RIS 2009-09, Withdrawn NRC Regulatory Issue Summary 2009-09: Use of Multiple Dosimetry and Compartment Factors in Determining Effective Dose Equivalent from External Radiation Exposures: Difference between revisions

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{{#Wiki_filter:Withdrawn NRC Regulatory Issue Summary 2009-09, Use of Multiple Dosimetry and Compartment Factors in Determining Effective Dose Equivalent from External Radiation Exposures, dated July 13, 2009, has been withdrawn.
{{#Wiki_filter:Withdrawn  


ADAMS Accession Number: ML082320040
NRC Regulatory Issue Summary 2009-09, Use of Multiple Dosimetry and Compartment Factors in Determining Effective Dose Equivalent from External Radiation Exposures, dated July 13, 2009, has been withdrawn.
  See Federal Register notice dated October 25, 2016
                    81 FR 73448


UNITED STATES
ADAMS Accession Number:  ML082320040
                            NUCLEAR REGULATORY COMMISSION
 
                        OFFICE OF NUCLEAR REACTOR REGULATION
See Federal Register notice dated October 25, 2016
                OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
81 FR 73448 
                    OFFICE OF FEDERAL AND STATE MATERIALS AND
 
                        ENVIRONMENTAL MANAGEMENT PROGRAMS
UNITED STATES  
                                WASHINGTON, DC 20555-0001 July 13, 2009 NRC REGULATORY ISSUE SUMMARY 2009-09 USE OF MULTIPLE DOSIMETRY AND COMPARTMENT FACTORS IN
NUCLEAR REGULATORY COMMISSION  
  DETERMINING EFFECTIVE DOSE EQUIVALENT FROM EXTERNAL
OFFICE OF NUCLEAR REACTOR REGULATION  
                                RADIATION EXPOSURES
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS  
OFFICE OF FEDERAL AND STATE MATERIALS AND
ENVIRONMENTAL MANAGEMENT PROGRAMS  
WASHINGTON, DC 20555-0001  
 
July 13, 2009  
 
NRC REGULATORY ISSUE SUMMARY 2009-09 USE OF MULTIPLE DOSIMETRY AND COMPARTMENT FACTORS IN  
DETERMINING EFFECTIVE DOSE EQUIVALENT FROM EXTERNAL  
RADIATION EXPOSURES  


==ADDRESSEES==
==ADDRESSEES==
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==INTENT==
==INTENT==
The NRC is issuing this regulatory issue summary (RIS) to inform licensees of an acceptable method for determining effective dose equivalent (EDE) from external sources of radiation. This method is documented in a plant specific safety evaluation and has been determined to be generically applicable to licensees when employed consistent with the assumptions, limitations, and commitments identified in this safety evaluation. This RIS communicates the NRCs determination of generic applicability and provides a summary of the information contained in the safety evaluation. No specific action or written response is required. NRC is providing this RIS to the Agreement States for their information and for distribution to their licensees as appropriate.
The NRC is issuing this regulatory issue summary (RIS) to inform licensees of an acceptable method for determining effective dose equivalent (EDE) from external sources of radiation. This method is documented in a plant specific safety evaluation and has been determined to be generically applicable to licensees when employed consistent with the assumptions, limitations, and commitments identified in this safety evaluation. This RIS communicates the NRCs determination of generic applicability and provides a summary of the information contained in the safety evaluation. No specific action or written response is required. NRC is providing this RIS to the Agreement States for their information and for distribution to their licensees as appropriate.


The NRC staff will issue a Regulatory Guide that will combine and identify approved methods for determining EDE from external sources (EDEex), allowing the use of EDEex in place of deep dose equivalent (DDE) for demonstrating compliance with total effective dose equivalent (TEDE) requirements in Title 10 of the Code of Federal Regulations (10 CFR) Chapter 1.
The NRC staff will issue a Regulatory Guide that will combine and identify approved methods for determining EDE from external sources (EDEex), allowing the use of EDEex in place of deep dose equivalent (DDE) for demonstrating compliance with total effective dose equivalent (TEDE) requirements in Title 10 of the Code of Federal Regulations (10 CFR) Chapter 1.


==BACKGROUND==
==BACKGROUND==
Effective January 3, 2008, the definition of TEDE in 10 CFR Part 20, Standards for Protection against Radiation, was amended (see Volume 72, page 68043, of the Federal Register, dated December 4, 2007). The amendment redefined TEDE as the sum of the effective dose equivalent (for external exposures) and the committed effective dose equivalent (for internal exposures). This change clarified that the EDEex could be used to demonstrate compliance with TEDE-based regulations.
Effective January 3, 2008, the definition of TEDE in 10 CFR Part 20, Standards for Protection against Radiation, was amended (see Volume 72, page 68043, of the Federal Register, dated December 4, 2007). The amendment redefined TEDE as the sum of the effective dose equivalent (for external exposures) and the committed effective dose equivalent (for internal exposures). This change clarified that the EDEex could be used to demonstrate compliance with TEDE-based regulations.


In addition, the NRC revised 10 CFR 20.1201(c) to require that, when external exposure is determined by measurement with an external personal monitoring device, the DDE must be used in place of the EDEex, unless the licensee determines EDEex using a dosimetry method approved by the NRC. The NRC has approved several methods for determining EDEex, allowing the use of EDEex in place of DDE for demonstrating compliance with the TEDE
In addition, the NRC revised 10 CFR 20.1201(c) to require that, when external exposure is determined by measurement with an external personal monitoring device, the DDE must be used in place of the EDEex, unless the licensee determines EDEex using a dosimetry method approved by the NRC. The NRC has approved several methods for determining EDEex, allowing the use of EDEex in place of DDE for demonstrating compliance with the TEDE  
requirements in 10 CFR Part 20. These methods are discussed in RIS 2002-06, Evaluating Occupational Dose for Individuals Exposed to NRC-Licensed Material and Medical X-Rays, dated April 16, 2002; RIS 2003-04, Use of the Effective Dose Equivalent in Place of the Deep Dose Equivalent in Dose Assessments, dated February 13, 2003; and RIS 2004-01, Method for Estimating Effective Dose Equivalent from External Radiation Sources Using Two Dosimeters, dated February 17, 2004. The method described in this RIS is another approved method.
requirements in 10 CFR Part 20. These methods are discussed in RIS 2002-06, Evaluating Occupational Dose for Individuals Exposed to NRC-Licensed Material and Medical X-Rays, dated April 16, 2002; RIS 2003-04, Use of the Effective Dose Equivalent in Place of the Deep Dose Equivalent in Dose Assessments, dated February 13, 2003; and RIS 2004-01, Method for Estimating Effective Dose Equivalent from External Radiation Sources Using Two Dosimeters, dated February 17, 2004. The method described in this RIS is another approved method.


On December 20, 2004, Southern California Edison submitted a request to the NRC to use the compartment factors found in American National Standard Institute/Health Physics Society (ANSI/HPS) N13.41-1997 as part of a proposed method of multiple dosimetry (see Agencywide Documents Access and Management System (ADAMS) Accession No. ML043630036). The NRC staff found ANSI/HPS N13.41-1997 deficient in certain areas, thereby limiting its use for demonstrating compliance with TEDE-based regulations. For example, the ANSI/HPS standard lacks specificity for the placement of personal monitoring devices.
On December 20, 2004, Southern California Edison submitted a request to the NRC to use the compartment factors found in American National Standard Institute/Health Physics Society (ANSI/HPS) N13.41-1997 as part of a proposed method of multiple dosimetry (see Agencywide Documents Access and Management System (ADAMS) Accession No. ML043630036). The NRC staff found ANSI/HPS N13.41-1997 deficient in certain areas, thereby limiting its use for demonstrating compliance with TEDE-based regulations. For example, the ANSI/HPS standard lacks specificity for the placement of personal monitoring devices.


The NRC staff determined that the method proposed by Southern California Edison, to use the ANSI/HPS N13.41-1997 compartment factors for determining EDEex, including their commitment to monitor each compartment at the location of highest exposure, is acceptable. On May 10,
The NRC staff determined that the method proposed by Southern California Edison, to use the ANSI/HPS N13.41-1997 compartment factors for determining EDEex, including their commitment to monitor each compartment at the location of highest exposure, is acceptable. On May 10,  
2005, the NRC approved the licensees request (see Safety Evaluation at ADAMS Accession No. ML051320194) concluding that the proposed method, as discussed further in this RIS, was technically sound and acceptable for the purposes of determining compliance with the TEDE-
2005, the NRC approved the licensees request (see Safety Evaluation at ADAMS Accession No. ML051320194) concluding that the proposed method, as discussed further in this RIS, was technically sound and acceptable for the purposes of determining compliance with the TEDE-
based regulations in 10 CFR Chapter 1.
based regulations in 10 CFR Chapter 1.


In developing this RIS, a stakeholder concern was raised by comment at a meeting, that some licensees using multiple dosimeters to monitor external radiation exposure (as with this EDE
In developing this RIS, a stakeholder concern was raised by comment at a meeting, that some licensees using multiple dosimeters to monitor external radiation exposure (as with this EDE  
method) may inappropriately reduce their work place radiation survey programs. Nothing in this RIS relieves the licensee of the survey requirements in 10 CFR 20 .1501(a), nor the requirements in 10 CFR 19.12 to inform the workers of workplace radiological hazards.
method) may inappropriately reduce their work place radiation survey programs. Nothing in this RIS relieves the licensee of the survey requirements in 10 CFR 20 .1501(a), nor the requirements in 10 CFR 19.12 to inform the workers of workplace radiological hazards.


==SUMMARY OF ISSUE==
==SUMMARY OF ISSUE==
The method for determining EDEex described in this RIS, includes the use of the compartment factors provided in ANSI/HPS N13.41-1997, Criteria for Performing Multiple Dosimetry.
The method for determining EDEex described in this RIS, includes the use of the compartment factors provided in ANSI/HPS N13.41-1997, Criteria for Performing Multiple Dosimetry.


The multiple dosimetry method in ANSI/HPS N13.41-1997 divides the whole body into seven separate compartments. Each compartment, or composite compartment (since the ANSI/HPS
The multiple dosimetry method in ANSI/HPS N13.41-1997 divides the whole body into seven separate compartments. Each compartment, or composite compartment (since the ANSI/HPS  
standard allows combining adjacent compartments), is monitored separately. The dose measurement for each compartment is the personal dose equivalent for penetrating radiation at a depth of 10 millimeters, or Hp(10). This Hp(10) is equivalent to the DDE as defined in 10 CFR
standard allows combining adjacent compartments), is monitored separately. The dose measurement for each compartment is the personal dose equivalent for penetrating radiation at a depth of 10 millimeters, or Hp(10). This Hp(10) is equivalent to the DDE as defined in 10 CFR  
Part 20. The Hp(10), or measured DDE, value is then weighted with the associated compartment factor (W c).
Part 20. The Hp(10), or measured DDE, value is then weighted with the associated compartment factor (Wc).  
The factor for each compartment was developed by summing the stochastic weighting factors given in International Commission of Radiological Protection (ICRP) Publication 26 for all the organs located within that compartment. For each tissue that resides in more than one compartment (e.g., red bone marrow), the weighting factor is apportioned among the compartments based on the fraction of the total mass of the tissue residing in each using the information in ICRP Publication 23, Report of the Task Group on Reference Man.
 
The factor for each compartment was developed by summing the stochastic weighting factors given in International Commission of Radiological Protection (ICRP) Publication 26 for all the organs located within that compartment. For each tissue that resides in more than one compartment (e.g., red bone marrow), the weighting factor is apportioned among the compartments based on the fraction of the total mass of the tissue residing in each using the information in ICRP Publication 23, Report of the Task Group on Reference Man.
 
Table 1 of ANSI/HPS N13.41-1997 lists the compartment factors as shown below:   
 
Area of the Body/Compartment (c)
Compartment Factor (Wc)
 
Head and neck 
 
0.10 
 
Thorax, above the diaphragm 


Table 1 of ANSI/HPS N13.41-1997 lists the compartment factors as shown below:
0.38  
                          Area of the Body/Compartment (c)            Compartment Factor (W c)
                          Head and neck                                        0.10
                          Thorax, above the diaphragm                          0.38 Abdomen, including the pelvis                        0.50
                          Upper right arm                                      0.005 Upper left arm                                      0.005 Right thigh                                          0.005 Left thigh                                          0.005 EDEex is the sum of the products of the personal dose equivalent measured for each compartment and its associated compartment weighting factor, or:
                                              HE =  W C Hp,c(10)
        Where HE = effective dose equivalent (or EDEex), W c = compartment factor for compartment c, and Hp,c(10) = personal dose equivalent (or DDE) for compartment c.


As noted above, ANSI/HPS N13.41-1997 allows two or more adjacent compartments to be combined into a single composite compartment. The compartment weighting factor for a composite compartment is the sum of the weighting factors of the individual compartments that make up the composite compartment. Although not a condition of the NRC approval, several of the licensees who have obtained a site-specific approval to use this method, monitor the thorax and abdomen compartments as a single composite compartment similar to the original proposal by Southern California Edison.
Abdomen, including the pelvis


Fundamental to the compartment method of determining EDEex are the assumptions that (1) the average dose to the tissues in each compartment can be reasonably measured, and (2) the dose distribution across the compartment is sufficiently constant so that this average dose can be applied to each tissue in the compartment. The compartments defined in the standard are small enough so that under most normal exposure situations these assumptions are met and a single determination of DDE in each compartment is sufficient. However, this may not be the case in those unusual situations in which a significant dose gradient exists across one or more compartments (particularly the thorax and abdomen compartments). In these cases, the number and placement of dosimeters in each compartment becomes critical to ensuring that the EDEex is not underestimated.
0.50


To ensure that the estimates of EDEex are conservative, the licensee must measure the dose to each compartment (or composite compartment) by locating the dosimeter (calibrated to DDE) at the highest exposed portion of the respective compartment. The dosimeter location for each compartment is subject to the same criteria currently used to demonstrate compliance with
Upper right arm
10 CFR 20.1201(c). [Note: monitoring each compartment, or composite compartment, at the location of highest exposure results in a conservative estimate of EDEex no matter what combination of compartments and composite compartments are used - even in the extreme case of combining all compartments into a single whole body composite compartment.] CONCLUSION
NRC licensees may use the compartment factors of ANSI/HPS N13.41-1997 and the methodology described in this RIS for implementing a multiple dosimetry program in compliance with TEDE-based regulations. This methodology is consistent with the NRC Safety Evaluation issued to Southern California Edison on May 10, 2005 (ADAMS Accession No. ML051320194).
It should be noted that the NRC has not directly approved ANSI/HPS N13.41-1997, in and of itself, for use by licensees in a personnel monitoring program. The NRC has only approved the use of the compartment factors and associated method for calculating EDEex, as described in this RIS, for use in a multiple dosimetry program when combined with the method presented herein.


This RIS communicates the generic applicability of this method to determine EDEex . Licensees may use this method for demonstrating compliance with TEDE-based regulations. Therefore, licensees are no longer required to apply for approval to use this method on a site-specific basis.
0.005
 
Upper left arm 
 
0.005
 
Right thigh
 
0.005 
 
Left thigh
 
0.005
 
EDEex is the sum of the products of the personal dose equivalent measured for each compartment and its associated compartment weighting factor, or: 
 
HE =  WC Hp,c(10)
 
Where HE = effective dose equivalent (or EDEex), Wc = compartment factor for compartment c, and Hp,c(10) = personal dose equivalent (or DDE) for compartment c.
 
As noted above, ANSI/HPS N13.41-1997 allows two or more adjacent compartments to be combined into a single composite compartment.  The compartment weighting factor for a composite compartment is the sum of the weighting factors of the individual compartments that make up the composite compartment.  Although not a condition of the NRC approval, several of the licensees who have obtained a site-specific approval to use this method, monitor the thorax and abdomen compartments as a single composite compartment similar to the original proposal by Southern California Edison.
 
Fundamental to the compartment method of determining EDEex are the assumptions that (1) the average dose to the tissues in each compartment can be reasonably measured, and (2) the dose distribution across the compartment is sufficiently constant so that this average dose can be applied to each tissue in the compartment.  The compartments defined in the standard are small enough so that under most normal exposure situations these assumptions are met and a single determination of DDE in each compartment is sufficient.  However, this may not be the case in those unusual situations in which a significant dose gradient exists across one or more compartments (particularly the thorax and abdomen compartments).  In these cases, the number and placement of dosimeters in each compartment becomes critical to ensuring that the EDEex is not underestimated.
 
To ensure that the estimates of EDEex are conservative, the licensee must measure the dose to each compartment (or composite compartment) by locating the dosimeter (calibrated to DDE) at the highest exposed portion of the respective compartment.  The dosimeter location for each compartment is subject to the same criteria currently used to demonstrate compliance with
10 CFR 20.1201(c).  [Note:  monitoring each compartment, or composite compartment, at the location of highest exposure results in a conservative estimate of EDEex no matter what combination of compartments and composite compartments are used - even in the extreme case of combining all compartments into a single whole body composite compartment.] CONCLUSION
 
NRC licensees may use the compartment factors of ANSI/HPS N13.41-1997 and the methodology described in this RIS for implementing a multiple dosimetry program in compliance with TEDE-based regulations.  This methodology is consistent with the NRC Safety Evaluation issued to Southern California Edison on May 10, 2005 (ADAMS Accession No. ML051320194). 
It should be noted that the NRC has not directly approved ANSI/HPS N13.41-1997, in and of itself, for use by licensees in a personnel monitoring program.  The NRC has only approved the use of the compartment factors and associated method for calculating EDEex, as described in this RIS, for use in a multiple dosimetry program when combined with the method presented herein.
 
This RIS communicates the generic applicability of this method to determine EDEex . Licensees may use this method for demonstrating compliance with TEDE-based regulations. Therefore, licensees are no longer required to apply for approval to use this method on a site-specific basis.


==BACKFIT DISCUSSION==
==BACKFIT DISCUSSION==
The purpose of this RIS is to inform licensees of a method for determining EDEex that has been approved by the NRC for use in determining TEDE in several site-specific licensee requests for approval (See additional safety evaluations at ADAMS Accession Nos. ML051320194, ML080570154, ML072220355, and ML061870512). The staff positions and guidance discussed in this RIS are the same as those that provide the technical basis for these site-specific approvals. This RIS requires no action or written response. 10 CFR Part 20 provides several options for demonstrating compliance with the TEDE dose limits. Any action on the part of addressees in accordance with the guidance contained in this RIS is voluntary. Consequently, the staff did not perform a backfit analysis.
The purpose of this RIS is to inform licensees of a method for determining EDEex that has been approved by the NRC for use in determining TEDE in several site-specific licensee requests for approval (See additional safety evaluations at ADAMS Accession Nos. ML051320194, ML080570154, ML072220355, and ML061870512). The staff positions and guidance discussed in this RIS are the same as those that provide the technical basis for these site-specific approvals. This RIS requires no action or written response. 10 CFR Part 20 provides several options for demonstrating compliance with the TEDE dose limits. Any action on the part of addressees in accordance with the guidance contained in this RIS is voluntary. Consequently, the staff did not perform a backfit analysis.


===FEDERAL REGISTER NOTIFICATION===
===FEDERAL REGISTER NOTIFICATION===
The NRC did not publish a notice of opportunity for public comment on this RIS in the Federal Register because this RIS is informational and does not represent a departure from current regulatory requirements. Stakeholder comment was solicited in a September 10, 2008, public meeting. The draft RIS was attached to the meeting announcement (ADAMS ML082340248).
The NRC did not publish a notice of opportunity for public comment on this RIS in the Federal Register because this RIS is informational and does not represent a departure from current regulatory requirements. Stakeholder comment was solicited in a September 10, 2008, public meeting. The draft RIS was attached to the meeting announcement (ADAMS ML082340248).
A summary of the comments received, and their resolutions, can be found at ADAMS Accession No. ML082540738.
A summary of the comments received, and their resolutions, can be found at ADAMS Accession No. ML082540738.


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===PAPERWORK REDUCTION ACT STATEMENT===
===PAPERWORK REDUCTION ACT STATEMENT===
This RIS does not contain new or amended information collection requirements subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et. seq.). Existing requirements were approved by the Office of Management and Budget (OMB), approval numbers 3150-0114,
This RIS does not contain new or amended information collection requirements subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et. seq.). Existing requirements were approved by the Office of Management and Budget (OMB), approval numbers 3150-0114,  
3150-0005, and 3150-0006.
3150-0005, and 3150-0006.


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Please direct any questions about this matter to the technical contact listed below.
Please direct any questions about this matter to the technical contact listed below.


/RA by MTschiltz for/                                                       /RA/
/RA by MTschiltz for/  
Daniel Dorman, Director                             Robert J. Lewis, Director Division of Fuel Cycle Safety                       Division of Materials Safety and Safeguards                                     and State Agreements Office of Nuclear Material Safety                   Office of Federal and State Materials and Safeguards                                     and Environmental Management Programs
 
/RA/
/RA/  
Timothy J. McGinty, Director Division Policy and Rulemaking Office of Nuclear Reactor Regulation Technical Contacts:   Joshua Palotay                       Roger Pedersen
 
                      (301) 415-6231                       (301) 415-3162 E-mail: Joshua.Palotay@nrc.gov       E-mail: Roger.Pedersen@nrc.gov Enclosure: List of Recently Issued Office of Federal and State Material and Environmental Management Programs Generic Communications  
Daniel Dorman, Director
 
Robert J. Lewis, Director Division of Fuel Cycle Safety
 
Division of Materials Safety and Safeguards  
 
and State Agreements
 
Office of Nuclear Material Safety
 
Office of Federal and State Materials and Safeguards  
 
and Environmental Management Programs  
 
/RA/  
 
Timothy J. McGinty, Director Division Policy and Rulemaking Office of Nuclear Reactor Regulation  
 
Technical Contacts: Joshua Palotay  
 
Roger Pedersen  
 
(301) 415-6231  
 
(301) 415-3162  
 
E-mail: Joshua.Palotay@nrc.gov E-mail: Roger.Pedersen@nrc.gov  
 
Enclosure: List of Recently Issued Office of Federal and State Material and Environmental Management Programs Generic Communications  


===PUBLIC PROTECTION NOTIFICATION===
===PUBLIC PROTECTION NOTIFICATION===
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Please direct any questions about this matter to the technical contact listed below.
Please direct any questions about this matter to the technical contact listed below.


/RA by MTschiltz for/                                                         /RA/
/RA by MTschiltz for/  
Daniel Dorman, Director                             Robert J. Lewis, Director Division of Fuel Cycle Safety                       Division of Materials Safety and Safeguards                                     and State Agreements Office of Nuclear Material Safety                   Office of Federal and State Materials and Safeguards                                     and Environmental Management Programs
 
/RA/
/RA/  
Timothy J. McGinty, Director Division Policy and Rulemaking Office of Nuclear Reactor Regulation Technical Contacts:     Roger Pedersen
Daniel Dorman, Director
                        (301) 415-3162 E-mail: Roger.Pedersen@nrc.gov Enclosure: List of Recently Issued Office of Federal and State Material and Environmental Management Programs Generic Communications Distribution ADAMS ACCESSION NO. ML082320040                     TAC NO. MD9331 OFFICE         NRR/IRIB         NRR/IRIB           Tech Ed         NRR/IRIB     NRR/DIRS
 
    NAME           JPalotay       RPedersen           email           TKobetz       FBrown DATE         11/ 03 /08       11/ 03 /08       08/ 27 /08         11/10/08     11/10/08 OFFICE       D:NRR/DORL       FSME/DMSSA       FSME/DMSSA       D:FSME/DMSSA   D:NMSS/FCSS
Robert J. Lewis, Director Division of Fuel Cycle Safety
    NAME             JGitter         AMcIntosh         JDeCico           RLewis     DDorman DATE         12/ 05/08         11/23/08         11/26/08         12/02/08     11/14/08 OFFICE         OGC-NLO         OGC-CRA               OE               NRO         PMDA
 
                                                  CCarpenter NHilton NAME             BJones           JAdler                             GTracy         LHill for DATE           11/25/08         11/17/08         11/14/08         01/ /09       11/10/08 OFFICE           OIS           LA:PGCB             PGCB           BC:PGCB     D:NRR/DPR
Division of Materials Safety and Safeguards  
    NAME           GTrussell         CHawes           SStuchell         MMurphy       TMcGinty DATE           11/17/08         06/10/09         06/11/09         07/06/09     07/13/09 OFFICIAL RECORD COPY List of Recently Issued Office of Federal and State Material and Environmental Management Programs Generic Communications Date           GC No.                       Subject                                
 
and State Agreements
 
Office of Nuclear Material Safety
 
Office of Federal and State Materials and Safeguards  
 
and Environmental Management Programs  
 
/RA/  
Timothy J. McGinty, Director Division Policy and Rulemaking Office of Nuclear Reactor Regulation  
 
Technical Contacts: Roger Pedersen  
 
(301) 415-3162  
 
E-mail: Roger.Pedersen@nrc.gov  
 
Enclosure: List of Recently Issued Office of Federal and State Material and Environmental Management Programs Generic Communications  
 
Distribution ADAMS ACCESSION NO. ML082320040             TAC NO. MD9331 OFFICE  
NRR/IRIB  
NRR/IRIB  
Tech Ed NRR/IRIB  
NRR/DIRS  
NAME  
JPalotay RPedersen email TKobetz FBrown DATE  
11/ 03 /08  
11/ 03 /08  
08/ 27 /08  
11/10/08  
11/10/08 OFFICE  
D:NRR/DORL  
FSME/DMSSA  
FSME/DMSSA  
D:FSME/DMSSA  
D:NMSS/FCSS  
NAME  
JGitter AMcIntosh JDeCico RLewis DDorman DATE  
12/ 05/08  
11/23/08  
11/26/08  
12/02/08  
11/14/08 OFFICE  
OGC-NLO  
OGC-CRA  
OE  
NRO  
PMDA  
NAME  
BJones JAdler CCarpenter  NHilton for GTracy LHill DATE  
11/25/08  
11/17/08  
11/14/08  
01/   /09  
11/10/08 OFFICE  
OIS  
LA:PGCB  
PGCB  
BC:PGCB  
D:NRR/DPR  
NAME  
GTrussell CHawes SStuchell MMurphy TMcGinty DATE  
11/17/08  
06/10/09  
06/11/09  
07/06/09  
07/13/09 OFFICIAL RECORD COPY List of Recently Issued Office of Federal and State Material and Environmental Management Programs Generic Communications Date GC No.
 
Subject  


==Addressees==
==Addressees==
05/13/08     RIS-2008-10     Notice Regarding Forthcoming         All U.S. Nuclear Regulatory Commission Federal Firearms Background          licensees, certificate holders, and Checks                                applicants for a license or certificate of compliance who use armed security personnel as part of their physical protection system and security organization. All Radiation Control Program Directors and State Liaison Officers.
05/13/08 RIS-2008-10  
Notice Regarding Forthcoming Federal Firearms Background Checks All U.S. Nuclear Regulatory Commission licensees, certificate holders, and applicants for a license or certificate of compliance who use armed security personnel as part of their physical protection system and security organization. All Radiation Control Program Directors and State Liaison Officers.


05/12/08     RIS-2008-11     Precautions to Protect Children Who   All U.S. Nuclear Regulatory Commission May Come in Contact with Patients    medical-use licensees, master material Released After Therapeutic            licensees, Agreement State Radiation Administration of Iodine-131          Control Program Directors, and State Liaison Officers
05/12/08 RIS-2008-11 Precautions to Protect Children Who May Come in Contact with Patients Released After Therapeutic Administration of Iodine-131 All U.S. Nuclear Regulatory Commission medical-use licensees, master material licensees, Agreement State Radiation Control Program Directors, and State Liaison Officers  
    05/09/08     RIS-2008-12     Considerations for Extended Interim   All holders of U.S. Nuclear Regulatory Storage of Low-level Radioactive      Commission fuel cycle and materials Waste by Fuel Cycle and Materials    licenses. All Radiation Control Program Licensees                            Directors and State Liaison Officers
05/09/08 RIS-2008-12 Considerations for Extended Interim Storage of Low-level Radioactive Waste by Fuel Cycle and Materials Licensees All holders of U.S. Nuclear Regulatory Commission fuel cycle and materials licenses. All Radiation Control Program Directors and State Liaison Officers  
    06/16/08     RIS-2008-13     Status And Plans for Implementation   All U.S. Nuclear Regulatory Commission of NRC Regulatory Authority for      materials licensees, Radiation Control Certain Naturally Occurring and      Program Directors, State Liaison Officers, Accelerator-Produced Radioactive      and the NRCs Advisory Committee on the Material                              Medical Uses of Isotopes
06/16/08 RIS-2008-13 Status And Plans for Implementation of NRC Regulatory Authority for Certain Naturally Occurring and Accelerator-Produced Radioactive Material All U.S. Nuclear Regulatory Commission materials licensees, Radiation Control Program Directors, State Liaison Officers, and the NRCs Advisory Committee on the Medical Uses of Isotopes  
    07/18/08     RIS-2008-17     Voluntary Security Enhancements       All U.S. Nuclear Regulatory Commission for Self-Contained Irradiators        Materials Licensees Authorized to Possess Containing Cesium Chloride            Self-Contained Irradiators Containing Sources                              Cesium Chloride (CsCl) ; all Agreement State Radiation Control Program Directors and State Liaison Officers; all members of the Advisory Committee on the Medical Uses of Isotopes.
07/18/08 RIS-2008-17 Voluntary Security Enhancements for Self-Contained Irradiators Containing Cesium Chloride Sources All U.S. Nuclear Regulatory Commission Materials Licensees Authorized to Possess Self-Contained Irradiators Containing Cesium Chloride (CsCl) ; all Agreement State Radiation Control Program Directors and State Liaison Officers; all members of the Advisory Committee on the Medical Uses of Isotopes.


05/16/08       IN-2008-03     Precautions to Take Before Sharing   All U.S. Nuclear Regulatory Commission Sensitive Security-Related            licensees who are implementing U.S.
05/16/08 IN-2008-03 Precautions to Take Before Sharing Sensitive Security-Related Information All U.S. Nuclear Regulatory Commission licensees who are implementing U.S.


Information                          Nuclear Regulatory Commissions Order Imposing Increased Controls (IC Order) or implementing IC requirements by license condition; all Agreement State Radiation Control Program Directors and State Liaison Officers Note: This list contains the six most recently issued generic communications, issued by the Office of Federal and State Materials and Environmental Management Programs (FSME). A full listing of all generic communications may be viewed at the NRC public website at the following address: http://www.nrc.gov/reading-rm/doc- collections/gen-comm/index.html
Nuclear Regulatory Commissions Order Imposing Increased Controls (IC Order) or implementing IC requirements by license condition; all Agreement State Radiation Control Program Directors and State Liaison Officers Note:   This list contains the six most recently issued generic communications, issued by the Office of Federal and State Materials and Environmental Management Programs (FSME). A full listing of all generic communications may be viewed at the NRC public website at the following address: http://www.nrc.gov/reading-rm/doc- collections/gen-comm/index.html
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Latest revision as of 15:29, 14 January 2025

Withdrawn NRC Regulatory Issue Summary 2009-09: Use of Multiple Dosimetry and Compartment Factors in Determining Effective Dose Equivalent from External Radiation Exposures
ML082320040
Person / Time
Issue date: 07/13/2009
From: Dan Dorman, Robert Lewis, Mcginty T
NRC/FSME/DMSSA, NRC/NMSS/FCSS, Division of Policy and Rulemaking
To:
lgs1
References
RIS-09-009
Download: ML082320040 (8)
v • d • e


Withdrawn

NRC Regulatory Issue Summary 2009-09, Use of Multiple Dosimetry and Compartment Factors in Determining Effective Dose Equivalent from External Radiation Exposures, dated July 13, 2009, has been withdrawn.

ADAMS Accession Number: ML082320040

See Federal Register notice dated October 25, 2016

81 FR 73448

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

OFFICE OF FEDERAL AND STATE MATERIALS AND

ENVIRONMENTAL MANAGEMENT PROGRAMS

WASHINGTON, DC 20555-0001

July 13, 2009

NRC REGULATORY ISSUE SUMMARY 2009-09 USE OF MULTIPLE DOSIMETRY AND COMPARTMENT FACTORS IN

DETERMINING EFFECTIVE DOSE EQUIVALENT FROM EXTERNAL

RADIATION EXPOSURES

ADDRESSEES

All U.S. Nuclear Regulatory Commission (NRC) licensees, Agreement State Radiation Control Program Directors, and State Liaison Officers.

INTENT

The NRC is issuing this regulatory issue summary (RIS) to inform licensees of an acceptable method for determining effective dose equivalent (EDE) from external sources of radiation. This method is documented in a plant specific safety evaluation and has been determined to be generically applicable to licensees when employed consistent with the assumptions, limitations, and commitments identified in this safety evaluation. This RIS communicates the NRCs determination of generic applicability and provides a summary of the information contained in the safety evaluation. No specific action or written response is required. NRC is providing this RIS to the Agreement States for their information and for distribution to their licensees as appropriate.

The NRC staff will issue a Regulatory Guide that will combine and identify approved methods for determining EDE from external sources (EDEex), allowing the use of EDEex in place of deep dose equivalent (DDE) for demonstrating compliance with total effective dose equivalent (TEDE) requirements in Title 10 of the Code of Federal Regulations (10 CFR) Chapter 1.

BACKGROUND

Effective January 3, 2008, the definition of TEDE in 10 CFR Part 20, Standards for Protection against Radiation, was amended (see Volume 72, page 68043, of the Federal Register, dated December 4, 2007). The amendment redefined TEDE as the sum of the effective dose equivalent (for external exposures) and the committed effective dose equivalent (for internal exposures). This change clarified that the EDEex could be used to demonstrate compliance with TEDE-based regulations.

In addition, the NRC revised 10 CFR 20.1201(c) to require that, when external exposure is determined by measurement with an external personal monitoring device, the DDE must be used in place of the EDEex, unless the licensee determines EDEex using a dosimetry method approved by the NRC. The NRC has approved several methods for determining EDEex, allowing the use of EDEex in place of DDE for demonstrating compliance with the TEDE

requirements in 10 CFR Part 20. These methods are discussed in RIS 2002-06, Evaluating Occupational Dose for Individuals Exposed to NRC-Licensed Material and Medical X-Rays, dated April 16, 2002; RIS 2003-04, Use of the Effective Dose Equivalent in Place of the Deep Dose Equivalent in Dose Assessments, dated February 13, 2003; and RIS 2004-01, Method for Estimating Effective Dose Equivalent from External Radiation Sources Using Two Dosimeters, dated February 17, 2004. The method described in this RIS is another approved method.

On December 20, 2004, Southern California Edison submitted a request to the NRC to use the compartment factors found in American National Standard Institute/Health Physics Society (ANSI/HPS) N13.41-1997 as part of a proposed method of multiple dosimetry (see Agencywide Documents Access and Management System (ADAMS) Accession No. ML043630036). The NRC staff found ANSI/HPS N13.41-1997 deficient in certain areas, thereby limiting its use for demonstrating compliance with TEDE-based regulations. For example, the ANSI/HPS standard lacks specificity for the placement of personal monitoring devices.

The NRC staff determined that the method proposed by Southern California Edison, to use the ANSI/HPS N13.41-1997 compartment factors for determining EDEex, including their commitment to monitor each compartment at the location of highest exposure, is acceptable. On May 10,

2005, the NRC approved the licensees request (see Safety Evaluation at ADAMS Accession No. ML051320194) concluding that the proposed method, as discussed further in this RIS, was technically sound and acceptable for the purposes of determining compliance with the TEDE-

based regulations in 10 CFR Chapter 1.

In developing this RIS, a stakeholder concern was raised by comment at a meeting, that some licensees using multiple dosimeters to monitor external radiation exposure (as with this EDE

method) may inappropriately reduce their work place radiation survey programs. Nothing in this RIS relieves the licensee of the survey requirements in 10 CFR 20 .1501(a), nor the requirements in 10 CFR 19.12 to inform the workers of workplace radiological hazards.

SUMMARY OF ISSUE

The method for determining EDEex described in this RIS, includes the use of the compartment factors provided in ANSI/HPS N13.41-1997, Criteria for Performing Multiple Dosimetry.

The multiple dosimetry method in ANSI/HPS N13.41-1997 divides the whole body into seven separate compartments. Each compartment, or composite compartment (since the ANSI/HPS

standard allows combining adjacent compartments), is monitored separately. The dose measurement for each compartment is the personal dose equivalent for penetrating radiation at a depth of 10 millimeters, or Hp(10). This Hp(10) is equivalent to the DDE as defined in 10 CFR

Part 20. The Hp(10), or measured DDE, value is then weighted with the associated compartment factor (Wc).

The factor for each compartment was developed by summing the stochastic weighting factors given in International Commission of Radiological Protection (ICRP) Publication 26 for all the organs located within that compartment. For each tissue that resides in more than one compartment (e.g., red bone marrow), the weighting factor is apportioned among the compartments based on the fraction of the total mass of the tissue residing in each using the information in ICRP Publication 23, Report of the Task Group on Reference Man.

Table 1 of ANSI/HPS N13.41-1997 lists the compartment factors as shown below:

Area of the Body/Compartment (c)

Compartment Factor (Wc)

Head and neck

0.10

Thorax, above the diaphragm

0.38

Abdomen, including the pelvis

0.50

Upper right arm

0.005

Upper left arm

0.005

Right thigh

0.005

Left thigh

0.005

EDEex is the sum of the products of the personal dose equivalent measured for each compartment and its associated compartment weighting factor, or:

HE = WC Hp,c(10)

Where HE = effective dose equivalent (or EDEex), Wc = compartment factor for compartment c, and Hp,c(10) = personal dose equivalent (or DDE) for compartment c.

As noted above, ANSI/HPS N13.41-1997 allows two or more adjacent compartments to be combined into a single composite compartment. The compartment weighting factor for a composite compartment is the sum of the weighting factors of the individual compartments that make up the composite compartment. Although not a condition of the NRC approval, several of the licensees who have obtained a site-specific approval to use this method, monitor the thorax and abdomen compartments as a single composite compartment similar to the original proposal by Southern California Edison.

Fundamental to the compartment method of determining EDEex are the assumptions that (1) the average dose to the tissues in each compartment can be reasonably measured, and (2) the dose distribution across the compartment is sufficiently constant so that this average dose can be applied to each tissue in the compartment. The compartments defined in the standard are small enough so that under most normal exposure situations these assumptions are met and a single determination of DDE in each compartment is sufficient. However, this may not be the case in those unusual situations in which a significant dose gradient exists across one or more compartments (particularly the thorax and abdomen compartments). In these cases, the number and placement of dosimeters in each compartment becomes critical to ensuring that the EDEex is not underestimated.

To ensure that the estimates of EDEex are conservative, the licensee must measure the dose to each compartment (or composite compartment) by locating the dosimeter (calibrated to DDE) at the highest exposed portion of the respective compartment. The dosimeter location for each compartment is subject to the same criteria currently used to demonstrate compliance with

10 CFR 20.1201(c). [Note: monitoring each compartment, or composite compartment, at the location of highest exposure results in a conservative estimate of EDEex no matter what combination of compartments and composite compartments are used - even in the extreme case of combining all compartments into a single whole body composite compartment.] CONCLUSION

NRC licensees may use the compartment factors of ANSI/HPS N13.41-1997 and the methodology described in this RIS for implementing a multiple dosimetry program in compliance with TEDE-based regulations. This methodology is consistent with the NRC Safety Evaluation issued to Southern California Edison on May 10, 2005 (ADAMS Accession No. ML051320194).

It should be noted that the NRC has not directly approved ANSI/HPS N13.41-1997, in and of itself, for use by licensees in a personnel monitoring program. The NRC has only approved the use of the compartment factors and associated method for calculating EDEex, as described in this RIS, for use in a multiple dosimetry program when combined with the method presented herein.

This RIS communicates the generic applicability of this method to determine EDEex . Licensees may use this method for demonstrating compliance with TEDE-based regulations. Therefore, licensees are no longer required to apply for approval to use this method on a site-specific basis.

BACKFIT DISCUSSION

The purpose of this RIS is to inform licensees of a method for determining EDEex that has been approved by the NRC for use in determining TEDE in several site-specific licensee requests for approval (See additional safety evaluations at ADAMS Accession Nos. ML051320194, ML080570154, ML072220355, and ML061870512). The staff positions and guidance discussed in this RIS are the same as those that provide the technical basis for these site-specific approvals. This RIS requires no action or written response. 10 CFR Part 20 provides several options for demonstrating compliance with the TEDE dose limits. Any action on the part of addressees in accordance with the guidance contained in this RIS is voluntary. Consequently, the staff did not perform a backfit analysis.

FEDERAL REGISTER NOTIFICATION

The NRC did not publish a notice of opportunity for public comment on this RIS in the Federal Register because this RIS is informational and does not represent a departure from current regulatory requirements. Stakeholder comment was solicited in a September 10, 2008, public meeting. The draft RIS was attached to the meeting announcement (ADAMS ML082340248).

A summary of the comments received, and their resolutions, can be found at ADAMS Accession No. ML082540738.

CONGRESSIONAL REVIEW ACT

This RIS is not a rule as designated by the Congressional Review Act (5 U.S.C. § 801-886) and therefore is not subject to the Act.

PAPERWORK REDUCTION ACT STATEMENT

This RIS does not contain new or amended information collection requirements subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et. seq.). Existing requirements were approved by the Office of Management and Budget (OMB), approval numbers 3150-0114,

3150-0005, and 3150-0006.

PUBLIC PROTECTION NOTIFICATION

The NRC may not conduct or sponsor, and a person is not required to respond to, a request for information or an information collection requirement unless the requesting document displays a current valid OMB control number.

CONTACT

Please direct any questions about this matter to the technical contact listed below.

/RA by MTschiltz for/

/RA/

Daniel Dorman, Director

Robert J. Lewis, Director Division of Fuel Cycle Safety

Division of Materials Safety and Safeguards

and State Agreements

Office of Nuclear Material Safety

Office of Federal and State Materials and Safeguards

and Environmental Management Programs

/RA/

Timothy J. McGinty, Director Division Policy and Rulemaking Office of Nuclear Reactor Regulation

Technical Contacts: Joshua Palotay

Roger Pedersen

(301) 415-6231

(301) 415-3162

E-mail: Joshua.Palotay@nrc.gov E-mail: Roger.Pedersen@nrc.gov

Enclosure: List of Recently Issued Office of Federal and State Material and Environmental Management Programs Generic Communications

PUBLIC PROTECTION NOTIFICATION

The NRC may not conduct or sponsor, and a person is not required to respond to, a request for information or an information collection requirement unless the requesting document displays a current valid OMB control number.

CONTACT

Please direct any questions about this matter to the technical contact listed below.

/RA by MTschiltz for/

/RA/

Daniel Dorman, Director

Robert J. Lewis, Director Division of Fuel Cycle Safety

Division of Materials Safety and Safeguards

and State Agreements

Office of Nuclear Material Safety

Office of Federal and State Materials and Safeguards

and Environmental Management Programs

/RA/

Timothy J. McGinty, Director Division Policy and Rulemaking Office of Nuclear Reactor Regulation

Technical Contacts: Roger Pedersen

(301) 415-3162

E-mail: Roger.Pedersen@nrc.gov

Enclosure: List of Recently Issued Office of Federal and State Material and Environmental Management Programs Generic Communications

Distribution ADAMS ACCESSION NO. ML082320040 TAC NO. MD9331 OFFICE

NRR/IRIB

NRR/IRIB

Tech Ed NRR/IRIB

NRR/DIRS

NAME

JPalotay RPedersen email TKobetz FBrown DATE

11/ 03 /08

11/ 03 /08

08/ 27 /08

11/10/08

11/10/08 OFFICE

D:NRR/DORL

FSME/DMSSA

FSME/DMSSA

D:FSME/DMSSA

D:NMSS/FCSS

NAME

JGitter AMcIntosh JDeCico RLewis DDorman DATE

12/ 05/08

11/23/08

11/26/08

12/02/08

11/14/08 OFFICE

OGC-NLO

OGC-CRA

OE

NRO

PMDA

NAME

BJones JAdler CCarpenter NHilton for GTracy LHill DATE

11/25/08

11/17/08

11/14/08

01/ /09

11/10/08 OFFICE

OIS

LA:PGCB

PGCB

BC:PGCB

D:NRR/DPR

NAME

GTrussell CHawes SStuchell MMurphy TMcGinty DATE

11/17/08

06/10/09

06/11/09

07/06/09

07/13/09 OFFICIAL RECORD COPY List of Recently Issued Office of Federal and State Material and Environmental Management Programs Generic Communications Date GC No.

Subject

Addressees

05/13/08 RIS-2008-10

Notice Regarding Forthcoming Federal Firearms Background Checks All U.S. Nuclear Regulatory Commission licensees, certificate holders, and applicants for a license or certificate of compliance who use armed security personnel as part of their physical protection system and security organization. All Radiation Control Program Directors and State Liaison Officers.

05/12/08 RIS-2008-11 Precautions to Protect Children Who May Come in Contact with Patients Released After Therapeutic Administration of Iodine-131 All U.S. Nuclear Regulatory Commission medical-use licensees, master material licensees, Agreement State Radiation Control Program Directors, and State Liaison Officers

05/09/08 RIS-2008-12 Considerations for Extended Interim Storage of Low-level Radioactive Waste by Fuel Cycle and Materials Licensees All holders of U.S. Nuclear Regulatory Commission fuel cycle and materials licenses. All Radiation Control Program Directors and State Liaison Officers

06/16/08 RIS-2008-13 Status And Plans for Implementation of NRC Regulatory Authority for Certain Naturally Occurring and Accelerator-Produced Radioactive Material All U.S. Nuclear Regulatory Commission materials licensees, Radiation Control Program Directors, State Liaison Officers, and the NRCs Advisory Committee on the Medical Uses of Isotopes

07/18/08 RIS-2008-17 Voluntary Security Enhancements for Self-Contained Irradiators Containing Cesium Chloride Sources All U.S. Nuclear Regulatory Commission Materials Licensees Authorized to Possess Self-Contained Irradiators Containing Cesium Chloride (CsCl) ; all Agreement State Radiation Control Program Directors and State Liaison Officers; all members of the Advisory Committee on the Medical Uses of Isotopes.

05/16/08 IN-2008-03 Precautions to Take Before Sharing Sensitive Security-Related Information All U.S. Nuclear Regulatory Commission licensees who are implementing U.S.

Nuclear Regulatory Commissions Order Imposing Increased Controls (IC Order) or implementing IC requirements by license condition; all Agreement State Radiation Control Program Directors and State Liaison Officers Note: This list contains the six most recently issued generic communications, issued by the Office of Federal and State Materials and Environmental Management Programs (FSME). A full listing of all generic communications may be viewed at the NRC public website at the following address: http://www.nrc.gov/reading-rm/doc- collections/gen-comm/index.html


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