10 September 2020
Comments on the IRPA statement
Japan Health Physics Society
IRPA statement on ‘Reasonableness’ in optimization of protection is very timely todeepen the discussion in each sector. As far as we know, ‘IRPA Statement’ has neverbeen issued. For clarification, it would better to replace the title by “IRPA Position
Statement on ‘Reasonableness’ in Optimisation of Protection”. Since this will be the firsttime IRPA issues a position statement. IRPA should consider whether it may be necessaryto specify its role and purpose in IRPA's regulations.
ICRP defines ‘prudence’ as a core ethical value. Most of Japanese people thinkthat ”prudence” is a sort of tactic for protecting oneself in living without a failure andthus they feel that it is unnatural to regard it as an ethical value. When ‘prudence’ will beapplied to radiological protection, it would be helpful to show cases by using some specificscenarios in terms of ‘prudence’. JHPS hopes the statement will be helpful for all theIRPA associate societies that have different languages and cultures.

IRPA Statement on ‘Reasonableness’ in Optimisation of Protection

Optimisation of protection, including the inherent judgement on what is ‘reasonable’, is a cornerstoneof radiation protection. There is a very wide experience of its application in practice across all fields ofprotection. However, there are some concerns that the interpretation of what is ‘reasonable’ inapplying the ALARA concept has in some cases become too cautious and limiting, with a tendency
towards an approach of minimisation of exposure rather than exercising a balanced judgement on
what is ‘reasonable’.
These concerns were expressed in the IRPA consultation on the system of protection1, and since thenthere have been several workshops and exercises to deliberate on ‘Reasonableness’. The Frenchradiation protection society (SFRP) held two workshops on this topic, and published the proceedings2.
The European ALARA Network has published guidance on optimisation3, and recently the NEA held aworkshop on ‘Rethinking the Art of Reasonableness’ (Lisbon, January 2020).
In general terms these workshops and deliberations have been based around specific exposure
scenarios for the optimisation of protection, and the conclusions relate principally to the specifics ofthe chosen scenario. Whilst these outcomes are indeed very valuable, IRPA believes that it isnecessary to learn wider generic lessons which underpin the process of optimisation of protection for
all situations. To this end we have committed to preparing an “IRPA Statement on Reasonableness in
Optimisation of Protection”, for which we seek the widest review and comment by the IRPA AssociateSocieties. Following this review within the IRPA family we intend to go out for wider consultation withother key international parties in the field of radiation protection.
The draft statement is attached, and Associate Societies are invited to review and comment on thisdraft. The closing date for such comment is 13 September 2020.

Roger Coates
IRPA President
May 2020
References:
1. Coates et al, 2017 J. Radiol. Prot. https://doi.org/10.1088/1361-6498/aa9e5c
2. Lecomte et al, 2019 Radioprotection https://doi.org/10.1051/radiopro/2019037
3. Optimisation of Radiation Protection ALARA: A Practical Guidebook. 2019 European ALARA Networkwww.eu-alara.net

IRPA Statement on ‘Reasonableness’ in Optimisation of Protection
Draft May 2020
Optimisation of protection is a fundamental principle of radiation protection. It is often referred to asALARA – keeping the likelihood of incurring exposure (where these are not certain to be received), thenumber of people exposed, and the magnitude of individual doses As Low As Reasonably Achievable,
taking account of economic and societal factors. Optimisation of protection is a wider picture than justconsideration of dose or exposure, although exposure is a key parameter in the concept. Experiencehas demonstrated that the optimisation principle is the central pillar for the practical implementationof radiation protection, and is the dominant factor controlling exposures in any well-developed systemof protection.
Whilst noting the successes in the application of optimisation, there are concerns in the professionthat we are moving to an expectation of ‘ever lower doses’ and an emphasis on minimisation ofexposure, irrespective of judgements on what is ‘reasonable’. Perhaps this results from a voluntary
efforts to improve radiation safety within practitioner.
Spending huge resources to reduce trivial harm might be judged to be unreasonable from theviewpoint of the economic factor, but sometimes might be judged to be reasonable from theviewpoint of societal factor. As the cost increases or the harm decreases, the judgment ofreasonableness becomes fuzzier and faces challenges. It is therefore helpful to seek broad agreement
on how to judge what is ‘reasonable’ in how we approach optimisation of protection.

What is ‘Reasonableness’?
ICRP Publication 138 defines Reasonableness as “To make rational, informed, and impartial decisions
that respect other views, goals, and conflicting interests”. In IRPA’s view the following key factors
should be taken into account in seeking reasonableness in protection.
1. Optimisation of protection is a judgement call which is essentially situation-based, often termed‘taking account of the prevailing circumstances’ (which of course is how all decisions in life should bemade). What is judged reasonable in one situation does not automatically determine, or necessarilystrongly influence, what may be reasonable in another situation. Whilst it is helpful to follow astructured approach to assessing optimisation, none the less there can be no automatic judgementfree process which leads to a decision. It is important that local circumstances are always taken into
account, and an uncritical assertion that the lowest exposure for a particular activity is ‘best practice’,and should therefore be achieved by all relevant practitioners, should not be made without proper
justification.

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コメントの追加 [A1]: Reference needed.
削除: an ingrained conservatism
削除: s, and also from a reaction by some regulatory authorities toa broad public perception that ‘any dose is dangerous’, whichconsequently influences required protection standards
コメントの追加 [A2]: Judged by whom?
削除: Consumption of
削除: is easily
コメントの追加 [A3]: Judgment by whom?
削除: However, a
削除: reduces
削除: increases
コメントの追加 [A4]: Judge by whom?

コメントの追加 [A5]: Judgement by whom?
コメントの追加 [A6]: Reference needed

2. It is widely acknowledged that the effort and resources allocated to optimisation should in broad
terms be proportionate to the level of risk (which may be judged in terms of individual dose,collective dose as well as issues of perceived risk). This aligns with common sense approaches
generally across society, and also with the regulatory principle of a graded approach.
3. Protection judgements must take account of the balancing of key ethical values, and the balance
point will depend on circumstances:•Prudence: this is the ability to make informed and carefully considered choices without the fullknowledge of the scope and consequences of actions. The optimisation of protection is a

コメントの追加 [A7]: Reference needed for ICRP Pub 138.

principle of action that allows the practical implementation of prudence, and also allows theintroduction of equity and fairness in the distribution of exposure among people exposed,
which refers directly to the ethical value of justice (see below. Whilst in many ways this is aneutral concept, in practice it is often interpreted as a need for precaution, which in turnrequires judgement. ICRP emphasizes that prudence should not be taken to be synonymouswith conservatism or never taking risks [ICRP, Pub. 138]. In practical implementation theweight given to prudence should reflect the level of risk. The relative emphasis given toprudence at say tens of µSv should be lower than at tens of mSv, where risks are at least afactor of one thousand higher.
•Dignity and Justice: these values are reflected in the need to involve stakeholders in thejudgement process•Beneficence (in association with Non Maleficence) - ‘to increase the direct and indirect
benefits for individual, community and the environment’ (ICRP 138): in broad terms thisimplies that we strive for the best value for society, with an expectation that the use ofresources should be seen to deliver appropriate benefits.

Looked at in broad terms, the ethical values in radiation protection support the concept ofproportionality in the approach to reasonableness and in the use of resources.
4. It is important that optimisation processes are based on realistic assessments of doses. The use ofmultiple conservative assumptions in assessments, which result in significant over-estimates ofexposure, or the use of ‘worst case scenarios’, can lead to a misallocation of resources.
5. It is essential to involve all those parties potentially impacted by the outcome, usually termed‘stakeholders’, in the process of reaching agreement on the judgement of what is reasonable in theparticular circumstances. In doing this it must be recognised that it might not be possible to reach afull consensus on what is reasonable, but it is important that the stakeholder process is open and fair,with clarity on the responsibility for making the final decision. Stakeholder involvement should also be
educative for all parties. A key to informed decision making is a shared understanding of the science,related policies and perceived and actual risks. The ideal objective should be that all parties agree thatwhat is to be implemented is ‘safe enough’.
6. The party ultimately responsible for associated expenditure of resources in implementing theoutcome must be fully engaged and represented in the stakeholder engagement process, and must
accede to the outcome. This may involve careful consideration of who is really paying the true costs,
especially where it may involve imposed costs to customers/consumers or the use of wider societyresources.
7. The optimisation process should take account of all relevant hazards and not necessarily focus
solely on radiation – i.e adopt an ‘All Hazards’ approach. Indeed, a complete consideration should
address not just all hazards, but all negative considerations (detriments) such as expense or loss ofincome, decrease or loss of services, social disruption, discrimination, and so on. Furthermore, it must
consider all benefits, not just the abatement of hazards or other negative considerations. In somesituations the total risk could be increased if only radiation hazards are considered. Radiation is often
not the most significant hazard, although it often receives the most regulatory attention.

コメントの追加 [A8]: If so, reference needed.

コメントの追加 [A9]: The meaning of this phrase is not clear
enough.

コメントの追加 [A10]: Too much emphasis on the use ofresources is not appropriate.
コメントの追加 [A11]: What is important is the consideration
about the distribution of individual doses and to reduce theinequity by optimizing the protection.
コメントの追加 [A12]: The meanings of “assessments” in not
clear in this sentence.
コメントの追加 [A13]: Too much emphasis on resources is notappropriate. What should be emphasized is that we need to act
wisely without full knowledge of the scope and consequences of anaction.

コメントの追加 [A14]: Too much emphasis on resources is not
appropriate.8. Some consideration has previously been given to the concept of a minimum cut-off, below which
no further efforts to address optimisation are necessary. Various proposals for such a threshold havecovered the range from 10µSv/a up to doses around 5-10% of a dose limit. Whilst this sentiment isunderstandable and has some rationale, it is difficult to apply in practice:•••

コメントの追加 [A15]: Reference needed.
コメントの追加 [A16]: Reference needed.
コメントの追加 [A17]: For members of the pubic?

The simple declaration of a fixed ‘de minimis’ value carries an imputation that above thisvalue it would indeed be necessary to take action, which may be totally inappropriate.
Exposure situations are so varied that a single numerical minimum does not seemappropriate.
Experience has shown that even at low doses there are often simple, realistic and inexpensive
actions that can still be taken to improve the exposure situation.

ICRP recommends in its Publication 101 that it is not relevant to determine, a priori, a dose level below
which the optimisation process should stop. Depending on the exposure situation, the best option
could be close to or well below the appropriate constraint. This means that the optimisation process
may result in doses lower than any level that could be proposed as an “entry level” into the system ofradiological protection [ICRP, Pub. 101].
IRPA’s view is that at small fractions of a dose limit, or significantly below reference levels, there
should be no ‘a priori’ expectation of dose reduction measures or formal demonstration of ALARA.
However, it would still be reasonable to implement actions arising from stakeholder engagement
where these improve stakeholder confidence, even if there is no significant benefit in direct safety
terms, provided that these do not impose a disproportionate burden on society’s resources.
9. The concept of wider societal ‘value for money’ (VFM) in the use of society’s resources, as
introduced above, should always be taken into consideration in optimisation judgements. Based on
general principles of good governance as noted in ICRP104, regulators and governments haveobligations to pursue the optimal use of societal resources. Previously in international
recommendations there was an emphasis on Cost Benefit Analysis, with a monetary value placed on
the manSv as a part of the judgement process. This was aimed at aligning societal VFM across different
options for resource spending. Whilst such quantitative analysis can provide important information, inpractice the technique has been limited both in scope and application, and rarely makes a significant
contribution to optimisation judgements. It is recognised that VFM judgements are in practice quitedifficult, but this is still an essential factor that stakeholders, regulators and authorities must consider.
This would be consistent with a ‘graded approach’ to optimisation and with the ethical principle ofbeneficence.
10. Most radiation protection decisions involve doses less than ‘a few’ mSv/a, or indeed much lower.
The overwhelming majority of exposures are well within the variability of natural backgroundexposure, and hence make very little difference to the total dose received by any individual, with total
exposure from all sources remaining within the normal range of natural background. In this low dose
exposure range there is little direct evidence of harm, hence giving uncertainty over the true risk,
although for protection purposes we prudently assume an LNT relationship. Whilst we cannot ignore
the optimisation of such exposures, we should none the less be cognisant of society’s ‘common sense’approach to these variations of background exposure levels. In normal day to day life the many
individual decisions (and associated allocation of resources) contributing to such exposure variations
are not generally based on concerns or considerations of radiation risks. Whilst such reflection may

コメントの追加 [A18]: For members of the public?
コメントの追加 [A19]: For what?
コメントの追加 [A20]: This view is not align with the ICRP
approach.

コメントの追加 [A21]: (Phillips, 2006) is the appropriate
reference to this sentence as ICRP 104 just cites this paper.
コメントの追加 [A22]: Delete regulators. Para. 13 of ICRP 104
only mentions about Governments.
コメントの追加 [A23]: Reference needed.

well not apply in all situations, it does none the less reinforce the need to ensure that the radiation
protection decisions we make are seen to result in reasonable value for society.
11. Especially in the cases of occupational and medical exposures there is a very strong alignment
between the key aspects of an ALARA process and the key attributes of a wider safety culture whichshould be an inherent feature of any organisation. The common essential components include:
••
•
•
•
•

Engaging with all parties involved in the activity
Implementing appropriate education and training
Maintaining an environment allowing openness and challenge
Learning and sharing from experience
Strong commitment from the leadership
Integration of the above commitments into a clear management system

These fundamental safety culture attributes apply irrespective of the level of risk/dose, and they
therefore provide a platform for ensuring appropriate attention in those lower dose situations wherea more formal assessment of optimisation is not necessary.
These basic commonalities are also applicable in many situations involving public exposure, especiallywhere longer term stakeholder engagement is necessary. In such situations it is often necessary togive greater attention to the process of engagement, due to the unfamiliarity of many stakeholders
with the concepts of radiation protection.
12. The above list of factors which should be taken into account in the optimisation of protection is
not exhaustive. In the various scenarios there are many other considerations which are appropriate,but IRPA believes that the above factors represent the key generic issues.
Conclusions – What is ‘Reasonable’ in Optimisation of Protection?
Optimisation of protection is an essential component of radiation protection, and usually is thedominant factor controlling exposures in any well-developed system of protection.
Based on the principles of proportionality and the graded approach, the greatest attention should befocussed on the introduction of equity and fairness in the distribution of exposure among people
exposed and also those who have higher levels of exposure. Lower levels of exposure are also subject
to optimisation, but the considerations should be proportionate and integrated into a broader pictureof all hazards, ideally within a general safety culture approach, and not focussed around specificexpectations of minimising exposures.
Optimisation of protection should always take account of ensuring reasonable value for the use ofsociety’s resources.
The effective engagement of stakeholders, i.e. those persons impacted by the exposure and thedecisions to be made, is a key to success.

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