CONTAINER DESIGN CONSIDERATIONS

•. Waste form and shape

• Target containment period

• Temperature during disposal

• Ease of manufacture, inspection and handling

• Materials availability and cost

• Method of emplacement

• Shielding·

• Service stresses

CONTAINER PERFORMANCE ISSUES

• Minimum lifetime of 500 years required, with options for muchlonger lifetimes

• Manufacturing defects may cause 1 in 5000 containers to bedefective

• Likely mode of failure would be corrosion because goodengineering design would preclude structural failures

AECL EACLAECL Research EACL Recherche

STRUCTURAL PERFORMANCE. MODELING OF CONTAINERS

To predict, by analysis, the structural behaviour of candidatecontainer designs, during extended periods typica,l of thoserequired for safe disposal, to ensure that the proposeddesigns possess the structural durability to meet, andexceed, the required containment target.

AECL EACLAECL Research EACL Recherche .

These studies must therefore take into account

· anticipated structural loading on the container duringlong-term disposal

· long-term time-dependent mechanical properties of. .

proposed materials of construction for containers

· container-materials degradation proce~~e.~ duringdisposal

AECL EACLAECL Research EACL Recherche

APPROACHES TO LONG-TERM.STRUCTURAL-PERFORMANCE MODELING

. Experimental determination of long-term mechanical. properties of container-construction materials and.. formulation of mathematical descriptions of time-

dependent ,responses of materials under stress.

. ,

. Full- and/or scale-model testing of prototype containerdesigns under typical vault loads and temperatures.

. .f!t AECL EACLAECL Research EACL Recherche

. Verification and improvement of structural-performancecomputer models through comparison of predictedperformance of prototypes during testing with actual testresults.

. Integration of materials properties studies, scale-modeltesting and computer-model development with materialsdegradatiQn pr'oge~s~s, ~o develop container lifetimepredictions.

tStrainsustained bythe material

Criteria for Failure by Creep Rupture

Full Creep Curvedetermined by CreepTesting and thee. Projection Model

Time Since Emplacement

Since Creep Rates could be rapid and difficult topredict in theTertiary Region, rupture is assumed to occurat the Limiting Strain for the onset of Tertiary Creep

MP96-028.23

CREEP TEST C3 (SAMPLE PERPENDICULAR TO P.R.D.)Gr.2 TI @ 80% of 0.2% YS @100 DEG. C (187 MPa)

0.3 ..--------------------------,

0.25 -

0.05

3025201050'-----.1.----.1.----.1.----.1----.1----1

o

AECL EACLAECL Research EACL Recherche

CONTAINER DESIGN CONCEPTS

. STRESSED SHELL

metallic shell sufficiently thick to resist service stresses and provide requiredcorrosion lifetime (500 years)

. SUPPORTED SHELL

- relatively thin metallic shell with required corrosion lifetime (500 years),supported internally to prevent failure due to service stresses:

•

•

•

solid metal matrix (e.g. lead)packed particulate (e.g. glass beads)interna! .st~·..l(~ture

OclOb.r/l993

1189mm

k------- 860mm ----+I

Ufting RIng --~

Spacer Ring

Fuel Bundle

Basket Tubes

Packed Particulate

--- ------

1349

1+------ 994 ----...Copper ---..Head(31.8mm)

Lifting ---...Ring

SteelHead(8Omm)

Spacer -----­Ring

Fuel ~Bundle

BaSket ---­Tubes

SteelShell(65mm)

Copper ---­Shell(25.4mm)

e TR'741' COG·96-116-~ J.D. Garronl et aI.

ANSYS 5.1 35OCT 31 199510:35:29PLOT NO. 1ELEMENTSTYPE HUMf1PRES

Finite Element Model for Borehole-Emplacement Container Design

2

]

•

TR-741, COG-96-116.~ J.D. Garronl et 81.

ANSYS 5.1 35OCT 31 199510:30:55PLOT NO. 1_ 2.963_ 31.192_ 59.42_ 87.649_ 115.878I!!!J 144.106c:::J 172.335I!!:I 200.563_ 228.792

257.02

Von Mises Stress (in MPa) in Titanium/Carbon Steel Borehole­Emplacement Container Design Under 13 MPa External Pressure,Full Model

-----II!!lIlIc::::J--

1

carbon .t •• l inn.r v•••• l

2

copper out.r v••• el

ANSYS 5.1 35OCT 30 199513:21:31PLOT NO. 1_ 16.612_ 46.613

76.615.. 106.616- 136.618- 166.62IIIIIIII 196.621c::::J 226.623- 256.625- 286.626

5.25913.25121. 24329.23537.22745.2253.21261.20469.19677 .189

Von Mises Stress (in MPa) in Composite Copper/Carbon SteelIn-Room Container Design at 13 MPa

ATR.741, COG·96-116..., J.D. Garrool et aL

ANSYS 5.1 35OCT 30 199513:2L42PLOT NO. 2_ 0.112E-03_ 0.3l8E-03_ 0.524E-03.. 0.729E-03.. 0.935E-03

0.00114.. 0.001346c:::J 0.00155211IIIII 0.001757- 0.001963

carbon steel inner vessel

2

copper outer vessel

-----..c:::J--0.231E-030.0037670.0073020.0108380.0143740.017910.0214460.0249820.0285180.032054

Total Strains in Composite Copper/Carbon Steel In-RoomEmplacement Container Design at 13 MPa

IATR·741, COG-960116• J.D. Garronl et aL

ANSYS 5.1 35OCT 27 199508:59:01PLOT NO. 1.. 24.112II1II 76.544_ 128.976_ 181.408_ 233.84IIIIIIiII 286.272c:::J 338.7041IIIIIIII 391.136_ 443.568

496

1

von Mises stress, MPa

2

von Mi s esst r a i n

-----llIIIIiIIc:::J..E-.

0.676E-030.0397860.0788950.1180040.1571140.1962230.2353320.2744420.3135510.35266

Von Mises Stress (in MPa) and Strains in the Carbon Steel Vesselfor the In-Room Emplacement Container Design, Near the CollapsePressure (-50 MPa)

•

TR·741, CQG·96-116.~ J.D. Garron! et aL

•

TR-741, COG-96-116-~ J.D. Garronl et 81.

AHSYS 5.1 35OCT 30 199513:37:38PLOT NO. 1IJPRES

2

.­-----=m:l!l--..---Iil!!Zl=CZIII:lIIII

0.0130150.1343010.2555860.3763720.4981580.6194440.7407290.8620150.9833011.1050.0130150.1343010.2555860.3768720.4981580_6194H0.7407290.8620150.9833011.105

Von Mises Stress (in MPa) in Dual Vessel, Carbon SteeV25.4 mmThick Copper Container Due to Handling Loads

Cost of Cost/kg U02 Cost/kg UContainer Design Shell Contained1 Contained2

Material ($ Can.) ($ Can.)($ Can.)

6.35-mm ASTM Gr 2 Titanium-Sheil, 3800 2.45 2.78Packed-Particulate(Reference UFDC Design)

6.35-mm ASTM Gr 12 Titanium-Sheil, 4940 3.19 3.61Packed-Particulate

6.35-mm ASTM Gr 16 Titanium-Shell, 6460 4.17 4.72Packed-Particulate

25.4-mm Copper-Shell, 7150 4.62 5.23Packed-Particulate

50.8-mm Copper Shell, 15800 10.21 11.55Packed-Particulate

50.8-mm Copper Shell, with 24600 15.89 17.9850.8-mm Carbon Steel Support Linerand Packed-Particulate

. 1 Bruce fuel, 21.5 kg UO/bundle2- B"ruce fuel~ 19.0 kg Ulbundle

Container-Shell Welding

Titanium

• Resistance/Diffusion (RID) Bonding• Gas-Tungsten-Arc (GTA) Welding

Copper

• Electron-Beam (EB) Welding

Closure-Weld InsQection

• Ultrasonic Inspection

• Helium Leak Detection

Welding of Copper Containers• Electron-beam welding (EB) would be used for

closure welds on copper containers• Pore-free welds in 25-mm-thick oxygen-free copper

have been produced in the Canadian program• Studies for the Swedish program have shown that

high-quality EB welds can be produced in copperup to 100 mm thick

• Welds can be inspected ultrasonically

TopPlate

BottomPlate

50mm

EIS3-3.23Draft 1 July 93

INSPECTION OF CLOSUREWELDS

• ALL PREFABRICATION INSPECTIONCAN BE ACHIEVED WITH STANDARDRADIOGRAPHY AND TOMOGRAPI-IY

• FOR FINAL CLOSURE WELDS THEONLY TECHNIQUES AREULTRASONICS AND POSSIBLY·TOMOGRAPHY

· ii

Reliability Analyses

• Principal Finding: The proportion of containers

with initial failures or liable to eariy failure due

to incipient manufacturing defects not detected

during inspection -"Jill be about 1 in 5000.