ML12349A151
| ML12349A151 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 12/12/2012 |
| From: | Omaha Public Power District |
| To: | Lynnea Wilkins Plant Licensing Branch IV |
| Wilkins L | |
| References | |
| TAC MF0307 | |
| Download: ML12349A151 (58) | |
Text
Fort Calhoun Station Fort Calhoun Station Containment Internal Structures (CIS)
Introductions
Introductions
Station (FCS)
Bruce Rash
- Recovery Director Terry Simpkin
- Manager, Site Regulatory Assurance Brian Davis - Recovery Engineering Director Bernie Van Sant - CIS Project Engineering Lead Bernie Van Sant - CIS Project Engineering Lead Tom Dailey - CIS Project Manager Russ Placke - Design Engineer 2
Introductions - Contd
Introductions
Cont d
- Stevenson and Associates (S&A)
D T i i
T
- Dr. Tsiming Tseng
- Mike Allison
- Doug Seymour
- Automated Engineering Services Corp. (AES)
- Eric Halverson Andrew Carmean
- Andrew Carmean
- Sargent & Lundy (S&L)
- P. K. Agrawal
- MPR Associates, Inc. (MPR)
- Caroline Schlaseman 3
Agenda Agenda Opening Remarks D
i d O t Desired Outcomes History and Identification of Containment Internal Structures (CIS) Issue Structures (CIS) Issue Discovery Process and Extent of Condition Modeling Methodology, Inputs and Assumptions Licensing Basis and Operability Criteria Planned Actions for Restart Support for NRC Inspection Activities Post-Restart Actions Closing Remarks Closing Remarks 4
Opening Remarks Opening Remarks
- Containment pressure boundary is unaffected by this issue
- Current calculations show containment internal
- Current calculations show containment internal structures (CIS) nonconforming but operable for outage conditions g
- Continue to evaluate the online case
- OPPD is determined to establish licensing basis g
safety margins for CIS
- OPPD dedicated to support NRC inspection of CIS operability for restart 5
D i
d O t Desired Outcomes NRC understanding and feedback on OPPD CIS
- NRC understanding and feedback on OPPD CIS operability criteria
- NRC understands OPPDs path forward on
- NRC understands OPPD s path forward on resolution of CIS issue
- NRC inspection team is provided with solid NRC inspection team is provided with solid foundation on CIS problem identification, scoping and resolution to support inspection planning 6
History and Identification of CIS History and Identification of CIS Issue Bernie Van Sant CIS Project Engineering Lead CIS Project Engineering Lead 7
History and Identification of CIS History and Identification of CIS Issue
- Issue involves the concrete containment internal structure (CIS)
- CIS involves:
- CIS involves:
- Support for plant components and systems inside containment
- CIS does not involve:
- Containment pressure boundary
- Steam Generator compartments or reactor cavity 8
Elevation 1013 9
History and Identification of CIS History and Identification of CIS Issue
- Original Analyses of the CIS P
f d h d
l l
i i
d i h
- Performed hand calculations in accordance with American Concrete Institute (ACI) 318-63 during the 1960s using the load combinations identified in Updated Safety Analysis Report (USAR) Section 5 11 Updated Safety Analysis Report (USAR) Section 5.11
- Atomic Energy Commission (AEC) review confirmed design was adequate prior to issuance of operating g
q p
p g
license
- No significant design changes to CIS 10
History and Identification of CIS History and Identification of CIS Issue
- Discrepancy discovered during an extended power uprate analysis for containment cooling water system pipe supports
- Loads on one beam at the 1060 elevation exceeded design capacity design capacity
- Extent of condition investigation initiated 11
Discovery Process and Extent of Discovery Process and Extent of Condition
- Issues identified with original CIS calculations
- Incorrect, incomplete or missing calculations
- Inconsistencies between calculations and drawings
- Incomplete consideration of all load combinations Incomplete consideration of all load combinations
- Simple numerical errors 12
Discovery Process and Extent of Discovery Process and Extent of Condition
- Extent of condition evaluation done for 2 beams:
B-59 and B-103 B 59 and B 103
- B-59 did not meet working stress design (WSD) acceptance criteria
- Companion beam (B-58) also evaluated - did not meet WSD acceptance criteria 13
Discovery Process and Extent of Discovery Process and Extent of Condition
- Extent of condition assessment expanded to sampling of CIS on all three elevations g
- 9 more beams and 1 column selected
- Assessment stopped after 6 beams - all beams did not meet acceptance criteria
- Given results, decision was made to completely reanalyze the CIS reanalyze the CIS 14
Modeling Methodology Inputs and Modeling Methodology, Inputs and Assumptions Russ Placke Design Engineer 15
Modeling Methodology Inputs and Modeling Methodology, Inputs and Assumptions
- Built 3-dimensional model of CIS
- GTSTRUDL TM Version 29.1 selected for analysis
- GOTHIC TM Version 8.0 selected for analysis of differential pressure (dP) across CIS floors p
(
)
16
M d li M th d l I
t d
Modeling Methodology, Inputs and Assumptions
- Performed rigorous analysis
- Design for dead loads live loads seismic loads
- Design for dead loads, live loads, seismic loads, and pipe break pressure loads
- Confirmed as-built configuration through t
i lkd extensive walkdowns
- Validated assumptions and input parameters
- Conducted challenge boards and independent
- Conducted challenge boards and independent third party reviews
- Analysis rigorously documented 17
M d li M th d l I
t d
Modeling Methodology, Inputs and Assumptions CIS Model Description Doug Seymour (S&A) 18
Modeling Methodology Inputs and Modeling Methodology, Inputs and Assumptions CIS Design Model Description
- Finite element frame analysis
- Loads evaluated include dead loads, live loads, seismic loads and pipe break pressure loads seismic loads, and pipe break pressure loads
- Differential pressure load increased by dynamic load factor (DLF)
USAR seismic response spectrum utilized
- USAR seismic response spectrum utilized 19
Modeling Methodology Inputs and Modeling Methodology, Inputs and Assumptions CIS Design Model Different from Licensing Basis CIS Design Model Different from Licensing Basis
- Modal analysis performed Includes flexibility of beams and columns
- Includes flexibility of beams and columns
- Modal and directional responses combined in accordance with NRC Regulatory Guide 1.92
- Licensing Basis does not require modal analysis
- CIS taken to be vertically rigid above basemat
- Constant non-varying vertical acceleration provided Constant, non varying vertical acceleration provided
- Design model more conservative than licensing basis 20
Reanalysis Elements Flowchart of foundational S&A reports FC08157 S&A Report 12Q4070-RPT-002 FC08156 S&A Report 12Q4070-RPT-001 p
Q Walkdown Report FC08159 S&A Report 12Q4070-RPT-004 FC08158 S&A Report 12Q4070-RPT-003 FC08163 S&A Report 12Q4070-RPT-008 p
Q Design Basis Review S&
epo t Q 070 00 Discrete Loads Report S&
epo t Q 070 003 Structural Starting Point S&
epo t Q 070 008 Distributed Loads Report FC08164 S&A Criteria 12Q4070 RPT 009 S&A Criteria 12Q4070-RPT-009 hi d i
f d
h l Third party reviews were performed on each element.
21
GTSTRUDL TM Model of CIS GTSTRUDL Model of CIS 22
Modeling Methodology Inputs and Modeling Methodology, Inputs and Assumptions GOTHIC Model Description Andrew Carmean (AES) 23
Modeling Methodology Inputs and Modeling Methodology, Inputs and Assumptions
- Analysis to more accurately calculate dPs GOTHIC Model Description Analysis to more accurately calculate dPs across CIS floors for input to GTSTRUDL TM
- NUREG-0800 was used as guidance, specifically Section 6.2.1.2.II
- Conservative Assumptions
- No credit for heat sinks (increases dP)
No credit for heat sinks (increases dP)
- Conservative initial conditions were assumed
- Subdivided containment into 10 separate volumes V l d fl th b d
l t d i
- Volumes and flow paths based on plant drawings 24
GOTHIC Model Volumes Vol. 1 - Upper Containment Vol. 2 - SG RC-2A Vol. 3 - RC-2B (994'-1009')
Vol. 4 - Cont. Outer Annulus (1013')
Vol. 5 - Cont. Outer Annulus (994')
Vol. 6 - Pressurizer Room l
h k
Vol. 7 - Quench Tank Room Basement Vol. 8 - RC-2B (1009'-1028')
Vol. 9 - RC-2B (1028'-1046')
Vol 10 - RC-2B (1046'-1056')
Vol. 10 RC 2B (1046 1056 )
25
M d li M th d l I
t d
Modeling Methodology, Inputs and Assumptions CIS Design Model Preliminary Results Russ Placke Russ Placke Design Engineer 26
Modeling Methodology Inputs and Modeling Methodology, Inputs and Assumptions CIS Design Model Preliminary Results
- Model utilized modal analysis which is more
- Model utilized modal analysis, which is more conservative than licensing basis
- Of 135 beams, 47 beams did not meet acceptance criteria for working stress and/or ultimate strength criteria for working stress and/or ultimate strength
- Of 14 columns, 5 columns did not meet acceptance criteria for working stress and/or ultimate strength
- Design issues principally in beams that support the
- Design issues principally in beams that support the safety injection tanks, ventilation coolers or reactor vessel head laydown areas
- All beams and columns are currently operable
- All beams and columns are currently operable 27
Licensing Bases and Operability Licensing Bases and Operability Criteria
- Based on the design model results, an initial operability evaluation analysis has been performed
- Modeling methodology for the operability evaluation is different from the design model
- Comparison of licensing and operability evaluation criteria is discussed in subsequent slides
- Continuing to refine operability evaluation analysis to ensure adequate conservatism and margin ensure adequate conservatism and margin 28
Licensing Bases and Operability Licensing Bases and Operability Criteria CIS D i
P
- CIS Design Purpose
- Licensing Basis
- Functional integrity with licensing basis design margins under
- Functional integrity with licensing basis design margins under the most extreme environmental loadings
- Operability Criteria
- Structure functions to support equipment and system operability and safe shutdown functions
- Primary Code y
- Licensing Basis and Operability Criteria
- ACI 318-63 29
i i
B d O bili Licensing Bases and Operability Criteria
- Loads considered Li i
B i
d O bilit C it i
- Licensing Basis and Operability Criteria
- Dead loads (D)
- Live loads (L)
( )
- Accident pressure loads (Pc)
- Design earthquake loads (E)
- Maximum hypothetical earthquake loads (E)
- Maximum hypothetical earthquake loads (E )
30
Licensing Bases and Operability Criteria
- Load Combinations
- Licensing Basis
- Working Stress D L d D L E D+L and D+L+E
- No Loss of Function D+E D+L+E D+/-0.05D+1.5Pc D+/-0.05D+1.25Pc+1.25E D+/-0.05D+Pc+E
- Operability Criteria
- Same as Licensing Basis for No Loss of Function Same as Licensing Basis for No Loss of Function 31
Licensing Bases and Operability Criteria Licensing Bases and Operability Criteria Doug Seymour (S&A) 32
Licensing Bases and Operability Criteria Licensing Bases and Operability Criteria
- Ductility Ductility
- Ductility not permitted (licensing basis)
- Ductility not used (operability criteria)
- Material Properties
- Concrete strength for CIS not specified in licensing basis (design basis for CIS is 4 ksi) basis for CIS is 4 ksi)
- Concrete 28-day strength test data rolling average (operability criteria for CIS is 5.5 ksi)
S i i M d li
- Seismic Modeling
- The CIS is considered vertically rigid per the USAR, Appendix F, Revision 8, Section 2.5 (licensing basis and operability criteria) 33
Licensing Bases and Operability Licensing Bases and Operability Criteria Moment Redistrib tion
- Moment Redistribution
Licensing Basis and Operability Criteria
- Per ACI 318-63, Section 1502(d)
( )
- Damping for Concrete Structures
Licensing Basis and Operability Criteria
- 2% for design earthquake (E)
- 5% for maximum hypothetical earthquake (E)
- Success Criteria
- Success Criteria
Licensing Basis and Operability Criteria
- Interaction Ratio = demand/capacity
- Less than or equal to 1.0 34
Summary of Licensing Bases and Summary of Licensing Bases and Operability Criteria Differences Differences Between Licensing Basis and Operability Criteria Item Licensing Basis Operability Criteria Purpose Functional integrity with licensing basis design margins under the most extreme Structure functions to support equipment and system operability and u de t e ost e t e e
environmental loadings syste ope ab ty a d safe shutdown functions Load Combinations Working stress design and no loss of function No loss of function CIS Concrete Strength CIS concrete strength not specified in licensing basis (design basis for CIS is 4 ksi) 5.5 ksi 35
Licensing Bases and Operability Licensing Bases and Operability Criteria
- Conservatisms in Operability Criteria
- Increase in concrete strength from age hardening is g
g g
conservatively neglected
- Ductility and increased damping for the dynamic pressure loading is conservatively neglected p
g y
g
- Higher permissible moment redistribution, which later concrete codes permit, is conservatively neglected
- Stair live loads used are conservatively high Stair live loads used are conservatively high
- Damping and ductility for lateral seismic loads on laterally-unrestrained beams are conservatively neglected g
36
Operability Assessment Preliminary Results
- Outage Case
- All structural members in CIS are operable - meet no l
f f ti l
d t
it i
loss of function load case acceptance criteria
- Normal Operation Case
- Normal Operation Case
- 3 beams exceed 1.0 interaction ratio
- Continuing to refine analyses, assumptions, and inputs 37
Pl d A ti f
R t
t Planned Actions for Restart Brian Davis Recovery Engineering Director 38
Pl d A ti f
R t
t Planned Actions for Restart
- Issue final calculations December 20 2012 Issue final calculations December 20, 2012
- Third party review of calculations December 28, 2012
- Address third party review comments January 4, 2013 V
if t
l ti J
8 2013
- Verify comment resolution January 8, 2013
- Owner acceptance review January 11, 2013
- Issue operability evaluation January 11, 2013
- NRC inspection of operability evaluation during January 2013
- Continue engineering and construction planning activities 39
Support for NRC Inspection Activities Pro ide a ailabilit of calc lations and
- Provide availability of calculations and operability evaluation
- Support technical teleconferences as needed
- Support technical teleconferences as needed
- FCS site familiarization and CIS walkdowns Proposed Week of January 7 2013
- Proposed - Week of January 7, 2013
- Modeling reviews in Boston, MA Proposed Week of January 14 2013
- Proposed - Week of January 14, 2013
- FCS onsite inspection or additional visits to Boston MA as needed Boston, MA as needed 40
Post Restart Actions
- Optimize modification designs
- Complete engineering change packages for modifications
- Install modifications during future outages 41
Design Options Tom Dailey CIS Project Manager 42
Design Options Design Options
- Structural Steel
- Easiest to design and install g
- Discounted due to thermal expansion-induced loads on columns
- Precast Concrete
- Caused excessive interferences along haul path
- Required large footprint to up-end column sections
- Excessive weight has inherent handling & rigging risks g
g gg g
- Cast-in-place Concrete (current preferred option)
- Fewer interferences compared to structural steel and precast concrete option
- Formwork can be transported manually
- Proven methodology, less labor and shortest duration 43
Modification General Areas 44
Mod-1 General Arrangement 45
Mod-1 General Arrangement 46
Mod-1 General Arrangement El 1060 47 El. 1060
Mod-2 General Arrangement 48
Mod-2 General Arrangement 49
I t ll ti Ch ll Installation Challenges
- Numerous interferences
- Numerous interferences
- 4 kV reactor coolant pump motor cable/conduit
- Large ventilation ductwork
- Conduit banks
- Component Cooling Water piping
- Pipe supports p
pp
- Miscellaneous steel platforms, stairs, etc.
- Containment configuration not conducive to material handling material handling
- Concrete must be pumped long distances 50
Typical Interferences 51
Typical Interferences 52
Typical Interferences 53
Modification Analysis Bernie Van Sant Bernie Van Sant CIS Project Engineering Lead 54
Modification Analysis
- Analyses required to complete CIS engineering Analyses required to complete CIS engineering change packages
- Finalize structural analysis of CIS
- Optimize design of new columns and beams
- Design relocation of interferences
- Seismic and hydraulic analysis of piping rerouting Seismic and hydraulic analysis of piping rerouting
- Seismic and cable analysis for conduit rerouting
- Seismic and air flow analysis of ductwork rerouting
- Structural analysis of new commodity supports Structural analysis of new commodity supports 55
Other Design Considerations I
h l
ill h b
- Impact on other analyses will have to be addressed
- Containment pressure analysis
- High energy line break analysis for columns and relocated equipment q p
- Containment sump analysis
- Other analyses, as required 56
Closing Remarks Bruce Rash Recovery Director 57
Closing Remarks Closing Remarks
- Containment pressure boundary is unaffected by this issue
- Current calculations show CIS nonconforming but
- Current calculations show CIS nonconforming but operable for outage conditions
- Continue to evaluate the online case Continue to evaluate the online case
- OPPD is determined to establish licensing basis safety margins for CIS y
g
- OPPD dedicated to support NRC inspection of CIS operability for restart 58