ML19329E158

App 5A of AR Nuclear 1 PSAR, Design Bases for Structures, Sys & Equipment. Includes Revisions 1-18

ML19329E158
Person / Time
Site:	Arkansas Nuclear
Issue date:	11/24/1967
From:	ARKANSAS POWER & LIGHT CO.
To:
References
NUDOCS 8005300762
Download: ML19329E158 (9)

Text

---

- -,.

NM

==

dG 8005300 m ~22

APPENDIX 5-A DESIGN BASES FOR STRUCTURES, SYSTEMS AND ECUI24ENT 1.0 GENERAL The design bases for structures for normal operating conditions are governed by the applicable building design codes. The design bases for specific systems and equipment are stated in the appropriate PSAR Section. The basic design criterion for the maximum loss of coolant accident and seismic con-ditions is that there be no loss of function if that function is related to public safety.

2.0 CLASSES OF STRUCTURES, SYSTEMS AND EQUIR4ENT 2.1 CLASS 1 Class 1 structures, systems and equipment are those whose failure could cause uncontrolled release of radioactivity or those essential for immediate and long-term operation following a loss of coolant accident. When a system as a whole is referred to as Class 1, portions not associated with loss of function of the system may be designated as Class 2.

The following are typical Class 1 structures:

Containment structure shell.

Portions of the auxiliary building that house safeguards systems, con-trol rocm, fuel storage facilities, and radioactive materials.

Enclosures for the service water pumps and auxiliary feedwater pumps.

Supports for Class 1 system components.

Typical Class 1 equipment and systems follow:

Reactor vessel and internals including control rods and control rod drives.

Other reactor coolant system components (steam generators, pressurizer, pumps, etc.) and piping, including vent and drain piping inside the containment.

Containment penetrations up to and including the first isolation valve outside contairment.

Main steam and main feedwater piping up to the stop valves.

Atmospheric dump and main steam safety valves and associated piping from main steam headers.

5-A-1 ,

0323

New and spent fuel storage racks and fuel handling equipment.

Steam-driven auxiliary feedwater pump.

Main emergency generator including fuei supply.

Containment building crane (unloaded condition).

Control boards, switchgear, load centers, batteries, and cable runs serving Class 1 equipment.

Critical service water.

Component cooling.

Containment spray system.

Containment air recirculation.

Low pressure injection and decay heat removal system.

Injection and purification system.

Safety injection tanks and piping.

Radioactive waste treatment.

)

2.2 CLASS 2 Class 2 structures, systems and equipment are those whose failure would not result in the release of radioactivity and would not prevent reactor shutdown.

The failure of Class 2 structures, systems and equipment may interrupt power generation.

30 DESIGN BASES 3.1 CLASS 1 STRUCTURES DESIGN Normal Operation -- For leads to be encountered during normal plant operation (excluding earthquake loads), Class 1 structures are designed in accordance with design methods of accepted standards and codes insofar as they are applicable.

Accident, Seismic and Tornado Loads -- The Class 1 structures are in general proportioned to maintain elastic behavior when subjected to various com-binations of dead loads, thermal loads, accident loads, seismic and tornado loads. The upper limit of elastic behavior is considered to be the yield strength of the effective load-carrying structural materials. The yield strength (Y) for steel (including reinforcing steel) i,s , considered to be the guaranteed minimum given in appropriate ASTM specifications. The yield _

5-A-2 '

strength (Y) for reinforced concrete structures is considered to be the ul-timate resisting capacity as calculated from the " Ultimate Strength Design" portion of the ACI-318-63 code when % is taken as unity. Reinforced concrete structures are designed for ductile behavior whenever possible; that is, with steel stresses controlling the design.

The final desi 6n of Class 1 structures (except the containment structure) satisfies the most severe of the following load cabination equations. (Design equations for the containment structure are given in Section 5, Containment System.)

.Y = (1.25D + 1.OR + 1.25E)

Y= (1.25D + 1.25H + 1.25E)

Y= (1.25D + 1.25H + 1.25W)

(0 90 D is used where dead load subtracts for critical stress in the above three equations.)

Y = 1/p (1.0D + 1.8E) (For structural elements carrying mainly earthquake forces .)

Y = 1/%

Y=1// 1.0D((1.0D

+ 1.0H + + 1.0E')

1.OR + 1.0E')

However, limited yielding is allowable under load conditions specified by the last two equations and under jet or missile forces, provided the deflection is checked to insure that the affected Class 1 systems and equipment (except shielding in the containment vessel under LOCA loading) do not suffer loss of function and the structure retains its required integrity.

Y = required yield strength of the structures.

D = dead load of structure and equipment plus any other permanent loads contributing stress, such as soil or hydrostatic loads. In addition, a portion of " live load" is added when such load is expected to be present when the plant is operating. An allowance is also made for future permanent loads.

R = force or pressure on structure due to rupture of any one pipe.

H = force on structure due to thermal expansion of pipes under operating conditions.

E = " design' seismic load resulting from ground surface acceleration of 0.lg.

E'= " maximum seismic load" resulting from ground surface acceleration of 0.2g.

LW = tornado load.

,/ = 0 90 for reinforced concrete in flexure.

p=0.85for. tension, shear, bond,andanchorageinreinforcedconcrete.

5-A-3 t ,. >

N

p = 0 75 for spirally reinforced concrete ecmpression members.

p=070fortiedcompressionmembers.

p = 0 90 for fabricated structural steel.

p = 0 90 for reinforcing steel (not prestressed) in direct tension.

p=095forprestressedtendonsindirecttension.

The contaire nt structure and engineered safeguards systems ccmponents are protected by barriers frcm all credible missiles which might be generated from the primary system. Local yielding or erosion of barriers is permis-sible due to jet or missile impact, provided there is no general failure.

The final design of the missile barrier and equipment support structures in-side the containment will be reviewed to assure that they can withstand applicable pressure loads, det forces, pipe reactions and earthquake loads without loss of function. The deflections or deformations of structures and supports will be checked to assure that the functions of the containment and engineered safeguards equipment are not impaired.

32 CLASS 1 SYSTEMS AND EQUIIMENT DESIGN Components and systems classified as Class 1 will be designed in accordance with the following criteria:

(a) Primary steady state stresses, when combined with the seismic 3

stress resulting from the response to a ground acceleration of 2 0.lg acting horizontally and 0.067g acting vertically and occurr-ing simultaneously shall be maintained within the allowable working stress limits accepted as good practice as set forth in the appropriate design standards, e.g., ASME Boiler and Pressure Vessel Code, ASA B.31.1 Code for pressure piping.

(b) Primary steady state stress when combined with the seismic stress resulting from the response to a ground acceleration of 0.2g acting horizontally and 0.133g acting vertically and occurring simultaneously, shall be limited so that the function of the component or system shall not be impaired as to prevent a safe and orderly shutdown of the plant.

33 CLASS 2 STRUCTURE DESIGN Class 2 structures are designed in accordance with design methods of accepted codes and standards insofar as they are applicable. Seismic design is in accordance with the Uniform Building Code with the appropriate working stress allowance and shear coefficients.

3.4 CLASS 2 SYSTES AND EQUIEMENT DESIGN Class 2 systems and equipment are designed in accordance with design methods of accepted codes and standards. Wind loads and seismic loads, where applic-able, conform to the requirements of the Uniform Building Code.

g 5-A-4 03 %

L-

4.0 MITID A3D EARTHGUAKE LOADS FOR CLASS 1 STRUCTURES 4.1 WIND FORCE Class 1 structures (except the enclosure over the fuel storage facilities) are designed to resist the effects of a tornado.

The structure will be analyzed for tornado loading (not coincident with ac-cident or earthquake) on the following basis:

(a) Differential bursting pressure between the inside and outside of the containment structure is assumed to be 3 pounds per square inch positive pressure.

(b) Lateral force will be assumed as the force caused by a tornado funnel having a peripheral tangential velocity of 300 mph and a forward progression of 60 mph. The applicable portiens of wind design methods described in ASCE Paper 3269 will be used, par-ticularly for shape factors. The provisions for gust factors and variation of wind velocity with height do not apply.

(c) Tornado driven missiles equivalent to an airborne 4 inch by 12 inch by 12 foot plank traveling end-cn at 300 mph, or a h000 pound automobile flying thrcugh the air at 50 mph and at not more than 25 feet above the ground, will be assumed.

4.2 SEISMIC FORCES (E MID E')

AEC publication TID 702k, "Huclear Reactors and Earthquakes," is used as the basic desi 6n guide for seismic analysis.

The " design earthquake" to be used for this plant is a ground acceleration of 0.10g horizontally and 0.067g vertically, acting simultaneously. The " maximum earthquake" is a ground acceleration 0.20g horizontally and 0.133g vertically, acting simultaneously.

Seismic loads on structures, systems and equipment are determined by realistic evaluation of dynamic properties and the accelerations from the attached ac-celeration spectrum curves. (Figures 5-A-1 and 5-A-2) 5 Critical Dancing

" Design Earthquake" (E) " Maximum Earthquake" (E')

(0.lg ground surface (0.2g ground surface acceleration) acceleration)

Welded steel plate assembilies 1 1 Welded steel framed structures 2 2 Bolted or rivited steel fremed structures 25 25 Reinforced concrete equipment supports 2 3 Reinforced concrete frames and buildings 3 5 Prestressed concrete structures 2 5 Steel piping 05 05 5-A-5 I

0327

50 FLOODING Class 1 structures are designed for 358 feet "=aximum probable" flood level.

Class 2 structures are designed for 338 feet " design flood level."

6.o LOADINGS COM40N TO ALL STRUCTURES Ice or Snow Loading -- a uniformly distributed live load of 20 pounds per square foot on all roofs provides for any anticipated snow and/or ice loading.

REFERENCES 1.

AEC Publication TID-7024, " Nuclear Reactors and Earthquakes."

2. Housner, G.W.,

"Desisrn of Nuclear Power Reactors against Earthouakes,"

Proceedings of the Second World Conference on Earthquake Engineering, Volume, Japan 1960, Page 133 3 Housner, G.W.,

" Behavior of Structures During Earthcuakes," Journal of the Engineering Mechanics Division, Proceedings of the American Society of Civil Engineers, October 1959, Page 109 4.

Task Comittee on Wind Forces, ASCE Paper No. 3269, " Wind Forces on Structures."

N 5-A-6 03'db .

$:x W 9'2 D LX Y N DI / x M I'/x^/ X N E N/x / A ^^ N NNwE x M I I5 O N Y N ( M e^^ ^ x xNw

/NA u m ea (( ~V'\

\ X

\t'N Y\\Y//X/*I /\A \Mbb Y ey\

' Q*<) oc _ E ot. ./YMsW/V^\ /V\ $W/NA/Y i XX >22M XX MON 'xx Wrd .a um . K'NWY l h m xx&@WNN?IAWYW)N$; /wswwx/wwww ,, 4:x 8 - M/V>O^.;DNQ A M37'/f@NNd "3 o E ' ~l';-0)tNd f ,o q, e / IN A /N vNYMW 'ev i x ^ ^ NNwa ! w/:. wAxM M 2,.,777 WW 09% x A x Ye ~ g A sys ge ,, = W/YiX AN LXJMNMIC // AANM:'l v"xXV NN O Oj" M A N tXJ y E. 694/h/N /Vi^\LM?FRA^//\V/%WWM /> . M. L E, MNDfdfS'8[RMMs2R$83t4 @@Di / '4X ME64/M !hMNYM T x NN*lNM/NN<Mk 9%MNIN!$2Ikh%a -' N>v / Q msw=mm Qa R m E u N x5 , = a x n A u<1m /uey / A A A NNxw ~, -//IN /N /N NfiflW///X/s/ /N /\ VN N% vev x A n x x yNw -* WAYlX /\ X/#V#6x//Y!X - /N Xiy %X, ,f@jfy/s / /N /N W NNN X / N IXJS ^ W <Q. * . 6K)(/V\ /\///V491$$4 /h/\ /VNM$5 '[# 'v'N /bf\ 'Z$b W 'XY442NS83K X'd M 26$88K X'x h$2 ' , Mk /. I .$$/w%+),$$ )@ f@ @N )@ d 2'I o@cnk7ux euxjwnmaxu' % 2 7 d E. .o.N 2 E . .. E. .o' .o n .o .o. ., ,a . 92 M M@. . 9, ,o .o , , PERIOD (secs) e\. DES.GN RESPONSE SPECTRUV " DESIGN EARTHQUAKE" cam Jak s:#c,, 5-A-1 1 :s xx-'// -w xwx xaix^x u,xm ^ noa eexw:Nr

a cm X m^Oca x x A na uw: m C ea I/ O Y\>b>bI//I/ \/ /\/N YYYi '/ I/'* !N 'A Y'E XDb eo e / \ X >?MW/X X/\ !X: X'['il ~ 7dXlX A \ iXi XVi

_RSKs M /WX$3W/V'N /V\f . f ' J/N^4/Vf\M ., M XX ?#2NS8K XX:3326 8X XX :8B @Mb)@$2f$!@MhMNd*NM$M)Es2f$5 www<mymmutt ext 2)$N@k6?<> ?@ .g-n:s- vu/ve s xx ^n oa ^m xs%a ^rw[ x^M EkNd.MM$?<0? ursu un rarn e '/'m 19 M e ^^c x o xmwwcJ N=, '/N M A M vsymw.u//vm A V-nNw/HM ^ M wc _ e wxxx /x txjvwmvuvx3 xwwxxix A tx4  : ". E5iW/A /vf\DKN6'fX#b/N//V"N3ds%!M/N/\/ !M . E M XX W32N25<X 332N XX M922 5,w@MN)$$f5E6M$)@$$f$!@@$IMM2f?5

• emmxxxwa xxamax/

, 2)$E@ didN 7 )$D@N<d?@M@@<0? . :s x3x^r ^ war N xm^&xa n xm^o^xw > -,' = u,v/ x ^ auwss uev e x n xmw u, vex ^ xmw , '//I N A /Yl/ANB\Y//XM /M/\ h/N WN'"#/ AA h/'O&NS myx m4xwwmx n x y ',p . pVNx^ ax xm - .W/VN//V\%$$$?M/W /VM V /A /V\xsi WSK 'XY X32 MMX 'xx MCRS&SK XX >22C ' ' .@@[ d ,$$f (! w er*xe@@hO(@$2 exmx fdk@ 3 % ) $2fd!! w</ ~ S. 2 ) M.@.. .. 5.. Y i @ @ .e MS@8$i@9 , , . ..~ l l l DES G\ RESPONSE SPECTRUV " MAXIMUM E ARTHQUAKE" FIG- 5-A-2 0330