materials from the stored spent fuel assemblies,' the expected radiological dose to a member of the public from an ISFSI has been limited to the radiation from the spent fuel assemblies that penetrates the shielding provided by the cask and transverses the distance between the ISFSI and the individual. The 1995 Annual Radiological Environmental Monitoring Report for Prairie Island and its l associated ISFSI, Enclosure 4, provides information regarding measurements of g%

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L '- Mr. Charles Smit i the radiation levels taken at various sites near that facility. Chapter 7 of -

the safety analysis report for the Prairie Island ISFSI provides the results  ;

.of analyses related to the offsite dose as a result of direct radiation and  :

skyshine (radiation emanated upward and scattered by air into the surrounding area) and is provided as Enclosure 5. As mentioned in NRC Technical Issue i' Paper 18, " Monitoring Environmental Impacts of Nuclear Power Plants" (Enclosure 6), the NRC maintains a network of thermoluminescent dosimeters (TLDs) around each commercial power reactor and provides measured radiation  ;

levels on a quarterly basis in NUREG-0837, "NRC TLD Direct Radiation  :

Monitoring Network." A copy of the most recent report is provided as Enclosure 7. In addition, selected portions (those parts related to ISFSIs) of ~ reports describing ~ environmental monitoring programs at the Calvert Cliffs  ;

and Robinson facilities (April 29, 1996 submittal from Baltimore Gas &

Electric and August 29,'1996, from Carolina Power & Light) are provided as  !

Enclosures 8 and 9. General information regarding ISFSIs at various reactor i sites is provided in Enclosure 10, NUREG-1571, "Information Handbook on l Independent Spent Fuel' Storage Installations." ,

The installation of the berm around the Prairie Island ISFSI is intended to offer additional shielding from the direct radiation coming from the storage ,

nasks. _ As discussed in the enclosed chapter from the Prairie Island ISFSI  :

safety analysis report, the berm effectively eliminates direct radiation from

-the casks as a source for offsite exposure. An opening in.the berm was required to provide access to the ISFSI but is oriented to minimize the potential impact on radiation doses received by members of the public. In regard to the specific placement of casks within the ISFSI, the dose estimates presented in the safety analysis report continue to be conservative with

. respect to the actual loading pattern implemented at Prairie Island.

Monitoring data recorded around the Prairie Island ISFSI will provide information regarding the radiological effect of adding the sixth and seventh casks.

Regulatory responsibility for spent fuel transportation safety is shared by- ,

the NRC and the U.S. Department of Transportation (D0T). DOT regulations in  !

Part 173 of Title 49 of the Code of Federal Reaulations (49 CFR 173) limit the i radiation level at the cask surface to 1000 millirem / hour, 200 millirem / hour i at the vehicle surface, and 10 millirem / hour at 2 meters from the vehicle  !

surface. Additional information related to the transport of spent fuel is provided in Enclosure 11, NUREG-0725, Rev. II, "Public Information Circular i for Shipments of Irradiated Reactor Fuel," and Enclosure 12, NRC Technical  ;

Issue Paper 30, " Transportation of Radioactive Materials."

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Mr. Charles Smit 1 I hope the information provided will be useful to you. Please contact i William Reckley on 301-415-1314 if you have any additional questions or l concerns. '

Sincerely, Original signed by:

Gail H. Marcus, Project Director Project Dire:torate III-3 Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation Docket Nos.: 50-282, 50-306, 72-10

Enclosures:

As stated (12) cc w/o enc 1: see attached page DISTRIBUTION (w/c enc 1):

Docket File (50-282/306, 72-10) )

PD33 R/F PUBLIC R. Zimmerman i J. Roe E. Adensam (EGAl) B. Wetzel B. Reamer (OGC) M. Delligatti, NMSS P. Eng, NHSS V. Tharpe, NMSS (w/ incoming) R. Landsman, RIII NAME: G:\ DRY CASK \SAIT.LTR *See previous concurrence , ,#

To receive e copy, indicate in the boa: "C" " Lepy without enclosurejk T . copy wth p, , og teP = No copy 0FC P033:PM E PD33:LA l C WSS:SFPO LN OGC F i l"W 7633:0 l r4ME WReckley a:% EBarnhill El% CMaughney (EEi / MMWa IIl JiMercus (jflM DATE 2/f4/97 2/pc/97 2/18/97 ' 5 2/d' /97 / ih 2/1997 0FFICIAL RECORD COPY

Mr. Charles Smit .

I hope the information'provided;will'be useful to you. Please contact William Reckley on 301-415-1314;if.you have any' additional questions or concerns. , ,

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Sincerely,y l

' i Origi'nal signed by: 1

)

Gail H. Marcus, Project Director i Project Directorate III-3 1 Division of Reactor Projects III/IV )

Office of Nuclear Reactor Regulation

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Docket Nos.: 50-282, 50-306,'72-10 i

Enclosures:

As stated (12) cc w/o encl: see attached page j DISTRIBUTION (w/o encl)* i Docket File (50-282/306, 72-10)  !

PD33 R/F PUBLIC R. Zimmerman J. Roe' E. Adensam (EGA1) B. Wetzel B. Reamer (0GC) M. Delligatti, NMSS P. Eng, NMSS V. Tharpe, NMSS (w/ incoming) R. Landsman, RIII NAME: Gi\ DRY CASK \ SMIT.LTR *See previous concurrence r To receive a copy, Indicate in the box: "C" = copy without enclosurqh T . copy with odeL -d = No copy OFC PD33:PM E PD33:LA l C NMSS:SFPU lfo N OGC N i l' ~t FPD33:D l NAME WReckleY ulhE- EBarnhiLL Y PV CMaughney / M/ VlMS /f\ llMarcus (rftP1 DATE 2/ft/97 2/pc/97 2/]J/97 5 2/?j/97 (i( 2/1f/97 0FFICIAL RECORD COPY

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Northern States Power Company Prairie Island Nuclear Generating i Plant cc:

Mr. Roger 0. Anderson, Director Site 1.icensing l Licensing and Management Issues Prairie Island Nuclear Generating l Northern States Power Company Plant I 414 Nicollet Mall Northern States Power Company Minneapolis, Minnesota 55401 1717 Wakonade Drive East Welch, Minnesota 55089 J. E. Silberg, Esquire Shaw, Pittman, Potts and Trowbridge Tribal Council 2300 N Street, N. W. Prairie Island Indian Community ,

Washington DC 20037 ATTN: Environmental Depertment i 5636 Sturgeon Lake Road i Plant Manager Welch, Minnesota 55089  !

Prairie Island Nuclear Generating Plant Philip A. Gartner, Esq.

Northern States Power Company Gartner & Shulman, Ltd.

1717 Wakonade Drive East P. O. Box 149 Welch, Minnesota 55089 120 West Center Lake City, MN 55041 Adonis A. Neblett Assistant Attorney General Office of the Attorney General 455 Minnesota Street Suite 900 St. Paul, Minnesota 55101-2127 U.S. Nuclear Regulatory Commission Resident Inspector's Office 1719 Wakonade Drive East Welch, Minnesota 55089-9642 Regional Administrator, Region III U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle, Illinois 60532-4351 i l

Mr. Jeff Cole, Auditor / Treasurer Goodhue County Courthouse Box 408 Red Wing, Minnesota 55066-0408 Kris Sanda, Commissioner Department of Public Service 121 Seventh Place East l Suite 200 St. Paul, Minnesota 55101-2145 i Novameer 1996