ML19225A222

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Discusses Info to Be Included in Offsite Dose Calculation Manual.Forwards 790126 Draft Offisite Dose Calculation Manual
ML19225A222
Person / Time
Site: Farley  Southern Nuclear icon.png
Issue date: 07/11/1979
From: Clayton F
ALABAMA POWER CO.
To: Schwencer A
Office of Nuclear Reactor Regulation
Shared Package
ML19225A223 List:
References
NUDOCS 7907180576
Download: ML19225A222 (2)


Text

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,-Mabama POWCT July 11, 1979 Mr. A. Schwencer U. S. Nuclear Regulatory Commission Division of Operating Reactors Branch Number 1 Washington, D.C. 20555

Dear Mr. Schwencer:

Revision 3 to NUREG 0472, Draf t Radiological Ef fluent Technical Speci-ficaticas for PWR's states that the following information should be included in an Offsite Dose Calculation Manual:

STS Section

1. 3.3.3.9 Procedure for calculating liquid ef fluent monitor alarm setpoints.
2. 3.3.3.10 Procedure for calculating gaseous effluent monitor alarm setpoints.
3. 4.11.1.1 Procedure for determination of site boundary concentra-tions for liquid ef fluents.

4 Table 4.11-1 Procedure for mixing liquid batches prior to release.

5. 4.11.1.2 Methodology for determination of offsite doses from _

liquid effluents.

6. 4.11.2.1 Methodology for determination of site boundary dose rates due to gaseous effluents.
7. 4.11.2.2 Methodology for determination of offsite Joses from noble gases.
8. 4.11.2.3 Methodology for determination of of f site deses f rom radiciodines and particulates.
9. 4.12.1 Table and figures sc. awing environmental monitoring sampling locations.

Only items 5, 7, and 8 are directly related to offsite dose calculations.

Based on our discussion with your staff on June 6, 1979, these sections of the FNP ODCM submitted on April 16, 1979 were tentatively agreed upon. An gQ attachment is enclosed to clarify the source of the constant 110 (rounded v value) used in the gaseous dose equations. (L 7 i44 79071gosyg 346

Mr. A. Schwencer PAGE TWO July 11, 1979 Items 1, 2, and 3 do not relate to the calculation of of f site doses.

Liquid and gaseous effluent monitor setpoints are calculated for the isotopes of primary concern (Co-60 or I-131 for liquids and Xe-133 for gases). This is accomplished by assuming the highest expected effluent flow and lowest expected dilution or dispersion. The site boundary concen-trations of liquid isotopes are derived by dividing the measured concentra-tions by the measured dilution factor. As none of these calculations are related to of f site dose calculations it is our position that their inclusion in the ODC' 'iould be inappropriate.

Itc pertains to operational sampling techniques. It is adequately covere/ plant procedures and should therefore not be addressed in the O'

. eu 6 does not concern the calculation of exposure doses for assurance

r compliance with 10CFR50, Appendix I. It concerns the calculation of relesse rates, in dose terms, to assure compliance with 10CFR20. Alabama Power Company has developed the first (and to the best of our knowledge, the only) dose based calculational software for the monitoring of releases. This software, which was developed at considerable expense, does not consider the ground plane or food pathways for dose rate calculations. While these path-ways are excluded, a conservatism of 36% is included in the Plant Farley software as the infant respiration rate used for inhalation pathway calcu-lations is 1900 m 3/ year vice the NRC staff's recommended number of 1400 m3/ year. Also, the Farley Nuclear Plant computer utilizes real time meteorology in the dose rata calculation, thereby providing a major enhance-ment of the accuracy of our calculations.

As the incorporation of food and ground plane pathways into the software would require a major rewrite of our programs, Alabama Power Company is re-questing NRC approval of this gaseous dose rate portion of the ODCM as it is written. The existing software for calculation of doses to the public in-cludes all pathways recommended in NUREG-0133, Section 5.3. Thus, no error is introduced into the calculated doses. Also, any caissions in the calcu-lations of dose rates are offset by the above mentioned conservatism.

Item 9 is acceptable to Alabama Power although it is unrelated to effluents. A table and three (3) figures are included in the attached copy of the revised ODCM.

Sincerely yours, s' , C -

% K . Wm F. L. Clayton, Jr.

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