RIS 2002-06, Withdrawn NRC Regulatory Issue Summary 2002-06, Evaluating Occupational Dose for Individuals Exposed to NRC-Licensed Material and Medical X-rays.
| ML021080436 | |
| Person / Time | |
|---|---|
| Issue date: | 04/16/2002 |
| From: | Cool D A NRC/NMSS/IMNS |
| To: | |
| DeCicco J E, NMSS/IMNS, 415-7833 | |
| References | |
| RIS-02-006 | |
| Download: ML021080436 (8) | |
Withdrawn NRC Regulatory Issue Summary 2002-06, "Evaluating Occupational Dose for Individuals Exposed to NRC-Licensed Material and Medical X-Rays," dated April 16, 2002, has been withdrawn. ADAMS Accession Number: ML021080436 See Federal Register notice dated October 25, 2016 81 FR 73448 UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDSWASHINGTON, D.C. 20555-0001April 16, 2002NRC REGULATORY ISSUE SUMMARY 2002-06EVALUATING OCCUPATIONAL DOSE FOR INDIVIDUALS EXPOSED TO NRC-LICENSED MATERIAL AND MEDICAL X-RAYS
Addressees
- All medical licensees.
Intent
- The U.S. Nuclear Regulatory Commission (NRC) is issuing this regulatory issue summary (RIS)to inform addressees of a personnel radiation monitoring compliance issue identified during recent inspections of medical licensees. In addition, this RIS provides specific guidance for determining doses to individuals who receive exposures from medical x-ray radiation, while wearing protective apparel (i.e., protective apron, or protective apron and thyroid shield). No specific action nor written response is required.Background:The NRC staff has observed that some medical licensees assigned whole body doses tooccupationally exposed employees in a manner that did not conform with the requirements, in10 CFR Part 20, for calculating occupational doses. These employees were subject to NRC
dose limits because they were exposed to NRC-licensed material. The individuals also received occupational exposure from medical x-ray equipment, which is not regulated by NRC.
The licensees had used fluoroscopy-specific dose methodologies approved by their States to demonstrate compliance with NRC dose limits. These methodologies differed from the methodology specified in Part 20. The licensees had not requested prior NRC approval for the use of these methodologies in demonstrating compliance with NRC dose limits.This RIS provides specific guidance for appropriate methodologies when licensees receiveoccupational exposures from medical x-ray radiation, while wearing protective apparel.
Summary of Issue
- The NRC regulations [10 CFR 20.1201(a)] require that occupational doses from radiation shallnot exceed annual limits of 0.05 sievert (Sv) (5 rem) total effective dose equivalent (TEDE), or
0.5 Sv (50 rem) to any one organ. In accordance with Section 20.1001(b), the limits apply to the total dose from both licensed and unlicensed sources. Section 20.1201(c) also requires that the assigned deep dose equivalent (DDE) be for the part of the body that receivesthe highest exposure. In addition, Footnote 2 to the "Organ Dose Weighting Factors" table in
10 CFR 20.1003 states that "For purposes of weighting the external dose (for adding to the internal dose), a single weighting factor wT = 1.0, has been specified. The use of otherweighting factors for external exposure will be approved on a case-by-case basis until such time as specific guidance is issued." The use of weighting factors for organs or tissues is defined in 10 CFR 20.1003 only in thecontext of calculating an effective dose equivalent. However, the definition of TEDE in Section 20.1003 [i.e., the sum of the DDE (external) and the committed effective dose equivalent (internal)] does not use the effective dose equivalent for external exposures.
Footnote 2 in the "Organ Dose Weighting Factors" table in 10 CFR 20.1003 does permit approval of the use of organ and tissue weighting factors for external exposures on a case-by- case basis. NRC, reading Part 20 as a whole, to give meaning to the footnote concerning external exposure, concludes that the footnote provides the staff with the discretion to permit the use of effective dose equivalent for external exposures in place of DDE, in the definition of TEDE. In accordance with the discretion provided by the footnote, TEDE may be redefined, for purposes of applying the footnote, as the sum of the effective dose equivalent for external exposure and the committed effective dose equivalent for internal exposure. When this redefinition of TEDE is used, 10 CFR 20.1201(c) does not apply, because the DDE is no longer used in the definition of TEDE.NRC will allow licensees to implement radiation protection programs that redefine TEDE inparticular situations when reliable, accurate, and predictable estimates of the effective dose equivalent are possible, given the conditions of exposure, and are based on methods that are acceptable to NRC. The proposed methods should be appropriate for the exposure conditions.
NRC will accept methods approved by appropriate State regulatory agencies with jurisdiction over the radiation source. For the specific case of occupational exposure to medical x-ray radiation while wearing protective apparel, the guidance that follows may be used to demonstrate compliance with the Part 20 occupational dose limits. This guidance does not apply to any other exposure scenarios.A licensee will be considered to be in compliance with Part 20 for the determination ofoccupational dose when occupational exposures result in part from medical x-ray radiation, while wearing protective apparel, under the following conditions:1) A licensee uses a method approved by a State that has regulatory jurisdictiongoverning the use of its medical x-ray generating equipment.2) Federal licensees, where a State regulatory entity does not have jurisdiction, may useone of the alternative methods outlined in Attachment 1.3) If a State has not approved a specific alternative method, then one of the alternativemethods in Attachment 1 is acceptable to NRC. Nothing in this RIS relieves a licensee from the need to comply with applicable State regulatory requirements or laws. ) Any alternative method that is used must have been incorporated into the licensee'sprocedures and radiation safety program before the exposure for which the alternative method is to be applied. 5) The effective date of the guidance in this RIS is April 16, 2002. Licensees may notapply this guidance to exposures received before the effective date of the RIS. Licensees who receive occupational exposures from medical x-ray radiation, while wearingprotective apparel, are not required to submit an exemption or amendment request if they adhere to the above conditions of this RIS.In addition, NRC is issuing an Enforcement Guidance Memorandum (EGM) 02-002 on thisissue. This EGM provides that enforcement discretion should be exercised for violations of Sections 1201(a) and (c) involving x-ray exposures that have already occurred. This policy of exercising enforcement discretion is being made effective for 60 days following issuance of this RIS to allow for receipt of the RIS, and implementation of its guidance. Violations of Sections 1201(a) and (c) involving x-ray exposures after the 60 day grace period will be considered for enforcement action in accordance with the NRC Enforcement Policy.For all licensees, all other occupational exposures should continue to be evaluated using theDDE provisions of 10 CFR 20.1201(c), unless specific application has been made and approved. Licensees are reminded that Section 20.1201 also contains annual occupational dose limits for individual organs, the lens of the eye, extremities, and the skin. The guidance in this RIS does not affect the determination of occupational dose for those parts of the body.This RIS requires no specific action nor written response. If you have any questions about thissummary, please contact the technical contact listed below or the appropriate regional office.Donald A. Cool, Director /RA/Division of Industrial and Medical Nuclear Safety Office of Nuclear Material Safety and Safeguards
Technical Contact:
Joseph E. DeCicco, NMSS (301) 415-7833 E-mail: jxd1@nrc.govAttachments:1.Acceptable Alternative Methods for Compliance with 10 CFR Part 20 with OccupationalExposure to Medical X-ray Radiation When Protective Apparel is Used2. List of recently issued NRC Regulatory Issue Summaries Attachment 1 Acceptable Alternative Methods for Compliance with 10 CFR Part 20 with OccupationalExposure to Medical X-ray Radiation When Protective Apparel is Used 1. From the Conference of Radiation Control Program Directors, Inc., "Suggested StateRegulations for Control of Radiation, Volume 1 (Ionizing)", 1995, Frankfort, KentuckyWhen a protective apron is worn while working with medical fluoroscopic equipment andmonitoring is conducted as specified in D.502a.iv., the effective dose equivalent for external radiation shall be determined as follows:(1) When only one individual monitoring device is used and it is located at theneck outside the protective apron, the reported deep dose equivalent shall be the effective dose equivalent for external radiation; or(2) When only one individual monitoring device is used and it is located at theneck outside the protective apron, and the reported dose exceeds 25 percent of the limit specified in D.201.a., the reported deep dose equivalent value multiplied by 0.3 shall be the effective dose equivalent for external radiation;or(3) When individual monitoring devices are worn, both under the protective apronat the waist and outside the protective apron at the neck, the effective dose equivalent for external radiation shall be assigned the value of the sum of the deep dose equivalent reported by the individual monitoring device located at the waist under the apron multiplied by 1.5 and the deep dose equivalent reported for the individual monitoring device located at the neck outside the protective apron multiplied by 0.04.2. From the National Council on Radiation Protection and Measurement, NCRP Report 122, "Use of Personal Monitors to Estimate Effective Dose Equivalent andEffective Dose to Workers for External Exposure to Low-LET Radiation," 1995,Bethesda, Maryland.When two personal monitors are used, one worn under a protective apron at the waistor on the chest [where HW is the Hp(10) value for this personal monitor] and the otherworn outside and above the apron at the neck, it is recommended that the value of HEbe estimated from the formula:HE (estimate) = 1.5HW + 0.04HN .[NRC Note: Hp(10) is the personal dose equivalent for strongly-penetrating radiationdetermined at a depth of 10 mm, and is synonymous with deep dose equivalent. HNdenotes the monitor located at the neck]
Attachment 1 . From an American National Standard Institute / Health Physics Society, ANSI/HPSN13.41 - 1997, "Criteria for Performing Multiple Dosimetry," Health Physics Society,McLean, VirginiaThe resultant effective dose equivalent estimate is the under-apron dosimeter providingan estimated dose equivalent for the thorax, abdomen, right and left thigh, multiplied by
0.89, plus the unshielded dosimeter providing a dose equivalent estimate for the head/neck and upper arms, multiplied by 0.11.[NRC Note: This method uses two dosimeters, worn similarly as in 2.] 4. Updated versions of methods listed in 1, 2, or 3. ) Any alternative method that is used must have been incorporated into the licensee'sprocedures and radiation safety program before the exposure for which the alternative method is to be applied. 5) The effective date of the guidance in this RIS is April 16, 2002. Licensees may notapply this guidance to exposures received before the effective date of the RIS. Licensees who receive occupational exposures from medical x-ray radiation, while wearingprotective apparel, are not required to submit an exemption or amendment request if they adhere to the above conditions of this RIS.In addition, NRC is issuing an Enforcement Guidance Memorandum (EGM) 02-002 on thisissue. This EGM provides that enforcement discretion should be exercised for violations of Sections 1201(a) and (c) involving x-ray exposures that have already occurred. This policy of exercising enforcement discretion is being made effective for 60 days following issuance of this RIS to allow for receipt of the RIS, and implementation of its guidance. Violations of Sections 1201(a) and (c) involving x-ray exposures after the 60 day grace period will be considered for enforcement action in accordance with the NRC Enforcement Policy.For all licensees, all other occupational exposures should continue to be evaluated using theDDE provisions of 10 CFR 20.1201(c), unless specific application has been made and approved. Licensees are reminded that Section 20.1201 also contains annual occupational dose limits for individual organs, the lens of the eye, extremities, and the skin. The guidance in this RIS does not affect the determination of occupational dose for those parts of the body.This RIS requires no specific action nor written response. If you have any questions about thissummary, please contact the technical contact listed below or the appropriate regional office.Donald A. Cool, Director /RA/Division of Industrial and Medical Nuclear Safety Office of Nuclear Material Safety and Safeguards
Technical Contact:
Joseph E. DeCicco, NMSS (301) 415-7833 E-mail: jxd1@nrc.govAttachments:1.Acceptable Alternative Methods for Compliance with 10 CFR Part 20 with OccupationalExposure to Medical X-ray Radiation When Protective Apparel is Used2. List of recently issued NRC Regulatory Issue SummariesDistribution:WITS200100105Coordinated with:NMSS 200100388L Bolling, OSTP, S Merchant, OE, J Lieberman, OGC, RZelac, IMNS, S Sherbini, NMSS, State Radiation ControlPrograms, ACMUIDOCUMENT NAME: G:\DeCicco/mixed_dose_RIS_2.wpdOFCMSIBIMNSMSIBIMNSNAMEJDeCiccoE Kraus/TechEdJHickeyDCoolDATE03/25/0203/25/024/2 /024/9/02OFFICIAL RECORD COPY
______________________________________________________________________________________OL = Operating License CP = Construction PermitAttachment 2 LIST OF RECENTLY ISSUEDNRC REGULATORY ISSUE SUMMARIES_____________________________________________________________________________________Regulatory Issue Date of Summary No. Subject IssuanceIssued to_____________________________________________________________________________________2002-05NRC Approval of Boiling WaterReactor Pressure Vessel Integrated Surveillance Program04/08/2002All holders of operating licensesfor boiling-water-reactors (BWRs),
except those who have permanently ceased operations and have certified that fuel has been permanently removed from the reactor vessel.2002-04Results of the Pilot Test of theProposed Changes to the Unplanned Scrams Performance Indicator and the Scrams with Loss of Normal Heat Removal Performance Indicator03/01/2002All holders of operating licensesfor nuclear power reactors, except those who have permanently ceased operations and have certified that fuel has been permanently removed from the reactor vessel.2002-03Guidance on the ContentMeasurement Uncertainty Recapture Power Uprate Applications01/31/2002All holders of operating licensesfor nuclear power reactors, except those that have permanently ceased operations and have certified that fuel has been permanently removed from the reactor vessel.2002-02Lessons Learned Related toRecently Submitted Decommissioning Plans and License Termination Plan01/16/2002All NRC licensees.2002-01Changes to NRC Participation inthe International Nuclear Event Scale01/14/2002All NRC licensees and certificateholders.2001-25NEI-099-02, Revision 2, VoluntarySubmission of Performance Indicator Data12/12/2001All holders of operating licensesfor nuclear power reactors, except those who have permanently ceased operations and have certified that fuel has been permanently removed from the reactor vessel.