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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

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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

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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.