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Proposed Rule

Occupational Radiation Protection; Revision

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Department of Energy.


Proposed rule and opportunity for public comment.


The Department of Energy (DOE) proposes to revise the values in an appendix to its Occupational Radiation Protection requirements. The derived air concentration values for air immersion are calculated using several parameters. One of these, exposure time, is better represented by the hours in the workday, rather than the hours in a calendar day, and is therefore used in the revised calculations.


Public comments on the proposed revisions must be received on or before February 24, 2011.


You may submit comments, identified by Docket No. HS-RM-09-835 and/or RIN 1901-AA-95, by any of the following methods:

  • Federal eRulemaking Portal: Follow the instructions for submitting comments.
  • E-mail: Include Docket Number HS-RM-09-835 and/or RIN 1901-AA-95 in the subject line of the message.
  • Mail: Dr. Judith D. Foulke, Office of Worker Safety and Health Policy (HS-11), U.S. Department of Energy, 1000 Independence Avenue, SW., Washington, DC 20585.
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Judith Foulke, (301) 903-5865, e-mail:

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The requirements in title 10, Code of Federal Regulations, part 835 (10 CFR part 835), Occupational Radiation Protection, are designed to protect the health and safety of workers at DOE facilities. One situation that must be addressed is the exposure of workers to radioactive material dispersed in the air. Start Printed Page 4259Based on calculations involving doses to the organs of the body, levels of contamination in the air that will not cause the dose limits for workers to be exceeded are established for specified radionuclides. These values are given in appendix C.

DOE first published, a final rule on December 14, 1993, (58 FR 65485), amending 10 CFR part 835. In the June 8, 2007, (72 FR 31903) amendment to part 835, DOE revised the values in appendix C to part 835, Derived Air Concentration (DAC) for Workers from External Exposure during Immersion in a Cloud of Airborne Radioactive Material. The calculations done for the 2007 amendment were based on a 24-hour day. However, to be consistent with other occupational exposure scenarios, such as those used in developing the appendix A DACs, an 8-hour per day exposure scenario is more reasonable.

Need for Revisions

This proposed rule revises the values in appendix C to part 835, Derived Air Concentration (DAC) for Workers from External Exposure during Immersion in a Cloud of Airborne Radioactive Material.

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List of Subjects in 10 CFR Part 835

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Issued in Washington, DC, on January 11, 2011.

Glenn S. Podonsky,

Chief Health, Safety and Security Officer, Office of Health, Safety and Security.

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Accordingly, for the reasons set forth in the preamble, part 835 of Chapter III of 10 CFR is proposed to be amended as set forth below:

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1. The authority citation for part 835 continues to read as follows:

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Authority: 42 U.S.C. 2201, 7191; 50 U.S.C. 2410.

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2. Amend appendix C to part 835, by revising the table to read as follows:

Appendix C to Part 835—Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of Airborne Radioactive Material

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Air Immersion DAC

Ar-3735.02 d3E+001E+11
Ar-39269 yr1E-035E+07
Ar-411.827 h3E-061E+05
Kr-7411.5 min3E-061E+05
Kr-7614.8 h1E-053E+05
Kr-7774.7 h4E-061E+05
Kr-7935.04 h1E-056E+05
Kr-812.1E+05 yr7E-042E+07
Kr-83m1.83 h7E-022E+09
Kr-8510.72 yr7E-042E+07
Kr-85m4.48 h2E-051E+06
Kr-8776.3 min4E-061E+05
Kr-882.84 h1E-067E+04
Xe-12040.0 min1E-054E+05
Xe-12140.1 min2E-068E+04
Xe-12220.1 h8E-053E+06
Xe-1232.14 h6E-062E+05
Xe-12516.8 h1E-056E+05
Xe-12736.406 d1E-056E+05
Xe-129m8.89 d2E-047E+06
Xe-131m11.84 d5E-041E+07
Xe-1335.245 d1E-045E+06
Xe-133m2.19 d1E-045E+06
Xe-1359.11 h1E-056E+05
Xe-135m15.36 min1E-053E+05
Xe-13814.13 min3E-061E+05
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[FR Doc. 2011-1500 Filed 1-24-11; 8:45 am]

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