Occupational Radiation Exposure at Commercial Nuclear Power Reactors and other Facilities 2017, Fiftieth Annual Report (NUREG-0713, Volume 39)
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Publication Information
Manuscript Completed: March 2019
Date Published: March 2019
Prepared by:
T.A. Brock
M.N. Nguyen
D.A. Hagemeyer*
D.B. Holcomb*
* ORAU
1299 Bethel Valley Road, SC-200, MS-21
Oak Ridge, TN 37830
M.N. Nguyen, NRC Project Manager
Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001
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Abstract
This report summarizes the occupational exposure data that are maintained in the U.S. Nuclear Regulatory Commission (NRC) Radiation Exposure Information and Reporting System (REIRS) database. The bulk of the information contained in this report was compiled from the 2017 annual reports submitted by five of the seven categories1 of NRC licensees subject to the reporting requirements of Title 10 of the Code of Federal Regulations (10 CFR) 20.2206, "Reports of Individual Monitoring." Because there are no geologic repositories for high-level waste currently licensed and no NRC-licensed low-level waste disposal facilities currently in operation, only five categories are considered in this report. The annual reports submitted by these licensees consist of radiation exposure records for each monitored individual. These records are analyzed for trends and presented in this report in terms of collective dose and the distribution of dose among the monitored individuals.
Annual reports for 2017 were received from a total of 191 NRC licensees from the five categories included in this report. The summation of reports submitted by the 191 licensees indicated that 166,526 individuals were monitored, 71,238 of whom received a measurable dose (Table 3.1). When adjusted for transient individuals, there were actually 118,715 unique individuals that were monitored, 52,861 of whom received a measurable dose (see Section 5).
The collective dose incurred by these individuals was 8,521 person-rem (85,210 person-millisieverts [mSv]), which represents a 21 percent increase from the 2016 value. The 2017 collective dose is 4 percent lower than the 5-year average of 8,910 person-rem (2012 – 2016), which is not a statistically significant change.2 The increase in collective dose in 2017 was due to an increase in three of the five reporting categories; industrial radiographers (35 percent increase), commercial nuclear power reactor licensees (20 percent increase), and spent fuel storage licensees (9 percent increase). Two reporting categories reported decreases; manufacturing and distribution (M&D) licensees (3 percent decrease) and fuel cycle licensees (8 percent decrease). When compared to the 5-year average of collective dose for each category, fuel cycle licensees had a statistically significant decrease. The increases or decreases for the remaining four categories were not statistically significant.
The number of individuals receiving a measurable dose increased by 9 percent from 2016, but was still 7 percent below the 5-year average and not statistically significant. When adjusted for transients, the average measurable dose of 0.16 rems (1.6 mSv) increased for 2017, but is not statistically significant when compared to the 5-year average. The average measurable dose is defined as the total effective dose equivalent (TEDE) divided by the number of individuals receiving a measurable dose. In 2017, two individuals exceeded 5 rem (50 mSv) TEDE at an industrial radiography licensee. (see Section 6).
In calendar year 2017, the average annual collective dose per reactor for light-water reactor (LWR) licensees was 65 person-rem (650 person-mSv). This is a 20 percent increase from the value reported for 2016 (Table 4.3) but is not statistically significant when compared to the 5-year average. The total outage hours at commercial nuclear power plants increased 4 percent from 2016 to 2017 [Ref. 1]. The collective dose for the LWR licensee category increased 1,051 person-rem (10,510 person-mSv) to 6,417 person-rem (64,170 person-mSv). The average annual collective dose per reactor was 118 person-rem (1,180 person-mSv) for the 34 boiling-water reactors (BWRs) and 37 person-rem (370 person-mSv) for 65 pressurized-water reactors (PWRs). The BWR 2017 value is 2 percent higher than the 5-year average annual collective dose per BWR reactor. The 2017 value for PWR licensees is 16 percent below the 5-year average annual collective dose per PWR reactor. Neither of these differences is statistically significant. The primary driver for the increase in collective dose for both PWRs and BWRs was a 16 percent increase in refueling outage hours from 2016 to 2017. Refueling activities generally result in increased individual and collective doses as the reactor vessel is opened and the spent fuel is removed. Conversely, a decrease in refueling outages and activities would result in lower individual and collective dose.
There were 26,950 individuals that were monitored at two or more licensees during the monitoring year. The assessment of the average measurable dose per individual is adjusted each year to account for the reporting of a measurable dose for transient individuals by multiple licensees. The adjustment to account for transient individuals has been specifically noted in footnotes in the figures and tables for commercial nuclear power reactors.
1 Commercial nuclear power reactors and test reactor facilities; industrial radiographers; fuel processors (including uranium enrichment facilities), fabricators, and reprocessors; manufacturing and distribution of byproduct material; independent spent fuel storage installations; facilities for land disposal of low-level waste; and geologic repositories for high-level waste. There are currently no NRC licensees involved in low-level waste disposal or geologic repositories for high-level waste.
2 This report presents additional Statistical Comparisons in Section 2.2.
Page Last Reviewed/Updated Tuesday, March 09, 2021