ML23241A965
| ML23241A965 | |
| Person / Time | |
|---|---|
| Issue date: | 01/31/2024 |
| From: | NRC/RES/DE/CIB |
| To: | |
| Shared Package | |
| ML23234A027 | List: |
| References | |
| RG 1.204 Rev 1 DG-1409 | |
| Download: ML23241A965 (6) | |
Text
1 Response to Public Comments on Proposed Revision 1 to Regulatory Guide (RG) 1.204 - Draft Regulatory Guide (DG)-1409 Guidelines for Lightning Protection for Production and Utilization Facilities On May 3, 2023 the U.S. Nuclear Regulatory Commission (NRC) published a notice in Federal Register Citation 88 FR 27714 (Docket ID: NRC-2023-0089) that Draft Regulatory Guide DG-1409, a proposed regulatory guide revision, was available for public comment. The Public Comment Period ended on June 2, 2023; the NRC received comments from the following:
Alan Campbell - Technical and Regulatory Services Nuclear Energy Institute (NEI) 1201 F Street, NW, Suite 1100 Washington, DC 20004 ADAMS Accession No. ML23158A216 NUCLEAR UTILITY GROUP ON EQUIPMENT QUALIFICATION Richard T. McCarty Winston & Strawn LLP 1901 L Street, N.W.
Washington, DC 20036-0081 ADAMS Accession No. ML23158A215 Comments are in ADAMS at their accession numbers, or through Federal Register Docket Number 2023-09390, and their proposed resolutions are in the following Public Comment Resolution table:
2 Table of Public Comments and their NRC Resolutions to Proposed Revision 1 of Regulatory Guide 1.204 (Draft Regulatory Guide DG-1409)
Commenter Section of DG-1409 Specific Comments NRC Resolution NEI C
Staff Regulatory Guidance NEI-1 Comment Each of the four (4) primary references proposed for endorsement (IEEE 665-1995, IEEE 666-2007, IEEE 1050-2004, IEEE C62.23-2017) provides limited guidance specific to lightning protection. For example, IEEE 665-1995 only contains guidance for lightning protection in Section 5.6; however, DG-1409 endorses the entire guide. These guides primarily provide guidance for grounding methods for both protection and noise elimination. Only the portions of the IEEE guides associated with lightning protection should be within the scope of this draft guide. Regulatory Guide 1.180 provides guidance for electromagnetic compatibility (EMC) issues. The broad endorsement of these IEEE guides, as currently described in the draft guide, present potential conflicts related to other regulatory guidance.
Recommendation NRC should specify the specific sections/requirements associated with lightning protection.
NRC staff disagrees with the recommendation to list specific sections and requirements.
Guidance is endorsed in same manner as RG 1.204, November 2005.
The DG does not specify requirements. There is no requirement to follow these guides. As the additional secondary references are not endorsed but provided solely for additional information, they also form no requirements.
In addition, while there are specific sections that include the term lightning, such as IEEE 665-1995 Section 5.6, Lightning protection for generating station structures, of IEEE-665, there are other portions of this document that have important information. For example, consider the grounding rods for a lightning protection system (LPS). Placement of the rods requires a consideration of (among other things) grid resistance. The soil type at that location impacts the resistance. The section of IEEE 665-1995 that addresses this topic is not part of Section 5.6.
Some information applicable to lightning protection may be called out in a specific section, as shown above. However, as also shown above, relevant information is also included throughout the guidance as part of the interrelated topic that is being addressed. This is applicable to all 4 primary references.
The complex nature of this topic, along with the form of endorsement of these primary references in the original RG 1.204, and the findings in NUREG/CR-6866 to endorse these documents, leads to the determination that the references should be endorsed as they are currently in this draft.
3 RG 1.180 is included under Related Guidance as additional information on the topic of lightning protection in the DG. In part it discusses some methods for addressing multiple sources of electromagnetic interference in safety related I&C systems. This includes interference and impacts from lightning. RG 1.180, Rev 2, Dec 2019, refers to RG 1.204 as Related Guidance. While not an endorsed primary reference or a secondary reference, RG 1.180 has status as Related Guidance on the topic.
The staff made no changes to DG-1409 as a result of this comment.
NEI C
Staff Regulatory Guidance NEI-2 Comment The four (4) primary references proposed for endorsement (IEEE 665-1995, IEEE 666-2007, IEEE 1050-2004, IEEE C62.23-2017) are IEEE Guides, not Standards. According to the IEEE Standards Association (IEEE SA) a standard is a document with mandatory requirements, whereas a guide is a document in which alternative approaches to good practice are suggested but no clear-cut recommendations are made. The endorsement of these Guides results in unclear expectations regarding their intended use (i.e.,
informational purposes vs. conformance) since these documents provide no clear-cut recommendations, nor mandatory requirements. The NRC should clarify the intended use of these endorsed guides (and their associated secondary references) to meet regulatory requirements.
Recommendation NRC should clarify the intended use of these endorsed guides (and their associated secondary references) to meet regulatory requirements.
The staff is in partial agreement with the comment recommendation.
IEEE 665-1995 was incorrectly referred to as a Standard. It was corrected to be referred to as a Guide. The staff disagrees with the remainder of the comment for the following reasons.
As this is to be a Regulatory Guide (RG) update, the intent is not to specify requirements. The DG provides guidelines that are acceptable to staff. By endorsing these IEEE Guides (referred to by IEEE Std - Name per IEEE terminology), staff provides information that may be used. There is no requirement to follow these guides. As the additional secondary references are not endorsed but provided solely for additional information, they also form no requirements.
The following is from DG-1409, page 3:
Purpose of Regulatory Guides The NRC issues RGs to describe methods that are acceptable to the staff for implementing specific parts of the agencys regulations, to explain techniques that the staff uses in evaluating specific issues or postulated events, and to describe information that the staff needs in its review of applications for permits and licenses. Regulatory guides are not NRC regulations and compliance with them is not required. Methods and solutions that differ from those set forth in RGs are acceptable if supported by a
4 basis for the issuance or continuance of a permit or license by the Commission.
As stated above, an error in the title for IEEE 665-1995 was identified and corrected. The use of the title wording IEEE Standard. was replaced with IEEE Guide.
Locations in DG-1409 that refer to the IEEE Standards. 665-1995, 666-2007, 1050-2004 and C62.23-2107, as well as the references in Appendix A, as standard(s) have been changed to refer to them as guidance.
No other changes were made to DG-1409 as a result of this comment.
NUGEQ Section A Pages 1-2 Applicable Regulations NUGEQ-1 Current Wording 10 CFR 50.49(d) requires an applicant or licensee to prepare a list of electric equipment important to safety as listed in 50.49(b) and to include information for this electric equipment on performance specifications under conditions existing during and following design basis accidents; the voltage, frequency, load, and other electrical characteristics for which these performance specifications can be ensured; and the environmental conditions, including temperature, pressure, humidity, radiation, chemicals, and submergence at the location where the equipment must perform as specified.
Comment or Feedback 10 CFR 50.49 (d) is not an applicable regulation for lightning protection and should not be listed as an applicable regulation in DG-1409. Lightning is a natural phenomenon that is explicitly excluded from the provisions of the EQ Final Rule (§50.49) by 10 CFR 50.49(c), which states:
(c) Requirements for (1) dynamic and seismic qualification of electric equipment important to safety, (2) protection of electric equipment important to safety against other natural phenomena and external events, and (3) environmental qualification of electric equipment important to safety located in a mild environment are not included within the scope of this section. A mild environment is an environment that would at no time be significantly more severe than the environment that would occur during normal The staff accepts the recommended changes, and as a result the staff made the following changes to DG-1409:
10 CFR 50.49(c) excludes the other clauses in 10 CFR 50.49 from being applicable. Reference to 50.49(d), and 50.49(b) and the associated paragraph is removed. A general statement for 10 CFR 50 is included.
GDC 2 is listed.
Regarding RG 1.89, the RG specifically states that electrical equipment important to safety for protection from other (non-seismic - which is listed separately) natural phenomena are excluded from the scope of 10 CFR 50.49. Thus, staff agrees that 10 CFR 50.49 is not applicable to the other natural phenomena of lightning.
5 plant operation, including anticipated operational occurrences. [Emphasis added]
Note that lightning is not an environmental parameter that results from design basis accidents nor is it required to be addressed under 10 CFR 50.49(e).
Basis for Comment or Proposed Changes (as applicable):
Citing §50.49(d) as an applicable regulation for lightning protections is:
a) Contrary to the specific exclusion of natural phenomenon in §50.49(c).
b) Inconsistent with RG 1.89 (Rev 1 or Rev 2) as neither edition indicates that lightning protection is an environmental parameter that is within the scope of the EQ Final Rule (§50.49).
The currently listed General Design Criteria 2 from 10 CFR 50 Appendix A, Design Bases for Protection Against Natural Phenomena. is the applicable regulation.
NUGEQ Section A Page 2 Applicable Regulations NUGEQ-2 Current Wording 10 CFR 50.49(b) defines electric equipment important to safety as safety-related electric equipment (Class 1E equipment in IEEE 323-1974) that is relied upon to remain functional during and following design basis events to ensure the integrity of the reactor coolant pressure boundary; the capability to shut down the reactor and maintain it in a safe shutdown condition; or the capability to prevent or mitigate the consequences of accidents that could result in potential offsite exposures.
Comment or Feedback Similar to Comment 1 above, 10 CFR 50.49 (b) is not an applicable regulation for lightning protection and should not be listed as an applicable regulation in DG-1409.
Basis for Comment or Proposed Changes (as applicable):
See Basis for Comment for Comment #1.
Similar to the staffs agreement noted in the response to NUGEQ-1, above, staff accepts the recommended changes, and the following changes are made to DG-1409:
10 CFR 50.49(c) excludes the other clauses in 10 CFR 50.49 from being applicable. Reference to 50.49(b) and the associated paragraph is removed.
A general statement for 10 CFR 50 is included.
GDC 2 is listed.
6 NUGEQ Section A Page 2 Applicable Regulations NUGEQ-3 Current Wording
- 10 CFR 52.47(a)(13) requires that an applicant for a design certification must provide the list of electrical equipment important to safety as specified in 10 CFR 50.49(d).
- 10 CFR 52.137(a)(13) requires that an applicant for a standard design approval must provide the list of electric equipment that is important to safety as defined by 10 CFR 50.49(d).
Comment or Feedback Similar to Comment 1 above, 10 CFR 50.49(d) is not an applicable regulation for lightning protection for plants licensed under Part 52.
Basis for Comment or Proposed Changes (as applicable):
See Basis for Comment for Comment #1.
The staff agrees that 10 CFR 50.49(d) is not an applicable regulation for lightning protection for plants licensed under Part 52 due to the exclusion in 10 CFR 50.49(c). As a result, the staff made the following changes to DG-1409:
As 10 CFR 50.49(d) is not applicable, per 10 CFR 50.49(c), then 10 CFR 52.47 and 10 CFR 52.137 (both which refer to 10 CFR 50.49(d)) are not applicable. Reference to 10 CFR 52.47 and 10 CFR 52.137 and their associated paragraphs are removed.
A general statement for 10 CFR 52 is included.