ML20024E915

Statement of Matl Facts as to Which There Is No Genuine Issue Re Eddleman Contention 80 on Atmospheric Dispersion Model

ML20024E915
Person / Time
Site:	Harris
Issue date:	09/01/1983
From:	Patricia Anderson CAROLINA POWER & LIGHT CO., SHAW, PITTMAN, POTTS & TROWBRIDGE
To:	Atomic Safety and Licensing Board Panel
Shared Package
ML20024E900	List: ML20024E899 ML20024E903 ML20024E906 ML20024E910 ML20024E915 ML20024E916 ML20024E917 ML20024E919
References
NUDOCS 8309070200
Download: ML20024E915 (4)

Text

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S:ptember 1, 1983 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of )

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CAROLINA POWER & LIGHT COMPANY )

AND NORTH CAROLINA EASTERN ) Docket Nos. 50-400 OL MUNICIPAL POWER AGENCY ) 50-401 OL y

(Shearon Harris Nuclear Power )

Plant, Units 1 and 2) )

APPLICANTS' STATEMENT OF MATERIAL FACTS AS TO WHICH THERE IS NO GENUINE ISSUE TO BE HEARD ON EDDLEMAN CONTENTION 80 Pursuant to 10 C.F.R. S 2.749 (a) , Applicants state, in support of their Motion for Summary Disposition of Eddleman Contention 80 in this proceeding, that there is no genuine issue to be heard with respect to the following material facts:

1. Eddleman Contention 80 alleges that Applicants' mixing and dispersion models are deficient in that they assume more complete mixing and dispersion than will actually take place and take insufficient account of rainout and thus do not assure compliance with 10 C.F.R. S 20.106, the 25 rem whole body and 300 rem thyroid exposure limits for an accident (contained in 10 C.F.R. S 100,11) and the below 10-3 of these values limit for normal operation.

2. Modeling is an approved tool used to provide an estimate of the dispersion of the effluent released and its concentration at various locations. Exhibit B attached to McFeaters Affidavit, at 3 (hereinafter " Exhibit B").

8309070200 830901 PDR ADOCK 05000400 Q PDR

3. Applicants use a Gaussian dispersion model to estimate atmospheric dispersion of the plume of radioactivity which could be released from SENPP. Exhibit B at 17.

4. The Gaussian dispersion model is an approved methodology adopted in NRC Regulatory Guides 1.4, 1.24, 1.25, 1.77, 1.09, 1.111 and 1.145. Exhibit B at 4-5.

5. The NRC has developed. computer codes based on the Gaussian dispersion model for use by the staff in evaluating routine and accidental releases from commercial nuclear power plants. NUREG/CR-2919; NUREG/CR-2858.

6. Applicants do not account for rainout in their dispersion model. Exhibit B at 26.'

7. , Rainout is wet deposition due to precipitation in a cloud. Exhibit B at 14; see Eddleman Contention 80.

8. Rainout decreases the concentration of radioactive releases in the atmosphere. Exhibit B at 26-27.

9. When radioactive materials are scavenged from the atmosphere into the soil and water, or " rained out," the environmental and time barriers to uptake into food pathways result in doses to individuals smaller than those that could I

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result from direct inhalation of radionuclides. Lei Affidavit I at Paragraph 4.

10. The omission of rainout from the dispersion model increases the conservatism of the model. Exhibit B at 27.

11. Mixing of the released material increases in the wake of a building. Exhibit B at 11-12.

12. The-Gaussian dispersion-model contains-a factor 4

to account for this increased mixing. Exhibit.B at 11-12.

.13 . . Due to the conservatism of:the factor used;to

- simulate-building wake effect, the generic; form of-the Gaussian model predicts concentrations in excess of those actually observed in-the wake of the building. Exhibit B'at 13.

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14. At Shearon Harris Nuclear Power Plant (SHNPP) the. building wake adjustment factor is minimized by using the I

smallest cross-sectional area of a building in estimating wake effect. Exhibit B at 24. This approach adds additional conservatism to the conservative wake adjustment factor normally incorporated into the Gaussian dispersion.model.

15. Stable atmospheric conditions lead to less mixing and dispersion and higher concentrations of pollutants.

. Exhibit.B at 19-25.

16. In applying the Gaussian model to SHNPP, Applicants

- assume an atmospheric stability "G." Exhibit B at 20.

17. "G" stability represents extremely' stable conditions and has been adopted by the NRC to ensure conservatism in dispersion modeling. Exhibit B at 20.

18. Applicants assume wind persistence in one direc-tion at . 75 mph (.333 m/sec) in applying the Gaussian dispersion model to SHNPP. Exhibit B at 19.

19. The assumptions of wind persistence in one i

direction, low wind speed and extremely stable atmospheric 9  %%

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conditions add additional conservatism to the Gaussian model.

Exhibit B at 22.

20. In applying the Gaussian dispersion model, Applicants assume that releases occur at ground level. This assumption is a " worst case" analysis because relative concen-tration will be highest at ground level. Exhibit B at 18-19.

21. Applicants' releases could actually occur at

-more than 150 feet above ground. By assuming ground level release, Applicants have incorporated additional conservatism into their model. Exhibit B at 18.

-22. Applicants' model complies with the requirements set forth in 10 C.F.R. Part 20.106 and with the guidelines contained in Regulatory Guides 1.111, 1.4 and 1.145.

Dated: September 1, 1983 Respectfully submitted, Thomas A. Baxter, P.C.

John H. O'Neill, Jr.

Pamela H. Anderson SHAW, PITTMAN, POTTS & TROWBRIDGE 1800 M Street,-N.W.

Washington, D.C. 20036 (202) 822-1000 Richard E. Jones Samantha Francis Flynn CAROLINA POWER & LIGHT COMPANY P.O. Box 1551 Raleigh, North Carolina 27602 (919) 836-6517 Counsel for Applicants l

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