ML23115A086
| ML23115A086 | |
| Person / Time | |
|---|---|
| Site: | 07103035 |
| Issue date: | 04/03/2023 |
| From: | Boyle R, Neely R Edlow International Co, Govt of Japan, Atomic Energy Agency |
| To: | Division of Fuel Management |
| Garcia-Santos N | |
| Shared Package | |
| ML23115A059 | List: |
| References | |
| CAC 001794, EPID L-2023-DOT-0006 JRC-80Y-20T | |
| Download: ML23115A086 (775) | |
Text
Chapter : Package description A. Introduction This packaging is dry type, and is named JRC-80Y-20T. The transportation appearance is shown in ()-Fig.A.1.
The JRC-80Y-20T packaging is used to transport spent fuels from reactors for research (JRR-3) of Japan Atomic Energy Agency (former Japan Atomic Energy Research Institute) to reprocessing plants in foreign countries.
A.1. Name of the packaging JRC-80Y-20T A.2. Type Type B(U) package for fissile material A.3. Allowable number of packages and allowable arrangement of packages Allowable number of packages : Unlimited Allowable arrangement of packages : No restriction A.4. Transport index and criticality safety index Transport index : Less than 5.8 Criticality safety index : 0 A.5. Maximum weight of the package 23.2 x 103 kg (at loading the basket for box type fuel)
A.6. Size of the packaging (at body lifting lug)
Diameter approx. 1.9m Height approx. 2.1m A.7. Maximum weight of the packaging 22.8 x 103 kg (at loading the basket for box type fuel)
()-1
B(U) package for fissile material This package corresponds to the requirement for Type B(U) package because the radioactivity exceeds the A2 value as shown in (I)-Table D.2. Additionally, it corresponds to requirements for packages containing fissile material because it is loaded with spent fuels where the enrichment is 20wt% or less, and which contains more than 15g of uranium-235, as shown in table (I)-Table D.1.
B.2. Allowable number of packages No restriction
()-3
Dimenslon Reference agure C.4.5 Tie down device (I) Fig.C.3 Length Width Height C,4.6 Li ing device Length about 4,200mm C.5.
Veight (a)Body(with fins) a kg (b)Lid,hd bolt (1)Lid(with ins) h: kg (2)Lid bo b2 : lIIIIII,kg (c)Basket (1)Basket for box type fuel kg (2)Basket for MNU type fuel kg (3)Spacer(40 pieces)
(d)Tie dOwn device d : 1,9x 103 kg (e)Lilting device e 0 2X103 kg (I) 39
confirmed that the subcriticality is maintained for the nuclear fuel package under routine conditions of transport, for the nuclear fuel package in isolation, and for the package in isolation and in array under the normal and accident conditions of transport pertaining to package containing fissile material.
(6) Consideration of Aging of Nuclear Fuel Package As a result of the evaluation of aging effects due to the factors such as heat, radiation, and chemical changes under the conditions of use expected during the planned period of use, it was confirmed that such effects need not be considered in confirming compliance with the technical criteria. For the lifting and containment devices, it is necessary to consider aging effects due to fatigue as stress will be generated repeatedly. For the lifting and containment devices, each fatigue was evaluated considering the conservative repeat count expected during the period of use, and it was confirmed that there is no impact on compliance with the technical criteria as fatigue failure does not occur.
The details of each analysis and the evaluations are described in Chapter A through Chapter F.
For the purpose of conservative evaluation, the safety analysis assumes the cases where following fuel elements are loaded, which will pose more severe conditions than the current contents.
()-3
1 Drop height 9m Target Flat rigid body
[ass ofthe package (kg)
Body (Stainless steel)
Lid Packaging (Stainless steel)
Lid bo (Stainless steel)
(when the basket for bOx type fuel such as Contents Basket tt fuel elements RI 3 standard silicide type fuel is contained)
Total mass ofthe package 23.2x 103 Operating temperature of the materials Part Temperature (° C)
Body Lid Lid bolt Fin a (II) A 144
a) Strength for the drop to the Xrdirection ln the analysis,the inertia force of the basket itself,the fuel element and the neutron poisons generated by the deceleration are taken into.
The partition plate and the compart nent plate are modeled with the shell element.As the l ass of the fuel element in the analysis,the largest lnass of standard type fuel element is used. RR 3 standard silicide type fuel is assumed as a representative.
The partition plate and the compart nent plate are 140deled with the shell element.As the l ass of the fulll element in the analysis,the largest l ass of standard type fuel element is used. It is assumed JRR 3 standard silicide type fuel as a representative. The fuel element,whose cross sectional form is a rectangle mmamm),is modeled with the solid element that has equivalent stiffness.
The equivalent stiffness Eetis obtained by the fol10wing equation, Eeq Ex Where,E :MOdulus oflongitudinal elasticity of aluminum alloy(
at c (MPa)
Al :Cross sectional area of aluHlinunl a1loy in the cross seCtiOn ofthe fuel element (mm2)
A2 :Rectangular cross sectional area of the fuel element lnodeled 5.81x 103(mm2)
Consequently,the following is given, Eeq x
=1,74x 104 wIPa The analytical model is shown in(II) Fig.A.94.
The analysis resutts are shOwn in(II) Fi .A.95 through(II) Fig.A.97.
(II) FigoA.95 and(II) Fig.A.96 are the deformation in the state where deceleration IDg iS acting and after decelerationllllDg acting, respectively.
The lnaxi nuHl displacement values in the state where deceleration is acting and after deceleratiOn acting aretllDmm andCII}n 1,respectively.
(II) A 219
4 Strength of the fuel elements Since each basket has the sufficient strength against the horizontal drop as described in(II) A.6.1,2, 3, no significant defOrmatiOn occurs in the fuel element due tO deformation of the basket. This paragraph shows that each fuel element is never damaged due to the inertia force at the hOrizontal drop.
4.1 Strength of RI 3 standard silicide type fuel The horizOntal drop direction of RR 3 standard silicide type fuel is considered tO the X directiOn and the Y directiOn as shown in(II) Fig.A.106.The drop to the X directiOn is severe,since the pressure area to the X direction is smaller than that to the Y direction.
Accordingly,this paragraph describes the compressive strength against the fuel side plate at the drop tO the X directiOn.
The compressive stress( c)due tO the inertia fOrce is given by the f0110wing equation, W gC GH c=
A where, W :Mass of the fuel elernent=(kg) g :Gravitational acceleratiOn=9.8( 1/se c2)
GH :In pact deceleration=II(g)
A i Cross sectional area Of the fuel side plate(mm2)
= xx= (mm2)
TherefOre, c= = MPa Irl this case, since the yield stress of lnaterial AIIIIIIIl at the ternperature of R3 is less than that of rnaterial AIIIIIl as shown in (H) Fig.A.6,the yield stress( y)OfIIMPa ofmaterialAl lis used.
Consequently,the allowable cOmpressive stress( ac)at the temperature ofI is given as follows, ac=1.5x y=1.5x = MPa Consequently,the safety factor(RF)and the safety margin( IS)is given as fOl10ws, (II) A 242
4.2 Strength Of RR 3 follower silicide type fuel The inertia force due tO the vertical drop acts On the fuel element in the same manner as RR 3 standard silicide type fuel element. The horizontal drop di lection of RR 3 follower silicide type fuel element is cOnsidered to the X direction and the Y direction as shown in(II) Fig.A.107 in the same manner as RR 3 standard silicide type fuel element.
The drop to the X direction is severe,since the pressure receiving area to the X direction is smaller than that tO the Y direction in terms of compressive stress on fuel elements.
Accordingly, this paragraph describes the cOmpressive strength against the fuel side plate at the drop tO the X direction.
The compressive stress( c)due tO inertia force is given by the follOwing equation, W g GH c=
A where, W :WIass of the fuel elernent=(kg) g :Gravitational acceleratiOn=9.8( 1/sec2)
GH I Inlpact deceleration=II(g)
A :Cross sectional area Of the fuel side plate(mm2)
= xx= (mm2)
TherefOre, c= WIPa In this case, the yield stress( y)Of maaterial A at te nperature of kD is less than that of material AIIIIIIIII. Thex efoxle, the yield stress
( y)ofill WIPa ofnaaterialA is used.
COnsequently,the a1lowable compressive stress( ac)at the temperature of is giVen as fol10ws, ac=1.5x y=1.5x = MPa Consequently,the safety factOr(RF)and the safety margin(MS)are given as fol10ws, (H) A 244
- 3. Lid bolt 3.1 Allowable stress At the time of minutes after occurrence of the fire accident when the maximum temperature gradient is appeared, the axial temperature distribution of the lid bolt is greatly different in upper part and in lower part. The temperature of the lid bolt is in the upper part and is in the lower part, where JRR-3 MNU type fuel is stored.
Furthermore, the shape of the upper part of the bolt is different from that of the lower part. Namely, there are threads in the lower part where contact to the body flange, and the upper part is mm in the diameter round bar.
Therefore, the allowable stress ( a) of the lid bolt sets another value respectively in the upper part and in the lower part.
Though the temperature of the lid bolt is in the upper part and in the lower part, and are used conservatively. When the tensile strength ( u )
used for the allowable stress ( a ) of the lid bolt, a for each temperatures are as follows; a = MPa at a = MPa at 3.2 Stress of the lid bolt This analysis is performed by using the analytical model and method described in (II)-A.5.1.3. The longitudinal stress contours of the lid bolt is shown in (II)-Fig.A.121.
The minor diameter of lid bolt (JIS- ) is modeled. The upper part of the model is mm in the diameter round bar so that the maximum stress in the upper part of the bolt is converted in the ratio of the sectional areas. On the other hand, since there are threads in the lower part of the bolt, the result value of the analysis is used as it is for the maximum stress in the lower part of the bolt.
The maximum stress in the upper part of the lid bolt is given as follows; 1
1 = m x 2
where, 1 : Sectional area of minor diameter of external thread (II)-A-275
4 Thermal expansion ofthe shell and the basket generated during the are accident Thc hollow cytindttcal modet shown in(H) F .A.123 is considered to calculate the thermal expansion of the shell. The displacement value(expanSiOn value)is to be found.
where r :Displacement value at arbitrary radius( )
a : Inside radius b : Outside radius r i Arbitrary radius (a r b) ta : Temperature at inside radius tb : Temperature at outside radius t : Temperature at radius(r)
- coefacient of hnear thermal expansion V : Poisson's ratio model ofthe hollow cvlinder In this case,the values of ta,tb,and t are the values IIom which the reference temperature(the temperature at which no thermal expansion is generated,20° C)is subtracted.
The expansion value( r)in thiS Case is given by the foliowing equation; r=1 x 1 E t r dr ttCir+I r
ln this case,Cl,C2and k2 are given as fonows i (1+V)(12v)
Cl= 1v X b2a2 tr dr vk2 1+v a2 b C2 =
1v x
b2a2 tr dr
=
i)In the case of axisymmetric temperature distribution(t)in the Steady condition The temperature at radius(r)iS g en as follows; (II) A 277
A.7 Enhanced water inllmersion test Since this nuclear fuel package is a package cOntaining nuclear fuel material, etco with an amOunt of radiOactivity exceeding 100,000 tilnes A2 valuc(the ratio of the radiOactivity ofthe contents to be loaded to the 100,000 tines A2 value is approximately 4.5 80 eXCeeds l), it will be evaluated whether the cOntainment device is not damaged for the 200m i mmersion test.
- 1. Strength of the packaging when the external pressure equivalent tO the water depth of 200 m is applied l.l Strength of the shell (H) FigoA.127 shows the analytical mOdel of the shell tO which the external pressure is applied.
As shOwn in Table 32,case lc and case ld Of the literature(14),the principal stress generated at the shell under the external pressure equivalent tO the water depth of 200 m is given as fol10ws, l=
(10ngitudinal stress) a2(r2+b2) 2= q r2(a2b2) (circumferential stress) a2(r2b2) 3= q r2(a2b2) (radial stress)
(II) A 308
A.10.4 Appendix-4 Compatibility with the ASME Code under design conditions
- 1. Summary This package is used to transport to the reprocessing facilities in foreign countries, such as U.S.A and U.K. etc, for reprocessing the spent fuels of JRR-3 standard silicide type, JRR-3 follower silicide type, JRR-3 MNU type, It is necessary to acquire the permission and approval of U.S.A and relevant countries as well as Japanese Government.
According to the U.S Government (the ASME Code), the performance of a pressure vessel is required for the body and the lid forming this package.
Therefore, for reference, the analysis is made on the following items.
Minimum required thickness for the body and the lid Minimum required size for the lid bolt Minimum required thickness for the valve disc Minimum required sectional area for the valve main bolt Minimum required sectional area for the valve protection cover bolt Reinforcement of the valve hole Exclusions of fatigue analysis As a result of the analysis, the dimensions of this packaging satisfy the requirements in the ASME code as shown in (II)-Fig.A.10.4-1.
(II)-A-348
Therefore, the minimum required thickness is as follow.
tm = mm 4.3 Conclusion The thickness of the shell is greater than the minimum required thickness of the ASME Code.
- 5. Thickness of the bottom plate (Refer to (II)-Fig.A.10.4-1) 5.1 Data Material : SA-182 forging (equivalent to )
Allowable stress : Sm = MPa ( kgf/ mm 2)
Inside diameter of the bottom plate : d = mm Thickness : t = to mm 5.2 Minimum required thickness (t m )
According to NE 3325.2 in the reference [7], the minimum required thickness for the bottom plate is expressed by the following equation.
tm = d C P/Sm Where, C is a constant determined according to NE 3325.3 in the reference [7].
C is 0.3 or 0.33xtr / t s which is larger.
tr : Minimum required thickness for the shell = mm t s : Actual thickness of the shell excluding the corrosion allowance = mm Therefore, 0.33xtr / t s =
Consequently, C = 0.3 and t m = mm Remark: Though the requirements in NE 3358.4 are not satisfied, it is confirmed in (II)-A.5.1.3 that there is no problem on strength in the weld-joint as a result of the structural analysis using the general-purpose finite element code ABAQUS.
(II)-A-350
- 12. Cycle As shOwn below, all requirements specified in NE 3221 5(d)in the reference[7]are satished.
Consequently,no analysis is required.
12.l Cycle between atmospheric pressure and operating pressure Sa=3xI= I MPa( kg mm According to Fig.I 9.2.l in the reference[1],the nunber Of cycles corresponding to the above Sa value is about llllll cycles.
Since the maxilmum predicted number of cycles used is 300 cycles, it f0110ws that the requirements in the ASME Code are satisied.
12.2 Pressure uctuations in 40rmal operating pressure The signiacant pressure ttuctuation defined in the ASttIE Code is obtained by the fo1lowing equation.
x÷ x = x ttx = Mh( ,mm2)
Where I Pd,Design pressure Sa;Fatigue strength at 106 til.eS It is nOt expected that the pressure nuctuation during nor mal conditions Of transport exceeds the above value.
Consequently,the requirements in the ASWIE Code are satisied.
12.3 Tettperature difference startup and stop The maximun distance d between two a"acent points is d=2 where,R,Average radius of the pressure vessel==IIIl mm t,Thickness ofthe bOdy=II Ixlm (II) A 361
The su lxnatt ofthis package design is as follows, This package is composed ofthe packaging with fins and the baskets cOntained.
Each basket has the basket lodgement corresponding to the kinds of fuel elements, and the fuel elements are contained in the basket lodgement. Air is enclosed in the cavity of the package at atmospheric pressure when it is closed up. The cooling method Ofthis package lnainly depends on natural coolingo Name the decay heat generating from the spent fuel elements transfers to the body and the lid through the cavity air and the basket lnade ofthe neutron poison and stainless steel,and further is diffused from the outer surface ofthe package including the fins to ambient air by natural convection and radiation. Thermal analyses are carried out using above analytical models.
Each fuel ele lent has ditterent decay heat as shown in( ) Table B.4. In the evaluation,assurling a case where 40 assemblies of lnore conse ative fuel element (hereattter referred to as fuel elerlent A)than the cOntents are loaded so as to maxilnize the decay heat per nuclear fuel package,the value was set to 2.25 kW.
These decay heats are calculated by using ORIGEN and ORIGEN R code.
The results ofthermal analysis are summarized as follows.
(1)Normal conditions oftransport The lnaxilnum temperature ofthe outer surface ofthis package without insolation is CC at ambient temperature of 85 when Fuelelement As are contained.The maxilnurn surface te aperature ofthis nuclear fuel package in the shade is C on the surface ofthe container body when fuel element A is contained, and will not exceed 85° C as specitted in the technical crieria.
The lnaxilnum temperature of the contents in the solar insolation is 223 when Fuel element As are contained and this is less than lnelting point ofAlunlinum a1loy, E ,that is used for fuel dadding.The maximum internal pressure is MPaGF)under normal conditions of transports and this is less than the hydrostatic test pressure of the packaging,0.98 MPaG(10 kgfrcln2G). These results are shown in( ) Table B.6. Furtherlnore the package under the ambient temperature of 40 is evaluated when the temperature of the package is 40 and the decay heat is consldered.
( ) B2
(2) Accident conditions of transport q(3 at the fuel elernent, The ternperatures rise up to
,qc at the outer surface ofthe package, ,k3 at the containment boundary ofthe drain valve when Fuel element As are contained under the accident conditions oftransport.The internalpressurerisesuptot
, [PaGttl in this condition. These results are shown in( Table B.8. Those temperature do not exceed the melting point of
)
aluminum a1loy ofthe fuel cladding,E ,that Of stainless steel ofthe packaging, 1IIII) C and also the maxilnuln permissible telnperature the packing,E .
Under the above lnentioned normal and accident conditions of transport, the fol10wings can be said about the package in the lowest temperature,in the highest temperature and in the lnaxilnum inner pressure.
Stainless steel used for the main material of the packaging and aluminum a1loy for the fuel cladding have enough toughness at low temperature,and the melting points of these material exceed the maximuni temperature obtained by the thermal analysis.
The norlnalse ice temperature O ring used for the contact portion ofthe body and the lid and each valve is fro al C tdl IB and the lnaxi14um peralissible temperature ofthe s 250 . Therefore, the calculated temperatures of()"ring are within these conditions,
) In the structural analysis, the values of increase pressure used in the normal conditions of transport and in the accident conditions of tl,ansport are assumed conservatively to bel ,MPaG andl ,AttPaG respectivel and the obtained values ofstlless are rounded up for the stress calculations.
In the containment analysis, the value of the pressure is assumed also consewat elytobeEPaGakg?cm2G)
( ) B3
ignored.
2.Ma mum temperature(Melting)
The maxi num temperature of each 10catiOn of the package under the accident conditions Of transport occurs when the packaging contains Fuel element A.The value is at the fuel element.It is much below l ,
melting point of the fuel cladding lnade of aluHlinuHl alloy.Also,the lnaxilnum temperature of the packaging occurs at the top of the fin lnade of stainless steel which is the main lnaterial of the packaging, and the value is lll , which is muchbelowEEIIl k3,Inelting point of the stainless steel.
3.Iaxilnuna internal pressure, maxilnuni thermal stress and thermal expansion (deformationl i )The maxilnuln internal pressure of this package under the accident conditions oftransport is llllll IPaG. This value is n uch below O.98 MPaG (10 kg/cm2G),pressure of the hydro test.
)The lnaxil um ther mal stress under accident cOnditions of transport occurs when the packaging cOntains JRR 3 MNU type fuels. In this case, the rnaxilnurn plastic strain is ll1 0/O and the safety lnaI:gin is . The stress caused on the lid bolt is lllI IPa and the safety lnargin is llll. For the thermal expansion, the temperature of the basket dOes not increase abnormally and the packaging does not shrink rapidly because the heat capacity ofthe packaging is large.
As lnentioned above, the stress caused on the package has enough margins compared with the allowable stress, Moreover, neithexi the fuel elements nor the basket are restrained by the packaging.
4 Containment The temperature of the packing ofthe cOntainment boundary ofthe package under the accident conditions of transport is ttoln 40 R3 to lll . For above, the normal service temperature range(normal use)of silicon rubber of the
( ) B55
E. Criticality analysis ln this analysis, it is investigated that any of packages during normal transportatiOn,a package in isolation,and a package in isolation and array under general and special test conditions for packages containing fissile xnaterial would not reach criticahty.
E.l Summary This section shows that subcriticality would be maintained under analysis conditions lbr isolation during normal transportation,and isolation and array under general and special test conditions for packages containing fissile lnaterial.
The containment ofthe packaging is lnaintained,since there is no change ofthe configuratiOn of the packaging which affects the criticality analysis under routine,norrnal and accident conditions of transport.
The configuration of the basket is maintained under routine, normal and accident conditions of transport.
The stuck parts of the fuel elelnents are lnaintained in the basket lodgel ent under routine,norlmal and accident conditions of transport.
From the above,the same criticality analysis lnodel for the package shall be used during norlnal transportation, and under general and special test conditions for packages containing fissile lnaterial.
In the analysis, it is conservatively assumed that the enrichment of the fuel element contained is the same as the initial enrichment and as a neutron poison is ignored. The three dilnensiOnal multigrbup Ionte Car10 KENO Va codel)is used to obtain the effective multiplication coefficient of the package.
Frona the result of the analysis, the maximuHl value of the effective multiplication coefficient(keff+3 )is O.873 when RR 3 standard silicide type fuel are contained.
Therefore,the criticality safety for the package is conirlned.
( ) E1