IR 05000259/2020010
| ML20174A300 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry |
| Issue date: | 06/19/2020 |
| From: | James Baptist NRC/RGN-II/DRS/EB1 |
| To: | Jim Barstow Tennessee Valley Authority |
| References | |
| IR 2020010 | |
| Download: ML20174A300 (11) | |
Text
June 19, 2020
SUBJECT:
BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 - TRIENNIAL INSPECTION OF EVALUATION OF CHANGES, TESTS AND EXPERIMENTS BASELINE INSPECTION REPORT 05000259/2020010 AND 05000260/2020010 AND 05000296/2020010
Dear Mr. Barstow:
On May 8, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Browns Ferry Nuclear Plant, Units 1, 2, and 3. On June 18, 2020, the NRC inspectors discussed the results of this inspection with Mr. Steven M. Bono and other members of your staff. The results of this inspection are documented in the enclosed report.
No findings or violations of more than minor significance were identified during this inspection.
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 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely,
/RA/
James B. Baptist, Chief Engineering Branch 1 Division of Reactor Safety
Docket Nos. 05000259 and 05000260 and 05000296 License Nos. DPR-33 and DPR-52 and DPR-68
Enclosure:
Distribution via LISTSERV
ML20174A300____________
SUNSI Review
Non-Sensitive Sensitive
Publicly Available Non-Publicly Available
OFFICE RII DRS RII DRS RII DRS R II DRS
NAME G. Ottenberg M. Riley T. Su J. Baptist
DATE 06/19/2020 06/19/2020 06/19/2020 06/20/2020
Enclosure
U.S. NUCLEAR REGULATORY COMMISSION
Inspection Report
Docket Numbers:
05000259, 05000260 and 05000296
License Numbers:
Report Numbers:
05000259/2020010, 05000260/2020010 and 05000296/2020010
Enterprise Identifier: I-2020-010-0040
Licensee:
Tennessee Valley Authority (TVA)
Facility:
Browns Ferry Nuclear Plant, Units 1, 2, and 3
Location:
Athens, AL 35611
Inspection Dates:
May 04, 2020 to May 08, 2020
Inspectors:
G. Ottenberg, Senior Reactor Inspector
M. Riley, Reactor Inspector
T. Su, Reactor Inspector
Approved By:
James B. Baptist, Chief
Engineering Branch 1
Division of Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a triennial inspection of evaluation of changes, tests and experiments baseline inspection at Browns Ferry Nuclear Plant, Units 1, 2, and 3, 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.
List of Findings and Violations
No findings or violations of more than minor significance were identified.
Additional Tracking Items
Type Issue Number Title Report Section Status URI 05000260/2020010-01 Water Hammer Analysis for Unit 2 HPCI Turbine Exhaust Piping 71111.17T Open
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
71111.17T - Evaluations of Changes, Tests, and Experiments Sample Selection (IP Section 02.01)
The inspectors reviewed the following evaluations, screenings, and/or applicability determinations for 10 CFR 50.59 from May 4, 2020, to May 8, 2020.
- (1) Evaluation DCN 70515, Replace Traveling Water Screens for Unit 1, 2, and 3, Rev.
C, Revision 4
Pathway Modification, Rev. 0, Revision 0
- (3) Evaluation DCN 71987, Replace Unit 1 HPCI Vacuum Breaker Valves, Rev. A, Revision 0
- (4) Evaluation DCN 71988, Replace Unit 2 HPCI Vacuum Breaker Valves, Rev. A, Revision 1
- (5) Evaluation DCN 71865, Replace U3 HPCI Vacuum Breaker Valves and Modify Existing Piping, Rev. B, Revision 2
- (6) Screen DEC 72833, MS Alternate Leakage Treatment Pathway Valve Vibration Tie-Back Support, Revision 3
- (7) Screen SCN 72378, Increase Relief Valve Setpoints to Limit Undesired Actuations, Revision A
- (8) Evaluation DCN 71212, Unit 2 Replace Existing Obsolete 50KV SOLA Type I&C Bus Voltage Regulators, Rev. A, Revision 0
- (9) Screen DCN 71802, Create ECP to Install SLC Pump Suction Accumulator, Revision A
- (10) Screen DCN 72238, Install Viscoelastic Dampers on Main Steam Lines, Revision A
- (11) Screen DCN 70510, Replace Unit 2 DIV I and II HDR Inverters with Suitable Replacements, Revision A
- (12) Screen DCN 70819, Isolation fuses for EDG Protective Relaying Circuits, Rev. A, Revision 0
- (13) Screen DCN 72675, Torque Switch TS-17 Will be Eliminated from the Valve Closing Circuit Logic, Revision 0
- (14) Screen BFN-18-216-01, BFN Unit 2 Steam Leak Detection Upgrade, Revision 0
- (17) Evaluation DCN 69532, Replace Unit 1/2 & Unit 3 Emergency Diesel Generator Governors, Rev. A, Revision. 3
- (18) Screen DCN 69626, Replace Obsolete SOR Pressure Switch in Various Systems, Rev. A, Revision. 0
- (19) Screen DCN 69710, Replace Obsolete MCR Recorder with Westronics Paperless Recorders, Rev. A, Revision 1
- (20) Screen DCN 71265, Reconfigure Valve Control to Prevent Spurious Operation, Rev.
A, Revision 1
- (21) Screen 2-AOI-47-3, Rev 22, Revised reactor power level from 30% to 26R RTP to support EPU, Revision
INSPECTION RESULTS
Unresolved Item (Open)
Water Hammer Analysis for Unit 2 HPCI Turbine Exhaust Piping URI 05000260/2020010-01 71111.17T
Description:
Engineering Change (EC) 71988 implemented a modification to the Unit 2 high pressure coolant injection (HPCI) turbine exhaust line and HPCI vacuum breaker subsystem to minimize backflow from the suppression pool to the HPCI exhaust line following a HPCI turbine trip. Updated final safety analyses (UFSAR) Section 6.4.1 states that the function of the vacuum breakers is to prevent intermittent negative pressure in the exhaust piping from pulling water out of the torus and causing a water hammer problem. The UFSAR also states that the HPCI system piping material is composed of carbon steel and is designed to USA Standard (USAS) B31.1.0-1967, Power Piping, which required in section 101.5, Dynamic Effects, that impact forces caused by all external and internal conditions (e.g., water hammer)be considered in the piping design.
The purpose of calculation MDQ0020732016000535, "Analysis of Browns Ferry Nuclear Unit 2 HPCI Turbine Exhaust Steam Line Transient Loads Following HPCI Turbine Exhaust System Plant Modifications," Revision 1, was to enable analysis of water hammer induced piping loads in the exhaust lines following the plant modifications to ensure the exhaust lines could handle the stresses upon restarting. Section 5.3 of the calculation determined HPCI could be restarted automatically and reach full speed as soon as 20 seconds following a HPCI turbine trip. This is due to a potential single failure of the HPCI turbine overspeed trip device. UFSAR Section 6.4.1 states that the HPCI system is automatically shutdown on turbine overspeed and is capable of automatically restarting if an injection signal is received and the shutdown signal no longer exists.
During the review of the EC package, the team identified that MPR Report 0048-0052-RPT-001, "Independent Technical Review on Browns Ferry Unit 2 HPCI Turbine Exhaust Piping Proposed Modification," Revision 1, stated that the calculation used a non-conservative assumption of 2% water volume in the exhaust piping as an input into the water hammer analysis and recommended that a transient analysis be performed to determine the actual amount of water in the exhaust line at the time of HPCI turbine restart. This transient analysis was documented in calculation 0048-0053-CALC-001, HPCI Turbine Exhaust Siphoning Transient, Revision 0, and determined that a water volume of up to approximately 43.8%
would exist in the exhaust piping at the time of restart. The team identified that this was a discrepancy from the 2% water volume used in calculation MDQ0020732016000535, which is used as an input into the piping stress analysis, CDQ0020732016000533, "Browns Ferry Nuclear Plant Summary of Piping Analysis N1-273-01R," Revision 4, that is used to conform to the requirements of USAS B31.1.0.
This unresolved item is being opened to determine if a violation of 10 CFR 50.59 exists. In order to make this determination, the team will need to determine whether the change would have resulted in exceeding code allowances or other applicable stress or deformation limits set in USAS B31.1.0 for the HPCI exhaust piping.
Planned Closure Actions: The licensee plans to provide an analysis detailing how the piping stresses resulting from the original 2% water volume in calculation MDQ0020732016000535 bounds the piping stresses resulting from the water volume used in Calculation 0048-0053-CALC-001, due to the differences in assumptions used in both calculations. The team will need to review the analysis to verify that the stresses caused by a HPCI restart on the turbine exhaust piping would not result in exceeding code allowances or other applicable stress limits set in USAS B31.1.0.
Licensee Actions: The licensee determined there was reasonable assurance that the HPCI system could perform its intended function until the analysis can be completed.
Corrective Action References: Condition Report
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On June 18, 2020, the inspectors presented the triennial inspection of evaluation of changes, tests and experiments baseline inspection results to Mr. Steven M. Bono and other members of the licensee staff.
- On May 8, 2020, the inspectors presented the Initial Inspection Results Debrief inspection results to Steven M. Bono and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
71111.17T Calculations
0048-0053-CALC-001
HPCI Turbine Exhaust Siphoning Transient
Rev. 0
CDQ0020732016000533 Browns Ferry Nuclear Plant Summary of Piping
Analysis N1-273-01R
Rev. 4
ED-Q-0254-880142
FUSE PROGRAM - 125Vdc Boards A, B, C, D, 3A, 3B,
3C, 3D
Rev. 7
ED-Q2000-870048
25Vdc System Short Circuit Calculations
Rev. 9
MDQ002073201600535
Analysis of Browns Ferry Nuclear Unit 2 HPCI Turbine
Exhaust Steam Line Transient Loads Following HPCI
Turbine Exhaust System Plant Modifications
Rev. 1
MDQ0068930029
MINIMUM PIPE WALL THICKNESS AND
CORROSION ALLOWANCE FOR REACTOR WATER
RECIRCULATION (RWR) SYSTEM
Rev. 5
MDQ2073910103
MOV 2-FCV-73-44 Operator Requirements and
Capabilities Calculation
Rev. 12
NDQ099920010019
Ex-Containment Removal Coefficients for Alternative
Source Term Analyses
Rev. 6
W81930916002
1/3-PS-71-1A, 1B, 1C and 1D Setpoint and Scaling
Calculation
Rev. 4
Corrective Action
Documents
CR 1341458, PER
200863, CR 1038747,
CR 1415269
Corrective Action
Documents
Resulting from
Inspection
CR 1606544
Detail in FSAR for ALT Leak Path
05/07/2020
CR 1606578
Evaluate BFN-18-216 50.59 Screening for NEI 01-01
05/07/2020
CR 1606604
During NRC 50.59 Inspection the need to review SCN
2738 screening criteria was identified.
05/07/2020
CR 1606616
Revise MDQ0020732016000535 to Clarify
Methodology
05/07/2020
CR 1606630
Revise 50.59 screen and Evaluation to incorporate
screen wash strainers
05/07/2020
CR 1606686
DCN 69710 Replace MCR Recorders. The Dry-well
effluent recorder was an analog to digital replacement
and the 50.59 was not screened in.
05/07/2020
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
CR 1606688
Revise the 10 CFR 50.59 Review for DCN 68532 to
incorporate a discussion of the failure mode for the
surge suppressor and capacitors
05/07/2020
Drawings
0-47W490-2
Mechanical Service Water, Air, Fire Protection
Rev. 8
0-47W491-7
Mechanical Service Water, Air, & Fire Protection
Rev. 14
0-47W491-9
Mechanical Service Water, Air, & Fire Protection
Rev. 3
1-47BD400-43
DC 72175, Sheets 1 and 2
Rev. 0
1-47E225-100
Harsh Environmental Data Drawing Series Index,
Notes and References
Rev. 8
1-47E225-110
Harsh Environment Data EL 565.0
Rev. 5
1-47E831-1
Flow Diagram Condenser Circulating Water
Rev. 41
1-47E850-1
Flow Diagram Fire Protection & Raw Service Water
Rev. 27
1-47E850-2
Flow Diagram Fire Protection & Raw Service Water
Rev. 31
2-45E714-1
Wiring Diagram 250 DC Reactor MOV BDS Schematic
Diagram
Rev. 16
2-45E714-4
Wiring Diagram 250V DC Reactor MOV BD 2B
Schematic Diagram
Rev. 36
2-47E610-73-1
Mechanical Control Diagram - HPCI System
Rev. 56
3-47E812-1
Flow Diagram High Pressure Coolant Injection System
Rev. 73
3-47E820-2
Flow Diagram Control Rod Drive Hydraulic System
Revs. 19
and 21
3-47E820-2-APPJ
Appendix J Testing Boundary for Control Rod Drive
Hydraulic System
Rev. 4
3-47E820-2-ISI
ASME Section XI Control Rod Drive Hydraulic System
Code Class Boundaries
Rev. 14
961111MA
Relief Valve Drawing
Rev. 0
Engineering
Changes
DCN 51607
Respan of Tech Spec Instruments for EPU
Rev. A
PIC 70629A
Revise Proposed Diesel Generator Governor Logic for
Emergency Fast Start
Rev. A
Engineering
Evaluations
BFN0EQ-IPS-003
Static-O-Ring Pressure Switches
Rev. 3
EWR18PROG064241
Review and Approval SOR Test Report 9058-102 Rev.
11/15/2018
Miscellaneous
Safety Evaluation of GE Topical Report NEDC- 31858P, Revision 2, "BWROG Report for Increasing
03/03/1999
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
MSIV Leakage Limits and Elimination of Leakage
Control Systems," September 1993
BROWN FERRY NUCLEAR PLANT, UNITS 2 AND 3 -
ISSUANCE OF AMENDMENTS REGARDING LIMITS
ON MAIN STEAM ISOLATION VALVE LEAKAGE
(TAC NOS. MA6405 AND MA6406)
03/14/2000
BROWNS FERRY NUCLEAR PLANT (BFN) -UNITS 1,
2, AND 3 -LICENSE AMENDMENT -ALTERNATIVE
SOURCE TERM
07/31/2002
Browns Ferry Nuclear Plant, Units 1, 2, and 3 -
Proposed Technical Specification Change To Revise
The Leakage Rate Through MSIVs - TS-485
11/22/2013
8001206-EMI-1
EMI/RFI Qualification Report for Engine Governor
Control System Upgrade
Rev. 0
EWR17PROJ073080
Rev. 2
MPR Report 0048-0052-
RPT-001
Independent Technical Review on Browns Ferry Unit 2
HPCI Turbine Exhaust Piping Proposed Modification
Rev. 1
SR-473
2-FCV-73-44 Weak Link Analysis
Rev. 2
SS-E18.15.01
Requirements for Digital Systems(Real-Time Data
Acquisition and Control Computer Systems)
Rev. 9
TVA-BFN-TS-405
BROWNS FERRY NUCLEAR PLANT (BFN) - UNITS
1, 2, AND 3-SUPPLEMENTAL INFORMATION
ASSOCIATED WITH RESPONSE TO
REQUEST FOR ADDITIONAL INFORMATION (RAI)
RELATED TO TECHNICAL SPECIFICATIONS (TS)
CHANGE NO. TS-405 - ALTERNATIVE SOURCE
- S. MB5733, MB5734, MB5735).
08/24/2004
TVA-BFN-TS-436
BROWNS FERRY NUCLEAR PLANT (BFN) UNIT 1 -
TECHNICAL SPECIFICATION (TS) 436 - INCREASED
(MSIV) LEAKAGE RATE LIMITS AND EXEMPTION
FROM 10 CFR 50, APPENDIX J
07/09/2004
US14525-EMIR/RFIR-
TVA Browns Ferry Unit 2 and 3 Digital Controls
Upgrade Electromagnetic and Radio Frequency
Rev. A
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Interference Report
Procedures
1-AOI-100-1
Reactor Scram
Rev. 24
1-OI-68
Reactor Recirculation System
Rev. 40
2-AOI-100-1
Reactor Scram
Rev. 113
2-OI-68
Reactor Recirculation System
Rev. 158
3-AOI-100-1
Reactor Scram
Rev. 71
3-OI-68
Reactor Recirculation System
Rev. 99
NPG-SPP-09.3
Plant Modifications and Engineering Change Control
Revs. 24,
2, and 33
NPG-SPP-09.3 IP-ENG-
001
Standard Design Process
Rev. 1
Work Orders
119872578, 113122016,
118008166, 118299683,
113122016, 114128873,
20136104, 118031889,
118035236, 119538467,
119873861, 118491608
PM 126676 Evaluation
Disassembly, inspection, cleaning and refurbishment of
actuator
PM126675 Evaluation
Disassembly, inspection, cleaning and refurbishment of
actuator