Preparedness and
Response for a
Nuclear or Radiological
Emergency Involving
the Transport of
Radioactive Material

Transport packages are designed with a graded approach, meaning that the higher activity and more mobile forms of radioactivity get transported in more robust containers. This is designed to ensure that most emergencies during transport have limited radiological consequences and can be resolved in a relatively short period. However, there are always the low probability, high consequence accidents to keep us awake.

The objective of this publication is to provide recommendations on emergency preparedness and response for the transport of radioactive material. These recommendations form the basis of achieving the goals of emergency response described in GSR Part 7.

The recommendations in this Safety Guide are aimed at States, regulatory bodies and response organizations, including consignors, carriers and consignees.

Section 2 covers national arrangements which should integrate and coordinate the capabilities of responders and ensure that their roles and responsibilities are clearly specified and understood.

“The government shall make adequate preparations to anticipate, prepare for, respond to and recover from a nuclear or radiological emergency at the operating organization, local, regional and national levels, and also, as appropriate, at the international level.”

There is a lot of detail, 14 pages of it, including a description of what the consignor’s and carrier’s plan should contain (para 2.57). These are not a-plan-on-a-page.

Section 3 is about preparedness and response. It talks about a concept of operations as “a brief description of an ideal response to a postulated emergency, used to ensure that all the personnel and organizations involved in the development of emergency response capabilities share a common understanding”. It also discusses the objectives to consider.

The report then goes through the urgent response phase where those on the scene and first responders are determining the situation and, in particular, looking for evidence of failure of containment or shielding and acting accordingly. It gives an aide-memoir for reporting the situation (3.14), the priorities for response (3.19) and protective actions to consider (3.30).

A transition to either a planned exposure situation or an existing exposure situation, depending on the circumstances might be required if the environment is contaminated. We are told that “the transition phase commences as early as possible once the source has been brought under control and the situation is stable; the transition phase ends when all the necessary prerequisites for terminating the emergency (these are given in 3.34) have been met” (3.38).

There is a section on Training, Drills and Exercises (3.43 – 3.53).

Section 4 focuses on road, rail, sea, inland waterway and air in turn, talking about how and why these modes are used and any special features to consider.

Section 5 looks at transport events initiated by nuclear security events and the extra considerations put into play, including the requirements for crime scene preservation.

Appendices give advice on (1) developing national capability and (2) types of events that might lead to a transport emergency (useful for setting scenarios).

Annex 1 reviews IAEA advice on transport regulations, including classification, signage and packages.

Annex 2 is a model event notification form.

Annex 3 is a template carrier or consignor emergency response plan.

Annex 4 provides 7 scenarios to consider.


The ONR have a considerable body of reference material relating to the transport of radioactive material which can be found at

This includes guidance on risk assessment under IRR-17 and Guidance on emergency planning and notification for the transport of class 7 goods

This states that “CDG09(19) require duty holders (both the consignor and the carrier) to have a plan where they have reached the conclusion that a radiation emergency might occur. The emergency plan must detail the arrangements to restrict, so far as is reasonably practicable, the radiation exposure of any person that may be affected by a radiation emergency before the carriage of radioactive material takes place. This includes the vehicle crew, the public, attending emergency services and any persons exposed to ionising radiation as a result of a loss of radiation shielding, release of all or part of the contents of a package or an uncontrolled criticality when transporting radioactive material”.

It also notes that “Provision of information in the event of an emergency to those likely to be affected is placed on local authorities through Regulation 22 of REPPIR19.”

In their November 2020 document Five Steps to Transport Emergency Planning ONR outline five steps:

  1. Evaluate whether an Emergency Plan is required
  2. Preparing an Emergency Plan
  3. Test, Review and Revise the Emergency Plan
  4. Implementing the Emergency Plan
  5. reporting requirements after an emergency

NAO on the decommissioning of the AGRs

I think that this report by the National Audit Office (NAO) is quite worrying. It seems that the only thing we know about the defuelling and decommissioning of the AGR sites is that it will cost a lot of money; almost certainly more than has been put aside for the job.

The current agreement is that as soon as EDF declare a station off the bars permanently the costs of the site transfers to the decommissioning fund, EDF are paid to defuel the site and then ownership “of all land, assets and contracts required by Magnox Ltd to commence (commence not finish!) deconstruction on the sites” transfers to the NDA i.e. it seems that EDF can maybe choose to retain the assets they fancy.

EDF estimated that the fixed costs to manage and maintain a station that is not generating electricity but still holds fuel are around £140 million per station per year, compared with around £25 million to £35 million per station per year once the fuel has been removed. It does, of course, remain to be seen how realistic these values are.

The NDA will not know the exact details of what will transfer nor have a full understanding of the associated costs and liabilities until closer to the expected transfer. The long-term success of this scheme then depends on the ability of the NDA to deliver efficiencies from combining the AGR stations with the existing portfolio. Not that they have an unblemished history.

Since 2021 the NDA has adopted what it terms a rolling decommissioning strategy for its Magnox stations. This approach, it believes, could allow reactors to be decommissioned sooner. Stakeholders the NAO spoke to with technical expertise and knowledge of the AGR stations expressed differing views on the applicability of a rolling strategy to the AGR fleet.

I find it worrying that the way in which EDF, NDA and Magnox Ltd will work together to plan for transfer of the stations is set out in a Memorandum of Understanding because they could not agree the terms of a legally binding agreement. Meanwhile the Department is reliant on there being continuing goodwill between EDF and the NDA to resolve potential differences.

The UK government has yet to put in place arrangements by which it can assure itself that the Department is fulfilling these roles and the decommissioning programme is performing effectively.

Finally, what does the statement that it should be possible to save £1 billion in an estimated cost range of £3.1 billion to £8.0 billion mean? Surely you save £4.9 billion by hitting the lower estimate rather than the higher.

Impressions of the Emergency Services Show 2021

I attended the Emergency Services Show yesterday (7/9/21). As in the past this offers access to a large number of exhibitors and a range of short presentations.  I don’t plan my visit very well and just wondered up and down hoping to find all the interesting stalls. This meant I stopped and chatted to random people rather than worked down a list and that this review is therefore rather random.

Themes include vehicles and vehicle fittings, lights (lots of LEDs!), care for responders physical and mental wellbeing, cameras on drones, people, vehicles and poles, more drones with different capabilities, handheld devices to detect and measure threats, PPE & RPE and command and control systems, kit bags, ropes, pulleys etc.

There were several IT systems that allow you to integrate information feeds from cameras and other sensors dotted around the incident, radio messages from those on the ground and geographic knowledge. I didn’t take a close at these but now wish I’d spoken to someone about them. My concern (from a far!) with these is that they disrupt the information pyramid. You need a new team of people to sift through the information and identify what is important and what is changing. Having a sit-rep from the commander on the ground available to all to listen to when they wish is great, but how do you ensure that people are not still interpreting it as hot news long after it has been superseded? Having the reports of all the people on the ground, and all the videos, is also great but again come with a time cost if everybody stops to hear them. Will the remote Gold Commanders be tempted to take time to look at the video feeds and make their own situation analysis, by passing the Command structure on the ground? Is that always good, always bad or does it depend?

There were several immersive training environments, including VR sets and tents with scenes projected onto all the surfaces. These must be helpful in certain circumstances.

Handheld radiation monitors continue to develop with new crystal materials, larger crystals and, more importantly, much more on-board computing capability. Southern Scientific were showing CBRNe handhelds while kromek were showing a range of handheld and wearable gamma and neutron detectors with Bluetooth and USB comms, including some with the ability to identify isotopes. I find some of the claims a little hard to believe but these companies have happy customers whose expertise and judgement in these matters I’d place ahead of mine.

There are also a number of training tools that are realistic looking handhelds, such as those offered by Argon Electronics, that report injected exercise data rather than live readings. Obviously potentially useful.

It was interesting to talk to the people at the Defence and Security Accelerator (DASA) stand. This organisation tries to find innovations that can be exploited by the UK defence and security services and help with their development. They do this by a combination regional “innovation partners”, who provide advice to organisations and individuals about the potential merits of their ideas and how best to develop them and through more focussed “competitions” to cover identified needs. Funds are available for promising technologies at different stages of development and for the full range of company size. Their website has interesting case studies.

A car sized fire blanket from Fire Hosetech caught my attention. This is designed to manage lithium-ion battery fires which must be contained until they burn out. These reusable blankets can withstand temperatures up to 1,600 degC and reduce the spread of toxic fumes and contamination.

I also stopped to look at Fortress Distribution’s attempt to reduce the world’s usage of disposable shoe covers with plastic “Yuleys” which you step into and out of in a hands-free manner. Their design use seems to be for trades working indoors and out to prevent treading dirt inside but I wondered if they could replace single use shoe covers in contaminated areas. One issue being that they cover the sole of the shoe and the sides to a certain extent but not the top which I suspect is an idea killer. The other questions would include how much work was involved keeping them clean and how many reuses would be required to cover their own environmental costs?

Also worthy of a mention is the National Emergency Services Museum in Sheffield which showed a few of its vehicles. Got to be worth a visit if in the area.

The Emergency Services Show is well worth a visit by emergency planning and response professionals although it is not focussed on us. It gives an opportunity to see how the Emergency Services, with whom we work, are developing and an opportunity to keep an eye on technology developments and themes.

Small Modular Reactors and Advanced Modular Reactors – State of Play

The trajectory taken by mainstream nuclear power reactors over the years has tended towards more powerful units with ever more layers of backup safety systems. These are complex and therefore difficult to build and eye-wateringly expensive (Hinkley Point C costs have risen from £18bn in 2016 to £22bn – £23bn in 2021). There have been several attempts to simplify nuclear power designs by introducing passive safety and reducing the lengths of pipes and number of systems.

The concept of the Small Modular Reactors (SMR) has a long history. In the UK the Safe Integral Reactor (SIR) proposed by Rolls Royce in the 1980s and 90s used PWR technology but with reduced size and the steam generator inside the main pressure vessel. This reduces the lengths of vulnerable primary circuit pipes and other external components which greatly reduces the chances of a loss of cooling accident. It also provides more effective decay heat removal by natural circulation leading to improved safety at reduced cost and complexity. Several other SMR designs were proposed at about this time (see ASME Symposium 2011).

Picking winners? In 2016 a report written for the UK government (SMR Techno-Economic Assessment Project 3 – SMRs: Emerging Technology) reviewed over 40 SMR concepts in 6 technology groups looking for those that could be deployed by around 2030 and contribute to the UK’s 2050 decarbonisation commitment. An important conclusion was that “A combination of a lack of technical maturity, together with the likely time and effort for licensing and deployment indicates that all Emerging Technologies except SM-HTGR are at least significantly challenged on ‘Time and Cost to Deployment’ relative to SM-PWRs”. This begs the question “is the UK in danger of missing a better long-term solution by placing undue emphasis on short deployment targets?”

At about the same time another report looked at Micro Nuclear Reactors (typically under 30 MW electrical) and concluded that there were no great technical barriers to their development and that the finances looked good. It suggested that two barriers existing were uncertainly in how the regulatory process will apply to such reactors and uncertainty in long term political commitment to manage a predictable nuclear industry environment.

It was concluded that Small Modular PWRs represent the least cost generation option for SMR technologies in the short or medium term. That these can provide low grade heat for district heating and some industrial processes was seen as an advantage despite no market penetration for UK nuclear in these areas. It was also concluded that emerging technologies, particularly the Small Modular – High Temperature Gas-cooled Reactor, could offer other advantages in UK energy futures where high temperature process heat is used directly to decarbonise industrial and/or transport activities. It appears that the government accepted these conclusions.

A RR SMR brochure (2017) claimed that “A Small Modular Reactor (SMR) programme represents a once in a lifetime opportunity for UK nuclear companies to design, manufacture and build next generation reactors to meet the UK’s energy needs”. They promised SMRs providing 220 MW to 440 MW, cheaper per MW than large scale reactors, low technical risk, high fraction of UK content, 1/10th the land requirement, running by 2028.

The brochure listed a several conditions that would be required:

Condition Apparent progress (my judgement!)
Selection of one preferred technology HM Government have confirmed that they will support SM-PWR and SM-HTGR.
A UK industrial policy that supports UK intellectual property, advanced manufacturing and long-term high value jobs in the UK Difficult to assess but the recent purchase by the Government of Sheffield Forgemasters is a good sign.
Match funding until the end of the Critical Design Review It seems that funding has now been achieved to complete the GDA process.
A Generic Design Assessment (GDA) slot to ensure the process of licensing GDA is now open to SMR and AMR designs.
A suitable site to develop a First of a Kind (FOAK) power station There seems to be a view that the FOAK SM-PWR will be built on a previous nuclear power site which seems sensible.
A policy supporting a UK electricity market of at least 7 GWe for SMRs Current declared strategy looks to demonstrator (FOAK) rather than fleet. We do not yet have a declared siting and policy framework.
Export support to reach international markets Too soon to say


They don’t seem to tackle the issue of who would pay for them to be built after the FOAK, who would own them, who would operate them and how they would all be paid. RR want to build and sell 7 GW electrical, they don’t want to own and operate them.

A World Nuclear Association (WNA) report (2021) discusses an aspiration for a worldwide nuclear environment where internationally accepted standardized reactor designs can be deployed without major design changes. It reports a range of different SMR designs and a wide variety of licensing processes and diversity of overall national regulatory structures. It concluded that a country’s regulatory framework is generally either heavily prescriptive and rule-driven (such as the USA) or goal- or risk-driven (such as the UK); some are a combination of both. The report seems to hold out little hope for international approval but it does provide advice on best practice on licensing reactor designs in other host countries.

A later WNA webinar about streamlining the licensing of Small Modular Reactors again spoke of the potential gains for vendors from an international approvals system but offered few ideas on how that might be achieved.

The UK Government Ten Point Plan for a Green Industrial Revolution (November 2020) suggested that the UK electricity system could double in size by 2050 as demand for low-carbon electricity in sectors such as heat and transport rises. It looked to large scale nuclear to contribute and promised to look at the future of SMR and AMRs and invest where appropriate.

A Government Energy White paper (December 2020) states that “Nuclear power provides a reliable source of low-carbon electricity. We are pursuing large-scale nuclear, whilst also looking to the future of nuclear power in the UK through further investment in Small Modular Reactors and Advanced Modular Reactors.” It reports an aim to bring at least one large-scale nuclear project to the point of Final Investment Decision by the end of this parliament (it seems to be running out of viable options with Sizewell C being based on the hard-to-build EPR, Wylfa Newydd and Moorside inactive and Bradwell B embroiled in international politics).

The White Paper also promised that “We will provide up to £385 million in an Advanced Nuclear Fund for the next generation of nuclear technology aiming, by the early 2030s, to develop a Small Modular Reactor (SMR) design and to build an Advanced Modular Reactor (AMR) demonstrator”.

The UK government has opened the Generic Design Assessment (GDA) to Advanced Nuclear Technologies and the ONR released new guidance on the process.

A public dialogue was held in early 2021 to “inform future policy development and engagement with the public”. The output does not seem to be available yet.

The UK Research and Innovation Low-cost nuclear challenge (24th May 2021) aims to develop a compact, standardised nuclear power station product based on the Rolls-Royce led SMR. It has ear-marked £215 million investment from the UK government, to be matched with £300 million investment from industry (19/11/20) with Tom Samson, the CEO of the UK SMR consortium promising “We will continue our current work and then move seamlessly into our next phase in May 2021 beyond which we can begin creating 40,000 high quality jobs, £52 billion of value to the UK economy; and targeting the £250 billion in exports”.

The government has also sought views on the potential of high temperature gas cooled reactors with the aim to have a demonstrator by the early 2030s asking if people think they have a role in the net zero CO2 target, if there is further evidence they are unaware of and how well the UK supply chain could support the programme.

A report written by the University of Manchester, Dalton Nuclear Institute supports the development of a demonstration HTGR and suggests adding hydrogen generation to the aspirations for the demonstrator. It also recommends a suitable body that is equipped and empowered to deliver the HTGR project be constituted. This, it suggests, should be complemented by an independent body “unconflicted by claims and lobbying by any particular system proposer” to maintain an ongoing UK view of developments in AMR systems, a broad-based advisory body offering the government advice on the nuclear programme.

Meanwhile Canada has a comprehensive Small Modular Reactor Action Plan resulting from a pan-Canadian effort bringing together key enablers from across Canada including the federal government, provinces and territories, Indigenous Peoples and communities, power utilities, industry, innovators, laboratories, academia, and civil society”. It comes with a statement of principles, 117 chapters written by participants and 513 tracked actions each linked back to the recommendations made in an earlier roadmap document. This is a credible programme.

In Russia Small Modular Reactors are being built for icebreakers, for floating power plant and for land-based systems. They have the KLT-40S Integral PWR which has been evolved into the RITM-200 which is smaller and lighter. This has several variants for land and floating applications (the floating applications include providing propulsion for icebreakers and providing electricity and heat for coastal communities). There are proposals for a land-based SMR at Yakutia in the Russian Far East.

China has started to build an ACP100 SMR demonstration project at the Changjiang nuclear power site in Hainan. Designed for electricity production, heating, steam production or seawater desalination the 125 MWe PWR. The plan envisages sites with 2 to 6 ACP100 reactors with a 60-year lifespan and 24-month refuelling. A floating version is also planned.

In the US NuScale power are planning to build a 6 unit site for the Utah Associated Municipal Power Systems (UAMPS) (down from the 12 units originally planned).  The first module is scheduled to be operational in 2029, and the full plant in 2030. Meanwhile funding is being collected to build a demonstration Natrium reactor in Wyoming on the site of a retiring coal power station. This is a sodium cooled fast reactor with a thermal storage device allowing load following, including electrical outputs rates higher than the reactor’s power output for periods of time.

France has announced another new SM-PWR design, the “NUWARD”TM, while saying that they are “open to international cooperation, notably to foster the harmonisation of regulation, the standardisation of design and design optimisation”. (If that really was the case then why didn’t they join an existing project rather than develop their own?).

Japan is reported to be interested in developing and deploying SMR and AMR. Their aspiration is for a SMR demonstration site by 2030 and the establishment of the technology to use high temperature reactors to generate hydrogen.

This is clearly an interesting time for Small and Advanced Modular Reactors. They are being built in Russia and China, both of which see a good market. They are being developed in the USA, Canada, the UK and several other countries, seemingly with coherent government support. They are seen as an affordable route into the nuclear industry providing an opportunity to decarbonise the energy market and reduce dependence on imported fuels. We need to see continuing progress on the design and licensing of this technology, demonstrator sites for those that have not got there yet and a siting policy, financial model and operating regime that enables the full market potential to be realised. Meanwhile we can expect to see many of the systems currently under development to fall by the wayside.

The NEI Small and Advanced Reactors event (4th November 2021) will be a follow up to their virtual event held in February 2021. It will look at the development plans and licensing activities for a range of small and advanced reactor technologies from across the world. It will cover all aspects of industry, with insight from reactor developers, utilities, regulators, supply chain, academics and the financial community with sessions covering market development, manufacturing and construction, the utility view of the role of SMR/AMR, finance and economics, Fuel and progress towards demonstration plant and beyond. One to watch.



Keeping the ICRP Recommendations Fit for Purpose

The science behind radiological protection is complex. It starts with the physical interaction between ionising radiations and the material that composes the human body (and other biota), then considers the potential changes induced by these interactions, including the response of different issues within the body and the whole body implications of those local responses, and tries to quantify the harm that might be done (detriment). It then considers the acceptability of this harm in terms of the tolerability of risks and by putting them into perspective with other risks.  It also considers how different groups and individuals might respond if exposed, recognising workers, the public and patients as different groups with different potential gains and losses and planned, existing and emergency exposure situations. The field thus encompasses physics, biology, sociology, ethics and politics.

The International Commission on Radiological Protection was “established to advance for the public benefit the science of radiological protection, in particular by providing recommendations and guidance on all aspects of protection against ionising radiation. The Main Commission is the governing body, setting policy and giving general direction” (Ref).  The recommendations of the ICRP form the basis of radiological protection around the globe. A useful review of the effects of this last major restatement of the recommendations can be found in a PHE paper “Application of the 2007 Recommendations of the ICRP to the UK”. (Ref)

ICRP have now pre-released a major discussion document as an early step in the consultation process for the next round of recommendations. Christopher Clement et al 2021 J. Radiol. Prot. in press. On line (updated version) available at This article is based on the accepted manuscript 20 July 2021.

In this we are reminded that the objective of the system of radiological protection described in ICRP-103 is “to contribute to an appropriate level of protection for people and the environment against the detrimental effects of radiation exposure without unduly limiting the desirable human actions that may be associated with such exposure”. The review that preceded this document started 20 years ago and took 10 years. “While it is safe to conclude that the System is robust and has performed well in relation to the protection objectives, the System must adapt to address changes in science and society to remain fit for purpose.

It is suggested that the ICRP-103 objective to prevent tissue reactions (deterministic effects to us oldies) should be modified to recognise that there are medial situations, emergency situations (and space exploration) where tissue reactions may be tolerated to achieve the desirable benefit of a particular activity. This seems sensible but is going to add, rather than remove, complexity.

A review of the lifetime risk estimates imbedded in the concept of detriment is due a review to reflect the evolution of scientific knowledge of risks and expert judgement. “In addition, explicit recognition of differences in detriment with age at exposure and between males and females could improve the clarity of application of the System, showing, in particular, that risks to young children are greater than risks to adults, and that risks to older individuals are low.” This could be useful, for example, in removing the perceived need to evacuate elderly people from their homes during a radiological or nuclear emergency to avert radiation doses of as little as 30 mSv which are of no real threat to them.

The discussion paper points out that the current system “principally deals with health effects resulting directly from exposure to radiation” which is not entirely in line with the WHO definition of health as “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”. Including mental and social wellbeing in the system can only make it much more complicated, situation dependent and subjective (but pretty much removes the need to worry about the physics of the fundamental interactions).

There is a section (Section 2.3) on the protection of the environment and non-human biota. I have always considered this a job creation scheme for radiobiologists and mathematical modellers (of which I used to be one) and of little practical value in the real world of radiation safety. I realise that this view sees me ejected from the moral high ground.

In Section 2.5 the paper reports that “There have been many requests for more guidance on how to balance societal, economic, and other factors in the optimisation of protection and safety, requiring input from many fields of expertise” and summarises the work that ICRP have published in this general area. This includes ICRP Task Group 114 which seems to suggest that there are occasions where the lowest exposures or risks are sought when a better balance could be achieved to advantage.

Also in this section is a discussion of a more holistic approach in safety assessments of medical facilities. Again, this seems to be running the risk of making the system more complex and maybe asking too much of one stream of work.

Section 2.6 discusses dose limitation and worries that, since it only applies to planned exposure situations, it fails the “ethical obligation to protect individual people under all circumstances”. This seems to me to be a bit like worrying that the seat belt and airbags in my car don’t provide me with any protection when I am walking around a shopping centre.

The report suggests a broader principle which would apply in all situations and encompass the concepts of limits, constraints and reference levels, possibly combining the latter two concepts into one. This is an interesting thought, worth thinking about provided the ICRP are willing to back peddle if it does not work out as hoped.

Dose constraint

A prospective and source-related restriction on the individual dose from a source, which provides a basic level of protection for the most highly exposed individuals from a source and serves as an upper bound on the dose in optimisation of protection for that source. For occupational exposures, the dose constraint is a value of individual dose used to limit the range of options considered in the process of optimisation. For public exposure, the dose constraint is an upper bound on the annual doses that members of the public should receive from the planned operation of any controlled source.

Reference level

In emergency or existing controllable exposure situations, this represents the level of dose or risk, above which it is judged to be inappropriate to plan to allow exposures to occur, and below which optimisation of protection should be implemented. The chosen value for a reference level will depend upon the prevailing circumstances of the exposure under consideration.


The report states that “defining a fundamental principle to protect the individual would result in a System where all three fundamental principles apply under all circumstances regardless of the exposure situation or category. This change would require the re-examination and clarification of the distinctions between limits, constraints, and reference levels”. (I’m not sure how you can put a useful dose limit on an accident or malicious use of radiation).

Section 2.7 suggests that the experience of using the three exposure situations introduced by ICRP-103 has led to the opportunity to update, clarify and expand the guidance. This seems reasonable and the application to space travel interesting.

ICRP identify ethics, communications and stakeholder involvement and education and training as important overarching considerations and briefing discuss each in turn in Section 3.

It is proposed to use absorbed dose (in gray) for the control of doses to individual organs and tissues for the avoidance or minimisation of tissue reactions leaving equivalent dose (in sievert) as an intermediate step in the calculation of effective dose. “Radiation weighting could then be considered separately for tissue reactions and stochastic effects for the calculation of radiation-weighted absorbed dose in Gy and effective dose in Sv, respectively.” This is intended to “apply scientific knowledge more appropriately and simplify radiological protection, with a clearer distinction between organ/tissue doses in absorbed dose in Gy and effective dose in Sv”. This does seem more transparent than the switch we currently make from seiverts to grey at (an arbitrary) high dose as at low dose you are concerned about stochastic effects and high doses with tissue reaction.

The paper reports discussions with ICRU with the intention that “the measured quantities for the estimation of effective dose would be related directly to effective dose in the reference phantoms, renamed as ‘dose quantities’ (ambient and personal dose) rather than ‘dose equivalent quantities’. Operational quantities for the measurement of doses to the skin and lens of the eye will become ‘absorbed dose quantities’”. Another episode where those of us who work around radiological protection are required to forget the hard learned jargon we work with and replace it with a different set.

In Section 4.2, discussing effective dose, the paper discusses the increased use of more accurate and differentiated anthropomorphic phantoms leading to more accurate and transparent values of detriment and relative detriment separately for males and females of different age groups. The report suggests that “Revisions to the methodology of calculation of effective dose could improve its suitability for the assessment of risk. Best estimates of health risk should be calculated using estimates of absorbed doses to organs/tissues and age- and sex-specific risk models for individual types of cancer, but risk estimates at low doses will still be subject to the uncertainties inherent in risk projection models”. The question this raise in my mind is “are the age and sex differences larger than the uncertainties in the estimates?”

It is suggested in Section 4.4 that the revision of dose per unit intake values in the light of the new recommendations should be more rapid than previous experiences due to preparatory work and experience gained. This seems to be a reasonable hope.

Section 5 suggests a review of the classification of radiation effects as either stochastic effects or harmful tissue reactions to ensure that it remains fir for purpose, suggesting that “For example, for protection purposes, it may be useful to distinguish between severe and other tissue reactions, or between short-term and long-term health effects”. This seems reasonable. There are occasions where the gain from a process may be worth suffering a mild or temporary tissue effect.

Since the last recommendation were made there has been considerable research and epidemiological study of the impacts of low exposures to ionising radiation. A Task Group is currently reviewing the linear no threshold assumption in the light of this work. It looks likely to survive.

It is almost certain that different people have different susceptibility to harm from ionising radiation but likely that there is insufficient information to include this in a system to protect workers and the public. “However, there are already efforts to individualise radiological protection of patients which should be considered in the review of the System, taking into account scientific, ethical, and practical aspects”.

Similarly, there is now more information on heritable effects that should be considered.

Likewise, there is more data on relative biological effectiveness and it is likely that a more sophisticated approach may now be appropriate.

The idea that “detriment could be calculated separately for males and females and at different ages at exposure, and the corresponding values of relative detriment could be used directly in the calculation of effective dose, rather than the current use of simplified age- and sex-averaged tissue weighting factors” sounds good. As does “explicit treatment of detriment from irradiation in utero could also be re-evaluated”.

There will also be a conversation about the replacing detriment with other proposed measures of harm such as fatality or disability-adjusted life years.

The discussion paper concludes that “The last review of the System of Radiological Protection was initiated 23 years ago, and the current General Recommendations (ICRP, 2007) were published 14 years ago. The System has performed well and remains robust, and there are significant practical benefits to stability in the System. Nonetheless, it must progress to remain fit for purpose as society evolves, scientific understanding advances, and new uses of ionising radiation emerge”.

The ICRP and others continue to research the effects of ionising radiation on people, biota and the environment. A time comes when the strengths and weaknesses of the current system should be discussed and new knowledge should be systematically reviewed incorporated into a revised international system of radiological protection. It appears that that time is approaching. This paper is one step in the consultation process. An ICRP Digital Workshop on 19 – 20th October is another step (Ref).

I shall watch this process develop with interest and get involved if I deem it good use of my time.






FEMA – Key Planning Factors and Considerations

What would you do?FEMA report

…if a dozen dead birds are found near a truck accident site?

…if 20 people complain of tingling in the mouth after eating at a fast-food restaurant?

FEMA have some answers. They have published a new 324-page document discussing key planning factors and considerations for response to and recovery from a chemical incident August 2021).

The report shows the potential complexity of responding to a chemical event. Unlike radiological events, chemical events could result in overwhelming numbers of acute casualties, some of which require urgent medical attention with the correct treatments and anti-toxins for the chemical involved – which may not be identified at the start of the event. First responders may be in immediate danger from the contamination themselves, something that is not likely to be true to the same extent for radiological emergencies.

There are broad similarities between the response to a chemical event and to a radiological event (a dangerous substance that can move with air and/or water movements, the need to make decisions with weak information, a complex issue to explain to the public while needing them to urgently take heed of advice, a potentially complex recovery process) but also important differences (rapid onset of medical crisis, wider range of substances to understand).

The FEMA report provides brief details of several chemical accidents, showing the range of events that are included in this class and the complexity of response. It also identifies and discusses the characteristics that are common to chemical accidents which includes the fact that their on-set can be rapid, a quick and effective response is required to save lives, first responders can become exposed, decisions need to be made quickly with a limited understanding of what has occurred, large areas can be affected, communications with the public and between responders is important, medical facilities can be overwhelmed and recovery may take a long time.

It then lists seven Key Planning Factors (KPF), each of which is then given a chapter:

    1.   “Prime the Pump” Pre-Event Planning;
    2.   Recognize and characterise the Incident;
    3.   Communicate with External Partners and the Public;
    4.   Control the Spread of Contamination;
    5.   Augment Provision of Mass Care and Human Services to Affected   Population;
    6.   Augment Provision of Health and Medical Services to Affected   Population;
    7.   Augment Essential Services to Achieve Recovery Outcomes.

It justifies pre-planning with the observation that “A large-scale chemical incident with mass casualties is a realistic threat facing both urban and rural communities nationwide. The risk of misuse or accidents involving toxic industrial chemicals (TIC), which are widely stored in large quantities and are routinely transported by rail, waterway, highway, and pipeline, is substantial”. They also believe that a terror attack using chemicals is credible.

Multiagency planning and preparation are required to face this threat and enable a prompt and effective response. A “whole community” concept of operations is suggested.

The report suggests a systematic approach to planning and preparedness with several discrete steps recommended, each of which is explained in detail with lists of suggested consultees, reference documents, check lists and resource requirements.

It stresses the importance of agreeing how decisions will be made suggesting a process whereby stakeholders agree which decisions will need to be made, the minimum information needed to make them and the potential sources for that information. Decision making processes should be established to select among available options for evacuation, shelter-in-place, decontamination and waste management balancing political/social priorities and public health protection against time and cost constraints, and, therefore, should include discussion of reimbursement/ compensation for resources provided and contingencies if resources are damaged, destroyed, etc.

Another important area for discussion is medical resources. The planning process should establish protocols and procedures for the prioritization of medical resources.

There are a range of ways in which a chemical event can become known – this varies from automatic alarms on chemical plant, reports of smells or gas clouds, reports of unexplained illnesses or collapses of people or animals, active monitoring of public spaces and food. The quicker these signs can be picked up the better. The report discusses possible indicators, what they might mean and how best to use them. By considering what signs might be available and what they might mean in advance the planners increase the likelihood that an event can be detected earlier allowing a better response.

The next step is to characterise the release and its extent with the safety of first responders as a high priority. This requires equipment, training and coordination.

There is a nice discussion about atmospheric dispersion and modelling.

The third KPF refers to communication with external partners and the public. It stresses the importance of communication to enable a coordinated response across multiple agencies, jurisdictions and levels of authority and to inform the public providing key information and advice on self-preservation while countering misinformation and misperceptions.

The section discusses how communications can support a coordinated response, how to inform the public, how to provide time-critical messaging, strategies for effective communications, and best practice (the latter being a useful checklist of 13 elements).

Controlling the spread of contamination (KPF 4) may save lives and will protect the environment. Depending on the nature of the incident, controlling the spread of contamination may involve environmental containment and/or remediation efforts; decontamination of people, goods, or property; and interventions such as evacuations and food recalls. A lot of important decisions may be needed, and considerable expertise and resource bought to bear.

The support of the affected population (Augment provision of mass care and human services to affected population) (KPF-5) provides life-sustaining and human services to disaster- affected populations, including feeding operations, emergency first aid, distribution of emergency items, and family reunification. Additional resources and services may need to be mobilized to support individuals with disabilities, limited mobility, limited English proficiency, children, household pets, and service and assistance animals. Mass evacuations result in a varied group requiring a range of support services.

The basic objective for Emergency Mass Care is to provide for basic survival needs including food, water, emergency supplies, and a safe, sanitary, and secure environment but hopefully it would go beyond that and cater for other needs, reducing the potential for psychological harm.

The report discusses the support that sheltered and evacuated populations might have and the multi-agency strategies that might be considered to prepare to meet these needs, the facilities that may be required to manage evacuations, provide respite, assistance and shelter.

KPF 6 is concerned with augmenting the provision of health and medical services to the affected population. A chemical event could result in a rapid build-up of casualties requiring specialist assistance, including determination of the active agent, the appropriate medical care and the steps required to protect the responders and medical facilities from contamination.

The report discusses medical treatment for chemical casualties which may require that the symptoms presented are treated while the active agent is unknown i.e. provision of oxygen to those exposed to a lung irritant.

The report mentions “CHEMPACKS” which are containers of nerve agent antidotes placed in safe locations around the country (the USA). I do not know if this system is replicated in the UK. The report recognises limitations to this system.

The Tokyo nerve agent attack in March 1995 was serious – 12 people died, 54 were severely injured, and around 980 were mildly to moderately affected. However, most of the 5000-seeking help, many of them with psychogenic symptoms, were understandably worried that they might have been exposed. This demonstrates the value of rapid information dissemination via the media in reassuring the public. It also shows the importance of effective triage at receiving centres in ensuring that medical resources are reserved for those who really have been exposed.

The final KPF is “augment essential services to achieve recovery outcomes”. This section suggests that recovery begins during the planning and response phases. It divides the recovery into three overlapping stages: short term (days), intermediate (weeks – months) and long term (months – years).

Activities and resources needed to attain recovery outcomes will vary depending on the scenario, context, and location of the chemical incident as well as the incident’s impacts on the local infrastructure, economy, and workforce.

The overall objectives of recovery plans and prioritizations are to restore critical services as quickly as possible to limit cascading effects, and to return the affected community to a sense of normality.

After discussing each of the KPFs the report discusses federal preparedness, response and recovery, outlining the four escalating tiers of federal response. These are (1) an on-scene coordinator assessing the situation and watching the response (2) escalation to invoke the National Oil and Hazardous Substances Pollution Contingency Plan (3) a request to the Department of Homeland Security for coordination capabilities and additional federal agency support (4) a Presidential Disaster Declaration under the Stafford Act. These are discussed in turn with examples.

The report provides links to a wide range of additional information and both planning and response tools. Appendices provide a wealth of information including an overview of nine common toxidromes (syndromes caused by exposure to dangerous levels of toxins), a review of US chemical incident policy, legislation and regulation and chemical planning and notification requirements for responsible parties, environmental containment and remediation options, a flow chart showing how medical attention can be targeted and coordinated.

This is a detailed document covering a wide range of material. For a person with responsibility for planning for, or responding to, a chemical incident in the US it is probably a must read. For people with similar responsibilities elsewhere it is a recommended read – read it and compare your level of readiness with that described.




Book: Nuclear Emergency Planning and Response by Keith Pearce

Book coverI have just published a revised and much expanded version of my nuclear emergency response book. It now covers the wider UK nuclear industry with some comparisons to approaches in other countries. It looks at risk assessment, plan scoping, concept of operations, radiation protection, dose limits, the planning community, response and recovery. It mentions REPPIR-19 a few times.

This was a lockdown project, started when I found that my workload had significantly dwindled. It was not written with any group in mind but may be of interest to planners, responders and regulators in industry, local authorities and the emergency services.

It is printed in black and white which allows the cost to be kept down to £12 of which £3 goes to me as the author. I shall be donating my share to the Prince’s Trust since I believe that while lockdown has done me little damage, we need to give some extra help to those transitioning from education to work in these unusual times and the Trust will be far better at that than me.

I would be grateful for feedback if anybody does read it. Being “print on demand” It is quite easy to squash typos if they are pointed out and more chunky revisions are not too much of a problem.

Find it on Amazon at


Improved public messaging for evacuation and shelter in place.

FEMA have just published on the internet a very interesting paper entitled “Improving Public Messaging for Evacuation and Shelter‐in‐Place Findings and Recommendations for Emergency Managers from Peer-Reviewed Research” (April 2021) (link here). It reports the findings of a comprehensive literature review on the factors that affect the level of compliance with advice on personal protective actions (Shelter in place and Evacuation) in the event of a storm, flood or wild-fire. While these situations are not entirely analogous to radiation emergencies and there may be differences in the behaviour of UK and US populations when faced with an external event, there may be some important messages for UK planners to be gleaned from this work.

The work is related to the Protective Action Decision Model proposed in the literature (see figure) which attempts to identify the cues people may be sensitive to, the level and nature of prior consideration, and the on-the-day perception of the threat, possible responses and how others are responding which may influence decision making.

The key advice to those planning systems to warn and inform the public is to understand the potential impediments to action and take steps to address these barriers in advance, provide consistent advice through multiple trusted channels and to provide frequent updates.

Among many observations, those that seemed most relevant to the UK nuclear industry include:

  • Individuals find environmental cues such as sights, sounds or smells that indicate an impending threat an aid to decision making. This puts the nuclear industry at a disadvantage because we cannot show pictures of storm clouds, fast flowing rivers about to burst their banks or raging forest fires. On the other hand, we have the dread many people feel about radiation helping to focus minds.
  • It was noted that, in response to a wildfire, individuals could be categorised into three broad groups:
      • Wait and see (the largest group);
      • Stay and defend;
      • Likely to evacuate.
  • Seeing neighbours evacuate or other leave was a predictor of increased evacuation across a number of hazard types. This is a well-documented response to an alarm and most people will have observed it where they have been in a building when the fire alarm is tested; many people look to others and copy their behaviour.
  • Receiving messages from family and friends in addition to the local authority influenced decision making. Many people will seek confirmation of the preferred path of action from their social circles before acting.
  • Local governments and businesses provide important social cues that can impact on risk perception. Advice to evacuate an area, or even to shelter in place, could be undermined if council employees continued activities such as cutting grass and collecting waste in those areas.
  • Receiving several consistent warning messages from multiple, credible and trusted sources increases the rates of compliance.
  • People tend to use social media as a complementary rather than their primary source of information. Social media was also often used to amplify or share information with others.
  • As mobile phone ownership is now more prevalent than home landlines, public alert and warning calls to landline phone numbers are becoming less effective. The increased reliance on mobile phones may also result in bandwidth congestion during an incident. In the UK where fraction of homes and offices with land lines is falling while the procession of mobile phones is increasing. (See Table A45 in ONS report here which implies that 82% of households have land lines and 90% have mobile phones).
  • Households with multiple vehicles evacuated in multiple vehicles often with staggered leaving times. This is in the context of an impending storm but is plausible in a radiation accident if only as a mechanism for protecting their vehicles. This would add to traffic congestion.
  • There is strong agreement across studies and hazards that women are more likely to take appropriate protective action (SIP or evacuate) than men.
  • Parents with children in the household tended to have more difficulties with making the decision to stay or to leave for hurricanes and flooding. While some of their concerns may be similar to those of other households (e.g., traffic congestion, fuel availability, uncertainty regarding destination, cost), children in the household, especially younger children and larger numbers of children, raised the anxiety level and increased logistical challenges, which caused delays in decision making. Again the dread of nuclear may balance these concerns.
  • Having a pet, especially where there is a strong attachment to the pet, decreased the likelihood of evacuation. Many studies highlighted concerns about shelters accepting pets, the added cost of evacuating with pets and the logistics of having a pet at a shelter as impediments to evacuation.
  • Adults who have dementia or other cognitive disabilities and a caregiver(s) who would evacuate with them have evacuation rates that are the same as, or lower than, others. Caregivers were concerned with the potential for those in their care to be exposed to stigma and lack of privacy in a shelter. They were also concerned that unfamiliar settings would exacerbate their symptoms. Family and friends (the social network) tended to play an important role in determining whether to evacuate or not.
  • Adults with dementia and their caregivers who did go to shelters experienced a range of difficulties, including increased agitation, emotional distress and disorientation. It was challenging for caregivers to provide normal levels of care and comfort in this environment.
  • Care facilities and their caregivers were challenged in making the decision whether to evacuate or not, given their sense of responsibility to their residents. This research also indicated the importance of care facility residents and their families deciding (and documenting) who would care for them in a disaster (e.g., whether or not they would evacuate to a family’s residence) and then not changing that decision as the threat neared.
  • Having a household plan increased the likelihood of taking the appropriate Shelter in Place protective action for a tornado. This may be presumed to apply for any threat, underlining the importance of prior information that encourages preparation.
  • Studies found that individuals grapple with many concerns when deciding to evacuate. According to these studies, the following concerns delayed or negatively influenced the decision:
      • Traffic congestion and the availability of fuel;
      • The ability and cost of evacuating with pets;
      • Costs of evacuation, including travel costs;
      • Potential issues around the legal status of undocumented immigrants;
      • Individuals faced with a public shelter as their primary destination had more reluctance to evacuate. Their concerns include crowding with strangers and being located farther away from social networks.

On the basis of the observations a number of recommendations were made:

  • Use websites and social media platforms and work with local media to provide authoritative, time-stamped, geo-tagged photos and videos of hazards such as rising waters and wildfires. Encourage individuals to share those visuals with friends and family, including via social media. Again, there are differences between these events and radiation emergencies to take into account but there is something to take away from this recommendation.
  • Warning messages should be clear, consistent and strong but not overly dramatic. Mandatory evacuation orders had more weight than voluntary ones and also carried increased media coverage.
  • Changing the geographic areas subject to advice can cause confusion and a resulting drop in compliance. This should be minimised where practical.
  • Messages that clearly described the probable personal impact of the hazard helped individuals realise that they would be personally impacted which motivated protection action.
  • Visuals such as maps and photos improve message comprehension and support decision making.
  • Authority figures acting as role models and being seen to comply is helpful.
  • Tourists who sought information from tourist offices rather than hotel staff were more likely to evacuate (this was in the context of a major storm brewing).
  • The current event should be compared to those that have posed similar threats. Hopefully nuclear industry will ever have a good back catalogue.
  • In the preparation stage relationships should be built with television and radio forecasters and other journalists likely to cover the story should it arise.
  • People should be encouraged to sign up to relevant alert and news feeds, including during the event.
  • There should be a mechanism in place to follow and monitor the social media of authoritative sources to keep information consistent and address inconsistencies and inaccuracies if they occur. In the UK we also try to coordinate the media lines taken before media releases are issued.
  • Communications strategies should be tailored to gender differences. For example, given that women are more likely than men to take protective actions, messaging on preparedness should consider the use of outreach channels geared toward women.
  • Include individuals with disabilities, access and functional needs, and associated advocacy organizations in developing and reviewing community plans for evacuation.
  • If an evacuation may be called for then consider breaking the news at a time that allows the travel to be completed during daylight hours.
  • When issuing evacuation orders, explain the risks that led to the decision to evacuate some zones and why other zones are not evacuating.
  • Provide information about public shelters, including items associated with comfort (e.g., availability of power, air conditioning, rest rooms, and space for families and pets) as well as services for individuals with disabilities and access and functional needs.

The slide library available here is a very good way to assimilate the information given in this report.

NEI Small and Advanced Reactors: Virtual Event 18/2/21

This was an on-line event organised by Nuclear Engineering International bringing together a collection of speakers to provide updates on the development of, and potential for, small and advanced reactors.

The website opened with a picture of a conference centre with signs to various “places” which you could enter with a click. Entering the auditorium showed a timetable for the conference and allowed the user to listen to the current talk. After the event all presentations were available to listen to again. The Exhibition Hall allowed you to read or download publicity material and watch promo videos from a number of developers of SMRs. The Networking Lounge allowed you to read and join a number of text threads with representatives of the Companies involved.

This was a brave, and very welcome attempt, to recreate the functionality of a conference. It couldn’t provide the impromptu chats in the queue for a cup of tea, which are a vital part of conferences in the real world, nor recreate the sensation of sitting in an uncomfortable chair wishing the tea break was nearer while trying to concentrate on a talk. I admit to doing other things, such as catching up on shredding old documents, while listening to talks.

We live in an interesting time where there are limited funds for investment, a growing need for energy, a growing urgency to be more careful with the planet we call home and a lack of consensus on the way forward. Candidate solutions for the future include greater energy efficiency, reduced per-capita consumption, renewable energy solutions with solar and wind being the main growth areas, and more nuclear power. Within nuclear power there is competition between ever larger and more complex reactor systems, large but “simplified” reactors, and smaller reactor systems.

This conference was about the small reactors, seen by many as the solution to the “too big” problem with full sized reactor systems. One stated advantage are that smaller cores make less demand on the engineering of large pressure vessels and containment buildings. The control and safety systems can be bought closer, even into the pressure vessel, and a greater reliance can be put on passive accident management systems. But the unique selling point is the contention that these reactors can be produced, either as a number of modules or complete, in factories, shipped to site by road, plugged in and they are off. This considerably reduces the construction risks and build time resulting in a quicker achievement of a positive cash flow. The reactors are less powerful but it is easy to line up multiple reactors to give higher outputs while the smaller output makes them suitable in areas that cannot be served by 1000+ MW units.

It was explained that the UK SMR reuses existing design and technology but the innovation is chiefly working out how to factory build it. The system is “low cost, deliverable and investable” with 80% of UK content. The next step, which starts this year, is GDA. This is important for the UK context but is also a badge of honour around the world. The ambitious plan for acceleration includes parallel identification and development of the site and the placing orders before the GDA is complete. It is suggested that they might fit well on NDA sites which have a nuclear history but are not big enough for gigawatt plant such as Trawsfynydd. After the first of kind a factory might be expected to produce two systems a year. If orders were to be higher then further factories could be built. In this manner the 5th unit should be 20 – 30% cheaper than first, down to about £50 kW.

Funding is in place for the GDA phase but not beyond. The company is lobbying for the UK policy situation to develop and sites to be identified. The company is confident that once production is underway then debt and equity vehicles will be sufficient to move them forward but government bridging funds may be needed to get there.

This was an upbeat talk but the reality is that they are playing in a crowded field and the UK has a poor record of being able to deliver fleet savings in nuclear build (except maybe in the nuclear submarine world where the figures are less well publicised) and has, for years, lacked a suitably forward looking and coherent energy policy. They are also competing with Russians and Canadians with a more obvious local market and a clearer path to that market and the Chinese with their very large investments in a range of nuclear technology. Too much depends on the UK government.

The IAEA has set up an International Technical Working Group on Small and Medium-Sized or Modular Reactors (SMR) with a number of sub-groups enabling international collaboration in the development of SMR and their applications. They have produced a booklet reviewing 72 designs, developed technology roadmaps for SMR deployment, generic user’s requirements and criteria and a tool for the economic appraisal. Interestingly (for me anyway) they have a project running looking at the emergency planning requirements for SMRs due to report in December of this year. (See IAEA material at The fact that there are 72 designs on offer shows up a problem. It is relatively cheap and sexy to design a reactor system and many organisations do this hoping to get a slice of future markets. Most fall out of the race and represent a waste of effort.

Rosatom claim to have “SMR solutions in Russia and for the global market”. They are developing and building small reactors for icebreakers, for floating power plant and for land based systems. Floating power plant are expected to be used in the North, replacing diesel, coal and old nuclear generators and providing heat and electricity. Because they are built in a shipyard they need very little local building and are floated away at end of life rather than decommissioned in-situ. They can also be repositioned mid-life if required. Their newer reactor designs are more compact.

By using these reactors in icebreakers (4 vessels each with 2 reactors) they have already achieved significant fleet savings (that pun was not intended). They also have identified markets, home and foreign, for the floating and land-based variants.

It appears that Russia has a very credible SMR programme with proven designs and proven markets.

We were told about “The Progress of HTR-PM in China”. This is a high temperature gas cooled reactor with ceramic coated fuel (TRISO particles, pebble bed format) and helium coolant. The programme has a long history including the reactors HTR-10 & HTR-PM and extensive engineering laboratory work. Almost all of the components are built in China. Unusually they have two reactors in parallel providing steam to a single turbine. Each reactor can provide 250 and 210 MW.e with cores 3m diameter x 11m high. Inlet 250 oC out 750 oC producing superheated steam. HTR-PM is currently in hot-testing with first criticality expected this year.

They now have proven technology and have plans to move forward. HTR-PM600 (650MW) will have six reactors feeding one turbine.  These will be used for co-generation and to repower coal power stations. An aspiration is to go to higher temperatures for hydrogen production.

Some ideas on financing SMRs and Advanced Reactors were presented. The poor track record of on-time completion, very high capital requirements and long times before return have given the industry a bad name and mean that nuclear is often a “bet-the-company” investment. Contract for difference and Regulated Asset Base are two attempts to manage the high cost of money in big build public interest projects.

It was suggested that SMRs significantly reduce all of the finance and risk problems of big-nuclear. They should be able to complete on programme, capital demands are lower, lead times are shorter, costs of delays are less and costs are such that they are not bet-the-company investments. Therefore they can be treated as conventional assets.

SMRs are like aircraft in many respects. Both are built in factories, safety critical, and highly regulated and are deployed as a fleet.  Interestingly it was claimed that an SMR requires a similar investment as an Airbus A-380 [I tried to verify this and found getting the numbers quite difficult but seems to be in the right ball park. The clearest cost estimate I found was a 12 unit NuScale (924 MWe) estimated to cost $2,850 per kWe giving costs of $2,633 Million (NuScale brochure) compared to $428 Million for an Airbus A380 (one unit not 12) ).  As for large aircraft it is conceivable that SMRs could be sold on a Sale and Leaseback in which the lessee pays purchase price in instalments over a set period of time before becoming owners. The payments are treated as expenses rather than capital investment and the utility doesn’t have the liability for the plant on its books. An alternative is an operating lease in which the Lessor pays only rent and not pay-down of the capital costs, making it more affordable and viable in areas that could not afford nuclear power under current arrangements. It is hard to see a factory owner or a community buying one of these for cash to provide their energy needs over the next 20 years but they might lease one if it gives them reliable low-cost energy. It is noted that if the SMR is mobile (for example floating) it can be moved mid-life and follow the money.

There were a series of shorter presentations within chaired panel discussions. These provided a number of viewpoints.

Micro-reactors (up to about 10 MWe) are in various stages of development and licensing with some hoping to be building first of a kind systems in the next few years. Russia and China are further along the development line.

They use a range of technologies; some use components from existing larger reactors or the aviation industry, some use more novel components such as heat tubes to remove the heat. All of these reactors are designed to be accident tolerant, they can be used to produce heat or electricity and some are combined with molten salt energy stores to balance supply and demand.

It was claimed that the NuScale Advanced Small Reactor with 12 (or 4 or 6) 77 MWe units would have a site fence emergency planning zone (I’ll wait to see the ONR judgement on that!) and no radioactive release in normal operation, events or decommissioning.

A joint study which shows small nuclear being cost-competitive was cited ( A representative of the WNA put forward the view that the world should concentrate its efforts into a smaller number of design concepts (I agree) and that international harmonisation of reactor design approval was required (not very likely in my opinion).

All of the speakers agreed that the demand for electricity will rise, outstripping the capacity of renewables, as it is increasingly used for transport and domestic heating while the burning of hydrocarbons becomes less acceptable. (Estonia has an additional issue in that its grid connections to Russia are expected to be cut in 2025 and they want to move away from dirty shale gas that they currently burn).

The initial target market is remote communities with a need for district heating and electricity although industrial uses, mining, disaster response, hospitals, campuses, military bases, data centres, desalination, and hydrogen production were all mentioned as potential users.

A question about competition from solar power/wind power and batteries was dodged. But a later speaker stated that small grids with wind and solar would benefit from a nuclear component providing reliable generation and also the “spinning metal” required to control frequency and voltage and also reported an ability to black start (without grid supplies) some micro-reactors.

Interestingly all speakers were more fluent when discussing the potential market than when discussing operators. If these reactors are to penetrate markets as single, remote units it will not on sites with 500+ nuclear skilled employees. Getting licensed to operate them will have to be no more difficult than getting licences to run industrial process plant or they will run into difficulty. Will the regulators accept local “semi-skilled” operators with remote technical support?

Canada’s action plan for SMR was the subject of a panel discussion. It introduced the Candu Users Group (COG) and its Small and Modular Reactor Group. Canada has a proud history in nuclear technology and now has a large industry of strategic importance. The action plan ( has 53 recommendations which have translated to 497 actions. This is a broad coalition of 210 partners.

The Canadians have identified three streams of effort; fast development of SMRs with the potential to replace coal generation (a requirement of Canada’s environmental policy), the development of advanced reactors for a variety of purposes including use of used fuel, and the development of very small SMRs (vSMR) to replace diesel in off-grid situations (remote communities and industrial sites).

The Canadian Nuclear Safety Commission is readying itself for the SMR programme with recruitment, a regulatory framework and reports on the potential issues. Their aim is to ensure safety and social acceptance without putting barriers in the path of progress.

The coherence and comprehensiveness of the Canadian plan is impressive. If only the UK could do something along the same lines.

This was an interesting day and provided ample evidence that there is a market position for small and micro reactors, with small reactors feeding national grids, process heat and hydrogen production and micro reactors providing power to remote communities and industries. There seem to be no insurmountable technology issues. The issues will be development finance and public acceptability and then the costs of ownership. Canada and Russia have advantages from obvious domestic markets at the high cost end. China has the advantage of a diverse nuclear industry and seemingly no limit to development funds. The UK obviously has the technical ability in this area with its commercial nuclear industry and nuclear powered submarine programme but it lacks the niche markets, clear funding and national strategy. There will be more in the market for multiple players. The UK will have to work hard to get a slice of that market.

The remote conference was not without technical issues and the posing of questions by text during the talk couldn’t replicate post-talk discussions. But the presentations and Q&As were available to review after the event.

I am grateful to Nuclear Engineering International for organising this event and to the speakers for their efforts. Next time I’d prefer to attend in person but this was a very welcome interlude in a lockdown.

Keith Pearce, Feb 2021