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| {{#Wiki_filter:UNITED STATES | | {{#Wiki_filter:}} |
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| NUCLEAR REGULATORY COMMISSION
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| OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
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| WASHINGTON, DC 20555-0001 August 4, 2021 NRC INFORMATION NOTICE 2021-02: RECENT ISSUES ASSOCIATED WITH
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| MONITORING OCCUPATIONAL EXPOSURE
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| TO RADIATION FROM LICENSED AND
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| UNLICENSED RADIATION SOURCES
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| ==ADDRESSEES==
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| All U.S. Nuclear Regulatory Commission (NRC) materials licensees. All Radiation Control
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| Program Directors and State Liaison Officers.
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| ==PURPOSE==
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| The NRC is issuing this information notice (IN) to inform addressees of recent issues
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| associated with monitoring occupational exposure to radiation from licensed and unlicensed
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| radiation sources under the licensees control. The NRC expects that recipients will review
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| the information for applicability to their facilities and consider actions, as appropriate, to
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| avoid similar problems. Any suggestions contained in the IN are not new NRC
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| requirements; therefore, no specific action or written response is required. The NRC is
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| providing this IN to the Agreement States for their information and for distribution to their
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| licensees as appropriate.
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| ==DESCRIPTION OF CIRCUMSTANCES==
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| From August 2018 to October 2020, the NRC identified issues at seven NRC medical-use
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| licensees involving compliance issues associated with monitoring individuals occupational
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| exposure to radiation from licensed and unlicensed radiation sources that were under the
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| control of the licensees. The issues were associated with occupational radiation exposures
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| received by interventional radiology (IR) physicians who were involved in the conduct of
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| NRC-licensed activities under the provisions of 10 CFR 35.1000, Other medical uses of
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| byproduct material or radiation from byproduct material. Although the issues described in
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| this IN were identified at NRC medical-use licensees, the information provided is applicable
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| to all NRC licensees where occupational radiation exposures from licensed and unlicensed
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| radiation sources can occur.
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| Monitoring Exposure to Unlicensed Radiation Sources Under Licensee Control
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| The IR physicians performed activities involving the administration of yttrium-90
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| microspheres, which is an NRC-licensed radioactive byproduct material. Additionally, the IR
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| physicians were exposed to unlicensed radiation sources. Unlicensed radiation sources are
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| not licensed by the NRC and include radiation from certain radiation-producing devices, such as fluoroscopy equipment and other x-ray-generating devices. Although not licensed
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| by the NRC, these sources of radiation may be subject to registration with state regulatory
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| agencies.
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| ML21152A239 Specifically, at the seven NRC medical-use licensees, IR physicians used fluoroscopic
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| (x-ray) guidance to place an intraarterial microcatheter to the targeted delivery area for the
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| yttrium-90 microspheres. The IR physicians who administered the yttrium-90 microspheres
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| also performed numerous other IR procedures using fluoroscopic guidance that did not
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| involve the use of NRC-licensed radiation sources.
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| During NRC inspections at the medical-use licensees, the NRC identified several issues, including licensees understanding of the NRC regulatory requirement in
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| 10 CFR 20.1502(a). This regulation requires that each licensee monitor exposure to
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| radiation and radioactive material at levels sufficient to demonstrate compliance with the
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| occupational dose limits specified in 10 CFR Part 20, Standards for protection against
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| radiation. In accordance with 10 CFR 20.1502, Conditions requiring individual monitoring
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| of external and internal occupational dose, requires monitoring of exposure to licensed and
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| unlicensed radiation sources under the control of the licensee:
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| As a minimum, each licensee shall monitor occupational exposure to radiation
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| from licensed and unlicensed radiation sources under the control of the licensee
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| and shall supply and require the use of individual monitoring devices by
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| (1) Adults likely to receive, in 1 year from sources external to the body, a dose in
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| excess of 10 percent of the limits in 10 CFR 20.1201(a); (2) Minors likely to
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| receive, in 1 year, from radiation sources external to the body, a deep dose
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| equivalent in excess of 0.1 rem (1 mSv), a lens dose equivalent in excess of
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| 0.15 rem (1.5 mSv), or a shallow dose equivalent to the skin or to the extremities
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| in excess of 0.5 rem (5 mSv); (3) Declared pregnant women likely to receive
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| during the entire pregnancy, from radiation sources external to the body, a deep
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| dose equivalent in excess of 0.1 rem (1 mSv); and (4) Individuals entering a high
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| or very high radiation area.
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| The NRC observed that some IR physicians wore assigned individual monitoring devices
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| (personnel dosimeters) inconsistently. For example, some IR physicians wore the assigned
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| personnel dosimeter only during yttrium-90 procedures, but not during IR procedures that
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| did not involve yttrium-90, under the misunderstanding that their exposure to unlicensed
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| x-ray sources was not required to be monitored. The inspectors also observed that some IR
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| physicians did not wear assigned personnel dosimeters at all when working with either
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| licensed or unlicensed radiation sources.
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| In accordance with 10 CFR 20.1101(a), licensees are required to develop, document, and
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| implement radiation protection programs commensurate with the scope and extent of
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| licensed activities and sufficient to ensure compliance with the provisions of 10 CFR Part 20,
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| Standards for protection against radiation. NRC inspectors found that licensees radiation
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| protection programs, specifically their policies and procedures for occupational dosimetry
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| programs, often did not have provisions to address 10 CFR 20.1201(f) and 10 CFR 20.2104, Determination of prior occupational dose. As a result, licensees did not account for
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| occupational radiation exposure received by individuals either: (1) concurrently while
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| employed at other facilities, including other NRC-licensed facilities, Agreement
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| State-licensed facilities, or unlicensed facilities, or (2) during the same calendar year, prior to
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| the individual performing licensed activities under the licensees control. Consequently, licensees were not cognizant of the total radiation dose received by those individuals and
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| whether this additional occupational dose would result in any radiation doses in excess of
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| the NRCs regulatory limits. Improper Use and Implementation of Dosimetry Approaches
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| The NRC found that the proper use of personnel dosimeters varied significantly among IR
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| physicians. In some cases, IR physicians wore their personnel dosimeter improperly, which
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| included not wearing the personnel dosimeter in the assigned location in accordance with
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| licensees policies (e.g., collar vs. waist, or above lead shielding vs. under lead shielding).
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| At one licensee, personnel dosimeters not being worn were stored improperly in a radiation
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| area. Several IR physicians did not exchange assigned personnel dosimeters at the
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| indicated frequency or often wore them significantly beyond the monitoring period indicated
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| on the dosimeter.
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| Dosimetry vendors often offer single- and double-dosimeter approaches with correction
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| factors to take nonuniform radiation exposures into account, such as those occupational
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| exposures received when wearing a lead apron during the performance of IR procedures.
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| Some licensees did not establish policies or procedures to address the dosimetry approach
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| used.
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| As a result, licensees inconsistently applied correction factors, which most often occurred
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| with double-dosimeter approaches. Double-dosimeter approaches typically rely on one
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| dosimeter to be worn at the collar outside of the lead, and one dosimeter to be worn at the
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| waist under the lead. Licensees that used a double-dosimeter approach often did not have
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| policies and procedures that addressed issues that would reasonably be expected to arise
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| from this dosimetry approach. For example, licensees did not have policies or procedures
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| for actions to be taken if one or both assigned personnel dosimeters were not turned in for
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| processing at the end of the assigned wear period. Licensees policies often did not
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| address actions to be taken if the personnel dosimeters were not worn at the assigned
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| location, such as if the waist dosimeter were worn at the collar outside of the lead. The NRC
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| observed that when this occurred, the licensee-assigned radiation exposures were often
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| higher, and in some cases grossly higher, than those that would have been expected for the
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| individual IR physician caseload.
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| Radiation Safety Programs: Training and Oversight
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| The NRC also identified various deficiencies regarding licensees implementation and
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| oversight of their radiation safety programs. These included deficiencies in licensees
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| radiation safety program content and implementation and their training programs.
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| Licensees also did not implement corrective actions to address identified personnel
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| dosimetry issues.
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| In the area of licensees radiation safety program content and implementation, the
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| inspectors found that licensees did not comply with 10 CFR 20.1101(a), which requires that
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| licensees develop, document, and implement radiation protection programs that are
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| commensurate with the scope and extent of licensed activities and sufficient to assure
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| compliance with 10 CFR Part 20. For several of the medical-use licensees involved in these
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| cases, the NRC found that the licensees radiation safety policies and procedures did not
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| adequately describe their personnel dosimetry program or to require the use of individual
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| monitoring devices.
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| In some cases, through routine audit and oversight activities, licensees or their third-party
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| auditors identified issues with individuals not wearing, or improperly wearing, their assigned
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| personnel dosimeters. However, when issues were identified, licensees either did not investigate these matters and implement corrective actions, or the corrective actions that
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| they implemented were not sufficient to correct the issues and prevent recurrence.
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| Although the NRC found most licensees policies and procedures for occupational dosimetry
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| programs to have established thresholds to identify unusually high radiation exposures, the
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| licensees did not to establish mechanisms to identify occupational radiation exposure values
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| that were unusually lower than expected, or where no results were reported. For example, several IR physicians performed over 100 IR procedures a month, but their monthly
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| personnel dosimeter reading was less than 1 millirem. It is unlikely that the performance of
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| over 100 IR procedures in 1 month would result in little to no measurable radiation dose.
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| These licensees did not have mechanisms to identify or flag these unusually low dosimeter
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| readings for further review or investigation.
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| Some licensees performed routine reviews of dosimeter results and identified unusually high
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| radiation exposures for IR physicians. However, in many cases, the licensees did not
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| investigate the cause of these excessively high or anomalous dosimeter readings. In some
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| cases, the licensees investigations consisted of a written warning to the IR physicians, but
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| the licensees did not actually investigate or attempt to understand the causes of the high or
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| anomalous dosimeter readings. In one case, a licensee observed high dosimeter results for
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| an IR physician and investigated the matter. The licensee determined that the IR physician
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| was wearing the assigned dosimeter correctly, while the other IR physicians with lower
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| dosimeter results were not wearing their assigned dosimeters correctly. However, the
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| licensee took no corrective actions to address the noncompliant dosimeter use by the other
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| IR physicians.
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| Licensees also did not provide adequate instruction to individuals in accordance with
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| 10 CFR 19.12, Instruction to workers. In all cases, the NRC found that the licensees
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| provided the IR physicians with personnel dosimeters, but the IR physicians rarely received
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| instruction or training in the licensees policies and procedures for dosimeter use. NRC
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| inspectors observed that some licensees assumed that IR physicians would already
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| possess such knowledge, based on their education and credentials, and that licensee- specific training was not required or necessary. Some licensees simply did not include IR
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| physicians in licensee training programs. This was observed to be more prevalent when the
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| IR physicians were contracted individuals or independent radiology providers rather than
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| licensee employees.
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| ==DISCUSSION==
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| The NRC regulates the possession and use of radioactive byproduct material, special
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| nuclear material, and source material. Licensed radiation sources are byproduct material, special nuclear material, and source material that are (1) authorized by a specific license
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| issued by the NRC or (2) authorized under a general license as specified in the NRC
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| regulations. Unlicensed radiation sources are those radiation sources that are not licensed
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| by the NRC under a specific or general license. Unlicensed sources include radiation from
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| certain radiation-producing devices, such as fluoroscopy equipment and other x-ray- generating devices. These unlicensed sources of radiation may be subject to registration
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| with state regulatory agencies.
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| Although the NRC identified the issues described in this IN at its medical-use licensees,
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| 10 CFR 20.1501(a) is applicable to all NRC licensees where occupational radiation
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| exposures from licensed and unlicensed radiation sources can occur. For example, some industrial radiography licensees use radiographic exposure devices with NRC-licensed
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| byproduct material radioactive sources, such as cobalt-60 and iridium-192, and also use
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| radiographic exposure devices that employ x-ray-generating sources, which are not licensed
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| by the NRC. If occupationally exposed individuals, such as industrial radiographers, use
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| byproduct material radioactive sources and x-ray-generating sources under the control of
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| the licensee, the licensee is required to monitor the occupational radiation exposures to
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| these individuals from both of these radiation sources.
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| In accordance with 10 CFR 20.1502(a), licensees are to supply and require the use of
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| individual monitoring devices for the specified categories of occupationally exposed
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| individuals. It is only through the proper use of these individual monitoring devices that
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| licensees can evaluate radiation doses to determine compliance with the NRCs
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| occupational dose limits.
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| The NRC identified compliance issues associated with the licensees occupational radiation
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| monitoring programs resulted in escalated enforcement action against several licensees and
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| required extensive licensee actions to correct the deficiencies. The licensees efforts
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| included significant revisions to licensees radiation safety programs, procedures and
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| policies, training programs, and oversight practices. Further, licensees corrective actions
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| included complex evaluations of radiation exposure data to determine radiation dose
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| estimates. Many of the licensees had to make radiation dose estimates for multiple IR
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| physicians for occupational radiation exposures that occurred over several years for
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| licensed and unlicensed radiation sources under the control of the licensees. Although
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| licensees radiation dose estimates resulted in no individual exceeding the NRCs
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| occupational dose limits specified in 10 CFR Part 20, several individuals closely approached
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| those limits.
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| The NRC expects that licensees will develop, implement, and maintain radiation protection
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| programs, including programs for monitoring occupational radiation exposures, that are
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| commensurate with the scope and extent of their activities, in accordance with
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| 10 CFR 20.1101(a). NRC inspectors have found that effective licensee radiation protection
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| programs include policies and procedures associated with monitoring occupational radiation
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| exposures. NRC inspectors found that comprehensive and effective policies and
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| procedures for monitoring occupational radiation exposures included provisions to address:
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| (1) criteria for occupational monitoring at the licensees facility; (2) prior or concurrent
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| occupational radiation exposures to licensed and unlicensed radiation sources;
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| (3) responsibilities for individuals to properly wear dosimeters; (4) licensee-specified
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| dosimeter wear locations; (5) expectations for turning in dosimeters for processing at the
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| end of assigned wear periods; (6) lost or missing dosimeters; (7) proper storage of
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| dosimeters when not in use; (8) prompt evaluation of dosimeter results; (9) criteria to
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| evaluate or investigate unusually low or high dosimeter results; and (10) periodic reviews
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| and oversight of licensee dosimetry programs. Because dosimetry approaches and
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| programs vary widely, it is important for individuals to receive licensee-specific training on
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| the policies and procedures that pertain to dosimeter use.
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| In accordance with 10 CFR 20.1101(c), licensees shall periodically (at least annually) review
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| the radiation safety program content and implementation. Effective auditing and radiation
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| safety program reviews may allow licensees to promptly identify compliance issues
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| associated with occupational monitoring programs and take actions to correct any identified
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| deficiencies and prevent recurrence. Licensees with effective auditing programs typically
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| use a combination of auditing techniques, including records review and direct observation of occupationally exposed individuals. For records reviews, licensees may find it beneficial to
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| compare dosimeter results data with information or data related to individuals licensed
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| activities (i.e., radioisotopes used, quantity used, frequency of use) and unlicensed activities
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| (i.e., characteristics of specific x-ray-generating devices used, duration of use, frequency of
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| use). Some licensees have found that such comparisons can be accomplished through
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| automated data collection systems that can flag discrepant data or be set to flag or identify
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| values that meet certain thresholds established by the licensee. For direct observation, licensees may elect to perform periodic spot-checks of occupationally exposed individuals
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| during licensed and unlicensed activities to determine whether dosimeters are being worn
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| properly. If licensee evaluations determine that occupational radiation doses exceed the
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| limits in 10 CFR Part 20, licensees are required report to the NRC in accordance with
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| 10 CFR 20.2203, Reports of exposures, radiation levels, and concentrations of radioactive
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| material exceeding the constraints or limits.
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| ==CONTACT==
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| This IN requires no specific action or written response. If you have any questions about the
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| information in this notice, please notify the technical contact listed below or the appropriate
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| regional office.
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| /RA/ /RA/
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| Christopher G. Miller, Director Kevin Williams, Director
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| Division of Reactor Oversight Division of Materials Safety, Security, Office of Nuclear Reactor Regulation State, and Tribal Programs
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| Office of Nuclear Material Safety
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| and Safeguards
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| ===Technical Contact:===
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| ===Janine F. Katanic, PhD, CHP, NRC Region IV===
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| (817) 200-1151 E-mail: Janine.Katanic@nrc.gov
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| ML21152A239 EPIDS No. L-2021-GEN-0006 OFFICE Author QTE Authors BC OE NRR/DRO/IOEB/PM NRR/DRO/LA
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| NAME JFKatanic/RA/ JDougherty /RA/ LRoldanOtero/RA/ JPeralta BBenney IBetts
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| DATE 6/8/21 6/3/21 6/2/21 6/16/21 6/22/21 06/21/21 OFFICE NRR/DANU/NPUF/BC NRR/DRO/IOEB/BC NMSS/MSST/D NRR/DRO/D
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| KMorgan- NAME JBorromeo LRegner KWilliams Butler for
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| CMiller
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| DATE 6/22/21 7/22/21 7/29/21 8/04/21}}
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| {{Information notice-Nav}} | | {{Information notice-Nav}} |