ML20126K076

to Evaluation Rept for Nonconforming 2X2 Storage Cell Module for Calvert Cliffs Unit 1 Nuclear Plant High Density Spent Fuel Storage Racks

ML20126K076
Person / Time
Site:	Calvert Cliffs
Issue date:	10/22/1980
From:	Husain I, Ravishankar N NUCLEAR ENERGY SERVICES, INC.
To:
Shared Package
ML20126K068	List: ML20126K064 ML20126K076
References
81A0569, 81A0569-R02, 81A569, 81A569-R2, NUDOCS 8105110206
Download: ML20126K076 (24)

Text

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mr DOCUMENT NO. 81A0569 g gy, 2 NUCLEAR ENERGY SERVICES. INC. '

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EVALUATION REPORT FOR NON-CONFORMING 2 x 2 STORA_,GE C_ Ett MODULE _ .-  :

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DOCUMENT NO.

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NUCLEAR ENERGY SERVICES, INC. PAGE OF TABLE OF CONTENTS Pace

1. INTRODUCTION - - 4 "'

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2. METHODS OF EVALUATION

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2.1 Rack Strue: ural Analyses 7 ~T 2.2 Local Loading Eff ec s Testing 9 '"

3. RESULTS OF EVALUATION 12 3.1 Rack structural Analyses 12 3.2 Local Loading Eff ects Testing 19 0 CONCLUSIONS 23

5. REFERENCES 24 e

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t 81A0569 DOCUMENT NO. {

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NUCf EAR ENERGY SERVICES. INC.

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1. INTRODUCTION l

During :he fabrica: ion of the Ca! vert Cliffs Uni 1 Nuclear Plan: high censity spen:

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fue! 5:orage racks, a 2 x 2 ceu module was damagec by an accicen;aj crop during ..

nancling. The 2 x 2 ceu module was se: aside and la:er cisr6Etie~c to remo've :St; ~~'

assv.iated poison material. Eignt of :ne nine high density fuel racks were assemblec --

a: the time the damage: 2 x 2 cell mocule was dismantled. ~ '

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An examination of :he removec outer stainless steel 'shee:s ' indicated that the :hird  ;

ver;ical row of spot welcs (see Figure 1) was def ective. The vast majority of welds in j

the third rows (> 90%) incicated a complete lack of f usion. An investigation of the '

i problem indicated that some fif y (50) 2 x 2 ceu mocules may have a similar problem and that the assembled fuel racks contained up to thirteen of these suspec: mocules (ou cf a possible 25 modules). It was evicen tha: the defective spot welcs would

{

i recuce module stiff ness and, hence, the na: ural frequencies of the non-conforming i rack. The reduced natural frequencies could, in turn, increase the seismic j accele acion values appiled to the rack struc:ure. Increased accelera: ion values and I reduced rack stiffness properties would likely increase the stress levels in :ne 2 x 2 cell modules and :ne rack base structure.

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Consecuently it was concluced tha: the abill:y of a non-conforming fuel rack to I accommocate the imposed seismic loads mus: be evalua:ec maicng :ne conservative j assurnpilon that each 2 x 2 cell mocule in the rack is ceficient. I i

Two evaluations were ceterminec to be necessary:  ;

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A. A s:ructural analysis to evaluate :he effec: :na: :he cef ec:ive :hird rew 6 i

i spot welds have on the results cf the seismic analyses previously performec  ;

f or the Calver: Cliffs Uni i fuel racks. t' i

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E. l load tes: to cetermine :he eff ec tha: :ne cefective spot welds have on t

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ne ability of the 2 x 2 ceu mocule :o accommoca:e the local loads applied  !

by the fuel assemblies during a seismic even:. A load tes; was conciuced '

to be necessary since sufficiently accurate local stress calcula: ions cowc no: be perf ormec to make cefini:ive concbsiens.

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, DOCUMENT NO. SlA0560 jig ' 6

NUCLEAR ENEAGY SERVICES. INC. O C"

• This report presents a description of :he snuctural analysis anc loac tes evaluatien  ;

rnethods, the resul:s cf :hese evaluations anc ine conc!usions regsrding :ne nructural anc f unctionaJ acequacy of -he non-conforming fuel rack.

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NUCLEAR ENERGY SERV 1CES, INC. ' AGE Oc

2. METHODS OF EVALUATION l t,

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.2.1 RACK STRUCTURAL AN ALYSIS '

The first step in the structural evaluation was to determing the effect of the - -

defective third row welds on the module stiffness and, hence, the natural -

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f requencies of the non-conforming rack. The recuced natural f requencies, in -

turn, established the seismic acceleration values to be appliec :o :be "

mocule/ rack base configuration. The following mathematical models were ceveloped to determine the reducec stiffness and natural f requencies of the non- )

conforming 2 x 2 storage cell mocule and the seismic and stress analysis of the i modified configuration of the fuel rack s:ructure. t i

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Non-Conf ormine 2 x 2 Storane Cel! Module i

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The first model required for the struc: ural evaluations was a deta!!cc three i dimensional finite element mocel of the non-conforming 2 x 2 storage cell module. In this mocel the outer s:ainless steel shee:s of :ne 2 x 2 mocuie were ,

separa ed from the inner cell walls at :he defective (missing) vertical spot welcs.

This model with its distributed lumped masses and bouncary conditions is shown in Figure 2. This mocel was used to determine the reduced ' stiff ness, reduced natural frequency, and seismic response (cisplacement, velocity, accelera: ion,

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member forces and stresses) of the non-conf orming 2 x 2 module.

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10 x 10 Rack Model '

The second mocei requirec fer the evaluation consis:ed of twenty five sing!e l mass cantilever beams (representing twenty five 2 x 2 mocules) rigidly attached {

o the rack base structure anc attacned :o each other at the top by spacer bars.

Each single mass can:llever beam has :ne same dynamic (f recuency)  !

characteristics as tha of the non-c:rderming 2 x 2 mocule. Tne distributed t masses corresponding to the fuel assemoly storage ceils, poison e!ements anc I l

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, DOCUMENT NC, SlA0569 1 NUCLEAR ENERGY SERVICES. INC.

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contained plus hydrodynamic mass are lumped at appropriate nodal points. The '

horizonta! weights are cistributed such tha: the resulting lumoec mass mu!!1-cegree-of-freeoom mecel bes: represen:s :ne cynamic cnarcieris:!cs of :ne fuel  !

storage rack. This model was used to calculate :he maximum stresses in :ne t l

rack base structure and the reac: ion loacs and s:resses in :he rack support feet. '

_ ~ - .

The seismic analyses are performed for tne fully loaded racks only since this .

loading condition results in lower frequency, higher seismic accelerations, higher ~~

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stresses and reaction loacs. The boundary conditions an'c'idmped mass locations 9 for the heri: ental seismic analyses are shown in Figure 3. The oe:Eils of the T' mathematical model of the non-conforming 10 x 10 rack and the methods of seismic / stress analyses are same as those given in Section 7.1 of NES Document i

31 A0566. Revision 2, " Structure Design Analysis Reports for the Calver: Cliffs Unit #1 Nuclear Plan: High Density Spent Fuel Storage Racks". Only the  !

stiffness characteristics (moment of inertia) and sec:!cn properties were modified to reflect the reduced stiffness and natural frequencies of the non-  ; i conforming configuration of the 2 x 2 cell module. -

1 2.2 LOCAL LOADING EFFECTS TESTING Three local stress / loading conditions were of concern because of :he missing '

t vertical spot welds: i A. The bending stress in the outer cell wall a the :cp of :ne cell mocule  ;

B. The bending stress in the outer cell wall at an intermedia:e cell elevation corresponding to a spacer elevation for the stored fuel assemblies C. The combined shear /:ension loads on the remaining cell wall spot weids.

i Three basic :es:s were devised to evaluate the~ above local conditions f or :ne  ;

CBE and DBE seismic loadings associated wi:h fuel assembly and " loose pin"  !

storage. For :hese :ests, a 2 x 2 ce!! module of half-neign: was fabrica:ec using i stancard production spot welcs a: all loca:: ens excep for the nirc ve :ical row t i

loca:!on on each ou er sneet, wnich con:ained no welcs. A :ull-ne2g .: mocule could not be c:nstructec secause of the lack of suffic:ent formec sieces. The i

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module, however, contained all of :he principal items comprising a full size  !

med:le excep: f or :he center spacer assemoly. The 2 x 2 mocule, in turn, was r t

teided to a carben steel s:ructure :ha supported :ne module in a horizontal -

r.::!:ude entirely from :he module base plate (see Figure 1). Steel blocks were  !

dis.ributed inside the storage cells and on the module in accordance wl h the -

f loading requirements specified f or the three tests. The specifiec loadings are [. I s a:ic ecuivalents of the maximum dynamic loacs applied to the local areas and -- '

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ake into account :he effects of virtual water mass and fuel assembly impact. A ' "?  !

more de:alled description of :he loacing tests, (and :ne specified lead -"

l requirements)is presented in A:tachmen: 1, Test Plan for Non-Conforming 2 x3 Storage Cell Modules.

j 5

Tne effec:s of theloads were evaluated against the following general criteria:  !

A. h For the OBE loads, no evidence of permanen: cef ormation af ter the

, appliedloads were removed. f B. For the DBE loads, no evidence : hat the 2 x 2 cell module and/or i i

incividual cells have lost structural integrity. Permanent i deformation was permitted provided the mocule remains function  ?

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a DOCUMENT NO. 81A0569 j pr GE 12 me

"~ 24 NUCLEAR ENERGY SERVICES. INC.

3. RESULTS OF EVALUATION i

I The results of static anc seismic struc ural / stress analysis of the non-conf orming Calver: Cliffs Nuclear Plan: Ura: I hign density fuel storage racks performed with :he ,.

ANSYS and STARDYNE computer coce are con:alned in Referene - - -- -!

The cetailed seismic /strue: ural ana!yses calcu!a: ions to evaluate :he effec: of tne  !

non-conforming 2 x 2 cell modules on :ne resul:s of :he seismic analyses previously ,,

perf ormed f or the Calver: Cliffs Uni: #1 fuel racks are given in Ref erence 3.  !

The cetails of :ne :es:s for the local loading eff ects are contained in Reference 3.

/k  !

3.1 RACK STRUCTURAL ANALYSES The natural f recuencies of vibra: ion of :he non-conf orming 10 x 10 fuel storage rack are given in Table 1 along with their corresponcing modal participation i factors. The first mode f recuency of 3.02 cycles per second represents the firs l

moce frequency of the non-conforming storage rack structure including the flexicility cnaracteris ics of :ne rack base structure and support pads. The  ;

fundamen:al f requency of the non-conf orming mocular cel! eni.t is 6.37 cycles  !

l per seconcs. Referring to ne norizontal seismic response acceleration spec:ra (Figure 3.1 of Ref erence 2), it can be seen that the firs moce spectral 1 i

acceleration values for :he non-conf orming rack (0.22G at 3.02H ) is same as tha f or the cesign rack (0.22G at 3.39H:).

The results of :he non-conf orming rack structural /s:ress analyses are summarized and compared wi:n those of :ne design rack analyses (Reference 2) in Tacles 2 and 3. Tacle 2 presenu the analyses results and comparisons f or f ue! /I l 1sssembly s:orage. Table 3 presen:s the analyses resul:s anc comparisons f or '

loose fuel pin storage (165% of the weigh: of the norma! fuel assemoly).

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A i DOCUMENT NO . ~1A0569 l pf.c = 13 -= 2 NUCLEAR ENERGY SERVICES. INC.

i TABLE 1 l

PERTINENT NATURAL FREQUENCIES ,

OF VIBRATION AND MOD.-\L PARTICIPATION FACTORS (10 x 10 Rack Fully Loaded) i l

Modal Particioation Facters_- .

a Mode A"s l

Frecuencv XI X2 X3 - t Number (CPS) ' Direc-ion 9 Direc-16n ' Direc-ion l ~i !

! 5.015 t 0.06 w C 0.6330 0.002u

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2 3.041 0.6243 -0.6242 0.0  ?

3 5.210 0.330u 2

0.3304 0.0001 l 5.229 0.2268 -0.2268 0.00 i 5 5.625 -0.0299 -0.0300 0.00 '

6 5.626 -0.0272 0.0272 0.00 7 6.017 0.0264 0.0264 0.0007 )

8 6.019 0.0229 -0.0229 0.000 9 6.338 -0.0138 0.0139

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0.000  !

10 6.339 0.0139 0.0138 0.0004 11 35.723 0.0009 0.0009 i [

0.06uS 21 c6.133 0.0152 22 60.234 0.0152 m.czz y '

-0.01598 0.01598 ' v.vo

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81A0569 l DOCUMENT NO.

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TABLE 2 i

SUMMARY

OF STRUCTURAL EVALUATION OF NONCONFORMING 2 x 2 CELL MODULE -

FOR FUEL ASSEMBLY STORAGE  !

~ ~ '

Design Non~ conf orsg' A!!cwabie Configuratien Confizuration. Stress (ksi) -

n,.

Frequency Analysis.

Frecuency (H2) of 2x2 Detail Model (Figure 2) 7.13 6.57 N/A First Moce Frecuency (H2) of Fue! Rack Model (Figure 3) 5.39 5.02 N/A k Average Accelera:icn (G) f or all i 25 Masses (Figure 3) 1.04 1.% N/A Stress Analysis ,

Rack Base 5:ructure and same a.s same as Supper Leg Table 8.2 Table S.2 ,

of Ref.2 of Ref. 2 '

Storare Cell Tall a: Base:

Bencing S:ress (ksi) f b./f 53 due :: OBE 3.59/3.59 5.15/3.15 23.96 (actua!

material) ,

Bencing Stress (ksi) -

f b/f b3 cue to DBE 6.73/6.73 9.66/9.66 33.3 (actua!  !

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I DOCUMENT NO. 8:.A0569  !

pace* 15 - 24 NUCLEAR ENERGY SERVICES. INC,

• 5 TABLE 2 I' (Con:inuec) I Design Nonconf orming A!!cwable Confieuration Configuration f

Stress (ksi) . . ,

a .;i Stress Analysis ,

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'? j Comoined Stress Railo (CBE) 0.30 0.43 (actua! material) j r I. ik

,s Combined Seess Ratio (DSE) 0.35 0.30 (actua! materia!) ii Storage Cell Wall a: Sase '

Consiciering Local Buckling Effects: I 4

1 l

e Bending 5:ress (ksi) 4.4/4.4 6.1/6.1 19.6a (actual 4 f 52/f b3 (OSE) material) i I

i Bencing Stress (ksi) S.24/ S.2 t. 11.4/11.4 31.42 (actual I l

f b2/f b3 (DBE) material) l 1

1 Combinec Stress Ratio (CBE) 0.45 0.62 (ac ual material) l Combined 5:ess Ra:io (DBE) 0.52 0.73 (actual material)

Max. Sress (ksi) in wele 15.07 15.07 33.6 (actua!

be: ween 2 x 2 cell wall anc base plate (DSE) material) hI I

Max. Sress (ksi)in weld 13.32

~

13.32 33.6 (actual be: ween 2 x 2 cell wall ma eria!) >

i base plate anc base structure (DSE) i

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i SIA056c' i

DOCUMENT NO. I 16

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NUCLEAR ENEAGY SERVICES. INC. i t

TABLE 3 +

SUMMARY

OF STRUCTURAL EVALUATION OF NONCONFORMLNG 2 x 2 CELL MODULE l t

FOR LOOSE FUEL FIN STORAGE t Desigr. Nonconf ormi"5- - A!!cwable - -

f Confizu-ation Configuration . 5:ress (ks0 _.

• ~ -

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Frequency Analysis r

i Frequency (H2) of 2x2 Detail <

l i

Mode!(Figure 2) 3.99 5.30 N/A l First Moce Frequency (H2) of  :

Fuel Rack Mocel (Figure 3) L.c9 4.26 N/A l:

Maximurn Accelera:lon (G) f or all {

25 Masses (Figure 3) 1.C97 0.37 N/A l Stress Analysis ,

l Rack Base 5:ructure and same as less than //\ f Supper Leg Table F.2 Table P.2 of Ref.2 of Ref. 2 i i

Storare Cell ';'all a: Base:

i l

i Sencing 5:ress (ksU i i

fb 2/fb cue y to OSE 5.33/5.S.3 5.92/5.92 23.96 (actua!

f material) ,

Sending Stress (ksi) -

fb/f b. due to DBE 11.0"'11.02 11.09/11.09 38.3 (ac ual -

> 1 i materia!) l i  !

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, 81A0569 DOCUM ENT NO.

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NUCLEAR ENERGY SERVICES. INC.

l' l TABLE 3 L (Continued) I t

1 Design Nencenforming Allowable [

Confirura:ien ~

Conf 12cratien _ Siress (ksi)

[

Stress Analysis . .

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Combined Seess Ratio (OBE) 0.a 9 0.a 9 (actual materia!) '"

i Combined 5:ress Ratio (DBE) 0.5 S 0.58 (actual material) i Storage Cell Wall a: Base I s

Considering Local Buckling i

Effects: '

f Bending Stress (k'si) 7.33/7.33 6.98 19.6L (ac:ual  !

f b2/f b3 (CBE) material) ,

Bending Stress (ksi) 13.7'3/13.73 13.10 f b2/f b3 (DBE) 31.a2 (ac: cal ma:eria!)

[ ,

Combined Stress Ratio (CBE) 0.75 0.71 (actual materia!)

t Combined Sness Ra:lo (DBE) 0.37 0.33 (actual material) l Max. 5:rets (ksi)in weld 27.12 17.22 33.6 (ac:ual  ;

be: ween 2 x 2 cell wall material)  !

and base plate (DBE) >

Max. 5: ess (ksi) in weld 23.95 15.21 33.6 (actual i between 2 x 2 cell wall base material) plate anc base structure 1

(DSE) i

81.A0569 DOCUMENT WO.

NUCLEAR ENERGY SERVICES, lNC, PAGE OS t From Table 2 it can be seen tha: cue to :he recuced stiffness of tre non-conforming 2 x 2 mocule, its frequency has recuced from 7.1 S H: (design configuration) o 6.57 Hz. The first moce frequency of the non-conforming rack -

f is 3.02 H: compared with that of 3.39 H: for the desigo rack'corifiguration. g- ,

.l Since there is no change in the first mode spectral acceleration values, th'e - ~~

average acceleration values for the non-conforming And, d'esign rack are the .

^-7 same. Since there is no change in the average acceleration value, the maximum i

_a stresses in the rack base struc ure anc suppor: leg and the maximum floor i

)

loading are :ne same as those presentec in Tables 8.2 and 8.3 of Reference 2.  ;

Tacle 2 incicates that due to the reduced section moculus of the non-conforming 2 x 2 module the stresses at base of the cell wall are higher than the stresses f or j

the design configuration. The combined stress ratios for bi-axial bencing a e ,

calculated using the yield stress for the actual material (39.2 KSD. The

{'

combined stress ratios are less than 1.0 for both the OBE anc DBE even:s. Local buckling stress analyses at the base of the cell wall were performed using the

' methods given in AISI " Stainless Steel Cold-Formed Structural Design Manual" (Reference 4). The combined stress ratios are less than 1.0 for both the CBE and DBE events. The stresses in the welds between the cell wall and the base plate and between the base plate and the rack base structure are less inan the allowable stress values using the actual material yield stress value.

Initial Analysis for the fuel racks conservatively assumed that all the twenty-five 2 x 2 cell modules were cefective. This conservative analysis indicated tha:

r f or the loose pin storage condition, the cell wall at the base of tne 2 x 2 mocule may buckle under a DBE event.

It was concluced from an ultrasonic test program :na: a more reasonable assumption was :nat eight 2 x 2 modules could be defective. For subsequent seismic analyses, a conserva:1ve mode! was used /

wi:n thirteen non-conforming 2 x 2 modules placed a: he most critical locations '

in a rack along with twelve normal 2 x 2 modules. The moment of inertia of the l

thirteen nonconforming 2 x 2 mocules was recuted to account f or the cell wall buckling. These analyses were performed using the revised response spectra of Ref erence 5. The results cf :ne analyses are given in Table 3.

f

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From Table 3 i can be seen that for the loose pin storage condition, the fundamental frequency of the non-conf orming 2 x 2 celi module is 3.3: Hz  !

cornpared wi:n the 5.99 H: for the cesign cell mocule configura: ion. The firs:

I moce frecuency cf the non-conforming rack (4.26 Hz) is slightly smaller :han  ;

that of :ne cesign rack configuration (4.: 9 Hz). The maximum s.:resses in the <-  !

rack base s:. uc:ure anc supper: leg and the maximum Tio _er loacing will .ce sma!!er than : nose presented in Tacles F.2 anc F.3 of Appendix F (Reference 2). -

Ta.cle 3 incicates na: due to the recucec sec:!cn mocul0s 6f the non-conforming '

2 x 2 module, the stresses. a: the base of the cell wall are higner than tne aa ,

stresses in :ne cesign configura:!cn. The combined stress ra:ios for ci-axial i bending are !ess than 1.0 for coth the CBE anc DBE events.

t Tne loca! buc41ng stress analysis at the base of the cell wall indicates :nat the combined s ress ratios are less than 1.0 for be:h the OBE and DBE events. The  ;

maximum s:resses in :he welcs between the cell wall and base plate and between the base pla:e and rack base structure are less than the allowable stress values /

using the ac tal material yielc stress value.

3.2 LOCAL LOADISG EFFECTS TESTING i

i The resu!:s of :be local loading eff ects :esting are presentec in Table 4 Taole 4  ;

!ists the tes:s in the actual sequence tha: they were completed. This sequence 1 was cnosen curing :be test to expedite the performance of the tests. ,

~

c As can be seen from Tr.ble 4, none of :ne OBE tes:s resulted in any coservaole t

ceformation when :ne loads were applied anc consecuently no perm anen:

ceforma::en when :ne CBE loads were removec. Only one DEE :es: (Tes: 6) i resulted in a minor permanen ceformation which would have assolute!y no effec: on :ne function of :ne module (s:orage of fuel in a safe geome:ry).

Af ter :his deforma:lon occurred (Tes: 6 was :he seconc tes to be perforrned) no e ner significant def orma:: ens were observaole when the loi.cs were appliec f or tre remaining DES :es:s .nc no additional permanen: ceformation occurrec af:er the DBE loacs were removed.

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81A0569 DOCUMENT NO.

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NUCLEAR ENERGY SERVICES. INC. PAGE "F A visual examination of the module spot welcs, the module to base plate welds 1

and the welcs at:acning the top spacer :o the four cells incicated that a!! welds were sound. In f ac:. the integrity of top spacer welcs was verified by a'pplying  ;

sufficien: impac: loacs to shear each welc. For completeness, i: was cecided to repeat Tes: 9 with the top spacer displaced to a location. wnere it-was no longer e supporting Cell 1. With the Test 9 load applied to _ Cell 1 a downward _

displacement of less than 1/3 inch was observed uncer this condition. ' Some ~

permanent def ormation was observed af ter the DBE leid was removed. I: was -

evident tha; even in the unlikely event that a top spacer is displacec curing a Td >

OBE seismic event no significant structural deformation will occur in a non. }

conf orming module.

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M 4 96 TAllLii 4 TliST IlliStil.TS Test Seisinic Specifical Cell " " CcIl "

No. Test Descrigition livent 1.oading (Ibs) No. [

Test flesults / o i 1. oral lillec t, 01111 573 3 and 4 No def niniation was observed in m inteimediate Aiea intermediate s egions of Cells 3 and 4.

(truct Assembly) m O

6 1. oral litlec ts, 1075 Olili 3 and 4 liottom outer sheet of module developed inte mediate Asea outward bulges (.c I/16 to 1/8") under (1: net /\ssembly) p Cell 4 over middle 2/3 of anodule length. 6 liulge remained after load was m r emoved. a a " This deformation for a liitti 1 _

condition woulit not allect f unc tional f per toimance of inodule/iacl<.

2 1.ocal tillec t, Top-Area Otill 885 I only (1:uel Assembly) No deformation was observed in top areas of module and Cell 1. .

4 1.ocal tilletI, Top Area Ollii 1243 I only (l.oose Pin) No defoimation was obsqrveti in top areas of module and Cell 1. i 0 i f O 7 1.ocal lif fects, Top Area I)llii 1660 I only 1 o (1 uct Assembly) No deformation was observ'ed inj top G areas of module and Cell 1. i;;

3 Spot Weld e Z 01\l1 (Fuel Assembly) 755 All No tieformation was obser ved in vicinities of snodule spot welds. No de'los ina t ion l'

)

,o obses veil in any as ca of module. ,

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See I;igur e 1 of I'est Plan (see A t tachinent 1) f Actual < cil loatlings were esgual to or gecates than the specified cell loading. 3

g liais bulge remained f or the remainier of the tests. There was no indication that it increased in climension 'd 4

(depth, width, or length)

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7; TAllt.li 4 i' (Continued)

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No. lest flescription livent Loading (lin) No. Test itesults y m

m z

m 5' Spot Weld OliE 1870 All No deformation was oliserved in vicinities $4 (l.oose Pin) of module spot welds. No def orma tion

, o!> set ved in any cell of anodule. $m M Spot Wqld 1)lili 1530 All <

(l;uct Assemlity) No def ormation was ol3 served in vicinities o of snodule spot welds. No def or mation @

ol> served in any area of module. '.Z

'> l.ocal lillects, Top Asea ITisE 2131 1 only o

No perinanent delormation was o!>ses ved in ^

(l.oose Pin) top as ea of Modiale and Cell I.

10 $ pot Weld 2192 All 111511 No permanent deformation was observed in (l.oose Pin) vicinities of : nodule spot welds. No a permanent deformation observed in area of module. Only suinor cliangep 8 sheet appearances were obsesyg(n ble. Ilie outer O C

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NUCLEAR ENERGY SERVICES, INC. *

4. CONCLUSIONS i

Basec on the results of the struc: ural analysis and loca! loacing effects evalu'a: ions,

ne following conclusions have been mace:

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1. The results of :ne structural analysis incicate tha: the stresses in the non- -

conf orming storage rack structure resulting from the, loadings assocla:ec with the normal and abnormal conditions are within the allowable stress limits f or the actual material usec in the rack f abrication. Consequently '

the non-conf erming rack is structurally acequate :o mee: the requirements for Seismic Category i structures.

I 2.

The results of the non-conferming 2 x 2 module local loading effects i testing indicate that uncer OSE loading conditions there will not be anv permanent def ormation of the 2 x 2 mode!e.

3.

The results of the norsorderming 2 x 2 module local loading effects .

testing indicate that the small permanent ceformation in some loca.1 areas i of the 2 x 2 module resulting from DBE loading conditions will no:

adversely affec: the structural and func:ional integrity of the storage rack.

t te. l The Calvert Cliffs Uni: 1 non-cordorming high density fuel storage rack is >

structurally acequate to perform i s functon (the storage of fue! in a safe geometry) during and af:er all anticipated loacing conditions.  :

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A0569 >

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NUCLEAR ENEAGY SERVICES, INC. i

5. REFERENCE.S

1. '

Ca.! vert Cliffs Urdt ! Fue! Storage Racks. Structura! Analysis Project 5134. Task 770, NES Compu:er Output Bincer No. 5-55, Octooer 1980.

~ -- . ~ .

2. Nuclear Energy Services, Inc. Document SI A0566 " Structural Analysis Design ~ -~

j Report for the Calven Cliffs Unit 1 Nuclear Plant Hign Density Fuel Storare . +

.~-.

Racks," Revision 2. ~ .

._ u li

3. Calvert Cliffs Urdt 1 Fue15torage Racks Structural Analysis Design Calculation  ;

Notebook, Volume 1, Project 513c, Task 300.  !

, f 4

American Iron and Steel Institute, " Stainless Steel Cold-Formed Structural ' '

Design Manual," 1974 Ecition.

i 5.

Bechtel Power Corporation, " Acceleration Spectra f or the Auxiliary Builcing of I BC&E's Calvert C11ffs Units No. I and 2," Job 6750, November.20,1976. i 1 ,

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