ML20209C545
| ML20209C545 | |
| Person / Time | |
|---|---|
| Site: | Satsop |
| Issue date: | 11/01/1983 |
| From: | Knight J Office of Nuclear Reactor Regulation |
| To: | Novak T Office of Nuclear Reactor Regulation |
| References | |
| CON-WNP-1465 NUDOCS 8311110167 | |
| Download: ML20209C545 (14) | |
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[. -t i b NOV 1 1983 Docket No. 50-508 e MEMORANDUM FOR: Thomas M. Novak, Assistant Director for Licensing, Division of Licensing FROM: James P. Knight, Assistant Director for Components &
Structures Engineering, Division of Engineering
SUBJECT:
DRAFT SAFETY EVALUATION REPORT, WASHINGTON NUCLEAR PROJECT N0. 3 FSAR REVIEW, STRUCTURAL TOPICS Plant Name: WNP3 Docket Number: 50-508 Licensing Stage: Operating License Responsible Branch and Project Manager: LB#3, A. Vietti Requested Completion Date: 10/31/83 Review Status: Open items exist. Reviews will continue on schedule as directed by Project Manager.
The FSAR submitted by the applicant has been reviewed and evaluated by the Structural and Geotechnical Engineering Branch (SGEB). The applicant has suspended construction. This SER was prepared in order to indicate open items and staff concerns as of this time in an effort to preserve the continuity of the review.
Our sections of the safety evaluation report are provided in the enclosure.
This evaluation is based on information provided by the applicant through Amendment No. 3, dated April 1, 1983 and the design audit conducted during September.1983. The enclosure was prepared by 0. Rothberg of Section B of the Structural and Geotechnical Engineering Branch.
/S/ M / a f d i m N w ,1 f y, James P. Knight, Assistant Director
/ for Components and Structures Engineering Division of Engineering
Enclosure:
As stated cc: R. Vollmer A. Vietti G. Lear P. Kuo
- 0. Rothberg D. Gupta J. Kimball j$k*
- 0. Rothbe P. Kuo G. Lear t SGEB SGEB SGEB-CH /
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ENCLOSURE WASHINGTON NUCLEAR PROJECT UNIT 3 STRUCTURAL ENGINEERING BRANCH DOCKET NO. 50-508 SAFETY EVALUATION REPORT 3.3.1 Wind Design Criteria All Category I structures exposed to wind forces were designed to withstand the effects of the design wind. The design wind specifi.ed has a velocity of 105 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 and ANSI -
A58.1-1972. These documents are acceptable to the staff.
The staff concludes that the plant design is acceptable and meets the requirements of General Design Criterion 2. This conclusion is based on the following:
The app'licant 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 consideraton 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 structures geometry and physical configuration.
The applicant has designed the plant structures with sufficient margin to prevent structural damage during the most severe wind loadings that have been determined appropriate for the site so that the requirements of Item 1 'isted 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 combination 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 provida 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 i 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 Design Criteria '
All Category I structures exposed to tornado forces and needed for the safe shutdown of the plant were designed to resist a tornado of 240 mph tangential wind velocity and a 60 mph translational wind velocity. The simultaneous atmospheric pressure drop was assumed to be 2.25 psi in 1.9 seconds. Tornado missiles are also considered in the design as discussed in Section 3.5 of this report.
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- We conclude that the plant design is acceptable and meets the recommendations of Standard Review Plan 3.3.2 and the requirements of General Design Criterion 2.
This conclusion is based on the following:
The applicant has met the recommendations of Standard Review Plan 3.3.2 and the requirements of GDC 2 with respect to the structure 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;
- 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 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 structures geometry i and physical configuration.
l The applicant has designed the plant structures with sufficient margin to l prevent structural damage during the most severe tornado loadings 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 tornado wind load and l
the loads resulting from normal and accident conditions.
l l The procedures utilized to determine the loadings on structures induced by the design basis tornado specified for the plant are acceptable since these procedures i
have been used in the design of conventional structures and proven to provide n
a conservative basis which together with other engienering design considerations assures that the structures will withstand such environmental forces.
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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 tornadoes will not be impaired and, in consequence, safety-related 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.
3.4.2 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.
With the exception noted at the end of this section we conclude that the plant flood structural design procedures are acceptable and meet the recommendations of Standard Review Plan 3.4.2 and the requirements of General Design Criterion 2.
This conclusion is based on the following:
The applicant has met the recommendations of Standard Review Plan 3.4.2 and the requirements of GDC 2 with respect to the capability to withstand the effects of the floor or highest groundwater level so that their design reflects
- 1. appropriate consideration for the most severe flood recorded for the site wi.th 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
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prevent 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 I listed above are met. In addition, the 3-4
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design of seismic Category I 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 loads and the loads resulting from normal and accident conditions.
The procedures used to determine the loadings on seismic Category I structures 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 en~vironmental 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 requirement of item 3 listed above.
The applicant has used PVC as a Waterstop material in the RAB (question 220.11 and reply). Since such material is subject to radiation deterioration and attendant production of destructive chemical reactions, the staff will require additional studies to show that these materials, as used, will not be hazardous to the plant structures and will perform their intended functions throughout the lifetime of the plant. It was noted that the reply to question 220.11 is not complete. The applicants answer was compared with information shown on ,
drawing WPSS-3240, G-2520-51, "RAB Internal Structures - Sheet 1." In that
! drawing reference is made to silicone rubber joint sealer, non-specific mate-l rial premolded joint filler, polyethylene and epoxy grout. A complete discus-l sion of this issue, which demonstrates that all of the organic materials used l
in waterstop and structural joint filler applications are satisfactory to I
resist chemical and radiation deterioration, is required.
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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 e internal missiles, such at those associated with a loss-of-coolant accident.
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.
We conclude that the barrier design is acceptable and meets the recommendations of Standard Review Plan 3.5.3 and the requirements of General Design Criteria 2 and 4 with respect to the capabilities of the structures, shields, ano l barriers to provide sufficient protection to equipment that must withstand the effects of natural phenomena (tornado missiles) and environmental effects l
including the effects of missiles, pipe whipping and discharging fluids. This conclusion is based on the following:
! The procedures utilized to determine the effects and loadings on saismic I
Category I structures and missile shields and barriers induced by design basis i missiles selected for the plant are acceptable since these procedures provide a conservative basis for engineering design t'o assure that the structure or barriers are adequately resistant to and will withstand the effects of such forces.
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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 barriors 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 .
The peak ~ accelerations associated with SSE were selected based on the seismicity evaluation described in Section 2.5 of the FSAR. The earthquake on which SSE is modeled has a Richter magnitude of 7 1/2, and originates at a distance of approximately 22 miles from the site. The peak horizontal baserock acceleration at the site asscciated with this earthquake is 0.32 g (SSE). The duration of strong motions for this earthquake is estimated to be approximately 30 , seconds.
Theoperatingbasifearthquake(OBE)ischosentobe1/2,SSEor0.16g. Verti-cal accelerations are 2/3 of horizontal, that is, 0.22 g SSE and 0.11 g OBE.
Horizontal design response spectra conform to the recommendations of Reg.
Guides 1.60 and 1.61.
Theverticaldesignresponsespectradoesnotcompg withtherecomendationsofReg.
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Guide 1.60inthe33to50Hzrang[*pp,
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" *- y : m :y M & d.* S A A@ c.a & An d,.Sr Q Although the duration of the earthquake record was to be 30 seconds it was found that the duration of earthquake was truncated to 20 seconds in the horizontal direction (Structural Design Audit Finding #5). This matter is under investigation at this writing.
The horizontal and vertical acceleration time histories were derived by applying a deconvolution methodology to a finite element model of the rock site. The
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staff disagrees with the results of this analysis (question 220.13, and Structural Design Audit Finding #1). Essentially, the applicant has allowed a significant 3-7
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reduction in the earthquake excitation at the base mat based on his deconvolu-tion analysis of a rock site. This issue remains unresolved as of this writing.
3.7.2 Seismic System Analysis 3.7.3 Seismic Subsystem Analysis The scope of review of the Seismic System and Subsystem Analysis for the plant included the seismic analysis methods for all Category I structures, systems and components. It included review of procedures for modeling, seismic soil-structure interaction, development of floor response spectra, inclusion of torsional effects, evaluation of Category I structure overturning, and determi-nation of composite damping. The review has included design criteria and procedures for evaluation of interaction of non-Category I structures and piping, with Category I structures and piping and effects of parameter variations on floor response spectra. The review has also included criteria and seismic analysis procedures for reactor internals and Category I buried piping outside the containment.
The system and subsystem analyses were performed by the applicant on an elastic bases. Modal time history methods form the bases for the analyses of all major Category I structures. Response spectra methods were used in the design of Category I systems and components.
The finite element approach is used to evaluate soil-structure interaction and structure to structure interaction offacts from seismic excitation. ,
As noted above in Section 3.7.1 of this report, the seismic acceleration input at the base mat used by the applicant is in question. (See questions 220.15 and 220.16). In addition several issues regarding the construction and use of floor response spectra are also unresolved at this time. These issues are:
a) Derivation of floor response spectra without consideration of out-of plane acceleration factors (See question 220.18 and Audit Funding #17). It is noted that the torsional-effects analysis described in paragraph 3.7.2.11 of,the FSAR was not made available to the audit team at the Structural 3-8
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Design Audit. It is hereby requested that the applicant make this analysis available to the staff as part of his resolution of this issue.
b) Actual application of methods for peak-broadening and smoothing of response spectra are not in accordance with methods recommended by Reg. Guide 1.122 (to which the applicant is committed). See question 220.22, 220.23, and ;
Structural Design Audit Findings #11 and #19.
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 containment s'tructure were compared with Regulatory Guide 1.12 requirements. Supporting instrumentation is to be installed on Category I structures, systems and components in order to provide data for the verification of the seismic responses determined analytically for such Category I items.
The ranges of the types of instrumentation as well as the readout locations
. have not been provided. A seismic surveillance scheme as outlined in the SRP was not provided although it is said to be incorporated in the technical e specifications for the plant (See question 220.19). The technical specifications for the plant were not available, as of this writing, in order that the i surveillance scheme could be verified.
3.8.2 Steel Containment The containment consists of a free-standing steel shell located within a reinforced concrete shield butiding. These are founded on a common mat with (but separated by seismic gaps above the mat) a reactor auxiliary building.
The containment was designed, fabricated, constructed and tested as a Class MC vessel in accordance with Subsection NE of the ASME Boiler and Pressure Vessel Code,Section III. Loads include an appropriate combination of dead and live loads; thermal loads; seismic and loss-of-coolant accident-induced loads including pressure and jet forces.
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The analysis of the containment was based on elsstic thin shell theory. The allowable stress ar.d strain limits are in accordance with those delineated in the app 11:able sections of Subsection NE of the ASME -Code,Section III, for the various loading condittuns.
The following issNs are unresolved at this time:
- a. Question 220.25, whicn is a reouest for drawings, remains unsintwered.
- b. Question 220.26 which teque.sts validation of computer prcgrr.mo used in the containment design itmains unanswered. An advance ccpy of tha applicants proposed answer was provided to the staff in reply to portion (<:) pf Structural Desian Audit Fintif t #4. However, tne staff consider.s thit, proposeo answer to be ircomplete and lack 1rg in specific details. '
- c. Portions (a) and (b) of St.ruct.ir.11 Cesign Audit Finding #4 regarding complitnce with ASPIE code requiremants and buckling analysis rcmain unresolved.
- d. The answer to question 220.28 is not responsive. Neither a complete desciiption nor results of calculations for the containment static analysis was provided. .
- e. Question 220.27 was a staff request for an ultimate capacity analysis of the containment in accordance with the criteria contained in the SRP.
The answer provided by the applicant indicated that the ultimate capacity analysis would not be prepared.
- f. According to Table 1.8-3 of the FSAR a Design Report meeting the guidelines set forth in Appendix C to SRP Section 3.8.4 was prepared for the containment.
The staff was to examine the design report at the Structural Design Audit but did not do so. Therefore, the applicant is requested to make the Design Report available for staff review. This comment also applies to SER sections 3.8.3, 3.8.4 and 3.8.5.
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- g. Question 220.30 regarding use of plastic filler materials remains unanswered.
3.8.3 Concrete and Structural Steel Internal Structures The containment interior structures consist of walls, compartments and floors.
The major code used in the design of concrete internal structuras is ACI 318-71.
For steel internal structures the AISC Specification, " Specification for the Design, Fabrication and Erection of Structural Steel for Building," is used.
(For equipment supports, Subsection NF cf the ASME Code is used.
The containment concrete and stoel internal structures were designed to resist various combinations of dead and live loads, accident induced loads, including pressure and jet loads, and saia le loads. Tne load combinations used cover those cases likely to cccur and include all loads which may act simultaneously.
The design and analysis procedures that were used for the internal structures are the same as those on previously licensed applications and, in general, are in accordance with procedures delineated in the ACI 318-71 Codes and in the AISC Specification for cencrete and steel structures, respectively.
Ne containment internal structures were designed and proportioned to remain within limits estoD11shed by the Regulatory staff under the various load concinatior.s. These limits e.re, in general, based on the ACI 318-71 Code and on tne AISC Specification for concrete and steel structures, repectively, ,
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 and AISC Specification for concrete ;
and steel structures, respectively. ,
The response to question 220.35 is unsatisfactory. Differences between the application of ACI 318-71 and the staffs referenced design standard consisting of Reg. Guide 1.142 and ACI 349 were not documented. All that is stated in Table 1.8-3 is that ACI 318-71 was used in accordance with PSAR commitments.
This is not considered to satisfy the applicant's obligation to document 3-11
deviations from NUREG 0800. This comment applies to SER sections 3.8.4 and .
3.8.5 as well.
[ 3.8.4 Other Category I Structures y Category I structures other than containment and its interior structures are IL all cf structural steel and concrete. The structural components consist of slabs, walls, beams and columns. The major code used in the design of concrete Category I structures is the ACI 318-71, "8uilding Code Requirements for Reinforced Concrete." For steel Category I structures, the AISC, " Specification for the Design, 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, y and impact e.'fects of whipping pipes.
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The design and analysis procedures that were used for these Category I' structures are the same as those approved on previously licensed applications and, in 1 general, are in accordance with procedures delineated in the ACI 318-71 Codes c
? and in the AISC Specification for concrete and steel structures, respectively.
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{ The various Category I structures are designed and proportioned to remain within' limits established by the Regulatory staff under the various load 5
h combinations. These limits are, in general, based on the ACI 318-71 Code and
[ not the AISC Specification for concrete and steel structures, respectively, modified as appropriate for load combinations that are considered extreme.
The traterials of construction, their fabrication, construction and installation L are in accordance with the ACI 318-71 Code and the AISC Specification for concrete and steel structures, respectively.
With respect to Other Category I structures, the following issues remain outstanding:
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a) Structural Design Audit Finding #18 regarding the arbitrary reduction of seismic accelerations obtained from the NASTRAN analysis of the shield building remains unresolved at this time, b) Structural Design Audit Finding #21 regarding use of negative signs on load factors in the shield building analysis is not resolved.
c) Structural Design Audit Finding #22 regarding computer printouts with compressive stresses undefined in the output is not resolved.
d) Structural Design Audit Finding #23 regarding verification of the static vs. dynamic analysis of the dry cooling tower is not resolved.
3.8.5 Foundations 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. These concrete foundations have been designed to resist various combination of dead loads, live loads, environmental loads including winds, tornadoes, OBE and SSE, and loads generated by postulated ruptures of high energy pipes. .
The design and analysis procsdures 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 wtih procedures 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 349 Code modifed 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.
Structural Design Audit Finding #24 regarding foundation uplift in the stability analysis remains outstanding.
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r General Comments (Section 3.8) a) Structural Design Audit Finding #25 regarding the applicants documentation of load and load combination values in the various analyses remains unresolved.
b) The staff has not completed its review of all of the answers provided by the applicant to staff questions. Further issues may therefore become apparent as these reviews are completed.
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