ML19326D031
| ML19326D031 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 08/31/1968 |
| From: | Hall W, Newmark N, Webb Patricia Walker NATHAN M. NEWMARK CONSULTING ENGINEERING SERVICES |
| To: | |
| Shared Package | |
| ML19326D030 | List: |
| References | |
| NUDOCS 8004300653 | |
| Download: ML19326D031 (10) | |
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8004300 U M.
NEWAARK NATHAN CONSULTING ENGINEERING SERVICES 1114 CIVIL ENGINEERING BUILDING URBANA, ILLINOIS 61801 REPORT TO AEC REGULATORY STAFF ADEQUACY OF THE STRUCTURAL CRITERIA FOR THE RUSSFLLVILLE NUCLEAR UNIT ARKANSAS F0WER AND L ICHI COMPANY (AEC Docket No. 50-313) by A.
M.
Newa r k, W.
J. Hall and W.
H.
Walker August 1968 I
l
~s AD600/ ICY Of l it f 'ilRutfl!RAL rRITTRIA F'OR THE RUSSELLVILLE NUCLEAR tlNIT Arkansas Power and 1ight Company by N.
H.
Newma r k, W. J. Hall and W.
H. Walker INTRODUCTION This report is concerned with the adequacy of the containment structures and components for the Russellville Nuclear Unit for which application for a construction permit has been rde to the U.
S. Atomic Energy Commiss ion by the Arkansas Power and Light Comoany.
The f acility is located on a peninsula in the Dardanelle Reservoir, Arkansas River, Pope County, Arkansas, about 6 miles WNW of Russellville, and 2 miles SE of London, Arkansas.
Specifically this report is concerned with the design criteria that determine the abilit y of t he contairment s ystem and Class I equipnent and piping as well as Class il s t ruc tures and equipnwnt, to wi ths tand an Ope rat i ng Bas is Farthquake of 0.109 maximum hori/ontal ground acceleration simultaneously with the other loads forming the basis of the desion.
The f acility also is to be des igned to wi ths tand a Des ign Bas is Eart hquake of 0.209 maximum horizontal ground acceleration to the extent of ensuring saf e s hutdewn and conta i nment, ibis report is based on information and criteria set forth in the Preliminary Saf et y Analys is Repor ts (PSAR) and supplement s thereto listed at 5e end of this report.
Also, we have partic.aot-d in discuss ions with the 2
applicant and the AEC Regulatory '.taf f concerning the des ign of this unit.
DE S CR IP T ION :F FACILITY The Russellville Nuclear Unit is described in the PSAR as cons is t ing of a pressurized-water type reactor employing two closed cooling loops connected
.in parallel to the reactor vessel.
The s ys t em is ar ranged as two heat t ra ns por t
m
?
loops,' each with two c ircela t ing pumes and one s team generator ; one of the loops contaie.s an elect rically beated pressuri7er.
The nuc lear s team suppl y system will be f urnished by the Babcock and Wilcox Company, and the turbine generator is to be supplied by the Wes t inghouse Elect ric Corporat ion.
The plant is to be designed for a power level of 7452 MWt (350 Mwe).
The reactor containnent structure is a f ully continuous reinforced concrete structure in the shape of a cylinder with a shallow domed roof and a flat foundation slab.
The cylindrical portion is prestressed by a post-tensioning system of borizontal and vertical tendons.
the done is pos t-tens ioned us ing a 3-wa y s ys t em.
The hoop tendons are to be placed in three 2L0 s ys tems us i ng t hree but t resses as anchorages, wi th t he tendons s te.ggered so that half of the tendons at each buttress t e rmi na t e a t that buttress.
The foundation slab is conventionally reinforced with high-strength reinforcing steel.
The cylinder has an internal dianeter of 116 ft. and an ins ide height of 706 ft.
The distance from the too of the foundation slab to the springline of the domed roof i s approx ine ta l y 16f-ft.
The vertical wall thickness is noted 3 in.
The foundation slab to be 3 ft. - 9 ie. and the dome thickness, 3 ft.
thickness is about 9 ft.
For prestressing, the applicant proposes to se 90 to 184 wire tendons, unbnnded, lhe discuss ion nresented i n t h e P' "- < -v,oes t s
- hat
'he neRV type anchor aele s ys tem will be emoloved, although the P' AR notes that other prestressinq *ystoms wi1l inetinue to bo <tudied.
he pres t ress ing t endons ressure fo;"'!..? t a' ; nu eiller.
w;1I t.,
r t r *.a c a..a'rst
.ir e o* i n t-The liner plate will conform to spec i f ica t ion ASTM-Akk2, Grade 60, and will be 1/4 In. in thickness.
The reinforcing steel in the base slab of the
-containment structure will conform to ASTM designation A432-65; this steel
3 possesses a minimum yield strength of 40,000 psi.
Solices in bars larger than No. II will be made by the Cadweld method.
'he desisin of t he enr t a i nrre n t structure for th is f ac ilit v s essant* ally similar to that employed for the Rancho teco Nuclear Cencrat ing $ tat ion Unit No.
I.
Ihc geological description of the site indicates a stif f clay and silty clay of 13 to 23 foot thickness overlying hard and dense horizontally bedded shale of the Pennsylvanian McAlester formation.
All maj or s t ructures of the facility will be founded on the underlying Mc Alester f ormat ion shale bedrock.
No active or recent faultina has been mapped in the area of the proposed site.
The closest known faults are the London and Ferry View faults located 5 or 6 miles f rom the s ite.
COURCES OF STRr;$ES IN CONTAINMINT SiRUCTURf5 TN CIASS i COMPONENTF The reactor containment structure is to be des igned for the following load ings and condi t ions :
dead load, live load (i nc l ud i ng s now a nd eq u i pme n t loads); prestressed loadings; design accident temperature of about 285 f and pressure of 59 ps ig; an air test pressure of Ils percent of the desinn pressure, an external pressure loading with a differential of approximately 2) psi from outside to inside; wind loading corresponding to 60 mph bas ic wind at 30 ft. above grade; buoya nc y load irigs ; tornado load ing assoc iated wi th a 300 mph-tangential wind velocity and a k0 mph forward progression velocity, including a differential pressure of 3 psi from inside to outs ide with associated miss iles ; and ear t hquake loading as described next.
The seismic design is to be made f or a n Dr.. e e r i ng Eas i s :arthquake i
hated upon a maximum horizontal ground acceleration
.it 0.199 and e Design Bas is Ear thquake based upon a maximum hor izontal grrano accelerat ion of ' 20.
9 l
.s 4
The containment wells and liner are shielded by various types of barriers f rom impact ' f rom miss iles which poss ibly could have enough energy to strike or penetrate them.
The high-pressure reactor cooling system equipment which could be the source of missiles is screened either by the contair.+ tnt shield wall enclosing the reactor cooling loops, by the concrete operating floor, or by a special missile shield to block any passage of misslie to the containment walls.
The general criteria controlling the des ign of piping and reactor internals for seismic loadings are presented in various places in the PSAR.
COMPENTS ON ADEQUACY OF DESICN Foundatiors and Cams The moJor f acility s tructures are to be founded directly on competent bedrock, and on the basis of the information presented in the PSAR and amendments,
the foundation conditions appear acceptable to us.
The Dardanelle Reservoir f rom which the plant will draw i t s cool i ng waters is discussed in several places in the PSAR and particularly in Appendix 2F and in t he answers to Ques t ions 2.7 and 7.8 of Supplement No. 3.
The ana l ys i s of the Dardanelle Lock and Dam as reported in Appendix 2F sugges ts that some danuge to the t ck and Dam f acili ty night be expected.
Thus, the applicant notes in the answer to Ques t ion 2. 7 that emergency shutdown cooling water will be supplied f rom an emergency reservoir to be located northwest of the plant site.
The emergency reservoir will be excavated in impervious clay and will have an effective storage capacity of about 35 acre feet.
We concur in this approach for an assured source of cooling water in view of the possible effects i.
of an earthquake on the Dardanelle 1.ock and Dam.
I 1
i w
5 The effect of a flood on the structure is discussed in the answer to Ques t ion 2.8 of Supplement No. 3.
It is noted there that the plant grade level is elevation 353 ft. and the maximum elevation of a flood is estimated to be 3(>l it.
The applicant indicates that the early forecast of a severe f l ood o f t h i s t ype wou l d prov i de amp l e t i me for precautionary measures in terms of plant shutdown.
All Class I equipment is either loca ted above maximum proballe flood level or protected by waterproof Class I structures which are designe for Luoyancy effects.
ras l'ipe l i ne In the answer to Question 2.11 of Supplement No. 3, there appears a discussion of the natural gas t ransmiss ion pipeline which crosses t he discharge water channel.
It is indicated in the answer to that question that 'ne existing piocline cross ing will be re-layed beneath the water channel with k (t. of earth cover.
We understand that it will be possible to valve off this section of line in the event of difficulty.
It is noted that t he pipel i ne will he at its closest about 400 ft. from the intake structure and f00 ft, from t he c ont a i nnert structure, lhese dis tances are suf f ic ient,
believe, to we prec lude any ser ious cons equences wi th regard to plant safety in the event of a pipe rupture.
Seismic fics ign and C ri ter ia We are in agrecrent with the carthquake loading criteria selected for the seismic des ign, name l y t ha t associated with an Operating Basis Ear t h<loake of ').179 maximum horimntal ground accelerat ion and a Design B* sis farthquake of 0.209 maximum horizontal oround acceleration, these earthquake design criteria are in agr eement with those given by the U.
t.
Coast and Ceodet ic Survey (Ref. 2).
., 'The. response spectra for the Operating Easis Earthquake and Design l
Basis Earthquake to be employed in the dynamic analysis are presented as Fig. 5A-1 and 5A-2 of Appendix 5A of the PSAR.
These spectra are scaled after-those presented in publications.by Dr. G. W. Housner, and we concur in their use.
The earthquake analysis will include the effects of vertical earthquake' excitation which will be taken as 2/3 of the horizontal component as noted on page 5-3 of the PSAR.
It is noted in the answer to Question 12.3.6 i
j that the effects of vertical and horizontal earthquake motions will be combined I
linearly and directly with each other and with the other applicable stresses.
We are in agreement with these design criteria.
i The percentage of critical damping to be employed in the analysis is listed on page 5-A-5 of the PSAR, and we are in agreement with the values given there.
i.
l The method of dynamic analysis is described in Section 5.1.5.6 of the l
I PSAR.
The methed of analysis is not described in detail and we have not l
[
evaluated it completely.
The applicant advises in Supplement 8-that a standard modal analysis procedure will be employed to take account of structural rock-ing, lateral translation, and the shearing and flexural distortion of the.
structure. -With proper attention to damping, to. coupling of the various L
l-modes,- and to the procedures for combining modal responses, we believe it is i
- possible to arrive at. reasonable and consistent values of direct stress, l
' shear, moment, etc.
'The~ loading combinations to be employed for the design of the con-l
-tainment structure ~ are _ given in Section 5.1.4 of' the PSAR.
The loading
~
- combination. expressions given appear acceptable. to us, and it is noted that
'.for these; load factor combinations, 'the resistance will be less than the
. yield _ strength ofIthe struct'ure.
We concur in this approach, m
a_
=
s s7 The design of Class II structures ik discussed in the answer to Question 12.3.2 where it is noted that the des ign of such items will be for Zone I of the Uniform Building Code.
It would be our recommendation that for critical Class II Items that are of special significance in terms of plant safety, the design be made on the basis of about 2/3 of Zone 3 of the l
Uniform Building Code.
The design approach as outlined for handling principal concrete tension and combined tension and membrane shear appear acceptable to us.
The design of the liner and anchors is discussed in various sections of the pSAR.
We are advised that the liner design is s t ill under s t udy and that further information will be forthcoming during the design phases.
It is our belief that the liner design can be carried out sat isfactorily and adequately, and we can see no particular dif ficulty here which wil'. preclude going forward with the cons truct ion permit.
The general approach outlined for the prestressed design receives attentios; in various parts of the PSAR and Supplements and other material made available to us.
The design for this plant employing three buttresses and 90 to 184 wire tendons Is relatively new.
The apolicant indicates that many f actors associated with this pos t-tens ioning are receiving added s tudy, as for example the problems associated with the f riction arising f rom the large pulling arc (240 ).
On the bas is of the information available to us, and realizing that additional studies are underway and will be carried forward during the des ign phases, we can see no reason why the proposed syst em will not be acceptable.
The des ign procedure for handling the s ta t ical des ign, numely use of the finite element technique, coupled with special s tudy and procedures
~.
8 for handling the primary and secondary loading around penetrations, appears satisfactory to us.
Class T Pfoina, Ecuiement, Vessels and Reactor Internals Only general statements are made in the PSAR concerning the design of Class I piping, equipment, vessels and reactor internals.. However, the f
answer ' to Ques tion 10.4.3 of Supplement No. 3 suggests that the criteria employed for Crystal River Unit 3 of the Florida Power Corporation will be applicable to this plant, and reference is made to the answer to
.Questlon 9 11 of the Crystal River application.
It is noted that the calcula-tions and design will not be completed until mid 1969.
On the assumption that the approach outlined in the Florida Power Corporation application for Crystal River Unit 3 will be.followed, i
we concur in the proposed approach.
Cont rols. Ins t rumentat ion, Bat te ries, e tc.
Only general information is noted in the PSAR concerning the seismic design criteria for critical elements of control, instrumentation, batteries,
etc.
It would be our recommendation that criteria for these items be e'xamined in detail during the design phases, to insure that the items can withstand the forces, motions and tilt that might be associated with an earthquake.
Quality Control and Inspection The matter of quality control, inspection and acceptance is disc'ussed throughout the PSAR and amendments.
The procedures outlined appear acceptable to.us.
CONCLUDING COP.MENTS On the basis of the information presented in the PSAR and supplements, l
l
. and in keeping with the design goal of providing serviceable structures and
T 5
o, 9
ccmponents with a reserve of strength and ductility, we believe that the design outline for the containment and other-Class I structures and equipment and for Class II structures and components can provide -an adequate margin of safety for seismic resistance. However, in the body of the report we have offered ccaments concerning tne method of dynamic analysis, and the design criteria for Class II structures.
It is understood that studies will continue during the design phases on the design of the liner anchorage and the pre-stressing tendon system, and it is suggested that the seismic design criteria for critical instrumentation be developed and implemented during the design phases.
RFJERENCES 1.
" Preliminary Safety Analysis Report - Volumes I, II (and Supplements No.1, 3, 4, 5, 6, 7, and 8)," Russellville Nuclear Unit, Arkansas Power and Light Company,1968.
2.
" Report on the Seismicity of the Russellville Nuclear Unit Site," U.S.
Coast and Geodetic Survey, Rockville, Maryland, August 14, 1968.