NL-24-0386, License Amendment Request: Changes to Technical Specification 3.7.6, Main Control Room Emergency Habitability System (Ves) Air Storage Tanks Response to Request for Additional Information
| ML24302A308 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 10/28/2024 |
| From: | Coleman J Southern Nuclear Operating Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NL-24-0386 | |
| Download: ML24302A308 (1) | |
Text
Regulatory Affairs Director 3535 Colonnade Parkway Birmingham, AL 35243 October 28, 2024 Docket Nos.: 52-025 NL-24-0386 52-026 10 CFR 50.90 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Vogtle Electric Generating Plant - Units 3 and 4 License Amendment Request: Changes to Technical Specification 3.7.6, Main Control Room Emergency Habitability System (VES) Air Storage Tanks Response to Request for Additional Information On June 21, 2024, Southern Nuclear Operating Company (SNC) submitted a license amendment request (LAR) for Vogtle Electric Generating Plant, Units 3 and 4. The proposed amendment revises Combined License (COL) Appendix A, Technical Specifications (TS) 3.7.6, Main Control Room Emergency Habitability System (VES), Surveillance Requirement (SR) 3.7.6.5 to refer to the Compressed Gas Association (CGA) G-7.1, Commodity Specification for Air, Grade E, for the requirements for acceptable compressed air quality in the main control room emergency habitability system (VES) air storage tanks (ADAMS Accession No. ML24173A220).
On September 27, 2024 the NRC Staff provided a draft request for additional information (RAI).
These RAIs were clarified on a call with the NRC Staff on October 15, 2024. SNC has incorporated appropriate clarifications regarding the RAIs into the enclosed responses.
The Enclosure to this letter provides the SNC response to the RAIs.
The additional information provided in the Enclosure to this letter does not impact the regulatory evaluation (including the Significant Hazards Consideration Determination) or environmental considerations for the proposed changes provided in the June 21, 2024, submittal.
This letter contains no regulatory commitments. This letter has been reviewed and determined not to contain security-related information.
In accordance with 10 CFR 50.91, SNC is notifying the State of Georgia by transmitting a copy of this letter and its enclosure to the designated State Official.
If you have any questions, please contact Ryan Joyce at (205) 992-6468.
U. S. Nuclear Regulatory Commission NL-24-0386 Page 2 I declare under penalty of perjury that the foregoing is true and correct. Executed on the 28th of October 2024.
Respectfully submitted, Jamie M. Coleman Director, Regulatory Affairs Southern Nuclear Operating Company
Enclosure:
Response to Request for Additional Information cc:
NRC Regional Administrator, Region ll NRR Project Manager - Vogtle 3 & 4 Senior Resident Inspector - Vogtle 3 & 4 Director, Environmental Protection Division - State of Georgia Document Services RTYPE: VND.LI.L00
Enclosure to NL-24-0386 Response to Request for Additional Information The NRC request for additional information is repeated below and followed by the Southern Nuclear Operating Company (SNC) responses for Vogtle Electric Generating Plant (VEGP)
Units 3 and 4.
REQUEST FOR ADDITIONAL INFORMATION (RAI)
The U.S. Nuclear Regulatory Commission (NRC) staff has determined that additional information is required for the staff to complete its review.
Regulatory Evaluation General Design Criterion 19, "Control room," states, in part, that a control room shall be provided from which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions, including loss-of-coolant accidents. Equipment at appropriate locations outside the control room shall be provided: (1) with a design capability for prompt hot shutdown of the reactor, including necessary instrumentation and controls to maintain the unit in a safe condition during hot shutdown, and (2) with a potential capability for subsequent cold shutdown of the reactor through the use of suitable procedures.
Currently, Vogtle, Units 3 and 4, Updated Final Safety Analysis Report (UFSAR)
(ML23165A215) subsection 6.4.5.3 and TS Surveillance Requirement (SR) 3.7.6.5 describe the acceptance criterion of the air quality requirements for the VES Air Storage tanks to be based upon the current air quality limits specified in American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) 62-1989 standard in Table 1 and Appendix C, Table C-1.
SNC is proposing to replace this acceptance criterion in both areas with the CGA G-7.1-1997, Commodity Specification for Air, Grade E, for the purposes of establishing a sampling and testing periodicity for the VES tanks. However, in review of Table 1 of the CGA G-7.1-1997 standard, the following limiting characteristics for air pollutants are listed for Grade E without a maximum limiting characteristic as compared to what is provided for the ASHRAE 62-1989 standard: nitrogen dioxide and sulfur dioxide. The NRC staff also observed that there are additional air pollutants with maximum limited characteristics for air quality in ASHRAE 62-1989 standard that are not listed under Grade E for the CGA G-7.1-1997 standard.
Enclosure to NL-24-0386 Response to Request for Additional Information RAI #1 The NRC staff requests additional information on how SNC will account for the sampling and testing of air pollutants without maximum limiting characteristics in switching to the CGA G-7.1-1997 standard and how the provisions of the air quality as listed in the CGA G-7.1-1997 standard will be acceptable for operators in the Main Control Room if the VES tanks are activated.
SNC Response to RAI #1 CGA G-7.1-1997, Section 2.1, Quality verification levels (grades), describes that the Table 1, Directory of limiting characteristics, with an absence of a listed quality verification level, merely indicates that the test is not required for compliance with the specification.
Consistent with the guidance of CGA G-7.1-1997, sampling and testing of air pollutants without maximum limiting characteristics is not required. The acceptability of air supplied from the VES tanks for operators in the Main Control Room is established by providing bottled air quality that exceeds the standard deemed acceptable by the NRC in its Regulations for personnel being supplied bottled air for breathing. Specifically, 10 CFR 20.1703 Use of Individual Respiratory Protection Equipment, Paragraph (g) requires that respirators must be supplied with respirable air of grade D quality or better as defined by CGA G-7.1-1997 and included in the regulations of the Occupational Safety and Health Administration (29 CFR 1910.134(i)(1)(ii)(A) through (E)).
The VEGP Units 3 and 4 VES bottled air is required to meet grade E quality, which exceeds the 10 CFR 20.1703 minimum requirements for bottled breathing air.
As added protection, post-VES actuation both the VES bottled air supply and main control room air are processed through the VES safety-related passive filtration unit prior to distribution within the MCR. The filtration unit is designed to satisfy the guidelines of Regulatory Guide 1.52 and includes a high efficiency particulate air (HEPA) filter, a charcoal adsorber, and a downstream postfilter. The filtered air is circulated and distributed throughout the MCR, providing an additional means of minimizing the presence of pollutants within the MCR.
Together, the VES respiratory-grade bottled air and post-actuation VES safety-related passive filtration system, provide assurance of acceptable air quality for the operators in the Main Control Room.
In summary, CGA G-7.1-1997 Table 1 air pollutants without maximum limits for Grade E air quality merely indicates that sampling and testing is not required for compliance with the specification. Meeting the air quality standards for Grade E in CGA G-7.1-1997 exceed the NRC Regulatory requirements specified in 10 CFR 20.1703 for bottled breathing air.
Enclosure to NL-24-0386 Response to Request for Additional Information RAI #2 In the Vogtle, Units 3 and 4, UFSAR, the licensee references NUREG-0700, Human-System Interface Design Review Guidelines, Revision 2. In requesting the change from the ASHRAE 62-1989 standard to the CGA G-7.1-1997 standard, the NRC staff requests that SNC provides the analysis of how the two areas cited in Section 12.1.2.2, Ventilation, which are air quantity and air velocity, will be impacted.
SNC Response to RAI #2 The VEGP Units 3 and 4 current UFSAR Section 6.4, Habitability Systems, addresses the VES licensing basis. The citations for NUREG-0700 (i.e., UFSAR Section 6.4 Reference 14) are addressing main control room temperature and humidity, and do not address air quantity or air velocity. The proposed changes do not involve any physical modifications. Therefore, there is no impact to the VES air quantity or air velocity delivered by the VES air bottles as a result of the proposed change.