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Frequently asked questions on ALARA

 

PART 3: What can we do to implement ALARA properly?

11. ALARA and design, dismantling phases
47. Should ALARA be applied from the design stage?
48. What can be done to ensure that the ALARA approach is implemented from the design stage?
49. Are there any specific points to bear in mind when applying ALARA to dismantling a facility?
50. How should we take timescales into account in determining optimized objectives for dismantling projects?
51. Can a dismantling strategy be modified solely for the purposes of radiation protection?
52. How important is the maintenance of the collective knowledge of a facility?
53. What is the best way to motivate workers to take the ALARA approach on board when "their" facility is to be shut down?
12. ALARA and good practices
54. What is the difference between implementing good practices and an ALARA approach?
13. Commitment on the part of various stakeholders
55. Who is legally responsible for implementing an ALARA approach?
56. Who should be responsible for an ALARA approach?
57. Should only the Radiation Protection specialists perform the ALARA approach?
58. Should those involved in the process of purchasing services and equipment be integrated into the ALARA approach?
59. Is a specific structure needed to implement ALARA?
60. How can the "ALARA culture and commitment" be sustained in the long term?
14. How should a licensee take into account service providers' workers in an ALARA approach?
61. Is it necessary to have access to the dose records of subcontracted workers that occasionally work on a task?
62. As a part of optimization, should the dose records of workers who work on a task on a one-off basis at a licensee`s site be taken into account?
63. Does ensuring that subcontractors` workers do not exceed the annual dose limit satisfy the requirements of the ALARA approach?
15. ALARA tools
64. What are the main tools that are essential for the ALARA approach?
65. What are the additional tools that are useful for the ALARA approach in more complex situations?
66. How can use of ALARA tools be promoted?
67. What information should be recorded during tasks to perform ALARA studies?
68. Are there any decision-aiding tools for implementing ALARA?
16. ALARA and taking account of exposure times
69. Is it enough to use nominal working hours in implementing an ALARA approach?
70. What is the exposure correction coefficient?
17. ALARA and decision aiding techniques
71. Depending on the type of data included in the cost-benefit study (or cost-effectiveness study), is there not a risk of drawing the most convenient conclusions?
72. Should the cost of the ALARA study be included in the cost of the protection actions?
18. A special tool: the monetary value of the man.Sievert
73. What is meant by the monetary value of the man.Sievert?
74. Is it possible to implement ALARA without a system defining the monetary value of the man.Sievert?
75. Are there different types of monetary value of the man.Sievert?
76. Are these monetary values of the man.Sv often used in the nuclear field?
77. Is it possible to define a specific system for the monetary value of the man.Sievert to address the problem of doses to the extremities?
78. How is the problem of subcontractor workers dealt with in terms of the monetary value of the man.Sv?

 

47. Should ALARA be applied from the design stage?

Yes, the ALARA approach should be applied from the design stage (for a facility, refurbishment, maintenance, dismantling, etc.) since, on the one hand, the earlier it is implemented, the more freedom you have and the lower the cost (it is easier to change something on paper than once construction work has been completed) On the other hand, the earlier ALARA is implemented, the more can be done regarding radioactive sources and dose rates.

48. What can be done to ensure that the ALARA approach is implemented from the design stage?

One has to include radiation protection as one of the main criteria in the design process, and therefore it is essential to:

  • Study feedback on radiation protection carried out for similar facilities or for similar tasks
  • Analyze the alternatives (or various scenarios), taking account of radiation protection measures
  • Set optimized dose objectives.

49. Are there any specific points to bear in mind when applying ALARA to dismantling a facility?

Yes, some of which are problematic insofar as radiation protection is concerned, especially in the case of the oldest facilities. For example, dismantling involves a significant increase in the degree of uncertainty regarding the radiation conditions that may be encountered at the various stages of the dismantling, especially when very little is known about any modifications that may have been made to the facility in relation to the available plans; or when nothing is known, or is no longer known, about the sources or their composition.

On positive side, there is a possibility of making use of the decay law, as there is much more time to perform all the tasks required than is the case for facilities that are still in operation, together with the possibility of removing the most hazardous sources as work progresses.

All these specific characteristics confirm the need for a predictive ALARA approach, which includes scenarios that integrate sensitivity analyses while taking account the fact that hypothetical situations may vary considerably. Such analyses must be much more detailed than is the case for facilities in operation and must answer the question, “What will we do if…”

50. How should we take timescales into account in determining optimized objectives for dismantling projects?

As in the case of facilities in operation, the optimized objectives will be collective and individual dose objectives. It is crucial not to make use of the fact that there is more time available to artificially reduce the annual doses. The objectives must therefore be overall objectives covering the entire dismantling project (or each technical stage), and only then should they be set with regard to target dates.

51. Can a dismantling strategy be modified solely for the purposes of radiation protection?

Of course, and this has happened many times. Some strategies would result in exposures in excess of the limits or produce dose profiles that are not at all reasonable. It is recommended that every eventuality be planned for, rather than waiting for a strategy to be underway before becoming aware that it has to be stopped for reasons related to radiation protection. Experience has shown that it is much less expensive to be well prepared in advance.

52. How important is the maintenance of the collective knowledge of a facility?

Often there are differences between the original specifications or detailed plans for a facility and how the facility is actually built. Often this is due to the building process identifying practical difficulties and overcoming them with minor modifications. Similarly over the life-time of a facility much can change in its physical structure, fittings, services and how the facility is used. It is important that plans are accurately updated and logs maintained of maintenance, what operations have been undertaken in the facility, successful approaches, lessons learned and the range of radionuclides that have been used.

This knowledge base is particularly important in taking an ALARA approach to routine maintenance work, refurbishment, rarely carried out operations and decommissioning. The knowledge of those that have been involved with the facility needs to be captured in an accessible form and where appropriate included in training. In some older facilities this enlightened approach to maintaining a collective knowledge base may have only recently started. Here it may be necessary to introduce processes to capture knowledge from long serving staff and those leaving / retiring or even by contracting former staff members.

53. What is the best way to motivate workers to take the ALARA approach on board when "their" facility is to be shut down?

In this case, it is important to remind them that they remain responsible for preparing for dismantling. The facility must be clean so that dismantling can take place in the best possible conditions. In many cases the groundwork for the motivation to take this professional approach, will need to have been made during the preceding years of normal operation, with an ALARA approach as integral part of the attitude of management and workers.

54. What is the difference between implementing good practices and an ALARA approach?

  • Extensive knowledge of the company’s radiation protection culture helps in implementing certain common practices, which can be termed “good practices” (e.g.: systematic deployment of radiation protection measures at hot spots). It may nonetheless be useful to carry out analysis from time to time in order to verify that these good practices are optimised. The results of that study should then be very clearly explained to all involved stakeholders.
  • Options for which the benefits in terms of limiting both doses and costs are immediately obvious will also be considered as good practices to be integrated as part of the optimized solution.

55. Who is legally responsible for implementing an ALARA approach?

At nuclear, industrial or medical facilities, implementation of the ALARA principle is primarily the responsibility of the licensee, who is required to implement, through management, all that is “reasonably” possible to ensure that contracted or subcontracted workers benefit from the best working conditions The employer in some cases may have the primary responsibility when he is sub-contracted to do work for the licensee The contract will define the respective roles played by the two parties in implementing ALARA. Thus, there is a level at which responsibility is shared between the employer, the plant manager and the holder of the operating license for the source take responsibility for general ALARA coordination.

56. Who should be responsible for an ALARA approach?

The management of the facility has the overall responsibility. This involves clearly identifying and delegating responsibilities together with the necessary resources to implement the ALARA approach. Those individuals with these responsibilities may call for advice, expert appraisal and, whenever it seems useful and necessary, assistance from all types of specialists and also from the "subcontractors" involved.

57. Should only the Radiation Protection specialists perform the ALARA approach?

Certainly not, the ALARA approach is a "team project" that requires the know-how, participation and commitment of all concerned, including the operating team, maintenance, planners, designers, contractors, radiation protection officers and workers.

58. Should those involved in the process of purchasing services and equipment be integrated into the ALARA approach?

Where they can have an impact: Yes. They should be immersed in the ALARA culture to ensure that they do not systematically choose to work with the “lowest bidder” service providers, but rather with the “lowest responsible bidders”, who will have incorporated ALARA in their bid proposals and in their good practices (examples of this can be found in the contracting of industrial radiographers to carry out work on different facilities; 5th EAN Workshop on "Industrial Radiography: Improvements in Radiation Protection, in particular session 3" Rome, Italy, October 2001).

59. Is a specific structure needed to implement ALARA?

Generally speaking, no, as long as Management has a clear, pro-active policy. Nonetheless, special meetings should be planned, attended by radiation protection specialists, the operation or maintenance manager, the project manager and the contractors, whenever it is necessary to officially define specific procedures for implementing ALARA. In some cases, especially when the type and level of collective and individual doses makes it necessary, as in the nuclear industry, it may be advantageous to set up an ALARA decision-making committee headed by the plant manager or the head of department, or his/her deputy.

60. How can the "ALARA culture and commitment" be sustained in the long term?

It is necessary to organize regular reminders to demonstrate to all those involved the progress made from one year to the next, any new problems that may have arisen recently and to show them how their suggestions for improvement have been taken into account. To this end, internal training may be organized and staff may be sent to external training courses on ALARA culture and commitment.

61. Is it necessary to have access to the dose records of subcontracted workers that occasionally work on a task?

Yes, to ensure that the regulatory dose limits are not exceeded during the task in question. The corollary to such knowledge is, naturally, the fact of having drawn up an optimized prediction of the collective dose and of the individual dose distribution for the task.
This requirement is specified very clearly in the International BSS:

“Registrants or licensees shall, as a precondition for engagement of workers who are not their employees, obtain from the employers, including self-employed individuals, the previous occupational exposure history of such workers and other information as may be necessary to provide protection and safety in compliance with the Standards.” (BSS Appendix 1; 1.6; 1996)

62. As a part of optimization, should the dose records of workers who work on a task on a one-off basis at a licensee`s site be taken into account?

No. Of course, knowing their dose history is fundamental to ensure that the task will not mean they will exceed a dose limit, but this is not at all the case for optimizing the dose received during the task. This would be tantamount to making other licensees unaccountable.

63. Does ensuring that subcontractors` workers do not exceed the annual dose limit satisfy the requirements of the ALARA approach?

No, no more than for the licensee’s own workers. This would only mean complying with the dose limits rather than the correct procedure of reducing the doses to levels as low as reasonably achievable.

64. What are the main tools that are essential for the ALARA approach?

  • Risk assessments for each new piece of work and a pro-active predictive approach
  • Operational monitoring (individual and workplace)
  • Feedback databases
  • Plant layouts with surveys of dose rates and contamination at workstations
  • ALARA check lists
  • Task related Radiation Work Permits (RWP)
  • Simple codes for calculating dose rates.

65. What are the additional tools that are useful for the ALARA approach in more complex situations?

  • More complex codes for calculating dose rates
  • Analytical codes for calculating doses, including 3D modeling of the installation
  • The monetary value of the man.Sievert.

66. How can use of ALARA tools be promoted?

  • By spreading a culture of radiation protection as widely as possible
  • Through effective information sharing on good practices, through international and national symposia and networks, and inside the facilities themselves
  • Through management leadership
  • By providing support for radiation protection officers, etc.

67. What information should be recorded during tasks to perform ALARA studies?

The information recorded must provide answers to the following questions:


Questions

Examples of answers from the nuclear sector

Who receives the doses?

List of professions of all the workers, and dose records per profession.

When and how are the doses received?

Daily dose records, a coding system for activities and records of any unforeseen event.

Where are the doses received?

Appropriate area classification where doses and dose rates are recorded,

For how long?

Collection of exposure times for each individual, for each task and for each area.


If all the above-mentioned information is known, it should be possible to cross-check and analyze it after the task in question has been completed. This information may be gathered by hand (on paper) or by using computer systems.

In all cases, the amount of detail required in the information to be gathered must be aligned with the stakes i.e. types and levels of doses (see question 27).

68. Are there any decision-aiding tools for implementing ALARA?

Yes. There are decision-aiding methods, such as the cost-effectiveness method and the cost-benefit method. There are also "multi-criteria" methods (for more details, see the Commission of the European Communities report, "ALARA from theory towards practice", EUR 13796 EN and ICRP 55 published in 1989, "Optimization and decision-making in radiological protection". Annals of ICRP 20). Drawing on feedback from the last few decades, the ICRP analyzed the most useful methods in an appendix to its recent document,"The optimisation of radiological protection: Broadening the process", Annals of the ICRP, Volume 36, Issue 3, Pages 89: 104, 2007.

69. Is it enough to use nominal working hours in implementing an ALARA approach?

No. Multiplying a dose rate at the workstation by the nominal working hours (8 hours of work a day, for example) is likely to result in significantly overestimating the predicted dose. This arises from the fact that of the nominal working hours includes breaks, movement outside the area and, in some sectors, the time taken to put on and take off protective clothing.

For every job then, the actual Exposed working hours (EWH) should be estimated.

70. What is the exposure correction coefficient?

During a task, a worker does not spend all his time at a specific point of the workstation where the dose rate at the workstation is estimated. While still exposed, he moves to and from this point. Feedback shows that the product (dose rate times the exposure time) often overestimates the actual dose.

In a predictive study, it is, therefore, often justifiable to multiply the product (dose rate times the exposure time) by an exposure correction coefficient. For example, a coefficient of 0.7 has been found to be appropriate for a range of tasks in nuclear facilities).

71. Depending on the type of data included in the cost-benefit study (or cost-effectiveness study), is there not a risk of drawing the most convenient conclusions?

As with any study, the results depend to a large extent on the assumptions taken. It is the role of the different players (radiation protection officers, the manager and subcontractor, etc.) to mutually challenge each other’s assumptions. The fact that the issue has been raised a number of times shows that a sensitivity analysis is essential to test the robustness of the results.

72. Should the cost of the ALARA study be included in the cost of the protection actions?

No, because implementing ALARA is a regulatory requirement: the law must be applied regardless of the cost. This cost is therefore part of the total cost of radiation protection at a site and cannot be charged against a specific ALARA study.

However, the cost of the study must be in line with the level of doses: thus, taking several man-months to carry out an ALARA study for a non-repetitive project of a few man.mSv would be totally unreasonable!

73. What is meant by "the monetary value of the man.Sievert"?

To facilitate the practical implementation of the ALARA principle, the International Commission for Radiological Protection (ICRP) has, since 1973 (Publication No.22) up to the last recommendations (“The optimisation of radiological protection: Broadening the process”, Annals of the ICRP, Volume 36, Issue 3, 2007), proposed interfacing costs related to radiation protection options with the benefits in terms of reducing exposure. To do this, it suggested using an analysis in which the benefit or efficiency are given a monetary value, using a reference monetary value for the unit of avoided dose: the monetary value of the man.Sv.
Allocating a monetary value to the health benefits of radiation protection measures, or, in other words, the choice of a reference monetary value for the collective dose unit reflects how much the company is prepared to pay to avoid any radiation-induced effects on health.
The monetary value of the man.Sv helps in decision making on:

  • Reducing the level of collective exposure
  • Reducing the distribution of individual exposures
  • Reducing the dose dispersion by making it a priority to reduce the highest levels of individual exposure.

74. Is it possible to implement ALARA without a system defining the monetary value of the man.Sievert?

Yes. It depends on the type and quantity of doses and the amount of money required to optimize them. If a significant dose reduction is achieved for a modest sum, there is no need to apply the monetary value of the man.Sv. In some situations, quantitative information may not be available (or needed) on all the factors and as a result a qualitative decision must be made. However, in all cases, the basis on which the decision was made should be recorded so the future reviews of the achievement of ALARA can assess its continued effectiveness.

75. Are there different types of monetary value of the man.Sievert?

Yes, there are two types of values:

  • Those recommended by some regulatory bodies at national level, such as in Canada, Czech Republic, Finland, the Netherlands, Sweden, Switzerland, the United Kingdom and the United States.
  • Those which are used as a managerial tool at over three-quarters of the nuclear facilities in the world.

The values recommended by the regulatory bodies are generally to the order of tens or a few hundreds of US $ per man.mSv (as of the beginning of the first decade of the 21st century), while the facilities’ managerial values are one order of magnitude higher: they often range between one thousand and three thousand US $ per man.mSv (ISOE ETC Information sheet 18 and 34).

76. Are these monetary values of the man.Sv often used in the nuclear field?

In all countries, the use, by nuclear facilities, of the monetary value of the man.Sievert is mainly limited to important decisions both in terms of budget and (or) impact on the operation and safety of the plant. A formalized use of the monetary value of the man.Sv appears then, except for a few users, not to be part of day-to-day life.

More information is available in an ISOE ETC survey published in 2006 as Information Sheet Number 34.

77. Is it possible to define a specific system for the monetary value of the man.Sievert to address the problem of doses to the extremities?

No, this would not be relevant (see question 44, as regards to optimization of doses to the extremities).

78. How is the problem of subcontractor workers dealt with in terms of the monetary value of the man.Sv?

If we use the monetary value of the man.Sv, this value should be the same for all workers, both utility and subcontracted workers.

 


| Last update: Wednesday, 01 July, 2015.