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Comment Sheet

REVIEW DOCUMENT TITLE/NUMBER

Title: DISPOSAL FACILITIES FOR INTERMEDIATE LEVEL RADIOACTVE WASTE Reviewer: M. Garamszeghy (#1-#53)J. Noronha (#54-#62)M. Ion (#63-#91)(NWMO, Canada)

Version: Draft Version 3 (distributed on 20. Oct. 2014 by e-mail) Date: 22-Oct-2014Item # Page # Sect. # Line # REVIEWER’S COMMENTS RESOLUTION

1. 7 1.1 96-98This is a very key point and should be extended to include other important factors, such as disposal depth, repository concept, conditioning method, etc. All of these need to act as an integrated system rather than individual components.

2. 7 1.2 106

Re response to comment LJ1: co-location is important for the context of the safety case. For example, if ILW is co-located with LLW, the characteristics of the ILW will probably dominate whereas if ILW is co-located with HLW, the characteristics of the HLW will be dominant.

3. 8 2.1 159-164

A key point mentioned in the last line is that a WAC needs to be facility specific.

4. 11 3.3 322-It is important to note that the safety concept needs to define and understand the roles and functions of individual barriers and how they interact. They safety case needs to consider the integrated effects of the system, not the each barrier individually.

5. 11 3.3 326The word “plausible” should be replaced by “credible”. In strict usage, “plausible” has the connotation that while it may appear to be true on first glance, it might not be true in reality.

6. 12 3.5

The goal of demonstrating safety should be to show that the selected concept is “safe”, not that it is the “safest”. Objectively showing that a repository is the “safest” is not possible due to all the assumptions required for long-term modelling. However, I recognize that ranking a number of options on the basis of relative safety may be a decision criterion for making a choice, but it is only one of many selection criteria.

7. 14 4.2 461-463

Forecasting of future amounts of waste is a very important aspect that many countries do not currently do (at least in an open manner). The current “Status and Trends” project in the IAEA Waste Technology Section is an attempt to consolidate a global inventory and future forecast.

8. 15 4.3 502Chapter 8 does not discuss WAC. Should this be 5.4?

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9. 17 5.2 586-

It is important to distinguish “conditioning” from “immobilization”. The terms seem to be used interchangeably in this chapter. The Safety Glossary defines “conditioning” as “Those operations that produce a waste package suitable for handling, transport, storage and/or disposal. Conditioning may include the conversion of the waste to a solid waste form, enclosure of the waste in containers and, if necessary, provision of an overpack.” For some ILW wastes and disposal concepts, “conditioning” may be just a container or overpack, without immobilization.

10. 17 5.2 592Voidage in a waste package can also be beneficial, e.g. to provide expansion space for degradation products, swelling, etc.

11. 18 5.2 622-625

For near surface especially, the waste package may also provide structural support for the cap and cover system (to prevent subsidence). This structural support is less important for deep facilities which rely on cap rock for support.

12. 18 5.2 637-639

It is also important to note the converse: if the other engineered and natural barriers are strong, it may reduce the requirements for conditioning.

13. 18 5.3 643-

It is also important to note that in the case of storage, the waste package must remain in retrievable condition throughout the storage period and be safely retrievable from storage at the end of that period.

In addition, storage of ILW may require remote handling due to radiation fields. An optimization will be required between use of self-shielded packages and shielded storage facilities. In the case of decay storage for high dose rate, but short lived waste, a shielded storage facility may be better than self-shielded waste packages since the amount of shielding required (and hence waste package size and mass) at time of disposal will be significantly less at time of disposal than time of first storage.

14. 18 5.4 653

An illustration of the role of a WAC is shown in figure 1 below. The WAC is primarily an operational document for the operator to use to ensure that the licence conditions are not exceeded. Some better references for WAC may be TECDOCs 285, 560, 864, 1129, 1397 and 1515

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15. 18 5.4 658-664

This section should refer to further guidance in section 10.2 and/or make reference to IAEA docs on “waste inventory record keeping systems”, such as TRS 434.

16. 19 6.2 711-714

See comment #4 above.

17. 20 6.2.1 722-723

Typo – “meters” should be “metres”“constraints” should be “constrains”

18. 20 6.2.1.1It should be mentioned that landfill disposal is generally not suitable for ILW, only for VLLW.

19. 21 6.2.1.4 774Re comment KY8: the sentence could be re-worded as “In general, the isolation capability of the facility increases with depth, although this will depend on the precise geological setting.”

20. 21 6.2.1.4 778It is not clear what “smooth transition” means in this context.

21. 21 6.2.2 790Human intrusion scenarios also depend on the geological setting. Areas rich in resources may be prone to intrusion at great depths.

22. 21 6.2.2 808

Existing mines are generally not preferred for ILW since the condition and nature of the original mine is difficult to confirm and understand. Mining techniques for mines are generally not concerned with minimizing the EDZ. Configuration of mines is also often not well documented.

23. 22 6.3.1 853

Note that expansion of an underground facility is not necessarily “expensive”. In this case, you would be comparing the incremental cost of mining out more underground space (which is generally very cheap) against the cost of developing a new facility on the surface (which could be much more expensive). Also, the disposal of short-lived waste in a deep facility may have less stringent conditioning requirements that disposal of same waste near-surface, thus reducing total costs.

24. 23 6.3.3 879-TECDOC 1552 is a good reference for this section.

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25. 23 6.3.4 890TECDOC 1556 is a good reference for this section.

26. 23 6.3.4 893-897

NW-T-1.19 is a good reference for this section.Also, it should be noted that the drivers for retrievability for used fuel are different than those for ILW. Used fuel may have a future value as a resource, e.g. for fast reactors, whereas most ILW truly is waste with no future value.

27. 24 7Is there a need to include a sub-section on the potential impact of human activities, either deliberate (acts of sabotage) or accidental (airplane crashes, rail crashes, etc)

28. 24 7.1TECDOCs 991, 1199 and 1717 are good references for this section.

29. 26 7.2.2 1053Typo? Instead of “superficial” do you mean “surficial”?

30. 27 7.2.4 1079The mention of an exact depth of 100m can be very misleading. This will depend on the site and it will undergo in the future. The zone of influence could be much higher in various circumstances.

31. 27 7.2.5Is there a need to include a separate discussion on the potential impact of plate tectonics, seismic activity, meteor impacts, etc over the longer term?

32. 28 7.2.7 1114Another item is general socio-political / societal preferences, which may be very different in different countries.

33. 29 8.1 1127However, the overall goal is to produce a safe design, not “the safest”, which can never be achieved in practice or proven.

34. 29 8.1 1127The iteration process is complex and involves design, safety case, WAC (as well as cost and other factors). A simplified version can be seen below in Fig 2.

35. 29 8.1 1131Typo – “emphases” should be “emphasis”

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36. 29 8.1.1 1135The facility lifecycle also includes design and licensing.

37. 29 8.1.1 1137It should be mentioned that these are listed in no particular order. The order of importance will be different for different countries or organizations within a country.

38. 29 8.1.1 1168

The key message is that the facility needs to be designed to accept the intended wastes; not “design the facility, then decide which wastes it can accept”. This latter approach seems to have been used in some countries in the past and has led to an unnecessary proliferation of facilities.

39. 30 8.1.2

A key concept in design development (especially when it goes through several iterations) is configuration management. It is very important to control the design configuration and to clearly document, understand and communicate any changes to affected stakeholders (e.g. safety assessment personnel, construction crews, etc). Configuration management continues through the construction, operation . and eventual decommissioning. It is important to provide and accurate representation of the current state of the facility prior to closure. Example references are NW-T-1.2 and SRS 65.

40. 31 8.2.1

Environmental effects also need to be considered during construction, such as noise, dust, stormwater runoff, waste rock management (from underground facilities), blasting residues on rocks, etc.

Provision of infrastructure services is also important during construction, such as electrical supplies, worker amenities, underground ventilation (for both construction equipment and breathing).

41. 31 8.2.2 1262 -

Operations may also involve remote handling equipment for waste emplacement. The complexity of such systems needs to be considered in the design.

A communications system is also required underground. Most conventional radio systems will not work in these situations, so special designs are required.

42. 32 8.2.2 1279Is the first part correct? “Compared with HLW, gas production during operation from radiolysis may be a significant issue…” Won’t HLW produce more radiolysis effects than ILW?

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43. 32 8.2.2 1282

Underground ventilation requirements are normally set by combustion air needs for vehicles (construction equipment, waste handling equipment, etc). However, even when such activities are not going on, a minimum ventilation flow is often maintained to prevent gas build-up, either from the waste or from natural seepage sources (methane, radon, etc).

44. 33 8.3.1 1364-1366

Another way to control gas pressure is to provide deliberate void space to accommodate it.

45. 33 8.3.1 1378Typo – “activate” should be “activated”

46. 34 8.3.1 1389The phrase “Therefore it particularly impact to…” does not make sense. What do you mean?

47. 34 8.3.3 1416The cross section of the accessways also needs to take into account any services provided, such as piping, ventilation ducting, wiring, etc, as well as passing bays for vehicles, space for pedestrians where needed, etc.

48. 35 8.3.5 1458In most cases, the key function of the ventilation system is to handle exhaust gases from vehicles used during construction and waste handling.

49. 38 9.2 1571-1573

This is a key point. See also comment #2

50. 38 9.3 1589Management Systems are an important consideration and deserves its own section. See GS-G-3.4, NW-T-1.2 and TECDOC 1740 for references. It could be here or as part of Chapter 10.

51. 39 9.3 1600The type of intrusion scenario also depends on the host geology (e.g. whether there are mineral resources nearby)

52. 40 10.1This section is too general. It needs to discuss the specifics of institutional controls, what they are, what role they have in safety and how they are applied to near surface and deep facilities.

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53. 40 10.2

There are numerous IAEA references on record keeping requirements for waste management that should be cited, such as TRS 467, TRS 434, TECDOCs 1097, 1222, 1398 and 1548.

One of the key points is that electronic records require very active maintenance to convert them as often as every few years into current technological standards. Some records produced even a few years ago using then “state of the art” equipment can no longer be accessed because they are based on long obsoleted technologies. The lifecycle of data technology is extremely short compared to the required lifetime of the records.

Data on both waste and the facility configuration need to be maintained in “human readable” form as well as electronically.

54. 11 3.3Section 3.2 addresses safety of people and the environment. Section 3.3 focuses on the engineered barriers. There could be an addition sentence added emphasizing that that safety aspects for people and the environment need to be designed in wherever possible.

55. 29 8.1.1 1155, 1156

Not clear what these requirements mean.

56. 30 8.1.1 1176The conceptual design should also be assessed during site selection and construction phases

57. 30 8.1.2 1210Might switch the word from demonstration tests to simulation tests

58. 31 8.2.2 1275Ventilation underground is also very important for worker health and safety which needs to be mentioned

59. 33 8.3.1 1342Seems to be an extra the --- increase in the excavated the size

60. 34 8.3.3 1409Need to add that ventilation cross section has to also consider traffic patterns during construction and operation and the size of construction/operation equipment

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61. 34 8.3.4 1453Ventilation purpose should also include emission monitoring and worker egress

62. 35 8.3.7 1489For concurrent construction and operations would prefer if we don’t say it is desirable to have separate access tunnels and ventilation systems since this is costly and not justified.

63. 5 Foreword Title

Typo: “Foreward” should be “Foreword”

64. 6 1.1 42-44

The sentence “While it is clear that near surface facilities are applicable […], there is no specific guidance for ILW” should be revised. As is, it implies that there is no mentioning of options for ILW disposal facilities, which is included Sec. 1.14(c) of SSR-5.It also implies that low-level waste is to be disposed of only in near surface facilities. SSR-5 notes in Sec. 1.14 (a) that near surface facilities may be designated as disposal facilities for LLW, which does not preclude using other disposal options for LLW.

65. 7 1.2 114It is unclear what the scope of this document is. Please add clarification.

66. 8 2.1 160Typo: “each Member States” should be “each Member State”

67. 8 2.2 175-176

Please consider revising this sentence. The information provided in Sec. 1.14 of SSR-5 regarding near surface disposal and geological disposal facilities is not documented as “definitions”, rather than types of disposal facilities adopted in one or more Member States.

68. 9 2.2 187Should include here the information from Sec. 1.14(c) of SSR-5 with respect to ILW disposal facilities options.

69. 9 2.2 192Since the intent of this document is to cover ILW, suggest deleting the reference to LLW from “the selection of appropriate disposal options for LLW and ILW may take into account”.

70. 10 3.1 262Please clarify what conflicts is being referred to here (legal, organizational, technical?).

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71. 12 3.5 363-364

For consistency, the SSR-5 requirements referred to by this section should be reproduced, similarly to other sections.

72. 12 3.5 378Typo: “there is no significant detrimental interactions” should be “there are no significant detrimental interactions”

73. 13 3.6 388-389

Suggest deleting the following sentence: “Significant efforts are to be taken to define the WAC for ILW disposal facility considering the diversity of the waste”.

74. 13 3.6 397Chapter 4 does not address the WAC, it rather discusses the characteristics of ILW.

75. 13 3.6 420For consistency with the rest of this chapter (and Chapter 2), a sentence should be added discussing the management systems in relation to ILW disposal facilities.

76. 14 4.1 441Justification should be added to clarify why is “particularly important” to have information the radionuclides included in the bulleted list.

77. 14 4.2 466Editorial: “contribute to optimize the waste stream” should be “contribute to optimization of waste stream”

78. 15 4.2 472Editorial: “which will be discussed” should change to “which are discussed”

79. 15 4.3 476Editorial: “as a function of its origin” should change to “based on their origin”

80. 15 4.3 502Suggest changing “the waste can meet the requirements of WAC” to “the waste can meet the WAC”

81. 16 4.5 514-515

Suggest keeping the original text as it provides further background information.

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82. 17 5.1 571Please clarify “and/or economy” with respect to treatment of ILW.

83. 18 5.4 652-653

This section does not discuss the identification of waste acceptance criteria, which is referred to in its title.

84. 19 6.1 675Suggest deleting “See confinement for a more extensive discussion” or adding the definition of confinement.

85. 21 6.2.2 790Human intrusion is also dependent on the availability of natural resources in the area.

86. 25 7.1 984Editorial: for consistency, 14C should be C-14.

87. 27 7.2.4 1079Please clarify the basis for the depth of 100 m used in this section.

88. 28 7.2.7 1117-1118

The entire section 7.2 seems to address long-term environmental, climate, and geologic considerations. Control of releases during operations is short-term. Please revise or delete.

89. 29 8.1.1 1136Suggest deleting “external” from “The external requirements…”

90. 29 8.1.1 1161Please clarify the need of an engineered barrier system to “be protected by the site”.

91. 38 9.3 1578Typo: “as described” should be “As described”

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Design basis – assumes all barriers are intact, conservative (high) waste inventory, etc

Safety case – based on conservative, but somewhat realistic assumptions

Licence conditions – provides some margin to safety case

WAC – provides facility operator with assurance they will not exceed operating licence conditions

Figure 1 (not to scale) – related to comment #14

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Current waste characteristics

Increasing certainty in repository design & WAC

Conceptual Design

Preliminary Design

Detailed Design

Repository Construction

Safety Assessment

Rev 1

Safety Assessment

Rev 2

Safety Assessment

Final

PreliminaryWAC WAC Rev 2

Repository WAC -Final

Repository Operating Licence

WAC Rev 1

Figure 2 (related to comment #34)

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Documents

gnssn.iaea.org Web viewThe word “plausible” should be replaced by “credible”. ... seismic activity, ... such as piping, ventilation ducting, wiring,