ML20213C883
| ML20213C883 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 03/05/1979 |
| From: | Schauer F Office of Nuclear Reactor Regulation |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| CON-WNP-0264, CON-WNP-264 790305, NUDOCS 7903210534 | |
| Download: ML20213C883 (12) | |
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- 5. A. Varga, 061cf Light Water Reactors Gracch th). 4 Division of Project !!anage.cr.t FI'G':
Frt,nz Schauce, Chief Structural Engineering Crancit Oivisiott of Systems 5 doty S!8ECT:
L%5ilINGT0l! P(CLIC PEEP, S!!PPLY SYSTT:li hPPSS 50, 2, FIPST RECUEST FCF. ItFtEKIOC, FSAR REVIDf (sed: 1233)
F1.u t caco: LFFSS No. 2 Licencing Sta9c: OL Docket hes.: EC-397
.hsponsi:Tc 3r:nci Sa Project :'cnager: UC 3 O. Lych Applicant's Perponse Date Necessary for Camletion of :Iext Action Planned on Project:.W.kan
!?cscription of Ecsponse: Answers to Guestions Ecviou St:tus: C xplete The first rcund revice of tita F5hl has been eccpleted by P. Kuo of Sectica A of t!:e Structural Casincering Branca. We find that additionni Ir.fcreation is required before we can cociate cur revies. Tne addt-tional fr. formation requested, 6.tich corcerns structurci aspce's, is contained in the enclosure. Ge caterial reviewed to date consistc6ff inforcation provided tarow;h /cens:cr.t M. 2, January 9,1979. Cuer.tions r.crtaining to the str::ctural area of the trk II ccatairent util be furntshed later pending the review of the Plant Ecsig asscr.wnat itcport for SR'.' and LCCA loadse Frer.h schauer, Chief 5tructural Enginecring Brcnc.h Division of Systas: Inicty Encinsure:
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WASHINGTON PUBLIC POWER SUPPLY SYSTEM WPPSS NO. 2 FSAR STRUCTURAL ENGINEERING BRANCH DOCKET NO. 50-397 FIRST REQUEST FOR INFORMATION 130.10 Your response to Question 130.1 is not satisfactory. The load, (3.3.2) included in Table 3.8-15 and 3.8-16 is the combined effect of three loads generated by the Design Basis Tornado. Describe the procedures used to combine the tornado wind load, tornado differential pressure load, and tornado missile load. Provide, also, the procedures by which tornado generated missiles were transformed into effective loads.
130.11 Airborne dust loadings have been identified as a design basis meteor-(3.3.2) ological parameter. Describe the procedures by which the airborne dust loadings were determined.
i 130.12 Clarify which formula was used to determine penetration depth into (3.5.3) steel barriers.
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130.13 You indicated on Pages 3.7-2 and 3.7-3 that "These design response (3.7)
(RSP) spectra are not identical to the design response spectra as defined in Regulatory Guioe 1.60, Revision 1, scaled to 0.25g maximum hori-zontal ground acceleration. However, the latter are used with higher damping values as defined in Regulatory Guide 1.61, Revision 0.
A response spectrum dynmnic modal analysis was performed on the reactor building structure for an SSE input earthquake using:
(a) the design 1
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response spectra defined in Figure 3.7-1 and the damping values of Table 3.7-1, and (b) the design response spectra, scaled to 0.25g maximum horizontal ground acceleration, and damping values defined in Regulatory Guides 1.60, Revision 1, and 1.61, Revision 0, res-pectively. The structural responses of each of these modal analyses were within 10% of each other at almost all locations."
We request that you also compare floor response spectra at a few typical locations using the two sets of input criteria mentioned above. Also, perform these comparisons in the vertical direction as well.
We, also, request that the above comparisons for structural responses (i.e., seismic shear, moment, deflection, and floor response spectra) in the horizontal ~and vertical directions be repeated for all other seismic Category I structures.
Comparison of floor response spectra at 2% and 5% of critical damping should be provided at the operating floor, reactor stabilizer level, the reactor vessel support, divider barrier, base mat and the refueling hatchleveiforthereactorbuildingandatthebasemat,aninter-mediate elevation, and an upper elevation for all otner seismic Category I structures.
130.14 Clarify if and how the base line correction was made for the design (3.7.1) time history shown in Figure 3.7-5.
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l 130.15 The footnote on Page 3.7 -45 stated that " damping values tabulated (3.7.1.3) in Regulatory Guide 1.61, Revision 0, are utilized for designs which include the ground response spectra in accordance with Regulatory Guide 1.60, Revision 1, either independently, or in conjunction with LOCA and S/R valve discharge related hydrodynamic loads."
This statement contradicts to the statements on Page 3.7-2 and 3.7-5, which indicated that Regulatory Guide 1.61.was not used.
Clarify these statements. Also, clarify what damping values were used for soil.
130.16 Clarify in Section 3.7.2.1.7 and other sections how the stresses due (3.7.2.1) to relative support displacements are combined with other stresses.
Also, define on the bottom of page 3.7-15 the cases where the relative displacementswereinsigkificantandthusneglectedinanalysis.
130.17 You stated in Sections 3.7.2.1.8.1 and 3.7.2.1.8.2 that only one (3.7.2.1) horizontal and the vertical components of seismic responses were combined in determining maximum stresses. It is our position that maximum stresses should be determined using three component responses on a square-root-of-the-sum-of-the squares basis.
Provide justifications for your approach or revise your analysis to incorporate the staff's position.
130.18 You stated in Section 3.7.2.8.2 that "when piping system is anchored (3.7.2.1) and supported at points with different excitations, the response spectrum analysis is performed using the response spectra at or above 1
the center of mass of the piping system for the NSSS systems and components."
It is the staff's position that for systems and components supported at different locations, an envelop response spectrum should be used for the analysis. Provide justification for your approach or revise your analysis to incorporate the staff's position.
130.19 You stated on Page 3.7-15 that "the load factors are derived by (3.7.2.1) utilizing the response spectra for a conservatively chosen fundamental frequency based on the maximum span length of an assumed simply sup-ported beam." Provide details of the method employed.
130.20 You stated on Page 3.7-16 that "the stresses thus obtained for each (3.7.2.1) natural mode are then superimposed for all modal displacements of the structure by the square root of the sum of the squares (SRSS method)."
i Clarify if there is any closely-spaced modes as defined by Equation 3.7.2.1-13.
If so, clarify how the responses of the closely-spaced modes were combined with other model responses in your calculations.
130.21 Your response to Question 130.3 regarding criteria used for decoupling (3.7.2.3) i subsystems is unclear, but appear different from the acceptance criteria delineated in Paragraph II.3b of the SRP, Section.3.7.2. Provide e
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-s clarification and/or justification for your decoupling criteria used in modeling structure, systems and components.
130.22 It is unclear how the values of shear modulus, G, were arrived at.
(3.7.2.4)
Provide for all seismic Category I structures the pertinent infor-mation referred to in your Reference 3.7-6 of the FSAR.
130.22 Provide the cases where the peaks of floor response spectra were (3.7.2.5) widened by less than 10% of the structural frequancies. Justifi-cation for widening peaks of floor response spectra less than 10%
is required.
130.24 It is the staff's position that responses due to three components of (3.7.2.6)
(RSP) an earthquake motion should be combined in accordance with Regulatory Guide 1.92, Revision 1, in determining the total seismic response.
Provide technical justification for considering only two components of an earthquake motion as stated in the FSAR or revise your analysis to incorporate the staff's position.
130.25 For non-symmetric structures, there may be dynamic coupling between (3.7.2.11) translationai and torsional motions. Use of torsional moment as the product of the inertia force and the distance between the centers of mass and rigidity may or may not be adequate. Provide technical bases for your approach. Also, clarify how torsional effects were included in the generation of floor response spectra.
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. 130.26 Table 3.7-17 did not have the information regarding comparisons of (3.7.2.12) seismic responses obtained from the response spectrum approach and the time history approach as stated in your FSAR. Provide this information.
130.27 Your response to Question 130.6 is not satisfactory. Provide tech-(3.7.2.14)nical details cf the procedures employed in calculating the capa-bility-of safety-related structures to resist overturning and sliding,
Provide also, the factors of safety against overturning and sliding for each of the safety-related structures.
120.18 You stated on Page 3.7-31 that "the selected design values are (3.7.2.15) significantly smaller than the calculated values (see Table 3.7-2)."
However, the information as stated cannot be found in Table 3.7-2.
Provide the cited information and the technical bases for Equation 3.7.2.15-1.
130.29 Reference 10 cited on Page 3.7.33 does not exist. Clarification and (3.7.3.2) justification for the number of cycles used are requested.
130.30 You stated on Page 3.7-36 that the following two conditions are (3.7.3.3) satisfied in selecting field locations of seismic supports and restraints:
a.
The location selected must furnish the required response to control strain within allowable limits.
b.
Adequate building strength for attachment of the components must be availatie.
Elaborate on how these two objectives were met.
j 130.31 The methods of analysis described in subsections 3.7.3.12.1.3 and (3.7.3.12) 3.7.3.12.1.5 are unacceptable. The procedure for predicting the seismic stresses in buried pipes suggested by Newmark (your Reference
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3.7-12) is based on the hypothesis that pipes will move along with the soil during an earthquake shaking. There can be no slippage developing at the soil-pipe interface. The extension of these pro-cedures to include consideration of friction and slippage as proposed by your equations 3.7.3.12.1.3-2 through 3.7.3.12.1.3-5 and Equation 3.7.3.12.1.5-3 has no technical basis.
Use the procedures as suggested in your Referenced 3.7-12 or provide theoretical or experimental justifications for the equations cited above. For either case, provide the values of "Vm" used and explain now it was~obtained.
For buried pipes connected to various buildings, clarify what is the clearance between pipes and sleeves as shown in Figures 3.8-48 and 3.8-49 and what are the differential displacements of the pipes relative to the buildings. Also, provide the details of the procedures used for predicting the stresses of the portion of the buried pipes at the connections to buildings.
130.32 Provide the mechanical properties of the material used to separate (3.8.2.1) the containment vessel from the reinforced concrete biological shield i
as indicated on Pages 3.8-5 and 3.8-7.
Indicate if these properties would be affected by radiation.
's 8-130.33 You stated on Page 3.8-6 that "under emergency condition, the jet (3.8.2.1) impingment force of 534 kios as outlined in 3.8.2.3 might cause local yielding of the drywell shell. An analysis (plastic analysis in accordance with the requirements of the ASME Code,Section III) demonstrates that rupture will not occur. Local deformation caused by the jet impingment force does not affect the leak tightness of the containment vessel."
Provide the details of the cited analysis and ductility ratio resulted from this analysis. Also, provide technical bases for the last sentence quoted above..
130.34 You stated on Page 3.8-17 that " structural steel attachments beyond (3.8.2.2) the boundaries established for the steel primary containment vessel are designed and constructed according to the AISC Specification for the Design, Fabrication and Erection of Structural Steel for Building, February 12, 1969, where applicable. The allowable stress limits are in accordance with Sub-Article NE-3131 (3) of Section III of the ASME Code."
Clarify what the structural steel attachments are and provide rationale for applying two different codes for the design of the same structural elements.
130.35 Clarify if the airborne dust load was included in any of the loads (3.8.2.3) and load combinations defined in Section 3.8.2.3.
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130.36 The load com.binations considered in your analysis appear to deviate (3.8.2.3)
(3.8.3) from those delineated in Section 3.8.2 of the SRP. Justify the deviations and/or assess the significance of the deviations with respect to the adequacy of the structural design. Also, clarify how the quantity of interest (moment, shears, stress, etc.) resulting from different loads were combined (e.g., by using the absolute sum rule or the square-root-cf-the-sum-of-the-squares rule).
130.37 Computer programs AXl, AX2, and AX3 are for analysis of axisymmetric (3.8.2.4 structures as indicated on Page 3.8-42.
Explain how these programs take account of vertical and horizontal stiffeners used for the reinforcement of the primary containment vessel.
130.38 Provide in detail the buckling criteria and the procedures used to (3.8.2.5) establish these criteria for the primary containment vessel.
130.34 Your References 3.8-5, 3.8-6, and 3.8-7 were not previously submitted (3.8.3) for review. Referring to references for definitions, criteria, and method of analysis of SAR can not be accepted until these referenced reports are made available and reviewed and accepted by the staff.
130.40 For reinforced concrete internal structures, the load combinations for (3.8.3.3) abnormal / severe environmental loads were not considered. For steel internal structures, the load combinations for extreme environmental, abnormal, and abnormal / severe environmental loads were not considered.
Live loads were not considered in some of the load combinations.
.. Provide technical justifications for these omissions and/cr assess the significance of these emissions with respect to the adequacy of the structural design.
130.41 Elaborate on the method of analysis used for computing forces and (3.8.3.4) displacements in all internal structures.
If computer codes were used for analysis, indicate the names of the codes. Provide or describe, wherever applicable, the models used in performing such analyses. Also, indicate the comparisons between the designed values and the allowable values (or capacity).
130.42 You indicated in Tables 3.8-13 and 3.8-17 that plastic section modulus (3.8.3.5)
(3.8.4.5) might be used for factored load conditions using elastic working stress design method. Clarify if this was done in your analysis.
If so, justification is needed for using plastic section modulus in conjunction with the elastic working stress design method.
130.43 In both steel and reinforced concrete structures, the load combinations (3.8.4) used were different from those of the SRP. Provide technical bases for the deviations and/or assess the significance of the deviations, with respect to the adequacy of the structural design.
130.44 For the reactor building foundations mat, clarify if ASME Boiler and (3.8.5)
Pressure Vessel Code,Section III, Division 2 was used in your analysis and design.
If not, provide technical justification and assess the significance of any deviation from this code with respect to the adequacy of the reactor building foundatiori mat design.
11 130.45 Indicate if there was any uplifting predicted for the foundation (3.8.5) mats of all structures considered. If so, indicate the names of the structures and the amount of uplifting predicted.
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