GTSTRUDL User’s Group Dynamic Analysis of Service Water Pump for Seismic Restraint June 24, 2011 Parimal Gandhi, PE Sr. Engineer 1 Annual Meeting
PURPOSE 2 Dynamic Analysis of Service Water Pump to Evaluate Seismic Loads on the Restraint. AND NRC Reg. Guide 1.92 & NRC Gupta Method for Missing Mass Impact on Seismic Loads.
AGENDA 3 Background of Plant Service Water System, Pump, and Seismic Restraint. Failure of Seismic Restraint. Dynamic Analysis of SW Pump With and Without Seismic Restraint. Impact of NRC Reg.Guide 1.92, Rev. 2 on SW Pump Dynamic Analysis. Conclusion.
BACKGROUND PLANT SERVICE WATER SYSTEM 4 The Service Water Pond covers approximately 94 surface acres, and is required to provide adequate cooling for 30 days following an accident.
BACKGROUND PLANT SERVICE WATER SYSYEM 5 The Plant Service Water System is designed to: Withstand the design basis earthquake (DBE) without impairing its function. Have sufficient capacity and redundancy to provide reliable cooling. Be operable during loss-of-offsite power
BACKGROUND SW PUMP 6 The SW pumps' capable to withstand a design basis earthquake (DBE) without a loss of function. If the seismic restraints are degraded to the point that their design function can-not be met, then the associated SW pumps may not be able to withstand a DBE.
7 BACKGROUND SW PUMP PUMP MOTOR COLUMN ASSEMBLY BOWL ASSEMBLY DISCHARGE HEAD ASSEMBLY PUMP BASE PLATE SEISMIC RESTRAINT
BACKGROUND SEISMIC RESTRAINT 8
FAILURE SEISMIC RESTRAINT 9
10 CORROSION MAINTANCE LOAD (VERTICAL) ZERO GAP FOR LATERAL RESTRAINT FAILURE SEISMIC RESTRAINT
EXAMPLE: STRUDL Math Model For Pump With Seismic Restraint FLOOR PUMP BASEPLATE 17- UPPER SEISMIC RESTRAINT 12 - LOWER SEISMIC RESTRAINT
DYNAMIC ANALYSIS 12
13 DYNAMIC ANALYSIS
14 EIGENPROBLEM SOLUTION
15 DYNAMIC MASS PARTICIPATION FACTORS
16 RESPONSE SPECTRA CURVE EAST-WEST RESPONSE SPECTRA CURVE EAST-WEST
17 STORING RESPONSE SPECTRA EAST-WEST STORING RESPONSE SPECTRA EAST-WEST
18 RESPONSE SPECTRA CURVE VERTICAL RESPONSE SPECTRA CURVE VERTICAL
19 STORING RESPONSE SPECTRA VERTICAL STORING RESPONSE SPECTRA VERTICAL
20 RESPONSE SPECTRA CURVE NORTH-SOUTH RESPONSE SPECTRA CURVE NORTH-SOUTH
21 STORING RESPONSE SPECTRA NORTH-SOUTH STORING RESPONSE SPECTRA NORTH-SOUTH
22 RESPOSNSE SPECTRUM LOADING
23 NRC REG. GUIDE 1.92 Rev.1 LOADING Reg.Guide Rev.1: TOTAL = [(LOAD1-Z) 2 + (LOAD2-X) 2 +(LOAD3-Y) 2 ] 1/2
24 SUPPORT REACTIONS & DISPLACEMENT WITH SEISMIC RESTRAINT SUPPORT REACTIONS & DISPLACEMENT WITH SEISMIC RESTRAINT Reg.Guide Rev.1: TOTAL = [(LOAD1-Z) 2 + (LOAD2-X) 2 +(LOAD3-Y) 2 ] 1/2 UNITS: FORCE LBS, MOMENT IN-LBS UNITS: DISPACEMENT INCH, ROTATION RAD
STRUDL MATH MODEL FOR PUMP WITHOUT SEISMIC RESTRAINT FLOOR PUMP BASEPLATE
26 SUPPORT REACTIONS & DISPLACEMENT WITHOUT SEISMIC RESTRAINT SUPPORT REACTIONS & DISPLACEMENT WITHOUT SEISMIC RESTRAINT Reg.Guide Rev.1: TOTAL = [(‘LOAD1-Z’) 2 + (‘LOAD2-X’) 2 +(‘LOAD3-Y’) 2 ] 1/2 UNITS: FORCE LBS, MOMENT IN-LBS UNITS: DISPACEMENT INCH, ROTATION RAD
27 PUMP STRESSES & DISPLACEMENT Check Pump Base Plate Stresses Forces At Pump Base Plate Due to Seismic Condition With Seismic Restraint Without Seismic Restraint Remarks Fx (kips) Fy (kips)2.05 Fz (kips) Mx (in-kips) My (in-kips)00 Mz (in-kips) Bolt Tensile Stress with Nozzle & Seismic Loads 10.0 ksi20.2 ksiAllowable 19.2 ksi for 1 ¼” Bolts A-307 Check Pump Displacement Displacement At Lower end of Pump Due to Seismic Condition With Seismic Restraint Without Seismic Restraint Remarks Δ x ( inch) Δ y ( inch)0.0 Δ z ( inch) `
28 NRC Reg Guide 1.92, Rev 1 Missing Mass Positions NRC Reg Guide 1.92, Rev 1 Missing Mass Positions All modes are assumed to be out-of-phase with the ground acceleration and out-of-phase with each other All modes having frequencies ≤ “significant” frequency If frequencies are not closely spaced: SRSS Mode Combination Method
29 Frequency Low Frequency Out-of-Phase Response Mid Frequency Transition from Out-of-Phase to In-Phase Response High Frequency In-Phase Rigid Static Response F 1 =frequency at which peak spectral acceleration is observed F 2 = frequency above which the SDOF (modal) oscillators are in-phase with the transient acceleration input used to generate the spectrum and in phase with each other F ZPA =frequency at which the spectral acceleration returns to the zero period acceleration; maximum base acceleration of transient acceleration input used to generate the spectrum NRC GUPTA METHOD Missing Mass Positions NRC Reg Guide 1.92, Rev 2 NRC GUPTA METHOD Missing Mass Positions NRC Reg Guide 1.92, Rev 2
30 ● For each mode i, in each ground motion direction k, the response is separated into a periodic part and a rigid part: ● The periodic modal response portions are combined using a double sum rule: NRC GUPTA METHOD Missing Mass Positions NRC Reg Guide 1.92, Rev 2 NRC GUPTA METHOD Missing Mass Positions NRC Reg Guide 1.92, Rev 2
31 ● The rigid modal responses are combined algebraically, including the residual rigid contribution from the missing mass: ● The total response in each ground motion direction is computed from the SRSS of the modal combinations of the periodic and rigid responses: NRC GUPTA METHOD Missing Mass Positions NRC Reg Guide 1.92, Rev 2 NRC GUPTA METHOD Missing Mass Positions NRC Reg Guide 1.92, Rev 2
32 NRC Reg.Guide Rev.2: TOTAL+MM = [(‘LOAD1-Z’+’Z-MAS’) 2 + (‘LOAD2-X’+’X-MAS’) 2 +(‘LOAD3-Y’+ ‘Y-MASS’) 2 ] 1/2 Missing Mass NRC Reg Guide 1.92, Rev 2 Missing Mass NRC Reg Guide 1.92, Rev 2
33 NRC Gupta Method Reg Guide 1.92, Rev 2 NRC Gupta Method Reg Guide 1.92, Rev 2
34 NRC Gupta Method Reg Guide 1.92, Rev 2 NRC Gupta Method Reg Guide 1.92, Rev 2
35 NRC Gupta Method Reg Guide 1.92, Rev 2 NRC Gupta Method Reg Guide 1.92, Rev 2
36 NRC Gupta Method Reg Guide 1.92, Rev 2 NRC Gupta Method Reg Guide 1.92, Rev 2 ‘GUP-ZT’= [(‘ZR’+’ZPMM’) 2 + (‘Z-PERDC’) 2 ] 1/2 ‘GUP-XT’= [(‘XR’+’XPMM’) 2 + (‘Z-PERDC’) 2 ] 1/2 ‘GUP-YT’= [(‘YR’+’YPMM’) 2 + (‘Z-PERDC’) 2 ] 1/2 ‘GUP-TOTL’= [(‘GUP-ZT’) 2 + [(‘GUP-XT’) 2 + (‘GUP-YT’) 2 ] 1/2
37 Reg.Guide Rev.1: TOTAL = [(‘LOAD1-Z’) 2 + (‘LOAD2-X’) 2 +(‘LOAD3-Y’) 2 ] 1/2 NRC Reg.Guide Rev.2: TOTAL+MM = [(‘LOAD1-Z’+ ‘Z-MAS’) 2 + (‘LOAD2-X’+ ‘X-MAS’) 2 +(‘LOAD3-Y’+’Y-MASS’) 2 ] 1/2 ‘GUP-TOTL’= [(‘GUP-ZT’) 2 + [(‘GUP-XT’) 2 + (‘GUP-YT’) 2 ] 1/2 Missing Mass Positions NRC Reg Guide 1.92, Rev 1 & 2 NRC Gupta Method Missing Mass Positions NRC Reg Guide 1.92, Rev 1 & 2 NRC Gupta Method
38 FREQUENCY SPECIFICATONS O TO 900 NUMBER OF MODES 50 NRC Reg Guide 1.92, Rev 1, 2 & Gupta Method Missing Mass Positions NRC Reg Guide 1.92, Rev 1, 2 & Gupta Method Missing Mass Positions Frequency Acceleration
39 NRC Reg Guide 1.92, Rev 1 & 2 Missing Mass Positions NRC Reg Guide 1.92, Rev 1 & 2 Missing Mass Positions
40 DYNAMIC MASS PARTICIPATION FACTORS
41 Reg.Guide Rev.1: TOTAL = [(‘LOAD1-Z’) 2 + (‘LOAD2-X’) 2 +(‘LOAD3-Y’) 2 ] 1/2 NRC Reg.Guide Rev.2: TOTAL+MM = [‘(LOAD1-Z’+ ‘Z-MAS’) 2 + (‘LOAD2-X’+ ‘X-MAS’) 2 +(‘LOAD3-Y’+ ‘Y-MASS’) 2 ] 1/2 ‘GUP-TOTL’= [(‘GUP-ZT’) 2 + [(‘GUP-XT’) 2 + (‘GUP-YT’) 2 ] 1/2 Missing Mass Positions NRC Reg Guide 1.92, Rev 1 & 2 NRC Gupta Method Missing Mass Positions NRC Reg Guide 1.92, Rev 1 & 2 NRC Gupta Method
42 Reg.Guide Rev.2: TOTAL-X = [(X LOAD2) 2 + (MM LOAD2) 2 ] 1/2 NRC Gupta Method: GUP XT = [(X RIGID+MM-XPERD) 2 + ( X PERDC) 2 ] 1/2 Reg. Guide 1.92, Rev. 1: X LOAD 2 Missing Mass Positions NRC Reg Guide 1.92, Rev 1, 2 & NRC GUPTA Method Missing Mass Positions NRC Reg Guide 1.92, Rev 1, 2 & NRC GUPTA Method
CONCLUSION 43 Seismic Restraint : To Reduce Pump Deflection and Stresses No Impact of NRC Reg.Guide 1.92, Rev. 2 on Pump Dynamic Analysis
Questions? Thank you. 44