AIR EMISSION PERMIT NO Total Facility Operating Permit - Reissuance IS ISSUED TO. Northern States Power Co a Minnesota Corporation

AIR EMISSION PERMIT NO. 04900030-006 Total Facility Operating Permit - Reissuance IS ISSUED TO Northern States Power Co a Minnesota Corporation XCEL ENERGY - PRAIRIE ISLAND NUCLEAR PLANT 1717 Wakonade Drive East Welch, Goodhue County, Minnesota 55089 The emission units, control equipment and emission stacks at the stationary source authorized in this permit reissuance are as described in the Permit Applications Table. This permit reissuance supersedes Air Emission Permit No. 04900030-005, and authorizes the Permittee to operate the stationary source at the address listed above unless otherwise noted in Table A. The Permittee must comply with all the conditions of the permit. Any changes or modifications to the stationary source must be performed in compliance with Minn. R. 7007.1150 to 7007.1500. Terms used in the permit are as defined in the state air pollution control rules unless the term is explicitly defined in the permit. Unless otherwise indicated, all the Minnesota rules cited as the origin of the permit terms are incorporated into the SIP under 40 CFR 52.1220 and as such as are enforceable by U.S. Environmental Protection Agency (EPA) Administrator or citizens under the Clean Air Act. Permit Type: Federal; Part 70/Limits to Avoid NSR Operating Permit Issue Date: < > Expiration Date: < > All Title I Conditions do not expire. Don Smith, P.E., Manager Air Quality Permits Section Industrial Division for John Linc Stine Commissioner Minnesota Pollution Control Agency TDD (for hearing and speech impaired only): (651) 282-5332 Printed on recycled paper containing at least 10% fibers from paper recycled by consumers

Permit Applications Table Permit Type Application Date Permit Action Number Total Facility Operating Permit Reissuance 6/29/2011 006 Administrative Amendment 6/11/2012 006 Minor Amendment 11/14/2011 TABLE OF CONTENTS Notice to the Permittee Permit Shield Facility Description Table A: Limits and Other Requirements Table B: Submittals Appendix I: Insignificant Activities and General Applicable Requirements

NOTICE TO THE PERMITTEE: Your stationary source may be subject to the requirements of the Minnesota Pollution Control Agency s (MPCA) solid waste, hazardous waste, and water quality programs. If you wish to obtain information on these programs, including information on obtaining any required permits, please contact the MPCA general information number at: Metro Area 651-296-6300 Outside Metro Area 1-800-657-3864 TTY 651-282-5332 The rules governing these programs are contained in Minn. R. chs. 7000-7105. Written questions may be sent to: Minnesota Pollution Control Agency, 520 Lafayette Road North, St. Paul, Minnesota 55155-4194. Questions about this air emission permit or about air quality requirements can also be directed to the telephone numbers and address listed above. PERMIT SHIELD: Subject to the limitations in Minn. R. 7007.1800, compliance with the conditions of this permit shall be deemed compliance with the specific provision of the applicable requirement identified in the permit as the basis of each condition. Subject to the limitations of Minn. R. 7007.1800 and 7017.0100, subp. 2, notwithstanding the conditions of this permit specifying compliance practices for applicable requirements, any person (including the Permittee) may also use other credible evidence to establish compliance or noncompliance with applicable requirements. FACILITY DESCRIPTION: This air emission facility is part of the Xcel Energy Prairie Island Nuclear Plant, a facility that generates 1076 MW of electricity in the city of Welch, Goodhue County, Minnesota. The air emission facility is composed of one distillate oil-fired heating boiler and 19 emergency internal combustion engines used to generate power, pump cooling, and pump water for firefighting, and potentially used in flood response. The generators and water pumps are required by the U.S. Nuclear Regulatory Commission.

Permit Number: 04900030-006 A-1 Table A contains limits and other requirements with which your facility must comply. The limits are located in the first column of the table (What To do). The limits can be emission limits or operational limits. This column also contains the actions that you must take and the records you must keep to show that you are complying with the limits. The second column of Table A (Why to do it) lists the regulatory basis for these limits. Appendices included as conditions of your permit are listed in Table A under total facility requirements. Subject Item: Total Facility What to do SOURCE-SPECIFIC REQUIREMENTS Permit Appendix: This permit contains an appendix as listed in the permit Table of Contents. The Permittee shall comply with all requirements contained in Appendix I. This Permit establishes limits on the facillity to keep it a minor source under New Source Review. The Permittee cannot make any change at the source that would make the source a major source under New Source Review until a permit amendment has been issued. This includes changes that might otherwise qualify as insignificant modifications and minor or moderate amendments. OPERATIONAL REQUIREMENTS The Permittee shall comply with National Primary and Secondary Ambient Air Quality Standards, 40 CFR pt. 50, and the Minnesota Ambient Air Quality Standards, Minn. R. 7009.0010 to 7009.0080. Compliance shall be demonstrated upon written request by the MPCA. Air Pollution Control Equipment: Operate all pollution control equipment whenever the corresponding process equipment and emission units are operated. Circumvention: Do not install or use a device or means that conceals or dilutes emissions, which would otherwise violate a federal or state air pollution control rule, without reducing the total amount of pollutant emitted. Operation and Maintenance Plan: Retain at the stationary source an operation and maintenance plan for all air pollution control equipment. At a minimum, the O & M plan shall identify all air pollution control equipment and control practices and shall include a preventative maintenance program for the equipment and practices, a description of (the minimum but not necessarily the only) corrective actions to be taken to restore the equipment and practices to proper operation to meet applicable permit conditions, a description of the employee training program for proper operation and maintenance of the control equipment and practices, and the records kept to demonstrate plan implementation. Operation Changes: In any shutdown, breakdown, or deviation the Permittee shall immediately take all practical steps to modify operations to reduce the emission of any regulated air pollutant. The Commissioner may require feasible and practical modifications in the operation to reduce emissions of air pollutants. No emissions units that have an unreasonable shutdown or breakdown frequency of process or control equipment shall be permitted to operate. Fugitive Emissions: Do not cause or permit the handling, use, transporting, or storage of any material in a manner which may allow avoidable amounts of particulate matter to become airborne. Comply with all other requirements listed in Minn. R. 7011.0150. Noise: The Permittee shall comply with the noise standards set forth in Minn. R. 7030.0010 to 7030.0080 at all times during the operation of any emission units. This is a state only requirement and is not enforceable by the EPA Administrator or citizens under the Clean Air Act. Inspections: The Permittee shall comply with the inspection procedures and requirements as found in Minn. R. 7007.0800, subp. 9(A). The Permittee shall comply with the General Conditions listed in Minn. R. 7007.0800, subp. 16. NONROAD ENGINES Why to do it Minn. R. 7007.0800, subp. 2 Title I Condition: To avoid classification as major source and modification under 40 CFR Section 52.21 & Minn. R. 7007.3000 40 CFR pt. 50; Minn. Stat. Section 116.07, subds. 4a & 9; Minn. R. 7007.0100, subp. 7(A), 7(L), & 7(M); Minn. R. 7007.0800, subps. 1, 2 & 4; Minn. R. 7009.0010-7009.0080 Minn. R. 7007.0800, subp. 2; Minn. R. 7007.0800, subp. 16(J) Minn. R. 7011.0020 Minn. R. 7007.0800, subps. 14 and 16(J) Minn. R. 7019.1000, subp. 4 Minn. R. 7011.0150 Minn. R. 7030.0010-7030.0080 Minn. R. 7007.0800, subp. 9(A) Minn. R. 7007.0800, subp. 16

Permit Number: 04900030-006 A-2 The Permittee shall keep the following records for each nonroad engine that meets the definition of Nonroad engine at 40 CFR Section 1068.30, "Nonroad engines", (1)(iii). This applies to this category of nonroad engines that is owned by the permittee, or rented and operated by the permittee, or brought onsite under a non-seasonal contract: 1) Date that the nonroad engine is brought onsite. 2) Date that the nonroad engine is taken offsite and/or moved to a different location. 3) Identification number. 4) Rated capacity of the nonroad engine. 5) The model year and date of manufacture (as defined by the applicable nonroad engine rule). 6) Which nonroad provision that the nonroad engine is certified under. 7) Rental company information. 8) Function of the nonroad engine. While on site, each engine shall be labeled in such way that it can be determined that it is a nonroad engine and not one of the permitted engines covered by this air permit. 40 CFR Section 1068.30, "Nonroad engines", (2)(iii); Minn. R. 7007.0800, subp. 4 and 5 For the purpose of this permit, a nonroad engine seasonal contract is a binding agreement to have a third party operate a nonroad engine onsite for seasonal activities and that will remain onsite for no more than 9 consecutive months. Minn. R. 7007.0800, subp. 4 and 5; 40 CFR 1068.30(1)(iii) Each seasonal contract engine and associated equipment onsite that meets the definition of nonroad engine at 40 CFR Section 1068.30, "Nonroad engines", (1)(iii), must be labeled with an identification that can be traced to the seasonal contract. The permittee must keep at the facility, a copy of the seasonal contract which identifies: 1) The type of contract engines and associated equipment. 2) The purpose of contract engines and associated equipment. 3) The required schedule of operation for the contract engines and associated equipment. The residence-time requirements of paragraph (2)(iii) of the nonroad engine definition in 40 CFR Section 1068.30 apply to seasonal contract equipment. The Permittee shall not bring nonroad engines onsite the stationary source for periodic operation for more than 12 consecutive months. 40 CFR Section 1068.30, "Nonroad engines", (2)(iii) The Permittee shall not have nonroad engines in one location within the stationary source for more than 12 consecutive months. A location is any single site at a building, structure, facility, or installation. Any engine, or engines, that replaces an engine at a location and that is intended to perform the same or similar function as the engine it replaced will be included in calculating the consecutive time period. For a nonroad engine that is excluded from any requirements of 40 CFR Part 1068 because it is a stationary engine, the Permittee may not move it or install it in any mobile equipment, except as allowed by the provisions of 40 CFR Part 1068. The Permittee may not circumvent or attempt to circumvent the residence-time requirements of paragraph (2)(iii) of the nonroad engine definition in 40 CFR Section 1068.30. PERFORMANCE TESTING Performance Testing: Conduct all performance tests in accordance with Minn. R. ch. 7017. Performance Test Notifications and Submittals: Performance Tests are due as outlined in Table A of the permit. See Table B for additional testing requirements. 40 CFR Section 1068.101(b)(3) Minn. R. ch. 7017 Minn. R. 7017.2018; Minn. R. 7017.2030, subps. 1-4; Minn. R. 7017.2035, subps. 1-2 Performance Test Notification (written): due 30 days before each Performance Test Performance Test Plan: due 30 days before each Performance Test Performance Test Pre-test Meeting: due 7 days before each Performance Test Performance Test Report: due 45 days after each Performance Test Performance Test Report - Microfiche Copy: due 105 days after each Performance Test The Notification, Test Plan, and Test Report may be submitted in an alternative format as allowed by Minn. R. 7017.2018.

Permit Number: 04900030-006 A-3 Limits set as a result of a performance test (conducted before or after permit issuance) apply until superseded as stated in the MPCA's Notice of Compliance letter granting preliminary approval. Preliminary approval is based on formal review of a subsequent performance test on the same unit as specified by Minn. R. 7017.2025, subp. 3. The limit is final upon issuance of a permit amendment incorporating the change. MONITORING REQUIREMENTS Monitoring Equipment Calibration: The Permittee shall calibrate all required monitoring equipment at least once every 12 months (any requirements applying to continuous emission monitors are listed separately in this permit). Operation of Monitoring Equipment: Unless otherwise noted in Tables A and B monitoring a process or control equipment connected to that process is not necessary during periods when the process is shutdown, or during checks of the monitoring systems, such as calibration checks and zero and span adjustments. If monitoring records are required, they should reflect any such periods of process shutdown or checks of the monitoring system. RECORDKEEPING Recordkeeping: Retain all records at the stationary source, unless otherwise specified within this permit, for a period of five (5) years from the date of monitoring, sample, measurement, or report. Records which must be retained at this location include all calibration and maintenance records, all original recordings for continuous monitoring instrumentation, and copies of all reports required by the permit. Records must conform to the requirements listed in Minn. R. 7007.0800, subp. 5(A). Recordkeeping: Maintain records describing any insignificant modifications (as required by Minn. R. 7007.1250, subp. 3) or changes contravening permit terms (as required by Minn. R. 7007.1350, subp. 2), including records of the emissions resulting from those changes. If the Permittee determines that no permit amendment or notification is required prior to making a change, the Permittee must retain records of all calculations required under Minn. R. 7007.1200. For expiring permits, these records shall be kept for a period of five years from the date the change was made or until permit reissuance, whichever is longer. The records shall be kept at the stationary source for the current calendar year of operation and may be kept at the stationary source or office of the stationary source for all other years. The records may be maintained in either electronic or paper format. REPORTING/SUBMITTALS Shutdown Notifications: Notify the Commissioner at least 24 hours in advance of a planned shutdown of any control equipment or process equipment if the shutdown would cause any increase in the emissions of any regulated air pollutant. If the owner or operator does not have advance knowledge of the shutdown, notification shall be made to the Commissioner as soon as possible after the shutdown. However, notification is not required in the circumstances outlined in Items A, B and C of Minn. R. 7019.1000, subp. 3. At the time of notification, the owner or operator shall inform the Commissioner of the cause of the shutdown and the estimated duration. The owner or operator shall notify the Commissioner when the shutdown is over. Breakdown Notifications: Notify the Commissioner within 24 hours of a breakdown of more than one hour duration of any control equipment or process equipment if the breakdown causes any increase in the emissions of any regulated air pollutant. The 24-hour time period starts when the breakdown was discovered or reasonably should have been discovered by the owner or operator. However, notification is not required in the circumstances outlined in Items A, B and C of Minn. R. 7019.1000, subp. 2. Minn. R. 7017.2025, subp. 3 Minn. R. 7007.0800, subp. 4(D) Minn. R. 7007.0800, subp. 4(D) Minn. R. 7007.0800, subp. 5(C) Minn. R. 7007.0800, subp. 5(B) Minn. R. 7007.1200, subp. 4 Minn. R. 7019.1000, subp. 3 Minn. R. 7019.1000, subp. 2 At the time of notification or as soon as possible thereafter, the owner or operator shall inform the Commissioner of the cause of the breakdown and the estimated duration. The owner or operator shall notify the Commissioner when the breakdown is over. Notification of Deviations Endangering Human Health or the Environment: As soon as possible after discovery, notify the Commissioner or the state duty officer, either orally or by facsimile, of any deviation from permit conditions which could endanger human health or the environment. Minn. R. 7019.1000, subp. 1

Permit Number: 04900030-006 A-4 Notification of Deviations Endangering Human Health or the Environment Report: Within 2 working days of discovery, notify the Commissioner in writing of any deviation from permit conditions which could endanger human health or the environment. Include the following information in this written description: 1. the cause of the deviation; 2. the exact dates of the period of the deviation, if the deviation has been corrected 3. whether or not the deviation has been corrected; 4. the anticipated time by which the deviation is expected to be corrected, if not yet corrected; and 5. steps taken or planned to reduce, eliminate, and prevent reoccurrence of the deviation. Minn. R. 7019.1000, subp. 1 Application for Permit Amendment: If a permit amendment is needed, submit an Minn. R. 7007.1150-7007.1500 application in accordance with the requirements of Minn. R. 7007.1150 through Minn. R. 7007.1500. Submittal dates vary, depending on the type of amendment needed. Extension Requests: The Permittee may apply for an Administrative Amendment to Minn. R. 7007.1400, subp. 1(H) extend a deadline in a permit by no more than 120 days, provided the proposed deadline extension meets the requirements of Minn. R. 7007.1400, subp. 1(H). Performance testing deadlines from the General Provisions of 40 CFR pt. 60 and pt. 63 are examples of deadlines for which the MPCA does not have authority to grant extensions and therefore do not meet the requirements of Minn. R. 7007.1400, subp. 1(H). Emission Inventory Report: due on or before April 1 of each calendar year following Minn. R. 7019.3000-7019.3100 permit issuance, to be submitted on a form approved by the Commissioner. Emission Fees: due 60 days after receipt of an MPCA bill. Minn. R. 7002.0005-7002.0095

Facility Name: Permit Number: Xcel Energy - Prairie Island Nuclear Plant 04900030-006 Subject Item: GP 001 Internal Combustion Engines A-5 Associated Items: BG 025 Gas House EU 002 Diesel Engine D1 EU 003 Diesel Engine D2 EU 004 Diesel Cooling Water Pump 12 EU 005 Diesel Cooling Water Pump 22 EU 006 Diesel Fire Pump 121 EU 007 Diesel Engine D3 EU 008 Diesel Engine D4 EU 009 Security Diesel Engine EU 010 Diesel Engine D5-1 EU 011 Diesel Engine D5-2 EU 012 Diesel Engine D6-1 EU 013 Diesel Engine D6-2 EU 017 Diesel flexible response pumps - B5b No.1 EU 018 Diesel Air Compressor EU 019 Flexible Response Diesel Driven Pump A EU 020 Flexible Response Diesel Driven Pump B EU 021 Flexible Response Diesel Driven Pump C EU 022 Warehouse Emergency Generator EU 024 B5b Generator 1 EU 025 B5b Generator 2 EU 026 B5b Generator 3 EU 027 B5b Generator 4 What to do LIMITS AND OPERATING RESTRICTIONS Note: See GP002, GP003, GP004, GP005, GP006, GP007, GP008 and EU018 for additional requirements applicable to these units. Fuel Usage: less than or equal to 67,000 gallons/month using 12-month Rolling Average for all GP001 internal combustion engines. All emission units or stacks added to GP001 as allowed in this permit shall be included in this calculation. Nitrogen Oxides: less than or equal to 4.0 lbs/million Btu heat input for each emission unit in GP 001 with a brake hp rating of greater than 600 hp (EU 002, EU 003, EU 004, EU 005, EU 007, EU 008, EU 010, EU 011, EU 012, EU 013). This limit is not applicable to EU 006, EU 009, EU 017, EU 018, EU 019, EU 020, EU 021, EU 022, EU024, EU025, EU026, and EU027. All internal combustion engines at the facility, including existing or new, except non-road engines, are subject to the requirements of GP001 and GP007. Opacity: less than or equal to 20 percent opacity once operating temperature has been attained. This applies individually to each emission unit in GP 001. Sulfur Dioxide: less than or equal to 0.50 lbs/million Btu heat input (equivalent to a fuel oil sulfur content of 0.49 percent by weight). This applies individually to each emission unit in GP 001. Fuel Type: Distillate Fuel Oil only. Sulfur Content of Fuel: less than or equal to 0.49 percent by weight MONITORING AND RECORDKEEPING Why to do it Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000 Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000 Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000 Minn. R. 7011.2300, subp. 1 Minn. R. 7011.2300, subp. 2 Minn. R. 7005.0100, subp. 35a Minn. R. 7005.0100, subp. 35a

Permit Number: 04900030-006 A-6 Daily Recordkeeping --fuel usage: On each day of operation, the Permitte shall calculate, record, and maintain daily totals of: 1) number of gallons of distillate fuel for all engines >600hp, and 2) number of gallons of distillate fuel for all engines <600hp, based on written usage logs or flowmeters. Monthly Recordkeeping - fuel usage: By the last day of the month, the Permittee shall calculate and record the following: 1) The total fuel usage in gallons for all GP001 emission units for the previous calendar month using the daily fuel usage records. 2) The 12-month rolling average fuel usage for the previous 12-month period by averaging the monthly fuel usage for the previous 12 months. Fuel Sulfur Content Monitoring: The permittee shall determine fuel sulfur content according to one of the following methods for all fuel oil combusted in all engines: Title I Condition: To avoid classification as major source and modification under 40 CFR 52.21 & Minn. R. 7007.3000; Minn. R. 7007.0800, subps. 4 and 5 Minn. R. 7007.0800, subps. 4 & 5 Minn. R. 7007.0800, subps. 4 & 5 (1) Test each shipment of diesel fuel according to current ASTM or EPA method(s) and keep records of lab analyses of sulfur content; or (2) Obtain and maintain a fuel supplier certification for each shipment of diesel fuel, showing that the sulfur content does not exceed the appropriate limit.

Facility Name: Permit Number: Xcel Energy - Prairie Island Nuclear Plant 04900030-006 Subject Item: GP 002 Emergency Internal Combustion Engines A-7 Associated Items: EU 017 Diesel flexible response pumps - B5b No.1 EU 019 Flexible Response Diesel Driven Pump A EU 020 Flexible Response Diesel Driven Pump B EU 021 Flexible Response Diesel Driven Pump C EU 022 Warehouse Emergency Generator EU 024 B5b Generator 1 EU 025 B5b Generator 2 EU 026 B5b Generator 3 EU 027 B5b Generator 4 EMISSION LIMITS What to do Why to do it Note: See GP001 and GP007 for additional requirements applicable to these units. Carbon Monoxide: less than or equal to 5.0 grams/kilowatt-hour 40 CFR Section 60.4205(b); 40 CFR Section 89.112; Minn. R. 7011.2305;40 CFR Section 63.6590(c); Minn. R. 7011.8150 Total Particulate Matter: less than or equal to 0.30 grams/kilowatt-hour 40 CFR Section 60.4205(b); 60.4205(b); 40 CFR Section 89.112; Minn. R. 7011.2305; 40 CFR Section 63.6590(c); Minn. NMHC + NOx: less or equal to than 4.00 grams/kilowatt-hour 40 CFR Section 60.4205(b); 60.4205(b); 40 CFR Section 89.112; Minn. R. 7011.2305; 40 CFR Section 63.6590(c); Minn. Opacity: less than or equal to 20 percent during acceleration mode; 15 percent during the lugging mode; and 50 percent during the peaks in either the acceleration or lugging modes. Opacity: less than or equal to 20 percent once operating temperatures have been attained. This applies to each emission unit in the group. 40 CFR Section 60.4205(b); 40 CFR Section 89.113; Minn. R. 7011.2305; 40 CFR Section 63.6590(c); Minn. R. 7011.8150 Minn. R. 7011.2300, subp. 1 Sulfur Dioxide: less than or equal to 0.5 lbs/million Btu heat input. Minn. R. 7011.2300, subp. 2 OPERATING REQUIREMENTS Fuel Type: Distillate Fuel Oil only. Sulfur Content of Fuel: less than or equal to 0.49 percent by weight Owners and operators of stationary CI ICE must operate and maintain stationary CI ICE that achieve the emission standards as required in Section 60.4205 over the entire life of the engine. The Permittee shall operate and maintain the stationary CI internal combustion engine and control device according to the manufacturer's emission-related written instructions; change only those emission-related settings that are permitted by the manufacturer: and meet the requirements of 40 CFR part 89, 94 and/or 1068, as applicable. Minn. R. 7005.0100, subp. 35a Minn. R. 7005.0100, subp. 35a 40 CFR Section 60.4206; Minn. R. 7011.2305; 40 CFR Section 63.6590(c); Minn. R. 7011.8150 40 CFR Section 60.4206; 40 CFR Section 60.4211(a); 40 CFR Section 63.6590(c); Minn. R. 7011.2305; Minn. MONITORING AND RECORDKEEPING REQUIREMENTS Fuel Use: EU017 may be operated only on diesel fuel that meets the requirements of 40 CFR Section 80.510(a) for nonroad diesel fuel: (1) 500 ppm maximum of sulfur content; (2) Minimum cetane index of 40; or Maximum aromatic content of 35 volume percent Fuel Use:EU019-EU022 and EU024-027 may be operated only on diesel fuel that meets the requirements of 40 CFR Section 80.510(b) for nonroad diesel fuel: (1) 15 ppm maximum sulfur content; (2) Minimum cetane index of 40; or Maximum aromatic content of 35 volume percent 40 CFR Section 60.4207(a); 40 CFR Section 80.510(a); 40 CFR Section 63.6590(c); Minn. R. 7011.2305; Minn. 40 CFR Section 60.4207(b); 40 CFR Section 80.510(b); 40 CFR Section 63.6590(c); Minn. R. 7011.2305; Minn.

Permit Number: 04900030-006 A-8 If the emergency stationary CI internal combustion engine does not meet the standards applicable to non-emergency engines, the Permittee must install a non-resettable hour meter prior to start up of the engine. 40 CFR Section 60.4209(a); 40 CFR Section 63.6590(c); Minn. R. 7011.2305; Minn. Hours of Operation Records: The Permittee shall maintain records of hours of operation on site that document that the unit is an emergency diesel generator by design that qualifies under the U.S. EPA memorandum entitled "Calculating Potential to Emit (PTE) for Emergency Generators" dated September 6, 1995, limiting operation to 500 hours per year. The Permittee must comply with the emission standards specified in Section 60.4205 (b) by purchasing an engine certified to those emission standards, for the same model year and maximum engine power. The engine must be installed and configured according to the manufacturer's emission-related specifications. The Permittee may conduct maintenance checks and readiness testing provided that the tests are recommeded by Federal, State, or local government; the manufacturer; the vendor; or the insurance company associated with the engine. Maintenance checks and readiness testing are limited to 100 hours/year. There is no time limit on the use of emergency stationary ICE in emergency situations unless otherwise prohibited by your permit. The Permittee may petition the Administrator for approval of additional hours. A petition is not required if the Permittee maintains records indicating that the Federal, State or local standards require maintenance and testing beyond 100 hours/year. continued Emergency stationary ICE may operate up to 50 hours/year in non-emergency situations, but those 50 hours are counted towards the 100 hours/year provided for maintenance and testing. The 50 hours/year for non-emergency situations cannot be used for peak shaving or to generate income for a facility to supply power to an electric grid or otherwise supply non-emergency power as part of a financial arrangement with another entity. For owners and operators of emergency engines, any operation other than emergency operation, maintenance and testing, and operation in non-emergency situations for 50 hours/year, as permitted in this section, is prohibited. Minn. R. 7007.0800, subp. 4 & 5 40 CFR Section 60.4211(c); 40 CFR Section 63.6590(c); Minn. R. 7011.2305; Minn. 40 CFR Section 60.4211(f); Minn. R. 7011.2305; 40 CFR Section 63.6590(c); Minn. 40 CFR Section 60.4211(f); Minn. R. 7011.2305; 40 CFR Section 63.6590(c); Minn. If the emergency engine does not meet the standards applicable to non-emergency engines in the applicable model year, the Permittee must keep records of the operation of the engine in emergency and non-emergency service that are recorded through the non-resettable hour meter. The Permittee must record the time of operation of the engine and the reason the engine was in operation during that time. Each engine in GP002 is an affected source as defined under 40 CFR pt. 63, subp. ZZZZ, and the facility is an area source as defined at 40 CFR Section 63.2. The Permittee shall meet the requirements of 40 CFR pt. 63, subp. ZZZZ by meeting the requirements of 40 CFR pt. 60, subp. IIII. No further requirements of 40 CFR pt. 63, subp. ZZZZ apply to GP002 at the time of permit issuance. 40 CFR Section 60.4214(b); Minn. R. 7011.2305; 40 CFR Section 63.6590(c); Minn. 40 CFR Section 63.6590(c); Minn.

Facility Name: Permit Number: Xcel Energy - Prairie Island Nuclear Plant 04900030-006 Subject Item: GP 003 Performance Testing - EU002/003 A-9 Associated Items: EU 002 Diesel Engine D1 EU 003 Diesel Engine D2 What to do Note: See GP001, GP007 and GP008 for additional requirements applicable to these units. PERFORMANCE TESTING - EU 002/EU 003 Performance Test: due before end of each calendar 60 months starting 10/09/2006 to measure NOx emissions from EU 002 or EU 003. Testing shall commence with EU 002, and subsequently alternate between EU 002 and EU 003 at intervals not to exceed 60 months. Performance Test: due before end of each calendar 36 months starting 06/01/2004 to measure opacity emissions from EU 002 or EU 003. Testing shall commence with EU 002 and subsequently alternate between EU 002 and EU 003 at intervals not to exceed 36 months. Why to do it Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000; Minn. R. 7017.2020, subp. 1; Minn. R. 7017.2030, subp. 4 Minn. R. 7017.2020, subp. 1; Minn. R. 7017.2030, subp. 4

Facility Name: Permit Number: Xcel Energy - Prairie Island Nuclear Plant 04900030-006 Subject Item: GP 004 Performance Testing - EU004/005 Associated Items: EU 004 Diesel Cooling Water Pump 12 EU 005 Diesel Cooling Water Pump 22 A-10 What to do Note: See GP001, GP007 and GP008 for additional requirements applicable to these units. PERFORMANCE TESTING - EU 004/EU 005 Initial Performance Test: due 90 days after Notification of resuming operation of either EU 004 or EU 005 for more than 100 hours in any calendar year. This performance test shall measure NOx emissions from EU 004 or EU 005. Initial Performance Test: due 90 days after Notification of resuming operation of either EU 004 and EU 005 for more than 100 hours in any calendar year. This performance test shall measure opacity from EU 004 and EU 005. Recordkeeping - EU 004 and EU 005 Operating Hours: by the last day of each month, the Permittee shall separately record EU 004 and EU 005 operating hours for the previous month, and separately record cumulative operating hours for EU 004 and EU 005 during the current calendar year. Why to do it Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000; Minn. R. 7017.2020, subp. 1; Minn. R. 7017.2030, subp. 4 Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000; Minn. R. 7017.2020, subp. 1; Minn. R. 7017.2030, subp. 4 Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.0300; Minn. R. 7007.0800, subps. 4 & 5

Facility Name: Permit Number: Xcel Energy - Prairie Island Nuclear Plant 04900030-006 Subject Item: GP 005 Performance Testing - EU007/008 A-11 Associated Items: EU 007 Diesel Engine D3 EU 008 Diesel Engine D4 What to do Note: See GP001, GP007 and GP008 for additional requirements applicable to these units. PERFORMANCE TESTING - EU 007/EU 008 Performance Test: due before end of each calendar 60 months starting 08/12/2005 to measure NOx emissions from EU 007 or EU 008. Testing shall commence with EU 008, and subsequently alternate between EU 007 and EU 008 at intervals not to exceed 60 months. Performance Test: due before end of each calendar 60 months starting 08/12/2005 to measure opacity emissions from EU 007 or EU 008. Testing shall commence with EU 008, and subsequently alternate between EU 007 and EU 008 at intervals not to exceed 60 months. Why to do it Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000; Minn. R. 7017.2020, subp. 1; Minn. R. 7017.2030, subp. 4 Minn. R. 7017.2020, subp. 1; Minn. R. 7017.2030, subp. 4

Facility Name: Permit Number: Xcel Energy - Prairie Island Nuclear Plant 04900030-006 Subject Item: GP 006 Performance Testing - EU010 & EU011/EU012 & EU013 Associated Items: EU 010 Diesel Engine D5-1 EU 011 Diesel Engine D5-2 EU 012 Diesel Engine D6-1 EU 013 Diesel Engine D6-2 A-12 What to do Note: See GP001, GP007 and GP008 for additional requirements applicable to these units. PERFORMANCE TESTING - EU 010 & EU 011/EU 012 & EU 013 Performance Test: due before end of each calendar 60 months starting 08/15/2005 to measure NOx emissions from an emission unit pair (EU 010 & 011 or EU 012 & 013) that has not been tested in the previous five years. Testing shall commence with EU 010 & 011 and subsequently alternate between EU 010 & 011 and EU 012 & 013 at intervals not to exceed 60 months. Performance Test: due before end of each calendar 60 months starting 08/15/2005 to measure opacity emissions from an emission unit pair (EU 010 & 011 or EU 012 & 013) that has not been tested in the previous five years. Testing shall commence with EU 010 & 011 and subsequently alternate between EU 010 & 011 and EU 012 & 013 at intervals not to exceed 60 months. Why to do it Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000; Minn. R. 7017.2020, subp. 1; Minn. R. 7017.2030, subp. 4 Minn. R. 7017.2020, subp. 1; Minn. R. 7017.2030, subp. 4

Permit Number: 04900030-006 Subject Item: GP 007 NOx-Limit Associated Items: EU 001 Auxiliary Boiler 1 EU 002 Diesel Engine D1 EU 003 Diesel Engine D2 EU 004 Diesel Cooling Water Pump 12 EU 005 Diesel Cooling Water Pump 22 EU 006 Diesel Fire Pump 121 EU 007 Diesel Engine D3 EU 008 Diesel Engine D4 EU 009 Security Diesel Engine EU 010 Diesel Engine D5-1 EU 011 Diesel Engine D5-2 EU 012 Diesel Engine D6-1 EU 013 Diesel Engine D6-2 EU 017 Diesel flexible response pumps - B5b No.1 EU 018 Diesel Air Compressor EU 019 Flexible Response Diesel Driven Pump A EU 020 Flexible Response Diesel Driven Pump B EU 021 Flexible Response Diesel Driven Pump C EU 022 Warehouse Emergency Generator EU 023 Radio Tower Emergency Generator EU 024 B5b Generator 1 EU 025 B5b Generator 2 EU 026 B5b Generator 3 EU 027 B5b Generator 4 A-13 What to do EMISSION LIMITS Note: See additional requirements applicable to these units in GP001, GP002, GP003, GP004, GP005, GP006, GP008, EU001, EU018 and EU023. Nitrogen Oxides: less than or equal to 240 tons/year using 12-month Rolling Sum All NOx-emitting equipment at the Facility including existing, new, and modified equipment, are subject to this limit except for non-road engines and insignificant activities. continued If the Permittee replaces any existing NOx-emitting equipment, adds new NOx-emitting equipment, or modifies the NOx-emitting existing equipment, such equipment is subject to this permit limit as well as all of the requirements GP007. Prior to making such a change, the Permittee shall apply for and obtain the appropriate permit amendment, as applicable.the Permittee is not required to complete NOx calculations described in Minn. R. 7007.1200, subp. 2. A permit amendment will still be needed regardless of the emissions increase if the change will be subject to a new applicable requirement or requires revisions to the limits or monitoring and recordkeeping in this permit. MONITORING AND RECORDKEEPING Why to do it Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000 Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000

Permit Number: 04900030-006 A-14 Monthly recordkeeping-- NOx Emissions. By the last day of the month, the Permittee shall calculate and record the following: Minn. R. 7007.0800, subps. 4 & 5 1. The total NOx emissions for the previous calendar month using the daily usage records from GP001 or EU001 and using the formulas specified in this permit; 2. The total NOx emissions for the previous calendar month using the daily usage records from fuel oil or propane using the formula #4 specified in this permit; and 3. The 12-month rolling sum NOx emissions for the previous 12-month period by summing the monthly NOx emissions data for the previous 12 months. Monthly Recordkeeping Calculation - NOx Emissions. Minn. R. 7007.0800, subps. 4 & 5 The Permittee shall calculate NOx emissions using the following equations: NOx (tons per month) = NOx from boiler (EU001) + NOx from engines<600hp + NOx from engines > 600hp + NOx from new equipment Equation 1. NOx emissions for EU001: NOx (tons per month) = (B*C*D)/2000 Where: B= gallons per month of fuel used in EU001 during the previous month. C= 0.144 lb/mmbtu, NOx emission factor from permit. D= 0.137 MMBtu/gal, heat content of distillate fuel oil. continued Minn. R. 7007.0800, subps. 4 & 5 Equation 2. NOx for engines <600hp: NOx (tons per month) = (B*C*D)/2000 Where: B= gallons per month of fuel used in engines <600hp in GP001 during the previous month. C= 4.41 lb/mmbtu, NOx emission factor from AP-42 Section 3.3. D= 0.139 MMBtu/gal, heat content of distillate fuel oil. Equation 3. NOx for engines >600hp: NOx (tons per month) = (B*C*D)/2000 Where: B= gallons per hour of fuel used in engines in GP001 >600hp during the previous month. C= 4.00 lb/mmbtu, NOx emission factor from permit. D= 0.139 MMBtu/gal, heat content of distillate fuel oil. Equation 4. NOx from new emission units: Minn. R. 7007.0800, subps. 4 & 5 NOx (tons per month) = (E*F)/2000 Where: E= quantity of fuel (units/month) F= emission factor (lb/unit) from most recent published version of AP-42. Daily Recordkeeping for all fuels except fuel in GP001 and EU001: On each day of operation, the Permittee shall calculate, record, and maintain daily totals of cubic feet of propane or gallons of fuel oil of all boilers, based on written usage logs or flowmeters. Title I Condition: To avoid classification as major source and modification under 40 CFR 52.21 & Minn. R. 7007.3000; Minn. R. 7007.800, subps. 4 and 5

Permit Number: 04900030-006 A-15 Monthly Recordkeeping - for all fuels except fuel in GP001 and EU001: Minn. R. 7007.0800, subps. 4 & 5 By the last day of the month, the Permittee shall calculate and record the following: 1) The total fuel usage in gallons or cubic feet for all new emission units for the previous calendar month using the daily fuel usage records. 2) The 12-month rolling average fuel usage for the previous 12-month period by averaging the monthly fuel usage for the previous 12 months.

Facility Name: Permit Number: Xcel Energy - Prairie Island Nuclear Plant 04900030-006 Subject Item: GP 008 Emergency Internal Engines A-16 Associated Items: EU 002 Diesel Engine D1 EU 003 Diesel Engine D2 EU 004 Diesel Cooling Water Pump 12 EU 005 Diesel Cooling Water Pump 22 EU 006 Diesel Fire Pump 121 EU 007 Diesel Engine D3 EU 008 Diesel Engine D4 EU 009 Security Diesel Engine EU 010 Diesel Engine D5-1 EU 011 Diesel Engine D5-2 EU 012 Diesel Engine D6-1 EU 013 Diesel Engine D6-2 EMISSION LIMITS What to do Why to do it Note: See GP001, GP003, GP004, GP005, GP006 and GP007 for additional requirements applicable to these units. RECORDINGKEEPING REQUIREMENTS Hours of Operation: The Permittee shall maintain documentation on site that the unit is an emergency diesel generator by design that qualifies under the U.S. EPA memorandum entitled "Calculating Potential to Emit (PTE) for Emergency Generators" dated September 6, 1995, limiting operation to 500 hours per year. SUBPART ZZZZ REQUIREMENTS Comply with the applicable emission limitations and operating requirements of Subpart ZZZZ no later than May 3, 2013. The Permittee shall meet the following requirements, except during periods of startup: a. Change oil and filter every 500 hours of operation or annually, whichever comes first; b. Inspect air cleaner every 1000 hours of operation or annually, whichever comes first; and c. Inspect all hoses and belts every 500 hours of operation or annually, whichever comes first, and replace as necessary. The Permittee must be in compliance with the applicable emission limitations and applicable operating limitations of 40 CFR Part 63, Subpart ZZZZ, at all times. The Permittee must at all times operate and maintain any affected source, including associated air pollution control equipment and monitoring equipment, in a manner consistent with safety and good air pollution control practices for minimizing emissions. The general duty to minimize emissions does not required the Permittee to make any further efforts to reduce emissions if levels required by Subpart ZZZZ have been achieved. Determination of whether such operation and maintenance procedures are being used will be based on information available to the Administrator which may include, but is not limited to, monitoring results, review of operation and maintenance procedures, review of operation and maintenance records, and inspection of the source. The Permittee must operate and maintain the stationary RICE and after-treatment control device (if any) according to the manufacturer's emission-related written instructions. The Permittee must install a non-resettable hour meter if one is not already installed. If the Permittee operate a new, reconstructed, or existing stationary engine, the Permittee must minimize the engine's time spent at idle during startup and minimize the engine's startup time to a period needed for appropriate and safe loading of the engine, not to exceed 30 minutes, after which time the non-startup emission limitations apply. Minn. R. 7007.0800, subp. 4 & 5 40 CFR Section 63.6595(a)(1); Minn. 40 CFR Section 63.6603(a); Minn. 40 CFR Section 63.6605(a); Minn. 40 CFR Section 63.6605(b); Minn. 40 CFR Section 63.6625(e); 40 CFR Section 63.6655(d); Minn. R. 7011.8150 40 CFR Section 63.6625(f); Minn. 40 CFR Section 63.6625(h); Minn.

Permit Number: 04900030-006 A-17 If the Permittee owns or operates a stationary CI engine that is subject to the work, operation or management practices in items 1 or 4 of Table 2d to this subpart, the Permittee has the option of utilizing an oil analysis program in order to extend the specified oil change requirement in Tables 2c and 2d to this subpart. The oil analysis must be performed at the same frequency specified for changing the oil in Table 2c or 2d to this subpart. The analysis program must at a minimum analyze the following three parameters: Total Base Number, viscosity, and percent water content. The condemning limits for these parameters are as follows: Total Base Number is less than 30 percent of the Total Base Number of the oil when new; viscosity of the oil has changed by more than 20 percent from the viscosity of the oil when new; or percent water content (by volume) is greater than 0.5. If all of these condemning limits are not exceeded, the engine owner or operator is not required to change the oil. the Permittee must operate the emergency stationary RICE according to the requirements in paragraphs (f)(1) through (4) of this section. In order for the engine to be considered an emergency stationary RICE under this subpart, any operation other than emergency operation, maintenance and testing, emergency demand response, and operation in non-emergency situations for 50 hours per year, as described in paragraphs (f)(1) through (4) of this section, is prohibited. If the Permitee does not operate the engine according to the requirements in paragraphs (f)(1) through (4) of this section, the engine will not be considered an emergency engine under this subpart and must meet all requirements for non-emergency engines. continued (1) There is no time limit on the use of emergency stationary RICE in emergency situations. 40 CFR Section 63.6625(i); Minn. 40 CFR Section 63.6640(f); Minn. 40 CFR Section 63.6640(f); Minn. (2) You may operate your emergency stationary RICE for any combination of the purposes specified in paragraphs (f)(2)(i) through (iii) of this section for a maximum of 100 hours per calendar year. Any operation for non-emergency situations as allowed by paragraphs (f)(3) and (4) of this section counts as part of the 100 hours per calendar year allowed by this paragraph (f)(2). (i) Emergency stationary RICE may be operated for maintenance checks and readiness testing, provided that the tests are recommended by federal, state or local government, the manufacturer, the vendor, the regional transmission organization or equivalent balancing authority and transmission operator, or the insurance company associated with the engine. continued The owner or operator may petition the Administrator for approval of additional hours to be used for maintenance checks and readiness testing, but a petition is not required if the owner or operator maintains records indicating that federal, state, or local standards require maintenance and testing of emergency RICE beyond 100 hours per calendar year. (ii) Emergency stationary RICE may be operated for emergency demand response for periods in which the Reliability Coordinator under the North American Electric Reliability Corporation (NERC) Reliability Standard EOP-002-3, Capacity and Energy Emergencies (incorporated by reference, see Section 63.14), or other authorized entity as determined by the Reliability Coordinator, has declared an Energy Emergency Alert Level 2 as defined in the NERC Reliability Standard EOP-002-3. The Permittee must keep the following records: 1.Operating and maintaining the stationary RICE according to the manufacturer's emission-related operation and maintenance instructions; or 2.Develop and follow your own maintenance plan which must provide to the extent practicable for the maintenance and operation of the engine in a manner consistent with good air pollution control practice for minimizing emissions. continued (iii) Emergency stationary RICE may be operated for periods where there is a deviation of voltage or frequency of 5 percent or greater below standard voltage or frequency. The Permittee must keep records of the hours of operation of the engine as recorded through the non-resettable hour meter. The owner or operator must document how many hours are spent for emergency operation, including what classified the operation as emergency and how many hours are spent for non-emergency operation. If the engine is used for demand response operation, the owner or operator must keep records of the notification of the emergency situation, and the time the engine was operated as part of demand response. The Permittee must keep records of the maintenance conducted on the stationary RICE in order to demonstrate that the stationary RICE and after-treatment control device (if any) are operated and maintained according to the maintenance plan. 40 CFR Section 63.6640(f); Minn. 40 CFR Section 63.6640(f); Minn. 40 CFR Section 63.6640(f); Minn. 40 CFR Section 63.6655(f); Minn. 40 CFR Section 63.6655(e); Minn.

Permit Number: 04900030-006 A-18 a. Records must be in a form suitable and readily available for expeditious review according to 40 CFR Section 63.10(b)(1). b. As specified in 40 CFR Section 63.10(b)(1), keep each record for 5 years following the date of each occurrence, measurement, maintenance, corrective action, report, or record. c. Keep each record readily accessible in hard copy or electronic form for at least 5 years after the date of each occurrence, measurement, maintenance, corrective action, report, or record, according to 40 CFR Section 63.10(b)(1). 40 CFR Section 63.6660; Minn. R. 7011.8150

Facility Name: Permit Number: Xcel Energy - Prairie Island Nuclear Plant 04900030-006 Subject Item: EU 001 Auxiliary Boiler 1 A-19 Associated Items: GP 007 NOx-Limit SV 001 Heating Boiler What to do LIMITS AND OPERATING RESTRICTIONS Why to do it Note: See GP007 for additional requirements. Fuel Usage: less than or equal to 28,838 gallons/month using 12-month Rolling Average Nitrogen Oxides: less than or equal to 0.144 lbs/million Btu heat input Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000 Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.3000 Total Particulate Matter: less than or equal to 0.60 lbs/million Btu heat input Minn. R. 7011.0510, subp. 1 Opacity: less than or equal to 20 percent opacity except for one six-minute period per hour of not more than 60 percent opacity. Fuel Type: Distillate Fuel Oil only. Sulfur Content of Fuel: less than or equal to 0.49 percent by weight RECORDKEEPING Daily Recordkeeping - fuel usage: On each day of operation, the Permittee shall calculate, record, and maintain daily totals of number of gallons of permitted fuel of EU001, based on written usage logs or flowmeters. Monthly Recordkeeping - fuel usage: By the last day of the month, the Permittee shall calculate and record the following: 1) The total fuel usage in gallons for EU001 for the previous calendar month using the daily fuel usage records. 2) The 12-month rolling average fuel usage for the previous 12-month period by summing the monthly fuel usage for the previous 12 months. Minn. R. 7011.0510, subp. 2 Minn. R. 7005.0100, subp. 35a Minn. R. 7005.0100, subp. 35a Title I Condition: To avoid classification as major source and modification under 40 CFR 52.21 & Minn. R. 7007.3000; Minn. R. 7007.0800, subps. 4 and 5 Title I Condition: To avoid classification as a major source under 40 CFR Section 52.21 & Minn. R. 7007.0800, subp. 5; Minn. R. 7007.3000 Requirements under 40 CFR pt. 63, Subpart JJJJJJ: National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial and Institutional Boilers Area Sources OPERATIONAL REQUIREMENTS The Permittee must comply with the requirement to conduct a tune-up according to 40 CFR Section 63.11223(b); no later than March 21, 2014 or a later date as determined by EPA rulemaking to amend Subpart JJJJJJ. The Permittee must demonstrate initial compliance with each applicable work practice standard, management practice, or emission reduction measure no later than March 21, 2014 and according to the applicable provisions in 40 CFR Section 63.7(a)(2). Limited-use boilers must conduct a tune-up every 5 years as specified in paragraphs (b)(1) through (7) of this section. Each 5-year tune-up must be conducted no more than 61 months after the previous tune-up. For a new or reconstructed limited-use boiler, the first 5-year tune-up must be no later than 61 months after the initial startup. 40 CFR Section 63.11196(a)(1) 40 CFR Section 63.11210(c) 40 CFR Section 63.11223(f) You may delay the burner inspection specified in paragraph (b)(1) of this section and inspection of the system controlling the air-to-fuel ratio specified in paragraph (b)(3) of this section until the next scheduled unit shutdown, but you must inspect each burner and system controlling the air-to-fuel ratio at least once every 72 months. The standards in 40 CFR Section 63.11201 apply at all times. At all times the Permittee must operate and maintain affected boilers, including associated air pollution control equipment and monitoring equipment, in a manner consistent with safety and good air pollution control practices for minimizing emissions. Determination of whether such operation and maintenance procedures are being used will be based on information available to the Administrator that may include, but is not limited to, monitoring results, review of operation and maintenance procedures, review of operation and maintenances records, and inspection of the source. 40 CFR Section 63.11201(d) 40 CFR Section 63.11205(a)