IR 05000456/2019010

Design Basis Assurance (Team); Inspection Report 05000456/2019010 and 05000457/2019010 (DRS-J.Corujo-Sandin)

ML19113A233
Person / Time
Site:	Braidwood
Issue date:	04/23/2019
From:	Karla Stoedter NRC/RGN-III
To:	Bryan Hanson Exelon Generation Co
References
IR 2019010
Download: ML19113A233 (25)

Text

ril 23, 2019

SUBJECT:

BRAIDWOOD STATION, UNITS 1 AND 2DESIGN BASIS ASSURANCE (TEAM); INSPECTION REPORT 05000456/2019010 AND 05000457/2019010

Dear Mr. Hanson:

On April 10, 2019, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Braidwood Station, Units 1 and 2, and discussed the results of this inspection with Mr. John Keenan and other members of your staff. The results of this inspection are documented in the enclosed report.

The NRC inspectors documented two findings of very-low safety significance (Green) in this report. These findings involved violations of NRC requirements.

If you contest the violations or significance or severity of the violations documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:

Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; the Director, Office of Enforcement; and the NRC resident inspector at Braidwood. This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 Code of Federal Regulations, Part 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely,

/RA/

Karla K. Stoedter, Chief Engineering Branch 2 Docket Nos.: 05000456; 05000457 License Nos.: NPF-72; NPF-77

Enclosure:

IR 05000456/2019010; 05000457/2019010

Inspection Report

Docket Numbers: 05000456 and 05000457 License Numbers: NPF-72 and NPF-77 Report Numbers: 05000456/2019010 and 05000457/2019010 Enterprise Identifier: I-2019-010-0033 Licensee: Exelon Generation Company, LLC Facility: Braidwood Station, Units 1 and 2 Location: Braceville, IL Inspection Dates: January 14, 2019, to February 06, 2019 Inspectors: J. Benjamin, Senior Reactor Inspector J. Corujo-Sandin, Senior Reactor Inspector W. Hopf, Contractor V. Meghani, Reactor Inspector J. Robbins, Senior Reactor Inspector M. Yeminy, Contractor Approved By: Karla K. Stoedter, Chief Engineering Branch 2 Division of Reactor Safety Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a Design Basis Assurance (Team) Inspection at Braidwood Station,

Units 1 and 2, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.

Findings and violations being considered in the NRCs assessment are summarized in the table below.

List of Findings and Violations Failure to Translate the Design Basis for the Refueling Water Storage Tank Hatch Barrier Modification Cornerstone Significance Cross-cutting Report Aspect Section Mitigating Systems Green Unable to Identify 71111.21M NCV 05000457,05000456/2019010-01 Open/Closed The inspectors identified a Green finding and an associated Non-Cited Violation of Title 10 of the Code of Federal Regulations, Part 50, Appendix B, Criterion III, Design Control, when the licensee failed to correctly translate the design basis for the new refueling water storage tank hatch steel covers installed as barriers for protection against the design basis tornado missiles.

Failure to Correctly Translate Design Bases Information for the Turbine Building High Energy Line Break Mitigation Strategy Cornerstone Significance Cross-cutting Report Aspect Section Mitigating Systems Green None 71111.21M NCV 05000457,05000456/2019010-02 Open/Closed The inspectors identified a Green finding and an associated Non-Cited Violation of Title 10 of the Code of Federal Regulations, Part 50, Appendix B, Criterion III, Design Control, when the licensee failed to correctly translate regulatory requirements and the design basis for the Turbine Building High Energy Line Break mitigation strategy.

Additional Tracking Items None.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs)in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html.

Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

REACTOR SAFETY

===71111.21M - Design Bases Assurance Inspection (Teams)

The inspectors evaluated the following components, permanent modifications, and operating experience. The components inspected were selected using the risk-significance/low margin approach.

Design Review - Large Early Release Frequency (LERFs) (IP Section 02.02) ===

Check Valve (1SI8948A)

• Licensing and Design Basis Requirements:

o Updated Final Safety Analysis Report, Technical Specifications and Technical Requirements Manual

• Review of Normal Operating Procedures

• Review of In Service Testing:

o Testing requirements o Testing configurations o Recent test results o Leakage requirements and compliance with acceptance criteria

• Review for recent modifications

• System health:

o Recent failures o Condition Reports o Operability Evaluations Design Review - Risk-Significant/Low Design Margin Components (IP Section 02.02)

(5 Samples)

The inspectors reviewed, as applicable, the following attributes for all selected components.

• Licensing and Design Basis Requirements:

o Updated Final Safety Analysis Report, Technical Specifications and Technical Requirements Manual

• Visual non-intrusive inspection to assess:

o Installation configuration o Material condition o Potential vulnerability to hazards

• Procedures:

o Normal operating procedures o Emergency operating procedures o Abnormal operating procedures o Alarm response procedures o Mitigation Strategies (i.e., FLEX)o Title 10 of the Code of Federal Regulations, Part 50.54

(hh) strategies (i.e., B.5.b)

• Maintenance effectiveness:

o Maintenance Procedures o Maintenance Rule scope o Maintenance Rule a1/a2 determination o Maintenance Rule monitoring o Maintenance Rule a(1) recovery o Vendor recommended maintenance

• Recent modifications

• System health:

o Recent failures o Condition Reports o Operability Evaluations Component specific attributes are listed below.

(1) Emergency Diesel Generator (EDG 1A)

• Protection against external events:

o Flooding o Tornado

• Time dependent operator action validation:

o Emergency Diesel Generator local start & control

• Design calculations and considerations:

o Room heat up and environmental considerations o Fuel oil transfer design including flow capacity

• Test/inspection procedures, acceptance criteria, and recent results:

o Load testing o Technical Specifications surveillances o Relay calibration

• Electrical design calculations and considerations:

o Loading calculations o Short circuit calculations o Sequencer timer versus voltage and frequency o Coordination calculations o Overcurrent protection o Overvoltage analysis with load rejection

(2) 4KV Feed Breaker (1415X)

• Test/inspection procedures, acceptance criteria, and recent results:

o Technical Specification surveillances o Relay calibration

• Electrical design calculations and considerations:

o Loading calculations o Short circuit calculations o Coordination calculations o Bus capacity

(3) Miscellaneous Electrical Equipment Room Exhaust Fan (1VE04C)

• Time dependent operator action validation:

o VE04C B6, MEER auto trip alarm response procedure (VX01J)o VE04C B7, MEER differential pressure high alarm response procedure (VX01J)o VE04C, MEER differential pressure low alarm response procedure (VX01J)

• Test/inspection procedures, acceptance criteria, and recent results:

o Flow balance/capacity tests

• Protection against external events:

o High Energy Line Break o Fire

• Translation of vendor specifications

• Mechanical/structural design:

o Flow/head capacity/balance o Minimum flow o Level setpoints and instrument uncertainty o Room heat up o Room ventilation

• Control logic for fan start/stop

• Electrical design:

o Degraded voltage effects o Minimum voltage o Protective relays o Cable ampacity o Brake horsepower

(4) Miscellaneous Electrical Equipment Rooms Outlet Damper (1VE07Y)

• Protection against external events:

o Seismic o High Energy Line Break o Fire

• Translation of vendor specifications

• Part 21 applicability

• Miscellaneous operating experience applicability

• Recent operability evaluations

• Operator work around applicability

(5) Refueling Water Storage Tank (1SI01T)

• Protection against external events:

o Flooding o Seismic o Tornado

• Test/inspection procedures, acceptance criteria, and recent results:

o Technical Specification surveillances

• Calculations:

o Level o Set points o Volume capacity

• Part 21 applicability

• Recent operability evaluations

• Operator work around applicability

• Time dependent operator action validation

• Heat tracing of vent (circuit monitoring and Loss of Offsite Power effects)

• Heat tracing of level instrument (circuit monitoring and Loos of Offsite Power effects)

Modification Review - Permanent Mods (IP Section 02.03) (5 Samples)

(1) Engineering Change 392851, A1R18 Degraded Voltage 5 Minute Timer Resolution - Unit 1

(2) Engineering Change 395730, Miscellaneous Electrical Equipment Room Battery Room Exhaust Fan 1(2)VE03C Diff Pressure Low Alarm Setpoint Change 1(2)PDS VE123

(3) Engineering Change 618920, Tornado Missile Protection For Refueling Water Storage Tank Roof Hatches

(4) Engineering Change 624150, Review of the Seismic Test Report for Process Controllers

(5) Engineering Change 403447, Wiring Changes for Unit 1 Train B SSPS Wiring Review of Operating Experience Issues (IP Section 02.06) (3 Samples)

(1) SOER 83-6, Unavailability of Emergency Diesel Generator due to diesel and control design

(2) SOER 98-2, Circuit breaker reliability

(3) Information Notice 2007-34, Operating Experience Regarding Circuit Breakers

INSPECTION RESULTS

Failure to Translate the Design Basis for the Refueling Water Storage Tank Hatch Barrier Modification Cornerstone Significance Cross-cutting Report Aspect Section Mitigating Systems Green Unable to Identify 71111.21M NCV 05000457,05000456/2019010-01 Open/Closed The inspectors identified a Green finding and an associated Non-Cited Violation of Title 10 of the Code of Federal Regulations, Part 50, Appendix B, Criterion III, Design Control, when the licensee failed to correctly translate the design basis for the new refueling water storage tank hatch steel covers installed as barriers for protection against the design basis tornado missiles.

Description:

Per Updated Final Safety Analysis Report Section 3.2.1, Safety Classification, and Table 3.2-1, Safety Category and Quality Group Classification for Structures and Components, the refueling water storage tank (one in each Unit) is a Safety Category I structure required to remain functional under impact from tornado missiles with the characteristics as described in Section 3.5.1.4, Missiles Generated By Natural Phenomena.

The Updated Final Safety Analysis Report Section 3.5.3, Barrier Design Procedures, describes the two types of structural response to missile impacts which have been investigated for the design-basis tornado-generated missiles discussed in Updated Final Safety Analysis Report Section 3.5.1.4. The two types of structural responses are the local effect and the overall response. In addition, Section 3.5.3 lists the types of barriers designed to resist missile impacts. For steel plate barriers, it states, The thickness of steel plate required to resist the impacting design-basis missile is calculated using the Stanford formula (Reference 8). The overall structural response, including structural stability and deformation is investigated using concepts and methods presented in Reference 9.

The inspectors further noted that the use of TORMIS methodology for assessing tornado missile protection was not applicable to the refueling water storage tank hatch covers. The U.S. Nuclear Regulatory Commission Safety Evaluation Report dated November 8, 2018, allowing use of TORMIS per Amendment 199 to the facility operating license, indicated that the approval was based on the licensee's commitment and subsequent completion of the engineering changes needed to protect the hatches.

During review of Calculation 8.1.16-BRW-17-0026-S, Revision 1, dated September 25, 2017, associated with Engineering Change 618920, Tornado Missile Protection for Refueling Water Storage Tank Roof Hatches, the inspectors identified the licensee had not evaluated the overall structural response of the hatch following the impact of a design basis tornado missile. As a result, the licensee had not demonstrated the steel plate barriers (hatch covers)would deform and absorb sufficient energy to preclude debris from entering the refueling water storage tank allowing the refueling water storage tank to remain functional.

Corrective Action(s): The licensee performed an engineering review of the steel barrier details concluding that in case of a missile strike, the structure will be able to deform and absorb sufficient energy to preclude debris from entering the refueling water storage tank, thus maintaining its functionality. The licensee also initiated an investigation for identification of follow-on actions.

Corrective Action Reference(s): Action Request 04217133

Performance Assessment:

Performance Deficiency: The failure to assure the design bases were correctly translated, as described in Updated Final Safety Analysis Report Section 3.5.3, for the overall structural response to an impacting design basis tornado generated missile on the refueling water storage tank hatch cover steel plate barriers was a performance deficiency. Specifically, the licensee only considered local effects of a tornado missile impact on the new barriers while the Updated Final Safety Analysis Report requires both the local effects and the overall structural response including structural stability and deformation be considered when evaluating steel plate barriers. The failure to follow this standard resulted in a violation of Title 10 of the Code of Federal Regulations, Part 50, Appendix B, Criterion III, Design Control.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Protection Against External Factors attribute of the Mitigating Systems cornerstone. Specifically, blockage of the refueling water storage tank flow path by debris from a missile impacting the tank could result in the unavailability of a water source for core heat removal during operation of an emergency core cooling system.

Significance: The inspectors assessed the significance of the finding using Appendix A, Significance Determination of Reactor Inspection Findings for At - Power Situations.

Specifically, the inspectors determined that this finding is of very-low safety significance (Green) because the finding did not result in degradation or loss of function of the hatch cover to protect against a tornado generated missile impact. Specifically, additional engineering review performed by the licensee indicated that while the barrier structure could deform, it would be able to prevent any debris from entering into the refueling water storage tank ensuring the refueling water storage tank remained operable.

Cross-cutting Aspect: Unable to Identify. No cross cutting aspect was assigned to this finding because the inspectors were unable to identify a cross-cutting aspect that represents the cause or most-significant contributor as to why the performance deficiency exists using Inspection Manual Chapter 0310.

Enforcement:

Violation: Title 10 of the Code of Federal Regulations, Part 50, Appendix B, Criterion III, Design Control, requires, in part, that measures be established to assure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions.

Updated Final Safety Analysis Report Section 3.5.3, Barrier Design Procedures, describes the two types of structural response to missile impacts which have been investigated for the design-basis tornado-generated missiles discussed in Updated Final Safety Analysis Report Section 3.5.1.4. The two types of structural responses are the local effect and the overall response. In addition, Section 3.5.3 lists the types of barriers designed to resist missile impacts. For steel plate barriers, it states, The thickness of steel plate required to resist the impacting design-basis missile is calculated using the Stanford formula (Reference 8). The overall structural response, including structural stability and deformation is investigated using concepts and methods presented in Reference 9.

Contrary to the above, on September 25, 2017, when Calculation 8.1.16-BRW-17-0026-S, Revision 1, Refueling Water Storage Tank Roof Hatches Tornado Missile Protection Barriers, was approved, the licensee failed to assure that applicable regulatory requirements and the design basis were correctly translated into specifications, drawings, procedures, and instructions. Specifically, the safety-related refueling water storage tank hatch steel plate barriers were designed and installed for the specific purpose of providing protection against tornado generated missiles. However, Structural Calculation, 8.1.16-BRW-17-0026-S, developed to support hatch barrier installation failed to evaluate the overall structural response including structural stability and deformation of the barriers plates to the postulated missile impact as discussed in the Updated Final Safety Analysis Report Section 3.5.3.

Enforcement Action: This violation is being treated as an Non-Cited Violation, consistent with Section 2.3.2 of the Enforcement Policy.

Failure to Correctly Translate Design Bases Information for the Turbine Building High Energy Line Break Mitigation Strategy Cornerstone Significance Cross-cutting Report Aspect Section Mitigating Systems Green None 71111.21M NCV 05000457,05000456/2019010-02 Open/Closed The inspectors identified a Green finding and an associated Non-Cited Violation of Title 10 of the Code of Federal Regulations, Part 50, Appendix B, Criterion III, Design Control, when the licensee failed to correctly translate regulatory requirements and the design basis for the Turbine Building High Energy Line Break mitigation strategy.

Description:

In 2013, as part of major modifications work related to the Turbine Building High Energy Line Break mitigation strategy, the licensee issued Design Change Package Engineering Change 390487, Revision 0, Turbine Building High Energy Line Break Design and Licensing Basis. In this Design Change Package, the licensee discussed the new Turbine Building High Energy Line Break mitigation strategy. Included in the package were the associated Title 10 of the Code of Federal Regulations, Part 50.59, Changes, Tests, and Experiments, documentation and the Licensing Documentation Updates, i.e., the proposed changes to the Updated Final Safety Analysis Report.

The 50.59 Review Coversheet Form from the Design Change Package includes the following information under the Description of Activity section (50.59 Screening BRW-S-2013-081, Revision 0 and 50.59 Evaluation BRW-E-2013-078, Revision 0):

The proposed activity is a change in the thermal-hydraulic analysis of a HELB

[High Energy Line Break] in the Turbine Building and the resulting environmental affects in rooms containing safety-related equipment that have ventilation intake and or exhaust openings to the Turbine Building. The changes include the mitigation strategy for these rooms/areas that are currently credited to demonstrate these rooms/areas maintain suitable environmental conditions to safely shut down the plant following a HELB in the Turbine Building. Engineering Change EC-390487 describes the changes in design being credited and in the thermal-hydraulic analysis of the Turbine Building HELB and the resulting environmental profiles in the affected rooms/areas, and the justification that demonstrates the environmental conditions in these rooms/areas are suitable to safely shutdown the plant following the HELB. The EC [Engineering Change]

describes the changes to the UFSAR [Updated Final Safety Analysis Report] that will be made to incorporate the new thermal-hydraulic analysis as well as the analysis to reflect that safety-related equipment/components are protected from HELB induced jet effects. The affected ventilation systems are the Emergency Diesel Generator (EDG) Room Ventilation (VD) System, the Engineered Safeguards Features (ESF) Switchgear Room Ventilation (VX) System, the Miscellaneous Electric Equipment Rooms (MEER) Ventilation (VE) System.

The 50.59 description also provided a summary of the changes being implemented with regards to the mitigation strategy to protect against a High Energy Line Break in the Turbine Building.

From (previous strategy):

room cooling manually restored by operator action (room fans trip due to closure of the exhaust flowpath, with subsequent loss-of-HVAC [heating, ventilation, and air conditioning] resulting in room temperatures substantially exceeding design basis temperatures);

To (current strategy):

room cooling automatically restored (automatically restarting of the room ventilation fans following a time delay after tripping on high differential pressure, to minimize the temperature peak and to minimize time room temperatures are elevated; i.e., keep the rooms within their design basis temperature limits).

As discussed in the Design Change Package, the proposed Updated Final Safety Analysis Report changes (DRP# 14-084) removed all the references to operators taking manual actions to restore ventilation to the affected rooms following a Turbine Building High Energy Line Break and replaced them with descriptions of the automatic restarting of the cooling ventilation fans in the affected rooms. A review of the Updated Final Safety Analysis Report at the time of the inspection found no references to manual operator actions being taken and/or being credited to restore ventilation to the Emergency Diesel Generator, Engineered Safeguards Features Switchgear or Miscellaneous Electrical Equipment Rooms.

The review of the sites design and licensing bases identified the protection and mitigation from a High Energy Line Break in the Turbine Building are discussed in the Updated Final Safety Analysis Report. Applicable sections include, but are not limited to, Updated Final Safety Analysis Report Section 3.6.2, Determination of Break Locations and Dynamic Effects Associated with the Postulated Break of Piping; and Updated Final Safety Analysis Report Section 3.11, Environmental Design of Mechanical and Electrical Equipment. As discussed in these sections there are rooms in the Auxiliary Building which communicate with the Turbine Building through ventilation openings. These rooms include the Emergency Diesel Generator Rooms, the Engineered Safeguards Features Switchgear Rooms and Miscellaneous Electrical Equipment Rooms. The Updated Final Safety Analysis Report discusses these rooms must be protected from or shown to be able to withstand the effects of a High Energy Line Break in the Turbine Building (Updated Final Safety Analysis Report Section 3.11.10.3). There are two rooms of each type, per unit, for a total of 12 rooms on site.

The Updated Final Safety Analysis Report Table 3.11-2, Plant Environmental Conditions, provides the following information for the environmental zones of interest. For environmental zone A3 (Miscellaneous Electrical Equipment Rooms and Engineered Safeguards Features Rooms) the expected environmental conditions following all events were expected to remain normal (as annotated in Note 5) with a maximum bulk average temperature of 108 degrees Fahrenheit in each room. The referenced Note 5 establishes a postulated peak temperature of 132 degrees Fahrenheit for the Engineered Safeguards Features Switchgear Rooms and 114 degrees Fahrenheit for the Miscellaneous Electrical Equipment Rooms (under certain High Energy Line Break scenarios). These temperature excursions are described as very brief (on the order of minutes) and are too short to significantly affect equipment temperatures.

For Environmental Zone A6 (Emergency Diesel Generator Rooms) the expected environmental conditions following all events were expected to remain normal (as annotated in Note 6)with a maximum bulk average temperature of 132 degrees Fahrenheit in each room. The referenced Note 6 establishes a postulated peak temperature of 150 degrees Fahrenheit for the Emergency Diesel Generator Rooms (under certain High Energy Line Break scenarios).

These temperature excursions are described as very brief (on the order of minutes) and are too short to significantly affect equipment temperatures.

Each of these rooms is supplied by an independent, safety-related ventilation system. The safety design bases for each of these rooms are discussed in Updated Final Safety Analysis Report Section 9.4.5.2.1.1.a (Emergency Diesel Generator Rooms), Section 9.4.5.3.1.1 (Miscellaneous Electrical Equipment Rooms) and Section 9.4.5.4.1.1 (Engineered Safeguards Features Switchgear Rooms). For all three rooms the Updated Final Safety Analysis Report describes that in the event of a Turbine Building High Energy Line Break which causes the High Energy Line Break dampers to close and the room ventilation fans to trip, the High Energy Line Break dampers will automatically reopen when Turbine Building pressure decreases. After a short delay (approximately 60 seconds) the fans will automatically restart to restore room cooling. Ventilation in these rooms is required to maintain the safety-related equipment inside operable and capable to mitigate design bases events and accidents.

Prior to the change described in the Design Change Package, if a Turbine Building High Energy Line Break occurred these rooms would be isolated from the Turbine Building via closure of the fire dampers separating both spaces, resulting in room ventilation shutting off. Ventilation would have been restored via manual actions by an operator. The manual operator actions could take up to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to complete post-High Energy Line Break.

After the modifications described in the Design Change Package were implemented, new High Energy Line Break backdraft dampers were installed to separate the Turbine Building from the adjacent Auxiliary Building rooms. These High Energy Line Break dampers are spring loaded and can automatically close or open depending on the pressure differential between the Auxiliary Building rooms and the Turbine Building. These High Energy Line Break dampers are designed to close upon a minor pressure increase in the Turbine Building (about 0.25 inch Water Gauge pressure differential across the damper). This will result in increasing the outlet pressure of the operating fans causing them to trip at their high differential pressure setpoint.

This will result in a loss of cooling to these rooms. To counter the effect of the loss of cooling, the design change installed a 60 second timer which will restart the fans and restore room ventilation upon expiration. The restart logic assumed the Turbine Building pressure would have decreased sufficiently following a High Energy Line Break due to a Turbine Building relief panel blowing out allowing the backdraft dampers to re-open. However, the inspectors identified a subset of Turbine Building High Energy Line Breaks which would not cause the first Turbine Building relief panel to blow outward (setpoint of approximately 20.2 inches of Water Gauge) and reduce Turbine Building pressure within 60 seconds. As a result, the Emergency Diesel Generator, Engineered Safeguards Features Switchgear and Miscellaneous Electrical Equipment Room ventilation fans would experience a common cause failure due to restarting following the expiration of the 60 second timer and then immediately tripping again due to a high differential pressure condition. In such a case, restoring ventilation would require operator action. The inspectors determined the Emergency Diesel Generator Room ventilation fan(s) can be restarted from the main control room. However, ventilation to the Engineered Safeguards Features Switchgear Rooms and Miscellaneous Electrical Equipment Rooms would require operators to go into the plant to restart the equipment. For the Engineered Safeguards Features Switchgear Rooms and some of the Miscellaneous Electrical Equipment Rooms, operators would need to traverse the Turbine Building in order to reach the controls necessary to restart the fans.

The inspectors identified potential complications surrounding the need to enter the Turbine Building to perform the manual operator actions to restore the ventilation systems. Specifically, hydrazine totes are located near the Turbine Building entrance to the Emergency Diesel Generator Rooms and immediately below the entrance to the Engineered Safeguards Features Switchgear Rooms. During a High Energy Line Break, the hydrazine totes will be heated and may vent via the totes relief valves. If vented, the hydrazine, which is a volatile chemical, will be dispersed into the Turbine Building, thereby affecting the operators ability to reach the Engineered Safeguards Features Switchgear Rooms and some of the Miscellaneous Electrical Equipment Rooms (not all Miscellaneous Electrical Equipment Rooms require access to the Turbine Building to restore ventilation). Furthermore, some of the areas the operators would need to traverse and/or access could be experiencing high temperatures (e.g., 149 degrees Fahrenheit in the Engineered Safeguards Features Switchgear Rooms after 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> without ventilation) or high differential pressure across doors they would need to open. These complications had not been evaluated by the licensee and would result in additional delays before ventilation could be restored to the affected rooms. Via conversations with licensee personnel at the time of the inspection, the inspectors were informed there were active procedures to perform the manual actions needed to restore room ventilation. However, there were no active calculations or evaluations to determine how much time operators had to restore ventilation before room temperatures begin to affect the equipment inside; there were no evaluations to account for potential delays which might occur if there were a hydrazine toxic gas release, high temperature and/or pressure in the areas to be accessed or traversed; and there was no discussion of credited manual actions to mitigate a High Energy Line Break and restore ventilation for the affected rooms in the Updated Final Safety Analysis Report nor in active design bases calculation/evaluations. All discussions in the Updated Final Safety Analysis Report and active calculations/evaluations referenced the automatic restart of the fans. Preliminary analysis performed by the licensee showed temperatures in the Miscellaneous Electrical Equipment Rooms and in the Engineered Safeguards Features Switchgear Rooms could reach 145 degrees Fahrenheit and 149 degrees Fahrenheit (respectively) after losing room ventilation for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

In summary, the inspector were concerned certain Turbine Building High Energy Line Breaks would result in a common cause failure of multiple safety-related ventilation systems, including their redundant trains. If these failures occurred, actions to restore the equipment would be delayed beyond the time assumed in the Updated Final Safety Analysis Report and applicable calculations. This could result in safety-related equipment inside these rooms exceeding their operating design temperatures preventing them from performing their design bases safety functions.

Corrective Action(s):

1. Licensee entered the concern into the Corrective Action Program.

2. Licensee performed a preliminary analysis to demonstrate after 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> without room ventilation the temperature will rise and exceed the Updated Final Safety Analysis Report maximum temperatures. However, the temperatures would remain below the maximum temperatures evaluated for the equipment in the affected rooms.

3. Licensee performed preliminary time validations of the needed manual actions to

restore ventilation.

4. Licensee preliminarily evaluated the actions needed to mitigate and/or cope with a hydrazine toxic gas, high temperature and high differential pressure environment in the areas to be traversed and/or accessed. The licensee determined they would have reasonable assurance their operators would be able to complete the required actions.

Corrective Action Reference(s): Action Request 04217023

Performance Assessment:

Performance Deficiency: The licensee failed to translate into calculations and/or procedures, for certain Turbine Building High Energy Line Breaks, the automatic restart of the safety-related ventilation fans in the Emergency Diesel Generator Rooms, Miscellaneous Electrical Equipment Rooms and Engineered Safeguards Features Switchgear Rooms would not restore room cooling to ensure the equipment in those rooms remained capable of performing their design basis safety functions. Although the fans would restart after a timed delay, in certain High Energy Line Break scenarios, the fans would re-trip on high differential pressure, and there were no other automatic actions to restore cooling to the rooms. This was contrary to Title 10 of the Code of Federal Regulations, Part 50, Appendix B, Criterion III, Design Control, and was a performance deficiency.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Design Control attribute of the Mitigating Systems cornerstone. Specifically, the performance deficiency could result in a common-cause failure of multiple safety-related trains of ventilation. In addition, the available procedures to perform the manual actions failed to account for the potential delays due to:

(1) performing manual actions instead of an automatic recovery;

(2) account for the potential to have a hydrazine toxic gas environment in the Turbine Building; and

(3) account for the potential to have a high temperature or high pressure environment in the areas required to be traversed/accessed to complete the manual actions.

Significance: The inspectors assessed the significance of the finding using Appendix A, Significance Determination of Reactor Inspection Findings for At - Power Situations.

Specifically, the inspectors determined this finding was of very-low safety significance (Green)because even though the deficiency affected the design of mitigating systems the affected components were able to maintain their operability. The preliminary evaluations performed by the licensee concluded there was reasonable assurance the operators would have enough time to restore the ventilation systems before the affected rooms temperatures prevented the equipment inside from performing their safety functions.

Cross-cutting Aspect: Not Present Performance. No cross cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance. The Design Change Package for the modifications, which resulted in this performance deficiency, was completed in 2013.

Enforcement:

Violation: Title 10 of the Code of Federal Regulations, Part 50, Appendix B, Criterion III, Design Control, requires, in part, that measures be established to assure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions.

The Updated Final Safety Analysis Report Section 3.11.10.3, Turbine Building, describes the design bases for a High Energy Line Break in the Turbine Building and its associated High Energy Line Break mitigation strategy. For certain adjacent rooms in the Auxiliary Building (e.g., Miscellaneous Electrical Equipment Rooms, Engineered Safeguards Features Switchgear Rooms and Emergency Diesel Generator Rooms), the equipment in these rooms is described as:

(1) must be protected from or shown to be able to withstand the effects of High Energy Line Break in the Turbine Building;

(2) the High Energy Line Break mitigation strategy for the Auxiliary Building rooms involves the automatic restoration of room cooling by the installation of an auto-restart capability for the room ventilation fans; and

(3) due to the limited magnitude and short duration of the transient, the environmental parameters within these

[adjacent rooms] would not be significantly more severe than the environment that would occur during normal plant operation.

The Updated Final Safety Analysis Report Sections 9.4.5.2.1.1.a.1, 9.4.5.3.1.1.a, and 9.4.5.4.1.1.b describe the Safety Design Bases for the Emergency Diesel Generator Rooms, Miscellaneous Electrical Equipment Rooms and Engineered Safeguards Features Switchgear Rooms ventilation systems respectively. These sections describe how the ventilation systems will respond following a Turbine Building High Energy Line Breaks as follows:

(1) the High Energy Line Breaks dampers will close;

(2) the fans will trip on high differential pressure; and

(3) after a short delay the fans will automatically restart to restore room cooling.

Contrary to the above, on December 12, 2013, when Design Change Package Engineering Change 390487 was approved, the licensee failed to assure applicable regulatory requirements and the design basis were correctly translated into specifications, drawings, procedures, and instructions. Specifically, the licensee failed to translate into calculations and procedures that for certain Turbine Building High Energy Line Break scenarios, the automatic restart of the safety-related ventilation fans in the Emergency Diesel Generator Rooms, Miscellaneous Electrical Equipment Rooms, and Engineered Safeguards Features Switchgear Rooms (12 in total) would not restore room cooling to ensure that the equipment in those rooms remained capable of performing their design basis safety functions. Although the fans would restart after a timed delay, in certain High Energy Line Break scenarios, the fans would re-trip on high differential pressure, and there are no other automatic actions to restore cooling to the rooms.

Enforcement Action: This violation is being treated as an Non-Cited Violation, consistent with Section 2.3.2 of the Enforcement Policy.

Observation 71111.21M In accordance with IP 71111.21M, Section 02.05 c, the inspectors reviewed the previous effectiveness of corrective actions taken by the licensee to address issues identified during Component Design Basis Inspections and/or Design Basis Assurance Inspections. No Findings or Violations were identified. Item(s) reviewed are listed below:

1. Non-Cited Violation 05000456/2010007-06; 05000457/2010007-06, Emergency Diesel Generators Fuel Oil Consumption Calculation Failed to Account for Frequency Variations.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

• On April 10, 2019, the inspector presented the Design Basis Assurance (Team)

Inspection results to Mr. John Keenan and other members of the licensee staff.

LIST OF

DOCUMENTS REVIEWED

Procedures

BwAR 1VX01J-1-A7; Miscellaneous Electrical Equipment Room Exhaust Fan 1VE04C Auto

Restart Disabled; Revision 0

BwAR 1VX01J-1-B6; Miscellaneous Electrical Equipment Room Exhaust Fan 1VE04C Auto

Trip; Revision 10

BwAR 1VX01J-1-B7; Miscellaneous Electrical Equipment Room Exhaust Fan 1VE04C

Differential Pressure High; Revision 10

MA-MW-772-702; Calibration of Voltage Protection Relays; Revision 2

BwAR 1-21-C7; BUS 141 Overload Or Volt Low; Revision 16

BwAR 1VX01J-1-A6; Battery Room 111 Exhaust Fan 1VE03C Differential Pressure High;

Revision 12

0BWFSG-50; Flex Support Equipment Operation Unit 0; Revision 4

BWOP DG-13T1; Diesel Generator Troubleshooting Checklist; Revision 54

1BwOA ELEC-8; Loss Of All AC Power While On Shutdown Cooling Unit1; Revision 4

BwOP DG-13; Trouble-Shooting Diesel Generators; Revision 7

BWAR 1VX01J-1-A7; MISC Elect Equip Room Exhaust Fan 1VE04C Auto Restart Disabled;

Revision 0

BWAR 1VX01J-1-B3; ESF SWGR RM Vent Fan 1VX04C Auto Restart; Revision 000

BWAR 1VX01J-1-B6; Misc Elect Equip Room Exhaust Fan 1VE04C Auto Trip; Revision 10

BWAR 1VX01J-1-B7; Misc Elect Equip Room Exhaust Fan 1VE04C Diff Press High;

Revision 10

BWAR 1VX91J-1-A7; Misc Elect Equip Room Exhaust Fan 1VE04C Auto Restart Disabled;

Revision 0

BwOP PBI-1; Plant Barrier Impairment Program Pre-Evaluated Barrier Matrix; Revision 2

BwOP VE-2; Miscellaneous Electrical Equipment Room Division 1 Ventilation System

Shutdown; Revision 8

0BwOS OALE-Q1; Operating Abnormal Procedure Local Equipment Check Surveillance;

Revision 39

BwOP VE-1; Miscellaneous Electrical Equipment Room Division 1 Ventilation System Startup;

Revision 11

1BwEP ES-1.3; Transfer to Cold Leg Recirculation, Unit 1; Revision 300

1BwCA-0.1; Loss Of All AC Power Recovery Without SI Required Unit 1; Revision 301

1BwCA-0.3; Response To Opposite Unit Loss Of All AC Power Unit 1; Revision 300

BwOP DG-E1; Electrical Lineup-Unit 1 1a Diesel Generator; Revision 7

1BwOS DG-2A; 1A Diesel Generator Overspeed Trip Test; Revision 3

1BwOSR 5.5.8.SI-4, Safety Injection System Accumulator Check Valve Stroke Test; Revision 7

BwVSR 3.8.1.A; Diesel Generator Governor And Voltage Regulator Evaluation; Revision 1

1BwOSR 3.4.14.1; Reactor Coolant System Pressure Isolation Valve Leakage Surveillance;

Revision 9

1BwOL 3.5.4; LCOAR Refueling Water Storage Tank (RWST) Tech Spec LCO 3.5.4; Revision 6

1BwOSR 3.8.1.10-1; 1A Diesel Generator Full Load Rejection And Simulated SI In Conjunction

With UV During Load Testing; Revision 15

1BwOSR 3.8.1.11-1; 1A Diesel Generator Loss of ESF Bus Voltage With No SI Signal;

Revision 19

1BwOSR 3.8.1.19-1; 1A Diesel Generator ECCS Sequencer Surveillance; Revision 23

BWOP CV-E1; Electrical Lineup - Unit 1 Operating; Revision 11

BWOP VD-5; DG Room Ventilation System Operation; Revision 23

BWOP DG-M1; Operating Mechanical Lineup Unit 1 1ADF; Revision 017

BwOP DG-11T2; Diesel Generator Operating Log; Revision 31

BW DG-1; Diesel Generator Alignment to Standby Condition; Revision 30

BwOP DG-11; Diesel Generator Startup And Operation; Revision 50

BwOP DG 12; Diesel Generator Shutdown; Revision 30

1BwOA ELEC-4; Loss Of Offsite Power Unit1; Revision 106

1BwOA ELEC-3; Loss of 4KV Buses; Revision 102

1BwGP 100-1; Plant Heatup; Revision 35

1BwCA-0.0; Loss Of All AC Power Unit 1; Revision 302

BwVS 900-35; Diesel Generator Governor Set-Up Following Governor Replacement;

Revision 18

Corrective Action Documents Reviewed

AR 01629465; 1A DG Failed to Start - 1DG01KA; 03/05/2014

AR 01677343; HELB Dampers on 1A and 2A DG Went Close; 07/01/2014

AR 01694264; 2B D/G HELB Dampers Found Closed; 08/19/2014

AR 01695818; 1B Diesel Generator HELB Dampers Found Closed; 08/24/2014

AR 02479985; OSP-A Slow Response in 1AP10EC Tripping Open; 4/4/2015

AR 02497548; 1A DG Maintenance Run Manual Trip - 1DG01KA; 05/08/2015

AR 02497554; 1A Diesel Generator Trip - 1DG01KA; 05/08/2015

AR 02498312; Negative Level Trend in the Unit 1 RWST-1SI01T; 05/09/2015

AR 02499713; 1A, 1B and 2B DG Room HELB Dampers Found Closed; 05/12/2015

AR 02644573; CDBI - IST Design Basis Impact of EDG Operation; 03/23/2016

AR 03982772; Documentation of 2A EDG Exhaust Stack UT; 03/07/2017

AR 04126995; MCC FD Bkr 1AP 10EQ (131X-5B) did not Open FR External Button; 4/15/2018

AR 04126996; MCC FD Bkr 1AP10EG (131X-3B) did not Open Immediately; 4/15/2018

AR 04126999; MCC FD Bkr 1AP10EF (131X-3A) did not Open Immediately; 4/15/2018

AR 04202972; 1B Diesel Generator Low Output Voltage; 12/31/2018

AR04187501; 1VX04F Division 11 MEER Room Filter 1VX04F is Dirty

AR 00007732; Braidwood Actions associated with INPO SOER 98-02; 06/30/1999

AR 01058641; CDBI: EDG Fuel Calculation not Revised for Frequency Variation; 04/19/2010

AR 01565559; HELB Damper Closure During Division 21 Integrated Test; 09/30/2013

AR 01504332; PM Deferral SR 81403 For U1 HTR 1SI01T UT PM 43856-01; 04/19/2013

AR 02497936; 1A DG Tripped Unexpectedly During Surveillance - 1DG01KA; 05/08/2015

AR 02498087; 1A DG Tripped Unexpectedly During Surveillance - 1DG01KA; 05/09/2015

AR 02506852; Evaluation of Previous Leakby Past 1DO001C for Reportability; 10/22/2014

AR 02509594; 1A DG Tripped During Monthly Surveillance - 1DG01KA; 06/03/2015

AR 02519208; 2A DOST Tank Valve 2DO001A Leakage Impacts 2B EDG; 06/24/2015

AR 02673854; Non-Conforming Conditions Identified - Tornado Missiles; 05/25/2016

AR 02724958; Feed Bkr to MCC 134Z4 did not Immediately Open During Swap; 10/6/2016

AR 04004956; ESF Switchgear Room Division 11 Vent System Vent Filters Are Dirty;

05/01/2017

AR 04021601; B/D Diesel Oil Storage Tank Room Ladder Vibrating Excessively; 06/14/2017

AR 04128714; OSP-A Loss of ESF Buss 141 during 1A EDG Sequencer Testing; 04/19/2019

AR 04132395; Work Request to Adjust 1DG01KA Butterfly Valve Cable Length; 04/30/2018

AR 04173580; Low DP Alarm came in For 1VX02C and is Locked in; 09/16/2018

AR 04185704; ESF Switchgear Room Division 11 Vent System Vent Filter Has small Holes in it.

Corrective Action Documents Generated as a Result of Inspection

AR 04211152; UFSAR Editorial Error of Reference; 01/15/2019

AR 04215040; BWAR Setpoint Not Updated; 01/29/2019

AR 04217023; DBAI HELB Manual Actions; 02/04/2019

AR 04216345; DBAI: Unevaluated Condition MCC Feed Breaker; 02/01/2019

AR 04210753; DBAI - UFSAR Typo Error for Reference; 01/14/2019

AR 04211596; DBAI NRC Identified Dust Collecting on EDG Room Exhaust Screens;

01/16/2019

AR 04215030; DBAI 1VX04C Fan Differential Pressure Trip Calculation Discrepancy;

01/29/2019

AR 04215108; Incomplete Documentation for SQ of Process Controllers; 01/29/2019

AR 04216355; DBAI: Evaluate PM for Battery Replacement of MOORE Controllers; 02/01/2019

AR 04217133; DBAI - Global Effects of Missile Impact on RWST Hatch Cover; 02/04/2019

AR 04217475; DBAI: Weakness In Administrative Control Of Vendor Test Procedures;

2/05/2019

AR 04217491; DBAI: Unevaluated Compensatory Measures in BWOP PBI-1 Rev 2; 02/05/2019

Work Orders

WO 00595683; Contingency Package for Troubleshooting 1A Governor/EDG; 07/15/03

WO 00747554; ODEN Testing 1AP48E-A1 Breaker Out of Tolerance; 08/07/2015

WO 01106507; Perform 4KV Breaker Swap; 03/18/2010

WO 01175260; 1AP26E Oden Trip Test and MCCB Setting Changes; 03/26/2009

WO 01216758; 1VE04C-M Perform Dynamic Motor Baker Testing; 08/04/2009

WO 01292903; 1DG01EA Diesel Generator-Exciter Inspection (1A DG); 11/30/11

WO 01411998; Perform a Full PM on Breaker; 07/23/2013

WO 01453589; Install TCC 1VE04C Due to HELB Concerns; 07/13/2011

WO 01517240; Perform a Full PM on Breaker; 09/20/2013

WO 01545707; Install Time Delay Relays for U-1 (1VE04C VE Fan Div. 11; 08/27/2013

WO 01545714; Install Time Delay Relays for U-1 (1VX04C VX Fan Div. 11; 09/12/2013

WO 01661295; Perform a Full PM on Breaker; 01/03/2017

WO 01662416; Division 11/12 Integrated Mod Testing; 08/17/2013

WO 01678861; 1A Diesel Gen 24 Hour Load Test and ECCS SRV; 03/21/15

WO 01749920; Perform a Full PM on Breaker; 03/12/2018

WO 01821580-01; OP IST-AC-1SI8948A and 1SI8956 Stroke Test; 10/09/2016

WO 01897939; SI Signal Override of Test Mode; 04/03/18

WO 01923995; HELB Backdraft Damper Inspection; 05/31/2018

WO 04819982; 1A D/G Operability Monthly; 8/27/2018

WO 01064354; 18 Month Visual Inspection of Non-ETL SR Fire Dampers for VE/VX;

04/24/2009

WO 01520763; Breaker Swap Cubicle - Bus 141 Cubical 08, Feed to Aux. Feed PP 1A;

09/20/2013

WO 01538426; 1AP05EH PM SWGR Cubicle - BUS 141 Cubicle 08, Feed to Aux. Feed PP 1A;

09/20/2013

WO 01538743; Sequencing 1A AF Pump Caused Abnormal DG Voltage Response; 05/07/12

WO 01564088; Install HELB dampers and Hi Temp Thermal Links-1VE07Y; 03/05/2013

WO 01681667; 1A Diesel Gen Loss of ESF Bus VLTG with No SI Signal; 03/21/15

WO 01705529-01; Unit 1&2 Area NA Maintenance Rule INSP SI Storage Tanks (PMRQ 95011-

09); 11/14/2016

WO 01827469-01; OP Pressure Isolation Valve Leakage Surveillance; 10/24/2016

WO 01967027; Unit 1A Diesel Generator Hot Restart Test 18 Month; 11/22/17

WO 04592229-01; OP Pressure Isolation Valve Leakage Surveillance; 04/28/2018

WO 04774957; Loss of ESF Bus 141 During 1 A EDG Sequencer Testing; 4/20/2018

WO 04774957; Loss of ESF Bus 141 During 1A EDG Sequencer Testing; 04/23/18

WO 04836090; U1 ESF Onsite Power Distribution during Operation Division 11 Weekly

Surveillance; 10/04/18

WO 04837661-01; OP Borated Water Source Operability Weekly SRV; 10/09/2018

WO 700019984; Door-201 - Inspection & Maintenance; 10/27/2017

Calculations or Engineering Products

15-6-003; Specification for HELB Dampers and Fire Dampers with Security Barriers; Revision 4

19-AN-29; Second-Level Undervoltage Relay Setpoint; Revision 002C

19-AN-5; Diesel Generator Protective Relay Settings; Revision 3

19-T-6; Diesel Generator Loading During LOOP/LOCA - Braidwood Units 1 & 2; Revision 8

208438; Certification Report from BS&B Safety Systems L.L.C. for Rupture Disk; 02/24/2015

20E-1-4006B; 4160V ESF Switchgear Bus 142 (1AP06E); Revision L

20E-1-4007D; 480V ESF Substation Bus 132X (1AP12E); Revision P

20E-1-4008AA; 480V Auxiliary Building ESF MCC 132X4 (1AP28E) & MCC 132X4A

(1AP28EA); Revision AC

20E-1-4008AC; 480V Auxiliary Building ESF MCC 132X5 (1AP32E); Revision AF

20E-1-4008J; 480V Auxiliary Building ESF MCC 132X1 (1AP23E); Revision AJ

20E-1-4008L; 480V Auxiliary Building ESF MCC 132X2 and 132X2A (1AP27E & 1AP27EA);

Revision AP

20E-1-4008T; Tabulation of Trip Settings 480V Auxiliary Building ESF MCC 131X4 1AP26E;

Revision AB

20E-1-4008Y; 480V Auxiliary Building ESF MCC 132X3 (1AP24E); Revision AF

20E-1-4020B; Relaying and Metering Diagram Diesel Generator 1A-1DG01KA Generator

Control and Engine Governor Control System Part 2; Revision W

20E-1-4030AP30; 4160V ESF Switchgear Bus 141 Undervoltage Relays - PR9A-427-B141 and

PR9C-427-B141, PR29A-427-ST11 & PR29C-427-ST11; Revision V

25-023-DC1; Determine The Maximum Generator Voltage Magnitude On A Full Load Reject

Test When Operated At Rated And Unity Power Factor. Assess The Risk Of Damage To The

Diesel Generator Winding Insulation; Revision 9

Analysis No. 19-T-3; Station Blackout - Diesel Generator Loading; Revision 001C

ATD-0072; MEER Transient Temperature Following Turbine Building HELB; Revision 0

BRW-11-0101-M / BYR11-036; Turbine Building HELB and Room Heat Up Analyses for MUR

PU; Revision 0

BRW-12-0084-M; Aux Building Environment Following a High Energy Line Break in the Turbine

Building BYR12-070; Revision 2

BRW-13-0048-I; ESF Switchgear Room Fan 1(2)PDS-VX011 Setpoint Analysis; Revision 0

BRW-96-089-M, Verification of Braidwood 125 VDC Battery Room 111, 112, 211 and 212

Ventilation Requirements, Revision 3

BYR12-182 / BRW-12-0283-M; Effects of High Energy Line Break in the Turbine Building on

Fire Dampers in L Row Walls; Revision 0

Calculation 19-AN-29; Second Level Undervoltage Relay Setpoint; Revision 2 and 2A-C

Calculation 19-AN-3; Protective Relay Settings for 4.16kV ESF Switchgear; Revision 16 and

16A-H

Calculation 19-AQ-68; Division Specific Degraded Voltage Analysis; Revision 6 and 6A

Calculation EQC-BB-007; Diesel Generator Electrical Component Thermal Endurance; Revision

and 2A

Calculation No.07-035; Internal Flooding Analysis; Revision 0

Calculation No. 18.7.1.11.4; Tornado Missiles - Local Effects, FSAR; Revision 0

Calculation No. 18.7.1.11.8; Tornado Loads, FSAR; Revision 0

Calculation No. 7.16.20.1; Air Conditioner Temporary Supports; Revision 3

Calculation No. 8.1.16, Refueling Water Storage Tanks analysis and Design; Revision 5

Calculation No. 8.1.16-BRW-17-0026-S; RWST Roof Hatches Tornado Missile Protection

Barriers; Revision 1

Calculation No. BRW-03-0001-E; Review of the Seismic Test Report for Process Controllers;

Revision 2

Calculation No. BRW-07-00085-M; Determination of the Correlation for the critical

Submergence Height (Vortexing) for the RWST; Revision 0

Calculation No. CQD-043914; Minimum Flow Velocity for Swing Check Valves; Revision 0

Calculation No. SITH-1; RWST Level Setpoints; Revision 8

DBLHELB-57x58-1; Drawing 57x58 Double HELB Damper Wall Sleeve Assembly With 3HR

Fire Damper Sheet 1; Revision 7

DBLHELB-57x58-1; Drawing 57x58 Double HELB Damper Wall Sleeve Assembly With 3HR

Fire Damper Sheet 2; Revision 7

DBLHELB-57x58-1; Drawing 57x58 Double HELB Damper Wall Sleeve Assembly With 3HR

Fire Damper Sheet 3; Revision 7

DBLHELB-57x58-1; Drawing 57x58 Double HELB Damper Wall Sleeve Assembly With 3HR

Fire Damper Sheet 4; Revision 7

EC 25800; Equivalence of ESI Recommended Replacement of EDG SCR Relays; Revision 1

EC 364036; 1AP48E-A1 MCCB Replacement Set Point Change Required for WO 747544-01;

Revision 0

EC 381410; Time Dependent Loading and Fuel Consumption for EDGs following LOOP/LOCA;

Revision 0

EC 385208; Susceptibility of Safety Related Equipment and Components in the following

Locations to a Postulated High Energy Line Break; Revision 1

EC 388473 / 388944 / DRP 14-084; 50.59 Screening Install Time Delayed Auto Restart for VE

Fans in Support of HELB Mitigation Strategy; Revision 0

EC 388742; Install VE HELB Dampers for MEER Room Div. 11/12 to Support HELB Project;

Revision 3

EC 390487; Turbine Building High Energy Line Break Licensing and Design Basis; Revision 0

EC 392818/392819; Voltage Drop Calculation for 4160V Switchgear Breaker Control Circuits;

Revision 1

EC 393180; ESF Switchgear Room Fan DP Switch Setpoint Change; Revision 0

EC 394912; EC Evaluation of Integrated Testing of VD VE and VX Systems for ECs 388398

388397 and 388742; 10/18/2013

EC 396121; Engineering Review of 4" Cooper Expansion Joint for the Emergency Diesel

Generators; Revisions 0 and 1

EC 402059; Revise 4 Calculations Due to Discrepancies During HELB Project Reviews;

2/03/2015

EC 403447; Wiring Changes for SSPS Unit 1 Train B; Revision 0

EC 405576; Minor Revision for DOST Calculation BRW-96-362-I and DGD09301 to Identify

Margin Availability; Revision 0

EC 618920; Tornado Missile Protection for RWST Roof Hatches; Revisions 0 and 1

EC 624150; Review ATC Nuclear Report QTR16M2000-01-02, Revision 1; Revision 0

F2774/L-2774; Specification for Ventilation fans; 06/29/1987

F7118; Wave Analysis of the Byron and Braidwood KSV Diesel Engines; 08/26/1997

HELB-1VE07Y-1; Drawing 42x27 Double HELB and 3HR Fire Damper Wall Assembly Sheet 1;

Revision 4

HELB-1VE07Y-1; Drawing 42x27 Double HELB and 3HR Fire Damper Wall Assembly Sheet 2;

Revision 4

HELB-1VE07Y-1; Drawing 42x27 Double HELB and 3HR Fire Damper Wall Assembly Sheet 3;

Revision 4

HELB-1VE07Y-1; Drawing 42x27 Double HELB and 3HR Fire Damper Wall Assembly Sheet 4;

Revision 4

HELB-1VE07Y-1; Drawing 42x27 Double HELB and 3HR Fire Damper Wall Assembly Sheet 5;

Revision 4

L-VE-503; Calculation for Differential Static Pressure Across the Suction and Discharge Sensing

Ports; Revision 1A

L-VE-800; Heat capacity Ventilation for Division 11 and Division 12 Miscellaneous Electrical

Equipment Room; Revision 0

L-VX-500; Determining Static Pressure Differential Across the Suction and Discharge Sensing

Ports for Fans 1VX01C/2C/4C/3C; Revision 0

L-VX-803; Heat Capacity Verification for Essential Switchgear Room Ventilation System;

Revision 3

M-115; Drawing Diagram of Essential and Non Essential Switchgear and Miscellaneous

Electrical Equipment Rooms Ventilation Systems; Revision 8

M-1293; Drawing Switchgear Room Vent Floor Plan Elevation 451 feet; Revision 8D

N1803-DamperBladeDeflection; Damper Blade Deflection Analysis for Byron/Braidwood

HELB/Fire Dampers; Revision 1

NES-E/I&C 10.01; Molded Case Circuit Breaker Selection and Setting Design Standard;

Revision 2

NES-EIC-13-01; Sizing Low Voltage Three Phase Copper Cables in Tray and Conduit;

Revision 0

SM-VE125; Equipment Room Vent Fan 1VE04C DP Switch 1PDS-VE125; 09/24/2004

VA/VC/VE/VP/VQ/VX; Ventilation System Health Report; 06/18/2018

VX-205; Pressure Drop for Intake Shaft; Revision 0

Others

(a)(1) Action Plan 02516976; AP 480 V and Above, Revision 0

(a)(1) Action Plan 4144695; Emergency 4kV Power to ESF Buses; Revision 0

1/2VE04C; Joy Manufacturing Fan Curves; 08/13/1981

11-173; Task Report T0400Containment System Response; Revision 1

17601578/585; A.C. Machine Design (information related to generator design); 04/01/1977

1DG01KA-MECHGOV; Mechanical Governor Actuator Oil; 03/29/2017

1YF-882936; Letter from Reliance Electric, Name Plate Data and Test Characteristics for

1VE04C Fan Motor; 06/17/1981

4683-00; Slice Report for Cable 1VE032; 06/04/03

83-54S2; Operating Experience Report associated with INPO SOER 83-6; 12/10/1984

BRW-11135; Special Test of Rectifier Diodes; 09/10/2018

BwOA ELEC-3; Background Document; October 1993

Component Specification Sheet associated with Diode 1N3091 from International Rectifier; No

date or revision number provided

Condition Monitoring Plan CVD8S-1; Valves 1SI8948A/B/C/D and 2SI8948A/B/C/D; 05/18/2012

Current System Health Report associated with Auxiliary Power; 12/19/2018

Current System Health Report associated with Diesel Generators; 12/19/2018

DBD-T.08; Design Basis Document- Internal Flooding; Revision 5

Drawing No. 8372D14; Swing Check Valve; Revision 2

Drawing No. M-2061 Sheet 5; P&ID/ C&I Diagrams, Safety Injection System; Revision E

Drawing No. M-61 Sheet 18; Diagram of Safety Injection Unit 1; Revision BF

Drawing No. M-61 Sheet 5; Diagram of Safety Injection Unit 1; Revision AC

Drawing No. M-61 Sheet 6; Diagram of Safety Injection Unit 1; Revision AX

Drawing No. M-835 Sheet 3; Instrument Locations Elevation 379-6 Refueling Water Pipe

Tunnel; Revision K

Drawing No. S-1404; Refueling Water Storage Tank Section and Details; Revision W

EC 392851; Degraded Voltage 5 Minute Timer Resolution - Unit 1; Revision 4

IST Basis Document; Valve EPN 1SI8948A, Group 1/2SI8948A-D;

N1819/1820-OP-1; Operability Test Procedure for Byron and Braidwood Nuclear Power Plant

Class II Leakage HELB / Fire Damper Assemblies; Revision 1

N1819/1820-PTR-3; Performance Test Results for 1VE07Y 2VE07Y 1VE05Y 2VE05Y,

2/26/2013

PI&D 20E-1-4010; Key Diagram 125V DC ESF Distribution Center Bus 112; 9/23/76

Project 4391/4392/4683/4684-00; Environmental Qualification of Nuclear Standby

Engine/Generator Electrical Components; Revision 0

RS-13-227 Letter Exelon to NRC; Response to NRC HELB Audit Request for Information

Supporting Request for License Amendment Regarding Measurement Uncertainty Recapture

Power Uprate; 09/05/2013

SF38750; Nuclear Axivane Fan Operators Handbook; 08/26/1980

2