NRC 2018-0022, Request to Extend Enforcement Discretion Provided in Enforcement Guidance Memorandum 15-002 for Tornado-Generated Missile Protection Nonconformances Identified in Response to Regulatory Issue Summary 2015-06, Tornado Missile Protection
ML18116A306 | |
Person / Time | |
---|---|
Site: | Point Beach ![]() |
Issue date: | 04/26/2018 |
From: | Craven R Point Beach |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
NRC 2018-0022, RIS 2015-006 | |
Download: ML18116A306 (14) | |
Text
EXTera EN ERGY ~
POINT BEACH April 26, 2018 NRC 2018-0022 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington , DC 20555 Point Beach Nuclear Plant, Units 1 and 2 Docket 50-266 and 50-301 Renewed License Nos. DPR-24 and DPR-27 Request to Extend Enforcement Discretion Provided in Enforcement Guidance Memorandum 15-002 for Tornado-Generated Missile Protection Nonconformances Identified in Response to Regulatory Issue Summary 2015-06, "Tornado Missile Protection"
References:
- 1. NRC Regulatory Issue Summary 2015-06, Tornado Missile Protection, dated June 10, 2015 (ML15020A419)
- 2. NRC memorandum, Enforcement Guidance Memorandum 15-002, Enforcement Discretion for Tornado-Generated Missile Protection Noncompliance, June 10, 2015 (ML15111A269)
- 3. NRC memorandum, Enforcement Guidance Memorandum 15-002, Revision 1: Enforcement Discretion for Tornado-Generated Missile Protection Non-Compliance, February 7, 2017 (ML16355A286)
- 4. NRC Interim Staff Guidance DSS-ISG-2016-01 , Clarification of Licensee Actions in Receipt of Enforcement Discretion Per Enforcement Guidance Memorandum EGM 15-002, Enforcement Discretion for Tornado-Generated Missile Protection Noncompliance, Revision 1, November 2017 (ML17128A344)
In Reference 1, the NRC issued Regulatory Issue Summary (RIS) 2015-06, Tornado Missile Protection, to, in part, remind licensees of the need to conform to a plant's current, site-specific licensing basis for tornado-generated missile protection.
In Reference 2, the NRC provided guidance to exercise enforcement discretion when an operating power reactor licensee does not comply with a plant's current site-specific licensing basis for tornado-generated missile protection. The NRC would exercise this enforcement discretion only when a licensee implements initial compensatory measures to provide additional protection followed by implementation of more comprehensive, long-term compensatory measures within 60 days of discovery. The enforcement discretion would expire three years after issuance of RIS 2015-06 for plants of a higher tornado missile risk (Group A Plants) and five years after RIS issuance for plants of a lower tornado missile risk (Group B Plants).
Reference 2 categorized Point Beach Nuclear Plant (Point Beach) as a Group A plant.
NextEra Energy Point Beach, LLC 6610 Nuclear Road , Two Rivers , WI 54241
NRC 2018-0022 Page 2 of 2 In Reference 3, the NRC provided an acceptable approach to extending enforcement discretion such that an extension would be granted on a case-by-case basis with proper justification .
Accordingly, NextEra Energy Point Beach, LLC (NextEra) hereby requests that the NRC extend the expiration date for the period of enforcement discretion for Point Beach from June 10, 2018 to June 10, 2020.
NextEra has completed a comprehensive assessment for Point Beach and has identified nonconforming conditions regarding tornado missile protection requirements that affect the operability of structures, systems, or components addressed in the Point Beach Technical Specifications. A summary of the assessment methodology, scope, and results is provided in the attachment. The nonconforming conditions have been documented in the Point Beach corrective action program in accordance with NextEra procedures, and required notifications have been completed as discussed in the attachment.
Consistent with the guidance provided in Reference 4, initial compensatory measures have been implemented and comprehensive compensatory measures are planned for the Point Beach nonconforming conditions as described in the attachment. Additionally, an aggregate review of the planned comprehensive compensatory measures, including expected operator actions in response to severe weather and a subsequent loss of offsite power, determined that the site could perform these compensatory measures and operator actions in an effective manner.
These comprehensive compensatory measures will remain in place until the nonconformances are resolved. The requested enforcement discretion due date extension would provide NextEra sufficient time to address the nonconforming conditions and achieve compliance . NextEra has concluded that there is no undue risk associated with the requested extension and requests NRC approval of this extension to enforcement discretion by June 1, 2018.
This letter identifies no new commitments and no revisions to existing commitments.
Sincerely, Robert Craven Plant General Manager Attachment cc: Administrator, Region Ill , USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC
NRC 2018-0022 Attachment Page 1 of 10 ATTACHMENT Justification for Request to Extend the Expiration Date for Enforcement Discretion Regarding Tornado Missile Protection Requirements for Point Beach Nuclear Plant Units 1 and 2
NRC 2018-0022 Attachment Page 2 of 12 Justification for Request to Extend the Expiration Date for Enforcement Discretion Regarding Tornado Missile Protection Requirements for Point Beach Nuclear Plant Units 1 and 2
- 1. Introduction In accordance with EGM 2015-002, Revision 1, NextEra Energy Point Beach, LLC (NextEra) is requesting that the NRC extend the expiration date for the period of enforcement discretion for Point Beach from June 10, 2018 to June 10, 2020. This attachment provides the justification for NextEra's request to extend the expiration date for enforcement discretion using the guidance in Appendix B of Interim Staff Guidance DSS-ISG-2016-01, Revision 1.
NextEra completed a comprehensive tornado missile protection assessment for Point Beach and has identified nonconforming conditions regarding tornado missile protection requirements. In accordance with the applicable regulatory guidance, initial compensatory measures were implemented to address the nonconforming conditions, and comprehensive compensatory measures are being implemented within 60 days of discovery of the nonconforming conditions.
NextEra plans to submit a license amendment request (LAR) to modify Point Beach's current licensing basis to credit a Regulatory Guide 1.200-compliant high winds probabilistic risk assessment (PRA) as the basis for eliminating the spectrum of high wind events as a hazard for the plant given that the associated core damage frequency is below the regulatory screening threshold. Following approval, the amendment will be the basis for resolving the recently identified nonconforming conditions.
- 2. RIS 2015-06 Assessment Methodology The methodology followed by NextEra for the Point Beach assessment in response to RIS 2015-06 included the following three objectives:
(1) document the Point Beach current licensing basis (CLB) for tornados and tornado missile protection, (2) evaluate the site's conformance with the tornado missile protection CLB through a design review and plant walk downs, and document any nonconforming conditions, and (3) resolve the nonconforming conditions within the NextEra corrective action program (CAP).
- 3. Summary of CLB for Tornado and Tornado Missile Protection Design Point Beach's site-specific General Design Criterion 2, Performance Standards, is found in UFSAR Table 1.3-1 and reads:
NRC 2018-0022 Attachment Page 3 of 12 Performance Standards Those systems and components of reactor facilities which are essential to the prevention or to the mitigation of the consequences of nuclear accidents which could cause undue risk to the health and safety of the public shall be designed, fabricated, and erected to performance standards that enable such systems and components to withstand, without undue risk to the health and safety of the public, the forces that might reasonably be imposed by the occurrence of an extraordinary natural phenomenon such as earthquake, tornado, flooding condition, high wind, or heavy ice. The design bases so established shall reflect: (a) appropriate consideration of the most severe of these natural phenomena that have been officially recorded for the site and the surrounding area and (b) an appropriate margin for withstanding forces greater than those recorded to reflect uncertainties about the historical data and their suitability as a basis for design.
The Point Beach CLB for tornados and tornado missiles pertinent to the RIS 2015-06 assessment is also described in various sections of the Point Beach Updated Final Safety Analysis Report (UFSAR), including:
UFSAR Section 1.3 The containments and Seismic Class I portions of the Auxiliary Building, the turbine hall, the pumphouse, and the diesel generator building are designed to withstand the effects of a tornado. The design criteria of the containment and the Class I portions of the auxiliary and turbine buildings to withstand the effects of a tornado, including wind force, pressure differential, and missile impingement are described in Bechtel Topical Report B-TOP-3, Design Criteria for Nuclear Power Plants Against Tornadoes.
UFSAR Section 2.6 The frequency of occurrence and history of tornados occurring near the plant site as input to original station licensing is described in Section 2.6.
UFSAR Section 5.1 All components and supporting structures of the reactor containment are designed so that there is no loss of function of such equipment in the event of maximum potential ground acceleration acting in the horizontal and vertical directions simultaneously, or other extraordinary natural phenomena referred to in Criterion 2, Performance Standards.
The containment is designed to withstand tornado loadings equal to the design basis tornado.
The containment is analyzed for tornado loading, including tornado driven missiles equivalent to an airborne 4 in. by 12 in. by 12 ft. plank traveling end on at 300 mph (440 fps) or a 4000 lb. automobile flying through the air at 50 mph (74 fps) and at not more than 25 feet above the ground.
For design purposes, it is assumed that objects of low cross sectional density, such as boards, metal siding, and similar items may be picked up and carried at the maximum wind velocity of 300 mph. The behavior of heavier, oddly shaped objects such as an automobile, is less predictable. The design values of 50 mph for a 4000 lb. automobile lifted 25 feet in the air is felt to be representative of what would happen in a 300 mph wind as the automobile was lifted, tumbled along the ground, and ejected from the tornado funnel by centrifugal force. These missile velocities are consistent with reported behavior of such objects in previous tornadoes.
NRC 2018-0022 Attachment Page 4 of 12 The containment was analyzed for the depth of penetration of tornado missiles. Bechtel Topical Report B-TOP-3 established the weight of the licensing basis plant missile.
UFSAR Section 9.4 The walls and the base of the spent fuel pool will withstand all design tornado missiles.
Calculations demonstrate that tornado generated winds will not remove any critical amount of water from the spent fuel pool. Any water removed in this way will leave adequate coverage to maintain cooling of the stored fuel elements.
UFSAR Section 9.6 The pumphouse structure has been designed to remain intact under a tornado wind having a tangential velocity of 300 mph plus a forward progress of 60 mph. The structure is capable of remaining intact for a pressure drop of 1/2 psi. Before this pressure drop is realized, the building would be vented by the failure of the louvers and doors. Interior missile shield walls and exterior walls protecting the service water pumps are constructed of reinforced concrete with a minimum thickness of 12". The internal missile shield walls have been located to preclude the possibility of damage from a missile passing through a louver or door. Reinforced concrete walls of 12" thickness cannot be penetrated by the design tornado missiles.
UFSAR Section 10.2 The purpose of the Auxiliary Feedwater System (AFW) tornado event analysis is to ensure the AFW pumps are not damaged by low suction pressure resulting from damage to the suction supply piping from the Condensate Storage Tanks.
UFSAR Section 11.2 The Gas Treatment System gas decay tanks and surge tank are located in a tornado-proof Class I structure and are protected from overpressure by automatic controls and relief valves.
UFSAR Appendix D Tornado loads have been considered in the design of the Emergency Diesel Generator (G03/G04) building.
- 4. Description of the Nonconformances Where the EGM was Applied
- a. Steam Supply to Turbine Driven Auxiliary Feedwater Pumps (TDAFP)
Point Beach Units 1 and 2 each have a TDAFP capable of being supplied with steam from either or both steam generators. The steam supply lines to the TDAFP in each Unit are not fully protected by a Class I structure and are potentially vulnerable to a tornado missile.
- b. TDAFP Exhaust Stacks The TDAFP turbine exhaust stacks above the 66-foot elevation are not fully protected by a Class I structure. Consequently, the Units 1 and 2 TDAFPs are vulnerable to a tornado missile due to exposed exhaust stacks.
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- c. Main Steam System Valves The large bore Main Steam System piping is sufficiently robust to withstand a strike by a design basis tornado missile without loss of pressure integrity; however, a tornado missile could damage the pressure boundary integrity of the associated valves or their active functions. The Main Steam System safety valves, atmospheric dump valves, and main steam isolation valves are not protected by a Class I structure and are vulnerable to a tornado missile.
- d. Diesel Generator Fuel Oil Storage Tank Vent The fuel oil storage tank (T-1758) associated with the train 8 emergency diesel generators (EOG), G03 and G04, is directly vented through a single 4-inch diameter pipe.
This entire pipe, with the exception of the final few inches (a single down-turned elbow to exclude rain and snow from the end of the horizontal pipe) is located within the Class I EOG building. It has been postulated that the protruding elbow on the pipe could be crimped shut by a tornado missile strike and the resulting closure could result in a vacuum in the tank due to the fuel oil transfer pumps removing inventory. This could ultimately lead to a failure of the pumps due to lack of net positive suction head or structural collapse of the tank. However, the fuel oil storage tank is also indirectly vented through the G03 and G04 fuel oil day tanks which have overflow lines to the fuel oil storage tank. This alternate vent path provides additional assurance that the tank would continue to be vented if the fuel oil storage tank normal vent was obstructed.
Nonetheless, the two EDGs (G-03 and G-04) associated with fuel oil storage tank T-1758 are considered vulnerable to a tornado missile due to the lack of missile protection for the tank vent.
- 5. Description of Prompt Compensatory Measures Initial Actions NextEra initially identified a nonconforming condition associated with the TDAFP steam supply piping. The following initial actions were performed in accordance with EGM 15-002 and Interim Staff Guidance DSS-ISG-2016-01:
- a. Operations declared both Units 1 and 2 TDAFPs inoperable. Subsequently, NextEra implemented initial compensatory measures and restored the TDAFPs to operable but nonconforming status in accordance with EGM 15-002.
- b. NextEra reported the nonconforming condition as an eight-hour notification on March 1, 2018 (Event Number 53239) under the following regulations:
- 10 CFR 50.72(b)(3)(ii)(8), "The nuclear power plant being in an unanalyzed condition that significantly degrades plant safety."
- 10 CFR 50.72(b){3)(v)(A), "Shut down the reactor and maintain it in a safe shutdown condition;"
- 10 CFR 50.72(b)(3)(v)(D), "Mitigate the consequences of an accident."
- c. A review of the extent of condition identified the additional nonconforming conditions.
The affected components were declared inoperable and subsequently returned to
NRC 2018-0022 Attachment Page 6 of 12 operable but nonconforming status in accordance with EGM 15-002 after confirmation that the previously implemented initial compensatory measures were applicable to the additional nonconforming conditions.
Prompt Compensatory Measures NextEra implemented prompt compensatory measures as required by DSS-ISG-2016-01.
Abnormal operating procedure AOP-13C, Severe Weather Conditions, provides actions to respond to a tornado watch or warning. The procedure was reviewed and shift personnel have been trained on the procedure so that hazards from tornados can be minimized. In addition, shift personnel have been trained on the station's Diverse and Flexible Coping Strategies (FLEX), and FLEX equipment and procedures are in a state of readiness to support response to a tornado or other hazard.
The information below describes Point Beach procedural guidance pertaining to the initial compensatory measures as described in DSS-ISG-2016-01, Appendix A, Section 1.1, item numbers 2 and 3.
- 2. Verify that procedures are in place and training is current for the following actions to be taken if a tornado watch is issued for the area, such as:
- a. Remove, relocate, or secure potential missiles.
In response to high winds, AOP-13C provides guidance to the Shift Manager to consider a walk down to identify materials that may need to be secured.
In addition, in the event of a severe thunderstorm or tornado watch or warning, Operations standing order, Tornado Missile Protection, requires the Shift Manager to direct a walk down and removal of potential airborne objects, provided personnel safety can be assured.
- b. From a work management/configuration control perspective, protect equipment important to maintaining safe shutdown conditions.
In the event of a tornado watch or warning, the Operations standing order requires protecting the EDGs, auxiliary feedwater pumps (AFPs), service water (SW) pumps, and safety injection (Sl)/residual heat removal (RHR) pumps. The operators will also walk down these components and the FLEX equipment to identify any challenges to readiness as resources allow.
(Operations presently performs walk downs monthly.)
AOP-13C suspends use of the turbine building crane. The procedure also closes access openings in site buildings, including the primary auxiliary building, turbine hall, and circulating water pump house.
- c. Promptly complete or restore equipment from maintenance activities in progress on equipment important to maintaining safe shutdown conditions.
As required by a fleet procedure, during plant operation in Mode 1, Operations performs a review of aggregate risk each shift and takes actions as required to reduce elevated risk. A severe weather watch or warning is a condition that contributes to increased risk. With a tornado watch or warning in effect, the Operations standing order requires expediting the completion of maintenance or testing on EDGs, AFPs, SW pumps, Sl/RHR pumps, and FLEX equipment.
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- d. Restore equipment important to maintaining safe shutdown conditions if undergoing maintenance or testing, if possible.
Upon entry into AOP-13C, the procedure directs stopping non-vital activities potentially affected by the severe weather conditions. As discussed above, Operations will expedite the return-to-service of equipment that is undergoing maintenance or testing upon issuance of a tornado watch or warning.
- e. Verify equipment is ready to use by visual inspection, surveillances and preventive maintenance are current, and review pending equipment maintenance requests.
In addition to the equipment walk down required by the standing order, any new work (maintenance or testing) involving the EDGs, AFPs, SW pumps, Sl/RHR pumps, or FLEX equipment requires approval from the Shift Manager. The work control process assigns Operations the responsibility of performing safety and operability reviews of submitted work requests and initiating immediate actions as required for reported plant deficiencies.
- 3. Verify that procedures are in place and training is current for actions to be taken if a tornado warning is issued for the area, such as:
- a. Warning and protection strategies for site personnel.
In the event of a tornado sighting or warning, AOP-13C directs the operators to notify personnel inside and outside the protected area to take shelter in a heavily constructed building. The announcement is repeated periodically until the condition clears.
- b. Strategies for prompt damage assessment and initiation of restorative actions (e.g., pre-staging of equipment and plant staff at safe, strategic locations to promptly implement any necessary mitigative actions).
Upon entry into AOP-13C, the procedure notifies key personnel (duty station manager, shift technical advisor, duty maintenance, and duty operators) of the severe weather condition. After the tornado warning and high winds condition have passed, the procedure directs an assessment of plant damage, a walk down, and radiation surveys of the independent dry fuel storage installation.
- 6. Description of Long-Term Compensatory Actions The following are planned comprehensive measures that will strengthen the station's response to a tornado missile event:
- 1. The immediate compensatory measures (Operations standing order) related to use of AOP-13C that provide additional actions to take in the event of a severe thunderstorm or tornado watch or warning are being incorporated into station procedures:
- Provided personnel safety can be assured, a walk down for and removal of potential airborne objects will be directed by the Shift Manager.
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- Expedite completion or recovery of the following equipment if out of service for maintenance or testing: EDGs and equipment associated with the auxiliary feedwater (AFW), SW, Sl/RHR systems, and FLEX equipment.
- Operations crews will walk down the following equipment to identify any challenges to readiness: EDGs and equipment associated with the AFW, SW, Sl/RHR systems, and FLEX equipment.
- Guard the following equipment and control work being performed on guarded equipment: EDGs, equipment associated with the AFW, SW and Sl/RHR systems, and FLEX equipment.
- Any new work (maintenance and/or testing) shall be challenged (require Shift Manager permission) for the following equipment: EDGs, AFPs, SW pumps, Sl/RHR pumps, and FLEX equipment.
Additionally, Attachment A of AOP-13C, Response to High Winds, will be entered upon a severe thunderstorm and tornado watch or warning. The procedure will also be revised to specifically identify the equipment associated with the nonconforming conditions that should be inspected during the plant damage assessment following the severe weather condition.
- 2. The following actions will ensure heightened and strengthened availability of FLEX equipment:
- a. Notify NextEra fleet FLEX program owners and NextEra fleet management team of Point Beach's tornado missile vulnerability and the potential need for shared FLEX equipment in an expedited manner if the need should arise.
- b. Develop a matrix of critical FLEX equipment (e.g., pumps, generators) available within the NextEra fleet that meets the Point Beach design requirements that could be obtained if the station falls below the "N" (required quantity) requirement.
- c. Determine and evaluate (within 60 days) availability of critical FLEX equipment spare parts, then generate actions to initiate approval and procurement of spare parts, as deemed necessary.
- d. In the event of a nonfunctional FLEX component:
- i. Return to service should be expedited (e.g., work around the clock (24/7), as necessary, to obtain required parts/service, prepare work package, conduct repairs, and perform return-to-service testing).
ii. Administrative controls should be placed on the redundant FLEX component(s) to ensure required "N" quantity remains available (e.g., label functional component, or similar, so it is not removed from protected storage).
iii. If the FLEX equipment falls below FLEX capability "N":
A. Initiate immediate action to pursue restoration of the site FLEX capability "N" (e.g., maintenance callout).
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- 8. Initiate immediate action to develop compensatory measures to return to "N" capability (e.g., Engineering/Operations callout, as needed).
C. Implement compensatory measures within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, as required by OM 3.42, Control of WR SFP Level Instrumentation and Credited FLEX Equipment.
- 7. Assessment of all Compensatory Measures Procedural Guidance for Equipment Nonconformances
- a. Steam Supply to Turbine-driven Auxiliary Feedwater Pumps (TDAFP)
In the event of a plant trip, the operators would verify operation of the auxiliary feedwater (AFW) pumps in accordance with emergency operating procedure EOP-0, Reactor Trip or Safety Injection. The procedure checks that both the motor-driven and turbine-driven AFW pumps are running and directs starting any non-running AFW pumps. If no AFW pumps can be started, the procedure directs starting the standby steam generator feed pumps. Therefore, the procedure would establish flow using alternate pumps if the turbine-driven AFW pump became unavailable due to damage from a tornado-generated missile.
As a result of the FLEX mitigating strategies order, a modification was installed to provide additional flexibility in the event that both steam supply lines from a Unit to a TDAFP are rendered unavailable. The modification installed a manually isolated cross-connect line that connects the two Units' common steam supply headers. This cross-connect allows steam from Unit 1 to power the Unit 2 TDAFP or vice-versa.
The modification also installed a cross-connect on the discharge of the TDAFPs such that either TDAFP could supply either Unit. This modification supports beyond design bases external event response, and FLEX Support Guidelines are available for use of the cross-tie capability.
- b. TDAFP Exhaust Stacks Refer to procedure guidance in response to item a., above.
As a result of the FLEX mitigating strategies order, a modification was installed to provide additional flexibility in the event that a TDAFP turbine exhaust line becomes obstructed by a tornado missile strike. The modification installed a passive cross-connect line that connects the two Units' TDAFP exhaust stacks. Either stack is capable of passing sufficient exhaust steam for both turbines operating at maximum load. This added redundancy substantially reduces the likelihood that a tornado missile would incapacitate either or both TDAFPs in a single event. The modification was installed to address a beyond design basis external event. No operating procedures are required for this passive, normally open design.
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- c. Main Steam System Valves The Main Steam safety valves (MSSVs), atmospheric dump valves, (ADVs), and Main Steam isolation valves (MSIVs) are vulnerable to tornado-generated missiles. A missile strike on the MSSVs or ADVs could cause the valves to stick open or fail to open on demand at the required setpoint. The impact on MSIVs could result in a failure of the valves to close on demand.
A failure of the MSSVs or ADVs to open as necessary could result in high pressure in the associated steam generators. The directions for responding to such a condition are included in critical safety procedure CSP-H.2, Response to Steam Generator Overpressure. The procedure isolates AFW to the affected steam generators and directs efforts to dump steam from the steam generators.
Stuck open MSSVs or ADVs could result in depressurization of the steam generators.
The emergency operating procedures provide actions that address stuck open MSSVs or ADVs following a plant trip. EOP-0 checks for faulted steam generators and directs the operators to EOP-2, Faulted Steam Generator Isolation, as appropriate. If both steam generators are faulted, procedure ECA-2.1, Uncontrolled Depressurization of Both Steam Generators, directs the operators' response.
The emergency operating procedures also provide directions for responding to a failure of the MSIVs to close on demand. EOP-0 checks the position of the MS IVs and directs closing the MSIVs as required. If an open MSIV caused a faulted steam generator, the operators would respond in accordance with EOP-2, which directs closing the MSIV remotely, or locally, if there is a demand for main steam isolation.
During implementation of the emergency operating procedures, the operators periodically monitor critical safety functions and implement critical safety function procedures as required. Included in this monitoring are steam generator parameters such as feed flow, levels, and pressures.
- d. Diesel Generator Fuel Oil Storage Tank Vent The T-1758 fuel oil storage tank provides a source of fuel to automatically maintain level in the associated EOG fuel oil day tanks. If a tornado-generated missile rendered the fuel oil tank incapable of performing its function, the operators would be alerted to the condition by low-level alarms on the EOG day tanks. The existing alarm response procedures would direct the operators to check the status of the fuel oil transfer system.
Assessment of Long-Term Compensatory Measures Coincident with Other Operator Actions The planned, long-term compensatory measures will not add any new operator actions related to operation of plant systems and components. The revision to AOP-13C will add administrative requirements to perform walk downs to locate and remove loose objects that could become airborne missiles and to ensure the readiness of important plant equipment.
Additionally, the procedure revision will add administrative controls that ensure important equipment undergoing maintenance or testing is returned to service expeditiously and that the Shift Manager approves any new work on the equipment. These administrative controls
NRC 2018-0022 Attachment Page 11 of 12 have minimal impact on operator actions that may be required following an event involving severe weather and a loss of offsite power (LOOP).
The long-term measures are primarily preventative activities taken in preparation for adverse weather conditions. In the event of damage to the equipment vulnerable to tornado-generated missiles during a severe weather event, existing procedures provide contingency actions for unavailability of the equipment. For the case that the severe weather condition is accompanied by a LOOP or extended loss of AC power (ELAP), the operators would perform certain time critical and time sensitive actions to:
- Restore power to the safety related battery chargers within one hour following LOOP
- Connect the opposite Unit EOG to a safety related bus in the blacked out Unit
- Shed DC loads within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> from the start of an ELAP
- Realign safety related batteries to ensure extended DC power is available for approximately 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> from the start of an ELAP
- Energize and align battery chargers to the required station batteries within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> from the start of an ELAP
- Align diesel fire pump to supply the AFPs within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and 45 minutes from the start of an ELAP The planned, long-term compensatory measures do not include any new operator actions that must be performed during a severe weather or LOOP event. Therefore, NextEra concludes that the long-term measures have minimal impact on other operator actions that may be required in response to an event or off-normal condition.
- 8. Basis for the Need for Additional Enforcement Discretion Time The NRC provided guidance to exercise enforcement discretion when an operating power reactor licensee does not comply with a plant's current site-specific licensing basis for tornado-generated missile protection. The NRC would exercise this enforcement discretion only when a licensee implements initial compensatory measures to provide additional protection followed by implementation of more comprehensive, long-term compensatory measures within 60 days of discovery. The enforcement discretion would expire three years after issuance of RIS 2015-06, dated June 10, 2015, for plants of a higher tornado missile risk (Group A Plants) and five years after RIS issuance for plants of a lower tornado missile risk (Group B Plants). The EGM categorized Point Beach Nuclear Plant (Point Beach) as a Group A plant.
Enforcement Guidance Memorandum 15-002, Revision 1, Enforcement Discretion for Tornado-Generated Missile Protection Non-Compliance, discusses that licensees may request an extension to their expiration date if proper justification is provided. The extension will be granted on a case-by-case basis and compensatory measures should remain in place until compliance is achieved. In addition, DSS-ISG-2016-01, Revision 1, Appendix B, Clarification of Actions in EGM-15-002, Revision 1, provides an acceptable methodology to extend enforcement discretion. The issues involving tornado-generated missiles are believed to be of low risk and low probability, and the generic analysis used to establish the three and five-year timeframes for enforcement discretion did not take into account the compensatory
NRC 2018-0022 Attachment Page 12 of 12 actions, redundancy of components, and the site-specific footprint. Therefore, the NRC is extending enforcement discretion on a case-by-case basis.
NextEra intends to resolve the issue of tornado missile protection noncompliance by submitting a license amendment request (LAR) to modify the current licensing basis to credit a Regulatory Guide 1.200-compliant high winds PRA as the basis for eliminating the spectrum of high wind events as a hazard for the plant. As discussed in EGM 15-002, NextEra's LAR to establish compliance must be submitted and found acceptable for review in accordance with LIC-109, Acceptance Review Procedures, by June 10, 2018 for enforcement discretion to continue. However, NextEra expects to submit the LAR no earlier than the third quarter of 2018, and the NRC requires approximately one month to determine if the LAR is acceptable for review. NextEra has also considered alternative resolution strategies, and if one of those strategies becomes the preferred path to restoration of compliance, additional time will be required. If the next likely resolution is pursued (i.e., Tornado Missile Risk Evaluator), additional time would be required to prepare and submit that LAR. Therefore, NextEra is requesting a two-year extension to the expiration of the enforcement discretion.
- 9. Timeline for Restoring Compliance with the Licensing Basis Restoring compliance with the licensing basis for tornado missile protection is contingent on NRC approval of a LAR to credit use of a high winds PRA. NextEra expects to submit the LAR in the second half of 2018. If the NRC accepts the LAR and completes the review and approval within approximately one year, NextEra expects to receive the amendment by the end of 2019. With a 90-day implementation period, NextEra expects to restore compliance by the end of the first quarter of 2020.
EXTera EN ERGY ~
POINT BEACH April 26, 2018 NRC 2018-0022 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington , DC 20555 Point Beach Nuclear Plant, Units 1 and 2 Docket 50-266 and 50-301 Renewed License Nos. DPR-24 and DPR-27 Request to Extend Enforcement Discretion Provided in Enforcement Guidance Memorandum 15-002 for Tornado-Generated Missile Protection Nonconformances Identified in Response to Regulatory Issue Summary 2015-06, "Tornado Missile Protection"
References:
- 1. NRC Regulatory Issue Summary 2015-06, Tornado Missile Protection, dated June 10, 2015 (ML15020A419)
- 2. NRC memorandum, Enforcement Guidance Memorandum 15-002, Enforcement Discretion for Tornado-Generated Missile Protection Noncompliance, June 10, 2015 (ML15111A269)
- 3. NRC memorandum, Enforcement Guidance Memorandum 15-002, Revision 1: Enforcement Discretion for Tornado-Generated Missile Protection Non-Compliance, February 7, 2017 (ML16355A286)
- 4. NRC Interim Staff Guidance DSS-ISG-2016-01 , Clarification of Licensee Actions in Receipt of Enforcement Discretion Per Enforcement Guidance Memorandum EGM 15-002, Enforcement Discretion for Tornado-Generated Missile Protection Noncompliance, Revision 1, November 2017 (ML17128A344)
In Reference 1, the NRC issued Regulatory Issue Summary (RIS) 2015-06, Tornado Missile Protection, to, in part, remind licensees of the need to conform to a plant's current, site-specific licensing basis for tornado-generated missile protection.
In Reference 2, the NRC provided guidance to exercise enforcement discretion when an operating power reactor licensee does not comply with a plant's current site-specific licensing basis for tornado-generated missile protection. The NRC would exercise this enforcement discretion only when a licensee implements initial compensatory measures to provide additional protection followed by implementation of more comprehensive, long-term compensatory measures within 60 days of discovery. The enforcement discretion would expire three years after issuance of RIS 2015-06 for plants of a higher tornado missile risk (Group A Plants) and five years after RIS issuance for plants of a lower tornado missile risk (Group B Plants).
Reference 2 categorized Point Beach Nuclear Plant (Point Beach) as a Group A plant.
NextEra Energy Point Beach, LLC 6610 Nuclear Road , Two Rivers , WI 54241
NRC 2018-0022 Page 2 of 2 In Reference 3, the NRC provided an acceptable approach to extending enforcement discretion such that an extension would be granted on a case-by-case basis with proper justification .
Accordingly, NextEra Energy Point Beach, LLC (NextEra) hereby requests that the NRC extend the expiration date for the period of enforcement discretion for Point Beach from June 10, 2018 to June 10, 2020.
NextEra has completed a comprehensive assessment for Point Beach and has identified nonconforming conditions regarding tornado missile protection requirements that affect the operability of structures, systems, or components addressed in the Point Beach Technical Specifications. A summary of the assessment methodology, scope, and results is provided in the attachment. The nonconforming conditions have been documented in the Point Beach corrective action program in accordance with NextEra procedures, and required notifications have been completed as discussed in the attachment.
Consistent with the guidance provided in Reference 4, initial compensatory measures have been implemented and comprehensive compensatory measures are planned for the Point Beach nonconforming conditions as described in the attachment. Additionally, an aggregate review of the planned comprehensive compensatory measures, including expected operator actions in response to severe weather and a subsequent loss of offsite power, determined that the site could perform these compensatory measures and operator actions in an effective manner.
These comprehensive compensatory measures will remain in place until the nonconformances are resolved. The requested enforcement discretion due date extension would provide NextEra sufficient time to address the nonconforming conditions and achieve compliance . NextEra has concluded that there is no undue risk associated with the requested extension and requests NRC approval of this extension to enforcement discretion by June 1, 2018.
This letter identifies no new commitments and no revisions to existing commitments.
Sincerely, Robert Craven Plant General Manager Attachment cc: Administrator, Region Ill , USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC
NRC 2018-0022 Attachment Page 1 of 10 ATTACHMENT Justification for Request to Extend the Expiration Date for Enforcement Discretion Regarding Tornado Missile Protection Requirements for Point Beach Nuclear Plant Units 1 and 2
NRC 2018-0022 Attachment Page 2 of 12 Justification for Request to Extend the Expiration Date for Enforcement Discretion Regarding Tornado Missile Protection Requirements for Point Beach Nuclear Plant Units 1 and 2
- 1. Introduction In accordance with EGM 2015-002, Revision 1, NextEra Energy Point Beach, LLC (NextEra) is requesting that the NRC extend the expiration date for the period of enforcement discretion for Point Beach from June 10, 2018 to June 10, 2020. This attachment provides the justification for NextEra's request to extend the expiration date for enforcement discretion using the guidance in Appendix B of Interim Staff Guidance DSS-ISG-2016-01, Revision 1.
NextEra completed a comprehensive tornado missile protection assessment for Point Beach and has identified nonconforming conditions regarding tornado missile protection requirements. In accordance with the applicable regulatory guidance, initial compensatory measures were implemented to address the nonconforming conditions, and comprehensive compensatory measures are being implemented within 60 days of discovery of the nonconforming conditions.
NextEra plans to submit a license amendment request (LAR) to modify Point Beach's current licensing basis to credit a Regulatory Guide 1.200-compliant high winds probabilistic risk assessment (PRA) as the basis for eliminating the spectrum of high wind events as a hazard for the plant given that the associated core damage frequency is below the regulatory screening threshold. Following approval, the amendment will be the basis for resolving the recently identified nonconforming conditions.
- 2. RIS 2015-06 Assessment Methodology The methodology followed by NextEra for the Point Beach assessment in response to RIS 2015-06 included the following three objectives:
(1) document the Point Beach current licensing basis (CLB) for tornados and tornado missile protection, (2) evaluate the site's conformance with the tornado missile protection CLB through a design review and plant walk downs, and document any nonconforming conditions, and (3) resolve the nonconforming conditions within the NextEra corrective action program (CAP).
- 3. Summary of CLB for Tornado and Tornado Missile Protection Design Point Beach's site-specific General Design Criterion 2, Performance Standards, is found in UFSAR Table 1.3-1 and reads:
NRC 2018-0022 Attachment Page 3 of 12 Performance Standards Those systems and components of reactor facilities which are essential to the prevention or to the mitigation of the consequences of nuclear accidents which could cause undue risk to the health and safety of the public shall be designed, fabricated, and erected to performance standards that enable such systems and components to withstand, without undue risk to the health and safety of the public, the forces that might reasonably be imposed by the occurrence of an extraordinary natural phenomenon such as earthquake, tornado, flooding condition, high wind, or heavy ice. The design bases so established shall reflect: (a) appropriate consideration of the most severe of these natural phenomena that have been officially recorded for the site and the surrounding area and (b) an appropriate margin for withstanding forces greater than those recorded to reflect uncertainties about the historical data and their suitability as a basis for design.
The Point Beach CLB for tornados and tornado missiles pertinent to the RIS 2015-06 assessment is also described in various sections of the Point Beach Updated Final Safety Analysis Report (UFSAR), including:
UFSAR Section 1.3 The containments and Seismic Class I portions of the Auxiliary Building, the turbine hall, the pumphouse, and the diesel generator building are designed to withstand the effects of a tornado. The design criteria of the containment and the Class I portions of the auxiliary and turbine buildings to withstand the effects of a tornado, including wind force, pressure differential, and missile impingement are described in Bechtel Topical Report B-TOP-3, Design Criteria for Nuclear Power Plants Against Tornadoes.
UFSAR Section 2.6 The frequency of occurrence and history of tornados occurring near the plant site as input to original station licensing is described in Section 2.6.
UFSAR Section 5.1 All components and supporting structures of the reactor containment are designed so that there is no loss of function of such equipment in the event of maximum potential ground acceleration acting in the horizontal and vertical directions simultaneously, or other extraordinary natural phenomena referred to in Criterion 2, Performance Standards.
The containment is designed to withstand tornado loadings equal to the design basis tornado.
The containment is analyzed for tornado loading, including tornado driven missiles equivalent to an airborne 4 in. by 12 in. by 12 ft. plank traveling end on at 300 mph (440 fps) or a 4000 lb. automobile flying through the air at 50 mph (74 fps) and at not more than 25 feet above the ground.
For design purposes, it is assumed that objects of low cross sectional density, such as boards, metal siding, and similar items may be picked up and carried at the maximum wind velocity of 300 mph. The behavior of heavier, oddly shaped objects such as an automobile, is less predictable. The design values of 50 mph for a 4000 lb. automobile lifted 25 feet in the air is felt to be representative of what would happen in a 300 mph wind as the automobile was lifted, tumbled along the ground, and ejected from the tornado funnel by centrifugal force. These missile velocities are consistent with reported behavior of such objects in previous tornadoes.
NRC 2018-0022 Attachment Page 4 of 12 The containment was analyzed for the depth of penetration of tornado missiles. Bechtel Topical Report B-TOP-3 established the weight of the licensing basis plant missile.
UFSAR Section 9.4 The walls and the base of the spent fuel pool will withstand all design tornado missiles.
Calculations demonstrate that tornado generated winds will not remove any critical amount of water from the spent fuel pool. Any water removed in this way will leave adequate coverage to maintain cooling of the stored fuel elements.
UFSAR Section 9.6 The pumphouse structure has been designed to remain intact under a tornado wind having a tangential velocity of 300 mph plus a forward progress of 60 mph. The structure is capable of remaining intact for a pressure drop of 1/2 psi. Before this pressure drop is realized, the building would be vented by the failure of the louvers and doors. Interior missile shield walls and exterior walls protecting the service water pumps are constructed of reinforced concrete with a minimum thickness of 12". The internal missile shield walls have been located to preclude the possibility of damage from a missile passing through a louver or door. Reinforced concrete walls of 12" thickness cannot be penetrated by the design tornado missiles.
UFSAR Section 10.2 The purpose of the Auxiliary Feedwater System (AFW) tornado event analysis is to ensure the AFW pumps are not damaged by low suction pressure resulting from damage to the suction supply piping from the Condensate Storage Tanks.
UFSAR Section 11.2 The Gas Treatment System gas decay tanks and surge tank are located in a tornado-proof Class I structure and are protected from overpressure by automatic controls and relief valves.
UFSAR Appendix D Tornado loads have been considered in the design of the Emergency Diesel Generator (G03/G04) building.
- 4. Description of the Nonconformances Where the EGM was Applied
- a. Steam Supply to Turbine Driven Auxiliary Feedwater Pumps (TDAFP)
Point Beach Units 1 and 2 each have a TDAFP capable of being supplied with steam from either or both steam generators. The steam supply lines to the TDAFP in each Unit are not fully protected by a Class I structure and are potentially vulnerable to a tornado missile.
- b. TDAFP Exhaust Stacks The TDAFP turbine exhaust stacks above the 66-foot elevation are not fully protected by a Class I structure. Consequently, the Units 1 and 2 TDAFPs are vulnerable to a tornado missile due to exposed exhaust stacks.
NRC 2018-0022 Attachment Page 5 of 12
- c. Main Steam System Valves The large bore Main Steam System piping is sufficiently robust to withstand a strike by a design basis tornado missile without loss of pressure integrity; however, a tornado missile could damage the pressure boundary integrity of the associated valves or their active functions. The Main Steam System safety valves, atmospheric dump valves, and main steam isolation valves are not protected by a Class I structure and are vulnerable to a tornado missile.
- d. Diesel Generator Fuel Oil Storage Tank Vent The fuel oil storage tank (T-1758) associated with the train 8 emergency diesel generators (EOG), G03 and G04, is directly vented through a single 4-inch diameter pipe.
This entire pipe, with the exception of the final few inches (a single down-turned elbow to exclude rain and snow from the end of the horizontal pipe) is located within the Class I EOG building. It has been postulated that the protruding elbow on the pipe could be crimped shut by a tornado missile strike and the resulting closure could result in a vacuum in the tank due to the fuel oil transfer pumps removing inventory. This could ultimately lead to a failure of the pumps due to lack of net positive suction head or structural collapse of the tank. However, the fuel oil storage tank is also indirectly vented through the G03 and G04 fuel oil day tanks which have overflow lines to the fuel oil storage tank. This alternate vent path provides additional assurance that the tank would continue to be vented if the fuel oil storage tank normal vent was obstructed.
Nonetheless, the two EDGs (G-03 and G-04) associated with fuel oil storage tank T-1758 are considered vulnerable to a tornado missile due to the lack of missile protection for the tank vent.
- 5. Description of Prompt Compensatory Measures Initial Actions NextEra initially identified a nonconforming condition associated with the TDAFP steam supply piping. The following initial actions were performed in accordance with EGM 15-002 and Interim Staff Guidance DSS-ISG-2016-01:
- a. Operations declared both Units 1 and 2 TDAFPs inoperable. Subsequently, NextEra implemented initial compensatory measures and restored the TDAFPs to operable but nonconforming status in accordance with EGM 15-002.
- b. NextEra reported the nonconforming condition as an eight-hour notification on March 1, 2018 (Event Number 53239) under the following regulations:
- 10 CFR 50.72(b)(3)(ii)(8), "The nuclear power plant being in an unanalyzed condition that significantly degrades plant safety."
- 10 CFR 50.72(b){3)(v)(A), "Shut down the reactor and maintain it in a safe shutdown condition;"
- 10 CFR 50.72(b)(3)(v)(D), "Mitigate the consequences of an accident."
- c. A review of the extent of condition identified the additional nonconforming conditions.
The affected components were declared inoperable and subsequently returned to
NRC 2018-0022 Attachment Page 6 of 12 operable but nonconforming status in accordance with EGM 15-002 after confirmation that the previously implemented initial compensatory measures were applicable to the additional nonconforming conditions.
Prompt Compensatory Measures NextEra implemented prompt compensatory measures as required by DSS-ISG-2016-01.
Abnormal operating procedure AOP-13C, Severe Weather Conditions, provides actions to respond to a tornado watch or warning. The procedure was reviewed and shift personnel have been trained on the procedure so that hazards from tornados can be minimized. In addition, shift personnel have been trained on the station's Diverse and Flexible Coping Strategies (FLEX), and FLEX equipment and procedures are in a state of readiness to support response to a tornado or other hazard.
The information below describes Point Beach procedural guidance pertaining to the initial compensatory measures as described in DSS-ISG-2016-01, Appendix A, Section 1.1, item numbers 2 and 3.
- 2. Verify that procedures are in place and training is current for the following actions to be taken if a tornado watch is issued for the area, such as:
- a. Remove, relocate, or secure potential missiles.
In response to high winds, AOP-13C provides guidance to the Shift Manager to consider a walk down to identify materials that may need to be secured.
In addition, in the event of a severe thunderstorm or tornado watch or warning, Operations standing order, Tornado Missile Protection, requires the Shift Manager to direct a walk down and removal of potential airborne objects, provided personnel safety can be assured.
- b. From a work management/configuration control perspective, protect equipment important to maintaining safe shutdown conditions.
In the event of a tornado watch or warning, the Operations standing order requires protecting the EDGs, auxiliary feedwater pumps (AFPs), service water (SW) pumps, and safety injection (Sl)/residual heat removal (RHR) pumps. The operators will also walk down these components and the FLEX equipment to identify any challenges to readiness as resources allow.
(Operations presently performs walk downs monthly.)
AOP-13C suspends use of the turbine building crane. The procedure also closes access openings in site buildings, including the primary auxiliary building, turbine hall, and circulating water pump house.
- c. Promptly complete or restore equipment from maintenance activities in progress on equipment important to maintaining safe shutdown conditions.
As required by a fleet procedure, during plant operation in Mode 1, Operations performs a review of aggregate risk each shift and takes actions as required to reduce elevated risk. A severe weather watch or warning is a condition that contributes to increased risk. With a tornado watch or warning in effect, the Operations standing order requires expediting the completion of maintenance or testing on EDGs, AFPs, SW pumps, Sl/RHR pumps, and FLEX equipment.
NRC 2018-0022 Attachment Page 7 of 12
- d. Restore equipment important to maintaining safe shutdown conditions if undergoing maintenance or testing, if possible.
Upon entry into AOP-13C, the procedure directs stopping non-vital activities potentially affected by the severe weather conditions. As discussed above, Operations will expedite the return-to-service of equipment that is undergoing maintenance or testing upon issuance of a tornado watch or warning.
- e. Verify equipment is ready to use by visual inspection, surveillances and preventive maintenance are current, and review pending equipment maintenance requests.
In addition to the equipment walk down required by the standing order, any new work (maintenance or testing) involving the EDGs, AFPs, SW pumps, Sl/RHR pumps, or FLEX equipment requires approval from the Shift Manager. The work control process assigns Operations the responsibility of performing safety and operability reviews of submitted work requests and initiating immediate actions as required for reported plant deficiencies.
- 3. Verify that procedures are in place and training is current for actions to be taken if a tornado warning is issued for the area, such as:
- a. Warning and protection strategies for site personnel.
In the event of a tornado sighting or warning, AOP-13C directs the operators to notify personnel inside and outside the protected area to take shelter in a heavily constructed building. The announcement is repeated periodically until the condition clears.
- b. Strategies for prompt damage assessment and initiation of restorative actions (e.g., pre-staging of equipment and plant staff at safe, strategic locations to promptly implement any necessary mitigative actions).
Upon entry into AOP-13C, the procedure notifies key personnel (duty station manager, shift technical advisor, duty maintenance, and duty operators) of the severe weather condition. After the tornado warning and high winds condition have passed, the procedure directs an assessment of plant damage, a walk down, and radiation surveys of the independent dry fuel storage installation.
- 6. Description of Long-Term Compensatory Actions The following are planned comprehensive measures that will strengthen the station's response to a tornado missile event:
- 1. The immediate compensatory measures (Operations standing order) related to use of AOP-13C that provide additional actions to take in the event of a severe thunderstorm or tornado watch or warning are being incorporated into station procedures:
- Provided personnel safety can be assured, a walk down for and removal of potential airborne objects will be directed by the Shift Manager.
NRC 2018-0022 Attachment Page 8of12
- Expedite completion or recovery of the following equipment if out of service for maintenance or testing: EDGs and equipment associated with the auxiliary feedwater (AFW), SW, Sl/RHR systems, and FLEX equipment.
- Operations crews will walk down the following equipment to identify any challenges to readiness: EDGs and equipment associated with the AFW, SW, Sl/RHR systems, and FLEX equipment.
- Guard the following equipment and control work being performed on guarded equipment: EDGs, equipment associated with the AFW, SW and Sl/RHR systems, and FLEX equipment.
- Any new work (maintenance and/or testing) shall be challenged (require Shift Manager permission) for the following equipment: EDGs, AFPs, SW pumps, Sl/RHR pumps, and FLEX equipment.
Additionally, Attachment A of AOP-13C, Response to High Winds, will be entered upon a severe thunderstorm and tornado watch or warning. The procedure will also be revised to specifically identify the equipment associated with the nonconforming conditions that should be inspected during the plant damage assessment following the severe weather condition.
- 2. The following actions will ensure heightened and strengthened availability of FLEX equipment:
- a. Notify NextEra fleet FLEX program owners and NextEra fleet management team of Point Beach's tornado missile vulnerability and the potential need for shared FLEX equipment in an expedited manner if the need should arise.
- b. Develop a matrix of critical FLEX equipment (e.g., pumps, generators) available within the NextEra fleet that meets the Point Beach design requirements that could be obtained if the station falls below the "N" (required quantity) requirement.
- c. Determine and evaluate (within 60 days) availability of critical FLEX equipment spare parts, then generate actions to initiate approval and procurement of spare parts, as deemed necessary.
- d. In the event of a nonfunctional FLEX component:
- i. Return to service should be expedited (e.g., work around the clock (24/7), as necessary, to obtain required parts/service, prepare work package, conduct repairs, and perform return-to-service testing).
ii. Administrative controls should be placed on the redundant FLEX component(s) to ensure required "N" quantity remains available (e.g., label functional component, or similar, so it is not removed from protected storage).
iii. If the FLEX equipment falls below FLEX capability "N":
A. Initiate immediate action to pursue restoration of the site FLEX capability "N" (e.g., maintenance callout).
NRC 2018-0022 Attachment Page 9 of 12
- 8. Initiate immediate action to develop compensatory measures to return to "N" capability (e.g., Engineering/Operations callout, as needed).
C. Implement compensatory measures within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, as required by OM 3.42, Control of WR SFP Level Instrumentation and Credited FLEX Equipment.
- 7. Assessment of all Compensatory Measures Procedural Guidance for Equipment Nonconformances
- a. Steam Supply to Turbine-driven Auxiliary Feedwater Pumps (TDAFP)
In the event of a plant trip, the operators would verify operation of the auxiliary feedwater (AFW) pumps in accordance with emergency operating procedure EOP-0, Reactor Trip or Safety Injection. The procedure checks that both the motor-driven and turbine-driven AFW pumps are running and directs starting any non-running AFW pumps. If no AFW pumps can be started, the procedure directs starting the standby steam generator feed pumps. Therefore, the procedure would establish flow using alternate pumps if the turbine-driven AFW pump became unavailable due to damage from a tornado-generated missile.
As a result of the FLEX mitigating strategies order, a modification was installed to provide additional flexibility in the event that both steam supply lines from a Unit to a TDAFP are rendered unavailable. The modification installed a manually isolated cross-connect line that connects the two Units' common steam supply headers. This cross-connect allows steam from Unit 1 to power the Unit 2 TDAFP or vice-versa.
The modification also installed a cross-connect on the discharge of the TDAFPs such that either TDAFP could supply either Unit. This modification supports beyond design bases external event response, and FLEX Support Guidelines are available for use of the cross-tie capability.
- b. TDAFP Exhaust Stacks Refer to procedure guidance in response to item a., above.
As a result of the FLEX mitigating strategies order, a modification was installed to provide additional flexibility in the event that a TDAFP turbine exhaust line becomes obstructed by a tornado missile strike. The modification installed a passive cross-connect line that connects the two Units' TDAFP exhaust stacks. Either stack is capable of passing sufficient exhaust steam for both turbines operating at maximum load. This added redundancy substantially reduces the likelihood that a tornado missile would incapacitate either or both TDAFPs in a single event. The modification was installed to address a beyond design basis external event. No operating procedures are required for this passive, normally open design.
NRC 2018-0022 Attachment Page 10of12
- c. Main Steam System Valves The Main Steam safety valves (MSSVs), atmospheric dump valves, (ADVs), and Main Steam isolation valves (MSIVs) are vulnerable to tornado-generated missiles. A missile strike on the MSSVs or ADVs could cause the valves to stick open or fail to open on demand at the required setpoint. The impact on MSIVs could result in a failure of the valves to close on demand.
A failure of the MSSVs or ADVs to open as necessary could result in high pressure in the associated steam generators. The directions for responding to such a condition are included in critical safety procedure CSP-H.2, Response to Steam Generator Overpressure. The procedure isolates AFW to the affected steam generators and directs efforts to dump steam from the steam generators.
Stuck open MSSVs or ADVs could result in depressurization of the steam generators.
The emergency operating procedures provide actions that address stuck open MSSVs or ADVs following a plant trip. EOP-0 checks for faulted steam generators and directs the operators to EOP-2, Faulted Steam Generator Isolation, as appropriate. If both steam generators are faulted, procedure ECA-2.1, Uncontrolled Depressurization of Both Steam Generators, directs the operators' response.
The emergency operating procedures also provide directions for responding to a failure of the MSIVs to close on demand. EOP-0 checks the position of the MS IVs and directs closing the MSIVs as required. If an open MSIV caused a faulted steam generator, the operators would respond in accordance with EOP-2, which directs closing the MSIV remotely, or locally, if there is a demand for main steam isolation.
During implementation of the emergency operating procedures, the operators periodically monitor critical safety functions and implement critical safety function procedures as required. Included in this monitoring are steam generator parameters such as feed flow, levels, and pressures.
- d. Diesel Generator Fuel Oil Storage Tank Vent The T-1758 fuel oil storage tank provides a source of fuel to automatically maintain level in the associated EOG fuel oil day tanks. If a tornado-generated missile rendered the fuel oil tank incapable of performing its function, the operators would be alerted to the condition by low-level alarms on the EOG day tanks. The existing alarm response procedures would direct the operators to check the status of the fuel oil transfer system.
Assessment of Long-Term Compensatory Measures Coincident with Other Operator Actions The planned, long-term compensatory measures will not add any new operator actions related to operation of plant systems and components. The revision to AOP-13C will add administrative requirements to perform walk downs to locate and remove loose objects that could become airborne missiles and to ensure the readiness of important plant equipment.
Additionally, the procedure revision will add administrative controls that ensure important equipment undergoing maintenance or testing is returned to service expeditiously and that the Shift Manager approves any new work on the equipment. These administrative controls
NRC 2018-0022 Attachment Page 11 of 12 have minimal impact on operator actions that may be required following an event involving severe weather and a loss of offsite power (LOOP).
The long-term measures are primarily preventative activities taken in preparation for adverse weather conditions. In the event of damage to the equipment vulnerable to tornado-generated missiles during a severe weather event, existing procedures provide contingency actions for unavailability of the equipment. For the case that the severe weather condition is accompanied by a LOOP or extended loss of AC power (ELAP), the operators would perform certain time critical and time sensitive actions to:
- Restore power to the safety related battery chargers within one hour following LOOP
- Connect the opposite Unit EOG to a safety related bus in the blacked out Unit
- Shed DC loads within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> from the start of an ELAP
- Realign safety related batteries to ensure extended DC power is available for approximately 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> from the start of an ELAP
- Energize and align battery chargers to the required station batteries within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> from the start of an ELAP
- Align diesel fire pump to supply the AFPs within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and 45 minutes from the start of an ELAP The planned, long-term compensatory measures do not include any new operator actions that must be performed during a severe weather or LOOP event. Therefore, NextEra concludes that the long-term measures have minimal impact on other operator actions that may be required in response to an event or off-normal condition.
- 8. Basis for the Need for Additional Enforcement Discretion Time The NRC provided guidance to exercise enforcement discretion when an operating power reactor licensee does not comply with a plant's current site-specific licensing basis for tornado-generated missile protection. The NRC would exercise this enforcement discretion only when a licensee implements initial compensatory measures to provide additional protection followed by implementation of more comprehensive, long-term compensatory measures within 60 days of discovery. The enforcement discretion would expire three years after issuance of RIS 2015-06, dated June 10, 2015, for plants of a higher tornado missile risk (Group A Plants) and five years after RIS issuance for plants of a lower tornado missile risk (Group B Plants). The EGM categorized Point Beach Nuclear Plant (Point Beach) as a Group A plant.
Enforcement Guidance Memorandum 15-002, Revision 1, Enforcement Discretion for Tornado-Generated Missile Protection Non-Compliance, discusses that licensees may request an extension to their expiration date if proper justification is provided. The extension will be granted on a case-by-case basis and compensatory measures should remain in place until compliance is achieved. In addition, DSS-ISG-2016-01, Revision 1, Appendix B, Clarification of Actions in EGM-15-002, Revision 1, provides an acceptable methodology to extend enforcement discretion. The issues involving tornado-generated missiles are believed to be of low risk and low probability, and the generic analysis used to establish the three and five-year timeframes for enforcement discretion did not take into account the compensatory
NRC 2018-0022 Attachment Page 12 of 12 actions, redundancy of components, and the site-specific footprint. Therefore, the NRC is extending enforcement discretion on a case-by-case basis.
NextEra intends to resolve the issue of tornado missile protection noncompliance by submitting a license amendment request (LAR) to modify the current licensing basis to credit a Regulatory Guide 1.200-compliant high winds PRA as the basis for eliminating the spectrum of high wind events as a hazard for the plant. As discussed in EGM 15-002, NextEra's LAR to establish compliance must be submitted and found acceptable for review in accordance with LIC-109, Acceptance Review Procedures, by June 10, 2018 for enforcement discretion to continue. However, NextEra expects to submit the LAR no earlier than the third quarter of 2018, and the NRC requires approximately one month to determine if the LAR is acceptable for review. NextEra has also considered alternative resolution strategies, and if one of those strategies becomes the preferred path to restoration of compliance, additional time will be required. If the next likely resolution is pursued (i.e., Tornado Missile Risk Evaluator), additional time would be required to prepare and submit that LAR. Therefore, NextEra is requesting a two-year extension to the expiration of the enforcement discretion.
- 9. Timeline for Restoring Compliance with the Licensing Basis Restoring compliance with the licensing basis for tornado missile protection is contingent on NRC approval of a LAR to credit use of a high winds PRA. NextEra expects to submit the LAR in the second half of 2018. If the NRC accepts the LAR and completes the review and approval within approximately one year, NextEra expects to receive the amendment by the end of 2019. With a 90-day implementation period, NextEra expects to restore compliance by the end of the first quarter of 2020.