ML20135E657
| ML20135E657 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 12/31/1996 |
| From: | NORTHERN STATES POWER CO. |
| To: | |
| Shared Package | |
| ML20135E653 | List: |
| References | |
| NUDOCS 9703100084 | |
| Download: ML20135E657 (5) | |
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i Attachment B 2
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l Off-Site Radiation Dose Assessment i
January 1 - December 31,1996 ii i
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(The attached Report contains 4 pages.)
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P 9703100084 970228 1
PDR ADOCK 05000263 R
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NORTIIERN STATES POWER COMPANY MONTICELLO NUCLEAR GENERATING PLANT Off Site Radiation Dose Assessment for January 1,- December 31,1996 An assessment of radiation dose due to releases from the Monticello Nuclear Generating Plant during 1996 was performed in accordance with the Technical Specifications. Computed doses were well below the 40 CFR 190 Standards and 10 CFR Part 50, Appendix 1 Guidelines.
Off. site dose calculation formulas and meteorological data from the Off-site Dose Calculation hianual were used in making this assessment. Source terms were obtained from the two Semi-Annual Effluent Release Reports for 1996.
Off-Site Doses from Gaseous Releases Computed doses due to gaseous releases are reported in Table 1. Critical receptor location and pathways for organ doses are reported in Table 2. Doses, both whole body and organ, are a small percentage of Appendix 1 Guidelines.
Off-Site Doses From Liquid Releases Doses from liquid releases are listed in Table 1.
Doses to Individuals Due to Activities Inside the Site lloundary Occasionally sportsmen enter the hionticello site for recreational activities. In addition, an Environmental Protection Agency Field Station is located at the Monticello site (see Figure 3.8.1 and 3.8.2 of the Monticello Technical Specifications). While this station is no longer operational, workers occasionally visit this field station. Using an assumption of 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> / week would be very conservative and would represent the most exposed individuals. Whole body doses to these individuals have been computed using plant stack and reactor building vent X/Q values for the Field Station location. Annual computed doses were reduced by the factor of 40/168 to account for the limited occupancy for workers at this location. Organ doses to workers at the EPA Field Station due to gaseous releases have been computed. Doses at this location are reported in Table 1.
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'.I Doses to Most Exposed Member of the General Public from Reactor Releases and Other Uranium Fuel Cycle So There are no other uranium fuel facilities in the vicinity of the Monticello site. The only other artificial source of exposure to the general public in addition to the plant eftluent releases is from direct radiation of the reactor and the steam turbines.
A review of environmental TLDs, which provides data on direct and skyshine radiation, and effluents usin the GASPAR code, which provides data on airborne pathways, shows that the whole body and organ doses to the nearest residence from the Monticello Plant are less than 5 mrem.
i Therefore, the most exposed member of the general public will no' receive an annual radiation dose from reactor efiluent releases and all other fuel cycle activities in excess of 40 CFR 190 standards of 25 mrem to the whole body,75 mrem to the thyroid, and 25 mrem to any other organ.
Radiological Environmental Monitoring Program Sampling Deviations There were no changes to the monitoring program and no milk or vegetable sampling deviations during this reporting period.
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Table 1 Off-Site Radiation Dose Assessment - Monticello PERIOD: January 1, through December 31,1996 i
i Niaximum Site Boundary Gamma Air Dose l
l (mrad /> ear) l 0.166 l
10 Ntaximum Site Boundary Beta Air Dose l
l (mrad / year) l 0.305 20 l
Maximum Off-Site Dose to Any Organ l
l (mrem / year) 0.187 l
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EPA Field Station (mrem / year) i Whole Body 0.002 5
Skin 0.003 15 Organ (Thyroid) 0.003 15 Maximum Off Site Dose (mrem)
Whole Body 0.000 3
Organ 0.000 10 Page 3 of 4
a Table 2 Off Site Radiation Dose Assessment-Monticello Supplemental Information PERIOD: January 1, through December 31,1996 Maximum Site Boundary Dose Location (from Reactor Building Vents)
Sector SSE Distance (miles) 0.40 EPA Field Station I
Sector SE Distance from Plant Stack (miles) 0.26 Distance from Reactor Building Vents 0.36 hlaximum Off Site Dose Location Sector SSW Distance (miles) 0.70 Pathways Ground, Inhalation, Vegetable Age Group Teen Organ GI Tract Ala.simum Off-Site Dose Location Downstream Pathways Drinking Water Drinking Water, Fish Age Group Infant Adult Organ Whole Body GI Tract Dilution Factor (drinking water) 7.1 7.1 1
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