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Re: Questions on NRC Regulatory Guide 1.109
Claude,
This issue was raised when the NRC made the major revisions to 10 CFR 20
back in 1991 and was addressed in the Q&A's developed jointly by industry
and the NRC to address questions raised by the proposed revisions.
Specifically, see the following Q&A's:
"Question 21: Is it time to update Regulatory Guide 1.109 and its
corresponding codes due to the updated dose conversion factors in the
revised Part 20?
Answer: Perhaps, but such an update could only be a partial update at
this time. The full updating could only occur if and when Appendix I is
recast as an effective dose equivalent. The evaluation of whether Appendix
I should be changed is currently underway. (Reference: Regulatory Guides)
Question 384: Nuclear power plant licensees are required to meet the
criteria in 10 CFR 50 Appendix I and 40 CFR 190 with regards to maintaining
doses to individual members of the public ALARA. Related Regulatory Guides
(e.g., 1.21, 1.109, and 4.1) describe programs which are acceptable to the
NRC staff to demonstrate compliance with 10 CFR 50 Appendix I and 40 CFR
190 criteria. Specific requirements for monitoring, sampling, dose
calculation and reporting
are included in each plant's Technical Specifications and related Offsite
Dose Calculation Manual. Does compliance with plant Technical
Specifications, applicable Regulatory Guides, and the radiation standards
in 40 CFR 190 fully meet the requirements of 20.1301? The purpose in
asking this question is to obtain clarification that, although the revised
10 CFR 20 introduces new dose limits for individual members of the public
and new effluent concentration values in 10 CFR 20 Appendix B, the scope of
monitoring, sampling, dose calculation and reporting are not changed for
nuclear power plants by the revised 10 CFR 20 from the previously
applicable requirements and guidance.
Answer: Not necessarily. See the questions and answers in sections 10
CFR 20.1301 and 10 CFR 20.1302. Generally, for nuclear power plants, no
major changes are needed in "the scope of monitoring, sampling, dose
calculation, and reporting" that has been adequate for compliance with
plant Technical Specifications and 40 CFR 190, and for conformance with
applicable regulatory guides. However, some relatively minor changes may
be needed. For example, at some plants, changes may be needed for
demonstrating compliance with the requirements of 10 CFR 20.1301 as they
apply in members of the public in controlled areas. (See the answer to
Question 104.) (References: 10 CFR 20.1301, 10 CFR 20.1302)."
To the best of my knowledge, neither Appendix I nor RG 1.109 have been
revised to address these issues.
Leon E. Brown, CHP
Staff Consultant
Big Rock Point Restoration Project
231-547-8419
lebrown@cmsenergy.com
"Claude Laney"
<cflaney@BELLSOUTH.NET To: <radsafe@list.vanderbilt.edu>
> cc:
Sent by: Subject: Questions on NRC Regulatory Guide 1.109
owner-radsafe@list.van
derbilt.edu
05/20/2003 08:56 AM
Please respond to
"Claude Laney"
NRC Regulatory Guide 1.109, Calculation of Doses to Man From Routine
Releases of Reactor Effluents For the Purpose of Evaluating Compliance with
10 CFR 50, Appendix I, indicates in the introduction that Regulatory Guide
1.109 contains methods that may be used for demonstrating compliance with
the provisions of 10 CFR 50, Appendix I.<?xml:namespace prefix = o ns
= "urn:schemas-microsoft-com:office:office" />
Question: Are the methods contained in Regulatory Guide 1.109 still in
use by commercial nuclear power facilities for the purpose of demonstrating
compliance with 10 CFR 50, Appendix I?
Comment: Regulatory Guide 1.109, Appendix E, item (3.) indicates that the
dose factors for the total body contained in Table E-6 are for the dose
rate in air at 1 meter above the ground for a tissue depth of 5 cm. The 5
cm tissue depth may be converted to a density thickness of 5000 mg per
square cm, assuming a tissue density of 1000 mg per cubic cm. 10 CFR 50.2,
Definitions, contains the definitions of the committed dose equivalent,
committed effective dose equivalent, and the deep dose equivalent (DDE)
with the DDE defined at a tissue depth of 1000 mg per square cm. 10 CFR 20
references the same tissue depth (1000 mg per square cm) in the definition
of the DDE.
Question: How do the dose factors for the total body contained in
Regulatory Guide 1.109, Appendix E, Table E-6 demonstrate compliance with
the 10 CFR 50 Appendix I limits, and the dose limits for members of the
public contained in 10 CFR 20.1301, if the tissue depths differ by a factor
of 5 (i.e., 1000 mg per square cm compared to 5000 mg per square cm)?
Thanks for any comments.
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