United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 90-48: Enforcement Policy for Hot Particle Exposures

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                    OFFICE OF NUCLEAR REACTOR REGULATION
                          WASHINGTON, D.C.  20555 

                               August 2, 1990


Information Notice No. 90-48:  ENFORCEMENT POLICY FOR HOT PARTICLE 
                                   EXPOSURES 


Addressees: 

All holders of operating licenses or construction permits for nuclear power 
reactors. 

Purpose:

This information notice is intended to alert addressees to a policy 
statement that the U.S. Nuclear Regulatory Commission (NRC) is issuing 
concerning the use of enforcement discretion in cases involving occupational 
doses to the skin from exposure to radioactive particles ("hot particles") 
that exceed the limits in Section 20.101 of Title 10 of the Code of Federal 
Regulations (10 CFR).  It is expected that recipients will review the 
information for applicability to their facilities.  However, the enforcement 
policy is a policy statement concerning NRC actions, not a regulation 
imposing requirements on licensees, and suggestions contained in this 
information notice do not constitute NRC requirements; therefore, no 
specific action or written response is required. 

Background:

The limits on occupational dose specified in the table in paragraph (a) of 
10 CFR 20.101 for the hands and forearms, feet and ankles, and the skin of 
the whole body apply to all exposures, including hot particle exposures.  
However, because of the nature of the principal radiation involved (beta 
particles), the extremely localized effects, and the lower risk of 
biological injury compared to nonlocalized effects, the NRC believes a 
different limit for hot particle exposures should be established through 
rulemaking action.  To begin the necessary rulemaking process, the 
Commission has directed the NRC staff to prepare an advance notice of 
proposed rulemaking by September 1990.  In addition, NRC enforcement 
discretion will be applied until a new limit for hot particle exposures is 
established by rule.  

Earlier this year, the staff proposed an NRC enforcement policy statement 
(Reference 1) concerning the use of enforcement discretion in cases 
involving occupational doses to the skin from hot particle exposures that 
exceed the 







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                                                            IN 90-48
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limits in 10 CFR 20.101.  On July 9, 1990, the Commission approved this 
statement, which is enclosed as Attachment 2.  The enforcement policy 
statement is based on the recommendations in Report No. 106 of the National 
Council on Radiation Protection and Measurements (NCRP) (Reference 2). 

In general, the policy statement increases the dose threshold for issuing a 
notice of violation and decreases the severity levels for violations of the 
skin dose limits and for failures to report those violations in cases of hot 
particle exposures.

Discussion: 

On July 30, 1990, the NRC published the new policy statement in the Federal 
Register and the policy became effective on the date of publication.  

As indicated in the Scope section of the attached policy, the policy applies 
to occupational doses to the skin that exceed the limits of 10 CFR 20.101 
for the "hands and forearms, feet and ankles" or the "skin of the whole 
body" and that result from radiation emitted by a hot particle on the body 
or clothing of the exposed individual.  The policy does not change the 
limits of 10 CFR 20.101, the methods for determining compliance with those 
limits, or reporting and notification requirements of 10 CFR Parts 19 and 
20.  The NRC will use the notifications and reports to address issues during 
the rulemaking process and to monitor licensees' continuing programs to 
protect workers from hot particle exposures. 

Consistent with the recommendations in NCRP Report No. 106, the definition 
of a "hot particle" in the attached policy includes an upper limit on 
particle size of 1 mm in any dimension.  However, the NRC staff expects that 
an actual measurement of the size of a particle will be necessary only if 
the particle appears to have some dimension that is estimated to approach 1 
mm.  All particles that are not visible without magnification can be assumed 
to be smaller than the limit. 

NCRP Report No. 106 includes a recommendation for medical evaluation in 
cases of hot particle exposures that exceed the NCRP-recommended limit of 75 
microcurie hours.  Because this recommendation is not considered an 
enforcement issue, it is not addressed in the attached enforcement policy.  
However, the NRC staff agrees with this NCRP recommendation.

The NRC staff does not intend that the implementation of this policy will 
significantly alter licensee programs established to contain hot particles 
within each nuclear power plant and prevent the particles from being 
inadvertently transported offsite. 

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                                                            IN 90-48
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                                                            Page 3 of 3


This information notice requires no specific action or written response.  If 
you have any questions about the information in this notice, please contact 
one of the technical contacts listed below or the appropriate NRC regional 
office. 




                              Charles E. Rossi, Director 
                              Division of Operational Events Assessment 
                              Office of Nuclear Reactor Regulation 


Technical Contacts:  John D. Buchanan, NRR 
                     (301) 492-3184 

                     James E. Wigginton, NRR 
                     (301) 492-1059 


Attachments:
1.  References 
2.  Enforcement Policy for Cases of Occupational 
      Doses to the Skin from Radiation Emitted 
      from Hot Particles 
3.  List of Recently Issued NRC Information Notices 
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                                                            Attachment 1 
                                                            IN 90-48 
                                                            August 2, 1990
                                                            Page 1 of 1


                                 REFERENCES

1.   "Modified Enforcement Policy for Hot Particle Exposures - Revision to 
     Incorporate Recommendations Made in NCRP Report No. 106," memorandum 
     for the Commissioners from James M. Taylor, Executive Director for 
     Operations, SECY-90-169, May 11, 1990.  This NRC document is available 
     in the NRC Public Document Room, 2120 L Street, N.W., Washington, D.C.

2.   Limit for Exposure to "Hot Particles," National Council on Radiation 
     Protection and Measurements (NCRP) Report No. 106, December 31, 1989.  
     This report is available from NCRP, 7910 Woodmont Avenue, Bethesda, MD  
     20814.
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                                                            Attachment 2
                                                            IN 90-48
                                                            August 2, 1990
                                                            Page 1 of 4


                           Enforcement Policy for
                       Cases of Occupational Doses to
                           the Skin from Radiation
                         Emitted from Hot Particles


1.   Purpose

     The purpose of this policy statement is to explain the enforcement 
     policy that the Commission intends to follow (notwithstanding the 
     current enforcement policy in 10 CFR Part 2, Appendix C), regarding the 
     use of enforcement discretion in cases that involve an occupational 
     dose to the skin resulting from exposure to radiation emitted from a 
     hot particle on or near the skin.  The provisions of this policy will 
     be followed by the NRC staff until a new limit applicable to such cases 
     is established by revision of 10 CFR Part 20.  

2.   Scope

     This policy applies only to occupational doses to the skin that exceed 
     the limits of 10 CFR 20.101 for the "hands and forearms, feet and 
     ankles" or the "skin of the whole body" and that are the result of 
     radiation emitted from a hot particle on the body or clothing of the 
     exposed individual.  This policy does not change criteria for 
     whole-body doses.  

3.   Definitions

     As used in this policy --

     "Beta emission" means either (1) the number of beta particles emitted 
     from the radionuclide(s) in the hot particle during the time period of 
     the occupational exposure of the skin or (2) the number of beta 
     particles emitted from the surface of the particle during that time 
     period.  

     "Hot particle" means a discrete radioactive fragment that is insoluble 
     in water and is less than 1 mm in any dimension.  

     "Hot particle exposure" means an occupational dose to the skin 
     resulting from exposure to radiation emitted from the radionuclides in 
     a hot particle on the body or on the clothing of the exposed 
     individual.  

     "Occupational dose" includes exposure of an individual to radiation (1) 
     in a restricted area or (2) in the course of employment in which the 
     individual's duties involve exposure to radiation, provided, that 
     "occupational dose" shall not be deemed to include any exposure of an 
     individual to radiation for the purpose of medical diagnosis or medical 
     therapy of such individual.  (Note:  This is the definition of this 
     term given in 10 CFR Part 20.)  

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                                                            Attachment 2
                                                            IN 90-48
                                                            August 2, 1990
                                                            Page 2 of 4


4.   Occupational Exposure Criteria 

     The limits on occupational dose specified in the table in paragraph (a) 
     of 10 CFR 20.101 for the hands and forearms, feet and ankles, and the 
     skin of the whole body apply to all exposures, including hot particle 
     exposures.  However, because of the nature of the principal radiation 
     involved (beta), the extremely localized effects, and the lower 
     biological risk, the NRC believes a different limit for hot particle 
     exposures should be established through rulemaking action and that 
     enforcement discretion should be applied until a new limit for hot 
     particle exposures is established by rule.  Consequently, the staff 
     will use a new beta emission criterion and a new skin dose criterion 
     for determining appropriate discretionary enforcement actions and 
     appropriate severity levels for hot particle exposures; however, the 
     staff will continue to evaluate hot particle exposures in terms of 
     absorbed dose for comparison with the limits of 10 CFR 20.101.  
     
     For a hot particle exposure of an individual above the limits of 10 CFR 
     20.101 that results from a hot particle in contact with the skin, the 
     NRC will issue a notice of violation if the beta emission from the 
     particle is greater than the beta emission criterion.  For purposes of 
     this policy, the beta emission criterion is established as a beta 
     emission value of 1010 beta particles (75 microcurie hours).  A notice 
     of violation will not be issued when an individual receives a hot 
     particle exposure that is equal to or less than the beta emission 
     criterion.  

     For each hot particle exposure, the hot particle will be assumed to 
     have been in contact with the skin throughout the possible irradiation 
     period, even if the particle was found on the hair or clothing of the 
     exposed individual, unless it can be determined that the particle was 
     never in contact with the skin (for example, if the particle was 
     between two layers of clothing).  
     
     If it can be determined that the particle was never in contact with the 
     skin, the skin dose criterion, rather than the beta emission criterion, 
     applies.  That is, in this case, the NRC will issue a notice of 
     violation if the dose to the skin exceeds the skin dose criterion.  For 
     purposes of this policy, the skin dose criterion is established as an 
     occupational dose to the skin of 50 rad at a depth of 7 mg/cm 2 
     averaged over an area of 1 cm 2 in the region of the highest dose.  A 
     notice of violation will not be issued when an individual receives a 
     hot particle exposure that is equal to or less than the skin dose 
     criterion.  
     
     The beta emission criterion or the skin dose criterion will be used for 
     each hot particle exposure.  There are no quarterly or annual 
     limitations.  

     In any case, a notice of violation may be issued for violations of 
     other regulatory requirements associated with an event involving hot 
     particle exposures (e.g., violation of 10 CFR 20.201, "Surveys") 
     regardless of the magnitude of the hot particle exposure.  
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                                                            Attachment 2
                                                            IN 90-48
                                                            August 2, 1990
                                                            Page 3 of 4


     In determining whether a hot particle exposure has exceeded the limits 
     of 10 CFR 20.101, the beta emission criterion, or the skin dose 
     criterion, hot particle exposures will not be added to skin doses from 
     sources other than hot particles, nor will hot particle exposures from 
     different particles be summed unless the different particles result in 
     doses to the same area (location) of skin.  

5.   Records, Notifications, and Reports

     Nothing in this policy should be construed as changing, or in effect 
     changing, other requirements of 10 CFR Parts 19 and 20.  In particular, 
     the requirements of 10 CFR 20.401 (records), 10 CFR 20.403 
     (notifications of incidents), 10 CFR 20.405 (reports of overexposures), 
     10 CFR 20.408 (reports of personnel monitoring on termination), and 
     10 CFR 20.409 and 10 CFR 19.13 (notifications and reports to 
     individuals) remain in effect and concern the current dose limits in 
     10 CFR 20.101.  For example, a hot particle exposure resulting in a 
     skin dose of 75 rads to the feet, ankles, hands, or forearms must be 
     reported to the NRC within 24 hours.  However, no notice of violation 
     will be issued for a failure to make an immediate notification required 
     by 10 CFR 20.403(a) for a skin dose that is a result of a hot particle 
     exposure.  A Notice of Violation will be issued for a failure to make a 
     24-hour notification required by 10 CFR 20.403(b) or to report as 
     required by 10 CFR 20.405 for a dose that is a result of hot particle 
     exposure.  

6.   Enforcement Examples

     In addition to the enforcement discretion concerning issuing notices of 
     violations, enforcement discretion also will be used concerning the 
     severity levels of violations.  For a dose to the skin from hot 
     particle exposures, the following examples will be used for determining 
     severity levels:  

     a.   Severity Level III - Violations involving, for example -- 

          (1)  Hot particle exposures for which the dose to the skin exceeds 
               the limits of 10 CFR 20.101 and exceeds three times the 
               relevant criterion (either the beta emission criterion or the 
               skin dose criterion).  

          (2)  Failure to make a notification required by 10 CFR 20.403(b) 
               or a report (required by 10 CFR 20.405) for a hot particle 
               exposure that results in a skin dose that exceeds the limits 
               of 10 CFR 20.101 and exceeds three times the relevant 
               criterion (either the beta emission criterion or the skin 
               dose criterion).  

     b.   Severity Level IV - Violations involving, for example --

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                                                            Attachment 2
                                                            IN 90-48
                                                            August 2, 1990
                                                            Page 4 of 4


          (1)  Hot particle exposures for which the dose to the skin exceeds 
               the limits of 10 CFR 20.101 and exceeds the relevant 
               criterion but does not exceed three times the relevant 
               criterion (either the beta emission criterion or the skin 
               dose criterion).  

          (2)  Failure to make a notification required by 10 CFR 20.403(b) 
               or a report (required by 10 CFR 20.405) for a hot particle 
               exposure that results in a skin dose that exceeds the limits 
               of 10 CFR 20.101 and exceeds the relevant criterion but does 
               not exceed three times the relevant criterion (either the 
               beta emission criterion or the skin dose criterion).  

     c.   Severity Level V - Violations involving, for example -- 

          (1)  Failure to make a notification required by 10 CFR 20.403(b) 
               or a report (required by 10 CFR 20.405) for a hot particle 
               exposure that results in a skin dose that exceeds the limits 
               of 10 CFR 20.101 but that does not exceed the relevant 
               criterion (either the beta emission criterion or the skin 
               dose criterion).  

     Note:  No numerical criteria (beta emission values or skin doses) have 
            been established as examples for Severity Levels I and II.  

.ENDEND
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