ML20213D827
| ML20213D827 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 09/30/1981 |
| From: | Knight J Office of Nuclear Reactor Regulation |
| To: | Tedesco R Office of Nuclear Reactor Regulation |
| References | |
| CON-WNP-0391, CON-WNP-391 NUDOCS 8110190033 | |
| Download: ML20213D827 (32) | |
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DISTRfBUTION DCD 016 Phillips SEB Reading File SEP 3 61931 J. Knight F. Schauer D. Jeng K. Leu Docket No. 50-397 HEMORANDUf1 FOR: Robert L. Tedesco Assistant Director for Licensing Division of Licensing FROM:
James P. Knight Assistant Director for Components and Structures Engineering Division of Engineering
SUBJECT:
WASHINGTON PUBLIC POWER SUPPLY SYSTEf1 NUCLEAR PROJECT NO. 2 REQUEST FOR ADDITIONAL INFORMATION Enclosed are requests for additional information to complete our review of the structural aspects of the WNP-2 OL application. Our review covered the infonnation subnitted by the applicant through Amendment 13 of the FSAR. tie plan to conduct an audit at A/E's office in the week of September 28, 1981.
The review was conducted by K. C. Leu of Section A of the Structural Engineering Branch.
Origin 11 Sic *ied By:
James P. & t t.
James P. Knight Assistant Director for Components and Structures Engineering Division of Engineering
Enclosures:
As stated
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i ENCLOSURE 1 220.0 Structural Enoineering 220.01 You state in Section 3.5.1.3 of the FSAR that the reorientation
( 3. 5.1 )
of the turbine generator building to limit potential missile l
strike is not considdred. Rather, the barrier capability of the massive radiation shielcing structures, characteristic of 3WR's, is utilized to contro? postulated turbine missile hazards, and probability studies provide the assurance that the chance cf missile strike is remoto.
Describe your probability studies with emphasis on the chance of turbine missile strike and penetration of the structural
- barrier, If in your analysis the value of p3 is assumed as 1.0, please so indicate.
220.02 You state in Section 3.5.3 of the FSAR that for the design of (3.5.3) concrete nissile barriers,.a concrete thickness of twice the penetration thickness determined for an infinitely thick slab is provided to prevent perforation, spalling or scabbing.
Compare your results with the minimum requirements cantained in Tsble 1 (Attachnent 1) and provide justification if deviations exist.
220.03 Indicate the allewable ductility values used in the overall (3.5.3) damage prediction of structural barriers in Section 3.5.3 of the FSAR. Compare these niues sith those given in Attachment 2 and justify the deviations, if any.
220.04 With regard to previous staff question 130.013 and your response, (3.7.1) provide the detailed comparisons as indicated in your earlier (RSP) response for staff review.
220.05 In your response to previous question (Q133.020) you stated (3.7.2) that for the NSSS equipment wnere the response spectrum method of seismic analysis was used the closely-spaced modal responses were combined by the SRSS method. The staf f position is that for closely-spaced modes, rules set forth in Regulatory Guide 1.92 should be used. Accordingly, state your intent to comply with the position or provide justification and assess the impact for the deviations.
220.06 in Section 3.7.2.4 of the FSAR, it is stated that the lumped mass (3.7.2) spring Method representing soil / structure interaction is obtained from a simplified mechanical analog to the rodel of a rigid mat resting on the surface of an elastic balf 3 pace.
The current position of the regulatory staff regarding the soil-structure interaction is described in Section 3.7.2.II.4 of the SRP ( Attach-ment 3). Note that this position, in addition to the use of elastic half-space approach, requires the use of finite element method. State your intent to comply with the position or justify the deviations, i
t i 220.07 As indicated in Section 3.7.2.6 of the FSAR, two components (3.7.2) of the ecrthquake motion (one horizontal r.nd one vertical) are used to calculate the maximum stresses. Prove the conserative-ness of this method over the SRSS of three components of earth-quake motion contained in Regulatory Guide 1.92, or justify the deviations.
220.08 Indicate your intent to comply with the staff position on the (3.7.2) response spectral peak widening or provide justification for your practice as stated in Section 3.7.2.5 of the FSAR where the peaks of floor response spectra were widened by only 10 percent of the peak spectral frequencies. The current staff position on this subject is contained in Regulatory Guide 1.122 and Section 3.7.2. II.9 of the SRP.
220.09 You state in 3.7.2.14 of the FSAR that detemination of seismic (3.7.2)
Categury I structure overturning and sliding effects consists of two horizontal orthogonal and vertical components of earthquake motions. Each horizontal component is taken separately and is applied concurrently with the vertical component. Demonstrate that the requirements of Section 3.7.2.II.14 of the SRP are met or justify your deviations from the staff requircments.
220.10 Confirm if an accidental torsicnal effect (Si of the base (3.7.2) dimension) was considered in you'r design of all Category I structures iri addition to the geometrical torsional effect, if a ppl ica bl e.
220.11 Provide an ultimate capacity analysis of the steel containment (3.8.1) resconding to the irternal pressure build up due to accidents.
The guideline and the staff position on this subject is enclosed (Attachment 4).
220.12 You state in Section 3.8.2.5.4 of the FSAR that to assure safety (3.8.2) against buckling, the rules set forth in the ASME Code,Section III, NE 3133 are utilized. However, the ASME Code are applicable to unstif fened continuous steel containment shell without signif-icant openings. Assess the effects of shell stiffening and openings on the applicability of the NE 3133 for buckling analysis and discuss remedial analyses you can perfom to address this
- issue, iho following questions (220.13 to 220.2 2) pertain to revision 2 of WNP-2 Design Assessment Report (DAR).
220.13 Revision 2 of WNP-2 Cesign Assessment Report (DAR) was completed (3.8.2) in August 1979.
Since then more information has been generated from the Mark II Generic Program.
Indicate if further assessment i
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of WNP-2 containment and its internal structures has been made or needs to be made and what is your commitment, if any, to the further findings of the Mark II Generic Program.
Provide a more detailed description of your analysis of fatigue 220.14 (3.8.2) for the steel containment shell and indicate the assumptions you made.
220.15 In Sect' ion 4.1.1.1.1. 4 of the DAR it is stated that additional (3.8.2) considerations relating to effects of subsequent actuation will be covered in a subsequent revision of DAR. Provide the status of these additional considerations.
In Section 4.1.1.1.3 of the DAR under Item C (P. 4.1-6) the staff 220.16 (3.8.2) cannot understand the second sentence in the paragraph. An explanation should be provided.
In Section 4.1.1.5.2 of the DAR design margins for the containment 220.17 (3.8.2) structure and containment tees under various load combinations are given without indicating the contribution of stresses from each of the loads in the load combination. Provide a table to indicate the stress contributions from each of the loads indicated in the governing load combinations.
220.18 In Section 4.1.1.4.1 it is stated that for assessing the stresses (3.8.2) in the containment shell due to chugging, building model in Chapter 5 is used.
It appears that the building model shown in Fig. 5.1-1 does not contain the fluid.
Indicate that with such a mathematical model how the fluid shell structure interaction can l
be considered. Furthermore, the bottom part of the model appears to be dif ferent from the actual.
Explain this model discrepancy or provide justification for the discrepancy.
In the assessment of the base mat indicate what structural 220.19 l
(3.8.2) functions are assumed for the portions of concrete above and below the steel containment bottom head, and how these portions I
are designed.
In Section 5.1.2 of the DAR it is stated that damping is applied 220.20 (3.8.2) as a material dependent property so that specific damping values may be imposed for each of the different structural elements, f
Express in mathematical term the formulation of this material dependent damping used in the actual analysis. What damping values are used for fluid and the soil? In all floor spectra j
provided the applicable structural damping values for the floor l
j response spectra should be indicated.
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220.21 Provide the figures which are' missing in Section 5.1 of'the j
4 (3.8.2)
DAR.
220.22 In Figure 4.1-20 of the DAR, a seismic bracket to provide (3.8.2) lateral support of the down comers is indicatede Provide a drawing showing the details and its attachment to-the contain-i ment shell.
Indicate what are the effects on stresses and behavior of the containment shell as a result of such attach-mentsundertheactionofLyCAandSRVloads.
The following questions (220.23 and 220.24) pertain to the report titled
" Chugging Loads - Revised Definition and Application Methodol,ogy for Mark II I
Containments".
220.23 It is noted in Secti7n 3.3.3 on Page 32 of the above referenced (3.8.2) report that viscous damping coefficients Dw and Ds are represented in the form of dashpots connecting the water elements and steam elements respectively. However, in the model shown in Figure 3-17a there is no identification of water or steam elements nor is there any representation of, viscous damping in the form of dashpots.
Provide in a figure a model incorporating the various elements as described.
In your evaluation of Dw and Ds by a trial and error nethod, how the effects of the structural damping of the tank can be isolated? Are the damping values thus j
determined co'nsidered in the theoretical formulation of the fluid-structure interaction analysis as discussed in the following question? How are they, considered?
In, the theoretical formulation of the equation for the fluid-J 220.24 st,ructure interaction analyff s as indicated in Section 5.2 of (3.8.2)
.the report, a so called dynamic stiffness matrix is definqd in "tenus'of Ms', Ma, Cs and Ks' materices.
Provide a discussion'how tne structural damping matt x Cs is established, and why the,
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natural frequency of the structure is not involved in the fo rmul a tion.
In the model shown. in Figure 5-4, no water is indicated, therefore, how Ma is considered? Provide a model used in the analysis which includes allithe physical elements,
as contained in equation 5.3 of the report. How do you verify the validity of your theoretical formulation?
j
, With regard to Table 3-8-10 of the FSAR where the abnormal /
220.25 severe environmental loads for internal concrete structures (3.8.3) were not considered, and to Table 3.8-11 of the FSAR where
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(RSP) live loads were not considered in some load combinations for the inte'rnal steel structures. Provide overall assessment on tne impact of such omissions and demonstrate that the corresponding requirements of the Section 3.8.3 of the SRP are complied with.
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5-220.26 The loads and load canbinations used in Tables 3.8-15 and (3.8.4) 3.8-16 of Section 3.8.4 of the FSAR are different from those presented in Section 3.8.4 of the SRP.
Demonstrate that the applicable requirements are met in the design or justify the deviations from the SRP.
220.27 Are there any spent fuel pool structures used in WNP-2?
(3.8.4)
If so, describe key dimensions, structure modeling, static and seismic analysis criteria, procedures, assumptions and computer codes used and the key results. A copy " Minimum Requirements for Design of Spent Fuel Pool Racks" is enclosed (Attachment 5).
220.28 Confirm if safety-related concrete masonry walls are used in (3.8.4)
WNP-2 buildings, if so, the criteria contained in Attachment 6 should be followed.
220.29 Your response to previous question Q130.043 regarding reactor (3.8.5) building foundation mat design code is unacceptable to the staff. The staff position is that Section III, Division 2 of the ASME Boiler and Pressure Yessel Code should be used in the design and analysis of the reactor building foundation mat.
t Accordingly, identify and discuss the deviations of your reactor building foundation mat design from the requirements of the ASME Code Section III, Division 2, and demonstrate that the intent of the code is' fully complied with or justify the deviations.
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TABLE 1 TOSRPSECTION3.(--
ATTACH!1ENT 1
(
Minimum Acceptable Barrier Thickness Requirements
)
For Local Damage Prediction Against Tornado Generated Missiles Concrete Strength Wall Thickness Roof Thickness Regions" (psi)
(inches)
(inches) 3000 23 18 Region I 4000 20 16 5000 18 14 3000 16 13 Region II 4000 14 11 5000 13 10 3000 Region III 4000
<6
<6
<6
<6 5000
<6
<6
- For definition of Region I, II, and III, refer to Regulatory Guide 1.76 (Ref. 8).
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ATTACH".ENT 2 APPENDIX A TO SRP SECTION 3.5.3 1
ALLOWABLE DUCTIILITY RATIO
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FOR OVERALL DAMAGE PREDICTION I.
INTRODUCTION In the eealuation of overall response of reinforced concrete structural elements (e.g., missile barriers, columns, slabs, ets.) subjected to impactive or impulsive loads, such as impacts due to. missiles, assump-tion on non-linear response (i.e. ductility ratios greater than unity) of the structural elements is generally acceptable provided that the intended safety functions of the structural elements and thcse of safety-related systems and components supported or protected by the g
elements are maintained. The following summarizes specific positions and review and acceptance of dactility ratios for reinforced concrete and steel structural elements subjected to impactive and impulsive loads.
II.
SPECIFIC POSITIONS 1.
REINFORCED CONCRETE MEMBERS a.
For beams, slabs, and walls where flexure controls design, the permissible ductility ratio under impactive and impulsive loads should be taken as 0.05,< 10 where p and p' are the ratios of P-P tensile and compressive reinforcing as defined in ACI 349-76 Code.
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b.
If use of ductility ratio greater than 10 (i.e.,u > 10) is re-quired to demonstrate design adequacy of structural elements against impactive or implusive loads, e.g, missile irpact, such
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I e's usage should be identified and justified by submi,ttal of applicable experimental evidence in the plant SAR./
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a For beam-columns, walls, and slabs carrying axial compression c.
loads and subject to impactive loads (e.g., af ssile impact) producing flexure, the pemissible ductility ratio in flexure should be as follows:
(i)
When compression controls the design, as defined by an interaction diagram, the permissible ductility ratiou should be 1.3.
(ii)
When the compression load does not exceed 0.lf cAg or one-third of that which would produce balanced conditions, whichever is smaller, the permissible ductility ratiou should be as given in 1.a.
(iii) Tne permissible ductility ratio should vary linearly from 1.3 to that given in 1.a for conditions between thase specified in (1) and (ii) (see Fig.1).
d.
For beam-columns, walls, and slabs, carrying axial compression loads subject to implusive loads (e.g., compartment pressuri-ration) producing flexure, the pemissible ductility ratio u in flexure should be 1.0.
For structural elements resisting axial compressive impulsive or e.
impactive loads only, without flexure, the pemissible axial ductility ratio y should be 1.3.
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For shear carried by concrete only
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u = 1.0 For shear carried by concrete and stirrups or bent bars u = 1.3 For shear carried entirely be stirrups p= 3.0 2.
STRUCTURAL STEEL MEMBERS a.
For tension due to flexure u= 10.
b.
For columns with slenderness ratio ( t /r) equal or less than 20 4= 1.3 Where L = effective length of the member r = the least radius of gyration For columns with slenderness ratio greater than 20 U= 1.0 c.
For members subjected to tension u= 0.5 Eu Ey Where c u = ultimate strain cy = yield strain e
ATTACHMENT 3 i
_!. i.l.S._t_ruc t u re I n t e ra c t i o n_
'a N ilytical rodel of a soil-structure interaction syst.a is 'cceptc.ble i f ':.)Lh f.he structure i.mdal and the scpporting soil :.;dal ara J.:7.arly c z.,',' M and the desiga
.) tion is pecparly cJdressed.
Tha c..;12d : del _
is s ')f acted to the desii,n grcund notion as speci fied in SD Sacti.)n 3./.1 or to the rey:narated excitation systeri describad in Sactica II.4 7 h i : ' '.. y ut' :d (iii) halow.
A s':it Bla r'yna lic coalysis using '.ba ti:
is,..cforrad for tha Gai. ire soil-str :ctura systra c::d
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. ious locli.!aas of che sys te:a are calcu!itad.
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,.ay c,ynmaic o,ccoupling or condensatien pre,,~ >
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. :i,.antiated by 3.h. oretical verification and nathe:.:atical pr;;fs.
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ATTACHMENT 4-CAPACIIY. ASSESSMENT OF STEEL CONTAINMENT 7
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.s The analysis should be performed to provide a reasonable assurance that the integrity of the containment will be maintained during an accident that re-leases hydrogen generated from 75% fuel clad metal-water reaction accompanied by either hydrogen burning or the added pressure from post-accident inerting assuming carbon dioxide is the inerting agent, depending upon which option is chosed for control of hydrogen.
As a criterion of such an assurance, it should be demonstrated through an analysis that in case of an accident described above, the requirements of the ASME Boiler and Pressure Vessel Code, Division 1, (Code) Subsubarticle e
NE-3220, Service level C Limits, considering presiJr0 and dead load alone, will be met.
As a minimum, the code requirements set above should be met for a combination of dead load and an internal pressure of 45 psig.
If the option chosen for hydrogen control is post-accident inerting, the fol-lowing must be demonstrated by the analysis:
(a) Containment structure loading produced by an inadvertent full inerting (assuming carbon dioxide), but not including seismic or design basis accident loading will not produce stresses in steel containment in ex-cess of the limits set forth in the ASME Boiler and Pressure Vessel Code, Division 1, Subsubarticle NE-3220, Service level A Limits, except that evaluation of instability is not required.
Page 2 7
(b) A pressure test, which is required, of the containments 1.10 times,,
the pressure calculated to result from carbon dioxide inerting can be safely conducted, and, (c)
In advertent full inerting of the containment can be safely accomo-dated during plant operation.
In order to be acceptable, the analysis used for determination of ultimate capacity of the containment should be based on the general principles of structural mechanics and consistent with sound engineering practices. The model used in the analysis should be realistic representation of the con-tainment structure.
c The pressure capacity of localized areas as well as of the overall contain-ment structure should be examined for the static and dynamic pressures re-spectively. The static and dynamic pressures to be used in the analysis should be approved by the Containment Systems Branch.
The analysis should be made on the basis af the allowables specified in the Code. However, if the actual material properties, s'uch as the tested material strength, strength variations indicatd by mill test certificates and other material uncertainities are available, the lower and upper bounds l
of the containment capacity may be established statistically. The details of the analysis and the results should be submitted in a report form with i
the following identifiable information.
l 1.
The original design pressure, Pa, as defined in the Code, Subsubarticle NE-3220; 2.
Calculated static pressure capacity; i
P[ge3 l
3.
Equivalent static pressure response calculated from dynamic p,r' essure; l
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The associated failure mode;'
5.
The criteria governing the original design and the criteria used to establish failure; 6.
Analysis details and general results; and, 7.
Appropriate engineering drawings adequate to allow verification of modeling and evaluation of analyses employed for the containment d
structure.
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ATTACHMEhi S
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APPENDIX D TO SRP SECTION 3.8.4 y
MINIMUM REQUIREMENTS FOR DESIGN OF SPENT
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a FUEL POOL RACKS INTRODUCTION The purpose of this appendix is to provide the minimum requirements and criteria for review of spent fuel pool racks. The criteria for the structural design of the spent fuel pool proper are contained in the main body of this section. This appendix describes the acceptable criteria 'of the spent fuel pool structure as it relates to the racks.
(1)
Description of the Spent Fuel Pool and Racks Descriptive information including plans and sections showing the spent fuel e
pool in relation to other plant structures shall be provided in order to de-fine the primary structural aspects and elements relied upon to perform the safety-related functions of the pool, spent fuel pool liner and the racks.
The main safety function of the spent fuel pool, the liner and the racks is to maintain the spent fuel assemblies in a safe configuration through all environ. ental and abnormal loadings, such as earthquake, and impact due to spent fuel cask drop, drep cf a spent fuel assembly or drop of any other heavy object during routine spent fuel handling.
The major structural c7ements reviewed and the extent of the descriptive information required are indicated below.
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(a) Support of the Spent' Fuel Racks:
The general arrangements and prin-cipal features of the horizontal and the vertical supports to the spent fuel racks should be provided indica ing the methods of transferring
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Fage 2 "the loads on the racks to the fuel pool wall and the fdbndation slab.
All gaps (clearance or expansion allowance) and sliding cont [ cts should be indicated. The extent of interfacing between the new rack system and the old fuel pool walls and base slab should be discussed, i.e.,
interface loads, response spectra, etc.
If connections of the racks are made to the base and to the side walls of the pool such that the pool liner may be perforate,d, the provisions for avoiding leakage of radioactive water of the pool should be indi-cated.
(b) Fuel Handling: Postulation of a drop accident, and quanlification of the drop parameters are reviewed by the Accident Evaluation Branch (AEB). Structural Engineering Branch accepts the findings of the AEB review for the purpose of review of integrity of the racks and the fuel pool including the fuel pool liner due to a postulated fuel handling accident.
Sketches and sufficient details of the fuel handling system should be provided to facilitate this review.
(2) Apolicable Codes, Standards and Specifications Construction materials should conform to Section III, Subsection NF of Reference 3.1.
All materials should be selected to be compatible with the fuel pool environment to minimize corrosion and galvanic effects.
Design, fabrication, and installation of spent fuel racks of stainless steel material may be performed based upon Subsection NF requirements of Reference 3.1 for Class 3 component supports.
l Page 3 (3) Seismic and Impact Loads
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For plants where @namic input data such as floor response'/
.i spectra or ground response spectra are not available, necessary @namic analyses suIy be per-formed using the criteria described in Section 3.7 of this plan. The ground response spectra and damping values should correspond to R. G.1.60 and 1.61 respec.tively. For plants where dynamic data are available, e.g., ground response spectra for a fuel pool supported by the ground, floor response spectra for fuel pools supported on soil where soil-structure interaction was considered in the pool design or a floor response spectra for a fuel pool supported by the reactor building, the design and analysis of the new rack system ray be performed by using either the existing indut parameters
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including the old damping values or new parameters in accordance with R. G. 1. 60 a nd 1. 61. The use of existing input with new damping values in R. G. 1.61 is not acceptable.
Seismic excitation along three orthogonal directions should be imposed si-multaneously for the design of the new rack system. Tne peak response from each direction should be combined by square root of 'the sum of the squares in accorda. ice with R. G. 1.92.
If response spectra are available for a ver-tical and horizontal directions only, the same horizontal response spectra may be applied along the other horizontal directions.
Submergence in water should be taken into account. The effects of subrner-gence are considered on case-by-case basis.
Due to gaps between fuel assemblies and the walls of the guide tubes, addi-
- s tional loads will be generated by the impact of fuel assemblies during a postulated seismic excitation. Additional loads due to this impact effect
Page 4 may b'e deterviined by estimating the kinetic energy of the f,u$1 assembly.
The maximum velocity of the fuel assembly may be estimated' to be 'the spectral velocity associated with the natural frequency of the submerged fuel assembly. Loads thus generated should be considered for local as well as overall effects on the walls of the rack and the supporting framework.
It should be demonstrated that the consequent loads on the fuel assembly do not lead to a damage of the fuel.
Loads generated from other postulated irnpact events may be acceptable, if the following parameters are described:
the total mass of the impacting missile, the maximum velocity at the time of impact, and the. ductility ratio of the target material utili::ed to absorb the kinetic energy.
g (4) Loads and Load Combinations Any change in the temperature distribution due to the proposed modification should be identified.
Information pertaining to the applicable design loads and various combinations thereof should be provided indicating the thermal load due to the effect of the maximum temperature distribution through the pool walls and base slab. Temperature gradient acr'oss the rack structure l
due to diffenntial heating effect between a full and an empty cell should l
be indicated and incorporated in the design of the rack structure. Maximum uplif t forces available from the crane should be indicated including the con-sideration of these forces in the design of the racks and the analysis of the ext sting pool. floor, if applicable.
The fuel pool racks, tne fuel pool structure, including the pool slab and fuel pool liner, should be evaluated for the accident load combinations which include j
the impact of the spent fuel cask, the heaviest, postulated load drop, and/or
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accidental drop of fuel assembly from maximum height as described in paragraph (1) a.
The acceptable limits (strain or stress lisits) in this case will be reviewed on a case by case basis but, in general.>, the applicant is required to demonstrate that the functional capability and/
or the structural integrity of each component is maintained.
The specific loads and load combinations are acceptable if they are in conformance with the applicable portions of Section 3.8.4-II.3 of this plan and Table 1.
(5)
Design and Analysis Procedures Details of the mathematical model including a description of how the important parameters are obtained should be provided including' the following:
the methods used to incorporate any gaps between the sup-port systems and gaps between the fuel bundles and the guide tubes; the methods used to lump the masses of the fuel bundles and the guide tubes; the methods used to account for the effect of sloshing water on the pool walls; and, the effect of submergence on the mass, the mass distribution and the effective damping of the fuel bundle and the fuel racks.
The design at:d analysis procedures in accordance with Section 3.8.4-II.4 of this plan are acceptable. The effect on gaps, sloshing water, and increase of effective mass and damping due to submergence in water should be quantified.
When pool walls are utilized to provide lateral restraint at higher elevations, a determination of the flexibility of the pool walls and 8
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,l Fage 6 the capability of the walls to sustain such loads should be provided.
If the pool walls are flext,ble (having a fundamental frequehey less than 33 hertz) the floor response spectra corresponding to the lateral restraint point at the higher elevation are likely to be greater than those at the base of the pool.
In such a case using the response spectrum approach, two separate analyses should be performed as indicated below:
(a) A spectrum analysis of the rack system using resp,onse spectra cor-responding to the highest support elevation provided that there is not significant peak frequency shift between the response spectra at the lower and higher elevations; and, (b) A static analysis of the rack system by subjecting it to the maximum C
relative support displacement.
The resulting stresses from the two analyses above should be combined by tne absolute sum method.
In orcer to determine the flexibility of the pool wall it is acceptable for the applicant to use equivalent mass and stiffness properties obtained from j
calculations similar to those described in Reference 4.I'.
Should 'he l
fundamental frequency of the pool wall model be higher than or equal to 33 l
l hertz, it may be assumed that the response of the pool wall and the corre-
~
l sponding lateral support to the new rack system are identical to those of the base slab, for which appropriate floor response spectra or ground response spectra may already exist.
l
~.-~ - -.._..
.~
\\
f.,: 3 -
o (6) Structural Acceptance Criteria When ' subsection NF, Reference 3.1 is used for the racks, theestructural 1
acceptance criteria are tho,se given in the Table 1.
When hcklinyloads are considered in the design, the structural acceptance criteria shall be limited by the requirements of Appendix XVII to Reference 3.1.
For impact loading tne ductility ratios utilized to absorb kinetic energy in the tensile, flexural, compressive, and shearing modes should be quan-tified.
When considering the effects of seismic loads, factors of safety against gross sliding and overturning of racks and rack modules under all probable service conditions shall be in accordance with the Section 3.8.5.
11-5 of this plan. This position on factors of safety against sliding and tilting need not be met provided any one of the following conditions is met:
(a) it can be shown by detailed nonlinear dynamic analyses that the am-plitudes of sliding motion are minimal, and impact between adjacent rack modules or between a rack module and the pool walls is prevented provided tnat the factors of safety against tilting are within the values permitted by Section 3.8.5.11.5 of this, plan.
(b) it can be shown that any sliding and tilting motion will be contained within suitable geort.;tric constraints such as thermal clearances, ar.d that any impact due to the clearances is incorporated. The fuel pool structure should be designed for the increased loads due to the new
- le i a nd /or exaanded high density racks. The fuel pool liner leak tight integrity should be maintained or the functional capabil,Jty of the fuel pool should be demonstrated.
/
z (7) Materials. Quality Control, and Special_ Construction Technicues:
The materials, quality control procedures, and ar.y special construction techniques should be described. The sequence of in,sta11ation of the new fuel racks, and a description of the precautions to be taken to prevent damage to the stored fuel curing the constructior, phase a
should be provided.
If connections between the racks and the pool liner are mace by welding, the welder as well as the welding procedere for tre welding assembly shall be qualified in accordance with the applicable ccdt.
8 TABLE 1 LOAD COMBINATION
_ ACCEPTANCE LIMIT D+L level A service limits D + L + To
~
D + L + To + !
D + L + Ta + E ------.--------------------------------------- level B service limitt D + L + To + Pf D + L + Ta + E' ---------------------+----------------------- level D seryice limits D + t + Fd ------------------------- - ---------------------- Tne functional cacability of the feel racks should be demonstratec Limit Analysis li.mits of Appendix XVII 44000 to ASME 1.7 (D + L)
Ccde Section III, 1.3 (D + L) + To)
Division 1.
1.7 (D + L + El 1.3 (D + L + E + To) 1.3 (D + L + E + Ta) 1.3 (D + L + To + Pf) 101 (D + L + Ta + E*)
O 2
Fage 9 Notes:
1.,
The abbreviations in the table above are those used in Subsection 1
II.3.a of where each term is defined except for Ta which is defined a
here as the highest temperature associated with the postulated abnorral design conditions.
2.
Deformation limits specified by the design specification limits shal'1 be satisfied, and such deformation limits should preclude damage to the assemblies.
a 3.
The provision of NF 3231.1 of' Reference 3.1 shall be amended by the requirements of the paragraphs c. 2, 3 and 4 of the R. G.1.124 entitled " Design Limits and Load Combinations for Class 1 Linear-Type Cceponent Supports."
+
4.
Fd is the force caused by the accidental drop of the heaviest load frcm the maximum possible height and Pf is upward force on the racks caused by postulated structural fuel assembly.
e i
7
s ia9-10 REFERENCES
?
1.
Regulatory Guides 1.29 Seismic Design Classification 7.60 Design Response Spectra for Seismic Design of Nuclear Power Plants Damping Values for Seismic Design of Nuclear Power Plants 1.61 1.76 Design Basis Tornado for Nuclear Power Plants 1.92 Combining Modal Responses.and Spatial Compo'nents in Seismic Response Analysis 1.124 Design Limits and Leading Combinations for Class 1 Linear-Type Compenents Supports 2.
Standard 9.eview Plan 3.7
- Seismic Design 3.3.4 - Other Category I structures 3.
Industry Codes and Standards 1.
American Society of Mechanical Engineers, Boiler and Pressure
essel Coce,Section III, Division 1 2.
American National Standards Institute, N210-76 3.
A,mericen Society of Civil Engineers, Suggested Specification for Structures of A1Leinium Ailoys 6061-T6 and 6067-T6 4.
The Aluminium Association, Specification for Alumnium Structures Otner 1.
Siggs, John M.,
- Introduction to Structural Dynamics,"
NcGraw-Hill Book Co. New York.1954 i
.gyw. *
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(
l ATTACHMENT 6
/
/
SEB CRITERIA FOR SAFETY-RELATED fMSOfiRY WALL EVALUATI0ti JULY 1931
i s
TABLE OF CONTENTS 1.
General Requeirements 2.
Loads and Load Combinations a.
Service load Conditions b.
Extreme Environmental, Abnormal, Abnormal / Severe Environmental, and Abnormal / Extreme Environmental Conditions C
2.
Allowable Stresses 4
Design and Analysis Considerations 5.
References L
General Recuirements The materials, testing, analysis, cesign, construction and inspecticr related to the design and construction of safety-related concrete masonry walls shall conform to the applicable requirements contained in Unifor Building Code - 1979, unless specified otherwise, by the provisions in this criteria.
The use of other standards or codes, such as ACI-531, ATC-3 or NCMA are also acceptable. However, when the provisions of these codes are '
less conservative than the correspending provisicms of the criteria, their use should be justified on a case-by-case basis.
In new construction, no unreir. forced masonry wall will be permitted.
E For operating plants, existing unreinforced walls will be evaluated l
l by the provisions of this criteria.
Plar.n a0 plying for operating l
license which have already built unreinfer:ed masonry walls, will be evaluated on a case-by-case basis.
Z.
Loads and Lcad 'emr ir.atior s The 'tds anc lc3J co-binatic s stali r.: i _ e cons idera t icr. of r.ormd loads, sen ce env;rcrar'al ': #, e.c.r5cs t rcr.r. ental lcads, and abnormal loads.
SDeCifically, for Cpe? tin; plants the lead combinati;ns provided in plant's TS*R shal', ;;vern.
T-cr cpera ting license applicat ens, the following load ccabinatiens shall appl;. ( ~or definiticn of load tir's,
see SRP Section 3.8.411-3).
m____--_-------"-----
--"--- -- ~-~-'- ----'--- ------ - '
e. ', ' '
(a) Service Load Conci tans (1)
D+L (2)
D+L+E (3)
D+L+W If thermal stresses due to T and P are present, they should be included o
o in the above combinations, as follows:
(la) D + L + T + P o
y (2a) D + L + T + P + E o
o (3a) D + L + T + P + W o
o Check load ccmbination for controlling condition for maximum
'L' and for no
'L'.
K (b)
Extreme Environmental, Abnormal, Abnormal /Servere Environmental and Abnorr.21/ Extreme Environmental Conditions (4)
D+L+T+P+E o
o (5)
D+L+T+P+W:
o o
(6)
D + L + T + P + 1. 5 P 3
3 a
(7)
D + L - T + P - 1. 25 P + 1. 0 (Y + Yj + Ym)A 1.25 E 3
3 a
p (8)
D + L - T - P + 1. 0 P,3 + 1.0 (Y + Y + Ym ) + 1. 0 E '
3 3
r j
In ccmbina:icns (5), (7), and (3) the maximum values of P, T, R, Yj, Y, a n d Y
, including an appropriate dynaric 3
3 3
r m
lead factor, shculd be used unless a time-history analysis is perforned ;o justify otherwise.
Combinations (5), (7) and :.2) and the correspor. sing structural acceptance criteria should be satisfied first witnout the tornado missile load in (5) and without Yr. ij, and h in (7) and (8).
When considering these
)
'y loads, local section strength ca:acities may be exceeded uncer these concentrated loads, provided tnere will-be no loss of function of any safety-related system.
Both cases of L having its full value or being completely absent should be checked.
3.
Allowable Stresses Allowable stresses provided in ACI-531-79, as supplemented by the following modifications / exceptions shall apply.
(a) When wind or seismic loads (05E) are considered in the loading ccmbinations, no increase in the allowable stresses in permitted.
4 (b)
Use of allcwabie stresses corres;onding to special inspection category shall be substantiated by demonstration of ccapliance with tne inspection requirements of the SEB criteria.
(c) When tension perpendicular to bed joints is used in cualifying the unreinfor:ec asonry walls, the allowable value will be justified by test procra or other ceans pertir.ent to the plar.: and icad:cc conditions.
- r reinforced rasonry walls, all the tensile stresse; will be res isted oy reinforcerent.
(d)
For load conditions, which represent extreme enviror. mental, abnormal, abnor.~al/ severe er.vironmental, and abnormal / extreme environmental conditions the allcwable working stresses may be multiplied by the factors shown in the following table:
TYPE OF STRESS FACTOP Axial or Flexural Compression (1) 2.5
- 2. 5 Bearing Reinforcement stress except shear 2.0 cut not to exceed 0.9 fy Shear reinforcement and/or bolts 1.5
~ Masonry tensior, parallel to bed joint 1.5 Shear carri,ed by masonry 1.3 Masonry tension perpendicular to bed joint for reinforced masonry O
for unreinforced masonry (2) 1.3 Notes i
(1)
'r: hen anchor bolts are used, design should prevent facial spailin; of masonry unit.
(2)
See 3 (c).
4 Design and Analysis Considerations (a)
The analysts should foli:. established principles c ~ er.;i.ierinc nechanics and take in:: account sound ercineering r ::: ice (b) Assumptions and modeling techniques used shall give procer considerations to boundary conditions, cracking of section:, if any, and the dynamic benavior of nasonry walls.
(c)
Danping values to be used for dynamic analysis shall bc U.:se for reinforced concrete :iven in Regulatory Guide 1.61.
r Le * *
- 5-(d)
In general, for operating plants the seismic analysis and Category I structural requirements of FSAR shall apply.
For other plants, corresponding SRP requirements shall apply. The seismic analysis shall account for the variations and uncer-tainties in mass, materials and other pertinent parameters used.
(e) The analysis should consider both in-plane and out-of-plane loads.
(f)
Interstory drif t effects should be considered.
(g)
In new construction, grout in concrete masonry walls, whenever used, shall be compacted by vibration.
(h) Fce masonry shear walls, the minimum reinforcerent requirements
~
of AC!-531 shall apply.
(i) Special constructions (e.g. multiwythe, composite) or other items not covered by this cede shall be reviewed on a case-by-case basis for their acceptance.
(j) Licensees or applicants shall submit QA/QC infor. nion, i f I
available, for staff's review.
t i
l
,w--vvg-,,-ea
+ + -,
,y t
w
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y----~-
-7w-Y T'w-y--*-,,--vu-v 3v-y--yyu.rvwe ve' v*WL----
--q--ep--
w--
e
-e-e
+-
i
- ... e In the event, QA/QC information is not available, a field survey and a test program reviewed and approved by the staff shall be implemented to ascertain the conformance of masonry construction to design drawings and specifications (e.g. rebar and grouting).
(k)
For masonry ;valls requirine protection from spalling and scabbing due to accident pipe reaccion (Y ), jet imping'ement (Y ) and r
j missile impact (Y ), the requirements similar to those of m
SRP 3.5.3 shall apply. However, actual review will be conca:ted on a case-by-case basis.
5.
References g
(a)
Uniforn Building Code - 1979 Edition (b)
Building Code Requirements for Concrete Masonry Structures ACI-531 - 79 and Correntary ACI-531R - 79.
(c)
Tentative Provisions for tne Develocment of Seismic Regulc - s f:r Eaiidings - Applied Te:r.nology Counci' ATC 3-06.
(d) 5;scification for the Design and Construction of Load-cear:n; Con: rate Masonry - NC'J August, 1979.
(e)
Trcjan Nuclear Plant Ccncrete Masonry Design Criteria Safety Evaluation Report Suppie ent - November, 1980.
.