ML20213E017
| ML20213E017 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 02/19/1982 |
| From: | Knight J Office of Nuclear Reactor Regulation |
| To: | Tedesco R Office of Nuclear Reactor Regulation |
| References | |
| CON-WNP-0471, CON-WNP-471 NUDOCS 8203050041 | |
| Download: ML20213E017 (29) | |
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f 1,9 Docket fio.: 50-397 [ +
l'El'ORAf DUil F0P.: Robert L. Tedesco, Assistant Director - 10*~d.TD -
for Licensing 94 7' Division of Licensing .~ "' EEB22IS82h 2')j -
FR0!1: James P. Knight Assistant Director c
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for Components and Structures Engineering b n Division of Engineering 4' /Q W SUCJECT: SAFETY EVALUATIO!! REPORT UASHIfiGT0ll PUBLIC POUER SUPPLY SYSTEl; fiUCLEAR PROJECT !!0. 2 Plant Itame: UPPSS Unit flo. 2 Docket flo.: 50-397 -
Responsible Branch and Project flanager: Licensing Branch 2, R. Auluck Requested Cmpletion Date: February 12, 1982 The FSAR submitted by the applicant has been reviewed and evaluated by the Structural Engineering Branch. A brief sur. nary of status and scope of review findings is contained in Enclosure 1. Our sections of the safety evaluation report are provided in Enclosure 2. This evaluation is based on information provided by the applicant through Amendment flo. 20, the results and the responses to action items from an audit meeting with the applicant held during the week of !!ovember 28, 1981. The enclosures ucre prepared by 1:. C. Leu of Section A of the Structural Engineering Branch.
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James P. Knight, Assistant Director l for Components and Structures Engineering Division of Engineering l
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- FE81 s 7992 MEMORANDUM OR
- Robert L. Tedesco, Assistant Director for Licensing Division of Licensing FROM: James P. Knight, Assistant Director for Components and Structures En neering Division of Engineering !
SUBJECT:
AFETY EVALUATION REPORT
- SHINGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT NO. 2 Plant Name
- WPPSS Un No. 2 i Docket No.: 50-397 Responsible Branch and Requested Completion Date.ojectManager:/1982icensing February 12 Branch 2, R. Auluck The FSAR submitted by the app 'can has been reviewed and evaluated by the Struc-tural Engineering Branch. A bi summary of status and scope of review findings is contained in Enclosure 1. Ou . sections of the safety evaluation report are provided in Enclosure 2. is valuation is based on information provitted by the applicant through Amendme No. issued in November 1981, the results and the responses to action ites from an udit meeting with the applicant held during the week of November 28, 1 1. The enc osures was prepared by K. C. Leu of Section A of the Structur 1 Engineering ranch.
i J es P. Knight, Assistant Director r Components and Structures
, En neering
] Divisi of Engineering l
Enclosures:
As stated cc: R. Vollmer F. Schauer i
A. Schwencer D. Jeng P. Tan R. Auluck K. Leu
Contact:
K. C. Leu, SEB x28984 l ,
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"\ j UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20666 e
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FEB 191982 Docket No.: 50-397 -
MEMORANDUM 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:
SAFETY EVALUATION REPORT WASHINGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT NO. 2 ,
Plant Name: WPPSS Unit No. 2 Docket No.: 50-397 Responsible Branch and Project. Manager: Licensing Branch 2, R. Auluck Requested Completion Date: February 12, 1982 The FSAR submitted by the applicant has been reviewed and evaluated by the
, Structural Engineering Branch. A brief sumary of status and scope.of review findings is contained in Enclosure.l. Our sections of the safety evaluation report are provided in Enclosure 2. This evaluation is based on information provided by the applicant through Amendment No. 20, the results and the responses to action items from an audit meeting with the applicant held during the week of November 28, 1981. The enclosures were prepared by K. C. Leu of Section A of the Structural Engineering. Branch.
V ~
imes . Kn ht, istant Director for Compon ts d Structures Engineering Division of Eng ering
Enclosures:
As stated cc: R. Vollmer F. Schauer A. Schwencer C. Jeng C. Tan R. Auluck K. Leu CONTACT: K. C. Leu, SEB, x28984 i .
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ENCLOSURE 1
SUMMARY
OF STATUS AND SCOPE OF WPPSS UNIT 2 REVIEW Section 3.3.1 Wind Loadings: Review is complete, no open items exists.
Section 3.3.2 Tornado Loadings: Review is complete, no open items exists.
Section 3.4.2 Water Level (Flood) Design Procedures: Review is complete, no open item exists.
Section 3.5.3 Barrier Design Procedures: Review is complete, no open item exists.
Section 3.7.1 Seismic Input: Review is complete, no open item exists.
Section 3.7.2 Seismic System Analysis and Section 3.7.3 Seismic Subsystem Analysis: Review is complete, no open item exists.
Section 3.7.4 Seismic Instrumentation Program: Review is complete, no open item exists.
Section 3.8.1 Concrete Containment: Not applicable Section 3.8.'2 Steel Containment: The evaluation is subject to the resolution of providing assessment of WNP-2 containment with respect to the effect of revisions to pool dynamic /
SRV load definitions. The applicant committed to provide the information before fuel. load date. With this commitment, we consider this item resolved.
Section 3.8.3 Concrete and Structural Steel Internal Structures: Review is complete. No open items exist.
Section 3.8.4 Other Category I Structures: Review is complete, no open item exists.
Section 3.8.5 Foundations: Review is complete, no open item exists.
1
Enclosure 2 WASHINGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT NO. 2 STRUCTURAL ENGINEERING BRANCH SAFETY EVALUATION REPORT 3.3.1 Wind Loadings ~
All Category I structures exposed to wind forces were designed to withstand the effects of the design wind. The design wind specified has a velocity of 100 mph based on a recurrence of 100 years.
The procedures that were used to transform the wind velocity into pressure loadings on structures and the associated vertical distribution of wind pressures and gust factors are in accordance with ASCE paper 3269. This document is acceptable to the staff.
The staff concludes that the plant design is acceptable and meets the require-ments of General Design Criterion 2. This conclusion is based on the following:
The applicant has met the requirements of GDC 2 with respect to the capability of the structures to withstand design wind loading so that their design reflects
- 1. appropriate consideration for the most severe wind recorded for the site with an appropriate margin;
- 2. appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena; and
- 3. the importance of the safety function to be performed.
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The applicant has met these requirements by using ANSI A58.1 and ASCE paper No. 3269, which the staff has reviewed and found acceptable, to transform the wind velocity into an effective pressure on structures and for selecting pressure coefficients corresponding to the structural geometry and physical configuration.
The applicant has designed the plant structures with sufficient margin to pre-vent structural damage during the most severe wind loadings that have been determined appropriate for the site so that the requirements of Item I listed above are met. In addition, the design of seismic Category 1 structures, as required by Item 2 listed above, has included in an acceptable manner load combinations which occur as a result of the most severe wind load and the loads resulting from normal and accident conditions.
The procedures used to determine the loadings on structures induced by the design wind specified for the plant are acceptable since these procedures have been used in the design of conventional structures and proven to provide a con-servative basis which together with other engineering design considerations assures that the structures will withstand such environmental forces. The use of these procedures provides reasonable assurance that in the event of design basis winds, the structural integrity of the plant structures that have to be designed for the design wind will not be impaired and, in consequence, safety-related systems and components located within these structures are adequately protected and will perform their intended safety functions if needed, thus satisfying the requirement of Item 3' listed above.
3.3.2 Tornado Loadings All Category I structures exposed to tornado forces and needed for the safe shutdown of the plant, were designed to resist a tornado of 300 mph tangential wind velocity and a 60 mph translational wind velocity. The simultaneous atmospheric pressure drop was assumed to be 3 psi in 3 seconds. Tornado missiles are also considered in the design as discussed in Section 3.5 of this report.
4 The procedures that were used to transform the torando wind velocity into pres-sure loadings are similar to those used for the design wind loadings as discussed in Section 3.3.1 of this report. The tornado missile effects were determined using procedures to be discussed in Section 3.5 of this report. The total effect of the design tornado on Category I structures is determined by appropriate combinations of the individual effects of the' tornado wind pressure, pressure drop, and tornado associated missiles. Structures are arranged on the plant site and protected in such a manner that collapse of structures not designed for the tornado will not affect other safety-related structures.
The staff concludes that the plant design is acceptable and meets the require-ments of General Design Criterion 2. This conclusion is based on the following:
The applicant has met the requirements of GDC 2 with respect to the structural capability to withstand design tornado wind loading and tornado missiles so that their design reflects
- 1. appropriate consideration for the most severe tornado recorded for the site with an appropriate margin; i
- 2. appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena; and 1
- 3. the importance of the safety function to be performed.
The applicant has met these requirements by using ANSI A58.1 and ASCE paper No. 3269, which the staff has reviewed and found acceptable, to transform the wind velocity generated by the tornado into an effective pressure on structures and for selecting pressure coefficients corresponding to the structural geometry and physical configuration.
The applicant has designed the plant structures with sufficient margin to pre-
. vent structural damage during the most severe tornado loadings that have been determined appropriate for the site so that the requirements of Item 1 listed 02/16/82 3 WPPSS 2 SER SEC 3
above are met. In addition, the design of seismic Category 1 structures, as required by Item 2 listed above, has included in an acceptable manner, load combinations which occur as a result of the most severe tornado load and the loads resulting from normal and accident conditions.
The procedures used to determine the loadings on structures induced by the design basis tornado specified for the plant are acceptable since these pro-cedures have been used in the design of conventional structures and proven to provide a conservative basis which together with other engineering design considerations assures that the structures will withstand such environmental forces.
The use of these procedures provides reasonable assurance that in the event of design basis tornado, the structural integrity of the plant structures that have to be designed for the tornadoes will not be impaired and, in consequence, safety related systems and components located within these structures are adequately protected and will perform their intended safety functions if needed, thus satisfying the requirement of Item 3 listed above.
3.4.2 Water Level (Flood) Design Procedures The design flood level resulting from the most unfavorable condition or combination of conditions that produce the maximum water level at the site is discussed in Section 2.4, Hydrology. The hydrostatic effect of the flood was considered in the design of all Category I structures exposed to the water head.
The procedures utilized to determine the loadings on seismic Category I struc-tures induced by the design flood or highest groundwater level specified for the plant are acceptable since these procedures provide a conservative basis for engineering design to assure that the structures will withstand such environmental forces.
The staff concludes that the plant design is acceptable and meets the require-
,ents m of General Design Criterion 2. This conclusion is based on the following:
i The applicant has met the requirements of GDC 2 with respect to the structural capability to withstand the effects of the flood or highest groundwater level so that their design reflects
- 1. i appropriate consideration for the most severe flood recorded for the site j
with an appropriate margin;
- 2. appropriate combinations of the effects of normal and accident conditions with the effects of the natural phenomena; and
- 3. the importance of the safety function to be performed.
The applicant has designed the plant structures with sufficient margin to pre-vent structural damage during the most severe flood or groundwater and the associated dynamic effects that have been determined appropriate for the site so that the requirements of Item 1 listed above are met. In addition, the design of seismic Category 1 structures, as required by Item 2 listed above, has included in an acceptable manner load combinations which occur as a result of the most severe flood or groundwater-related load and the loads resulting from normal and accident conditions.
The procedures utilized to determine the loadings on seismic Category I struc-tures induced by the design flood or highest groundwater level specified for the plant are acceptable since these procedures have been used in the design of conventional structures and proven to provide a conservative basis which together with other engineering design considerations assures that the structures will withstand such environmental forces.
The use of these procedures provides reasonable assurance that in the event of floods or high groundwater, the structural integrity of the plant seismic Category I structures will not be impaired and, in consequence, seismic Category I systems and components located within these structures will be adequately protected and may be expected to perform necessary safety functions, as required, thus satisfying the requirement of Item 3 listed above.
3.5.3 Barrier Design Procedures The plant Category I structures, systems, and components are shielded from, or designed for, various postulated missiles. Missiles considered in the design of structures include tornado generated missiles and various containment internal missiles, such as those associated with a loss-of-coolant accident.
7 Information has been provided indicating that the procedures that were used in the design of the structures, shields, and barriers to resist the effect of missiles are adequate. The analysis of structures, shields, and barriers to determine the effects of missile impact was accomplished in two steps. In the first step, the potential damage that could be done by the missile in the immediate vicinity of impact was investigated. This was accomplished by estimating the depth of penetration of the missile into the impacted structure.
Furthermore, secondary missiles are prevented by fixing the target thickness well above that determined for penetration. In the second step of the analysis, the overall structural response of the target when impacted by a missile is determined using established methods of impactive analysis. The equivalent loads of missile impact, whether the missile is environmentally [
generated or accidentally generated within the plant, are combined with other applicable loads as is discussed in Section 3.8 of this report.
The staff concludes that the barrier design is acceptable and meets the requirements of General Design Criteria 2 and 4 with respect to the capabilities of the structures, shields, and barriers to provide sufficient I protection to equipment that must withstand the effects of natural phenomena (tornado missiles) and environmental effects including the effects of missiles, pipe whipping, and discharging fluids. This conclusion is based on the following:
The procedures utilized te determine the effects and loadings on seismic Category I structures and missiles shields and barriers induced by design basis missiles selected for the plant are acceptable since these procedures provide a conservative basis for engineering design to assure t. hat the structures or barriers are adequately resistant to and will withstand the effects of such forces.
t The use of these procedures provides reasonable assurance that in the event of -
design basis missiles striking seismic Category I structures or other missile shields and barriers, the structural integrity of the structures, shields, and barriers will not be impaired or degraded to an extent that will result in a loss of required protection. Seismic Category I systems and components ;
protected by these structures are, therefore, adequately protected against the '
effects of missiles and will perform their intended safety function, if needed.
Conformance with these procedures is an acceptable basis for satisfying in part the requirements of General Design Criteria 2 and 4.
3.7.1 Seismic Input In the design of WNP-2 seismic Category I structures, systems, and components, an operating basis earthquake (OBE) of 0.125g and a safe shutdcWn earthquake (SSE) of 0.25g were specified. The input seismic design response spectra (08E and SSE) are defined at foundation level of the nuclear power plant structures.
These design response spectra, corresponding to those of Newmark and Hall, are not ' identical to the design response spectra as defined in Regulatory Guide 1.60, Revision 1, scaled to 0.25g maximum horizontal ground acceleration; however, the latter are used with higher damping values as defined in Regulatory Guide 1.61, Revision 0. In order to prove the adequacy of the design response spectra used by the applicant, we requested the applicant to compare the structural responses in the reactor building and other Category I structures using the two design response spectra mentioned above. The applicant has provided the comparisons for reactor building which show that the ,
structural responses due to each of the two methods are within 10% at almost all locations. The applicant also provided the comparisons for radwaste '
building which show that the input seismic design response spectra used by the applicant is conservative. These comparisons constitute the basis for the staff acceptance of the WNP-2 input design spectra.
The synthetic time history used for seismic design of Category I plant structures, systems, and components is adjusted in amplitude and frequency !
content to obtain response spectra that envelop the response spectra specified
,for the site.
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The seismic inputs to Category I structures, systems, and components are adequately defined. The applicant has demonstrated that the requirements of Regulatory Guides 1.60 and 1.61 are met. The evaluation is based on an operating basis earthquake (OBE) of 0.125g and a safe shutdown earthquake (SSE) of 0.25g. The discussion of free field ground motion response spectrum development and its adequacy is addressed in Section 2.5.2 of the SER.
The staff concludes that the seismic design parameters used in the plant struc-ture design are acceptable and meet the requirements of General Design Criterion 2 and Appendix A to 10 CFR Part 100.
This conclusion is based on the following:
The applicant has met the relevant requirements of GDC 2 and Appendix A to 10 CFR Part 100 by appropriate consideration for the most severe earthquake recorded for the site with an appropriate margin and considerations for two levels of earthquakes--the safe shutdown earthquake (SSE) and operating basis earthquake (08E). The applicant has met these requirements by the use of the methods and procedures indicated below:
The seismic design response s,pectra (OBE and SSE) applied in the design of i seismic Category I structures, systems, and components comply with the requirements of Regulatory Guide 1.60, " Design Response Spectra for Nuclear Power Plants." The specific percentage of critical damping values used in the seismic analysis of Category I structures, systems, and components are in 1 conformance with Regulatory Guide 1.61, " Damping Values for Seismic Analysis of i Nuclear Power Plants." The artificial synthetic time history used for seismic i
design of Category I plant structures, systems, and components is adjusted in amplitude and frequency content to obtain response spectra that envelop the j design response spectra specified for the site. Conformance with the requirements of Regulatory Guides 1.60 and 1.61 assures that the seismic inputs to Category I structures, systems, and components are adequately defined so as i
to form a conservative basis for the design of such structures, systems, and components to withstand seismic loading.
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_ _ = ,
3.7.2 Seismic System Analysis 3.7.3 Seismic Subsystem Analysis The scope of review of the Seismic System and Subsystems Analysis for the plant included the seismic analysit methods for all Category I structures, systems, and components.
It included review of procedures for modeling, seismic soil-structure interaction, development of flopr resoonse spectra, inclusion of torsional effects, evaluaticn of Category I stracture overturning, and deter-minaticn of composit.e damoing. The review has included design criteria and procedures for evaluation of -interactinn on non-Category I structures and piping with Category I s' tructures anc piping and effects of parameter varia-tions on floor response spectra. The review has also ificluded criteria for seismic analysis procedures for reactor irt.ernals and Category I buried piping outside th.e coctairment.
The system and subsystem analyses were performed by the applicant on elastic basis.
Modal respense spectrum multidegree of freedom and time history methods form the bases for the analyses of all major Category I structures, systems, and components.
When the modal response soectrym method was used, governing response parameters were combined by the square r90t of the sum of the squares rule, including the closely spaced medes. However, for modes with clos 91 y spaced frequencies, assessment was made by the applicant, and shown to freet the 4 requirements of Regulatory Guide 1.92.
The absolate sum (ABS) of two earthquake componants tif the maximum codirectiopal responses was used instead of SRSS of three components of the earthquake motion for both the time history and response spectrur methods.
Comparisons of the results obtained from both the ABS and SRSS methods were made by the applicant t.ad it was demonstrated that for all frequencies larger than 1.25 Hz the A85 method used by the applicant is conservative. This fiqding is acceptable to the staff since the frequency range of interest / concern in WNP-2 Category I structures and systems is always larger than 5 Hz.
The present technical position ut the staff requires that tne accidental torsion, minimum of 5% of the base dimensicn, be included in the cesign of 02/16/82 9 WPPSS 2 SER SEC 3
_ , - _ _ - - - . -- - -- - ~ ~ ~ ~
es structures.
This is in addition to that which results from the actual geometry and mass distribution of the building. In response to staff request, the 4
applicant provided calculation of design margin accounting for the accidental torsion for all Category I structures and showed that even for the structures with the lowest design margin, the factor of sa'fety values changed by less than 2%
and w*re still adequate. This is acceptable to the staff.
Floor spectra inputs used for design and test verifications of structures, systems, and components were generated from the time history method, taking into account variation of parameters by peak widening. A vertical seismic system dynamic analysis is employed for all structures, systems, and components where analyses show significant structural amplification in the vertical direction. Torsional effects and stability against overturning are considered.
The lumped mass-spring method was used to evaluate soil-structure interaction and structure-to structure interaction effects upon seismic responses.
However, the current staff position regarding the soil-structure interaction requires, in addition to the use of elastic half space approach, the use of finite element method.
4 The applicant provided the comparisons of the original soll spring analysis versus the finite element approach at different key.
locations in the reactor building and concluded that the soil spring analysis results envelop those from the finite element method. Furthermore, the applicant submitted the comparison results using the two different methods for radwaste/ control building and demonstrated that the floor response spectra for the original soil spring analysis are much higher than the response spectra obtained using the finite element method.
The applicant used the equivalent analysis for the spray ponds retaining wall and slabs and submitted analysis procedures and calculations which the staff reviewed and determined to be conservative.
The staff concludes that the plant design is acceptable and meets the require-ments of General Design Criterion 2 and Appendix A to 10 C'FR Part 100. This conclusion is based on the following:
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The applicant has met the requirements of 60C 2 and Appendix A to 10 CFR Part 100 with respect to the capability of the structures to withstand the effects of the earthquakes so that their design reflects (1) appropriate consideration for the most, severe earthquake recorded for the site with an appropriate margin .(GDC 2). Consideration of two levels of earthquakes (Appendix A, 10 CFR Part 100),
(2) appropriate combinations of the effects of normal and accident conditions with the effect of the natural phenomena, arid (3) the importance of the safety function to be performed (GDC 2). The ijse of a suitable dynamic analysis or a suitable qualification test to '
demonstrate that structures, systems, and components can withstand the seismic and other concurrent loads, except where it can be demonstrated that the use of an equivalent static load method provides adequate consideration (Appendix A, 10 CFR Part 100).
The applicant has met the requirements of item 1 listed above by use of the acceptable seismic design parameters as per SRP Section 3.7.1. The combination of earthquake resulted loads with those resulting from normal and accident conditions in the design of Category I structures as specified in SRP Sections 3.8.1 through 3.8.5 is in conformance with item 2 listed above.
We conclude that the use of the seismic structural analysis procedures and '
criteria delineated above by the applicant provides an acceptable basis for the seismic design which are in conformance with the requirements of item 3 listed above.
3.7.4 Seismic Instrumentation Program The type, number, location, and utilization of strong motion accelerographs to record seismic events and to provide data on the frequency, amplitude, and phase relationship of the seismic response of the Category I structures comply with Regulatory Guide 1.12. Supporting instrumentation is being installed on Category I structures, systems, and components in order to provide data for the 02/16/82 11 WPPSS 2 SER SEC 3
verification of the seismic responses determined analytically for such Category I items.
The staff wiudes that the seismic instrumentation system provided for the plant is accept.able and meets the recairements of GDC 2, 10 CFR Part 100, Appendix A and 10 CFR Part 50, S 50.55t. This conclusion is based on the following:
The applicant has met the requirements of 10 CFR Part 100, Appendix A by providing the instrumentation that is capable of measuring the effects of an earthquake which meets the requirements of GDC 2. The applicant has met the requiremerts of 10 CFR Part 50, S 50.55a by providing the inservice inspection program that will verify operability by performing channel checks, calibrations, and functional test at acceptable intervals. In addition, the installation of the specified seismic instrumentation in the reactor containment structure and other Category I structures, systems, and components constitutes an acceptable program to record data on seismic ground motion as well as data on the frequency and amplitude relationship of the seismic response of major structures and systems. A prompt readout of pertinent data at the control room can be expected to yield sufficient information to guide the operator on a timely basis for the purpose of evaluating the seismic response in the event of an earthquake. Data obtained from such installed seismic instrumentation will be sufficient to determine that the seismic analysis assumptions and the analytical model used for the design of the plant are adequate and that allowable stresses are not exceeded under conditions where continuity of operation is intended. Provision of such seismic instrumentation complies with Regulatory Guide 1.12.
3.8.1 Concrete Containment Not applicable for this facility.
3.8.2 Steel Containment The kNF-2 containment is a steel shell structure consisting of a truncated cone closed by a dome on the top and connected to a cylinder which is closed by an 02/16/82 12 WPPSS 2 SER SEC 3
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' inverted dome on the bottom. The truncated cone and the cylinder are separated by a diaphragm thus forming a drywell on the top and a suppression pool on the bottom. The suppression pool is connected to the drywell by a series of pipes penetrating through the diaphragm. The containment is supported on a -
reinforced concrete foundation mat. The containment as described is designated by General Electric Company as Mark II containment. The containment is enclosed in a reinforced concrete biological shield wall.
The WNP-2 containment was originally designed to resist various combinations of dead loads, live loads, environmental loads, including those due to wind and tornado, operating basis earthquake (OBE) and safe shutdown earthquake (SSE),
j and loads generated by the design basis accident (DBA) resulting mainly in high pressure and temperature. However, it was later identified that besides these loads traditionally associated with normal operation and DBA, additional sup-pression pool hydrodynamic loads had not been included explicitly in the original design basis of all Mark II containments of BWR plants under construc-tion including WNP-2. These additional loads will occur not only from postulated LOCA but also as a result of the actuation of safety relief valve (SRV) in normal plant operation. The required consideration of the additional i
loads is generic to all plants using Mark II cor.tainments. In an attempt to f
resolve the issue generically, a Mark II Owners Group was formed and the '
applicant of WNP-2 is a member of the group. s The initial effort of 'the group resulted in the issuance of the Dynamic Forcing i
Function Information Report (DFFR). The information contained in DFFR either is preliminary or needs further verification. Consequently, there is some uncertainty in the information contained in the DFFR and it can only be resolved on a long-term basis. In order to meet the needs of the lead plants, that is, plants in the later stage of construction, the staff issued NUREG-0487 ;
report entitled " Mark II Containment Lead Plant Program Load Evaluation and Acceptance Criteria," dated October 1978, with Supplements 1 and 2 dated August !
i 1980 and January 1981, respectively. In August 1981, the regulatory staff issued NUREG-0808 report entitled, " Mark II Containment Program Load Evaluation f
i and Acceptance Criteria" in which the staff concludes that the improved condensation-oscillation and chugging loads for the suppression pool boundary as proposed by the Mark II Owners' Group and the lead plant pool-swell loads l
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adopted by the Mark Il cwners as the final load specifications are conservative.
On the basis of DFFR and NUREG-0487, the structural components forming the boundary of the suppression pool were evaluated by the applicant for their capability to resist the effects of the additional hydrodynamic loads and were found to have adequate margins of safety. Through the use of a finite element model with the inclusion of the water as fluid mass, the effect of fluid-structure interaction was considered in the evaluation. The evaluation is con-tained in the applicant's Design Assessment Report (DAR). The staff has reviewed the DAR and found that the Revision 2 to the DAR was completed in August 1979, since then more information has been generated from the Mark II Generic Program. Therefore, the criteria used in the evaluation are not totally in conformance with those delineated in NUREG-0808. In view of this fact, the applicant has committed to make an assessment of WNP-2 containment with respect to the effect of revisions to load definitions as delineated in NUREG-0808 as a confirmation of the adequacy of the evaluation as presented in the August 1979 DAR before fuel load. With this commitment, we consider this item resolved.
The staff concludes that the design of the steel containment is acceptable and meets the relevant requirements of 10 CFR Part 50, S50.55a, and General Design Criteria 1, 2, 4, 16, and 50. This conclusion is based on the following:
- 1. The applicant has met the requirements of Section 50.55a and GOC 1 with
! respect to assuring that the steel containment is designed, fabricated, erected, constructed, tested and inspected to quality standards commensurate with its safety function to be performed by meeting the gtidelines of regulatory guides and industry standards indicated below.
- 2. The applicant has met the requirements of GDC 2 by designing the steel containment to withstand the most severe earthquake that'has been established for the site with sufficient margin and the ccmbination- of j
the effects of normal and accident canditions with the effects of environmental loadings such as earthquakes and other natural phenomena.
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3.
The applicant has met the requirements of GDC 4 by assuring that the design of steel containment is capable of withstanding the dynamic effects associated with missiles, pipe whipping, and discharging fluids.
4.
The applicant has met the requirements of GDC 16 by designing the steel containment so that it is an essentially leaktight barrier to prevent the uncontrolled release of radioactive effluents to the environment.
5.
The applicant has met the requirements of GDC 50 by designing the steel containment to accommodate, with sufficient margin, the design leakage rate, calculated pressure and temperature conditions resulting from accident conditions, and by assuring that the design conditions are not exceeded during the full course of the accident condition. In meeting these design requirements, the applicant has used the recommendations of regulatory guides and industry standards indicated below. The applicant has also performed appropriate analysis which demonstrates that the ultimate capacity of the containment will not be exceeded and establishes a reasonable margin of safety for the design.
- The criteria used in the analysis, design, and construction of the steel containment structure to account for anticipated loadings and postulated conditions that may be imposed upon the structure during its service lifetime are in conformance with established criteria, codes, standards, and guides acceptable tc the Regulatory staff. These include meeting the position of Regulatory Guide 1.57 and industry standard ASME Boiler and Pressure Vessel Code,Section III, Division 1, Subsection NE.
The use of these criteria as defined by applicable codes, standards, and guides; the loads and loading combinations; the design and analysis procedures; the structural acceptance criteria; the materials, quality control programs, and special construction techniques; and the testing and inservice surveillance requirements, provide reasonaole assurance that, in the event of earthquakes and various postulated accidents occurring within and outside the containment, the structure will withstand the specified conditions without inpairment of structural integrity or safety function.
A Category I concrete shield building protects the steel containment from 02/15/82 15 WPPSS 2 SER SEC 3
4 the effects of wind and tornadoes and various postulated accidents occurring outside the shield building.
3.8.3 Concrete and Structural Steel Internal Structures The containment interior structures consist of sacrificial shield wall, radial beam framing and stabilizer truss in the drywell, and drywell floor and its support columns, reactor pedestal, concrete lining above the steel bottom head and catwalks in the suppression pool. The major code used in the design of concrete internal structures was American Concrete Institute Standard 318-71,
" Building Code Requirements for Reinforced Concrete." For steel internal structures, the American Institute of Steel Ccnstruction Specification,
" Specification for the Design, Fabrication and Erection of Structural Steel for Buildings," was used.
The containment concrete and steel internal structures are designed to resist various combinations of dead and live loads, accident-induced loads, including pressure and jet loads, and seismic loads. The design of the containment internal structures to withstand the effects of suppression pool hydrodynamic loads was accomplished in the same manner as that for the containment structure as described in Section 3.8.2. The detailed reevaluation of the capability of containment internal structures to resist these newly identified loads is described in the applicants' Design Assessment Report. We have reviewed the design and analysis procedures and criteria that were used for the original design and for the reevaluation of the internal structures in the suppression pool. The containment internal structures were designed and proportioned to remain within limits established by the Regulatory staff under various load combinations. These limits as well as the design and analysis procedures are, in general, based on the American Concrete Institute 318-71 Code and on the American Institute of Steel Construction Specification for Concrete and Steel Structures, respectively, modified as appropriate for load combinations that are considered as extreme.
The loads and load combinations used in Tables 3.8-10 and 3.8-11 in Section 3.8.3 of the FSAR are different from those of Section 3.8.4 of the SRP.
However, the applicant provided reevaluation design calculations and showed 02/16/82 16 WPPSS 2 SER SEC 3
l j
l that the structures internal to containment have enough capacity to meet the applicable requirements of Section 3.8.4 of the SRP. The staff reviewed the results of the reevaluation and accepted the applicant's justification.
The materials of construction, their fabrication, construction, and installa-tion, are in accordance with the American Concrete Institute 318-71 Code as amended by ACI-349 Code and Regulatory Guide 1.142 and American Institute of Steel Construction Specification for Concrete and Steel Structures, respectively.
The staff concludes that the design of the containment internal structures is acceptable and meets the relevant requirements of 10 CFR Part 50, S 50.55a, and General Design Criteria 1, 2, 4, 5, and 50. This conclusion is based on the following:
- 1. The applicant has met the requirements of Section 50.55a and GDC 1 with respect to assuring that the containment internal structures are designed, fabricated, erected, constructed, tested, and inspected to quality stand-ards commensurate with its safety function to be performed by meeting the guidelines of Regulatory Guides and industry standards indicated below.
- 2. The applicant has met the requirements of GDC 2 by designing the containment' internal structure to withstand the most severe earthquake that
^ '
has been established for the site with sufficient margin and the combinations of the effects of normal and accident conditions with the effects of environmental loadings such as earthquakes and other natural phenomena.
- 3. The applicant has met the requirements of GDC 4 by assuring that the design of the internal structures are capable of withstanding the dynamic effects associated with missiles, pipe whipping, and discharging fluids.
- 4. The applicant has met the requirements of GDC 5 by demonstrating that structures, systems and components are not shared between units or that if 02/16/82 17 WPPSS 2 SER SEC 3
shared, they have demonstrated that sharing will not impair their ability to perform their intended safety function.
- 5. The applicant has met the requirements of GDC 50 by designing the containment internal structures to accommodate, with sufficient margin, the calculated pressure and temperature conditions resulting from accident conditions and by assuring that the design conditions are not exceeded during the full course of the accident condition. In meeting these design requirements, the applicant has used the recommendations of Regulatory Guides and industry standards indicated below.
The criteria used in the design, analysis, and construction of the containment internal structures to account for anticipated loadings and postulated conditions that may be imposed during its service lifetime are in conformance with established criteria, and with codes, standards, and specifications acceptable to the Regulatory staff. These include meeting the positions of Regulatory Guides 1.10, 1.15, 1.55, 1.57, 1.94, and 1.142 and industry standards ACI-349; ASME, "ASME Boiler and Pressure Vessel Code,Section III, Division 2, Code for Concrete Reactor Vessels and Containments;" ASME " Boiler Pressure Vessel Code,Section III, Subsections NE and NF;" AISC, " Specifications for the Design, Fabrication, and Erection of Structural Steel for Buildings," and ANSI N45.2.5.
The use of these criteria as defined by applicable codes, standards, and specifications; the loads and loading combinations; the design and analysis procedures; the structural acceptance criteria; the materials, quality control programs, and special construction techniques; and the testing and inservice surveillance requirements, provide reasonable assurance that, in the event of earthquakes and various postulated accidents occurring within the containment, the interior structures will withstand the specified design conditions without impairment of structural integrity or the performance of required safety functions.
f -
3.8.4 Other Category I Structures .
Category I structures other than containment and its interior structures are all of structural steel and concrete. The structural components consist of slabs, walls, beams, and columns. The major code used in the design of con-crete Category I structures is ACI 318-71, " Building Code Requirements for Reinforced Concrete." For steel Category I structures, the AISC, "Specifica-tion for the Deeign, Fabrication and Erection of Structural Steel for Buildings," is used.
The concrete and steel Category I structures were designed to resist various combinations of dead loads; live loads; environmental loads including winds, tornadoes, OBE, and SSE; and loads generated by postulated ruptures of high energy pipes such as reaction and jet impingement forces, compartment pressures, and impact effects of whipping pipes.
The design and analysis procedures that were used for these Category I struc-tures are the same as those approved on previously licensed applications and in general, are in accordance with procedures delineated in the'ACI 318-71 Code arid in the AISC Specification for concrete and steel structures, respectively.
The various Category I structures are designed and proportioned to remain within limits established by the Regulatory staff under the various load combinations. These limits are, in general, based on the ACI 318-71 Code and on the AISC Specification for concrete and steel struct'ures, respectively, modified as appropriate for load combinations that are(considered extreme.
The materials of construction, their fabrication, construction, and installation, are in accordance witn the ACI 318-71 Code and the AISC Specification for concrete and steel structures, respectively.
The loads and load combinations used in Table 3.8-15 and 3.8-16 in 1
i 1
Section 3.8.4 of the FSAR are different from those presented in Section 3.8.4 of the SRP. The appli~ cant has reevaluated the design of WNP-2 and indicated, j
that the load combinations and acceptance criteria specified in Section 3.8.4 l
of the SRP are satisfied. This is acceptable to the staff.
, 02/16/82 19 WPPSS 2 SER SEC 3 n .
The applicant confirmed that there are no safety-related masonry walls for WNP-2 facility.
The criteria that were used in the analysis, design, and construction of all the plant Category I structures to account for anticipated loadings and postu-lated conditions that may be imposed upon each structure during its service lifetime are in conformance with established criteria, codes, standards, and specifications acceptable to Regulatory staff.
The staff concludes that the design of safety related structures other than containment is dcceptable and meets the relevant requirements of 10 CFR Part 50, S 50.55a, and General Design Criteria 1, 2, 4, and 5. This conclusion is based on the following:
1.
The applicant has met the requirements of Section 50.55a and GDC 1 with respect to assuring that the safety-related structures other than containment are designed, fabricated, erected, constructed, tested, and inspected to quality standards commensurate with its safety function to be performed by meeting the guidelines of Regulatory Guides and industry standards indicated below.
2.
The applicant has met the requirements of GDC 2 by designing the safety related structures other than containment to withstand the most severe earthquake that has been established for the site with sufficient margin and the combinations of the effects of normal and accident conditions with the effects of environmental loadings such as earthquakes and other natural phenomena.
3.
The applicant has met the requirements of GDC 4 by assuring that the design of the safety-related structures are capable of withstanding the dynamic effects associated with missiles, pipe whipping, and discharging fluids.
4.
The applicant has met the requirements of GDC 5 by demonstrating that structures, systems, and components are not shtred between units or that 02/16/82 20 WPPSS 2 SER SEC 3
if shared they have demonstrated that sharing will not impair their ability to perform their intended safety function.
- 5. The applicant has met the requirements of Appendix B because their quality assurance program provides adequate measures for implementing guidelines relating to structural design audits.
The criteria used in the analysis, design, and construction of all the plant Category I structures to account for anticipated loadings and postulated conditions that may be imposed upon each structure during its service lifetime are in conformance with established criteria, codes, standards, and specifications acceptable to the Regulatory staff. These include meeting the positions of Regulatory Guides 1.10, 1.15, 1.94, and 1.142 and industry standards ACI-349 and AISC, " Specifications for the Design, Fabrication, and Erection of Structural Steel for Buildings."
The use of these criteria as defined by applicable codes, standards, and specifications; the loads and loading combinations; the design and analysis procedures; the structural acceptance criteria; the materials, quality control, and special construction techniques; and the testing and inservice surveillance requirements, provide reasonable assurance that, in the event of winds, tornadoes, earthquakes, and various postulated accidents occurring within the structures, the structures will withstand the specified design conditions without impairment of structural integrity or the performance of required safety functions.
3.8.5 Foundations l
l Foundations of Category I structures are described in Section 3.8.5 of the SAR.
Primarily, these foundations are reinforced concrete of the mat type. The major code used in the design of these concrete mat foundations is ACI 318-71 l Code. These concrete foundations have been designed to resist various combinations of dead loads; live loads; environmental loads including winds, tornadoes, OBE, and SSE; and loads generated by postulated ruptures of high
. energy pipes.
l 02/16/82 21 WPPSS 2 SER SEC 3
The design and analysis procedures that were used for these Category I founda-tions are the same as those approved on previously licensed applications and, in general, are in.accordance with proced'ures delineated in the ACI 318-71 Code. The various Category I foundations were designed and proportioned to remain within limits established by the Regulatory staff under the various load combinations. These limits are, in general, based on the ACI 318-71 Code modified as appropriate for load combinations that are considered extreme. The materials of construction, their fabrication, construction, and installation are in accordance with the ACI 318-71 Code.
The criteria that were used in the analysis, design, and construction of all the plant Category I foundations to account for anticipated loadings and postu-lated conditions that may be imposed upon each foundation during its service lifetime are in conformance with established criteria, codes, standards, and specifications acceptable to the NRC staff.
The staff concludes that the design of the seismic Category I foundations are acceptable and meets the relevant requirements of 10 CFR Part 50, S 50.55a, and General Design Criteria 1, 2, 4, and 5. This conclusion is based on the following:
- 1. The applicant has met the requirements of Section 50.55a and GDC 1 with respect to assuring that the seismic Category I foundations are designed, fabricated, erected, constructed, tested, and inspected to quality standards commensurate with its safety function to be performed by meeting the guidelines of Regulatory Guides and industry standards indicated below.
- 2. The applicant has met the requirements of GDC 2 by designing the seismic Category I foundation to withstand the most severe earthquake that has been established for the site with sufficient margin and the combinations of the effects of normal and accident conditions with the effects of environmental loadings such as earthquakes and other natural phenomena.
- 3. The applicant has met the requirements of GDC 4 by assuring that the design of seismic Category I foundations are capable of withstanding the 02/16/82 22 WPPSS 2 SER SEC 3
dynamic effects associated with missiles, pipe whipping, and discharging fluids.
- 4. The applicant has met the requirements of GDC 5 by demonstrating that structures, systems and components either are not shared between units or that if shared, they have demonstrated that sharing will not impair their ability to perform their intended safety function.
The criteria used in the analysis, design, and construction of all the plant seismic Category I foundations to account for anticipated loadings and postulated conditions that may be imposed upon each foundation during its service lifetime are in conformance with established criteria, codes, standards, and specifications acceptable to the Regulatory staff. These include meeting the positions of Regulatory Guide 1.142 and industry standards ACI-349 and AISC, " Specification for Design, Fabrication, and Erection of Structural Steel for Building."
The use of these criteria as defined by applicable codes, standards, and specifications; the loads and loading combinations; the design and analysis procedures; the structural acceptance criteria; the materials, quality control, and special construction techniques; and the testing and inservice surveillance requirements provide reasonable assurance that, in the event of winds, tornadoes, earthquakes, and various postulated events, I
seismic Category I foundations will withstand the specified design conditions without impairment of structural integrity and stability or the performance of required safety functions.
1 02/16/82 23 WPPSS 2 SER SEC 3
Bibliography Section 3.3 - Wind and Tornado Loadings 3.3-1 " Wind Forced on Structures," Final Report of the Task Committee on Wind Forces of the Committee on Load and Stresses of the Structural Division, Transactions of the American Society of Civil Engineers, 345 East 47th Street, New York, NY, 10017, Paper No. 3269, Vol. 126, Part II, 1961, p. 1124-1198.
-or-3.3-1 "American National Standards Building Code Requirements 'for Minimum Design Loads in Buildings and Other Structures," American National Standards Institute, A58.1 - 1972.
3.3-2 USNRC Standard Review Plan (NUREG-0800, Rev. 2, July 1981)
Section 3.5 - Missile Protection 3.5-1 A. Amirikian, " Design of Protective Structures, " Bureau of Yards and Docks, Publication No. NAVDOCKS P-51, Department of the Navy, Washington, DC, August 1950.
3.5-2 Williamson, R. A., and Alvy, R. R., " Impact Effect of Fragments Striking Structural Elements," Holmes and Narver, Revised Edition, 1973.
3.5-3 USNRC Standard Review Plan (NUREG-0800, Rev. 1, July 1981).
Section 3.7 - Seismic Design 3.7-1 USAEC Regulatory Guide 1.60, " Design Response Spectra for Nuclear Power Plants."
<~
3.7-2 USAEC Regulatory Guide 1.61, " Damping Values for Seismic Analysis of Nuclear Power Plants."
3.7-3 USAEC Regulatory Guide 1.12 " Instrumentation for Earthquakes."
3.7-4 USNRC Standard Review Plan (NUREG-0800, Rev. 1, July 1981).
Section 3.8 - Design of Category I Structures 3.8-1 American Institute of Steel Construction, " Specification for Design, Fabrication & Erection of Structural Steel for Buildings," 101 Park Avenue, New York, NY 10017, Sixth Edition, 1969.
3.8-2 American Concrete Institute, " Building Code Requirements for Reinforced Concrete (ACI 318-1971)," P.O. Box 4754, Redford Station, Detroit, MI 48219.
3.8-3 American Society of Mechanical Engineers, "ASME Boiler and Pressure Vessel Code,"Section III, and Addenda United Engineering Center,
,345 East 47th Street, New York, NY 10017.
3.8-4 USNRC Standard Review Plan (NUREG-0800, Rev. 1, July 1981) l .
l 02/12/82 25 WPPSS 2 SER SEC 3 l
l a