ML25192A201
| ML25192A201 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 07/30/2025 |
| From: | Gregory Bowman Office of Nuclear Reactor Regulation |
| To: | Entergy Operations |
| Galvin D, NRR/DORL/LPL2-2 | |
| Shared Package | |
| ML25192A193 | List: |
| References | |
| EPID L-2024-LLA-0092 | |
| Download: ML25192A201 (1) | |
Text
July 30, 2025 ANO Site Vice President Arkansas Nuclear One Entergy Operations, Inc.
N-ADM-8 1448 S.R. 333 Russellville, AR 72802
SUBJECT:
ARKANSAS NUCLEAR ONE, UNIT 1 - RELAXATION OF CERTAIN PRESSURIZER HEATER POWER SUPPLY REQUIREMENTS FROM CONFIMATORY ORDER DATED JANUARY 2, 1980 (EPID L-2024-LLA-0092)
Dear Sir or Madam:
By application dated July 2, 2024 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML24184B775), as supplemented by letters dated February 26, 2025 (ML25057A318) and April 8, 2025 (ML25098A194), Entergy Operation, Inc. (Entergy, the licensee) submitted a license amendment request (LAR) for Arkansas Nuclear One, Unit 1 (ANO-1). The proposed changes would relax the U.S. Nuclear Regulatory Commission (NRC, the Commission) Confirmatory Order dated January 2, 1980 (hereafter 1980 Order)
(ML021220215) for ANO-1 to allow an alternate means of addressing the post Three Mile Island Unit No. 2 (TMI-2) recommendation that any changeover of the pressurizer heaters from normal offsite power to emergency onsite power is to be accomplished manually in the control room.
The proposed changes would allow the performance of manual actions at 120-volt alternating current (VAC) instrument panels Y01 and Y02 outside the control room to restore power to the pressurizer low-low level interlock to allow operation of required pressurizer heaters on emergency onsite power for certain loss of offsite power (LOOP) events. The supplements dated February 26, 2025, and April 8, 2025, provided additional information that clarified the application. Amendment No. 284 to Renewed Facility Operating License No. DPR-51 for ANO-1 (ML25188A184) is being issued concurrently to authorize corresponding safety analysis report changes.
Following the TMI-2 accident on March 28, 1979, a TMI-2 Lessons Learned Task Force of the NRC staff conducted an intensive review of the design and operational aspects of nuclear power plants and the emergency procedures for coping with potential accidents. The Task Force identified measures to be taken in the short-term to reduce the likelihood of accidents and to improve emergency preparedness in responding to accidents. These measures are set forth in NUREG-0578, TMI-2 Lessons Learned Task Force Status Report and Short-term Recommendations dated July 1979 (ML090060030). The NRC concluded that prompt implementation of the actions denominated as Category A requirements at operating nuclear power plants was necessary to provide continued assurance of public health and safety. These Category A requirements were transmitted to all licensees operating nuclear power plants by Generic Letter (GL) 79-40, Followup Actions Resulting from the NRC Staff Reviews Regarding the Three Mile Island Unit 2 Accident, dated September 13, 1979 (ML112990325). GL 79-56, Discussion of Lessons Learned Short Term Requirements, dated October 30, 1979 (ML031320403), provided further clarification of the Category A requirements.
Applicable Requirements Imposed by the 1980 Order Section IV of the 1980 Order required, in part:
The Licensee by January 31, 1980, implement all Category A requirements...
referred to in Part II of this Order,...
Part II of the Confirmatory Order referred to NUREG-0578, which set forth measures identified by the NRC TMI-2 Lessons Learned Task Force. Section 2.1.1, Emergency Power Supply Requirements for the Pressurizer Heaters, Power-Operated Relief and Block Valves, and Pressurizer Level indicators in PWRs [Pressurized Water Reactors], of NUREG-0578, provides, in part, the following recommendation for the emergency power supply for the pressurizer heaters.
Provide redundant emergency power for the minimum number of pressurizer heaters required to maintain natural circulation conditions in the event of loss of offsite power.
NUREG-0578, Appendix B, NRR [NRC Office of Nuclear Reactor Regulation] Lessons Learned Task Force Implementation of Short-term Recommendations, designated the recommendations in section 2.1.1 of NUREG-0578 as Category A.
The 1980 Order also refers to a letter dated October 30, 1979, specifically GL 79-56. GL 79-56 provided clarifications to the recommendations in NUREG-0578. Specifically, section 2.1.1, Emergency Power Supply, of enclosure 1 to GL 79-56 stated, in part, that:
Any change-over of the heaters from normal offsite power to emergency onsite power is to be accomplished manually in the control room.
Licensee Request In the enclosure to the letter dated July 2, 2024, the licensee stated that:
The pressurizer low-low level heater interlock prevents the heaters from being damaged due to being uncovered.... This interlock is powered by the Green-train electrical power distribution system only. If this interlock is de-energized, it would prevent the ability to utilize the required heaters, even if Red-train power and adequate pressurizer level exists.
In the event of the LOOP with failure of Green-train emergency power, the design of ANO-1 requires manual operator actions outside the control room to restore power to the pressurizer low-low level heater interlock allowing for minimum TS required pressurizer heater capacity powered by Red-train emergency power.
This is contrary to the NUREG-0737 requirement of Any change-over of the heaters from normal offsite power to emergency onsite power is to be accomplished manually in the control room.1 The licensees July 2, 2024, letter is a LAR addressing this issue and requesting conforming changes to the ANO-1 Safety Analysis Report (SAR) and the 1980 Order requirement described above. After review, the NRC staff concluded that the appropriate mechanism to address the licensees request for compliance with the 1980 Order was through relaxation of the order. The normal process for relaxing an order is a request in writing (by letter) showing good cause for the specific requirement to be relaxed. Although the exception, the staff may self-initiate a relaxation. In this case, based on the information provided through the licensees LAR dated July 2, 2024, as supplemented, the staff believes sufficient information is on the docket for the staff to appropriately consider relaxation of the 1980 Order requirement.
Good Cause Justification Amendment No. 284, dated July 30, 2025, addresses the ANO-1 SAR revision associated with the same issue. The NRC staff safety evaluation for the amendment discusses both the order relaxation and the SAR change since they are interdependent. Accordingly, consideration of the licensees stated good cause is documented in the Amendment No. 284 safety evaluation for the revision to the ANO-1 SAR.
Accordingly, based upon the authority granted to the Director of NRR, the requirement of the 1980 Order for full change-over of the pressurizer emergency heaters from normal offsite power to emergency onsite power is to be accomplished manually in the control room is relaxed.
If you have any questions, please contact Hannah McLatchie at 301-415-8507.
Sincerely, Gregory T. Bowman, Acting Director Office of Nuclear Reactor Regulation 1 You inappropriately referred to the NUREG-0737 in the original letter. However, applicable requirements imposed by the 1980 Order were unchanged in NUREG-0737, so the stated requirement is appropriate.
The licensee referenced the appropriate documents in its letter dated April 8, 2025.
Groom, Jeremy signing on behalf of Bowman, Gregory on 07/30/25
Package: ML25192A193 Relaxation Letter: ML25192A201 Amendment: ML25188A184
- via eConcurrence NRR-106 OFFICE NRR/DORL/LPL2-2/PM*
NRR/DORL/LPL4/LA*
NRR/DORL/LPL4/BC*
NAME DGalvin PBlechman TNakanishi DATE 7/7/2025 7/10/2025 7/16/2025 OFFICE OE/EB/BC*
OGC - NLO*
OE/D (A)*
NAME JPeralta RCarpenter BPham DATE 7/16/2025 7/21/2025 7/23/2025 OFFICE NRR/DORL/D (A)*
NRR/D (A)*
NAME JPelton (ARivera-Varona for)
GBowman (JGroom for)
DATE 7/28/2025 7/30/2025