ML19114A301
| ML19114A301 | |
| Person / Time | |
|---|---|
| Site: | 07103052 |
| Issue date: | 03/05/2019 |
| From: | Salaun A TN Americas LLC, Orano USA |
| To: | Division of Spent Fuel Management |
| Shared Package | |
| ML19115A128 | List:
|
| References | |
| Download: ML19114A301 (16) | |
Text
NON PROPRIETARY VERSION TN International CHAPTER 1 - APPENDIX 1 TN-MTR Names Signatures Date Prepared by A. SALAÜN Ref.
DOS-18-011415-007-NPV Rev. 1.0 Form: PM04-3-MO-3 rev. 2 Page 1/16 RESISTANCE OF THE TN-MTR PACKAGING TO REGULATORY PRESSURES TABLE OF CONTENTS REVISION STATUS
SUMMARY
- 1. PURPOSE
- 2. CALCULATION FOR THE CONTAINMENT UNDER NORMAL CONDITIONS ACCORDING TO CODAP 95 RULES
- 3. CALCULATION FOR THE CONTAINMENT AT AN EXTERNAL PRESSURE OF 20 BARS.
- 4. CONCLUSION
- 5. REFERENCES
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 2/16 NON PROPRIETARY VERSION REVISION STATUS Revision Date MODIFICATIONS Prepared by/
Checked by Old reference: DOS-16-00173678-151 1
N/A Document first issue. Revision number intentionally set to correspond to the source document revision number.
ASA / LMA New reference: DOS-18-011415-001 1.0 N/A New reference due to new document management system software.
ASA / LMA
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 3/16 NON PROPRIETARY VERSION
SUMMARY
This appendix to Chapter 1 presents the verification that the TN-MTR packaging will resist pressure. In particular, this analysis is used to define the maximum allowable internal pressure (used to analyse the activity released) and the resistance to external test pressure as defined by the IAEA <1> <1>.
The TN-MTR packaging is designed to obtain a type B(U) approval and for packages of fissile materials.
Requirements for this type and concerning the containment pressure are:
- 1. Water immersion test (<1> <1>): resistance to an external gauge pressure of at least 150 kPa = 1.5 bars.
- 2. Water Immersion test for packages containing irradiated nuclear fuels (<1> <1>):
resistance to an external gauge pressure of at least 2 MPa = 20 bars.
The check on point 1. water immersion test is combined with the calculation of the maximum allowable internal pressure and is made by calculating maximum allowable pressures according to CODAP 95 rules <2>. This calculation shows that the allowable pressure in the cavity is 11 bars for an internal or external pressure. This value is higher than the water immersion test pressure (<1> <1>): 1.5 bars Considering this result concerning the maximum allowable internal pressure, the test pressure for the TN-MTR packaging is fixed at 11 bars.
The check on point 2. water immersion test for packages containing irradiated nuclear fuels, is made using analytic calculations by applying a pressure of 20 bars to the internal containment of the TN-MTR packaging and comparing the stresses in the steel (calculated maximum stress = 384 MPa) at 1.5 times the yield stress.
Conservatively, the mechanical properties of the containment steels are considered at 200°C. Chapter 2 contains calculations to demonstrate that the containment temperature is actually less than 200°C.
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 4/16 NON PROPRIETARY VERSION
- 1. PURPOSE This appendix to chapter 1 describes the calculation of the maximum allowable pressure according to CODAP 95 calculation rules (internal pressure) and the check on the resistance of the TN-MTR packaging to regulatory pressures defined by the IAEA <1>
<1> (external pressures).
The TN-MTR packaging is designed to obtain a type B(U) approval and for packages of fissile materials.
Requirements for this type and concerning the containment pressure are:
- 1. Water immersion test (<1> <1>): resistance to an external gauge pressure of at least 150 kPa = 1.5 bars.
- 2. Water Immersion test for packages containing irradiated nuclear fuels (<1> <1>):
resistance to an external gauge pressure of at least 2 MPa = 20 bars.
Conservatively, the mechanical properties of the containment steels are considered at 200°C. Chapter 2 contains calculations to demonstrate that the containment temperature is actually less than 200°C.
- 2. CALCULATION FOR THE CONTAINMENT VESSEL UNDER NORMAL CONDITIONS ACCORDING TO CODAP 95 RULES This calculation verifies the mechanical resistance of the packaging to the test in section 629 of the IAEA rules <1> (see chapter 00-2 for <1>).
This check is carried out by comparing the allowable pressure under normal operating conditions, as calculated using the CODAP <2> rules, with the test pressure.
2.1 - Calculation for the cylindrical containment enclosure subjected to internal pressure The e/De ratio (thickness of the cylindrical enclosure on the external diameter of the containment) is equal to 20/1000 = 0.02 and is less than 0.16. This means that chapter C2.1 in <2> is applicable.
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 5/16 NON PROPRIETARY VERSION The allowable relative pressure in the cavity is deduced using the formula in C.2.1.4.1 general formula:
P e z R
e i
0 5, where:
. P:
pressure within the cavity, e:
thickness of the cylindrical wall
. f = nominal stress calculated for normal operating conditions.
The stress is defined in Table C.1.7.2 for austenitic stainless steels.
The criterion 1 = max r 3
is set; e 15,
where:
. r: ultimate strength of steel type A at 200°C = 360 MPa (see chapter O),
. r: yield stress of steel type A at 200°C = 118 MPa (see chapter O),
therefore 1 = max 360 3
- 118 15,
= 120 MPa.
. Z: Welding coefficient as defined in Table C.1.8.
Due to the nature of the elements transported, the construction category of the TN-MTR is B.
The coefficient, Z, is equal to 1 due to the severe production acceptance criteria.
. R:
internal radius of the cylindrical enclosure = 480 mm Thus, allowable pressures can be calculated according to CODAP 95 under normal operating conditions:
P = 20 120 1
480 0 5 20 x
x x
= 4.89 MPa or 48.9 bars.
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 6/16 NON PROPRIETARY VERSION 2.2 - Calculation for the containment cylindrical enclosure subjected to internal pressure and other loads This check is covered in Chapter C.2.4 in <2>.
Refer to section C.2.4.5 Calculation rule for cylindrical enclosures without torsion, case a): minimum thickness of a cylindrical enclosure without torsion.
e e
e e
cyl C
max 1
2 where:
ecyl: cylinder thickness = 20 mm, eC: minimum thickness calculated according to C.2.1.4, described in section 2.1 in this document eC = 20 mm e1: 1 4
4 2
PD F
D M
D m
m m
where:
. : calculated nominal stress already defined in section 2.1 in this document,
= 120 MPa
. P: calculated pressure
. Dm: average cylinder diameter Dm = 980 mm,
. F: value of the force applied to the cylinder in addition to the internal pressure.
It is assumed that 2/3 of the mass of the lid and the flange and half the mass of the shock absorbing cover is transmitted to the floor through this cylinder (the remainder of the mass being transmitted to the floor through the outer containment of the packaging body).
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 7/16 NON PROPRIETARY VERSION The result obtained using the masses given in chapter 4466-Z-0 is:
. F = m =
23 12 2700 1500 1700
x 9.81 = 35 800 N.
.M: absolute value of the bending moment applied in a plane containing the enclosure centreline = 0.
P1 =
e F
D D
m m
1 4
P = 120 20 35800 980 4
980 x
= 9.75 MPa or 97.5 bars.
e2 =
8 4
4 2
D PD F
D M
D KE m
m m
m
Since the moment M is zero, the calculation for e2 is null and void since the quantity under the radical is negative (section c) in C2.4.5 in <2>).
The allowable pressure under normal conditions is therefore P = min (Pe, P1) = 48.9 bars.
2.3 Calculation of the welded circular flat bottom under pressure only under normal operating conditions (section C.3.2 in <2>)
The chosen calculation case most similar to the case of the TN-MTR is the flat bottom with discharge groove (section C 3.2.6 in <2>).
The required minimum thickness of the bottom is given by the relation:
ebottom = Max C
D P
C D P
i i
1 2
min C 3.2.5.a in <2>
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 8/16 NON PROPRIETARY VERSION where and min, nominal calculated stresses:
The steel used for the bottom is type B (see chapter O) with yield stress 320 MPa at 200°C and ultimate strength 580 MPa at 200°C.
= max 580 3
320 15
= 213 MPa.
According to section 2, the nominal calculated stress of the cylindrical enclosure is equal to 120 MPa, min = min( ; v) = 120 MPa.
therefore for this design case, we have:
v min 213 MPa 2130 bars 120 MPa 1200 bars 120 MPa 1200 bars C1: given in graph C.3.2.4 in which the value used for is min = 120 MPa, ev: thickness of the cylindrical enclosure = 20 mm D: inside diameter of the enclosure = 960 mm ev/Di = 20 / 960 = 0.021, reduced by 0.02.
The following table gives values of C1 as a function of the internal pressure.
C2: given by graph C.3.2.5, where min = 120 MPa,
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 9/16 NON PROPRIETARY VERSION The following table gives the required minimum thickness under normal operating conditions, as a function of the internal pressure.
internal pressure (bars) p/min C1 C2 C1 Di (P/)0.5 (mm)
C2 Di (P/min)0.5 (mm) minimum thickness of the bottom.
(mm) 1 0.001 0.304 (1) 6.3 (1) 6.3 3
0.003 0.306 (1) 11.0 (1) 11.0 5
0.004 0.308 (1) 14.3 (1) 14.3 7
0.006 0.334 (1) 18.4 (1) 18.4 9
0.008 0.353 (1) 22.0 (1) 22.0 11 0.009 0.36 0.32 24.8 29.4 29.4 13 0.011 0.37 0.38 27.7 38.0 38.0 15 0.013 0.377 0.41 30.4 44.0 44.0 17 0.014 0.379 0.42 32.5 48.0 48.0 19 0.016 0.384 0.44 34.8 53.2 53.2 21 0.018 0.387 0.46 36.9 58.4 58.4 (1): not applicable, since C2 is less than 0.30.
0,0 10,0 20,0 30,0 40,0 50,0 60,0 70,0 0
5 10 15 20 25 M
inim um bottom thickness (m m
)
Internal pressure (bars)
Minimum required bottom thickness as a function of the internal pressure It is deduced that the maximum internal pressure under normal operating conditions and for a bottom thickness of 30 mm, is 11 bars.
Minimum bottom thickness (mm)
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 10/16 NON PROPRIETARY VERSION 2.4. Calculation for the bolted flat circular bottom subjected to internal pressure only This calculation is described in chapter C.3.3 in CODAP 95 <2>.
The applicable section is C.3.3.4 - Calculation rules for bottoms with seals inside the bolt drilling circle.
The minimum thickness of the bottom is given by the relation:
e = max
e e
A P
in which:
+ eA =
3 C D
D F
j j
A A
C:
diameter of hole drilling circle = 1225 mm Dj: diameter of the circle on which the seal is seated= 1130 mm, F'A: tensile force exerted on the bolts when the seal is seated, as defined in section C.6.1.4 in CODAP 95.
F'A: nS S
r b A
2
- (formula C 6.1.4 e) where n
- number of bolts = 36, Sr: stressed area of an M30 bolt = 561 mm2, S: minimum required cross-section for all n bolts, S = FA b A FA: minimum force to be applied by the n bolts in the situation in which seals are seated determined in section C.6.A.4 FA = Dj Y2 Y2 minimum linear force to be applied to the seal in the seal situation. According to section C6.A4, Y2 can be neglected for the layout of the seals corresponding to the case of the TN-MTR.
Y2 = 0
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 11/16 NON PROPRIETARY VERSION FA
= 0 N S = 0 mm² F'A = 36 561 2
x 178 = 1 797 450 N.
A: nominal calculated stress in the bottom material in the seal seated situation.
The flange fitted to the lid is made of type A steel (see chapter O).
Therefore we have A = 120 MPa (see section 2.1 in this document).
We therefore deduce:
eA =
3 1225 1130 1130 1797450 120
x x
= 34.7 mm.
This calculation shows that the thickness of the disk forming the bottom of the lid (301), which is equal to 65 mm, is sufficient because it is more than eA = 34.7 mm.
+ ep =
3 3 32 3
4 2
D D
Y P
C D
P j
j m
j where Ym is negligible according to section C6.A4 in <2>
P =
ep x 2
3 3 32 3
4 2
D D
C D
j j
j ep: thickness of the plate of the containment lid = 65 mm.
- nominal calculated stress for steel type B (see chapter O) = 213 MPa, according to section 2.3 in this note.
- Poisson's ratio for steel = 0.30 (see Table C1.6.6 in section C1.6.6 in the CODAP 95).
Dj: diameter of the circle on which the seal is seated= 1130 mm,
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 12/16 NON PROPRIETARY VERSION C:
diameter of hole drilling circle = 1225 mm P =
65 213 2
3 3 0 3 32 1130 3 1130 4
1225 1130 2
P = 1.89 MPa or 18.9 bars.
+ The thickness of the region around the bottom is such that the maximum allowable pressure obtained (section C.3.3.4.b) is:
P =
e x
D Y
P C
D P
j m
j 2
3 4
with the same notations as above.
P =
65 213 2
3 1130 4
1225 1130
= 11.2 MPa or 112 bars.
The allowable internal pressure in the cavity is determined taking account of the above two calculations, allowing for the thickness of the bottom of the lid, P = 18.9 bars.
2.5 - Calculation for the containment subjected to external pressure only The calculation is presented in section C.4.1.5. The De e ratio is 100020 = 50 and is more than 10.
L De 1080 1000 = 1.08 D
e e = 50 The coefficient A determined on the chart C.4.9.1 is A = 0.004. Coefficient B determined on chart C.4.9.2-13: austenitic stainless steels of grades type low carbon Cr-Ni and low carbon Cr-Ni with nitrogen for a temperature equal to 205°C.
B = 48.
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 13/16 NON PROPRIETARY VERSION The maximum allowable external pressure is:
Pa = 4 3
B D
e K e /
where K = 1 for normal operating conditions, Pa = 4 3
48 50 1
1 x
x MPa
,28 or 12.8 bars.
2.6. CONCLUSION The maximum allowable pressure for the containment vessel subjected to internal or external pressure loading, calculated using CODAP 95 rule criteria during normal operating conditions, is P = 11 bars.
The design basis element is the bottom of the packaging.
It is thus demonstrated that the TN-MTR packaging resists a pressure of more than 1.5 bars corresponding to the water immersion test.
The test pressure applied during acceptance of the packaging is fixed at 11 bars (see chapter 7A).
- 3. CALCULATION FOR THE CONTAINMENT VESSEL AT AN EXTERNAL PRESSURE OF 20 BARS.
This calculation corresponds to the test verification in section 630 of IAEA rules <1> (see chapter 00-2 for <1>).
The stresses in disks and then the stresses in the containment shell are calculated by applying classical material strength formulas. These stresses are compared with 1.5 times the yield stress, which is justified by the accident-related nature of this test and by the requirement in section 550 in IAEA rules: if the water immersion test described in section 630 were applied to the package, the containment would not fail.
3.1 CALCULATIONS FOR BOTTOM AND LID DISKS The calculations for the disks are made using the formula taken from <3>,
corresponding to the calculations for the circular plates with a constant thickness, uniformly loaded across the whole plate and with the periphery fixed (case 10b, Table
- 24)
Maximum moment at the periphery of the plate: Mmax = -q a² / 8
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 14/16 NON PROPRIETARY VERSION Maximum bending stress: max = - 6 q a² / (8 t²)
Maximum deflection at the centre of the plate: yc = - 12 q a4 (1-²) / (64 E t3)
Where:
q: pressure applied to the disk, q = 2 MPa a: disk radius, variable depending on the disk being calculated t: disk thickness, variable depending on the disk being calculated
- Poisson's ratio: = 0.3 E: Modulus of elasticity of steel: E = 200,000 MPa The allowable limit for stresses is calculated based on the criterion classically used for plasticity, i.e. 1.5 times the yield stress for bending stresses. This choice is justified by the fact that immersion is an accident case.
Calculation cases and results are shown in the table below:
Designation Containment bottom (See Figure O.1)
Containment lid disk (see figure O.1).
Material Type B steel Type B steel Yield stress (see table O.7) 320 MPa at 200°C 320 MPa at 200°C Allowable limit for stresses (see Table O.7) 480 MPa 480 MPa Disk radius (a) 480 mm 480 mm Disk thickness (t) 30 mm 35 mm Maximum stress within the disk
- 384 MPa
- 282 MPa Maximum deflection on the disk 3.3 mm 2.1 mm Stresses on the bottom internal disk and the lid external disk are less than the allowable limit and guarantee that the containment remains leak-tight.
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 15/16 NON PROPRIETARY VERSION 3.2 CALCULATION FOR THE SHELLS The calculations for the disks are made using the following formula taken from <3>,
corresponding to the calculation for a thin wall circular shell with constant thickness, uniformly loaded over the entire surface, case 1c, Table 28, page 519; Maximum tensile stress: max = q R / t Maximum displacement: R = - q R² (1 - /2) / (E t)
Where:
q: pressure applied to the disk, q = 2 MPa t: radius of shell, t = 480 mm t: thickness of shell, t = 20 mm
- Poisson's ratio: = 0.3 E: Modulus of elasticity of steel = 200,000 MPa.
The allowable limit for the stress is the yield stress.
Calculation cases and results are shown in the table below:
Designation Containment shell (See Figure O.1)
Material type A steel Yield stress (see Table O.7) 118 MPa at 200°C Allowable limit for stresses (see Table O.7) 118 MPa Inside radius of shell (R) 480 mm Shell thickness (t) 20 mm Maximum stress in the shell 48 MPa Maximum displacement on the shell 0.1 mm Calculated stresses are less than the allowable limit (yield stress) and leak-tightness of the containment is guaranteed.
TN International Ref. DOS-18-011415-007-NPV Rev. 1.0 Page 16/16 NON PROPRIETARY VERSION
3.3 CONCLUSION
Therefore the containment can resist an external pressure of 20 bars, corresponding to the water immersion test imposed for packages containing irradiated nuclear fuels.
- 4. CONCLUSION The calculations given in this document show that the TN-MTR packaging will resist pressure tests applicable for a type B(U) packaging and for fissile material packages:
- 1. Water immersion test (<1> <1>): resistance to an external gauge pressure of at least 150 kPa = 1.5 bars.
The allowable pressure under normal operating conditions calculated according to CODAP 95 rules <2>, is 11 bars. This pressure is used as the test pressure for the packaging.
- 2. Water Immersion test for packages containing irradiated nuclear fuels (<1> <1>):
resistance to an external gauge pressure of at least 2 MPa = 20 bars.
Stresses induced in the containment vessel by the application of this pressure to the containment are less than 1.5 times the yield stress.
- 5. REFERENCES
<1> IAEA Safety Collection No. 6 - Rules for the Transportation of Radioactive Materials - 1985 Edition (Amended 1990)
<1>
IAEA Safety Standards Series No. TS-R Regulations for the Safe Transport of Radioactive Material - 1996 Edition (revised)
<2> CODAP 1995 edition (June 30, 1995).
Revision 96-12: January 1 1997.
SNCT - AFIAP.
<3>
ROARK'S formulas for stress and strain 6th Edition - Warren C Young.