L-MT-25-008, Xcel Energy - License Amendment Request to Revise the Emerency Action Level Scheme
| ML25038A114 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 02/07/2025 |
| From: | Hafen S Northern States Power Co, Xcel Energy |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| L-MT-25-008 | |
| Download: ML25038A114 (1) | |
Text
2807 West County Road 75 Monticello, MN 55362 February 7, 2025 L-MT-25-008 10 CFR 50.54(q) 10 CFR 50.90 10 CFR 50.91(a)(6)
ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Monticello Nuclear Generating Plant Docket No. 50-263 Renewed Facility Operating License No. DPR-22 License Amendment Request to Revise the Emergency Action Level Scheme In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), requests to revise the Emergency Action Level (EAL) scheme used at Monticello Nuclear Generating Plant (MNGP). The proposed change is being requested on an exigent basis pursuant to 10 CFR 50.91(a)(6).
Specifically, the proposed change will permanently revise EAL HU3.6. The MNGP Emergency Plan, as changed, would continue to meet the standards in 10 CFR 50.47, "Emergency plans,"
paragraph (b) and the requirements in Appendix E to 10 CFR 50, "Emergency Planning and Preparedness for Production and Utilization Facilities." The proposed EAL change is being submitted for approval prior to implementation, as required by 10 CFR 50.54, "Condition of licenses," paragraph (q)(4) and 10 CFR 50, Appendix E, Section IV, "Content of Emergency Plans," paragraph B.2.
The enclosure provides NSPM's evaluation and justification of the proposed change and includes the technical evaluation and associated no significant hazards consideration analysis and environmental evaluation. The attachment to the enclosure provides marked up EAL and Basis pages to reflect the proposed change.
Approval of the proposed amendment is requested by February 25, 2025, to preclude the potential for unnecessary emergency notification. Upcoming seasonal changes and potential external dam operational challenges could cause transient variations in the Mississippi River level and necessitate emergency notifications absent this proposed change. Once approved, the amendment shall be implemented within 3 days.
In accordance with 10 CFR 50.91, a copy of this application, with attachments, is being provided to the designated Minnesota State Official.
fl Xcel Energy
Document Control Desk L-MT-25-008 Page2 This letter makes no new commitments and no revisions to existing commitments.
If you should have any questions regarding this submittal, please contact Ron Jacobson at (612) 330-6542 or ronald.g.jacobson@xcelenergy.com.
I declare under penalty of perjury, that the foregoing is true and correct.
Executed on February 7, 2025.
- Ii~
Site Vice President, Monticello Nuclear Generating Plant Northern States Power Company - Minnesota Enclosure cc:
Administrator, Region 111, USNRC Project Manager, Monticello, USNRC Resident Inspector, Monticello, USNRC State of Minnesota
L-MT-25-008 NSPM Enclosure Page 1 of 9 ENCLOSURE MONTICELLO NUCLEAR GENERATING PLANT EVALUATION OF PROPOSED CHANGE License Amendment Request Revise the Emergency Action Level Scheme 1.0
SUMMARY
DESCRIPTION.................................................................................. 2 2.0 DETAILED DESCRIPTION.................................................................................. 2 2.1 Current EAL............................................................................................... 2 2.2 Reason for the Proposed Change............................................................. 2 2.3 Proposed Change...................................................................................... 3
3.0 TECHNICAL EVALUATION
.................................................................................. 3
4.0 REGULATORY EVALUATION
............................................................................. 4 4.1 Applicable Regulatory Requirements/Criteria............................................ 4 4.2 No Significant Hazards Consideration Analysis......................................... 6 4.3 Conclusion................................................................................................. 8
5.0 ENVIRONMENTAL CONSIDERATION
................................................................ 9
6.0 REFERENCES
..................................................................................................... 9 ATTACHMENT:
EAL Basis Pages Marked-Up
L-MT-25-008 NSPM Enclosure Page 2 of 9 License Amendment Request Revise the Emergency Action Level Scheme 1.0
SUMMARY
DESCRIPTION In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), hereby requests to revise the Emergency Action Level (EAL) scheme used with the Xcel Energy Standard Emergency Plan (SEP) at Monticello Nuclear Generating Plant (MNGP). The proposed change is being requested on an exigent basis pursuant to 10 CFR 50.91(a)(6).
Specifically, the proposed change will permanently revise the current MNGP EAL HU3.6, "River level less than 902.4 ft elevation" to include a duration. The SEP, as changed, would continue to meet the standards in 10 CFR 50.47, "Emergency plans,"
paragraph (b) and the requirements in Appendix E to 10 CFR 50, "Emergency Planning and Preparedness for Production and Utilization Facilities." The proposed EAL change is being submitted for approval prior to implementation, as required by 10 CFR 50.54, "Condition of licenses," paragraph (q)(4) and 10 CFR 50, Appendix E, Section IV, "Content of Emergency Plans," paragraph B.2.
2.0 DETAILED DESCRIPTION 2.1 Current EAL NSPM declares a Notification of Unusual Event (NUE) for:
HU3.6: River level less than 902.4 ft elevation.
2.2 Reason for the Proposed Change The instrument used to measure and monitor river level is located between the log boom and the bar rack outside the plant intake structure building. The instrument accurately indicates water level at the plant intake. Dynamic river conditions can cause a differential level between the plant intake and the river. Any restrictions in the flow path from the river to the intake due to ice and/or debris can cause sudden changes in level where the instrument is located although actual river level does not change rapidly.
For example, during the winter of 2024/2025, a transient that began at an upstream dam created a disruption that ultimately led to significant icing and debris challenges at the MNGP intake. The indication for river level during this transient approached the 902.4 foot limit, lowering to 902.8 feet for a period of 3-4 minutes before recovering above 903 feet. Actual level in the river during this transient remained well above the
L-MT-25-008 NSPM Enclosure Page 3 of 9 NUE threshold. There was no degradation in the availability of the Ultimate Heat Sink (UHS) as steady-state river level remained about 904.6 feet.
The definition of a NUE is an emergency classification level indicating that events are in progress or have occurred which indicate a potential degradation of the level of safety of the plant or indicate a security threat to facility protection. No releases of radioactive material requiring offsite response or monitoring are expected unless further degradation of safety systems occurs.
Notification to the NRC and the state and local governments due to an indicated river level transient which does not threaten the UHS nor does it meet the intent of the classification would create unnecessary burden for offsite agencies and could degrade stakeholder confidence.
The reason for the exigent review is to preclude an unnecessary emergency declaration should another transient challenge the indication during the remaining months (at least two) of the winter. The negative consequences of declaring an NUE when the UHS is not degraded or threatened is sufficient to request an exigent review.
2.3 Proposed Change MNGP proposes to add a 60-minute duration to EAL HU3.6 similar to the fire EALs. The HU3.6 EAL would be changed to:
HU3.6: River level less than 902.4 ft elevation for 60 minutes or longer.
A note will be added stating that the Emergency Director should declare the Unusual Event promptly upon determining that 60 minutes has been exceeded, or will likely be exceeded; i.e., if river level lowered to 902.4 feet and it was expected to remain at that level or lower, the Emergency Director would declare the NUE before the full 60-minute duration elapsed.
The emergency classification and EAL change scheme has been agreed upon by the state and county governmental authorities that support the MNGP site. Concurrences from the State of Minnesota, Sherburne County, and Wright County were received for this proposed EAL HU3.6 change.
3.0 TECHNICAL EVALUATION
The Mississippi River is the UHS for MNGP. Normal river level is approximately 905 feet to 906 feet above sea level which varies with seasonal changes in weather and precipitation.
EAL HU3.6 addresses Mississippi River low flow conditions. The Xcel Energy standard emergency plan and MNGP EAL matrix require an emergency declaration (Notification
L-MT-25-008 NSPM Enclosure Page 4 of 9 of Unusual Event) if river level drops to 902.4 feet. The basis for the EAL is that this level may be a precursor to loss of the UHS and warrants further management attention. A river level of 902.4 feet is not associated with any safety-related or operating pump limits; for example, the circulating water pumps trip at 901.5 feet and the Technical Specifications UHS river level for operability is 899 feet. The intent of this EAL is to ensure that an emergency classification is declared based upon the effects that natural or technological hazard events may have on the facility, which are considered to be precursors to a more significant event or condition or have potential impacts that warrant emergency notification to local, state, and federal authorities.
The level instrument measuring river level is located between the log boom and the bar rack outside the plant intake structure (measures water level at the plant intake) and can be affected by transient river conditions such as periods of icing and heavy debris flows. River water to the plant goes under the log boom to the bar rack in a (relatively) narrow path compared to the width of the river. Restrictions in the path due to ice/debris can cause sudden variations in intake level, which are not representative of the actual river level.
On December 1, 2024, an upstream Mississippi River dam (St. Cloud) temporarily tripped offline creating transient river conditions, and MNGP experienced increased ice and debris in the plant intake. River level indication varied over several minutes and at one point neared the EAL threshold. Actual river level during the transient varied from about 904.6 feet down to 903.3 feet over a 24-hour period based on a best-fit curve.
On January 27, 2025, another river transient occurred due to an upstream dam trip at Sartell. In this case, coordinated efforts by the dam operators at St. Cloud, Sartell and MNGP plant operating staff, combined with the river conditions present at the time, were effective in reducing the amplitude of the river change experienced at MNGP. No icing or debris issues occurred.
Sixty minutes was selected as a threshold to exclude transient events affecting river level.
4.0 REGULATORY EVALUATION
4.1 Applicable Regulatory Requirements/Criteria 10 CFR 50.47, "Emergency Plans," sets forth the NRC emergency plan requirements for nuclear power plant facilities. Section (a)(1)(i) of 10 CFR 50.47 states in part:
No initial operating license for a nuclear power reactor will be issued unless a finding is made by the NRC that there is a reasonable assurance that adequate protective measures can and will be taken in the event of a radiological emergency.
L-MT-25-008 NSPM Enclosure Page 5 of 9 Title 10 Code of Federal Regulations 50.47(b):
(b) The onsite and, except as provided in paragraph (d) of this section, offsite emergency response plans for nuclear power reactors must meet the following standards:
(4) A standard emergency classification and action level scheme, the bases of which include facility system and effluent parameters, is in use by the nuclear facility licensee, and State and local response plans call for reliance on information provided by facility licensees for determinations of minimum initial offsite response measures.
10 CFR 50, Appendix E, IV.B.1, B.2, and C.1 B. Assessment Actions
- 1. The means to be used for determining the magnitude of, and for continually assessing the impact of, the release of radioactive materials shall be described, including emergency action levels that are to be used as criteria for determining the need for notification and participation of local and State agencies, the Commission, and other Federal agencies, and the emergency action levels that are to be used for determining when and what type of protective measures should be considered within and outside the site boundary to protect health and safety. The emergency action levels shall be based on in-plant conditions and instrumentation in addition to onsite and offsite monitoring. By June 20, 2012, for nuclear power reactor licensees, these action levels must include hostile action that may adversely affect the nuclear power plant. The initial emergency action levels shall be discussed and agreed on by the applicant or licensee and state and local governmental authorities, and approved by the NRC. Thereafter, emergency action levels shall be reviewed with the State and local governmental authorities on an annual basis.
- 2. A licensee desiring to change its entire emergency action level scheme shall submit an application for an amendment to its license and receive NRC approval before implementing the change. Licensees shall follow the change process in §50.54(q) for all other emergency action level changes.
C. Activation of Emergency Organization
- 1. The entire spectrum of emergency conditions that involve the alerting or activating of progressively larger segments of the total
L-MT-25-008 NSPM Enclosure Page 6 of 9 emergency organization shall be described. The communication steps to be taken to alert or activate emergency personnel under each class of emergency shall be described. Emergency action levels (based not only on onsite and offsite radiation monitoring information but also on readings from a number of sensors that indicate a potential emergency, such as the pressure in containment and the response of the Emergency Core Cooling System) for notification of offsite agencies shall be described. The existence, but not the details, of a message authentication scheme shall be noted for such agencies. The emergency classes defined shall include:
(1) Notification of unusual events, (2) alert, (3) site area emergency, and (4) general emergency. These classes are further discussed in NUREG-654/FEMA-REP-1.
44 CFR 350.5(a)(4)
A standard emergency classification and action level scheme, the bases of which include facility system and effluent parameters, is in use by the nuclear facility licensee, and State and local response plans call for reliance on information provided by facility licensees for determinations of minimum initial offsite response measures.
NSPM established and maintains a standard emergency classification and action level scheme for MNGP as required by 10 CFR 50.47(b)(4); 10 CFR 50, Appendix E, IV.B and C; and 44 CFR 350.5(a)(4). EALs at Xcel Energy nuclear sites have been developed in accordance with NEI 99-01 Revision 6, "Development of Emergency Action Levels for Non-Passive Reactors" (Reference 1). The NRC has reviewed and approved the present MNGP EAL scheme (Reference 2). The bases of the MNGP EAL scheme includes facility system and effluent parameters, is in use by NSPM, and State and local response plans call for reliance on information provided by facility licensees for determinations of minimum initial offsite response measures.
4.2 No Significant Hazards Consideration Analysis In accordance with 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), requests an amendment to Subsequent Renewed Facility Operating License DPR-22 for the Monticello Nuclear Generating Plant (MNGP). The proposed change to the Xcel Energy Standard Emergency Plan (SEP) is associated with the initiating conditions for low Mississippi River water level and considers temporary short-term fluctuations in river level.
Specifically, the proposed change will permanently revise the current SEP MNGP EAL HU3.6, "River level less than 902.4 ft elevation" to include a duration.
L-MT-25-008 NSPM Enclosure Page 7 of 9 The SEP, as changed, would continue to meet the standards in 10 CFR 50.47, "Emergency plans," paragraph (b) and the requirements in Appendix E to 10 CFR 50, "Emergency Planning and Preparedness for Production and Utilization Facilities." The proposed EAL changes are being submitted for approval prior to implementation, as required by 10 CFR 50.54, "Condition of licenses," paragraph (q)(4) and 10 CFR 50, Appendix E, Section IV, "Content of Emergency Plans," paragraph B.2.
NSPM has evaluated the proposed amendment as to whether a significant hazards consideration is involved by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:
- 1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The proposed change to the EAL for low river level does not impact the physical function of plant structures, systems, or components (SSCs) or the manner in which SSCs perform their design function. The proposed change neither adversely affects accident initiators or precursors, nor alters design assumptions.
The proposed change does not alter or prevent the ability of operable SSCs to perform their intended function to mitigate the consequences of an initiating event within assumed acceptance limits. No operating procedures or administrative controls that function to prevent or mitigate accidents are affected by the proposed change.
Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No The proposed change does not impact the accident analysis. The change does not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed), a change in the method of plant operation, or new operator actions. The proposed change will not introduce failure modes that could result in a new accident, and the change does not alter assumptions made in the safety analysis. The proposed change revises an EAL, which establishes the threshold for placing the plant in an emergency classification. EALs are not initiators of any accidents.
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
L-MT-25-008 NSPM Enclosure Page 8 of 9
- 3. Does the proposed amendment involve a significant reduction in a margin of safety?
Response: No Margin of safety is associated with confidence in the ability of the fission product barriers (i.e., fuel cladding, reactor coolant system pressure boundary, and containment structure) to limit the level of radiation dose to the public. The proposed change is associated with an EAL and does not impact operation of the plant or its response to transients or accidents. The change does not affect the operating license including Appendix A, the technical specifications. The proposed change does not involve a change in the method of plant operation, and no accident analyses will be affected by the proposed change.
Additionally, the proposed change will not relax any criteria used to establish safety limits and will not relax any safety system settings. The safety analysis acceptance criteria are not affected by this change. The proposed change will not result in plant operation in a configuration outside the design basis. The proposed change does not adversely affect systems that respond to safely shutdown the plant and to maintain the plant in a safe shutdown condition.
The revised EAL provides more appropriate criteria for determining protective measures that should be considered within and outside the site boundary to protect health and safety. The emergency plan will continue to activate an emergency response commensurate with the extent of degradation of plant safety.
Therefore, the proposed change does not involve a significant reduction in a margin of safety.
Based on the above, NSPM concludes that the proposed change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of "no significant hazards consideration" is justified.
4.3 Conclusion Based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
L-MT-25-008 NSPM Enclosure Page 9 of 9 5.0 ENVIRONMENTAL EVALUATION The proposed change would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed change does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed change meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed change.
6.0 REFERENCES
- 1. NEI 99-01, Revision 6, "Development of Emergency Action Levels for Non-Passive Reactors," dated November 2012
- 2. NRC letter to NSPM, "Monticello Nuclear Generating Plant - Issuance of Amendment No. 197 to Adopt Changes to the Emergency Plan (CAC NO. MF9560; EPID: L-2017-LLA-0184), dated March 6, 2018 (ADAMS Accession No. ML17345A046)
ENCLOSURE ATTACHMENT MONTICELLO NUCLEAR GENERATING PLANT, UNIT 1 License Amendment Request Revise the Emergency Action Level Scheme EAL Basis Pages Marked-Up (2 Pages Follow)
Monticello Emergency Action Level (EAL) Technical Basis Document Revision: 0 EPLAN-04 Page 121 of 171 HU3 ECL: Notification of Unusual Event Initiating Condition: Hazardous event.
Operating Mode Applicability: All Emergency Action Levels: (HU3.1 or HU3.2 or HU3.3 or HU3.4 or HU3.5 or HU3.6)
NOTE:
EAL HU3.4 does not apply to routine traffic impediments such as fog, snow, ice, or vehicle breakdowns or accidents.
HU3.1 A tornado strike within the Plant PROTECTED AREA.
HU3.2 Internal room or area flooding of a magnitude sufficient to require manual or automatic electrical isolation of a SAFETY SYSTEM component needed for the current operating mode.
HU3.3 Movement of personnel within the Plant PROTECTED AREA is impeded due to an offsite event involving hazardous materials (e.g., an offsite chemical spill or toxic gas release).
HU3.4 A hazardous event that results in on-site conditions sufficient to prohibit the plant staff from accessing the site via personal vehicles.
HU3.5 River level greater than 918 ft elevation.
HU3.6 River level less than 902.4 ft elevation.
Basis:
PROTECTED AREA: The area surrounding the plant encompassed by the chain link fence and certain structures as defined in the Security Plan; excludes the ISFSI Protected Area. In areas where two fences are present, the inner fence is designated as the Protected Area barrier.
SAFETY SYSTEM: A system required for safe plant operation, cooling down the plant and/or placing it in the cold shutdown condition, including the ECCS. These are typically systems classified as safety-related.
This IC addresses hazardous events that are considered to represent a potential degradation of the level of safety of the plant.
River level less than 902.4 ft elevation for 60 minutes or longer.
Note: With EAL HU3.6 the Emergency Director should declare the Unusual Event promptly upon determining that 60 minutes has been exceeded, or will likely be exceeded.
Monticello Emergency Action Level (EAL) Technical Basis Document Revision: 0 EPLAN-04 Page 122 of 171 EAL HU3.1 addresses a tornado striking (touching down) within the Protected Area.
EAL HU3.2 addresses flooding of a building room or area that results in operators isolating power to a SAFETY SYSTEM component due to water level or other wetting concerns. Classification is also required if the water level or related wetting causes an automatic isolation of a SAFETY SYSTEM component from its power source (e.g., a breaker or relay trip). To warrant classification, operability of the affected component must be required by Technical Specifications for the current operating mode.
EAL HU3.3 addresses a hazardous materials event originating at an offsite location and of sufficient magnitude to impede the movement of personnel within the Plant PROTECTED AREA.
EAL HU3.4 addresses a hazardous event that causes an on-site impediment to vehicle movement and significant enough to prohibit the plant staff from accessing the site using personal vehicles. Examples of such an event include site flooding caused by a hurricane, heavy rains, up-river water releases, dam failure, etc., or an on-site train derailment blocking the access road.
This EAL is not intended apply to routine impediments such as fog, snow, ice, or vehicle breakdowns or accidents, but rather to more significant conditions such as the Hurricane Andrew strike on Turkey Point in 1992, the flooding around the Cooper Station during the Midwest floods of 1993, or the flooding around Ft. Calhoun Station in 2011.
EAL HU3.5 addresses a potential flood condition. The 918 ft elevation is selected for this EAL because it is the first elevation at which procedure actions are required to address flooding situations.
EAL HU3.6 addresses low river flow conditions. The low river water level threshold (902.4 ft elevation) corresponds to the low river flow threshold of 240 CFS. Low river level (i.e., flow) may be a precursor to loss of the ultimate heat sink and warrants further management attention.
Escalation of the emergency classification level would be based on ICs in Recognition Categories A, F, S or C.
MNGP Basis Reference(s):
- 1.
Ops Man A.6 (ACTS OF NATURE)
- 2.
USAR Section 10.3, Plant Auxiliary Systems - Plant Service Systems
- 3.
USAR Section 12.2, Plant Structures and Shielding - Plant Principal Structures and Foundations NEW LINE: Sixty minutes was selected as a threshold to exclude transient events affecting river level.