[Federal Register Volume 76, Number 71 (Wednesday, April 13, 2011)]
[Rules and Regulations]
[Pages 20489-20490]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-8836]
========================================================================
Rules and Regulations
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains regulatory documents
having general applicability and legal effect, most of which are keyed
to and codified in the Code of Federal Regulations, which is published
under 50 titles pursuant to 44 U.S.C. 1510.
The Code of Federal Regulations is sold by the Superintendent of Documents.
Prices of new books are listed in the first FEDERAL REGISTER issue of each
week.
========================================================================
Federal Register / Vol. 76, No. 71 / Wednesday, April 13, 2011 /
Rules and Regulations
[[Page 20489]]
DEPARTMENT OF ENERGY
10 CFR Part 835
[Docket No. HS-RM-09-835]
RIN 1992-AA-45
Occupational Radiation Protection
AGENCY: Office of Health, Safety and Security, Department of Energy.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The Department of Energy (DOE) today amends the values in
appendix C 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.
DATES: This rule is effective May 13, 2011.
FOR FURTHER INFORMATION CONTACT: Dr. Judith Foulke, U.S. Department of
Energy, Office of Worker Safety and Health Policy, 1000 Independence
Avenue, SW., Washington, DC 20585; (301) 903-5865, e-mail:
[email protected].
SUPPLEMENTARY INFORMATION:
I. Background
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 Department of Energy (DOE)
facilities. One situation that must be addressed is the exposure of
workers to radioactive material dispersed in the air. Based 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.
DOE proposed amending the values in appendix C to take account of
the 8-hour per day exposure scenario on January 25, 2011 (76 FR 4258).
Today's final rule modifies 10 CFR part 835 appendix C values resulting
from calculations using an 8-hour day.
II. Discussion of Changes to 10 CFR 835
The values for air immersion derived air concentrations in the
present part 835 are based on a 24-hour day. Because the work day is 8
hours long, it was decided to base calculations of air immersion
derived concentrations on an 8-hour day for workers occupationally
exposed.
DOE received two comments from one commenter. The commenter stated
that the derived conversion factors differed by a factor of 20 billion
to 70 billion. DOE noted that values calculated in Bq/m\3\ and in
[mu]Ci/L differ by a factor of 37 billion, but use of truncated numbers
explained the difference. The commenter stated that the half-life of
Kr-77 was wrong. DOE agreed with the correct value and replaced the
incorrect value.
A second commenter stated that the change in calculation for
exposure time from calendar day hours to workday hours will lessen the
amount of protection provided to employees. The commenter incorrectly
stated that the effects of the radiation will continue after the
employees have gone home. These radionuclides in appendix C are inert
gases and are not absorbed by the body; they affect the worker only
while immersed in a cloud of airborne radioactivity.
A third commenter agreed with DOE's approach.
III. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this final
rule.
List of Subjects in 10 CFR Part 835
Federal buildings and facilities, Nuclear energy, Nuclear
materials, Nuclear power plants and reactors, Nuclear safety,
Occupational safety and health, Radiation protection, and Reporting and
recordkeeping requirements.
Issued in Washington, DC, on March 28, 2011.
Glenn S. Podonsky,
Chief Health, Safety and Security Officer, Office of Health, Safety and
Security.
Accordingly, for the reasons set forth in the preamble, part 835 of
Chapter III of Title 10 of the Code of Federal Regulations is amended
as set forth below:
PART 835--OCCUPATIONAL RADIATION PROTECTION
0
1. The authority citation for part 835 continues to read as follows:
Authority: 42 U.S.C. 2201, 7191; 50 U.S.C. 2410.
0
2. In appendix C to part 835, the table at the end of paragraph c. is
removed and a new table is added 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
* * * * *
c. * * *
Air Immersion DAC
------------------------------------------------------------------------
([micro]Ci/
Radionuclide Half-life mL) (Bq/m\3\)
------------------------------------------------------------------------
Ar-37........................ 35.02 d......... 3E+00 1E+11
Ar-39........................ 269 yr.......... 1E-03 5E+07
Ar-41........................ 1.827 h......... 3E-06 1E+05
Kr-74........................ 11.5 min........ 3E-06 1E+05
Kr-76........................ 14.8 h.......... 1E-05 3E+05
Kr-77........................ 74.7 min........ 4E-06 1E+05
Kr-79........................ 35.04 h......... 1E-05 6E+05
Kr-81........................ 2.1E+05 yr...... 7E-04 2E+07
Kr-83m....................... 1.83 h.......... 7E-02 2E+09
Kr-85........................ 10.72 yr........ 7E-04 2E+07
Kr-85m....................... 4.48 h.......... 2E-05 1E+06
Kr-87........................ 76.3 min........ 4E-06 1E+05
Kr-88........................ 2.84 h.......... 1E-06 7E+04
[[Page 20490]]
Xe-120....................... 40.0 min........ 1E-05 4E+05
Xe-121....................... 40.1 min........ 2E-06 8E+04
Xe-122....................... 20.1 h.......... 8E-05 3E+06
Xe-123....................... 2.14 h.......... 6E-06 2E+05
Xe-125....................... 16.8 h.......... 1E-05 6E+05
Xe-127....................... 36.406 d........ 1E-05 6E+05
Xe-129m...................... 8.89 d.......... 2E-04 7E+06
Xe-131m...................... 11.84 d......... 5E-04 1E+07
Xe-133....................... 5.245 d......... 1E-04 5E+06
Xe-133m...................... 2.19 d.......... 1E-04 5E+06
Xe-135....................... 9.11 h.......... 1E-05 6E+05
Xe-135m...................... 15.36 min....... 1E-05 3E+05
Xe-138....................... 14.13 min....... 3E-06 1E+05
------------------------------------------------------------------------
* * * * *
[FR Doc. 2011-8836 Filed 4-12-11; 8:45 am]
BILLING CODE 6450-01-P