ML20198H286

Forwards Encl to Cj Temis Ltr to J Stohr Re Nuclear Packaging,Inc High Integrity Containers EA-142 & EA-50, Series A,Inadvertently Left Out of D Nussbaumer 860325 Memo

ML20198H286
Person / Time
Issue date:	05/23/1986
From:	Maupin C NRC OFFICE OF STATE PROGRAMS (OSP)
To:	Greeves J NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
References
REF-WM-85 NUDOCS 8605300256
Download: ML20198H286 (10)

Text

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NuPas Envirs11cy EA-142 Sarios A HIC R:v. 1, 3/86 i

l 6.0 BURIAL STRENGIH j

j The NnPac Enviralloy EA-142 Series A High Integrity Container (HIC) has been j designed to mee t all strength and structural stability requirements of 10 CFR Part 61 for burial.

.i 6.1 Burial Loads I,

The maximum burial depth at the Hanford, Washington site will be 55 fee t.

Conservatively assaning hydrostatic pressure loading from the soll, this depth corresponds to a container external pressure of:

P H = (55 f t)(120 lb/f t')/(12 in/f t)*

= 45.83 psi i

6.2 Design Criteria The allowable component stresses and buckling criteria are derived from Sec-f tion III of the ASME Boiler and Pressure Vessel Code (6.1) for Metal Contain-ment structures and Code Case N-284 (6.2). Additional guidance has been pro-l vided by the USNRC. Margins of Safety (M.S.) are calculated based on the following relationship:

M.S. = (Sailowable/Sactual) ~ 1 6.3 Allowable Stresses The physical properties of Ferralium Alloy 255 are given in Section 2.0. Per

the USNRC, the maximum stress intensity for the uniformly corroded container 4 should not exceed ASME III Service Level A limits.

In the buried environment, there are two pos sible configurations of the con-I tainer: nominal and uniformly corroded. From a stress standpoint, the worst j condition is the uniformly corroded container. For either condition, the I allowable stress intensities per Reference 6.1 are:

o General Membrane Stress: P, 1 S,,

P,136.67 ksi (252 MPa) 6-1 1

NmPas Envirs11cy EA-142 Serios A HIC Rav. 1, 3/86 j o Local Membrane Stress: Pg i 1.5S,,

Pg 1 55.0 ksi (378 MPa) o Local Membrane plus Bending: (P g + Pb ) I 1*38 mc 4  !

(Pg + Pb ) 155.0 ksi (3 78 MPa) o 'S,, = 1/3 Salt = 36.67 kai (252 MPa)

~

Secondary stresses (thermal and peak stresses) are not evaluated for the buried container since these stress types are only of concern for precluding i fatigue failures, which does not exist for HIC's. Note that the HIC is loaded for only one-half of a cycle.

Components subjected to compressive loads shall be evaluated against buckling limits set by the appropriate structural code. For shell and plate e l eme nt s, ASME Code Case N-284 in conjunction with Subsection NE-3000 will be utilized.

For structural steel e l eme nt s, the American Institute of Steel Cons truc tion (AISC) (6.4) buckling allowables will be utilized.

6.4 Analytic Model The NuPac Enviralloy EA-142 Series A HIC was analyzed for displacements and l stresses utilizing the general purpo se finite element code ANSYS, Rev ision i 4.2. The finite element model consisted of a 45 degree section of the HIC, divided along the axes of symmetry defined by the center of an internal vertical support and halfway between the adjacent internal vertical support.

Five distinct components were evaluated in this analysis: the bottom plate, the side or shell, the top plate, the lid plate, and the internal vertical support angle.

The container was modeled using quadrilateral shell elements. These elements have both bending and membrane capabilities with six degrees of freedom at i each node: translations and rotations in the nodal I, Y, and Z directions and axes. The elements may be either triangular or quadrilateral in shape, de-fined by three or four nodes in a plane. The internal vertical angle supports were also modeled in this manner. Finite element geome try plot s of this configuration may be found in Appendix D.

The model was constrained from circumferential displacement s and rota tions l

along the radial and axial axes, tha axes of symmetry, to simulate the effects 1 of a solid, 360 model. The thicknesses of the elements are specified in the i analysis according to the values presented in Table 6.4.1-1.

4 6-2

I NmPas Envirs11cy EA-142 Serios A HIC R;v. 1, 3/86 i.

Table 6.4.1-1 HIC Component Material Thicknesses

! Disposal Side Wall Top / Bottom Internal Supports

Site (in) (in) (le)

Hanford 3/8 3/8 3/8 x 4.25 x 4.25 i

l 6.5 Structural Analysis Results Maximum stress intensities were determined for each component of the con-t aine r. The controlling stress intensity is the combined bending plus local membrane stress intensity. All membrane stress intensities were found to be ve ry low (with subsequent high margins of safe ty) compared to the combined membrane and bending stress intensities.

l The combined local membrane and bending stress intensity (Pt + Pb) of each

]

j most highly stressed component is compared to the allowable stress intensity

as described in Section 6.3. A s umma ry of the maximum s tres s inten sitie s, with the corresponding element number, for the maximum burial pressure in the

nominal and uniformly corroded (0.120 inch allowance) is shown in Table 6.5.1-l 1. The minimum margin of safety (M. S.) for the highest stressed component is ~

i also provided for each case.

u l

! Table 6.5.1-1 j Container Component Stress Intensities (ksi) j Condition Bot t on , Side Top Lid Minimum (Element) (142) (742) (1147) (1820) M. S.

I Nominal l Thic knes s

• 23.83 18.75 23.45 27.94 +0.97 i

0.120 in.

Corrosion 51.54 40.56 50.72 48.37 +0.07 Allowance

• Ratioed from corroded thickness analysis.

! 6-3 i

i.,___._..--------. _ _ _ . , , . . . , - ,_ . . _ . , , . . , . . , . _ -.._,._.,.-...-,____..,___.,;_._..__._-,_,,mm.,.,,,_. . - - . _ ._ . - ,

, +

NuPa3 Envir 11cy EA-142 S2 ries A HIC Rev.1, 3/ 86 i  ;

1 j Note that the requirements of 10 CFR 71.71(c) for maximum compressive load is less than 25% of the burial pressure that the container is designed and analyzed to withstand over a 300 year design life. Derefore, this require-me n t is satisfled by the finite element analysis.

1 The adequacy of the end plate welds to the container shell wall werc verified with the containe r in the uniformly corroded burial condition. The e nd s of

! the HIC are attached with a combination 3/8-inch bevel and a 3/16-inch fillet weld (bevel on the out side and fillet on the inside - refer to Zone B-7 of 3

NuPac Drawing I-201-002, Appendix A). The total area that may transfer moment at the joint is based on the full weld leg length for the bevel (groove) weld ,

y plus the leg length of the fillet weld (sin 45* or 70.7% of fillet weld size).

The ratio of weld thickness to shell wall thickness is:

~

! Weld /Shell = [(3/3 + 0.707(3/16))/(3/8)] x 100 = 135%

l The maximum stress intensity at the outer shell-end plate joint was found to j be 40.56 ksi. This stress intensity is based on the container in the uni-

! formly corroded condition (i.e., 0.120 inch corrosion allowance). Since the I

bending the plate thickne stress in s sa (i.e.,

thin platea = is6M/t prop)ortional , the adjusted to themaximum inverse ofstress the square intensityof j

in the weld j oint may be computed as:

4 S, = (40.56)/(1.35) * = 22.26 ksi (153 MPa) 1 The weld stress margin of safety, based on an allowable of 55.0 ksi, is:

M. S. = (55.0/ 22.26) - 1 = +1.4'i i

The ef fect s of pit ting, localized or crevice corrosion on the weld stresses have been addressed in Section 5.3. From that discussion, it was determined that the weldsents will perform as well as the base metal. Therefore, no weld

structural problems are anticipated due to these corrosion effects.

The structural stability of the EA-142 Series A can be conservatively demon-j strated for burial in both the vertical and horizontal or side orientations.

In the vertical orientation, the pressure from the soil overburden is reacted j through the internal angle supports and the container shell. The horizontal orientation is reacted primarily through the container shell. Each orienta-tion will be discussed separately.

I i

j Vertical Orientation

! The structural stability of the container is maintained by the internal angle l supports and the container shell. The stability of the top and bottom plates is assured as long as the stability of the angles is maintained. l i 6-4 ,

- , _ _ _ _ _ _ _ . . , _ _ _ - , _ _ _ _ _ _ _ _ _ . _ _ _ - , . _ _ . _ . _ , _ , _ _ . , _ ~ . _ . . _ _ _ _ . , . . - . , . , _ _ _ _ . , _ . - . , _ , . _ _ . ,

- ~ . - . .. . . - . - , . - - , . . - _ -

- -,.n.- . - . . -_..

NnPac Envirs11cy EA-142 Series A HIC R3v. 1, 3/86 P

From the ANSYS computer model, the forces on each internal support were deter-

, mined to be:

1 i Agial comoressive EgIgg Maximus Bendina Noment

22,670 lbs 8,699 in-lbs i.

The maximum bending moment in the support angle occurs at the end and is I induced by the deflection of the top and bottom plates of the container due

! the applied pressure load (with the 0.120 inch corrosion allowance applied).

By symme try, no bending about the radial axis occurs in the vertical support

l eg. Therefore, all bending is about the tangential axis. In addition, the

] percentage of the total load that each of the axial members must carry (due to

the applied hydrostatic pressure load of 45.83 psi) is determined by the j fo11owing me thod

Total Force on Container End = pA = (45.83) n (64.0)*/4 4 = 147,435 lbs.

Total Force on Angles = 4(22,670) = 90,680 lbs.

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! Therefore, the percentage of the total force carried in each support angle is j 22,670/147,435 or 15.38% while the shell carries 38.48% or 56,755 lbs.

1

]

The stability of the angle support is based on AISC criteria (6.4). Per

AISC, the allowable stress for compressive loading only is given by

l l F, = Fy [1-((K1/r)*/2C,*)]/[5/3 + (3(E1/r)/8C,)-((E1/r)'/8C,')]

]

where: C, = [2(n) *E/Fy ] *l* = 86.75 j F, = allowable compres sive stres s, kal 1 .

j Fy = minimen yield strength = 80 kai l

1 E = length factor, conse rva tively = 1 i

1 = member length = 67.0 in.

E = Young's Nodulus = 30.5 x 10' psi i r = radiu s of gyration = 1.33 in.

i i

Substituting the values into the above empression, the allowable compressive s tres s F, becomes 35.76 ksi. The actual compressive stress in the angle i i

6-5

__.__ __ _ _ .~ _ . _ _ _ _ _ . _ _ _ _ _ _ _ . . . _ _ _ _ . _ , _ _ . -

.. . = -. . _ _. . --- . .--_ _ - _ . . - _ - - - __ -_-

NuPn3 Envirallcy EA-142 Serios A HIC Rsv. 1, 3/86 4

3 support is 22,670/2.06 or 11.00 ksi. H erefore, the margin of safety for axial 4 compression alone is:

i l M. S. = (35.76/11.0) - 1 = +2.25 1

l For combined axial and bending loading, the following relationships must be

< satisfied (6.3):

(f,/F,) + ((C,,fbx)/III-If /F',,))Fbx) a + ((C,7fbyIIIII-If /F',7))Fby) a 1 1.0

and

(f,/0.6F7) + (fbx/Fb x)

• IIby/Fby) i 1.0 I

where: f, = actual compressive stress = 11.0 ksi F, = allowable compressive stress = 35.76 ksi fbx " Iby = sctual bending stress = M,,,/Z

= 8,699/1.19 = 7.31 kai l

Fbx = Fby = allowable bending stress = 0.6F7 l F = 80.0 kai 7

C,= 0.85 F',,= F',7 = Euler Stress = 61.89 kai i Substituting the above values yields:

i (11.0/35.76) + 2(0.85(7.31))/(1 - (11.0/61.89))(48.0) = 0.62 < 1.0 and j

(11.0/48.0) + 2(7.31/48.0) = 0.53 ( 1.0 t

herefore, the inte rnal angle supports remain stable in the corroded condi-tion. Since the container experiences constant burial pressure and the sup-ports would be larger in the non-corroded condition, the angle supports are

, stable under all burial conditions.

I 1

I i

f 6-6

nap 3 Envirc11cy EA-142 Serios A HIC 1:v. 1, 3/86 The compressive stability of the EA-142 Series A shell can be conservatively demonstrated by assuming a simple cylinder with a uniform hydrostatic pressure

! loading. Per Code Case N-284 (6.2), the following interaction equation must i

be satisfied if a6s 10.5ag,:

((a6s - 0.5aheLIII'6eL - 0.5aheL I ) + I'es/*heL) i 1.0 Note: Not required if ag, ( 0.5aheL where: ag,g = 0.605 E/(R/t) = 144160 psi a0eL * 'heL " CohE/(R/t) = 19847 psi

ag, = (R/t) P (FS/agg) = 14378 psi i

agg = Hoop Capacity Reduction Factor = 0.8 h

a6s = (R/t) P (FS/(2agg)) = 10905 psi l

Axial Capacity Reduction Factor a6L == 1.52 - (0.4731ogs.(R/t)) = 0.527 l

l P = External Pressure = 45.83 psi i

FS = Factor of Safety = 2.0 R = Outside radius of cylinder = 32.0 in.

t = Shell thickness = 0.255 in.

f E = Young's Modulus = 30.5 x 10' psi Subs tituting these values into the interaction equation yields a value of 0.74, which is below the required value of 1.0. The nominal thickness container will have a significantly lower interaction value, and thus, a larger design margin.

From the preceding analysis, the structural stability of the EA-142 Series A j HIC in the vertical orientation has been conservatively demonstrated.

1 i

Horizontal Orientation i The container in the horizontal orientation can be treated as a buried conduit

or pipe. For this condition, the structural support from the end plates is not considered. Per Reference (6.5), the critical buckling pressure can be j expres sed by

I I

6-7 I

NmPm3 Envirt11cy EA-142 Serios A HIC Esv. 1, 3/86 S cr = 4.5 [(M* EI)/D'] */

• where: M* = constrained madulus of soil, psi

E = Young's Modulus = 30.5 x 10' psi I = In plane wall bending stiffness, in*/in D = con t aine r di ame te r = 64.0 in.

i .

For compacted soil with a density of 120,1bs/f t' at a , burial dgpth of 55 feet, the constrained modulus of the soil (M ) is 2.9 x 10 lbs/ft minimum (6.5).

The in plane bending stiffness per unit length is:

I = bh'/12 = (1) (0.255) '/12 = 1.38 x 10~' in*/in .

Substituting these values into the above equation yields a critical buckling I pre s sur e of 80.97 psi. With the actual hydrostatic burial pressure at 45.83 i p a i, the margin of safety against buckling in the horizontal, uniformly cor- I roded orientation is:

M. S. - (80.97/45.83) - 1 = +0.77 a

' Based on this analysis,.the EA-142 Series A container stability has been conservatively demonstrate'd in the horizontal orientation.

Damazed Container Effects

! The effects of damage on the structural integrity of the EA-142 container is j not expected to alter the preceding analyses. This conclusion is based on the

) resultant container damage of several drop tests of a single container. As noted in Section 15.0, the maximos deformation that resulted from these tests l was 5/8-inch. From these test observations, very little container damage can i be expected to occur from any mishandling. Howeve r, should a container sus-i tain a large amount of damage during use, a separate evaluation and any ,

neces sa ry repairs will be performed to assure tha t the .tructural inte grity '

of the container is maintained.

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! 4-:

- _ .- .__ ---- _.- -_ .-