IAEA · Web viewIn the event of an emergency, the pressure in the cabin and cargo compartments of a pressurized aircraft may drop suddenly to the pressure existing outside the aircraft

Comment No.

Para/Line No.

Proposed new text Reason Accepted Accepted, but modified as follows Rejected Reason for modification/rejection

J/24-(1) 520.2[New]

520.2. The basic concept of allowing transport of SCOs unpackaged is that, though unpackaged, the objects will most likely comply with the applicable Type IP package requirements, when the outer envelope (shells, etc.) is considered as packaging. In addition to being allowed to be transported unpackaged, certain requirements for Type IP packages may need to be excluded, provided that compensatory safety measures in the form of more stringent operational controls are demonstrated in order to ensure the same level of safety.

Paras 520s are structured as:

- 520.2: Concept of SCO-III,- 520.3-5: Transport plan for SCO-

III, and- 520.6: Safety assessment for SCO-

III.

Thus, new 520.2 proposed is moved from 520.5.

See Attachment J-1.

Note by the Secretariat: see Attachment J/1, at the end.

X Note by the Secretariat:For discussion in TRANSSC 37TTEG Radiation Protection / Transport operational matters

J/24-(2) 520.2 520.3 2 . A written transport plan should be used to … Consequential change of para. number.See Attachment J-1.


J/24-(3) 520.3 520.4 3 . As part of the SCO-III transport plan, special attention should be paid …

Consequential change of para. number.See Attachment J-1.Note by the Secretariat: see Attachment J/1, at the end.


J/24-(4) 520.4 520.5 4 . The transport plan should also address the following points:…

Consequential change of para. number.See Attachment J-1.Note by the Secretariat: see Attachment J/1, at the end.


F/4 520.4 (a) (…) Therefore, due to the size of these objects and their slow movement compared to most packages, the transport plan should contain special precautions to ensure the radioprotection of workers and the public, including during loading and unloading phases if applicable, and the control of access to the object.

Clarification X The word “radioprotection” is not used in the guide

J/24-(5) 520.5 520.5. The basic concept of allowing transport of SCOs unpackaged is that, though unpackaged, the objects will most likely comply with the applicable Type IP package requirements, when the outer envelope (shells, etc.) is considered as packaging. In addition to being allowed to be transported unpackaged, certain requirements for Type IP packages may need to be excluded, provided that compensatory safety measures in the form of more stringent operational controls are demonstrated in order to ensure the same level of safety.

Moved to new 520.2.See Attachment J-1.


Note by the Secretariat:For discussion in TRANSSC 37TTEG Radiation Protection / Transport operational matters

J/24-(6) 520.6 to 520.8

520.6. T he pre-shipment safety assessment for the SCO-III shipment should demonstrate that the maximum activity intake for a person in the vicinity of an accident would be no more than that accepted for Type A packages (see Appendix VII). In

New introductory sentence of para. 520.6 is moved from para. 522.3.Then former paras 520.6 to 520.8 are placed as subparagraphs.


document.docx

Comment No.

Para/Line No.


the assessment the following should be considered:

- 520.6. For SCO-III, t The free drop test requirement of para. 722 of the Transport Regulations …

- 520.7. As addressed in para. 722.6, if the conditions in the transport plan …

- 520.8. The SCO-III, including all sealed openings and crevices, …

See Attachment J-1.


B/1 520.7 520.7. As addressed in para. 722.6, iIf the conditions in the transport plan effectively prevent the SCO-III from dropping or colliding in certain orientations during transport including handling, then these orientations could be ignored in assessing the maximum damage. Demonstration of compliance may be performed in accordance with any of the methods referred to in para. 701 of the Transport Regulations.

Maintain consistency with para 722.6 and see document in attachment

Note by the Secretariat: see Attachment B/1, at the end.


J/24-(7) 522.3 522.3. The pre-shipment safety assessment should demonstrate that the maximum activity intake for a person in the vicinity of an accident would be no more than that accepted for Type A packages (see Appendix VII).

Moved to the introductory sentence of para. 520.6.See Attachment J-1.Note by the Secretariat: see Attachment J/1, at the end.


J/24-(8) 522.4 522.34. For SCO-III, it is permitted to exceed the limit of 100 A2 per conveyance, …

For inland waterway craft, … such as:

- precautions on the craft …; - the designation of an organisation …;- features of the SCO-III …

For conveyances other than inland waterway craft, … such as:

- controls or features …;- routing constraints …;- features of the SCO-III …

For the pre-shipment safety assessment for SCO-III shipment, see para. 520.6.

For the safety assessment, para. 520.6 is referred.See Attachment J-1.



UK/5 522.4 Current proposed text is as follows “For inland waterway craft crafts, there is a risk of activity accumulation in the case of a sinking, as

there is are no strong currents in the inland waterways and as nor are there is any probably probable human activities near the waterways.”

Query why the inclusion of “nor are” in the text as this changes the original aim of the second part of the sentence. In the UK inland waterways have significant human activity and so this guidance would not be consistent with UK inland waterways.


UK/6 523.7 Query whether guidance on the use of “correction factor” is available.

Introducing regulatory requirement with limited guidance on application.

Note by the Secretariat:For discussion in TRANSSC 37.TTEG Radiation Protection

UK/7 523.7 The radiation protection programme should then take into account the corrected final TI.

Use of “corrected” may imply that it was incorrect initially.

Note by the Secretariat:For discussion in TRANSSC 37.TTEG Radiation Protection

document.docx

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F/6 527.1 (…) Moreover, the radiation protection programme (RPP) should also take into account the corrected dose rates.

The IAEA proposal clarifies the text. But it seems also important to stress the point on the interest to introduce the corrected dose rates in the RPP as in the original text agreed during the CSMs.

X Para. 527 of SSR-6 does not relate to RPP.

See also UK/10

UK/11 617.2527.2

Current proposed text – “617.2. For emptied uranium hexafluoride cylinders, location and radionuclides spectrum of the remaining radioactive material is not precisely known.”

Query whether “emptied” is as defined in ISO 7195 for “empty cylinder” which includes a “heel”

Clarification of term Note by the Secretariat:Moved here due to deletion of 617.2.For discussion in TRANSSC 37.TTEG Radiation Protection

UK/12 617.2527.2

If “worst case” method is used then how would this be identified in the paperwork as there would be no measured dose rate on dispatch which may lead to confusion at receipt at consignee.

Query of process described. Note by the Secretariat:Moved here due to deletion of 617.2.For discussion in TRANSSC 37.TTEG Radiation Protection

UK/9 573.1 As for comments 6 & 7 above Note by the Secretariat:For discussion in TRANSSC 37.TTEG Radiation Protection

UK/10 573.1 “In any case, a dose rate measurement should be performed before shipment.”

Query on timescales expected on “before shipment”Is it expected that a dose measurement occur even in cases where normally a dose measurement would not be carried out – e.g. NORM

Adds regulatory expectation without criteria.

Note by the Secretariat:Same text in paras 516.5, 523.7 and 527.1.For discussion in TRANSSC 37.TTEG Radiation Protection

UK/13 621.2 “….In the particular case of solid material, in order to comply with para. 621, other means of demonstration than pressure resistance may be used by the designer of a package design.

621.2(bis) If no loss or dispersal of the radioactive contents from the containment system can be justified when the package is exposed to pressure differential….”

In order to maintain the intent of the report of the Ad Hoc Working Group WP45 DGP17, 621.2 should be split as shown in the revised text

621.2. Pressure reductions due to altitude will be encountered during flight (see para. 578.1). The pressure differential that occurs at an increased altitude should be taken into account in the packaging design. The pressure differential of 95 kPa plus the MNOP (see paras 229.1–229.3) is the pressure differential to be accommodated by the package design, without loss or dispersal of radioactive contents from the containment system. This design specification results from a consideration of aircraft depressurization at a maximum civil aviation flight altitude together with any pressure already inside the package, with a safety margin. In the case of solid material, to comply with para. 621, means other than pressure resistance may be used to demonstrate compliance. If it can be demonstrated that there is no loss or dispersal of the radioactive contents from the containment system when the package is exposed to the pressure differential expected during flight, the package design can be considered to meet the requirement even if the internal pressure is not maintained. The following information about pressure variations should be considered when

Note by the Secretariat:

Presented text is the TE review. The complete text for the 2 paragraphs proposed in UK/13 should be submitted.

For discussion in TRANSSC 37.TTEG Transport operational matters

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evaluating the pressure differential:(a) In normal flight conditions, the decrease in

pressure in the cabin and cargo compartments of a pressurized aircraft may reach 150 Pa/s (2500 ft/min) during climbing, and the increase in pressure may reach 90 Pa/s (1500 ft/min) during descent of the aircraft;

(b) Cargo-only aircraft may be designed and operated such that the cargo compartment is not pressurized during flight: for these types of aircraft the normal rate of pressure change experienced by the cargo is the actual rate associated with the climb and descent of the aircraft;

(c) In normal flight conditions, the pressure in the cabin and cargo compartments of an aircraft may decrease from the atmospheric pressure at sea level (about 100 kPa) to 75 kPa in a pressurized aircraft and to 25 kPa in a non-pressurized aircraft;

(d) In the event of an emergency, the pressure in the cabin and cargo compartments of a pressurized aircraft may drop suddenly to the pressure existing outside the aircraft (rapid decompression): in these emergency flight conditions it is considered that the cabin and cargo compartment pressure may drop linearly from a minimum normal equivalent altitude of 6000 ft, i.e. a maximum normal pressure of 81 kPa in cruise flight, to the standard ambient pressure of 15 kPa at 45000 ft altitude in a duration of 1 s.

B/2 722.6 722.6. During the revision process leading to the 1996 Edition of the Transport Regulations, it was agreed that all possible drop test orientations need not be considered when conducting the drop test for normal conditions of transport. Provided that it is not possible under ‘normal’ conditions for the package to be dropped in certain orientations, these orientations could be ignored in assessing the worst damage. It was envisaged that this relaxation would only be allowed for large dimension and large aspect ratio packages. In addition, this relaxation relief would require documented justification by the package designer. Package designs requiring approval by the competent authority should be tested in the most damaging drop test attitudes irrespective of package size or aspect ratio. Nevertheless, some drop test attitudes can be disregarded if they result in delivery of a significantly higher energy to what can be expected after a drop test performed with the package initially in its transport configuration. For example, for large packages, it is not necessary to

See document in attachment

Note by the Secretariat: see Attachment B/1, at the end.


For discussion in TRANSSC 37.TTEG Package performance and assessment

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consider secondary impact when the package is dropped with an angle in regards to its horizontal position, as shown in Figure X (as, in this case, the secondary impact will deliver to the package an amount of energy significantly higher to what can be expected in normal conditions of transport).

WNTI/20 722.6

Proposed new text:“Package designs requiring approval by the competent authority should be tested in the most damaging drop test attitudes irrespective of package size or aspect ratio. Nevertheless, some drop test attitudes can be disregarded if they result in delivery of a significantly higher energy respectively unlikely damage to what can be expected after a drop test performed with the package initially in its transport configuration. For example, for large packages, it is not necessary to consider secondary impact when the package is dropped with an angle in regards to its horizontal position, as shown in Figure X (as, in this case, the secondary impact will deliver to the package an amount of energy significantly higher to what can be expected in normal conditions of transport).”

The Regulation considers most damaging conditions. In this sense, the damage on the package is additionally referred to.


For discussion in TRANSSC 37.TTEG Package performance and assessment

J/32 Appendix ITable I.2P258Ir-193m

QD or QE: 3.0 × 10+00 4.0 × 10+00A2: 3.0 × 10+00 4.0 × 10+00

A2 value of Ir-193m is different from that in the No. SSR-6 (Rev. 1).However, there may be possibility that A2 value in SSR-6(Rev.1) is incorrect. This should be checked in the A1-A2 WG.

Note by the Secretariat:For discussion in TRANSSC 37.

A1/A2 WORKING GROUP

J/33 Appendix ITable I.2P264Tb-149

Tb-140 Tb-149 Mistype Note by the Secretariat:Tb-149 and Tb-161 are missing.For discussion in TRANSSC 37.A1/A2 WORKING GROUP

J/34 Appendix II, p. 279

Ir-193m, Iridium (77), 10.53 d(add reference)

An appropriate reference should be added somewhere in the document as the ICRP Pub. 38 [ref II.1] does not provide the half-life of Ir-193m. The coverage of ICRP Pub. 38 for Iridium (p. 878-910) is Ir-182, 184, 185, 186, 187, 188, 189, 190m, 190, 192m, 192, 194m, 194, 195m, and 195.

Note by the Secretariat:For discussion in TRANSSC 37.A1/A2 WORKING GROUP


Ni-57, Nickel (28), 35.60 hNi-57, Nickel (28), 36.08 h

ICRP Pub. 38 [ref II.1], p. 66 Note by the Secretariat:For discussion in TRANSSC 37.A1/A2 WORKING GROUP

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Sr-83, 32.41 hSr-83, 32.4 h


J/37 Appendix II, p.286

Tb -149, Terbium (65), 4.12 hTb -149, Terbium (65), 4.15 h


J/38 General comment to Appendix II

[General comment to Appendix II]As for other radionuclides that are added in this revision (i.e., Ba-135m, Ge-69, Tb-161), the half-life is correctly cited from the ICRP Pub. 38 published in 1983[ref II.1]. The IAEA Nuclear Data Services (https://www-nds.iaea.org) provides the up-to-date half-life, but it is not necessary to reflect it in the Transport Safety regulation.

Appropriate references for nuclear data.

Note by the Secretariat:For discussion in TRANSSC 37.A1/A2 WORKING GROUP

CDN/2 Fig. IV.1 The label “Tie-down Member” in the second, lower illustration should be replaced with “Retention Member”.

The labelled feature is not a tie-down member.

Note by the Secretariat:For discussion in TRANSSC 37TTEG Transport operational matters

CDN/3 IV.6 Retention: The use of mechanical devices to restrain a package and prevent movement within or on a conveyance during routine transport.

The proposed change makes the wording of the definition more consistent with the description of “retention” provided in Para. 564.2.


CDN/4 IV.6 Retention member: A mechanical device, such as dunnage, a braces, a block, a tie-down member, a stillages, a cargo net, flange, including attachment points and anchor points, used as a component of a retention system.

The definition is for a single retention member. Therefore the singular form of each example should be used (e.g. “a brace” not “braces”).Attachment points and anchor points are deliberately excluded from this definition to prevent confusion about which requirements (SSR-6 versus model requirements) are applicable.“Tie-down member” is used instead of “tie-down” to be consistent with the terms and definitions in Appendix IV.“Cargo net” is used instead of “net” to indicate that it is a particular type of net.“Flange” is deleted since it is assumed that it was originally included in the list as a package feature that could be used as an attachment point.The last phrase is added to make it clear what is meant by “member”.


CDN/5 IV.6 Retention system: An assembly or arrangement of retention members, attachment points and anchor points, as applicable, designed for package retention consisting of an attachment point, an anchor point and a retention member, as applicable.

“Retention member” has already been defined so it is not necessary to list examples again. The qualifier “as applicable” is kept because a retention system does not necessarily have to include attachment and anchor points; for example, dunnage.


6

https://www-nds.iaea.org/

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The term “arrangement” is added because “assembly” implies some sort of fastening together of components which would not be applicable to a dunnage-type retaining system.

CDN/6 IV.6 Tie-down member: A type of retention member The connecting component (e.g. wire rope, chain or tie-rod) between the that connects one or more attachment points and the to one or more anchor points.

It was not clear from the original definition if a tie-down member was a type of retention member or was a different category of device.It is possible with tie-down members such as chain to connect the member to multiple attachment and anchor points. Therefore the phrase “one or more” has been added to precede attachment and anchor points.


CDN/7 IV.6 Tie-down system: A type of retention system consisting of one or more attachment points, tie-down members, and anchor points.

The phrase “one or more” is added because it is possible that only one attachment point is used.The sequence of the listing of the retention members has been rearranged so it is an analogue of the physical reality: the tie-down members are between the attachment points and the anchor points.


CDN/8 IV.8 The method of retention should not cause the package to be damaged, and should not stress the components of the package or its attachment points beyond the yield strengths of the constituent materials during routine conditions of transport.

The addition was made to clarify the assumed intent of this paragraph.


CDN/9 Table IV.1 No proposed text. The following format correction is requested.The alignment of the values should show all possible combinations of accelerations and that all three components can act simultaneously.

The current formatting of the table implies that the two horizontal components cannot act simultaneously, and with the vertical components. In the case of a road conveyance travelling over a bumpy curved ramp all three components would act simultaneously.


CDN/10 IV.16 Additional text:The package designer should give consideration to the following issues when selecting safety factors for the design of retention systems:

It is usually necessary for the retention system to be designed to fail at an anchor point or at a retention member, but not at an attachment point, to prevent damage to the package when acceleration factors exceed routine transport conditions.

Typically modal requirements incorporate strength values for retention members that are based on their working load limit (WLL) ratings. These ratings incorporate generous factors of safety (>2) on the yield or ultimate strengths of the constituent materials.

If the attachment points and the remainder of the retention

The following example supports the proposed text.The Canadian modal requirements for cargo retention systems for road transport are specified in National Safety Code Standard 10 – “Cargo Securement”.Part 1, Division 2 of the Standard states:5(1) The cargo securement system shall be capable of withstanding the forces that result if the vehicle is subjected to each of the following accelerations:

(a) 0.8 g deceleration in a forward


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system are designed for the same acceleration factors, but the attachment points are designed to be near their yield strength, while the other components are selected using their WLL ratings, then there is a risk that the attachment points will be the weakest component of the retention system.

direction; (b) 0.5 g deceleration in a rearward direction; (c) 0.5 g acceleration in either sideways direction.

(2) The cargo securement system shall provide a downward force equal to at least 20 % of the weight of an article of cargo if the article is not fully contained within the structure of the vehicle.

(3) The load on a component of a cargo securement system that reacts to a force referred to in subsection (1) or (2), shall not exceed the working load limit of the component.It can be seen that the accelerations factors have similar values to those listed in Table IV.1 but the strength requirement is the working load limit of the retention member.

IL/1 IV.16 – IV.17

Table IV.1 shown in paragraph IV.16 contains standard acceleration values for all modes of transport. A similar table shown in paragraph IV.17 (table IV.2), contains different acceleration values from those shown in table IV.1 for all modes of transport. It may be appropriate to explain the reason (from a technical point of view) for the different acceleration values for the same modes of transport. The references mentioned in the context of the tables do not provide technical basis for the acceleration values.

ClarificationNote by the Secretariat:For discussion in TRANSSC 37TTEG Transport operational matters

UK/14 Appendix IVRef IV.3

Current issue is dated 2018 – need to confirm reference is correct and main body text is still appropriate to new issue.


F/11 Appendix VII

See attached proposal During the last CSM, a proposal was made to reword the appendix VII to be clearer. The attached proposal comes from the CSM work and take also into account the IAEA suggestions.

Note by the Secretariat: see Attachment F/1, at the end.

Note by the Secretariat:For discussion in TRANSSC 37TTEG Radiation Protection

WNTI/23 Appendix VII

GUIDANCE FOR CALCULATION OF ACTIVITY INTAKE FOR TRANSPORT OF SCO-III

To replace the Guidance by the one posted on IAEA TRANSSC 36

Note by the Secretariat:For discussion in TRANSSC 37

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website document INF11e. TTEG Radiation Protection

Attachment J/1:

- Proposal on paras 520 and 522 of DS496-Step 11 from Japan (J/23)

- REQUIREMENTS AND CONTROLS FOR TRANSPORT OF LSA MATERIAL

-

- AND SCOs IN INDUSTRIAL PACKAGES OR UNPACKAGED

- 520.1. According to paras 413(a)(iii) and 520(c), SCO-I is allowed to have non-fixed contamination on inaccessible surfaces in excess of the values specified in para. 413(a)(i). Items such as pipes derived from the decommissioning of a facility should be prepared for unpackaged transport in a way to ensure that there is no release of radioactive material into the conveyance. This can be done, for example, by using end caps or plugs at both ends of the pipes (see para. 413.7).

- 520. 25 . The basic concept of allowing transport of SCOs unpackaged is that, though unpackaged, the objects will most likely comply with the applicable Type IP package requirements, when the outer envelope (shells, etc.) is considered as packaging. In addition to being allowed to be transported unpackaged, certain requirements for Type IP packages may need to be excluded, provided that compensatory safety measures in the form of more stringent operational controls are demonstrated in order to ensure the same level of safety.

- 520.3 2 . A written transport plan should be used to govern the transport of SCO-III. The transport plan should contain lines of authority, responsibilities, requirements, precautions, prerequisites, instructions, personnel restrictions, emergency response actions, a radiation protection programme that includes any conveyance transfers, and the sequence of events regarding the transport.

- 520.4 3 . As part of the SCO-III transport plan, special attention should be paid to the radiation protection programme since the transport of the object as SCO-III would be conducted in a different manner from the routine transport of packages and may involve workers not familiar with transport of radioactive material. As such, it should take into account all steps and activities of transport and all relevant transport workers and members of the public. Dose rates of the object, transport and handling methods, including for each operation the duration and distance of workers from the object, should be carefully examined and doses to workers should be optimized.

- 520.5 1 bis3 . The transport plan should also address the following points:

- - There is no explicit limit on the dose rate on the external surface (there is nevertheless a limit of 10 mSv/h at 3 m of the object and there is a limit of 2 mSv/h at the external surface of the vehicle). However, due to the size of these objects and their slow movement compared to most packages, the transport plan should contain special precautions to ensure workers and public radioprotection, including during loading and unloading phases if applicable, and control of the access to the object.

- - There is no obligation to label a SCO-III. Therefore, the transport plan should contain provisions to ensure that the workers are informed of the dose rate in the vicinity of the object, so that they can protect themselves. The transport plan should also contain provisions to allow that the public is informed in accordance with the radiation protection programme.

- - Any supplementary requirements for loading, stowage, carriage, handling or unloading for the SCO-III.

- 520.5. The basic concept of allowing transport of SCOs unpackaged is that, though unpackaged, the objects will most likely comply with the applicable Type IP package requirements, when the outer envelope (shells, etc.) is considered as packaging. In addition to being allowed to be transported unpackaged, certain requirements for Type IP packages may need to be excluded, provided that compensatory safety measures in the form of more stringent operational controls are demonstrated in order to ensure the same level of safety.

- 52 0.62.3 . T he pre-shipment safety assessment for the SCO-III shipment should demonstrate that the maximum activity intake for a person in the vicinity of an accident would be no more than that accepted for Type A packages (see Appendix VII). In the assessment the following should be considered:

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- - 520.6. For SCO-III, t T he free drop test requirement of para. 722 of the Transport Regulations should be applied to the SCO-III as prepared for transport, including parts permanently attached to the component, such as closures and shielding, without the benefit of any securing devices or systems.

- - 520.7. As addressed in para. 722.6, if the conditions in the transport plan effectively prevent the SCO-III from dropping or colliding in certain orientations during transport including handling, then these orientations could be ignored in assessing the maximum damage. Demonstration of compliance may be performed in accordance with any of the methods referred to in para. 701 of the Transport Regulations.

- - 520.8. The SCO-III, including all sealed openings and crevices, as well as additional shieldings, should be capable of withstanding the effects of any acceleration, vibration or vibration resonance which may arise under routine conditions of transport. This is set to comply with para. 613 of the Transport Regulations under routine conditions of transport.

- 521.1. The higher the potential hazards of LSA material and SCO, the greater should be the integrity of the package. In assessing the potential hazards, the physical form of the LSA material has been taken into account in the Transport Regulations.

- 521.2. See para. 226.1.

- 522.1. The conveyance activity limits for LSA material and SCO account for the greater hazards presented by liquids, gases, and combustible solids as well as possible contamination levels in the event of an accident.

- 522.2. ‘Combustible solids’ in Table 6 of the Transport Regulations means all LSA-II and LSA-III materials in solid form which are capable of sustaining combustion either on their own or in a fire.

- 522.3. The pre-shipment safety assessment should demonstrate that the maximum activity intake for a person in the vicinity of an accident would be no more than that accepted for Type A packages (see Appendix VII).

- 522.34. For SCO-III, it is permitted to exceed the limit of 100 A2 per conveyance, other than for an inland waterway craft, or to exceed the limit of 10 A2 per hold or compartment except for an inland waterway craft, provided that the transport plan contains precautions. The precautions are to be employed during transport to obtain an overall level of safety at least equivalent to that which would be provided if the limits had been applied.

- For inland waterway craft, there is a risk of activity accumulation in the case of a sinking, as there are no strong currents in inland waterways nor are there any probable human activities near the waterways. The total activity limit per hold or compartment addresses this risk. The transport plan could provide provisions such as:

- - precautions on the craft to minimize the risk of sinking; - - the designation of an organisation capable of removing the SCO-III from the water in the event of sinking;- - features of the SCO-III that ensure that in the case of a realistically long stay in the water, the activity release into the water would be minimized.

- For conveyances other than inland waterway craft, there is a risk of activity accumulation in the event of an accident in confined space (e.g., in a tunnel). The total activity limit addresses this risk. The transport plan could provide provisions such as:

- - controls or features that minimize the risk of an accident;- - routing constraints to avoid confined spaces;- - features of the SCO-III that ensure that in the case of an accident in a confined space, the activity release into the air would be minimized.

For the pre-shipment safety assessment for SCO-III shipment, see para. 520.6.

Attachment B/1

Belgium: Comments on proposed change of SSG-26 para. 722.6

Proposed changeThe text of the modified proposed change F/51 is:

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722.6. During the revision process leading to the 1996 Edition of the Transport Regulations, it was agreed that all possible drop test orientations need not be considered when conducting the drop test for normal conditions of transport. Provided that it is not possible under ‘normal’ conditions for the package to be dropped in certain orientations, these orientations could be ignored in assessing the worst damage. It was envisaged that this relaxation would only be allowed for large dimension and large aspect ratio packages. In addition, this relief would require documented justification by the package designer. Package designs requiring approval by the competent authority should be tested in the most damaging drop test attitudes irrespective of package size or aspect ratio. Package designs requiring approval by the competent authority should be tested in the most damaging drop test attitudes irrespective of package size or aspect ratio. Nevertheless, some drop test attitudes can be disregarded if they result in delivery of a significantly higher energy to what can be expected after a drop test performed with the package initially in its transport configuration. For example, for large packages, it is not necessary to consider secondary impact when the package is dropped with an angle in regards to its horizontal position, as shown in Figure X (as, in this case, the secondary impact will deliver to the package an amount of energy significantly higher to what can be expected in normal conditions of transport).

In the rest of this text, the relaxation described in the original text of this para. (all possible drop test orientations need not be considered when conducting the drop test for normal conditions of transport) shall be called "the relaxation".

Comments Comments regarding proposed change of para. 722.6 Necessity of the proposed changeAccording to the Table of resolution of MSs Comments for the revision of SSG-26, the change of para. 722.6 has been proposed to be consistent with the added para. 520.7.

520. 47. As addressed in para. 722.6 in this publication, if the conditions in the transport plan effectively prevent the SCO-III from dropping or colliding in certain orientations during transport including handling, then these orientations could be ignored in assessing the maximum damage. Demonstration of compliance may be performed in accordance with any of the methods referred to in para. 701 of the Transport Regulations.

Firstly, the original text of para. 722.6 is only applicable to package designs. SCO-III however is not a package design, it is a special kind of radioactive material. It is not the SCO-III itself that requires a package approval, but it is the transport of SCO-III that requires a shipment approval. Since paras. 722.6 and 520.7 clearly concern different kinds of approvals, there is in principle no inconsistency that needs to be resolved.

Secondly, para. 520(e)(iv) of SSR-6 states:The requirements of para. 624 for a Type IP-2 package shall be satisfied, except that the maximum damage referred to in para. 722 may be determined based on provisions in the transport plan, and the requirements of para. 723 are not applicable.

For SCO-III, the possibility of the relaxation is explicitly mentioned in SSR-6 (as opposed to package designs) and the explanation in added para. 520.7 of SSG-26 of what this relaxation means is clear enough as such. We do not believe that any further explanation in para. 722.6 of SSG-26 is necessary.The only reason (related to the introduction of SCO-III) for changing 722.6 of SSG-26 seems to be the reference to this para. in added para. 520.7 of SSG-26 ("As addressed in para. 722.6…"). We believe that there would be no need to change para. 722.6 of SSG-26 if the reference in added para. 520.7 of SSG-26 is omitted.

Coherence of the possibility of and the conditions necessary for the relaxationThe relaxation is possible for three different provisions in the regulations:SCO-III;package designs requiring approval;package designs not requiring approval.

Firstly, the way the relaxation is allowed in the regulations is incoherent:For SCO-III, the relaxation is explicitly allowed in para. 520(e)(iv) of SSR-6.For package designs requiring approval, the relaxation is not explicitly allowed in SSR-6, but the possibility is suggested in the second paragraph of the proposed change of 722.6 of SSG-26.For package designs not requiring approval, the relaxation is also not explicitly allowed in SSR-6, but the possibility is suggested in the first paragraph of the proposed change of 722.6 of SSG-26 1.We believe that the existence of guidance that modifies the requirements of the regulations is a bad practice and should be avoided. If the relaxation is to be allowed for package designs, whether they require approval or not, we believe it should be allowed via a provision in SSR-6 (e.g. para. 722), as is the case for SCO-III.

Secondly, the conditions necessary to allow the relaxation for these three provisions are also incoherent:

1 Because the second paragraph of the proposed change of 722.6 of SSG-26 explicitly targets package designs requiring approval, we assume that the first paragraph is supposed to target package designs not requiring approval.

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For SCO-III, drop orientations can be ignored if they are prevented by the operational controls in the transport plan.For package designs requiring approval, drop orientations can be ignored if they result in the delivery of a significantly higher energy to what can be expected after a drop test performed with the package

initially in its transport configuration.For package designs not requiring approval, drop orientations can be ignored for large dimension and large aspect ratio packages, provided that it is not possible under ‘normal’ conditions for the package to be

dropped in these orientations.The conditions for allowing the relaxation for package designs requiring approval refer to the transport configuration of the package. We believe this does not include handling of the package. However, according to para. 722.1 of SSG-26, "the free drop test simulates the type of shock that a package would experience if it were to fall off the platform of a vehicle or if it were dropped during handling".We believe that certain drop orientations that result in the delivery of a significantly higher energy can only be ignored if operational controls that prevent these drop orientations under ‘normal’ conditions (including handling) are specified, as is the case for SCO-III.These operational controls should be specified in a document. For SCO-III, both para. 520(e)(iv) of SSR-6 and added para. 520.7 of SSG-26 clearly refer to a transport plan, which according to added para. 520.4 of SSG-26, should contain "Any supplementary requirements for loading, stowage, carriage, handling or unloading for the SCO-III".For package designs requiring approval, this document could be the package design approval certificate, which according to para. 838(r) of SSR-6 shall include "a detailed listing of any supplementary operational controls required for preparation, loading, carriage, unloading and handling of the consignment, including any special stowage provisions for the safe dissipation of heat".

Logical structureIn the first paragraph of the proposed change of para. 722.6, the relaxation is allowed in general (i.e package designs requiring approval or not) for large dimension and large aspect ratio package designs.In the first sentence of the second paragraph, the relaxation is however repealed for package designs requiring approval by the competent authority. In the rest of the second paragraph, the relaxation is then allowed again in case the energy dissipated in a certain drop orientation is significantly higher compared to the energy dissipated in the drop orientation corresponding to the normal orientation of the package during transport.We believe the logical structure of the proposed change of para. 722.6 is not very clear (yes, but no, but yes) and should be simplified.

Energy vs secondary impactIn the text added to the second paragraph of para. 722.6, two distinct phenomena caused by the inclination of a package have been discussed:an increase of the potential energy of the package, due to the rise of the center of gravity of the package;a secondary impact, which sometimes leads to considerable more damage on the side of the package that experiences the second impact (slap-down effect).We believe the consequences of these two phenomena have become somewhat mixed up in the text added to the second paragraph of para. 722.6. The statement that " the secondary impact will deliver to the package an amount of energy significantly higher to what can be expected in normal conditions of transport" is not correct. It is not the secondary impact as such that is responsible for the increased potential energy, but the rise of the center of gravity.Furthermore, the worst case consequences of these two phenomena do not necessarily appear for the same angle of inclination of the package. For large aspect ratio package designs, the increase of the potential energy is typically greatest for high inclination angles, whereas the slap-down effect is typically greatest for low to moderate inclination angles.

We agree with the observation that in some cases, certain drop orientations of the package can lead to a significantly increased potential energy of the package that is not credible if operational controls effectively prevent these orientations during normal conditions of transport (minor transport and handling incidents) and we agree that there might be an opportunity to allow the relaxation in these cases.For the drop orientation shown in figure 1, the relative potential energy increase (i.e. the rise of the center of gravity divided by the drop height) is about 260 %, which indeed seems exaggerated for normal conditions of transport if such orientation is prevented by operational controls. However, for the drop orientation shown in figure 2, the relative potential energy increase is only about 30 %, which we believe to not be large enough to exclude this orientation.As can be seen in these examples, the relative potential energy increase depends on the size of the package compared to the drop height and the aspect ratio of the package. We believe a more advanced mathematical examination of this relationship and even the establishment of quantitative criteria for allowing the relaxation might be possible, but that is outside of the scope of our comments.

Due to the current specification of the free drop test in SSR-6 ("The height of the drop, measured from the lowest point of the specimen to the upper surface of the target…"), it is not possible to perform a drop test to examine the damage caused by a secondary impact without the corresponding increase of the potential energy.In reality however, it is possible to have a secondary impact of a package even without an increase of the potential energy of the package, as is shown in the following example.Consider a truck on which fresh fuel containers (e.g. Traveller, FCC, ANF 18…) are being loaded. One package is already loaded on the vehicle platform at a height h above ground. Due to an unexpected operation, the fork-lift truck bringing a second package to the vehicle pushes the package that is already loaded off the platform in such a way that the axis of the loaded package is not parallel to the side of the platform. As soon as the center of gravity of the package moves over the side of the platform, the package first starts pivoting around the side of the platform and then falls down to the ground in an oblique orientation.

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A video of a similar incident is available on the internet 2.In these examples, there is definitely a possibility of a secondary impact, but the potential energy of the package falling off the platform is the same as during a free drop test of the package in its horizontal orientation.Therefore, we believe it is inappropriate to suggest that it is not necessary to consider the possibility of a secondary impact for large packages.

FuzzinessThe original text of para. 722.6 already contains a few fuzzy concepts ( large dimension and large aspect ratio packages), and the proposed change introduces an additional fuzzy concept (significantly higher energy).We believe that this is not conducive to a clear and common understanding of the guidance and that it would be beneficial to all involved parties to determine quantitative limits for these concepts.

Comments regarding related proposed change of para. 520.7It should be noted that the words "or colliding" are still present in the text of proposed change of para. 520.7, although the addition of the words "or collided" to para. 722.6 has been rejected according to the Table of resolution of MSs Comments.In order to maintain consistency, we believe it is appropriate to remove the words "or colliding" from the proposed change of para. 520.7.

Alternative changesOn the basis of our comments, we propose the following modifications to the proposed changes to SSG-26.For para. 520.7, we propose to:remove the text "As addressed in para. 722.6,";remove the text "or colliding".The alternative text of para. 520.7 thus becomes:

520.7. If the conditions in the transport plan effectively prevent the SCO-III from dropping in certain orientations during transport including handling, then these orientations could be ignored in assessing the maximum damage. Demonstration of compliance may be performed in accordance with any of the methods referred to in para. 701 of the Transport Regulations.

For para. 722.6, we propose to: replace the word "relief" by the word "relaxation" for the sake of uniform terminology;either reject the modified proposed change and to provide the issue to a TTEG for further discussion;

If a consensus would be reached in the TTEG that the relaxation should also be admitted for package designs, we believe that:The possibility of the relaxation for package designs should be implemented in the same way as it has been for SCO-III.The relaxation should be linked to operational controls during transport and handling of the package.The possibility of a secondary impact during the free drop test of the package should be maintained.Quantitative criteria should be established for the characteristics of the package designs (size relative to the drop height, aspect ratio…) to serve as a guide to determine in which case the relaxation can be

admitted.We prefer this option.

or remove the last sentence of the original text.In case there is a strong consensus to already move forward on this matter (i.e. to allow the relaxation for package designs requiring approval) now, we believe it is simpler to remove the denial of the possibility of the relaxation by removing the last sentence of the original text of para. 722.6. The previous sentence of the original text of para. 722.6 ("In addition, this relief would require documented justification by the package designer.") still allows the competent authority the opportunity to review and approve or reject any proposed relaxation for package designs requiring approval.

2 See https://www.youtube.com/watch?time_continue=35&v=scK6I6IG2FU.

https://www.youtube.com/watch?time_continue=35&v=scK6I6IG2FU

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The alternative text of para. 722.6 thus becomes:722.6. During the revision process leading to the 1996 Edition of the Transport Regulations, it was agreed that all possible drop test orientations need not be considered when conducting the drop test for normal conditions of transport. Provided that it is not possible under ‘normal’ conditions for the package to be dropped in certain orientations, these orientations could be ignored in assessing the worst damage. It was envisaged that this relaxation would only be allowed for large dimension and large aspect ratio packages. In addition, this relaxation would require documented justification by the package designer.

Figures

figure 1: first example of Fig. X of draft SSG-26 (modified)

figure 2: second example of Fig. X of draft SSG-26 (modified)

Legend to the figuresBlack arrows: drop heightRed arrows: rise of the center of gravity

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ATTACHMENT F/1

Appendix VIIGUIDANCE FOR CALCULATION

OF ACTIVITY INTAKE FOR TRANSPORT OF SCO-III

VII.1.1. Introduction In an accident involving SCO-III, the maximum activity intake for a person in the vicinity of the accident should be approximately the same level as that from Type A packages, i.e. a value of 10-

6A2 or a corresponding inhalation dose of 50 mSv.

VII.1.2. General

VII.1.2.1. The activity intake for a person in an accident is given by:

QINT = QINT,FIX_INT + QINT, NF + QINT, FIX_EXT (VII.1)

where- QINT is the intake activity of radionuclides (Bq);

- QINT, FIX_INT is the intake activity of radionuclides due to the fixed contamination on the internal surface (Bq);

- QINT, NF is the intake activity of radionuclides due to the non-fixed contamination on the internal surface (Bq);

- QINT, FIX_EXT is the intake activity of radionuclides due to the fixed contamination on the external surface (Bq).

VII.1.2.2. The intake activity of radionuclides due to the fixed contamination on the internal surface, Q INT, FIX_INT, can be calculated as follows.

- Inventory of fixed contamination scraped from the internal surface, QSCRAP, FIX_INT:

QSCRAP, FIX_INT = QIV, FIX_INT × FSCRAP_INT

where o QIV, FIX_INT is the inventory of fixed contamination on the internal surface of the object (Bq);

o FSCRAP_INT is the fraction of the internal surface area that is scraped in an accident.

- Inventory released from scraped fixed contamination on the internal surface, QREL, FIX_INT

QREL, FIX_INT = QSCRAP, FIX_INT × FREL, FIX_INT

whereo FREL,FIX_INT is the fraction of the activity that is freed from the scraped internal surfaces and released from the object in an accident.

- Inventory of the released activity from fixed contamination on the internal surface which is in the form of a respirable aerosol, QRSUS, FIX_INT:

QRSUS, FIX_INT = QREL, FIX_INT × FRSUS

whereo FRSUS is the fraction of the released activity that is in a form of respirable aerosol.

- Intake activity from fixed contamination on the internal surface, QINT, FIX_INT:

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QINT, FIX_INT = QRSUS, FIX_INT × FINT

whereo FINT is the fraction of the respirable released activity that is taken in by a person in the vicinity of the accident.

Then:QINT, FIX_INT = QIV, FIX_INT × FSCRAP_INT × FREL,FIX_INT × FRSUS × FINT (VII.2)

In Eq. (VII.2), for objects with a homogeneous surface contamination, QIV, FIX_INT can be determined from:QIV, FIX_INT = CFIX_INT × AINT × 104 (VII.3)

whereo CFIX_INT is the level of fixed surface contamination on the internal surface (Bq/cm2);

o AINT is the internal surface area of the object (m2).

VII.1.2.3. The intake activity of radionuclides due to the non-fixed contamination on the internal surface, Q INT,NF, can be calculated in a similar way, except that 100% of the non-fixed contamination present on the object should be assumed to be available for release without any scraping of the surfaces required.

- Inventory released from non-fixed contamination on the internal surface, QREL,NF

QREL,NF = QIV, NF × FREL_NF

whereo QIV,NF is the inventory attributed to the non-fixed contamination on the internal surface of the object (Bq);

o FREL_NF is the fraction of the activity that is free (i.e. the non-fixed contamination on the internal surface) and released from the object in an accident (F REL_NF should be taken as unity (100%) unless the use of a lower release fraction can be justified).

- Inventory of the released activity from non-fixed contamination which is in the form of a respirable aerosol, QRSUS, NF:

QRSUS,NF = QREL,NF × FRSUS

whereo FRSUS is the fraction of the released activity that is in respirable aerosol.

- Intake activity from non-fixed contamination on the internal surface, QINT, FIX_INT:

QINT,NF = QRSUS,NF × FINT

whereo FINT is the fraction of the respirable released activity that is taken in by a person in the vicinity of the accident.

Then:QINT,NF = QIV,NF × FREL_NF × FRSUS × FINT (VII.4)

In the formula above, for objects with a homogeneous surface contamination, Q IV,NF can be determined from:

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QIV,NF = CNF × AINT × 104 (VII.5)

whereo CNF is the level of non-fixed surface contamination (Bq/cm2);

o AINT is the internal surface area of the object (m2).

VII.1.2.4. The intake activity of radionuclides due to the fixed contamination on the external surface, Q INT, FIX_EXT, can be calculated in a similar way as the intake activity of radionuclides due to the fixed contamination on the internal surface.

Then, by substituting the subscript INT by the subscript EXT:

QINT, FIX_EXT = QIV, FIX_EXT × FSCRAP_EXT × FREL,FIX_EXT × FRSUS × FINT (VII.6)and

QIV, FIX_EXT = CFIX_EXT × AEXT × 104 (VII.7)

whereo QIV, FIX_EXT is the inventory attributed to the fixed contamination on the external surface of the object (Bq);

o FSCRAP_EXT is the fraction of the external surface area that is scraped in an accident;

o FREL,FIX_EXT is the fraction of the activity that is freed from the scraped external surfaces and released from the object in an accident;

o FRSUS is the fraction of the released activity that is in a form of respirable aerosol;

o FINT is the fraction of the respirable released activity that is taken in by a person in the vicinity of the accident;

o CFIX_EXT is the level of fixed surface contamination on the external surface (Bq/cm2);

o AEXT is the external surface area of the object (m2).

VII.1.3. Example

VII.1.3.1 Levels of contamination

VII.1.3.1.1. Since the internal surface of a SCO-III is considered as an inaccessible surface, the contamination limit is 8 × 10 5 Bq/cm2 for the fixed contamination plus the non-fixed contamination on the internal surface. In the evaluation below, a value close to this limit is chosen for the level of the fixed contamination on the internal surface.

CFIX_INT = 7.5 × 105 Bq/cm2

VII.1.3.1.2. In the evaluation below, the value of 400 Bq/cm2 is assumed for the level of the non-fixed contamination on the internal surface.

CNF = 400 Bq/cm2

VII.1.3.1.3. There is no limit for the fixed contamination on the external surface of SCO-III in the Transport Regulations. For example, in the following calculation, the value of 4 ×104 Bq/cm2 is assumed.

CFIX_EXT = 4 × 104 Bq/cm2

VII.1.3.2. Surface areas

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For example, in the following calculations, the value of 10 m2 is assumed for both the internal surface and the external surface areas.

AINT = 10 m2 and AEXT = 10 m2

VII.1.3.3. Fraction of surface which is scraped in an accident

As in the SCO-I model (see para 413.4), it is considered that 20% of the internal and external surfaces are scraped during an accident.

FSCRAP_INT = 0.2 and FSCRAP_EXT = 0.2

VII.1.3.4. Fraction of the contamination from the scraped surface which is released

For example, in the following calculations, it is considered that 1% of the fixed contamination from the scraped internal surface is released and that 20% of the fixed contamination from the scraped external surface is released.

FREL, FIX_INT = 0.01 and FREL, FIX_EXT = 0.2

It is also considered that 100% of the non-fixed contamination on the internal surface is released from the object in an accident.

FREL_NF = 1

VII.1.3.5. Fraction of the released activity which is a respirable aerosol and fraction of respirable activity that a person in the vicinity of an accident intakes

It is considered that 100% of the released activity is a respirable aerosol and that a person in the vicinity of the accident intakes 0.01% of the respirable released activity (to be consistent with the basic assumption of the Q system developed for Type A packages: see Appendix I).

FRSUS = 1 and FINT = 10-4

VII.1.3.6. Intake activity of radionuclides due to the fixed contamination on the internal surface

The inventory of fixed contamination on the internal surface of the object is (equation VII.3): QIV, FIX_INT = CFIX_INT × AINT = 7.5 × 105 Bq/cm2 × 10 m2 × 104 = 7.5 × 1010 Bq = 75 GBq

The intake activity of radionuclides due to the fixed contamination on the internal surface is (equation VII.2):QINT, FIX_INT = QIV, FIX_INT × FSCRAP_INT × FREL,FIX_INT × FRSUS × FINT

QINT, FIX_INT = 75 GBq × 0.2 × 0.01 × 1 × (1 × 10-4) = 15 kBq

VII.1.3.7. Intake activity of radionuclides due to the non-fixed contamination on the internal surface

The inventory of non-fixed contamination on the internal surface of the object is (equation VII.5):QIV,NF = CNF × AINT = 400 Bq/cm2 × 10 m2 × 104 = 4 × 107 Bq = 40 MBq

The intake activity of radionuclides due to the non-fixed contamination on the internal surface is (equation VII.4):QINT,NF = QIV,NF × FREL_NF × FRSUS × FINT

QINT,NF = 40 MBq × 1 × 1 × (1 × 10-4) = 4 kBq

VII.1.3.8. Intake activity of radionuclides due to the fixed contamination on the external surface

The inventory of fixed contamination on the external surface of the object is then (equation VII.7): QIV, FIX_EXT = CFIX_EXT × AEXT = 4 × 104 Bq/cm2 × 10 m2 × 104 = 4 × 109 Bq = 4 GBq

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The intake activity of radionuclides due to the fixed contamination on the external surface is (equation VII.6):QINT, FIX_EXT = QIV, FIX_EXT × FSCRAP_EXT × FREL,FIX_EXT × FRSUS × FINT

QINT, FIX_EXT = 4 GBq × 0.2 × 0.2 × 1 × (1 × 10-4) = 16 kBq

VII.1.3.9. Total intake activity of radionuclides from the object (equation VII.1)QINT = QINT, FIX_INT + QINT, NF + QINT, FIX_EXT = 15 kBq + 4 kBq + 16 kBq = 35 kBq

VII.1.3.10 Conclusion of the example

Assuming A2 = 0.04 TBq (4 × 1010 Bq), then the activity intake is:

QINT = 35 kBq= 0.875 × 10-6A2

An SCO-III, with the above assumptions, provides a level of safety equivalent to a Type A package related to the intake to a person in the vicinity of the accident.

VII.2. In an approval of a SCO-III shipment, every parameter in para. VII.1 should be examined and justified. Parameter A can be calculated from the design drawings of the components. Distributions and radionuclide compositions of parameters CFIX, CNF and QIV throughout the component can be measured, or properly modelled, for a series of components, together with a verification measurement for representative points on each component. Parameters FSCRAP, FRSUS and FREL are sensitive and should be demonstrated as being appropriate through the literature [VII. 1, VII. 2], tests or reasoned argument. Parameter F INT may have a value of 10–4–10–3, which is used in para. I.37, relative to the Q System.

VII.3. Care should be taken about the radionuclide composition of the inventory. For example, in the case of β and γ emitting unknown radionuclides, an inventory limit of 10A 2 corresponds to 0.2 TBq, then to 4 × 103

Bq/cm2, when a surface area of 5000 m2 (a typical internal surface area for a steam generator) is assumed. This is two orders of magnitude lower than the contamination level limit on the inaccessible surface of a SCO-III, that is 8 × 105 Bq/cm2. In contrast, when Co-60 is the only radionuclide present in the inventory, the allowable level of inaccessible surface contamination increases up to 4 TBq and 8 × 10 4 Bq/cm2.

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