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1
Recalculation of RG 1.109 Milk Consumption Rates
Bill EakinDominion – Millstone Power Station
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RG 1.109 Milk Consumption Rates
Tables E-4 and E-5: Recommended Values for Average and Maximum Exposed Individual In-Lieu of Site Specific Data
RG footnote: Average consumption rates obtained from Ref. 19 and age-prorating and maximums from techniques contained in Ref. 10.
Regulatory Guide 1.109 Milk Pathway Comsumption (Liters/Year) Parameter Adult Teen Child Infant RG Avgage 110 200 170 - RG Maxage 310 400 310 310
3
Why Re-calculate Milk Consumption?• Event
– Bad fuel caused increased iodine releases in outage
• Dose assessment– Method 1 calculation yielded thyroid >2.5 mrem
– Condition Report generated
• NRC comparison– Reviewed event calculation, performed verification with
PCDOSE
• Recommendation– Reduce conservatism in method (lower consumption)
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Millstone
5 miles
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RG 1.109 FootnoteAverage consumption rates obtained from Ref. 19
and age-prorating and maximums from techniques contained in Ref. 10.
• Ref. 10 – HERMES code, contains a relationship assumed between age specific maximum consumption to age specific average consumption
• Ref. 19 - AER-138 lists total fluid dairy consumed from 1960-1973
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HERMESHanford Engineering Regional Model for Environmental Study
Based on local dietary surveys, HERMES estimates:• Maximum to average milk consumption ratio
Child Teen Adult
Ratio 2 2 3
• Comparison of HERMES with RG 1.109
Max Individual Consumption Rate (Liters/Year) Urban Rural
Farm Rural
Non-Farm ALL RG 1.109
Table E-5 Child 348 402 361 357 330 Teen 414 477 429 424 400 Adult 326 377 339 335 310
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Agricultural Economic Report AER-138 (1974)
• Average milk consumption around the period when RG 1.109 was probably being developed was ~130 Liters/Year
• Compare with RG 1.109 Table E-4Using RG Avgage: Adult (110), Teen (200), Child (170) Liters/Year &Age fractions from RG 1.109 App. D: Adult (.71), Teen (.11), Child (.18)
RG Avg 0.71·110 + 0.11·200 + 0.18·170 = 130.7 Liters/Year
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Per Capita Milk Consumption Rate Trend
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020
Year
Liters/Year
SB 965 (04/99)
AER 820 (02/03)
AER 138 (12/74)
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Agricultural Economic Report AER-820 (2003)
• Average milk consumption since year 2000 is <65 Liters/Year
• Projected to remain relatively level for the next 20 years
• Why is milk consumption lower?– Dietary habits– Soda
10
Average Milk Consumption Comparison
1970: 32 Gallons consumed yearly per person
2000: 16 Gallons consumed yearly per person
Consumption considers fluid milk products
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New Milk Consumption RatesAssumption 1:RGAvgper capita FAdult·RGAvgAdult + FTeen ·RGAvgTeen + FChild ·RGAvgChild
Assumption 2:
Assumption 3:
capitaper
capitaper
age
age
AvgRG
AvgNew
AvgRG
AvgNew
ageage
age
age
age ConstantAvgRG
MaxRG
AvgNew
MaxNew
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New Milk Consumption Rates
• New values are essentially ½ of original RG recommended values
• Since consumption rates are U.S. averages, these values are applicable to the entire industry.
Recalculated Milk Pathway Comsumption (Liters/Year) Parameter Adult Teen Child Infant New Avgage 55 100 85 - New Maxage 155 200 165 165
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Justification for Change• RG 1.109 encourages licensees to develop
site or regional specific parameters in-lieu of general approaches and assumptions provided
• Method used to develop original RG values remains unchanged
• Up-to-date consumption estimates, from a similar source, show consumption at ½ of original basis value
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References
• Ref 10: USAEC Report HEDL-TME-71-168 HERMES Computer Code, 1971.
• Ref 19: AER-138, “Food Consumption, Prices and Expenditures”, USDA, 1974.
• AER-820, Food and Agricultural Commodity Consumption in the United States: Looking Ahead to 2020”, USDA, 2003.