Pathways of exposure to the population from releases of radionuclides to the atmosphere include inhalation,
air submersion, and consumption of contaminated food. Pathways of exposure associated with
Hanford-generated radionuclides present in the Columbia River include consumption of drinking water, fish,
and irrigated foods, and external exposure during aquatic recreation. The regional population dose from 1994
Hanford operations was estimated by calculating the radiation dose to the population residing within an
80-km (50-mi) radius of the onsite operating areas. Results of the dose calculations are shown in Table 6.0.2.
Food pathway, dietary, residency, and recreational activity assumptions for these calculations are given in
Appendix D.
The potential dose calculated for the population was 0.6 person-rem (0.006 person-Sv) in 1994, compared to 0.4
person-rem (0.004 person-Sv) in 1993. The 80-km (50-mi) population doses attributed to Hanford operations from
1990 through 1994 are compared in Figure 6.0.3
.
Primary pathways contributing to the 1994 dose to the population were
- consumption of drinking water contaminated with radionuclides (principally tritium and uranium) released to the
Columbia River at Hanford (44%)
- consumption of foodstuffs contaminated with radionuclides (principally iodine-129 released with gaseous
effluents primarily from the PUREX Plant stack [29% of the total dose])
- inhalation of radionuclides (principally iodine-129) that were released to the air from the PUREX Plant stack
(24%).
The average per capita dose from 1994 Hanford operations, based on a population of 380,000 within 80 km (50
mi), was 0.002 mrem (
). This dose estimate may be compared with doses from other routinely
encountered sources of radiation such as natural terrestrial and cosmic background radiation, medical treatment and
X rays, natural radionuclides in the body, and inhalation of naturally occurring radon. The national average
radiation doses from these other sources are illustrated in Figure 6.0.4. The estimated per capita dose to individual
members of the public from Hanford sources is a small fraction (approximately 
) of the annual per
capita dose (300 mrem) from natural background sources.
The doses to the MEI and to the 80-km (50-mi) population from Hanford effluents are compared to appropriate
standards and natural background radiation in Table 6.0.3. This table shows that the calculated radiation doses from
Hanford operations in 1994 are a small percentage of the standards and of natural background.
Doses from Other Than DOE Sources
DOE maintains an awareness of other manmade sources of radiation (other than DOE sources), which if
combined with the DOE sources might have the potential to exceed a dose contribution to any member of the
public of 10 mrem (0.1 mSv). Various non-DOE industrial sources of public radiation exposure exist at or
near Hanford. These include the low-activity commercial radioactive waste burial ground at Hanford
operated by US Ecology, the nuclear generating station at Hanford operated by Washington Public Power
Supply System, the nuclear fuel production plant operated by Siemens Power Corporation, the commercial
low-activity radioactive waste compacting facility operated by Allied Technology Group Corporation, and a
commercial decontamination facility operated by Vectra Technology, Inc. (Figure 6.0.1). With information
gathered from these companies, it was conservatively determined that the total 1994 individual dose from their
combined activities is on the order of 0.05 mrem (
). Therefore, the combined dose from
Hanford area non-DOE and DOE sources to a member of the public for 1994 was well below any regulatory
dose limit.
Figure 6.0.4
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