ML21050A428

Comment (2) of Frances Pimentel on DG-1303, Application and Testing of Safety-Related Diesel Generators in Nuclear Power Plants

ML21050A428
Person / Time
Site:	Nuclear Energy Institute
Issue date:	02/18/2021
From:	Pimentel F Nuclear Energy Institute
To:	Office of Administration
References
86FR5267 00002, DG-1303, NRC-2020-0279
Download: ML21050A428 (15)

Text

2/19/2021 blob:https://www.fdms.gov/fb1f6fd9-41dd-4a25-be0f-86623a52ba77 SUNI Review Complete Template=ADM-013 As of: 2/19/21 4:22 PM E-RIDS=ADM-03 Received: February 18, 2021 PUBLIC SUBMISSION ADD: Stanley Gardocki, Liliana Status: Pending_Post Tracking No. 1k5-9lv6-teyn Ramadan, Mary Neely Comments Due: February 18, 2021 Comment (2) Submission Type: Web Publication Date:

1/19/2021 Docket: NRC-2020-0279 Citation 86 FR 5267 DG-1303 Application and Testing of Safety-Related Diesel Generators in Nuclear Power Plants Comment On: NRC-2020-0279-0001 Application and Testing of Safety-Related Diesel Generators in Nuclear Power Plants Document: NRC-2020-0279-DRAFT-0004 Comment on FR Doc # 2021-00940 Submitter Information Name: Frances Pimentel General Comment See attached file(s)

Attachments 02-18-2021_NRC_Industry Comments DG-1303 blob:https://www.fdms.gov/fb1f6fd9-41dd-4a25-be0f-86623a52ba77 1/1

FRANCES PIMENTEL Senior Project Manager, Risk and Technical Support 1201 F Street, NW, Suite 1100 Washington, DC 20004 P: 202.739.8132 fap@nei.org nei.org February 18, 2021 Office of Administration Mail Stop: TWFN-7-A60M U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTN: Program Management, Announcements and Editing Staff Project Number: 689

Subject:

NEI Comments on Draft Regulatory Guide DG-1303, Application and Testing of Onsite Emergency Alternating Current Power Sources in Nuclear Power Plants, Docket ID NRC-2020-0279.

Subm itted via regulations.gov

Dear Program Management,

Announcements and Editing Staff:

The Nuclear Energy Institute (NEI) 1, on behalf of our members, appreciates the opportunity to provide comments on Draft Regulatory Guide DG-1303, Application and Testing of Onsite Emergency Alternating Current Power Sources in Nuclear Power Plants. The purpose of this letter is to provide the attached comments which recommend several changes to improve clarity and consistency on the recommended practices, testing, and maintenance guidance provided and to raise backfitting and forward fitting concerns to your attention, as further described below. Please note that the comments in the attachment are prioritized by importance with 1- (high), 2- (medium), and 3- (low), followed by editorial.

While the industry agrees with many of the proposed changes in this revision, several other changes raise concerns with how the associated industry guidance documents (IEEE 387-2017 and IEEE 2420-2019) are approved and supplemented. Of greatest concern is a statement in the discussion section that [t]he onsite emergency AC power source should be capable of operating for a minimum of 30 days The industry does not agree that there is a generic minimum requirement regarding mission time for emergency AC power sources. The industry's position is best articulated in the PWROG PA-LSC-1707, Industry position paper -

Emergency Diesel Generator Mission Time, which states: [u]nless a plant was licensed with a specific

'mission time' for the EDGs, there is none. The term 'mission time' applied to the EDGs is not a part of any 1

The Nuclear Energy Institute (NEI) is responsible for establishing unified policy on behalf of its members relating to matters affecting the nuclear energy industry, including the regulatory aspects of generic operational and technical issues. NEIs members include entities licensed to operate commercial nuclear power plants in the United States, nuclear plant designers, major architect and engineering firms, fuel cycle facilities, nuclear materials licensees, and other organizations involved in the nuclear energy industry.

February 18, 2021 Page 2 standard plant licensing basis. Rather, the establishment of EDG mission time is highly unit-specific based on primary system design, vital bus scheme and environmental risk factors as determined by each stations IPEEE and approved by the NRC in NUREG 1742. Given the plant-specific nature of this issue, the statement indicating that there is a generic requirement for, or expectation of, a 30-day mission time raises both backfitting and forward fitting concerns, which have not been evaluated in the associated regulatory analysis. Thus, we request that this statement be removed from the regulatory guide. This issue is discussed in Attachment 1 to this letter (see comments 1 and 2).

The current version of DG-1303 also includes a number of supplements to the approved IEEE standards that appear to have been misapplied. This includes supplements for provisions already included in the IEEE standards (but the wrong section was referenced), duplicate supplements with the same requirements, supplements for accelerated maintenance schedules that do not apply to all EDG makes and models, requirements for simulated environmental conditions during testing and supplements for off-site power supplies beyond the scope of this Regulatory Guide and the associated IEEE standards. Finally, the inclusion of Combustion Turbine Generators (CTGs) in this revision of the Regulatory Guide is considered appropriate and welcome. However, several sections discussing and providing the regulatory position for CTGs used EDGs as a starting point and did not appropriately modify the requirements based on the unique design of CTGs. These discrepancies are considered to hinder the intent and effectiveness of the Regulatory Guide as a useful tool to both end users and the NRC.

We appreciate the NRCs effort in developing this draft guidance and encourage your consideration of all stakeholder comments prior to finalizing this draft Regulatory Guide. Given the long-lasting impact of the final document, we recommend a public meeting be scheduled to discuss in more detail the priority 1 and 2 comments included in the attachment and how the staff plans to address them. We trust that you will find these comments useful and informative as you finalize the draft and we look forward to future engagement on this important matter. Please contact me at fap@nei.org or (202) 739-8132 with any questions or comments about the content of this letter or the attached comments.

Sincerely, Frances A. Pimentel Attachment c: Liliana Ramadan, RES/DE/ICEEB/EET, NRC Stanley Gardocki, RES/DE/RGGIB, NRC

Attachment 1 Consolidated Comments on Draft Regulatory Guide DG-1303 Application and Testing of Onsite Emergency Alternating Current Power Sources in Nuclear Power Plants No. Section Comment/Basis Recommendation Priority Background, Onsite Emergency AC Power Sources: Paragraph 8, Last Sentence This should be removed since, per 1 (Page 7), The onsite emergency AC power source should be capable of operating for PWROG PA-LSC-1707, Unless a plant a minimum of 30 days with replenishment of fuel oil and other fluids/materials, as was licensed with a specific Mission required. Time for the EDGs, there is none. The inference of a 30-day capability The IEEE/PES/NPEC/SC-4 WG 4.2 infers this statement refers to an EDG mission time requirement of the EDGs is not a part capability of 30 days; however, it is not in Section C, Staff Regulatory Guidance, of of any standard plant licensing basis.

1. B. the Draft Guide. This was not part of any qualification type-testing and also was not part of any original design specifications used by the OEM when furnishing EDGs to If the item regarding 30-day capability the nuclear industry. for EDGs is to remain in the Reg.

Guide, further clarification needs to be provided for mechanism of verification (test). This is not part of any NUREG 1431, 1432, or 1433 Tech Specs.

Background, Onsite Emergency AC Power Sources: Paragraph 8, Last Sentence Delete this sentence. The issue is well 1 (Page 7), The onsite emergency AC power source should be capable of operating for described in the first paragraph of the a minimum of 30 days with replenishment of fuel oil and other fluids/materials, as background section and is consistent required. with other versions of RG 1.9:

The minimum time of operation of the emergency AC power source should not be An onsite emergency AC power included in this RG due to the following reasons: 1) minimum EDG time of operation source selected for use in an electric for some plants is established by accident analysis in their licensing basis, and power system should be able to (1)

2) minimum EDG time of operation should be based on plant design and established start and accelerate a number of large

2. B. by the nuclear vendors analysis vs. a common time for all. motor loads in rapid succession, while maintaining voltage and frequency Some plants have performed site-specific plant accident analysis to determine the within acceptable limits, (2) provide minimum operating time for an emergency AC power source, with results less than 30 power promptly to engineered safety days. One example is the Callaway analysis that was approved by the NRC. features if a loss of offsite power (LOOP) and an accident occur at the In addition, the PWROG has developed a document PWROG-20014-NP, that same time, and (3) supply power addresses this concept. Perhaps this document would be the place to address any continuously to the equipment concerns with the industry, vs. in the background discussion for this Regulatory needed to maintain the plant in a safe Guide.

No. Section Comment/Basis Recommendation Priority condition if an extended LOOP In the many revisions of RG 1.9 and associated NRC documents on EDGs, the first occurs.

mention of a 30 requirement was in parentheses in Revision 4 which was added following the industry review, without a chance for industry comment. The text in Section B states: supply power continuously to the equipment needed to maintain the plant in a safe condition if an extended (e.g., 30-day period should be considered with refueling every 7 days) LOOP occurs. The NRC was questioned in a public meeting (by NEI) on why this was added in the final version without industry review, and requested it be deleted. The NRCs written response was that The staff intended that the 30-day mission time for EDG should be considered if an extended LOOP occurs. Though in Section B, with the use of the word should the statement now can be read like a requirement that will be used to challenge operating plants Section 2.2 should be deleted because 1) Provisions are already provided in IEEE 387- Section 2.2 should be deleted 1 2017, and 2) it is not practical to simulate environments during testing. Additional because 1) Provisions are already information is provided as follows: provided in IEEE 387-2017, and 2) it is

1) Provisions are already provided in IEEE Std 387-2017: not practical to simulate

a. 7.5 Test description (pre-lubrication and manufacturers recommendations for environments during testing.

reducing wear)

b. 7.5.1 Slow-start test (manual start, standby conditions)

c. 7.5.3 Fast-start test (manual start; standby conditions)

d. 7.5.4 Loss of offsite power test (load shedding, automatic start, load sequencing)

e. 7.5.5 Safety injection auction signal (SIAS) test (automatic start)

f. 7.5.6 Combined SIAS and LOOP test - (load shedding automatic start, load sequencing)

g. 7.5.9 Endurance and load test (operating time)

3. C.2.2 2) It is not practical to simulate environments during testing.

a. NEIs comment on the 4th revision of RG 1.9 was regarding environments (e.g.

temperature, humidity): Sites currently have no capability to control the environment - outside temperature and/or humidity - for current testing. For future plants controlling these parameters would be very cost prohibitive to test at these extremes. Testing from normal standby conditions is appropriate.

b. The NRC Response to RG 1.9, R4 comments (August 22, 2007 letter to NEIs Mr. Adrian P. Heymer, from NRCs William Reckley): The staff agrees that the use of the words simulate...environments in Regulatory Position 1.5 is subject to different interpretations. The staff intended that the effects of environments (temperature and humidity) should be considered in establishing the rating of the diesel generator.

i. It is our position that these items are covered in IEEE Section 4, Principal design criteria, subsection 4.1.2.a Design conditions, items 3) Temperatures

No. Section Comment/Basis Recommendation Priority at equipment locations (minimum and maximum with durations and average annual ambient) and 6) Humidity (minimum and maximum with durations)

c. Continued response from the NRC was The tests should confirm that the capacity margin provided in the design of the EDG is continued to be adequate for design basis event mitigation during worst case expected temperature and humidity condition for a given plant.

i. It is our position that the existing diesel rooms do not have the capability to simulate temperature and humidity during testing, and that for future plants controlling these parameters would be very cost prohibitive to test at these extremes. Testing from normal standby conditions is appropriate. This proposed C.2.2 position should be eliminated.

d. The NRC stated in the letter that, The staff agrees to include this clarification in the next revision of RG 1.9 regarding this issue. It does not appear that this was addressed in this revision.

Most but not all manufacturers do not require accelerated maintenance This requirement should be removed 1 requirements for operating time above the nominal rating. In addition, this time as IEEE Std 387-2017, Section 6.5.1 should be limited to the 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of the endurance run at 105-110% load. The Reg. covers establishing a maintenance Guide should clarify this is planned loading. Additionally, the Reg. Guide needs to program (with sufficient technical acknowledge the variety of rating schemes currently in place in the industry. Each of basis) that factors in operating hours, these rating levels represents the manufacturers estimated liability for warranty testing, condition, operating claim at a given load level. Accordingly, the resulting ratings lack consistent basis and experience, or a combination of these their application toward maintenance interval adjustments is of questionable validity. for emergency diesel generator units.

The application of the proposed guidance should be reviewed by the EDG manufacturer against their rating basis with appropriate clarification/changes Also consider adding language that

4. C.2.3 documented for the licensee. There are, however, some EDG manufacturers that no acknowledges and accepts longer exist, meaning that a valid review of rating basis is not possible. In these cases, momentary episodes where the load the Reg. Guide needs to include allowance for EDG owner group recommendations is above the EDG rating.

for accelerated maintenance as appropriate.

Current STS recognizes that grid instability and cycling plant loads can perturbate EDG load while paralleled with offsite power. Accordingly, allowance is specifically provided for short-term momentary episodes where load is above the specified level. Likewise, if kept, NRC should allow momentary excursions without penalty or superfluous accounting burden.

IEEE Std 387, Clause 4.4, Table 1 scope is for design considerations for the EDG. It is This should be removed because this 1

5. C.2.4 not intended to address considerations for off-normal preferred power supply. If is out of scope of RG 1.9.

protection design criteria, the EDG system boundary should be respected. Any Class

No. Section Comment/Basis Recommendation Priority 1E bus protection (IEEE Std 308) or Preferred Power Supply (IEEE Std 765) is out of scope of IEEE Std 387.

Section 2.8 is redundant to Section 2.2. Delete Section C.2.8 1

6. C.2.8 In IEEE 387, "Continuous rating" with 8760 hours0.101 days <br />2.433 hours <br />0.0145 weeks <br />0.00333 months <br /> operation is defined along with Remove requirement 3.1. See 1 "short time rating" which requires 2-hour operation in any 24-hour period. However, Comment/Basis.

IEEE Std 2420 does not have "short time rating," and therefore uses only term of

7. C.3.1 rating instead of continuous rating. Because the rating of combustion turbine-generator unit is already defined in IEEE Std 2420, Section 3.1, this requirement should be removed from RG 1.9.

In case of emergency (accident or LOOP) startup, purge process affects startup time Recommend the follow change to 1 of emergency power system. In order to conform with safety requirement, it may be item 3.6 (blue italics):

appropriate to be done during shutdown.

Because of the potential for explosion Also, if automatic purge system is provided, starting sequence should probably of residual fuel or fuel vapor override purge process to start up the CTG within a required time. remaining in the CTG, the exhaust

8. C.3.6 system should be purged before startup or during shut down. The starting and / or shut down sequence should include a gas purge process of the turbine to prevent damage to the turbine and downstream components by explosion.

Automatic switch to open the bypass door should not be required unconditionally. Recommend revising item 3.8 to the 1 following (or similar):

The inlet air design should consider preventing excessive increase in pressure loss due to particle

9. C.3.8 deposition on inlet air filter. When increase of pressure loss is not acceptable for CTG performance, inlet air filter should be removed, replaced, or cleaned without power reduction of CTG.

No. Section Comment/Basis Recommendation Priority This item does not need to specify "under a standard load." Recommend changing to: 1 Also, it seems monitoring under standard load operation is required, but item b In addition to IEEE Std 24202019, (deposits or deterioration of the turbine blades or vanes (as inferred from ideal model Section C.3, the following items results)) cannot be monitored during operation. observed under a standard load indicate the need for an overhaul and should be monitored when

10. C.3.12 appropriate for a CTG based on the manufacturer's recommendations: a.

decreasing run out time after shutdown, and b. deposits or deterioration of turbine blades or vanes (as inferred from ideal model results).

Background, Onsite Emergency AC Power Sources, Paragraph 6, Second Sentence: Please revise sentence as follows: 2 Increased operational reliability can be achieved through appropriate testing and Increased operational reliability can maintenance, as well as an effective root cause analysis of all failures of the onsite be achieved through appropriate emergency power source. testing and maintenance per RG a) The section does not have a reference for direction here. RG 1.160, 1.160 (Monitoring the Effectiveness

11. B.

Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, should be of Maintenance at Nuclear Power the reference. Plants), as well as appropriate level b) A full root cause analysis may not be warranted for each failure. In some cases, causal analyses of all failures of the apparent cause analyses may be more effective. An appropriate level causal onsite emergency AC power source.

analysis would be a better Clarify the fire source being considered in this guidance. Other guidance and Add "originating from the emergency 2

12. C.1.13 regulations cover fires originating elsewhere. AC power source" to the end of the 2nd sentence.

Clause 1.4, Inclusions for Site Testing: NRC Draft Guide recommends supplementing Delete C.2.1. see basis. 2 field flashing devices. Field flashing devices are already included within the scope of

13. C.2.1 IEEE Std 387-2017 (Section 1.3.1.b.1)

The maximum design-basis loads should be within the continuous rating (as defined Change C.2.7 to state that IEEE Std 2 in IEEE Std 387-2017, Section 3.2) of the EDG with margin. 387-2017, Clause 4.1.2.D, T Design Load, should be supplemented with

14. C.2.7 IEEE Section 4.1.2.d discusses Design load. C2.7 should be revised to reference and the following: The maximum design-supplement this section. basis loads should be within the continuous rating (as defined in IEEE

No. Section Comment/Basis Recommendation Priority Std 387-2017, Section 3.2) of the EDG with margin.

This sentence seems like an opinion, and it does not provide direction. The rest of the Delete the 7th sentence: "If test 3 paragraph already clearly states the requirements. programs are not ..."

15. C.1.8 Item b is for Lube Oil and the IEEE Std 387 Section 4.5.1.7 is solely for Fuel Oil. If this is If a requirement for lube oil is to be 3 intended to remain in the Reg. Guide, it should be its own item. presented in the Reg. Guide, it should

16. C.2.5 have its own section (see Comment/Basis).

Current wording only includes ISOC testing w/ plant vital bus loads, but the intent Change a. (3) to "... planned to run 3 should be to include parallel operation at varying load levels. loaded for at least 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> at 50%

17. C.3.3 continuous rating."

Editorial Comments Included Below:

Purpose:

2nd to last paragraph from Section B of Rev. 4 provides additional discussion 1. Copy 2nd to last paragraph from N/A of purpose but was not included in this draft. Section B of Rev. 4 to make 2nd paragraph of Purpose section.

1. A.

2. Change "emergency diesel generators" to "onsite emergency AC power sources" (2x).

Purpose:

Note in Rev. 3 the root cause statement was limited to just the EDGs. In Add clarification to be sure that this N/A Rev. 4 and DG-1303 the wording changed to onsite emergency power source applies only to Class 1E GDC 17 On-potentially opens the door to failures beyond EDGs, CTGs or other sources. At first site AC Emergency Power Sources.

glance it seems a small change but the purpose states it addresses onsite emergency alternating current (AC) power sources, including emergency diesel generators (EDGs) and combustion turbine generators (CTGs), in nuclear power plants. This RG may also

2. A. be used for other types of onsite emergency AC power sources. This leaves the door open to applying the RG wording to other power sources on site.

RG 1.9 Rev. 3 High reliability, can be achieved by appropriate testing, maintenance, and operating programs and by institution of a reliability program that implements effective root cause analysis of all emergency diesel generator failures and that is designed to monitor, improve, and maintain reliability at selected levels.

No. Section Comment/Basis Recommendation Priority DG-1303, Page 7, Increased operational reliability can be achieved through appropriate testing and maintenance, as well as an effective root cause analysis of all failures of the onsite emergency power source.

Applicability: Be consistent with the use of "all." Use in both locations or neither one Delete "all" from "... and all applicants N/A (recommended). and ..." OR add "all" up front, as in, "...

3. A. applies to all applicants..."

Related Guidance: Be consistent with the use of "AC power" vs "ac power". Change "ac" to "AC" under N/A NUREG-0800 discussion of SRP

4. A. Chapter 8.

Reason for Revision: Language not specific enough Change first sentence to "This revision N/A (Revision 5) of RG 1.9 endorses, ..."

5. B.

Background, Onsite Emergency AC Power Sources, Paragraph 2: The word is implied Delete "active" from the 2nd sentence N/A and doesn't need to be stated. of the 2nd paragraph.

6. B.

Background, Onsite Emergency AC Power Sources, Paragraph 2: Do not need to list Delete "EDG, CTG, or other" from the N/A the three types of generators every time. 4th sentence of the 2nd paragraph.

7. B.

Background, Onsite Emergency AC Power Sources, Paragraph 2: Language not specific Add "of the emergency generator N/A enough prime mover" after the word

8. B. "overspeed" in the 7th sentence of the 2nd paragraph.

Background, Onsite Emergency AC Power Sources, Paragraph 3: Awkward wording Change the middle of the 2nd N/A sentence of the 3rd paragraph to "...

9. B. and selecting EDGs or CTGs with continuous ratings that exceed the sum ..."

Background, Onsite Emergency AC Power Sources, Paragraph 3: Redundant wording Combine last 2 sentences of 3rd N/A paragraph to "However, the DBE loads

10. B. during the operating license or COL stages should be within the

No. Section Comment/Basis Recommendation Priority continuous (or nominal) rating of the selected onsite emergency AC power source(s) with margin."

Background, Onsite Emergency AC Power Sources, Paragraph 4: Words are implied Delete "boiling or pressurized" from N/A the 2nd sentence of the 4th

11. B. paragraph.

Background, Onsite Emergency AC Power Sources, Paragraph 4: Excessive/awkward Combine the last 2 sentences of the N/A wording 4th paragraph to "... provided with an

12. B. ECCS capable of maintaining the core temperature at an acceptably low value and removing decay ..."

Background, Onsite Emergency AC Power Sources, Paragraphs 4 & 5: The author is Move the 1st sentence of the 5th N/A trying to convey the continuous rating should bound ECCS loads, but long-term ECCS paragraph to the end of the 4th

13. B. loads are significantly lower than during the first 2-24 hrs. The previous paragraph paragraph and delete the 2nd already said DBE loads should be within the continuous rating; this is the message sentence of the 5th paragraph.

that needs to be conveyed. The deleted part confuses the issue.

2. Add "AC" for consistency. Change the last part of the last N/A sentence in paragraph 6 to "as well as

14. B. effective root cause analyses of all failures of the onsite emergency AC power source."

Background, Emergency Diesel Generators: Information for EDGs and CTGs is Change Section title to "Emergency N/A redundant and should be combined into one section. Diesel Generators and Combustion

15. B. Turbine Generators" Background, Emergency Diesel Generators: The concern is not limited to EDGs. Change the 1st sentence of the 1st N/A paragraph to 2 sentences: "Motor-starting transients can also affect the

16. B. frequency of the emergency AC power source. This is primarily an EDG concern but may apply to other generator types."

No. Section Comment/Basis Recommendation Priority Background, Emergency Diesel Generators: Mostly redundant/awkward wording Delete existing 2nd and 3rd sentences N/A of 1st paragraph and move the

17. B. revised sentences above to the beginning of the 2nd paragraph.

Background, Emergency Diesel Generators: Section is being revised to apply to more Change the 3 uses of "EDG" in the 2nd N/A than just EDGs paragraph to "emergency AC power

18. B. source" (one is plural).

Background, Emergency Diesel Generators: Captures previously deleted material that Change the last part of the 2nd N/A was not redundant sentence in the 2nd paragraph to "...

ECCS motor loads (e.g., pumps,

19. B.

motor-operated valves and fans) and bypass power supplies associated with uninterruptible power systems."

Background, Emergency Diesel Generators: Section is being revised to apply to more 1. Change 1st sentence of 3rd N/A than just EDGs paragraph to "Protection of an EDG or CTG from ... operation of an overspeed trip device (usually set at

20. B. 115 percent of nominal speed for EDGs)."

2. Add "or CTGs" after "EDGs" in the 2nd and 3rd sentences of the 3rd paragraph.

Background, Emergency Diesel Generators: It is not clear the author wishes these to Change the last 3 sentences of the 3rd N/A be Test mode-only trips. Also, a trip obviously interferes with operation; this does not paragraph to "Conversely, spurious need to be stated. operation of a trip circuit lowers EDG/CTG availability and reliability.

21. B. Consequently, it is important to ensure these other protective trips are only enabled in Test mode so they do not prevent the EDGs/CTGs from performing ..."

Background, Combustion Turbine Generators: The concern is not limited to CTGs. 1. Move the 1st paragraph to be the N/A 1st paragraph of the combined EDG/CTG section.

22. B.

2. Add "EDGs or" before "CTGs" in the 1st and last sentences of the 1st paragraph.

No. Section Comment/Basis Recommendation Priority Background, Combustion Turbine Generators: Information is redundant for combined Delete 2nd and 3rd paragraphs. N/A EDG/CTG section.

23. B.

Awkward/incomplete wording Change section title to "Design and N/A Testing Considerations for Onsite

24. C.1 Emergency AC Power Sources other than EDGs and CTGs" Enhancement Suggestion: Paragraph is cumbersome and contains many items. Consider putting the individual N/A requirements in bullet form.

25. C.1.4 Consistency and grammar 1. In the 5th sentence: N/A

a. Change "power AC" to "AC power"

b. Replace the comma after

26. C.1.4 "controls" with "and"

2. Change "internal" to "internally" in the last sentence Words are implied Delete "for these plants" from the last N/A sentence.

27. C.1.6 Grammar Change "i.e." to "e.g." in the 2nd N/A sentence.

28. C.1.8 Wording not copied and modified properly from IEEE 387-2017. Add "of the system" after "status" in N/A the 6th sentence.

29. C.1.8 Awkward/incomplete wording 1. Change section title to "Design and N/A Testing Considerations for Emergency

30. C.2 Diesel Generators"

2. Add "and testing" after "design" in the opening sentence.

No. Section Comment/Basis Recommendation Priority Grammar Delete hyphen in "lubricating-oil" in N/A subsection b.

31. C.2.5 2.7 refers to IEEE 387-2017, Section 3.2. There is no Section 3.2 in IEEE 387-2017. It is Refer to Section 3 definition of N/A Definitions Clause, second definition and should be clarified as such. continuous rating (of diesel generator

32. C.2.7 unit)

Words are redundant to the word "independently" Delete "of the redundant units" from N/A the end of the opening sentence.

33. C.2.9 Awkward/incomplete wording 1. Change section title to "Design and N/A Testing Considerations for

34. C.3 Combustion Turbine Generators"

2. Add "and testing" after "design" in the opening sentence.

Language not specific enough Add "following maintenance" after N/A "declare the CTG operable" in the last

35. C.3.3 sentence of the opening paragraph.

Grammar 1. Change "load run" to "load/run" in N/A 3rd paragraph of subsection c.

36. C.3.3 2. Delete hyphen in "high-lubricant" in subsection c. (1).

Redundant wording Delete "consideration" from the N/A opening sentence.

37. C.3.9 Words are redundant to the word "independently" Delete "of the redundant units" from N/A the end of the opening sentence.

38. C.3.13 Grammar - proper nouns should be capitalized 1. Capitalize "technical specification N/A surveillance requirements" and add

39. C.3.15 "(TSSRs)" in the 1st sentence.

No. Section Comment/Basis Recommendation Priority

2. Change "technical specification surveillance requirement" to "TSSR" in the last sentence.

References:

1) IEEE 387 (2017), IEEE Standard for Criteria for Diesel Generator Units Applied as Standby Power Supplies for Nuclear Power Generating Stations.

2) Letter to Mr. Adrian P. Heymer, Senior Director, New Plant Development, Nuclear Energy Institute, from William Reckley, U.S. NRC, Chief, Rulemaking, Guidance, and Advanced Reactors Branch, Division of New Reactor Licensing, Office of New Reactors, dated August 22, 2007,

Subject:

Response to Nuclear Energy Institute (NEI) Letter Dated May 23, 2007 - Re: Industry Comments on Recent Guidance Documents. ML072330563